放电等离子烧结法和热压法制备的镀钛金刚石/铜多层复合材料的结构和热性能

采用放电等离子烧结技术(SPS)和热压法(HP)分别制备用于电子封装领域的多层镀钛金刚石/铜复合材料获得。借助扫描电子显微镜(SEM)分析了复合材料的显微组织,同时对热导率(TC)和热膨胀系数(CTE)等热性能参数进行了分析。层状复合材料的热导率理论值参考改良的哈塞尔曼-约翰逊(HJ)模型,同时考虑TiC界面的影响计算,结果为446.66 W·(m·K)~(-1),而热膨胀系数则通过热膨胀仪测试确定。结果显示,经放电等离子烧结的试样与经热压制备的试样相比,缺陷相对较少,界面的结合对于复合材料热导率的影响十分明显。提出了一个界面影响的模型示意图,热导率随着碳化物层厚度的增加和气孔的出现而减小。由此可见,实现高热导率的条件是复合材料中的碳化物层较薄、同时没有气孔的出现。

Structure and thermal properties of layered Ti-clad diamond/Cu composites prepared by SPS and HP

Layered Ti-clad diamond/Cu composites used in electronic packaging were prepared by spark plasma sintering (SPS) and hot pressing (HP), respectively. The structure was determined by Scanning Electron Microscopy (SEM) and the thermal properties, including the thermal conductivity (TC) and the coefficient of thermal expansion (CTE) were analyzed. The theoretical TC of the layered composites (446.66 W.m_-1K_-1) was calculated by the modified Hasselman and Johnson (HJ) model considering the influence of the TiC interface and the CTE was determined by dilatometer. The results show that the sample of SPS has fewer defects than that of HP and the interfacial bonding affects the TC of the composites significantly. A schematic graph of the interface influences is proposed and the TC decreases with the increasing thickness of carbide layer and air pores. In this regard, the composites with a thin carbide layer and no air pores should be processed to achieve a high TC.