Heat sinks are well-known mechanisms aiding to dissipate heat efficiently. In this study, we designed and evaluated the cooling performance of heat sinks with diverse fin geometries, base materials, and fans. Also, we optimized the performance by using design optimization of the variables related to the shape of fins. Thus, by changing the fin geometries of the heat sink, adding trenches to the straight fins, and the related modifications, it was found that the optimized heat sink achieves a higher cooling performance than the (baseline) straight-fin heat sink. We also investigated the relationship between the depth of the trench and the cooling performance to find the optimal parameters.