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GLOSSARY of Printed Circuits

by John Walt Childers, IPC-CID, Founder of Golden Gate Graphics

   SYMBOLS    A    B    C    D    E    F    G    H    I    J    K    L    M    N    O    P    Q    R    S    T    U    V    W    X    Y    Z   

Pronunciation Key

Formerly known as

GLOSSARY of Printed Circuit Design and Manufacturing

This glossary has key terminology in use in PCB design and manufacturing, with a smattering of electronics. The definitions were chosen so that their context would likely apply to reading material encountered by a PCB designer. Therefore, many of these terms will have other meanings not given here. See recommended dictionaries below.

This collection of terms came about as I, a PCB designer, ran across words and acronyms in my field for which meanings were hard to find. As I tracked them down, I made them part of this glossary. If you are a PCB designer, then this glossary could be a good place to start when you find a need to look up the meanings of words related to printed circuits or electronics.


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Index to terms on this page:

I   IBC   IBIS Models   IC   ICMP   ICT   IDC   IDE   IDF   IDM   IDT   IEC   IF   IGES   IGS   IIoT   I/L  
IMT-Advanced   inductive coupling   insulation displacement connector   in series   in parallel  
integrated circuit   internal layer pairs   IoT   IP   IPC   IPC-D-356   IPC-DPMX   IPC-2581   IP rating   Ipp   I/Q   IRQ   isolation resistor   ISP   ITAR  



I — See I/Q

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IBC — impedance boundary condition. Used as a parameter in 2D and 3D electromagnetic field solvers.

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IBIS Models — I/O Buffer Information Specification Models

The need for higher system performance leads to faster output transitions. Signals with fast transitions cannot be considered purely digital; it is important to understand their analog behavior for signal integrity analysis.
To simulate the signal integrity on printed circuit boards (PCB) accurately and solve design problems before the PCB is fabricated, models of the I/O characteristics are required.
SPICE models are most frequently used for this purpose. A manufacturer's SPICE models, however, contain proprietary circuit-level information. Therefore, simpler models are devised to extract SPICE parameters for the proprietary information to remain protected. One such standard is the I/O Buffer Information Specification (IBIS) format originally suggested by Intel.
In the early 1990's, the IBIS Open Forum was formed and the first IBIS specification was written to promote tool independent I/O models for system signal integrity analysis.
IBIS is now the ANSI/EIA-656 and IEC 62014-1 standard. IBIS accurately describes the signal behavior of the interconnections without disclosing the actual technology and circuitry used to implement the I/O. The standard is basically a black-box approach to protecting proprietary information. [Source Xilinx Why IBIS?]

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IC Integrated Circuit.

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ICMP — Internet Control Message Protocol

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The Internet Control Message Protocol (ICMP) is a supporting protocol in the Internet protocol suite. It is used by network devices, including routers, to send error messages and operational information indicating success or failure when communicating with another IP address, for example, an error is indicated when a requested service is not available or that a host or router could not be reached.
Forouzan, Behrouz A. (2007). Data Communications And Networking (Fourth ed.). Boston: McGraw-Hill. pp. 621–630. ISBN 978-0-07-296775-3.

ICT — In Circuit Test.

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IDC — See Insulation Displacement Connector

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IDE — --Computer programming Integrated Development Environment

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IDF — Intermediate Data Format. A vendor-neutral format for exchanging printed circuit assembly (PCA) information between PCB layout design (ECAD) systems and Mechanical CAD systems. If you need instruction on how to use it, Google "Altium Designer export IDF board" or "<other ECAD system> export IDF board."

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IDM — Integrated Device Manufacurer.

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IDT — Insulation Displacement Termination

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IEC — International Electrotechnical Commission. The IEC is an international standards organization established in 1906 that prepares and publishes international standards for all electrical, electronic and related technologies – collectively known as "electrotechnology". Headquarters in Geneva, Switzerlando.

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Wikipedia.org

IF — Intermediate Frequency. This has application in a digital IF interface. When you mix two signals of different frequency together, you get two new signals, the sum and the difference. This is exploited in RF (radio frequency) circuits to create a lower frequency signal which is easier to work with. So in come the satellite signal at 12000 mhz, the local oscillator beats out a constant 10750 mhz. This generates an intermediate frequency of 1250, which is more easily conducted down the coax to the receiver for demodulation. The receiver probably also contains one or more similar stages which convert the signal into a lower frequency once again, for eventual processing for signal.

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IGES — Initial Graphics Exchange Specification (IGES) (pronounced eye-jess) defines a neutral data format that allows the digital exchange of information among Computer-aided design (CAD) systems. 3D models can be found in this format in files with the extension .IGS or .IGES.

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IGS  

IGS — A file extension used on IGES model files.

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IIoT — Industrial Internet of Things. An aspect of Industry 4.0, automation of automation and also CFX, IPC Connected Factory Exchange.

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I/L noun  [PCB Manufacturing] Inner Layer, any layer of a PCB inside the stackup (not one of the two outer layers) or all of the inner layers as a group.
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IMT-Advanced — International Mobile Telecommunications-Advanced. These standards are the requirements issued by the ITU Radiocommunication Sector (ITU-R) of the International Telecommunication Union (ITU) in 2008 for what is marketed as 4G (or sometimes as 4.5G mobile phone and Internet access service.

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inductive coupling — Two conductors are said to be inductively coupled or magnetically coupled when they are configured such that a change in current through one wire induces a voltage across the ends of the other wire through electromagnetic induction.

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insulation displacement connector — Aka Insulation piercing connector. A connector that pierces the insulation on a wire to make the connection removing the need to strip the wire before connecting. Such connections are usually seen in low current applications such as telecoms, networking and signal connections between parts of an electronic or computer system. When properly made, the connector blade cold-welds to the wire, making an airtight, high quality connection.

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in series — (electrical circuits) Regarding discrete electrical components: Physically and electrically connected end-to-end to form a chain. See specifically capacitors in series and resistors in series.

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in parallel [Electrical Circuits] Regarding discrete electrical components: Best visualized as physically arranged side-by-side with the terminals at one end of the group all electrically connected and the terminals at the other end of the group all electrically connected. (It is not actually necessary for them to be so arranged physically as long as the eletrical connections are equivalent to that arrangement.) See specifically capacitors in parallel and resistors in parallel .

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integrated circuit — 1)miniaturized electronic circuit that has been manufactured as a chip ( die ). 2)A packaged chip.
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internal layer pairs — - A type of stack-up, the standard PCB stack-up. This is Altium's term for the most common stackup of multi-layer boards, where the outer dielectrics are pre-preg. If the outer dielectrics are core (not common in practice), Altium refers to this type of stack-up as "layer pairs." Altium is the only group I have been able to find that uses this terminology for stack-up types.0

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IoT — Internet of Things. Example, a condomium exteror electronic combination lock has its combination changed through Internet data transfer to the lock electronics.

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IP

  1. Intellectual Property
  2. Internet Protocol. Transmission Control Protocol/Internet Protocol. (We'll call it IP for short.) IP stands for 'Internet Protocol. ' A protocol is a guideline that must be followed in a set, specific way. IP is actually networking software. 3)Ingress Protection (see IP rating).


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IPC — The Institute for Interconnecting and Packaging Electronic Circuits, the final American authority on how to design and manufacture printed wiring.   In 1999, IPC changed its name from Institute of Interconnecting and Packaging Electronic Circuits to IPC. The new name is accompanied with an identity statement, Association Connecting Electronics Industries.
(IPC Home Page)

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IPC-D-356 — A The was designed to define a standard netlist format by which bare board test information can be represented. In the simplest of forms, this means it must be able to store netlist information along with XY coordinates, and even reference designators and pin numbers (if they exist). [See this source:
IPC-D-356 Simplified written by Rich Nedbal] (See also IPC)

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IPC-DPMX — aka IPC-2581 Digital Product Model eXchange. PCB designs can be output for manufacturing to to IPC-2581 format, rather than Gerber and drill files, fab and assembly drawings and also rather than ODB++. Has sometimes been referred to as Digital Product and Process Modeling eXchange.

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IPC-2581 — aka IPC-DPMX Digital Product Model eXchange. PCB designs can be output for manufacturing to to IPC-2581 format, rather than Gerber and drill files, fab and assembly drawings and also rather than ODB++. Has sometimes been referred to as Digital Product and Process Modeling eXchange.

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IP rating — P (or "Ingress Protection") ratings are defined in international standards. They are used to define levels of sealing effectiveness of electrical enclosures against intrusion from foreign bodies (tools, dirt etc) and moisture. IP Rated Enclosures Explained by The Enclosure Company (International) Ltd.

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Ipp — Peak Pulse Current. The maximum peak pulse current rating (IPP) of a TVS device parallels the peak pulse power curve. The maximum peak pulse power (PPP) is equal to the maximum clamping voltage (VC) multiplied by the maximum peak pulse current (IPP), where the maximum clamping voltage is considered a constant independent of time. https://www.protekdevices.com/xyz/documents/kb/tech/ta1017.pdf

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I/Q [Electronics] A pair of amplitudes of carrier sine wave forms out of phase with each other, which are part of modulation circuits in communication applications. I stands for in-phase and Q stands for quadrature phase. I is the amplitude of the in-phase carrier. Q is the amplitude of the quadrature-phase carrier.

Put simply, I/Q data shows the changes in magnitude (or amplitude) and phase of a sine wave. If amplitude and phase changes occur in an orderly, predetermined fashion, you can use these amplitude and phase changes to encode information upon a sine wave, a process known as modulation.

Modulation changes a higher frequency carrier signal in proportion to a lower frequency message, or information, signal. I/Q data is highly prevalent in RF communications systems, and more generally in signal modulation, because it is a convenient way to modulate signals.
Cited Work:

"What is I/Q Data?" RF Simulation Demo: IQ Data NITM (nee National InstrumentsTM), 2019. Web. 3 Dec. 2019.

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IRQ — Interrupt ReQuest. From FOLDOC (https://foldoc.org//IRQ): The name of an input found on many processors which causes the processor to suspend normal instruction execution temporarily and to start executing an interrupt handler routine.

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isolation resistor — A resistor used to limit current as in isolate a component from a static discharge.

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ISP [Components] In-system programmable, a feature of some types of flash memory.

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ITAR — International Traffic in Arms Regulations is a set of United States government regulations that control the export and import of defense-related articles and services on the United States Munitions List (USML). These regulations implement the provisions of the Arms Export Control Act (AECA).



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Alphabetizing Method

Terms that begin with a symbol or a digit are placed in the SYMBOLS page. Terms that contain digits within them are alphabetized as if the numeric characters were spelled in English.

Terms with two or more words are alphabetized "dictionary style." They are alphabetized as though the spaces between the terms have been removed.
   If there are other characters in the term, such as a slash (/), dash (-) or plus sign (+), these are treated the same as spaces and ignored for the purpose of alphabetizing.

Example Printed Boards

Click for Examples of PCBs designed by Golden Gate Graphics



References and Dictionaries

Modern Dictionary of Electronics by Rudolf F. Graf

This is the best, most usable dictionary for electronics, because its definitions help you grasp the terms and therefore the subject. Lesser dictionaries define electronics terms with even more difficult technical jargon, leading one into endless"word chains." Not this one.
You can buy the Modern Dictionary of Electronics new or used via the Internet.

Citation:
Graf, Rudolf F. Modern Dictionary of Electronics. Newnes, 1999.


The Random House Dictionary of the English Language, Unabridged, 2nd Edition

You need a big, comprehensive dictionary. Get this one. Despite being a big dictionary, The Random House has great definitions, quick to grasp.

Although out of print, as of 2022 you could still buy a great used copy online for $40 including shipping or possibly for much less. Two versions are available of the 2nd Edition, Unabridged:

I have no idea what the difference is for the deluxe edition, but there seem to be fewer copies of it available in 2020 than the regular edition. I'm sure they both have the same set of definitions. My copy has both ISBNs listed in the front matter, and it is the regular edition.

Citation:
Flexner, Stuart Berg, and Leonore Crary Hauck, editors. The Random House Dictionary of the English Language. Unabridged, 2nd Edition, Random House, 1987.

Golden Gate Graphics in an official Altium Service Bureau
Golden Gate Graphics is an official Altium Service Bureau

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