Application of the transient liquid phase bonding to microelectronics and MEMS packaging

For high performance microelectronics and MEMS packaging, ceramic-based packages are preferred over plastics. There are a number of ways that ceramic-to-metal joining is of important concern in such applications. In this paper, the partial transient liquid phase bonding (PTLPB) method for ceramic-to-metal joining is reviewed. This method does not require high joining pressure and stringent surface preparation for cleanliness as in diffusion bonding. With a proper selection of filler metals, this method can produce more heat-resistant joints than those manufactured by brazing. In this study, Si₃N₄ has been successfully joined to Inconel 718 using PTLPB with thin multi-layers of Ti-Cu, Ti-Ni and Ti-Cu-Ni at temperatures lower than 1000°C. The interfacial structure has been investigated using SEM and TEM. The processing conditions for high joint strength are also discussed