Introduction
Electrical connectors are essential components in almost every electronic system. They allow power and signals to move between devices, circuit boards, cables, and equipment. However, not every connector is designed for the same operating conditions.
Standard connectors are suitable for many everyday applications, but equipment operating in vacuum environments, high-pressure systems, or contamination-sensitive conditions may require a different solution. Hermetic connectors are specifically designed to maintain a sealed electrical interface.
Understanding the differences between hermetic and standard connectors can help engineers select the right technology for their projects.
What Are Standard Connectors?
Standard electrical connectors are designed to establish electrical connections between two or more components. They are available in many forms, including circular, rectangular, board-mounted, cable-mounted, and plug-and-socket configurations.
Depending on their design, standard connectors may provide protection against dust and water. Some are manufactured with environmental seals and are suitable for outdoor or industrial use.
However, environmental protection ratings do not automatically mean that a connector is hermetic. A connector can resist water or dust while still allowing gas to pass through its construction under certain conditions.
What Makes Hermetic Connectors Different?
Hermetic connectors are engineered to provide a gas-tight or airtight sealing boundary around electrical contacts. Their purpose is to allow electrical connections to cross an enclosure wall without compromising the protected internal environment.
A hermetic feedthrough is commonly used when electrical conductors need to pass through a sealed housing. It can be installed in vacuum chambers, pressure vessels, and other controlled environments.
The sealing technology may use glass-to-metal or ceramic-to-metal construction. These methods create a sealed interface between the electrical contacts and the connector body.
Differences in Sealing Performance
The most important difference is the sealing requirement. Standard connectors may use elastomeric gaskets, O-rings, or other protective features to reduce the entry of water and dust.
Hermetic connectors use specialized sealing structures designed to meet defined leakage requirements. Their performance is typically evaluated using appropriate leak-testing methods.
A hermetic electrical feedthrough is therefore suitable for applications where maintaining the internal atmosphere or vacuum is important.
Differences in Construction Materials
Standard connectors may use plastic housings, metal shells, rubber seals, and conventional insulating materials. These components are selected according to cost, electrical performance, and environmental requirements.
Hermetic connectors often use carefully matched metal, glass, or ceramic materials. Material compatibility is important because differences in thermal expansion can create stress at sealing interfaces.
The construction must maintain both electrical insulation and sealing integrity under the expected operating conditions.
Application Differences
Standard connectors are widely used in consumer electronics, office equipment, household appliances, communication systems, and general industrial products.
Hermetic connectors are more common in specialized applications. These include aerospace electronics, medical devices, scientific instruments, vacuum systems, and equipment exposed to demanding environmental conditions.
Hermetic feedthrough connectors are particularly useful when electrical signals must pass through a sealed chamber wall.
Cable Connection Requirements
Some systems require a complete cable to pass through a protected enclosure. A standard cable gland may be sufficient for ordinary environmental protection, depending on the application.
However, systems with strict leakage requirements may need a hermetic cable feedthrough. This component is designed to maintain the required seal around the cable assembly.
The correct solution depends on cable construction, installation conditions, and the level of sealing performance required.
Cost and Design Considerations
Hermetic connectors can involve more specialized materials, manufacturing processes, and testing than standard connectors. As a result, they may have a higher initial cost.
However, product selection should consider the total system requirements. Using a standard connector in an application that requires hermetic sealing may create reliability problems and additional maintenance costs.
The appropriate choice should be based on operating conditions rather than price alone.
Conclusion
Standard and hermetic connectors serve different purposes. Standard connectors are suitable for general electrical connections, while hermetic connectors are designed for applications requiring a highly reliable sealed interface.