JP2010199350A

JP2010199350A - Solid-state electrolytic capacitor

Info

Publication number: JP2010199350A
Application number: JP2009043390A
Authority: JP
Inventors: Takashi Mizukoshi; 崇水越; Takeshi Saito; 猛齋藤; Takeo Kasuga; 健男春日; Yuji Yoshida; 雄次吉田; Koji Sakata; 幸治坂田
Original assignee: NEC Tokin Corp
Current assignee: Tokin Corp
Priority date: 2009-02-26
Filing date: 2009-02-26
Publication date: 2010-09-09

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid-state electrolytic capacitor which has high reliability and is made thin. <P>SOLUTION: A capacitor element which includes a valve action metal as an anode body and is provided with a cathode having a dielectric layer formed of an oxide film on its surface and also having a conductive polymer film, a graphite layer, and a silver paste layer formed on the dielectric layer is sandwiched between opposed metal foils 4 forming the exterior, and the metal foils 4 are connected together in a bag shape along a periphery of the capacitor element except a lead-out hole for an anode terminal 2. A sealing resin 3 is injected into the bag of the metal foils 4 containing the capacitor element through the lead-out hole for the anode terminal, and the metal foils 4 and the cathode of the capacitor element are connected together using a conductive adhesive 7. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

本発明は、耐湿、耐熱信頼性の向上と、薄型化を目的とした表面実装型の固体電解コンデンサに関する。 The present invention relates to a surface mount type solid electrolytic capacitor for the purpose of improving moisture resistance and heat reliability and reducing the thickness.

導電性高分子を固体電解質として用いた固体電解コンデンサは、等価直列抵抗（ＥＳＲ）を下げることが出来るが、導電性高分子は耐湿、耐熱信頼性試験といった高湿度や高温の環境において劣化し易いことが知られている。劣化の程度は導電性高分子周辺の気密性(ガス透過性)に大きく依存しており、気密性を上げることで高い信頼性を実現することが出来る。 A solid electrolytic capacitor using a conductive polymer as a solid electrolyte can lower the equivalent series resistance (ESR), but the conductive polymer is likely to deteriorate in high humidity and high temperature environments such as moisture resistance and heat reliability tests. It is known. The degree of deterioration largely depends on the airtightness (gas permeability) around the conductive polymer, and high reliability can be realized by increasing the airtightness.

また、近年、電子機器は小型、薄型化が進み、使用される電子部品も小型、低背化が求められている。表面実装型固体電解コンデンサにも同様の要求があり、これらを実現することは製品にとって大きな特徴となる。 In recent years, electronic devices have been reduced in size and thickness, and electronic components to be used have been required to be reduced in size and height. Surface mount type solid electrolytic capacitors have similar requirements, and realizing them is a major feature for products.

したがって、気密性を高め、小型、低背化を実現することが出来れば、従来よりも厳しい環境下で使用でき、部品自体の小型、低背化による省スペース化や、これまで電子機器回路基板のデッドスペースだった部分への搭載が可能となるなど、電子機器の小型、薄型化に貢献できる。 Therefore, if the airtightness can be improved, and the size and height can be reduced, it can be used in harsher environments than before. This makes it possible to reduce the size and thickness of electronic devices.

従来の表面実装型の固体電解コンデンサは、缶ケースに表面実装用の樹脂部品を付けた構造(例えば特許文献１)、モールド樹脂による樹脂外装した構造(例えば特許文献２)がほとんどである。缶ケースを用いた場合は、気密性は高いが薄型化する事は構造上非常に困難である。一方、モールド樹脂で外装する場合は、缶ケースより薄型化出来るが、モールド樹脂を１００μｍ以下の厚みに成形することが困難であることと、導電性高分子の劣化を防ぐため気密性を確保するには樹脂厚みを厚く設計しなければならない。特許文献２ではリードフレームの形状を工夫し外装樹脂の薄肉化を行っているが薄型化には限界がある。 Conventional surface mount type solid electrolytic capacitors are mostly structured by attaching a resin component for surface mounting to a can case (for example, Patent Document 1) and a structure in which a resin exterior is provided with a mold resin (for example, Patent Document 2). When a can case is used, the airtightness is high, but it is very difficult to make it thin. On the other hand, when packaged with a mold resin, it can be made thinner than the can case, but it is difficult to mold the mold resin to a thickness of 100 μm or less, and airtightness is secured to prevent deterioration of the conductive polymer. The resin must be designed with a large thickness. In Patent Document 2, the shape of the lead frame is devised to reduce the thickness of the exterior resin, but there is a limit to reducing the thickness.

特開平８−１１５８４２号公報JP-A-8-115842 特開２０００−３４０４６３号公報JP 2000-340463 A

表面実装型の固体電解コンデンサを薄型化するためには従来のモールド樹脂による外装では限界があり、外装が薄くなると気密性が低下し、製品の信頼性が低下する。本発明の課題は信頼性の高い薄型化した固体電解コンデンサを提供することにある。 In order to reduce the thickness of a surface mount type solid electrolytic capacitor, there is a limit to the exterior with a conventional mold resin. When the exterior is thin, the airtightness is lowered and the reliability of the product is lowered. An object of the present invention is to provide a solid electrolytic capacitor with high reliability and reduced thickness.

本発明は、コンデンサ素子を金属箔で挟み、陽極端子の引き出し部を除いたコンデンサ素子の周囲の金属箔を密封させて袋状にすることにより気密性を向上させたものである。即ち、本発明の固体電解コンデンサは、板状または箔状の弁作用金属からなる陽極体の一端の陽極部と、弁作用金属陽極体前記陽極部を除く前記陽極体の表面に形成された酸化皮膜からなる誘電体層と、前記誘電体層上に形成された導電性高分子膜、グラファイト層、銀ペースト層からなる陰極部とを有するコンデンサ素子と、前記コンデンサ素子の前記陽極部に接続された陽極端子と、前記陽極部と陽極端子の接続された部分の周囲に形成された封止樹脂と、前記陽極端子の周囲を除いて前記コンデンサ素子を挟む金属箔とを有することを特徴とする。 In the present invention, the capacitor element is sandwiched between metal foils, and the metal foil around the capacitor element excluding the lead portion of the anode terminal is hermetically sealed to improve the airtightness. That is, the solid electrolytic capacitor of the present invention includes an anode part at one end of a plate-like or foil-like valve action metal and an oxidation formed on the surface of the anode body excluding the valve action metal anode body. A capacitor element having a dielectric layer made of a film and a cathode part made of a conductive polymer film, a graphite layer, and a silver paste layer formed on the dielectric layer, and connected to the anode part of the capacitor element An anode terminal; a sealing resin formed around a portion where the anode portion and the anode terminal are connected; and a metal foil sandwiching the capacitor element except for the periphery of the anode terminal. .

また、前記陰極部と前記金属箔とを接続する導電性接着剤を有することを特徴とする。また、前記陽極端子の周囲を除いて前記コンデンサ素子を密封する金属箔を有することを特徴とする。また、前記金属箔の前記陽極部との対向面に絶縁樹脂を有することを特徴とする。 Moreover, it has an electroconductive adhesive which connects the said cathode part and the said metal foil. Moreover, it has the metal foil which seals the said capacitor | condenser element except the circumference | surroundings of the said anode terminal, It is characterized by the above-mentioned. Moreover, it has an insulating resin in the surface facing the said anode part of the said metal foil.

また、本発明の固体電解コンデンサは、前記コンデンサ素子の陽極部に接続された陽極端子と、前記陽極部と前記陽極端子の接続された部分の周囲に形成された封止樹脂と、前記陽極端子の周囲を除いて前記コンデンサ素子を挟む金属箔と、前記コンデンサ素子の側面に引き出されて折り曲げられて底面に導出された陽極端子と、前記金属箔の底面側に接続された陰極端子を有することを特徴とする。 Further, the solid electrolytic capacitor of the present invention includes an anode terminal connected to the anode portion of the capacitor element, a sealing resin formed around a portion where the anode portion and the anode terminal are connected, and the anode terminal A metal foil that sandwiches the capacitor element except for the periphery of the capacitor element, an anode terminal that is drawn out to the side surface of the capacitor element and bent to the bottom surface, and a cathode terminal that is connected to the bottom surface side of the metal foil. It is characterized by.

さらに、本発明の固体電解コンデンサは、前記コンデンサ素子の陽極部に接続された陽極端子と、前記陽極端子の陽極実装端子面を除いて前記陽極部と前記陽極端子の接続された部分の周囲に形成された封止樹脂と、前記陽極端子の周囲を除いて前記コンデンサ素子を挟み周囲が密封された金属箔と、前記陰極部と前記金属箔を接続する導電性接着剤と、前記金属箔の少なくとも底面側に陰極実装端子面を除いてレジストを有することを特徴とする。 Furthermore, the solid electrolytic capacitor of the present invention has an anode terminal connected to the anode part of the capacitor element, and a periphery of a portion where the anode part and the anode terminal are connected except for an anode mounting terminal surface of the anode terminal. A sealing resin formed; a metal foil sandwiched around the capacitor element except for the periphery of the anode terminal; a conductive adhesive that connects the cathode part and the metal foil; It has a resist at least on the bottom side except for the cathode mounting terminal surface.

本発明によれば、コンデンサ素子の陰極部の周辺は、金属により外部と遮断されており、ガスが浸入する経路は陽極端子を取り出すための外装用の金属箔の開口部からコンデンサ素子の陰極部までの封止樹脂が充填されている部分のみである。このガスが透過する経路は、通常のモールド樹脂外装と比較すると、外部からコンデンサ素子の陰極部までの距離が長く、開口部の面積が非常に小さいため、気密性が高く、高信頼性の固体電解コンデンサを得ることができる。また、外装が金属であるため気密性を低下させることなく、樹脂外装では実現不可能な外装の薄型化を実現することができる。 According to the present invention, the periphery of the cathode portion of the capacitor element is shielded from the outside by the metal, and the gas intrusion path is from the opening of the metal foil for exterior to take out the anode terminal. Only the portion filled with the sealing resin up to. This gas permeation path has a long distance from the outside to the cathode part of the capacitor element and the area of the opening is very small compared to a normal molded resin sheath, so the airtightness is high and a highly reliable solid An electrolytic capacitor can be obtained. Further, since the exterior is made of metal, it is possible to reduce the thickness of the exterior that cannot be achieved with a resin exterior without reducing the airtightness.

本発明の実施の形態１の固体電解コンデンサを説明する図、図１（ａ）は断面図、図１（ｂ）は底面図、図１（ｃ）は平面透視図。BRIEF DESCRIPTION OF THE DRAWINGS The figure explaining the solid electrolytic capacitor of Embodiment 1 of this invention, FIG.1 (a) is sectional drawing, FIG.1 (b) is a bottom view, FIG.1 (c) is a plane see-through | perspective view. 本発明の実施の形態１の固体電解コンデンサの製造工程を示す平面図。The top view which shows the manufacturing process of the solid electrolytic capacitor of Embodiment 1 of this invention. 本発明の実施の形態２の固体電解コンデンサを説明する図、図３（ａ）は断面図、図３（ｂ）は底面図、図３（ｃ）は平面透視図。FIG. 3A is a cross-sectional view illustrating a solid electrolytic capacitor according to a second embodiment of the present invention, FIG. 3B is a bottom view, and FIG. 3C is a plan perspective view. 従来の固体電解コンデンサの断面図。Sectional drawing of the conventional solid electrolytic capacitor.

（実施の形態１）
本発明の実施の形態１について図１、図２を参照して説明する。初めにコンデンサ素子について簡単に説明する。まず、板状または箔状の弁作用金属の表面にエッチング等により多数の空孔を形成して表面積を拡面化して、弁作用金属からなる陽極体を得る。弁作用金属からなる陽極体の厚みは、３０〜２００μｍが好ましく、定格電圧、静電容量、製品厚み、生産性を考慮して決定する。ここで、弁作用金属としては、タンタル、アルミニウム、ニオブ等を用いることができる。図１に示すように、陽極体の一端を陽極部９とし、陽極部９を除く陽極体の表面に陽極酸化により酸化皮膜からなる誘電体層を形成する。次に、この酸化皮膜からなる誘電体層が表面に形成された弁作用金属からなる陽極体に、導電性高分子膜を形成し、さらにその上にグラファイト層、銀ペースト層を順に形成し陰極部８としコンデンサ素子を完成する。導電性高分子膜には、ピロール、チオフェン等を用いることができる。コンデンサ素子の陽極部９に陽極端子２をレーザ溶接等によりで接続する。陽極端子２は、４２合金等の金属片を用いることができる。接続方法としては、レーザ溶接の他、導電性接着剤、超音波溶接、抵抗溶接等を用いることができる。 (Embodiment 1)
Embodiment 1 of the present invention will be described with reference to FIGS. First, the capacitor element will be briefly described. First, a large number of pores are formed on the surface of a plate-like or foil-like valve action metal by etching or the like to increase the surface area, thereby obtaining an anode body made of the valve action metal. The thickness of the anode body made of the valve metal is preferably 30 to 200 μm, and is determined in consideration of the rated voltage, capacitance, product thickness, and productivity. Here, tantalum, aluminum, niobium, or the like can be used as the valve metal. As shown in FIG. 1, one end of the anode body is used as an anode portion 9, and a dielectric layer made of an oxide film is formed on the surface of the anode body excluding the anode portion 9 by anodic oxidation. Next, a conductive polymer film is formed on an anode body made of a valve action metal having a dielectric layer made of an oxide film formed on the surface, and a graphite layer and a silver paste layer are formed on the conductive polymer film in order. The capacitor element is completed as part 8. For the conductive polymer film, pyrrole, thiophene, or the like can be used. The anode terminal 2 is connected to the anode portion 9 of the capacitor element by laser welding or the like. The anode terminal 2 may be a metal piece such as 42 alloy. As a connection method, in addition to laser welding, conductive adhesive, ultrasonic welding, resistance welding, or the like can be used.

外装用の金属箔４によるコンデンサ素子の外装は、まず、４２合金にスズメッキをした金属片等からなる陰極端子１を抵抗溶接等により底面に接続した外装用の金属箔４上にコンデンサ素子を配置し、陰極部８と外装用の金属箔４を接着銀からなる導電性接着剤７で接着する（図２参照）。さらに、コンデンサ素子の陰極部８上に接着銀からなる導電性接着剤７をディスペンスし、その上に外装用の金属箔４を載せ陽極端子２が側面から引き出されるように配置する。なお、陰極部８と外装用金属箔４との接続は必ずしも導電性接着剤である必要はなく、はんだ等金属による接続であってもよい。次に、図２に示す溶接部５をシーム溶接により接続する。溶接部は密封されていることが好ましいが必ずしも完全に密封されていなくともよい。その後、図２に示す一点鎖線線部分を金型で打ち抜く。陽極端子２側より、エポキシ樹脂等からなる封止樹脂３を外装用の金属箔４の間に注入した後、製品の形状を整え封止樹脂３を硬化させ封止し固体電解コンデンサとする。 The exterior of the capacitor element with the exterior metal foil 4 is first arranged on the exterior metal foil 4 in which the cathode terminal 1 made of a metal piece or the like plated with 42 alloy is connected to the bottom surface by resistance welding or the like. Then, the cathode portion 8 and the metal foil 4 for exterior are bonded with a conductive adhesive 7 made of adhesive silver (see FIG. 2). Further, a conductive adhesive 7 made of adhesive silver is dispensed on the cathode portion 8 of the capacitor element, and a metal foil 4 for exterior is placed thereon so that the anode terminal 2 is drawn out from the side surface. The connection between the cathode portion 8 and the outer metal foil 4 is not necessarily a conductive adhesive, and may be a connection using a metal such as solder. Next, the weld 5 shown in FIG. 2 is connected by seam welding. The weld is preferably sealed, but not necessarily completely sealed. Then, the dashed-dotted line part shown in FIG. 2 is punched with a metal mold | die. After the sealing resin 3 made of epoxy resin or the like is injected between the metal foils 4 for exterior from the anode terminal 2 side, the shape of the product is adjusted and the sealing resin 3 is cured and sealed to obtain a solid electrolytic capacitor.

外装用の金属箔４の材質は、アルミ、ステンレス、銅、４２合金等、また、それらにメッキを施したものを用いることができ、厚みは、ハンドリング、要求される製品強度、高さに応じて選択することができる。また、外装用の金属箔４には、コンデンサ素子の陽極部９、陽極端子２と接触する可能性がある部分にエポキシ系等の絶縁樹脂６をコートしておくことが望ましい。なお、陽極端子２、陰極端子１は、組み立て、シーム溶接等の邪魔にならないよう、例えばＬ字型のものを用い、封止樹脂３を硬化後に折り曲げることができる。また、２枚の金属箔４でコンデンサ素子を挟み込み３辺を接続する以外に、１枚の金属箔４を折りたたんでコンデンサ素子を挟み込み、２辺を接続してもよい。また、コンデンサ素子は１枚でなく複数枚積層し、陰極部同士を例えば導電性接着剤で接続し、陽極部同士と陽極端子を例えばレーザ溶接等で接続することもできる。 The metal foil 4 for the exterior can be made of aluminum, stainless steel, copper, 42 alloy, etc., or can be plated, and the thickness depends on handling, required product strength and height. Can be selected. Further, it is desirable that the exterior metal foil 4 is coated with an insulating resin 6 such as an epoxy-based material on a portion that may come into contact with the anode portion 9 and the anode terminal 2 of the capacitor element. The anode terminal 2 and the cathode terminal 1 are, for example, L-shaped so as not to interfere with assembly, seam welding, and the like, and the sealing resin 3 can be bent after curing. Further, in addition to sandwiching the capacitor element between the two metal foils 4 and connecting the three sides, the capacitor element may be sandwiched by folding the one metal foil 4 and the two sides may be connected. In addition, a plurality of capacitor elements may be laminated instead of one, the cathode portions may be connected to each other by, for example, a conductive adhesive, and the anode portions may be connected to the anode terminal by, for example, laser welding.

（実施の形態２）
本発明の実施の形態２について図３を参照して説明する。実施の形態１とは、コンデンサ素子は同様であるが、端子部の構造が異なる。外装用の金属箔４をコンデンサ素子の周囲４辺すべてをシーム溶接等により接続し、陽極実装端子面１０は外装用の金属箔４に穴をあけて取り出す構造とする。コンデンサ素子の陽極部９と陽極端子２は、図３（ｃ）に示すように、陽極端子レーザ溶接位置１３でレーザ溶接し、この溶接部分が、実装面として露出しないように、陽極実装端子面１０は図３（ｃ）に示すように陽極実装端子面露出形状１４の枠内となるように金属箔４の表面にレジスト１２を塗布する。陰極端子は、外装用の金属箔４を直接端子とする構造とし、陽極端子と同じ端子面形状に外装用の金属箔４が露出するように、陽極側のレジスト塗布と同時に陰極実装端子面１１を形成する。 (Embodiment 2)
A second embodiment of the present invention will be described with reference to FIG. The capacitor element is the same as that of the first embodiment, but the structure of the terminal portion is different. The exterior metal foil 4 is connected to all four sides of the capacitor element by seam welding or the like, and the anode-mounted terminal surface 10 is formed by opening a hole in the exterior metal foil 4. As shown in FIG. 3C, the anode portion 9 and the anode terminal 2 of the capacitor element are laser-welded at an anode terminal laser welding position 13 so that the welded portion is not exposed as a mounting surface. 10, a resist 12 is applied to the surface of the metal foil 4 so as to be within the frame of the anode mounting terminal surface exposed shape 14 as shown in FIG. The cathode terminal has a structure in which the exterior metal foil 4 is used as a direct terminal, and the cathode mounting terminal surface 11 is applied simultaneously with the application of the resist on the anode side so that the exterior metal foil 4 is exposed in the same terminal surface shape as the anode terminal. Form.

次に製造方法について説明する。コンデンサ素子は、実施の形態１と同様のものを用いる。外装用の金属箔４上にコンデンサ素子の陰極部８を接着銀からなる導電性接着剤７で接続し、陰極部８の上に接着銀からなる導電性接着剤７をディスペンス後、陽極端子取り出し用の穴を開けた外装用の金属箔４をのせ接続する。次に、コンデンサ素子の周囲４辺すべてをシーム溶接により溶接した後、封止樹脂３を外装用の金属箔４の陽極端子取り出し部分の穴から注入し、製品となる金属箔４および陽極端子２を上下から加圧し形状を整え封止樹脂３を硬化させる。陽極実装端子面１０には封止樹脂３が付着しないようにマスキングテープを貼っておく。次に図３（ｂ）に示すように陽極実装端子面１０および陰極実装端子面１１が実装端子形状になるようにレジスト１２を塗布した後、金型を用いて製品形状に打ち抜き固体電解コンデンサとする。 Next, a manufacturing method will be described. A capacitor element similar to that of the first embodiment is used. The cathode portion 8 of the capacitor element is connected to the exterior metal foil 4 with a conductive adhesive 7 made of adhesive silver, and after dispensing the conductive adhesive 7 made of adhesive silver on the cathode portion 8, the anode terminal is taken out. The metal foil 4 for the exterior which opened the hole for is put and connected. Next, after welding all four sides of the capacitor element by seam welding, the sealing resin 3 is injected from the hole of the anode terminal take-out portion of the metal foil 4 for exterior, and the metal foil 4 and the anode terminal 2 as products are obtained. Is pressed from above and below to adjust the shape and cure the sealing resin 3. A masking tape is stuck on the anode mounting terminal surface 10 so that the sealing resin 3 does not adhere. Next, as shown in FIG. 3B, a resist 12 is applied so that the anode mounting terminal surface 10 and the cathode mounting terminal surface 11 have a mounting terminal shape, and then punched into a product shape using a mold. To do.

本発明の実施例１の固体電解コンデンサについて実施の形態１で用いた図１、図２を参照して説明する。製品は、形状が７．３×４．３ｍｍ、定格電圧は２．５［Ｖ］とした。まず、アルミ箔からなる弁作用金属の表面にエッチング等により多数の空孔を形成して表面積を拡面化し、弁作用金属からなる陽極体を得て陽極体の表面に陽極酸化により酸化皮膜からなる誘電体層を形成した。本実施例１では、アルミ箔をエッチング後、陽極酸化した厚さ１００μｍのアルミ化成箔を用いた。次に、この陽極酸化皮膜からなる誘電体層が表面に形成された弁作用金属陽極体の陰極形成部に、ポリピロールからなる導電性高分子膜を形成し、さらにその上にグラファイト層、銀ペースト層を順に形成した。コンデンサ素子の陽極部に陽極端子２をレーザ溶接で接続した。陽極端子２は、厚み１００μｍの４２合金を用いた。 A solid electrolytic capacitor according to Example 1 of the present invention will be described with reference to FIGS. 1 and 2 used in the first embodiment. The product had a shape of 7.3 × 4.3 mm and a rated voltage of 2.5 [V]. First, a large number of pores are formed by etching or the like on the surface of the valve action metal made of aluminum foil to increase the surface area, an anode body made of valve action metal is obtained, and the surface of the anode body is oxidized from an oxide film by anodization A dielectric layer was formed. In Example 1, an aluminum conversion foil having a thickness of 100 μm that was anodized after etching the aluminum foil was used. Next, a conductive polymer film made of polypyrrole is formed on the cathode forming portion of the valve-acting metal anode body on which the dielectric layer made of this anodic oxide film is formed, and a graphite layer and a silver paste are further formed thereon. Layers were formed in order. The anode terminal 2 was connected to the anode part of the capacitor element by laser welding. As the anode terminal 2, 42 alloy having a thickness of 100 μm was used.

外装用の金属箔４によるコンデンサ素子の外装は、まず、母材を厚み１００μｍの４２合金とし、コンデンサ素子と接続する面に銀メッキを施した外装用金属箔４上にコンデンサ素子の陰極部８と外装用の金属箔４を接着銀からなる導電性接着剤７で図２に示したように接着し、さらに、コンデンサ素子の陰極部８上に接着銀からなる導電性接着剤７をディスペンスし、その上に外装用の金属箔４をのせた。次に、図２の溶接部５をシーム溶接により溶接し、図２の一転鎖線部分を金型で打ち抜いた。溶接幅は、４００μｍとした。陽極端子２側より、封止樹脂３のエポキシ樹脂を外装用の金属箔４の間に注入した後、製品の形状を整え封止樹脂３のエポキシ樹脂を硬化させ封止した。なお、外装用の金属箔４には、コンデンサ素子の陽極部９、陽極端子２と接触する可能性がある部分にエポキシ系の絶縁樹脂６をコートしたものを用いた。また、陰極端子１は厚み１００μｍの４２合金にスズメッキをしたものを用い、コンデンサ素子を挟む前に外装用の金属箔４に抵抗溶接で接続しておいた。陽極端子２は厚み１００μｍの４２合金にスズメッキをしたものを用い、外装用の金属箔４と対向する面にはエポキシ系の絶縁樹脂を塗布した。陽極端子２、陰極端子１は、組み立て、シーム溶接の邪魔にならないよう、Ｌ字型のものを用い、封止樹脂３を硬化後に図１（ａ）に示したように底面に折り曲げ固体電解コンデンサを製作した。 The exterior of the capacitor element with the exterior metal foil 4 is as follows. First, the base material is made of 42 alloy having a thickness of 100 μm, and the surface to be connected to the capacitor element is silver-plated on the exterior metal foil 4 and the cathode portion 8 of the capacitor element. 2 and a metal foil 4 for exterior packaging with a conductive adhesive 7 made of adhesive silver as shown in FIG. 2, and further, a conductive adhesive 7 made of adhesive silver is dispensed on the cathode portion 8 of the capacitor element. The metal foil 4 for exterior was put on it. Next, the welded portion 5 in FIG. 2 was welded by seam welding, and the one-dot chain line portion in FIG. 2 was punched out with a mold. The welding width was 400 μm. After injecting the epoxy resin of the sealing resin 3 between the metal foils 4 for exterior from the anode terminal 2 side, the shape of the product was adjusted and the epoxy resin of the sealing resin 3 was cured and sealed. In addition, the metal foil 4 for exterior use used what coat | covered the epoxy-type insulating resin 6 in the part which may contact the anode part 9 and the anode terminal 2 of a capacitor | condenser element. Further, the cathode terminal 1 was made by tin-plating 42 alloy having a thickness of 100 μm, and was connected to the outer metal foil 4 by resistance welding before sandwiching the capacitor element. The anode terminal 2 was a tin-plated 42 alloy having a thickness of 100 μm, and an epoxy insulating resin was applied to the surface facing the outer metal foil 4. The anode terminal 2 and the cathode terminal 1 are L-shaped so as not to interfere with assembly and seam welding, and after the sealing resin 3 is cured, it is bent to the bottom as shown in FIG. Was made.

本発明の実施例２の固体電解コンデンサについては、外装用の金属箔４の厚みを３０μｍとした以外は構成部材の材質、形状は実施例１と同様として固体電解コンデンサを製作した。 For the solid electrolytic capacitor of Example 2 of the present invention, the material and shape of the constituent members were the same as those of Example 1 except that the thickness of the metal foil 4 for exterior was 30 μm, and a solid electrolytic capacitor was manufactured.

本発明の実施例３の固体電解コンデンサについて実施の形態２で用いた図３を参照して説明する。コンデンサ素子は実施例１と同様のものを使用した。母材を厚み１００μｍの４２合金とし、コンデンサ素子と接続する面に銀メッキを施した外装用金属箔４をコンデンサ素子の周囲４辺すべてをシーム溶接し、厚み１００μｍの４２合金を用いた陽極端子は外装用の金属箔４に穴をあけて取り出す構造とした。即ち、外装用の金属箔４上にコンデンサ素子の陰極部８を接着銀からなる導電性接着剤７で接続し、陰極部の上に接着銀からなる導電性接着剤７をディスペンスした後、陽極端子取り出し用の穴を開けた外装用の金属箔４をのせ接続した。次に、コンデンサ素子の周囲４辺すべてをシーム溶接により溶接した。コンデンサ素子の陽極部９と陽極端子２は、予め図３（ｃ）に示すように陽極端子レーザ溶接位置１３でレーザ溶接しておく。封止樹脂３を外装用の金属箔４の陽極端子取り出し部分の穴から注入し、製品を上下から加圧し形状を整え封止樹脂３を硬化させた。陽極実装端子面１０には封止樹脂３が付着しないようにマスキングテープを貼った。陽極端子レーザ溶接位置１３が、実装面として露出しないように、陽極実装端子面１０は図３（ｃ）に示す陽極実装端子面露出形状１４の枠内となるようにレジスト１２を塗布した。陰極端子は、外装用の金属箔４を直接端子とする構造とし、陽極端子と同じ端子形状に外装用の金属箔４が露出するように、陽極側のレジスト塗布と同時に陰極実装端子面１１を形成した。その後、金型を用いて製品形状に打ち抜き固体電解コンデンサを作製した。 A solid electrolytic capacitor according to Example 3 of the present invention will be described with reference to FIG. 3 used in the second embodiment. The same capacitor element as in Example 1 was used. An anode terminal using a 42 alloy having a thickness of 100 μm, seam-welding all four sides of the outer periphery of the capacitor element, and a metal foil for exterior 4 having a silver plating on the surface to be connected to the capacitor element. Has a structure in which a metal foil 4 for exterior use is punched out. That is, the cathode part 8 of the capacitor element is connected to the exterior metal foil 4 with the conductive adhesive 7 made of adhesive silver, and the conductive adhesive 7 made of adhesive silver is dispensed on the cathode part, and then the anode The metal foil 4 for the exterior which opened the hole for terminal extraction was put and connected. Next, all four sides around the capacitor element were welded by seam welding. The anode portion 9 and the anode terminal 2 of the capacitor element are previously laser welded at the anode terminal laser welding position 13 as shown in FIG. The sealing resin 3 was injected from the hole at the portion where the anode terminal of the metal foil 4 for exterior was taken out, and the product was pressed from above and below to adjust the shape and harden the sealing resin 3. A masking tape was applied to the anode mounting terminal surface 10 so that the sealing resin 3 did not adhere. The resist 12 was applied so that the anode mounting terminal surface 10 was within the frame of the anode mounting terminal surface exposed shape 14 shown in FIG. 3C so that the anode terminal laser welding position 13 was not exposed as the mounting surface. The cathode terminal has a structure in which the exterior metal foil 4 is a direct terminal, and the cathode mounting terminal surface 11 is formed simultaneously with the application of the resist on the anode side so that the exterior metal foil 4 is exposed in the same terminal shape as the anode terminal. Formed. Thereafter, a solid electrolytic capacitor was produced by punching into a product shape using a mold.

本発明の実施例４の固体電解コンデンサについては、外装用の金属箔４の厚みを３０μｍとした以外は構成部材の材質、形状は実施例３と同様として固体電解コンデンサを製作した。 For the solid electrolytic capacitor of Example 4 of the present invention, the material and shape of the constituent members were the same as in Example 3 except that the thickness of the outer metal foil 4 was 30 μm, and a solid electrolytic capacitor was manufactured.

コンデンサ素子を２枚積層した以外は構成部材の材質、形状は実施例４と同様として固体電解コンデンサを製作した。２枚のコンデンサ素子の陰極部８は接着銀からなる導電性接着剤７で接続し、コンデンサ素子の陽極部９は実装端子に２枚重ねてレーザで溶接して固体電解コンデンサを製作した。 A solid electrolytic capacitor was manufactured in the same manner as in Example 4 except that two capacitor elements were laminated. The cathode portions 8 of the two capacitor elements were connected by a conductive adhesive 7 made of adhesive silver, and two anode portions 9 of the capacitor elements were stacked on the mounting terminals and welded with a laser to produce a solid electrolytic capacitor.

（比較例１）
図４に示した従来の固体電解コンデンサを比較例１とする。コンデンサ素子は実施例１と同じ構成とした。モールド樹脂１７の肉厚は０．１ｍｍ以下で成形すると成形時に樹脂が回り込まない部分ができることや、気密性が著しく低下するため、若干余裕を持ち最薄部分の肉厚が０．１５ｍｍとなるように成形し固体電解コンデンサを製作した。 (Comparative Example 1)
The conventional solid electrolytic capacitor shown in FIG. The capacitor element had the same configuration as in Example 1. If the mold resin 17 is molded with a thickness of 0.1 mm or less, a portion where the resin does not wrap around at the time of molding is formed, and the airtightness is remarkably lowered, so that the thickness of the thinnest portion is 0.15 mm with some margin. To produce a solid electrolytic capacitor.

（比較例２）
コンデンサ素子を２枚積層した以外は構成部材の材質、形状は比較例１と同様とした。２枚のコンデンサ素子の接続方法は実施例５と同様とし固体電解コンデンサを製作した。 (Comparative Example 2)
The material and shape of the constituent members were the same as in Comparative Example 1 except that two capacitor elements were stacked. The method of connecting the two capacitor elements was the same as in Example 5, and a solid electrolytic capacitor was manufactured.

実施例１〜５、比較例１、２を各３０個作製し、特性を比較した結果を表１に示した。気密性の影響を調べるため信頼性試験として、１２５℃、２．５［Ｖ］電圧印加と、６５℃、９５％Ｒ.Ｈ.、２．５［Ｖ］電圧印加試験を行い、測定周波数１００ｋＨｚの等価直列抵抗（ＥＳＲ）の初期値に対する１０００時間後の上昇率を表１に示した。あわせてそれぞれの固体電解コンデンサの高さ寸法を示した。 Examples 1 to 5 and Comparative Examples 1 and 2 were prepared 30 times, and the results of comparing the characteristics are shown in Table 1. In order to investigate the influence of airtightness, 125 ° C., 2.5 [V] voltage application and 65 ° C., 95% RH, 2.5 [V] voltage application test were conducted as a reliability test, and the measurement frequency was 100 kHz. Table 1 shows the rate of increase after 1000 hours with respect to the initial value of the equivalent series resistance (ESR). In addition, the height dimensions of each solid electrolytic capacitor are shown.

まず、各水準の信頼性試験の結果を比較する。全て同じ内部素子を使用していることから、この結果は外装の気密性の影響であると考えられる。実施例１〜実施例５は、比較例１、比較例２に比べ劣化が小さいことが分かり、モールド樹脂外装に比べ本発明による外装は気密性が高いと考えられる。また、実施例１と実施例２、実施例３と実施例４をそれぞれ比較した場合、外装である外装用金属箔４が１００μｍと３０μｍと３倍以上異なるにも関わらず劣化の程度は同じであり、外装用金属箔４を用いることで、モールド樹脂外装では実現できない極薄で高い信頼性の外装を実現出来ることが分かった。 First, the results of reliability tests at each level are compared. Since all the same internal elements are used, this result is considered to be due to the hermeticity of the exterior. Examples 1 to 5 are found to be less deteriorated than Comparative Examples 1 and 2, and the exterior according to the present invention is considered to have higher airtightness than the molded resin exterior. Moreover, when Example 1 and Example 2 and Example 3 and Example 4 are compared, respectively, the extent of deterioration is the same even though the exterior metal foil 4 that is the exterior differs from 100 μm and 30 μm by three times or more. In other words, it was found that by using the metal foil 4 for the exterior, it is possible to realize an extremely thin and highly reliable exterior that cannot be realized by the mold resin exterior.

実施例５に示した積層素子を用いた場合についても、同様に積層素子を用いた比較例２に比べ高い信頼性を確保できることが分かった。実施例１、実施例２と実施例３、実施例４で劣化の程度に差が現れたのは、実施例３、実施例４の場合の方が陽極端子を取り出すための外装用の金属箔４の開口部がコンデンサ素子の陰極部８に近いため、陰極部分の気密性が低かったためと考えられる。各水準の製品高さは、比較例１に比べ、外装用の金属箔４として厚み３０μｍを用いた実施例２、実施例４は高さが低くなっており、特に実施例４では比較例１に比べ、３５０μｍ程度も低くすることができた。 Also in the case where the laminated element shown in Example 5 was used, it was found that high reliability can be secured as compared with Comparative Example 2 using the laminated element. The difference in the degree of deterioration between Example 1 and Example 2 and Example 3 and Example 4 is that the metal foil for the exterior for taking out the anode terminal in the case of Example 3 and Example 4 This is probably because the airtightness of the cathode portion was low because the opening portion 4 was close to the cathode portion 8 of the capacitor element. Compared with Comparative Example 1, the product height at each level is lower in Examples 2 and 4 where the thickness of the metal foil 4 for exterior use is 30 μm. Compared to, it could be as low as 350 μm.

１陰極端子
２陽極端子
３封止樹脂
４金属箔
５溶接部
６絶縁樹脂
７導電性接着剤
８陰極部
９陽極部
１０陽極実装端子面
１１陰極実装端子面
１２レジスト
１３陽極端子レーザ溶接位置
１４陽極実装端子面露出形状
１５陰極リードフレーム端子
１６陽極リードフレーム端子
１７モールド樹脂 DESCRIPTION OF SYMBOLS 1 Cathode terminal 2 Anode terminal 3 Sealing resin 4 Metal foil 5 Welding part 6 Insulating resin 7 Conductive adhesive 8 Cathode part 9 Anode part 10 Anode mounting terminal surface 11 Cathode mounting terminal surface 12 Resist 13 Anode terminal laser welding position 14 Anode Mounting terminal surface exposed shape 15 Cathode lead frame terminal 16 Anode lead frame terminal 17 Mold resin

Claims

板状または箔状の弁作用金属からなる陽極体の一端の陽極部と、弁作用金属陽極体前記陽極部を除く前記陽極体の表面に形成された酸化皮膜からなる誘電体層と、前記誘電体層上に形成された導電性高分子膜、グラファイト層、銀ペースト層からなる陰極部とを有するコンデンサ素子と、前記コンデンサ素子の前記陽極部に接続された陽極端子と、前記陽極部と陽極端子の接続された部分の周囲に形成された封止樹脂と、前記陽極端子の周囲を除いて前記コンデンサ素子を挟む金属箔とを有することを特徴とする固体電解コンデンサ。 An anode portion at one end of a plate-like or foil-like anode metal, a valve metal anode body, a dielectric layer made of an oxide film formed on the surface of the anode body excluding the anode portion, and the dielectric A capacitor element having a cathode part made of a conductive polymer film, a graphite layer and a silver paste layer formed on the body layer; an anode terminal connected to the anode part of the capacitor element; and the anode part and the anode A solid electrolytic capacitor comprising: a sealing resin formed around a portion where terminals are connected; and a metal foil that sandwiches the capacitor element except around the anode terminal.

前記陰極部と前記金属箔とを接続する導電性接着剤を有することを特徴とする請求項１に記載の固体電解コンデンサ。 The solid electrolytic capacitor according to claim 1, further comprising a conductive adhesive that connects the cathode portion and the metal foil.

前記陽極端子の周囲を除いて前記コンデンサ素子を密封する金属箔を有することを特徴とする請求項１に記載の固体電解コンデンサ。 The solid electrolytic capacitor according to claim 1, further comprising a metal foil that seals the capacitor element except around the anode terminal.

前記金属箔の前記陽極部との対向面に絶縁樹脂を有することを特徴とする請求項１に記載の固体電解コンデンサ。 The solid electrolytic capacitor according to claim 1, further comprising an insulating resin on a surface of the metal foil facing the anode portion.

前記コンデンサ素子の陽極部に接続された陽極端子と、前記陽極部と前記陽極端子の接続された部分の周囲に形成された封止樹脂と、前記陽極端子の周囲を除いて前記コンデンサ素子を挟む金属箔と、前記コンデンサ素子の側面に引き出されて折り曲げられて底面に導出された陽極端子と、前記金属箔の底面側に接続された陰極端子を有することを特徴とする請求項１に記載の固体電解コンデンサ。 An anode terminal connected to the anode portion of the capacitor element, a sealing resin formed around a portion where the anode portion and the anode terminal are connected, and the capacitor element is sandwiched except for the periphery of the anode terminal The metal foil, an anode terminal drawn to the side surface of the capacitor element, bent and led to the bottom surface, and a cathode terminal connected to the bottom surface side of the metal foil. Solid electrolytic capacitor.

前記コンデンサ素子の陽極部に接続された陽極端子と、前記陽極端子の陽極実装端子面を除いて前記陽極部と前記陽極端子の接続された部分の周囲に形成された封止樹脂と、前記陽極端子の周囲を除いて前記コンデンサ素子を挟み周囲が密封された金属箔と、前記陰極部と前記金属箔を接続する導電性接着剤と、前記金属箔の少なくとも底面側に陰極実装端子面を除いてレジストを有することを特徴とする請求項１に記載の固体電解コンデンサ。 An anode terminal connected to the anode portion of the capacitor element; a sealing resin formed around a portion where the anode portion and the anode terminal are connected except for an anode mounting terminal surface of the anode terminal; and the anode A metal foil sandwiched between the capacitor elements except for the periphery of the terminal and sealed around the conductive element, a conductive adhesive connecting the cathode part and the metal foil, and a cathode mounting terminal surface at least on the bottom side of the metal foil The solid electrolytic capacitor according to claim 1, further comprising a resist.