Effects of Microstructure on Thermal and Mechanical Properties of PBGA Substrates

In this study, five different plastic substrates manufactured for Pb-free PBGA assembly were tested. Thermo-gravimetric analysis (TGA), scanning electron microscope (SEM) and X-ray analysis were employed to disclose the material compositions, microstructure and filler loading. Elastic modulus and Poisson's ratio of the substrates were determined at room temperature by tensile tests. Thermo-mechanical analysis (TMA) was performed to determine the CTE and the glass transition temperature in x-, y- and z-directions. Dynamic mechanical analyzer (DMA) was used to determine the dynamic behavior under cyclic loadings. The effects of the glass fibers, polymer matrix, fillers and plated through hole (PTH) on the thermal and mechanical properties of the substrates were discussed.