Thermo-fluid analysis of micro pin-fin array cooling configurations for high heat fluxes with a hot spot

• Maximum temperature of hot spots can be reduced using hydrodynamically shaped closely packed array of pin-fins.
• Pumping power requirements can be reduced by reshaping and resizing pin-fins.
• It is possible to remove all heat from a chip by using an array of micro pin-fins.
• Larger cross section pin-fins should be under the hot spot to facilitate local heat conduction.
• Multiobjective design optimization and high conductivity thin film coatings are recommended.

Effect of micro pin-fin shapes on cooling of high heat flux electronic chips with a single hot spot was investigated numerically. Hydrothermal performances of different micro pin-fin shapes were evaluated. Circular shape, hydrofoil shape, modified hydrofoil shape, and symmetric convex shape were the cross section shapes used for micro pin-fins. All cooling configurations had the same staggered arrangements for micro pin-fins. An electronic chip with a 2.45 × 2.45 mm footprint having a hot spot of 0.5 × 0.5 mm at its centre was used for simulations. Uniform heat flux of 2000 W cm−2 was applied at the hot spot. The rest of the chip was exposed to 1000 W cm−2 uniform heat load. The cross section area of the circular shape and hydrofoil shape micro pin-fins was kept the same to have a fair comparison. Convex and hydrofoil shape designs showed significant reduction in the required pumping power as well as the maximum required pressure. In the last case, the height of micro pin-fins was increased from 200 μm to 400 μm to remove 100% of the total heat load via convection, and at the same time keep the maximum temperatures within an acceptable range.