JPS61165947A - Metallic vapor discharge lamp - Google Patents

Abstract

PURPOSE:To produce a simple-tube metallic vapor discharge lamp of an electric power level exceeding 3KW by charging the luminous tube with a specific amount of a gallium halide per unit volume and restricting the tube wall load and the potential gradient to within specified ranges. CONSTITUTION:A luminous tube made of quartz is charged with a pair of electrodes 2, 0.06-0.1mg of a gallium halide per ml, an excess amount of gallium, mercury and argon gas for aiding ignition. In this metallic vapor discharge lamp, the tube wall load and the potential gradient are restricted to 25-35W/cm<2> and 16-22V/cm respectively. The luminous output of gallium per wat is increased by charging a proper amount of a gallium per wat is increased by charging a proper amount of gallium halide. The output maintenance rate of the lamp is increased and its ignition voltage is reduced by properly adjusting the tube wall load and the potential gradient. Consequently, it is possible to produce a metallic vapor discharge lamp of an electric power level of at least 3KW while maintaining the performance of the lamp at a high level.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a metal vapor discharge lamp, and particularly to a high wattage metal vapor discharge lamp used in photolithography and the like.

[Conventional technology]

Conventionally, this type of discharge lamp is known as disclosed in Japanese Patent Publication No. 42-27228, but this is a 3KW discharge lamp.
These are as follows.

The figure is a configuration diagram showing a conventional discharge lamp, and in the figure, 1
2 is an arc tube made of quartz, 2 is an electrode, 3 is a sealing foil welded to the electrode 2 and sealed to the end of the arc tube 1, and 4 is a cap. For I KW discharge lamps.

The distance between the electrodes 2 is 10 m, the tube wall load is 17 pieces, and 0.05 mm of gallium iodide (GaIa) is contained in the source tube 1.
/cc of excess gallium, appropriate amount of mercury, and starting aid argon gas are sealed.

When this discharge lamp is placed horizontally and a voltage is applied via a ballast, a discharge occurs between the electrodes 2, and stable lighting occurs after several minutes.

The electrical characteristics of the discharge lamp at this time were: lamp voltage 130v% rung current 8.3A, lamp power 1.000W, and potential gradient 13v/α. The light emission of gallium during stable lighting, that is, the wavelength of 403 nm and 4170 m, which is the spectrum of gallium, is used for photolithography.

[Problem that the invention seeks to solve]

The amount of gallium iodide enclosed per unit volume.

If the tube wall load and potential gradient are applied as they are to a high-wattage discharge lamp exceeding 3 KW, it will not be possible to improve the luminous output of gallium per unit watt, and the initial wJ voltage will increase, and conversely, the unit volume If the amount of gallium iodide filled in this tube is too large, the light emitting output of gallium will decrease, and if the tube wall load is too high, the output maintenance rate during the working cycle will decrease, and if the potential gradient is too high, the gallium There was a problem in that the light emitting output of the device decreased.

The purpose of the present invention was to solve these problems, and to provide a metal vapor discharge lamp that improves the luminous output of gallium, lowers the starting voltage, and further increases the output maintenance rate during the working cycle. It is about providing.

[Failure to solve the problem]

In the metal vapor discharge lamp according to the present invention, gallium halide of υ0.06 to 0.1 W/CC per unit volume is sealed in the arc tube, and the tube wall load is 25 to 35, and the potential gradient is 16 to 35. 22 V/cm.

[Effect]

In this invention, by filling an appropriate amount of gallium halide per unit volume in the arc tube, the gallium light emission output per unit watt is improved, and by optimizing the wall load of the arc tube, the working efficiency is improved. The aim is to increase the light emission output without reducing the internal output maintenance rate, and to lower the starting voltage without reducing the light emission output by optimizing the potential gradient.

〔Example〕

Hereinafter, five preferred embodiments of the metal vapor discharge lamp of the present invention will be described in more detail.

The metal vapor discharge lamp of the present invention also has the same shape and configuration as the conventional one as shown in the drawings. However, in a 4 KW discharge lamp, the distance between two electrodes is 19 meters.

The tube wall load is 30 W/-, and gallium iodide (GaI3) is present in the arc tube 1 (Co 8 +g/cc, excess gallium).

It is filled with a suitable amount of mercury and argon gas for starting aid.

When a discharge lamp configured in this way is placed horizontally and a voltage is applied through a ballast, it starts discharging at a sufficiently low voltage.
The light will turn on steadily after a few minutes. The electrical characteristics of the discharge lamp at this time were: lamp voltage 380V, lamp current 11.4A, lamp force 4-000W, and potential gradient 20V/6.
It is. The gallium light emission output per unit watt during stable lighting is 1
．． It was three times as many. Also.

The gallium light emitting output maintenance rate during the working cycle was 85 cm after 1,000 hours of lighting, which was a good result.

In addition, the gallium light emission output, starting voltage, and output maintenance rate during the working cycle are as follows when experiments are conducted with various changes in the amount of gallium halide sealed per unit volume, tube suction load, W, and position gradient gold. be.

That is, when the amount of potassium halide per unit volume is less than 0.06 WI9, the gallium light emission output per unit watt decreases to the same level as the conventional IKW, and 0.06 WI9.
When I Trq was exceeded, the amount of unevaporated gallium iodide attached to the tube wall increased, resulting in a shielding effect and a decrease in light emission output.

When the tube wall load is less than 25 W/-, the temperature of the coldest part of the arc tube 1 decreases, the vapor pressure of gallium iodide decreases, and the light emission output decreases, and when it exceeds 35 W/-, the temperature of the arc tube 1 increases. Due to the release of impure gas from the quartz, the output maintenance rate during the working process decreases significantly, and the output maintenance rate at 40 W/cM is 100
After 0 hours of lighting, it became 50 inches.

If the potential gradient is less than 16 V/cm, the distance between the two subspecies becomes longer, so the starting voltage increases, and the starting voltage increases to 15 V/1.
In the case of 3, the starting voltage is about 1.5 times that of the discharge lamp of the above example, and if it exceeds 22 V/cm f, a large amount of mercury is required, and the mercury vapor pressure becomes high, causing an increase in the arc. The float became larger, and as a result, the temperature difference between the top and bottom of the arc tube became larger, and the point pressure of gallium iodide decreased, resulting in a decrease in output.

〔Effect of the invention〕

As explained above, this invention is effective in reducing the amount of gallium halide per unit volume sealed in the arc tube.

By optimizing the tube wall load and potential gradient, the starting voltage is low and the gallium light emission output can be increased without reducing the output maintenance rate during the working cycle.

[Brief explanation of the drawing]

The figure is a configuration diagram of a conventional metal vapor discharge lamp. DESCRIPTION OF SYMBOLS 1... Arc tube, 2... Electrode, 3... Sealing foil, 4...
・Cap.

Claims (1)

[Claims] In a high-wattage single-tube discharge lamp exceeding 3KW, in which the arc tube is filled with gallium halide, excess gallium, mercury, and starting aid gas, 0.0% per unit volume in the arc tube.
Filled with 6 to 0.1 mg/cc of gallium halide,
And the tube wall load is 25 to 35 W/cm^2, and the potential gradient is 1.
A metal vapor discharge lamp characterized by having a voltage of 6 to 22 V/cm.