Effect of solder alloy composition on its solid-state bonding quality with Ni microcones

摘要

A novel type of low-temperature bonding technique which uses metallic microcones to thermocompressively bond with solder is currently being extensively studied for its potential in achieving fine-pitch interconnection in advanced packaging and system integration. This paper compares the bonding of three different solder alloys with Ni microcones: Sn-3.5Ag, Sn-3.0Ag, and Sn-9Zn, in terms of deformation behavior during bonding process, joint morphology, and bonding strength. Solder composition affects the bonding process in three aspects: the deformation behavior during bonding process, the resistance to shear destruction, and the reactive diffusion that leads to IMC formation on the interface. Optimization of soft side material used for solid-state insertion bonding is also discussed in principle.