Experimental study on closed-loop two-phase thermosyphon devices for cooling MCMs

Thermosyphan cooling modules, to cool multichip modules (MCMs), were design ed and tested. The cooling module consists of a cold plate with microfinned channels and a plate-type integrated condenser. A separate flow model was employed to predict the mass flux and the pressure drop in the correspondin g wall superheat were calculated using Chen's correlation. Experiments were performed to find out how the thermal performance of the cooling module wa s affected by the condenser size and the amount of charging fluid. Great em phasis was placed on the transient characteristics of the cooling module. F or an allowable temperature rise of 58 degreesC on the surface of the heate r, the cooling module can handle a heat flux of as much as 2.5 W/cm(2). No boiling retardation was observed inside the cold plate, which resulted in s mooth transition from the transient state to the steady one. It was also fo und that the appropriate size of the condenser and the adequate amount of c harging liquid are crucial factors affecting the performance of a closed tw o-phase thermosyphon device.