TAT- and cost-reduction strategies in LSI manufacturing test process

Testing strategies in the test process composed of a wafer-probe testing phase, an LSI assembly and packaging phase, and a final testing phase are discussed to reduce the turn around time and costs with the manufacturing yield as a parameter through an event-driven simulation analysis. Three screening strategies considered in the wafer-probe testing phase are exhaustive testing, checkerboard sample testing and no wafer testing [NW]. The application of the simulation program to a test process for one-chip microcomputers showed that the NW strategy becomes effective in a yield range of larger than 70%. The simulation allows one to predict the effectiveness of the testing strategy with the manufacturing yield as a parameter