摘要
To overcome the reliability and manufacturing drawbacks in 3D-IC, such as warpage and low thermal budget, low temperature solder alloys are increasingly studied. Although Indium-rich solder has a beneficial low melting point of 156 °C, the formation of interfacial voids after bonding has raised concerns for reliability. By introducing Cu and Sn, the solder retained low melting points and the interfacial voids in microbumps were significantly reduced. The melting point of Cu-Sn-In alloys were measured to ensure that there is no additional phase transformation at higher temperature. In addition, the interfacial IMCs phases were characterized.