SIMULATION AND CHARACTERIZATION ON MOISTURE SENSITIVITY PERFORMANCE FOR ELECTRONIC PACKAGES

Abstract

Polymeric materials swell upon absorbing moisture and this differential swelling of polymeric materials with non-polymeric materials induces hygroscopic stress in an IC package. Moisture diffusivity, saturated moisture concentration, and coefficient of moisture expansion of polymeric materials of a LFBGA package were characterized in order to evaluate the hygroscopic swelling during moisture pre-conditioning and also the vapor pressure created during reflow. Combining with the thermal stress at high reflow temperature, the vulnerability of the package to interface delamination, subjected to moisture sensitivity test, was analyzed using finite element analysis. CSAM and cross sectioning inspections, and the FEA results had correlated well.