| Insulating materials for electronic packaging with outstanding properties, such as high strength, high thermal conductivity, are becoming more and more necessary as the semiconductor industry is being developed at an accelerating pace. In recent years, ceramic/polymer composite materials have been extensively studied. In this work, Al2O3/epoxy composites were prepared using a new processing technique consisting of the gelcasting, sintering and vacuum infiltration methods. The following three part results were obtained:?1? At first, the process conditions of gelcasting were discussed, and the optimum process conditions for AM-MBAM system were obtained, including ball-milling time, contents of dispersant, p H value, raw materials' feed method and protection in the solidification process.?2? Alumina ceramics with complex shapes were conveniently fabricated, such as ceramic substrates and relay shell, by using the optimum process conditions of gelcasting.?3? The Al2O3/epoxy composites exhibited very high flexural strength and thermal conductivity because the Al2O3 and epoxy phases exist as two interpenetrating networks. After being degreased at 600 °C, the green bodies were sintered at different temperatures from 1200 °C to 1500 °C, and porous Al2O3 ceramic skeletons with different porosity were resulted. Higher sintering temperature resulted in lower porosity and larger average grain size in the Al2O3 ceramic skeletons. Epoxy was vacuum infiltrated into the sintered porous Al2O3 ceramic skeletons to form Al2O3/epoxy composites by curing. High Al2O3 loadings up to 70 vol.% in the composites were achieved. The flexural strength and thermal conductivity of the Al2O3/epoxy composites were found to reach 305 MPa and 13.46 W·m-1K-1, respectively. These results are remarkably higher than those previously reported in the literature.This work provides an effective approach for fabricating high performance ceramic/polymer composites for electronic packaging. |
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