Mechanical Properties of Solderable Polymer Composites with Low- and High-Melting-Point Solder Mixed Filler

Abstract

A solderable polymer composite (SPC) with a low-melting-point solder (LMPS)/high-melting-point solder (HMPS) mixed filler was formulated to solve the bonding property and reliability problems in an SPC system with an LMPS filler. In addition, the possibility of enhancing the mechanical bonding properties of SPC with LMPS/HMPS mixed fillers was investigated. Three types of SPCs (mixing ratios for LMPS and HMPS: 100:0, 50:50, and 0:100) were prepared, and two types of mechanical property investigations (i.e., ball shear and microhardness tests) were performed to measure the mechanical bonding properties of SPCs according to the LMPS/HMPS mixing ratios. The SPC with an LMPS/HMPS mixed filler exhibited enhanced mechanical bonding properties compared with the Sn–58Bi solder paste and SPC with LMPS or HMPS only due to the change in composition and subsequent microstructure transformation of the solder joint after adding HMPS.

Fig. 2 Cross-sectional morphology of the formulated solder ball for (a) Sn–58Bi solder paste, and SPCs with (b) LMPS filler, (c) LMPS/HMPS mixed filler, and (d) HMPS filler.