Golden Gate Graphics logo

GLOSSARY of Printed Circuits

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

   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

Golden Gate Graphics in an official Altium Service Bureau

Golden Gate Graphics is an official Altium Service Bureau

Terms that contain digits 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 (/), these are treated the same as spaces and ignored for the purpose of alphabetizinig.

TOP       G

Index to terms on this page:

gang clearance   gate   GC-Prevue   gerber   Gerber  
Gerber file  
glob top  

gang clearance — (GANG CLEER-ans)  Pronunciation Key  noun   HDI (High Density Interconnect) A clearance (space or separation) around a group of PCB objects. As this applies especially to solder mask, it is drawn as an object on the solder mask layer to surround fine pitch (0.5-mm-or-less pitch) pads. On the printed board it becomes an opening in the solder mask that exposes copper.
To create a gang clearance around a group of pads, draw a fill (rectangular object) or region (irregular-shaped object) on the solder mask layer. Because solder mask objects in PCB designs are negative-image (the object represents an absence of material), the shape on the solder mask layer creates an area on the printed board where there is no solder mask. But use of gang clearances with HDI leads to shorts that have to be re-worked, because there is no solder mask dam (ridge of solder mask between pads) to prevent solder from bridging over from one pad to another. Fine-pitch pads, being so close together, result in solder mask dams that are too narrow (less than 4 mils) to manufacture and so can cause defects (lumps of solder mask) that can interfere with soldering during the assembly of components. Solder mask gang clearances have often been used to prevent this type of defect. Is there a solution to enable solder mask dams of 4-mils between fine pitch parts? Well, yes. See this article: Design For Assembly-HDI Prevention of Solder Bridging

Page Index

gate — (GAYT)  Pronunciation Key  noun  [Electronics] A circuit or digital logic element usually with one output and one or more inputs. If two or more inputs, the output is a function of a combination of the inputs. If one input, the output is always the same. The two-input logic gates perform a computation of Boolean logic.
   Incidentally, Gate has this meaning in the Colorado-registered trade name "Golden Gate Graphics." And the general form of my logo is the shape of a gate rotated 180 degrees.
Page Index

GC-Prevue — A CAM file viewer and printer made by Graphicode. Their low cost version can store Gerber and NC Drill files within a file (.GWK extension), which makes it extremely useful for sharing electronic data:   It can be used for importing Gerber files in a logical sequence, displaying them in perfect register , annotating (adding labels to the filenames to describe their use and position in the stackup) and viewing them, saving all that and then passing the resulting .GWK file on to another for examination. Besides merely looking at the files or printing them, GC-Prevue has features for measuring objects' size and relative distance from each other. GC-Prevue sets-up and saves Gerber data in a single file. Free Gerber viewers require one to set up the Gerber files each time and won't allow saving the set-ups unless one buys an upgrade. (From the viewpoint of a printed circuit designer serving engineers or customers, this inability to save set-ups makes the free Gerber viewers completely useless for sharing Gerber data.)

Page Index

gerber or Gerber — see Gerber file.

Gerber file — ASCII data file used to control a photoplotter. Named after H. Joseph Gerber, founder of Gerber Scientific Co., who invented the original vector photoplotter.

Page Index

glob top — A blob of non-conductive plastic, often black in color, which protects the chip and wire bonds on a packaged IC and also on a chip on board. This specialized plastic has a low coefficient of thermal expansion so that ambient temperature changes will not rip loose the wire bonds it is designed to protect. In high-volume chip on board production, these are deposited by automated machinery and are round. In prototype work, they are deposited by hand and can be custom-shaped; however, in designing for manufacturability, one assumes a prototype product will "take- off" and ultimately have high market demand, and so lays out chip on board to accommodate a round glob top with adequate tolerance for machine-driven "slop-over".

Page Index

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.

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 2020 you could still buy a great used copy online for $30 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.

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