Relay Propagation Scheme for Testing of MCMs on Large Area Substrates

This paper addresses the issue of testing MCMs on large area substrates. The cost of testing MCMs may be as high as 40 % of the total manufacturing cost. It is critical that the test process be parallelized in order that multiple MCMs may be tested for the cost of testing one MCM. With this objective in mind, we propose a parallel and pipelined relay propagation scheme for the testing of MCMs on large area substrates. In this scheme, the test vectors and the corresponding correct-response vectors are both scanned into the MCM scan chain sequentially. They are then relayed on from one MCM to the next down the chain. Simultaneously the MCMs are tested in parallel. Our algorithm allows an order of magnitude speed-up in test time over conventional boundary scan based testing schemes.