The volume fraction of silicon in alsi42 alloys is adjusted to obtain high-silicon aluminum alloy materials with different properties, which have low thermal expansion coefficient CTE, low density, high thermal conductivity, good electrical conductivity (with excellent EMI/RFI shielding performance), and high hardness. , Excellent thermo-mechanical stability, high density, easy machining, easy plating and protection, and compatibility with standard microelectronic assembly processes.