JP5421686B2 - Capacitor - Google Patents

Description

  The present invention relates to a capacitor in which an electrode portion on an end face of a capacitor element and an electrode plate are connected via a lead terminal.

  Since inductance in an IGBT (insulated gate bipolar transistor) used in a power conversion device or the like causes a switching loss, a low-inductance is required for a filter capacitor or a snubber capacitor connected to the IGBT. For this reason, a pair of electrode plates to which capacitor elements are connected are overlapped with each other via an insulator, and magnetic fluxes generated on the electrode plates are canceled out to reduce inductance (see Patent Document 1).

JP 2006-245170 A

  By the way, for the connection between the electrode part at the end of the capacitor element and the electrode plate, a lead wire is usually used in consideration of the ease of connection work and the processability of the electrode plate. In this case, one end portion of the lead wire is connected to the end face electrode portion of the capacitor element, and the other end portion of the lead wire is connected to the electrode plate by soldering or the like. The entire board is heated, exceeding the allowable temperature of the capacitor element and the insulating paper, and the capacitor element and the insulating paper may be damaged. In recent years, in particular, from the viewpoint of environmental protection, lead-free solder, which has a higher melting point than conventional solder, is often used. Therefore, it is necessary to devise such as connecting work while cooling the solder heat. The work is complicated and time-consuming, resulting in poor productivity.

  In addition, in the case of solder, shrinkage cavities (cracks) are likely to occur at the soldering location, and it is difficult to visually determine whether it is defective or not. I had a problem.

  Accordingly, the present invention provides a capacitor that solves the above-described problems and facilitates the connection between the capacitor element and the electrode plate, has a high connection reliability, and can prevent the influence of heat on the capacitor element. Is.

In order to solve the above problems, a capacitor according to the present invention includes a capacitor element 1 having electrode portions 2 and 2 on an end face, and a lead terminal 3 having one end connected to the electrode portions 2 and 2 of the capacitor element 1; 4 and electrode plates 5 and 13 in which through holes 8 and 16 provided for connection to the other ends of the lead terminals 3 and 4 are arranged in parallel. , 16 are provided with projections 11, 19 on a part of the electrode plates 5, 13, and the other end of the lead terminals 3, 4 is inserted into the through-holes 8, 16. The guide converges toward the protrusions 11 and 19 in the plate surface direction of the electrode plates 5 and 13 so that the protrusions 11 and 19 naturally come into contact with the protrusions 11 and 19 when moved in the state. parts 9, 17 are provided, further, the guide portion 9 and 17 The lead terminals 3 and 4 are connected to the capacitor elements 1 and 1 facing each other between the electrode parts 2 and 2 between the through holes 8 and 16 arranged side by side. 3 and 4 have elongated guide portions 9 and 17 for guiding the projections 3 and 4 to the projections 11 and 19, respectively. The projections 11 and 19 face each other through the elongated guides 9 and 17. One of the opposing lead terminals 3 and 4 is inserted into one side of the through holes 8 and 16 located on both sides of the elongated guides 9 and 17. The other lead terminals 3 and 4 among the opposed lead terminals 3 and 4 are inserted into the other side of the through-hole portions 8 and 16 located on both sides of the elongated guide portions 9 and 17, respectively. The lead terminals 3 and 4 are moved toward the protrusions 11 and 19 side. , To the projections 11 and 19, leads the other end of the terminals 3 and 4 respectively by abutting the guide unit 9 and the other ends of the elongate lead terminals 3 and 4 to the opposite to the opposing , 17 and facing each other, and in this state, the projections 11 and 19 and the lead terminals 3 and 4 are connected.

In addition, a plurality of capacitor elements 1... Having electrode portions 2 and 2 on both end faces, and one end portion connected to the electrode portions 2 and 2 of the capacitor element 1 are connected to the lead terminals. 3 and 4, capacitors having first and second electrode plates 5 and 13 which are overlapped via an insulator 21 and connected to the electrode portions 2 and 2 of the capacitor element 1 and the lead terminals 3 and 4. in, the first, second electrode plates 5 and 13, together with the through hole portions 8 and 16 to be subjected to the connection to the other end of the lead terminals 3, 4 are juxtaposed, the The second electrode plate 13 is disposed so as to be positioned between the capacitor element 1 and the first electrode plate 5, and is formed on a part of the electrode plates 5 and 13 around the through-hole portions 8 and 16. Are provided with protrusions 11 and 19, and the other end of the lead terminals 3 and 4 is The protrusions in the plate surface direction of the electrode plates 5 and 13 so that the protrusions 11 and 19 naturally come into contact with the protrusions 11 and 19 when they are moved to the protrusions 11 and 19 while being inserted through the holes 8 and 16. Guide portions 9 and 17 that converge toward 11 and 19 are provided. The guide portions 9 and 17 are further opposed to the electrode portions 2 and 2 between the through-hole portions 8 and 16 arranged in parallel. The elongated guide portions 9, 17 are connected to the capacitor elements 1, 1 to be connected to the opposite lead terminals 3, 4 facing each other, and lead the lead terminals 3, 4 to the projections 11, 19, respectively. the has, above the lugs 11 and 19 provided to face each other via the guide portion 9, 17 of the elongate, of the lead terminals 3 and 4 to the opposing, one lead terminals 3, 4, it is located on opposite sides of the guide portions 9 and 17 of the elongate Inserted into one side of the hole portion 8, 16, of the lead terminals 3 and 4 to the counter, through hole portion 8 of the other lead terminals 3 and 4, located on opposite sides of the guide portions 9 and 17 of the elongate , was inserted into 16 the other side of the lead terminals 3 and 4 of the facing by moving toward the protruding portions 11 and 19 side, to the projections 11 and 19, the lead terminals 3 and 4 to the opposite The other end portions are brought into contact with each other, and the other end portions of the opposing lead terminals 3 and 4 are opposed to each other through the elongated guide portions 9 and 17, and in this state, the protrusion portions 11 and 19 And the lead terminals 3 and 4 are connected to each other.

  Furthermore, the projections 11 and 19 and the other end of the lead terminals 3 and 4 are connected by welding.

  In the capacitor according to the present invention, since the end of the lead terminal and the protrusion are connected, the connection work can be performed at a position away from the electrode plate, and the capacitor element and insulation can be performed without spreading the heat during connection to the entire electrode plate. Damage to the body due to heat can be prevented. Further, since the guide portion for guiding the end portion of the lead terminal to the protruding portion is formed, the operation of arranging the end portion of the lead terminal on the protruding portion is facilitated, and the working efficiency can be improved.

  Further, by superimposing the first electrode plate and the second electrode plate via an insulator, the magnetic fluxes generated in the first electrode plate and the second electrode plate cancel each other, and a reduction in inductance can be achieved. .

  Furthermore, by connecting the projections of the electrode plate and the lead wires by welding, the welds become an alloy of the projections and the lead wires, and the strength and connection reliability of the welds are markedly greater than solder bonding. improves. Further, since the welded portion is spherical, it becomes easy to check the welded state, and it is possible to prevent poor welding or forgetting to weld.

  Furthermore, by forming a protrusion by bending a part of the electrode plate, the protrusion can be easily formed, and since it is integral with the electrode plate, the protrusion is formed separately. The connection reliability is improved as compared with the case of attaching to the electrode plate.

It is sectional drawing which showed the capacitor | condenser which concerns on embodiment of this invention. It is the same top view.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIGS. 1 and 2, the capacitor according to one embodiment of the present invention includes a first electrode plate 5 and a second electrode plate 13 that are stacked with an insulator 21 interposed therebetween. , 13 are connected to a plurality of capacitor elements 1 through the first lead terminal 3 and the second lead terminal 4, and this is housed in a case (not shown), and the case is filled with resin and cured. Is formed.

  The capacitor element 1 is provided with electrode portions 2 and 2 at both axial end portions thereof. Further, for example, three capacitor elements 1 are arranged in parallel in a state where the adjacent electrode portions 2 and 2 are opposed to each other with respect to the A direction shown in FIG. For example, four capacitor element rows are arranged in parallel on the same plane in the B direction to form a capacitor element group. In the capacitor element row, the opposing electrode parts 2 and 2 of the capacitor elements 1... Have the same potential, and when the capacitor element 1 has polarity, the polarities of the electrode parts 2 and 2 adjacent to each other. Are arranged to be the same. Further, the electrode portions 2 and 2 of the capacitor element 1 have two first lead terminals 3 on one side (for example, a positive pole) and two second lead terminals 4 on the other side (for example, a negative pole) by spot welding or the like. It is connected. Each lead terminal 3 and 4 is made of a copper wire, a square pin, a terminal punched from a copper sheet metal, or the like, but is not limited thereto and may be conductive. Further, the number of connection of the first and second lead terminals 4 to the electrode portions 2 and 2 of the capacitor element 1 is not limited to two, and can be appropriately changed according to the capacitance of the capacitor element 1.

  The first electrode plate 5 is made of, for example, a copper plate, and as shown in FIG. 2, as shown in FIG. 2, a flat plate-like main body portion 6 and a terminal portion that is extended from the outer periphery of the main body portion 6 and bent into a substantially L shape. 7 As shown in FIG. 1A, the main body 6 of the first electrode plate 5 has a through hole 8 through which the first lead terminal 3 can pass, and a second lead as shown in FIG. A lead terminal escape hole 12 is provided in a size that allows the terminal 4 and the first electrode plate 5 to be inserted without being connected.

As shown in FIG. 2, the through-hole portion 8 is formed in a substantially hat shape in which slit portions 10 and 10 wider than the width of the first lead terminal 3 are formed from both ends of the substantially trapezoidal base. The waist portion represented by the hat portion is a guide portion 9 having an inclination from the top toward the flange, and is connected to the electrode portions 2 and 2 of the capacitor element 1 and is inserted through the through-hole portion 8. The first lead terminals 3 and 3 are urged in a direction away from each other, and are guided to the flanges (slit portions) 10 and 10 according to the inclination of the guide portion 9. Protrusions 11 and 11 formed by bending the first electrode plate 5 by approximately 90 degrees are formed at the ends of the slit parts 10 and 10, and the first lead terminal 3 led to the slit part 10 11 is brought into contact. The through-hole portions 8 are provided at positions facing the first lead terminals 3 connected to the capacitor element group, and are arranged in parallel in the B direction shown in FIG. At locations where they are adjacent to each other, the through holes 8 are juxtaposed with the bases of the substantially trapezoids facing each other, and a bridge-shaped guide portion 9 is formed between the through holes 8 and 8. . The bridge-shaped guide portion 9 is for reliably guiding the first lead terminal 3 to the protruding portion 11 formed at the end of the slit portion 10, but does not need to have a bridge-like form, a cantilevered to a substantially central portion of the bridge-like is notched yet good.

  The lead terminal relief holes 12 are provided at positions facing the second lead terminals 4, and are arranged in parallel in the B direction shown in FIG. The lead terminal escape hole 12 is for preventing electrical connection between the second lead terminal 4 and the protruding portion 19 of the second electrode plate 13 and the first electrode plate 5. The shape such as a mold or a square can be changed as appropriate.

  The second electrode plate 13 is made of, for example, a copper plate, and as shown in FIG. 2, as shown in FIG. Fifteen. In addition, the terminal part 15 extended from the main-body part 14 is extended from the position which does not overlap with the terminal part 7 of the 1st electrode plate 5 planarly. As shown in FIG. 1B, the main body portion 14 of the second electrode plate 13 has a through-hole portion 16 through which the second lead terminal 4 can pass, and a first lead as shown in FIG. A lead terminal escape hole 20 is provided in a size that allows the terminal 3 and the second electrode plate 13 to be inserted without being connected.

As shown in FIG. 2, the through-hole portion 16 is formed in a substantially hat shape in which slit portions 18 and 18 wider than the width of the second lead terminal 4 are formed from both ends of the substantially trapezoidal base. The waist portion represented by the hat portion is a guide portion 17 having an inclination from the top toward the flange, and is connected to the electrode portions 2 and 2 of the capacitor element 1 and is inserted into the through-hole portion 16. The second lead terminals 4, 4 are urged in directions away from each other, and are guided to the flanges (slit portions) 18, 18 according to the inclination of the guide portion 17. Protrusions 19 and 19 formed by bending the second electrode plate 13 by approximately 90 degrees are formed at the ends of the slits 18 and 18, and the second lead terminal 4 led to the slit part 18 is provided with a protrusion. 19 is brought into contact. The through holes 16 are provided at positions facing the second lead terminals 4 connected to the capacitor element group, and are arranged in parallel in the B direction shown in FIG. At locations where they are adjacent to each other, the through-hole portions 16 are arranged in parallel with the bottoms facing each other, and a bridge-shaped guide portion 17 is formed between the through-hole portions 16 and 16. The bridge-shaped guide portion 17 is used to reliably guide the second lead terminal 4 to the protrusion portion 19 formed at the end of the slit portion 18, but does not need to have a bridge shape, a cantilevered to a substantially central portion of the bridge-like is notched yet good.

  The lead terminal relief holes 20 are provided at positions facing the first lead terminals 3 and are arranged in parallel in the B direction shown in FIG. Since the lead terminal relief hole 20 is for preventing electrical connection between the first lead terminal 3 and the first electrode plate 5, the shape such as a round shape or a square shape in plan view can be changed as appropriate. It is.

  That is, the second electrode plate 13 is formed in substantially the same manner as the first electrode plate 5 except that the extension location and the number of extension of the terminal portion 15 and the positions of the through hole portion 16 and the lead terminal escape hole 20 are different. ing.

  The insulator 21 is made of, for example, insulating paper, the size of which is slightly larger than each of the electrode plates 5 and 13, and the lead terminals 3, 4 and the protrusions are positioned at positions facing the lead terminals 3, 4. A through hole 22 that can be inserted through the portion 19 and that is smaller than the lead terminal relief holes 12 and 20 formed in the electrode plates 5 and 13 is formed. The insulator 21 is not limited to insulating paper and may be any insulating material such as an insulating film.

  The first electrode plate 5, the second electrode plate 13, and the insulator 21 configured as described above are overlapped with the insulator 21 interposed between the first electrode plate 5 and the second electrode plate 13. . At this time, the through-hole portion 8 of the first electrode plate 5, the lead terminal escape hole 20 of the second electrode plate 13, and the through-hole 22 of the insulator 21 face each other, and the lead of the first electrode plate 5. The terminal escape hole 12, the through hole portion 16 of the second electrode plate 13, and the through hole 22 of the insulator 21 are overlapped so as to face each other. Then, the second electrode plate 13 and the capacitor element group are opposed to each other, and one end of the other end of the first lead terminal 3 connected to the electrode parts 2 and 2 of each capacitor element 1 by spot welding or the like. The second electrode plate 13 and the capacitor element group are inserted into the lead terminal escape hole 20 of the second electrode plate 13 while the other end of the second lead terminal 4 is inserted into the through-hole portion 16 of the second electrode plate 13. Are superimposed. At this time, the other end portion of the first lead terminal 3 inserted through the lead terminal escape hole 20 of the second electrode plate 13 is superimposed on the upper surface of the second electrode plate 13 via an insulator 21. Will be inserted through the through-hole portion 8.

  In this state, the first lead terminal 3 and the second lead terminal 4 respectively connected to the electrode portions 2 and 2 of the capacitor element 1 are urged in a direction in which the two lead wires 3 and 2 are separated from each other. The guides 9 and 17 of the holes 8 and 16 are guided to the protrusions 11 and 19 while being guided. Then, the contact portions of the lead terminals 3 and 4 and the protrusions 11 and 19 are locally welded for a short time in a non-contact manner using an extremely high energy density device such as pulse YAG laser welding. The lead terminals 3 and 4 and the electrode plates 5 and 13 are connected. The contact portions between the lead terminals 3 and 4 and the projecting portions 11 and 19 are in a state of protruding from the main body portions 6 and 14, and the heat capacity is extremely smaller than that of the main body portions 6 and 14, so that laser welding is performed. It is a shape suitable for a welding method in which high-density heat energy is locally and instantaneously applied. Further, in the welding, since the lead terminal escape hole 12 is provided in the first electrode plate 5, the second electrode plate 13 and the second lead terminal 4 can be welded from above the first electrode plate 5, The efficiency of connection work is improved.

  After the connection between the lead terminals 3 and 4 and the electrode plates 5 and 13, the capacitor element group integrally connected, the first electrode plate 5, the second electrode plate 13, and the insulating paper 21, The terminal portions 7 and 15 of the electrode plates 5 and 13 are extended to the outside so as to be accommodated in a case and further molded with a resin to obtain a capacitor.

  According to the capacitor having the above configuration, the welded portions between the lead terminals 3 and 4 and the projections 11 and 19 of the electrode plates 5 and 13 are made of a copper alloy, and have higher strength and connection reliability than bonding by solder. improves. Moreover, since the lead terminals 3 and 4 and the tip portions of the projections 11 and 19 of the electrode plates 5 and 13 are welded, the shape after welding becomes spherical, making it easy to check the welded state, resulting in poor welding and welding. Forgetting to do so can be prevented. Furthermore, since welding is performed instantaneously, the connection work between the lead terminals 3 and 4 and the electrode plates 5 and 13 can be performed in a short time, and heat from the welding causes the lead terminals 3 and 4 and the protrusions 11 to be connected. , 19 is locally applied to the abutting portion, and the heat influence on the electrode plates 5 and 13 is extremely small, and the capacitor element 1 and the insulator 21 are hardly affected. In addition, when connecting by soldering, the lead terminals 3 and 4 and the protrusions 11 and 19 need to be plated to ensure connectivity with the solder. 3 and 4 and the projections 11 and 19 are melted and directly joined to each other, so that it is not necessary to perform plating, and the cost can be reduced.

  Although specific embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention. For example, the shape of the through holes 8 and 16 is substantially hat-shaped, but the lead terminals 3 and 4 can be guided to the protrusions 11 and 19 formed around the through holes 8 and 16. Any semi-circle or triangle may be used. In connection with this, the inclination of the guide parts 9 and 17 can also be changed suitably. Moreover, the material of each electrode plate 5 and 13 and each lead terminal 3 and 4 should just have electroconductivity other than copper or brass. Further, when the lead terminals 3 and 4 are brought into contact with the protrusions 11 and 19, the lead terminals 3 and 4 are inserted in the through-hole portions 8 and 16, and then the lead terminals 3 and 4 are attached in a direction away from each other. In addition to this, when connecting each lead terminal 3, 4 to the capacitor element 1, the interval between the two lead terminals 3, 4 connected to the electrode part 2 is made larger than the through-hole parts 8, 16. When passing through the through-hole portions 8 and 16, the lead terminals 3 and 4 are guided to the projections 11 and 19 by urging them in directions close to each other and releasing them after insertion. Also good.

  1 .. Capacitor element 2 .. Electrode part 3 .. First lead terminal 4.. Second lead terminal 5.. First electrode plate 8, 16. Guide part, 11, 19 ... Projection part, 13 ... Second electrode plate, 21 ... Insulator

Claims (3)

Capacitor element (1) having electrode portions (2) and (2) on the end face, and lead terminals (3) and (4) having one end connected to electrode portions (2) and (2) of capacitor element (1) ) And electrode plates (5) and (13) in which through holes (8) and (16) provided for connection to the other ends of the lead terminals (3) and (4) are arranged in parallel. In the capacitor, projections (11) and (19) are provided on part of the electrode plates (5) and (13) around the through-hole portions (8) and (16), and the lead terminals (3 If the other end of (4) is inserted into the through hole (8) (16) and moved to the protrusion (11) (19), the protrusion (11) (19) ) That converges toward the protrusions (11) and (19) in the plate surface direction of the electrode plates (5) and (13). 9) (17) is provided with further, the guide portion (9) (17), the juxtaposed holes section between (8) (16), the electrode unit (2) (2) The lead terminals (3) and (4) of the same polarity that are connected to the opposing capacitor elements (1) and (1) and that face each other are separated from each other, and these lead terminals (3) and (4) are connected to the protrusions (11) ( 19) are provided with elongate guide portions (9) and (17) respectively leading to the respective projecting portions (11) and (19) through the elongate guide portions (9) and (17). One of the opposing lead terminals (3) and (4) is provided with one lead terminal (3) and (4) , and the through holes are located on both sides of the elongated guide portions (9) and (17). (8) inserted into one side of (16), lead terminals (3) to the counter (4) of the other lead terminal (3) (4 And the guide portion of the elongated (9) is inserted into the other side of the hole portions located on opposite sides of (17) (8) (16), lead terminals (3) to the counter (4) the projections ( 11) By moving toward the (19) side, the other ends of the opposing lead terminals (3) and (4) are brought into contact with the protrusions (11) and (19 ), respectively , and the opposing The other ends of the lead terminals (3) and (4) to be opposed to each other through the elongated guide portions (9) and (17), and in this state, the protrusions (11) and (19) and the lead terminals (3) A capacitor configured to connect (4). There are electrode portions (2) and (2) on both end faces, and a plurality of capacitor elements (1)... Housed in the case and one of the electrode portions (2) and (2) of these capacitor elements (1) Lead terminals (3) and (4) to which end portions are connected, and electrode parts (2) and (2) of the capacitor element (1) which are overlapped via an insulator (21) and the lead terminals (3) and (4). In the capacitor having the first and second electrode plates (5) and (13) connected via the first and second electrode plates (5) and (13), the first and second electrode plates (5) and (13) are connected to the lead terminals (3) ( 4) The through-hole portions (8) and (16) provided for connection with the other end portion are arranged in parallel , and the second electrode plate (13) is connected to the capacitor element (1) and the first end portion. Of the electrode plates (5) and (13) around the through-hole portions (8) and (16). Protrusions (11) and (19) are provided on the part, and the other end of the lead terminal (3) and (4) is inserted through the through hole (8) and (16). The protrusion (11) in the plate surface direction of the electrode plates (5) and (13) so that the protrusion (11) (19) naturally comes into contact with the protrusions (11) and (19). Guide portions (9) and (17) that converge toward (19) are provided, and the guide portions (9) and (17) are further provided between the through-hole portions (8) and (16) arranged side by side. In addition, the lead terminals (3) (4) are connected to the capacitor elements (1) (1) opposed to each other with the electrode portions (2) (2) facing each other, and the lead terminals (3) (4) facing each other are separated from each other. 4) has elongated guide portions (9) and (17) for guiding the projections to the protrusions (11) and (19), respectively. The protrusions (11) (19) is provided so as to face each other through the elongated guide section (9) (17), of the opposite lead terminals (3) (4), one lead terminal (3) (4) is inserted into one side of the through hole portions (8), (16) located on both sides of the elongated guide portions (9), (17), and the opposing lead terminals (3), (4) are inserted. of), and insert the other lead terminal (3) (4), on the other side of the elongated guide section (9) (hole portions located on opposite sides of 17) (8) (16), the counter By moving the lead terminals (3) and (4) to be moved toward the projections (11) and (19 ), the lead terminals (3) and (4) facing the projections (11) and (19 ) are moved. the other end respectively to contact the lead terminals (3) to the counter (4) other end portions of the elongate draft of Part (9) (17) is opposed via, characterized by being configured for connecting the protruding portion in this state (11) (19) and the lead terminals (3) (4) Capacitor . The capacitor according to claim 1 or 2, wherein the protrusion (11) (19) and the other end of the lead terminal (3) (4) are connected by welding .