Foil Based Transient Liquid Phase Bonding as a Die-Attachment Method for High Temperature Devices

In this study, a foil-based transient liquid phase (TLP) bonding method is proposed as a die-attachment technique for high temperature devices. Silver-indium and silver-tin based binary systems are investigated for high temperature die bonds. An electroplating method was used for producing multi-layered foils as TLP bonding material. In this work, an optimization and characterization of the process was performed. Local microstructure and composition of the TLP bonded joints were studied using SEM and EDX. The bonding layers of Ag-In and Ag-Sn joints proved to be uniform and virtually void-free. The shear strength of the die-attachments exceeds the requirements of usual test standard. The die-attachment stresses induced by the TLP bonding process are analyzed using optical investigation technique such as digital image correlation (DIC).