MEMS-Based Spatial and Temporal Thermal Management of High Heat Flux Electronics

Abstract

This presentation describes the development of EDIFICE: Embedded Droplet Impingement For Integrated Cooling of Electronics. The EDIFICE project seeks to develop an integrated droplet impingement cooling device for removing chip heat fluxes over 100 W/cm2, employing latent heat of vaporization of dielectric fluids. Micro-manufacturing and MEMS (Micro Electro-Mechanical Systems) will be discussed as enabling technologies for innovative cooling schemes recently proposed. Micro-spray nozzles are fabricated to produce 50–100 micron droplets coupled with surface texturing on the backside of the chip to promote droplet spreading and effective evaporation. A novel feature to enable adaptive on-demand cooling is MEMS sensing (on-chip temperature, remote IR temperature and ultrasonic dielectric film thickness) and MEMS actuation. EDIFICE is integrated within the electronics package and fabricated using advanced micro-manufacturing technologies (e.g., Deep Reactive lon Etching (DRIE) and CMOS CMU-MEMS). The development of EDIFICE involves modeling, CFD simulations, and physical experimentation on test beds. This lecture will then examine jet impingement cooling of EDIFICE with a dielectric coolant and the influence of fluid properties, micro spray characteristics, and surface evaporation. The development of micro nozzles, micro-structured surface texturing, and the system integration of the evaporator is discussed. Results of a prototype testing of swirl nozzles with dielectric fluid HFE-7200 on a notebook PC are presented. This paper also reviews liquid and evaporative cooling research applied to thermal management of electronics. It outlines the challenges to practical implementation and future research needs.