Thermally stable high temperature die attach solution

Abstract

A new design for semiconductor die attach results in a thermodynamically stable microstructure for high temperature electronics applications. The design takes advantage of solid–solid interdiffusion bonding utilizing silver nanoparticles and gold mesh interposer. This results in a die attach assembly with a continuous, non-porous gold-silver interdiffusion layer running all the way from the die to the substrate. The processing of these assemblies is simple and does not require any applied pressure on the die. These assemblies resisted degradation to shear strength for at least 1000h storage at 450°C and at least 100h storage at 600°C. The random porosity of standard pressure-free sintered silver die attach is converted into single voids at the center of each mesh cell and can be controlled by the mesh geometry.