A new sink should be in simple shapes for reasonable manufacturing process. On the other hand, the heat sink tends to be complicated shape for high cooling performance. Recently, 3D printer is able to process complicated shapes. However, manufacturing cost by 3D printing method is expensive. Thus it is important to verify and improve fluid flow and thermal conductivity at the design stage of the heat sink. This study provides a simulation model and a new high performance heat sink by using finite element method and using optimization method. The new heat sink decreases the thermal resistance about 15% in comparison with the conventional one.