Power Management Using Test-Pattern Ordering for Wafer-Level Test During Burn-In

Wafer-level test during burn-in (WLTBI) is a promising technique to reduce test and burn-in costs in semiconductor manufacturing. However, scan-based testing leads to significant power variations in a die during test-pattern application. This variation adversely affects the accuracy of predictions of junction temperatures and the time required for burn-in. We present a test-pattern ordering technique for WLTBI, where the objective is to minimize the variation in power consumption during test application. The test-pattern ordering problem for WLTBI is formulated and solved optimally using integer linear programming. Efficient heuristic methods are also presented to easily solve the pattern-ordering problem for large circuits. Simulation results are presented for the ISCAS'89 and the IWLS'05 benchmark circuits, and the proposed ordering technique is compared with two baseline methods that carry out pattern ordering to minimize peak power and average power, respectively. A third baseline method that randomly orders test patterns is also used to evaluate the proposed methods.