JP2012104622A - Capacitor and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve reduced capacitor resistance and a robust connection structure, and to provide a configuration and a method capable of improving insulation quality between different electrodes.SOLUTION: A capacitor comprises: a capacitor element 4; a plurality of electrode overhanging parts (anode part 6, cathode part 8) in which a part of electrode bodies (anode body, cathode body) is extracted to an element end surface 5 of the capacitor element by a predetermined overhanging width, bent, and disposed on the element end surface 5, and insulation intervals 21, 23 set between different electrodes are larger than the overhanging width of the electrode body; and collecting plates (anode collecting plate 12, cathode collecting plate 16) connected to the electrode overhanging parts and the external terminals (anode terminal 10, cathode terminal 14).

Description

The present invention relates to a connection between a capacitor element and an external terminal on a sealing member of an exterior member of the capacitor element, and uses a welding technique for the connection, for example, a capacitor such as an electrolytic capacitor or an electric double layer capacitor, and its manufacture Regarding the method.

  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 Laid-Open No. 11-21857 JP 2001-068379 A JP 2007-335156 A JP 2010-093178 A JP-A-6-275476

  By the way, in the configuration in which the current collector plate is provided on each end face of the wound element, when the external terminal on the anode side and the cathode side is installed adjacent to the exterior member that covers the wound element, It is necessary to secure a connection distance between the electric plate. Further, in the wound type element, since the distribution of the internal resistance is different between the inner part and the outer part, it is necessary to take measures against it, and it is necessary to pay attention to the connection between the element and the current collector plate. In addition, the structure using the current collector plate can reduce the internal resistance of the element, but depending on the stress applied to the current collector plate interposed between the external terminal and the element during manufacturing, the reliability of the connection is reduced and the connection resistance is large. There is a case.

  Regarding such connection, there is a slight space between the capacitor element and the sealing member, but when this space is increased and the interval required for the connection member and connection is increased, the resistance is increased accordingly. Furthermore, the height dimension of the capacitor increases. If this distance (distance) is shortened, the size of the capacitor can be reduced by reducing the space, but the connection interval between the capacitor element and the sealing member is shortened, and it takes time to connect or incomplete connection. There are challenges.

  Also, the more portions that are drawn from the capacitor element for terminal connection, the larger the connection point of the capacitor element electrode body to that portion and the external terminal, so that the internal resistance of the capacitor element decreases. On the other hand, if the lead-out portion from the capacitor element is increased, it is difficult to bend the lead-out portion with high accuracy in the laminated state. In the winding element, the lead-out portion from the electrode body is curved and wrinkles when bent, and the wrinkle becomes an obstacle to the connection with the current collector plate, and the connection portion becomes unstable.

  In addition, when the lead-out portion from the capacitor element is formed adjacently between different poles, if the insulation between the two is insufficient, the performance of the capacitor is degraded.

  Regarding such demands and problems, Patent Documents 1 to 5 do not disclose or suggest them, and do not disclose or suggest a configuration for solving them.

Therefore, in view of the above problems, an object of the present invention is to increase the insulation between different poles as well as to reduce the resistance of the capacitor and to strengthen the connection structure.

  In order to achieve the above object, a capacitor of the present invention is arranged by bending a capacitor element and a part of an electrode body on the element end face of the capacitor element with a predetermined overhanging width and bending it on the element end face. A plurality of electrode overhang portions in which an insulation interval set between different electrodes is set larger than the overhang width of the electrode body; and a current collector plate connected to the electrode overhang portion and connected to an external terminal member. ing.

  In order to achieve the above object, in the capacitor, the insulation interval set between the different poles of the current collector plate may be smaller than the insulation gap set between the different poles of the electrode overhanging portion.

In order to achieve the above object, in the capacitor, when the capacitor element is a wound element, the electrode projecting portion has a width narrower than the arc length of the half circumference for each half circumference of the capacitor element. It is good also as a structure which is an electrode body exposed from the end surface.

  In order to achieve the object, in the capacitor, the insulation interval may be set to 3 to 15 [mm].

  In order to achieve the above-described object, the capacitor manufacturing method of the present invention is arranged such that a part of the electrode body is drawn out with a predetermined overhanging width on the element end face of the capacitor element and bent on the element end face. A step of forming a plurality of electrode overhang portions in which an insulation interval set between them is set larger than the overhang width of the electrode body, and a current collector plate connected to an external terminal member is connected to the electrode overhang portions by welding Process.

  According to the capacitor of the present invention or the manufacturing method thereof, any one of the following effects can be obtained.

  (1) A space necessary for insulation can be ensured in the electrode overhanging portion between the different electrodes that are bent and overlapped with a predetermined width from the element end face of the capacitor element.

  (2) It is possible to stabilize the connection between the current collector plate that is overlapped and connected to the electrode overhanging portion and the electrode overhanging portion, and to reduce the resistance of the capacitor element and the capacitor.

  (3) Space for connection can be reduced, and connection can be strengthened and connection reliability can be improved.

  (4) Since the current collector plate is interposed between the electrode extension drawn from the electrode body of the capacitor element and the terminal member on the sealing member side, the connection structure is simplified and the connection structure is robust. Can be achieved.

  (5) Since the current collector plate is interposed by the above structure, the connection between the external terminals on the capacitor element side and the sealing side can be facilitated, the connection process is simplified, and the connection process can be performed in a short time. The manufacturing cost can be reduced.

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 a disassembled perspective view which shows each member of an electric double layer capacitor. 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 an example of an anode body and a cathode body. It is a figure which shows an example of an anode body, a cathode body, and a separator. It is a perspective view which shows an example of a capacitor | condenser element. It is a figure which shows an example before and behind shaping | molding of the anode part of a capacitor | condenser element, and a cathode part. It is a figure which shows an example of the formation process of the anode part of a capacitor | condenser element, and a cathode part. It is a figure which shows an example of an anode current collecting plate and a cathode current collecting plate. It is a figure which shows an example of the laser welding with a collector plate and the electrode part of a capacitor | condenser element. It is a figure which shows an example of a connection with the current collection board on a capacitor | condenser element, and the external terminal of a sealing side.

[First Embodiment]

  In the first embodiment, electrode overhang portions having different polarities are formed on the element end surface of the capacitor element, and each electrode overhang portion is bent with a predetermined width as a crease and overlapped on the element end surfaces. An electric double layer capacitor (hereinafter simply referred to as a “capacitor”) in which a sufficient interval for obtaining sufficient insulation is maintained is disclosed.

  Refer to FIGS. 1 and 2 for this capacitor. FIG. 1 shows a longitudinal section showing an example of an electric double layer capacitor, and FIG. 2 shows an example of each member of the electric double layer capacitor.

  This capacitor 2 is an electric double layer capacitor, and is an example of the capacitor of the present invention and a method for manufacturing the same. In the capacitor 2 shown in FIG. 1, 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. 5) drawn from the element end face 5 of the capacitor element 4. . The anode portion 6 is drawn from the anode body 60 to the element end face 5 of the capacitor element 4, and the cathode portion 8 is similarly drawn from the cathode body 80 to the element end face 5 and has a predetermined width from the element end face 5 of the capacitor element 4. The fold line 46 (FIGS. 4, 5, and 6) is used to be folded and overlapped on 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. For these connections, for example, laser welding or electron beam welding is used, and the anode portion 6 and the anode terminal 10, and the cathode portion 8 and the cathode terminal 14 are connected by a welding connection portion 18. 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. An insulation interval 23 is set between the anode current collector plate 12 and the cathode current collector plate 16 corresponding to the insulation interval 21 formed between the anode portion 6 and the cathode portion 8.

  In this embodiment, the capacitor element 4 is a cylindrical body, and an anode body 60 is formed by projecting an anode body 60 on one of the element end faces 5, and a cathode body 80 (FIG. 6) is projected. Thus, the cathode portion 8 is formed. A holding tape 25 is wound around the capacitor element 4 to prevent the anode body 60 and the cathode body 80 from unwinding. In this embodiment, an insulating means 19 is installed on the outer periphery 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. The insulating means 19 insulates the capacitor element 2 from the outer case 20. For the insulating means 19, for example, an insulating material such as insulating paper or insulating tape may be used.

  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 an example of a sealing body that closes the opening of the outer case 20 and maintains the airtightness of the space 24, and is a fixing member that fixes the anode terminal 10 and the cathode terminal 14. A support member 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 (FIG. 2) of the exterior case 20 and is positioned at a caulking step 32 formed in the middle part on the opening 30 side. 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. As shown in FIG. 2, 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.

  The features and advantages of the capacitor 2 are listed below.

  (1) The electrode overhanging portion that is uniformly bent and overlapped with respect to the crease line 46 formed with a predetermined width from the element end surface 5 of the capacitor element 4 is flattened on the element end surface 5, and this electrode overhanging portion The connection of the anode current collector plate 12 and the cathode current collector plate 16 that are connected in a stacked manner to the anode portion 6 and the cathode portion 8 is stabilized, and the resistance of the capacitor element and the capacitor is reduced.

  (2) On the element end face 5 of the capacitor element 4, an insulation interval 21 is set between the anode part 6 and the cathode part 8, and an anode current collector plate 12 connected to the anode part 6 by welding, and a cathode An insulation interval 23 is also set between the cathode current collector plate 16 connected to the portion 8 by welding. The anode portion 6 is formed by bending a plurality of anode bodies 60, and the cathode portion 8 is also formed by bending a plurality of cathode bodies 80, whereas the anode current collector plate 12 and the cathode current collector plate 16 are metal plates. These are connected to the anode body 60 or the cathode body 80 by welding, and the insulation interval between the anode portion 6 and the cathode portion 8 is maintained by holding the insulation interval 23 by the anode current collector plate 12 and the cathode current collector plate 16. 21 can be maintained firmly.

  (3) Since the anode portion 6 and the cathode portion 8 are flattened on the element end face 5 of the capacitor element 4 and the anode terminal 10 and the cathode terminal 14 are connected via the anode current collector plate 12 and the cathode current collector plate 16. The space for these connections can be narrowed, the proportion of the space occupied in the electric double layer capacitor 2 can be reduced, and the connection can be strengthened and the connection reliability can be improved.

  (4) Since the connection structure includes the anode part 6 and the cathode part 8 of the capacitor element 4 and the anode current collector plate 12 and the cathode current collector plate 16, the connection structure is simplified and the connection structure is strengthened. Can do.

  (5) With the above structure, the anode current collector plate 12 and the cathode current collector plate 16 can be interposed to facilitate the connection of the anode terminal 10 and the cathode terminal 14 on the sealing plate 22, simplifying the connection process, and connection processing Can be performed in a short time, and the manufacturing cost can be reduced.

[Second Embodiment]

  The second embodiment discloses a method for manufacturing the capacitor 2 described above.

  The manufacturing process of the capacitor 2 will be described with reference to FIGS. 3, 4, 5, 6, 7, 8, 9, 10, and 11. 3 is an example of a manufacturing process of an electric double layer capacitor, FIG. 4 is an example of a process of forming an electrode body and an electrode part, FIG. 5 is an example of the size and arrangement of electrodes and separators of a capacitor element, and FIG. An example, FIG. 7 is an example before and after forming an electrode part, FIG. 8 is an example before and after forming an electrode part, FIG. 9 is an example of a current collector plate, FIG. 10 is an example of welding of a current collector plate, FIG. 11 shows an example of a connection process between the current collector plate and the external terminals.

  The manufacturing process of the capacitor 2 is an example of the manufacturing method of the capacitor of the present invention. As shown in FIG. 3, the manufacturing process includes an electrode body forming process (step S1) and a crease forming process (step S2). ), Electrode part formation process (step S3), winding process (step S4), electrode part formation process (step S5), connection process (step S6), electrolyte solution impregnation and encapsulation process (step S7). .

  (1) Electrode body formation process (step S1)

  In this electrode body forming step, an anode-side or cathode-side electrode body is formed. In this electrode body forming step, as shown in FIG. Uncoated portions 44 (anode portion 6 and cathode portion 8) are formed.

  For the anode body 60 and the cathode body 80, for example, an aluminum foil is used for the base material 40. The base material 40 is a strip having the same width, and the polarizable electrode 42 including an active material such as activated carbon and a binder is formed on both surfaces of the base material 40. When the polarizable electrode 42 is formed, the base material 40 is formed with an uncoated portion 44 (FIG. 6) having a different width L in accordance with the radius of curvature on one edge side. Is a non-formation part of the polarizable electrode. The uncoated portion 44 is the electrode extension portion described above, and the anode portion 6 or the cathode portion 8 described above is formed with a predetermined width on the edge side of the uncoated portion 44.

  (2) Crease formation process (step S2)

  In this crease forming step, a crease line 46 having a constant width is formed from the edge portion of the above-mentioned uncoated portion 44 as shown in FIG. The crease line 46 is not a flaw but a marking line, and can prevent buckling of the anode portion 6 and the cathode portion 8 during bending. The crease line 46 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 46. The crease line 46 may be one as shown in B of FIG. 4, or may be plural according to the width of the unfinished part 44. The formation surface portion of the crease line 46 may be one surface of the uncoated portion 44, or may be both surfaces. The crease line 46 as an example is formed so that the surface of the element end surface 5 facing the winding center portion 52 is valley-folded.

  (3) Electrode part formation process (step S3)

  In this electrode portion forming step, a plurality of anode portions 6 having different widths are formed on the anode body 60 as shown in FIG. 4C, and the cathode body 80 has a width as shown in FIG. A plurality of different cathode portions 8 are formed. The anode portions 6 are formed at different intervals so as to be drawn out from the element end face of the capacitor element 4 every half circumference. Further, each cathode portion 8 is also drawn out to the element end face of the capacitor element 4 every half circumference, and the above-described insulation interval 27 is set between the anode portion 6 and the cathode portion 8. The fold lines 46 (FIG. 6) described above are formed in each anode portion 6 and each cathode portion 8.

Referring to FIG. 5 for the anode body 60, the cathode body 80, and the separators 48 and 50, the width W _{1 of the} anode body 60 and the cathode body 80, the width of the separators 48 and 50 is W ₂ , and the width of the polarizable electrode 42 is W. ₃ , the width of the uncoated portion 44 described above is W ₄ , and the anode bodies 60 and 80 exposed from the separators 48 and 50, that is, the width of the anode portion 6 and the cathode portion 8 is W ₅ , and the separator 48 having a width W ₄ Assuming that 50 is the width of the overlapping portion W ₇ , W _{6 is} the formation width of the element end surface opposite to the element end surface 5, and W ₈ is the folding width of the anode portion 6 and the cathode portion 8, the magnitude relationship as an example is
W ₁ > W ₂ > W ₃ > W ₄ > W ₅ > W ₈
It is. Further, W ₆ = W ₇ . Fold line 46 for bending a width W ₈ folded inward is formed in the width W _5.

If these widths W ₁ , W ₂ , W ₃ , W ₄ , W ₅ , W ₆ , W ₇ , W ₈ are exemplified, W ₁ = 100 [mm], W ₂ = 99 [mm], W ₃ = 89 [mm], W ₄ = 11 [mm], W ₅ = 6 [mm], W ₆ = W ₇ = W ₈ = 5 [mm].

With this arrangement, the element end surface 5 of the capacitor element 4 is formed by the edges of the separators 48 and 50 exposed from the capacitor element 4. The dimension from the element end face 5 to the crease line formed with a certain width is preferably 0.5 [mm] to 3 [mm], and the anode portion 6 and the cathode portion 8 from the element end face 5 The overhang length dimension (W ₅ ) is preferably 3 [mm] to 10 [mm].

  (4) Winding process (step S4)

  In this winding step, by using a winding shaft (not shown), the anode body 60 and the cathode body 80 are wound with separators 48 and 50 interposed therebetween as shown in FIG. The capacitor element 4 is formed. One end face 5 of the capacitor element 4 is covered with the edges of the separators 48 and 50, and as described above, the anode portion 6 and the cathode portion 8 are formed every half circumference.

  (5) Electrode part forming process (step S5)

  In the step of forming the electrode portion, as shown in FIG. 7A, the anode portion 6 or the cathode portion 8 is connected to the element end surface 5 of the capacitor element 4 before the connection with the anode current collector plate 12 or the cathode current collector plate 16. As shown in FIG. 7B, the capacitor element 4 is molded into a close contact state on the element end surface 5.

As shown in FIG. 7A, an anode portion 6 and a cathode portion 8 constituting an electrode extension portion are erected on the element end surface 5 of the capacitor element 4, and between the anode portion 6 and the cathode portion 8. The insulation interval 27 for forming the insulation interval 21 having the predetermined width is set. When the width of the insulating interval 27 is Wa and the width of the insulating interval 21 is Wb, Wa> Wb is set so that the insulating interval 21 is secured even by bending the anode portion 6 and the cathode portion 8 described later. Wa is set larger than the overhang width of the electrode body, that is, the anode part 6 or the cathode part 8 before bending. Further, the magnitude relation of the folding width W ₈ of the anode 6 and the cathode portion 8 the width of the foregoing and Wa of the insulating gap 27 is Wa> W _8.

The insulation interval 27 is centered on the Y axis, 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 with the X axis as the center. A plurality of cuts 54 are made in a radial direction around the winding center portion (core portion) 52 of the capacitor element 4 at an angle θ ₁ , and a plurality of partition portions 6A, 6B, 6C partitioned by the respective cuts 54 are anode portions. 6 side is formed. Similarly, a plurality of partition portions 8A, 8B, and 8C are also formed on the plurality of cathode portions 8 side. For example, if the angle θ ₁ is set to 33 °, the partition portions 6A and 8A have 2θ ₁ = 66 °, 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 (5) is set to θ ₂ = 57 [°].

The depth of the cut 54 is set, for example, to the height h ₁ of the anode portion 6 and the cathode portion 8 with the overhang length. The magnitude relationship between the height h ₁ and the width Wa of the above-described insulation interval 27 is Wa> h ₁ . The partition portions 6A, 6B, and 6C of the anode portion 6 set at the height h ₁ and the partition portions 8A, 8B, and 8C of the cathode portion 8 are bent in the middle, and the winding center portion 52 of the capacitor element 4 is bent. By pressing down in the direction and compression molding, the partition parts 6A, 6B, 6C and the partition part 8A, 8B, 8C of the cathode part 8 are formed as shown in FIG. In this embodiment, the partition sections 6B and 6C and the partition sections 8B and 8C are set as weld portions. 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 and the partition part 8A of the cathode part 8 The heights 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 element 4 are suppressed in height by compressing and molding the anode part 6 and the cathode part 8 as a whole toward the center direction of the capacitor element 4 in this way. . In this embodiment, the partition portions 6B and 6C of the anode portion 6 are compression-formed to form a stable flat connecting surface (that is, a welding surface), and then the partition portion 6A that is a non-connecting surface is compression-molded. And the height dimension of the boundary part produced by the overlap between division part 6A-6B and division part 6A-6C is suppressed.

  In the forming process of each anode part 6 and each cathode part 8, after winding the capacitor element 4, the anode part 6 and the cathode part 8 exposed on the element end face 5 are formed by a crease line 46 as shown in FIG. The winding center portion 52 is bent in the opposite direction. Therefore, as shown in FIG. 8B, in order to connect the anode current collector plate 12 and the cathode current collector plate 16, the partition portions 6B and 6C described above are used by using the crease line 46 on the winding center 52 side. 8B and 8C are bent.

  Then, after the partition portions 6B, 6C, 8B, and 8C are bent, the partition portion 6A and the partition portion 8A are bent on the element end surface 5 using a crease line 46, as shown in FIG.

  (6) Connection process (step S6)

  In this connection step, each of the anode current collector plate 12 and the cathode current collector plate 16 connected to the anode current collector 12 and the cathode 8 is formed on the element end surface 5 of the capacitor element 4, and the anode current collector 12 and the cathode current collector. Connection of external terminals to the plate 16 is included.

  As shown in FIG. 9, the anode current collector plate 12 connected to the anode part 6 and the cathode current collector plate 16 connected to the cathode part 8 are formed of the same electrode material as, for example, an aluminum plate, as described above. Covering the partition portions 6A, 6B, and 6C (B of FIG. 7) of the anode portion 6, having a laser welding area with the partition portions 6B and 6C, and having a shape and an area with a laser welding area with the anode terminal 10. Yes. In this embodiment, the size is one-half of the element end face 5 of the capacitor element 4, and the shape in which the insulation interval 23 is secured is a substantially semicircular plate.

In the anode current collector plate 12 (or the cathode current collector plate 16), as shown in FIG. 9A, an arcuate cutout portion 58 is formed at the chord side center portion corresponding to the winding center portion 52 of the capacitor element 4. On the arc side, there is formed a connection surface portion 63 that is cut off linearly in the direction orthogonal to the X axis with the X axis as the center. Further, as shown in FIG. 9B, the anode current collector plate 12 (or the cathode current collector plate 16) has an arc-shaped cutout 58, that is, an angle θ ₁ left and right about the X axis. Arc-shaped terminal connecting portions 12A (16A) and element connecting portions 12B and 12C (16B and 16C) are formed by stepped portions 62 bent at right angles. Each of the terminal connection portions 12A (16A) and the element connection portions 12B and 12C (16B, 16C) are formed on a flat surface and constitute parallel surfaces with the stepped portion 62 interposed therebetween.

In the anode current collecting plate 12 and the cathode current collecting plate 16, the height of the terminal connecting portions 12A and 16A is h ₄ , the thickness of the anode current collecting plate 12 and the cathode current collecting plate 16 is t, and the inside of the terminal connecting portion 12A. and of the height and h _5,
h ₅ = h ₄ −t ≧ h ₂ −h ₃ (1)
Is set to Therefore, the inner height h ₅ of the terminal connecting portion 12A is the difference Δh (≧ h) 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. ₂₋ h ₃ ) is absorbed, the element connection portions 12B and 12C of the anode current collector plate 12 are in close contact with the respective partition portions 6B and 6C, and the partition portion 6A is housed in the lower surface portion of the terminal connection portion 12A. The thickness t of the anode current collecting plate 12 can be changed at the element connecting portions 12B and 12C and the element connecting portion 12A of the anode current collecting plate 12. For example, the thickness of the element connection portion 12A can be set thicker (1.2 times or more) than the element connection portions 12B and 12C. According to this, the element connection portion 12B, The heat generated in 12C is absorbed by the element connecting portion 12A having a predetermined thickness, and the connection accuracy of laser welding is improved. This configuration and the relationship with other members are the same for the cathode current collector plate 16.

  Next, as shown in FIG. 10, the anode current collector plate 12 and the cathode current collector plate 16 are centered on the winding center portion 52 at one end face of the capacitor element 4, and the arc-shaped notch portion 58 is formed in the winding center portion 52. And an insulation interval 23 is set corresponding to the insulation interval 21 between the anode portion 6 and the cathode portion 8. The anode current collecting plate 12 includes a partition 6A of the anode 6 of the capacitor element 4 on the lower surface side of the terminal connecting portion 12A, and an anode portion of the capacitor element 4 on the lower surfaces of the element connecting portions 12B and 12C of the anode current collecting 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 68, the partition portions 6B and 6C and the element connection portions 12B and 12C are partially or entirely melted and connected by laser irradiation from the peripheral direction of the capacitor element 4 toward the core direction. Yes. Such connection is the same on the cathode current collector plate 16 side. The width of the insulation interval 21 between the anode portion 6 and the cathode portion 8 is Wb, the width of the insulation interval 23 between the anode current collector plate 12 and the cathode current collector plate 16 is Wc, and at least the winding center. The magnitude relationship in the vicinity of the portion 52 is Wb> Wc. Thus, by reducing the width Wc of the insulation interval 23 between the anode current collector plate 12 and the cathode current collector plate 16, each partition portion of the anode portion 6 and the cathode portion 8 compression-molded on the element end face ( In particular, the vicinity of the winding center 52 of each partition portion is covered with each current collector plate, so that the anode portion 6 and the cathode portion 8 are reliably welded to each current collector plate by laser irradiation.

  In this embodiment, as shown in FIG. 10, the laser irradiation sites are set at two locations of the element connecting portions 12B and 12C separated by the step portions 62 of the anode current collector plate 12 and the cathode current collector plate 16, respectively. The anode current collector plate 12 or the cathode current collector plate 16 is welded to the anode portion 6 or the cathode portion 8 of the capacitor element 4 by a plurality of laser irradiation connection portions 68. In this case, laser irradiation is performed as indicated by arrows [I], [II], [III] and [IV] attached to the laser irradiation connection portion 68. 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.

  [I] This laser irradiation is applied from the outer peripheral side of the capacitor element 4 to the element connecting portion 12B of one anode current collecting plate 12 in a straight line toward the element center direction.

  [II] Next, the device connection portion 16B of the other cathode current collector plate 16 opposed across the winding center portion 52 is irradiated with laser on a straight line from the device center side toward the device outer peripheral direction. It is welded by the operation.

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

  [IV] In a series of operations of irradiating the laser beam linearly from the element center side toward the element outer peripheral side to the element connecting part 16C of the other cathode current collector plate 16 opposed across the winding center part 52. Welded.

  In this way, the anode 6 and the anode current collector 12, and the cathode 8 and the cathode current collector 16 are connected by a series of operations in which laser irradiation is performed linearly across the winding center 52. 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 68) directed in the diameter direction of the capacitor element 4 with the winding center part 52 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 [I] and [II] of laser irradiation is repeated twice. Alternatively, it is possible to further reduce the connection resistance by repeating the series of operations [I] to [IV] of laser irradiation twice and arranging a weld in the vicinity. Although it is possible to connect by a series of operations [I] and [II] of laser irradiation, the element connection portions 12B and 12C of the anode current collector plate 12 and the cathode current collector plate 16 are respectively connected to the element center side. It can also be connected individually, such as by irradiating a straight line toward the element outer peripheral side.

  In addition, regarding the continuous operation of laser irradiation [I] to [IV], laser welding is performed from [I] to [IV] instead of continuously irradiating the same portion with laser, and then from [I] again. When laser irradiation is performed on [IV], 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 [I] to [IV], and laser welding is performed again from [I] to [IV]. Therefore, laser irradiation can be performed continuously while taking a cooling interval, and the welding time by laser irradiation can be shortened.

As shown in FIG. 7, the anode portion 6 and the cathode portion 8 are led out from the element end face 5 of the capacitor element 4 with a predetermined insulation interval 27 (width Wa: A in FIG. 7). The anode portion 6 and the cathode portion 8 have an insulating interval 21 (width Wb: B in FIG. 7) that does not contact the anode portion 6 and the cathode portion 8 when compression-molded toward the center direction. Therefore, the anode portion 6 and the cathode portion 8 are not formed in the vicinity of the winding center portion 52 of the capacitor element 4 (within 2 mm from the winding center portion). 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 27 (A in FIG. 7). That is, with respect to the width Wa of the insulating interval 27, the lead-out height h ₁ of the anode part 6 and the cathode part 8 from the element end face 5 of the capacitor element 4 is set as Wa> h _1. Even if the portion 8 is bent and formed on the element end face 5, the anode portion 6 and the cathode portion 8 do not come into contact with each other.

  Further, at the outermost periphery of the capacitor element 4, the anode part 6 and the anode part 6 are arranged so that the anode part 6 and the cathode part 8 do not come into contact with the outer case 20 even if the anode part 6 and the cathode part 8 are displaced during compression molding. Insulating means 19 (FIG. 1) such as insulating paper or insulating tape may be installed on the outer peripheral surfaces of the current collector plate 12 and the cathode portion 8 and the cathode current collector plate 16. If the insulating means 19 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 The insulation with 20 can be strengthened.

  Next, as shown in FIG. 11, the anode terminal 10 and the cathode terminal 14 on the sealing plate 22 are positioned on the capacitor element 4 to which the anode current collector plate 12 and the cathode current collector plate 16 are connected. A terminal-side connection surface 70 is formed on the anode terminal 10 and the cathode terminal 14, and the terminal-side connection surface 70 is a side wall surface that forms the same surface as the connection surface portion 63 on the anode current collector plate 12 and the cathode current collector plate 16. It is. Therefore, if the connection surface portion 63 and the terminal side connection surface 70 are matched and laser irradiation 72 is performed, the above-described weld connection portion 18 (FIG. 1) is laser welded, and the connection surface portion 63 and the terminal side connection surface 70 are connected. Can be welded.

  Here, if the distance (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. The distance (distance) from the sealing plate 22 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 63 and the terminal side connection surface 70 are matched. The welding is simplified and strengthened by using the common surface portion and welding by laser irradiation that can be locally welded to this portion. 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 63 and the terminal side connection surface 70) 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 63 and the terminal side connection surface 70 are installed in the vicinity of 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, each external terminal and the current collector plate can be stabilized, and the electrical characteristics can be enhanced, such as lowering the resistance of the capacitor element and strengthening the connection. .

  Therefore, the anode terminal 10 which is an external terminal is connected to the anode portion 6 of the capacitor element 4 via the anode current collector plate 12 via the weld connection portion 18, and the cathode current collector plate is connected to the cathode portion 8 of the capacitor element 4. The cathode terminal 14 that is an external terminal is connected via a laser irradiation connection portion 18 that is a laser welding portion, and the external terminal is connected to the capacitor element 4.

  Further, as the distance (distance) between the capacitor element 4 and the sealing plate 22 is increased, the resistance increases as the length increases, and the height dimension of the capacitor 2 increases. For this reason, the distance (distance) between the capacitor element 4 and the sealing plate 22 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, the terminal-side connection surface 70 and the connection surface portion 63 are connected as described above. Since welding is performed on the same surface with a laser that can be locally welded to this part, welding is simplified and strengthened. 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 are dimensions that allow laser welding and do not increase the internal resistance, and the height dimensions of the capacitor 2 In this embodiment, the distance is set in the range of 0.5 mm to 5 mm. According to this, the laser welding is possible and the internal resistance is hardly increased. The height dimension of the electric double layer capacitor 2 can be shortened.

  Further, the terminal-side connection surface 70 and the connection surface 63 are installed in the vicinity of the outer peripheral surface of the capacitor element 4, thereby causing excessive stress on other members (the anode portion 6 and the cathode portion 8) during laser irradiation. Is prevented from being added. Specifically, it may be set within 10 mm from the outer peripheral surface of the capacitor element 4.

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, each external terminal and the current collector plate can be stabilized, and the electrical characteristics can be enhanced, such as lowering the resistance of the capacitor element and strengthening the connection. .

  (7) Electrolyte impregnation and encapsulation process (Step S7)

  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 to complete the electric double layer capacitor 2 (FIG. 1) as a product. .

  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.

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

  (1) The anode body 60 and the cathode body 80 are projected over the element end face 5 by a predetermined width, and are bent to form the anode section 6 and the cathode section 8, but the insulating interval set on the element end face 5 Even if it is bent and approached 27, since the insulation space | interval 21 is formed in the width | variety which can be set, the insulation between different poles can be ensured. Moreover, since the setting of the insulation interval 27, the insulation interval 21 formed after bending, and the overhang width necessary for welding are taken into account, along with the parallelization by welding of the anode body 60 or the cathode body 80 of the capacitor element 4, Insulation intervals 21 and 27 are set, and the resistance of the capacitor element 4 is reduced, and the electric double layer capacitor 2 having good insulation characteristics can be obtained, and the reliability of the product can be improved. Moreover, if the insulation interval 27 is set to 3 to 15 [mm], it is possible to realize a highly insulating capacitor element 4 as well as a low resistance by paralleling the electrode bodies of the capacitor element 4.

  (2) On one end face side of the capacitor element 4, the anode portion 6 is formed by the base material of the anode body 60, the cathode portion 8 is formed by 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.

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

  (4) The capacitor element 4 is firmly supported by the sealing plate 22 which is an exterior member. That is, the capacitor element 4 is firmly fixed to the anode terminal 10 and the cathode terminal 14 by laser welding of the anode portion 6 and the cathode portion 8 of the capacitor element 4 via the anode current collector plate 12 and the cathode current collector plate 16. 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.

  (5) 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.

  (6) 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.

  (7) 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 made the same surface, the laser irradiation with respect to both can be stabilized, and the complete connection and Reliability can be increased.

  (8) Since a shielding gas is used during laser irradiation, the capacitor element 4 can be protected from laser heat and flying spatter, and the characteristics of the capacitor element 4 and the product capacitor 2 can be prevented from being deteriorated, thereby improving reliability. it can.

  (9) The more the overhang from the electrode foil, the lower the internal resistance.Therefore, when the overhang is increased, multiple overhangs will occur when winding and stacking, and it is difficult to bend with high accuracy. In addition, in the winding element, when a continuous overhanging portion is provided on the circumference, wrinkles are likely to occur when bent, and it becomes difficult to connect to the current collector plate. In addition, by bending the overhanging portion with high accuracy, the connection with the current collector plate can be stabilized and a low-resistance capacitor can be provided. That is, by forming a crease in the electrode overhanging portion, it is possible to bend the electrode overhanging portion with high accuracy, and there is no rattling during connection with the current collector plate, and a stable connection can be realized.

  (10) By separating the crease position from the end face of the element by a predetermined dimension, laser heat and spatter to the element side do not fly during laser welding with the current collector plate, and the influence on the element can be reduced.

  (11) By forming a crease in the projecting portion in advance before forming the capacitor element, the crease can be easily formed.

  (12) A crease is formed in the electrode foil (uncoated part), and then the end of the electrode foil is cut out to form an overhanging portion, so that the effect that the position of the fold is not shifted in the overhanging portion can also be obtained. .

[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 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.

  (3) In the above embodiment, the anode current collector plate 12 and the cathode current collector plate 16 are exemplified as the current collector plates, but the present invention is not limited to the above embodiment. Also, the welded connection portion 18 (side wall surface forming the same surface as each connection surface portion 63 and the terminal side connection surface 70) by laser irradiation 72 of the anode portion 6, the cathode portion 8, the anode current collector plate 12, and the cathode current collector plate 16 is The flat surface may be a curved surface as the shape matching the shape of the external terminal.

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

  (5) Although the anode 6 and the cathode 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, Only 6C, 8B, and 8C are formed so as to protrude, and the anode portion 6A and the cathode portion 8A do not need to protrude.

  (6) Although the anode terminal 10 is used as the anode external terminal member and the cathode terminal 14 is illustrated as the cathode external terminal member in the above embodiment, the present invention is not limited to the above embodiment. The external terminal member may be an external terminal to which a connection plate made of thin plate aluminum or the like is separately connected. In this case, the anode connecting plate 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 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. In such a configuration using the anode connection plate and the cathode connection plate, the anode terminal 10 and the cathode terminal 14 which are external terminals are connected to the anode current collector plate 12 and the cathode current collector plate 16 connected to the capacitor element 4 side. Is performed over a wide range, the connection resistance can be reduced, and the connection strength can be increased.

  (7) In the above-described embodiment, the section 12B, 12C or 16B, which is an element connection region between the anode section 6 and the cathode section 10, and 16C, terminal connection, according to the section divided into three as different positions of the current collector plate Although the partition part 12A or 16A 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, it is not limited to this. The element connection region (laser irradiation connection portion 68) may be set in a part of the current collector plate, and the terminal connection region (weld connection portion 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 welding connection portion 18 may be set at a site where the welding position does not overlap between the laser irradiation connection portion 68 and the front and back surfaces of the current collector plate in the partition portion 12B which is an element connection region.

(8) In the above embodiment, W ₁ > W ₂ is exemplified. However, for example, W ₁ = W ₂ may be used, and the above numerical values and magnitude relations can be arbitrarily set, and are limited to the above embodiment. Not.

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.

The capacitor and the manufacturing method thereof according to the present invention contribute to simplification of the terminal connection structure and the connection process, and are advantageous in that excellent capacitor characteristics such as improvement of the insulation of the electrode portion can be realized.

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 12A Terminal connection portion 12B, 12C Element connection portion 14 Cathode terminal 16 Cathode current collector plate 16A Terminal connection portion 16B, 16C Element connection portion 18 Weld connection portion 20 Exterior case 22 Sealing plate 24 Space portion 25 Holding tape 26 Base portion 21, 23, 27 Insulation interval 28 Sealing portion 32 Caulking step portion 34 Open end portion 36 Through hole 38 Pressure Opening mechanism 44 Uncoated part

Claims (5)

A capacitor element;
A part of the electrode body is drawn out to the element end face of the capacitor element with a predetermined overhanging width and bent on the element end face, and an insulation interval set between different polarities is the overhang width of the electrode body A plurality of electrode overhangs set larger,
A current collector connected to the electrode extension and connected to an external terminal member;
A capacitor comprising:   2. The capacitor according to claim 1, wherein an insulation interval set between different poles of the current collector plate is smaller than the insulation interval set between different poles of the electrode extension portion.   When the capacitor element is a wound element, the electrode overhanging portion is an electrode body that is exposed from the element end face of the capacitor element with a width narrower than the arc length of the half circumference for each half circumference. The capacitor according to claim 1.   The capacitor according to any one of claims 1 to 3, wherein the insulation interval of the capacitor element is 3 to 15 [mm]. A part of the electrode body is drawn out to the element end face of the capacitor element with a predetermined overhanging width and bent on the element end face, and the insulation interval set between the different polarities is larger than the overhang width of the electrode body. Forming a plurality of large electrode overhang portions,
Connecting a current collector plate connected to the external terminal member to the electrode overhanging portion by welding;
A method for producing a capacitor, comprising:

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