Beryllium window sealing method

A technology of beryllium window and beryllium sheet, which is applied in the field of beryllium window, can solve problems such as poor stability, difficulty in ensuring sealing effect, and increased energy consumption, so as to achieve the effect of ensuring the reliability of sealing and the firmness and reliability of brazing performance

Inactive Publication Date: 2015-10-14
CHENGDU KAISAIER ELECTRONICS
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the chemical properties of beryllium are active, and it is easy to form a dense and stable oxide film at room temperature. This film makes the wettability between beryllium and solder extremely poor, the air leakage rate is high after sealing, and the stability during operation is poor.
At present, because the domestic ray tube manufacturers cannot solve the problem of beryllium sealing well, the output window often uses copper windows, which reduces the transmittance of rays and increases energy consumption.
[0003] Chinese patent CN103715045A discloses a beryllium window and its sealing method. A layer of metal nickel is plated on the sealing edge area of ​​the lower surface of the beryllium window, and it is a sealing method for the beryllium window that needs to be protected. The sealing time Short, complex process, it is difficult to guarantee the sealing effect

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0016] In the embodiment of the present invention, a method for sealing a beryllium window involves immersing a beryllium sheet in a mixture of sulfuric acid and hydrogen peroxide at a ratio of 9:1, and the temperature of the mixture is controlled at 50°C. The response time is 13s. The cleaned beryllium flakes were rinsed with deionized water for 8 min, then dried in an oven at 75°C and stored in a vacuum cabinet. Since the oxide film formed by beryllium at room temperature is dense and stable, the method of breaking the film at high temperature will easily increase the brittleness of beryllium and the film breaking is not easy to complete, and the ideal sealing strength cannot be obtained. Therefore, we choose copper, which has strong mutual corrosion with beryllium at the sealing temperature, as the base metal of the output window. The solder is silver-copper 28 silver-based solder. Through the mutual dissolution of beryllium sheet, copper and solder at high temperature, the...

Embodiment 2

[0018] In the embodiment of the present invention, a method for sealing a beryllium window involves immersing a beryllium sheet in a mixture of sulfuric acid and hydrogen peroxide at a ratio of 11:1, and the temperature of the mixture is controlled at 55°C. The response time is 17s. The cleaned beryllium flakes were rinsed with deionized water for 12 min, then dried in an oven at 85°C and stored in a vacuum cabinet. Since the oxide film formed by beryllium at room temperature is dense and stable, the method of breaking the film at high temperature will easily increase the brittleness of beryllium and the film breaking is not easy to complete, and the ideal sealing strength cannot be obtained. Therefore, we choose copper, which has strong mutual corrosion with beryllium at the sealing temperature, as the base metal of the output window. The solder is silver-copper 28 silver-based solder. Through the mutual dissolution of beryllium sheet, copper and solder at high temperature, t...

Embodiment 3

[0020] In the embodiment of the present invention, a method for sealing a beryllium window involves immersing a beryllium sheet in a mixture of sulfuric acid and hydrogen peroxide at a ratio of 10:1, and the temperature of the mixture is controlled at 52°C. The response time is 15s. The cleaned beryllium flakes were rinsed with deionized water for 10 min, then dried in an oven at 80 °C and stored in a vacuum cabinet. Since the oxide film formed by beryllium at room temperature is dense and stable, the method of breaking the film at high temperature will easily increase the brittleness of beryllium and the film breaking is not easy to complete, and the ideal sealing strength cannot be obtained. Therefore, we choose copper, which has strong mutual corrosion with beryllium at the sealing temperature, as the base metal of the output window. The solder is silver-copper 28 silver-based solder. Through the mutual dissolution of beryllium sheet, copper and solder at high temperature, ...

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PUM

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Abstract

The invention discloses a beryllium window sealing method. The method includes the steps: immersing a beryllium sheet in a mixed liquid of sulfuric acid and hydrogen peroxide with a mass ration of 9:11, the temperature of the mixed liquid being controlled within 50-55 DEG C, and the reaction time being 13-17s; cleaning the immersed beryllium sheet with deionized water for 8-12min, drying the beryllium sheet in a 75-85 DEG C baking oven, and storing the dried sheet in a vacuum cabinet for standby application; selecting copper as a core metal of an output window, performing a sealing step at the heating rate of 3 DEG C/min for 60min at the holding temperature of 730 DEG C, then making the temperature rise to 800 DEG C and the holding time last 8min, the beryllium sheet, the copper and a solder dissolving each other at the temperature of 800 DEG C, forming a metallic compound of the beryllium sheet, the copper and the solder on a sealing surface, and thus forming a firm and airtight soldering surface. The sealing reliability of the beryllium window is guaranteed, and the beryllium window can be greatly applied to ray tubes. The well sealed output window exhibits firm and reliable solderability. The output window can stand repeated thermal shock at the temperature of 800 DEG C, and the leak rate of the output window is better than 10<-9>pa.m<3>/s.

Description

technical field [0001] The invention relates to the technical field of beryllium windows, in particular to a method for sealing beryllium windows. Background technique [0002] Beryllium is a rare metal. Due to its small neutron absorption cross-section, beryllium absorbs less X-rays and has strong penetrating ability. Therefore, beryllium is an ideal output window material in ray tubes. However, the chemical properties of beryllium are active, and it is easy to form a dense and stable oxide film at room temperature. This film makes the wettability between beryllium and solder extremely poor, the air leakage rate after sealing is high, and the stability during operation is poor. At present, because domestic ray tube manufacturers cannot solve the problem of beryllium sealing well, the output window often uses copper windows, which reduces the transmittance of rays and increases energy consumption. [0003] Chinese patent CN103715045A discloses a beryllium window and its sea...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01J35/18H01J9/26
Inventor 刘斌
Owner CHENGDU KAISAIER ELECTRONICS
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