Simulation of temperature fields for Cu/Cu joining process by self-propagating reaction

Self-propagating reaction is presented as a new heat source for the joining of MEMS and high power devices. However, due to the complex thermal process of self-propagating reaction, the temperature in solder or multilayer foil during the joining process is difficult or even impossible to measure and control. Therefore, more simulation efforts should be carried out to get a better understanding of self-propagating reaction. In this paper, the temperature field is simulated by the finite element method based on Cu/Cu joining using Ni/Al self-propagating multilayer foil. The simulative results are verified by the measured temperature in the actual experiments. Through the simulation, the temperature curves in the multilayer foil, solder and base metal are obtained. The temperature field under different solder thickness and preheating temperature are compared to analyze their effects. In summary, the present study characterizes the temperature field in the joining, and can provide deep understanding for material joining by multilayer foil based self-propagating reaction.