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The most prominent failure in electronic devices is due to excessive heating of the device during its operation. And the modern trend of miniaturization of electronic devices with better performance and features further extends the need for a proper cooling system. The phase change material (PCM) cooling technique is one of the most economical passive cooling methods which avoids mechanical vibration of the cooling system and provides stable cooling with repeated uses. This review paper presents the thermo-physical properties of commonly used PCMs and different types of thermal conductivity enhancers (TCE) for electronic devices. The findings of this literature consisting of both experimental and numerical works can be used as a guideline for future researches in this field. Heat transfer enhancement in PCM can be achieve using fins, porous media, mixing with carbon additives, microencapsulation of PCM, and by adding nanoparticles. For heat sink with fins, the volume fraction of the PCM and TCE is found to be directly affecting the performance of the cooling system. Also, distributed pin fins, the pattern of arrangement, shape, and size of the fin affects the heat transfer to the PCM. Microencapsulation also increases the heat transfer surface area of PCM. However, the selection of shell material and the core material is important to obtain the targeted thermal properties. Also, metal and metal oxide nanoparticles can significantly increase the heat conduction and diffusion capacity of the PCM. But, each of these enhancement methods has certain demerits which constantly required to be addressed to achieve a more efficient cooling system for modern electronics. [ABSTRACT FROM AUTHOR]

We had introduced a microscopic technique to obtain heat capacity peaks near first-order phase transitions in polycrystalline phase change materials (PCMs). Such PCMs are composed of a large number of segments or grains, so that the total heat capacity of a PCM is a double average of heat capacities in the individual grains. One average is over surface (or boundary) effects occurring due to interactions of grains with their surroundings, while the other average is over grain sizes. Using this approach, we were able to derive a formula for heat capacity peaks and use it to very accurately fit experimental data for three selected PCMs measured by adiabatic scanning calorimetry. The fitted values of the phase change temperature for these three PCMs were not convincing, however. In this paper we argue that the reason for this controversy stems from too a crude approximation of surface effects that was used originally. Therefore, here we propose an improvement of our technique by suggesting a more appropriate approximation that still leads to as accurate fits as the original one. We illustrate this for one of the three PCMs. [ABSTRACT FROM AUTHOR]