When opening an IPC-D-356 file, the bare-board test pads for both the top and bottom sides are extracted to the Test pads top and Test pads bottom layers, respectively. The net name, designator and pin number is also extracted for each test pad. Other information in the IPC-D-356 file is ignored.
Note: Do not confuse test pads with test points or test pins.
Test pads are the locations for bare-board testing of the PCB during manufacture, which are extracted from an IPC-D-356 file to the Test pads layers.
Test points are specific pads or pins on the PCBA which would be used for in-circuit testing. For each test point, a “component” (with the Test point component class) should be added to the appropriate component layer. Ideally, test points (with TPxx designators) should be included in Pick and Place data, but they may also be created manually.
Test pins are the pins in a test fixture which will make contact with the PCBA during in-circuit testing.
In the Assembly Data Manager (ADM), information from the test pads is used to specify the outline and the location of the key pin for components where this information is lacking.
In the Test fixtures Designer, information from the test pads is used to specify the designator, pin number and net name for test pins where this information is lacking.
An IPC-D-356 file contains important information for electrical test of the bare PCB during manufacture. Since only a subset of this information is imported to the test pads layers, the complete file is also attached to the product, so that it is available to the manufacturer.