TWI470666B - A discharge lamp, a discharge lamp electrode, and a discharge lamp electrode - Google Patents

Description

Discharge lamp, electrode for discharge lamp, and electrode for discharge lamp

The present invention relates to a discharge lamp used in an exposure apparatus or the like, and particularly relates to an electrode structure of a high-output discharge lamp such as a short-arc discharge lamp.

The short arc type discharge lamp irradiates high-brightness light to an object to be exposed such as a substrate. As the size of the object to be exposed increases and the amount of processing increases, the discharge lamp is required to have a high output, and the continuous charging is required to increase the power consumption. When the electric power is increased, the electron emission, heat release, durability, and the like are affected by the conventional electrode structure. Therefore, it is necessary to combine electrode structures of different metals such as crystals and types.

For example, when the standing grid power is increased, the electrode is consumed excessively due to the large current density at the tip end portion of the cathode, and the spot of the arc discharge moves to cause an unstable discharge. Therefore, an electrode structure in which the front end portion of the cathode is melted by the DC discharge treatment device and the crystal structure of the tip end portion is coarsened can be used as a structure for stable arc discharge (refer to Patent Document 1).

When the constant grid power is increased, the amount of current flowing between the electrodes of the lamp increases, and the temperature of the electrode rises. In particular, the front end portion of the anode is in a high temperature state, so that the front end portion of the anode melts and evaporates over time. Finally, in addition to the decrease in luminous efficiency due to unstable arc discharge, or adhesion of the inner surface of the metal tube due to anode melting, the life of the lamp is lowered due to electrode consumption.

In order to prevent the electrode from being melted by the overheating, an electrode structure in which a metal material having a higher thermal conductivity and a lower melting point than the metal electrode body is sealed in the internal space of the body is proposed (see Patent Document 2). In this configuration, the cover member is welded to the bottom cylindrical metal member to form an electrode having a sealed space.

[Patent Document 1] JP-A-2002-110083

[Patent Document 2] JP-A-2004-259644

Even if the crystal structure or the metal composition in the vicinity of the electrode surface is changed, the electrode characteristics such as thermal conductivity, conductivity, and durability cannot be greatly improved as a whole. In particular, a discharge lamp having a large output power cannot be expected to have a large increase in heat release characteristics. However, when the same type or different types of members are combined to form an electrode, the joint state between the members affects durability, thermal conductivity, and the like.

For example, when a metal member is joined by a welding method such as an electron beam to form an electrode, the metal crystal grain size along the joint surface is enlarged, and the particle size is not uniform. On the other hand, the crystal grain size along the direction of the electrode axis is discontinuous, and a crystal boundary is formed in the joint portion. Therefore, the strength of the electrode will drop at the joint portion.

When the metal structure such as the size of the crystal grain size is not uniform or discontinuous in the vicinity of the joint surface, the heat conduction characteristics along the electrode axis direction are not uniform throughout the joint surface, and heat inside the electrode cannot be smoothly transferred. As a result, a local overheating state is generated inside the electrode to accelerate the consumption of the electrode.

Therefore, in order not to adversely affect the electrode characteristics, it is necessary to combine a plurality of members to constitute an electrode.

The discharge lamp of the present invention comprises: a discharge tube and a pair of electrodes disposed in the discharge tube, such as a short arc type discharge lamp (particularly a high output discharge lamp). At least one electrode of the discharge lamp is an electrode formed by solid phase bonding of a plurality of solid components, at least one of which is a metal component. For example, a plurality of metal members can be joined, and the number of solid members constituting the electrodes is arbitrary. It is possible to join directly to a solid part or to a part that mediates the bonding between the parts (it can also be considered as a plurality of solid parts).

The plurality of solid members constituting the electrode body include a solid member supported by the electrode support rod (hereinafter referred to as a rear end solid member), and a solid member having an electrode front end surface (hereinafter referred to as a front end solid member), a rear end solid member and a front end solid member The electrodes are formed by solid phase bonding. In the solid phase bonding, the solid members are joined while the joint surfaces between the solid members are brought into contact with each other, pressurized, and heated.

In the present invention, at least a part of the crystal grains (hereinafter referred to as the joint surface crystal grains) forming the joint surface of the metal member is deformed by the joining, and the other crystal grains are not substantially deformed before and after the joining. For example, the crystal grains on the joint surface cause deformation of the crystal grains or grain boundary movement on the entire joint surface (the surface contributing to the joint), and the deformation of the crystal grains is a deformation that contributes to the joint. In particular, when the joint surface is not an ultra-smooth surface, large crystal grains are easily formed, and a minute gap is generated.

On the other hand, the metal crystal grains other than the crystal grains on the joint surface do not substantially deform by the joining in the vertical direction of the joint surface in the vicinity of the joint surface. Here, "does not occur substantially" means that crystal grain deformation (crystal grain formation) and grain boundary movement which do not directly contribute to bonding do not occur, and crystal grains before bonding are hardly deformed after bonding.

Such solid phase bonding, that is, the use of the joint surface crystal grains by direct bonding, and the additional metal structure (crystal grains) are not affected by the joint, and the jointed metal parts are in the vicinity of the joint surface. The crystal grain size has uniform properties. That is to say, the crystal grains of the metal member are almost uniform along the joint surface of the metal member, and are almost uniform along the vertical direction of the joint surface.

Therefore, in the vicinity of the joint surface, the enlarged crystal grains which are once and twice recrystallized, such as electron beam welding, are not formed, and the enlarged crystal grains are not formed in a layered manner along the vertical direction of the joint surface. The metal structure characteristics such as the crystal grain size do not discontinuously change in the direction of the joint surface and the vertical direction of the joint surface.

Thereby, the metal crystal structure on the joint surface has an excellent structure in which durability and thermal conductivity are balanced. The necessary strength can be obtained by the solid phase bonding at the joint surface, and the heat transfer, conductivity, and crystallization characteristics are different from other metal structures only on the joint surface. Therefore, this ability does not significantly decrease compared to the integrally formed electrode.

Since the electrical conductivity, the thermal conductivity, and the durability in the vicinity of the joint surface are relatively stable as described above, there is no fear that the thermal conductivity, the durability, and the like are locally lowered, and the partial electrode is rapidly consumed. Therefore, in order to improve thermal conductivity, electron emission characteristics, durability, and the like, solid members of different types or the same can be selected, and electrode shapes can be freely designed and joined to obtain an electrode structure having excellent characteristics.

An electrode for a discharge lamp according to another aspect of the present invention is disposed in a discharge tube of a discharge lamp, and is composed of a plurality of solid members including a front end solid member having an electrode tip end surface and a rear end solid member supported by the electrode support rod. The electrode for a discharge lamp is formed by solid-phase joining of a plurality of solid members between a front end solid member and a rear end solid member, and at least one of the plurality of solid members is a metal member. At least a part of the crystal grains on the joint surface on which the metal member joint surface is formed is deformed by joining, and the metal crystal grains other than the crystal grains on the joint surface do not substantially cause joint deformation in the vertical direction of the joint surface in the vicinity of the joint surface.

On the other hand, the discharge lamp according to another aspect of the present invention or the electrode for a discharge lamp may include an electrode that inclines the joint surface during solid phase bonding. That is, the discharge lamp includes a discharge tube and a pair of electrodes disposed in the discharge tube, and at least one of the electrodes is an electrode formed by solid-phase bonding of a plurality of solid members.

At least one of the plurality of solid components is a metal component, and the crystal grain size of the metal component is nearly uniform along the joint surface between the components, and the metal crystal and the crystal structure are along the joint surface near the joint surface of the metal component. Tilt in the vertical direction.

The "inclination" is described, for example, in the following references 1 and 2.

[Reference 1] "Patent Circulation Support Form" 15th Annual Chemistry 14 Light Metal Matrix Composites

Independent administrative legal entity industrial ownership ‧ training hall

1. 1. 1 technology of light metal matrix composites (7) tilting

(http://www.ryutu.inpit.go.jp/chart/H15/kagaku14/1/1-1.pdf)

[Reference 2] "Technology Development of Tilting Functional Materials" CMC Publishing September 22, 2009

Chapter 1 Appearance of Tilting Functional Materials

1. 3 Basic Concepts of Tilting Functional Materials Pages 5 and 6

1. 6 Outlook for Tilting Functional Materials Page 10

As described in the documents 1 and 2, the term "tilt" refers to a state in which the composition, the organization, or the other functions are continuously changed inside. In the case of the present invention, it is a structure of a metal crystal, that is, a metal member, and its characteristics, properties, and functions are continuously or stepwise changed in the vertical direction of the joint surface, and a distributed (tilted) structure is found in the vicinity of the joint surface. A specific feature is that when the solid phase is joined to a plurality of solid members including metal members, the crystal grain size continuously changes from the direction in which the joint faces away.

In the solid member prepared by solid phase joining in the present invention, the composition of the metal crystal grains and the metal structure at the joint surface have a structure having excellent durability and thermal conductivity. The metal crystal grain size is almost uniform along the joint surface between the solid members, and the crystal along the vertical direction of the joint surface is inclined near the joint surface. That is, the crystallization near the joint surface may be staged or continuous without intense crystallization changes.

Even in the vicinity of the joint surface, since conductivity, thermal conductivity, and durability are stabilized, there is no fear that the thermal conductivity, the durability, and the like are locally lowered, and some of the electrodes are rapidly consumed. In order to improve thermal conductivity, electron emission characteristics, durability, and the like, solid members of different types or the same can be selected and joined to obtain an electrode structure having excellent characteristics.

The deformation or tilting of the crystal grains at the joint surface can be formed as a whole under the condition that the partial portion or the partial portion is avoided. As the solid phase bonding method, a solid phase bonding method using thermal diffusion, electric field diffusion, or the like can be employed. For example, diffusion bonding using one of the solid phase bonding methods is preferred. Specifically, the solid member can be joined by discharge plasma sintering (SPS bonding method) or the like. In the solid phase bonding process, heating conditions, pressurization conditions, and the like are set such that crystal grain deformation/inclination is achieved.

There are many cases in which the joint surface of the solid part is smooth, and in the case of a non-super smooth surface, the joint surface produces a slight gap. Therefore, it is considered that the crystal particles are not deformed as much as possible by heating with a small gap as much as possible. In this case, a preferred method is to join the solid members by means of spark plasma sintering bonding (SPS bonding).

Regarding the combination of the solid members, the combination of the solid members can be determined in accordance with the purpose of heat transfer effect, durability, and the like, and the shape of the electrodes can be determined depending on the purpose. The number of solid parts constituting the electrode is arbitrary. For example, an electrode such as a short arc discharge lamp is composed of a tip end portion of a truncated cone shape and a columnar electrode body portion, and the joint surface can be positioned at the tip end portion of the electrode or the electrode body portion in accordance with the combination and shape of the solid member.

The specific solid component composition may be a combination of both the front end solid part and the rear end solid part to constitute the electrode body. For example, in the case of an electrode shape composed of a conical portion and a truncated cone portion, a solid member constituting a part of the electrode tip end portion and the electrode body portion and a solid member constituting the remaining electrode body portion may be joined or may be joined to each other. The electrode body portion and a solid member of a part of the electrode tip end portion and a solid member constituting the remaining electrode tip end portion. Alternatively, the electrode tip end portion and the electrode body portion are formed of individual solid members, and the two are joined together.

For example, when the entire electrode tip end portion is formed of one solid member, the first solid member can be configured by a truncated cone electrode tip end portion and a cylindrical joint portion having the same diameter as the second solid member. According to this configuration, the composition of the main body portion can be relatively freely designed, for example, the internal space is formed in the main body portion, or the heat radiating fins are formed in the circumferential direction.

On the other hand, when one solid member constitutes only a part of the tip end portion of the electrode, the second solid member can be configured by the main body portion and the truncated cone-shaped electrode joint portion joined to the first solid member. If such a configuration is made, a design can be made which only changes the characteristics of the tip end portion of the electrode.

When it is considered to improve the heat transport effect in the direction of the electrode axis, it is preferable to join a solid member having a different thermal conductivity, and then to form an electrode body portion at the end of the electrode support rod with a solid member having a relatively high thermal conductivity. For example, the electrode main body portion can be formed of a high melting point solid member such as pure tungsten. On the other hand, for the purpose of forming a free electrode shape, it is also possible to form a solid by joining solid members of the same type and the same characteristics.

When the tip end portion of the electrode is composed of one solid member, the tip end solid member can be configured by a joint portion between the tip end portion of the truncated cone shape and the columnar shape. According to this configuration, the composition of the main body portion can be relatively freely designed, for example, the internal space is formed in the main body portion, or the heat radiating fins are formed in the circumferential direction. On the other hand, it is also possible to use only one solid member to constitute only a part of the tip end portion of the electrode.

Usually, the shape of the electrode is symmetrical about the electrode axis, and heat and current move along the electrode axis. Therefore, it is preferred to dispose the solid member in an appropriate position along the electrode shaft with a suitable material. The solid member may be solid-phase bonded such that the joint faces are formed perpendicular to the electrode axis. For example, when the electrode is formed by cutting after the solid phase bonding and the bonding surface is formed along the vertical direction of the electrode axis, the electrode stability during operation is relatively high.

When the anode is placed in a discharge lamp vertically above, when the solid member having high thermal conductivity is joined to the tip end portion of the electrode such as tungsten, the distance from the tip end surface of the electrode to the joint surface in the direction of the electrode axis is equal. Therefore, the heat transfer along the electrode axis is not uneven, and the temperature distribution in the lighting is symmetrically distributed around the electrode axis without causing electrode friction due to local overheating.

In consideration of preventing the electrode from being overheated, it is preferable to enhance the heat release effect while heat transport. If the contact surface of the solid member to be joined is not completely flat (ultra-smooth surface), the gap along the joint surface remains partially even after the joint, and heat is released from the gap during lighting. Therefore, it is also possible to solid-bond a solid member having a contact surface forming a gap along the joint surface. For example, a wedge may be formed in the circumferential direction near the surface of the electrode and a gap may be provided.

As described above, a plurality of solid members can be joined in the electrode manufacturing process by, for example, SPS bonding. In this case, it is preferred to locally heat the joint surface by increasing the current density supplied to the joint surface as much as possible. Therefore, if the area of the joint surface along the metal member (the area contributed to the joint) is represented by S01, the cross-sectional area of the filling portion of the metal member along the vertical direction of the electrode axis is represented by S02, preferably satisfying S02>S01. condition. For example, the vicinity of the joint surface can be tapered to reduce the joint surface area.

Alternatively, a sealed space may be provided inside the electrode so that the joint surface is a peripheral portion. It is considered that the joint portion (that is, the heating portion) is uniformly distributed with respect to the electrode axis, and the strength balance at the time of joining is excellent. It is preferable that the formed S01 minimizes the cross-sectional area of the substantially cylindrical electrode body portion in the radial direction, that is, The joint surface is round or ring-shaped.

In order to improve the joint state between the solid members regardless of the smoothness of the joint surface, a soft member may be placed between the solid members to be joined. In order to increase the strength, it is preferred to join the metal member to other solid members through the intermediate solid member. For example, the intervening solid component is constructed of a component that is softer than the solid component to be joined. Here, the term "soft" means a member which is large in deformation at the time of joining, because it is low in hardness, ductile or malleable, and deformed at the time of joining.

For example, when the metal component is tungsten, the metal softer than tungsten may include at least one of molybdenum, niobium, vanadium, niobium, titanium, gold, platinum, and rhodium. Considering the stability of thermal conductivity and electrical conductivity, the intermediate solid component may be an alloy including tungsten.

As the electrode structure, the heat transfer efficiency in the direction of the electrode axis can be improved by providing a concave metal member and joining the plurality of solid members to form a sealed space inside the electrode, and sealing the low-melting metal which is melted at the time of lighting into the sealed space.

In this case, after the electrode body is formed, the electrode support rod is joined to the rear end solid member. At this time, the pressure from the electrode support rod side deforms the rear end solid member, and the pressure may be transmitted to the joint surface to cause the joint surface to peel off.

In order to prevent this from occurring, it is preferable that the joint surface of the concave metal member is located closer to the center of the discharge lamp (the other electrode) than the joint front end portion between the rear end solid member and the electrode support rod. It is preferable that the joint surface (for example, the joint surface of the recess wall surface and the end surface constituting the metal member) has a gap that does not reach the sealed space. While it is considered to prevent the molten metal from flowing into the joint surface, it is preferable that the joint surface of the concave metal member is located closer to the electrode support rod than the solidification range of the molten metal at the time of lighting.

In order to increase the heat release effect of the electrode body, it is preferred to increase the surface area. The electrode can be formed in a fin shape or a sheet shape by joining a plurality of solid members, and a deep groove electrode structure which is difficult in a conventional manufacturing method can be obtained.

For example, the electrode may have a plurality of plate-like solid members having different sizes and diameters, and the plurality of plate-like solid members may be joined to change the electrode diameter along the direction of the electrode axis. The plate-shaped solid member having a different joining length can constitute an electrode whose electrode diameter in the vertical direction of the electrode axis is intermittently increased or decreased with respect to the columnar electrode main portion.

Alternatively, the electrode shape in which the fins are arranged along the direction of the electrode axis can be formed. For example, as a plurality of solid members, an electrode tip end member having an electrode tip end surface may be prepared, and a plurality of fins may be arranged at a predetermined interval in the circumferential direction, and the plurality of fins may have a tubular member having a smaller size and a smaller diameter than the electrode tip end member. The body member extending in the radial direction constitutes an electrode that coaxially joins the electrode tip end member and the tubular member. Thereby, a deep groove can be formed on the columnar electrode main body portion along the direction of the electrode axis. Alternatively, the fin may be joined to the tip end portion of the electrode.

In the case of such an electrode having a fin shape, the fin is formed such that the joint surface of the electrode tip end member constitutes a part of the end face of the groove, the fin is protected from discharge, and the gas superheated by the discharge is prevented from directly entering the joint portion. The plurality of fins have a radial dimension that does not protrude from the joint surface of the electrode tip end member.

In order to increase the heat dissipation and increase the number of fins, the cross-sectional area of the electrode body portion is reduced, and the heat conduction in the direction of the electrode axis is lowered. Therefore, if the cross-sectional area along the vertical direction of the electrode axis of the body member is expressed by S11, The cross-sectional area in the vertical direction of the electrode axis of the virtual body member in the case of filling the groove between the plurality of fins is represented by S12, and preferably satisfies S12 × 2 / 3 ≦ S11.

According to another aspect of the invention, in the method of manufacturing an electrode for a discharge lamp, a plurality of solid members are solid-phase bonded between a front end solid member and a rear end solid member, wherein the plurality of solid members include a front end solid member including an electrode front end face and an electrode support rod. The back end solid component is supported, and at least one of the plurality of solid components is a metal component. In the manufacturing method, when a plurality of solid members are joined by solid phase, at least a part of the crystal grains of the joint surface forming the joint surface of the metal member are deformed by joining, and the metal crystal grains other than the crystal grains on the joint surface are not substantially in the vicinity of the joint surface. The joint produces a joint deformation along the vertical direction of the joint surface. For example, as the solid phase bonding method which contributes only to the bonding of the bonded crystal grains, it is preferable to employ SPS bonding which gives local heating of the joint surface with a small gap.

On the other hand, in the method for producing an electrode for a discharge lamp according to another aspect of the present invention, the plurality of solid members are solid-phase bonded between the first solid member and the second solid member, wherein the plurality of solid members include the first solid member including the front end face of the electrode. At least one of the plurality of solid members is a metal member, and the second solid member supported by the conductive electrode support rod. The manufacturing method is characterized in that when the solid phase is joined to the plurality of solid members, the crystal grain size of the metal member is nearly uniform along the joint surface between the members, and the metal crystal is perpendicular to the joint surface near the joint surface of the metal member. The direction is tilted.

The electrode for a discharge lamp or the discharge lamp according to another aspect of the present invention includes not only the above-described electrode for solid phase bonding, that is, an electrode which is substantially only surface-joined and inclined of the crystal grains of the joint surface, and further includes other bonding methods such as fusion bonding. An electrode that joins a plurality of solid components. The discharge lamp includes a discharge tube and a pair of electrodes disposed in the discharge tube, at least one of which is an electrode formed by fusing a plurality of solid components. At least one of the plurality of solid components is a metal component.

Such an electrode for a discharge lamp or a discharge lamp may be an electrode structure having one of the above-described features, that is, a structure in which an intermediate solid member is provided, a closed space is provided, and a position of a joint surface is adjusted with respect to an electrode support rod joint portion or a metal solidification range. A sheet structure and a fin structure that increase the surface area of the electrode.

According to the present invention, it is possible to constitute an electrode in which various solids are combined without affecting the electrode characteristics.

Embodiments of the invention are described below with reference to the drawings.

Fig. 1 is a plan view showing a short arc type discharge lamp of the first embodiment.

The short arc type discharge lamp 10 is a discharge lamp which can be used for a light source such as an exposure device (not shown) for forming a pattern, and is provided with a discharge tube (light-emitting tube 12) made of transparent quartz glass. In the discharge tube 12, the cathode 20 and the anode 30 are arranged to face each other with a predetermined interval therebetween.

The both sides of the discharge tube 12 have quartz glass sealing tubes 13A and 13B which are opposed to each other and integrally formed with the discharge tube 12. Both ends of the sealing tubes 13A, 13B are plugged by the metal 19A, 19B. The anode 30 of the discharge lamp 10 is on the upper side, and the cathode 20 is on the lower side, and both are arranged in the vertical direction. As will be described later, the anode 30 is composed of two metal members 40 and 50.

Electrode support rods 17A and 17B for supporting the metallic cathode 20 and the anode 30, metal rings (not shown), and metal foils 16A and 16B such as molybdenum are disposed in the inside of the sealing tubes 13A and 13B. Conductor bars 15A, 15B. The sealing tubes 13A and 13B are fused with glass tubes (not shown) provided inside the sealing tubes 13A and 13B, thereby closing the discharge space DS for sealing mercury and rare gases.

The conductor bars 15A and 15B are connected to an external power supply unit (not shown). A voltage is applied between the cathode 20 and the anode 30 through the conductor bars 15A, 15B, the metal foils 16A, 16B, and the electrode support bars 17A, 17B. When the discharge lamp 10 is supplied with electric power, an arc discharge is generated between the electrodes, and light is emitted from the mercury (ultraviolet light).

Fig. 2 is a schematic cross-sectional view of the anode.

The anode 30 is an electrode composed of a metal member (front end solid member) 40 having an electrode tip end surface 40S and a metal member (rear end solid member) 50 joined to the metal member 40. The metal member 40 is composed of a truncated cone shaped portion 40A of the electrode distal end surface 40S and a cylindrical shaped portion 40B having the same diameter as the cylindrical metallic member 50 and connecting the metallic member 50. The metal member 50 is supported by the electrode support rod 17B at the rear end surface 50B.

The metal member 40 is made of a high melting point metal such as pure tungsten or an alloy mainly composed of tungsten. On the other hand, the cylindrical metal member 50 is made of a metal containing a high thermal conductivity than the metal member 40 (for example, pure tungsten, molybdenum, a getter effect, and a highly thermally conductive nitrogen having a large shape. Made of aluminum, carbon raw materials, etc.).

The metal members 40 and 50 are solid-phase bonded by means of discharge plasma sintering (SPS sintering). In the present embodiment, the superheating and pressurization at the time of joining are adjusted, and the crystal grains of the metal members 40 and 50 constituting the joint surface, that is, the crystal grains on the joint surface are deformed to contribute to the joining, and the metal is added. Within the tissue, the crystal deformation resulting from the bonding does not substantially occur along the direction of the electrode axis.

The metal members 40 and 50 are each solidified by the sintered metal powder, and the metal structure is a primary recrystallization structure. On the other hand, when the metal members 40 and 50 are solid-phase bonded to constitute the electrode 30, secondary recrystallization does not occur in the vicinity of the joint surface S of the metal members 40 and 50 along the direction of the electrode axis and the joint surface. When the crystal grain is enlarged, the grain boundary moves, and the like, a bonding layer in which the crystal structure is enlarged and deformed is not formed along the electrode axis X.

That is to say, at the joint faces of the metal members 40, 50, only the opposite exposed joint crystal grains may undergo joint deformation, and the other metal crystal grains, whether in the joint surface direction or the vertical direction, hardly Deformation, recrystallization, and grain boundary movement that affect the joint occur. According to such solid phase bonding, the crystal grain size of the joined metal member in the vicinity of the joint surface is almost uniform along the joint surface of the metal member, and is also almost uniform along the vertical direction of the joint surface.

The metal structure having such a joint surface S is formed so that the heat conduction property and the conductivity do not become uneven along the joint surface S direction. While the electrode front end surface 40S (1000 ° C or higher) which is in a high temperature state due to lighting is supplied to the electrode support rod 17B, the temperature distribution inside the anode is symmetrically distributed around the electrode axis X, and the heat transfer is hardly engaged. The influence of the surface S.

Fig. 3 shows a discharge plasma sintering apparatus.

The bonding method using the discharge plasma sintering (SPS) is a bonding method in which the pulsed electric energy is directly supplied to the particle gap of the molded body, and the high-temperature energy of the discharge plasma instantaneously generated by the spark discharge phenomenon is thermally diffused and the electric field is diffused. .

The discharge plasma sintering apparatus 60 of Fig. 3 includes a vacuum chamber 65, and a metal member having the shape of Fig. 2 is disposed between the upper punch 80A, the lower punch 80B, and the graphite mold 80 provided inside the vacuum chamber 65. 40, 50, the metal members 40, 50 are in a state in which the joint faces of each other are in contact with each other. After the metal powders are solidified by sintering, the metal members 40 and 50 are formed by metal working such as cutting. The metal members 40 and 50 may be joined together and then formed by cutting or the like.

The upper punch 80A and the lower punch 80B made of graphite are connected to the upper punch electrode 70A and the lower punch electrode 70B, respectively. After the inside of the apparatus is evacuated, a voltage is applied between the upper punch 80A and the lower punch 80B by the pulse power supply 90.

Then, at the time of energization, pressure is applied between the upper punch 80A and the lower punch 80B through a pressurizing mechanism (not shown). Since the discharge plasma generated by the energization raises the temperature to a predetermined sintering temperature, the state of the pressure application is maintained for a certain period of time. Thereby, the anode having the shape shown in Fig. 2 can be obtained. The pressure and the sintering temperature are set such that the above-described joining state can be achieved. For example, the pressure is set at 50 to 100 MPa, the pressing time is set at 5 minutes to 20 minutes, and the sintering temperature near the joint surface is set at 1600 ° C to 1800 ° C. .

According to the present embodiment, the anode 30 of the short arc type discharge lamp 10 is configured by joining the high-melting-point metal member 40 and the metal member 50 having high thermal conductivity through the SPS. The metal member 40 having the truncated cone shape and the cylindrical metal member 50 are joined, and the joint surface S is along the direction of the vertical electrode axis X, that is, the anode sectional diameter direction.

During the lighting period, the vicinity of the electrode front end surface 40S is extremely high, but the heat transmitted through the front end portion of the metal member 50 is efficiently delivered to the electrode support rod. Thereby, electrode consumption due to overheating of the electrodes can be prevented. On the other hand, crystal grains along the joint surface S are crystal-deformed by joining, and on the other hand, other crystal grains hardly undergo recrystallization, enlargement, deformation, grain boundary movement, and the like due to joining.

Therefore, the thermal conductivity, the electrical conductivity, and the like are uniform on the joint surface S perpendicular to the electrode axis X, and there is no unevenness. Finally, heat transfer along the electrode axis is carried out entirely inside the anode without the concern of local overheating inside the electrode.

Next, the discharge lamp of the embodiment 2 will be described using FIG. In the second embodiment, a metal member (hereinafter referred to as an intermediate metal member) for improving the joint strength is provided between the metal members, and the other configuration is substantially the same as that of the first embodiment.

Fig. 4 is an anode sectional view showing a discharge lamp of the embodiment 2.

The anode 130 is an electrode formed by solid-bonding the metal member 140 and the metal member 150. There is an intermediate metal member 155 between the metal member 140 and the metal member 150 that makes the bonding more reliable.

The intervening metal member 155 is a member in which a mixture of tungsten and a metal (for example, molybdenum, niobium, vanadium, niobium, titanium, gold, platinum, rhodium, or the like) which is softer than tungsten (e.g., molybdenum, niobium, vanadium, niobium, titanium, gold, platinum, rhodium, etc. It is softer than the metal member 140 and the metal member 150.

Since the softer material is higher in bonding performance than the direct joint metal members 140 and 150, even if the joint faces of the metal members 140 and 150 are not smooth, a good joint state can be maintained. However, since tungsten is contained, thermal conductivity and conductivity are less likely to be uneven to the entire electrode.

According to the second embodiment, the metal member is joined by the intermediate metal member which improves the joint strength. Thereby, the bonding strength of the electrode can be further improved. In particular, even when the joint surface of the metal member includes minute irregularities that are not ultra-smooth surfaces, it can be reliably joined. As the intermediate metal member 155, in consideration of the electrode property, a metal member in which tantalum and tungsten are mixed is a preferable choice, but an intermediate metal member not containing tungsten may also be used.

Next, a discharge lamp of Embodiment 3 will be described using FIG. In the embodiment 3, a sealed space is formed inside the anode, and molten metal is sealed in the sealed space. The other structure is substantially the same as the embodiment 1.

Fig. 5 is an anode sectional view showing a discharge lamp of the third embodiment.

The anode 230 is composed of a metal member 240 in which a cylindrical recess 240P is formed and a metal member 250 that bonds the electrode support rod 217B. The annular peripheral portion 240W of the metal member 240 engages the metal member 250. The joint portion of the metal member 250 is formed with a step, and the peripheral portion 240W of the metal member 240 is fitted with a groove formed in the outer circumferential direction.

After the anode 250 is formed, the electrode support rod 217B is joined by the fitting portion 255 of the metal member 250. The joint surface S is closer to the center of the discharge lamp than the front end portion of the fitting portion 255. Thereby, when the electrode support rod 217B is fitted, the entire metal member 250 is deformed to prevent the joint portion from peeling off.

The sealed space 245 formed between the metal members 240 and 250 is sealed with a molten metal having a low melting point. The molten metal is melted at the time of lighting, and thermal cycling is generated along the electrode axis X in the sealed space 245. The joint surface S is more than the solidified end surface (upper end) of the electrode support rod, and there is no fear that the molten metal flows into the joint surface S.

The joint surface S is not provided with a gap passing through the sealed space 245, and the concave side surface 240T and the peripheral edge portion 240W of the concave metal member 240 are combined with the metal member 250, and the inner surface of the metal member 250 protrudes toward the center of the discharge lamp from the joint surface S. . Therefore, it is possible to surely prevent the molten metal from flowing into the vicinity of the joint surface S.

According to this embodiment 3, a sealed space is formed inside the anode, and a metal which is melted when lighting is enclosed. Thereby, the heat transfer from the front end of the anode to the electrode support rod can be effectively exerted.

Further, since the sealed space is formed, the cross-sectional area of the joint surface S along the joint surface S of the metal member 250 is small in the cross-sectional area of the joint surface (the area of the annular circumferential portion 240T). Thereby, the heating at the time of joining is local and uniform distribution with respect to the electrode axis, and joining can be performed more effectively. Generally, a configuration in which the joint surface area is smaller than the cross-sectional area of the metal member is sufficient.

Next, the discharge lamps of the embodiments 4 and 5 will be described using Figs. In the embodiment types 4 and 5, protrusions that contact the molten metal are provided. The other configuration is substantially the same as the embodiment 3.

Fig. 6 is an anode sectional view showing a discharge lamp of the embodiment 4. Fig. 7 is an anode sectional view showing a discharge lamp of the embodiment 5.

As shown in Fig. 6, the anode 330 is composed of metal members 340 and 350, and the metal member 350 has a columnar metal projecting member 390 joined thereto along the electrode axis X. Here, the columnar metal protruding member 390 may be integrally molded with the metal member 350, and the protrusions may be formed by cutting. The front end portion of the protruding member 390 is in contact with the molten metal 370. The heat transfer and melting point of the protruding member 390 are lower than that of tungsten and higher than that of the molten metal 370.

Providing this protruding member 390 can improve heat transfer efficiency. Further, the material of the protruding member 390 can be arbitrarily selected in consideration of thermal conductivity and melting point. The protruding member 390 can also contact the metal member 340.

Among the anodes 330A shown in Fig. 7, the metal member 340 is solid-phase bonded to the projecting member 390A. Thereby, the heat transfer is performed at an early stage after the lighting, and the strength of the metal member 340 is increased. The protruding member 390A is in contact with the metal member 350.

Next, a discharge lamp of the embodiment 6 will be described using Fig. 8. In Embodiment 6, a heat releasing fin is formed around the electrode body. The other configuration is the same as that of the embodiment 1.

Figure 8 is an anode sectional view of a discharge lamp of Embodiment 6.

The anode 430 is a structure in which disc-shaped metal members 480 and 490 having disc shapes different in size (diameter) are disposed between the metal member 450 supported by the electrode support rod 417B and the metal member 440 located at the tip end, and these members are joined by solid phase bonding. Together. The plate-shaped metal members 480 and 490 are penetrated by the shaft member 470 and arranged coaxially.

Thereby, the electrode structure in which the plate-shaped metal member 480 having a fin function is arranged along the electrode axis X at a predetermined interval can be realized. As a result, the heat release can be further improved. The shape of the plate-like metal members 480 and 490 may be any (quadrucle or the like) and solid-phase bonded by plate-like metal members of different materials.

Next, the discharge lamp of the embodiment 7 will be described using the ninth to eleventh drawings. In the embodiment 7, the heat releasing fin extending in the direction of the electrode axis is formed on the electrode shaft body. The configuration other than this is the same as that of the embodiment 1.

Fig. 9 is a plan view showing the anode of the embodiment 7 viewed from the rear end. Fig. 10 is a side view showing the anode of the embodiment 7. Figure 11 is an anode sectional view of Embodiment 7.

As shown in FIG. 9, the anode 530 is composed of a truncated cone-shaped distal end portion 540, a columnar body portion 550, and a fin portion 550A, and the solid phase is joined to the front end portion 540 and the main body portion 550 to constitute an anode 530.

The main body portion 550 has a fin portion 550A integrally formed with the main body portion 550, and protrudes in the radial direction by the columnar body portion 550S, and a plurality of fins are arranged at a predetermined interval in the circumferential direction. The fin portion 550A extending along the electrode axis X is joined to the rear end surface 540T of the front end portion 540. The distal end portion 540 is a metal member made of tungsten, and the columnar body portion 550S and the fin portion 550A are made of a metal member whose main component is molybdenum excellent in heat release property. Here, the columnar body portion 550S and the fin portion 550A are integrally molded by cutting.

The length of the fin portion 550A in the radial direction is set to a length that does not protrude from the rear end surface of the front end portion 540. Thereby, the heat released between the fin portions 550A of the main body portion 550 is released to the electrode support rod and the electrode side surface. Therefore, it is possible to prevent the front end surface of the electrode from being overheated (refer to Fig. 11). On the other hand, the fin portion 550A of the molybdenum or the joint portion thereof is not exposed to the front end of the anode because the rear end surface 540S of the front end portion 540. Therefore, protection can be obtained in the discharge. The configuration, number, and shape of the fins are arbitrary.

Increasing the fin size with respect to the body portion can increase the heat dissipation property, but the conductivity and thermal conductivity of the body portion 550 are lowered, which may cause the front end portion 540 to overheat. Therefore, when the cross-sectional area formed by the columnar body portion 550S of the main body portion 550 and the fin portion 550A is represented by S11, the cross-sectional area of the columnar portion when filling the groove between the fin portions 550A (here, the front end portion) The area of the rear end surface of the portion 540 is represented by S12, and is set to satisfy the condition of S12 × 2 / 3 ≦ S11.

Next, a discharge lamp of Embodiment 8 will be described using FIG. In the embodiment 8, the difference from the embodiment types 1 to 7 is the inclination near the joint surface. The configuration other than this is the same as that of the embodiment 1.

Fig. 12 is an anode sectional view showing a discharge lamp of the embodiment 8.

The anode 630 is an electrode formed by joining the metal member 680 and the metal member 670. The metal member 670 is composed of a cylindrical portion 672 and a truncated cone shaped portion 674 having a recess 674S. Then, the metal member 680 having the electrode leading end face 680S is fitted to the metal member 670. In the vicinity of the joint surface S of the SPS joint, the metal crystal is almost uniform in the radial direction of the joint surface, and "inclined" along the direction of the electrode axis X.

That is, the inclined layer is formed in the vicinity of the joint surface S, and the metal structure characteristics such as the crystal diameter are continuously or gradually changed along the electrode axis X, and do not change rapidly. Due to the tilting, the crystal diameter continuously changes along the electrode axis X.

Through such bonding, heat conduction characteristics and electrical conductivity are not uneven along the joint surface S. During the period in which the electrode front end surface 40S (1000 ° C or higher) in the high temperature state is heated to the electrode support rod 17B during lighting, the temperature distribution inside the anode is symmetrically distributed around the electrode axis X, and the heat transfer is not affected by the joint surface S. influences.

The method of making the tilted electrode near the joint surface can be performed by SPS bonding. The pressure and the sintering temperature are set to values that can achieve the above state. For example, the pressure is set at 50 to 100 MPa, the pressurization time is set at 10 minutes to 60 minutes, and the sintering temperature near the joint surface is set in the range of 1600 ° C to 2000 ° C, and the material is appropriately set.

According to the present embodiment, the anode 630 of the short arc type discharge lamp is constructed by bonding the high melting point metal member 680 and the high thermal conductivity metal member 670 by SPS. The joint surface S is along a direction perpendicular to the electrode axis, that is, a radial direction of the anode cross section. The anode structure shown in Embodiment 1 can also be formed (see Fig. 2).

During the lighting, although the vicinity of the electrode front end surface 680S is extremely high, the heat of the front end portion is efficiently transmitted to the electrode supporting rod through the metal member 670. Thereby, electrode consumption due to overheating of the electrodes can be prevented. On the joint surface S of the vertical electrode shaft, the thermal conductivity, the electrical conductivity, and the like are all uniform, and there is no unevenness. Therefore, heat transfer along the electrode axis is performed entirely inside the anode without fear of local overheating inside the electrode.

In the first to eighth embodiments, the electrode may be produced by a diffusion bonding method other than the SPS sintering method. For example, an electrode can be produced by a bonding method such as hot press (HP) or hot isostatic pressing (HIP) which is sintered while being pressurized. Other solid phase bonding methods (friction pressure bonding method, ultrasonic bonding method, etc.) can also be applied. Metal structures can also be uniformly stabilized by these methods. The cathode may also be an electrode structure in which a plurality of metal members are bonded by solid phase.

The bonding surface may be formed in a direction other than the vertical electrode axis direction in consideration of electrode characteristics other than heat transfer. The gap formed along the joint surface is formed into a wedge shape, and the electrode surface is formed into a fin shape to further enhance the heat release effect. Further, a configuration in which a gap is not provided on the joint surface may be employed.

The number of metals constituting the electrode may be arbitrary, and the electrode may be composed of three or more metals. Further, it may be a metal of a solid phase contract type, and the same intermediate metal member as that of the embodiment 2 may be used in the embodiment types 3 to 8.

In the third embodiment, since the sealed space is formed inside, the joint area is smaller than the cross-sectional area of the metal member. However, this configuration may be applied to the embodiment types 1 to 2 and 4 to 8. That is, if the area of the joint surface along the metal member (the area of the joint portion) is represented by S01, the cross-sectional area of the filled portion of the metal member along the direction of the vertical electrode axis is represented by S02, and the configuration satisfies S02>S01. conditions of.

Further, the metal member may be used at one end, and the other end may be solid-phase bonded using a non-metal member (tungsten or ceramic), and at least one of the joined members may be a metal. Even with such a combination of components, the metal structure is in the above-described joined state in the vicinity of the joint surface.

The electrodes shown in the first to seventh embodiments may be composed of an electrode having an inclined state in the vicinity of the joint surface as in the embodiment 8. On the other hand, in the embodiment 3 to 7, the electrode may be formed by a fusion bonding method (electron beam welding or the like) other than the solid phase bonding.

Next, Embodiments 1 to 3 of the present invention will be described using Figs. 13 to 16. Here, the anodes of the SPS joint molding and the joint surface state of the electron beam welding were compared using the anodes of the respective embodiments 1, 2, and 8.

Example 1

Fig. 13 shows the anodic bonding state of Example 1 by an electron microscope. According to the embodiment 1, two metal members having different shapes are joined to form an electrode by SPS bonding. The two metal members are solidified by a powder of sintered tungsten (WVMW W 15-40 ppmK), and are composed of a truncated cone shape and a cylindrical shape as shown in the first embodiment.

For the apparatus for performing SPS bonding, an SPS sintering apparatus manufactured by SPS Syntex Co., Ltd. can be used, and under a vacuum condition, a pressure of 90 MPa is applied from both sides of the metal member, and the sintering temperature in the vicinity of the joint surface is maintained at 1700 ° C for 10 minutes for bonding.

In Fig. 13, a photograph showing the vicinity of the joint surface of the anode surface with a resolution of a micron level is shown, and the metal structure of the joint surface is apparently exhibited. A joint surface is formed along the left and right direction of the paper surface.

As shown in Fig. 13, only the crystal grains of the joint surface forming the joint surface are deformed at the time of joining, and the crystal grains other than this do not cause deformation and enlargement of crystal grains contributing to the joint in the vertical direction of the joint surface. . In other words, a layered structure in which crystal grains are deformed and enlarged is not formed by joining. The crystal grain size is uniform along the direction of the joint surface and the direction of the vertical joint surface. The change in the length of the electrode before and after the bonding in the direction of the electrode axis can be used as evidence of deformation of the crystal grain on the joint surface.

Example 2

Fig. 14 shows the anodic bonding state of Example 2 with an electron microscope. According to the embodiment 2, a tungsten-rhenium alloy (thickness 0.5 mm) is interposed between the two tungsten metal members, and SPS bonding is performed. The conditions for SPS bonding were substantially the same as in Example 1.

As shown in Fig. 14, in the same manner as in the first embodiment, only the crystal grains of the joint surface forming the joint surface are deformed at the time of joining, and the crystal grains do not cause deformation of the crystal grains contributing to the joint in the vertical direction of the joint surface. Hypertrophy.

Example 3

Fig. 15 shows the anodic bonding state of Example 3 as an electron microscope. According to the embodiment 8, two metal members having different shapes are joined to form an electrode by SPS bonding. The electrode shape is different from that of Fig. 12, and is composed of two metal plates of a truncated cone shape and a cylindrical shape as shown in Embodiment 1.

In the SPS joining, under a vacuum condition, a pressure of 90 MPa was applied from both sides of the metal member, and the temperature in the vicinity of the joint surface was held at 1800 ° C for 20 minutes to form a tilting layer on the joint surface.

As shown in Fig. 15, the metal crystal grain size along the joint surface is almost uniform, and the metal crystal characteristics such as the crystal grain size continuously change and tilt along the electrode axis.

Fig. 16 is a comparison diagram showing the state of the anodic bonding surface of the electron beam bonding by an electron micrograph. The electron beam bonded anode is also composed of two pieces of metal. An electron beam welding device manufactured by NEC Control System Co., Ltd. is used for this electron beam bonding.

A photograph of the joint surface near the surface of the enlarged anode is shown in Fig. 16. In Fig. 16, it can be seen that the metal particle diameter along the joint surface is not uniform (refer to the vicinity of the electrode surface). On the other hand, the crystal grains in the direction of the electrode axis (the direction on the upper side of the paper) are also changed violently and intermittently.

As a result, the metal structure of the electrode formed by SPS sintering is relatively stable near the joint surface. Therefore, it is superior to the conventional electrode in terms of electrode strength and heat release characteristics in lighting.

10. . . Discharge lamp

12. . . Discharge tube

30. . . anode

40. . . Metal parts

50. . . Metal parts

S. . . Joint surface

Fig. 1 is a plan view showing a short arc type discharge lamp of the first embodiment.

Fig. 2 is a schematic cross-sectional view of the anode.

Fig. 3 shows a discharge plasma sintering apparatus.

Fig. 4 is an anode sectional view showing a discharge lamp of the embodiment 2.

Fig. 5 is an anode sectional view showing a discharge lamp of the third embodiment.

Fig. 6 is an anode sectional view showing a discharge lamp of the embodiment 4.

Fig. 7 is an anode sectional view showing a discharge lamp of the embodiment 5.

Figure 8 is an anode sectional view of a discharge lamp of Embodiment 6.

Fig. 9 is a plan view showing the anode of the discharge lamp of the embodiment 7 viewed from above.

Figure 10 is an anode side view of a discharge lamp of Embodiment 7.

Figure 11 is an anode sectional view of a discharge lamp of Embodiment 7.

Fig. 12 is an anode sectional view showing a discharge lamp of the embodiment 8.

Fig. 13 shows the anodic bonding state of Example 1 by an electron microscope.

Fig. 14 shows the anodic bonding state of Example 2 with an electron microscope.

Fig. 15 shows the anodic bonding state of Example 3 as an electron microscope.

Fig. 16 is a comparison diagram showing the state of the anodic bonding surface of the electron beam bonding by an electron micrograph.

17B‧‧‧electrode support rod

30‧‧‧Anode

40‧‧‧Metal parts

40A‧‧‧French table shape part

40B‧‧‧Cylindrical part

40S‧‧‧ front end face of electrode

50‧‧‧Metal parts

50B‧‧‧ rear end face

S‧‧‧ joint surface

Claims (18)

A discharge lamp comprising: a discharge tube and a pair of electrodes disposed in the discharge tube, wherein at least one of the pair of electrodes is an electrode formed by solid phase bonding of a plurality of solid components, at least one of the plurality of solid components It is a metal member characterized in that at least a part of the crystal grains of the joint surface forming the joint surface of the metal member is deformed by joining, and the metal crystal grains other than the crystal grains of the joint surface do not substantially follow the joint surface in the vicinity of the joint surface. Secondary recrystallization due to bonding occurs, and is a primary recrystallization structure. A discharge lamp comprising: a discharge tube and a pair of electrodes disposed in the discharge tube, wherein at least one of the pair of electrodes is an electrode formed by solid phase bonding of a plurality of solid components, at least one of the plurality of solid components It is a metal member characterized in that the crystal grain size in the vicinity of the joint surface of the metal member after joining is nearly uniform along the joint surface of the metal member, and is also nearly uniform along the vertical direction of the joint surface. A discharge lamp comprising: a discharge tube and a pair of electrodes disposed in the discharge tube, wherein at least one of the pair of electrodes is an electrode formed by solid phase bonding of a plurality of solid components, at least one of the plurality of solid components It is a metal member characterized in that the crystal grain size of the metal member is nearly uniform along the joint surface between the members, and the metal crystal is inclined in the vertical direction of the joint surface in the vicinity of the joint surface of the metal member. A discharge lamp as described in claim 3, wherein the gold In the vicinity of the joint surface of the member, the metal crystal grain size continuously changes in the vertical direction of the joint surface. The discharge lamp according to any one of claims 1 to 4, wherein if the area along the joint surface of the metal member is represented by S01, the filling portion of the metal member is cut along the vertical direction of the electrode axis. The area is represented by S02 and will satisfy S02>S01. The discharge lamp of any one of claims 1 to 4, wherein the metal member is joined to the other solid member through the intermediate solid member, the intermediate solid member being softer than the solid member to be joined. The discharge lamp of claim 6, wherein the intermediate solid member is a metal member comprising at least one of molybdenum, niobium, vanadium, niobium, titanium, gold, platinum, and rhodium. The discharge lamp of claim 7, wherein the intermediate solid member is a metal member including tungsten. The discharge lamp of any one of claims 1 to 4, wherein the plurality of solid members have a concave metal member and a rear end solid member supported by the conductive electrode support rod, by joining the concave metal The member and the rear end solid member form a sealed space in the electrode, and the joint surface of the concave metal member is located closer to the center of the discharge lamp than the joint front end portion between the rear end solid member and the electrode support rod. The discharge lamp according to claim 9, wherein the molten metal is sealed in the sealed space when the discharge lamp is turned on, and the joint surface of the concave metal member is located at a temperature higher than that of the molten metal. The solidification range is closer to the position of the electrode support rod. The discharge lamp according to any one of claims 1 to 4, wherein the electrode is provided with a plurality of plate-like solid members having different sizes, and the plurality of plate-like solid members are joined along the electrode axis direction. The discharge lamp according to any one of claims 1 to 4, wherein the plurality of solid components comprise: an electrode front end member having an electrode front end surface; and a main body member arranging the plurality of fins at a predetermined interval in the circumferential direction, The plurality of fins extend in a radial direction from a tubular member having a smaller size than the tip end member of the electrode, wherein the electrode tip end member is coaxially joined to the tubular member. The discharge lamp of claim 12, wherein the plurality of fins have a radial dimension that does not protrude from a joint surface of the electrode front end member. The discharge lamp of claim 12, wherein if the cross-sectional area along the vertical direction of the electrode axis of the body member is represented by S11, the imaginary will be along the gap between the plurality of fins. The cross-sectional area of the electrode member in the vertical direction of the electrode member is represented by S12 and satisfies S12 × 2 / 3 ≦ S11. An electrode for a discharge lamp is disposed in a discharge tube of the discharge lamp and is composed of a plurality of solid members including a front end solid member including an electrode front end surface and a rear end solid member supported by the electrode support rod. The electrode for a discharge lamp is formed by solid-phase joining the plurality of solid members between the front end solid member and the rear end solid member, at least one of the plurality of solid members being a metal member, forming the metal At least a part of the crystal grains on the joint surface of the joint surface of the joint is deformed by joining, and the metal crystal grains other than the crystal grains of the joint surface do not substantially cause secondary recrystallization due to the joint in the vertical direction of the joint surface in the vicinity of the joint surface. It is a recrystallized structure. An electrode for a discharge lamp is disposed in a discharge tube of the discharge lamp and is composed of a plurality of solid members including a first solid member including an electrode tip end surface and a second solid supported by a conductive electrode support rod a member characterized in that the electrode for a discharge lamp is formed by solid-phase bonding the plurality of solid members between the first solid member and the second solid member, and at least one of the plurality of solid members is a metal member. The crystal grain size of the metal member is nearly uniform along the joint surface between the members, and the metal crystal is inclined in the vertical direction of the joint surface in the vicinity of the joint surface of the metal member. A method of manufacturing an electrode for a discharge lamp, wherein a plurality of solid members are solid-phase bonded between a front end solid member and a rear end solid member, the plurality of solid members including the front end solid member including an electrode front end surface and the electrode supported by the electrode support rod a rear end solid member, at least one of which is a metal member, characterized in that when the plurality of solid members are joined by solid phase, at least a portion of the crystal grains of the joint surface forming the joint surface of the metal member are deformed by joining, The metal crystal grains other than the joint surface crystal grains do not substantially cause secondary recrystallization due to bonding in the vicinity of the joint surface in the vicinity of the joint surface, and are a primary recrystallization structure. A method for producing an electrode for a discharge lamp, wherein a plurality of solid members are solid-phase bonded between a first solid member and a second solid member, the plurality of solid members including the first solid member and the conductive electrode supporting rod including an electrode tip end surface Supporting the second solid member, at least one of the plurality of solid members is a metal member, characterized in that when the solid portion is joined to the solid member, the crystal grain size of the metal member is along the joint surface between the members Nearly uniform, in the vicinity of the joint surface of the metal member, the metal crystal is inclined in the vertical direction of the joint surface.