纳米多孔表面高热流密度下传热特性研究

发布时间：2018-11-20 07:00

【摘要】：随着微电子技术的高速发展,电子元器件的主频和集成度越来越高,导致单位面积上电子元件的功耗和产热量急剧增加。这些热量如果不能及时散失,会导致器件温度逐渐升高,从而影响其运行性能和使用寿命。因此,电子元器件热障问题已成为当前制约高集成度电子元器件技术发展的瓶颈之一。传统的风冷等散热方式已经无法满足高热流密度下微电子元器件散热要求,本课题以强化相变传热为研究内容,通过微加工和阳极氧化技术,制备出了不同结构尺寸的微槽群和纳米多孔传热表面,并对各类表面进行了传热特性研究。研究结果表明:在不同阳极氧化工艺条件下,纳米多孔表面的形貌会有所不同,进而会对其传热性能产生影响。在本文中,以草酸为电解液,控制温度在10oC电压40V时,可以成功制备出孔径约80nm且呈阵列分布的纳米多孔薄膜;而以磷酸为电解液,温度控制在10oC电压85V时,其纳米孔直径增大到200nm左右,且孔与孔之间存在融合交联。纳米孔的存在一方面可以作为汽化核心,另一方面增大了传热面积。纳米多孔表面的传热实验表明,纳米孔表面沸腾时汽泡脱离传热表面直径小、频率高,从而具有较高的传热系数,特别是在高热流密度下,强化传热效果更加明显。与微槽群表面相比,在热流密度相对较低时,传热系数小;随着热流密度增加,传热系数迅速增加。为此本文提出微纳米复合型结构表面以提高临界热流密度。实验结果表明,微纳米复合型结构表面传热效果强于纳米多孔表面以及微槽群表面。在相同实验条件下,传热系数是光滑表面的2倍。
[Abstract]:With the rapid development of microelectronic technology, the main frequency and integration of electronic components are becoming higher and higher, which leads to a sharp increase in power consumption and heat production of electronic components per unit area. If these heat can not be lost in time, the device temperature will rise gradually, which will affect its performance and service life. Therefore, the thermal barrier of electronic components has become one of the bottlenecks restricting the development of high integrated electronic components. The traditional cooling methods, such as air cooling, can no longer meet the requirements of heat dissipation of microelectronic components under high heat flux. In this paper, the enhancement of phase change heat transfer is considered as the research content, and the technology of micro-fabrication and anodic oxidation is adopted. Microgrooves and nano-porous heat transfer surfaces with different sizes were prepared and the heat transfer characteristics of various surfaces were studied. The results show that the morphology of nano-porous surface will be different under different anodizing conditions, which will affect the heat transfer performance of nano-porous surface. In this paper, with oxalic acid as electrolyte and controlling temperature at 40V 10oC voltage, nano-porous films with about 80nm pore size and array distribution can be successfully prepared. With phosphoric acid as electrolyte, the diameter of nano-pore increases to about 200nm when the temperature is controlled at 85V of 10oC, and there is fusion crosslinking between pore and pore. The existence of nano-pores can be used as the core of vaporization on the one hand, and increase the heat transfer area on the other. The experimental results of heat transfer on nano-porous surface show that the bubble with small diameter and high frequency has higher heat transfer coefficient, especially at high heat flux, the enhancement effect of heat transfer is more obvious. Compared with the surface of the microgroove group, the heat transfer coefficient is smaller when the heat flux is relatively low, and the heat transfer coefficient increases rapidly with the increase of the heat flux. In order to improve the critical heat flux, the surface of micro-nano composite structure is proposed in this paper. The experimental results show that the surface heat transfer effect of micro / nano composite structure is better than that of nano porous surface and micro groove group surface. Under the same experimental conditions, the heat transfer coefficient is twice that of the smooth surface.
【学位授予单位】：河北工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TK124

【相似文献】