JP6277620B2

JP6277620B2 - Capacitor and manufacturing method thereof

Info

Publication number: JP6277620B2
Application number: JP2013149053A
Authority: JP
Inventors: 航太福島
Original assignee: Nippon Chemi Con Corp
Current assignee: Nippon Chemi Con Corp
Priority date: 2012-07-25
Filing date: 2013-07-18
Publication date: 2018-02-14
Anticipated expiration: 2033-07-18
Also published as: JP2014042007A

Description

本発明は、電解コンデンサや電気二重層コンデンサなどのコンデンサに関し、たとえば、冷間圧接法により引出し端子に電極箔を接続するコンデンサおよびその製造方法に関する。
The present invention relates to a capacitor such as an electrolytic capacitor or an electric double layer capacitor, for example, a capacitor in which an electrode foil is connected to an extraction terminal by a cold welding method and a method for manufacturing the same.

コンデンサとしてたとえば、電解コンデンサでは、陽極側および陰極側の電極箔の間にセパレータを挟み込んで巻回したコンデンサ素子が用いられる。このコンデンサ素子の各電極箔には外部端子である引出し端子（タブ）が接続されている。この接続には冷間圧接法が用いられている。冷間圧接法は、重ね合わせた部材間を非加熱状態で圧接する方法である。 As the capacitor, for example, in an electrolytic capacitor, a capacitor element in which a separator is sandwiched and wound between electrode foils on the anode side and the cathode side is used. A lead terminal (tab) which is an external terminal is connected to each electrode foil of the capacitor element. For this connection, a cold welding method is used. The cold pressure welding method is a method of pressure welding the stacked members in a non-heated state.

この冷間圧接法による引出し端子および電極箔の接続では、電極箔と引出し端子の接続部に押圧する金型に台形状の押圧面を持つ金型を使用することが知られている（たとえば、特許文献１、特許文献２）。
In the connection between the extraction terminal and the electrode foil by this cold welding method, it is known to use a mold having a trapezoidal pressing surface as a mold that presses the connection portion between the electrode foil and the extraction terminal (for example, Patent Document 1 and Patent Document 2).

特開平７−２３５４５３号公報JP 7-235453 A 特開２００７−２７３６４５号公報JP 2007-273645 A

ところで、コンデンサの小型化により、コンデンサ素子に用いられる電極箔の幅が狭くなり、引出し端子との接続に必要な幅（領域）が制限される。図５のＡに示すように、引出し端子１０２に重ねられた狭い電極箔１０４では、２つの接続部１０６−１、１０６−２を従前の間隔で設定すると、一方の接続部１０６−２が電極箔１０４の接続可能領域１０８からはみ出してしまう。各接続部１０６−１、１０６−２には、冷間圧接法による接合部１１０が形成されている。この例では、接合部１１０が電極箔１０４の縁部から外れている。 By the way, with the downsizing of the capacitor, the width of the electrode foil used for the capacitor element is narrowed, and the width (region) necessary for connection with the lead terminal is limited. As shown in FIG. 5A, when the two connecting portions 106-1 and 106-2 are set at a conventional interval in the narrow electrode foil 104 overlaid on the lead terminal 102, one connecting portion 106-2 becomes an electrode. The foil 104 protrudes from the connectable area 108. In each of the connection portions 106-1 and 106-2, a joint portion 110 is formed by a cold pressure welding method. In this example, the joint portion 110 is detached from the edge portion of the electrode foil 104.

このような電極箔１０４からのはみ出しを防止するには、図５のＢに示すように、接続部１０６を電極箔１０４の中央の１箇所に設定すればよい。このような接続部１０６では、電極箔１０４から接続部１０６がはみ出すことはないが、引出し端子１０２との接続強度が不足する。このような接続形態では、コンデンサの製造工程中に引出し端子１０２に電極箔１０４の長さ方向の負荷が作用すると、接続部１０６の中心を支点に引出し端子１０２が回転してしまい、接合部１１０に負荷が掛かり、電極箔１０４の接合部１１０およびその周辺にひび割れや電極箔割れが生じることがある In order to prevent such protrusion from the electrode foil 104, the connecting portion 106 may be set at one central position of the electrode foil 104 as shown in FIG. In such a connection portion 106, the connection portion 106 does not protrude from the electrode foil 104, but the connection strength with the extraction terminal 102 is insufficient. In such a connection form, when a load in the length direction of the electrode foil 104 acts on the lead terminal 102 during the manufacturing process of the capacitor, the lead terminal 102 rotates about the center of the connection portion 106 as a fulcrum, and the joint portion 110. And a crack or electrode foil crack may occur at the joint 110 of the electrode foil 104 and its periphery.

このような接続強度の低下を防止するには図５のＣに示すように、接続部１１６−１、１１６−２を狭小化するとともに、接続部１１６−１、１１６−２の間隔を狭め、接続可能領域１０８内に接続部１１６−１、１１６−２を設定すればよい。 In order to prevent such a decrease in connection strength, as shown in FIG. 5C, the connection portions 116-1 and 116-2 are narrowed, and the interval between the connection portions 116-1 and 116-2 is narrowed. The connection units 116-1 and 116-2 may be set in the connectable area 108.

このような接続部１１６−１、１１６−２の狭小化や間隔を小さくすれば、従前の接続可能領域１０８に接続部１１６−１、１１６−２を設定できるものの、接続部１１６−１、１１６−２が狭小化した分だけ接合部１１０は小さくなるので、十分な接続強度が得られないという課題がある。 If the connection portions 116-1 and 116-2 are narrowed and the distance between the connection portions 116-1 and 116-2 is reduced, the connection portions 116-1 and 116-2 can be set in the conventional connectable region 108. Since the joint 110 becomes smaller by the amount that −2 is narrowed, there is a problem that sufficient connection strength cannot be obtained.

そこで、本発明の目的は、上記課題に鑑み、引出し端子に対する電極箔の接続可能領域の狭小化および接続強度を高めることにある。
Therefore, in view of the above problems, an object of the present invention is to narrow the area where the electrode foil can be connected to the lead terminal and to increase the connection strength.

上記目的を達成するため、本発明のコンデンサは、電極箔に引出し端子が冷間圧接法により接続されたコンデンサであって、前記引出し端子と前記電極箔とが圧接接続された圧接接続部と、前記圧接接続部内に複数の凹部を備え、前記複数の凹部は一部を重ねて隣接し、前記各凹部間で隣接する壁部が前記各凹部で形成された窪み内に存在している。 In order to achieve the above object, the capacitor of the present invention is a capacitor in which a lead terminal is connected to an electrode foil by a cold pressure welding method, wherein the lead terminal and the electrode foil are press-contact connected, wherein comprising a plurality of recesses in the insulation displacement connection portion, the plurality of recesses are adjacent overlapped portions, the wall portion to which the adjacent among the recesses that are present in the depressions the formed in each recess.

上記コンデンサにおいて、前記圧接接続部の形状が曲面状であってもよい。 In the capacitor, the shape of the press-contact connection portion may be a curved surface.

上記目的を達成するため、本発明のコンデンサの製造方法は、電極箔と引出し端子との接続に冷間圧接法を用いたコンデンサの製造方法であって、複数の凸部を重ねて隣接させ、前記各凸部間で隣接する壁部が前記各凸部で形成された突出部内に存在する押圧部を冷間圧接金型に形成し、前記引出し端子に前記電極箔を重ね、前記冷間圧接金型の前記押圧部により押圧する。 To achieve the above object, a manufacturing method of a capacitor of the present invention is a method of manufacturing a capacitor using a cold welding method to connect to the electrode foil and the lead terminal, are adjacent overlapping projections of several A pressing portion in which a wall portion adjacent to each convex portion is present in a protruding portion formed by each convex portion is formed in a cold pressure welding mold, and the electrode foil is stacked on the lead terminal, It presses with the said press part of a press-contact metal mold | die.

本発明によれば、次のような効果が得られる。 According to the present invention, the following effects can be obtained.

(1) 冷間圧接法で接続される引出し端子と電極箔の圧接接続部に複数の凹部を備えることにより、狭い電極箔に対して接続可能領域を拡大することなく、引出し端子と電極箔との接続強度を高めることができる。 (1) By providing a plurality of recesses in the pressure contact connection portion between the lead terminal and the electrode foil connected by the cold pressure welding method, the lead terminal and the electrode foil can be connected to the narrow electrode foil without expanding the connectable area. The connection strength can be increased.

(2) 複数の凹部を含むことで、コンデンサの製造工程中に引出し端子に電極箔の長さ方向に対して負荷が掛かった場合でも、凹部を中心にして引出し端子が回転することはなく、圧接接続部に生じるひび割れや電極箔割れを防ぐことができる。 (2) By including a plurality of recesses, even when a load is applied to the extraction terminal in the length direction of the electrode foil during the manufacturing process of the capacitor, the extraction terminal does not rotate around the recess, It is possible to prevent cracks and electrode foil cracks that occur in the pressure contact connection portion.

(3) 凹部間の金属流動を抑制でき、引出し端子から電極箔に対する反発力により、電極箔に対する引出し端子の接続強度が高められる。 (3) Metal flow between the recesses can be suppressed, and the repulsive force from the extraction terminal to the electrode foil increases the connection strength of the extraction terminal to the electrode foil.

そして、本発明の他の目的、特徴および利点は、添付図面および各実施の形態を参照することにより、一層明確になるであろう。
Other objects, features, and advantages of the present invention will become clearer with reference to the accompanying drawings and each embodiment.

一実施の形態に係るコンデンサの引出し端子と電極箔との接続を示す図である。It is a figure which shows the connection of the extraction terminal of the capacitor | condenser which concerns on one embodiment, and electrode foil. 図１のＡのII−II線で切断した切断端面を示す図である。It is a figure which shows the cut end surface cut | disconnected by the II-II line | wire of A of FIG. 冷間圧接接続を示す図である。It is a figure which shows a cold press-connection. 他の実施の形態に係るコンデンサの引出し端子と電極箔との接続を示す図である。It is a figure which shows the connection of the extraction terminal of the capacitor | condenser which concerns on other embodiment, and electrode foil. 従来の引出し端子と電極箔との接続を示す図である。It is a figure which shows the connection of the conventional drawer terminal and electrode foil.

〔一実施の形態〕 [One embodiment]

図１のＡおよびＢは、本発明の一実施の形態に係るコンデンサの引出し端子および電極箔の接続を示している。 1A and 1B show the connection between the lead terminal of the capacitor and the electrode foil according to one embodiment of the present invention.

引出し端子２は、電極箔４に接続されるタブの一例である。この引出し端子２には、電極箔４が重ねられる偏平部２−１、支持部２−２およびリード部２−３が備えられている。電極箔４は、陽極側または陰極側のいずれの電極箔であってもよい。この電極箔４にはたとえば、アルミニウム箔が使用される。陽極側の電極箔４では、エッチング処理されたアルミニウム箔の表面に化成処理により誘電体酸化皮膜が形成されている。陰極側の電極箔４では、陽極側の電極箔と同様でもよいし、化成処理が施されていないエッチング箔であってもよい。これら陽極側および陰極側の電極箔４の間にセパレータを介在させ、巻回または重ね合わせによりコンデンサ素子が形成される。 The lead terminal 2 is an example of a tab connected to the electrode foil 4. The lead terminal 2 is provided with a flat part 2-1, a support part 2-2 and a lead part 2-3 on which the electrode foil 4 is superimposed. The electrode foil 4 may be either an anode side or a cathode side electrode foil. For example, an aluminum foil is used for the electrode foil 4. In the electrode foil 4 on the anode side, a dielectric oxide film is formed on the surface of the etched aluminum foil by chemical conversion treatment. The electrode foil 4 on the cathode side may be the same as the electrode foil on the anode side, or may be an etching foil that has not been subjected to chemical conversion treatment. A separator is interposed between the anode-side and cathode-side electrode foils 4, and a capacitor element is formed by winding or overlapping.

引出し端子２は一例として偏平部２−１、支持部２−２およびリード部２−３を備えている。偏平部２−１は、アルミニウムの棒状体を偏平に圧縮成形した偏平部である。支持部２−２は、偏平部２−１が形成されていない既述の棒状体の原型部分であって、図示しないコンデンサ素子を収納した外装ケースの封口部材を貫通させ、封口部材に支持させる部分である。リード部２−３は、支持部２−２より細く、半田付け可能な金属を表面にめっきしたワイヤで形成されている。リード部２−３は支持部２−２に溶接によって接続されている。リード部２−３は半田付け可能な金属ワイヤで形成してもよい。 The lead terminal 2 includes a flat part 2-1, a support part 2-2, and a lead part 2-3 as an example. The flat part 2-1 is a flat part obtained by compression-molding an aluminum rod-like body into a flat shape. The support portion 2-2 is a prototype portion of the above-described rod-shaped body in which the flat portion 2-1 is not formed, and passes through the sealing member of the outer case housing the capacitor element (not shown) and is supported by the sealing member. Part. The lead part 2-3 is thinner than the support part 2-2, and is formed of a wire having a surface plated with a solderable metal. The lead part 2-3 is connected to the support part 2-2 by welding. The lead part 2-3 may be formed of a solderable metal wire.

この引出し端子２は、偏平部２−１に重ねられた電極箔４と冷間圧接法により圧接接続されている。引出し端子２と電極箔４との間には圧接接続部８が形成されている。この圧接接続部８には複数の凹部の一例として、平面視円形形状の２つの接続凹部８−１、８−２が形成されている。各接続凹部８−１、８−２は、冷間圧接金型１６（図３）の押圧により電極箔４および引出し端子２に生じている圧接接続の痕跡である。 The lead terminal 2 is pressure-welded to the electrode foil 4 stacked on the flat part 2-1 by a cold pressure welding method. A pressure contact portion 8 is formed between the lead terminal 2 and the electrode foil 4. As an example of the plurality of recesses, the press contact connection portion 8 is formed with two connection recesses 8-1 and 8-2 having a circular shape in plan view. Each of the connection recesses 8-1 and 8-2 is a trace of the press-contact connection generated in the electrode foil 4 and the extraction terminal 2 due to the pressing of the cold press-contact mold 16 (FIG. 3).

圧接接続部８には、結合された２つの円形の接続凹部８−１、８−２が形成されている。各接続凹部８−１、８−２には図１のＢに示すように、円形の一対の接合部１０が形成されている。各接合部１０は、円形の圧接ピーク部分であり、電極箔４と引出し端子２の偏平部２−１とが密着して冷間圧接されている接合エリアである。複数の凹部として２つの接続凹部８−１、８−２が引出し端子２の長さ方向に隣接して配置され、各接続凹部８−１、８−２間には山型の隆起部１２が形成されている。この隆起部１２は隣接する接続凹部８−１、８−２の壁部の一例である。この隆起部１２は隣接した接続凹部８−１、８−２からなる窪み内に存在しており、押圧によって形成された接続凹部８−１、８−２の重なり部分の一例である。 The pressure connection portion 8 is formed with two coupled circular connection recesses 8-1 and 8-2. As shown in B of FIG. 1, a pair of circular joints 10 is formed in each connection recess 8-1, 8-2. Each joint portion 10 is a circular pressure welding peak portion, and is a joint area where the electrode foil 4 and the flat portion 2-1 of the extraction terminal 2 are in close contact and are cold-welded. Two connection recesses 8-1 and 8-2 are arranged adjacent to each other in the length direction of the lead terminal 2 as a plurality of recesses, and a mountain-shaped raised portion 12 is provided between the connection recesses 8-1 and 8-2. Is formed. The raised portion 12 is an example of a wall portion of adjacent connection recesses 8-1 and 8-2. The raised portion 12 is present in a recess formed by adjacent connection recesses 8-1 and 8-2, and is an example of an overlapping portion of the connection recesses 8-1 and 8-2 formed by pressing.

この接合エリアは、電極箔４と引出し端子２が圧接により物理的及び電気的に接続している部位をいう。つまり、冷間圧接金型１６で圧接したとき、半球部１８−１、１８−２の頂点で圧接される電極箔４は、その圧接時の応力により表面の誘電体酸化皮膜が破壊分断され、誘電体酸化皮膜に覆われていない電極箔の基材が現れる。さらに、圧接を続けると、引出し端子２と基材が圧接により接続する。絶縁性である誘電体酸化皮膜が除去され、引出し端子２と基材とが直に接続した接合部１０については、機械的接続と電気的接続がなされる。一方、接合部１０以外の圧接接続部８については、電極箔４と引出し端子２の機械的接続のみが達成されている。つまり、接合部１０の周辺の電極箔４は、圧接時に圧接方向に伸びるため、誘電体酸化皮膜にひびが入る。しかし、接合部１０のように誘電体酸化被膜が破壊分断されることはなく、ひびが生じるだけであるため、該ひびに引出し端子２のアルミニウムが入り込み、アンカー効果で機械的接続が達成される。 This joining area refers to a portion where the electrode foil 4 and the lead terminal 2 are physically and electrically connected by pressure welding. In other words, when the electrode foil 4 is pressed at the apexes of the hemispherical portions 18-1 and 18-2 when the pressure welding is performed with the cold pressure welding mold 16, the dielectric oxide film on the surface is broken and divided by the stress at the time of the pressure welding. An electrode foil base material that is not covered with the dielectric oxide film appears. Further, when the press contact is continued, the lead terminal 2 and the base material are connected by press contact. The joint portion 10 in which the dielectric oxide film that is insulative is removed and the lead terminals 2 and the base material are directly connected is mechanically and electrically connected. On the other hand, only the mechanical connection between the electrode foil 4 and the extraction terminal 2 is achieved for the press-contact connection portion 8 other than the joint portion 10. That is, since the electrode foil 4 around the joint portion 10 extends in the press-contact direction at the time of press contact, the dielectric oxide film is cracked. However, since the dielectric oxide film is not broken and broken like the joint 10 and only cracks are generated, the aluminum of the lead terminal 2 enters the cracks, and mechanical connection is achieved by the anchor effect. .

図２は、図１のＡのII−II線で切断した切断端面を示している。このように圧接接続部８の底部には、接合部１０が形成されている。各接合部１０の間には既述した隆起部１２が偏平部２−１の幅方向、電極箔４の長さ方向に形成されている。この隆起部１２では、偏平部２−１の金属流動が抑えられ、偏平部２−１の隆起部１２によって電極箔４の一部が表面方向に突出した形態となっている。 FIG. 2 shows a cut end surface taken along line II-II in FIG. As described above, the joint 10 is formed at the bottom of the press-connecting portion 8. Between the joint portions 10, the above-described raised portions 12 are formed in the width direction of the flat portion 2-1 and the length direction of the electrode foil 4. In the raised portion 12, the metal flow of the flat portion 2-1 is suppressed, and a part of the electrode foil 4 protrudes in the surface direction by the raised portion 12 of the flat portion 2-1.

＜コンデンサの製造方法＞ <Capacitor manufacturing method>

図３は、コンデンサの製造方法における引出し端子２と電極箔４との接続工程を示している。 FIG. 3 shows a process of connecting the lead terminal 2 and the electrode foil 4 in the method for manufacturing a capacitor.

この製造工程において、引出し端子２、電極箔４、電極箔４を用いたコンデンサ素子の形成などは従前の例と同様であるので、詳細な説明は割愛する。 In this manufacturing process, the extraction terminal 2, the electrode foil 4, the formation of the capacitor element using the electrode foil 4 and the like are the same as in the previous example, and a detailed description thereof will be omitted.

引出し端子２の偏平部２−１には図３のＡに示すように、電極箔４が設置されている。この電極箔４と引出し端子２の接続に関し、圧接接続可能領域１４は電極箔４と引出し端子２の重なり部分であり、換言すれば、圧接金型１６の圧接領域である。この圧接接続可能領域１４には、冷間圧接法に用いる圧接金型１６が配置される。この圧接金型１６は、先端が円形の２つの円柱体を連結した形状である。つまり、先端に圧接部（押圧部）として一対の半球部１８−１、１８−２を備え、半円形の一対の柱状部２０−１、２０−２を一体に備えている。半球部１８−１、１８−２は複数の凸部の一例であり、突出部を構成する。つまり、圧接金型１６の先端部には複数の凸部の一例として２つの半球部１８−１、１８−２が隣接して配置されている。各半球部１８−１、１８−２の間には金型凹部２２が形成されている。この金型凹部２２は各半球部１８−１、１８−２の隣接する壁部の一例である。この金型凹部２２が各半球部１８−１、１８−２で形成された突出部内に存在している。 As shown in A of FIG. 3, an electrode foil 4 is installed on the flat part 2-1 of the lead terminal 2. Regarding the connection between the electrode foil 4 and the extraction terminal 2, the press-connectable region 14 is an overlapping portion of the electrode foil 4 and the extraction terminal 2, in other words, the press-contact region of the press-contact mold 16. In this press-connectable region 14, a press-contact mold 16 used for the cold press-contact method is disposed. The press contact mold 16 has a shape in which two cylindrical bodies having circular ends are connected. That is, a pair of hemispherical portions 18-1 and 18-2 are provided as pressure contact portions (pressing portions) at the tip, and a pair of semicircular columnar portions 20-1 and 20-2 are integrally provided. The hemispherical portions 18-1 and 18-2 are an example of a plurality of convex portions, and constitute projecting portions. In other words, two hemispherical portions 18-1 and 18-2 are arranged adjacent to each other at the tip end portion of the pressure welding die 16 as an example of a plurality of convex portions. A mold recess 22 is formed between the hemispherical portions 18-1 and 18-2. The mold recess 22 is an example of adjacent wall portions of the hemispherical portions 18-1 and 18-2. The mold recess 22 exists in the protrusion formed by the hemispherical portions 18-1 and 18-2.

この圧接金型１６を図３のＢに示すように、偏平部２−１上の電極箔４に押し付け、冷間圧接を行う。これにより、各半球部１８−１、１８−２に押し付けられた部分に一対の接合部１０が形成される。各接合部１０は、圧接金型１６の圧接ピーク点で生成された圧接接合箇所である。 As shown in FIG. 3B, the pressure welding mold 16 is pressed against the electrode foil 4 on the flat portion 2-1, and cold pressure welding is performed. Thereby, a pair of junction part 10 is formed in the part pressed on each hemispherical part 18-1 and 18-2. Each joint portion 10 is a press-contact joint portion generated at the press-contact peak point of the press-contact mold 16.

この実施の形態のように、圧接金型１６の先端が半球の場合、冷間圧接時に圧接部から電極箔４に加わる応力が半球状の圧接部から放射状に作用し、均等な応力となり、応力集中を回避できる。つまり、圧接金型１６の先端に角部がある形状の場合、圧接面の角部に電極箔４に押し付けた時の応力が集中する。この応力集中が押圧面の角部から電極箔４の押圧部に過剰な応力を生じさせ、電極箔４のひび割れや箔割れの起因となることがある。しかしながら、本実施の形態のように先端面を半球状とすることで応力集中を回避でき、電極箔４のひび割れや箔割れを防止できる。 As in this embodiment, when the tip of the pressure welding mold 16 is a hemisphere, the stress applied to the electrode foil 4 from the pressure contact portion during cold pressure pressure acts radially from the hemispheric pressure contact portion, resulting in uniform stress. Concentration can be avoided. That is, in the case of a shape having a corner at the tip of the press contact mold 16, stress when pressed against the electrode foil 4 concentrates on the corner of the press contact surface. This stress concentration may cause excessive stress from the corner of the pressing surface to the pressing portion of the electrode foil 4, which may cause cracking or foil cracking of the electrode foil 4. However, stress concentration can be avoided by making the tip surface hemispherical as in the present embodiment, and cracking and foil cracking of the electrode foil 4 can be prevented.

また、接合部に応力が集中して圧接した場合、応力集中した電極箔の部位の周辺は、接続部の他の部位と比較し、局所的に薄くなる。つまり、圧接金型接続部による圧接の際、応力が集中した接合部は、接合部周辺の電極箔と比べ、圧接される力が強い。そのため、応力集中した接合部の周辺部の電極箔が圧接方向に伸ばされ、局所的に薄くなる。局所的に薄くなると、その部分が脆弱部となるので、引出し端子に外部から応力が加わった場合に、ひび割れや箔割れを生じやすくなる。そのため、接続強度が低下する。しかしながら、本実施の形態のように先端面を半球状とすることで、電極箔４に加わる応力は均等に放射状に作用するため、電極箔４が局所的に圧接されて薄くなることはなく、脆弱部の発生を防止できる。 In addition, when stress is concentrated and pressed in the joint portion, the periphery of the stress-concentrated electrode foil portion is locally thinner than other portions of the connection portion. That is, in the pressure welding by the pressure welding mold connecting portion, the joint where the stress is concentrated has a stronger force to be pressed than the electrode foil around the joint. For this reason, the electrode foil in the peripheral portion of the joint where stress is concentrated is stretched in the press-contact direction and locally thinned. When the thickness is locally reduced, the portion becomes a fragile portion, and therefore, when an external stress is applied to the lead terminal, a crack or a foil crack is likely to occur. Therefore, the connection strength is reduced. However, since the tip surface is hemispherical as in the present embodiment, the stress applied to the electrode foil 4 acts radially evenly, so that the electrode foil 4 is not locally pressed and thinned. The generation of vulnerable parts can be prevented.

ひいては、引出し端子２と電極箔との接続強度の強化やコンデンサの信頼性をより高めることができる。なお、圧接金型１６の先端部を台形部とした場合にも、角部を曲面化（球面状化）すれば圧接応力を軽減できる利点がある。 As a result, the connection strength between the lead terminal 2 and the electrode foil can be enhanced and the reliability of the capacitor can be further increased. Even when the tip end portion of the press-contact mold 16 is a trapezoidal portion, there is an advantage that the press-contact stress can be reduced if the corner portion is curved (spherical).

＜一実施の形態の効果＞ <Effect of one embodiment>

この実施の形態では、接合面積を低減することなく、圧接接続部８に少なくとも２箇所の接続凹部８−１、８−２を重ね合わせて生成することができる。つまり、半球部１８の個数を増加すれば、２箇所を超える接合部を形成することができる。このような２箇所以上の接続凹部を備えれば、狭い電極箔４に対して圧接接続可能領域１４を拡大することなく、電極箔４と引出し端子２との接続強度を高めることができる。つまり、引出し端子２に電極箔４の長さ方向の負荷が加わっても、複数の接続凹部による接続強度により、引出し端子２と電極箔４との接続を維持することができる。単一の接合部１０では、接合部１０を回転中心として引出し端子２が可動するおそれがあるが、このような不都合が解消される。これにより、接続強度が強化され、電極箔４に無用な応力を作用させることがなく、電極箔４を箔割れなどから防護することができる。結果として、コンデンサの信頼性を維持することができる。 In this embodiment, at least two connection recesses 8-1 and 8-2 can be generated by being superimposed on the press-contact connection portion 8 without reducing the bonding area. That is, if the number of hemispherical portions 18 is increased, more than two joint portions can be formed. If two or more connection concave portions are provided, the connection strength between the electrode foil 4 and the lead terminal 2 can be increased without enlarging the press-connectable region 14 with respect to the narrow electrode foil 4. That is, even when a load in the length direction of the electrode foil 4 is applied to the extraction terminal 2, the connection between the extraction terminal 2 and the electrode foil 4 can be maintained by the connection strength due to the plurality of connection recesses. In the single joint 10, there is a possibility that the lead terminal 2 may move around the joint 10 as a rotation center, but such inconvenience is solved. Thereby, the connection strength is strengthened, and unnecessary stress is not applied to the electrode foil 4, and the electrode foil 4 can be protected from foil cracking and the like. As a result, the reliability of the capacitor can be maintained.

接合部１０に挟まれた隆起部１２では、引出し端子２側の金属流動を抑えることができ、たとえば隆起した金属により電極箔４側への反発力が得られる。つまり隆起部１２は、半球部１８−１と半球部１８−２が隣接して形成された金型凹部２２によって押圧されている。このとき隆起部１２には、たとえば金型凹部２２の周縁において半球部１８−１と半球部１８−２による押圧力が隆起部１２を中心として対向状態となる。このように引出し端子２は、隆起部１２において、対向する押圧力を受けることで金属流動が生じない。また、隆起部１２に作用する押圧力は、半球部１８−１、１８−２側への反発力となる。そして、図３のＢにおいて矢視するように、この反発力と圧接金型１６の金型凹部２２による押圧力により電極箔４と引出し端子２に挟まれた電極箔４の伸びを防止でき、電極箔４と引出し端子２との接続強度を向上させることができる。 In the raised portion 12 sandwiched between the joint portions 10, metal flow on the lead terminal 2 side can be suppressed, and for example, a repulsive force toward the electrode foil 4 side is obtained by the raised metal. That is, the raised portion 12 is pressed by the mold concave portion 22 formed by adjoining the hemispherical portion 18-1 and the hemispherical portion 18-2. At this time, for example, the pressing force by the hemispherical portion 18-1 and the hemispherical portion 18-2 is opposed to the raised portion 12 around the raised portion 12 at the periphery of the mold recess 22. In this way, the lead terminal 2 receives no opposing pressing force at the raised portion 12 so that no metal flow occurs. Further, the pressing force acting on the raised portion 12 becomes a repulsive force toward the hemispherical portions 18-1 and 18-2. And, as indicated by an arrow in FIG. 3B, the repulsive force and the pressing force by the die recess 22 of the press contact mold 16 can prevent the electrode foil 4 from being stretched between the electrode foil 4 and the lead terminal 2, The connection strength between the electrode foil 4 and the lead terminal 2 can be improved.

〔他の実施の形態〕 [Other Embodiments]

(1) 上記実施の形態に示すコンデンサは、電解コンデンサに限定されない。電気二重層コンデンサなどの他のコンデンサに適用できるものである。 (1) The capacitors described in the above embodiments are not limited to electrolytic capacitors. It can be applied to other capacitors such as electric double layer capacitors.

(2) 上記実施の形態では、圧接金型１６に２つの圧接部として半球部１８−１、１８−２を備えたが、３以上の圧接部を備え、接合部１０を引出し端子２の長手方向または幅方向に増加させてもよい。 (2) In the above embodiment, the press contact mold 16 includes the hemispherical portions 18-1 and 18-2 as the two press contact portions. However, the press contact die 16 includes three or more press contact portions, and the joint portion 10 is the longitudinal length of the lead terminal 2. It may be increased in the direction or the width direction.

(3) 上記実施の形態では、単一の圧接接続部８に複数の接合部１０（凹部）を備える形態について説明したが、複数の圧接接続部８を備え、各圧接接続部８に複数の接合部１０（凹部）を備えてもよい。斯かる接続形態は、狭い電極箔４に好適ではあるが、本発明は電極箔４が狭い場合に限定されるものではない。 (3) In the above-described embodiment, the mode in which the single pressure contact connecting portion 8 includes the plurality of joint portions 10 (concave portions) has been described. However, the plurality of pressure contact connecting portions 8 are provided, and each pressure contact connecting portion 8 includes a plurality of You may provide the junction part 10 (concave part). Such a connection form is suitable for the narrow electrode foil 4, but the present invention is not limited to the case where the electrode foil 4 is narrow.

(4) 上記実施の形態では、引出し端子２に電極箔４を重ねた後、電極箔４側から圧接金型１６を押し付けて接続している。このように、引出し端子２に加工をせず、接続させてもよいが、引出し端子２の圧接接続部８となる部分に予め凹部を形成した後、凹部を覆って引出し端子２に電極箔４を重ねた後、電極箔４側から圧接金型１６を押し付けて接続してもよい。このようにすることで、凹部に電極箔４が入り込んだ後、凹部の側面および底面に対して均等に押圧するため、電極箔４が局所的に押圧されて薄くなることはなく、脆弱部の発生を防止することができる。 (4) In the above embodiment, after the electrode foil 4 is overlaid on the lead terminal 2, the pressure contact mold 16 is pressed and connected from the electrode foil 4 side. As described above, the lead terminal 2 may be connected without being processed. However, after a concave portion is formed in advance in a portion to be the pressure contact portion 8 of the lead terminal 2, the concave portion is covered and the electrode foil 4 is attached to the lead terminal 2. Then, the press contact mold 16 may be pressed and connected from the electrode foil 4 side. In this way, after the electrode foil 4 enters the recess, the electrode foil 4 is not pressed and thinned locally because the electrode foil 4 is pressed evenly against the side and bottom surfaces of the recess. Occurrence can be prevented.

(5) また、圧接金型１６を圧接する際に、引出し端子２の偏平部２−１の変形を抑えるため、偏平部２−１の側面を囲うように拘束金型を用いてもよい。この拘束金型では、引出し端子２を載置する平坦面部と、引出し端子２の側面部に配置される拘束立壁と、偏平部２−１のリード部２−３と反対側の縁部に配置される拘束立壁を備え、拘束金型で引出し端子２の偏平部２−１を囲んだ状態で、圧接金型１６で圧接してもよい。このような構成とすれば、電極箔４に脆弱部が発生することがなく、引出し端子２の応力変形による箔割れを防止できる。 (5) In order to suppress deformation of the flat part 2-1 of the lead terminal 2 when the press-contacting mold 16 is pressed, a constraining mold may be used so as to surround the side surface of the flat part 2-1. In this constraining mold, the flat surface portion on which the lead terminal 2 is placed, the constraining standing wall disposed on the side surface portion of the lead terminal 2, and the edge portion on the opposite side of the lead portion 2-3 of the flat portion 2-1. The pressurizing die 16 may be press-contacted in a state where the restraint standing wall is provided and the flat part 2-1 of the lead terminal 2 is surrounded by the restraint die. With such a configuration, a weak portion is not generated in the electrode foil 4, and a foil crack due to stress deformation of the lead terminal 2 can be prevented.

つまり、拘束金型を配置すれば、圧接金型１６の押圧時、引出し端子２の幅方向への広がり、それによる電極箔４の追従による引き延ばしを防止できる。この結果、圧接時に幅方向への引出し端子２の広がりもなく、引出し端子２の応力変形による箔割れを防止でき、電極箔４と引出し端子２の接続強度を高めることができる。 In other words, if a constraining mold is arranged, it is possible to prevent the lead terminal 2 from spreading in the width direction when the press-contact mold 16 is pressed, and thereby extending the electrode foil 4 due to follow-up. As a result, there is no spread of the lead terminal 2 in the width direction at the time of pressure contact, and it is possible to prevent the cracking of the foil due to the stress deformation of the lead terminal 2, and to increase the connection strength between the electrode foil 4 and the lead terminal 2.

(6) 上記実施の形態では、冷間圧接（コールドウェルド接続）による圧接接続部８に形成される接続凹部８−１、８−２が引出し端子２の長さ方向に隣接して配置した場合を示したがこれに限られない。接続凹部８−１、８−２は、たとえば図４に示すように、引出し端子２の幅方向に隣接して配置してもよい。すなわちこの接続凹部８−１、８−２の配置方向は、たとえば引出し端子２を接続する電極箔４の長さ方向に沿って設定される。 (6) In the above embodiment, when the connection recesses 8-1 and 8-2 formed in the pressure connection portion 8 by cold pressure welding (cold weld connection) are adjacent to each other in the length direction of the lead terminal 2 However, the present invention is not limited to this. For example, as shown in FIG. 4, the connection recesses 8-1 and 8-2 may be arranged adjacent to each other in the width direction of the lead terminal 2. That is, the arrangement direction of the connection recesses 8-1 and 8-2 is set along the length direction of the electrode foil 4 that connects the lead terminals 2, for example.

このような構成によっても、上記のように、引出し端子２と電極箔４との接続強度を向上させることができる。また、接続凹部８−１、８−２を引出し端子２の幅方向に隣接して配置することで、コンデンサの低背化に伴ってコンデンサ素子の高さを低くする構造とした場合に、接続凹部８−１、８−２と電極箔４の端との間で箔割れの発生を防ぐことができる。つまり、コンデンサ素子の高さを低くするために電極箔４の幅を狭小化した場合、接続凹部８−１、８−２を電極箔４の幅方向の端部から距離をとって形成することができる。このように接続凹部８−１、８−２を電極箔４の端部または縁部に近接させないことで、接続凹部８−１、８−２と電極箔４の幅方向の端との間で、形成加工時などに箔割れが発生するのを防ぎ、コンデンサの低背化とともに、接続強度を高めることができる。 Even with such a configuration, the connection strength between the lead terminal 2 and the electrode foil 4 can be improved as described above. Further, when the connection recesses 8-1 and 8-2 are arranged adjacent to each other in the width direction of the lead-out terminal 2, the height of the capacitor element is reduced with a reduction in the height of the capacitor. Generation | occurrence | production of a foil crack can be prevented between the recessed parts 8-1 and 8-2 and the edge of the electrode foil 4. FIG. That is, when the width of the electrode foil 4 is reduced in order to reduce the height of the capacitor element, the connection recesses 8-1 and 8-2 are formed at a distance from the end in the width direction of the electrode foil 4. Can do. By not connecting the connection recesses 8-1 and 8-2 to the end or edge of the electrode foil 4 in this way, between the connection recesses 8-1 and 8-2 and the end of the electrode foil 4 in the width direction. It is possible to prevent the occurrence of foil cracking at the time of forming, etc., and to reduce the height of the capacitor and increase the connection strength.

また、接続凹部８−１、８−２を引出し端子２の幅方向に隣接して配置させることで、幅の狭い電極箔４に対しても複数の接続凹部８−１、８−２を設けることができる。これにより、接続凹部８−１、８−２の端部と電極箔４の縁部との隙間を確保でき、接続凹部８−１、８−２と電極箔４の縁部間のひび割れや箔割れを防ぐことができる。しかも、圧接金型１６を押圧した際、引出し端子２が放射線状に伸びるので、これに追従して電極箔４が伸びるので、接続凹部８−１、８−２と電極箔４の縁部との幅が少ない場合、接続凹部８−１、８−２と電極箔４の縁部との間にひび割れや箔割れが生じるのを防止できる。また、製造工程中に引出し端子２に電極箔４の長さ方向に対して負荷が掛かった場合でも、引出し端子２の回転を防止でき、圧接接続部８にひび割れや箔割れが生じるのを防止できる。 Further, by arranging the connection recesses 8-1 and 8-2 adjacent to each other in the width direction of the lead terminal 2, a plurality of connection recesses 8-1 and 8-2 are provided for the electrode foil 4 having a small width. be able to. Thereby, the clearance gap between the edge part of the connection recessed parts 8-1 and 8-2 and the edge part of the electrode foil 4 can be ensured, and the crack and foil between the connection recessed parts 8-1 and 8-2 and the edge part of the electrode foil 4 are ensured. Breaking can be prevented. In addition, when the press contact mold 16 is pressed, the lead terminal 2 extends radially, and the electrode foil 4 extends following this, so the connection recesses 8-1 and 8-2 and the edge of the electrode foil 4 When the width is small, it is possible to prevent cracks and foil cracks from occurring between the connection recesses 8-1 and 8-2 and the edge of the electrode foil 4. In addition, even when a load is applied to the extraction terminal 2 in the length direction of the electrode foil 4 during the manufacturing process, the extraction terminal 2 can be prevented from rotating, and cracks and foil cracks can be prevented from occurring in the pressure contact portion 8. it can.

そのほか接続凹部８−１、８−２を引出し端子２の幅方向に形成することで、常に接続凹部８−１、８−２が電極箔４内に設定される。これにより接続凹部８−１、８−２の形成間隔が大きく設定された場合でも、接合部１０が電極箔４からはみ出すことがなく、引出し端子２と電極箔４との接続状態を維持し、その接続強度を向上させることができる。 In addition, the connection recesses 8-1 and 8-2 are always set in the electrode foil 4 by forming the connection recesses 8-1 and 8-2 in the width direction of the lead terminal 2. Thereby, even when the formation interval of the connection recesses 8-1 and 8-2 is set to be large, the joining portion 10 does not protrude from the electrode foil 4, and the connection state between the lead terminal 2 and the electrode foil 4 is maintained. The connection strength can be improved.

(7) 上記実施の形態では、冷間圧接による圧接接続部８に形成される接続凹部８−１、８−２が引出し端子２の長さ方向もしくは幅方向に隣接して配置した場合を示したが、これに限られず、斜め方向に配置してもよい。このように圧接接続箇所を最も長く確保できる斜め方向に圧接接続部８を形成することで、圧接接続可能領域１４がより狭小化した場合であっても、電極箔４の端部からの距離をとって接続凹部８−１、８−２を形成できる。 (7) In the above embodiment, the case where the connection recesses 8-1 and 8-2 formed in the pressure connection portion 8 by cold pressure welding are arranged adjacent to each other in the length direction or the width direction of the lead terminal 2 is shown. However, the present invention is not limited to this and may be arranged in an oblique direction. In this way, by forming the press contact connection portion 8 in an oblique direction in which the press contact connection portion can be ensured the longest, the distance from the end of the electrode foil 4 can be reduced even when the press contact connectable region 14 is further narrowed. Thus, the connection recesses 8-1 and 8-2 can be formed.

(8) 上記実施の形態では、半球形の一対の柱状部２０−１、２０−２を一体に備えた圧接金型１６を用いているが、これに限定されない。たとえば、半球形の柱状部を別個に複数用意し、隣接した状態に配置した上で、同時に電極箔４に押し付けてもよい。 (8) In the above embodiment, the press contact mold 16 integrally including a pair of hemispherical columnar portions 20-1 and 20-2 is used, but the present invention is not limited to this. For example, a plurality of hemispherical columnar portions may be separately prepared and arranged adjacent to each other and then pressed against the electrode foil 4 at the same time.

(9) 上記実施の形態では、隆起部１２は隣接した接続凹部８−１、８−２からなる窪み内に存在しており、隆起部１２は偏平部２−１の電極箔４が載置した面より低く形成されているが、これに限定されない。偏平部２−１の電極箔４が載置された面まで形成されてもよい。半球部１８−１と１８−２とが隣接する面積が大きくなることで、電極箔４と引出し端子２の接続強度を向上させることができる。 (9) In the above-described embodiment, the raised portion 12 exists in the depression formed by the adjacent connection concave portions 8-1 and 8-2, and the raised portion 12 is placed with the electrode foil 4 of the flat portion 2-1. However, the present invention is not limited to this. It may be formed up to the surface on which the electrode foil 4 of the flat part 2-1 is placed. By increasing the area in which the hemispherical portions 18-1 and 18-2 are adjacent to each other, the connection strength between the electrode foil 4 and the extraction terminal 2 can be improved.

以上説明したように、本発明の最も好ましい実施の形態等について説明した。本発明は、上記記載に限定されるものではない。特許請求の範囲に記載され、または発明を実施するための形態に開示された発明の要旨に基づき、当業者において様々な変形や変更が可能である。斯かる変形や変更が、本発明の範囲に含まれることは言うまでもない。
As described above, the most preferable embodiment of the present invention has been described. The present invention is not limited to the above description. Various modifications and changes can be made by those skilled in the art based on the gist of the invention described in the claims or disclosed in the embodiments for carrying out the invention. It goes without saying that such modifications and changes are included in the scope of the present invention.

本発明ではたとえば、単一の接続部の凹部内に複数の接合部を備えることにより、電極箔と引出し端子との接続強度を高めており、電解コンデンサ、電気二重層コンデンサなどのコンデンサの端子接続の強化および信頼性を高めることができ、有用である。
In the present invention, for example, the connection strength between the electrode foil and the lead terminal is increased by providing a plurality of joints in the recess of the single connection part, and the terminal connection of a capacitor such as an electrolytic capacitor or an electric double layer capacitor is achieved. It is possible to strengthen and enhance the reliability.

２引出し端子
２−１偏平部
２−２支持部
４電極箔
８圧接接続部
８−１、８−２接続凹部
１０接合部
１２隆起部
１４圧接接続可能領域
１６圧接金型
１８−１、１８−２半球部
２０−１、２０−２柱状部
２２金型凹部
DESCRIPTION OF SYMBOLS 2 Lead terminal 2-1 Flat part 2-2 Support part 4 Electrode foil 8 Press contact connection part 8-1, 8-2 Connection recessed part 10 Joint part 12 Raised part 14 Pressure contact connection possible area 16 Press contact mold 18-1, 18- 2 Hemispherical parts 20-1, 20-2 Columnar part 22 Mold recess

Claims

A capacitor in which the lead terminal is connected to the electrode foil by a cold welding method,
A pressure contact connecting portion in which the lead terminal and the electrode foil are pressure connected, and
Provided with a plurality of recesses in the pressure connection portion,
Wherein the plurality of recesses are adjacent overlapping portions, said that exist in the recess adjacent wall portion are formed in each recess between the recesses,
Capacitor characterized by that.

The shape of the press-contact connection portion is a curved surface,
The capacitor according to claim 1 .

A capacitor manufacturing method using a cold welding method for connecting the electrode foil and the lead terminal,
Are adjacent overlapping projections of several, a pressing portion which the wall portions adjacent between the convex portions present on the projecting portion formed by the convex portions, formed on the cold weld die,
A method of manufacturing a capacitor, comprising: a process of superimposing the electrode foil on the extraction terminal and pressing the electrode foil by the pressing portion of the cold pressure welding mold.