Table of Contents
Introduction
Selecting the right hermetic connector is an important decision when designing electronic equipment for demanding environments. The connector must provide dependable electrical performance while maintaining a reliable seal against moisture, gases, pressure differences, and other external conditions.
Because hermetic connectors are available in different configurations and sealing technologies, choosing the correct option requires careful evaluation. Understanding the application requirements can help engineers identify a connector that meets both electrical and environmental needs.
Identify the Operating Environment
The first step is to understand where the connector will be installed. Some applications operate in clean indoor environments, while others face extreme temperatures, vibration, chemicals, pressure changes, or vacuum conditions.
For example, equipment installed inside a vacuum chamber requires a connector that can maintain a low leakage rate. A hermetic feedthrough is commonly considered for this type of installation because it allows electrical conductors to pass through a sealed chamber wall.
Outdoor industrial equipment may have different requirements. In these cases, resistance to moisture, temperature variation, and environmental exposure may be especially important.
Determine Electrical Requirements
Electrical specifications are another major factor. Engineers should identify the operating voltage, current capacity, contact resistance, insulation resistance, and dielectric strength required by the system.
A connector designed for low-voltage signal transmission may not be appropriate for high-power applications. Similarly, sensitive electronic equipment may require contact arrangements that reduce electrical interference.
A hermetic electrical feedthrough should be selected according to the electrical performance required by the equipment. The number of contacts, spacing, conductor dimensions, and insulation materials should all be checked.
Choose the Appropriate Sealing Technology
Hermetic connectors use different sealing methods depending on the intended application. Glass-to-metal sealing is a widely used approach because it can create a strong and reliable barrier around electrical contacts.
Ceramic-to-metal sealing is another option. Ceramic materials provide excellent electrical insulation and can offer useful thermal and mechanical characteristics.
The selection should be based on operating temperature, pressure conditions, chemical exposure, and long-term reliability requirements. Engineers should also review the manufacturer’s leakage specifications and testing procedures.
Consider Connector Configuration
Connector configuration affects installation, cable routing, and system compatibility. Circular connectors may be suitable for compact equipment, while rectangular connectors can support different contact layouts.
Hermetic feedthrough connectors are commonly selected when electrical connections must cross a sealed wall. They may be manufactured with different contact counts, pin arrangements, and mounting styles.
For cable-based installations, a hermetic cable feedthrough may be more appropriate. The connector must match the cable’s diameter and material to ensure that the sealing structure performs as intended.
Review Material Compatibility
Material selection can influence connector performance and service life. Housing materials, contact metals, insulation materials, and sealing components must be compatible with the operating environment.
For example, corrosion resistance may be important in equipment exposed to certain chemicals. Thermal expansion compatibility is also essential because different materials may expand at different rates when temperatures change.
These differences can place stress on sealing interfaces. A well-designed connector accounts for material compatibility to reduce the risk of seal damage.
Evaluate Mechanical Requirements
Hermetic connectors may experience vibration, shock, repeated handling, and installation stress. Their mechanical design must be suitable for the equipment in which they will be used.
Engineers should check mounting dimensions, connector retention, cable strain relief, and the mechanical strength of the housing. If the connector will be installed in a high-vibration environment, the assembly should be evaluated for that specific condition.
Check Testing and Certification
Before selecting a product, review the available technical documentation. Useful information may include leakage testing, electrical testing, temperature testing, and mechanical qualification.
The required standards depend on the industry and application. Aerospace, medical, and industrial projects may have different qualification requirements.
Manufacturers should be able to provide relevant specifications and explain how their products are tested.
Conclusion
Choosing the right hermetic connector requires a complete understanding of environmental, electrical, mechanical, and installation requirements. Engineers should evaluate sealing technology, material compatibility, connector configuration, and testing documentation before making a final decision.
