Research on the Reliability of Cu/Sn Copper Pillar Bump

As the electronic packaging density continues to increase, flip chip or stacked packaging via bump bonding is gradually replacing traditional wire bonding and will become the mainstream packaging form in the future. For copper bumps, this new type of electronic interconnection has not yet been fixed by industry standards. Therefore, this paper has made a preliminary study on the reliability of this new type of package. We find that the growth rate of IMCs was faster at the initial stage of aging and decreased with the aging time increasing. In the early stage of IMCs growth, the form of the IMCs was mainly Cu6Sn5. As the thickness of Cu6Sn5 layer increased, the brittle phase Cu3Sn appeared. The growth of IMCs increased the interfacial adhesion. But after aging for 750h, the interfacial adhesion had a certain degree of decline.