β-SiC(w+p)/Cu电子封装混杂复合材料界面调控及其对热传导影响机理的研究

So far, the low heat dispersion of packaging materials has caused failure of electron products, which restricts the development of electron packaging industry. Metal matrix composites, as main part of electron packaging materials, exhibited low thermal conductivity due to weak interface bonding, which deteriorated other properties.. The β -SiC whiskers and particles in proper sizes and Cu powder will be chosen as test materials in the project. A new idea to increase the thermal conductivity .of the composites by formation of strong bonding interface between SiC and Cu was proposed, which will made through ion impantation and magnetic sputtering technique on SiC dopped Cu ions and powder. . The diffusion mechanism of Cu ions in the SiC powder will be stated, and the formation of Cu film on the SiC powder will be explained and moulded by adjusting technology parameters of the ion implantation and sputtering , the microstructures and crystallography will be investigated during annealing treatment, The optimal bonding mechanism and characteristics of interface between SiC and Cu will be given by control the technology specifications of annealing and sintering , the sintering and densification mechanisms of the composites will be discussed, both the microstructures and the influences of the interface on thermal conductivity will be investigated in detail,the relationships among the thermal conductivity and components and interface will be established, and the control mechanism of interface between SiC and Cu and optimal regulation of thermal conductivity of β-SiC(w+p)/Cu electron packaging hybrid composites will be proposed.. The implementation and achievement of the project mentioned above will provide new point for the electron packaging materials.

目前，封装材料散热性致使电子产品失效的问题十分严重，制约了电子行业发展。作为电子封装材料主要组成的金属基复合材料虽得到了一定程度的应用，由于界面问题没有得到根本的解决，使其难以发挥更大的作用。.本课题选择导热性优于α-SiC的β-SiC增强体（颗粒和晶须）和铜粉为对象，提出利用等离子表面改性技术调控β-SiC增强体和铜间的界面结构，以达到进一步提高β-SiC(w+p)/Cu电子封装混杂复合材料热导率的新思路。.通过研究增强体注入层和铜膜随离子注入、磁控溅射和退火工艺的变化规律，研究铜在增强体中分布、扩散及铜膜形成机理，阐明增强体和铜间界面结构，揭示复合材料烧结和致密化机理，建立β-SiC增强体、界面和复合材料导热性间的内在关系，提出β-SiC(w+p)/Cu电子封装混杂复合材料界面调控机制和导热性的优化准则。.上述工作的开展及取得的结果将为电子封装材料的研制提供新的思考途径和理论基础。

采用自主设计和制造的翼鼓实验装置实现了微米β-SiC颗粒表面铜离子注入；利用国家纳米技术与工程研究院溅射仪在微米β-SiC颗粒(β-SiCp)表面沉积了铜膜；利用化学镀在纳米β-SiC颗粒(β-SiCn)和晶须(β-SiCw)上进行镀铜。将经过改性处理后、不同种类和体积分数（β-SiC）-Cu复合粉与铜粉混合后进行低温热压烧结，研制出含β-SiC (45-55) vol %的β-SiC（p+n）/Cu和β-SiC（p+w）/Cu可用于电子封装的复合材料。.系统地阐述了离子注入和磁控溅射对β-SiC微米颗粒铜膜质量和性能的影响规律；对β-SiC/Cu电子封装混杂复合材料的微观组织结构和界面状态进行了深入系统地分析；采用国家标准对β-SiC/Cu电子封装复合材料力学性能和热物性进行了评价。.研究发现：铜离子能够被注入β-SiCp颗粒内部，铜元素在β-SiCp颗粒中呈“正态”分布。经过离子注入后β-SiCp颗粒中出现了大量点缺陷和“半键”，这提高了其表面张力。同时，经过溅射后β-SiC颗粒形成一层均匀完整铜膜，该铜膜对颗粒具有较高结合力。这两者改善了烧结中β-SiC颗粒与铜粉间润湿性和界面结合状态，且前者作用优于后者。.结果表明，在β-SiCvol45%/Cu复合材料基础上再添加少量（～5%）β-SiCn和β-SiCw将明显提高β-SiC/Cu电子封装复合材料致密度，改善β-SiC与铜间界面结合状态，提高β-SiC/Cu混杂电子封装复合材料力学性能，改善了其热传导性能，降低其热膨胀系数，且β-SiCn的作用优于β-SiCw的作用。.通过本课题研究可以得到以下几点结果：.1. 在β-SiC微米颗粒表面上实施的离子注入和磁控溅射技术明显改善β-SiC陶瓷微粉与铜粉之间的润湿性和界面结构状态；.2.在充分发挥β-SiC微米、纳米颗粒、晶须和铜粉特性并优化组元比例的基础上，利用低温热压烧结技术研发出能够满足电子封装工程应用的β-SiC/Cu混杂复合材料；.3.提出了β-SiC/Cu混杂电子封装复合材料界面调控机制和导热性的优化准则；.4.与现有的国内同类电子封装材料相比，β-SiC/Cu混杂电子封装复合材料综合性能处于前列，但其热导率仍有提升空间。其他性能，如电磁屏蔽特性和气密性等还需要进一步研究。