Optimization of the Micro Channel Ladder Shape Heat Sink Chung-Hao Kang 1,2 , Shih-Hsiang Tai 1 , Sheng-Chung Chen 1 , David T.W. Lin 1,* 1 Institute of Mechatronic System Engineering, National University of Tainan, Tainan, Taiwan 2 New Energy Division, MAG Technology CO., LTD, Tainan, Taiwan Corresponding Author: David T.W. Lin, david@mail.nutn.edu.tw Abstract—The channel heat sink is in contact with the working fluid to remove the heat. But much channel will result higher pressure difference issue in the micro multi-channel heat sink. In this paper, a ladder shape channel (link between the parallel channel) is proposed to correct the problem of high pressure difference. The design of the link decreases the pressure difference for reducing the pump work of the micro multi- channel heat sink. The purpose of this paper is to maximize the efficiency of the micro multi-channel ladder shape heat sink by using optimization design. An optimization method based on the genetic algorithm and COMSOL 3-D conjugated thermal-fluid model is applied to establish the optimal geometry parameters of the link. The results show that this optimized heat sink design can improve the efficiency more than 43%. And the heat removal of the proposed device is significantly improved. Keywords- micro channel heat sink; ladder shape; optimization; genetic algorithm I. INTRODUCTION Enhance the heat removal capacity has been one of the important considerations in engineering design, many scholars proposed much kinds of heat sink to improve the performance of heat removal. With different electronic development trends and conditions, the traditional radiator has been inadequate. The micro channel heat sink is developed for the high heat flux electronic components on mini area, which can provide the heat conduction and convection to remove heat. The micro channel heat sink was first proposed in experimentation by Tuckerman and Pease [1]. For past few years, micro channel heat sink has been ameliorated with the advancement of semiconductor technology continuously. Kim and Mudawar [2] compared the heat diffusion effects with different aspect ratio, spacing and biot number. The results showed that the heat transfer performance can be improved by adjusting the cross sectional dimensions of the channel. Wang et al. [3] used inverse problem method to optimize the geometric design for micro channel heat sink. The optimal channel numbers and aspect ratio results of micro channel heat sink were presented in their paper. Wei and Joshi [4] used genetic algorithms to find the optimal parameters of stacked micro channel heat sink. Chen et al. [5] combined finite element method with genetic algorithm to improve the heat dissipative ability and decrease the weight of micro channel heat sink. Liu et al [6] proposed a honeycomb porous micro-flow channel electronic cooling system, Experiments to study the thermal performance of the heat sink under different heat source and the pump power, through the this specially designed fluid to perturbation and get better heat dissipation, The experimental results show that 18.2   ଶ ⁄ of heat can be removed when the pump power of 2.4W.Chen and Ding [7] investigated the effects of the inertial force for the flow on the heat transfer characteristics with nanofluids. Their study showed that the temperature distribution of the channel wall is insensitive to the inertial effect practically, while the fluid temperature distribution and total thermal resistance are varied due to the inertial force effect significantly. From the investigated for heat transfer of gas liquid mixture in micro channel heat sink, Hetsroni et al. [8] provided the crucial evidence that the micro channel are sensitive not only to inlet geometry but also the method of gas liquid injection. This proof is useful and important for future researches. In addition, Kumaraguruparan et al. [9] investigated the effects of channel configuration and fluid viscosity on flow distribution. More relevant research of characteristics for working fluids in the micro channel heat sink has been investigated in [10-17]. The advantages of the micro channel heat sink were shown in the previous studies. Most optimization designs of the micro channel heat sink focused on increasing the heat transfer performance. The high pressure difference problem of channel is thorny, especially in the modern of miniaturized electronics. The ladder shape (link between the parallel channels) is proposed to correct this problem. This study combines the finite element method with genetic algorithm to increase the efficiency of the ladder shape heat sink, which will obtain more comprehensive results for the design. II. THE MATHEMATICAL MODEL The micro channel heat sink is fabricated by the silicon wafers. Fig. 1 and Fig. 2 show the geometry diagram of model and parameters of micro channel with N silicon wafer 978-1-4673-6352-5/13/$31.00 ©2013 IEEE NEMS2013,Suzhou,China,April 7-10,2013 389