Remote Access to Manufacturing Test Facilities: a Reality in IC, a dream in MEMS
Abstract
Manufacturing test consists in verifying the quality of a product with respect to its specifications. For most of the manufactured products the cost of the final verification represents only a small part of the production costs. This is due to the fact that these products are either high-cost (e.g. automotive industry) or reliable enough to authorize randomly applied verification (e.g. food industry). This scheme doesn't apply in the microelectronics industry, where low-cost products are produced with a significant number of out-of-specification or non-functioning parts. Manufacturing tests are then required to verify the physical integrity and the correct behaviour of any produced parts at a reasonable cost. Mass production of MNT-based systems is following the same trend. That's the reason why we have to learn from this mature industry. The problem is that manufacturing test introduces a breakage in the batch fabrication concept. Indeed, speaking about malfunctions leads to singularities that cannot be dealt in a batch-based model. Even if test is undertaken at the wafer level and if parallelism is still possible each produced device must be tested independently.