Effects of polyester resin molecular weight on the performance of low temperature curing silver pastes

Four polyester resins with different molecular weights were used as the binder phase in silver pastes. The effects of the polyester resin molecular weight on the performance of low temperature curing silver pastes were investigated. With increasing molecular weight, the resistivity first decreased and then increased, and the sample that used a polyester resin with a weight-average molecular weight of approximately 150,000 had the lowest resistivity of 3.673 × 10⁻⁷ Ω m. After folding and smoothing the sample 10 times, the silver paste that used polyester A as the binder phase had the lowest rate of resistance change of −6.70 %, and the reason for why these values were negative was investigated using scanning electron microscopy images of sample cross sections. The adhesions and stabilities of the samples were also tested.