Molding Process Of Beo Ceramic Electronic Packaging Materials And Sintering Aids

BeO ceramics have several properities of high thermal conductivity, high melting point,high strength,high insulation property,high chemical and thermal stability,low dielectric constant,low dielectric loss and good processing applicability,so it is widely applied in vacuum electronics technology,nuclear technology,and microelectronics and photoelectron technology.With the development of science and technology,especially with the development of some industries such as electronic,energy,space and automobile,the requirement of high quality materials is increased,so the demand for BeO ceramics especially for high-purity and high-density BeO ceramics is much higher than it can be supplied.In this experiment,BeO ceramics forming process has been studied to develop a good BeO ceramic forming process.The parameters of BeO ceramics forming process is optimized.A lot of analysises and detections, such as metallographic analysis,SEM analysis,density detection,thermal conductivity detection,differential scanning calorimetry analysis, thermal expansion coefficient detection,flexure strenghth detection and so on,are used to study the effect of the different oxide additives and sintering conditions on the structure and properties of BeO ceramics chips.The concludes are obtained as follows:(1) The compression pressure,speed,holding time and forming agent can obviously improve the body density of the BeO ceramics. Keeping the pressure at 120MPa for 60s and adding 1%(mass) of the PVA as forming agent,dense BeO ceramics can be prepared whose density is 2.27g/cm³.(2) Under the conditions of this experimental design programs and materials,99%BeO ceramics can get excellent performance parameters.(3) A small amount of SiO₂ has a catalytic role and can enhance the performance parameters of 99%BeO ceramics.And 99%BeO ceramics have good performance parameters with 0.5%SiO₂.With the increase of SiO2 content,the parameters of 99%BeO ceramics decline.4) With the MgO-Al₂O₃-SiO₂ composite sintering additives,the best content ratio of MgO-Al₂O₃-SiO₂ content ratio is 0.25-0.25%-0.5%,BeO ceramics can get the best parameters of the additives,whose density is 2.87g/cm³,heat conductivity is 220.3W·m^-1·K^-1,flexutal strength is 231.3MPa.