Die Attach Pre-bond Inspection Innovation for Roughened Leadframe

Abstract

This paper studies the challenges and behavior of epoxy material between the roughened Leadframe during the Die Attach process. Die bond on the roughened die-attach paddle (DAP) of epoxy has been a challenge for its manufacturability in terms of maintaining the target epoxy volume. The study on the roughened Leadframe utilizing the Pre-bond inspection parameter causing machine inspection cannot fully detect the epoxy pattern. The uneven contrast of pad’s, causing pre-bond inspection problem. Hard to teach / set-up epoxy inspection due to the contrast between leadframe die pad vs. epoxy. The roughened leadframe property has different surface contrast causing Frequent “Bond Align” and epoxy inspection error on the Roughen leadframe. This occurrence leads to risks of insufficient epoxy which is detrimental to product reliability (delamination on die bottom) and can cause manufacturing yield loss due to insufficient epoxy coverage. Using the Design of Experiment (DOE) methodology and its applicable statistical tools, the author to come up with error-proofing solutions to resolve and reduce the Insufficient Epoxy. The innovative and breakthrough solutions implemented were the installation of ultra-bright light with double sidelights in pre-bond inspection which is the key in reducing defects rate.