Tungsten electrode and its preparation method, and high-pressure discharge lamp using the tungsten electrode

Abstract

The invention discloses a preparation method of a tungsten electrode, a tungsten electrode prepared by the method, and a high-pressure discharge lamp using the tungsten electrode, wherein the preparation method includes: S1) preparing the tungsten electrode in shape; S2) preparing the tungsten electrode Perform acid etching treatment; S3) Vacuum high-temperature sintering to coarsen the crystal; S4) Perform secondary acid etching treatment on the surface to make the surface appear similar to the surface shape of a polygonal mirror, and there are peaks and valleys on the surface. 25 μm. When the tungsten electrode (222) prepared by implementing the method of the present invention is used in a high-pressure discharge lamp, it can suppress the high-pressure discharge lamp from occurring due to the side tube of the tungsten electrode (222) and the discharge vessel (1) during the manufacturing process or the process of turning off the lamp. The cracks in the quartz glass (131) and the rupture of the high-pressure discharge lamp caused by the difference in thermal expansion and contraction coefficients between the quartz glasses in the part (11) improve the service life of the high-pressure discharge lamp.

Description

technical field [0001] The invention relates to the optoelectronic field, in particular to a preparation method of a tungsten electrode or a tungsten electrode mainly composed of tungsten, and the tungsten electrode prepared by the preparation method. The invention also relates to a high-pressure discharge lamp using the above-mentioned tungsten electrode. Background technique [0002] There are high-pressure discharge lamps that are widely required in optical equipment such as projectors and exposure machines. Two tungsten electrodes with tungsten as the main component are placed opposite to each other in a quartz discharge vessel. One end of the electrodes is buried in quartz glass, and The metal foil (such as molybdenum foil) with an expansion coefficient close to that of quartz is connected to the external power supply wire, and the metal foil (such as molybdenum foil) and quartz glass are fused and sealed by an external heat source to form a relatively sealed quartz disc...

AI Technical Summary

Problems solved by technology

[0012] The first problem of the high-pressure discharge lamps using methods 1 and 2 in the prior art is that the large amount of heat energy accumulated by the electrodes during the manufacturing process or lighting process cannot be released by conduction in time due to the reduced contact area between the electrodes and the quartz glass. Small contact surfaces or end faces / corners as described in a)b)c) above are prone to stress concentration sharply, leading to bulb rupture

[0013] The second problem that exists in the high-pressure discharge lamps prepared by methods 1 and 2 of the prior art is that after being isolated by the intermediate medium or after the groove is processed, an electric potential is easily formed between the electrode or the groove valley of the electrode groove and the quartz glass. Difference

When the potential difference is loaded with high voltage (such as 3KV) at the moment of lighting, it is easy to increase sharply at the root of the discharge vessel, forming a discharge phenomenon from the electrode to the quartz glass near the root of the discharge vessel, causing SiO2, which is the main component of the quartz glass, to decompose into Si and O. And enter the quartz container and combine with other substances to cause the bulb to turn black and have a short life

[0014] The third problem of high-pressure discharge lamps using methods 1 and 2 of the prior art is that, from an economic point of view, the manufacturing process of high-pressure discharge lamps using methods 1 and 2 of the prior art is obviously complicated and expensive

[0015] As for the high-pressure discharge lamp of method 3 in the prior art, the first defect is that it is usually installed after the assembly and processing of the discharge lamp is basically completed, and it cannot prevent cracks in the quartz glass during the manufacturing process (such as quartz hot-melt fixed electrodes); the defect Second, the outer layer of quartz glass coated with thermal insulation film or thermal insulation coil can only delay the cooling effect in low temperature areas (such as below 200 ℃), and it can hardly happen to the quartz glass near the root of the quartz discharge vessel (the lighting temperature inside the quartz glass is above 600 ℃). Can affect the role of quartz glass crack formation

In other words, it has no practical effect on preventing crack damage

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