JP2009004238A - Electrode, electrode assembly, and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To firmly weld a cup-shaped electrode of a cold-cathode discharge tube and a lead. <P>SOLUTION: The electrode (2) having an annular side wall (4) and the bottom wall (5) that closes one end of the side wall (4), and the lead (3) fixed in a recess (6) of the electrode (2) coaxially with the side wall (4) are installed at an electrode assembly. Since the bottom wall (5) can be formed in the thickness that approaches a shape complementary with the Gaussian distribution by installing a protrusion (7) having the maximum thickness at the center part on the bottom wall (5), the entire welded parts of the lead (3) and the bottom wall (5) can be welded by being heated at a more uniform temperature while preventing the welded parts of the lead (3) and the bottom wall (5) from being locally overheated. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electrode, an electrode assembly, and a method for manufacturing the same that can firmly weld a lead to an electrode of a cold cathode discharge tube.

  A cold cathode discharge tube having a pair of electrodes facing each other inside a glass tube filled with a rare gas and mercury vapor and having an inner wall of the glass tube coated with a fluorescent film has been conventionally used as a light source for backlights of liquid crystal displays. Widely used as etc. One end of an introduction line (lead) is connected to the pair of electrodes of the cold cathode discharge tube, and the other end of the introduction line is led out from both ends of the glass tube. When a voltage is applied between the pair of electrodes, electrons are emitted from one electrode, and the electrons collide with mercury atoms in the glass tube to generate ultraviolet rays. This ultraviolet light is wavelength-converted into visible light by a fluorescent film formed on the inner wall of the glass tube.

  In the following Patent Document 1, when manufacturing an electrode attached to the tip of an introduction metal body sealed at both ends of a glass bulb, an electrode is formed using a hollow metal body having a hole into which the introduction metal body can be inserted. In the state where the introduction metal body is inserted into the hole, laser light is irradiated from the side of the hollow metal body to form a joint between the hollow metal body and the introduction metal body in the hole. Without directly irradiating the inner surface of the hollow metal body with the laser beam, the laser beam is irradiated from the side portion of the hollow metal body, and the hollow metal body is used with the joint formed in the hole. Since the introduced metal body is joined, the formation of an oxide film on the surface of the hollow metal body can be suppressed by appropriately suppressing the temperature rise of the inner surface of the hollow metal body.

JP2003-272520 (FIG. 2)

  Generally, there are GI fiber (Graded Index Fiber) and SI fiber (Step Index Fiber) as fibers for guiding laser light used for laser welding. The GI fiber has a structure in which the refractive index gradually decreases toward the outer layer away from the central axis of the core to reduce the mode dispersion, and light converges in the center as it travels. Has higher properties than the outside. The SI fiber has a structure in which the refractive indexes of the core and the clad are distributed in a sharp step shape, and in the case of incident light having different incident angles, the passing light from the incident end to the exit end is different and the emitted light is dispersed. The energy of light is dispersed and made more uniform. Therefore, when welding is performed by entering laser beams having different incident angles, the SI fiber has a more uniform energy distribution than the GI fiber, and is suitable for a welding method in which a wide area is welded shallowly.

  However, even when an SI fiber having a more uniform energy distribution than a GI fiber is used, there is a difference in the difference in energy distribution (arrival depth) on the cross section between the focal (center) portion and the outer (peripheral) portion of the laser light. Will occur.

  On the other hand, it is preferable to provide a welding region on almost the entire surface where the bottom of the electrode and the lead are in contact with each other while maintaining a strong mechanical welding strength. However, when laser light is irradiated from the inside of the cup-shaped electrode and the electrode and the lead are welded, if the output of the laser light is weak as shown in FIG. 7, the bottom wall (5) of the electrode (2) With the energy absorbed through, the entire surface of the end (3a) of the lead (3) cannot be heated to a temperature sufficient to weld the electrode (2). In particular, as described above, since the energy reach depth is different between the focal portion of the laser beam and the outer portion of the laser beam, the outer peripheral wall (3b) side of the lead (3) does not reach the welding temperature, and the lead The welding between (3) and the electrode (2) becomes insufficient. On the contrary, as shown in FIG. 8, when the lead (3) made by strengthening the output of the laser beam and sintering a refractory metal (for example, tungsten) is used, the end (3a) of the lead (3) is used. When the entire region is raised to the welding temperature or higher, the energy distribution in the radial direction of the laser beam is non-uniform, so that the central portion of the lead (3) reaches the recrystallization temperature of tungsten exceeding the melting temperature. As a result, the recrystallization of tungsten spreads to the deep part, and the mechanical strength of the lead (3) is reduced. For example, the lead (3) is broken starting from the recrystallized part. In other words, if the intensity of the laser beam is high, the mechanical strength of the lead (3) decreases due to recrystallization, but if the intensity of the laser beam is low, welding is insufficient and sufficient welding strength cannot be obtained. Will occur. Further, since the energy distribution of the laser light changes not only in the depth direction but also in the width (horizontal width), as shown in Patent Document 1, even if the laser light is irradiated from the side of the electrode, the same problem as described above Is produced.

  Accordingly, an object of the present invention is to provide an electrode, an electrode assembly, and a method for manufacturing the same, in which the lead can be more firmly welded to the electrode and the mechanical strength of the lead can be kept relatively high.

The electrode according to the present invention comprises an annular side wall (4) and a bottom wall (5) that closes one end (4b) of the inner surface of the side wall (4), and the bottom wall through which the central axis (A) passes. The thickness (t ₀ ) at the center part (5c) of the bottom wall (5) is larger than the thickness (t ₁ ) of the bottom wall (5) at the peripheral part (5d) surrounding the center part (5c) of (5). A large protrusion (7) is provided on the bottom wall (5). The energy of the laser beam during welding is absorbed by the electrode (2) and converted into thermal energy, but in the electrode according to the present invention, the central portion (5c) of the bottom wall (5) through which the central axis (A) passes. Since the thickness (t ₀ ) at the center portion (5c) of the bottom wall (5) is larger than the thickness (t ₁ ) at the peripheral portion (5d) that surrounds the end portion (3a) of the lead (3) It is difficult for heat energy to be transmitted to the central part (3c) of the peripheral part from the peripheral part (3d). For this reason, the temperature rise is suppressed or delayed at the center portion (3c) of the end portion (3a) of the lead (3), and the peripheral portion (3d) of the lead (3) is compared with the center portion (3c). Since the temperature rise is not suppressed, the temperature distribution at the end (3a) of the lead (3) can be made uniform in the radial direction (the width direction of the lead (3)). Therefore, even if the output of the laser beam rises to a level at which the temperature on the outer peripheral wall (3b) side of the end (3a) of the lead (3) is equal to or higher than the recrystallization temperature, the center (3c Unlike the conventional electrode assembly (1), the central portion (3c) of the lead (3) differs from the conventional electrode assembly (1) because the temperature of the outer wall (3b) is less than or equal to that of the conventional one. It is possible to suppress recrystallization from the end portion (3a) to the deep portion and to form a network structure, and it is possible to suppress a decrease in mechanical strength of the lead (3) due to grain boundary fracture.

The electrode according to the embodiment of the present invention has an annular side wall (4) and a bottom wall (5) that closes one end (4b) of an inner surface (4a) of the side wall (4). The recess (6) is formed on the outer surface (5b) of the bottom wall (5), and the center of the recess (6) is determined from the thickness (t ₁ ) of the bottom wall (5) facing the side wall (4) side of the recess (6). The bottom wall (5) is provided with a protrusion (7) having a large thickness (t ₀ ) of the bottom wall (5) opposite to the bottom wall (5).

An electrode assembly according to the present invention includes an electrode (2) having an annular side wall (4) and a bottom wall (5) that closes one end (4b) of an inner surface (4a) of the side wall (4), and an electrode (2). In an electrode assembly comprising a lead (3) fixed to the bottom wall (5), a peripheral portion (5d) surrounding the central portion (5c) of the bottom wall (5) through which the central axis (A) passes. The bottom wall (5) is provided with a protrusion (7) that forms a thickness (t ₀ ) at the center (5c) of the bottom wall (5) larger than the thickness (t ₁ ).

An electrode assembly manufacturing method according to the present invention includes an annular side wall (4) and a bottom wall (5) that closes one end (4b) of an inner surface (4a) of the side wall (4) and a central axis (A). The thickness (t ₀ ) at the center part (5c) of the bottom wall (5) is larger than the thickness (t ₁ ) at the peripheral part (5d) surrounding the center part (5c) of the bottom wall (5) through which the Preparing the electrode (2) formed with the protrusion (7) and the lead (3), and contacting the end (3a) of the lead (3) with the outer surface (5b) of the bottom wall (5); The end of the lead (3) is irradiated with laser light from the opening (8) on the other end (4c) side of the inner surface (4a) of the side wall (4) toward the inner surface (5a) of the bottom wall (5). Welding (3a) to the outer surface (5b) of the bottom wall (5) of the electrode (2).

An electrode assembly manufacturing method according to an embodiment of the present invention includes an annular side wall (4) and a bottom wall (5) for closing one end (4b) of an inner surface (4a) of the side wall (4), and a bottom wall (5 ) Formed on the outer surface (5b) of the concave portion (6), and the center of the concave portion (6) from the thickness (t ₁ ) of the bottom wall (5) facing the side wall (4) side of the concave portion (6). A step of preparing an electrode (2) provided on the bottom wall (5) with a protrusion (7) having a large thickness (t ₀ ) of the bottom wall (5) opposite to the lead (3), and a lead ( 3) contacting the end (3a) of the bottom wall (5) to the outer surface (5b) and the opening (8) on the other end (4c) side of the inner surface (4a) of the side wall (4) from the bottom wall Irradiating a laser beam toward the inner surface (5a) of (5) and welding the end (3a) of the lead (3) to the outer surface (5b) of the bottom wall (5) of the electrode (2). .

  According to the present invention, the lead can be more firmly welded to the electrode, and the mechanical strength of the lead can be kept relatively high.

Embodiments of an electrode and an electrode assembly and a method for manufacturing the same according to the present invention will be described below with reference to FIGS.
[First Embodiment]

The electrode of the present invention has an annular side wall (4) and a bottom wall (5) that closes one end (4b) of the inner surface of the side wall (4). The thickness at the center portion (5c) of the bottom wall (5) from the thickness (t ₁ ) at the peripheral portion (5d) surrounding the center portion (5c) of the bottom wall (5) through which the central axis (A) passes ( Protrusions (7) having a large t ₀ ) are provided. By providing the protrusion (7) on the bottom wall (5), a thickness (t ₀ ) larger than the thickness (t ₁ ) of the bottom wall (5) facing the side wall (4) of the recess (6) is larger than the recess (6 ) Formed on the bottom wall (5) opposite the center. As shown in FIGS. 1 to 5, a slow curved shape with the center portion (5c) as the maximum height, or as shown in FIG. 6, a stepped protrusion (7) is formed on the inner surface (5a) of the bottom wall (5). Alternatively, it is formed on the outer surface (5b). A recess (6) whose center is aligned with the central axis (A) of the electrode (2) is formed on the outer surface (5b) of the bottom wall (5).

When manufacturing the electrode assembly (1), first, as shown in FIGS. 1 and 2, the bottom wall that closes the annular side wall (4) and one end (4b) of the inner surface (4a) of the side wall (4). The first space (10) having the (5) and surrounded by the inner surface (5a) and the side wall (4) of the bottom wall (5) is open to the opposite side of the first space (10) and the bottom. An electrode (2) having a second space (11) formed by a recess (6) formed on the outer surface (5b) of the wall (5) and a lead (3) are prepared. The diameter of the central portion (5c) of the protrusion (7) having a large thickness (t ₀ ) of the bottom wall (5) is equal to or smaller than the diameter of the lead (3).

  The electrode (2) is made of, for example, a metal selected from nickel, niobium, molybdenum, tungsten, and tantalum or an alloy containing at least one of these metals. However, it is desirable to form the electrode (2) with sputter-resistant metal particles selected from, for example, niobium, molybdenum, tungsten, and tantalum. Also, a metal material structure in which a base material is formed of a low melting point metal such as nickel as a binder for supporting a carrier of spatter-resistant metal particles, and a large number of sputter-resistant metal particles are dispersed in the base material. good.

  As shown in FIG. 2, the recess (6) of the electrode (2) is formed in a circular cross section having a diameter larger than the diameter of the lead (3), and the recess of the electrode (2) forming the second space (11). The central axis in the length direction (longitudinal direction) of (6) overlaps and aligns with the central axis (A) of the annular side wall (4) of the electrode (2) forming the first space (10). As a result, the end (3a) of the lead (3) is fitted into the recess (6) of the electrode (2), and the central axis of the electrode (2) and the central axis of the end (3a) of the lead (3) Are aligned on the same straight line, and the central part (5c) of the bottom wall (5) of the electrode (2) and the central part (3c) of the end part (3a) of the lead (3) are arranged on the same straight line. it can.

The thickness at the center portion (5c) of the bottom wall (5) from the thickness (t ₁ ) at the peripheral portion (5d) surrounding the center portion (5c) of the bottom wall (5) through which the central axis (A) passes ( Since t ₀ ) is large, the thickness (t ₀ ) of the bottom wall (5) of the electrode (2) is in contact with (or faces) the center (3c) of the end (3a) of the lead (3) by welding. ) Is larger than the thickness (t ₁ ) of the portion in contact (or facing) the outer peripheral wall (3b) of the lead (3). In the bottom wall (5) of the electrode (2), the bottom surface of the recess (6) forming the second space (11) is flat, and the bottom wall (5) forming the first space (10) is flat. On the inner surface (5a), from the peripheral part (5d) surrounding the central part (5c) corresponding to the end part (3a) of the lead (3), to the central part (3c) of the end part (3a) of the lead (3) It gradually becomes thicker toward the corresponding central part (5c). Therefore, if the center part (5c) of the bottom wall (5) of the electrode (2) and the center part (3c) of the end part (3a) of the lead (3) are arranged on the same straight line, the bottom of the electrode (2) On the inner surface (5a) of the wall (5), the highest and thickest protrusion (7) is formed at the central portion (5c).

The diameter of the side wall (4) of the electrode (2) is 2.7 mm, the thickness of the side wall (4) of the electrode (2) is 0.2 mm, and the diameter of the recess (6) of the electrode (2) is 0.9 to It is set to 1.0 mm, and is smaller than the recess (6), for example, 0.4 so that the heat energy generated by the laser beam on the inner surface (4a) of the electrode (2) is easily transmitted to the end (3a) of the lead (3). It is desirable to form the protrusion (7) of the electrode (2) with a diameter of ˜0.6 mm. Further, the thickness (t ₂ ) of the bottom wall (5) outside the recess (6) is 2.0 mm, and the bottom wall (5) having the recess (6) and the protrusion (7) on the bottom wall (5) is provided. The thickness may be 1.5 mm (t ₁ : side wall side) to 1.8 mm (t ₀ : center), and the thickness may be varied in a slow normal distribution curve as shown in FIG.

  The diameter of the substantially cylindrical lead (3) is equal to or less than the diameter of the recess (6), for example, 0.9 mm. The lead (3) is made of the same or different metal material as the electrode (2). However, even when the electrode assembly (1) is in use, the bottom wall (5) of the electrode (2) is sputtered and the end (3a) of the lead (3) is exposed. It is desirable to form the lead (3) from a powder of niobium, molybdenum, tungsten or an alloy thereof so as to keep the sputtering property of The powder metal having a high melting point is formed by heating and sintering the powder metal under pressure. However, if the sintered lead (3) is recrystallized by welding or the like, the crystal structure becomes a network structure, and there is a possibility that the lead (3) breaks due to grain boundary fracture.

  Therefore, a manufacturing method for forming the electrode assembly (1) by laser welding the electrode (2) and the lead (3) according to the first embodiment of the present invention will be described.

Fit the end (3a) of the lead (3) into the recess (6) of the electrode (2) and abut the end (3a) of the lead (3) against the outer surface (5b) of the bottom wall (5) The lead (3) is pressed against the electrode (2). Next, a laser beam is irradiated from the first space (10) through the opening (8) toward the inner surface (5a) of the bottom wall (5) of the electrode (2), and the lead (3) becomes the electrode (2). Welded to the bottom wall (5). In this case, it is desirable to introduce laser light through an SI fiber for laser welding. In this case, even if the SI fiber is used, the energy distribution of the emitted light is a Gaussian distribution with a sharp central portion. Therefore, in the electrode (2) of the first embodiment of the present invention, the lead (3 The thickness (t ₀ ) of the portion facing the center portion (3c) of the end portion (3a) of the end portion (3a), that is, the thickness of the bottom wall (5) facing the center of the recess (16) is determined by laser welding. A protrusion (7) thicker than the thickness (t ₁ ) of the end portion (3a) of the end portion (3a) facing the outer peripheral wall (3b), that is, the thickness facing the side wall of the recess (6) is formed. In order to form the projection (7), the bottom wall (5) of the electrode (3) becomes thicker at the center (5c) of the bottom wall (5) of the electrode (2), and the center (5c) of the bottom wall (5) ) Is less likely to transfer thermal energy to the end of the lead (3). Therefore, the shape is similar to the shape obtained by inverting the energy distribution of the Gaussian distribution that increases the thickness of the bottom wall (5) of the electrode (3) toward the center (5c) of the bottom wall (5) of the electrode (2). Protrusions (7) are formed to suppress or delay the temperature rise on the end (3a) side of the lead (3), and the temperature rise (heating) at the end (3a) of the lead (3) is radial. Can be made uniform. For this reason, even if the temperature of the end (3a) of the lead (3) on the outer peripheral wall (3b) side of the lead (3) rises to a level above the recrystallization temperature, the lead (3) The central portion (3c) of the end portion (3a) is not recrystallized from the end portion (3a) of the lead (3) to the deeper portion of the lead (3) as in the conventional electrode assembly (1). In this way, recrystallization up to the deep part of the end (3a) of the lead (3) suppresses the network from forming a network, and suppresses a decrease in the partial mechanical strength of the lead (3) due to grain boundary fracture. can do. Therefore, according to the present invention, it is possible to provide an electrode assembly (1) in which a lead can be more firmly welded to a cup-shaped electrode and the mechanical strength of the lead can be relatively maintained.

Further, in the second space (11), a sufficient amount of the metal material constituting the melting electrode (2) is provided with a lower energy than in the case of the bottom wall (5) thinned by the lead (3) and the recess (6). The bottom wall of the portion where the recess (6) of the bottom wall (5) is formed by being filled between the cylindrical wall surface welded with and forming the recess (6) and the outer peripheral wall (3b) of the lead (3) The thickness of (5) can be increased after laser welding compared to before laser welding, and the sputtering resistance of the electrode assembly (1) can be improved. Note that the height of the protrusion (7) formed on the electrode (2) before laser welding may decrease after laser welding and become flat zero or conversely concave and concave.
[Second Embodiment]

  FIG. 4 shows an electrode assembly according to a second embodiment. 4 to 6, the substantially same parts as those in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.

The electrode (2) of the embodiment shown in FIG. 4 is provided with a modified projection (7) instead of the projection (7), but the other configuration is the same as that of FIG. The electrode (2) in FIG. 3 has a projection (7) formed in a recess (6a) on the outer surface (5b) of the bottom wall (5) of the electrode (2) forming the second space (11), The inner surface (5a) of the bottom wall (5) of the electrode (2) forming the space (10) is a flat surface. The electrode (2) in FIG. 3 is the thickness of the portion facing the center portion (3c) of the end portion (3a) of the lead (3) in the same manner as the electrode of the first embodiment of the present invention shown in FIG. Since (t ₀ ) is thicker than the thickness (t ₁ ) of the portion facing the outer peripheral wall (3b) side of the end (3a) of the lead (3), the first embodiment of the present invention shown in FIG. It has the same effect as the electrode (2). Similarly, the electrode assembly (1a) combining the electrode (2) and the lead (3) shown in the second embodiment of FIG. 5 is also the electrode assembly (1a) of the first embodiment of the present invention shown in FIG. Has the same effect as 1). The protrusion (7) is gradually increased from the thickness (t ₁ ) of the peripheral part (5d) from the side of the concave part (6a) of the bottom wall (5) of the electrode (2) toward the central part (5c). The center portion (5c) can be formed to have a maximum thickness (t ₀ ).
[Third Embodiment]

In the electrode (2) of the embodiment shown in FIG. 5, the protrusion (7) is protruded from the inner surface (5a) and the outer surface (5b) of the bottom wall (5), respectively, but the other configuration is the same as FIG. is there. The electrode (2) in FIG. 5 includes a protrusion (7) protruding from the inner surface (5a) of the bottom wall (5) of the electrode (2) forming the first space (10) and the second space (11). A projection (7) is formed that protrudes into the recess (6a) on the outer surface (5b) of the bottom wall (5) of the electrode (2) that forms the electrode. Similar to the electrode (2) of the first embodiment of the present invention shown in FIG. 1, the electrode (2) in FIG. 5 is formed at the center (5c) opposite to the center (3c) of the lead (3). The thickness (t0) of the bottom wall (5) of the electrode (2) is the thickness of the bottom wall (5) of the electrode (2) in the peripheral portion (5d) facing the outer peripheral wall (3b) side of the lead (3) ( Since it is larger than t1), an effect similar to that of the electrode (2) of the first embodiment of the present invention shown in FIG. 1 is produced. Similarly, the electrode assembly (1b) in which the electrode (2) and the lead (3) shown in the third embodiment of FIG. 5 are welded is also the electrode assembly of the first embodiment of the present invention of FIG. Has the same effect as (1). Protrusions (7) are formed with a thickness that gradually increases from the thickness (t ₁ ) of the peripheral portion (5d) on the side of the bottom wall (5) of the electrode (2) toward the central portion (5c), and the center The portion (5c) can be provided with a maximum thickness (t ₀ ).
[Fourth Embodiment]

In the electrode (2) of the fourth embodiment shown in FIG. 6, a deformed protrusion (7) is provided, and the other configuration is the same as that of FIG. As shown in FIGS. 1 to 5, the electrode (2) in FIG. 6 is not formed in a slow curved shape but is formed in a stepped protrusion (7). The electrode (2) in FIG. 6 is similar to the electrode (2) in the first embodiment of the present invention shown in FIG. 1, and the electrode (2) at the portion facing the central portion (3c) of the lead (3). The thickness (t ₀ ) of the bottom wall (5) of the lead (3) is thicker than the thickness (t ₁ ) of the bottom wall (5) of the electrode (2) at the portion facing the outer peripheral wall (3b) side of the lead (3), This has the same effect as the electrode (2) of the first embodiment of the present invention shown in FIG. Similarly, the electrode assembly (1c) in which the electrode (2) and the lead (3) shown in the fourth embodiment of FIG. 6 are welded is also the electrode assembly (1c) of the first embodiment of the present invention of FIG. Has the same effect as 1). A protrusion (7) is formed with a thickness that gradually increases from the side thickness (t ₁ ) of the bottom wall (5) of the electrode (2) toward the center (5c), and the maximum is formed at the center (5c). Thickness (t ₀ ) is given.

  The present invention is not limited to the above-described embodiment, and further modifications are possible. For example, the protrusion (7) can be formed in a range of height 0.01 mm to 2.00 mm and diameter 0.20 mm to 2.00 mm, for example. Further, when manufacturing the electrode assembly (1), prepare the electrode (2) without forming the recess (6) on the outer surface (5b) of the bottom wall (5) coaxially with the side wall (4), The lead (3) may be welded to the bottom wall (5) of the electrode (2) without fitting the lead (3) into the recess (6) of the bottom wall (5). Although an example in which the laser welding method is applied has been described, the effect of the present invention can be obtained by welding the electrode (2) and the lead (3) by a resistance welding method instead of the laser welding method.

  The present invention can be applied to an electrode assembly in which a lead is firmly welded to an electrode of a cold cathode discharge tube.

Sectional drawing of the electrode assembly which shows 1st Embodiment by this invention Partial expanded sectional view which shows a part of bottom wall of the electrode assembly shown in FIG. 1 is an exploded sectional view of the electrode assembly shown in FIG. The exploded sectional view of the electrode assembly showing the 2nd embodiment by the present invention. The exploded sectional view of the electrode assembly showing a 3rd embodiment by the present invention. Exploded sectional view of an electrode assembly showing a fourth embodiment of the present invention Sectional drawing of the electrode assembly which shows one conventional method of welding a lead to an electrode with a laser beam Sectional drawing of the electrode assembly which shows the other conventional method of welding a lead to an electrode with a laser beam

Explanation of symbols

  (1) ・ ・ Electrode assembly, (2) ・ ・ Electrode, (3) ・ Lead, (4) ・ ・ Sidewall, (4b) ・ ・ One end, (5) ・ ・ Bottom wall, (5a) ・ ・Inner surface, (5b) ・ ・ Outer surface, (5c) ・ ・ Center part, (5d) ・ ・ Peripheral part, (6) ・ ・ Recess, (7) ・ ・ Protrusion, (8) ・ ・ Opening part,

Claims (12)

In an electrode having an annular side wall and a bottom wall closing one end of the inner surface of the side wall,
The bottom wall is provided with a protrusion having a thickness larger at the center of the bottom wall than a thickness of the bottom wall at a peripheral portion surrounding the center of the bottom wall through which a central axis passes. electrode.   The electrode according to claim 1, wherein the slow curved or stepped protrusion having a maximum height at the center is formed on the inner surface of the bottom wall. In an electrode having an annular side wall and a bottom wall closing one end of the inner surface of the side wall,
Forming a recess in the outer surface of the bottom wall;
An electrode, wherein a protrusion is formed on the bottom wall, the protrusion having a thickness larger than the thickness of the bottom wall facing the side wall of the recess, the thickness of the bottom wall facing the center of the recess.   The electrode according to any one of claims 1 to 3, wherein the concave portion whose center is aligned with a central axis of the electrode is formed on an outer surface of the bottom wall. An electrode assembly comprising an electrode having an annular side wall and a bottom wall closing one end of the inner surface of the side wall, and a lead fixed to the bottom wall of the electrode,
An electrode assembly, wherein a protrusion is formed on the bottom wall that has a thickness greater at the center of the bottom wall than a thickness at a periphery surrounding the center of the bottom wall through which a central axis passes.   The electrode assembly according to claim 5, wherein a center of a center portion of the lead is aligned on a center axis of the electrode, and a diameter of the protrusion is equal to or smaller than a diameter of the lead.   The electrode assembly according to claim 5, wherein the slow curved or stepped protrusion having a maximum height at the center is formed on the inner surface of the bottom wall. It has an annular side wall and a bottom wall that closes one end of the inner surface of the side wall, and the thickness at the center of the bottom wall is greater than the thickness at the periphery that surrounds the center of the bottom wall through which the central axis passes. Preparing an electrode having a large protrusion and a lead;
Abutting the end of the lead against the outer surface of the bottom wall;
Irradiating a laser beam from the opening on the other end side of the inner surface of the side wall toward the inner surface of the bottom wall, and welding the end of the lead to the outer surface of the bottom wall of the electrode. A method of manufacturing an electrode assembly.   By forming the curved or stepwise projections that are slow from the center of the bottom wall to the side, at least one of the inner surface or the outer surface of the bottom wall, the thickness of the bottom wall is more than the thickness at the peripheral portion. The method for manufacturing an electrode assembly according to claim 8, wherein the thickness at the center is large. Forming a recess in the outer surface of the bottom wall whose center is aligned with the central axis of the electrode;
10. The method of manufacturing an electrode assembly according to claim 8, wherein an end portion of the lead is fitted into the recess, and the end portion of the lead is brought into contact with an outer surface of the bottom wall. An annular side wall and a bottom wall that closes one end of the inner surface of the side wall, and a recess formed on the outer surface of the bottom wall, and the center of the recess is determined by the thickness of the bottom wall facing the side wall of the recess A step of preparing an electrode provided with a protrusion formed on the bottom wall, the lead having a large thickness of the bottom wall opposite to the lead, and a lead;
Abutting the end of the lead against the outer surface of the bottom wall;
Irradiating a laser beam from the opening on the other end side of the inner surface of the side wall toward the inner surface of the bottom wall, and welding the end of the lead to the outer surface of the bottom wall of the electrode. A method of manufacturing an electrode assembly.   The method of manufacturing an electrode assembly according to any one of claims 8 to 11, wherein the laser beam is irradiated with a focus on a straight line passing through a central portion of an end portion of the lead.

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