Thermal performance of an embedded heat source vapor chamber in microwave solid-state power amplifier cooling

In this work, an embedded heat source vapor chamber (EHS-VC) is proposed for efficient and cost-effective heat dissipation in a limited space of microwave solid-state power amplifiers. The effect of the filling liquid mass under different working conditions on the heat transfer performance are systematically investigated. EHS-VC is filled by deionized water with different filling liquid mass of 0.5 g, 0.75 g, 1.0 g, 1.25 g, and 1.5 g. The results indicate that the optimized EHS-VC with the filling liquid mass of 1.0 g shows superior heat transfer performance among all tested working conditions. The thermal resistance is stable and fluctuates within a small range (0.17°C/W). The temperature difference of the optimized EHS-VC fluctuates between 0.3 and 1.0°C, and the critical power is 140 W. Compared with diamond/copper composite plate (D/C CP), EHS-VC shows great potential for efficient and cost-effective heat dissipation in a limited space of aerospace electronics, resulting in a 30% reduction in thermal resistance.