Electronics cooling

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

Single chamber compact thermosyphons with micro-fabricated components

Abstract: This study presents the thermal performance evaluation of a compact single-chamber thermosyphon. The thermosyphon set-up has a central evaporator section with integrated fins for cooling along the edges. The evaporator employs a microfabricated three-dimensional copper structure for enhancing boiling heat transfer. The thermal performance of the system was characterized at various power levels and condenser cooling conditions. The size of the boiling enhancement structure and effects of liquid fill volumes on performance were also investigated. Incorporation of the enhancement structure resulted in an improvement in the thermosyphon performance by decreasing the wall temperature at the evaporator by 8/spl deg/C, for a power dissipation of 36 W/cm/sup 2/ at an air speed of 1 m/s. The maximum heat flux obtained based on a maximum evaporator temperature of 75/spl deg/C for an air speed of 1 m/s was 42.5 W/cm/sup 2/. Variation in the liquid fill volume showed negligible effect on the maximum temperature at the evaporator, as long as the enhanced structure was fully flooded. Increasing the footprint size of the enhancement structure showed marginal improvement in boiling heat transfer performance. This increased the number of pores in the enhancement structures and did not result in a corresponding increase in the performance.

Effect of piezoelectric fan height on flow and heat transfer for electronics cooling applications

Abstract: Piezoelectric fan is used to remove the heat from the microelectronic devices, owing to their low power consumption, minimal noise emission and small in size In the present study, a piezoelectric fan has been investigated to analyze the performance The paper also discusses the capability of piezoelectric fan to cool the microelectronic device and its performance The simulation and experimental investigations have been made for two different positions of piezoelectric fan ie vertical and horizontal positions The Fluent 623 software which is a computational fluid dynamics (CFD) code has been used in the simulation to predict the heat transfer coefficient and the flow fields In the experimental set-up, two heaters in line arrangement have been used in the set-up The flow measurements have been carried out by using the particle image velocimetry (PIV) system at different piezoelectric fan height The heat transfer coefficients have been plotted and compared with the experimental values The simulation results obtained are found in satisfactory agreement with the experimental results

Pressure effects on the pool boiling of the fluorinated ketone C 2 F 5 C(O)CF(CF 3 ) 2

Abstract: A low global warming potential dielectric fluid is under investigation for use in two-phase electronic cooling systems. The fluorinated ketone C 2 F 5 C(O)CF(CF 3 ) 2 , sufficient for either indirect cooling or direct immersion cooling, may be an environmentally friendly alternative for the cooling of power electronics and other high power density devices. This study examines pressure effects on the pool boiling heat transfer coefficient and critical heat flux of the fluorinated ketone. Using a pressurized boiling facility, an aluminum substrate is heated by conduction with a cartridge heater. By measuring the surface temperature and surface heat flux, the nucleate boiling heat transfer coefficient and critical heat flux are obtained for the fluorinated ketone under saturated conditions at various system pressures. Results are compared to the pool boiling of tetrafluoroethane (R-134a) in the same pressurized facility. Data are fitted using the Rohsenow correlation and surface-fluids parameters for R-134a and the fluorinated ketone are determined. Data indicate that the CHF and nucleate boiling heat transfer coefficient of the fluorinated ketone may be increased with only modest increases in the system pressure.

Thermal modeling and design of liquid cooled heat sinks assembled vvith flip chip ball grid array packages

Abstract: Development of advanced cooling techniques is required for electronic packages with high power dissipation such as microprocessors. In this paper, a liquid cooling setup is proposed and the thermal modeling and design of a liquid cooled microchannel heat sink assembled with a flip chip ball grid array (FCBGA) package are addressed, with an emphasis on the removal of a heat flux beyond 100W/cm2. A full model, which includes the microchannel heat sink with inletloutlet manifolds, the package and thermal test hoard, is developed. To reduce the overall modeling efforts, a compact package model is used. Two different flow pattems, the liquid flow through the microchannel heat sink populated with microchannellfms and the natural convection of air surrounding the package, are modeled simultaneously. The full model is compared with the heat sink model without the package assembly. Parametric studies are conducted on the effects of the channel width, the heat sink base thickness and the heat sink material. In line with the modeling analysis, a microchannel heat sink with a fmed array compatible with the FCBGA package was developed. The measurements show that the current liquid cooling setup can achieve 'a power dissipation of 130 W/cm2. The comparison with simulation shows agreement within 11% in pressure drop and 5% in thermal resistance.

Exhaust gas recirculation valve and method of cooling

Abstract: An exhaust gas recirculation valve has a cast metal body having at least one cooling circuit that is cast in to the cast metal body. The cooling circuit includes a coolant inlet, a coolant outlet, and passage between the inlet and the outlet. Another device has a cast metal body, and electronics cooling circuit cast into the metal body, and a valve cooling circuit cast into the metal body. The electronics cooling circuit cools at least one of a circuit board and a motor. The valve cooling circuit cools at least one of a valve shaft and a gear train. A method of manufacturing an exhaust gas recirculation valve includes providing a mold having a cast pattern comprising at least one cooling circuit in the mold. The cooling circuit includes a coolant inlet, a coolant outlet, and a coolant passage between the inlet and outlet. The method further involves introducing molten metal or alloy to the mold, and cooling the molten metal or alloy, to form a cast metal device having the pattern of the mold including the cooling circuit.