Surface Energy and Wettability Study of Flip Chip Packaging Materials

摘要

The surface energy of solid surfaces and surface tension of liquids are important parameters in the IC packageassembly process. Wettability analyses have been completed for various materials used in the assembly process offlip chip packages, including underfills, substrates, fluxes, and lead free solders. We will highlight some of theseresults in this paper. We will focus our discussion on substrate surface energy analysis. A brief discussion ofdifferent surface energy methods and the liquid selection criteria will be given. The advantage and limitation of thesurface energy calculation methods will be discussed. The data from several case studies will be presented. Ourresults show that contact angle and surface energy measurements are very useful for quality control and productdevelopment where interfacial properties are important.