by John Walt Childers, IPC-CID, Founder of Golden Gate Graphics
Formerly known as
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.
Q — See I/Q
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QED — quod erat demonstrandum - which was to be proved or demonstrated
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QFN — Quad Flat No-Lead, aka LCC, LFCSP and FQFP-N.
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QFP — Quad Flat Pack, a fine-pitch SMT package that is rectangular or square with gull-wing shaped leads on all four sides. The lead pitch of a QFP is typically either 0.8mm or 0.65mm, although there are variations on this theme with smaller lead pitches:
TQFP also 0.8mm;
PQFP tooled at either 0.65mm (0.026") or 0.025" and
SQFP at 0.5mm (0.020'). Any of these packages can have a wide variety of lead counts from 44 leads on up to 240 or more. Although these terms are descriptive, there are no industry- wide standards for sizes. Any printed circuit designer will need a spec sheet for the particular manufacturer's part, as a brief descrition like "PQFP-160" is inadequate to define the mechanical size and lead pitch of the part.
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QSOP — Quarter Size Outline Package, usually the same as an SSOP except that the lead pitch is 25-mils, which is one quarter the size of the original 100-mil pitch DIP.
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QTA — Quick Turn Around.
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QTP — noun Components Quick Turn Programming,
a programming service offered by Microchip for factory production orders. This service is ideal for customers who choose not to program a medium to high unit volume in their own factories, and whose production code patterns have stabilized.
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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.
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.
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:
