Ceramic-to-Metal Seals for High-Temperature and High-Voltage Systems

When Ceramic-to-Metal Seals Are Required

Ceramic-to-metal seals are selected when operating conditions exceed the temperature, voltage, or durability limits of glass-to-metal sealing technologies. These seals are engineered for extreme environments where high electrical isolation, thermal stability, and long-term reliability are essential. Applications involving high voltage, high temperature, vacuum, or radiation exposure often require ceramic sealing solutions to ensure performance and safety.

Advanced Ceramic Sealing Technology

Ceramic-to-metal seals are typically manufactured using high-purity alumina ceramics combined with metallization and brazing processes. The ceramic provides exceptional dielectric strength and thermal resistance, while the metal components ensure mechanical integrity and compatibility with system housings. This combination allows ceramic seals to maintain hermeticity under severe thermal cycling and electrical stress.

Mechanical and Electrical Performance

Unlike glass, ceramic materials maintain dimensional stability at very high temperatures and exhibit minimal deformation under load. This makes ceramic-to-metal seals ideal for applications where electrical insulation must remain stable over extended operating periods. Their resistance to arcing and electrical breakdown further enhances safety in high-voltage systems.

Extreme Conditions and Long-Term Stability

Ceramic-to-metal seals also perform exceptionally well in vacuum and radiation-sensitive environments due to their low outgassing and material purity. While these seals are more complex and time-intensive to manufacture than glass seals, their durability and performance justify their use in mission-critical systems where failure is unacceptable.

High-Performance Applications

Common applications include aerospace propulsion systems, medical imaging probes, vacuum chambers, semiconductor processing equipment, high-temperature sensors, and defense electronics. These environments demand sealing solutions that can withstand prolonged exposure to heat, pressure, and electrical stress without degradation.

 

Contact Complete Hermetics

Complete Hermetics designs and manufactures custom ceramic-to-metal seals and feedthroughs, along with glass-to-metal seals,  hermetic connectors, hermetic headers, and hermetically sealed packages for extreme environments. The company also supports specialized requirements with custom hermetic feedthroughs, power packages, and custom hermetic solutions tailored to demanding applications. By combining advanced materials with precision engineering, Complete Hermetics delivers sealing technologies customers can rely on.

Glass-to-Metal Seals for Precision Hermetic Technology

How Glass-to-Metal Seals Work

Glass-to-metal seals are created by heating glass to a molten state and bonding it directly to metal under carefully controlled conditions. As the materials cool, the glass forms a strong, hermetic bond with the metal, creating an airtight and electrically insulating seal. This process allows electrical conductors to pass through metal housings without permitting moisture, gas, or contaminants to enter the sealed environment. Because of their proven reliability, glass-to-metal seals remain one of the most widely used hermetic sealing technologies across multiple industries.

Performance Advantages of Glass Sealing

One of the key advantages of glass-to-metal seals is their ability to maintain hermetic integrity under pressure changes, humidity exposure, and moderate temperature extremes. Glass provides excellent dielectric strength, corrosion resistance, and chemical stability, making it suitable for long-term use in harsh environments. Compared to epoxy or mechanical sealing methods, glass-to-metal seals offer significantly longer service life and more predictable performance over time.

Material Compatibility and Stability

Successful glass-to-metal sealing depends on matching the coefficient of thermal expansion (CTE) between the glass and metal components. Materials such as Kovar, Alloy 52, stainless steel, and copper-based alloys are commonly used to achieve this balance. When properly engineered, these seals tolerate thermal cycling and mechanical shock without cracking or leakage, making them suitable for both static and dynamic applications.

Manufacturing Precision and Repeatability

Glass-to-metal sealing requires precise control over glass composition, firing temperature, and cooling rates. This level of control ensures consistent quality and repeatability across production runs. As a result, glass-to-metal seals are ideal for both prototype development and high-volume manufacturing, allowing manufacturers to scale production without sacrificing reliability.

Common Applications

Glass-to-metal seals are widely used in glass-to-metal sealed lids, battery end seals, capacitor end seals, sensors, medical implants, and industrial electronics. They are also commonly found in automotive systems, pressure sensors, and energy storage devices where cost-effective hermetic performance is required.

 

Contact Complete Hermetics

Complete Hermetics is a custom manufacturer of hermetic sealing solutions, specializing in glass-to-metal seals, ceramic-to-metal seals, hermetic connectors, hermetic feedthroughs, hermetic headers, TO headers, vacuum feedthroughs, and battery end seals. The company designs and produces hermetically sealed components and custom hermetic assemblies for aerospace, defense, medical, energy, and telecom applications, delivering reliable performance in extreme environments from prototype development through full-scale production, backed by deep engineering expertise.

Hermetic Seals for High-Pressure and Harsh Environments

What Are Hermetic Seals?

Hermetic seals are engineered to create a completely airtight barrier that prevents moisture, gas, and contaminants from entering sensitive electronic or mechanical systems. These seals are essential in applications where even microscopic leakage can cause performance degradation, safety issues, or catastrophic system failure. Industries such as aerospace, defense, medical devices, energy, and offshore drilling rely on hermetic sealing to protect mission-critical components operating in extreme conditions.

High-Pressure and Corrosion Resistance

Unlike conventional gaskets or epoxy-based sealing methods, hermetic seals prevent gas transmission through pressure boundaries. Glass-to-metal seals and ceramic-to-metal seals are the most widely used hermetic technologies because they offer excellent electrical insulation, corrosion resistance, and mechanical strength. These seals are specifically designed to withstand high pressure, vibration, thermal cycling, and chemically aggressive environments.

Materials and Sealing Technologies

Hermetic seals are manufactured using materials such as Kovar, stainless steel, Alloy 52, titanium, and aluminum, selected for controlled thermal expansion and long-term structural stability. Glass and ceramic sealing processes are precisely controlled to prevent cracking during temperature changes. These technologies ensure predictable performance across wide temperature ranges and long service lifetimes.

Lifecycle Reliability and Compliance

Hermetic seals also play a critical role in safety, regulatory compliance, and lifecycle cost reduction. Poor sealing can lead to corrosion, insulation breakdown, or electrical failure. Hermetic seals are commonly validated using helium leak detection, thermal shock testing, and pressure cycling to ensure long-term durability in regulated industries.

Applications Across Industries

Hermetic seals are used in medical implants, aerospace avionics, lithium battery assemblies, semiconductor housings, downhole drilling tools, and high-vacuum systems. They are also increasingly used in automotive and electric vehicle electronics, where moisture resistance and long operational life are essential.

Contact Complete Hermetics

Complete Hermetics is a custom manufacturer of glass-to-metal seals, ceramic-to-metal seals, hermetic connectors, hermetic feedthroughs, hermetic headers, and hermetically sealed packages engineered for extreme environments. In addition to precision sealing solutions, the company offers vacuum feedthroughs, battery end seals, TO headers,  and power packages for aerospace, defense, medical, energy, and telecom applications. From prototype development through full-scale production, Complete Hermetics partners closely with customers to deliver precision-engineered hermetic solutions with unmatched reliability.

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Advanced Ceramic-to-Metal Seals and Feedthroughs for High-Temperature Performance

Why Ceramic-to-Metal Seals Are Superior

Ceramic-to-metal seals provide unmatched insulation strength, temperature resistance, and structural durability—making them ideal for systems exposed to extreme conditions. Unlike glass seals, ceramics retain mechanical and electrical stability at temperatures exceeding 500°C and remain intact during rapid thermal cycling. These properties make CTM seals indispensable in aerospace propulsion, medical imaging equipment, semiconductor fabrication tools, and scientific instrumentation.

Material Properties & Bonding Precision

Complete Hermetics uses high-purity alumina ceramics, metalized with tungsten-molybdenum or moly-manganese layers, to enable strong brazed joints with Kovar, titanium, or stainless steel housings. This combination allows ceramic-to-metal seals to achieve extremely low leak rates and high dielectric breakdown voltage. Optional plating—gold, nickel, or silver—improves conductivity, corrosion resistance, and long-term material stability.

Applications Across High-Temperature Industries

Ceramic-to-metal seals are essential in:

  • High-voltage power systems
  • Vacuum and plasma processing equipment
  • RF amplifiers and radar transmitters
  • Aerospace ignition and propulsion assemblies
  • Nuclear diagnostic sensors
  • Industrial heating and furnace control systems

Engineering Collaboration & Testing

Complete Hermetics works closely with engineers to determine ceramic thickness, dielectric spacing, pin configurations, and mounting styles tailored to each application. Every component undergoes helium leak detection, thermal shock testing, vacuum cycling, and electrical qualification to ensure longevity and reliability.

Contact Complete Hermetics

Count on Complete Hermetics for robust, precision-engineered ceramic-to-metal seals and feedthroughsyour trusted partner for extreme-environment reliability.

Medical Hermetic Seals for Life-Critical Electronic Devices

Why Hermetic Seals Are Essential

Medical hermetic seals play a critical role in ensuring the safety, reliability, and biocompatibility of implantable and diagnostic electronics. When devices operate inside the human body or are exposed to sterilization processes, they must withstand moisture, bodily fluids, chemical exposure, and extreme thermal variations. Even the smallest leak can cause internal corrosion, signal failure, or biological contamination. As modern medical devices become smaller yet more capable, the demand for advanced hermetic sealing technologies grows significantly.

Glass-to-Metal & Ceramic-to-Metal Sealing Technologies

Complete Hermetics designs medical-grade seals using glass-to-metal (GTM) and ceramic-to-metal (CTM) sealing methods. Glass seals provide cost-effective, high-strength bonding between metal housings and conductive pins, while ceramic seals are ideal for high-voltage or long-term implants due to their exceptional dielectric strength. Using materials such as titanium, stainless steel, and high-purity alumina ceramics, these seals are engineered to perform reliably in demanding biological environments.

Regulatory-Ready Testing & Biological Safety

Medical hermetic seals must meet FDA, ISO 14708, IEC 60601, and biocompatibility standards. Complete Hermetics performs rigorous testing—including helium leak detection, sterilization simulation, thermal shock, electrical insulation analysis, and X-ray inspection—to ensure every seal meets life-critical reliability requirements. Traceability, cleanliness, and manufacturing consistency are maintained at every step.

Applications in Modern Healthcare

Medical hermetic seals enable secure operation in:

  • Pacemakers & implantable cardioverter defibrillators (ICDs)
  • Neurostimulation & pain-management implants
  • Implantable batteries & power modules
  • Surgical navigation tools
  • Diagnostic imaging equipment
  • Long-term biosensor implants

Contact Complete Hermetics

For precision-engineered medical hermetic seals that support life-critical technology, trust the expertise of Complete Hermetics.

Hermetic Seals and Feedthroughs for Extreme Environments

Why Hermetic Seals Are Essential

Hermetic seals are critical to protecting sensitive electronics from gas, liquid, and pressure infiltration. Whether in aerospace flight control systems, industrial power assemblies, or medical equipment, the success of an electronic device often depends on the integrity of its hermetic sealing. When systems operate under high stress or environmental fluctuation, a small leak can lead to catastrophic failure.

Complete Hermetics Expertise

Complete Hermetics is a trusted hermetic seal manufacturer with decades of engineering experience. The company designs and fabricates both glass-to-metal and ceramic-to-metal feedthroughs, each tailored to meet precise mechanical, thermal, and electrical requirements. Every product undergoes helium leak detection, electrical insulation testing, and dimensional verification to ensure it exceeds global reliability standards. Their multidisciplinary team collaborates closely with clients to optimize performance, durability, and manufacturability for each application. With a commitment to innovation, Complete Hermetics continues to advance sealing technologies that meet the evolving needs of aerospace, medical, and defense industries.

Glass-to-Metal Seals and Applications

A glass-to-metal seal is formed when molten glass bonds tightly to metal under carefully controlled thermal expansion. The resulting structure creates a gas-tight joint ideal for devices exposed to temperature swings or humidity changes. Common applications include aviation sensors, industrial pumps, high-voltage connectors, and sealed relays. Compression and matched seals are both available depending on the intended use environment.

Ceramic-to-Metal Alternatives

When systems demand higher operating voltages or extreme temperature resistance, ceramic-to-metal seals provide superior dielectric strength and corrosion resistance. Complete Hermetics engineers these seals for medical scanners, power distribution modules, and vacuum enclosures used in aerospace and research.

Customization and Finishing Options

Materials such as stainless steel, Inconel, Kovar, and titanium are combined with custom plating—gold, nickel, or silver—for enhanced conductivity and solderability. Each configuration is designed in collaboration with the customer to meet functional, thermal, and geometric requirements.

Contact Complete Hermetics

For precision-engineered hermetic seals and feedthroughs that perform in the harshest conditions, trust Complete Hermetics —your global partner in dependable sealing solutions.

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Ceramic-to-Metal Seals and Feedthroughs for High-Temperature Systems

The Advantage of Ceramic-to-Metal Technology

When environments exceed the limits of glass, ceramic-to-metal seals become the gold standard for thermal and electrical isolation. These seals are engineered to withstand extreme temperatures, voltages, and vacuum pressures without degradation—making them indispensable in aerospace propulsion, particle physics, and medical imaging systems.

High-Performance Applications

Ceramic-to-metal feedthroughs are used in high-voltage power transmission, RF systems, X-ray machines, and vacuum processing chambers. Their excellent dielectric strength ensures signal stability while maintaining full hermetic integrity.

Engineering and Design Excellence

Complete Hermetics produces custom ceramic-to-metal seals using alumina ceramics bonded to stainless steel, Kovar, or titanium through metallization and brazing. Each joint undergoes ultrasonic inspection, helium testing, and dimensional analysis to confirm long-term sealing reliability.

Benefits Over Traditional Glass Seals

Compared with glass, ceramics provide higher breakdown voltage, improved heat resistance, and lower leakage. This makes them ideal for applications exceeding 500 °C or operating under continuous voltage loads.

Collaborative Development Process

From prototype to production, Complete Hermetics works directly with customers to optimize designs for performance, manufacturability, and cost efficiency. Engineers can tailor electrode geometry, pin diameter, and insulation thickness to meet exact system needs.

Contact Complete Hermetics

Choose Complete Hermetics for high-reliability ceramic-to-metal seals and feedthroughs proven in extreme operating environments.

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Ceramic-to-Metal Seals and Feedthroughs for Harsh Conditions

Why Choose Ceramic-to-Metal Seals

Ceramic-to-metal seals provide exceptional performance in environments where high temperatures, high voltages, and extreme pressures are present. Compared to glass-to-metal alternatives, ceramic-to-metal feedthroughs are designed for applications that demand the highest durability and reliability.

Applications of Ceramic-to-Metal Feedthroughs

Industries that depend on ceramic-to-metal feedthroughs include:

  • Aerospace and defense systems
  • High-voltage and power equipment
  • Vacuum and semiconductor chambers
  • Medical devices and diagnostic systems

These seals ensure maximum protection against leaks, electrical breakdown, and environmental damage.

Advantages of Ceramic-to-Metal Technology

Unlike glass seals, ceramic-to-metal hermetic seals can withstand harsher environments for longer periods. Their resistance to electrical stress and thermal shock makes them ideal for applications where standard sealing methods may fail. While production is more labor-intensive, the results deliver unmatched strength and durability.

Complete Hermetics Ceramic-to-Metal Solutions

Complete Hermetics specializes in custom ceramic-to-metal seals and feedthroughs, offering solutions built to precise customer specifications. Their expertise in engineering and materials ensures each product performs reliably, even in the most demanding conditions.

Applications include high vacuum feedthroughs, electrical feedthroughs, and advanced power or defense-related systems where precision sealing is critical.

Contact Complete Hermetics

As a trusted hermetic seal manufacturer, Complete Hermetics provides custom ceramic-to-metal seals and feedthroughs for industries worldwide. Our team will design and manufacture components to meet your exact requirements for performance and reliability.

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Hermetic Seals and Feedthroughs for Reliable Protection

Why Hermetic Seals Are Important

Hermetic seals protect sensitive electronics from moisture, pressure, and gas leaks. In industries such as aerospace, defense, automotive, and medical, glass-to-metal seals and ceramic-to-metal seals provide airtight reliability where failure is not an option.

Complete Hermetics Seal Solutions

Complete Hermetics is a custom hermetic seal manufacturer specializing in glass-to-metal feedthroughs and ceramic-to-metal feedthroughs. Their engineers create custom prototypes and production-ready components to fit unique requirements across multiple industries.

Applications include:

  • Aerospace and defense electronics
  • High-voltage and vacuum systems
  • Medical devices, batteries, and sensors

Glass-to-Metal Seals

Glass is heated to a molten state and bonded to metal, creating a strong hermetic seal. These seals handle temperature changes, pressure variations, and corrosion resistance. Glass-to-metal feedthroughs are also cost-effective and versatile compared to ceramic alternatives. Options include compression seals for extreme pressure (up to 14,000 PSI) and matched seals for high thermal and mechanical shock resistance.

Ceramic-to-Metal Seals

For high-temperature, high-voltage, or harsh environments, ceramic-to-metal seals offer superior durability. While more labor-intensive to produce, they provide long-lasting performance in vacuum feedthroughs and electrical sealing applications.

Plating and Material Options

Complete Hermetics offers plating choices such as gold, silver, nickel, and tin to improve corrosion resistance and soldering capabilities. Materials include stainless steel, Inconel, Kovar, copper alloys, and high-performance ceramics, depending on application requirements.

Contact Complete Hermetics

As a leader in hermetic seals and feedthroughs, Complete Hermetics provides tailored solutions for both standard and custom designs. Whether you need glass-to-metal seals, ceramic-to-metal seals, or specialized hermetic feedthroughs, we deliver unmatched reliability.

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Top 15 Frequently Asked Questions About Hermetic Seals and Feedthroughs

Hermetic seals and feedthroughs are essential in industries that require airtight, corrosion-resistant, and high-temperature-capable components. From aerospace to medical devices, these components protect critical systems from environmental damage. Below are 15 top FAQs with concise answers to help you understand these vital technologies.

1. What is a hermetic seal?

A hermetic seal is an airtight and moisture-proof seal that prevents gas or fluid leakage between joined components.

2. What is a hermetic feedthrough?

A hermetic feedthrough allows electrical signals or power to pass through a sealed barrier without compromising the seal’s integrity.

3. What are glass-to-metal seals?

These glass-to-metal seals fuse molten glass with metal under controlled thermal expansion to create a strong, durable, and airtight bond.

4. What’s the difference between matched and compression seals?

Matched seals use materials with similar thermal expansion rates; compression seals use mismatched rates for higher strength and pressure resistance.

5. What applications use hermetic feedthroughs?

They are used in aerospace, military, medical implants, vacuum systems, and oil & gas instrumentation.

6. What materials are used in glass-to-metal seals?

Common materials include Kovar, stainless steel, Inconel, and alkali barium glass.

7. What’s the leak rate standard?

Complete Hermetics’ products meet or exceed 1×10⁻⁹ atm cc/sec He for superior hermeticity.

8. Are custom designs available?

Yes. Complete Hermetics offers fully customized solutions tailored to specific dimensions, materials, and electrical specs.

9. What are ceramic-to-metal seals used for?

For high-voltage, high-temperature, and corrosive environments that glass cannot withstand.

10. How do ceramic-doped glass seals differ?

They offer high thermal resistance (up to 600°C) at a lower cost than traditional ceramic-to-metal seals.

11. What plating options are available?

Platings include gold, silver, electroless nickel, and tin for corrosion resistance and solderability.

12. Can hermetic seals be used in medical devices?

Absolutely. Titanium terminals and headers are ideal for batteries, sensors, and diagnostic tools.

13. What electrical specs can be expected?

Typical insulation resistance exceeds 1 GΩ @ 100 VDC; dielectric strength depends on glass type.

14. What shapes and sizes are available?

Circular, rectangular, micro-D and custom headers are available across a wide range of standard and custom sizes.

15. Can feedthroughs handle high pressure?

Yes. Compression seals can withstand pressures up to 14,000 PSI, depending on design.

Why Choose Complete Hermetics?

Complete Hermetics is a leading custom manufacturer of glass-to-metal, ceramic-to-metal, and hermetic feedthroughs and seals. Our expert team designs hermetic connectors, headers, packages, and vacuum viewports to fit your exact requirements. Whether you’re in aerospace, defense, medical, or industrial sectors, we deliver high-performance, leak-proof solutions with precision and reliability.

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📧 Email: info@completehermetics.com
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Contact Complete Hermetics today – your partner in precision sealing solutions.