Design study of micro heat sink configurations with offset zigzag channel for specific chips geometrics

This paper focused on designing a cost-effective heat transfer for micro heat sink in high power electronic chip cooling for flow rates ranging from 18.8 to 72 ml/min. The water and silicon are used as fluid and solid for the computational domain. The inlet/outlet allocations and channel cross-section shapes of heat sink are investigated numerically for the specific chip of 2 mm ∗ 10 mm, which is same as channel region. The heat sink includes 10 channels, which has the width of 0.1-0.2 mm and depth of 0.2 mm. Firstly, the 2-port heat sinks with offset zigzag grooves in sidewalls are performed to study the effects of channel cross-section shapes on fluid flow and heat transfer characteristics. Results show the zigzag channel can enhance heat transfer albeit with great pressure drop penalty. For 2-port heat sink with Z2 at flow rates of 72 ml/min, the average temperature and maximum temperature is reduced by 5.08 K and 7.6 K respectively but pressure drop increased by 90.8 kPa. It can be interpreted that zigzag channel not enlarges heat transfer area, but enhances the fluid disturbance to make the fluid mixed better, heat transfer enhanced and pressure drop increased. Secondly, in order to reduce the pressure drop, the 4-port heat sink is proposed by reducing the channel length. Results show the 4-port configuration can reduce effectively pressure drop and reduce average temperature for fixed volume flow rates. Then, 4-port heat sinks with offset zigzag grooves are studied. For 4-port heat sink with Z2 at flow rates of 72 ml/min, the average temperature and maximum temperature are reduced by 4.86 K and 9.4 K respectively, and pressure drop also decreased by 80.7 kPa. It can be interpreted that 4-port configurations reduce the channel length and increase channel number, which lead fluid distributes more uniformly to enhance thermal performance and reduce flow resistance. Additional, the zigzag channel structures improve fluid disturbance to enhance heat transfer.