Glass-to-metal sealing is the most reliable kind.
Glass seals perform under high pressure, vacuum, high temperature, thermal cycling, radiation, shock and vibration. Totally inorganic, they won't degrade with time.
Benefits of glass-to-metal sealing:
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Extremely high durability
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Mechanical stress and strain resistance
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High shock and vibration resistance
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Thermal shock stability and resistance
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Chemical stability and resistance
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Absolute hermeticity: zero diffusion or leakage
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Long-term stability - inorganic, non-ageing
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60+ years of proven reliability
Proven in these environments
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Hydrostatic: over 25,000 psig
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Temperature shock: -40° to 204°C
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Synergistic HPHT exposure
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Vibration up to 2000 Hz
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Mechanical and explosive shock > 10,000 g
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Hermeticity: He leak rate less than 1 x 10-8 cm3/sec
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Radiation
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Steam
How is it done?
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Repeatable, controlled manufacturing process
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High temperature process > 1800°F (980°C)
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Programmable logic controlled furnaces, specialized atmosphere control
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Compression seal between conductor, glass and body
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Optimize coefficient of thermal expansions
Materials sealed: routine to exotic
Special materials processing is routine at Teledyne DGO. Direct glass-to-metal seals for body materials include titanium, Inconel, Monel®, K-Monel®, tantalum, Kovar and stainless steels such as 316L and Superduplex. Contact materials include copper, Alumel®, Chromel®, constantan, Kovar®, platinum, molybdenum, Inconel®, Hastelloy®, Incoloy®, tantalum and carbon steel.
In addition to glass-to-metal sealing, Teledyne DGO controls quality by performing the following key processes in-house; gold, nickel and solder plating; heat treating; and nickel, copper and silver brazing