伪半固态触变成形制备SiCp/Al电子封装材料的组织与性能

Microstructure and properties of SiCp/Al electronic packaging materials fabricated by pseudo-semi-solid thixoforming

采用伪半固态触变成形工艺制备了40%、56%和63%三种不同SiC体积分数颗粒增强Al基电子封装材料,并借助光学显微镜和扫描电镜分析了材料中Al和SiC的形态分布及其断口形貌,测定了材料的密度、致密度、热导率、热膨胀系数、抗压强度和抗弯强度.结果表明,通过伪半固态触变成形工艺可制备出的不同SiC体积分数Al基电子封装材料,其致密度高,热膨胀系数可控,材料中Al基体相互连接构成网状,SiC颗粒均匀镶嵌分布于Al基体中.随着SiC颗粒体积分数的增加,电子封装材料密度和室温下的热导率稍有增加,热膨胀系数逐渐减小,室温下的抗压强度和抗弯强度逐渐增加.SiC/Al电子封装材料的断裂方式为SiC的脆性断裂,同时伴随着Al基体的韧性断裂.

SiC particles reinforced Al matrix composites with three different SiC volume fractions of 40%, 56% and 63% for elec-tronic packaging were prepared by pseudo-semi-solid thixoforming. The Al and SiC distribution and the fractographs of the SiCp/Al electronic packaging materials were examined by optical microscopy and scanning electron microscopy. The density, relative density, thermal conductivity （ TC） , coefficient of thermal expansion （ CTE） , compressive strength and bending strength of the SiCp/Al elec-tronic packaging materials were tested. It is found that the SiCp/Al electronic packaging materials have controllable coefficients of ther-mal expansion and high relative density. The Al matrix is connected into a network, and SiC particles are uniformly distributed in the Al matrix. When the SiC volume fraction increases, the density and thermal conductivity at room temperature lightly increase, the coef-ficient of thermal expansion gradually decreases, and the compressive strength and bending strength increase. The main fracture mode of the SiC/Al electronic packaging materials is brittle fracture of SiC particles accompanied by ductile fracture of the Al matrix at the same time.