Collector tube glass-metal double-port hot-pressing sealing material and method

Abstract

The invention is a hot pressing sealing process, which is based on the solid state welding technology and belongs to the glass and metal sealing technology field. The process is characterized in that firstly, the sealing is conducted under heat and pressure; secondly, two curved symmetric glass flanges are adopted at the sealing part of a glass tube to support the force when under pressure; thirdly, alloy solder wires melted from Lead, Aluminum and Tin are adopted as sealing materials; fourthly, the sealing temperature is 0.7-0.9 times of the melting point of alloy metal solders, the applied impact pressure during the welding is 70-200kg / cm<2>, and the reaction time is 0.5s-1.5min; fifthly, the expansion coefficient of a heat-collecting glass tube is (3.2-3.4)*10<-6> / degree Celsius; sixthly, a metal end cover adopts low expansion alloys of iron-nickel or Kovar, etc. The double-port hot pressing sealing process can effectively reduce the sealing area of the glass flange and the metal end surface and reduce the expansion stress between glass and metal with small sealing stress. No annealing treatment has to be implemented after the sealing. The sealing time is greatly shortened, andthe sealing success rate is above 95 percent.

Description

technical field [0001] The invention relates to a glass-metal sealing process, in particular to a double-port sealing material and method for vacuum heat collecting tube glass and low-expansion alloy metal. Background technique [0002] The invention belongs to the technical field of glass and metal sealing, and relates to a thermal pressure sealing method utilizing solid-state welding. [0003] Different types of glass-metal sealing have different requirements for metal materials and glass. For a selected glass material, not any metal or alloy material can be sealed, the two must meet certain sealing conditions, the most basic conditions are: (1) the expansion of both glass and metal materials The coefficients should be close to each other to minimize the internal stress of the seal, which is called matching seal; (2) The melting point of the metal material should be higher than the softening temperature of the glass, that is, higher than the plastic temperature of the gla...

AI Technical Summary

Problems solved by technology

Patent No. 93101627.4 of the Chinese Invention Patent "Glass-Metal Thermocompression Sealing Process" and Patent No. 99100222.9 of the Chinese Invention Patent "Glass-Metal Thermocompression Sealing Process". Under the condition of high pressure, the welding uses metal lead with good plasticity as the solder for solid-state sealing. When sealing, the cylinder is used to impact and pressurize the solder, so that the solder is quickly deformed and decomposed, and an airtight seal is formed before it is oxidized. The sealing surface, thus solving the difficulty of mismatching between the expansion coefficient of the glass tube material and the sealing metal; the disadvantage of this process is that the melting point of solder lead is low (heating temperature 300°C), which reduces the exhaust temperature of the vacuum heat collecting tube, and the vacuum The heat collecting tube cannot be completely exhausted, and the gas is continuously released during use, which affects its service life

The disadvantage is that the sealing process device is relatively complicated, and coils and magnetic rings that generate strong magnetic pulses need to be configured, so the electric power required is large, which increases the cost, and the action time and impulse of thermocompression sealing need to be accurately controlled by a computer , not easy to operate

During the sealing process of heat-collecting glass tubes, there are generally disadvantages such as 30-40% tube explosion rate, poor safety of sealed components, and high production costs.

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