JP2005071942A - Light emitting tube for flash lamp, and manufacturing method of same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting tube for a flash lamp capable of preventing abnormal expansion/contraction of a trigger electrode due to the light emission of the flash lamp and damage due to an external disturbance like vibration, which can be manufactured at a low cost. <P>SOLUTION: The light emitting tube for the flash lamp has the trigger electrode on which a voltage, inducing light emission of a light transmitting cylinder-shaped body, is impressed, and the trigger electrode is arranged so as to tightly stick on the outer surface of the cylinder-shaped body in longitudinal direction. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a flash lamp arc tube for causing a flash lamp to emit light. In particular, a semiconductor substrate such as a liquid crystal substrate or a silicon wafer is rapidly heated by light irradiation, or is sterilized or toner fixed. The present invention relates to a technique used for curing a UV curable resin.

  2. Description of the Related Art Conventionally, a technique called spike RTA (Rapid Thermal Annealing) has been known in which a halogen lamp is used as a heat source for heat treatment of a semiconductor substrate, rapid heating is performed, a high temperature is maintained, and then rapid cooling can be performed. Yes. This RTA is used in a wide range of applications such as film formation (forming an oxide film on the surface of a semiconductor substrate) and diffusion (diffusing impurities inside the semiconductor substrate). For example, in terms of diffusion, when a silicon wafer is used as a semiconductor substrate, first, ions of impurities such as boron and arsenic are implanted into the surface layer of the silicon wafer and then subjected to a heat treatment at, for example, 1000 ° C. Is to diffuse.

  In recent years, there has been an increasing demand for higher integration and miniaturization of semiconductor integrated circuits. For example, in a shallow region of 20 nm or less from the surface layer of a silicon wafer, it is slightly shifted from the crystal lattice position of silicon by ion implantation. There is a growing demand for heat treatment that brings the atoms of the impurities that are close to each other back to the correct crystal lattice position. However, in the case of a halogen lamp arc tube using a conventional halogen lamp as a heat source, the irradiation energy is essentially low, so that the heat treatment takes a very long time. As a result, the ion-implanted impurity atoms are 25 nm from the surface layer. Diffusion to the above depths makes it difficult to meet the above requirements.

  By the way, as a method for achieving impurity diffusion in a very shallow region, there is a laser irradiation method (XeCL) in which a silicon wafer is scanned with a laser beam having an irradiation width of several millimeters.

  However, an apparatus that emits laser light is very expensive, and there is a problem that throughput cannot be increased when performing heat treatment while scanning the surface of a silicon wafer with a laser beam having a small spot diameter.

  Therefore, in order to solve the above-described problems, in Patent Document 1 and Patent Document 2, trigger bands 23 are provided at several places on a cylindrical body 21 made of glass in which a rare gas for light emission is enclosed, as shown in FIG. The flash lamp 20 is disclosed in which a trigger electrode 22 is disposed along the axial direction of a cylindrical body 21 by the trigger band 23. In this conventional technique, a method of heat-treating a silicon wafer by using the flash lamp 20 with a high current density and a short pulse has been proposed. Such a heat treatment by the flash lamp 20 is effective in that the irradiation time for the silicon wafer can be extremely shortened, so that the state of impurities in the silicon wafer is not disturbed.

Further, as described in Patent Document 1, it was also excellent in that yellowing of the flash lamp arc tube could be prevented.
JP 2001-185088 A JP-A-4-287076

  However, the arc tube for flash lamps proposed in Patent Document 1 and Patent Document 2 is equipped with a trigger band 23 wound in the circumferential direction of the cylindrical body 21, and does not contact the cylindrical body 21 by the trigger band 23. Thus, since the trigger electrodes 22a and 22b are structured to hold, the trigger electrodes 22a and 22b are abnormally expanded or contracted due to a temperature rise at the time of light emission, or are separated from the trigger band 23 due to disturbance such as vibrations and damaged. There was a problem.

  In particular, in the heat treatment of a semiconductor substrate such as a liquid crystal substrate or a silicon wafer, the temperature of the cylindrical body 21 at the time of lamp emission is only about 100 ° C. due to the difference in specific heat between the materials constituting the cylindrical body 21 and the trigger electrodes 22a and 22b. On the other hand, the trigger electrodes 22a and 22b became a high temperature of several hundred degrees C., and the abnormal expansion and contraction of the trigger electrodes 22a and 22b with respect to the cylindrical body 21 was remarkable.

  There is also a problem that the cost for manufacturing and mounting the trigger band 23 itself is required.

  An object of the present invention is to provide an arc tube for a flash lamp that can be manufactured at a low cost while preventing the trigger electrode from being abnormally expanded and contracted by light emission of the flash lamp or being damaged by disturbance such as vibration. .

  An arc tube for a flash lamp according to the present invention is an arc tube for a flash lamp having a trigger electrode to which a voltage for inducing light emission is applied to a light-transmitting cylindrical body, and the trigger electrode is formed in the longitudinal direction of the outer surface of the cylinder. It is characterized by being formed in close contact with the direction.

  The flash lamp arc tube has a plurality of the trigger electrodes, and is arranged side by side in the circumferential direction of the cylindrical body.

  In the flash lamp arc tube, the trigger electrodes are arranged at equal intervals.

  The flash lamp arc tube is characterized in that the material constituting the trigger electrode has a melting point of 660 ° C. or higher and a reflectance in the visible light region of 52% or higher.

  The arc tube for flash lamp is characterized in that the trigger electrode is formed of a metal mainly containing any one of silver, platinum, palladium, rhodium, tungsten, nickel, and aluminum.

  The flash lamp arc tube has a transmittance of 80% or more in the visible light region of the cylindrical body.

  The flash lamp arc tube is characterized in that the cylindrical body has a thickness of 0.8 to 2.5 mm.

  The arc tube for the flash lamp is selected from the group consisting of aluminum oxide polycrystal, yttrium aluminum garnet (YAG) polycrystal, yttria polycrystal, zirconia polycrystal, and spinel polycrystal. It is characterized by comprising a translucent ceramic or a composite thereof.

  The arc tube for flash lamp is characterized in that an average crystal grain size of a material constituting the cylindrical body is 1 to 30 μm.

  The arc tube for flash lamp is characterized in that the cylindrical body is formed of a sapphire single crystal.

  The trigger electrode used in the arc tube for flash lamp is formed on the outer surface of the cylindrical body by any one of physical vapor deposition, chemical vapor deposition, screen printing, metallization, plating, and thermal spraying. To do.

  As described above, according to the arc tube for a flash lamp of the present invention, the trigger electrode to which a voltage for inducing light emission is applied to the translucent cylindrical body is formed in close contact with the longitudinal direction of the outer surface of the cylindrical body. Even if the flash lamp is turned on, the trigger electrode is closely attached to the cylindrical body and restrained, so that the trigger electrode can be prevented from abnormal expansion and contraction, and the trigger electrode can be separated from the cylindrical body even if there is a disturbance such as vibration. And will not be damaged.

  In addition, since it is not necessary to produce a trigger band that conventionally holds the trigger electrode, a flash lamp arc tube can be manufactured at low cost.

  In the flash lamp arc tube according to the present invention, since the plurality of trigger electrodes formed in the longitudinal direction are formed side by side in the circumferential direction of the cylindrical body, plasma is dispersedly generated to constitute the cylindrical body. By reducing local corrosion on the material, adhesion and deposition of the powdery body on the inner surface of the cylindrical body can be reduced, and a decrease in the amount of radiation can be prevented.

  In addition, since the arc tube for a flash lamp of the present invention has the trigger electrodes arranged at equal intervals, the generation of plasma can be more evenly distributed, so that local corrosion is further reduced and the amount of radiation is reduced. This is preferable because it is possible to prevent a decrease in the thickness.

  In addition, the arc tube for flash lamp of the present invention reduces the absorption of visible light by setting the melting point of the material constituting the trigger electrode to 660 ° C. or higher and the reflectance in the visible light region to 52% or higher. Therefore, even if the flash lamp repeatedly emits light, damage such as melting and peeling of the trigger electrode can be prevented, and a highly reliable one can be obtained.

  In particular, in the arc tube for a flash lamp of the present invention, the trigger electrode is preferably formed from a metal containing silver, platinum, palladium, rhodium, nickel, or aluminum as a main component from the viewpoint of easy material availability. It is.

  Further, in the arc tube for flash lamp of the present invention, the illuminance on the semiconductor substrate is not lowered and the irradiation time can be shortened by setting the transmittance in the visible light region of the cylindrical body to 80% or more.

  Moreover, in the arc tube for flash lamps of the present invention, appropriate pressure strength and transmittance can be ensured by setting the thickness of the cylindrical body to 0.8 to 2.5 mm.

  In particular, in the arc tube for flash lamp of the present invention, the cylindrical body is made of aluminum oxide polycrystal, yttrium aluminum garnet (YAG) polycrystal, yttria polycrystal, zirconia polycrystal, spinel polycrystal from the point of corrosion resistance. It is preferable to form from a translucent ceramic selected from the group consisting of crystal bodies or a composite thereof.

  Further, in the arc tube for flash lamp of the present invention, the average crystal grain size of the material constituting the cylindrical body is set to 1 to 30 μm, so that the transmittance of the cylindrical body is not lowered and the flash lamp emits light. The internal pressure of the cylinder does not exceed the pressure strength, and the arc tube for flash lamp does not burst.

  In the arc tube for flash lamp of the present invention, it is preferable that the cylindrical body is formed of a sapphire single crystal from the viewpoint of corrosion resistance.

  Furthermore, in the arc tube for a flash lamp of the present invention, the trigger electrode is formed by any one of a physical gas phase method, a chemical gas phase method, screen printing, metallization, plating, and thermal spraying. An arc tube for a flash lamp having good adhesion can be obtained.

  Hereinafter, embodiments of the present invention will be described in detail.

  The flash lamp arc tube of the present invention is a flash lamp arc tube 10 having a trigger electrode 2 to which a voltage for inducing light emission is applied to a translucent cylindrical body 1 as shown in FIG. 2 is a structure in which the cylindrical body 1 is formed in close contact with the longitudinal direction of the outer surface.

  With such a structure, since the trigger electrode 2 is formed in close contact with the cylindrical body 1, the trigger electrode 2 is held in close contact with the cylindrical body 1 even when the flash lamp is caused to emit light. 2 is prevented, and the trigger electrode 2 is not separated from the cylindrical body 1 and damaged even if there is a disturbance such as vibration.

  Further, as shown in FIG. 2, the two trigger electrodes 2 a and 2 b may be formed side by side in the circumferential direction of the cylindrical body 1. That is, when the trigger electrode 2 is single as shown in FIG. 1, when a voltage is applied to the trigger electrode 2, the plasma P is generated only in a portion close to the trigger electrode 2, that is, locally, so If they are stacked, the material constituting the cylindrical body 1 is corroded, and the corroded material becomes a fine powdery body, which adheres to and accumulates on the inner surface of the cylindrical body 1. May cause decline. However, as described above, the two trigger electrodes 2a and 2b are formed side by side in the circumferential direction of the cylindrical body 1, and the trigger electrode 2a and 2b are alternately applied, for example, so that the plasma P2 is dispersedly generated. It is possible to reduce local corrosion of the material constituting the cylindrical body 1. As a result, it is possible to reduce the adhesion and deposition of the powdery material on the inner surface of the cylindrical body 1, and to prevent the radiation amount from being lowered.

  Further, as shown in FIG. 3, when the plurality of trigger electrodes 2 formed in the circumferential direction of the outer surface of the cylindrical body 1 are formed so that the intervals are equal, the generation of plasma can be more uniformly distributed. Is preferred.

  Further, the trigger electrodes 2 are not necessarily limited to selecting one by one and applying a voltage. For example, two trigger electrodes such as the trigger electrode 2a and the trigger electrode 2b may be selected for the first light emission, and the trigger electrode 2c and the trigger electrode 2d may be selected for the next light emission, and the voltages may be applied simultaneously.

  The cylindrical body 1 has an inner diameter of 8 to 15 mm, an outer diameter of 9.6 to 20 mm, a length of 200 to 550 mm, and the trigger electrode 2 has a width of 0.5 to 10 mm, a length of 200 to 550 mm, and a thickness, for example. The thickness is preferably 1 to 400 μm, but is not particularly limited. Therefore, the circumferential width of the trigger electrode 2 is set to 0.8 to 33.2%, preferably 1.6 to 15.9% with respect to the outer periphery of the cylindrical body 1. If this ratio is less than 0.8%, the trigger electrode 2 itself is likely to be disconnected. On the other hand, if it exceeds 33.2%, when there are a plurality of trigger electrodes 2, the ratio of the radiated light blocked by the trigger electrode 2 increases, and the heat treatment of a semiconductor substrate such as a liquid crystal substrate or a silicon wafer can be effectively performed. become unable.

  The melting point of the material constituting the trigger electrode 2 is preferably 660 ° C. or higher, and the reflectance in the visible light region is preferably 52% or higher.

  Among the materials constituting the trigger electrode 2, the material having a melting point of 660 ° C. or higher was selected because the trigger electrode 2 may be melted when the flash lamp emits light more than once when the melting point is less than 660 ° C. is there. On the other hand, a material having a melting point of 660 ° C. or higher has no fear of melting, and the reliability as a flash lamp can be easily ensured.

  Further, among the materials constituting the trigger electrode 2, a material having a reflectance in the visible light region of 52% or more is selected because the trigger electrode is used when the flash lamp repeatedly emits light with a material having a reflectance of less than 52%. No. 2 is because the heat generated by light emission is absorbed and stored, so that expansion and contraction occur and damage such as peeling easily proceeds. On the other hand, with a material having a reflectance of 52% or more, since the radiated light is reflected, the trigger electrode 2 does not absorb or store heat due to light emission, so that damage such as peeling is difficult to proceed and the reliability is high.

  The trigger electrode 2 is preferably made of a metal mainly composed of silver, platinum, palladium, rhodium, nickel, or aluminum.

  In addition, the trigger electrode 2 is not limited to a linear shape, and can be formed in the cylindrical body 1 in a spiral shape, for example.

  Further, the cylindrical body 1 preferably has a transmittance in the visible light region of 80% or more. This is because by setting the transmittance to 80% or more, the illuminance on the semiconductor substrate does not decrease, so that the irradiation time can be further shortened.

  The wall thickness of the cylindrical body 1 is preferably 0.8 to 2.5 mm. If the thickness of the cylindrical body 1 is less than 0.8 mm, the pressure strength is insufficient depending on the material constituting the cylindrical body 1, and the internal pressure of the cylindrical body 1 when the flash lamp emits light is higher than the pressure strength. This is because the arc tube may burst, and if it exceeds 2.5 mm, the transmittance of the cylindrical body 1 is reduced. On the other hand, by setting the thickness of the cylindrical body 1 to 0.8 to 2.5 mm, it is possible to ensure appropriate pressure strength and transmittance.

  Further, the cylindrical body 1 is a translucent ceramic selected from the group consisting of aluminum oxide polycrystal, yttrium aluminum garnet (YAG) polycrystal, yttria polycrystal, zirconia polycrystal, and spinel polycrystal. Or it is preferable to consist of the composite_body | complex. This is because such materials have good heat resistance and corrosion resistance, and the transmittance does not decrease even at a high temperature of about 1000 ° C.

  Moreover, it is suitable that the average crystal grain diameter of the material which comprises the cylindrical body 1 is 1-30 micrometers. If the average crystal grain size of the material constituting the cylindrical body 1 is less than 1 μm, the surface roughness of the cylindrical body 1 deteriorates due to crystal growth when the flash lamp repeatedly emits light. This is because if the thickness of the cylindrical body 1 is too small, the pressure resistance is likely to be low, and the flash lamp arc tube 10 may be ruptured. . On the other hand, when the average crystal grain size of the material constituting the cylindrical body 1 is set to 1 to 30 μm, the transmittance of the cylindrical body 1 is not lowered, and the internal pressure of the cylindrical body 1 at the time of flash lamp emission is the pressure strength. And the arc tube for flash lamps does not rupture.

  In particular, when the cylindrical body 1 is formed of a sapphire single crystal, the surface of the cylindrical body 1 does not become yellow and does not become clouded even if the number of times of light emission is repeated. As a result, the radiation itself to the semiconductor substrate does not become uneven, and the illuminance of the emitted light on the semiconductor substrate does not decrease.

  The manufacturing method of the arc tube for flash lamp of the present invention is obtained by the EFG method (pulling method), the Czochralski method, the HEM method, the Bridgman method, the VGF method, etc., when the cylindrical body 1 is formed of a sapphire single crystal. be able to. When the cylindrical body 1 is formed of any one of aluminum oxide polycrystal, yttrium aluminum garnet (YAG) polycrystal, yttria polycrystal, and quartz glass, a kneaded body in which predetermined raw material powders are kneaded is used. What is necessary is just to sinter at predetermined temperature after shape | molding by the extrusion method.

  Then, a trigger electrode 2 is formed on the outer surface of the obtained cylindrical body 1 by a physical vapor phase method such as vacuum deposition, ion plating, or sputtering, a chemical vapor phase method such as plasma CVD, thermal CVD, or photo CVD, a screen. By forming by any of printing, metallization, plating, and thermal spraying, the arc tube for flash lamp of the present invention can be obtained.

  Furthermore, a discharge electrode 3a that emits light from the flash lamp is disposed at one end of the flash lamp arc tube 10 by applying a voltage independent of the voltage applied to the trigger electrode 2 as shown in FIG. It seals with the sealing member 4a which consists of the same material as the material which forms the cylindrical body 1. FIG. And 1 type or 2 types or more of rare gases for light emission, such as argon, xenon, krypton, are enclosed by the pressure of 4-6 Mpa, for example. Thereafter, the discharge electrode 3b is arranged so as to face the discharge electrode 3a at the other end, and sealed with a sealing member 4b made of the same material as that forming the cylindrical body 1, so that light in the visible light region can be obtained. A flash lamp that can radiate well can be obtained.

  Examples of the present invention will be specifically described below.

(Example 1)
A flash according to the present invention shown in FIG. 1, in which a trigger electrode 2 to which a voltage for inducing light emission of a flash lamp is applied is formed in close contact with silver by vacuum deposition in the longitudinal direction of the outer surface of a cylindrical body 1 formed of a sapphire single crystal. A lamp arc tube 10 was produced.

  Next, as shown in FIG. 4, the discharge electrode 3a was disposed at one end of the flash lamp arc tube 10 and sealed with a sealing member 4a made of sapphire single crystal. Then, by enclosing xenon at a pressure of 5 MPa, disposing the discharge electrode 3b so that the other end faces the discharge electrode 3a, and sealing with a sealing member 4b made of a sapphire single crystal, visible light region A flash lamp that emits the light.

  Further, as comparative examples, trigger bands 23 are attached to three longitudinal directions of a cylindrical body 21 formed of a sapphire single crystal, and the trigger bands 23 hold the trigger electrodes 22a and 22b. Tube 20 was also made. Next, both ends of the flash lamp arc tube 20 were sealed in the same manner as described above to obtain a flash lamp that emits light in the visible light region.

  In both the above examples and comparative examples, the distance between the discharge electrodes was 300 mm, the input energy per flash lamp was 350 J, the pulse width was 100 μsec, light was emitted 20000 times, and then the trigger electrode 2 was abnormally expanded and contracted. It was observed whether or not.

The results are shown in Table 1.

  From Table 1, the arc tube No. 1 for the flash lamp of the comparative example. 2 shows that the trigger electrode expanded and contracted abnormally after 20000 light emission, whereas the flash tube arc tube No. 2 of the present invention. It can be seen that No. 1 is good because the trigger electrode does not cause abnormal expansion and contraction even when light is emitted 20000 times.

(Example 2)
An arc tube 10 for a flash lamp according to the present invention in which one, two, and three trigger electrodes 2 are formed in close contact with silver by vacuum deposition in the longitudinal direction of the outer surface of the cylindrical body 1 formed of a sapphire single crystal. .

  For the two or three trigger electrodes 2, the flash lamp arc tube 10 having a different interval between the trigger electrodes 2 and the flash lamp arc tube 10 having an equal interval were produced.

  Next, similarly to Example 1, the discharge electrode 3a was disposed at one end of the flash lamp arc tube 10 and sealed with a sealing member 4a made of a sapphire single crystal. Then, by enclosing xenon at a pressure of 5 MPa, disposing the discharge electrode 3b so that the other end faces the discharge electrode 3a, and sealing with a sealing member 4b made of a sapphire single crystal, visible light region A flash lamp that emits the light.

  Then, the distance between the discharge electrodes was 300 mm, the input energy per flash lamp was 350 J, the pulse width was 100 μsec, the radiation intensity after one emission and after 20000 emission was measured, and the attenuation rate was calculated.

  The attenuation rate of the radiation intensity defined here is defined by the following equation, and it can be said that the higher this value, the more unevenly the plasma is generated.

Decay rate of radiation intensity (%) = (radiation intensity after one light emission−radiation intensity after 20000 light emission) / radiation intensity after one light emission × 100

The results are shown in Table 2.

  From Table 2, a flash lamp arc tube No. 1 in which one trigger electrode is formed in close contact is shown. No. 3 had a large decay rate of the radiation intensity of 16%, whereas the flash lamp arc tube No. 3 having two and three trigger electrodes formed in close contact with each other. Nos. 4 to 7 have a small attenuation rate of radiation intensity of 4 to 11%, and in particular, the flash lamp arc tube No. 4 in which the intervals between the trigger electrodes are equal. Nos. 5 and 7 show that the attenuation rate of the radiation intensity is particularly small at 4%, and the plasma is generated in a uniformly dispersed manner, which is favorable in terms of long-term reliability.

(Example 3)
An arc tube for a flash lamp in which a trigger electrode 2 is formed in close contact with tin, silver, platinum, palladium, rhodium, tungsten, nickel, aluminum, and gold by vacuum deposition in the longitudinal direction of the outer surface of the cylindrical body 1 formed of a sapphire single crystal. 10 was produced.

  Table 3 below shows the melting point and the transmittance in the visible light region (measurement wavelengths: 450 nm, 550 nm, and 700 nm) of the material constituting the trigger electrode 2.

  Next, similarly to Example 1, the discharge electrode 3a was disposed at one end of the flash lamp arc tube 10 and sealed with a sealing member 4a made of a sapphire single crystal. Then, by enclosing xenon at a pressure of 5 MPa, disposing the discharge electrode 3b so that the other end faces the discharge electrode 3a, and sealing with a sealing member 4b made of a sapphire single crystal, visible light region The flash lamp arc tube 10 that emits the light of

  Then, the distance between the discharge electrodes was 300 mm, the input energy per flash lamp arc tube was 350 J, the pulse width was 100 μsec, and the molten state of the trigger electrode 2 after 20,000 times of light emission was confirmed.

The results are shown in Table 3.

  From Table 3, the flash lamp arc tube No. 2 in which the trigger electrode 2 is formed in close contact with tin, tungsten, and gold, respectively. Nos. 8, 13 and 16 have a melting point of the material constituting the trigger electrode 2 of less than 660 ° C. or a transmittance in the visible light region of less than 52%. You can see that On the other hand, a flash lamp arc tube No. 2 in which the trigger electrode 2 is formed in close contact with silver, platinum, palladium, rhodium, nickel, and aluminum, respectively. 9, 10, 11, 12, and 15 have a melting point of the material constituting the trigger electrode 2 of 660 ° C. or higher and a reflectance in the visible light region of 52% or higher. Melting is not confirmed and is good.

Example 4
The cylindrical body 1 is made of aluminum oxide polycrystal, yttrium aluminum garnet (YAG) polycrystal, yttria polycrystal, zirconia polycrystal, spinel polycrystal, quartz glass, and triggers in the longitudinal direction of the outer surface. An arc tube 10 for a flash lamp in which the electrode 2 is formed in close contact with silver by vacuum deposition was produced.

  Here, as shown in Table 4 for the cylindrical body 1 formed of aluminum oxide polycrystal, the thickness of the cylindrical body 1 is 0.6 to 3 mm, and the average crystal grain size of the aluminum oxide polycrystal is It set in the range of 0.8-35 micrometers.

  Next, similarly to Example 1, the discharge electrode 3a was disposed at one end of the flash lamp arc tube 10 and sealed with a sealing member 4a made of the same material as the cylindrical body 1. Then, the xenon is sealed at a pressure of 5 MPa, the discharge electrode 3b is arranged so that the other end faces the discharge electrode 3a, and sealed with a sealing member 4b made of the same material as the sealing member 4a. The flash lamp emits light in the light region.

The distance between the discharge electrodes is 300 mm, the input energy per flash lamp is 350 J, the pulse width is 100 μsec, and the transmittance T ₀ after light emission (hereinafter referred to as initial transmittance T ₀ ) and 20000 times. The transmittance T ₁ after light emission was measured, and the transmittance difference ΔT (= T ₀ −T ₁ ) was evaluated.

The results are shown in Table 4.

From Table 4, the arc tube for flash lamp No. 1 having a thickness of the cylindrical body 1 of less than 0.8 mm. No. 17 is broken when the number of times of light emission is 25000, and when the number of times of light emission is so large, it can be seen that the pressure resistance is insufficient. Further, the arc tube No. 1 for flash lamp having a wall thickness of the cylindrical body 1 exceeding 2.5 mm. 25 shows that the initial transmittance T ₀ itself is as low as 67%.

Furthermore, arc tube No. 1 for flash lamps in which the average crystal grain size of the aluminum oxide polycrystal exceeds 30 μm. No. 25 is broken when the number of light emission is 20000, and the pressure resistance is insufficient. In addition, the arc tube No. 1 for flash lamp having an average crystal grain size of aluminum oxide polycrystal of less than 1 μm. 18 shows that the transmittance T ₁ after 20,000 times of light emission is remarkably low.

On the other hand, while the cylindrical body 1 has a wall thickness of 0.8 to 2.5 mm and the average crystal grain size of aluminum oxide is 1 to 30 μm, the arc tube for flash lamp No. Nos. 19 to 21, 23, and 24 are not damaged, and the transmittance T ₁ after 20,000 times of light emission is sufficiently high as 70% or more.

  In addition, arc tube No. 1 for flash lamp in which the cylindrical body 1 is formed of quartz glass. 31 was eroded and became clouded, while cylindrical body 1 was made of aluminum oxide polycrystal, yttrium aluminum garnet (YAG) polycrystal, yttria polycrystal, zirconia polycrystal, spinel polycrystal, respectively. The formed arc tube for flash lamp No. It can be seen that 17 to 30 are not eroded and are good.

It is a figure which shows the arc tube for flash lamps of this invention, (a) is sectional drawing of a longitudinal direction, (b) is sectional drawing of a direction perpendicular | vertical with respect to a longitudinal direction. It is a figure which shows the arc tube for flash lamps which becomes other embodiment of this invention, (a) is sectional drawing of a longitudinal direction, (b) is sectional drawing of a direction perpendicular | vertical with respect to a longitudinal direction. It is a figure which shows the arc tube for flash lamps which becomes other embodiment of this invention, and is sectional drawing of a perpendicular | vertical direction with respect to the longitudinal direction. It is a figure which shows the arc_tube | light_emitting_tube for flash lamps of this invention while arrange | positioning a discharge electrode at both ends and sealing with the sealing member. It is a figure which shows the conventional arc tube for flash lamps, (a) is sectional drawing of a longitudinal direction, (b) is sectional drawing of a direction perpendicular | vertical with respect to a longitudinal direction.

Explanation of symbols

1: Cylindrical body 2: Trigger electrode 3: Discharge electrode 10, 20: Flash lamp arc tube 21: Cylindrical body 22: Trigger electrode 23: Trigger band

Claims (11)

An arc tube for a flash lamp having a trigger electrode to which a voltage for inducing light emission is applied to a light-transmitting cylindrical body, wherein the trigger electrode is formed in close contact with the longitudinal direction of the outer surface of the cylindrical body. Arc tube for flash lamp. 2. The arc tube for a flash lamp according to claim 1, comprising a plurality of the trigger electrodes and arranged in the circumferential direction of the cylindrical body. The arc tube for a flash lamp according to claim 2, wherein the trigger electrodes are formed at equal intervals. The arc tube for a flash lamp according to any one of claims 1 to 3, wherein the material constituting the trigger electrode has a melting point of 660 ° C or higher and a reflectance in the visible light region of 52% or higher. . The arc tube for a flash lamp according to claim 4, wherein the material constituting the trigger electrode is made of a metal mainly composed of silver, platinum, palladium, rhodium, nickel, or aluminum. The arc tube for a flash lamp according to any one of claims 1 to 5, wherein the cylindrical body has a transmittance in a visible light region of 80% or more. The arc tube for a flash lamp according to any one of claims 1 to 6, wherein a thickness of the cylindrical body is 0.8 to 2.5 mm. The cylindrical body is a translucent ceramic selected from the group consisting of aluminum oxide polycrystal, yttrium aluminum garnet (YAG) polycrystal, yttria polycrystal, zirconia polycrystal, spinel polycrystal, or the like The arc tube for a flash lamp according to any one of claims 1 to 7, wherein the arc tube is a composite. 9. The arc tube for flash lamp according to claim 8, wherein the material constituting the cylindrical body has an average crystal grain size of 1 to 30 [mu] m. The arc tube for a flash lamp according to any one of claims 1 to 7, wherein the cylindrical body is made of a sapphire single crystal. The trigger electrode used in the arc tube for a flash lamp according to any one of claims 1 to 5 is any one of physical vapor deposition, chemical vapor deposition, screen printing, metallization, plating, and thermal spraying on the outer surface of a cylindrical body. A method for manufacturing an arc tube for a flash lamp, characterized in that it is formed by such a method.

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