大功率LED微通道超疏水表面微铣削创成机理及控制策略

High power LED chip has the defects of large cooling system, low heat dissipation efficiency and other technical problems. This project researches the slip properties for liquid on superhydrophobic surfaces; explores the flow and heat transfer mechanism for liquid on micro-nano structure (micro mastoid with characteristic scale is 10μm and nano wax crystals with characteristic scale is 50-100nm) and reveals the drag and heat radiation mechanism for micro-nano structure superhydrophobic surface. Mapping model of structure and property for micro-nano structure surfaces is established. Surface structure design methods and micro milling technology are also proposed in this project. Obtained micro-nano structure micro channel can meet the needs of high power LED chip cooling requirements..By building circulation sample stage system, the test method for micro channel fluid dynamics and thermal performance parameters are proposed. The evaluation methods based on the drag and heat radiation mechanism for superhydrophobic surface contact angle are also established. The research result can help to guide the innovative design for micro structure surface, and provide the technical basis for processing of micro-nano structure superhydrophobic surface.

针对大功率LED芯片散热体系大、散热效率低等技术难题，开展液体在超疏水表面上的滑移特性研究，探索液体在微纳双结构（特征尺度在10μm左右的微米乳突和直径为50-100nm的纳米蜡质晶体）超疏水表面上的流动传热机制，揭示微纳双结构超疏水表面的减阻散热机理；建立微纳双结构表面结构-性能映射模型，提出微纳双结构微通道超疏水表面结构设计方法及其微铣削加工技术，获得微纳双结构的微通道，满足大功率LED芯片散热需求；搭建循环样品台系统，提出微纳双结构微通道流体动力学和热性能参数测试方法，建立基于超疏水表面接触角的微纳双结构微通道减阻散热性能评价方法。研究成果有助于指导微结构表面的创新设计，并为微纳双结构超疏水表面的加工提供技术基础。

在国家自然科学青年基金项目“大功率LED微通道超疏水表面微铣削创成机理及控制策略”（项目编号：51505255）的资助下，为提高大功率LED芯片散热效率，开展了高速微细切削加工超疏水表面机理研究。 建立了二维情况下基于最小吉布斯自由能的接触角预测模型，并且考虑斜壁对气-液接触线的影响对预测模型进行了修正。分析了水滴在沟槽、 方柱阵列、斜壁沟槽和斜壁阵列四种微结构表面的测量接触角与计算接触角的差异以及变化规律。揭示了不同几何参数尺寸、斜壁角度、直壁和斜壁微结构对接触角的影响规律。撷取了水滴滞后过程中关键性的五个状态(初始态、预前进态、前进态、预后退态、后退态)作为研究对象，用瞬时静态研究水滴的动态过程。考虑微铣刀刃口圆弧半径，齿数及螺旋角建立刀具参与切削实际几何形状，探讨对已加工表面粗糙度的扫琼机理。最后，对微铣削加工过获得的超疏水表面性能进行了检测。