JP2003323866A - Short-arc discharge lamp and welding method of its metal member and metal foil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a short-arc discharge lamp and a welding method of its metal member and a metal foil wherein breake of a wire does not occur and a stable lighting is made possible even when light for a long time. <P>SOLUTION: This lamp is composed of a metal member 7 mounted on the rear end side of a bead tube 6 to support the electrode lead rod 5 formed in the rear of the electrode 3 and on a rear end side of the electrode lead rod 5, a plurality of metal foils 8 to be welded to this metal member 7, the bead rod 9 to abut on the inner face side of these metal foils 8 and an outside lead wire mounting part 10 to connect the metal foils 8 with the outside lead wire 11 at the rear end part of this bead rod 9. Welding of the metal foils 8 to the metal member 7 is carried out by a welding means which becomes non- contact with the metal member 7 and the metal foils 8, and the welded parts are formed at least at one or more places, and a welded strength of the metal member 7 and the metal foils 8 is 15 N or more. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a short arc type discharge lamp used as a light source for an exposure apparatus for forming patterns on semiconductors, liquid crystal panels, printed wiring boards, projectors and projectors, and a metal member and metal foil thereof. Welding method.

[0002]

2. Description of the Related Art Conventionally, mercury-type short arc type discharge lamps,
Rare gas type short arc type discharge lamps, metal vapor type short arc type discharge lamps and the like are used in exposure apparatuses and the like.

These short arc type discharge lamps are shown in FIG.
It is configured as shown in. The discharge lamp 50 has an electrode 51.
The electrode lead rod 52 is supported by a cylindrical bead tube 53 made of quartz glass or the like. A cylindrical bead rod 55 made of quartz glass or the like is arranged at the rear end of the electrode lead rod 52, and the bead rod 55 is formed.
A plurality of metal foils 56 are provided on the outer peripheral side of.

A disk-shaped metal member 54, which is in contact with the tip of the metal foil 56, is brazed to the rear end surface of the electrode lead rod 52. An external lead wire 57 is inserted into and supported by the bead rod 55, and a metal cup-shaped external lead wire mounting portion 58 is supported at the rear end side of the bead rod 55. The rear end side of the metal foil 56 is connected to the outer peripheral portion of the external lead wire attachment portion 58 by electric spot welding. The external lead wire mounting portion 58 and the external lead wire 57 are brazed and connected.

[0005]

However, in the conventional short arc type discharge lamp, as shown in FIG. 5, the disk-shaped metal member 54 installed between the bead tube 53 and the bead rod 55, and the metal. When the tip end side of the foil 56 is brought into contact, resistance welding is used as the contact means. As shown in FIG. 6, this resistance welding is a means for performing fusion bonding (welding) by utilizing the resistance heat generation of the metal that is the welding material, and therefore the surface state (oxidation, unevenness) of the welding surface (contact surface) S is used. 56
a), the surface state of the electrodes 60 and 61 of the resistance welding machine is apt to be affected, and the welding strength varies widely. Further, since the work (the metal member 54 and the metal foil 56) has to be brought into contact with the electrodes 60 and 61 of the resistance welding machine, the welding work becomes difficult, and the part that depends on the experience of the operator is large and automation is performed. However, these are also factors that cause variations in welding strength. As a result, the welding surface S
However, it was difficult to stably discharge the discharge lamp for a long time.

Therefore, the present invention was devised to solve such a problem, and the purpose thereof is to enable a stable lighting state without causing a disconnection or the like even when lighting for a long time. It is an object of the present invention to provide a short arc type discharge lamp and a method for welding a metal member thereof and a metal foil.

[0007]

In order to solve the above-mentioned problems, the invention according to claim 1 provides a bead tube for supporting an electrode lead rod formed at the rear of the electrode and a rear end side of the bead tube. A metal member attached to the rear end side of the electrode lead rod, a plurality of metal foils welded to the metal member, a bead rod that abuts the inner surface side of the metal foils to support the metal foil, and the beads. An external lead wire attachment portion that connects the metal foil and an external lead wire at the rear end of the rod, and the welding of the metal foil to the metal member is in a non-contact state with the metal member and the metal foil. It is made by welding means, and the welding portion is formed at least at one or more places, and the welding strength between the metal member and the metal foil is 15 N or more, and is configured as a short arc type discharge lamp.

In the above structure, the welding of the metal foil to the metal member is performed by the welding means which is in a non-contact state with the metal member and the metal foil, so that the metal foil is quickly welded with only a simple positioning jig. Welding work is simple and quick, and variations in welding strength are reduced. Also,
Since the welding strength is set to 15 N or more, the welding strength becomes sufficient.

Further, in the invention according to claim 2 or 3, the welding direction of the welded portion is formed in parallel with the short side of the metal foil or in an arc with respect to the central axis of the electrode lead rod. It is configured as a short arc type discharge lamp that is used.

With the above structure, since the welded portion is in a direction orthogonal to the installation direction of the metal foil to be welded to the metal member, the welded state is stable, the variation in welding strength is reduced, and a more sufficient welding strength is obtained. Will be things.

Further, in the invention according to claim 4, the metal foil is a metal whose main component is molybdenum, and a thickness of a portion of the metal member to be welded to the metal foil is 0.1 mm to.
It is configured as a short arc type discharge lamp of 1.0 mm.

With the above structure, since the heat of welding is transferred well in the welded portions of the metal foil and the metal member, the welding state between the metal member and the metal foil is more stable, and the variation in the welding strength is further reduced. , And more than enough.

According to a fifth aspect of the present invention, there is provided a metal member which is attached to the rear end side of the bead tube which supports the electrode lead rod formed behind the electrode and which is attached to the rear end side of the electrode lead rod. In a method for welding a metal member and a metal foil of a short arc type discharge lamp having a plurality of metal foils to be welded to a metal member and a bead rod that abuts an inner surface side of the metal foil to support the metal foil, the electrode lead is provided. The step of connecting the metal member to a predetermined position of the rod, and the welding means for bringing the end of the metal foil into contact with the metal member to bring the metal member and the metal foil into non-contact with each other have a welding strength of 15
It is configured as a welding method of a metal member and a metal foil of a short arc type discharge lamp including a step of welding at N or more.

In the above construction, when the metal member is connected to the electrode lead rod, the metal member and the metal foil are welded by the non-contact welding means. It is welded, the welding work is simple and quick, and the variation in welding strength is reduced. Moreover, since the welding strength is set to 15 N or more, the welding strength becomes sufficient.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. 1A is a sectional view showing a main part of a short arc type discharge lamp, FIG. 1B is a perspective view showing a welded portion of a metal member and a metal foil of FIG. 1A, and FIG.
4B is a plan view, FIG. 4B is a plan view showing another embodiment of the welded portion of FIG. 3A, FIG. 3 is a schematic view showing a tensile test method for measuring welding strength, and FIG. 4 is laser irradiation. It is a graph which shows the transition of the welding strength with respect to time.

As shown in FIG. 1 (a), a short arc type discharge lamp (hereinafter referred to as a discharge lamp) 1 is provided on the base end side of an electrode (anode or cathode) 3 arranged inside a light emitting tube 2 so as to face each other. The electrode lead rod 5 to be connected, the bead tube 6 made of quartz glass or the like for supporting the electrode lead rod 5, and the bead tube 6
On the rear end side, the metal member 7 attached to the rear end side of the electrode lead rod 5, a plurality of metal foils 8 welded to the metal member 7, and the inner surface side of these metal foils 8 are abutted and supported. The bead rod 9 is composed of a bead rod 9 and an external lead wire attaching portion 10 for connecting the metal foil 8 and the external lead wire 11 at the rear end portion of the bead rod 9. Although the drawing shows the configuration on the cathode side, the configuration on the anode side is also the same. Further, the arc tube 2 is filled with an appropriate amount of mercury, a rare gas or a mixture thereof.

The external lead wire mounting portion 10 has a convex portion 10b protruding from both sides from the disc portion 10a formed in a disc shape, and one convex portion 10b is fitted to the rear end portion of the bead rod 9. It is supported, and the other convex portion 10 b is connected to the external lead wire 11. Further, the external lead wire attaching portion 10 is not limited to the form of FIG. 1, and for example, as shown in FIG. 5A, a cup-shaped external portion having a through hole for allowing the external lead wire 57 to pass therethrough at the center. The lead wire mounting portion 58 may be in the form. The external lead wire 57 is inserted and supported in the bead rod 55, and the external lead wire 57 and the external lead wire mounting portion 58 are brazed.

As shown in FIGS. 1 (a) and 1 (b), the metal member 7 includes a bead tube 6 for inserting and supporting the electrode lead rod 5 and a bead rod 9 for fitting and supporting the rear end portion of the electrode lead rod 5. It is installed in between. And. The metal member 7 includes a disk-shaped flange portion 7a having a through hole at the center, and the flange portion 7a.
The tubular support portion 7b is provided on one surface side of the tubular support portion 7b.
The rear end side of the electrode lead rod 5 is fitted and supported in the through hole. Further, the slit 7c may be formed over the flange portion 7a and the tubular support portion 7b in order to improve the fitting state. Further, the metal member 7 is not limited to the form shown in FIG. 1. For example, as shown in FIG. 5, the rear end face of the electrode lead rod 52 may be brazed to the surface of the disc-shaped metal member 54. Absent.

The metal member 7 is formed of a metal such as tungsten, tantalum, molybdenum, ruthenium, rhenium, or the like which is a high melting point metal, or an alloy thereof, and a metal foil 8
Tantalum is preferable in terms of weldability with. And metal foil 8
The thickness of the flange portion 7a to be welded is not particularly limited, but in consideration of weldability with the metal foil 8, the thickness is 0.1
It is preferably within the range of 1.0 mm.

The thickness of the flange portion 7a of the metal member 7 is 0.
If it is less than 1 mm, the thickness is too thin, and a hole is opened in the flange portion 7a due to welding heat during welding, and the welding strength may be extremely deteriorated. Further, if the thickness exceeds 1.0 mm, the thickness is too thick and the welding heat is not transmitted well during welding, and there is a possibility that a predetermined welding strength may not be obtained, and when sealing in the sealing tube portion 4. The degree of thermal expansion due to the heat of and the heat during lighting greatly differ between the metal member 7 and the bead tube 6 and the bead rod 9 made of quartz glass, which are in contact with the metal member 7 and whose thermal expansion coefficient is different from that of the metal member 7. As a result, cracks or the like may occur in the bead tube 6 and the bead rod 9.

The metal foil 8 is formed of a metal whose main component is molybdenum, which is a sealing metal. Further, it may be formed of a metal having a high melting point such as tungsten, tantalum, ruthenium, or rhenium, or an alloy thereof, but molybdenum is the main component because of the ease of welding and the good conductivity of welding heat. Metals are preferred.

The welding of the metal foil 8 to the metal member 7 is performed at least at one or more places by a welding means that makes a non-contact state with the metal member 7 and the metal foil 8, and the welding strength is 15 N or more. As a concrete example of the welding means in the non-contact state, laser welding using YAG laser, carbon dioxide gas laser, argon ion laser, light converging welding using light beam, gold image furnace, etc. are used. IR heater welding and the like.

In the non-contact welding means, the welding state does not depend on the surface state of the welding surface (oxidation or unevenness on the metal member 7, the metal foil 8 and the electrode surface of the welder). Further, since the welding electrode does not come into contact with the work (the metal member 7 and the metal foil 8), it is possible to perform the welding quickly with only a simple positioning jig, and the complicated process that depends on the experience of the operator is simplified and facilitated. It can be automated. Therefore, variations in welding strength are reduced.

Further, since the welding strength is set to 15 N or more, it is possible to achieve a welding strength sufficient, that is, a welding strength of 15 N or more, which is equivalent to the conventional one. If the welding strength is less than 15 N, the strength is insufficient,
When an external force is applied to the discharge lamp 1, the welded portion is likely to be broken. As a result, the discharge lamp 1 cannot maintain a stable lighting state for a long time.

As shown in FIGS. 1 (b) and 2 (a), at least one or more welded portions P1 to P5 are
It is preferable that the metal foil 8 is formed in parallel to the short side of the metal foil 8 or in a circular arc with respect to the central axis of the electrode lead rod 5 as shown in FIG. Is more preferable. In this way, the welded portions P1 to P5 are formed in the direction orthogonal to the installation direction of the metal foil 8 to be welded to the metal member 7, so that the metal member 7 and the metal foil 8 are formed.
The welded state is stable, the variation in welding strength is reduced, and the welding strength equal to or more than 15 N, which is the same as the conventional one, can be obtained.

Next, a method of welding the metal member 7 and the metal foil 8 of the short arc type discharge lamp 1 will be described. The welding method of the present invention is not particularly limited as long as it includes the following steps. (1) A step of connecting the metal member 7 to a predetermined position of the electrode lead rod 5. Here, the term "connection" means one that is electrically connected (energized). The form is, for example, FIG.
5, the cylindrical support portion 7b of the metal member 7 is inserted into the rear end portion of the electrode lead rod 5, and the metal member 54 is brought into contact with the rear end surface of the electrode lead rod 52 as shown in FIG. It can take the form. (2) A step of bringing the metal foil 8 into contact with the metal member 7 and performing welding with a welding strength of 15 N or more by a welding means that brings the metal member 7 and the metal foil 8 into a non-contact state. put it here,
Regarding the welding jig, welding conditions (welding time, welding temperature, etc.), depending on the type of welding means (laser welding, light condensing welding, IR heater welding, etc.) that results in the non-contact state,
The welding strength is appropriately set to 15 N or more.

By constructing the discharge lamp 1 as described above, even if the lamp is lit for a long time, a disconnection or the like due to defective welding of the metal member 7 and the metal foil 8 does not occur, and a stable lighting state is possible. It is possible to provide the short arc type discharge lamp and the method for welding the metal member thereof and the metal foil.

[0028]

EXAMPLES Next, more detailed description will be given with reference to examples of the present invention. The present invention is not limited to the examples.

Experiments and evaluations were conducted on the strength (welding strength) of the welded surface of the metal member and the metal foil of the discharge lamp of the present invention.

As shown in FIGS. 1 (b) and 2 (a), a metal foil 8 made of molybdenum is placed on the flange portion 7a of the metal member 7 made of tantalum, and the portion where the flange portion 7a and the metal foil 8 overlap each other. Was welded with a YAG laser to prepare a work. The thickness of the metal member 7 (flange portion 7a) at this time is 0.1 m
m, and the thickness of the metal foil 8 was 0.04 mm. The welding condition is that the irradiation cycle of the YAG laser is 0 to 5 ms.
-ON, 1ms-OFF, fiber diameter is about 0.4
The irradiation power was 1.15 J in mm. Further, the work was irradiated perpendicularly (perpendicular to the metal foil 8), and as a welding direction, it was irradiated at five points parallel to the short side (width direction) of the metal foil 8 at equal intervals (Fig. 2 ( See a) welds P1 to P5). The welding strength of the work was measured by a tensile test as shown in FIG. The measurement results are shown in FIG. As a comparison, instead of YAG laser welding, a work using conventional resistance welding was prepared and the welding strength was measured.

The welding strength of the work using conventional resistance welding was 15N. As shown in FIG. 4, when the irradiation time of the YAG laser was 1 to 5 ms, the same result as that of the conventional resistance welding was obtained. Also, as for the resistance value of the work, a result equivalent to 4.4 mΩ of the product of the present invention (YAG laser welding) was obtained as compared with 4.6 mΩ of the conventional product (resistance welding). It suggests that the product has the same welding strength as the conventional product. In addition, the metal member 7 (flange portion 7
a) Even when the thickness was changed from 0.1 mm to 1.0 mm and the same experiment as described above was performed, the same result as in FIG. 4 was obtained.

Next, the work (YA
Using a G laser irradiation time of 1 ms), a discharge lamp as shown in FIG. 1 was manufactured, and the illuminance maintenance rate (the illuminance decrease rate with respect to the lighting time, which is an index of the discharge lamp life) was measured. This discharge lamp is a mercury short arc type discharge lamp with a rated input current of approximately 84
A, rated input voltage of about 75V and rated power of 8KW class. Further, as a comparison, instead of YAG laser welding, the illuminance maintenance rate of a discharge lamp using a work using conventional resistance welding was also measured.

As a result of the measurement, the conventional product (resistance welding) has about 10
Inventive product (Y
(AG laser welding) about 1000 hours, illuminance maintenance rate about 8
It was 3.2%. The illuminance maintenance rate (discharge lamp life) of the product of the present invention was almost the same as that of the conventional product.

[0034]

As described above, in the short arc type discharge lamp of the present invention, the welding of the metal foil to the metal member is performed by the welding means that makes the metal member and the metal foil in a non-contact state. Is formed in at least one place, and the welding strength of the metal member and the metal foil is set to 15 N or more, and the welding direction of the welded portion is parallel to the short side of the metal foil,
Alternatively, the metal foil is formed in an arc with respect to the central axis of the electrode lead rod, and the metal foil is a metal whose main component is molybdenum, and the thickness of the metal member is 0.1 to 1.0 mm. Even if the lamp is lit for a long time, no disconnection occurs in the welded portion, a stable lighting state is possible, and the performance (life) of the discharge lamp is not deteriorated.

Further, as described above, the method of welding the metal member and the metal foil of the short arc type discharge lamp of the present invention includes the step of connecting the metal member to a predetermined position of the electrode lead rod and the metal foil to the metal member. A step of bringing the end portions into contact with each other and performing welding with a welding strength of 15 N or more by a welding means that makes a non-contact state with the metal member and the metal foil, so that the wire breaks in the welded portion even when the lamp is turned on for a long time. Does not occur, a stable lighting state is possible, and the performance (life) of the discharge lamp does not deteriorate.

[Brief description of drawings]

1A is a cross-sectional view showing a main part of a short arc type discharge lamp of the present invention, and FIG. 1B is a perspective view showing a welded portion of a metal member and a metal foil of FIG. 1A.

2 (a) is a plan view of FIG. 1 (b), and FIG. 2 (b) is (a).
It is a top view which shows other embodiment of the welded part.

FIG. 3 is a schematic view showing a tensile test method for measuring weld strength.

FIG. 4 is a graph showing changes in welding strength with respect to laser irradiation time.

5A is a sectional view showing a main part of a conventional short arc type discharge lamp, and FIG. 5B is a perspective view showing a welded portion of a metal member and a metal foil of FIG. 5A.

FIG. 6 is a schematic view showing resistance welding in a conventional short arc type discharge lamp.

[Explanation of symbols]

1 discharge lamp 2 arc tube 3 electrodes (cathode) 4 Sealing tube 5 electrode lead rod 6 beads tube 7 Metal members 7a Flange part 7b Cylindrical support 7c slit 8 metal foil 9 beads stick 10 External lead wire mounting part 11 External lead wire P1 to P5 welds

Claims (5)

[Claims] 1. A bead tube supporting an electrode lead rod formed behind an electrode, a metal member attached to the rear end side of the electrode lead rod at the rear end side of the bead tube, and welded to the metal member. A plurality of metal foils, a bead rod for supporting the metal foil by abutting the inner surface side of these metal foils, and an external lead wire attachment for connecting the metal foil and an external lead wire at the rear end of the bead rod. The metal member is welded to the metal member by a welding means that is in a non-contact state with the metal member and the metal foil, and the welded part is formed in at least one or more places. And a metal foil having a welding strength of 15 N or more, a short arc type discharge lamp. 2. The short arc type discharge lamp according to claim 1, wherein a welding direction of the welded portion is formed parallel to a short side of the metal foil. 3. The short arc type discharge lamp according to claim 1, wherein the welding direction of the welded portion is formed in an arc with respect to the central axis of the electrode lead rod. 4. The metal foil is a metal containing molybdenum as a main component, and a thickness of a portion of the metal member to be welded to the metal foil is 0.1 to 1.0 mm. The short arc type discharge lamp according to claim 1. 5. A metal member attached to the rear end side of the electrode lead rod on the rear end side of a bead tube supporting an electrode lead rod formed behind the electrode, and a plurality of metals welded to the metal member. Foil, and a method of welding a metal member and a metal foil of a short arc discharge lamp having a bead rod that abuts the inner surface of the metal foil to support the metal foil, wherein the metal member is provided at a predetermined position of the electrode lead rod. A step of connecting, and a step of bringing the end of the metal foil into contact with the metal member and performing welding at a welding strength of 15 N or more by a welding means that makes a non-contact state with the metal member and the metal foil. A method for welding a metal member and a metal foil of a short arc type discharge lamp characterized.