Abstract
To ensure the robustness of surface-mount technology, underfill resin should be applied between the chip device and the substrate. However, this application process is time consuming. Therefore, a novel chip surface-mounting process using hybrid resin containing solder particles is proposed to shorten the underfill application process. The hybrid resin consists of semicured thermoset epoxy resin containing a reducing reagent, Sn–Bi solder particles, and thermoplastic polyester thin resin film. Viscosity and reduction ability of the hybrid resin were investigated via various techniques. The semicured epoxy resin fabricated at lower temperature showed better bondability. Acetic acid was effective in reducing the oxide film on the solder particles. The coalescence behavior of molten solder particles depended on both the reduction reaction and the viscosity of epoxy resin at the bonding temperature. The epoxy resin with low viscosity was mounted on the substrate via an overcoat of the polyester film. A conductive path covered with the resin formed between the chip resistor and the substrate via the hybrid resin.
