Correlation between surface texturing on pre-plated leadframe and delamination phenomenon in automotive packaging

Abstract

Poor adhesion between mold compound and leadframe in integrated circuit packaging for automotive devices can cause serious reliability issue and degrade the package quality. This study aims to evaluate and understand the correlation between surface texturing procedure (roughening) on pre-plated leadframe (PPF) and delamination phenomenon in integrated circuit packaging. The pre-plated leadframe with textured surface was prepared by the leadframe supplier. Four major evaluations were conducted which based on morphology analysis, contact angle measurement, mold shear strength test and reliability test. For morphology analysis, textured PPF possessed higher surface roughness (284nm) compared with standard leadframe (174nm). The highest contact angle value was observed for textured PPF at room temperature (71°). Conversely, the lowest contact angle value was observed for textured PPF at 175°C (55°) which was simulated according to inline manufacturing condition. High shear strength test was obtained for textured PPF compared with standard leadframe. Furthermore, reliability test proved that no delamination was detected for PPF sample. However, this phenomenon was observed for standard leadframe. All the observations agreed that the interfacial adhesion between mold compound and leadframe was significantly improved by surface texturing procedure on the leadframe. The improvement of adhesion helps to eliminate delamination and improve package reliability.