KR101374022B1 - Excimer lamp - Google Patents

Abstract

In order to provide an optimal light source for PSA applications, an object of the present invention is to provide an excimer lamp that efficiently emits ultraviolet light having a wavelength range of 300 to 380 nm necessary for polymerizing monomers, and includes krypton gas, iodine gas and A discharge container filled with a discharge gas containing xenon gas, and a pair of electrodes disposed to face each other with a discharge space formed inside the discharge container, and an excimer (I ₂ ^*) of iodine in the discharge space; 2) emit light having a peak wavelength of around 342 nm and light having a peak wavelength of around exciter (XeI ^* ) of a compound of xenon (Xe) and iodine (I).

Description

EXCIMER LAMP}

The present invention relates to an excimer lamp which efficiently emits ultraviolet light in the wavelength range of 300 to 380 nm by using a discharge gas containing krypton gas, iodine gas and xenon gas as a discharge medium.

In the manufacturing process of a liquid crystal display, the technique (PSA: Polymer Sustained Alignment) which fixes the inclination direction of liquid crystal molecules by incorporating a monomer into a liquid crystal and polymerizing a monomer in the state which inclined the liquid crystal molecule when forming the pixel of a liquid crystal It is used. According to patent document 1 which discloses about PSA, as a light source for polymerizing a monomer, it considers that the damage to a liquid crystal is few, the sensitivity of a monomer, the transmittance | permeability of the glass for liquid crystals, etc., for example, is wavelength 300 It is said that it is preferable to irradiate ultraviolet light of -380 nm (paragraph 0237 of patent document 1).

Various kinds of ultraviolet light sources that emit ultraviolet light having a wavelength of 300 to 380 nm necessary for polymerizing monomers are known. In the present situation, studies on the light sources that are optimal for PSA applications have been repeated. For example, a mercury lamp which mainly emits ultraviolet light having a wavelength of 365 nm using mercury as a discharge medium, a metal halide lamp having metal halide as a discharge medium, and the like are candidates for a light source for PSA.

However, the mercury lamp has a problem in that the ultraviolet irradiation device is enlarged when a plurality of mercury lamps are mounted to form an ultraviolet irradiation device, and there is also a disadvantage that the load on the environment is large in order to make mercury a discharge medium. . The metal halide lamp has a problem in terms of energy efficiency that the output of the emitted ultraviolet rays is lower than the input power, and since the metal halide is used as the discharge medium, adverse effects on the environment cannot be ignored.

When the excimer lamp is equipped with a plurality of excimer lamps to form an ultraviolet irradiation device, the ultraviolet irradiation device can be made relatively small, and the output of the emitted ultraviolet light is high compared to the input power. Since rare gases, such as xenon gas and clipton gas, are used as the discharge medium, they have great advantages in terms of practicality that the load on the environment is small, and thus, they are promising as a light source for PSA.

Excimer lamps are conventionally used as a light source for surface modification of a workpiece by mainly irradiating vacuum ultraviolet rays to the surface of the workpiece, such as a liquid crystal substrate, but having a wavelength of 300-380 nm necessary for polymerizing monomers in PSA applications. The output of ultraviolet light in the wavelength range of was insufficient.

Japanese Patent Publication No. 2003-149647

In view of the above, an object of the present invention is to provide an excimer lamp for efficiently emitting ultraviolet light having a wavelength range of 300 to 380 nm necessary for polymerizing a monomer in order to provide a light source that is optimal for PSA use.

In order to solve the said subject, the excimer lamp of Claim 1 opposes the discharge container in which the discharge gas containing krypton gas, iodine gas, and xenon gas was enclosed, and the discharge space formed in the inside of the said discharge container was interposed. A pair of electrodes arranged so as to emit light having a peak wavelength of iodine excimer (I ₂ ^* ) around 342 nm, and an excimer (XeI) of a compound of xenon (Xe) and iodine (I) in the discharge space. ^* ) Both of light emission with a peak wavelength of around 320 nm occurs.

The excimer lamp of Claim 2 has a discharge container in which discharge gas containing krypton gas, iodine gas, and xenon gas is enclosed, and a pair of electrodes arrange | positioned so as to oppose through the discharge space formed inside the said discharge container. The concentration of xenon gas is 0.05 to 2.0%.

In the excimer lamp of Claim 3, the concentration of the xenon gas in the excimer lamp of Claim 2 is 0.2 to 2.0%.

As for the excimer lamp of Claim 4, the total pressure of the said discharge gas is 40-133 kPa in the excimer lamp of Claim 1 or Claim 2.

According to the excimer lamp of the invention of claim 1, by discharging a discharge gas containing krypton gas, iodine gas and xenon gas as a discharge medium, the peak wavelength emitted by the excimer (I ₂ ^* ) of iodine in the discharge space is 342 nm. Both light emission in the vicinity and light emission in which the peak wavelength emitted by the excimer (XeI ^* ) of the compound of xenon (Xe) and iodine (I) are around 320 nm are generated, and thus 300 to 300 necessary for polymerizing monomers in PSA applications are generated. The output of the ultraviolet light in the wavelength range of 380 nm can be improved.

According to the excimer lamp of the invention of claim 2, since the discharge gas containing krypton gas, iodine gas and xenon gas is sealed as a discharge medium, and the concentration of xenon gas is prescribed | regulated as 0.05 to 2.0%, a monomer is used for PSA use. The output of the ultraviolet light in the wavelength range of 300-380 nm which is necessary in order to superpose | polymerize can be improved.

According to the excimer lamp of Claim 3, since the density | concentration of the said xenon gas is prescribed | regulated as 0.2 to 2.0% in the excimer lamp of Claim 2, the wavelength range of 300-380 nm which is necessary in order to superpose | polymerize a monomer in PSA use. The ultraviolet light output can be further improved.

According to the excimer lamp of Claim 4, since the total pressure of discharge gas is 40-133 kPa in the excimer lamp of Claim 1 or Claim 2, 300-380 nm of what is needed in order to superpose | polymerize a monomer in PSA use. The output of the ultraviolet light in the wavelength range can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing of the tube axis direction which shows the outline of the structure of the excimer lamp of this invention.
FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1.
3 is a graph showing the results of Experiment 1. FIG.
4 is a graph showing the results of Experiment 2. FIG.
5 is a graph showing the results of Experiment 3. FIG.

1 is a perspective view showing an outline of a configuration of an excimer lamp of the present invention. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1. The excimer lamp 10 is provided with the discharge container 1 comprised so that a cross section may become square as shown in FIG. 2 by dielectric materials, such as quartz glass, for example. Inside the discharge vessel 1, a discharge gas mainly containing krypton gas, iodine gas and xenon gas is enclosed.

The discharge container 1 is airtight so that the discharge gas does not leak to the outside by disposing the sealing member 2 in the interior of both ends of the discharge container in the longitudinal direction and welding the discharge container 1 and the sealing member 2 to each other. Is sealed. In addition, on each outer surface of the upper and lower wall surfaces 3 and 4 of the discharge vessel 1, a pair of electrodes 5 and 6 in a mesh shape are formed in the discharge space S formed inside the discharge vessel 1 and It is provided so that the dielectric material which comprises the discharge container 1 may oppose. The electrodes 5 and 6 are formed by vapor deposition etc. so that a predetermined | prescribed mesh-like pattern may be formed.

Further, in the interior of the discharge vessel (1), for example, and an ultraviolet reflection film (7) containing SiO ₂ as a main component is formed in the wall 3 and the wall 4 of the side opposite to the light exit direction side, a discharge space Ultraviolet rays generated in S are reflected by the ultraviolet reflecting film 7 in the light exit direction and are emitted from the wall surface 3 located on the light exit direction side.

The excimer lamp having such a configuration generates, for example, a myriad of beardless discharges on the inner wall surface facing the discharge space S by supplying a high frequency wave of 1 to 120 kHz, for example, between the pair of electrodes 5 and 6. By this silent discharge, the entire discharge space S is discharged evenly.

With this discharge, cations (I ⁺⁾ and negative ion (I ^-) of iodine (I) enclosed in the discharge vessel is to Formula 1 as shown by, for krypton other than iodine contained in the discharge gas atoms or By reacting with the molecule (M), the excimer (I ₂ ^* ) of iodine is formed, and the excimer (I ₂ ^* ) of the iodine is repeated as shown in the following [Formula 2].

[Formula 1]

^{I + + I - + M →} I 2 * + M

[Formula 2]

_{^{I 2 * → I + + I}} -

As shown by the above [Formula 1], the excimer (I ₂ ^* ) of iodine formed in the discharge space emits iodine molecular light emission having a peak wavelength of 342 nm. Excimer of iodine (I ₂ ^*) iodine ion (I ⁺⁾ that is the basis for forming a and (I ^-) is the reaction called generation Penning effect (Penning effect) that iodine is ionized by metastable here Atomic Energy Is generated.

This penning effect occurs because the energy of the metastable excitation atom of krypton is slightly higher than the ionization energy of the iodine atom. For reference, the energy of the metastable excitation atom is 9.9 to 10.5 eV of krypton, and the ionization energy of the iodine atom is 10.4 eV. Thus, the krypton gas and when filled with a discharge gas containing iodine gas in the discharge vessel, an iodine ion (I ⁺⁾ and (I ^-) in the discharge space is more produced, excimer the number of iodine (I ₂ ^*) Is formed.

In addition, xenon (Xe) and iodine (I) encapsulated in a discharge vessel are associated with each other to form an excimer (XeI ^* ) of a compound of xenon (Xe) and iodine (I) as shown by the following [Formula 3]. In addition, the excimer (XeI ^* ) of the compound of xenon (Xe) and iodine (I) repeats the reaction which is isolate | separated as shown by following [Formula 4].

[Formula 3]

2Xe + I ₂ → 2XeI ^*

[Formula 4]

2XeI ^* → 2Xe + I ₂

The excimer (XeI ^* ) of the compound of xenon (Xe) and the compound of iodine (I) formed as represented by said Formula (3) emits the ultraviolet light in which the peak wavelength is around 320 nm.

That is, in the discharge space S, the peak wavelength radiated from the excimer (I ₂ ^* ) of iodine radiates from the ultraviolet light in the vicinity of 342 nm, the excimer (XeI ^* ) of the xenon (Xe) and the iodine (I) compound. Ultraviolet light with a peak wavelength around 320 nm is emitted simultaneously.

In addition, in order to form an excimer (I ₂ ^* ) of iodine, an excimer (XeI ^* ) of a compound of xenon (Xe) and an iodine (I) as described above, a sinusoidal high frequency of 1 to 120 kHz is applied to an excimer lamp and pulsed. It is preferable to drive lighting by an electric current. If the frequency of the sine wave is too high, the so-called rest period during which no excimer discharge is formed is shortened, thereby forming the excimer (I ₂ ^* ) of iodine and the excimer (XeI ^* ) of the compound of xenon (Xe) and iodine (I). It is thought that the light emission intensity of the ultraviolet light in which the peak wavelengths are around 342 nm and 320 nm respectively decreases. On the other hand, if the frequency of the sine wave is too low, the number of luminescences per unit time decreases, and therefore, it is considered that the luminescence intensity of ultraviolet light having peak wavelengths around 342 nm and 320 nm respectively decreases.

The excimer (I ₂ ^* ) of iodine is more likely to be formed as more atoms or molecules of krypton (Kr) collide with iodine ions (I ⁺ , I ⁻ ). The excimer (XeI ^* ) of the compound of xenon (Xe) and iodine (I) is easily formed when there are many atoms or molecules of iodine (I) and xenon (Xe) contained in the discharge gas. Therefore, it is, it tends to be the excimer (XeI ^*) of the compounds of the excimer of iodine (I ₂ ^*) and xenon (Xe) and iodine (I) is formed when the higher the total pressure of the discharge gas which is sealed in an excimer lamp, The luminescence intensity of ultraviolet light whose peak wavelength is around 320 nm and 342 nm is improved. Specifically, the total pressure of the discharge gas is preferably 40 to 133 kPa.

Here, in the excimer lamp of this invention, the density | concentration of xenon (Xe) is prescribed | regulated to 0.05 to 2.0%. The concentration of xenon (Xe) is expressed by the partial pressure of xenon gas with respect to the voltage of the discharge gas. That is, the concentration of xenon gas is obtained by dividing the partial pressure of xenon gas by the sum of the partial pressure of krypton gas, the partial pressure of iodine gas and the partial pressure of xenon gas.

Accordingly, without the peak wavelength emitted from an excimer (I ₂ ^*) of iodine with no decrease in the output of the ultraviolet light in the vicinity 342㎚, radiation from an excimer (XeI ^*) of the compounds of xenon (Xe) and iodine (I) The output of the ultraviolet light whose peak wavelength becomes around 320 nm can be raised. Therefore, since the output of the ultraviolet light of the 300-380 nm wavelength range required for PSA use improves, the optical energy required in order to superpose | polymerize a monomer can fully be supplied.

Hereinafter, the experiments 1-3 which were performed in order to determine the density | concentration of the xenon gas contained in the discharge gas enclosed in the excimer lamp of this invention are demonstrated. In experiments 1-3, the excimer lamp of the structure shown to FIG. 1 and 2 produced according to the specification shown to the following Examples 1-3 was used, respectively.

≪ Example 1 >

In Experiment 1, a plurality of excimer lamps manufactured to the following specifications were used so that the concentrations of xenon gas were different from each other.

The discharge container has a square cylinder shape having a square cross section, and has a total length of 200 mm, a width of 32 mm, a height of 14 mm, a discharge gap of 10 mm, and a thickness of 2 mm of glass.

The electrode is formed by screen printing gold, and has a total length of 130 mm, a width of 32 mm, and a thickness of 5 m.

The discharge gas contains krypton gas, iodine gas and xenon gas and has a total pressure of 120 kPa.

The concentration of iodine gas is common at 0.11%.

The concentration of xenon gas is different in the range of 0 to 5%.

Lighting frequency is 70 kHz.

(Experiment 1)

Experiment 1 lit each excimer lamp which concerns on Example 1, and investigated the change of the emission spectrum shape of the ultraviolet light of 300-350 nm wavelength range about each excimer lamp.

3 shows the emission spectrum of the excimer lamp when the concentration of xenon (Xe) contained in the discharge gas is varied in the range of 0 to 5%. In FIG. 3, the ordinate is a standard value of the luminescence intensity when the luminescence intensity of ultraviolet light having a wavelength of 342 nm when the vertical axis is 1% is 1%, and the horizontal axis is the wavelength (nm).

As shown in FIG. 3, when xenon (Xe) is not contained in the discharge gas (Xe: 0%), the peak radiated from the excimer (XeI ^* ) of the compound of xenon (Xe) and iodine (I) When the emission intensity of ultraviolet light having a wavelength of around 320 nm is low and xenon (Xe) is excessively contained in the discharge gas (Xe: 5%), the peak radiated from the excimer (I ₂ ^* ) of iodine The emission intensity of ultraviolet light in the wavelength of 342 nm vicinity fell.

On the other hand, as shown in FIG. 3, when the concentration of xenon (Xe) is 0.05 to 2.0%, the luminescence intensity of ultraviolet light with a peak wavelength emitted from iodine excimer (I ₂ ^* ) of around 342 nm is high. The emission intensity of ultraviolet light in which the peak wavelength emitted from the excimer (XeI ^* ) of the compound of xenon (Xe) and iodine (I) is around 320 nm can be increased.

In particular, when the concentration of xenon (Xe) is 0.2 to 2.0%, the peaks emitted from the excimer (XeI ^* ) and the iodine excimer (I ₂ ^* ) of the compounds of xenon (Xe) and iodine (I), respectively The light emission intensity of the ultraviolet light whose wavelength is around 320 nm and 342 nm can be raised.

<Example 2>

In Experiment 2, a plurality of excimer lamps manufactured to the following specifications were used so that the concentration of xenon gas was different for each concentration of iodine gas contained in the discharge gas.

The discharge container has a rectangular cylinder having a rectangular cross section, and has a total length of 125 mm, a width of 32 mm, a height of 14 mm, a discharge gap of 10 mm, and a thickness of 2 mm of glass.

The electrode is formed by screen printing gold, and has a total length of 130 mm, a width of 32 mm, and a thickness of 5 m.

The discharge gas contains krypton gas, iodine gas and xenon gas and has a total pressure of 120 kPa.

The concentration of iodine gas is 0.04%, 0.11% and 0.91%, respectively.

The concentration of xenon gas is different in the range of 0.05 to 5%.

Lighting frequency is 70 kHz.

(Experiment 2)

In Experiment 2, each excimer lamp was turned on and driven to measure the integrated illuminance of the ultraviolet light in the wavelength range of 300 to 350 nm. In Experiment 2, the effect of the concentration of iodine on the optimum concentration of xenon (Xe) was investigated.

FIG. 4 shows the integrated illuminance of the ultraviolet light in the wavelength range of 300 to 350 nm when various concentrations of xenon (Xe) contained in the discharge gas are varied in the range of 0.05 to 5% for each concentration of iodine. In Figure 4, the standard value when the vertical axis would have to 1 the light intensity of ultraviolet light having a wavelength in the case of I ₂ 342㎚ concentration 0.11% also Xe concentration of 1%, and the horizontal axis represents the concentration of xenon (Xe). The integrated illuminance on the vertical axis is a standard value when the integrated illuminance of the ultraviolet light in the wavelength range of 300 to 350 nm is 1 when the concentration of xenon (Xe) is 1%.

As shown in Fig. 4, regardless of the concentration of iodine (I), when the concentration of xenon (Xe) contained in the discharge gas is 5.0%, the integrated illuminance of ultraviolet light in the wavelength range of 300 to 350 nm is low. On the other hand, when the density | concentration of xenon (Xe) contained in discharge gas is 0.05 to 2%, it was confirmed that the integrated roughness of 300-350 nm wavelength region ultraviolet light is high.

In addition, in the result shown in FIG. 4, when the density | concentration of xenon (Xe) contained in discharge gas is 0.2 to 2%, regardless of the density | concentration of iodine (I), it is the ultraviolet-ray of the wavelength range of 300-350 nm. It was confirmed that integration intensity was especially high.

<Example 3>

In Experiment 3, a plurality of excimer lamps manufactured to the following specifications were used so that the concentration of xenon gas was different for each total pressure of the discharge gas.

The discharge container has a rectangular cylinder having a rectangular cross section, and has a total length of 125 mm, a width of 32 mm, a height of 14 mm, a discharge gap of 10 mm, and a thickness of 2 mm of glass.

The electrode is formed by screen printing gold, and has a total length of 130 mm, a width of 32 mm, and a thickness of 5 m.

Discharge gas contains krypton gas, iodine gas, and xenon gas, and total pressure is 93 and 120 kPa.

The concentration of iodine gas is common at 0.11%.

The concentration of xenon gas is different in the range of 0.01 to 5%.

Lighting frequency is 70 kHz.

(Experiment 3)

In Experiment 3, each excimer lamp was turned on and the integrated illuminance of the ultraviolet light in the wavelength range of 300-350 nm was measured. In Experiment 3, the influence of the total pressure of the discharge gas on the optimum concentration of xenon (Xe) was investigated.

FIG. 5 shows the integrated illuminance of the ultraviolet light in the wavelength range of 300 to 350 nm when the concentration of xenon (Xe) contained in the discharge gas is varied in the range of 0.01 to 5% for each voltage of the discharge gas. . In FIG. 5, the vertical axis | shaft is a standard value when the integrated illuminance of the ultraviolet light of the 300-350 nm wavelength range in the case of the total pressure of 120 kPa and Xe density | concentration of 1% is 1, and a horizontal axis is xenon concentration.

As shown in FIG. 5, when the concentrations of xenon (Xe) contained in the discharge gas are 0.01% and 5% regardless of the total pressure of the discharge gas, the integrated illuminance of the ultraviolet light in the wavelength range of 300 to 350 nm is shown. On the other hand, when the density | concentration of xenon (Xe) contained in discharge gas is 0.05 to 2%, it was confirmed that the integrated illuminance of the ultraviolet light of the wavelength range of 300-350 nm is high.

In addition, in the result shown in FIG. 5, when the concentration of xenon (Xe) contained in discharge gas is 0.2 to 2%, the integration of the ultraviolet light of the wavelength range of 300-350 nm regardless of the total pressure of discharge gas. High illuminance was confirmed.

From the results of the above experiment, in the excimer lamp of the present invention, the concentration of xenon (Xe) contained in the discharge gas is defined in the range of 0.05 to 2%, particularly preferably in the range of 0.2 to 2%, and thus iodine ( Regardless of the concentration of I) and the total pressure of the discharge gas, it was confirmed that the light emission intensity of the ultraviolet light in the wavelength range of 300 to 350 nm can be increased.

10: excimer lamp 1: discharge vessel
2: sealing member 3, 4: wall surface
5, 6: electrode 7: ultraviolet reflecting film

Claims (4)

An excimer lamp having a discharge container filled with a discharge gas including krypton gas, iodine gas and xenon gas, and a pair of electrodes disposed to face each other with a discharge space formed inside the discharge container,
An excimer lamp, wherein the concentration of the xenon gas obtained by dividing the partial pressure of xenon gas by the sum of the partial pressure of krypton gas, the partial pressure of iodine gas and the partial pressure of xenon gas is 0.05 to 2.0%. The method according to claim 1,
Excimer lamp, characterized in that the concentration of the xenon gas is 0.2 to 2.0%. The method according to claim 1,
The total pressure of the said discharge gas is 40-133 kPa, excimer lamp characterized by the above-mentioned. delete

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