electrical test

test at the bare board level consists of opens and shorts. It makes sure that all traces are hooked (connected) up to the appropriate place and they are not shorted to a non common conductor.

Russ

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You will have to be more specific about your boards and process to get any help. There are many different types of in circuit tests and functional tests throughout the manufacturing process. The nature of these tests depend on board function. Since Shocker has been around since the inception of pcb manufacturing, he should be able to answer this one.

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In-Circuit test, or ICT, is the most common method of electrical test for an assembled PCB. It is the most comprehensive and accurate method to ensure that both the PWB and components are working to specification. Not all components however can be electrically measured, such as filter capacitors of certain values. This method isolates components from the circuit to measure their respective values to tolerance, and can also take measurements on a circuit net. Test access is obtained by a fixture, either mechanical press or via vacuum, to bring the PCBA into contact with the test pins. This is referred to as �fixed pin ICT�. Another method is by flying probe (pins) tester. In this system the probes move X-Y-Z to programmed positions on the board to perform the same test as a fixture would. Functional tests can also be done on an ICT machineOther than ICT, there are testers that do node impedance, boundary scan or circuit analyzers whereby a norm good �golden� board has its signature taken and is compared to subsequent boards. Also, many assemblers employ functional test.

To see equipment and get more info, please go to these sites:

www.teradyne.com/ict

www.seica.com

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