摘要
高体积分数SiCp/Al复合材料具有优异的热物理性能,且密度较低,是非常理想的电子封装材料。但是由于其本身高的脆性和硬度,使得该材料很难通过二次机械加工成所需要的形状,严重制约了该材料的应用:采用粉末注射成形-无压熔渗工艺成功实现了高体积分数SiCp/Al复合材料的近净成形:采用该工艺所制备的复合材料的致密度高于99%,可实现热膨胀系数在(5—7)×10^-6K^-1范围内进行调节,材料的热导率高于185W/(m·K),抗弯强度高于370MPa,气密性可达10^-11Pa·m^3·s^-1,各项指标均叮以满足电子封装对材料的性能要求,另外为了实现SiCp/Al复合材料与其他材料的封接,项目成功开发了一种Al—Si—Cu系焊料,封接后器件的各项性能指标尤其是气密性也均能满足使用要求。
High volume fraction SiCp/Al composite is a perfect electronic packaging material because of its excellent thermal-physical properties and lower density. However, this material has not been widely used in the field of packaging because it is hard to be machined into complex-shape due to its greater hardness and brittleness. In this paper, the preparation of SiC preforms by ceramic injection molding (CIM) , pressureless infiltration of SiC preforms by Al alloys and some other basic questions have all been studied to found a CIM-pressure infiltration new technology, and in the end, the net-shape preparation of high volume fraction SiCp/Al composites have been successfully realized. The relative density of prepared SiCp/Al composite is high than 99% , CTE can be regulated in(5 - 7)× 10^-6 K^-1 according to actual needs, thermal conductivity is higher than 190 W/( m ·K) , bending strength is higher than 370MPa and gas impermeability value is near 10^-11Pa·m^3·s^-1. These thermal-physical and mechanical properties can better match the requirement of electronic: packaging technology on the materials. Furthermore, in order to seal SiCp / Al composites, a kind of Al - Si - Cn system solder has been successfully developed, the sealing performance of the device can also meet the requirements.
出处
《中国材料进展》
CAS
CSCD
2010年第11期39-47,共9页
Materials China
基金
国家973计划项目(2006CB605207)
国家自然科学基金项目(50774005)
关键词
铝基复合材料
SIC
成形
电子封装
Al matrix composites
SiC
forming
electronic packaging