Flip Chip Typical Failure Case Analysis Research

Abstract

With the rapid development of integrated circuits, flip-chip has become the mainstream packaging technology. The solder bumps in the connection area between the chip and the substrate mainly play the role of electrical connection, mechanical connection and heat exchange. Due to the miniaturization and multi-function development of electronic products, electronic packaging solder joints are becoming denser and smaller in size. Therefore, it is also exposed to higher electrical, mechanical and thermal stresses. According to statistics, solder joint failure accounts for more than half of the failure of electronic products. Therefore, in this study, we have extracted the classic failure cases of packaged products through daily failure analysis work, and explained the failure reasons. The open failure of solder joints mainly involves foreign material flux leading to solder joint rejection, and thermal expansion and contraction effect leading to the crack of the solder IMC on the substrate side; the short failure of solder joints mainly involves the bridging of adjacent solder joints caused by foreign material back gold; in addition, it is also found that abnormal circuit at the die level lead to leakage failure. All in all, finding the root cause for these failure will significantly help improve the manufacturing process.