Short arc type discharge lamp

Abstract

Object: To prevent the burst during lighting of short-arc discharge lamp with lighting inner pressure from 2.0 MPa to 3.0 MPa, satisfying well the characteristics of rise-time, irradiance and lifetime of lamp. Resolution: Cathode 3 and anode 4 are arranged in the discharge space 2 of the light tube 1 of short-arc discharge lamp. Rare gas and mercury are enclosed in the discharge space 2. L1 (mm) is the length from the edge of the spherical part of the light tube to the front edge of the sealing glass member 7. D (mm) is the diameter of the sealing glass member 7. P (MPa) is the inner pressure at lighting of the lamp. Under this condition, the shape of the lamp is decided to fulfill the inequality formula D<(-0.38*P+1.79)*L1+(-3.32*P+24.3). Moreover, the thickness of the sealing glass 6 is from 3.0 mm to 5.0 mm in the range L2 from the spherical edge X1 of the light tube to the point X2 where the inner surfaces of different curvature meet. And also, the input electric power to the lamp is in the range from 5 kW to 25 kW.

Description

Technical field [0001] The present invention relates to a short-arc discharge lamp, in particular to a short-arc discharge lamp with a switch-on power of 1kW or more, which is used as a light source in the exposure process of semiconductor and liquid crystal manufacturing. Background technique [0002] In an exposure process such as a manufacturing process, a short arc type discharge lamp used as a light source requires high illuminance. It is known that this type of short-arc discharge lamp (hereinafter referred to as a lamp) generally has an on-power of 1 kW or more, and the temperature and internal pressure during lighting are quite high. As a method for achieving the high illuminance, a method of increasing the luminous efficiency of the lamp in the ultraviolet band by enclosing a large amount of mercury, rare gas, etc., can be cited. In this case, there is a problem that the internal pressure of the lamp at the time of lighting increases due to the increase in the amount of ...

AI Technical Summary

Problems solved by technology

Although it is possible to qualitatively avoid lamp breakage, it is impossible to quantitatively judge how much margin there is in the mechanical strength until the breakage of the internal pressure of the lamp.

This implies that protection against lamp breakage may not be guaranteed in environments where lamp design specifications change frequently

[0013] For example, the shape of the cracked area thought to be directly related to cracking (diameter of the glass member, from the end of the bulb to the sealing part) is designed by adopting dimensions that are estimated to be no problem according to empirical rules, including the rise characteristic of the lamp, and the like. The length of the front end, the thickness of the sealing glass), and when trying to light it, it is found that due to the amount of mercury enclosed in the lamp and the size of the lamp, unexpected cracks often occur

Therefore, in the methods of avoiding cracks seen in these prior art, since the pressure resistance until cracking is qualitative, there is still a problem of not being able to flexibly prevent cracking with respect to the specification of the lamp

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