VTEP/TestJet Testing
Before beginning test development, determine if a VTEP1 test is appropriate for each device (see Table 6). Consider the following:
- There must be metallic surfaces (pins, leads, or leadframes in the device) to which the VTEP probe can couple.
- iVTEP enhances VTEP’s ablility to make reliable measurements where metallic surfaces (pins, leads, or leadframes in the device) to which the VTEP probe can couple are minimized. You should consider adding a VTEP test for all ICs.
- Signal, sense, and digital probes for through-hole devices need to be placed at locations other than on the device; otherwise, you can test only for bent pins that are not inserted in the PC board.
- Due to physical characteristics, some devices might require special fixturing.
- Standard and small VTEP probes can be used on either side of the fixture, top or bottom; VTEP connector probes can be used only on the top side.
Also consider the VTEP/TestJet fixturing requirements.
To use VTEP to test devices on the board, there are four approaches to consider. They are:
- VTEP Test Only — Test appropriate devices with VTEP to verify only the presence and connectivity of the device.
- VTEP Test with Disable Information — Test devices with VTEP and include setup-only library tests with disable information for devices that need to be disabled for powered tests of downstream devices.
- VTEP Test and Powered Test — Test devices with VTEP and include library tests for powered testing. To release the test and fixture to production as soon as possible you can test devices with VTEP only, but include setup-only tests and add powered testing later.
- VTEP Test and NPM Test — Test connectors with additional coverage for power, ground and fixed pin coverage. You do this by specifying a connector model from Table 5.
To request for a library file for a new connector not currently in your ICT software, go to www.agilent.com/see/npm and click the link under New NPM Connector Library File Request.
1 Information on VTEP also applies to TestJet, unless otherwise specified.
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