Advanced micro heat exchangers for high heat flux

Owing to the rapid development of semiconductor industry, the heat dissipated from electronic devices increases drastically with increasing device logic gate number and operation speed. The cooling technologies have undergone evolutionary changes from air cooled fin geometry to copper base and vapor chamber heat spreader and to more thorough methods such as forced convective liquid cooling in recent years. Three micro heat exchangers with long offset strip, short offset strip and chevron flow path based on the conventional heat transfer enhancement concepts were designed, fabricated and tested. A straight channel heat exchanger was also made for comparison. The test results show that there is no significant difference of the thermal resistance at various heating power for each heat exchanger. The chevron channel heat exchanger provides the lowest thermal resistance. However, its pressure drop is also the highest. It is approximately 250% higher than that for other three heat exchangers. The offset strip heat exchangers provide better thermal performance than the straight channel heat exchanger does. The performance of heat exchanger with shorter strip is better than that of heat exchanger with longer strip. Further improvement such as optimum strip length design or streamlined strip shape may be applied to reduce its flow pressure drop.