Regulation of the thermal performance of electrical components is a key aspect. Phase-change materials can be incorporated into a fin heat sink (FHS) to enhance thermal management by maintaining a stable temperature. Three types (square, triangular, and circular) of aluminum FHSs of different configurations are investigated numerically in this paper. Studies are conducted with and without PCMs. Paraffin wax, stearic acid, and polyethylene glycol are used as PCMs to find the best combinations for thermal cooling and to determine the impact of using PCMs in the heat sinks. The results obtained show that, by adding PCMs, temperature rise can be delayed, and polyethylene glycol performs better than other PCMs. Moreover, the square fin heat sink increases the thermal regulation period. As the height of the fins increases from 10 mm to 16 mm, thermal efficiency increases. Hence, the findings of this paper would be beneficial for effective thermal management in the electronic industry.