Introduce the advantages of vacuum eutectic soldering technology. The main process parameters of affecting the eutectic soldering quality were studied using vacuum eutectic solder machine, including soldering atmosphere, soldering temperature, soldering time, pressure and so on. It is approved that vacuum eutectic soldering can effectively restrain the oxide, reduce the rate of void, improve soldering quality, can solder several dies at same time, and greatly improve the efficiency of soldering. Put forward the feasible solution with vacuum eutectic soldering to achieve low void rate.