Mansour Tawk

Numerical and Experimental Investigations of the Thermal Management of Power Electronics With Liquid Metal Mini-Channel Coolers

Thermal management became a limiting factor in the development of high-power electronic devices, and new methods of cooling are required. Therefore, the use of liquid gallium alloys, whose thermal conductivity (approximately 28 W/m/K) is 40 times greater than thermal conductivity of water, is introduced. In the first part of this paper, we present a numerical modeling and an experimental study of a mini-channel liquid metal cooler. In these experiments, the working fluid is moved via an electromagnetic pump. Numerical and experimental results are compared. Then, a numerical study dealing with the influence of the thermal conductivity of the cooler material is conducted, and a discussion on the use of classical convective heat transfer correlations is presented. In the last part, a numerical study of the cooling of a silicon chip is carried out. The cooling capacity of the liquid metal is compared with that of the water cooling, and very attractive results are obtained. The concept discussed in this paper is expected to provide a powerful cooling strategy for high-power-density electronic devices.

Study and realization of a high power density electronics device cooling loop using a liquid metal coolant

Thermal management became the limiting factor in the development of high power electronic devices and new methods of cooling are required. Due to the low thermal conductivity of classical liquids (water, alcohols, dielectric fluids…), in many cases, the standard liquid cooling techniques cannot achieve the required cooling performances. Therefore the use of liquid gallium alloys whose thermal conductivity (approx. 28W/m/K) is 40 times greater than thermal conductivity of water, is introduced. In the first part of this paper, we present a numerical modeling and an experimental study of a minichannel liquid metal cooler. In these experiments, the working fluid is moved via an electromagnetic pump. Numerical and the experimental results are compared. Then we present a numerical study showing that the cooler performances depend largely on the thermal conductivity of its constitutive material. In the last part we present a numerical study of a silicon chip cooling. Simulations with different flow rates and heat powers were performed. The cooling capacity of the liquid metal is compared with that of the water cooling and very attractive results were obtained. The concept discussed in this paper is expected to provide a powerful cooling strategy for high power density electronic devices.

Modeling of power devices with drift region integrated microchannel cooler

This paper introduces the DRIMCooler — an innovative concept allowing to locate the heat exchanger directly inside the active region of a vertical power device. Based on vertical edge termination technique and the use of dielectric coolant fluid circulation, arrays of through wafer channels are drilled in the silicon substrate offering a large heat exchange coefficient while minimizing the pressure drops. The concept is introduced and discussed with respect to technological and electrical points of view. Thermal and fluidic issues are analyzed with numerical models and simulations. The obtained results show excellent thermal and hydraulic performances of the DRIM Cooler.

Numerical study of a liquid metal heat spreader for power semiconductor devices

This paper describes a new thermal management approach for cooling of power semiconductor devices. This new approach is based on a liquid metal fluid flow in order to spread the heat and evacuate it to the ambient. The work presented in this paper is considered as a first step to design and realize a liquid metal heat spreader (LMHS) for power electronics devices. In the first part of the paper, the geometry of a LMHS is described. In the second part, a fully multiphysics numerical study is presented. In order to demonstrate the advantage of the liquid metal heat spreader, a thermal performances comparison with a copper spreader (having the same external dimensions) is presented in the last part of this paper. First results show that the thermal resistance of the system could by reduced by about 40% using this new cooling solution.

Numerical and Experimental Investigations on Mini Channel Liquid Metal Coolers for Power Semiconductor Devices

The need to adopt new cooling techniques arouse because of the continuous increase in power dissipation of electronic parts and systems. Due to the low thermal conductivity of classical liquids (water, alcohols, dielectric fluid, etc.), in many cases, the standard liquid cooling techniques cannot achieve the required cooling performances. This paper deals with power semi conductor devices (IGBT, MOSFET or diodes) cooling. The major problem of those power components is that they can easily dissipate several hundreds W.cm−2 . Thus their cooling needs very high heat transfer coefficients. Therefore we introduce the use of liquid Ga alloys whose thermal conductivity (approx. 28Wm−1 K−1 ) is 40 times greater than thermal conductivity of water. In this paper a numerical modeling and an experimental study of liquid metal mini channel coolers are presented. In the experimental cooling loop the working fluid (Ga alloy) is moved via an electromagnetic pump. The values of the convection coefficient obtained by the numerical model are compared with the correlations founded in the bibliography and the experimental data.© 2010 ASME