Abstract: A kind of lead-free glass powders based on Bi₂O₃-B₂O₃-ZnO-BaO-CuO system was prepared in this paper for the performance requirements of micro-electromechanical system (MEMS) sealing glass. The effects of Bi₂O₃/B₂O₃ ratio (n(Bi₂O₃)/n(B₂O₃)) and β-eucryptite powder content on the network structure, thermal properties, sealing temperature and sintered micromorphology of MEMS sealing glass were separately studied by Raman spectra, XRD, coefficient of thermal expansion (CTE), sintering image and SEM. The results show that the content of [BiO₃] and [BiO₆] increases with the increase of n(Bi₂O₃)/n(B₂O₃), while the transition from [BO₄] tetrahedron to [BO₃] triangulation leads to the glass network connection strength weak and structure loose. With the increase of n(Bi₂O₃)/n(B₂O₃), the CTE of the glass increases while the characteristic temperature and sealing temperature decrease gradually, but later change slowed. The CTE of the composite glass decreases obviously while the characteristic temperature and sealing temperature change little with the increase of β-eucryptite powder content, at the same time the fluidity of the composite glass powder becomes worse.

Key words: micro-electromechanical system, sealing glass powder, low-melting glass, β-eucryptite powder, coefficient of thermal expansion, sealing temperature