JP2012104623A - Capacitor and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve reduced capacitor resistance, stable connection, and enhanced connection.SOLUTION: A capacitor comprises: an electrode overhanging part formed by overhanging an electrode body of a capacitor element (4) to an element end surface (5) of the capacitor element; an external terminal installed in a sealing plate of an exterior case which seals the capacitor element; and a collecting plate which is installed between the electrode overhanging part and the external terminal and in which a first connection region and a second connection region are set in different locations, the electrode overhanging part is connected to the first connection region, and the external terminal is connected to the second connection region.

Description

The present invention relates to a connection structure between a capacitor element and an external terminal. For example, the present invention relates to a capacitor such as an electrolytic capacitor or an electric double layer capacitor having a current collecting member in an electrode portion of the capacitor element, and a method for manufacturing the capacitor.

  In an electric double layer capacitor or an electrolytic capacitor, it is necessary to electrically connect the element and an 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).

Japanese Patent Laid-Open No. 11-21857 JP 2001-068379 A JP 2007-335156 A JP 2010-093178 A

  By the way, in the configuration in which the current collector is provided on each end face of the wound element, when external terminals on the anode side and the cathode side are installed adjacent to the exterior member that encloses the wound element, It is necessary to secure a connection distance between the electric body. Further, in the wound type element, the distribution of the internal resistance is different between the inner part and the outer part. Therefore, countermeasures are required, and attention must be paid to the connection between the element and the current collector. In addition, the structure using the current collector can reduce the internal resistance of the element, but depending on the stress applied during the manufacturing process to the current collector interposed between the external terminal and the element, the reliability of the connection is reduced and the connection resistance is large. There is a case.

  In a structure in which a current collector is connected to the device side and an external terminal is connected to this current collector, the matching state between the external terminal and the current collector affects the connectivity and connection strength, which affects the characteristics and reliability of the capacitor. Influence.

  Regarding such demands and problems, Patent Documents 1 to 4 do not disclose or suggest them, and do not disclose or suggest a configuration for solving them.

In view of the above problems, an object of the present invention is to reduce the resistance of a capacitor, stabilize the connection, and strengthen the connection strength.

  In order to achieve the above object, the capacitor of the present invention includes an electrode projecting portion formed by projecting an electrode body of the capacitor element on an element end surface of the capacitor element, and a sealing plate of an outer case enclosing the capacitor element. A first connection region and a second connection region are set at different positions by being installed between the installed external terminal, the electrode overhanging portion, and the external terminal, and the electrode overhang is formed in the first connection region. And a current collector plate to which the external terminal member is connected to the second connection region.

  In order to achieve the above object, in the capacitor, the first connection region of the current collector plate is set to at least two places across the second connection region, and the first connection region includes the first connection region. The electrode overhanging portion of the capacitor element may be connected.

  In order to achieve the above object, a method of manufacturing a capacitor according to the present invention includes a step of projecting an electrode body of the capacitor element on an element end face of the capacitor element to form an electrode projecting portion, an external terminal member, and the electrode projecting The first connection region and the second connection region are set at different positions on the current collector plate installed between the first connection region, the electrode extension portion is connected to the first connection region, and the second connection Connecting the external terminal member to the region.

In order to achieve the above object, in the method of manufacturing a capacitor, the first connection region of the current collector plate is set to at least two places sandwiching the second connection region, and the first connection region You may connect the said electrode overhang | projection part of the said capacitor | condenser element to each.

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

  (1) Since the anode part and the cathode part drawn out on the same end face of the wound capacitor element and the anode terminal member and the cathode terminal member in the exterior member are individually provided with a current collector plate and connected, the capacitor element The resistance can be reduced.

  (2) The first connection region and the second connection region are set at different positions on the current collector plate, the electrode projecting portion of the capacitor element is connected to the first connection region, and the external terminal is connected to the second connection region. Since they are connected, it is possible to stabilize the connection between the capacitor element and the current collector plate, the electrode extension portion and the current collector plate, and it is possible to reduce the resistance of the capacitor element and strengthen the connection.

  (3) With the above structure, it is possible to simplify and stabilize the connection between the anode terminal member and the anode part or the cathode terminal member and the cathode part through the current collector plate, and also to simplify the connection process. be able to.

  (4) If the first connection area is set on the current collector plate in at least two places across the second connection area on the external terminal connection side, the electrode overhanging portion of the capacitor element is connected to each of the first connection areas Therefore, the electrode extraction efficiency on the capacitor element side is increased, and the resistance of the capacitor element can be further reduced.

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

It is a top view which shows an example of the electric double layer capacitor which concerns on 1st Embodiment. It is the II-II sectional view taken on the line of the electric double layer capacitor of FIG. 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, a current collector plate installed between a capacitor element and an external terminal on the sealing side is provided with a first connection region and a second connection region at different positions. An electric double layer capacitor is disclosed in which the electrode overhanging portion of the capacitor element is connected to the connection region and the external terminal is connected to the second connection region.

  With respect to this electric double layer capacitor, reference is made to FIG. 1, FIG. 2 and FIG. FIG. 1 is a plan view of an electric double layer capacitor, FIG. 2 is a sectional view taken along the line II-II in FIG. 1, and FIG. 3 is an example of an exploded electric double layer capacitor.

  This electric double layer capacitor (hereinafter simply referred to as “capacitor”) 2 is an example of the capacitor of the present invention. In the capacitor 2 shown in FIGS. 1 and 2, an anode is formed on the same element end face 5 of the capacitor element 4. A part 6 and a cathode part 8 are formed. The element end face 5 is formed by the edges of the separators 48 and 50 (FIGS. 6 and 7) of the capacitor element 4. The anode portion 6 and the cathode portion 8 are an example of an electrode extension portion, and are configured by a part of an electrode body (anode body 60 or cathode body 80) drawn from the element end surface 5 of the capacitor element 4. The anode portion 6 and the cathode portion 8 are drawn from either one or both of the anode body 60 and the cathode body 80 to the element end face 5 of the capacitor element 4, and have a predetermined width from the element end face 5 of the capacitor element 4 with a crease line 46 (see FIG. 5, 6, and 7), the capacitor element 4 is folded and overlapped on the element end surface 5.

  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 the connection, for example, laser welding or electron beam welding is used, and the anode part 6 and the anode terminal 10 and the cathode part 8 and the cathode terminal 14 are connected by a laser welding connection part 18 (FIG. 2). The anode terminal 10 and the cathode terminal 14 are 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.

  The anode current collector plate 12 is semicircular, and is divided into, for example, three sections as a section of a predetermined angle θ (A in FIG. 10) with respect to the center of the arc, and the terminal connection section 12A and the element connection sections 12B and 12C are Is formed. That is, on the anode current collector plate 12, element connection portions 12B and 12C (FIG. 10) are set as the first connection region, and the terminal connection portion 12A (FIG. 10) is set as the second connection region. In this embodiment, the anode terminal 10 is connected to the upper surface side of the terminal connection portion 12A, and the partition portions 6B and 6C of the anode portion 6 are connected to the lower surfaces of the element connection portions 12B and 12C.

  Similarly to the anode current collector plate 12, the cathode current collector plate 16 is also semicircular. Similarly, the cathode current collector plate 16 is divided into, for example, three sections as a section having a predetermined angle θ (A in FIG. 10). Portions 16B and 16C (FIG. 10) are formed. Similarly, in the cathode current collector plate 16, element connection portions 16B and 16C are set as the first connection region, and the terminal connection portion 16A is set as the second connection region. The cathode terminal 14 is connected to the upper surface side of the terminal connection portion 16A, and the partition portions 8B and 8C of the cathode portion 8 are connected to the lower surfaces of the element connection portions 16B and 16C.

  In this embodiment, the capacitor element 4 is a cylindrical body, and an anode body 60 (FIG. 6) is drawn out from one element end face 5 to form an anode portion 6, and a cathode body 80 (FIG. 6) is provided. A cathode portion 8 is formed by being drawn out. 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 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. 3) 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) On the element end face 5 of the capacitor element 4, an anode portion 6 and a cathode portion 8 which are electrode overhang portions are formed. The anode portion 6 has an anode current collector plate 12, and the cathode portion 8 has a cathode current collector plate 16. Are connected by welding to reduce the resistance of the capacitor element 4 and the electric double layer capacitor 2.

  (2) The anode current collector plate 12 or the cathode current collector plate 16 has a terminal connection portion 12A or 16A (second connection region) and element connection portions 12B, 12C or 16B, 16C (first connection region). It is set at a different position, the anode part 6 or the cathode part 8 of the capacitor element 4 is connected to the element connection parts 12B, 12C or 16B, 16C, and the anode terminal 10 or the cathode terminal 14 is connected to the terminal connection part 12A or 16A. Yes. Since the anode part 6 or the cathode part 8 and the anode terminal 10 or the cathode terminal 14 are connected to different positions of the anode current collector plate 12 or the cathode current collector plate 16 on the anode side and the cathode side, respectively, the capacitor element and the current collector are collected. The connection with the electric plate can be stabilized, the resistance of the capacitor element can be lowered, and the connection can be strengthened.

  (3) The anode current collector plate 12 or the cathode current collector plate 16 is formed with element connection portions 12B, 12C or 16B, 16C across the terminal connection portion 12A or 16A, and two connection regions are arranged on the element side. Since it is set, the electrode extraction efficiency on the capacitor element 4 side is increased, and the resistance of the capacitor element 4 can be further reduced.

  (4) 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 collecting plate 12 and the cathode current collecting plate 16. The space 24 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.

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

  (6) With the above structure, the anode current collector plate 12 and the cathode current collector plate 16 can be interposed to facilitate the connection between 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]

  In the second embodiment, the first connection region and the second connection region are set at different positions on the current collector plate installed between the external terminal and the electrode extension, and the first connection region The method of manufacturing the electric double layer capacitor 2 includes connecting the electrode projecting portion to the second connection region and connecting the external terminal to the second connection region.

  This manufacturing process will be described with reference to FIGS. 4, 5, 6, 7, 8, 9, 10, 11, and 12. 4 is an example of the manufacturing process of the electric double layer capacitor, FIG. 5 is an example of the process of forming the electrode body and the electrode part, FIG. 6 is an example of the size and arrangement of the electrode and separator of the capacitor element, and FIG. An example, FIG. 8 is an example before and after forming the electrode part, FIG. 9 is an example before and after forming the electrode part, FIG. 10 is an example of the current collector plate, FIG. 11 is an example of welding the current collector plate, FIG. 12 shows an example of the 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. In the manufacturing process shown in FIG. 6, the capacitor element 4 forming step (step S11), the electrode portion forming step (step S12), 1st connection process (welding process of electrode part and current collector plate) (step S13), 2nd connection process (welding process of current collector plate and external terminal) (step S14), electrolyte solution impregnation and encapsulation process (step) S15) is included.

(1) Capacitor element 4 formation process (step S11)

  The formation process of the capacitor element 4 includes an electrode body formation process, a crease formation process, an electrode portion formation process, and a winding process. In the electrode body forming process, an electrode body on the anode side or the cathode side is formed, and in this electrode body forming process, 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 having a certain width on one edge side, and the uncoated portion 44 is a portion where the polarizable electrode 42 is not formed. is there. 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.

  In the crease formation step, a crease line 46 having a constant width is formed from the edge portion of the above-described 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 number of the crease lines 46 may be one as shown in FIG. 5B, 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.

  Next, in the electrode portion forming step, as shown in FIG. 5C, the anode body 60 is formed with a plurality of anode portions 6 having different widths, and as shown in FIG. A plurality of cathode portions 8 having different widths are formed. The anode portions 6 are formed at different intervals so as to be drawn out on 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 an insulating interval 27 for forming the above-described insulating interval 21 is set between the anode portion 6 and the cathode portion 8. Has been. The fold lines 46 described above are formed in each anode portion 6 and each cathode portion 8.

As for the anode body 60, the cathode body 80, and the separators 48 and 50, referring to FIG. 6, 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, width W ₄ of the uncoated portion 44 described above, the anode body 60, 80 that is, W ₅ the width of the anode 6 and cathode 8 are exposed from the separator 48, the uncoated width W ₄ Assuming that the width of the overlapping portion of the portion 44 and the separators 48 and 50 is W ₇ , the formation width of the element end surface opposite to the element end surface 5 is W ₆ , and the folding width of the anode portion 6 and the cathode portion 8 is W ₈ , The size relationship is
W ₁ > W ₂ > W ₃ > W ₄ > W ₅ > W ₈
And W ₆ = W ₇ is set. A crease line 46 for bending the folding width W ₈ 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 of the constant width W ₈ from the element end face 5 is preferably 0.5 [mm] or more, and the projecting length dimensions of the anode part 6 and the cathode part 8 from the element end face 5 are 3 [mm] to 10 [mm]. [Mm] is preferable.

  In the winding process, 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. A capacitor element 4 as an element 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.

  (2) Formation process of electrode part (step S12)

  In the step of forming the electrode portion, as shown in FIG. 8A, the anode portion 6 or the cathode portion 8 is connected to the element end face 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. 8B, molding is performed on the element end face 5 of the capacitor element 4 in a close contact state.

The element end face 5 of the capacitor element 4 is provided with an anode portion 6 and a cathode portion 8 that constitute an electrode extending portion, as shown in FIG. 8A, 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 of the anode portion 6 and the cathode portion 8, and the width Wa is It is set larger than the lead width of the electrode body, that is, the anode part 6 or the cathode part 8 before bending. The magnitude relation W ₈ and the width Wa of the insulation gap 27 folded width of the anode 6 and the cathode 8 of the above 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 portions 6A, 6B, 6C and the partition portions 8A, 8B, 8C of the cathode portion 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. It faces in a state where it is bent in the facing direction around the winding center 52. Therefore, as shown in FIG. 9B, the partition portions 6B and 6C described above are used by using the crease line 46 on the winding center portion 52 side in order to connect the anode current collector plate 12 and the cathode current collector plate 16 to each other. 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 the crease line 46 as shown in FIG. 9C.

  (3) 1st connection process (step S13)

  In this connection process, the anode current plate 12 is formed on the anode 6 formed on the element end surface 5 of the capacitor element 4, and the cathode current collector 16 is connected to the cathode 8.

  As shown in FIG. 10, the anode current collector plate 12 connected to the anode portion 6 and the cathode current collector plate 16 connected to the cathode portion 8 are formed of, for example, an aluminum plate that is the same as the electrode material. Covering the partition portions 6A, 6B, and 6C (B of FIG. 8) of the anode portion 6, having a laser welding area with the partition portions 6B and 6C, and having a shape and area with a laser welding area with the anode terminal 10 Yes. In this embodiment, the size of the capacitor element 4 is half the size of the element end face, and the insulating space 21 is ensured.

In the anode current collecting plate 12 (or the cathode current collecting plate 16), as shown in FIG. 10A, 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. In addition, as shown in FIG. 10B, 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. The element connection portions 12B, 12C or 16B, 16C set at different positions on the anode current collector plate 12 or the cathode current collector plate 16 constitute the first connection region, and the terminal connection portions 12A, 16A constitute the second connection region. ing.

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 terminal connecting portion 12A of the anode current collecting plate 12. For example, the thickness of the terminal connection portion 12A can be set thicker (1.2 times or more) than that of the element connection portions 12B and 12C. According to this, the element connection portion 12B, The heat generated in 12C is absorbed by the terminal connection 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.

  As shown in FIG. 11, 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 portion 52 and an arc-shaped notch portion 58 is aligned with the winding center portion 52. The insulating interval 23 is set corresponding to the insulating 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, the partition portions of the anode portion 6 and the cathode portion 8 that are compression-molded on the element end surface 5 are used. Since especially the vicinity of the winding center portion 52 of each partition portion is covered with each current collector plate, the anode portion 8 and the cathode portion 8 are reliably welded to each current collector plate 12 and 16 by laser irradiation. Note that the width Wb of the insulation interval 21 between the anode portion 6 and the cathode portion 8 is set to 3 [mm] to 15 [mm].

  In this embodiment, as shown in FIG. 11, 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 18. 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 performed from the outer peripheral side of the capacitor element 4 toward the element center, for example, linearly toward the winding center part 52 to the element connection part 12B of one anode current collector plate 12. .

  [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 outer periphery of the element.

  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 part 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. In addition, it is 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 again performed 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.

7 and 8, the anode portion 6 and the cathode portion 8 are led out from the element end face 5 of the capacitor element 4 by providing a predetermined insulation interval 27 (width Wa: A in FIG. 8). ing. The anode portion 6 and the cathode portion 8 have an insulation interval 21 (width Wb: B in FIG. 8) 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. 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. 8). That is, the extraction height h ₁ of the anode 6 and the cathode 8 from the element end face 5 of the capacitor element 4 with respect to the width Wa of the insulation interval 27 is Wa> h ₁ , so that the anode 6 and the cathode 8 are Even if it is bent and formed on the element end face 5, the anode part 6 and the cathode part 8 do not come into contact with each other.

  Further, at the outermost periphery of the capacitor element 4, the anode current collector plate 12 prevents the anode portion 6 and the cathode portion 8 from coming into contact with the outer case 20 even if the anode portion 6 and the cathode portion 8 are displaced during compression molding. Insulating means 19 such as insulating paper or insulating tape may be installed on the outer peripheral surface of the anode part 6 connected to the cathode part 8 and the cathode part 8 connected to the cathode current collector plate 16. 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. Is insulated.

  (4) Second connection process (step S14)

  This connection process includes a connection process between the anode current collector plate 12 and the cathode current collector plate 16 and the external terminals. That is, in this connection step, 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 collecting plate 12 and the cathode current collecting plate 16 are connected, as shown in FIG. Is done. 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 as shown in FIG. 12B, the weld connection portion 18 described above is laser welded, and the connection surface portion 63 and the terminal side The connection surfaces 70 can be welded.

  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 through the welding connection portion 18 by laser irradiation 72, and to the cathode portion 8 of the capacitor element 4. The cathode terminal 14, which is an external terminal, is connected via the cathode current collector plate 16 by the welding connection portion 18 by laser irradiation 72, 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 range is set to 0.5 [mm] to 5 [mm].

  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, 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.

  (5) Electrolyte impregnation and encapsulation 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 to complete the electric double layer capacitor 2 (FIG. 1) as a product. .

  According to such a manufacturing process, the above-described capacitor 2 can be easily manufactured, the terminal connection process can be simplified, and a 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) 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, 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.

  (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 collecting plate 12 or the cathode current collecting 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.

  (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) 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.

  (9) By separating the crease position by a predetermined distance from the end face of the element, laser heat and sputtering to the element side are not scattered during laser welding with the current collector plate, and the influence on the element can be reduced.

  (10) By forming a crease in the projecting portion in advance before forming the capacitor element, the formation of the crease is facilitated.

  (11) A crease is applied to the electrode foil (uncoated part), and then the edge of the electrode foil is cut out to form an overhanging portion, thereby obtaining the effect that the position of the fold is not shifted at the overhanging portion. .

[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) The above embodiment discloses a configuration in which the anode portion 6 and the cathode portion 8 are provided on one (same surface) of the element end faces of the capacitor element and connected to the external terminal. It is good also as a structure provided with a cathode part in a part and the other element end surface.

  (3) In the said embodiment, the division part 12B, 12C or 16B which is a 1st connection area, and the division part which is 16C and a 2nd connection area by the division | segmentation divided into 3 as a different position of a collector plate 12A or 16A is set on the front and back surfaces of the current collector and is set at a different position in the horizontal direction, but is not limited thereto. A first connection region (element connection region: laser irradiation connection portion 68) is set in a part of the current collector plate, and a second connection region (terminal connection region: weld connection portion 18) is set in other portions. Also good. That is, if the welding positions are different on the front and back surfaces, the first and second connection regions may be close to each other. That is, the laser irradiation connection portion 68 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 the first connection region.

  (4) 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.

  (5) 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. Further, the portions of the anode portion 6, the cathode portion 8, the anode current collecting plate 12, and the cathode current collecting plate 16 where the laser irradiation 72 is performed (the side wall surfaces forming the same surfaces as the connection surface portions 63 and the terminal side connection surfaces 70) are flat surfaces. However, the shape matching the shape of the external terminal may be a curved surface.

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

  (7) In the above embodiment, the anode terminal 10 is used as the anode external terminal member and the cathode terminal 14 is exemplified as the cathode external terminal member. However, 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.

(8) In the above embodiment, W ₁ > W ₂ is exemplified, but the present invention is not limited to this. W ₁ = W ₂ may be used, and other dimensions are only examples, and are not limited to these values.

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 can be realized by strengthening the connection.

2 Electric double layer capacitor 4 Capacitor element 5 Element end face 6 Anode part 60 Anode body 8 Cathode part 80 Cathode body 10 Anode terminal 12 Anode current collector plate 12A Terminal connection part 12B, 12C Element connection part 14 Cathode terminal 16 Cathode current collection board 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 release mechanism 44 Uncoated part

Claims (4)

An electrode projection formed by projecting the electrode body of the capacitor element on the element end face of the capacitor element;
An external terminal installed on a sealing plate of an outer case enclosing the capacitor element;
The first connection region and the second connection region are set between the electrode extension part and the external terminal, and the electrode connection part is connected to the first connection region. A current collector plate in which the external terminal member is connected to the connection region of 2;
A capacitor characterized by comprising.   The first connection region of the current collector plate is set at at least two places sandwiching the second connection region, and the electrode extension portion of the capacitor element is connected to each of the first connection regions. The capacitor according to claim 1. A step of projecting an electrode body of the capacitor element on an element end surface of the capacitor element to form an electrode projecting portion;
A first connecting region and a second connecting region are set at different positions on a current collector plate installed between an external terminal member and the electrode projecting portion, and the electrode projecting portion is connected to the first connecting region. And connecting the external terminal member to the second connection region;
A method for producing a capacitor, comprising:   The first connection region of the current collector plate is set to at least two places sandwiching the second connection region, and the electrode extension portion of the capacitor element is connected to each of the first connection regions. The method for manufacturing a capacitor according to claim 3.

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