For the purpose of electronic packaging applications, a homogenous and void free 4032Al (Al-12wt.%Si) matrix composite with 70vol.% SiC particles was fabricated by squeeze casting technology. TEM observations indicated that SiC particles acted as heterogeneous nucleation sites for Si phases in the matrix and the SiC-Al interfaces were clean and free from any interfacial reaction products. The composite possessed lower coefficients of thermal expansion (CTEs) and excellent thermal conduction properties, and the CTEs could be ftuther reduced by annealing treatment because of the alteration of original thermal residual stresses within the specimens. The incorporation of high volume fraction of SiC particles also induced enhanced mechanical properties for the composite, and its moduli even exceeded 200GPa. Some diodes were finally produced with nickel plated SiCp/Al baseplates and the results of thermal cycling tests between -55 degrees C and 150 degrees C for these diodes were presented.