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Applying Solder Preforms – Compression

Most people think of our alloys only in the ‘soldering’ sense. However, these same materials may be used in applications where they aren’t designed to melt and attach components. Four common uses for solder alloys that are not soldering applications are:

  • Fusible plugs or links (these melt but do not bond)
  • Gaskets
  • Liquid thermal interfaces (these also melt without bonding)
  • Solid compressible thermal interfaces


Gaskets and compressible thermal interfaces both rely on certain low-temperature alloys for a particular characteristic: low yield strength. For both of these applications, indium metal (or an alloy of) is usually well suited.

Let’s examine the gasket application first. Indium is commonly used as a seal for cryogenic equipment because it is soft enough to form a good gasket with pipe flanges as it is compressed. It also retains compliant properties at cryogenic temperatures.

As a thermal interface, indium metal can be used as a thermal gasket between hot active components and cooling devices such as heat pipes, heat spreaders, or heat sinks. In this role indium is used primarily for a different property – high thermal conductivity. Indium offers an impressive thermal conductivity of approximately 86W/m°K.

This clearly illustrates that our alloys are not just ‘solder’, they are materials that can be used in applications in addition to bonding components together.


*This post is part of the World of Solder Preforms series