Delamination Reduction by Material and Process Optimization

With bonding wire converted from Au to Cu, corroded Cu wedge defects observed with some packages. Epoxy Mold Compound (EMC) to lead frame delamination provide penetration path for corrosive chemicals to penetrate inside and react with Cu wedge. To improve delamination performance without changing exist production and Bill of Materials, study was carried out with molding process, Lead Frame strip's structure, EMC properties. Delamination performances were collected via C-SCAN. In depth study on delamination mapping vs mold flow influence been carried out through detail short shot analysis. Mold parameter influence on delamination was investigated [1]. EMC flowability vs lead frame surface wetting behavior was explored. Study result shows different LF strip location design, mold process optimization can influence delamination [2]. In this paper, wedge pad surface cleanness was checked via mechanical decapsulation on package, EMC viscosity curve were analyzed to explain mold parameter settings. These all helped well explained mechanism on support delamination improvement. This paper gives insight on material&process optimization approach to achieve minimum package delamination. Involves discussion on mold process factors, EMC material property that influence package delamination.