What Is a Glass-to-Metal Seal?

Frosted glass mainly refers to those glass used for bonding and sealing. It is a large class of glass that includes many different systems and different compositions. It is used as a bonding and sealing material for glass, metal, ceramics, mica, and other inorganic non-metal materials. It has been widely used in vacuum electronic devices, electronic technology and other scientific and technological fields ^[1] .

Frosted glass refers to a class of powdery glass materials with a softening temperature not higher than 500 degrees Celsius. Because it is easy to adhere to metals, ceramics and other materials, and it is not air-permeable, it can obtain high air tightness after forming a sealed cavity, at the same time it has non-flammability and good heat resistance, and its electrical properties are also superior. As an inorganic

According to its structure, frit glass can be divided into two categories. One type is crystalline glass, whose structure is a mixture of crystalline and amorphous forms, and its appearance is white opaque or translucent depending on the degree of crystallization. The other type is amorphous glass, which has an amorphous form and an external appearance. Transparent body ^[2]

The requirements for frit glass are the production requirements of the sealed device during the manufacturing process during the use of frit glass, such as sealing and welding. Can the bonded and sealed devices be safe, reliable and effective? The use of the ground, and to meet the requirements of the use of the device and other requirements.

(1) The softening temperature of the glass, especially the sealing temperature, must be lower than the highest temperature that the sealed device can withstand. For example, when the cone screen of a color television picture tube is sealed, because the color phosphor cannot withstand high temperatures, it is generally limited to below 450 ° C. When sealing with metal parts, the temperature of the fusion seal must be lower than the temperature that would be deformed. In general, the lower the sealing temperature, the better. It is best to seal at low temperature and use at high temperature.

(2) glass

Glassy substances have a series of excellent properties: have good chemical stability (not easy to age and crack like organic substances), good compactness and air tightness, good electrical insulation properties, and glass, metal, ceramics and other inorganic Non-metallic materials have good adhesion properties, forming a vacuum-tight seal. The unique excellent properties of glassy substance are inseparable from the tunability of its physical and chemical properties. With composition adjustment, process control and various processing methods, the physical and chemical properties of glass can be adjusted within a wide range to meet various special requirements. Therefore, people have always paid attention ^[1] .