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Data Requirements

GSC can design your custom fixturing from existing PCB data. Below are some considerations that can help accelerate the quoting and design process.

Send us your PCB Data


The following data formats are quickest and easiest for us to decipher. They are easily imported using our available CAD packages and will shorten the amount of time needed to quote your order.


Autocad drawing file extension


Stands for "Drawing Exchange Format". A universal data translator used by most CAD/CAM software and even some Gerber software.


Stands for "Initial Graphics Exchange Standard". An internationally recognized data translator also used by most CAD/CAM packages.


Gerber data is used throughout the world for printed circuit board design. Following is a breakdown of the eight Gerber files needed to design your fixture.

Topside Silkscreen:

Provides information about topside component layout, helping us to better decipher component hold-down location. When overlaid with the bottomside soldermask, the combined data allows us to locate through hole areas and possible conflicts with bottomside components and through hole areas.

Topside Soldermask:

This data is used with the topside silkscreen, and is necessary when building a double sided reflow or surface mount fixture.

Bottomside Silkscreen:

Used in conjunction with the Bottomside Soldermask and Solderpaste, gives the programmer component location on the backside of the circuit board. Very important for designing selective wave or selective solder fixtures.

Bottomside Solderpaste:

Provides the bottomside solder pad location. This is used in conjunction with the bottom silkscreen to establish bottomside components for clearance pocket locations.

Bottomside Soldermask:

Provides the bottomside solder pad and through hole locations. This data is used with the topside silkscreen for location of through hole areas and possible conflicts with bottomside components.

Assembly or
Fabrication File:

Useful when the circuit board is panelized or the above-mentioned files do not include an outline of the circuit board. These files can also give us the correct dimensions for the circuit board, both X and Y, as well as thickness.

Drill File:

Provides the necessary information on PCB hole diameters. If the PCB is to be oriented on the fixture using tooling pins, the appropriate hole location and diameter can be selected to ensure an accurate fit. This data is also needed when building press fit fixtures for exact hole location and diameter.

Aperture List:

This is the most important file to be included with Gerber data! Without this, the data is useless.

The list consists of "d-codes". These d-codes are the "maps" of the data; Rounds, Squares, Rectangles, Donuts, etc., and the dimensions for each of these. If at all possible, provide the data in an RS274-X format. This is called an "Embedded Aperture" list and actually embeds the d-codes into the Silk, Paste and, Mask files, making importation of the Gerber data almost automatic.

Readme File:

This file is useful when the data has not been separated between useable and non-usable files. It can provide the file names, the format in which they were created and the part number of the circuit board.


Whenever possible, send the data files zipped in a format useable by WinZip and labeled with the part number of the circuit board. Include a readme file if the Gerber data is not separated. INCLUDE AN APERTURE LIST!!

Adjustable Fixtures