The purpose of this glossary is to provide you with meanings of the words and phrases explaining the PCB design and circuit board construction while you deal with PCB POWER.
Air Gap: The minimum distance between copper features pad-pad, pad-trace, trace–trace.
Annular Ring: The portion of conductive material surrounding an entire hole.
PCB Power recommends,
Minimum Annular ring for Outer layers: 0.125 mm
Minimum Annular ring for Inner layers: 0.125 mm
IMPORTANT: For annular Ring calculations the production TOOLSIZE for the holes is more suitable than the finished hole ENDSIZE.
We recommend a minimum annular ring of 0.50 mm for connected non-plated (NPTH) holes since these holes have no plated barrel and an annular ring of a smaller size may lift during soldering or break away even during normal operating conditions.
Aperture List: An ASCII text data file which describes the size and shape of the apertures used by a photo plotter for any one photo plot.
Aperture file looks as the one given below: (This is the separate file for aperture detail and you can see the contents of this file by opening it with the notepad or WordPad.)
|D11||RECTANGULAR FLASH||24.000||80.000||0.000 FLASH
Assembly Drawing: A drawing representing component locations with their reference designators on a PCB.
Build time: It is a leading time to get your PCBs manufactured.
Clearances: It is referred as air gap between any copper features pad-pad, pad-trace, trace –trace, also referred as isolation between copper layers sometime.
Component Side: A board side onto which components are mounted.