The Research Of Lead-Free Low Melting Glass For Electronic Sealing

Low-melting sealing glass is an important manufacturing plasma display materials, but traditional sealing material contains large amounts of PbO. In recent years, as the environment attention increasingly, developing a new lead-free sealing material to replace conventional lead material has become a research hotspot.In this paper, both P2O5-B2O3-ZnO ternary system glass and P2O5-V2O5-B2O3-ZnO-Al2O3-Fe2O3 multi-component low-melting vanad-ium phosphate glass were studied by melting-quenching method. Transition temperature, thermal expansion coefficient and chemical stability of P2O5-B2O3-ZnO ternary system glass were investigated to further the possibility of exploring the phosphate system to replace lead glass. Then take the ternary P2O5-B2O3-ZnO as based components, adding another major component and auxiliary components V2O5, Al2O3 and Fe2O3 to prepare a lead-free sealing material which has a lower transition temperature, a reasonable thermal expansion coefficient and good chemical stability. It can provide a certain reference value for futher research on lead-free sealing material.1,Researche on P2O5-B2O3-ZnO phosphate sealing glass shows that P2O5/B2O3 is the most important factor on affecting the glass transition temperature, the glass transition temperature changes with P2O5/B2O3 into phase change, and when the rate of P2O5/B2O3 equals 8-9, the transition temperature significantly lower, but the thermal expansion coefficient in this range do not change significantly; Study of chemical stability found that weight loss rate is more than 140mgcm-2, which well below the industry standards 1 mgcm-2, and the weight loss increased rapidly with the lower P2O5, a small amount of B2O3 (5-10 mol%) then would increase the stability of the glass.2,P2O5-V2O5-B2O3-ZnO-Al2O3-Fe2O3 lead vanadium phosphate sealing glass is carried out based on the P2O5-B2O3-ZnO systems. Experimental results obtained research range of P2O5-V2O5-B2O3-ZnO and the P2O5/B2O3 on glass structure. The effects of V2O5 and B2O3 concentrations on the glass softening temperature, coefficient thermal expansion and thermal stability were also investigated. It showed that the Tf decreased when the V2O5 concentration increased, while as the content of B2O3 increased, the glass softening temperature first increased and then decreased, which appeared boron abnormal phenomenon.3,The chemical stability of P2O5-V2O5-B2O3-ZnO obviously increased by adding Metal Oxide Al2O3 and Fe2O3, when the Al2O3:Fe2O3=2:2, the chemical stability of glass was best.4,Consequently, a glass of 26.0P2O5-17.3V2O5-7.7B2O3-45.0ZnO-2.0 Al2O3-2.0Fe2O3 composition, with a low transition temperature of 340℃, a coefficient thermal expansion of 7.5×10-6/℃, and a weight loss of 0.63 mgcm-2 after immersed in 90℃water for 10 hours, has been successfully developed for electronic sealing applications. These properties are comparable with those of traditional low melting sealing glasses.