液固分离制备SiCp/Al封装壳体的组织和性能

Microstructure and properties of SiCp/Al functionally graded electronic packaging shell produced by liquid and solid separation

采用半固态触变液固分离工艺制备出底部具有高体积分数SiC(63 vol%)的Al基功能梯度电子封装壳体,借助光学显微镜和扫描电镜分析了壳体复合材料中SiC的形态分布及其断口形貌,并测定了其热物理性能和力学性能。结果表明,原始30vol%SiCp/Al复合材料在半固态触变成形中SiC颗粒和液相产生分离流动,液相从壳体中流出,SiC颗粒在壳体中聚集,其体积分数从壳体底面向四壁逐渐降低。组织和性能呈梯度变化。壳体底面具有高的热导率和低的热膨胀系数(CTE),这与芯片材料相匹配,壳体四壁具有良好的焊接性能。

The electronic packaging shell with high silicon carbide(63 vol% SiC) aluminum-base composites was produced by semi-solid thixoforming and liquid-solid separation technique.The morphology and distribution of SiC and the fracture surface were examined by optical microscopy and scanning electron microscopy,and the thermo physical and mechanical properties of the shell were also tested.The results show that there is a segregation phenomenon for 30 vol% SiCp / Al composite between the SiC particulate and the liquid phase during thixoforming,the liquid phase flows from the shell,and the SiC particles accumulate at the bottom of the shell.The volume fraction of SiC decreases gradually from the bottom to the walls.The microstructure and properties of the shell show gradient distribution.The walls of the shell have a good weldability and the bottom has a high thermal conductivity and low CTE matching with that of the chip material.