© 2022 Elsevier LtdThermal management of electronics is an essential issue since it affects the components' function and longevity. In this study, a novel mini channel heatsink comprised of 3D networks of cylinders with a diameter of 1 mm is investigated experimentally and numerically. The heatsink with the size of 20 × 60 ×60 mm3 was fabricated with AlSi7Mg0.6 powders using Direct Metal Laser Sintering. The Nusselt number and pressure drops for Reynolds numbers between 463.38 and 1443.7 were recorded. The numerical conjugate heat transfer model is validated using the experimental results. Three channel shapes, circle, square, and triangle + square, are studied. The square design has the best overall performance based on the thermal effectiveness factor. It is established that the primary temperature gradient happens along with the flow, and the square designs allow the flow of fluid in the desired direction without hindrance. Additionally, the number of rows in the transverse direction of flow is lowered at constant mass flow rates for the square design. Based on Nusselt number and pressure drop values, the case with six rows is the best performer.