Ceramic-to-Metal Seal

A tight seal effectively prevents air leakage

Unlike traditional mechanical connections and adhesives, our ceramic-metal seals form a tight, airtight barrier suitable for high vacuum (HV) and even ultra-high vacuum (UHV) environments, preventing gas leakage even under pressure differentials and repeated thermal cycling.

Through helium mass spectrometry leak detection, our products have a leakage rate ≤1×10⁻¹⁰ mbar·L/s. For more advanced UHV products, we can customize leak rates ≤1×10⁻¹¹ mbar·L/s, guaranteeing absolutely no leakage.

Excellent temperature resistance and can withstand multiple thermal cycles

Ceramic and metal seals can operate in environments ranging from -55°C to 400°C. GORGEOUS CERAMICS (GGS Ceramic) were designed with repeated thermal cycling in mind from the outset. The matching coefficients of thermal expansion of ceramics and metals minimize the stress caused by heating and cooling processes, maintaining the integrity of the seal for thousands of thermal cycles over a long period without cracking.

The combination of ceramic and metal ensures both insulation and strength

The ceramic body of ceramic-metal seals provides superior dielectric insulation, while the metal housing offers mechanical strength and reliable installation for transmitting electrical signals in sealed environments.

The ceramic insulation layer offers two purities of alumina (95%/99%), providing a volume resistivity of 10¹⁴ Ω·cm at room temperature, effectively preventing insulation breakdown and leakage.

The metal housing can be made of 304 stainless steel, 316L stainless steel (for enhanced corrosion resistance), or Kovar alloy (to reduce thermal stress), with a Mo/Mn base coating (15-25 μm) to ensure excellent adhesion to the alumina. Electroplating with nickel/copper/gold (8–10 μm) is also available upon request.

Each pin is individually sealed

Each pin of the ceramic-metal seal has an independent ceramic sealing ring, sealed inside the ceramic insulator, effectively preventing electromagnetic interference and eliminating leakage paths between adjacent pins.

GORGEOUS CERAMICS (GGS Ceramic) can provide 6, 8, and 12 pins as needed, with pin diameters customizable from 0.3mm to 5mm, catering to the diverse needs of users for both weak signals and high currents.

Case studies in the ceramic-metal sealing industry

Customer Case 1:

A medical imaging equipment manufacturer, during the development of an X-ray tube, encountered a vacuum leak in the seals used after repeated thermal cycling tests. Subsequent investigation revealed microcracks in the seals. They sought a solution from GORGEOUS CERAMICS (GGS Ceramic).

GGS Ceramic Solution:

We used a vacuum brazing process with 99% alumina and Kovar alloy, and repeatedly optimized the metallization layer and brazing parameters to enhance the bonding strength between the ceramic and metal. By matching the coefficients of thermal expansion, and through helium mass spectrometry leak detection and high-pressure withstand testing, we successfully met the requirement of maintaining a stable seal even after long-term thermal cycling.

Customer Case 2:

A semiconductor equipment supplier needed to introduce high voltage, power, and signal stability into a vacuum chamber. However, after several months of operation, the equipment experienced performance degradation, requiring frequent downtime for maintenance. Therefore, they were looking for more suitable vacuum sealing components.

GGS Ceramic Solution:

Based on the customer’s drawings, a customized ceramic-metal sealing assembly was completed. It utilizes an integral brazed structure to connect conductors, ceramics, flanges, etc., and the CF flange dimensions and pin layout were designed according to the drawings. A good supply partnership has been established with the customer.

Customer Case 3:

The customer needed to replace the original resin seal with a component that could transmit electrical signals from a sealed pressure chamber, requiring long-term pressure resistance and airtightness.

GGS Ceramic Solution:

We recommend using ceramic-metal seals to replace the original resin seals. Ceramic-metal seals offer long-term stable sealing and resistance to temperature and pressure, unlike resin seals which tend to age and crack under high temperatures. Furthermore, different materials can be selected to meet varying media pressures and operating temperatures.

Ceramic and metal sealing applications

Relay insulators, capacitors, magnetrons, traveling wave tubes, X-ray tube assemblies, electrosurgical instruments, implantable packaging and feedthrough devices, gas detectors, microscopes (transmission electron microscopes, scanning electron microscopes), high-voltage feedthroughs, high-temperature feedthroughs, radio frequency feedthroughs, optoelectronics and power transistors, laser tubes, thyristors, diodes

常问问题

What is the lead time?

The lead time depends primarily on the complexity and quantity of the product. Small batch production takes 3-5 weeks, while mass production takes 4-8 weeks or longer. For urgent projects, we can provide expedited production services.

Why use molybdenum manganese (Mo/Mn) as the base coating?

After high-temperature sintering, Mo/Mn forms excellent adhesion with alumina, resulting in greater reliability.

Can you provide customization?

Yes, we support OEM/ODM customization and can produce according to your provided drawings and technical requirements.

How does GORGEOUS CERAMICS (GGS Ceramic) guarantee product quality?

We have established a comprehensive quality control system, including raw material inspection, precision machining inspection, metallization quality inspection, brazing quality inspection, helium mass spectrometry leak detection, dimensional conformity inspection, electrical performance testing, and full appearance inspection, ensuring that the products delivered to our customers are perfect and flawless.

Besides individual seals, can you provide complete assemblies?

Yes, we can provide complete assemblies, such as vacuum high-pressure feedthroughs, multi-pin feedthroughs, RF feedthroughs, flange assemblies, vacuum sealing assemblies, etc., to improve your assembly efficiency.

Which suppliers of ceramic-metal seals are available in China?

China has a very complete industrial chain for advanced ceramic and vacuum seals.