A Comprehensive Guide to Hermetic Seals and Their Applications

As explained in Bel Fuse’s whitepaper “What Are Hermetic Seals?”, hermetic seals play an essential role in isolating sensitive components from external environments by creating an airtight barrier that prevents gases, liquids, and solids from passing through. Hermetically sealed connectors are indispensable in applications such as electronics, industrial processes, and chemical vapor deposition (CVD) ovens, where any leakage could compromise system performance or cause catastrophic failure.

Key Types of Hermetic Seals:

  1. Glass Seals (Matched Seals):
    • Offer a cost-effective, rigid structure that compresses against metal.
    • Require matching thermal expansion rates between glass and metal for reliable bonding.
  2. Compression Seals:
    • Designed for high-pressure applications and more demanding environments.
    • Capable of handling different thermal expansion rates but often require custom molds.
  3. Epoxy Seals:
    • Provide strong bonds to metal oxides and feature high dielectric strength.
    • Efficiently conduct heat, reducing the risk of overheating.
    • Resistant to chemicals and corrosion, making them durable in harsh environments.

Why Hermetic Seals Are Crucial:

Hermetic sealing is crucial across industries like aerospace, electronics, and medical technology for preventing contamination, ensuring system integrity, and enhancing performance. For example, connectors used in CVD ovens must withstand extreme temperature fluctuations, vibrations, and pressure changes to maintain controlled environments during batch processing.

Evaluating Hermetic Seal Performance:

The performance of hermetic seals is evaluated by their leak rate (measured in cubic centimeters per second, cm³/sec):

  • Lower-performing seals: 10⁻⁴ cm³/sec
  • High-quality seals: 10⁻⁸ cm³/sec
  • Highest-performance seals: 10⁻¹² cm³/sec

The leak rate varies based on the application. Medical devices, for instance, require the highest-performing seals to ensure long-term reliability, whereas industrial equipment may tolerate a lower-performing seal.

Hermetic seals play a pivotal role in shielding critical systems from environmental hazards, ensuring durability, and enhancing system performance. By selecting the right type of seal, industries can achieve optimal reliability and functionality in their applications.

Click here to learn more about Hermetic Seal Technology’s capabilities and products.

Article with all rights reserved, courtesy of belfuse.com.