• Home
  • Ceramic to Metal Seal
Ceramic to Metal Seal

Ceramic to Metal Seals; CTM: A ceramic to metal seal is a joined or bonded assembly of a ceramic on one side and a metal on the other side using one of the following techniques.

Ceramic Metallization and Brazing (or Soldering)

It is a sealing process by brazing or soldering a metallized ceramic and metal. IJ Research uses one of the metallization techniques listed in the PDF called Metallization (Please refer to the Corporate Literature). In industry, a temperature less than 450OC, it is called as soldering (often flux-less soldering at IJ Research) or soft brazing. Otherwise, it is called brazing.

Diffusion Bonding

This is a sealing process of a ceramic on one side and a metal on the other side with nothing in-between and is a direct inter-diffusion bonding process. IJ Research performs all the possible combinations such as glass/glass, glass/ceramic, ceramic/metal, ceramic/ceramic and metal/metal. Our process includes liquid phase and others. It is a thermo-diffusive and is one of a few IJ Research uses*.

*The terminology is the one what IJ Research prefers to adapt and use. It is by an (inter)diffusion processing at high temperature.

Active Metal Element Brazing

For certain geometry and layout of a ceramic and metal seal assembly, IJ Research uses a braze that contains a small amount of highly reactive element that has a function to bond to ceramic. In this process, the ceramic may not need to be metallized prior to the brazing. This IJ Research thermo-diffusively and thermo-metallurgically reactive braze has very different form and shape when it is compared with the commercially available counterparts. IJ Research product is not only material friendly, but also is process advantageous. In a contact angle analysis, it possesses very advantageous position leading superior bonding strength result.

This process performs the best when the thermal properties of the components are compatible. In some cases, this may the only process option to be used with no other options. However, for most of common geometries and layouts in a seal design, it would not be the best. Yet, if it would be the choice for any reasons, IJ Research has its own material that is believed to be superior to any others in terms of end result. Our material and process can provide its superiority and often is measurable and comparable again with outcomes. It will be another performance base result.

Co-Fired Bonding of Ceramic and Metal

In recent years, IJ Research has developed a braze-less ceramic and metal bonding and a sample sketch of the configuration below demonstrates no braze or no sealing glass in-between the pin and the ceramic header. It is a patent pending concept and the hermeticity goal is 10-11 He std. cc/sec at 1 atm. Diff.

Ceramic and Metal Seal Using a Glass In-between

This is a sealing technique using a glass, glass-ceramic or oxide composite. The sealing can be a hermetic seal of a combination of glass, ceramic and metal such as glass/ceramic, ceramic/metal, glass/metal, ceramic/ceramic, or metal/metal.

This inorganic oxide sealant requires a high temperature to process them together and IJ Research has developed various inorganic sealants (or simply a sealing glass) with a use temperature as low as 400OC. IJ Research has its technique how to formulate a sealing glass, sealing glass-ceramic or an inorganic oxide composite. Over the years, IJ Research formulated many and most of them are listed in our Corporate Literature called, Sealing Glass List.

Please click for a PDF copy of the brochures, Ceramic to Metal Seal, Hermetic Seal, Metallization, and Metal and Sealing Glass List.