3 Types of Hermetic Seals

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(Newswire.net — July 15, 2019) — A hermetic seal is a typical solution used to prevent material from leaking. It makes an object airtight using fusion welding. A weld is created by using a high-energy laser that raises the temperature of the material until it melts and becomes liquid. This liquid then cools rapidly and creates a weld.

Seals are crucial for the safe and correct functionality of many products. However, the superior protection of a hermetic seal depends on which type you use. The three main types are: 

  1. Glass-to-Metal

This type of seal is made by fusing glass and metal together. It is known for its strength and versatility which is why they can be seen in common household items such as light bulb bases and pressure tight glass windows. There are two types:

  • Matched Seals

These are made of metal alloys and components that have the same coefficient thermal expansion. It is the weaker of the two kinds.

  • Compression Seals

When the coefficients of thermal expansion are different, compression seals are created. It is the stronger of the two kinds because it can withstand the physical stress and high-pressure fluctuations.

  1. Ceramic-to-Glass

This type of seal is more robust and performs better in high voltage, high temperature, and high stress environments. It is considered an alternative to glass but is more time consuming to make and is more costly.

  1. Epoxy Seals

Epoxy resins are commonly used to seal brass, copper, and other materials with similar coefficients of thermal expansion. Although typically used in vacuum seals, their use is more limited because they cannot normally withstand high temperatures.

Before choosing a hermetic package, take note that hermetic seals have many different applications across various industries. It is vital to understand the different options first before choosing the most appropriate sealing method.