制备了一种由环氧树脂基体、咪唑类固化剂、微米级银粉和活性稀释剂体系构成的导电银胶。该导电银胶的常温体积电阻率为3.7×10^-4Ω·cm,搁置寿命大于48 h,粘度适中,耐热散热性能良好。将该导电银胶应用在3种引线框架并考察其可靠性,结果表明导电银胶与无镀层框架的粘接性最好,但在高温时各框架的粘接性相差不大。同时考察了该导电银胶应用于LGA封装的芯片粘接效果,封装后界面无气泡和分层现象。
High performance conductive silver adhesive were prepared using epoxy resin, micron-scale silver flake powder, imidazole curing agent, active thinner, et el. The volume resistivity of conductive silver adhesive was 3.7 ×10^-4Ω·cm. It had excellent properties such as long spot life, moderate viscosity, high thermal conductance and heat resistance. The reliabilities of that conductive silver adhesive used in three types of lead flame were studied. The results showed that the adhesive properties between conductive silver adhesive and bare Cu lead flame was best at room temperature, but the adhesive properties between conductive silver adhesive and three lead frames were the same at 250Ω. Finally, there were neither large bubbles nor delamination in the LGA module used that conductive silver adhesive.