Glass is a brittle material, easily damaged by tensile stress (Tension Stress) or thermal stress, and strongly resistant to Compression Stress (Compression Stress). The coefficient of thermal expansion (CTE) of metal and glass is very different. During the production of glass-to-metal sealing (GTMS), must accurately control the process temperature and thermal stress in glass to avoid glass cracking.
A. Matched Seals
Matched seals are used by varieties of metal and glass that have similar Coefficients of Thermal Expansion. Kovar housing and pins along with borosilicate glass are typically the materials used in a Matched seals。
B. Compression Seals
Compression seals are used by varieties of metal and glass that have not similar Coefficients of Thermal Expansion. The housing (1) material's Coefficients of Thermal Expansion rate tends to be higher than that of glass (2) and pins (3). Stainless steel housings, alloy pins are generally made using in a Compression Seals。
