Where can I find some basic information about ICT?
I read the link that Respawned Fluff posted, along with talking to some of our board vendors. However, if anyone has some real world experience I would be glad to hear it.


The code is mostly autogenerated from the PCB design files, and then manually tweaked. It seems like it is test-machine dependent.
The PCB/PCA manufacturer writes the code to work on their machine. It is the design engineers responsibility, however, to make sure that ICT is possible.
ICT is only used for low-level testing of groups/individual components. Functional testing should be performed afterwards on a custom test fixture.
Making the bed-of-nails fixture is expensive, so ICT tends to be used for large volume production. There is another type of ICT (flying-lead) which uses an automated probe to move around the board. The flying lead can be used for lower volume production, but takes more time to run the tests.
Bed-of-nails doesn't work for high-density boards with BGA-type parts--unless you make special pads where spring-loaded pins can go. Flying-lead has an easier time with small parts, but even that sometimes doesn't work. In that case, use boundary-scan type things or make other testing arrangements.