Effects of melting temperature and the presence of internal fins on the performance of a phase change material (PCM)-based heat sink

• Transient performance of PCM-based heat sinks under pulsed heating was studied.
• Effects of melting temperature and the use of internal fins were both concerned.
• A high melting temperature is usually favored for extended periods of protection.
• Selection of a pertinent melting temperature depends on the heat load exerted.
• The utilization of internal fins is always preferred regardless of the PCM adopted.

Experiments were conducted to investigate the effects of melting temperature and the presence of internal fins on the performance of a phase change material (PCM)-based heat sink for thermal management of electronics. At various intensive pulsed heat loads, comparisons were made between two PCMs with close thermophysical properties but different melting temperatures. The performance of an unfinned heat sink was also compared with its finned version. It was found that the use of a PCM with a higher melting temperature can extend a longer time of protection of the target devices from overheating, and that it also facilitates cooling for recovering the heat sink for subsequent operations. A lower melting temperature, however, is possibly favored because it may enable a prompt protection of the target devices. Selection of the PCM with an appropriate melting temperature depends strongly on the thermal conditions exerted. In contrast, employment of internal fins was shown to be always preferred as the performance of the heat sink can be improved, regardless of the PCM adopted. In the cases studied, the maximum temperature rise was lowered by up to 10 °C for the finned heat sink.