Kweon-Sam Hong

ESD tester parasitics and stress conditions and their impact on device failure levels and failure mechanisms

A comparative study of Human Body and Machine Model (HBM/MM) testers is performed using a very large sample size for statistical significance. Failure mechanisms and types of damage are categorized with the use of photoemission spectrum analysis. Tester parasitic values are extracted for each machine, and a correlation is established to failure thresholds, distributions and failure mechanisms.

Critical parameters for achieving optimum reflow profiles for plastic package preconditioning

Temperature profiles of surface mount components progressing through convection and infrared reflow systems are studied with respect to package size, inter-component spacing, and loading density. For constant forcing temperature, T/sub max/ varies inversely with component mass. A minimum component spacing required to minimize T/sub max/ variation is established. Package delamination and cracking are shown to depend primarily on T/sub max/.