Types of vacuum sealing

    Vacuum sealing includes metal-ceramic sealing, metal-glass sealing, glass-glass sealing, and glass welding.

     Metal-ceramic sealing and metal-glass sealing are usually used for vacuum electrodes or vacuum leads, glass-glass sealing is often used between the display screen and the tube body of a picture tube, and glass welding is often used for glass vacuum systems.

     Before metal-ceramic sealing, it is necessary to use metallization paste or vacuum coating technology to make the ceramic produce a metallization layer, and the sealing itself uses brazing technology.

     The key to metal-glass sealing is to properly oxidize the metal sealing surface.

     Glass-glass sealing uses low-melting glass as the sealing material.

     There are two types of sealing: matched sealing and unmatched sealing. The so-called matched sealing means that the difference in linear expansion coefficient from room temperature to slightly higher than the sealing temperature is less than 10%.

     Kovar is often used for metal-ceramic and metal-glass matching seals, but the Kovar grades used by the two are different. Kovar grades used for sealing with 95 porcelain are 4J34, and Kovar used for sealing with molybdenum glass The grade is 4J29.

(huiputech)