Thermal Performance and Reliability of Liquid Metal Alloys as Thermal Interface Materials for Computing Electronics Devices

Gallium-Indium and Galinstan are liquid metal alloys (LMAs) at room temperature that have been drawing attention for thermal management in microprocessor packages, including CPU, GPU, MCM in PCs and super computers. These alloys are widely considered to be used as thermal interface materials (TIM) because of their high thermal conductivity and extremely low thermal resistance. However, automating process of LMA for TIMs presents challenges due to the oxidation of Gallium (Ga) and poor wettability. The oxidation of Ga changes the rheologic behavior of Ga-based liquid metal alloys and causes a deterioration in the LMA thermal properties during deposition process and application. This study continues recent efforts to develop liquid metal TIMs containing organic compounds (LMO) that enhance deposit process and thermal performance for improved thermal management in electronics devices. The thermal conductivity and resistance and reliability of LMOs and LMAs were measured using TIMA 5 (ASTM-D5470) and evaluated by a house-made power cycler, respectively. We find that LMOs have thermal properties comparable to primary LMAs, with improved adhesion/wettability, anti-oxidation, and dispensing performance. Power cycler tests with input powers of 180W, 360W, 380W were cycled with various time of on/off to measure thermal resistance and evaluate the long-term reliability of LMOs. High temperature storage tests at 85°C are ongoing to explore the thermal stability of LMOs. Thermal cycling test (TCT) with a profile of - 10°C to 60°C, dwell time of 15min was used to evaluate thermal reliability of LMOs and LMAs.