Fabrication And Properties Of β-SiCp/Al Electronic Packaging Material By Pressureless Infiltration

With excellent high quality of high thermal conductivity, low expansion, high module, high chemical stability and low density,β-SiCP/Al composite enjoys great potential of application in the realm of electronic packaging. Pressureless infiltration processing is uaually used in producing particle with high volume fraction reinforced metal matrix composites since this technology has the advantage of low cost, simple practice and great availability of industrialization. In this paper, SiC particle with high volume fraction Electronic packaging meterails is produced by bimodal distribution in normal air pressure.Main contents and conclusion are followed: single grains of 50μm,5μm and double grain made by the two single grains above are employed in the experiment, and which are cold pressed to get the prefabricated parts. The volume ratio can be measured by boiling and the conclusion can be drawn that the double grain can effectively enhence the volume fraction ofβ-SiCP/Al. Under 30Mp, the volume ratio of SiC prefabricated parts with different grain ratios are tested, it is shown in the test that SiC volume ratio increases at the beginning and decreases then with the increase of the content of coarse SiC particles, and SiC volume ratio can reach maxium of 72% at the 3:1 of the mass of coarse grains and fine grains, and the volume fraction of theβ-SiCP/Al electronic packaging will be fluctuating at the range 51%⁷2%.The pretreatment on SiC surface(high–temperature oxidization and surface proofing), adding Mg with different mass fraction as reactive addition in alloy, adding some reagents with different mass fraction in prefabricated parts are used in the study to explore these methods'effects on the wetting and infiltrating of Al and SiC. It is shown in the experiment that wetting can be strenghtened by high–temperature oxidization and surface proofing of sillicasol, and the increase of Mg can increase the speed of infiltrating and shorten the incubation period. The optimal value of Mg content is 6.3%, and 15% some reagents can improve the effect of pervasion.By the SEM and X-ray diffraction analysis, the interface element concentration and response are studied, and the conclusion is that Mg,Si,N are the main elements in theβ-SiCp/Al electronic packaging materials; the interface response are mainly under the control of response time, response temperature and Mg in the alloy.The coefficient of thermal expansion of composite has been tested . The results show that theβ-SiCp/Al electronic packaging materials with 66% SiC volume ratio has lower coefficiency of thermal expansion than thoseÉ‘-SiCp/Al electronic packaging materials; the CTE under 30℃¹50℃is 3.25×10-6·K^-1, and the CTE under 30℃⁵00℃is 6.11×10-6·K^-1。The coefficient of thermal expnasion ofβ-SiCP/Al electronic packaging materials will decrease with the increase of the size of grain;The coefficient of thermal expnasion of single particleβ-SiCP/Al will decrease accompanied with the decrease of the size of grain;The thermal conductivity ofβ-SiCp/Al electronic packaging materials will decrease accompanied with the decrease of the size of grain.To sum up,β-SiCP/Al composite with 50μm and 5μm spherical SiC particles and the matrix with 6.3% Mg enjoy perfect comprehensive thermal and physical properties: its coefficient of thermal expansion is 6.11×10-6·K^-1 under 30～500℃; the thermal conductivity is 154.2 W·m^-1·K^-1 under 100℃. Obviously, it can reach the demand of the packaging of high-power electronic apparatus of latest generation.