Hermetic Seals: Guide to Understanding Their 5 Types

As explained by PAVE Technology Co. in their article Guide to Understanding the 5 Types of Hermetic Seals, hermetic sealing is essential for preventing material leaks and maintaining the integrity of systems in demanding environments. Hermetic connectors channel electricity through vacuum feedthroughs while withstanding high pressure and harsh conditions, making them indispensable in aerospace, pharmaceutical, and military applications.

The article outlines five primary types of hermetic seals:

  1. Glass-to-Glass Hermetic Seals
    These seals bond multiple layers of glass, typically requiring at least five layers due to the challenges of matching coefficients of thermal expansion. They are ideal for applications like glass windows and tubes.
  2. Glass-to-Metal Hermetic Seals
    Fusing glass components with metal surfaces, these seals act as electrical conductors while protecting mechanisms from dust and microbes. Common applications include light bulbs, where the glass insulates hermetic connector pins from the metal packaging. Two subtypes are:
    • Matched Seals, which bond glass with metal oxide, though they are less tolerant to pressure fluctuations.
    • Compression Seals, which use steel packaging to absorb pressure and shock, enhancing durability.
  3. Ceramic-to-Metal Hermetic Seals
    These seals are created by coating ceramics with metallic designs and running them through a furnace. They are resistant to high pressure and frequently used in high-voltage settings like automotive, medical, and aerospace applications.
  4. Ceramic-to-Glass Hermetic Seals
    Designed for high-stress, high-temperature, and high-voltage environments, these seals are capable of handling up to 3,000 volts of static electricity sparks. Although more expensive, they are an effective alternative to glass and are suited for motors and signal transmission devices.

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Article with all rights reserved, courtesy of pavetechnologyco.com