Experimental Study on Thermal Performance of Phase Change Heat Transfer Module with Roll Bond Aluminum Vapor Chambers

For the thermal management of high power consumption modules in 5G communication base stations, this study proposed a phase change heat transfer module with roll bond aluminum vapor chamber, in which the evaporation chamber of the module is interconnected with the flow channels of all vapor chambers. By constructing a performance testing platform, experimental studies were conducted to investigate the heat transfer performance of the module under different filling ratios. The impacts of the boiling state and the flow distribution of the working fluid on both temperature uniformity and heat dissipation efficiency of the module were analyzed. Additionally, the variation in surface temperature distribution of the heat source under different lateral inclination angles was also explored. The research results indicate that under the condition of an input power not exceeding 400 W, as the filling ratio increases, the total thermal resistance of the phase change heat transfer module initially decreases and then increases, reaching its minimum at a filling ratio of 15.0% with the lowest total thermal resistance being 0.2116 ℃/W. Appropriately reducing the filling ratio induces boiling of the liquid working fluid at the bottom of the vapor chambers, thereby promoting the balanced distribution of gaseous working fluid among different vapor chambers and enhancing both the heat dissipation efficiency and temperature uniformity of the phase change heat transfer module. At input powers of 350 W and 400 W respectively, reducing the filling ratio from 30.0% to 15.0% leads to a decrease in the standard deviation of temperatures among the vapor chambers by 40.92% and 34.04%, resulting in a significant improvement in temperature uniformity. When the tilt angle of the phase change heat transfer module changes, the liquid level in the evaporation chamber shifts, leading to uneven temperature distribution on the heat source surface. This adverse effect becomes more pronounced with increasing inclination. At a tilt angle of 10.0° (under the same power conditions), the maximum temperature difference on the heat source surface increases to more than 11.7 times that under horizontal placement.