Hot spot cooling evaluation using closed-channel cooling system (C3S) for MPU 3DI application

A novel closed-channel cooling system (C
³
S) for microprocessor application has been studied. A 0.038 cm
²
micro heaters as small as hot spot block in MPUs are fabricated. Maximum temperature was 350 °C at 28 W/cm
²
of power density. The cooling system enables decreasing temperature more than 30 °C with the liquid flow rate ranged 200 μl/min. It is found that micro bubble in water affects cooling efficiency due to vaporization kinetics. Cooling by water shows higher efficiency than that of IPA. With keeping lower micro bubble concentration of water, the heater temperature at 268 °C decreases to 143 and 63 °C at the flow rates of 100 and 600 μl/min, respectively.