At Amphenol Martec, our expertise in sealed interconnects means we know all about high temperatures. To achieve true hermetic leak rate performance of 1 x 10-7 atm cc/sec and beyond, we run furnaces at over 1,000°C to fuse glass to metal and achieve these high performance seals. The hermeticity of a glass or glass ceramic seal is achieved by both the permeability of the materials (i.e. glass & metal) and by the oxide bond formed between the two at elevated sealing temperatures. One of the benefits of glass in this application is its ability to form a strong, well adhered bond to appropriate metal oxides. Thus, a key enabler for a high performance glass to metal seal is the ability to form a well adhered metal oxide on the parent metal substrate prior to sealing.
This technology also allows for incredibly temperature resistant connectors and feedthroughs to be produced. Once successful glass wetting to the metal oxide has been achieved, the bond formed is remarkably persistent. Even elevated temperatures, above the glass softening point do not normally weaken the bond, with the result that glass to metal seals can provide an effective barrier at temperatures up to the working point of the glass, typically 900°C to 1,000°C.
This sort of performance is required in fire barrier feedthrough applications. The high temperature barrier performance depends on both thermal excursion and pressure differential, meaning requirements should be discussed with Martec’s design team to ensure compliance.
When electrical performance needs to be maintained for a period of time in a high temperature environment, Martec offers connectors rated at up to 450°C. These 83723 style connectors are designed with special matched materials to provide
continuous running at up to 450°C