Hybrid Genetic Optimization for IC Chips Thermal Control

Dr. Mathew V. K. holds a Ph.D. degree in Thermal Management Systems from Vellore Institute of Technology, Vellore, India; M.Tech in Heat Power from the University of Pune, India. He is working in the field of heat transfer enhancement using active and passive cooling. His research interest includes Active and passive safety, Crash energy management, Battery thermal management system, Computational fluid dynamics, Heat transfer, Numerical methods, Optimization using different algorithms (Genetic algorithm, Artificial neural network), and proficient in Experimental techniques.Dr. Tapano Kumar Hotta is currently working as an Associate Professor in the School of Mechanical Engineering, VIT Vellore, India. He has a Ph.D. degree in Mechanical Engineering from IIT Madras in the area of Electronic cooling. His area of research in a broad sense includes; Active and passive cooling of electronic devices, Heat transfer enhancement, Optimization of thermal systems, Thermal comfort modeling, etc. Dr. Hotta has about 13 years of teaching cum research experience and has around 40 publications to his credit in journals and conferences of international repute. He has guided more than 30 undergraduates, a dozen of postgraduates, and 2 doctorate students for their project work. He has also published 2 patents. He is a member of the editorial board and reviewer for various international journals and conferences related to heat transfer.

• ACKNOWLEDGEMENTNOMENCLATUREABBREVIATIONSCHAPTER 1INTRODUCTION1.1 Need for electronic cooling1.2 Printed circuit board (PCB) and Integrated circuit (IC) chips 1.3 Various cooling techniques1.3.1 Air cooling1.3.2 Phase change material based cooling 1.4 Optimization in heat transfer CHAPTER 2STATE OF THE ART STUDIES IN ELECTRONIC COOLING2.1 Introduction2.2 Studies pertaining to cooling of discrete IC chips2.2.1 Studies relevant to Natural convection2.2.2 Studies relevant to forced and mixed convection cooling of discrete IC chips2.2.3 Studies pertaining to the phase change material (PCM) based cooling of discrete IC chips 2.3 Summary of the literature survey2.4 Scope for development 2.5 Different parameters considered for the studyCHAPTER 3EXPERIMENTAL FACILITY3.1 Introduction3.2 Selection of the IC chips and the SMPS board3.3 Design of the IC chip and SMPS Board3.3.1 Design of IC Chips3.3.2 Design of the SMPS (Substrate) board3.3.2.1 Substrate board design to carry out the laminar forced convection experiments3.3.2.2 Substrate board design to carry out the experiments using the PCM filled mini-channels 3.4 Experimental setup and Instrumentation3.4.1 Instruments used for the experimental analysis3.4.1.1 DC power source3.4.1.2 Hot wire anemometer 3.4.1.3 Temperature data-logger 3.4.1.4 Digital multimeter 3.4.1.5 Kapton tape3.5 Experimental methodology3.5.1 Procedure for conducting laminar forced convection steady-state experiments3.5.2 Procedure for conducting transient experiments on the PCM filled mini-channels under the natural convection3.6 Experimental calculations3.6.1 Experimental calculations under laminar forced convection heat transfer mode3.6.2 Experimental calculations for the PCM filled mini-channels under the natural convection heat transfer mode3.7 Error analysisCHAPTER 4HYBRID OPTIMIZATION STRATEGY FOR THE ARRANGEMENT OF IC CHIPS UNDER THE MIXED CONVECTION4.1 Introduction4.2 Non-dimensional geometrics distance parameter (λ) 4.3 Numerical framework4.3.1 Governing equations4.3.2 Boundary conditions4.3.3 Grid independence study4.4 Results and discussion4.4.1 Maximum temperature excess variation of different configurations with λ4.4.2 Temperature variation for the IC chips of the lower (λ = 0.25103) and the upper extreme (λ = 1.87025) configurations4.4.3 Empirical correlation4.5 Hybrid optimization strategy4.5.1 Artificial neural network (ANN) 4.5.2 Genetic algorithm (GA) 4.5.3 Combination of ANN and GA4.6 ConclusionsCHAPTER 5HYBRID OPTIMIZATION STRATEGY TO STUDY THE SUBSTRATE BOARD ORIENTATION EFFECT FOR THE COOLING OF THE IC CHIPS UNDER FORCED CONVECTION5.1 Introduction.5.2 Different IC chips combinations considered for the experimentation5.3 Results and discussion5.3.1 Temperature variation of the IC chips for different substrate board orientations5.3.2 Temperature variation of IC chips for different air velocities5.3.3 Maximum temperature variation of the configurations for different substrate board orientations 5.3.4 Variation of maximum heat transfer coefficient of the configurations for different substrate board orientations5.4 Empirical Correlation5.4.1 Correlation for θ in terms of λ5.4.2 Correlation for θi in terms of the IC chip positions on the substrate board (Z), non-dimensional board orientation (φ) and IC chip sizes (S) 5.4.3 Correlation for Nusselt number of the IC chips in terms of fluid Reynolds number and IC chip’s size 5.5 Hybrid optimization strategy to identify the optimal board orientation and optimal configuration of the IC chips5.5.1 Artificial Neural Network5.5.2 Genetic algorithm5.5.3 Combination of ANN and GA5.6 Numerical investigation for the cooling of the seven asymmetric IC chips under the laminar forced convection5.6.1 Computational model with governing equations5.6.2 Boundary conditions5.6.3 Mesh independence study5.7 Numerical analysis for the IC chip’s temperature under the different substrate board orientations 5.8 ConclusionsCHAPTER 6NUMERICAL AND EXPERIMENTAL INVESTIGATIONS OF PARAFFIN WAX-BASED MINI-CHANNELS FOR THE COOLING OF IC CHIPS. 6.1 Introduction6.2 Experiment set-up6.3 Results and discussion6.3.1 Temperature variation of IC chips without PCM based mini-channels (WPMC) 6.3.2 Temperature variation of IC chips for case 1 with and without the PCM based mini-channels 6.3.3 Temperature variation of IC chips for case 4 with and without the PCM based mini-channels 6.3.4 Temperature variation of IC chips for all cases with PCM based mini-channels (PMC) 6.3.5 Convective heat transfer coefficient variation for all cases with PCM based mini- channels (PMC)6.3.6 Correlation6.4 Numerical simulation of PCM based mini-channels under natural convection6.5 ConclusionsCHAPTER 7CONCLUSIONS AND SCOPE FOR FUTURE WORK7.1 Introduction7.2 Major conclusions of the present study7.3 Scope for future workREFERENCESAppendix AMATLAB programme for generating all the possible configurations for the arrangement of 7 non-identical rectangular IC chips on a substrate board. Appendix BCalculation of Mixed convection considered for numerical studyAppendix CSample calculation for non-dimensional temperature (θ) and Fourier number (Fo) Index