Design and performance evaluation of an anti-expansion 3D vapor chamber for multi-chip cooling in high heat flux applications

Abstract

Diamond substrate-based liquid cooling effectively addresses the heat dissipation of high-heat-flux multi-chip due to the superior thermal diffusion properties. However, the high cost and limited machinability restrict commercial application of diamond substrate. Vapor chambers, with customizable profiles and lower manufacturing costs, present a promising alternative for efficient multi-chip cooling. This paper introduces an anti-expansion 3D vapor chamber for high-heat-flux multi-chip cooling. The shell and wick structures are optimized based on thermal resistance network analysis to minimize thermal resistance between the heat source and the working fluid. The heat transfer performance of the vapor chamber is evaluated through comprehensive experiments, assessing the impact of processing parameters and service conditions. Results demonstrate that the vapor chamber with a GCBP2 wick delivers optimal thermal performance, achieving a maximum heat dissipation capacity of 339.4 W/cm² at a 95 °C threshold temperature, observing an improvement of 52.7 W/cm² over diamond aluminum. Additionally, the GCBP2 vapor chamber maintains stable heat dissipation across various operating positions, with a performance fluctuation of less than 3 %. This vapor chamber not only outperforms diamond aluminum thermally but also reduces costs by 90 %, highlighting the potential for commercial applications in high-heat-flux multi-chip cooling.