Micron Sn-Cu Composite Solder for High-Temperature Applications Based on Transient Liquid Phase Bonding

With the development of the electronics industry, the heat-resistance of interconnect within the electronic components is becoming more and more prominent for the requirement in the multi-functionality, high-performance and high-density of electronic systems. Therefore, there is an urgent need to develop a kind of connecting material that can achieve interconnection at low temperatures and operate reliably at high temperatures. In this paper, novel composite solder based on micron-sized Sn and Cu metal particles was prepared. For the enhanced metallurgical reaction efficiency, high melting-point solder joints were achieved rapidly under low temperature reflowing conditions. The obtained solder joints have intermetallic compounds (IMC) of skeleton-network structure and accordingly excellent mechanical properties. The shear strength can attain 82 MPa and 40 MPa, respectively, at room temperature and 300 °C. Moreover, the metallurgical reaction process and thermal behavior between microparticles in the composite solder were also studied. The formation mechanism of skeleton IMCs and defects is analyzed, and the influence of process parameters is verified. The above results can be used to complete high performance packaging, and further realize the control and optimization for multi-functional high-density electronics.