Study On The Properties Of CNT-based Micro-Cooler For Heat Dissipation In Electronic Packaging

The development of electronic products towards miniaturization andmultifunction leads to an increase in the power density of chip and IC. As a result,thermal management becomes an imperative problem in electronic packaging, andmaterials of good thermal properties and methods of effective heat dissipation playmore and more important roles. In the thesis, firstly a numerical investigation on of aMulti-Chip Module (MCM) is carried out to analyze the influences of naturalconvection and forced convection with fan. Secondly, numerical simulation andexperimental measurement are applied to study the properties of CNT-based micro-pin-fin cooler with an impingement jet. Furthermore, experimental study on thethermal performance of CNT-based micro-channel cooler is carried out. The thesis ispresented as follows:1) A MCM model is develop and applied to study the thermal properties of MCMwith different heat powers. The influences of radiation, natural convection and forcedconvection on heat dissipation are analyzed.2) Modeling of a CNT-based micro-pin-fin cooler with an impingement jet iscarried out for understanding the flow field and thermal performance. Factorsinvolved in the model development such as the turbulent model, the near-wall grid,the boundary conditions as well as the convergence criteria are taken intoconsideration. Parameters affecting the jet impingement are also studied numerically.3) A thermal test platform is set up, and the thermal performance of CNT-basedmicro-pin-fin cooler samples are evaluated experimentally.4) Experimental measurements of micro-channel coolers with forced convectionare also carried out, where samples made of CNT and Si are tested and compared.The main conclusions obtained are:1) For the MCM with permissible temperature80℃, the natural convection cannot meet the cooling requirements when the power is larger than5w, other methodsuch as the heat sink or fan is necessary to improve the heat transfer. The heat transferred by the radiation has a proportion of about20%in the total heat dissipationin natural convection, so it shall not be ignored in the simulation and temperatureprediction.2) On the basis of case studies on influences such as the distance from the jetnozzle to the aimed surface, the fin width, the fin array on the CNT-basedmicro-pin-fin cooler with an impingement jet, optimized parameters are obtained.3) Experiment results of the CNT-based micro-pin-fin cooler with animpingement jet at0L/min,0.5L/min,1.0L/min,1.5L/min and2L/min are obtained.The pitch of CNT fins and their array arrangement have significant effects on theradiation of heat transfer.4) According to the experimental results comparing the thermal performance ofthe CNT-based micro-channel cooler and the silicon one with the same geometry andforced convection condition, the cooling efficiency of micro-CNT channel coolerexhibits an improvement of25%.