InSealing specializes in Glass-To-Metal Seals, where glass is heated to a molten state and then wetted to the metal, creating a tight bond while carefully controlling the thermal expansion of both materials to prevent breakage.
1. Components of glass and metal packaging production
The glass-to-metal sealing is widely used, such as: watch cover, lithium battery cover, 5G integrated signal box packaging, pressure sensor sealing, laser, infrared devices and electro -optical sources. Glass-to-metal sealing techniques are very high. It not only requires a certain mechanical strength, but also requires excellent gas tightness and conductivity in the case of high vacuum.
2. Brief description of glass-to-metal sealing process
The glass-to-metal sealing we commonly use are tube -shaped sealing, and the seal is composed of three parts: cover, vitreous, and core column (as shown in the figure below). Under a certain temperature, atmosphere, etc., as a good insulating material, the vitreous body seals the cover plates and core columns of different materials into sealing. The sealing glass has low breathability (can reach 10-10 Pa m3/s), good resistance to heat shock resistance, pressure resistance (340 MPa), and corrosion resistance.
The glass-to-metal sealing needs to be paid attention to the following questions:
(1) The thermal expansion coefficients of glass and metal alloy materials should be basically consistent or closer to achieve the internal stress reduction of the sealing parts to a minimum.
(2) The melting point of metal and alloy materials is higher than the softening temperature of the glass.
(3) Metal is required to have good plasticity and ductility.
(4) Glass and metals and alloys must be cleaned, otherwise it will cause air leakage or burst of air.
(5) Before certain metals or alloys and glass seal, hydrogen -burning gas treatment is required.
(6) The sealing parts should try to achieve annealing treatment like glass instruments to reduce stress.
3. The importance of thermodynamic performance of the glass-to-metal sealing, the importance of air tightness to product quality.
(1) Heat stability: After the sealing glass has gone through a large temperature change process, the physical properties and chemical properties of the glass remain stable as the thermal stability of the glass. During the application of components, the stability of the heating and cooling cycle is often considered. In this series of this series, the glass itself must be stable. Consistent.
(2) Heating and shock -resistant: Thermal shock resistance, also known as heat -resistant impact, is a comprehensive manifestation of the material of the material. It mainly represents the material that the material has undergone a very severe temperature change. The coefficient, elastic modulus, density, thermal conductivity, etc. In addition, the geometric shape of the material also affects thermal shock resistance. The heat shock is mainly the number of thermal cycles that seal the overall seal.
(3) Electric insulation performance: The factors that determine the insulation performance of the glass electrical insulation include the ingredients of the glass, the characteristic temperature of the glass, and the chemical stability of the glass. In terms of characteristics, the resistivity is calculated using a resistor tester to measure the glass resistance at a certain temperature, and then use the conversion formula to calculate the resistivity. The electrical insulation performance of glass in terms of electronic components is particularly important, which has different requirements for the medium loss, dielectric constant, and breakdown voltage of the glass.
(4)Air tightness: Air tightness is a shell and one of the important indicators of the component. The shell is not only the coat of the packaging chip, but also supports the role of components (electrical connection, heat transmission, mechanical protection, etc.). It is a component device. For important components, poor gas tightness will cause external water vapor, impurities ion or gas to enter the cavity of the component to produce surface leakage or pollution.
4. Conclusion
The glass-to-metal sealing technology processing processes are more demanding on materials, and they need to have comprehensive process conditions and mature material solutions in order to make the sealing of metal and glass materials in the actual application.