Test Method - Automatic Function Test

For the automatic function test the PCB is tested via an interface (connectors, test plugs, etc.) simulating normal service conditions. The test program then tests predefined functions.

As test equipment, test systems are available that offer a large range of software support and are equipped with sensors and synchronising devices when it comes to the hardware. The tests can be realized both static as well as dynamic with realtime-clock. If this is the case it is also possible to include selftests in the test program. It is important to achieve a certain pre-set fault coverage in order to meet the planned quality of delivery.

Another type of automatic function test is the use of an atomatic diagnosis, by means of fault catalogs. These fault catalogs can be knowledge-based or created manually as well as generated automatically through fault simulation. Additionally all test vectors for all nodes are generated or can be teached-in, in order to isolate the faults by means of a computer controlled test probe.

The last desribed test method needs a complex infra structure and knowhow as well as powerful simulators and are currently limited to digital parts of the circuit, therefore this method is not that common in production test. Typical uses are repairs of complex PCBs, that can not be contacted or are coated, for example in the areas of aerospace industry or military. In these areas fault coverage, as calculated by the simulator, is often required as a QA-criteria.

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