Effects of shape parameters on tensile strength of Cu bump

Three parameters, copper pad material, pad thickness, and bump patterns were chosen as three control factors. By using an L9(34)orthogonal array the copper stud bump solder joints which have 9 different combinations of parameters were designed. The finite element analysis models of 9 copper stud bump solder joints were established by using ANSYS/LS-DYNA, and analyzed the finite element tensile simulation. Tensile strain data of copper stud bump solder joint were obtained under 9 different parameters combinations; it was analyzed through range analysis and variance analysis. The result shows that of the three parameters, the descending order of affecting the copper stud bump solder joint tensile strain is copper pad material, bump patterns, and pad thickness. With 95% confidence, copper pad material has a significant effect on the copper stud bump solder joint tensile strain whereas bump patterns and pad thickness has little.