ABSTRACT
This paper reports 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 in the range 70-100 W/cm2, employing latent heat of vaporization of dielectric fluids (50-100 micron droplets) to achieve these high heat removal rates. Micro-manufacturing and MEMS (Micro Electro-Mechanical Systems) will be discussed as enabling technologies for innovative cooling schemes recently proposed. 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 will be integrated within the electronics package and fabricated using advanced micro-manufacturing technologies (e.g., Deep Reactive Ion Etching (DRIE) and CMOS CMU-MEMS). The development of EDIFICE involves modeling, CFD simulations, and physical experimentation on test beds.
In this study, numerical simulations are performed to investigate EDIFICE jet impingement cooling with a dielectric coolant and the influence of several parameters such as jet diameter, jet velocity, and latent heat effects. This paper also presents flow visualization of micro-jet break-up, induced by MEMS micro-nozzles of irregular shapes and flow swirling to generate droplets with desirable dispersion. To enhance liquid spreading on the impingement surface and to create a thin film for effective evaporation, MEMS micro-structured surfaces are fabricated. All of these components are made from silicon and enabled by integrated-MEMS process technologies.