AVS 47th International Symposium
    MEMS Thursday Sessions
       Session MM+BI-ThM

Paper MM+BI-ThM10
Development of a Micro Capillary Pumped Loop System for Microelectronic Device Cooling

Thursday, October 5, 2000, 11:20 am, Room 309

Session: Bio-MEMS and Microfluidics
Presenter: H. Yun, Samsung Advanced Institute of Technology, South Korea
Authors: H. Yun, Samsung Advanced Institute of Technology, South Korea
H. Lee, Samsung Advanced Institute of Technology, South Korea
K. Cho, Samsung Advanced Institute of Technology, South Korea
I. Song, Samsung Advanced Institute of Technology, South Korea
Correspondent: Click to Email
Increasing demand for processing data leads to faster clock speeds and large integration. As a result, the heat generation of microelectronic devices is increasing at rapid rate. Current PCs generate 20~30 Watts/cm@super 2@ of heat. If this trend continues, 100 Watts/cm@super 2@ of heat generation are expected within few years. Since conventional phonon diffusion based metal heat sinks can handle only up to 10 Watts/cm@super 2@, an alternative cooling technology is desired. In this paper, a micro capillary pumped loop (CPL), which is a microfabricated, capillary pressure driven fluid cycle is proposed as an alternative means of cooling microelectronic devices with large heat generation. The heat is absorbed at the evaporator by vaporizing the circulating fluid, and released out of the system at the condenser. The capillary forces of the microfabricated wick structure at the evaporator drives the fluid. Since the fluid particle directly carries the heat out of the system, the micro CPL is expected to be more effective than the conventional diffusion-based heat sinks. A prototype of 30 Watts/cm@super 2@ cooling capacity has been built and tested. Microchannels have been etched on a silicon wafer to form the evaporator and the condenser. The prototype operated successfully under 30 Watts/cm@super 2@ heat flux while keeping the junction temperature below 400K. The maximum heat flux was 50 Watts/cm@super 2@ before the dryout at the evaporator occurred. A nonlinear dynamic model has been developed to simulate the interaction between various components of the micro CPL. The simulation model successfully captured the overall trends of the experimental data. Further research on the underlying physics are desired for better understanding of this device.