JP2008279396A - Ultraviolet irradiation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultraviolet irradiation device, in which the illumination intensity in a longitudinal direction of an ultraviolet discharge lamp is uniform and the light distribution characteristics are also good. <P>SOLUTION: The ultraviolet irradiation device is provided with the tubular ultraviolet discharge lamp 111, a lamp housing receptacle 110 housing the ultraviolet discharge lamp and having a ray extraction mouth 109 extracting the ray discharged from the light-emitting part of the ultraviolet discharge lamp, and a light shielding board 115 which is installed at a position corresponding to a central portion of the longitudinal direction of the ultraviolet discharge lamp in the ray extraction mouth of the lamp housing receptacle and carries out a light shielding of 5-15% in an area ratio to the ray extraction mouth. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an ultraviolet irradiation device.

  In recent years, a discharge lamp in which mercury or a metal halide is enclosed has been studied as an ultraviolet discharge lamp that discharges ultraviolet light. Among these, metal halide lamps in which mercury, iron, tin, and thallium are enclosed are often used in the bonding process of semiconductors and liquid crystal displays.

  An ultraviolet irradiation device that mounts such a metal halide lamp as an ultraviolet light source has a light extraction port for extracting light emitted from the metal halide lamp, and has a lamp drawing mechanism that draws the metal halide lamp from its housing part in the longitudinal direction. The metal halide lamp is accommodated in a lamp container, and the irradiated object is irradiated with ultraviolet rays emitted from the light beam outlet from above.

  Conventionally, in such an ultraviolet irradiation apparatus, the arc is the thickest in an area where the illuminance of the apparatus is high, that is, a metal halide lamp, in order to adjust the surface uniformity so as to uniformly irradiate the irradiated surface of the irradiated object. Insert a light-shielding mesh plate at the position corresponding to the center of the lamp in the longitudinal direction, and take measures to improve the surface uniformity by making the area with high illuminance equal to that of other areas by shielding light. It was. The configuration of the conventional ultraviolet irradiation device is an effective measure for a lamp having a lamp emission length of less than 1 m.

However, in recent years, along with the increase in the size of irradiated objects, the length of the ultraviolet discharge lamp mounted on the apparatus has been increased, and it has become common to use an ultraviolet discharge lamp having a light emission length of 1 m or more and accommodate it. The light outlet of the lamp container is also getting larger. Such a large-sized lamp container has a problem that cannot be dealt with by simply inserting a light-shielding mesh plate into the central portion of the light extraction port as in the prior art.
JP 2006-35436 A Japanese Patent No. 3482442 JP 2002-292825 A

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide an ultraviolet irradiation device that can achieve uniform illumination in the longitudinal direction of an ultraviolet discharge lamp and has good light distribution characteristics.

  The present invention includes a tubular ultraviolet discharge lamp made of a light transmissive dielectric in which a discharge medium is enclosed and a pair of opposing electrodes are installed, and the ultraviolet discharge lamp is accommodated and emitted from a light emitting portion of the ultraviolet discharge lamp. An area ratio with respect to the light extraction port, which is disposed at a position corresponding to a central portion in the longitudinal direction of the ultraviolet discharge lamp in the light extraction port of the lamp container. And an ultraviolet irradiation device including a light shielding plate for shielding light of 5 to 15%.

  According to the ultraviolet irradiating device of the present invention, light shielding is performed at a position corresponding to the central portion in the longitudinal direction of the ultraviolet discharge lamp at the light extraction port of the lamp container in an area ratio of 5 to 15% with respect to the light extraction port. By installing a plate, a light shielding mesh plate is inserted at a position corresponding to the central part of the lamp longitudinal direction, which is the thickest part of the arc, and the area with high illuminance is equivalent to that of other areas by shielding the light. Thus, the surface uniformity can be improved, the light distribution characteristics in the longitudinal direction of the lamp can be improved, and the light distribution characteristics of the entire apparatus can also be improved.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an ultraviolet irradiation apparatus 100 according to one embodiment of the present invention, in which a plurality of ultraviolet irradiation units 102 are arranged side by side to irradiate an object to be irradiated 10 in a processing chamber 101 with ultraviolet rays. A filter 103 that suppresses transmission of visible light and ultraviolet light having a wavelength region of 380 nm or more is disposed below the plurality of ultraviolet irradiation units 102.

  As shown in FIGS. 2 and 3, each ultraviolet irradiation unit 102 includes an ultraviolet discharge lamp 111 disposed in the center of the interior of the lamp housing 110 having a light extraction opening 109 opened downward, and an interior of the lamp housing 110. And a main reflector 112 having a reverse U-shaped cross-sectional surface arranged so as to cover the side and upper side of the ultraviolet discharge lamp 111 and to reflect the ultraviolet ray from the ultraviolet discharge lamp 111 into a substantially parallel beam and to reflect downward. The auxiliary reflector 113 is disposed below the ultraviolet discharge lamp 111 at an angle on both sides. As the main reflector 112, a cold mirror capable of transmitting light of 500 nm or more is used. As the auxiliary reflector 113, a high-luminance aluminum plate having a regular reflectance of 90% at 365 nm is used.

  The ultraviolet discharge lamp 111 has an outer tube diameter of 27 mm, a wall thickness of 1.5 mm, and a light emission length L of 1000 mm, for example, an electrode made of tungsten (W) or the like is disposed inside an arc tube made of quartz tube having ultraviolet transparency. A metal halide lamp having a lamp voltage of 1100 V and a lamp voltage value of 11 A is used. The arc tube is filled with a rare gas such as argon (Ar) gas, mercury (Hg), and a metal halide having at least one emission other than the spectrum of mercury in the wavelength region of 300 to 400 nm. For example, a metal halide lamp in which mercury and a metal halide are sealed inside the arc tube, and a thallium lamp in which a thallium halide is sealed together with mercury and a small amount of rare gas inside an airtight container can be used.

  A light shielding plate 115 shown in FIG. 4 is installed at a position corresponding to the central portion of the ultraviolet discharge lamp 111 in the longitudinal direction at the light beam outlet 109 in the lamp container 110 of the ultraviolet irradiation unit 102. The light shielding plate 115 is made of a high-luminance aluminum plate having a regular reflectance of 90% at 365 nm, in which light passage holes 115A are formed at a rate described later for allowing a predetermined rate of light to pass through. These light passage holes 115A are such that the area of the real part of the light-shielding plate excluding the entire area of the light passage holes 115A with respect to the opening area (the area of the hatched portion in FIG. 4) is 5% to 15%. Is formed.

  According to the ultraviolet irradiation apparatus of the present embodiment, when the ultraviolet discharge lamp 111 is turned on and the illuminance distribution is measured at the position of the irradiated object 10, the uniformity is improved and good light distribution characteristics are obtained.

  As the ultraviolet discharge lamp 111, a metal halide lamp having an outer tube diameter of 27 mm, a wall thickness of 1.5 mm, a light emission length L of 1000 mm, a lamp voltage of 1100 V, and a lamp voltage value of 11 A, on which an electrode made of tungsten (W) is arranged, is adopted. In contrast, the high-luminance aluminum light-shielding plate of 150 mm × 150 mm is installed at a position corresponding to the central portion in the lamp longitudinal direction at a position 155 mm away from the lamp central axis, and the light-shielding area and illuminance uniformity are The relationship was measured. That is, a plurality of types of light shielding plates 115 having different light shielding areas with respect to the light beam extraction port 109 are installed at positions corresponding to the central portion of the metal halide lamp 111 in the longitudinal direction at the light beam extraction port 109 of the lamp container 102. The illuminance distribution in the longitudinal direction of the lamp was measured at the position, and the uniformity was determined by the following equation. The result was as shown in the graph of FIG.

(Uniformity) = (maximum illuminance value−minimum illuminance value) / (maximum illuminance value + minimum illuminance value) × 100%
The lower the numerical value, the better the uniformity, but the uniformity of 10% or less was shown when the area ratio of the light shielding area of the light shielding plate to the aperture area was 5 to 15%. When no light shielding plate was installed, the uniformity was 18.0%.

  Further, the illuminance distribution in the longitudinal direction of the lamp is as shown in FIG. In FIG. 6, a curve a indicates a distribution when no light shielding plate is installed, a curve b indicates a distribution when the area ratio is 10%, and a curve c indicates a distribution when the area ratio is 20%. From the graph of FIG. 6, it can be confirmed that good light distribution characteristics are exhibited at an area ratio of about 10%.

  The light shielding area ratio varies depending on the distance between the ultraviolet discharge lamp 111 and the light shielding plate 115 even with the same light shielding plate 115. That is, as shown in FIG. 7, when the light shielding plate 115 is 155 mm away from the ultraviolet discharge lamp 111, the distance to the lamp 111 for each light shielding plate having a light shielding area ratio of 15% and a light shielding area ratio of 7.5%. Since the light-shielding area ratio changes as shown in FIG. 8 in the design, an appropriate number is necessary so that the light-shielding area ratio becomes 5 to 15% according to the distance from the lamp 111 to the light-shielding plate 115. It is necessary to drill the optical hole 115A.

The sectional view of the ultraviolet irradiation device of one embodiment of the present invention. Sectional drawing in the cross section orthogonal to the lamp | ramp axis | shaft of the ultraviolet irradiation unit in the said embodiment. Sectional drawing in a cross section parallel to the lamp | ramp axis | shaft of the ultraviolet irradiation unit in the said embodiment. The top view of the light-shielding plate used in the said embodiment. The graph which shows the relationship between the light shielding area ratio of the light-shielding plate in the said embodiment, and the uniformity degree of the ultraviolet illumination intensity of an ultraviolet irradiation unit. The graph which shows the relationship between the light-shielding area ratio of the light-shielding plate in the said embodiment, and the light distribution characteristic of the illumination intensity of an ultraviolet irradiation unit. The front view which shows the distance relationship between the ultraviolet-ray radiation lamp and light-shielding plate in the said embodiment. The graph which shows the relationship of the change of the light-shielding area ratio of the light-shielding plate with respect to the change of the distance of the ultraviolet radiation lamp and light-shielding plate in the said embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Ultraviolet irradiation device 102 Ultraviolet irradiation unit 109 Light extraction port 110 Case 111 Ultraviolet discharge lamp 112 Main reflector 113 Auxiliary reflector 115 Light-shielding plate

Claims (1)

A tubular ultraviolet discharge lamp enclosing a discharge medium;
A lamp container that contains the ultraviolet discharge lamp and has a light extraction port for taking out the light emitted from the light emitting portion of the ultraviolet discharge lamp;
A light shielding plate that is installed at a position corresponding to a central portion in the longitudinal direction of the ultraviolet discharge lamp at a light beam extraction port of the lamp container and that blocks light by 5 to 15% in terms of an area ratio with respect to the light beam extraction port. UV irradiation device.

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