活性金属在非均质Diamond/Cu复合材料表面润湿机理研究

Diamond/Cu composite possess excellent thermophysical properties, which makes it a valuable packaging material. In view of the problems of its heterogeneous surface has poor wettability with the brazing metal, this project aims to improve the wettability of brazing filler/composites system and illustrate the mechanism of reactive metal spreading on heterogeneous surfaces. Firstly, the danymic wetting process and mass transfer mechanism is investigated, and the velocity and concentration fields of active element during spreading are accurately characterized through numerical simulation. Based on the results, the reaction rate of the interface reaction and Gibbs free energy change can be calculated, and then the model of quantitative prediction wettability between reactive metal and ceramic can be established. Secondly, combined with analysis and calculation on the basis of molecular kinetic theory, the wetting kinetics of reactive metal at high temperature can be verified. Finally, by researching the wetting behavior on heterogeneous surfaces with different proportion of constitution, the mechanism of reactive metal spreading on heterogeneous surfaces can be established. This project is expected to overcome the problem of existing wetting theory could not predict the wettability of reactive metal/ceramic system precisely, and can enrich and expand high temperature wetting theory. Besides, the research results can provide theoretical guidance for improving the wettability of diamond/Cu composites and active brazing filler, and exert positive effect on the establishment of theoretical and technological foundation for the application of diamond/Cu and other high thermal conductivity composites in microelectronic packaging field.

Diamond/Cu复合材料具有优异的热物理性能，是一种极具潜力的电子封装材料。本项目针对钎焊过程中复合材料的非均质表面与钎料润湿性差的问题，以改善钎料/复合材料润湿性和探明活性金属在非均质表面润湿机理为目标。首先研究润湿动态过程和传质规律，通过数值模拟精确表征活性元素在润湿过程中的浓度场和速度场，达到定量计算金属/陶瓷界面反应速率和吉布斯自由能变化的目的，从而建立定量预测金属/陶瓷润湿性能的理论模型；其次通过分子运动理论分析计算，揭示高温下活性金属的润湿动力学机理；最后研究在不同物质比例的非均质表面的润湿行为，建立活性金属在非均质表面的润湿理论模型。本项目的开展有望突破现有润湿理论无法定量预测金属与陶瓷润湿性能的难点，丰富和拓展高温润湿理论，同时可为改善活性钎料与Diamond/Cu复合材料的润湿性提供指导，为推动Diamond/Cu及其它高导热材料在封装领域的应用奠定理论和技术基础。

金刚石/铜复合材料具有优异的热物理性能使其成为一种极具潜力的电子封装材料。但由于其表面含有金刚石和铜两种物质，使其与钎料的润湿性较差，本研究针对该问题，首先系统研究了高温非反应润湿体系、溶解型润湿体系及高温反应性润湿体系的润湿热力学和动力学，其次，研究了表面粗糙度对上述三类高温润湿体系的影响机理，最后，通过研究活性金属在非均值金刚石/铜表面的润湿行为，建立了活性钎料在金刚石/铜非均值表面的润湿模型。本项目的开展有望突破现有润湿理论无法定量预测金属与陶瓷润湿性能的难点，丰富和拓展高温润湿理论，同时可为改善活性钎料与Diamond/Cu复合材料的润湿性提供指导，为推动Diamond/Cu及其它高导热材料在封装领域的应用奠定理论和技术基础。