Pressureless Infiltration Prepare For SiC/Al Electronic Packaging Materials

Since the21st century, with the rapid development of integrated circuit(IC), electronic packaging technology is also developing direct the miniaturization, high performance, high reliability and low cost, which put forward higher request for the performance of electronic packaging materials. Ceramic reinforced metal matrix composites combined the excellent performance of metal material and ceramic phase, which possess high thermal conductivity (TC) and low coefficient of thermal expansion (CTE). Silicon carbide(SiC) reinforced aluminum(Al) matrix composites is one of the most potential electronic packaging material because of its high TC, low CTE, high bending strength and low density. But present preparation process for SiC reinforced Al matrix composites is complex, the used equipment cost is very high, which highly restrict SiC reinforced Al matrix composites widespread application in production process. Because its simple preparation process and low production cost, pressureless infiltration is the most popular preparation method in SiC reinforced Al matrix composites preparation.In this paper, the method of pressureless infiltration is used to prepare bimodel and trimodel SiC particles reinforced Al matrix composites. Through analysis microstructure, phase composition, interfacial condition, TC, CTE, bending strength and fracture morphology of SiC particles reinforced Al matrix composites, prepared the most outstanding performance of SiC reinforced Al matrix composite materialsThe size of bimodel SiC used the experiment are150μm and15μm, The experimental results show that ceramic preforms of SiC volume fraction all above65%. Microstructure observation of different particles weight ratio of bimodel SiC/Al composites show that SiC particles uniformly distribute in Al matrix, the density of composites are very high and no obvious pore can be found. X-ray diffraction(XRD) analysis and interface line scanning analysis results indicate that interface reaction happened in interface and formed interfacial products MgAl2O4phase, MgAl2O4can improve the wettability of interface, thus promote the pressureless infiltration smoothly. The range of bimodel SiC/Al composites CTE is (7.48～9.54)×10-6K-1, TC is (135～147)W/mK and bending strength is (265～335) MPa, especially, we can get the best comprehensive properties when the particles mass ratio is3:2, the TC of SiC/Al composites can reach147W/mK, as well as the CTE reduce to8.35×10-6K-1and its bending strength in exceed of335MPa.The size of trimodel SiC used the experiment are150μm,20μm and15μm, microstructure uniformity and density of trimodel SiC/Al composites are worse than bimodel SiC/Al composites’, especially when the particles mass ratio is6:2:2, there are many pores found in composites. XRD analysis and interface line scanning analysis results indicate that In addition to MgAl2O4phase, interfacial products also find the existence of MgO phase compare with bimodel SiC/Al composites. Though microstructure uniformity and density of trimodel SiC/Al composites are worse than bimodel SiC/Al composites’, the TC and bending strength of trimodel SiC/Al composites are better than bimodel SiC/Al composites, we can get the best comprehensive properties when the particles mass ratio is8:1:1, the TC of SiC/Al composites can reach154W/mK, as well as the CTE reduce to8.90×10-6K-1and its bending strength can reach337MPa. Studies show that when SiC mass ratio is8:1:1sintered at1100℃for1h, and pressureless infiltrated at1100℃for2h, the final SiC/Al composite can get the best comprehensive properties, the TC of SiC/Al composites can reach159W/mK, as well as the CTE reduce to8.07×10-6K-1and its bending strength can reach307MPa.