Ball Grid Array Package Solder Joint Failure Analysis, And Thermal Stress Simulation,

At present, BGA is becoming the mainstream of the advanced IC package technology. Its development is based upon the solution of the reliability of solder ball, which is one of the key problems. Usually the invalidity of solder ball is the main cause of the invalidity of electronic package. But the invalidity analysis of solder ball is short of detailed report, at the same time, it is proved that thermal fatigue is the main cause of the invalidity of the package. Therefore, it is significant to research the reliability of solder ball under the thermal cycle. This paper shows the detailed causes of invalidity, the location of invalidity of crack, and the effect on its reliability of voids and intermetallic compounds. On the basis of invalidity analysis of solder ball,BGA is simulated and analyzed as implemented in the ANSYS finite element simulation software tool to describe the stress/strain behavior of BGA solder joint under the thermal loading. With the change of solder joint shape including drum, and column, the ingredient of solder joint under the thermal loading, stress/strain distribution are investigated. This paper finds the best the radius, height of drum solder joint, and the best height, pot spacing of column solder joint for the least equivalent Von Mises strain, and the best lead-free solder for the least equivalent Von Mises strain.