readme.txt

低价的usb芯片应用资料

This folder contains four sub folders; one with the BOM list (Bill Of Material), one with the schematics (Schematics), one with the Drill files (Drill) and one with the Gerber files (GerberFiles) for the design. 

The Gerber plot file names are appended with a unique extension that
identifies layer and plot type. The Gerber extensions are;

Top Overlay		.GTO
Bottom Overlay		.GBO
Top Layer		.GTL
Bottom Layer		.GBL
Top Solder Mask		.GTS
Bottom Solder Mask	.GBS
Top Paste Mask		.GTP
Bottom Paste Mask	.GBP
Pad Master, Top		.GPT
Pad Master, Bottom	.GPB
Keep Out Layer		.GKO	(used as outer contour)

The apertures are written into the Gerber files according to the RS274X Gerber file specification.

The Drill folder contains NC drill files in both Excellon and ASCII format.
*.drr :	Report file. Details the tools used, the hole sizes in both metric and imperial, the number of holes and the tool travel.
*.drl :	Excellon format drill file.
*.txt :	An ASCII version of the Excellon format file with the extension TXT.