Optimization of highly conductive insert architecture for cooling a rectangular chip ☆ A. Mazloomi a , F. Sharifi b , M.R. Salimpour b , A. Moosavi a, ⁎ a Department of Mechanical Engineering, Sharif University of Technology, PO Box 11155‐9567 Tehran, Iran b Department of Mechanical Engineering, Isfahan University of Technology, Isfahan 84156‐83111, Iran abstract article info Available online 18 June 2012 Keywords: Cooling Highly conductive Configuration Optimization Rectangular chip Conductive cooling of a rectangular chip heated from the bottom surface and connected to a heat sink is stud- ied. Different configurations of a highly conductive material embedded in the chip are investigated and an optimal configuration for transferring heat to the heat sink is achieved. Our results indicate that the optimal configuration can be obtained by using side branches, parallel with the main channel, and also increasing the thickness of the main channel. Many complex configurations are checked and it is shown that these struc- tures do not provide better performance. © 2012 Elsevier Ltd. All rights reserved. 1. Introduction A detailed understanding of the thermal failure of a specified elec- tronic component provides basis for establishing the thermal man- agement strategy including selection of the appropriate fluid, heat transfer mode, and inlet coolant temperature required to meet design specifications. Individual solid state electronic devices are inherently reliable. However, because a single microelectronic chip may include many transistors and leads, and because many tens of such compo- nents may be used in a single system, achieving failure-free operation over the useful life of a product is a formidable challenge. The reliability of a system is the probability that the system will meet the required specifications for a given period of time. Since an individual electronic component contains no moving parts, it can be used reliably for many years, especially when operating at or near room temperature. It is also quite common to attach heat sinks to the surface of a package to create additional surface area for heat removal by natural and/or forced convection. In very high power applications, it may be necessary to cool the chip directly by considering heat pipes, heat sinks, high-velocity air jets or a dielectric liquids [1]. Microchannels for electronic component cooling were first intro- duced by Tuckerman and Pease [2]. They showed that these kinds of cooling systems may be a practical solution for compact devices requiring high rates of heat removal. Since then, a myriad of investi- gations have been conducted on thermal and flow characteristics of microchannels. However, the conventional microchannels have some disadvantages. Although these facilities increase the convective heat transfer considerably but they need an additional power to operate and this increases the costs. Moreover, a non-uniform temperature distribution is obtained under constant heat flux conditions. With the introduction of constructal theory [3], the optimization approach was applied to minimize pumping power. Wang et al. [4] performed a comparison between the symmetrical and asymmetrical branching networks built into heat sinks. They considered both fluid flow and heat transfer characteristics and introduced many leaf like networks. Ghaedamini et al. [5] studied the effects of many parame- ters such as Reynolds number, and bifurcation angle on the pressure drop and flow uniformity of the dendritic configurations. Wang et al. [6] showed that grid patterns are more attractive than radial con- figurations when local junction losses are important. Xu et al. [7] in- vestigated numerically the flow and thermal performances of several tree-shaped nets without/with loops for application in cooling of electronic components. The effects of total branching level and loops on the thermal and flow performances of heat sink system were examined. They concluded that tree-shaped nets with loops provide a great advantage when the structure experiences accidental damage to one or more channel segments since the loop assures con- tinuity of coolant flow. The effects of the bifurcation angles in the constructal nets on the fluid flow and heat transfer characteristics of such networks have been investigated in Ref. [8]. The results indicat- ed that the global pressure drop increases with the increase of bifur- cation angle. Wang et al. [9] studied the conjugate fluid flow and heat transfer characteristics of fractal-like microchannel nets embedded in a disk-shape heat sink. In their work, the advantages of fractal-like microchannel nets such as low flow resistance, temperature unifor- mity, and reduced danger of blockage were compared with the tradi- tional parallel channel nets. Wang et al. [10] investigated the effect of combining loops in radial and constructal microchannel networks. The conjugated fluid flow and heat transfer through tree-shaped branching microchannel nets on a square chip were investigated nu- merically and compared with straight and serpentine networks in Ref. [11]. It was shown that such tree-shaped geometries can have many advantages such as more uniform temperature distribution and reduced risk for accidental blockage of channel segments. Alharbi International Communications in Heat and Mass Transfer 39 (2012) 1265–1271 ☆ Communicated by W.J. Minkowycz. ⁎ Corresponding author. E-mail address: Moosavi@sharif.edu (A. Moosavi). 0735-1933/$ – see front matter © 2012 Elsevier Ltd. All rights reserved. doi:10.1016/j.icheatmasstransfer.2012.06.010 Contents lists available at SciVerse ScienceDirect International Communications in Heat and Mass Transfer journal homepage: www.elsevier.com/locate/ichmt