The present work aims to examine the influence of designing mini channel heat sinks using Stereolithography (SLA) 3D printing. Stereolithography (SLA) is a common additive manufacturing technique. The internal mini channels of the heat sink are made of aluminium materials and the outer cover is made of commercial polymer. Three models of the mini channel heat sinks are considered. A constant heat flow is applied to the bottom wall of the heat sink, and water is used as a coolant. The flow and heat transfer were studied for different cooling speeds. The physical properties of the fluid provided good thermal performance for the heat sink, especially at increased flow rates. The acrylonitrile butadiene styrene (ABS) copolymer resin has shown its good insulator for the heat sink and has improved the performance of the heat sink. This study demonstrates that the ABS copolymer resin enhances the cooling of electronic components.