基于温敏型水凝胶的高热流密度芯片用自适应散热仿生微流道热质快速输运特性及机理研究

With the rapid development of nano-electronics and integrated technology, the heat heat flux of the electronic chip becomes higher and higher and the distribution of heating power of electronic chips is becoming uneven and localization. However, the traditional cooling system cannot meet its cooling needs, resulting in frequent thermal failure problems of the chip. In order to solve the local hotspots of high heat flux electronic chip, three kinds of bionic tree micro-channels are proposed based on the bionic principle. The influence of fractal parameters on pressure drop and temperature distribution is studied. The micro-channel with superior performance is obtained by optimizing the structural parameters. Then, the response to local hotpots and adaptive flow regulation mechanisms of Y-type basic micro-channel unit with temperature-sensitive hydrogel are explored. The key parameters of microfluidics flow and heat transfer enhancement are obtained. Next, the self-adaptive heat and mass transfer mechanism and the strengthening mechanism of the local hotspots with embedding temperature-sensitive hydrogel in bionic tree micro-channels are investigated. The influence of the location of hydrogel (series, inter-stage position) and local hotspot distribution on the self-adaptive response of bionic tree micro-channels is explored to achieve high efficiency coupling of bionic tree micro-channels and temperature-sensitive hydrogel for higher heat and mass transfer. This study can provide a new technology and enhanced method for the self-adaptive cooling of local hotpots on the electronic chip with high heat flux .

纳米电子及集成技术的飞速发展使电子芯片热流密度日益增高，功率分布趋于多热源、局域化，传统冷却方式已无法满足其散热需求，导致芯片的热失效问题频发。针对高热流密度电子芯片局部热点的散热问题，项目基于仿生原理建立了3种仿生树形微流道，对比研究分形参数对流动压降和温度分布的影响规律，优化结构参数，获得性能优越的仿生微流道结构；阐明Y型基本微流道单元嵌入温敏型水凝胶后对局部热点温度变化的响应和自适应流量分配机制，考察水凝胶的形状尺寸和嵌入位置对局部热点自适应响应特性的影响规律，获得影响微流道流动和传热强化的关键参数；揭示仿生树形微流道内嵌入温敏型水凝胶后对局部热点的自适应热质传输及强化机制，考察水凝胶嵌入位置（级数，级间位置）和局部热点分布方式对仿生树形微流道局部热点自适应响应特性的影响规律，实现仿生树形微流道和温敏型水凝胶热质传输的高效耦合，为高热流密度芯片自适应散热提供一种新技术和强化方法。

随着微电子芯片朝着高度集成化、高功率和三维堆叠化方向飞速发展，热流密度显著增大，热点问题频发，电子元器件面临的散热问题日趋严峻，传统冷却方式已无法满足散热要求，亟需发展芯片级冷却技术以满足平均热流密度100 W/cm2和局部热点热流密度1000 W/cm2的热管理要求。微流道冷却技术具有传热系数高、微型化和集成化的优点，被誉为微电子元器件最具前景的热管理方法之一。项目受自然界中植物分形网络的启发，将仿生分形网络应用到微流道热沉中，利用遗传算法对仿生微流道热沉进行构形优化。并在仿生分形微流道散热技术的基础上，结合热缩型水凝胶，利用其温度响应特性感知热点的温度变化并利用其热缩变形特性实现分形微流道内的流量的自适应调控和热点的自适应冷却，缓解局部热点，避免局部热失效问题。揭示了温敏型水凝胶的嵌入位置和雷诺数对仿生微流道内温度分布、速度分布、流动压降和局部热点自适应响应特性的影响规律及机制。探究了微针肋结构、阵列分布方式与热源分布对针肋微流道内单相流动压降、传热系数和壁面温度均匀性的影响，揭示流动扰动对传热的强化机制。提出新型梯级分布针肋-突扩旁路混合微流道，对比分析均匀针肋微流道和梯级分布针肋-突扩旁路混合微流道内流动沸腾传热特性，揭示两种针肋微流道内沸腾流型特征与传热机理，阐明梯级分布针肋-突扩旁路对流动沸腾不稳定性的抑制作用。项目实现了分形微流道和温敏型水凝胶对热点自适应冷却的高效耦合，进一步探索了提升芯片表面温度均匀性和微流道内流动沸腾稳定性的方法，揭示了微尺度下传热强化机理。项目研究成果为实现微流道散热系统对高热流密度芯片局部热点的快速响应和自适应散热的要求奠定了坚实的理论基础，为芯片级微流道冷却和微尺度下热质传输优化提供理论指导，为高热流密度芯片自适应散热提供了一种新技术和强化方法。