Since the solder residue is essential in the semiconductor manufacturing process, it has great impact on the flip chip quality considerably. This paper intends to improve the flip chip quality and try to obtain an optimal solution for the system parameters in the flip chip manufacturing process. The SMT manufacturing process is studied for discussion. The amount of solder and the size of solder are selected as the two quality properties. During the flux cleaning process, many solders are left on the passive component side. The balling might flow into the chip. It will cause the bump short in the chip which will affect the quality of the flip chip severely. In this paper, response surface method is adopted as the design of experiments. The objective function and subjective constrained conditions are defined to formulate the optimization problem. The confirmation experimental results are also provided to prove the validity. It is believed that the optimization results are helpful to the improvement of the semiconductor manufacturing process.