JP5343768B2 - High pressure discharge lamp - Google Patents

Description

  The present invention relates to a high-pressure discharge lamp, and more particularly to a high-pressure discharge lamp in which a discharge tube and an outer tube are provided in contact or in close contact with each other and the discharge tube is indirectly cooled from the periphery of the outer tube.

Conventionally, a high pressure discharge lamp that irradiates ultraviolet rays has been used in a curing process of a resin such as an adhesive and an exposure process of a printed circuit board. This type of lamp is usually cooled in order to prevent damage to the lamp itself and to avoid a thermal effect on the workpiece.
As a high-pressure discharge lamp having a structure capable of performing this cooling efficiently and effectively, the present applicant provides an outer tube in contact or in close contact with the outer periphery of the discharge tube, and cools the periphery of the outer tube. Therefore, it has been proposed to cool the discharge tube indirectly.
JP 2008-146962 A is one example.

FIG. 5 shows the prior art. In the figure, a lamp 1 comprises a straight tubular discharge tube 2 and an outer tube 3 provided concentrically on the outer periphery thereof. The discharge tube 2 includes a straight tubular inner tube 21 and sealing portions 22 and 22 at both ends thereof, and has a pair of electrodes 23 and 23 disposed to face each other in the discharge space S.
The discharge tube 2 is inserted into the outer tube 3, and at least a part of the outer surface thereof is disposed so as to be in contact with or in close contact with the inner surface of the outer tube 3.

The lamp 1 having the above configuration is covered with a cooling pipe 4 so as to have a gap, and the gap forms a cooling medium (water) passage 5. When the lamp is turned on, a cooling medium (water) is passed through the cooling medium passage 5 to cool the outer tube 3 of the lamp 1 and indirectly cool the discharge tube 2.
In the above prior art, since the discharge tube 2 is in contact with or close to the outer tube 3, the discharge tube 2 is effectively cooled through the outer tube 3.

In the lamp having such a structure, the cooling effect is improved as the discharge tube 2 and the outer tube 3 become closer to each other. On the other hand, the operation of inserting the discharge tube 2 into the outer tube 3 becomes very difficult. In recent years, objects (substrates) to be processed have been increased in size, and along with this, lamps have also become longer, making the operation more difficult.
The glass tube that originally constitutes the lamp has a problem in the uniformity in the axial direction, and if this is further increased to 1 m to 3 m, it is inevitable that the glass tube has a wavy shape in the axial direction. There is a problem that the discharge tube 2 and the outer tube 3 rub against each other at the time of insertion and damage the surface.

  In particular, the abrasion on the discharge tube 2 side is serious, and the discharge tube 2 is directly exposed to the discharge in the discharge space S and becomes extremely high temperature and high pressure, so that the outer surface can be scratched. There was a problem that the thermal stress often leads to breakage.

JP 2008-146962 A

  In the present invention, in view of the above-described problems of the prior art, a straight discharge tube is inserted into an outer tube, and at least a part of the discharge tube is disposed in contact with or in close contact with the inner surface of the outer tube. It is an object of the present invention to provide a high-pressure discharge lamp having a structure that does not cause scuffing even if it is rubbed between the two when the discharge tube is inserted into the outer tube.

In order to solve the above-described problems, a high-pressure discharge lamp according to the present invention is a scratch that transmits any or all of light in the wavelength region of 200 to 450 nm on the outer surface of the discharge tube and / or the inner surface of the outer tube. It is characterized by coating a protective film .
The scratch-preventing film is characterized by comprising ceramics mixed with particles of carbon, silicon carbide, or boron nitride.

According to the present invention, since the scratch preventing film is formed on the outer surface of the discharge tube and / or the inner surface of the outer tube, even if both are rubbed when the discharge tube is inserted into the outer tube, the scratch preventing film is formed. Since only the scratches can be made and the discharge tube or the outer tube itself cannot be damaged, the discharge tube, in particular, the discharge tube is not damaged by thermal stress.

It is sectional drawing of the high pressure discharge lamp which concerns on this invention, Comprising: (A) is whole sectional drawing, (B) is an expanded sectional view of the X section. The further expanded fragmentary sectional view of this invention. The light transmission characteristic figure of the abrasion-prevention film | membrane (silica) of this invention. The light transmission characteristic figure of the abrasion-prevention film | membrane (titania) of this invention. Sectional drawing of a prior art example.

FIG. 1A is a cross-sectional view of a high-pressure discharge lamp according to the present invention, and FIG. 1B is an enlarged cross-sectional view of a portion X thereof.
A high-pressure discharge lamp 1 according to the present invention shown in FIG. 1A includes a straight tubular discharge tube 2 and an outer tube 3 into which the discharge tube 2 is fitted. The discharge tube 2 has an outer surface. At least a portion is disposed so as to be in contact with or in close contact with the inner surface of the outer tube 3.
Here, the “contact state” means a state in which the outer surface of the discharge tube and the inner surface of the outer tube are in point contact or line contact, and includes a state in which a part is in surface contact. Further, the “close contact state” refers to a state in which the two are mainly in surface contact.
The dimensional relationship between the outer diameter of the discharge tube 2 and the inner diameter of the outer tube 3 is such that they are in contact or in close contact as much as possible, while the workability of inserting the discharge tube 2 into the outer tube 3 is good. The average gap between them is, for example, about 100 μm.

The discharge tube 2 includes an inner tube 21 and sealing portions 22 and 22 at both ends thereof. In the discharge space S, a pair of electrodes 23 and 23 are disposed to face each other. The electrode 23 is connected to a metal foil 24 in the sealing portion 22, and an external lead 25 is connected to the metal foil 24.
In addition, about another structure, it is the same as that of the structure which the same code | symbol shows in FIG.

As is apparent from FIG. 1B, the outer surface of the discharge tube 2 and the inner surface of the outer tube 3 are coated with scratch-resistant films 7 and 8, respectively.
As the scratch-preventing films 7 and 8, a material that can be coated without being bonded to the discharge tube 2 or the outer tube 3 made of quartz glass is used. For example, silica (SiO ₂ ), polycrystalline alumina (Al ₂ O ₃ ), yttria (Y ₂ O ₃ ), hafnia (HfO ₂ ), magnesia (MgO), titania (TiO ₂ ), niobium oxide (Nb ₂ O ₅₎ Or a multilayer film of these ceramics can be used.
In addition to ceramics, diamond-like carbon (DLC) can also be used.

Further, the high-pressure discharge lamp of the present invention, different transmission wavelength range required for the abrasion preventing films 7 and 8 depending on the application, one of the wavelength region of 200~450mm to abrasions prevention film in the present invention light or Those that transmit all the light are used.
This wavelength range is determined depending on the application. For example, when ultraviolet rays such as a hardening process after semiconductor resist exposure are used, a transmissive film that transmits a wavelength range of 200 to 350 nm is used.
On the other hand, in applications where an adhesive such as a liquid crystal sealing step is cured with visible light, a scratch-preventing film that transmits a wavelength region of 340 to 450 nm is used.
And the wavelength range which permeate | transmits is decided by the abrasion-resistant film | membrane material used, and the material mentioned above has the characteristic which permeate | transmits the light of any wavelength range of 200-450 nm or all the light.

FIGS. 2 and 3 show the light transmission characteristics of silica (FIG. 2) and titania (FIG. 3) as an example of a material used as a scratch-resistant film . In the case of silica of FIG. Light in the wavelength range is transmitted, and in the case of titania in FIG. 3, light in the wavelength range of 280 nm or more is transmitted.

Next, a method for forming the scratch preventing films 7 and 8 will be described. Here, the case where the scratch-preventing film is silica will be described.
The outer surface of the discharge tube 2 (inner tube 21) and the inner surface of the outer tube 3 are coated with silica alkoxide by dipping. This is baked in the atmosphere at a temperature of 600 ° C. or higher to evaporate organic matter. Thereby, the baked silica is coated as a scratch-resistant film . The thickness of the scratch preventing film thus formed is, for example, about 1 μm.
The discharge tube 2 is inserted into the outer tube 3 with the scratch-preventing films 7 and 8 formed on the outer surface of the discharge tube 2 and the inner surface of the outer tube 3. At this time, the inner surface of the outer tube 2 and the outer surface of the discharge tube 3 are in partial contact with each other and rub against each other, but both rub against each other via the scratch-preventing films 7 and 8.
Then, the abrasion preventing films 7 and 8 are not necessarily bound to the surface of the glass, since only is coated to be coated, abrasion-preventing film from the glass surface be applied rubbing by force a portion Therefore, the force can be absorbed and the surface of the discharge tube 2 or the outer tube 3 itself can be prevented from being damaged.
As described above, when the discharge tube 2 is inserted into the outer tube 3, both constitute a contact state or a close contact state via the scratch-preventing films 7 and 8.

In the above description, an example in which the scratch-preventing film is made of silica has been described. However, if the scratch- preventing film is a ceramic, it can be coated by dipping → firing as in the case of silica.

On the other hand, when the scratch-resistant film is DLC, the outer surface of the discharge tube 2 and the inner surface of the outer tube 3 can be coated by a vapor deposition method such as a CVD method or a PVD method. Even in this case, since the glass surface and DLC are not bonded and can be peeled off, even if rubbing occurs when the discharge tube is inserted, the DLC can be peeled off to absorb the force. It is possible to prevent the tube surface from being damaged.

Next, another embodiment will be described with reference to FIG. In the figure, the discharge tube 2 (inner tube 21) and its scratch-resistant film 8 are disclosed.
In the case of using ceramics as the scratch-preventing film 8, the ceramics are mixed with particles 10 such as carbon, silicon carbide and boron nitride. The center particle size of the particles 10 is, for example, 0.1 μm, which is extremely small compared to the gap between the discharge tube 2 and the outer tube 3, for example, 100 μm.

When the particle 10 has a carbon graphite structure or a boron nitride h-BN crystal structure, the layers in the graphite structure or the crystal structure can be easily separated. For this reason, when the discharge tube 2 is inserted into the outer tube 3, even if a rubbing force is applied, the layer of the particle 10 itself in the scratch preventing film 8 is easily peeled off and the rubbing force. Can be more easily absorbed, and the discharge tube 2 can be more effectively prevented from being scratched.

Further, even when the particle 10 has a carbon diamond structure, carbon silicon, or boron nitride c-BN crystal structure, the discharge tube can be prevented from being damaged.
In this case, when the discharge tube 2 is inserted into the outer tube 3, the friction force is absorbed by the particles 10 in the scratch preventing film 8 rotating, and the force is applied to the discharge tube 2. Can be suppressed, and can be prevented from being scratched.

The scratch-preventing films 7 and 8 including the particles 10 are formed by mixing the particles 10 in the silica alkoxide described in the previous embodiment, coating the particles by dipping, and baking the particles.

By the way, in the description of the above embodiment, it has been described that both the discharge tube 2 and the outer tube 3 are coated with the anti-scratch films 7, 8, but this is not always necessary, either the outer surface of the discharge tube 2 or the outer tube 3. It may be formed on any of the inner surfaces.
That is, the scratch-preventing film may be a coating on the outer surface of the discharge tube 2 and / or the inner surface of the outer tube 3.

As described above, in the high-pressure discharge lamp of the present invention, the scratch-resistant film that transmits any light or all light in the wavelength region of 200 to 450 nm on the outer surface of the discharge tube and / or the inner surface of the outer tube. When the discharge tube is inserted into the outer tube, the scratch-resistant film is rubbed and the scratch- resistant film is scratched or partially dropped, so that the discharge tube It is possible to prevent the discharge tube from being damaged without being scratched.

DESCRIPTION OF SYMBOLS 1 High pressure discharge lamp 2 Discharge tube 21 Inner tube 22 Sealing part 3 Outer tube 4 Cooling tube 7, 8 Scratch prevention film S Discharge space

Claims (2)

A straight tubular discharge tube in which a pair of electrodes are arranged opposite to each other and at least mercury is sealed inside an inner tube sealed at both ends, and an outer tube provided concentrically with the discharge tube. In the high-pressure discharge lamp, the discharge tube is disposed in contact with or in close contact with the inner surface of the outer tube at least at a part of its outer surface.
A high-pressure discharge lamp, wherein the outer surface of the discharge tube and / or the inner surface of the outer tube is coated with a scratch-resistant film that transmits any light in the wavelength region of 200 to 450 nm or all light. The high-pressure discharge lamp according to claim 1, wherein the scratch-preventing film is made of ceramics mixed with particles of carbon, silicon carbide, or boron nitride.

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