Abstract: An electronic package material,silicon-aluminum alloy （70%Si-Al） strip was developed by using spray deposition technique.The high-silicon alloy prepared has fine,isotropic microstructures with fine Si phase particles dispersing in Al matrix uniformly.Investigations show that the 70% Si-Al alloy has low constant of thermal linear expansion(7×10^-6-8×10^-6/℃) and excellent properties of heat conductivity（＞100W/m·K）.It is also shown that the alloy has good machinability.It can be readily processed by conventional carbon tools.Hot isostatic pressing（HIP） is used for compacting the as-deposited alloys.