Abbreviations & Industry Terms

EMS Industry Definitions & Abbreviations

The Electronic Manufacturing Services (EMS) industry for Printed Circuit Board (PCB) manufacturing is filled with many shortcodes, abbreviations and industry-specific definitions.

We provide this page as a Wiki to the electronics industry and invite you to make to revisions, credits and additions. Credit for some of these definitions goes to Wikipedia and IPC (Association Connecting Electronics Industries).

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Abbrev. Short Description Long Description
QSOP 1/4 small outline package See SOPs. An SO style IC package that has leads on a 25 mil pitch.  The name derives from the fact that the package is approximately ½ the length and ½ the width of a standard SOIC, and thus a package of the same pin count occupies approximately ¼ the area on a PWB.
AC 00-56 AC 00-56 The AC 00-56 is a program supported and strongly endorsed by the FAA for the voluntary accreditation of civil aircraft parts distributors.
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AEGIS AEGIS Digitized machine programs for manufacture of PCB boards – works with Gerber data, B.O.M. and CAD
A/C Air Conditioning Air Conditioning
AHU Air Handling Unit An air handler, or air handling unit (often abbreviated to AHU), is a device used to condition and circulate air as part of a heating, ventilating, and air-conditioning (HVAC) system.
AC Alternating Current Alternating Current
Al Aluminum Aluminum is a chemical element in the boron group with symbol Al and atomic number 13. It is silvery white, and it is not soluble in water under normal circumstances
ANSI American National Standards Institute American National Standards Institute
ASTM American Society for Testing and Materials American Society for Testing and Materials
ASM American Society of Metals American Society of Metals
ASTE American Society of Test Engineers American Society of Test Engineers
ASQC American Society Quality Control American Society Quality Control
AWG American Wire Gauge Abbreviation of American wire gauge. A measurement used in the United States and other countries as a standard method of denoting wire diameter. In AWG measurements, the larger the number is the smaller the diameter.
A Ampere The ampere (SI unit symbol: A), often shortened to amp, is the SI unit of electric current and is one of the seven SI base units. It is named after André-Marie Ampère (1775–1836), French mathematician and physicist, considered the father of electrodynamics.
Amp Ampere A measurement of electrical current or amount of electric charge per second in a circuit. Frequently shortened to Amp. Its symbol is the letter A but in formulas it is sometimes expressed as the letter I.
AIC Ampere Interrupting Capacity Ampere Interrupting Capacity. Breaking capacity or interrupting capacity is the current that a fuse, circuit breaker, or other electrical apparatus is able to interrupt without being destroyed or causing an electric arc with unacceptable duration. The prospective short circuit current which can occur under short circuit conditions should not exceed the rated breaking capacity of the apparatus. Otherwise breaking of the current cannot be guaranteed.
AR or A Amplifier An amplifier is a device for increasing the power of a signal by use of an external energy source. In an electronic amplifier, the input “signal” is usually a voltage or a current. Other types exist; a fluidic amplifier increases the power of signals represented as flow of gas or liquid, for example. Amplifiers may be classified in a variety of ways depending on their application, the frequency range they cover, or the active devices used. Ideally an amplifier increases the power of a signal without otherwise altering it; practical amplifiers have finite distortion and noise which they invariably add to the signal. A device that converts signals from one type to another (for example, a light signal in photons to a DC signal in amperes) is a transducer, a transformer, or a sensor. However, none of these amplify power.
Anode The electrode in a device that electrons flow out of to return to the circuit. In a battery or other source of direct current the anode is the negative terminal, but in a passive load it is the positive terminal.
ASIC Application Specific Integrated Circuit Application Specific Integrated Circuit – An application-specific integrated circuit, or ASIC /ˈeɪsɪk/, is an integrated circuit (IC) customized for a particular use, rather than intended for general-purpose use. For example, a chip designed to run in a digital voice recorder is an ASIC. Application-specific standard products (ASSPs) are intermediate between ASICs and industry standard integrated circuits like the 7400 or the 4000 series.
ASSP Application Specific Standard Product An application specific standard product or ASSP is an integrated circuit that implements a specific function that appeals to a wide market. As opposed to ASICs that combine a collection of functions and designed by or for one customer, ASSPs are available as off-the-shelf components. ASSPs are used in all industries, from automotive to communications.
AS5553 AS5553 The AS5553 standard was created to provide uniform requirements, practices and methods to mitigate the risks of receiving and installing counterfeit electronic parts.
AS9003 AS9003 AS9003 – Inspection and Test Quality System. The intent of the AS9003 standard is to ensure that the inspection, conformity and airworthiness of products are maintained. Based on the ISO 9002:1994 Quality Standard, the AS9003 standard contains the minimum requirements for an Inspection and Test Quality System and was intended for use by small build/machine to print organizations.
AS9100 AS9100 In the aerospace industry, AS 9100 is the aerospace industry-specific standard relating to ISO 9001 conformity, as it includes all ISO 9001 provisions, as well as a number of additional aerospace-related qualifiers.
AS9110 AS9110 AS9110B (also referred to as AS9110:2012) is the standard that was developed by aerospace professionals to meet the specific requirements of Aerospace Maintenance Organizations.
AS9120 AS9120 AS 9120 certifications and standards are essentially enhanced version of the IS 9001 standard, which was developed to provide management systems conformity standards for a broad range of industries. Because 9120 certifications contain all the provisions of IS 9001 plus aerospace industry-specific standards, they can pose additional challenges when seeking registration.
Assembly As a verb, it means the act of putting parts together. As a noun, it is a finished cable or harness, as in cable assemblies.
AOI Automated Optical Inspection The surface mount assembled board is automatically inspected by first scanning a barcode for traceability and then uses an assembly specific program to inspect each component for recognition, proper placement, orientation and solder joint integrity. The recorded data can then be mined for quality data such as first pass yield for a given customer, assembly and/or time period. Detects and collects data based on a set of standard pictures to insure all components are properly placed in the right location and orientation with the correct polarity per IPC standards. Test fixture method in which printed circuit boards are checked at bare-board, pre-or post-soldered stages of assembly by optical means.
ACI Automatic Component Insertion Automatic Component Insertion
ATC Automatic Temperature Control Automatic Temperature Control (ATC), also known as Automatic Climate Control, an industry name for automatic Heating, Ventilating, and Air Conditioning (HVAC) systems for automobiles
ATE Automatic Test Equipment Equipment designed to automatically analyze functional or static parameters in order to evaluate performance degradation.  It may also be designed to perform fault isolation.
ATG Automatic Test Generation Computer generation of a test program based solely on the circuit technology, requiring little or no manual programming effort.
ATS Automatic Transfer Switch A transfer switch is an electrical switch that reconnects electric power source from its primary source to a standby source. Switches may be manually or automatically operated. An Automatic Transfer Switch (ATS) is often installed where a backup generator is located, so that the generator may provide temporary electrical power if the utility source fails.
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BGAs Ball Grid Arrays Ball Grid Arrays – BGA is a surface mount component typically made of either plastic or ceramic. These parts are characterized by the lack of pins, instead they have balls of solder as their means of conduction to the board. The solder balls are made up of either Sn63Pb37 or Snl0Pb90. The advantage of BGAs over conventional quad flat packs is their ability to exceed the lead count limitations per area of quad flat packs. A component whose terminations are on the bottom of the package, and are in the shape of solder balls and in a grid array pattern.  This generally covers components that have them in a full array or in a partial array with “missing” balls in the center
Bed of Nails Tester A bed of nails tester is a traditional electronic test fixture which has numerous pins inserted into holes in an Epoxy phenolic glass cloth laminated sheet (G-10) which are aligned using tooling pins to make contact with test points on a printed circuit board and are also connected to a measuring unit by wires. Named by analogy with a real-world bed of nails, these devices contain an array of small, spring-loaded pogo pins; each pogo pin makes contact with one node in the circuitry of the DUT (device under test). By pressing the DUT down against the bed of nails, reliable contact can be quickly and simultaneously made with hundreds or even thousands of individual test points within the circuitry of the DUT. The hold-down force may be provided manually or by means of a vacuum, thus pulling the DUT downwards onto the nails. Devices that have been tested on a bed of nails tester may show evidence of this after the fact: small dimples (from the sharp tips of the Pogo pins) can often be seen on many of the soldered connections of the PCB.
BOM Bill of Materials A bill of materials (sometimes bill of material or BOM) is a list of the raw materials, sub-assemblies, intermediate assemblies, sub-components, parts and the quantities of each needed to manufacture an end product. No physical dimension is described in a BOM. It may be used for communication between manufacturing partners, or confined to a single manufacturing plant. A BOM can define products as they are designed (engineering bill of materials), as they are ordered (sales bill of materials), as they are built (manufacturing bill of materials), or as they are maintained (service bill of materials).
Black Pad See IPC-4522 Few topics in the printed circuit board industry are as controversial as black pad, a failure associated with a poorly formed joint at the solder/nickel interface. Although it is a rare phenomenon, appearing on only 1 to 2 percent of boards or less, when it happens it is expensive and frustrating. There are numerous theories as to the causes of black pad, but no definitive reason. Black pad only occurs during the electroless nickel phosphorus and immersion gold (ENIG) process that has established itself as a preferred solderable surface finish for high-reliability applications involving complex circuit designs. When a flawed joint is stressed, the connection is easily broken, leaving an open circuit exposing dark corroded nickel, which gives “black” pad its moniker. The latest research shows excessive nickel corrosion during the immersion gold deposition causes the condition, says George Milad, national accounts manager for technology at Southington, Connecticut, USA-based Uyemura International Corp., a chemical supplier that offers ENIG chemistry to the electronics industry. The “classical definition” of black pad is too much phosphorus, which is left behind when nickel is dissolved, says Engelmaier, who acknowledges that not everyone accepts it. “The more phosphorus, the weaker the interface,” he says. “You might start out at 7 percent phosphorus, but after one reflow you might end up at 9 percent or higher. If you have numerous reflows and repair procedures, the phosphorus content of the interface increases every time.
Blueprint A detailed plan or design.
Box Build, Box Assembly A turnkey mechanical assembly that may consist of any combination of printed circuit assemblies, protective enclosures, fasteners, hardware and software
BUT British Thermal Unit The British thermal unit (symbol Btu or sometimes BTU) is a traditional unit of energy equal to about 1055 joules. It is approximately the amount of energy needed to heat 1 pound (0.454 kg) of water, which is exactly one tenth of a UK gallon or about 0.1198 US gallons, from 39 °F to 40 °F (3.8 °C to 4.4 °C)
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Cable Two or more wires bound together and surrounded by an insulator.
CATV Cable Television or Community Antennae Television Cable television is a system of distributing television programs to subscribers via radio frequency (RF) signals transmitted through coaxial cables or digital light pulses through hybrid fibre coaxial (HFC) networks. This contrasts with traditional broadcast television (terrestrial television) in which the television signal is transmitted over the air by radio waves and received by a television antenna attached to the television. FM radio programming, high-speed Internet, telephone service, and similar non-television services may also be provided through these cables.
CD Candela The candela is the SI base unit of luminous intensity; that is, power emitted by a light source in a particular direction, weighted by the luminosity function (a standardized model of the sensitivity of the human eye to different wavelengths, also known as the luminous efficiency function). A common candle emits light with a luminous intensity of roughly one candela. If emission in some directions is blocked by an opaque barrier, the emission would still be approximately one candela in the directions that are not obscured.
C Capacitor A component capable of storing electrical energy. Stores and discharges electricity
Capacity Utilization Capacity Utilization – Total output of the business (in any units) divided by the total potential output based on existing facilities and equipment
Cash-to-Cash Cycle Time Cash-to-Cash Cycle Time – The number of days of inventory plus the number of days sales outstanding (DSO) minus the number of days payables outstanding
Cathode The electrode in a device that electrons flow into. In a battery or other source of direct current the cathode is the positive terminal, but in a passive load it is the negative terminal.
CBGA or CCGA Ceramic Ball Grid Array/Ceramic Column Grid Array A grid array packaged component that has ceramic as the substrate of the package, and may have
either solder balls or solder columns for connections.
CLCC Ceramic leaded chip carrier Leaded Chip Carriers are also known as Flat Packs, Quad Flat Packs (CQFP), and J-Bend Leaded Chip Carriers (CQFJ). Flat Packs are usually found in lower lead counts; 8-28 leads, have small body outlines, are lightweight, have parallel leads on two sides of the package, and are commonly used in High Reliability applications for military airborne equipment. J-Bend Lead Chip Carriers and Quad Flat Packs are usually found in higher lead counts; greater than 24 leads, have leads on all four sides of the package, are hermetically sealed, and commonly used for surface mount applications or socketing. The leads are flat, gull-wing or J-Bend configured and depending on the package, lead spacing can be .015, .020, .025, and .050 inches.
CBM Certified Ballast Manufacturer Association An independent organization of fluorescent lamp ballast manufacturers.
Chip The uncased and normally leadless form of an electronic component, either passive or active, discrete or integrated. Chip components have metallized terminations for interconnecting to the solder pad. The case type number of a chip component indicates its size. For example: a 1206 chip is 0.120″ long by 0.060″ wide, and a 1812 chip is 0.180″ long by 0.120″ wide.
CMT Chip Mount Technology Any packaging or electronic assembly manufacturing technology, such as TOB, COB, or flip chip, that connects bare (unpackaged) IC chips to the substrate.
COB Chip On Board A situation where the silicon IC chip is mounted directly to the electronic assembly substrate or PWB without an intermediate packaging step. Connections between the chip and the board are generally made with bond wired (also sometime called chip and wire), but the terminology is occasionally used for any chip connection technique such as flip chip (solderable bumps or tape automated bonding.
CSP Chip Scale Package Active, multi-I/O package that is no larger than 125% of the size of the silicon IC.
CFC Chlorinated Fluorocarbon Chlorinated Fluorocarbon.
CKT Circuit An electronic circuit is composed of individual electronic components, such as resistors, transistors, capacitors, inductors and diodes, connected by conductive wires or traces through which electric current can flow. The combination of components and wires allows various simple and complex operations to be performed: signals can be amplified, computations can be performed, and data can be moved from one place to another. Circuits can be constructed of discrete components connected by individual pieces of wire, but today it is much more common to create interconnections by photolithographic techniques on a laminated substrate (a printed circuit board or PCB) and solder the components to these interconnections to create a finished circuit. In an integrated circuit or IC, the components and interconnections are formed on the same substrate, typically a semiconductor such as silicon or (less commonly) gallium arsenide.
C/B Circuit Breaker A circuit breaker is an automatically operated electrical switch designed to protect an electrical circuit from damage caused by overload or short circuit. Its basic function is to detect a fault condition and, by interrupting continuity, to immediately discontinue electrical flow. Unlike a fuse, which operates once and then must be replaced, a circuit breaker can be reset (either manually or automatically) to resume normal operation. Circuit breakers are made in varying sizes, from small devices that protect an individual household appliance up to large switchgear designed to protect high voltage circuits feeding an entire city.
CMA Circuit Mil Area A unit of area equal to the area of a circle whose diameter is one mil (0.001”).  Used chiefly in specifying cross-sectional areas of conductors.
Class 1 General Electronic Products – Includes products suitable for applications where the major requirement is function of the completed assembly.
Class 2 Dedicated Service Electronic Products – Includes products where continued performance and extended life is required, and for which uninterrupted service is desired but not critical. Typically the end-use environment would not cause failures.
Class 3 High Performance Electronic Products – Includes products where continued high performance or performance-on-demand is critical, equipment downtime cannot be tolerated, end-use environment may be uncommonly harsh, and the equipment must function when required, such as life support or other critical systems.   At DCA we manufacture to Class 3 but inspect to customer standard.
CCTV Closed Circuit Television Closed-circuit television (CCTV) is the use of video cameras to transmit a signal to a specific place, on a limited set of monitors. It differs from broadcast television in that the signal is not openly transmitted, though it may employ point to point (P2P), point to multipoint, or mesh wireless links. Though almost all video cameras fit this definition, the term is most often applied to those used for surveillance in areas that may need monitoring such as banks, casinos, airports, military installations, and convenience stores. Videotelephony is seldom called “CCTV” but the use of video in distance education, where it is an important tool, is often so called
Coax Coaxial A cable that consists of two conductors laid concentrically along the same axis. One conducting wire is surrounded by a insulator, which is in turn surrounded by the other, outer conductor. The whole cable is wrapped in a protective plastic sheathing. Coaxial is frequently shortened to Coax (Co-ax)
CTE Coefficient of Thermal Expansion The linear thermal expansion per unit change in temperature. Thermal Coefficient of Expansion (Coefficient of Thermal Expansion).  The rate of expansion (ppm/C) of a material when its temperature is increased.
CMOS Complementary Metal Oxide Semiconductor Complementary Metal Oxide Semiconductor
Component A basic electronic element usually packaged in a discrete form with two or more connecting leads or metallic pads. Components are intended to be connected together, usually by soldering to a printed circuit board, to create an electronic circuit.
Component Preparation Mechanically trims and/or forms leads to prepare to be soldered to the PCB
CRD Component Reference Designator An electronic symbol is a pictogram used to represent various electrical and electronic devices (such as wires, batteries, resistors, and transistors) in a schematic diagram of an electrical or electronic circuit. These symbols can (because of remaining traditions) vary from country to country, but are today to a large extent internationally standardized. Some symbols represent components which ceased to be used routinely as newer technologies were introduced (such as vacuum tubes).
Component Side COMPONENT SIDE (TOP) – A term used to describe the component loaded side of a PWB using through hole technology.
CAD Computer Aided Design A computer based system to assist designers in the design, topological layout and drawing of an electronic component, assembly, or system.
Conductor Metal wires, cables, rods, tubes, and bus-bars used for the purpose of carrying electric current. In Electronics Mfg, an electrical path between two component pads. Also referred to as a “trace”, “path”, or “line”.
C Conduit Conduit – An electrical conduit is an electrical piping system used for protection and routing of electrical wiring. Electrical conduit may be made of metal, plastic, fiber, or fired clay. Flexible conduit is available for special purposes.
Conformal Coating Conformal coating material is applied to electronic circuitry to act as protection against moisture, dust, chemicals, and temperature extremes that, if uncoated (non-protected), could result in damage or failure of the electronics to function. When electronics must withstand harsh environments and added protection is necessary, most circuit board assembly houses coat assemblies with a layer of transparent conformal coating rather than potting.  Methods include brush coating, spray application coating, conformal coating dipping, robotical application.  Types include water-based acrylic (air drying or film forming) which drying can be accelerated in an oven.  There are also UV curing which is commonly used in automotive and consumer electronics due to its rapid cure speed. Another type of coating called parylene is applied with a vacuum deposition process versus a spray or needle application. The parylene is applied at the molecular level by a vacuum deposition process at ambient temperature.
J or P Connector Allow outside connections to be made to a PCB A device that allows wires in a cable to fasten together with equipment or other wires.
Consignment A process where customers provide the manufacturer with all the parts and materials. The manufacturer then builds the products and deliver completed assemblies or cables to the customer. Sometimes referred to as kitted.
Continuity Where there are no breaks in a circuit it is said to have continuity. When testing cables for continuity, you ensure that the wires lead to the appropriate areas.
CM Contract Manufacturer A contract manufacturer (“CM”) is a manufacturer that contracts with a firm for components or products. It is a form of outsourcing.
CPT Control Power Transformer Control Power Transformers (60 Hz) are designed to reduce supply voltages to control circuits. The complete line of transformers is available with optional factory-installed or panel-mount primary and secondary fuse block.
Cu Copper Copper is a chemical element with the symbol Cu (from Latin: cuprum) and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; a freshly exposed surface has a reddish-orange color. It is used as a conductor of heat and electricity, a building material, and a constituent of various metal alloys.
CAPA Corrective and Preventive Action procedures Corrective action and preventive action (CAPA, also called corrective action / preventive action) are improvements to an organization’s processes taken to eliminate causes of non-conformities or other undesirable situations. CAPA is a concept within good manufacturing practice (GMP). It focuses on the systematic investigation of the root causes of non-conformities in an attempt to prevent their recurrence (for corrective action) or to prevent occurrence (for preventive action). Corrective actions are implemented in response to customer complaints, undesired levels of internal nonconformity, nonconformities identified during an internal audit or adverse or unstable trends in product and process monitoring such as would be identified by SPC. Preventive actions are implemented in response to the identification of potential sources of non-conformity.  To ensure that corrective and preventive actions are effective, the systematic investigation of the root causes of failure is pivotal. CAPA is part of the overall quality management system (QMS).
COGS Cost of Goods Sold Cost of Goods Sold (COGS) – Direct expenses incurred in producing a particular good for sale, including the actual cost of materials that comprise the good and direct labor expense in putting the good in salable condition. Cost of goods sold includes factory overhead but does not include indirect expenses such as office expenses, accounting, shipping department, advertising, and other expenses that cannot be attributed to a particular item for sale.
CB Critical Branch Common in Hospitals – On the wiring front, it’s critical that you keep the life safety branch and critical branch circuits of the emergency system entirely independent of all other wiring and equipment.
Y or B Crystal Produces consistent electrical pulse (for clocks for instance)
CLF Current Limiting Fuse Current limiting is the practice in electrical or electronic circuits of imposing an upper limit on the current that may be delivered to a load with the purpose of protecting the circuit generating or transmitting the current from harmful effects due to a short-circuit or similar problem in the load. This term is also used to describe the ability of an overcurrent protective device (fuse or circuit breaker) to reduce the peak current in a circuit, by opening and clearing the fault in a sub-cycle time frame. The simplest form of current limiting for mains is a fuse. As the current exceeds the fuse’s limits it blows thereby disconnecting the load from the source. This method is most commonly used for protecting the house-hold mains. A circuit breaker is another device for mains current limiting.
CT Current Transformer In electrical engineering, a current transformer (CT) is used for measurement of electric currents. Current transformers, together with voltage transformers (VT) (potential transformers (PT)), are known as instrument transformers. When current in a circuit is too high to directly apply to measuring instruments, a current transformer produces a reduced current accurately proportional to the current in the circuit, which can be conveniently connected to measuring and recording instruments. A current transformer also isolates the measuring instruments from what may be very high voltage in the monitored circuit. Current transformers are commonly used in metering and protective relays in the electrical power industry.
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DSO Days Sales Outstanding Day Sales Outstanding (DSO) – Average accounts receivable divided by total sales for the quarter times number of days in the quarter
dB Decibel The decibel (dB) is a logarithmic unit that indicates the ratio of a physical quantity (usually power or intensity) relative to a specified or implied reference level. A ratio in decibels is ten times the logarithm to base 10 of the ratio of two power quantities. A decibel is one tenth of a bel, a seldom-used unit named in honor of Alexander Graham Bell.
DL Delay Line Delay line memory was a form of computer memory used on some of the earliest digital computers. Like many modern forms of electronic computer memory, delay line memory was a refreshable memory, but as opposed to modern random-access memory, delay line memory was sequential-access. In the earliest forms of delay line memory, information introduced to the memory in the form of electric pulses was transduced into mechanical waves that propagated relatively slowly through a medium, such as a cylinder filled with a liquid like mercury, a magnetostrictive coil, or a piezoelectric crystal.
DFM Design for Manufacturability Design for Manufacturability
DFT Design for Test Design for Test
DUT Device Under Test Component, PCB, or assembly subjected to a test.  Also known as unit under test (UUT) and loaded board. The term DUT is used within the electronics industry to refer to any electronic assembly under test. For example, cell phones coming off of an assembly line may be given a final test in the same way as the individual chips were earlier tested. Each cell phone under test is, briefly, the DUT. The DUT is often connected to the test equipment using a bed of nails tester of pogo pins. Another term used in place of DUT, is the term DUDE. DUDE refers to Device Under Determinative Experiment. The necessity for using the term DUDE arises because the item is not under test but under experiment. DUDE was created by necessity for accurate documentation by acoustics engineer Jon Schluckabier, in 2012, while documenting experiments on the Kinect device in a lab in Redmond Washington.
DIA Diameter American wire gauge (AWG), also known as the Brown & Sharpe wire gauge, is a standardized wire gauge system used since 1857 predominantly in the United States and Canada for the diameters of round, solid, nonferrous, electrically conducting wire. The cross-sectional area of each gauge is an important factor for determining its current-carrying capacity.
D or CR or V Diode Allows flow in chiefly in one direction and can convert AC to DC
D2PAKs Diode 2 Packages Largest SMT transistor made & include heat sink mounting pad
DPAKs Diode Packages Accommodate higher powered groups of transistors and diodes
DC Direct Current Direct current (DC) is the unidirectional flow of electric charge. Direct current is produced by sources such as batteries, thermocouples, solar cells, and commutator-type electric machines of the dynamo type. Direct current may flow in a conductor such as a wire, but can also flow through semiconductors, insulators, or even through a vacuum as in electron or ion beams. The electric charge flows in a constant direction, distinguishing it from alternating current (AC). A term formerly used for direct current was galvanic current.
Direct Services Direct Services includes special outside testing, routing, etc., that were needed to complete production of goods for the quarter
Drop Ship A process where customers buy the parts and materials and they are shipped to the manufacturer. The manufacturer then builds the products and deliver completed assemblies or cables to the customer.
DFN Dual Flat No-Leads Flat no-leads packages such as QFN (quad-flat no-leads) and DFN (dual-flat no-leads) physically and electrically connect integrated circuits to printed circuit boards. Flat no-leads, also known as MicroLeadFrame and SON (small-outline no leads), is a surface-mount technology, one of several package technologies that connect ICs to the surfaces of PCBs without through-holes. Flat no-lead is a near chip scale package plastic encapsulated package made with a planar copper lead frame substrate. Perimeter lands on the package bottom provide electrical connections to the PCB. Flat no-lead packages include an exposed thermal pad to improve heat transfer out of the IC (into the PCB). Heat transfer can be further facilitated by metal vias in the thermal pad. The QFN package is similar to the quad-flat package, and a ball grid array.
DIL Dual In-Line Component shape with two parallel rows of connection leads
DIPs Dual In-Line Packages Dual In Line Package – usually made of plastic or ceramic.  In microelectronics, a dual in-line package (DIP or DIL) is an electronic device package with a rectangular housing and two parallel rows of electrical connecting pins. The package may be through-hole mounted to a printed circuit board or inserted in a socket. A DIP is usually referred to as a DIPn, where n is the total number of pins. For example, a microcircuit package with two rows of seven vertical leads would be a DIP14. The photograph at the upper right shows three DIP14 ICs.
DRAM Dynamic RAM Read-write memory that must be refreshed (read or written into) periodically to maintain the storage of information.
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Ekra Stencil Printer Displaces solder paste and uses vision inspection to validate the solder paste alignment to the PCB pads
EC Electrical Code or Electrical Contractor Also NEC.  The National Electrical Code (NEC), or NFPA 70, is a regionally adoptable standard for the safe installation of electrical wiring and equipment in the United States. The NEC, while having no legally binding regulation as written, can be and often is adopted by states, municipalities and cities in an effort to standardize their enforcement of safe electrical practices within their respective jurisdiction. In some cases, the NEC is amended, altered and may even be rejected in lieu of regional regulations as voted on by the governing bodies of any given locale.
EMT Electrical Metallic Tubing Electrical metallic tubing (EMT), sometimes called thin-wall, is commonly used instead of galvanized rigid conduit (GRC), as it is less costly and lighter than GRC. EMT itself may not be threaded, but can be used with threaded fittings that clamp to it. Lengths of conduit are connected to each other and to equipment with clamp-type fittings. Like GRC, EMT is more common in commercial and industrial buildings than in residential applications. EMT is generally made of coated steel, though it may be aluminum.
EEPROM Electrically Erasable Programmable Read-Only Memory EEPROM (also written E2PROM and pronounced “e-e-prom,” “double-e prom,” “e-squared,” or simply “e-prom”) stands for Electrically Erasable Programmable Read-Only Memory and is a type of non-volatile memory used in computers and other electronic devices to store small amounts of data that must be saved when power is removed, e.g., calibration tables or device configuration.
ENIG Electroless nickel immersion gold Electroless nickel immersion gold (ENIG) is a type of surface plating used for printed circuit boards. It consists of an electroless nickel plating covered with a thin layer of immersion gold, which protects the nickel from oxidation. ENIG has several advantages over more conventional (and cheaper) surface platings such as HASL (solder), including excellent surface planarity (particularly helpful for PCB’s with large BGA packages), good oxidation resistance, and usability for untreated contact surfaces such as membrane switches and contact points.
EDS Electronic Data Submission Electronic data submission
EIAJ Electronic Industries Association in Japan Electronic Industries Association in Japan
EMS Electronic Manufacturing Services Abbreviation of Electronic Manufacturing Services, a term used for companies that design, test, manufacture, distribute and provide return/repair services for electronic component and assemblies.
ESA Electronic Sub-Assembly A subassembly is a group of parts put together to form part of a finished assembly. An assembly refers to a group of subassemblies put together to make something that performs a specific task. The most common areas where a subassembly will be used is in electronics, optical, and computers.Electronic subassemblies are used in a large variety of consumer electronics. Small home appliances such as microwaves and portable media players have subassemblies. In a microwave, there are heating elements, electrical plugs, and the actual control panel. All three of these areas may contain smaller groups of parts or subassemblies.The control panel will contain the electronic subassembly. Usually it consists of a printed circuit board, or PCB, and also a light emitting diode, or LED, display. The keypad that controls the cooking time is also part of the electronic subassembly. These three items are connected together using a soldering iron. The electronic subassembly is then mated with the heating elements, plugs, and casing to make the microwave.Electronic devices such as cell phones or televisions also have electronic subassemblies. The display and PCB for portable media player and cell phones, while much smaller than the ones in a microwave, work in a similar manner. Cell phones have additional radio frequency, or RF, components that allow them to pick up cell tower signals. The components are then mated with the outside housing to complete the gadget.
ESD Electrostatic Discharge Abbreviation of Electrostatic Discharge. ESD can be destructive to sensitive electronic components. Methods to reduce the risk of ESD include the use of grounding straps, anti-static mats, boxes, bags and packing materials. A transfer of electrostatic charge between bodies at different electrostatic potentials caused by direct contact or induced by an electrostatic field.
EM Emergency Emergency
EP Emergency Power Emergency Power
EPO Emergency Power Off (Button or Switch) Emergency Power Off
ESS Environmental Stress Screening Manufacturing stage in which all assemblies are subjected to abnormal stresses, with the aim of forcing all early failures to occur.  Also known as reliability testing.
EB Equipment Branch Equipment Branch
ESD S20.20 ESD S20.20 ANSI/ESD S20.20-1999 is the industry-wide standard for the Development of an Electrostatic Discharge (ESD) Control Program
EF Exhaust Fan Exhaust fan. See conformal coating booth.
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F Farad A unit of measure of the amount of electric charge or capacitance stored. The abbreviation is the letter F. The most common units of capacitance used in electronic circuits are the millifarad (mF), microfarad (µF), the nanofarad (nF) and the picofarad (pF).
Fiducial Mark A round pad or other mark on the surface of a PWB used for optically aligning automatic insertion equipment to the component footprints on the board.
FPGA Field Programmable Gate Arrays Field-programmable gate arrays (FPGA) are the modern-day technology for building a breadboard or prototype from standard parts; programmable logic blocks and programmable interconnects allow the same FPGA to be used in many different applications. For smaller designs and/or lower production volumes, FPGAs may be more cost effective than an ASIC design even in production.
FL Filter Pass one frequency band while blocking others (to filter electrical noise)
Final Assembly Where wire adds, sensitive components and sub-assemblies must be hand soldered as a final step
FPT Fine Pitch Technology The portion of surface mount technology that included components that typically have lead pitch, or center-to-center spacing, between 0.4mm and 0.8mm.
FA Fire Alarm Fire alarm
FAA Fire Alarm Annunciator An annunciator panel is a group of lights used as a central indicator of status of equipment or systems in an aircraft, industrial process, building or other installation. Usually, the annunciator panel includes a main warning lamp or audible signal to draw the attention of operating personnel to the annunciator panel for abnormal events or conditions.
FR4 Flame Retardant level 4 The most commonly used epoxy-fiberglass material standard for printed circuit boards.  The “FR” refers to flame retardant.
Flat lead package Leads extending from 2 sides. Leaded Chip Carriers are also known as Flat Packs, Quad Flat Packs (CQFP), and J-Bend Leaded Chip Carriers (CQFJ). Flat Packs are usually found in lower lead counts; 8-28 leads, have small body outlines, are lightweight, have parallel leads on two sides of the package, and are commonly used in High Reliability applications for military airborne equipment. J-Bend Lead Chip Carriers and Quad Flat Packs are usually found in higher lead counts; greater than 24 leads, have leads on all four sides of the package, are hermetically sealed, and commonly used for surface mount applications or socketing. The leads are flat, gull-wing or J-Bend configured and depending on the package, lead spacing can be .015, .020, .025, and .050 inches.
FP Flat Pack A low profile IC package, which typically has gull wing type of leads on two or four sides.
FMC Flexible Metal Conduit Flexible metallic conduit bends and twists easily, allowing turns at corners without the use of separate elbow joints. It is often used where rigid conduit is difficult to install or to connect permanently wired appliances, such as a water heater.
FCA Flip Chip Attach The technique of attachment of an IC chip to a substrate using solderable bumps between the silicon chip and substrate.
Flux A chemical compound used to remove surface oxides and impurities and to improve wettability when soldering.
FSSC 22000 FSSC 22000 Food Safety System Certification 22000 (FSSC 22000) is a robust, ISO-based, internationally accepted certification scheme for auditing and certification of food safety in the whole supply chain.
FLA Full Load Amperes Running load amps are the steady state operation of a device. The starting load when starting a motor peaks before it diminishes to the running load; when the resistance is applied to the maximum , the power load increases to “full load”.
Functional Test Electrically tests all or a portion of the circuits and components
F Fuse Wire with low melting point. In electronics and electrical engineering, a fuse (from the French fuser, Italian fuso, “spindle”) is a type of low resistance resistor that acts as a sacrificial device to provide overcurrent protection, of either the load or source circuit. Its essential component is a metal wire or strip that melts when too much current flows, which interrupts the circuit in which it is connected. Short circuit, overloading, mismatched loads or device failure are the prime reasons for excessive current.
FUSION analytics Dashboards, reporting and trace enable real time and historical analysis of qualit and process control data
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GRMC Galvanized Rigid Metal Conduit You will often see the following acronyms used: RSC (Rigid Steel Conduit), ERSC (Electrical Rigid Steel Conduit), or GRC (Galvanized Rigid Conduit) in place of RMC (Rigid Metal Conduit) in order to differentiate the type of metal used in the product. Rigid steel conduit (RSC) is a listed threaded metal raceway of circular cross section with a coupling which can be either a standard straight tapped conduit coupling or the integral type.
Gerber File / Gerber Data Gerber is a standard electronics industry file format used to communicate design information to manufacturing for many types of printed circuit boards. In many ways, Gerber  The Gerber format is a file format used by printed circuit board (PCB) industry software to describe the images of a printed circuit board (copper layers, solder mask, legend, drill holes, etc.). The Gerber format is the de facto industry standard for printed circuit board image transfer.
The Gerber format specification can be freely downloaded. There are two versions. RS-274X (“extended Gerber”) is the most commonly used today. The previous version was a subset of EIA RS-274-D (“standard Gerber”); it is deprecated and is largely superseded by RS-274X.
The Gerber format was developed by Gerber Systems Corp., a company founded by Joseph Gerber. The format is now controlled and owned by Ucamco through its acquisition of Barco ETS, a company that previously acquired Gerber Systems Corpis the electronics world’s equivalent of PDF.  This odd little format, a hybrid machine control language and image, is a core component of the Electronics Mfg supply chain. The content of a Gerber file is ASCII text (i.e. English letters, digits and a few special characters) and looks like a human could almost read and understand. About RS-274D and RS-274XThere are two “standards” for Gerber files out there:  the “old” and the “new”.  The old standard (D) spreads information for a single layer across at least two files.  The new standard (X) allows all the information for a layer to be contained in a single file.  The biggest benefit of this comes down to data management (or in plain English, the fact that it’s much easier to keep track of one file than two files).
GMP Good Manufacturing Practice A good manufacturing practice (GMP) is a production and testing practice that helps to ensure a quality product. Many countries have legislated that pharmaceutical and medical device companies must follow GMP procedures, and have created their own GMP guidelines that correspond with their legislation. Basic concepts of all of these guidelines remain more or less similar to the ultimate goals of safeguarding the health of the patient as well as producing good quality medicine, medical devices or active pharmaceutical products. In the U.S. a drug may be deemed adulterated if it passes all of the specifications tests but is found to be manufactured in a condition which violates current good manufacturing guidelines. Therefore, complying with GMP is a mandatory aspect in pharmaceutical manufacturing.
G or GND Ground In electrical engineering, ground or earth can refer to the reference point in an electrical circuit from which other voltages are measured, or a common return path for electric current, or a direct physical connection to the Earth. Electrical circuits may be connected to ground (earth) for several reasons. In mains powered equipment, exposed metal parts are connected to ground to prevent user contact with dangerous voltage if electrical insulation fails. Connections to ground limit the build-up of static electricity when handling flammable products or electrostatic-sensitive devices.
GFCI, GFI Ground Fault Circuit Interrupter A residual-current device (RCD), or residual-current circuit breaker (RCCB), is an electrical wiring device that disconnects a circuit whenever it detects that the electric current is not balanced between the energized conductor and the return neutral conductor. Such an imbalance may indicate current leakage through the body of a person who is grounded and accidentally touching the energized part of the circuit. A lethal shock can result from these conditions. RCCBs are designed to disconnect quickly enough to prevent injury caused by such shocks. They are not intended to provide protection against overcurrent (overload) or short-circuit conditions.
In the United States and Canada, a residual-current device is most commonly known as a ground fault circuit interrupter (GFCI), ground fault interrupter (GFI) or an appliance leakage current interrupter (ALCI). In Australia they are sometimes known as “safety switches” or simply “RCD” and in the United Kingdom, along with circuit breakers, they can be referred to as “trips” or “trip switches”.
Gull Wing Lead A lead configuration typically used on small outline integrated circuits (SOIC). The package and formed leads, when viewed together from the end, resembles a gull in flight.
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HDL Hardware Description Language In electronics, a hardware description language or HDL is any language from a class of computer languages, specification languages, or modeling languages for formal description and design of electronic circuits, and most commonly, digital logic. It can describe the circuit’s operation, its design and organization, and tests to verify its operation by means of simulation.
Harness An assembly with two or more wires that are ready for installation into a system.
J or P Header Similar to connectors but no housings around pins
Heat Sink In electronic systems, a heat sink is a passive heat exchanger component that cools a device by dissipating heat into the surrounding air. In computers, heat sinks are used to cool central processing units or graphics processors. Heat sinks are used with high-power semiconductor devices such as power transistors and optoelectronic devices such as lasers and light emitting diodes (LEDs), wherever the heat dissipation ability of the basic device package is insufficient to control its temperature.
HVAC Heating, Ventilation, Air Conditioning Heating, Ventilation, Air Conditioning
Heller Reflow Ovens Controls the travel rate, time and temp at which an unsoldered assembly travels through each heat zone to become surface mount solder PCB assembly
HZ Hertz The hertz (symbol Hz) is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon.[1] One of its most common uses is the description of the sine wave, particularly those used in radio and audio applications, such as the frequency of musical tones. The word “hertz” is named for Heinrich Rudolf Hertz, who was the first to conclusively prove the existence of electromagnetic waves.
HASL Hot Air Soldered Leveled Hot air is used to blow off the excess after the PWB is dipped in solder.  Typically used with the SMOBC process.
HIC Humidity Indicator Card Humidity Indicator Card – A humidity indicator card (HIC) is a card on which a moisture-sensitive chemical is impregnated such that it will change color when the indicated relative humidity is exceeded. This item is an inexpensive way to quantify relative humidity levels inside sealed packaging. They are available in many configurations and used in many applications, especially military and semiconductor.  If moisture gets too high you can see delamination or bubbling
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iLaunch Process planning and launch incorporates our customers’ bill of materials, CAD data and assembly requirements and provides the foundation for designing our processes and controls
iMaterials Materials verification and control manages the use of all materials, tools and equipment that are used in production
ICT In-Circuit Test In-circuit test (ICT) is an example of white box testing where an electrical probe tests a populated printed circuit board (PCB), checking for shorts, opens, resistance, capacitance, and other basic quantities which will show whether the assembly was correctly fabricated. It may be performed with a bed of nails type test fixture and specialist test equipment, or with a fixtureless in-circuit test setup.
L Inductor or Inductor Choke Coil of wire creates magnetic field (related to transformers, coils & toroids). An inductor (also choke, coil or reactor) is a passive two-terminal electrical component that stores energy in its magnetic field. For comparison, a capacitor stores energy in an electric field, and a resistor does not store energy but rather dissipates energy as heat. Any conductor has inductance. An inductor is typically made of a wire or other conductor wound into a coil, to increase the magnetic field. When the current flowing through an inductor changes, a time-varying magnetic field is created inside the coil, and a voltage is induced, according to Faraday’s law of electromagnetic induction, which by Lenz’s law opposes the change in current that created it. Inductors are one of the basic components used in electronics where current and voltage change with time, due to the ability of inductors to delay and reshape alternating currents
IR Infrared Reflow The process of soldering a surface mount assembly by using radiant (focused) or convective (non-focused) heat to melt the solder paste and form the solder fillet. Soldering process that uses infrared energy as the primary method of
heating.
ILB Inner Lead Bonding Process of bonding termination, which leads to a tape automated bond integrated circuit’s bumps.
IPC Institute for Interconnecting and Packing Electronic Circuits A worldwide organization that sets standards, specifications and guidelines for PCB design, manufacture and assembly. In 1999, IPC changed its name from Institute for Interconnecting and Packaging Electronic Circuits to IPC.
IEEE Institute of Electrical and Electronic Engineers Abbreviation of the Institute of Electrical and Electronics Engineers or IEEE (pronounced as eye-triple-e) is an international organization for the advancement of technology related to electricity.
W or P Insulated Jumper Insulated Jumper
Insulator A material such as ceramic, rubber, or plastic that blocks the flow of electric current. An insulator is a poor conductor because it has a high resistance to such flow.
IC or U Integrated Circuit A microscopic array of electronic circuits and components that has been implanted onto the surface of a single crystal, or chip, of semiconducting material such as silicon. It is called an integrated circuit because the components, circuits, and base material are all made together, or integrated, out of a single piece of silicon. An integrated circuit is commonly referred to as an IC.  A small, complete circuit made by vacuum deposition and other techniques, usually on a silicon chip, and mounted in a package.
INT Interlock Interlocking is a method of preventing undesired states in a state machine, which in a general sense can include any electrical, electronic, or mechanical device or system. In most applications an interlock is a device used to help prevent a machine from harming its operator or damaging itself by stopping the machine when tripped.
IMC Intermediate Metal Conduit Intermediate Metal Conduit (IMC) is a steel tubing heavier than EMT but lighter than RMC. It may be threaded.
IMC Intermetallic Compound Metallic compounds that form at the interfaces between different metals, such as copper-tin compounds that form at the interface of a solder joint and a copper lead.  IMCs typically have significantly different
properties, such as tensile strength.
IMAPS International Microelectronics and Packaging Society. International Microelectronics and Packaging Society.
SI International System of Units The International System of Units (abbreviated SI from French: Le Système international d’unités) is the modern form of the metric system. It comprises a coherent system of units of measurement built around seven base units, 22 named and an indeterminate number of unnamed coherent derived units, and a set of prefixes that act as decimal-based multipliers.
Inventory Days of Supply Inventory Days of Supply – Average net inventory for the quarter divided by the cost of goods sold (COGS) for the quarter divided by the number of days in the quarter
IPC-1601 IPC-1601 This document provides suggestions for proper handling, packaging materials and methods, environmental conditions, and storage for printed boards. These guidelines are intended to protect printed boards from contamination, physical damage, solderability degradation, electrostatic discharge (ESD) (when necessary), and moisture uptake. Moisture absorbed in printed board laminates expands at soldering temperatures, and in some cases, the resulting vapor pressure can cause internal delamination or excessive strain on plated-hole walls and other structures. This is especially challenging with the higher temperatures used for
lead-free soldering. This document covers all phases from the manufacture of the bare printed board, through delivery, receiving, stocking, assembly, and soldering. As a guideline, this information is to be used with, and is secondary to, the established requirements in such documents as the IPC-4550 series for alternate final finishes.
IPC-1752 IPC-1752 IPC-175x family of standards establishes a standard reporting format for material declaration data exchange between supply chain participants. IPC-1751A has the responsibility for developing the format and XML characteristics for various electronic product domains. This includes material, laminate, printed board and assembly declaration profiles. IPC-1751A defines the generic requirements for declaration process management. IPC-1752A supports reporting of bulk materials, components, printed circuit boards (PCBs), sub-assemblies, and products. IPC-1758 supports reporting of materials in pack, packing and shipping materials.IPC-1752A provides an improved standard for companies in the supply chain to share information on materials in products. IPC-1752A supports reporting multiple parts, reorganization and simplification of the reporting levels and relying on third party solution providers to develop tools instead of the 2-18b standards Committee developing tools. IPC-1752A also moves the lists of substances out of the standard and into informative annexes to improve the ease of updating data exchange tools without needing to change the standard.
IPC-2220 (Series) , IPC-7351, IPC-CM-C770 IPC-2220 (Series) , IPC-7351, IPC-CM-C770 Design requirements reflecting three levels of complexity (Levels A, B, and
C) indicating finer geometries, greater densities, more process steps to
produce the product.
Component and Assembly Process Guidelines to assist in the design of the
bare board and the assembly where the bare board processes concentrate on
land patterns for surface mount and the assembly concentrates on surface
mount and through-hole principles which are usually incorporated into the
design process and the documentation
IPC-4522 IPC-4522 See Black Pad
IPC-7711/7721 IPC-7711/7721 Documentation providing the procedures to accomplish conformal coating
and component removal and replacement, solder resist repair, and
modification/repair of laminate material, conductors, and plated through
holes.
IPC-A-610 IPC-A-610 Pictorial interpretive document indicating various characteristics of the
board and/or assembly as appropriate relating to desirable conditions that
exceed the minimum acceptable characteristics indicated by the end item
performance standard and reflect various out-of-control (process indicator or
defect) conditions to assist the shop process evaluators in judging need for
corrective action.  This document presents acceptance requirements for the manufacture of electrical and electronic assemblies. Historically, electronic assembly standards contained a more comprehensive tutorial addressing principles and techniques. For a more complete understanding of this document’s recommendations and requirements, one may use this document in conjunction with IPC-HDBK-001, IPC-AJ-820 and IPC J-STD-001.
IPC-D-325 IPC-D-325 Documentation depicting bare board specific end product requirements
designed by the customer or end item assembly requirements. Details may or
may not reference industry specifications or workmanship standards as well
as customer’s own preferences or internal standard requirements.
iQ Quality and test management montiros and controls the inspection, repair, and test processes utilizing route logic control
ISO ISO Abbreviation of the International Standards Organization or International Organization for Standardization
ISO 13485 ISO 13485 With regards to medical devices, there is no standard that better represents the requirements for a comprehensive management system than ISO 13485:2003. Compliance with ISO 13485:2003 is often seen as the first step in achieving compliance with regulatory requirements.
ISO 14001 ISO 14001 ISO 14000 is a family of ISO standards that applies to environmental management systems. ISO 14001 consists of two general standards. ISO 14001: 2004 lists the requirements necessary for an EMS system to be ISO-compliant, while 14004: 2004 provides general guidelines for EMS quality. Other ISO 14001 standards are more industry-specific in nature.
ISO 22000 ISO 22000 The ISO 22000:2005 standard outlines Food safety management system requirements for any organization in the good chain and is one of a family of standards focused at the development, implementation and improvement of a food safety management system.
ISO 27001 ISO 27001 ISO 27001 is the international standard for Information Security Management Systems (ISMS) based largely upon the previously adopted BS 7799 used commonly since 1995 for managing information security.
ISO 9001 ISO 9001 ISO 9001:2008 specifies quality system requirements to be used where an organization requires the ability to consistently provide conforming products, either material or services to meet a customers expectations. The requirements are aimed at achieving customer satisfaction by preventing nonconformances. The ISO 9001:2008 standard provides a model on which an organization may build an effective quality management system.
ISO IEC 20000-1 ISO IEC 20000-1 In a nutshell, ISO 20000 is a set of recognized international standards for IT service management systems established in 2005 to create guidelines for compliance with best practices in IT systems management.
ISO/TS 16949 ISO/TS 16949 The ISO/TS 16949 standard was developed to decrease the number of standards suppliers to the automotive industry need to be compliant with in order to conduct business internationally.
IG Isolated Ground An isolated ground is a local ground connection used with a supply, one of the common earthing arrangements used with domestic mains supplies.
The primary reason for the use of isolated grounds (IG) is to provide a noise-free ground return, separate from the equipment grounding (EG) return. The EG circuit includes all of the metal conduit, outlet boxes, and metal enclosures that contain the wiring and which must be grounded to provide a safe return path for any fault current that might occur. The IG’s purpose is to provide an insulated, separate ground path for the ground reference in electronic equipment, such as computers, hospital equipment, and audio equipment. The use of IG helps eliminate the potential for a “ground loop”, which can cause noise, data errors, and disruptions to these systems. The IG is typically insulated and separate all the way back to the point of origin of the circuit, either a main panel or sub-panel. The IG, EG and neutral are all bonded together at that point. Due to the installation of a separate, insulated conductor and the associated special outlets required, IG circuits are more expensive to install than standard power circuits.
iTrac Process tracking and control utilizes bar coded serial numbers to continuosly monitor job status from start to finish
iView Paperless shop floor delivers controlled worked instructions to the shop floor in real time and provides interface for inputting process and quality data.
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CQFJ J-Bend Leaded carriers Leaded Chip Carriers are also known as Flat Packs, Quad Flat Packs (CQFP), and J-Bend Leaded Chip Carriers (CQFJ). Flat Packs are usually found in lower lead counts; 8-28 leads, have small body outlines, are lightweight, have parallel leads on two sides of the package, and are commonly used in High Reliability applications for military airborne equipment. J-Bend Lead Chip Carriers and Quad Flat Packs are usually found in higher lead counts; greater than 24 leads, have leads on all four sides of the package, are hermetically sealed, and commonly used for surface mount applications or socketing. The leads are flat, gull-wing or J-Bend configured and depending on the package, lead spacing can be .015, .020, .025, and .050 inches.
J-Lead A lead configuration typically used on plastic leaded chip carriers (PLCC). The lead is rolled under the component body causing formed lead to resemble the letter “J” when viewed from the side.
JDEC Joint Electronic Devices Engineering Council Joint Electronic Devices Engineering Council, a part of the Electronic Industries Association (EIA) that publishes specifications and standards for electronic components.
J-STD-001 J-STD-001 Requirements for soldered electrical and electronic assemblies depicting
minimum end product acceptable characteristics as well as methods for
evaluation (test methods), frequency of testing and applicable ability of
process control requirements
W, P or R Jumper Connect two pins on an assembly together
JIT Just in Time A production strategy that strives to improve a business return on investment by reducing in-process inventory and associated carrying costs. To meet JIT objectives, the process relies on signals or Kanban between different points in the process, which tell production when to make the next part. Kanban are usually ‘tickets’ but can be simple visual signals, such as the presence or absence of a part on a shelf. Implemented correctly, JIT focuses on continuous improvement and can improve a manufacturing organization’s return on investment, quality, and efficiency. To achieve continuous improvement key areas of focus could be flow, employee involvement and quality.
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Kanban A scheduling system for lean and just-in-time (JIT) production. According to its creator, Taiichi Ohno, kanban is one means through which JIT is achieved. Kanban is not an inventory control system; it is a scheduling system that helps determine what to produce, when to produce it, and how much to produce. The need to maintain a high rate of improvement led Toyota to devise the kanban system. Kanban became an effective tool to support the running of the production system as a whole. In addition, it proved to be an excellent way for promoting improvements because reducing the number of kanban in circulation highlighted problem areas.
KVA Kilovolt-Amperes a unit of electrical power equal to 1000 volt-amperes
KVAR Kilovolt-Amperes Reactive Kilovolt-ampere reactive power (kVAR): One VAR is equal to a volt-ampere of reactive power; a kVAR is one thousand VARs: Reactive power does not do work like active power (kilowatts), but instead produces an electromagnetic field. Installing a capacitor can generate the required magnetic field on-site, reducing the total power (kilovolt-amperes) required to run a piece of equipment
Kitted See Consignment.
KGB Known Good Board A correctly operating PCB.  It is used in learning or debugging a test program in development and for comparison testers where it serves as the standard unit by which other PCBs are compared.
KGD Known Good Die Known good die.
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PAD Land A portion of a conductive pattern used for attachment or connection of components.
LANDS or PADS Land Pattern A combination of lands intended for the mounting and interconnection of a particular component.
LSI Large Scale Integration Arrays of ICs on a single substrate that comprise 100 or
more individual active circuit functions or gates.
LDCC Leaded Ceramic Chip Carrier Leaded Ceramic Chip Carrier.  A hermetically sealed ceramic package that has leads around its sided for solder connection in a surface mounting application. Typically, thee packages have over 28 leads.
LCCC or CLCC Leadless ceramic chip carrier Leadless Ceramic Chip Carrier (or CLCC for Ceramic Leadless Chip Carrier).  A hermetically sealed ceramic package that has pads (castellations) around its sides for solder connection in a surface mounting application.
LCC Leadless chip carrier Leadless Chip Carriers (LCC) are low profile multilayer packages used in surface mount applications or socketing. Due to their light weigh, low cost, and lead counts from 3 -84, they are suitable to a variety of applications. LCC’s have no metallic external leads and instead offer short internal electrical traces from the die to the metalized castellations around all 4 sides and bottom of the package. These contacts are normally .040” – .050” on center. JEDEC outlines come in different configurations with Type C the most popular.
Level 1 Traceability Level 1: Simple Process Flow In this lowest level, traceability is the simply matter of ensuring that the circuit boards go through all of the proper processes in the right order, without necessarily recording the conditions at each process. If a unique identifier is present on the board, it is read before (or after) each process.
Level 2 Traceability Level 2: Simple Lot-Based Traceability The most common form of traceability is related to the
materials placed on the circuit boards during the assembly operation. In order to gain control of materials, there are some simple procedures that may be adopted. Materials can for example be assigned specifically to each production lot as a “consignment”. This can enable the manufacturer to provide the customer with a simple list by part number of the suppliers’ names and batch numbers which have been used to manufacture each lot. This is usually done as an “off-line” preparation stage, since it can take considerable time to record the data, which otherwise would impact the operation time for the machines.
Level 3 Traceability Level 3: Unique ID Lot-Based Traceability – In this level of traceability, we introduce the unique identification of each reel of material. This can be achieved through the application of a unique bar-code or RF-ID tag to each unit of materials, for example reels or trays. This is typically done as part of the receiving and booking in process. If this is an integrated part of the normal receiving process, it has little effect on the overall operation.
Level 4 Traceability Level 4 – Panel-Based Full Material Traceability – This is regarded by many as the minimum requirement for a true traceability function. The additional feature of this level of traceability is the unique identification of each board. This is done by placing a unique identifier of some sort, for example a bar-code, 2-D bar code, or RF tag on the board before the first process.
As the panel moves into or out of each process, the ID is recorded. Information is therefore stored against each individual circuit board.  At DCA we have Level 4 Traceability
Level 4a Traceability Level 4a – Unique Individual Reference Traceability – This is applicable in only a few certain cases where certain conditions exist. As an addition to the regular level 4 traceability, the traceability data collected can be refined to include a record of individually identifiable (serialized) parts. In a very special cases where the key functionality of the board depends on a few major devices, the customer may require that only these critical parts need to be traced, thereby avoiding the need level 4 traceability. In either case, a simple system can be used to read the unique identifier of the board and at the same time read the serial numbers
and/or batch numbers of the key devices on the board.
Level 5 Traceability Level 5 – Panel-Based Full Material & Process Traceability – In level 4, the focus was on materials. In level 5, we address the process related information. This can include for example, temperature measurements made at the reflow oven, test results from AOI or ATE, whether a cleaning cycle had been performed on the screen printer etc. This produced therefore a complete historical record associated with each circuit board as to how it was manufactured.
DS Light Emitting See LED
LED Light Emitting Diode A light-emitting diode (LED) is a semiconductor light source.[4] LEDs are used as indicator lamps in many devices and are increasingly used for other lighting. Appearing as practical electronic components in 1962,[5] early LEDs emitted low-intensity red light, but modern versions are available across the visible, ultraviolet, and infrared wavelengths, with very high brightness. When a light-emitting diode is forward-biased (switched on), electrons are able to recombine with electron holes within the device, releasing energy in the form of photons. This effect is called electroluminescence and the color of the light (corresponding to the energy of the photon) is determined by the energy gap of the semiconductor.
LTG Lighting Lighting abbreviation
LFMC Liquid Tight Flexible Metal Conduit Flexible Liquid-tight Metal conduit (Liquid Tight Conduit) is ideal when used with liquid tight conduit fittings for applications where a high degree of liquid tightness is required. This product is suitable for a number of general purpose applications and ideal for environments with lots of oils and greases such as machine tool workshops.
LRA Lock Rotor Amps “Locked Rotor Current” also called LRA which stands for Locked Rotor Amps, is commonly found on electric motor nameplates. Locked Rotor essentially means the motor is not turning. The current or amps in this case have to do with the amount of electrical energy required to start the motor.
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MCB Main Circuit Breaker The main breaker is usually located atop the rest of the breakers in a panel, but sometimes the breaker panel is installed upside down. In this case, the main would be at the bottom. Some main breakers are bolted in place and others are snapped into place just like the branch circuit breakers.
Mask A peelable, water soluble, or solvent soluble compound that is used to prevent solder from filling in areas that need to be solder free.
MTBF Mean Time Between Failures The arithmetic or statistical mean average time interval, usually in hours, that may be expected between failures of an operating unit.  Results should be designated actual, predicted, or calculated.
MTTF Mean Time To Failure Average time between failures.
MTTR Mean Time to Repair A measure of how long it takes to access a failed system and identify, locate, and repair the fault.
MW Megawatt The megawatt is equal to one million (106) watts. Many events or machines produce or sustain the conversion of energy on this scale, including lightning strikes; large electric motors; large warships such as aircraft carriers, cruisers, and submarines; large server farms or data centers; and some scientific research equipment, such as supercolliders, and also in the output pulses of very large lasers. A large residential or commercial building may consume several megawatts in electric power and heat. On railways, modern high-powered electric locomotives typically have a peak power output of 5 or 6 MW, although some produce much more. The Eurostar, for example, consumes more than 12 MW, while heavy diesel-electric locomotives typically produce/consume 3 to 5 MW. U.S. nuclear power plants have net summer capacities between about 500 and 1300 MW
MC Metal Clad Cable The electrical contracting industry is moving rapidly to replace costly conduit installations with modern cable technology. The use of metal-clad cable for branch circuits has doubled in the past decade because it helps achieve faster job turns at a lower cost.
MELFs Metal Electrode Leadless Face Metalized terminally at both ends of cylindrical body (can be diodes, resistors, capacitors or inductors). A cylindrical component package having metallization on both ends. This type of package is commonly used for diodes, capacitors and resistors. Metal Electrode Face Bonding: A cylindrical leadless component with a round body and metals terminals on the ends.
MQFP Metric Quad Flat Pack See QFP
MIL-SPEC Military Standard United States Defense Standard, often called a military standard, “MIL-STD”, or “MIL-SPEC”. A MIL-SPEC for quality standards for electronic parts is MIL-STD-202.
MI Mineral Insulated Mineral-insulated copper-clad cable is a variety of electrical cable made from copper conductors inside a copper sheath, insulated by inorganic magnesium oxide powder. The name is often abbreviated to MICC or MI cable, and colloquially known as pyro (because the original manufacturer and vendor for this product in the UK is a company called Pyrotenax). A similar product sheathed with metals other than copper is called mineral insulated metal sheathed (MIMS) cable.
MSD Moisture Sensitive Device Moisture Sensitivity Level relates to the packaging and handling precautions for some semiconductors. The MSL is an electronic standard for the time period in which a moisture sensitive device can be exposed to ambient room conditions (approximately 30°C/60%RH).  Increasingly, semiconductors have been manufactured in smaller sizes. Components such as thin fine-pitch devices and ball grid arrays could be damaged during SMT reflow when moisture trapped inside the component expands.  The expansion of trapped moisture can result in internal separation (delamination) of the plastic from the die or lead-frame, wire bond damage, die damage, and internal cracks. Most of this damage is not visible on the component surface. In extreme cases, cracks will extend to the component surface. In the most severe cases, the component will bulge and pop. This is known as the “popcorn” effect.
IPC (Association Connecting Electronic Industries) created and released IPC-M-109, Moisture-sensitive Component Standards and Guideline Manual.
Moisture sensitive devices are packaged in a moisture barrier antistatic bag with a desiccant and a moisture indicator card which is sealed. IPC-M-109 includes seven documents. According to IPC/JEDEC’s J-STD-20: Moisture/Reflow Sensitivity Classification for Plastic Integrated Circuit (IC) SMDs, there are eight levels of moisture sensitivity. Components must be mounted and reflowed within the allowable period of time (floor life out of the bag).
‘MSL 6 – Mandatory Bake before use
MSL 5A – 24 hours
MSL 5 – 48 hours
MSL 4 – 72 hours
MSL 3 – 168 hours
MSL 2A – 4 weeks
MSL 2 – 1 year
MSL 1 – Unlimited
MSD Protection Steps Per J-STD-033B.1 As packages get smaller, the risk for damage to moisture-sensitive devices increases. With the higher temperatures required for Pb-free soldering, that risk is further compounded. That’s why it’s extremely important to be aware and vigilant of MSDs. ICs can act like a sponge. If they have semi-permeable membranes, moisture from the ambient air can get into those devices. When they get rapidly heated during reflow or rework, the result is rapid outgassing. In some cases, this excessive outgassing causes popcorning, which can damage the internal structures of a component
MCM Multi Chip Module A circuit comprised of two or more silicon devices bonded directly to a substrate by wire bond, TAB, of  flip chip.
MLB Multi Layer Board A PWB that has more than two conductor layers.  The layers are interconnected by the plated-through holes.
VOM Multimeter An instrument used to measure resistance, current and voltage.  A multimeter or a multitester, also known as a VOM (Volt-Ohm meter), is an electronic measuring instrument that combines several measurement functions in one unit. A typical multimeter may include features such as the ability to measure voltage, current and resistance. Multimeters may use analog or digital circuits—analog multimeters (AMM) and digital multimeters (often abbreviated DMM or DVOM.) Analog instruments are usually based on a microammeter whose pointer moves over a scale calibrated for all the different measurements that can be made; digital instruments usually display digits, but may display a bar of a length proportional to the quantity being measured
Mydata Pick and Place Accurately and reliably picks and palces specified components in their proper location and orientation on a pasted PCB
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NEC National Electrical Code The National Electrical Code (NEC), or NFPA 70, is a regionally adoptable standard for the safe installation of electrical wiring and equipment in the United States. The NEC, while having no legally binding regulation as written, can be and often is adopted by states, municipalities and cities in an effort to standardize their enforcement of safe electrical practices within their respective jurisdiction. In some cases, the NEC is amended, altered and may even be rejected in lieu of regional regulations as voted on by the governing bodies of any given locale.
NEMA National Electrical Manufacturers Association NEMA is the association of electrical equipment manufacturers, founded in 1926 and headquartered in Arlington, Virginia. Its member companies manufacture a diverse set of products including power transmission and distribution equipment, lighting systems, factory automation and control systems, and medical diagnostic imaging systems. Worldwide annual sales of NEMA-scope products exceed $120 billion.
NFPA National Fire Protection Association Publishes fire and building safety standards including the National Electrical Code.
NIST National Institute of Standards and Technology NIST is the federal technology agency that works with industry to develop and apply technology, measurements, and standards.
NPI New Product Introduction While early engagement provides the greatest opportunity for design and process improvement, new product introduction process provides a framework that allows engagement at any point in a product’s life cycle and ensures constant focus and attention to customer needs.
Nominal The measurement about which the tolerance is given. Halfway between minimum and maximum dimensions.
NDMD Non Solder Mask Defined Pad A pad design characterized by the opening in the solder mask being larger than the copper pad for a BGA.
NCNR Non-Cancelable Non Returnable Non-cancelable, non-returnable (NCNR) product refers to a product purchased under a written contract that specifies once the order is placed, the purchaser is not allowed to make any cancellations or reductions to the order, nor are they allowed to return product (except for warranty resulting from product defects). This product classification is passed along through the supply chain.Manufacturers implement NCNR as a way to manage production starts, improve the utilization of manufacturing and test facilities, manage inventory, and restrict the return of non-standard product that may be unique to the customer. Some distributors utilize NCNR as a way to internally manage inventory and restrict the return of product from customers. Sometimes also No Credit No Return
NRE Non-recurring Engineering Non-recurring engineering (NRE) refers to the one-time cost to research, develop, design and test a new product. When budgeting for a project, NRE must be considered to analyze if a new product will be profitable. Even though a company will pay for NRE on a project only once, NRE costs can be prohibitively high and the product will need to sell well enough to produce a return on the initial investment. NRE is unlike production costs, which must be paid constantly to maintain production of a product. It is a form of fixed cost in economics terms.
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Ω Ohm A unit of electrical resistance. Abbreviation is the Greek capital letter omega – Ω
OHSAS 18001 OHSAS 18001 Occupational Health & Safety is a subject that must be addressed by all organizations large and small. The organization’s management system should identify all legislative requirements, identify the hazards and control the risks of the organization.
OSP Organic Solder Preservative Layers of organic coatings applied to entire board surfaces to prevent oxidation and to retain solderability.
OEM Original Equipment Manufacturer An abbreviation of original equipment manufacturer, An OEM is a company that builds products or components which are used in products sold by another company
Y or G Oscillator An electronic oscillator is an electronic circuit that produces a repetitive, oscillating electronic signal, often a sine wave or a square wave.  Oscillators convert direct current (DC) from a power supply to an alternating current signal. They are widely used in many electronic devices. Common examples of signals generated by oscillators include signals broadcast by radio and television transmitters, clock signals that regulate computers and quartz clocks, and the sounds produced by electronic beepers and video games.
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PGA Pad Grid Array Similar to a pin grid array.  An IC package that has solderable connections in a grid layout on the bottom of the package, and is soldered to the surface of the substrate (PWB) with butt solder joints.
PTO Paid Time Off HR Policy
PPM Parts Per Million Parts per Million
PAS 220:2008 PAS 220:2008 PAS 220:2008 Prerequisite program on food safety for food manufacturing has been withdrawn and replaced by ISO/TS 22002-1.
PAS 222:2001 PAS 222:2001 PAS 222:2001 is the prerequisite program and design requirements for food safety in the manufacture and provision of food and feed for animals.
PAS 223:2011 PAS 223:2011 PAS 223:2011 – 2011 is the Prerequisite program and design requirements for food safety in the manufacture and provision of food packaging.
PCB Raw life expectancy 2 year window. Finishes start to oxidize and corrode over time creating solder issues.
PCMCIA Personal Computer Memory Card International Association The organization that has developed the early standards for the various sizes of modules which
were initially for memory expansion but are now used for many different electronic functions.
Φ Phase The number of phases in a power system in electrical engineering
Pick and Place Based on a specific assembly program, using miniature vacuum tools, this machine picks from multiple reels of various sizes and shapes of electrical components then places them on a solder pasted PBC in the proper location, rotation and polarity orientation
Pillarhouse Selective Solder Programmatically and consistently solders through hole components to the PCB assembly bringing it one step closer to a final PCB assembly
PGAs Pin Grid Arrays Similar to Ball Grid Arrays BGAs but for through hole technology – not commonly used anymore
PBGA Plastic Ball Grid Array A ball grid array component whose package substrate is made of plastic, most likely an FR-4 equivalent of epoxy-fiberglass, polyimidearramid, or similar resin-fiber combinations.
PLCCs Plastic leaded chip carrier Fits in a socket.  A square component package commonly having J-leads on all four sides. A plastic IC package for surface mounting applications that has leads, generally “J” leads, on all fours sides (sometimes given as PCC or PLDCC).
PQFP Plastic Quad Flat Pack See QFP. Plastic Quad Flat Pack.  An FP with leads on fours sides. Generally refers to a
plastic quad flat package that is built to JEDC standards.
PTH Plated Through Hole A hole in which electrical connection is made between external or internal layers or both, by the plating of metal on the wall of the hole. Also used for mounting the leads of through hole components. An interconnection from one side of a PWB (PCB) to another that is formed with the copper plating of the via (hole) sidewalls.
Polarity In electricity, the quality of having two oppositely charged poles, one positive one negative.
P Pole Pole
PT Potential Transformer Potential Transformer is designed for monitoring single-phase and three-phase power line voltages in power metering applications.
Potentiometer A variable resistor often used to control a circuit.  A potentiometer ( /pɵˌtɛnʃiˈɒmɨtər/), informally a pot, is a three-terminal resistor with a sliding contact that forms an adjustable voltage divider. If only two terminals are used, one end and the wiper, it acts as a variable resistor or rheostat. A potentiometer measuring instrument is essentially a voltage divider used for measuring electric potential (voltage); the component is an implementation of the same principle, hence its name. Potentiometers are commonly used to control electrical devices such as volume controls on audio equipment. Potentiometers operated by a mechanism can be used as position transducers, for example, in a joystick. Potentiometers are rarely used to directly control significant power (more than a watt), since the power dissipated in the potentiometer would be comparable to the power in the controlled load.
PWR Power Power shorthand
Pretax Earnings Pretax Earnings – Sales revenue for the period minus the cost of sales, operating expenses and interest, before income taxes have been paid
Pretax Profit Margin Pretax Profit Margin – Pretax earnings divided by net sales.
PCA Printed Circuit Assembly The generic term for a PCB after all electrical components have been attached.  Also referred to as a printed wiring assembly
(PWA).
PCB Printed Circuit Board A part manufactured from a rigid base material upon which a completely processed printed circuit has been formed. A self-contained module of interconnected electronic components. The circuits are formed by a thin layer of conducting material deposited, or “printed,” on the surface of an insulating board. A printed circuit board, or PCB, is used to mechanically support and electrically connect electronic components using conductive pathways, tracks or signal traces etched from copper sheets laminated onto a non-conductive substrate. It is also referred to as printed wiring board (PWB) or etched wiring board. Printed circuit boards are used in virtually all but the simplest commercially produced electronic devices. A PCB populated with electronic components is called a printed circuit assembly (PCA), printed circuit board assembly or PCB Assembly (PCBA). In informal use the term “PCB” is used both for bare and assembled boards, the context clarifying the meaning. Alternatives to PCBs include wire wrap and point-to-point construction. PCBs must initially be designed and laid out, but become cheaper, faster to make, and potentially more reliable for high-volume production since production and soldering of PCBs can be automated. Much of the electronics industry’s PCB design, assembly, and quality control needs are set by standards published by the IPC organization
PCBA Printed Circuit Board Assembly See Printed Circuit Board
PWA Printed Wiring Assembly The generic term for a PWB after all electrical components have been attached.
PWB Printed Wiring Board Commonly called PCB today. A substrate of epoxy glass and clad metal or other material upon which completely processed, printed wiring has been formed. The substrate, generally epoxy glass, used to provide component attachment lands and interconnections to form a functioning electronic circuit (also called a PCB or printed circuit board).
Prototype A physical model of a new product concept.
PS-Prep PS-PrepTM (Private Sector Preparedness Program) is a collaboration between the Department of Homeland Security and the private sector. Based on recommendations by the 9/11 Commission, it is intended to promote readiness and to encourage the creation of management plans so that private-sector organizations can continue to function in the event of a disaster or national emergency.
PB Push Button Push Button or Panic Button or Pull Box
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QFN Quad Flat No-Leads Flat no-leads packages such as QFN (quad-flat no-leads) and DFN (dual-flat no-leads) physically and electrically connect integrated circuits to printed circuit boards. Flat no-leads, also known as MicroLeadFrame and SON (small-outline no leads), is a surface-mount technology, one of several package technologies that connect ICs to the surfaces of PCBs without through-holes. Flat no-lead is a near chip scale package plastic encapsulated package made with a planar copper lead frame substrate. Perimeter lands on the package bottom provide electrical connections to the PCB. Flat no-lead packages include an exposed thermal pad to improve heat transfer out of the IC (into the PCB). Heat transfer can be further facilitated by metal vias in the thermal pad. The QFN package is similar to the quad-flat package, and a ball grid array.
QFP Quad Flat Pack Leaded Chip Carriers are also known as Flat Packs, Quad Flat Packs (CQFP), and J-Bend Leaded Chip Carriers (CQFJ). Flat Packs are usually found in lower lead counts; 8-28 leads, have small body outlines, are lightweight, have parallel leads on two sides of the package, and are commonly used in High Reliability applications for military airborne equipment. J-Bend Lead Chip Carriers and Quad Flat Packs are usually found in higher lead counts; greater than 24 leads, have leads on all four sides of the package, are hermetically sealed, and commonly used for surface mount applications or socketing. The leads are flat, gull-wing or J-Bend configured and depending on the package, lead spacing can be .015, .020, .025, and .050 inches. A FP with leads on four sides.  Generally refers to a plastic quad flat package that is built to EIJ standards.
QPL Qualified Products list A listing of manufacturers qualified by test and performance verification to produce items listed in the MIL specs.
QMS Quality Management Systems A quality management system (QMS) can be expressed as the organizational structure, procedures, processes and resources needed to implement quality management. Early systems emphasized predictable outcomes of an industrial product production line, using simple statistics and random sampling. By the 20th century, labour inputs were typically the most costly inputs in most industrialized societies, so focus shifted to team cooperation and dynamics, especially the early signalling of problems via a continuous improvement cycle. In the 21st century, QMS has tended to converge with sustainability and transparency initiatives, as both investor and customer satisfaction and perceived quality is increasingly tied to these factors. Of all QMS regimes, the ISO 9000 family of standards is probably the most widely implemented worldwide – the ISO 19011 audit regime applies to both, and deals with quality and sustainability and their integration.
QTY Quantity General shorthand
QBR Quarterly Business Review A structured meeting between two parties to gauge benchmarking, progress toward goals, and to talk about opportunities for improvement
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RAM Random Access Memory A type of memory that offers access to storage locations within it by means of X and Y coordinates.
REACH REACH Regulation REACH is the European Community Regulation on chemicals and their safe use (EC 1907/2006). It deals with the Registration, Evaluation, Authorization and Restriction of Chemical substances. The law entered into force on 1 June 2007.
ROM Read Only Memory A random access storage in which the data pattern is unchangeable after manufacture.
RCC Rectangular Chip Carrier A chip carrier with unequal length and width dimensions.
RoHS Reduction of Hazardous Substances A European Union directive that stands for “the Restriction of the use of certain Hazardous Substances in electrical and electronic equipment”. This directive bans the placing on the EU market of new electrical and electronic equipment containing more than agreed levels of lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyl (PBB) and polybrominated diphenyl ether (PBDE) flame retardants. It went into effect July 1, 2006.
Reflow Oven A reflow oven is a high-precision oven used primarily for soldering electronic components to printed circuit boards using surface mount techniques. The oven contains multiple zones, which can be individually controlled for temperature. Generally there are several heating zones followed by one or more cooling zones. The printed circuit board moves through the oven on a conveyor belt, and is therefore subjected to a controlled time-temperature profile. The multiple heat zones slowly and programmatically raise the temperature of the PCB, components and solder pasted until the paste flows out creating a wetted solder joint. The assembly then goes through cool down zones to solidify the solder joint and cool the assembly which in turn connects the component to the PCB
Reflow Solder A process of soldering surface mount components to a PWB by mass heating of the entire assembly. The heating process causes solder paste, preapplied to component land patterns, to melt and form solder fillets between the component leads and land patterns on the board. Two types of reflow soldering are used, infrared and vapor phase.
K Relay Switches that open and close when actuated by an applied signal
REQ Required Shorthand
R Resistor An electronic component that opposes the flow of electrical current.  Limit flow of current like narrowing six lanes to two lanes on a highway
Return on Value Added Return on Value Added – Profits (pre-tax earning) divided by (total sales minus the cost of direct materials and services). Do not include overhead.
RMS Root Mean Squared In mathematics, the root mean square (abbreviated RMS or rms), also known as the quadratic mean, is a statistical measure of the magnitude of a varying quantity. It is especially useful when variates are positive and negative, e.g., sinusoids. RMS is used in various fields, including electrical engineering.
RS-274D RS-274D See Gerber File (old)
RS-274X RS-274X See Gerber File (new)
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SCC SCC A chip carrier with a square body.
Selective Solder Machine automatically solders each joint of the through hole components on a PCB assembly
Shadowing The shadowing of the solder wave from small components by larger components or through hole component pins.
Shielded Cable that is protected from electromagnetic and radio-frequency interference by a metal sheathing. The shield may be composed of braided strands of copper (or other metal).
SSOP or SSOIC Shrink small outline package Same as VSOP but smaller case.  SSOIC Shrink Small Outline IC.  An SO style IC package that has leads on a 25 mil
pitch.
ST Shunt Trip A shunt trip breaker is a life-saving device used in elevators to shut down electricity when a fire is detected.
Silkscreen Line art and text may be printed onto the outer surfaces of a PCB usually by screen printing epoxy ink in a contrasting color, but can also be done with LPI or dry film like the solder resist. When space permits, the legend can indicate component designators, switch setting requirements, test points, and other features helpful in assembling, testing, and servicing the circuit board. Some digital printing solutions are used instead of screen printing. This technology allows printing variable data onto the PCB, including individual serial numbers as text and bar code.
SIPs Single In-Line Packages Single In Line Package – resistor networks or diode arrays. An IC package or multi-component sub-assembly that has connections or leads in a single row on one side.
SO Small outline See SOIC’s.  A package resembling a flat pack with leads on only two sides.
SOICs Small outline Integrated Circuit Variety of body styles. A small-outline integrated circuit (SOIC) is a surface-mounted integrated circuit (IC) package which occupies an area about 30–50% less than an equivalent DIP, with a typical thickness that is 70% less. They are generally available in the same pinouts as their counterpart DIP ICs. The convention for naming the package is SOIC or sometimes just SO followed by the number of pins. For example, a 14-pin 4011 would be housed in an SOIC-14 or SO-14 package. Small-outline J-leaded package (SOJ) is a version of SOIC with J-type leads instead of gull-wing leads.  An integrated circuit package having two parallel rows of gull wing leads. Packages currently range from 8 to 40 leads. A plastic IC package for surface mounting applications that has leads on two opposite sides.
SOL Small outline large See SOIC’s. Small Outline-Large/Small Outline Wide.  SO generally refers to a package that is approximately 150 mils wide, while SOL/SOW refers to packages that are approximately 300 mils wide
SOM Small outline medium See SOIC’s Small Outline-Large/Small Outline Wide.  SO generally refers to a package that is approximately 150 mils wide, while SOL/SOW refers to packages that are approximately 300 mils wide
SOP Small outline package See SOIC’s Small Outline-Large/Small Outline Wide.  SO generally refers to a package that is approximately 150 mils wide, while SOL/SOW refers to packages that are approximately 300 mils wide
SOT Small Outline Transistors Rectangular transistor or diode w/3 or more gull wings. A discrete semiconductor package having two gull wing leads on one side and one on the other side.  A plastic leaded package for diodes and transistors used in surface mounting applications.
SOL-J or SOJ Small outline w/ J-lead See SOIC’s. A plastic IC package with “J” leads on two sides.  It resembles a plastic DIP or an SOIC except for lead spacing and forming.
SOW Small outline wide See SOIC’s
SME Society of Manufacturing Engineers Society of Manufacturing Engineers
X, XAR, XL, XQ Socket Soldered on board and allow integrated circuit (IC) to be plugged in
Solder A metal alloy with a low melting point used to join components to boards.
Solder Bridging The formation of a conductive path or “short” between conductors during soldering.
Solder Fillet A general term used to describe the contour of the solder joints formed between the component termination and the PWB land pattern after soldering.
Solder Mask A coating of material used to protect or mask conductive traces or areas of a PWB against solder bridging.
SMD Solder Mask Defined A pad design characterized by an overlap of the opening of the solder mask on a copper pad (for a BGA).
SMOBC Solder Mask Over Bare Copper A printed wiring board manufacturing technique whereby solder mask is applied over bare copper, exposed and developed, and then the board is dipped in molten solder to coat the exposed copper.
Solder Paste A combination of minute spherical solder particles, flux, solvent and a suspension agent which is used in reflow soldering. Solder paste is deposited onto the substrate by solder dispensing and screen or stencil printing.
Solder Side (Bottom) A term used to describe the soldered side of a PWB using through hole technology.
Soldering Iron Tool with an internal heating element used to heat surfaces being soldered to the point where the solder becomes molten.
SP Spare Shorthand
SQF 1000 / SQF 2000 SQF 1000 / SQF 2000 Safe Quality Food (SQF) Program is recognized by retailers and foodservice providers around the world who require a rigorous, credible food safety management system.
SPC Statistical Process Control Statistical process control (SPC) is a method of quality control which uses statistical methods. SPC is applied in order to monitor and control a process. Monitoring and controlling the process ensures that it operates at its full potential. At its full potential, the process can make as much conforming product as possible with a minimum (if not an elimination) of waste (rework or trash). SPC can be applied to any process where the “conforming product” (product meeting specifications) output can be measured. Key tools used in SPC include control charts; a focus on continuous improvement; and the design of experiments. An example of a process where SPC is applied is manufacturing lines. The use of statistical techniques to analyze a process or its output to determine any variation from a benchmark and to take
appropriate action to restore statistical control, if required.
Stencil Printing Displaces solder paste using a metal foil stencil .004 – .005″ thick through apertures that match the PCB pad layout and which dictate the majority of solder paste volume used at each solder joint
SCAR Supplier Corrective Action Request/Report When it has been determined that corrective action is required from a supplier, a Supplier Corrective Action Request (SCAR) will be submitted to the responsible supplier with a response due date of 15 calendar days after issuance for final root cause analysis. If final root cause can not be provided by the response due date, at minimum the corrective action should be completed and submitted through the containment action tab in the Harris SCAR online process in SQANet to preclude a penalty assessment.
SIR Surface Insulation Resistance Surface Insulation Resistance
SMA Surface Mount Assembly An electronic assembly or module that is manufactured with surface mounted components and suing surface mount technology.
SMC Surface Mount Components Any electrical or mechanical component that can be attached to the surface of a substrate with solder.
SMD Surface Mount Device See also Surface Mount Technology.  A device that is not inserted into through holes, but designed for placement and soldering onto the surface of a substrate.
SMT Surface Mount Technology A method for constructing electronic circuits in which the components are mounted directly onto the surface of printed circuit boards. Frequently abbreviated as SMT. The technology of assembling printed wiring boards and hybrid circuits where components are mounted onto the surface of the substrate rather than onto through holes. The technology used to manufacture electronic assemblies using components that are soldered directly to the surface of the substrate or PWB.
SMTA Surface Mount Technology Association Surface Mount Technology Association is an international network of professionals who build skills, share practical experience and develop solutions in electronic assembly technologies, including microsystems, emerging technologies, and related business operations.
SOICs Swiss Outline Integrated Circuit See Small Outline Integrated Circuit
S or SW Switch Open and closes a circuit
SYM Symmetrical Shorthand
SOC System on Chip A system on a chip or system on chip (SoC or SOC) is an integrated circuit (IC) that integrates all components of a computer or other electronic system into a single chip. It may contain digital, analog, mixed-signal, and often radio-frequency functions—all on a single chip substrate. A typical application is in the area of embedded systems.
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Tantalum Capacitors Polarized chip capacitor with inward formed L-leads
TAB Tape Automated Bonding An IC interconnection process that uses organic tape to support pre-formed leads during bonding to the chip (inner lead bonding-ILB) and connection to the substrate (outer lead bonding-OLB).  The IC chip is usually bare during the interconnecting processes.
TBGA Tape Ball Grid Array A ball grid array component package that uses TAB techniques to make the connections between the IC chip and the solder balls. This results in a solder ball grid array that is only around the periphery, and
leaves compliant connections between the IC and the solder balls for better TCE reliability.
TPA Terminal Position Assurance Firmly holds terminals in connector housings. Helps reduce tension between terminal and wire connection. Made from heat stabilized, impact modified Polyamide 66 material.
TPA Test Point A test point is a location within an electronic circuit that is used to either monitor the state of the circuitry or to inject test signals. Test points have two primary uses: During manufacturing they are used to verify that a newly-assembled device is working correctly. Any equipment that fails this testing is either discarded or sent to a rework station to attempt to repair the manufacturing defects. After sale of the device to a customer, test points may be used at a later time to repair the device if it malfunctions, or if the device needs to be re-calibrated after having components replaced. Test points can be labelled and may include pins for attachment of alligator clips or may have complete connectors for test clips.
TMCB Thermal Magnetic Circuit Breaker Thermal magnetic circuit breakers, which are the type found in most distribution boards, incorporate both techniques with the electromagnet responding instantaneously to large surges in current (short circuits) and the bimetallic strip responding to less extreme but longer-term over-current conditions. The thermal portion of the circuit breaker provides an “inverse time” response feature, which provides faster or slower response for larger or smaller over currents respectively.
Thermistor Resists current flow based on temperature (looks like a disc capacitor)
TSOP Thin small outline package See SOIC’s
KCMIL Thousand Circular Mils A circular mil is a unit of area, equal to the area of a circle with a diameter of one mil (one thousandth of an inch). It is a convenient[citation needed] unit for referring to the area of a wire with a circular cross section, because the area in circular mils can be calculated without reference to pi (π).Electricians in Canada and the United States are familiar with the circular mil because the National Electrical Code (NEC) uses the circular mil to define wire sizes larger than 0000 AWG. In many NEC publications and uses, large wires may be expressed in thousands of circular mils, which is abbreviated in two different ways: MCM or kcmil. For example, one common wire size used in the NEC has a cross-section of 250,000 circular mils, written as 250 kcmil or 250 MCM, which is the first size larger than 0000 AWG used within the NEC.
Through-hole Insertion Manually place components in through holes on the proper side of the PCB
THT Through-hole Technology A method for constructing electronic circuits in which the components are inserted into holes drilled in printed boards and soldered to pads on the opposite side. Frequently abbreviated as THT. An alternate spelling is thru-hole.
Tie Wrap A type of fastener, especially for binding several electronic cables or wires together, and to organize cables and wires. It consists of a sturdy Nylon tape with an integrated gear rack, and on one end a ratchet within a small open case. It is also referred to as a “cable tie”, “strap”, “rat belt”, “mouse belt”, or “zip tie”.
Tinning The process of coating wires or contacts with a light layer of solder. This allow you to more easily melt them together when soldering.
TL 9000 TL 9000 The purpose of TL 9000 is to define the telecommunications quality system requirements for design, development, production and service. In addition, it specifies the cost and performance metrics for suppliers to measure progress and evaluate the results of quality implementation and improvement programs.
Tombstone (Drawbridge) The condition which exists when a defect in soldering, component orientation, component type or other factors have caused one end of a chip component to pull off the solder pad resulting in a solder open. The component may stand on end in a vertical or near vertical position.
Tooling Holes A general term used for holes or slots in PWBs or blank material to aid in the manufacturing process.
Trace A conductive path or line.
T or XFMR Transformer Primary & secondary coils wound on a common core. When alternating current flows through the primary coil, it induces alternating current in second coil. Induced voltage can cause current to flow to an external circuit.
Q Transistor Semiconductors that amplify oscillate and provide switching action, An electronic device used to control the flow of electricity.
Trim Pot See potentiometer. Trimpot Trimming potentiometers perform a variety of circuit adjustments in all types of electronic equipment.
Turnkey A process where the manufacturer procures all the parts and materials and deliver complete assemblies or cables to the customer.
TYPE I PCB All surface mount component technology with components mounted on one or both sides of the board. The assembly may be reflow soldered in one or two passes.
TYPE II PCB Mixed component technology, with surface mount components mounted on one or both sides of the board and through hole components mounted on the component side (top) of the board. Component side surface mount components are reflow soldered on the first pass and the solder side (bottom) surface mount components and through hole components are wave soldered on the second pass.
TYPE III PCB Mixed component technology, with through hole components mounted
on the component side (top) of the board and surface mount components mounted on the solder side (bottom) of the board. The assembly can be wave soldered in one pass.
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UG Under Ground Shorthand
UL Underwriters Laboratory Underwriters Laboratories: A not-for-profit product safety and testing and certification body. UL permits applying a number of their marks on products that comply with their standards.
Unshielded Cable that is not protected from electromagnetic and radio-frequency interference by a metal sheathing.
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VP Vapor Phase Reflow The process of soldering a surface mount assembly by using the latent heat of vaporization of an inert liquid to melt the solder paste.
VSP Vapor Phase Soldering Soldering accomplished by using heat generated by the condensing of a vapor ion a cooler assembly.  VSP is achieved with SMT by using a high temperature, approximately 215 degrees C, special prefluorinated fluid.
VC Variable Capacitor Screw moves plates closer and further apart in a capacitor
Variable Resistor (aka Potentiometer, trimpot, trimmer) – resistor value changed by turning a screw
VCAP Verified Conformity Assessment Program The National Conference of Weights and Measures has mandated that devices with NTEP Certificates of Conformance be subject to a third-party VCAP audit process in order to ensure that device performance is periodically tested to the appropriate environmental requirements per NIST Handbook 44, per the test protocols of NCWM Publication 14.
VFP Very Fine Pitch Very Fine Pitch.  The center-to-center lead distance of surface mount packages that are between 0.012 inch and 0.020 inch.
VLSI Very Large Scale Integration Very Large Scale Integration
VSOIC Very Small outline IC Very Small Outline IC.  An SO style IC package that has leads with a pitch of 30 mils or less.
VSOP or SSOP Very small outline package Higher density with gull wing leads. Another designation for the small outline ICP packages, i.e. Small Outline Package (Very Small Outline Package, Shrink Small Outline Package)
VIA Via A plated through hole used as a through connection for conductors from the component side to solder side of the board or an outer layer to an inner layer. A via is not intended for mounting components. High-density multi-layer PCBs may have microvias: blind vias are exposed only on one side of the board, while buried vias connect internal layers without being exposed on either surface. Thermal vias carry heat away from power devices and are typically used in arrays of about a dozen. A via consists of:
Barrel — conductive tube filling the drilled hole
Pad — connects each end of the barrel to the component, plane or trace
Antipad — clearance hole between barrel and no-connect metal layer
V Volt A unit of measurement of force, or pressure, in a circuit. The abbreviation is the letter V.
D or CR or V Voltage Rectifier A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction. The process is known as rectification. Physically, rectifiers take a number of forms, including vacuum tube diodes, mercury-arc valves, solid-state diodes, silicon-controlled rectifiers and other silicon-based semiconductor switches. Historically, even synchronous electromechanical switches and motors have been used. Early radio receivers, called crystal radios, used a “cat’s whisker” of fine wire pressing on a crystal of galena (lead sulfide) to serve as a point-contact rectifier or “crystal detector”. Rectifiers have many uses, but are often found serving as components of DC power supplies and high-voltage direct current power transmission systems. Rectification may serve in roles other than to generate direct current for use as a source of power. As noted, detectors of radio signals serve as rectifiers. In gas heating systems flame rectification is used to detect presence of flame.
Voltage Regulator A voltage regulator is designed to automatically maintain a constant voltage level. A voltage regulator may be a simple “feed-forward” design or may include negative feedback control loops. It may use an electromechanical mechanism, or electronic components. Depending on the design, it may be used to regulate one or more AC or DC voltages.  Electronic voltage regulators are found in devices such as computer power supplies where they stabilize the DC voltages used by the processor and other elements. In automobile alternators and central power station generator plants, voltage regulators control the output of the plant. In an electric power distribution system, voltage regulators may be installed at a substation or along distribution lines so that all customers receive steady voltage independent of how much power is drawn from the line.
VT Voltage Transformer Many types of transformers and all are made for different purposes.  Types include: Power transformers, Laminated core, Toroidal, Autotransformer, Variac, Induction regulator, Stray field transformer, Polyphase transformers, Resonant transformers, Constant voltage transformer, Ferrite core, Planar transformer, Oil cooled transformer, Cast resin transformers, Isolating Transformer, Instrument transformers, Current transformers, Potential transformers, Pulse transformers, RF transformers, Air-core transformers, Ferrite-core transformers,  Transmission-line transformers, Baluns, Audio transformers, Loudspeaker transformers, Output transformer, Small signal transformers, Interstage and coupling transformers, Homemade and obsolete transformers, Transformer kits, 100% homemade, Hedgehog, Variocouplers
VA Volt-Ampere A volt-ampere (VA) is the unit used for the apparent power in an electrical circuit, equal to the product of root-mean-square (RMS) voltage and RMS current.In direct current (DC) circuits, this product is equal to the real power (active power) in watts. Volt-amperes are useful only in the context of alternating current (AC) circuits (sinusoidal voltages and currents of the same frequency).
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WH Water Heater Shorthand
Water Wash A machine that uses jets of water to wash flux and water soluble mask off printed circuit boards after they have been through a wave solder machine.
W Watt The standard unit of measurement of electrical power.
Wave Solder The soldering of an assembly by passing the surface mount components, mounted on the solder side of the board, over an adhesive and then over a
molten wave of solder. Typically through hole components installed on the top side of the board are soldered at the same time. The application of solder paste is not required for this assembly.
Wave Solder Machine A large-scale soldering process where components are soldered to a printed circuit board to form an electronic assembly. The name is derived from the fact that the process uses a tank to hold a quantity of molten solder; the components are inserted into or placed on the board and the loaded board is passed across a wave of solder.
WP Weather Proof Shorthand
W Wire A single, usually cylindrical, elongated strand of drawn metal conductor that carries electricity over a distance,.
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X-Ray inspection Inspects the solder joint integrity on hidden leaded components such as DFN’s and BGA’s
D or VR Zener Diode A Zener diode is a diode which allows current to flow in the forward direction in the same manner as an ideal diode, but will also permit it to flow in the reverse direction when the voltage is above a certain value known as the breakdown voltage, “zener knee voltage” or “zener voltage”. The device was named after Clarence Zener, who discovered this electrical property. Many diodes described as “zener” diodes rely instead on avalanche breakdown as the mechanism. Both types are used. Common applications include providing a reference voltage for voltage regulators, or to protect other semiconductor devices from momentary voltage pulses.
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