Effect of Na2O content on wettability, crystallization and performances of sealing glass

Abstract

As an encapsulation material, glass has been used in electronic encapsulation, aerospace, and fuel cell applications due to its ease of fabrication, heat resistance, and stability. Thereinto, shear strength is one of the significant criteria for evaluating sealing glass. Nevertheless, shear strength is frequently influenced by the wettability of glass and interfacial interactions. Thus, the effect of Na2O content on the characteristic glass temperature, wettability, and crystallization was investigated to promote shear strength. Due to the fluxing effect of Na2O, the characteristic temperature points tend to drop as its concentration increases from 3 wt% to 12 wt%, and the wettability increases. Furthermore, Na2O promotes the precipitation of more types of lead-containing crystals in sealing glasses. With the sodium content of the glass reaching 12 wt% showed the best properties that shear strength of 326 MPa. The sodium-containing sealed glass was securely attached at the interface after being co-sintered with the Si substrate. This implies that the lead-containing crystalline phase will promote shear strength and improve the sealing ability of the glass. This gives sealing glass great potential for application in electronic packaging fields.