Assessment of the Thermal Conductivity of Transient Liquid Phase Sintered Interconnects

In this paper, we present a method for simulating the thermal properties of Transient Liquid Phase Sinter (TLPS) joints. Paste-based TLPS joints possess microstructures that are characterized by metallic particles embedded in matrices of intermetallic compounds (IMCs). Because of these complex microstructures, paste-based TLPS joints show complex mechanical and thermal behaviors. A simulation approach has been developed that enables their assessment. The influence of the size of metal particles and the size of voids on the thermal conductivity of sinter joints has been studied. The influence of the percentage of metal particles and IMCs in the sinter joint on the thermal conductivity was assessed. The TLPS systems investigated in this study were the Ni-Sn and Cu-Sn systems forming sinter joints consisting of Ni3Sn4 and Ni, Cu6Sn5 and Cu, and Cu3Sn and Cu, which have been demonstrated as paste-based TLPS interconnect technology.