Effects of Porosity on Thermal Resistance Aging at Submicron Silver Interfaces

The thermally conductive silver adhesive is widely used as a thermal interface material for thermal management of electronic device packaging. In engineering applications, the evolution of holes inside the silver adhesive interface seriously affects its service life. In this paper, we designed high-temperature accelerated aging experiments for submicron silver adhesive interfaces. The evolution of the pores during interfacial aging was characterized by X-ray scanning and scanning electron microscopy and counting the porosity. The temperature fields of interfaces with different porosities were simulated using finite element simulation. Both experimental and simulation results show that the increase in porosity accelerates the aging of the silver-glue interface. When the porosity is increased to 30%, the simulated equivalent thermal conductivity reduces by 52.50%, and the experimentally tested interfacial thermal resistance increases by 71.58%. The experimental test results of the interfacial thermal resistance are more significant than the simulated results, indicating that porosity is not the only factor influencing accelerated interfacial aging. It provides a theoretical and experimental basis for further research on porosity accelerated aging of silver adhesive interfaces.