EXPERIMENTAL STUDY OF A PCM HEAT SINK INTEGRATED WITH VAPOR CHAMBER FOR HIGH HEAT FLUX THERMAL MANAGEMENT

In the present paper, a rapid thermal management strategy (TMS) by combining composite phase change materials (PCM) and a vapor chamber (VC) is proposed to cope with high heat flux conditions. The performance of the heat sink with and without VC is experimentally investigated. Additionally, the low melting temperature alloy (LMTA) is applied to reduce the thermal contact resistance (TCR) between the VC base plate and copper foam, resulting in a significant improvement in thermal management performance (TMP). Our results reveal that the PCM heat sink exhibits poor thermal management in high heat flux conditions due to the low thermal conductivity of paraffin. However, the introduction of VC allows for initial heat diffusion of concentrated heat, demonstrating a higher equivalent thermal diffusion coefficient compared to using a copper plate of the same size. This extension leads to an effective thermal management time of up to 220 min. Furthermore, the application of LMTA substantially enhances temperature uniformity inside the PCM heat sink, reducing the average TCR between the VC base plate and copper foam by 71%, reaching 0.2 K/W. As a result, the overheat degree away from PCM melting temperature is alleviated from 37° to 29° during the quasi-steady state, and the effective thermal management time can be further extended by 11.4%, reaching 245 min. In practical applications, the rapid TMS not only extends the reliable operating time of electronic devices but also maintains the device at a lower temperature level compared to an individual PCM heat sink.