Investigation On Low-melting Point Bismuthate Sealing Glass

With the rapid development of modern microelectronics andoptoelectronics technology, as well as the high requirements for miniaturization andprecision of components to air-tightness and reliability of sealing products, especiallywith the environmental voice rising, the more stringent requirements for the sealingglass have been put forword.In the thesis, the composite glasses were prepared by using Bi₂O₃-B₂O₃-ZnO asbase glasses and β-eucryptite glass-ceramic and sodium zirconium phosphate asfillers. The structure and properties of base glasses, fillers and composite glasseswere characterized by differential thermal-weightlessness analyzer（TG-DTA）,thermal expansion analyzer（DIL）, X-ray diffraction （XRD）, scanning electronmicroscope（SEM）, fourier transform infrared spectroscopy （FTIR） and so on.（1） Three series of bismuthate glasses, Bi₂O₃-B₂O₃-ZnO, Bi₂O₃-B₂O₃-SiO₂andBi₂O₃-BaO-SiO₂-R_xO_y（R_xO_yis one or more of K₂O, Na₂O, CaO and Al₂O₃） wereprepared. The impacts of Bi₂O₃, B₂O₃, ZnO, alkaline earth metal oxides andmetalloid oxides on the structure and properties of Bi₂O₃-B₂O₃-ZnO glasses wereinvestigated. The impacts of SiO₂content on the structure and properties ofBi₂O₃-B₂O₃-SiO₂glasses were also investigated. At last, the impacts of TiO₂contenton the structure and properties of Bi₂O₃-BaO-SiO₂-R_xO_yglasses were investigated.The results indicated that the Bi₂O₃-B₂O₃-ZnO glasses were chosen for the base glassbecause of the widest application.（2） β-eucryptite glass-ceramic powders presented uniform particles, gooddispersion and a particle size of about5μm were prepared. Sodium zirconiumphosphate powders presented little agglomeration, good dispersion and a particle sizeof about100nm were also prepared.（3） Composite glasses included base glasses and fillers, the former wereBi₂O₃-B₂O₃-ZnO glasses and the latter were β-eucryptite glass ceramics and sodiumzirconium phosphate. The results indicated that the thermal expansion coefficient ofthe composite glasses decreased with increasing the contents of fillers, while theglass transition temperature, softening temperature and the usage temperatureincreased. At the same time, the strength of the glasses improved, the fluidity deteriorated.（4） The design of the sealing process route was completed. The sealing effects byusing different methods to prepare glass performs were also studied.