Quality-Effective Repair of Multichip Module Systems

This paper proposes a new analytical approach f o r evaluating ihe effects of a repair process on the defect level of multichip module ( M C M ) systems ai assembly. Repair of M C M s is usually required to improve the yield and quality of ihese systems, while preserving cost effectiveness. In the proposed approach, we develop a novel quality model, which is solved analytically in O ( r N 3 ) (where T is the maximum number of allowed repair cycles and N is the number of chips in ihe M C M ) . The proposed model is based on a previously proposed qualiry model [20] f o r M C M s which did noi incorporate ihe effect of a repair process on the defeci level. The proposed model relates ihe defect level to various figures of merit of repais such as the probability of successfully repairing a fault (referred IO as repairability), the probability of damaging the system and the maximum allowed number of repair cycles. Parametric results show that due io the repair process the overall defect-level decreases as the M C M yield increases; howeves there exists a bound in the number of repair cycles, io permit an increase iri repairability. Using these resulis, it is possible io predict a more accuraie value of ihe defeci level of MCMs by taking inio account the differeni parameters affeciing ihe repair process, while realisiically reducing ihe defeci level of the final M C M produci.