A Study Of Tungsten-Copper Composites Materials With Low CTE And High TC Used For Electronic Packaging

With the development of integrate circuit(IC)in direction of minitype,high performance and low cost,more advanced performance of high thermal conductivity,high density,high rigidity and low lost has been demand in electronic seal and thermal materials matching of IC. For the ttmgsten-copper metallic matrix composites(MMC)having high thermal conductivity and low coefficient of thermal expansion,this investigation aims at with discussion of grain size composition,preparing technology and process parameters optimization to prepare the electronic seal and thermal materials meet to commercial process and performance demand.Nanometer W/Cu composites powder has been preparation by heat-electroless plating method,colloidal sols and jell method and high energy ball milling method,and then produce the W/Cu composite material of addition nanometer particle and traditional methods of infiltration by cemented copper and injection sintering method.Powder and block material has been studied by the means of SEM,XRD,TEM and Laser instrument for thermal conduction, and discussion of parameters,which can affect the proprieties and microstructure of W/Cu composites,the following main results can be obtained:1.The craft of tungsten powder coated by copper has been optimized by the orthogonal experiment,and the surface of tungsten powder has been coating by copper powder,a better craft of tungsten powder coated by Cu is:Cu₂SO₄·5H·2O 20g/L,C₄H₄O₆KNa·4H₂O 13.6g/L,EDTA·2Na 27.3g/L,HCHO 15ml/L,PH=12,temperature 60℃,and particle diameter of tungsten powder is10μm。2.The thesis investigates the W/Cu nano-composite powder that prepared by high-energy ball milling and colloidal sols and jell,the size of composite powder by colloidal sols method is been effect through reductive temperature,PH value and addition agent;grain size of powder is reduce with high-energy ball milling time prolong,and drive to a sable value.3.Tungsten skeleton with homogeneous and controllable pore can be obtain by tungsten powder coated by copper through pressing and sintering,injection and addition nanoparticle method also obtain similar tungsten skeleton,they are better than traditional tungsten skeleton prepare technology.4.The coating W/15%wt.Cu alloy of microstructure homogeneous and high density can be fabricated by sintering and infiltration copper,the density is 16.18g/cm³,hardness is 217HB, specific conductance is 25μΩ·cm,thermal conductivity is 199W/(mk);the density of W/15%wt.Cu alloy by similarity injection method isl6.20g/cm³,hardness is 230HB,specific conductance is 25μΩ·cm,thermal conductivity is 205W/(mk);the density of W/15%wt.Cu alloy with doping nanoparticle is 16.59g/cm³,hardness is 252HB,specific conductance is 23μΩ·cm,thermal conductivity is 197W/(mk);the density of W/15%wt.Cu alloy doping opening bore additive is10.43g/cm³,hardness is less than 95.5HB,specific conductance is 16μΩ·cm,thermal conductivity is 123W/(mk);coefficient of thermal expansion of them is less than 7×10^-6/K。Meet the demand in electronic seal and thermal materials.This research's main conclusions provide many experimental foundations and bases for the industrialization and widely uses of high quality copper-tungsten nano-composite material.