The Laser Sintering Prepared Electronic Package With Tungsten-copper Composite Material

The copper tungsten composite material is typical of the metal matrixcomposite, and also has the characteristic of the copper of the metal tungsten andthe metal: good thermal capacity, low thermal expansion coefficient, and has agood mechanical strength and the like, and for tungsten, and copper are notmutually miscible metal group, we can use the existing model to designcalculation prepared in a certain ratio to a tungsten-copper composite materialthermal conductivity, thermal expansion coefficient and density, we can knowthese important parameters in advance, thereby determine the respective metalpowderstoichiometric. Due to the above features, tungsten copper composites arewidely used in electronic packaging materials and heat sink material, and havebroad prospects for development.The tungsten powder of300mesh and300mesh copper powder as a rawmaterial, through theoretical calculation, design a good ratio of each componentof the powder, the portion of the powder to do electroless plating treatment, usingthe preset powder method for laser sintering process. Cut sample of the sinteredsamples, testing the density, thermal conductivity and thermal expansioncoefficient, compared to each other, and its theoretical value, combining withsoftware simulation, and analyze the causes.The results show that:（1） Crossing the liquid reaction, the best temperature value is:68-70℃.（2） Chemical the plating reaction best PH value should be stable between11-13.（3） The optimum ratio of the respective components of the plating solutionused for the electroless plating of100g tungsten powder: CuSO₄: HCHO:EDTA-2Na=1:1:2, an amount of:125ml,125ml,250ml; passivating agentbenzodizepinestriazole amount of ethanol solution of40-50ml.（4） For the purpose of both300tungsten powder, copper powder compositepowder the best laser sintering process parameters: power:2200²400W;scanning speed:20mm/s; handmade shop powder thickness:1mm; spot:4mm.（5） Tungsten copper density of the process parameters of laser sinteredtungsten-copper composite prepared lower than by powder metallurgy compared toelectronic packaging materials. （6） The electronic package of the laser sintering with copper tungstencomposite materials its cause the density, thermal conductivity and thermalexpansion coefficient lower than the theoretical value, and the higher the coppercontent of the composite powder with the theoretical value, the difference ismore.（7） The same ratio of tungsten-copper composite laser sintering block afterelectroless plating process, the density, Thermal conductivity and thermalexpansion coefficient than not doing electroless plating treatment of the powder ishigh.（8） The temperature of the laser sintering field was a dynamic distribution,but also presents the oval laser sintering is a rapid thermal quench process, sothere will be a large temperature gradient sintered layer.（9） In the laser sintering process energy will continue to accumulate,resulting in the follow-up powder layer temperature rising.（10）1mm thick layer of powder is theoretically can burn through, for thepowder burn impervious chapter tungsten-copper composite powder sintered partof the region, is caused because manual dusting uneven.