Fabrication And Material Of Black Alumina Ceramic Substrate Used For SMD Quartz Crystal Oscillator

Quartz crystal oscillator as a high-precision,high stability of the oscillator components were widely used in automobiles,computers,networks,mobile communications,and so on.Alonging with the fast development of electronic communication industry and the trend of miniaturization and high-power,the market requirement of the crystal oscillator will grow up rapidly.But traditional crystal have been unable to meet requirements and began to surface mount type and light,thin,miniaturization size,and the ceramic package gradually replaced the traditional review of the bare metal plastic package.The ceramic package substrate with good light avoiding and minute volume was badly needed.In this paper,the Fe-Cr-Co system using Fe₂O₃,Cr₂O₃,CoO three transition metal oxides as the main raw material was prepared by wet process.By analyzing the coloration mechanism and the color different value,the best formula of black pigment was ascertained.And the article discussed the factors influencing the color presentation of the black pigment.The black alumina ceramic layer was prepared by tape casting on the base of fabrication and properties study of black pigment.The substrate material formulation,sintering process,shrinkage rate and different supplement content to properties of ceramic layers were discussed, and the formula of black alumina ceramic and the process parameters of tape casting were established.The result shows:by adding 11%pigment,15%sintering flux and sintering at 1150℃,it could obtain uniform black color and it could have the bulk density of 3.652 g/cm³, volume resistivity above of 10¹²Î©Â·cm,permittivity of 14;when the binder content is 5wt%, ceramic substrate has fewer defects such as cracking,with the pore rate of 4.8%.Through adjusting the slurry formula and the density of the green tape can effectively control the shrinkage rate of the substrates.The black alumina ceramic substrate with the dimensions:8.5mm×5.0mm×0.65±0.05mm was successfully prepared after cutting,punching,screen printing,heat bonding and sintering. then,the heat bonding process,thermal shock performance,size precision of the substrate and the factors influence the performance of electrode film on the substrate were analysised.The experiment indicated that:the substrates level after water hot-pressing combined compactly and have high thermal shock property and high dimensional accuracy,when the viscosity of electrode slurry was 5.2Pas,the adhesion of electrode film reach to 35 N and its resistance reach to 27mΩafter two times printing and sintering at 1150℃.the electrode was luminous,smooth and compact through microscope observation...