Investigation of Reactively Structured Al/Ni Multilayer Foils and their Applications in High Temperature Die Attach

Abstract

This work focuses on using a reactive layered Al/Ni foil as a localized heat source for electronic die attachment purposes. A two pronged approach was used to demonstrate the viability of this material for attaching die to substrates using AuSn braze. Both experimental sample creation and transient thermal modeling were conducted. This thesis will report thermal simulation and experimental results as well as discussing the joining process and the results of shear strength and thermal cycling reliability testing. A new pre-heating method was developed after results revealed that the initial temperature of the system is vital in predicting how successful a joint will be. Thermal cycling results have shown that die cracking is a significant reliability issue but with further study this reactive joining process shows promise.