JP5961939B2 - Capacitor manufacturing method - Google Patents

Description

The present invention relates to a connection between a capacitor element and an external terminal in a sealing member that seals an exterior member of the capacitor element. For example, an electrolytic capacitor or an electric double layer capacitor using laser welding or electron beam welding for the connection. a process for the manufacture of capacitors and the like.

  In the electric double layer capacitor or electrolytic capacitor, it is necessary to electrically connect the capacitor element and the external terminal. By this electrical connection, measures are taken to reduce the internal resistance on the element side and the contact resistance of the connection portion.

  Regarding such electrical connection, a current collecting terminal is provided on the end face of the element (for example, Patent Document 1), an anode current collecting plate is provided on one end face of the winding element, and a cathode current collecting plate is provided on the other end face. (For example, Patent Document 2), including a current collector foil that covers the current collector foil exposed on the end face of the winding element, and welding and connecting the current collector plate and the current collector foil (for example, Patent Document 3); It is known that a current collector plate is used for connection between an exterior case and an element or connection with an external terminal (for example, Patent Document 4).

In addition, a multilayer capacitor element having a connection terminal on the element end face side is known (for example, Patent Document 5).

Japanese Patent Application Laid-Open No. 11-219857 JP 2001-068379 A JP 2007-335156 A JP 2010-093178 A JP-A-6-275476

  Incidentally, in a configuration in which a current collector plate is provided on the element end face of the capacitor element and connected to an external terminal member such as an external terminal, the current collector plate and the external terminal member are connected by welding. For this connection, laser welding or electron beam welding is used. In these weldings, the welded portion is irradiated with a laser beam or electron beam to melt and integrate the metal in the welded portion. In such welding, since a laser beam or an electron beam is irradiated to the welding location, contact between the current collector plate and the external terminal is required, and the contact portion is required to have processing accuracy necessary for welding. . However, when the processing accuracy is low, such as variations in the shape accuracy of the current collector plate and the external terminal member, a gap is generated between the contact surfaces between the current collector plate and the external terminal member.

  When a laser beam or an electron beam is irradiated between the contact surfaces in which such a gap is generated, there is a problem in that the welding region changes due to the gap and the welding accuracy is lowered. Moreover, when the clearance gap between contact surfaces is large, there exists a subject that a welding range narrows, the connection strength between a current collecting plate and an external terminal member falls, or a connection resistance becomes large.

Therefore, in view of the above problems, an object of the present invention is to provide a capacitor with improved welding accuracy and connection strength between the current collector plate and the external terminal member without being affected by the processing accuracy of the current collector plate and the external terminal member. Is to provide.

To achieve the above Symbol object, method of manufacturing the capacitor of the present invention is a wound element or non-winding device comprising the electrode body on the anode side and cathode side, and a separator interposed between the electrode bodies capacitor A step of forming the electrode body on the element end face of the element and forming a single or a plurality of electrode overhanging portions on the element end face; and a sealing member for sealing the opening of the case member accommodating the capacitor element. A step of covering the contact surface between the external terminal member and the current collector plate with a cover portion on either one of the external terminal member or the current collector plate connected to the electrode extension portion; and An irradiation position of a laser beam or an electron beam is set on the cover, and the step includes welding the current collector plate and the external terminal member.

  In order to achieve the above object, in the capacitor manufacturing method, more preferably, the irradiation position of the laser beam or the electron beam may coincide with a contact surface between the current collector plate and the external terminal member. .

  In order to achieve the above object, in the method for manufacturing a capacitor, more preferably, the irradiation position of the laser beam or the electron beam is in a direction intersecting with a contact surface between the current collector plate and the external terminal member. It may be different.

  In order to achieve the above object, in the method of manufacturing a capacitor, more preferably, the irradiation position of the laser beam or the electron beam is ± 0.1 to 0.5 mm in the direction intersecting the contact surface. It may be different.

In order to achieve the above object, in the method for manufacturing a capacitor, more preferably, the defocus position of the laser beam or the electron beam is set to 0.2 mm to 2 mm from the irradiation position of the laser beam or the electron beam. It may be set to 0.0 [mm] or less.
In order to achieve the above object, in the method for manufacturing a capacitor, more preferably, the nugget depth of the laser beam welding or the electron beam welding may be 1.2 mm or less.

According to capacitor production method of the present invention, any of the following effects can be obtained.

  (1) Since the contact surface between the current collector plate and the external terminal member is covered with a cover portion on the current collector plate or the external terminal member, and this cover portion is irradiated with a laser beam or an electron beam, the current collector plate and the external terminal member Both can be welded regardless of the state of the contact surface.

  (2) Since a laser beam or electron beam can be irradiated by selecting a flat surface on the current collector plate that covers the contact surface between the current collector plate and the external terminal member, processing of the contact surface between the current collector plate and the external terminal member is possible. Even if the accuracy is low, even if there is a gap, an optimum welding range can be obtained, and the welding accuracy and welding strength between the current collector plate and the external terminal member can be increased.

Other objects, features, and advantages of the present invention will become clearer with reference to the accompanying drawings and each embodiment.

It is sectional drawing which shows an example of the electric double layer capacitor which concerns on 1st Embodiment. It is an exploded perspective view showing an electric double layer capacitor. It is a perspective view which shows an example of the capacitor | condenser element which decomposed | disassembled one part. It is a figure which shows an example before and behind shaping | molding of the electrode part of a capacitor | condenser element. It is a figure which shows an example of a current collecting plate. It is a figure which shows a capacitor | condenser element provided with the current collector plate welded by laser. It is a figure which shows the connection of the current collection board on a capacitor | condenser element, and an external terminal. It is the figure which expanded and showed the welding part of the anode current collecting plate and the anode terminal. It is a figure which shows the welding form of a laser beam. It is a figure which shows the nugget formed by heat conduction welding. It is a figure which shows the other nugget formed by heat conduction welding. It is a flowchart which shows an example of the manufacturing process of the electrical double layer capacitor which concerns on 2nd Embodiment. It is a figure which shows the molding state of the anode part and cathode part of a capacitor | condenser element. It is a figure which shows the connection process of a capacitor | condenser element and a current collecting plate. It is a figure which shows the connection of the current collection board which concerns on 3rd Embodiment, and an external terminal. It is a figure which shows the current collection board which concerns on 4th Embodiment, and its connection. It is a figure which shows the connection and positioning of the current collecting plate and external terminal which concern on 5th Embodiment. It is a disassembled perspective view which shows an electric double layer capacitor provided with the terminal connection board based on 6th Embodiment. It is a figure which shows the current collection board which covers the external terminal which concerns on other embodiment, and a welding process.

[First Embodiment]

  In the first embodiment, the irradiation position of the laser beam or electron beam is set at a position different from the contact surface between the current collector plate connected to the element end face of the capacitor element and the external terminal, and the current collector plate and the external terminal are connected. It is the structure which carried out laser welding.

  The electric double layer capacitor (hereinafter simply referred to as “capacitor”) according to the first embodiment will be described with reference to FIGS. FIG. 1 shows a longitudinal section of the capacitor, and FIG. 2 shows an exploded state thereof. The configuration shown in FIGS. 1 and 2 is an example, and the present invention is not limited to such a configuration.

  This capacitor 2 is an example of the capacitor of the present invention. In this capacitor 2, an anode portion 6 and a cathode portion 8 are formed on the same element end surface 5 of the capacitor element 4. The anode part 6 and the cathode part 8 are an example of an electrode projecting part, and are constituted by a part of an electrode body (anode body 60 or cathode body 80: FIG. 3) drawn from the element end face 5 of the capacitor element 4. . An anode current collector plate 12 interposed between the anode part 6 and the anode terminal 10 is used for the connection between the anode part 6 and the anode terminal 10, and a cathode current collector interposed between the two for the connection between the cathode part 8 and the cathode terminal 14. A plate 16 is used. The anode terminal 10 and the cathode terminal 14 are external terminal members for external connection. The anode terminal 10 is an example of an anode terminal member, and the cathode terminal 14 is an example of a cathode terminal member. The aforementioned laser welding or electron beam welding is used for the connection between the anode terminal 10 and the anode current collector plate 12 and the connection between the cathode terminal 14 and the cathode current collector plate 16, and a nugget 18 is formed at these connection portions. Yes. Each nugget 18 irradiates a welding position with a laser beam or an electron beam by defocusing, and the anode terminal 10 and the anode current collector plate 12 or the cathode terminal 14 and the cathode current collector plate 16 are fused and cured to be integrated. It is a lump and is a part generated by welding. The shape of each nugget 18 is a parabolic solid, and its size is defined by the nugget diameter and the length in the depth direction (nugget depth) from the center of the nugget surface.

  In this embodiment, insulating means 17 is provided on the outer peripheral surface of the anode portion 6 connected to the anode current collector plate 12 and the cathode portion 8 connected to the cathode current collector plate 16. By this insulating means 17, the capacitor element 4 and the outer case 20 are insulated. The insulating means 17 may be made of an insulating material such as insulating paper or insulating tape.

Next, as shown in FIG. 2, the capacitor element 4 is a cylindrical body, and an anode body 60 (FIG. 3) is drawn out from one element end face to form an anode portion 6, and a cathode body 80 (FIG. 2). 3) is pulled out to form a cathode portion 8. A holding tape 19 is wound around the capacitor element 4 to prevent the anode body 60 and the cathode body 80 from unwinding.

  An exterior case 20 and a sealing plate 22 are provided as exterior members of the capacitor element 4. The outer case 20 is a molded body made of a moldable metal material such as aluminum. The sealing plate 22 is a means for closing the opening 30 of the outer case 20 and maintaining the airtightness of the space 24, and is a fixing member for fixing the anode terminal 10 and the cathode terminal 14, and a support member for the capacitor element 4. Is configured. In this embodiment, the sealing plate 22 is provided with a base portion 26 and a sealing portion 28. The base portion 26 is formed of an insulating material, for example, synthetic resin, and the anode terminal 10 and the cathode terminal 14 are fixed and insulated. The sealing portion 28 is made of a material having high airtightness, for example, a rubber ring.

  The sealing plate 22 is inserted into the opening 30 of the outer case 20 and is positioned at a caulking step 32 formed in the middle of the opening 30. The open end 34 of the outer case 20 is crimped by a curling process and is bitten into the sealing portion 28. As a result, the outer case 20 is firmly sealed. The base portion 26 of the sealing plate 22 is formed with a through hole 36 and a pressure release mechanism 38 made of thin rubber.

  A cover portion 53 is formed on the anode current collector plate 12 as an example of a cover portion that covers the contact surface 65 (FIG. 8) with the anode terminal 10 on the connection surface portion 52 side. Similarly, a cover portion 53 is also formed on the cathode current collector plate 16 so as to cover the contact surface 65 with the cathode terminal 14 on the connection surface portion 52 side. Each cover portion 53 covers at least part or all of the terminal side connection surface 64 of the anode terminal 10 or the cathode terminal 14. The cover portion 53 is formed integrally with the anode current collector plate 12 or the cathode current collector plate 16 and is, for example, a standing wall portion having a triangular cross section. Correspondingly, a tapered surface 67 is formed on the connection surface 64 of the anode terminal 10 or the cathode terminal 14. The tapered surface 67 is covered with the cover portion 53.

  Next, the capacitor element 4 will be referred to FIG. FIG. 3 shows the capacitor element 4 partially disassembled.

  As shown in FIG. 3, the capacitor element 4 includes an anode body 60, a cathode body 80, and separators 40 and 42, and a separator 40 that insulates between the anode body 60 and the cathode body 80. , 42 are sandwiched and wound to form a cylindrical winding element. For example, an aluminum foil is used as a base material for the anode body 60 and the cathode body 80, and polarizable electrodes including an active material such as activated carbon, a binder, and the like are formed on both surfaces of the aluminum foil.

  In the capacitor element 4, an insulating interval 44 having a constant width is provided between the anode portion 6 and the cathode portion 8 formed on the same end face side. The anode portion 6 is formed of, for example, a base material of the anode body 60, and similarly, the cathode portion 8 is also formed of a base material of the cathode body 80. In the case where the anode body 60 and the cathode body 80 are formed of aluminum, the anode section 6 and the cathode section 8 are base material sections that expose an aluminum surface on which a polarizable electrode is not formed.

  The formation part of the anode part 6 or the cathode part 8 is formed so as to protrude from the width W of the separators 40 and 42 which are insulating means, and is formed in a length L corresponding to the arc length of the anode part 6 or the cathode part 8. . The anode part 6 and the cathode part 8 projecting with a length L are formed with crease lines 43 at positions where they are parallel to the element end face 5 and slightly exposed from the element end face 5 as a preparation process for the bending process. The crease line 43 is a bent portion that is valley-folded in the bending direction with respect to the anode portion 6 and the cathode portion 8.

  Then, the anode part 6 or the cathode part 8 of the capacitor element 4 is processed as shown in FIG. 2 (or FIG. 4B) before connection with the anode current collector plate 12 or the cathode current collector plate 16. Thus, the capacitor element 4 is formed in close contact with the element end surface 5.

  Next, FIG. 4 is referred with respect to the anode portion 6 and the cathode portion 8 of the capacitor element. FIG. 4 shows an example of the anode part and the cathode part of the capacitor element, (A) shows the anode part and the cathode part before molding, and (B) shows the anode part and the cathode part after molding. 4, the same parts as those in FIGS. 1, 2, and 3 are denoted by the same reference numerals.

As shown in FIG. 4A, the element end face 5 of the capacitor element 4 is erected with an anode portion 6 and a cathode portion 8 constituting an electrode extending portion, and between the anode portion 6 and the cathode portion 8. Is set with an insulation interval 44 having a predetermined width. The Y-axis is taken at the center of the insulation interval 44, the X-axis is orthogonal to the Y-axis, and the angles θ ₁ and θ ₂ (≧ θ ₁ ) are set to the left and right around the X-axis. A plurality of cuts 48 are made in the radial direction around the winding center portion (core portion) 46 of the capacitor element 4 at an angle θ ₁ , and a plurality of partition portions 6A, 6B, 6C partitioned by each cut 48 are anode portions. 6 side is formed. Similarly, a plurality of partition portions 8A, 8B, and 8C are also formed on the cathode portion 8 side. For example, if the angle θ ₁ is set to 30 °, the partition portions 6A and 8A have 2θ ₁ = 60 °, and the partition portions 6B and 6C or the partition portion 8A formed with the partition portion 6A interposed therebetween. The angle θ ₂ of the partition portions 8B and 8C formed in (1) is set to θ ₂ = 60 [°].

For example, the depth of the cut 48 is set to the height h ₁ of the anode part 6 and the cathode part 8 with the overhang length, the partition parts 6A, 6B, 6C of the anode part 6, and the partition parts 8A, 8B, 8C of the cathode part 8. Is bent at the part of the crease line 43 in the middle part, and is pushed down to the element center side of the capacitor element 4 and compression-molded, thereby forming the partition part 6A of the anode part 6 as shown in FIG. 6B, 6C and the partition part 8A, 8B, 8C of the cathode part 8 are formed. In this embodiment, the partition sections 6B and 6C and the partition sections 8B and 8C are set as welds. Therefore, the protruding height h ₂ of the partition parts 6A, 8A is set higher than the height h _{3 of} each partition part 6B, 6C, 8B, 8C, and the partition parts 6A, 6B, 6C of the anode part 6 and the cathode part 8 The heights of the partition portions 8A, 8B, and 8C correspond to the bent shapes of the anode current collector plate 12 and the cathode current collector plate 16.

  In addition, the anode part 6 and the cathode part 8 of the capacitor | condenser element 4 can suppress a height dimension by compression-molding the anode part 6 and the cathode part 8 whole toward an element center direction in this way. In this embodiment, the partition parts 6B and 6C of the anode part 6 are compression-molded to form a stable flat connection surface, and then the partition part 6A which is a non-connection surface is compression-molded, and each partition part The height dimension of the boundary portion caused by the overlap between the spaces 6A-6B and 6A-6C is suppressed. The suppression of the height dimension of the boundary portion is the same in the cathode portion 8.

  Next, FIG. 5 will be referred to regarding the anode current collector plate 12 (or the cathode current collector plate 16). FIG. 5 shows an example of the anode current collector (or cathode current collector), (A) shows the plane, and (B) shows the side when the anode current collector is viewed from the welded connection side.

  The anode current collecting plate 12 is formed of, for example, an aluminum plate that is the same as the electrode material, covers the partition portions 6A, 6B, and 6C (FIG. 4) of the anode portion 6 described above, and laser welds the partition portions 6B and 6C. A shape and an area having an area and a laser welding area with the anode terminal 10 are provided. In this embodiment, the size is a half of the element end face of the capacitor element 4, and is a substantially semicircular plate as a shape in which the insulation interval 44 is ensured.

As shown in FIG. 5A, the anode current collector plate 12 is formed with an arc-shaped notch 50 corresponding to the winding center 46 of the capacitor element 4 at the center of the string side, and on the arc side thereof. Is formed with a connection surface portion 52 that is cut off linearly in a direction orthogonal to the X axis with the X axis as a center. In addition, as shown in FIG. 5B, the anode current collector plate 12 is a step that is bent at a right angle with an arcuate notch 50 at the center, that is, with an angle θ ₁ left and right about the X axis. Arc-shaped terminal connection portions 56A and element connection portions 56B and 56C are formed by the portion 54. Each of the terminal connection portions 56A and the element connection portions 56B and 56C is formed on a flat surface, and forms a parallel surface with the step portion 54 interposed therebetween.

In the anode current collector plate 12, when the height of the terminal connecting portion 56A is h ₄ , the thickness of the anode current collector plate 12 is t, and the inner height of the terminal connecting portion 56A is h ₅ ,
h ₅ = h ₄ −t ≧ h ₂ −h ₃ (1)
Is set to Therefore, the inner height h ₅ of the terminal connection portion 56A is the difference Δh ( = h ₂₎ between the protruding height h ₂ of the partition portions 6A and 8A and the height h ₃ of the partition portions 6B, 6C, 8B, and 8C. -H ₃ ) is absorbed, and the anode current collector plate 12 is in close contact with each of the partition portions 6B and 6C, and the partition portion 6A is accommodated. Note that the thickness t of the anode current collector plate 12 can be changed at the portions of the element connection portions 56B and 56C and the terminal connection portion 56A. For example, the thickness of the terminal connection portion 56A can be set thicker (1.2 times or more) than the element connection portions 56B and 56C, and according to this, the element connection portion 56B, The heat generated in 56C is absorbed by terminal connecting portion 56A having a predetermined thickness, and the connection accuracy of laser welding is improved.

  And the cover part 53 which covers the contact surface 65 with the anode terminal 10 or the cathode terminal 14 to be welded is provided in the center part of the connection surface part 52. The cover portion 53 may be formed to have a width that covers at least the terminal side connection surface 64 of the anode terminal 10 or the cathode terminal 14, but may be the same width as the terminal side connection surface 64.

  This configuration and the relationship with other members are the same for the cathode current collector plate 16.

  Next, FIG. 6 is referred to regarding the connection between the anode current collector plate 12 and the cathode current collector plate 16 and the anode portion 6 and the cathode portion 8 of the capacitor element 4. FIG. 6 shows an example of the arrangement and connection state of the anode current collector plate and the cathode current collector plate on the element end face of the capacitor element. In FIG. 6, the same parts as those in FIG.

  As shown in FIG. 6, the anode current collector plate 12 and the cathode current collector plate 16 are arranged so that one end face of the capacitor element 4 is centered on the winding center 46 and the arc-shaped notch 50 is aligned with the winding center 46. The gap 61 is set corresponding to the insulation gap 44 between the anode 6 and the cathode 8. The anode current collector plate 12 includes a partition portion 6A of the anode portion 6 of the capacitor element 4 on the lower surface side of the terminal connection portion 56A, and an anode portion of the capacitor element 4 on the lower surface side of the element connection portions 56B and 56C of the anode current collector plate 12. The six partition portions 6B and 6C are positioned and brought into close contact with each other. In the laser irradiation connection portion 66, the partition portions 6B and 6C and the element connection portions 56B and 56C are partially or entirely melted and connected by laser irradiation from the peripheral direction of the capacitor element 4 toward the element center direction. Yes. Such connection is the same on the cathode current collector plate 16 side.

  As shown in FIG. 6, the laser irradiation sites in each of the element connection portions 56B, 56C and 58B, 58C separated by the step portions 54 of the anode current collector plate 12 and the cathode current collector plate 16 are shown in FIG. That is, the laser irradiation connection portion 66. In this case, laser irradiation is performed as indicated by arrows [1], [2], [3] and [4] attached to the laser irradiation connection portion 66. In this laser irradiation, the capacitor element 4 is shielded by using an inert gas such as argon gas or helium gas as a shielding gas, and the influence of laser heat or sputtering on the capacitor element 4 is avoided.

  [1] This laser irradiation irradiates the element connecting portion 56B of one anode current collector plate 12 linearly from the outer peripheral side of the capacitor element 4 toward the element center direction.

  [2] Next, a series of laser irradiation is performed in a straight line from the element center side toward the element outer peripheral direction to the element connection part 58B of the other cathode current collector plate 16 opposed across the winding center part 46. It is welded by the operation.

  [3] Similarly, laser irradiation is performed from the outer peripheral side of the capacitor element 4 to the element connecting portion 56C of one anode current collector plate 12 in a straight line toward the element center direction.

  [4] In a series of operations of irradiating the element connecting portion 58C of the other cathode current collector plate 16 facing the winding center portion 46 with a laser linearly from the element center side toward the element outer peripheral side. Welded.

  In this way, the anode section 6 and the anode current collector plate 12, and the cathode section 8 and the cathode current collector plate 16 are connected by a series of operations in which the laser irradiation is performed linearly across the winding center portion 46. That is, the anode part 6 and the cathode part 8 and the current collector plates 12 and 16 are welded by setting a welding line (laser irradiation connection part 66) directed in the diameter direction of the capacitor element 4 with the winding center part 46 therebetween. Therefore, it is possible to shorten the welding time for connecting the anode portion 6 and the cathode portion 8 to each of the current collector plates 12 and 16, and to simplify the manufacturing process. The series of operations [1] and [2] of laser irradiation is repeated twice, or the series of operations [1] to [4] of laser irradiation is repeated twice, and a weld is arranged in the vicinity. Thus, the connection resistance can be further reduced. Although it is possible to connect by a series of operations of laser irradiation [1] and [2], the element connecting portions 56B, 56C, 58B, 58C of the anode current collector plate 12 and the cathode current collector plate 16 are Each can be connected individually, such as irradiating in a straight line from the element center side toward the element outer peripheral side.

  In addition, in the continuous operation of laser irradiation [1] to [4], laser welding is performed from [1] to [4] instead of continuously irradiating the same part with laser, and then from [1] again. When the laser irradiation is performed in [4], a time interval can be provided for laser irradiation at the same location, and as a result, the laser irradiation location can be cooled and the connection by laser welding can be stabilized. It is also possible to perform laser irradiation a plurality of times with a time interval at the same location, but the first laser welding is performed from [1] to [4], and laser welding is performed again from [1] to [4]. Therefore, laser irradiation can be performed continuously while taking a cooling interval, and the welding time by laser irradiation can be shortened.

  Regarding the continuous operations [1] to [4] of this laser irradiation, the laser output to the welding line from the start point to the end point of each laser irradiation may be attenuated stepwise or continuously. Specifically, three sections are provided from the start point to the end point of the laser output, and the laser output Pa of the start point section, the laser output Pb of the intermediate section, and the laser output Pc of the end point section are set, and the laser output satisfies Pa> Pb and Pb> Pc. It is attenuated. The laser output Pa in the start point section is set to the highest value, and is 50 [W] to 3000 [W] as an example. The laser output Pb is a laser output of 90% or less of the laser output Pa, and the laser output Pc is a laser output of 80% or less of the laser output Pa. In this way, the laser output to the welding line from the start point to the end point of each laser irradiation is attenuated stepwise or continuously, so that the welding energy applied to the current collector plates 12, 16, the anode portion 6 and the cathode portion 8 can be reduced. Uniformity can be achieved, connectivity can be improved, and stable welding connection can be realized. That is, the welding line (laser irradiation connection part 66) of the anode current collector plate 12 or the cathode current collector plate 16 and the anode part 6 or the cathode part 8 which has been irradiated with the laser and the vicinity thereof are heated, and the laser irradiation is made into the welding line. If this is done, the heating moves in a chained state along with the scanning of the laser irradiation, so that even if the laser output is not set to the same, the molten state is chained. For this reason, even if the laser output is attenuated stepwise and continuously, the thermal energy by the laser irradiation applied to the welded portion becomes uniform. For this reason, the connectivity between the anode current collector plate 12 or the cathode current collector plate 16 and the anode portion 6 or the cathode portion 8 is improved.

  As shown in FIG. 4, an anode portion 6 and a cathode portion 8 are formed on the element end surface 5 of the capacitor element 4. The anode part 6 and the cathode part 8 have an insulation interval 44 at which the anode part 6 and the cathode part 8 do not come into contact with each other when compression-molded toward the center direction. In the vicinity of the portion 46 (within 2 [mm] from the element center), the anode portion 6 and the cathode portion 8 are not formed. Moreover, since the anode part 6 and the cathode part 8 lead to a reduction in resistance as the number of formation sites (or the area increases), the anode part 6 and the cathode part 8 do not come into contact with each other and the resistance is reduced. For example, 3 [mm] to 15 [mm] is set as the insulating interval 44 that can be achieved. In addition, at the outermost periphery of the capacitor element 4, the anode current collector plate 12 and the anode current collector plate 12 are arranged so that the anode 6 and the cathode 8 do not contact the outer case 20 even if a displacement occurs during compression molding of the anode 6 and the cathode 8. Insulating means 17 (FIG. 1) such as insulating paper or insulating tape may be installed on the outer peripheral surfaces of the connected anode section 6 and the cathode section 8 connected to the cathode current collector plate 16. If this insulating means 17 is installed along the outer periphery so as to cover the anode terminal 10, the cathode terminal 14, the anode current collector plate 12, and the cathode current collector plate 16 in addition to the anode portion 6 and the cathode portion 8, an outer case Insulation with 20 is achieved.

  Refer to FIG. 7 for the connection between the anode terminal 10 and the anode current collector plate 12 and the connection between the cathode terminal 14 and the cathode current collector plate 16. 7 shows the connection between the anode terminal and the anode current collector plate, the cathode terminal and the cathode current collector plate, and FIG. 7A shows the state before the connection between the anode terminal and the anode current collector plate and the cathode terminal and the cathode current collector plate. FIG. 7B shows laser irradiation. In FIG. 7, the same parts as those in FIG.

  The anode current collecting plate 12 and the cathode current collecting plate 16 connected to the element end face 5 of the capacitor element 4 are external terminal members on the sealing plate 22 as shown in FIGS. The anode terminal 10 and the cathode terminal 14 are positioned. A terminal-side connection surface 64 is formed on the side surface of the anode terminal 10 and the cathode terminal 14, and this terminal-side connection surface 64 is a side to be connected to the connection surface portion 52 on the anode current collector plate 12 and the cathode current collector plate 16. It is a wall surface. The contact surface 65 (FIG. 8) between the anode current collector 12 and the anode terminal 10 is provided by the cover 53 on the anode current collector 12 side, or the contact surface 65 between the cathode terminal 14 and the cathode current collector 16 is provided as the cathode current collector. Covered by the cover portion 53 on the plate 16 side. Therefore, if the irradiation position of the laser beam is set in each cover portion 53, the laser irradiation 68 is performed at the irradiation position, and further the laser irradiation 68 is performed in the direction parallel to the contact surface 65, the nugget 18 described above causes the cover portion 53 to move. Including the anode current collector plate 12 and the anode terminal 10, the cathode current collector plate 16 and the cathode terminal 14, and laser welding. Thereby, between the connection surface part 52 and the terminal side connection surface 64 can be welded.

  The welding of the anode current collector plate 12 and the anode terminal 10 (or the cathode current collector plate 16 and the cathode terminal 14) will be described with reference to FIG. FIG. 8 shows an enlarged view of the welded portion of the anode current collector plate 12 and the anode terminal 10.

  For example, the anode current collector plate 12 is formed by header processing an aluminum plate, and as an example, the connection surface portion 52 has a cover portion 53 having a triangular cross section. Similarly, the anode terminal 10 is formed by header processing an aluminum plate, for example, and a tapered surface 67 is formed. If the angle of the taper surface 67 is matched with the inclination angle of the inner wall surface of the cover portion 53, both can be matched. In this case, a gap or the like is generated on the contact surface 65 according to the processing accuracy. In other words, the contact surface 65 side includes a portion that is in close contact with each other and a non-contact portion 63 that is curved and expands in the vertical direction. The forms of the anode current collecting plate 12 and the anode terminal 10 are the same in the relationship between the cathode current collecting plate 16 and the cathode terminal 14.

  The irradiation center position (irradiation position 71) of the laser beam 69 is set at a position coinciding with the contact surface 65 between the anode current collector plate 12 and the anode terminal 10. The irradiation position 71 may coincide with the contact surface 65 in the drawing, or may be a different position.

  FIG. 9 is referred to regarding the welding mode of the laser beam 69. As the welding form of the laser beam 69, there are a heat conduction welding as shown in FIG. 9A and a keyhole welding as shown in FIG. 9B. Any type of welding may be used for welding between metals, but in keyhole welding, the sharp focus 75 of the laser beam 69 is applied to the welding surface, so that a sharp and long nugget 18 is generated. Depending on the output, a large number of spatters 77 may be formed as the nugget 18 grows.

  On the other hand, in the heat conduction welding, the focus 75 is defocused in front of the irradiation position 71 of the laser beam 69, and an irradiation portion 79 having a large aperture is formed at the irradiation position 71. Compared with the sharp focus 75, the irradiation portion 79 causes heat conduction more gently, and a slow nugget 18 is formed. That is, in the heat conduction welding, a nugget 18 having a spread in the radial direction of the irradiation portion 79 is generated. In this welding process, the laser beam 69 is defocused to increase the nugget diameter, and the keyhole welding is shifted to the heat conduction welding.

  The nugget 18 formed by such heat conduction welding will be described with reference to FIG. In FIG. 10, the irradiation position 71 is irradiated with a laser beam 69, and the irradiation form has a nugget diameter enlarged by defocusing. That is, in FIG. 10, the nugget center O is set so as to coincide with the contact surface 65, but it may be set upward or downward (different in the crossing direction with respect to the contact surface 65) in the drawing.

  In such heat conduction welding, since the irradiation position 71 coincides with the contact surface 65, the contact surface 65 is taken into the nugget 18 whose nugget diameter is enlarged, and the anode current collector plate 12 and the anode terminal 10 are welded. Has been. In FIG. 10, φ is the nugget diameter, Nd is the nugget depth, and Wd is the welding depth. Since the nugget diameter φ is large and the nugget 18 approaches a flat shape as compared with the keyhole welding, a welding depth Wd (≈Nd) equivalent to the nugget depth Nd can be obtained. That is, this improves the welding accuracy and welding strength.

  In addition, before welding, the outer surface portion of the nugget 18 is integrated by fusion with a portion where the cover portion 53 is in close contact with the contact surface 65 side and a non-contact portion that is curved and expands in the vertical direction. As a result, a gentle surface portion 81 is generated.

In addition, as shown to A of FIG. 11, the irradiation position 71 of the laser beam 69 is made to differ upward from the contact surface 65 in the range of the side surface of the current collector plate which provided the cover part 53 or the cover part 53, or a figure. As indicated by 11 B, the distance may be varied downward. Also in this case, the contact surface 65 is taken into the nugget 18 whose nugget diameter is enlarged, and the anode current collector plate 12 and the anode terminal 10 are welded. In FIG. 11, φ is the nugget diameter, Nd is the nugget depth, and Wd is the welding depth. Since the nugget diameter φ is large and the nugget 18 approaches a flat shape as compared with the keyhole welding, a welding depth Wd (≈Nd) equivalent to the nugget depth Nd can be obtained. That is, this improves the welding accuracy and welding strength. The desired welding strength can be obtained by setting the dimensional difference between the nugget depth Nd and the welding depth Wd within 0.5 [mm].

  The nugget 18 is parallel to the contact surface 65 between the anode current collector plate 12 and the anode terminal 10 or the contact surface 65 between the cathode current collector plate 16 and the cathode terminal 14 (along the connection surface portion 52 and the terminal side connection surface 64). (Parallel direction) is formed continuously or discontinuously.

  In this embodiment, the distance (distance) between the capacitor element 4 and the sealing plate 22 is made as short as possible. If the interval (distance) between the capacitor element 4 and the sealing plate 22 is increased, the resistance increases and the height of the electric double layer capacitor 2 increases. However, such inconvenience is caused by the capacitor element 4 and the sealing plate 22. The interval (distance) is made as short as possible. In such a small space, in order to connect the anode terminal 10 and the cathode terminal 14 to the anode current collector plate 12 and the cathode current collector plate 16, as described above, the connection surface portion 52 and the terminal side connection surface 64 are matched. Therefore, the welding is simplified and strengthened by welding to this portion, that is, the portion that does not coincide with the contact surface 65 by laser irradiation that can be welded. Here, the thicknesses of the anode current collector plate 12, the cathode current collector plate 16, the anode terminal 10 and the cathode terminal 14 (height dimensions of the connection surface portion 52 and the terminal side connection surface 64) are 0.5 mm to 5 mm, respectively. The range is set in the range of [mm]. According to this, it is possible to perform laser welding, the internal resistance is hardly increased, and the height of the electric double layer capacitor 2 can be shortened.

  Further, the connection surface portion 52 and the terminal-side connection surface 64 are installed near the outer peripheral surface of the capacitor element 4 in order to prevent excessive stress on other members (the anode portion 6 and the cathode portion 8) during laser irradiation. Specifically, it is preferable that the outer peripheral surface of the capacitor element 4 is, for example, within 10 mm.

  In the anode current collecting plate 12 and the cathode current collecting plate 16, the connection region between the anode part 6 and the cathode part 8 of the capacitor element 4 and the connection region between the anode terminal 10 and the cathode terminal 14 are set at different positions. Therefore, the connection between each electrode portion and the current collector plate, and each external terminal and the current collector plate can be stabilized, and the connection can be strengthened together with the lower resistance of the capacitor element.

  The features and advantages of the electric double layer capacitor 2 of the first embodiment described above are listed as follows.

  (1) On one end surface side of the capacitor element 4, the anode portion 6 is formed of the base material of the anode body 60, the cathode portion 8 is formed of the base material of the cathode body 80, and the anode portion 6 and the anode terminal 10 are connected to the anode current collector plate 12. Since the cathode part 8 and the cathode terminal 14 are connected via the cathode current collector plate 16, the terminal connection is simplified. In addition, the connection can be facilitated.

  (2) The space occupation rate occupied by the connecting portion in the space 24 of the outer case 20 is extremely low.

  (3) The capacitor element 4 is firmly supported by the sealing plate 22 which is an exterior member. That is, since the anode portion 6 and the cathode portion 8 of the capacitor element 4 are firmly fixed to the anode terminal 10 and the cathode terminal 14 by laser welding via the anode current collector plate 12 and the cathode current collector plate 16, the capacitor element 4 The support strength of is increased. As a result, a mechanically robust support structure is formed, and the seismic resistance of the product can be improved.

  (4) A plurality of side edge portions are assembled from the anode body 60 wound around the capacitor element 4 as a winding element to form the anode portion 6, and this anode portion 6 is laser welded to the anode current collector plate 12. Similarly, a plurality of side edge portions are assembled from the cathode body 80 to form the cathode portion 8, and the cathode portion 8 is laser welded to the cathode current collector plate 16. The resistance of the capacitor 2 can be reduced, and a product with a low equivalent series resistance can be provided.

  (5) Since the anode current collecting plate 12 and the cathode current collecting plate 16 are used, it is not necessary to connect a tab to the capacitor element 4.

  (6) Since the side surfaces of the anode current collector plate 12 or the cathode current collector plate 16 and the external terminal (the anode terminal 10 or the cathode terminal 14) are flush with each other, the laser irradiation with respect to both can be stabilized, and the complete connection and Reliability can be increased.

  (7) Since a shield gas is used during laser irradiation, the capacitor element 4 can be protected from laser heat and flying spatter, the characteristic deterioration of the capacitor element 4 and the capacitor 2 as a product can be prevented, and reliability can be improved. it can.

  (8) Although the laser beam 69 is used in the above embodiment, an electron beam may be used instead of the laser beam 69. Since the laser beam 69 or the electron beam is irradiated to a position different from the contact surface 65 between the anode current collector plate 12 or the cathode current collector plate 16 and the external terminal member, it is irrelevant to the state of the contact surface between the current collector plate and the external terminal member. Both can be welded together.

  (9) For the laser beam 69, in addition to the irradiation position 71 on the external terminal side, a surface portion suitable for laser irradiation may be selected, and any one of the flat surfaces can be selected and irradiated with the laser beam or the electron beam. In such a laser beam 69 or electron beam irradiation form, even if the processing accuracy of the contact surface between the anode current collector 12 (or cathode current collector 16) and the external terminal member is low, even if there is a gap, it is optimal. A large welding region (nugget depth) can be obtained, and the welding accuracy and welding strength between the current collector plate and the external terminal member can be increased.

  (10) The anode current collector plate 12 (or the cathode current collector plate 16) and the external terminal member are made of a metal material having a relatively low hardness such as aluminum, and the processing accuracy is limited when processing by header processing or the like. There is. The gap which arises between the contact surfaces between the anode current collecting plate 12 (or the cathode current collecting plate 16) and the external terminal member cannot be avoided. In such a case, the irradiation position 71 of the laser beam or electron beam described above is set on the cover portion 53 on the side surface of the anode current collector plate 12 (or cathode current collector plate 16), that is, for flat laser welding. A suitable surface portion can be selected, and the welding accuracy can be increased.

  (11) In the above embodiment, the irradiation position 71 of the laser beam or the electron beam may be different in the intersecting direction such as the orthogonal direction to the contact surface 65 or may be the same position as the contact surface 65.

  (12) The irradiation position 71 of the laser beam or the electron beam may be different from the contact surface 65 in the crossing direction, but the number and the range thereof are preferably, for example, ± 0.1 to ± 0.5 [mm]. . By setting to this range, the contact surface 65 can be included in the welding range by the laser beam or the electron beam.

  The depth of the nugget 18 of laser welding or electron beam welding is only required to be able to be welded, and is preferably 1.2 mm or less, for example. If this range is exceeded, the irradiation range of the laser beam or the electron beam is widened, and the thickness of the current collector plate and the external terminal member is increased, resulting in an increase in the size of the capacitor.

[Second Embodiment]

  The second embodiment discloses a method for manufacturing a capacitor as described above.

  The second embodiment will be described with reference to FIGS. 12, 13, and 14. FIG. FIG. 12 is a flowchart showing an example of a manufacturing process of the electric double layer capacitor according to the second embodiment, FIG. 13 is a molding state of the anode part and the cathode part, and FIG. 14 is laser welding of the current collector plate and the capacitor element. The process is shown.

  This manufacturing process is an example of a method of manufacturing a capacitor according to the present invention. As shown in FIG. 12, the capacitor element 4 and the electrode part (electrode overhanging part) forming step (step S11), the anode part 6 and the cathode part 8 forming step (step S12), first connecting step (step S13), second connecting step (step S14), electrolyte solution impregnation and sealing step (step S15).

  (1) Capacitor element 4 and electrode part (electrode overhanging part) forming step (step S11)

  As shown in FIG. 3, the separator elements 40 and 42 are sandwiched between the anode body 60 and the cathode body 80, and the capacitor element 4 is formed by winding it in a cylindrical shape around the winding center 46. In the capacitor element 4, a part of the anode body 60 and the cathode body 80 is projected on the element end face side, and an anode section 6 and a cathode section 8 are formed as electrode projecting sections. An insulation interval 44 is set in the anode portion 6 and the cathode portion 8.

  (2) Molding process of anode part 6 and cathode part 8 (step S12)

  In this molding step, the anode portion 6 and the cathode portion 8 as the electrode overhang portions are partitioned into the partition portions 6A, 6B, 6C, 8A, 8B, and 8C described above as shown in FIG. As shown in FIG. 4 (B), each is bent in the direction of the winding center 46 and molded (step S12). The molding corresponds to the bent shape of the anode current collector plate 12 and the cathode current collector plate 16 as shown in FIG. In FIGS. 13A and 13B, (A) and (B) show the partitions 6 B and 6 C of the anode 6 connected to the anode current collector 12 and the partitions 8 B and 8 C of the cathode 8 connected to the cathode current collector 16. A bent state (molded state) is shown, (A) shows a molded state before an anode current collector plate 12 and a cathode current collector plate 16 described later are installed, and (B) shows an anode current collector plate 12 and a cathode current collector. The molding state after installing the electric plate 16 is shown. That is, the anode current collector plate 12 and the cathode current collector plate 16 are pressed against the anode portion 6 and the cathode portion 8 or the anode portion 6 and the cathode portion 8 are pressed against the anode current collector plate 12 and the cathode current collector plate 16 for compression. Thus, the partition sections 6B and 6C of the anode section 6 and the partition sections 8B and 8C of the cathode section 8 become flat, and are in close contact with the anode current collector plate 12 and the cathode current collector plate 16. In addition, as shown in FIG. 3, a crease line 43 may be provided in advance in the anode part 6 or the cathode part 8 before the anode part 6 or the cathode part 8 is bent and molded. The crease line 43 is formed at a position having a certain width (0.5 mm or more) from the element end face 5, and thereby mechanical stress applied to the separator portion at the element end face position when the anode portion 6 or the cathode portion 8 is bent. It is possible to prevent a short circuit due to contact between the anode body 60 and the cathode body 80. Note that the crease line 43 is not a flaw but a marking line, and can prevent buckling of the anode part 6 and the cathode part 8 during bending. The crease line 43 is a groove, and the cross-sectional shape may be triangular, square, or curved (R). For example, a method such as pressing, laser, or cutting may be used to form the crease line 43. Although the crease line 43 may be one as shown in FIG. The formation surface portion of the crease line 43 may be one surface of the anode portion 6 or the cathode portion 8, but may be both surfaces. The crease line 43 as an example is formed so that the surface of the element end face facing the winding center 46 is valley-folded.

  (3) 1st connection process (step S13)

  In this connection step (step S 13), as shown in FIG. 14A, the anode current collector plate 12 is positioned on the anode portion 6 of the capacitor element 4 and the cathode current collector plate 16 is positioned on the cathode portion 8 of the capacitor element 4. As shown in FIG. 14B, the anode current collector plate 12 is connected to the anode portion 6 and the cathode current collector plate 16 is connected to the cathode portion 8 by laser welding. In this laser welding, an inert gas such as argon gas or helium gas is used as a shielding gas, so that the capacitor element 4 is shielded, and the capacitor element 4 is separated from laser heat or flying spatter.

  (4) Second connection process (step S14)

  In this connection step (step S14), as shown in FIG. 7, the terminal-side connection surface 64 of the anode terminal 10 on the sealing plate 22 is made to correspond to the connection surface 52 of the anode current collector plate 12 connected to the anode portion 6. The laser beam 69 or the electron beam is irradiated to any one of the irradiation positions 71 described above, which is the same position as the contact surface 65, and further the laser beam 69 or the electron beam is scanned in a direction parallel to the contact surface 65 described above. Weld. Similarly, the cathode terminal 14 of the sealing plate 22 is connected to the cathode current collector plate 16 connected to the cathode portion 8 by laser welding. Also in this laser welding, by using an inert gas such as argon gas or helium gas as a shield gas, the capacitor element 4 is shielded, and the capacitor element 4 is separated from laser heat or flying spatter.

  In this embodiment, as shown in FIG. 7A, the anode terminal 10 of the sealing plate 22 is positioned with respect to the anode current collector plate 12 connected to the anode portion 6 of the capacitor element 4, and at the same time, the capacitor element By positioning the cathode terminal 14 of the sealing plate 22 with respect to the cathode current collector plate 16 connected to the cathode portion 8 of 4, the laser welding is performed as shown in FIG. Reference numeral 18 denotes the nugget described above.

  The sealing plate 22 is formed of synthetic resin (insert molding) using inserts of the anode terminal 10 and the cathode terminal 14, whereby the base portion 26 and the sealing portion 28 are formed.

  (5) Electrolyte impregnation and sealing process (step S15)

  The capacitor element 4 is impregnated with an electrolytic solution, and then accommodated in the outer case 20 and sealed by curling the open end 34 of the outer case 20 (step S15), and the electric double layer capacitor 2 (FIG. 1) as a product. ) Is completed.

  According to such a manufacturing process, the above-described electric double layer capacitor 2 can be easily manufactured, the terminal connection process can be simplified, and the capacitor having the effect as described in the first embodiment. Can be realized.

  In this manufacturing process, the defocus position of the laser beam or the electron beam may be different from the irradiation position 71 of the laser beam 69 or the electron beam, for example, set in a range of 0.2 [mm] to 2.0 [mm] or less. It is preferable to do.

[Third Embodiment]

  In the third embodiment, the arrangement of external terminals and the form of a current collector are disclosed.

  The third embodiment will be described with reference to FIG. FIG. 15 shows the connection between the current collector plate and the external terminal according to the third embodiment, (A) shows the laser irradiation before the connection, and (B) shows the laser irradiation during the connection.

  The anode terminal 10 and the cathode terminal 14 installed on the sealing plate 22 of this embodiment are arranged close to the winding center 46 of the element end face 5 of the capacitor element 4 as shown in FIG. Has been. The terminal side connection surfaces 64 of the anode terminal 10 and the cathode terminal 14 are set back from the outer peripheral surface of the capacitor element 4 toward the winding center 46.

  In this embodiment, as shown in FIG. 15A, terminal connection of the anode current collector plate 12 and the cathode current collector plate 16 is made to the anode terminal 10, the cathode terminal 14, and the terminal side connection surface 64. A recess 70 that is recessed toward the winding center 46 is formed in the portions 56A and 58A. In the recess 70, the connection surface portion 52 described above is formed corresponding to the terminal side connection surface 64 of the anode terminal 10 or the cathode terminal 14. In this case, in the anode current collector plate 12 or the cathode current collector plate 16, the element connection portions 56 </ b> B and 56 </ b> C constitute a flat portion protruding in the outer peripheral direction of the capacitor element 4 with respect to the side surface portion of the terminal side connection surface 64. .

  With such a configuration, as shown in FIG. 15B, even if the anode terminal 10 and the cathode terminal 14 are arranged close to the winding center 46 of the element end face 5 of the capacitor element 4, The terminal-side connection surface 64 and the connection surface 52 are maintained in correspondence with each other, and the connection by the laser irradiation 68 can be performed on the flat surface selected from the irradiation position 71 as in the above embodiment.

  In this case, the cover portion 53 is formed on the connection surface 52 side, and can cover the contact surface 65 between the anode terminal 10 and the anode current collector plate 12, and the contact surface 65 between the cathode terminal 14 and the cathode current collector plate 16, The outer surface of the cover portion 53 can be irradiated with a laser beam 69 or an electron beam to stabilize welding.

  In this embodiment, the concave portion 70 is formed in the anode current collector plate 12 and the cathode current collector plate 16, but the connection surface 52 may be formed by a convex portion.

[Fourth Embodiment]

  In the fourth embodiment, other forms of the current collector plate are disclosed. However, even when such a current collector plate is used, a laser beam or an electron beam is placed at the same position as the contact surface 65 described above. The irradiation position may be set.

  For the fourth embodiment, reference is made to FIG. FIG. 16 shows the current collector plate according to the fourth embodiment, and the connection between the current collector plate and the external terminals. (A) is a current collector plate before connection, (B) is before connection, and (C) is connection. The laser irradiation inside is shown.

  As shown in FIG. 16A, the current collector plates 12 and 16 of this embodiment are configured to cover the element end face 5 of the capacitor element 4 with a gap 61, which is the same as in the first embodiment. On the back side, a recess 89 for accommodating the partition portions 6A and 8A is formed. On the surface portions of the current collector plates 12 and 16, the connecting portions with the partition portions 6 </ b> A and 8 </ b> A of the capacitor element 4 are fan-shaped protrusions 91, and the partition portions 6 </ b> B and 6 </ b> B of the capacitor element 4 are sandwiched between the protrusions 91. Recesses 93 and 95 corresponding to 6C, 8B and 8C are formed. The concave portions 93 and 95 constitute a flat portion that protrudes in the outer peripheral direction of the capacitor element 4 from the connection portion with the external terminal. The protrusion 91 is formed with a notch 97 on the peripheral side, and a peripheral surface facing the notch 97 is formed in an arc shape to form a connection surface 99 with the anode terminal 10 or the cathode terminal 14. A rectangular parallelepiped protrusion 101 is formed on the recesses 93 and 95 side as means for simultaneously gripping (chucking) the current collector plates 12 and 16.

  As shown in FIG. 16B, the current collector plates 12 and 16 of this embodiment are installed so as to cover the element end surface 5 of the capacitor element 4, and the anode portion 6 and the concave portions 93 and 95 of the current collector plate 12. Are connected by laser welding, and similarly, the cathode portion 8 and the recesses 93 and 95 of the current collector plate 16 are connected by laser welding.

  16C, the anode terminal 10 is overlaid on the current collector plate 12 connected to the capacitor element 4, the cathode terminal 14 is overlaid on the current collector plate 16, and the anode terminal 10 The connection surface 99 having a curved surface corresponding to the connection surface 64 is matched, and similarly, the connection surface 99 having a curved surface corresponding to the curved surface portion of the cathode terminal 14 is aligned and positioned. In this positioning state, the current collector plates 12 and 16 are connected to the anode terminal 10 or the cathode terminal 14 by performing laser irradiation 68. The recesses 93 and 95 protrude in the outer peripheral direction of the current collector plates 12 and 16 from the connection surface 99 connected to the anode terminal 10 or the cathode terminal 14, that is, the side surface portion welded to the external terminal member. The flat part is comprised. The element end surface 5 of the capacitor element 4 can be covered with the flat portion.

  In such a configuration, the element end face 5 of the capacitor element 4 is covered with the current collector plates 12 and 16, and the element end face 5 of the capacitor element 4 can be protected from spattering by the laser irradiation 68 on the connection face 99 side. Moreover, although the connection surface 99 is a curved surface corresponding to the curved surfaces of the anode terminal 10 and the cathode terminal 14, the contact surface 65 between the anode terminal 10 (or the cathode terminal 14) and the current collector plate 12 (or the current collector plate 16). Even if there is a gap, the laser beam or electron beam irradiation position 71 may be set at the same position as the contact surface 65. According to such a configuration, good laser welding can be performed as in the above embodiment, and the welding accuracy can be increased.

[Fifth Embodiment]

  The fifth embodiment discloses that positioning means is provided on any one of the sealing plate, the external terminal, and the current collecting plate, and the connection position between the external terminal and the current collecting plate is determined by the positioning means.

  The fifth embodiment will be described with reference to FIG. FIG. 17 shows a sealing plate according to a fifth embodiment, (A) shows a sealing plate viewed from the back side, and (B) shows an anode current collector plate and a cathode current collector plate positioned by the sealing plate. Yes.

  On the back side of the sealing plate 22 of this embodiment, as shown in FIG. 17A, a positioning convex portion 72 made of an insulating material is formed in a space portion between the anode terminal 10 and the cathode terminal 14. The positioning projection 72 is protruded toward the winding center 46 of the capacitor element 4 (FIG. 1). The positioning convex portion 72 includes a columnar portion 74 and a pair of flat plate-like standing wall portions 76. The columnar part 74 is a columnar part corresponding to the arc of each arcuate notch 50 of the anode current collector plate 12 and the cathode current collector plate 16. The columnar portion 74 includes a plate-like standing wall portion 76, and includes plate-like standing wall portions 76 that maintain the distance 61 between the anode current collector plate 12 and the cathode current collector plate 16 around the columnar portion 74.

  If the sealing plate 22 having such a positioning convex portion 72 is provided, the anode current collecting plate 12 and the cathode current collecting plate 16 are positioned at predetermined positions by the positioning convex portion 72 as shown in FIG. In addition, the interval 61 can be maintained at the predetermined width w. That is, the circular arc-shaped notch 50 of the anode current collecting plate 12 and the cathode current collecting plate 16 is fitted in the cylindrical portion 74 of the positioning convex portion 72, and the anode current collecting plate 12 and the cathode are arranged on the side surface of each flat plate-like wall portion 76. By contacting the current collector plate 16, the anode current collector plate 12 and the cathode current collector plate 16 are positioned at predetermined positions. By this positioning, the terminal-side connection surface 64 of the anode terminal 10 and the connection surface 52 of the anode current collector plate 12, and the terminal-side connection surface 64 of the cathode terminal 14 and the connection surface 52 of the cathode current collector plate 16 can be matched. The connection by laser irradiation can be stabilized, the connection accuracy can be improved, and the anode 6 and the cathode 8 are reliably insulated and isolated by the positioning projection 72.

  In this embodiment, the positioning projection 72 is formed on the sealing plate 22 side. However, the external terminals (the anode terminal 10 and the cathode terminal 14) or the current collectors (the anode current collector 12 and the cathode current collector 16). Positioning means may be provided in any of the above. Also with such a configuration, the connection position between the external terminal and the current collector plate can be determined by the positioning means, and the irradiation position 71 may be selected as the laser irradiation surface, and the welding connection with high reliability as well as stabilization of the connection can be achieved. can get.

[Sixth Embodiment]

  The sixth embodiment is configured to include a current collector plate and a connection plate as an external terminal member. In such a configuration, when the current collector plate and the connection plate are connected by laser welding or electron beam welding, the contact surface 65 of the current collector plate and connection plate may be different from the irradiation position of laser welding or electron beam welding. It may be the same. That is, even if the contact surface 65 is unstable, the cover portion 53 is melted by laser irradiation or electron beam irradiation, and the unstable surface portion can be supplemented with molten metal, so that stable welding can be obtained and welding accuracy can be improved. Can be increased.

  FIG. 18 is referred to for the sixth embodiment. FIG. 18 shows an electric double layer capacitor according to a sixth embodiment.

  In the sixth embodiment, as shown in FIG. 18, the anode connection plate 88 is provided with the anode terminal 10 as the anode terminal member, and the cathode connection plate 90 is provided with the cathode terminal 14 as the cathode terminal member. The anode connecting plate 88 is connected to the anode terminal 10 by laser welding and then connected to the anode current collecting plate 12 on the capacitor element 4 side. Similarly, the cathode connection plate 90 is connected to the cathode terminal 14 by laser welding and then connected to the cathode current collector plate 16 on the capacitor element 4 side. The anode connection plate 88 is formed with a connection recess 92 for positioning and connecting the anode terminal 10, and the cathode connection plate 90 is formed with a connection recess 94 for positioning and connecting the cathode terminal 14. A connection surface portion 96 corresponding to the connection surface 52 of the anode current collector plate 12 or the cathode current collector plate 16 is formed on a part of the peripheral surface of the anode connection plate 88 and the cathode connection plate 90. Laser welding is performed in correspondence with the connection surface 52 to be electrically connected.

  In such a configuration using the anode connection plate 88 and the cathode connection plate 90, the anode terminal 10 and the cathode terminal 14 which are external terminals, the anode current collector plate 12 and the cathode current collector plate 16 connected to the capacitor element 4 side. Can be connected in a wide range, connection resistance can be reduced, and connection strength can be increased.

  Also in this embodiment, the anode current collector plate 12 is provided with the cover portion 53, so that the contact surface 65 with the anode connection plate 88 is covered with the cover portion 53, and the laser beam 69 or the electron beam is covered on the cover portion 53. By setting the irradiation position 71 and performing laser welding or electron beam welding, the welding accuracy can be improved. Such a configuration is the same for the cathode current collector plate 16.

[Other Embodiments]

  (1) In the embodiment described above, the winding element is exemplified as the capacitor element, but is not limited to the winding element. A multilayer element or a solid element may be used.

  (2) In the above-described embodiment, a configuration in which the anode portion 6 and the cathode portion 8 are provided on one of the element end faces 5 of the capacitor element 4 and connected to an external terminal is disclosed. It is good also as a structure which equips the other element end surface with a cathode part.

  (3) In the above embodiment, the electric double layer capacitor 2 is exemplified, but the present invention is not limited to this. The same structure and method can be similarly applied to an electrolytic capacitor, and the same effect can be obtained.

  (4) In the above embodiment, the anode current collector plate 12 and the cathode current collector plate 16 are exemplified as the current collector plates. However, the present invention is not limited to the above embodiment. The connection surface 52 is a flat surface, but may be a curved surface as a shape that matches the shape of the external terminal. The position of the connection surface 52 may be either in the surface of the current collector plate or on the peripheral surface, and may be provided with a connecting convex portion.

  (5) In the above embodiment, an insulation interval is provided between the anode part and the cathode part, but an insulation member may be provided at this insulation interval.

(6) Although the anode part 6 and the cathode part 8 are formed in a semicircular shape in the above embodiment, the present invention is not limited to this. Of the partition sections 6A, 6B, 6C of the anode section 6 and the partition sections 8A, 8B, 8C of the cathode section 8 shown in the embodiment, the partition section 6B connected to the anode current collector plate 12 and the cathode current collector plate 16, 6C and 8B, formed overhanging 8C only partition portion 8A compartments 6A and cathode portion 8 of the anode portion 6 may not overhang.

  (7) In the above embodiment, the element connection portions 56B, 56C or 58B, 58C, which are element connection regions between the anode portion 6 and the cathode portion 8, are connected to the terminal by dividing into three parts as different positions of the current collector plate. The terminal connection portion 56A or 58A, which is a region, is set on the front and back surfaces of the current collector plate, and is set at a different position in the horizontal direction. The element connection region (laser irradiation connection portion 66) may be set in a part of the current collector plate, and the terminal welding region (that is, the nugget 18) may be set in other portions. That is, the element connection region and the terminal connection region may be close to each other as long as the welding positions are different on the front and back surfaces of the current collector plate. That is, the nugget 18 may be formed in a portion where the welding position does not overlap between the laser irradiation connection portion 66 and the front and back surfaces of the current collector plate in the element connection portion 56B, 58B, 56C, or 58C that is the element connection region.

  (8) The cover portion 53 that covers the contact surface 65 between the anode terminal 10 (or the cathode terminal 14) and the anode current collector plate 12 (or the cathode current collector plate 16) is connected as shown in FIG. The structure which extended the surface part 52 and was made to stand may be sufficient. When the irradiation position 71 is set and the laser beam or the electron beam is irradiated on the flat surface portion on the outer surface of the cover portion 53 as shown in FIG. The cathode terminal 14) and the anode current collector plate 12 (or the cathode current collector plate 16) can be melted to form the nugget 18, and the welding accuracy can be increased.

  (9) In the above embodiment, the cover portion 53 is formed on the current collecting plates 12 and 16 side. However, the cover portion 53 is formed on the anode terminal 10 or the cathode terminal 14 or the connection plate, which is an external terminal member, and covers the contact surface 65. The same effect as the above embodiment can be obtained.

As described above, the most preferable embodiment and the like of the present invention have been described. However, the present invention is not limited to the above description, and is described in the claims or a form for carrying out the invention. It goes without saying that various modifications and changes can be made by those skilled in the art based on the gist of the invention disclosed in the above, and such modifications and changes are included in the scope of the present invention.

Method for manufacturing a capacitor of the present invention, by covering the contact surface with the current collector plate and the external terminal member provided with a cover portion to either of the current collector plate or outer terminal member, the laser irradiation or electron to the cover portion Because beam irradiation is performed, it contributes to simplification of the terminal connection structure and connection process, can improve productivity and reliability, can improve the welding accuracy of laser welding and electron beam welding, and can improve the connection strength. Etc. are beneficial.

2 Electric double layer capacitor 4 Capacitor element 6 Anode portion 60 Anode body 8 Cathode portion 80 Cathode body 10 Anode terminal 12 Anode current collector plate 14 Cathode terminal 16 Cathode current collector plate 18 Nugget 19 Holding tape 20 Exterior case 22 Sealing plate 24 Space portion 26 Base part 28 Sealing part 32 Caulking step part 34 Open end part 36 Through hole 38 Pressure release mechanism 44 Insulation interval 53 Cover part 67 Tapered surface 71 Irradiation position

Claims (6)

The electrode body is protruded from the element end face of a capacitor element which is a winding element or a non-winding element provided with an anode-side and cathode-side electrode body and a separator interposed between the electrode bodies, Forming a single or a plurality of electrode overhangs;
Either one of the external terminal member installed on the sealing member that seals the opening of the case member that accommodates the capacitor element, or the current collector plate connected to the electrode overhanging portion includes a covering portion, Covering the contact surface between the external terminal member and the current collector plate;
A step of irradiating a laser beam or an electron beam to the cover, and welding the current collector plate and the external terminal member;
A method for manufacturing a capacitor, comprising: 2. The method for manufacturing a capacitor according to claim 1 , wherein the irradiation position of the laser beam or the electron beam is made to coincide with a contact surface between the current collector plate and the external terminal member. 2. The manufacturing method of a capacitor according to claim 1 , wherein the irradiation position of the laser beam or the electron beam is varied in a crossing direction with respect to a contact surface between the current collector plate and the external terminal member. Method. 4. The method of manufacturing a capacitor according to claim 3 , wherein the irradiation position of the laser beam or the electron beam is varied by ± 0.1 to ± 0.5 [mm] in a direction intersecting with the contact surface. Method. Characterized in that setting the defocus position of the laser beam or the electron beam from the irradiation position of the laser beam or the electron beam in 0.2 mm and 2.0 mm. Or less, according to claim 1 5. A method for producing a capacitor as described in any one of 4 to 4 . 6. The method of manufacturing a capacitor according to claim 1, wherein a nugget depth of welding by the laser beam or welding by the electron beam is 1.2 [mm] or less.

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