Comprehensive Study of Epoxy Die Attach Process to Achieve Zero Reject Performance

The epoxy die attach is one of the most preferred methods in mounting die on leadframe / substrate, mainly due to its flexibility and cost effectiveness. In a critical package called FETChip, several challenges occurred in the die attach process, due to upset flag/post, flag size smaller than die size, and small gap from flag to post leads. A comprehensive study performed in optimizing epoxy dispensing capability, from determining basic critical conditions, nozzle design, clamp design, idling effect, dispensing parameters, placement, pattern recognition, new machine features, until achieving six sigma process controls in epoxy performance.