Study on the microstructure of Si/solder/Si joint based on Al/Ni self-propagating exothermic reaction

The heat generated by self-propagating exothermic reaction can be used to melt solder and then join the components. However, the microstructure of self-propagating interconnects is different from those obtained through traditional soldering process for its unique thermal conditions. In this paper, a finite element model was established to simulate the temperature field of self-propagating joints at different time. And the Si/Au
₈₀
Sn
₂₀
/Si joint is prepared and subsequently characterized by TEM. From the TEM images, unique microstructure was observed, such as columnar Au-rich alloy, eutectic Au-Sn alloy and Ni-rich IMC. Then the formation of grains was analyzed with the simulation results.