Mechanical properties of a novel nano-thermal interface material

Continued miniaturization in combination with increased performance in microelectronics has generated an urgent need for improved thermal management techniques in order to maintain reliability in systems and devices. Thermal interface materials play a key role in the development of solutions for thermal management in microelectronics. In this paper, mechanical properties of a nanotechnology enhanced thermal interface material (Nano-TIM) were studied. The material is based on Sn-Ag-Cu based alloy reinforced with nano scale fiber matrix. Tensile tests were used to investigate and compare the elastic modulus at room temperature and mechanical strength between 20 to 100°C. Scanning Electron Microscopy (SEM) analysis techniques were used to investigate the morphology of the fracture section after tensile tests as well as the internal structure of the samples. The results show that the Nano-TIM can have a significantly lower elastic modulus compared to the pure alloy phase of SnAgCu due to its fiber phase. A lower elastic modulus of the solder joint can be important since it will reduce the stress transfer across the interface. This is particular important when the joint substrates have mismatching coefficients of thermal expansion. The findings of this study thus indicate that the Nano-TIM may provide a useful alternative to improve the thermomechanical reliability compared to pure solder joints.