Intermetallic formation on the fracture of Sn/Pb solder and Pd/Ag conductor interfaces

Abstract
[[abstract]]Intermetallic formation between a thick-film mixed bounded conductor and Sn/Pb solder is investigated. The microstructural evolution of the interfacial morphology, elemental and phase distribution is probed with the aid of electron microscopy and X-ray diffraction. There exists mechanical interlocking between conductor and substrate. Penetration of the element Bi into the substrate is observed. A decrease in adhesion strength occurs when the sample is aged at 130°C for a long period of time. Microstructural analysis reveals the segregation of Pb-rich and Sn-rich phases in aged samples and formation of intermetallic compounds Pd3Sn2, Pd 2Sn, Pd3Sn, PdSn, Ag5Sn, and Ag3 Sn. It is argued that conductor swelling caused by tin diffusion into the conductor film and volume change resulting from the intermetallic formation are major factors in the degradation of the peel strength[[fileno]]2020323010122[[department]]材料科學工程學