Charles Howard Henry

Environmental Stress Testing with Boundary-Scan

Environmental Stress Testing (EST) enhances product quality and reliability by detecting latent or marginal defects in a product. For EST to be effective, testing of a product must achieve a high fault coverage so that as many EST-induced defects can be detected. By utilizing Boundary-Scan (IEEE Std 1149.1-1990), EST can achieve a high fault coverage and at the same time, minimize test cost. The paper describes a complete infrastructure, both software and hardware, for using Boundary-Scan (B-S) in EST. In addition, the paper shows a simplified control mechanism to select individual circuit packs for Boundary-Scan testing. This control mechanism minimizes the number of wires required to drive the control interface and thus, the number of wires in the cable that connects a tester to the backplane of a system under test and across which Boundary-Scan tests are executed. Finally, the paper presents and discusses some study results for evaluating the effectiveness of monitored EST.