Effect of CuZnAl particles addition on microstructure of Cu/Sn58Bi/Cu TLP bonding solder joints

In order to reduce the formation of voids in the Cu/Sn58Bi/Cu solder joints during transient liquid phase (TLP) bonding, the effect of CuZnAl particles on microstructure of Cu/SnBi/Cu UP bonding solder joints was investigated. After bonding, the prism-type Cu(6)Sn(5 )Departure process intermetallic compounds (IMCs) were formed at the interface. The growth of Cu6Sn5 IMC grains was controlled by the interface reaction flux J(2). The prism-type Cu3Sn IMCs grew at the expense of Cu6Sn5 IMCs. With the increase of bonding time, the solder joints were converted into all IMCs, indicating that SnBi solder and SnBi-0.5 CuZnAl solder are suitable for low-temperature bonding and high-temperature applications. When the CuZnAl particles were added, the growth of the interfacial IMCs was inhibited, and the formation of voids was significantly reduced.