Electronics cooling

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

Copper-filled macroporous Si and cavity underneath for microchannel heat sink technology

Abstract: Thermal management in ICs becomes essential as integration density and total power consumption increase. The use of microchannels in high power density electronics cooling is a well-known technique for heat transfer. In this work we developed Cu-filled macroporous Si channels with a Cu-filled cavity underneath, which may be used as heat sinks in high power density electronics cooling. Macroporous Si is formed by electrochemical dissolution of bulk Si, while pore filling with copper is achieved by electro-deposition. Using appropriate design, the resulting composite material may be fabricated on selected areas on the silicon substrate for use as heat sink on Si. The surface area is defined by patterning. The macroporous Si structure is composed of either randomly distributed pores or pores arranged in two-dimensional (2-D) arrays, fabricated by pre-patterning the Si surface before anodization so as to form pore initiation pits. The pore size in this work was 5μm, while the porous layer and the cavity underneath had both a thickness of 40 μm. Copper deposition proceeds first by filling the micro-cavity underneath the porous layer. This is achieved by linearly increasing the applied potential during electro-deposition. After full Cu-filling of the cavity, pore filling starts from the bottom of each pore and proceeds laterally, while no nucleation takes place on pore wall. In this way, homogeneous copper wires within pores may be fabricated. The Cu/Si composite material is appropriate for forming channels with improved heat transfer within the Si wafer.

Flat Miniature Heat Pipes for Electronics Cooling: State of the Art, Experimental and Theoretical Analysis

Abstract: An experimental study is realized in order to verify the Mini Heat Pipe (MHP) concept for cooling high power dissipation electronic components and determines the potential advantages of constructing mini channels as an integrated part of a flat heat pipe. A Flat Mini Heat Pipe (FMHP) prototype including a capillary structure composed of parallel rectangular microchannels is manufactured and a filling apparatus is developed in order to charge the FMHP. The heat transfer improvement obtained by comparing the heat pipe thermal resistance to the heat conduction thermal resistance of a copper plate having the same dimensions as the tested FMHP is demonstrated for different heat input flux rates. Moreover, the heat transfer in the evaporator and condenser sections are analyzed, and heat transfer laws are proposed. In the theoretical part of this work, a detailed mathematical model of a FMHP with axial microchannels is developed in which the fluid flow is considered along with the heat and mass transfer processes during evaporation and condensation. The model is based on the equations for the mass, momentum and energy conservation, which are written for the evaporator, adiabatic, and condenser zones. The model, which permits to simulate several shapes of microchannels, can predict the maximum heat transfer capacity of FMHP, the optimal fluid mass, and the flow and thermal parameters along the FMHP. The comparison between experimental and model results shows the good ability of the numerical model to predict the axial temperature distribution along the FMHP.

Heat pumps using organometallic liquid absorbents

Abstract: A family of organometallic liquid absorbents that can have their thermophysical properties tailored for specific applications. Processes to manufacture these liquid absorbents and methods to optimize their thermodynamic properties are included. These organometallic liquid absorbents are used in compressor driven and heat driven heat pumps (50) and cryocoolers (99). With optimum thermodynamic properties, these heat pump systems are highly efficient. These liquid absorbents are not damaging to the environment, are non-toxic and non-corrosive and are applicable to environmentally clean and highly efficient heat pumps, refrigerators, air conditioners, process heating and cooling systems, electronics cooling systems, cryocoolers and gas separation processses.

Fundamental investigation of roll bond heat pipe as heat spreader plate for notebook computers

Abstract: A roll bond heat pipe (RBHP) is very promising in the cooling of electronic equipment such as notebook computers. This study presents prediction data on maximum capillary limit obtained for the RBHP with 7.8 mm wide flow channel. Further, experimental study has been conducted to show the difference between the highest and lowest temperatures on the RBHP. These data determine the optimum working fluid charge volume and number of capillary loops for the RBHP.