Hermetic Sealing

Ceramic-to-metal seals (typically alumina brazed to Kovar or stainless steel) offer superior mechanical strength, higher temperature capability, and better resistance to thermal cycling than glass-to-metal seals. Glass-to-metal seals (borosilicate or matched glasses bonded to Kovar or other alloys) are less expensive, well-characterized electrically, and adequate for moderate-temperature and pressure environments.

Ceramic-to-metal seals are manufactured through a multi-step process: the ceramic is formed, fired, and then metalized on the bonding surfaces using the molybdenum-manganese (Mo-Mn) process or active metal brazing (AMB). The metalized ceramic is then brazed to the metal component in a controlled-atmosphere furnace using a filler metal – most