This experimental study explores the passive cooling of electronic devices using phase change materials (PCM). Pin fin configurations made of aluminum are considered as thermal conductive enhancers and eicosane as the PCM for the study. The experiment considers four different heat sinks, with 40 and 56 numbers of pin fins. For the same number of pin fin, dual and constant height fin arrangements are study. The volume fractions of TCEs are 9%, 11%, 13%, and 16%. Apart from these heat sinks, a heat sink with no fin (blank heat sink) is considered for baseline comparison. Five different heat fluxes are considered (ranging from 1.17 kW/m2 to 2.35 kW/m2). The effect of number of fins, type of fins, and volumes of PCM has been reviewed. It has been observed that the introduction of fins enhances the heat transfer. An elongation in operational time is achieved in the case of dual height heat sinks compared to constant height heat sink filled with PCM. All the experiments are performed in a temperature-controlled room to avoid environment fluctuation.