This study implies experimental investigation for optimization of heat transfer in electronic integrated circuits using close packed phase change materials (PCMs) filled pin-fin heat sinks. The aim of this study is to find the most efficient pin-fin configuration filled with optimum PCM to extend the operating range of electronic circuits. The experimental methodology is based upon variation of pin fin configurations in rectangular, round and triangular cross-sections. Each configuration is allowed a pin fin volumetric percentage of 9%. For analysis using PCM a volume fraction of 90% is maintained and six PCMs with different thermo-physical properties (varying melting temperatures, latent heats and heat capacities) are selected. These include paraffin wax, RT-54, RT-44, RT-35HC, SP-31 and n-eicosane. Moreover, the power levels mimicking heat input range between 5 W and 8 W. The resulting information is analyzed for the performance of a heat sink with and without PCM. Besides that, PCM ascendency is manipulated in terms of operational time, enhancement ratios, Stefan number and storage ratio. The outcomes suggest that triangular pin-fins are found to be the most effective pin-fin configuration for heat transfer both with and without PCM. (C) 2018 Elsevier Ltd. All rights reserved.