Electronics cooling

About: Electronics cooling is a research topic. Over the lifetime, 1135 publications have been published within this topic receiving 17608 citations.

Thermal Management of Hotspots Using Diamond Heat Spreader on Si Microcooler for GaN Devices

Abstract: A diamond heat spreader has been applied on the hybrid Si microcooler for the improvement of the hotspots cooling capability for GaN devices. The microwave chemical vapor deposition diamond heat spreader under tests is of thickness 400 $\mu \text{m}$ and thermal conductivity as high as $1500\sim 2000$ W/mK, and is bonded through the thermal compression bonding process at chip level. Eight hotspots, each of size $450\times 300~\mu \text{m}^{2}$ , were fabricated on a Si thermal test chip to mimic the heating areas of eight GaN units. Heat dissipation capabilities were studied and compared through experimental tests and thermal/fluid simulations, and consistent results have been obtained. Using the diamond heat spreader, to dissipate 70-W heating power, the maximum chip temperature can be reduced by 40.4% and 27.3%, compared with the structure without a heat spreader and the one with a copper heat spreader, respectively. While maintaining the maximum hotspot temperature under 160 °C, 10-kW/cm $^{\mathrm {{2}}}$ hotspot heat flux can be dissipated. The thermal effects of the heat spreader thickness, the diamond thermal conductivity, and the bonding layer are investigated. Based on the simulation results, the higher power density of the GaN device can be dissipated, while maintaining the peak gate temperature under 200 °C. The concentrated heat flux has been effectively reduced using a diamond heat spreader, and much better cooling capability of the Si microcooler has been achieved for high-power GaN devices.

Microscale heat transfer systems

Abstract: This disclosure concerns micro-scale heat transfer systems. Some systems relate to electronics cooling. As one example, a microscale heat transfer system can comprise a microchannel heat exchanger defining a plurality of flow microchannels fluidicly coupled to each other by a plurality of cross-connect channels. The cross-connect channels can be spaced apart along a streamwise flow direction defined by the flow microchannels. Such a configuration of flow microchannels and cross-connect channels can enable the microchannel heat exchanger to stably vaporize a portion of a working fluid when the microchannel heat exchanger is thermally coupled to a heat source. Microscale heat transfer systems can also comprise a condenser fluidicly coupled to the microchannel heat exchanger and configured to condense the vaporized portion of the working fluid. A pump can circulate the working fluid between the microchannel heat exchanger and the condenser.

Thermoelectric micro modules for spot cooling of high density heat sources

Abstract: The paper represents further progress in the development of short-legged thermoelectric (TE) micro modules for cooling high power density electronic components. Theoretical analysis and experimental study are conducted to define an available temperature lowering and maximum heat flux densities for short-legged coolers with different kinds of substrates. Temperature differences exceeding 70 K are obtained with TE leg lengths down to 0.2 mm. A new series of micro modules with TE legs 0.2 and 0.3 mm long is developed with an aluminum nitride ceramic.

Direct-immersion cooling for high power electronic chips

Abstract: Several direct-immersion cooling techniques currently under examination are reviewed. They include cooling by means of pool boiling, falling films, channel flow boiling, and jet impingement. Both thermal performance and practical packaging concerns are discussed, and the suitability of each technique for dissipating high heat fluxes from isolated chips and multichip modules is assessed with respect to such considerations as chip junction temperature, cooling uniformity, and critical heat flux (CHF). It is shown that several means are available for greatly increasing CHF in order to satisfy the cooling requirements for future electronic devices. While high cooling fluxes are possible with a number of direct-immersion cooling techniques, the complexity of the coolant conditioning and delivery to the chips should be carefully considered in selecting a suitable cooling technique. >