With the development of the technological world, there is a growing trend of using electronic components with high heat outputs for short periods of time. This trend poses a new challenge in the thermal field: how can the temperature of the components be kept moderate during their operation, to prevent damaging the electronic components. To this end, ways of transferring or storing the large amounts of heat emitted in a short time must be rethought, either by active systems or by passive systems. A possible solution for this problem is the usage of phase-change materials (PCMs), which absorb heat at melting due to their latent heat capacity. A major disadvantage of these materials is their low thermal conductivity, therefore usage of these materials will often come along measures to enhance heat flow, such as porous media or fin arrays. The present work deals with thermal management of high output electronic component by using a passive system which combines optimal fin array, a spreader lowering the heat fluxes by increasing the area through which the heat enters the system, and a suitable PCM. In the current study, experimental and numerical investigations were carried out of a system that contains all the aforementioned heat sink parts using two different PCMs with very similar volumetric heat capacities: an organic paraffin, n-Octacosane and Field's metal, a eutectic alloy from the group of low melting point alloys. The experimental study serves for validation of the numerical investigation, which then can be extended to additional cases not covered in the experiments. It was found that by using Field's metal a lower chip temperature is obtained. Also, in that case the period at which a "plateau" is observed in the temperature evolution due to phase change is more pronounced.