Simulation Research on Solder Joint Residual Strain Energy of Au80/Sn20 Eutectic Soldering GaAs Chip

Abstract

After Au80/Sn20 eutectic soldering GaAs chips process, Au80/Sn20 solder joints will have large residual stress and strain because of materials' coefficient of thermal expansion (CTE) mismatch. Large strain deformation will lead to the chip position migration. On the other hand too much stress can make the interface micro cracks and affect the quality and long-term reliability of Au80/Sn20 solder joints. Choosing welding pressure, cooling rate and the thickness of the precast solder pieces as the key process parameters, and designing the L16 (43) orthogonal test table. According to the Au80 / Sn20 eutectic soldering real environment, using finite element analysis software ANSYS to establish the simulation model of Au80 / Sn20 eutectic soldering process. After simulation analysis, it got the maximum residual stress and the strain energy of the solder joint. The primary of the factors is cooling rate, the secondary of the factors is the thickness of the precast solder pieces and pressure is the last by range analysis. The achieved process parameters and forming residual stress and the strain energy of the relationship between solder joints can provide reference and guidance for practical production. Eutectic welding processAu80/Sn20 eutectic welding technology is a low melting point technology. Under the temperature (280℃), solder Au80/Sn20 appears eutectic fusion phenomenon, the alloy directly International Conference on Information Sciences, Machinery, Materials and Energy (ICISMME 2015)