JP4287674B2

JP4287674B2 - Film capacitor manufacturing method

Info

Publication number: JP4287674B2
Application number: JP2003050278A
Authority: JP
Inventors: 泰宏久保; 智哉安立; 隆志森
Original assignee: Nichicon Corp
Current assignee: Nichicon Corp
Priority date: 2003-02-27
Filing date: 2003-02-27
Publication date: 2009-07-01
Anticipated expiration: 2023-02-27
Also published as: JP2004260029A

Description

【０００１】
【発明の属する技術分野】
本発明はチップ形フィルムコンデンサに関するもので、特に耐電流特性に優れ、半田耐熱性を向上させたフィルムコンデンサおよびその製造方法に関するものである。
【０００２】
【従来の技術】
従来のチップ形フィルムコンデンサは図１８のような構造であり、一対の金属化フィルム、または両面金属化フィルムとフィルムを重ねて巻回した素子に、後巻用プラスチックフィルム３を巻回してコンデンサ素子７（断面図：図１５）を形成し、該コンデンサ素子７に、電極引出部としてメタリコン層からなる第１外部電極９を設け、エポキシ樹脂に真空含浸し熱硬化させた後、第１外部電極９と、凸部を設けた板状端子の第２外部電極１１と一体化接合して、図１６のように熱硬化性樹脂シート６ａ上に並置し、該コンデンサ素子７間に熱硬化性樹脂８を配し、加熱・加圧処理して図１７に示す帯状の樹脂外装硬化物とし、コンデンサ素子間の樹脂部分１０を切断して、作製されていた（例えば特許文献１参照）。
また、図１５のコンデンサ素子の第１メタリコン層４および第２メタリコン層５からなる第１外部電極９と一体化接合する第２外部電極１１としては、図１９のような２個の方形状窓部を設けた板状端子も知られている（例えば特許文献２参照）。
【０００３】
【特許文献１】
特公平７−７０４１５号公報（第１−４頁、第１図、第５−７図）
【特許文献２】
特開２０００−５８３６９号公報（第２−６頁、第５−６図）
【０００４】
【発明が解決しようとする課題】
上記のコンデンサ素子には、図１８に示す凸部１２を設けた板状端子、または、図１９に示す２個の方形状窓部１１ｄを設けた板状端子である第２外部電極１１が取り付けられているが、これらの形状では熱伝導が悪く、熱が分散され難いため、放熱性が悪く、リフロー半田付：２６０℃ １０秒、または、手半田付：３５０〜３８０℃ ５秒の条件で半田付けする時、容量減少、および誘電損失の増加が起こるという問題があった。
また、メタリコン金属材料自体の耐食性が大きな問題であり、アルミニウム７０％以上、ケイ素４％以上、およびスズ合金等という非常に高価なメタリコン金属材料を使用しなければならないという問題があった。
上記のように、リフロー半田付、および手半田付けのいずれにおいても、フィルムコンデンサの容量減少、誘電体損失の増加（電極材料との接触不良）が多発するため、高温半田付に対応できる手段が必要とされており、また、耐食性改善用の高価なメタリコン材料を使用しなくてすむ構成が必要とされていた。
【０００５】
【課題を解決するための手段】
本発明は、上記の課題を解決したものであり、半田耐熱性に対しては、第２外部電極の形状を検討して放熱性を高めて対応し、メタリコン材料の耐食性改善のためには、含浸性、耐熱性の高い樹脂材料にコンデンサ素子を含浸することにより吸湿を防止し、高融点で安価なメタリコン材料で対応しようとするものである。
【０００６】
すなわち、一対の金属化フィルム、または両面金属化フィルムとフィルムを重ねて巻回した素子に、後巻用プラスチックフィルム３を巻回してコンデンサ素子７を形成し、該コンデンサ素子７を略同一幅の帯状エポキシ樹脂プリプレグシートからなる熱硬化性樹脂シート上６ａに並置し（図２）、粘性比２〜７の液状熱硬化性樹脂８を該コンデンサ素子７間に充填し、その上に熱硬化性樹脂シート６ａと同一のシート６ｂを載せ、加熱・加圧処理して帯状の樹脂外装硬化物とし（図４）、
該樹脂外装硬化物の両端面の各電極引出部に、銅６０〜７０％残亜鉛からなる合金で構成した第１メタリコン層４と、スズ８０％以上残亜鉛、銅で構成した第２メタリコン層５とからなる第１外部電極９を形成し、
前記樹脂外装硬化物をエポキシ樹脂で含浸し、余剰のエポキシ樹脂を除去し、加熱硬化した後、第１外部電極面を切削研磨し、前記コンデンサ素子７間に充填された樹脂部分を切断した後、
前記第１外部電極面に、Ｃ字状、コの字状、または４個の方形状若しくは太鼓状の窓部を有し、窓部面積とメタリコン表面側の面積との比が０．０５〜０．３５である板状端子を第２外部電極として接合し、熱処理を行うことを特徴とするフィルムコンデンサの製造方法である。
【０００８】
さらに、前記樹脂外装硬化物を粘度２５０ｃｐｓ以下で、かつ表面張力３０ｄｙｎｅ／ｃｍ^２以下のエポキシ樹脂に含浸することを特徴とするフィルムコンデンサの製造方法である。
【０００９】
そして、上記の熱処理温度が１５０〜２５０℃であることを特徴とするフィルムコンデンサの製造方法である。
【００１０】
【発明の実施の形態】
一対の金属化フィルム、または両面金属化フィルムとフィルムを重ねて巻回した素子に、後巻用プラスチックフィルム３を巻回してコンデンサ素子７を形成し、該コンデンサ素子７を略同一幅の帯状エポキシ樹脂プリプレグシートからなる熱硬化性樹脂シート６ａ上に並置し、粘性比２〜７の液状熱硬化性エポキシ樹脂８を該素子７間に充填し、その上に熱硬化性樹脂シート６ａと同一のシート６ｂを載せ、加熱・加圧処理して帯状の樹脂外装硬化物とし、該樹脂外装硬化物の両端面の各電極引出部に第１メタリコン層4および第２メタリコン層５からなる第１外部電極９を設けた後、上記コンデンサ素子７間の樹脂部分１０を切断し、第１外部電極９と板状端子である第２外部電極１１とを一体化接合する。
【００１１】
ここで、第１メタリコン層４は、銅６０〜７０％残亜鉛からなる合金で構成され、第２メタリコン層５はスズ８０％以上残亜鉛、銅で構成される。
【００１２】
また、第２外部電極の板状端子１１には、Ｃ字状、コの字状、または４個の方形状若しくは太鼓状の窓部が設けられている。
そして、第２外部電極の板状端子１１の側面を、台形状（上底なし）またはレの字状に形成し、第２外部電極の板状端子１１の窓部面積とメタリコン表面側の面積との比を０．０５〜０．３５に設定する。
【００１３】
さらに、上記の帯状の樹脂外装硬化物に第１外部電極９を設けた後、該樹脂外装硬化物を粘度２５０ｃｐｓ以下で、かつ表面張力３０ｄｙｎｅ／ｃｍ^２以下のエポキシ樹脂に含浸し、余剰のエポキシ樹脂を除去し、加熱硬化し、外部電極面９を切削研磨し、上記コンデンサ素子間の樹脂部分１０を切断した後、該切削研磨した第１外部電極面９に第２外部電極の板状端子１１を接合し、１５０〜２５０℃で熱処理する。
【００１４】
【実施例】
次に、本発明の実施例を図１〜１４に基づいて説明する。
【００１５】
〔１〕第１メタリコン層組成の検討
図１は、本願発明の実施例によるフィルムコンデンサ（第２外部電極取付前）の断面図であり、誘電体フィルムＰＰＳ、ＰＥＴ、ＰＥＮ等にアルミニウムを蒸着した金属化フィルムの一対を重ねて巻回し、これに後巻用プラスチックフィルム３を巻回して、コンデンサ素子７を形成し、該コンデンサ素子７の両端面に各々、電極引出部として、第１メタリコン層４と、この上に形成した第２メタリコン層５とからなる第１外部電極９を構成する。なお、従来例は特開２０００−５８３６９号公報の実施例に開示された構成とした。
【００１６】
上記の第１メタリコン層４には、表１に示すように、（実施例）銅６５％と亜鉛３５％とからなる合金（黄銅）を使用し、第２メタリコン層５はスズ８９％残亜鉛，銅とからなるものを使用した。上記の第１および第２メタリコン層からなる第１外部電極について耐電流性試験を行った結果を、（従来例）の第１メタリコン層４：アルミニウム８８％とケイ素１２％、第２メタリコン層５：スズ８９％残亜鉛、銅によるものと比較して〔表１〕に示す。この結果より、実施例は従来例と比べて耐電流特性が優れていることが分かる。
【００１７】
【表１】

【００１８】
〔２〕第２外部電極板状端子の窓部面積／メタリコン表面側の面積の検討
上記のコンデンサ素子７を、略同一幅の熱硬化性エポキシ樹脂プリプレグシートからなる熱硬化性樹脂シート６ａ上に略等間隔で並置し（図２）、該コンデンサ素子間に粘性比３程度の液状熱硬化性エポキシ樹脂８を配し（図３）、その上に上記熱硬化性エポキシ樹脂プリプレグシート６ａと同一のシート６ｂを配置し、加熱・加圧処理して硬化させて帯状の樹脂外装硬化物とした（図４）。
該帯状樹脂外装硬化物の両端面に各々電極引出部として、アルミニウム４４％とケイ素６％と亜鉛５０％とからなる第１メタリコン層４、およびスズ８９％残亜鉛、銅とからなる第２メタリコン層５で構成された第１外部電極９を設けた（図５）後、該帯状樹脂外装硬化物を粘度２３０ｃｐｓ程度で、かつ表面張力２５ｄｙｎｅ／ｃｍ^２のエポキシ樹脂に真空含浸し、余剰のエポキシ樹脂を除去し、加熱硬化した後、第１外部電極面を切削研磨した。
ここで、上記したように、アルミニウム４４％とケイ素６％と亜鉛５０％とからなる第１メタリコン層４、およびスズ８９％残亜鉛、銅とからなる第２メタリコン層５で第１外部電極９を構成したが、板状端子の窓部形状を同一とする限り、第１メタリコン層の組成を、銅６０〜７０％残亜鉛からなる合金で構成しても、上記と同様の効果を得ることができる。
なお、上記のエポキシ樹脂は、粘度が２５０ｃｐｓを超え、表面張力が３０ｄｙｎｅ／ｃｍ^２を超えると、含浸性が低下し、吸湿を抑えられないため耐食性の面で問題がある。
上記処理を行った後、帯状樹脂外装硬化物のコンデンサ素子間の樹脂部分１０を切断した。
【００１９】
その後、上記の切削研磨した第１外部電極面に、図１０に示すＣ字状窓部１１ａを有し、側面が図１３のような台形状（上底なし）である第２電極の板状端子（Ｆｅ／Ｎｉ４２アロイ合金薄板、約０．１ｍｍｔ）を抵抗溶接により取り付けた（図９）。このとき、該板状端子の開口部面積とメタリコン表面側の面積との比を変えたものを〔表２〕の実施例１−１ａ〜１−１ｇとして、リフロー半田、および手半田付け時の放熱板となるようにし、その後、１６０℃で２時間熱処理して、フィルムを相互に固着させたフィルムコンデンサ１０個を作製した。
なお、上記の熱処理温度が１５０℃を下回ると、フィルム相互の固着が十分に行われず、吸湿しやすくなり、２００℃を超えると、製品特性が悪化するので好ましくない。
また、該コンデンサ素子７間に配する液状熱硬化性エポキシ樹脂８は、粘性比２〜７の範囲であれば寸法精度がよく、樹脂垂れも発生しない。粘性比２未満では樹脂垂れが発生し、粘性７を超えると寸法精度が低下し、外観不良になるおそれがある。
上記実施例１−１ａ〜１−１ｇのフィルムコンデンサにおける、手半田付前後のΔＣ／Ｃ、ｔａｎδ特性を、図２０の第２外部電極板状端子（窓部：２個の方形状）を取り付けた従来例と比較した結果を〔表２〕に示す。
【００２０】
【表２】

【００２１】
次に、上記実施例１−１ａ〜１−１ｇのフィルムコンデンサのリフロー前後のΔＣ／Ｃ、ｔａｎδ特性、絶縁抵抗、破壊電圧を、図２０の従来例と比較した結果を〔表３〕に示す。
【００２２】
【表３】

【００２３】
〔表２〕、〔表３〕から明らかなように、実施例１−１ａ〜１−１ｇの第１外部電極５に、上記の第２外部電極１のＣ字状窓部を有する板状端子を取り付けたものは、従来例の第２外部電極のように２個の方形状窓部を設けたものと比べて、手半田付け、リフロー半田付けのいずれにおいても優れた半田耐熱性（放熱性）を示していることが分かる。
【００２４】
なお、ここで上記実施例による第２外部電極板状端子の開口部の面積と第１外部電極表面側の面積との比は０．０５〜０．３５が最適であり、０．０５未満では、半田付け時に発生するガスの逃げ道がなくなるので不適当であり、０．３５を超えると、板状端子の熱伝導が悪くなり、熱が分散され難くなって放熱性が低下し、特性が悪くなるので不適当である。
【００２５】
また、他の実施例として、実施例の第１外部電極と、図１１に示すコの字状、または図１２に示す４個の方形状（若しくは太鼓状）の窓部を有し、側面が台形状（上底なし、図１３）の第２外部電極とを組み合わせたもの、または、上記形状の窓部またはＣ字状窓部を有し、側面がレの字状の第２外部電極とを組み合わせたフィルムコンデンサでも、リフロー半田、および手半田付け時の特性において、〔表２〕、〔表３〕とほとんど同様の結果が得られた。
【００２７】
【発明の効果】
本発明によるチップ形フィルムコンデンサは、第２外部電極としてＣ字状、コの字状、または４個の方形状若しくは太鼓状の窓部を設け、その窓部面積とメタリコン表面側の面積との比が０．０５〜０．３５である板状端子を用いることにより、リフロー半田、手半田付け時に優れた放熱効果を発揮し、半田耐熱特性が改善され、また、第１外部電極が、第１メタリコン層と第２メタリコン層とからなり、第１メタリコン層が銅６０〜７０％残亜鉛からなる合金で構成されているため、内部電極のアルミニウムとの機械的、電気的接合に優れ、特に耐電流性能が優れている。
さらに、含浸性の良好なエポキシ樹脂をコンデンサ素子に含浸しているため、吸湿が抑えられ、耐食性が改善されるので、信頼性の高いフィルムコンデンサが安価に得られ、産業上の効果大である。
【図面の簡単な説明】
【図１】本発明の実施例による、チップ形フィルムコンデンサ（第２外部電極取付前）の断面図である。
【図２】コンデンサ素子を熱硬化性樹脂シート上にほぼ等間隔に並置した状態の斜視図である。
【図３】図２のコンデンサ素子間に液状熱硬化性樹脂を充填した状態の斜視図である。
【図４】図３のコンデンサ素子、および液状熱硬化性樹脂上に熱硬化性樹脂シートを配置し、帯状の樹脂外装硬化物とした状態の斜視図である。
【図５】図４の帯状の樹脂外装硬化物に第１外部電極を設けた状態の斜視図である。
【図６】本発明の実施例によるコンデンサ完成品の平面図である。
【図７】本発明の実施例によるコンデンサ完成品の側面図である。
【図８】本発明の実施例によるコンデンサ完成品の正面図である。
【図９】本発明の実施例によるコンデンサ完成品の斜視図である。
【図１０】本発明の実施例による、第２外部電極の板状端子の正面図であり、窓部をＣ字状に形成したものである。
【図１１】本発明の他の実施例による、第２外部電極の板状端子の正面図であり、窓部をコの字状に形成したものである。
【図１２】本発明の他の実施例による、第２外部電極の板状端子の正面図であり、窓部を４個の方形状（太鼓状）に形成したものである。
【図１３】本発明の実施例による、第２外部電極の板状構造端子であり、側面を台形状（上底なし）に形成したものである。
【図１４】本発明の他の実施例による、第２外部電極の板状構造端子であり、側面をレの字状に形成したものである。
【図１５】従来例による、チップ形フィルムコンデンサ（第２外部電極取付前）の断面図である。
【図１６】従来例による、メタリコン層からなる第１外部電極と凸部を設けた板状端子の第２外部電極とを一体化接合し、熱硬化性樹脂シート上にほぼ等間隔に並置してコンデンサ素子間に液状熱硬化性樹脂を配した状態の斜視図である。
【図１７】図１６のコンデンサ素子および液状熱硬化性樹脂上に熱硬化性樹脂シートを配置し、加熱・加圧処理して、帯状の樹脂外装硬化物とした状態の斜視図である。
【図１８】図１７の樹脂外装硬化物から、コンデンサ素子間の樹脂部分を切断して、作製したチップ形フィルムコンデンサの斜視図である。
【図１９】他の従来例による第２外部電極の板状端子の正面図であり、窓部を２個の方形状に形成したものである。
【図２０】図１９の第２外部電極（窓部：２個の方形状）の板状端子をコンデンサ素子に取り付けた状態の正面図である。
【符号の説明】
１蒸着金属
２誘電体プラスチックフィルム
３後巻用プラスチックフィルム
４第１メタリコン層
５第２メタリコン層
６ａ，６ｂ熱硬化性樹脂シート
７コンデンサ素子
８熱硬化性樹脂
９第１外部電極
１０コンデンサ素子間の樹脂部分
１１第２外部電極の板状端子
１１ａ窓部（Ｃ字状）
１１ｂ窓部（コの字状）
１１ｃ窓部（方形状、太鼓状）
１１ｄ窓部（方形状、太鼓状）
１２凸部
１３抵抗溶接部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a chip-type film capacitor, and more particularly to a film capacitor having excellent current resistance characteristics and improved solder heat resistance, and a method for manufacturing the same.
[0002]
[Prior art]
A conventional chip-type film capacitor has a structure as shown in FIG. 18, and a plastic film 3 for subsequent winding is wound around an element in which a pair of metallized films or a double-sided metallized film and a film are wound and wound to form a capacitor element. 7 (cross-sectional view: FIG. 15) is formed, and the capacitor element 7 is provided with a first external electrode 9 made of a metallicon layer as an electrode lead-out portion, vacuum-impregnated with epoxy resin and thermally cured, and then the first external electrode 9 and the second external electrode 11 of the plate-like terminal provided with the convex portion, and are juxtaposed on the thermosetting resin sheet 6a as shown in FIG. 8 was prepared by heating and pressurizing to form a strip-shaped resin exterior cured product shown in FIG. 17, and cutting the resin portion 10 between the capacitor elements (see, for example, Patent Document 1).
Further, as the second external electrode 11 integrally joined to the first external electrode 9 composed of the first metallicon layer 4 and the second metallicon layer 5 of the capacitor element of FIG. 15, two rectangular windows as shown in FIG. A plate-like terminal provided with a portion is also known (see, for example, Patent Document 2).
[0003]
[Patent Document 1]
Japanese Examined Patent Publication No. 7-70415 (page 1-4, FIG. 1, FIG. 5-7)
[Patent Document 2]
JP 2000-58369 A (pages 2-6 and 5-6)
[0004]
[Problems to be solved by the invention]
The capacitor element is provided with the second external electrode 11 which is a plate-like terminal provided with the convex portion 12 shown in FIG. 18 or a plate-like terminal provided with two rectangular window portions 11d shown in FIG. However, in these shapes, heat conduction is poor and heat is not easily dispersed, so heat dissipation is poor, and reflow soldering: 260 ° C. for 10 seconds, or manual soldering: 350 to 380 ° C. for 5 seconds. When soldering, there is a problem that the capacity is reduced and the dielectric loss is increased.
Further, the corrosion resistance of the metallicon metal material itself is a big problem, and there is a problem that it is necessary to use a very expensive metallicon metal material such as aluminum 70% or more, silicon 4% or more, and a tin alloy.
As described above, in both reflow soldering and manual soldering, the capacity of the film capacitor is decreased and the dielectric loss is increased (contact failure with the electrode material). There has been a need for a configuration that eliminates the need for expensive metallicon materials for improving corrosion resistance.
[0005]
[Means for Solving the Problems]
The present invention solves the above-mentioned problem, and for solder heat resistance, consider the shape of the second external electrode to increase heat dissipation and cope with it, for improving the corrosion resistance of the metallicon material, By impregnating a capacitor element into a resin material having high impregnation and heat resistance, moisture absorption is prevented, and an attempt is made to cope with an inexpensive metallicon material having a high melting point.
[0006]
That is, a plastic film 3 for subsequent winding is wound around an element in which a pair of metallized films or a double-sided metallized film and a film are wound to form a capacitor element 7, and the capacitor element 7 is formed with substantially the same width. It is juxtaposed on a thermosetting resin sheet 6a made of a strip-shaped epoxy resin prepreg sheet (FIG. 2), and a liquid thermosetting resin 8 having a viscosity ratio of 2 to 7 is filled between the

capacitor

elements 7 and thermosetting thereon. The same sheet 6b as the resin sheet 6a is placed and heated and pressurized to form a belt-shaped resin exterior cured product (FIG. 4).
Each electrode lead portions of the end surfaces of the resin-coated cured, the first metallikon layer 4 constituted by the alloy of copper 60% to 70% residual zinc, 80% tin remaining zinc, second metallikon constructed of copper Forming a first external electrode 9 comprising the layer 5;
After impregnating the resin sheathed cured product with an epoxy resin, removing excess epoxy resin and heat-curing, cutting and polishing the first external electrode surface, and cutting the resin portion filled between the capacitor elements 7 ,
Said first outer electrode surface, C-shaped, have a shape, or four square-shaped or drum-shaped window portion co, 0.05 is the ratio of the area of the window portion area and metallikon surface A film capacitor manufacturing method is characterized in that a plate-like terminal of 0.35 is joined as a second external electrode and heat treatment is performed .
[0008]
Furthermore, the resin sheath cured in less viscosity 250 cps, and a method of manufacturing a film capacitor, which comprises impregnating the surface tension 30 dyne / cm ² or less epoxy resin.
[0009]
And it is a manufacturing method of the film capacitor characterized by the above-mentioned heat treatment temperature being 150-250 ° C.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
A capacitor element 7 is formed by winding a plastic film 3 for subsequent winding on a pair of metallized films or an element in which a double-sided metallized film and a film are wound, and the capacitor element 7 is formed into a strip-like epoxy having substantially the same width. A thermosetting resin sheet 6a made of a resin prepreg sheet is juxtaposed, and a liquid thermosetting epoxy resin 8 having a viscosity ratio of 2 to 7 is filled between the elements 7, and the same as the thermosetting resin sheet 6a. A sheet 6b is placed and heated / pressurized to form a strip-shaped resin sheathed cured product, and a first outer part composed of a first metallicon layer 4 and a second metallicon layer 5 at each electrode lead portion on both end faces of the resin sheathed cured product. After the electrode 9 is provided, the resin portion 10 between the capacitor elements 7 is cut, and the first external electrode 9 and the second external electrode 11 that is a plate-like terminal are integrally joined.
[0011]
Here, the 1st metallicon layer 4 is comprised with the alloy which consists of copper 60-70% residual zinc, and the 2nd metallicon layer 5 is comprised with 80% or more of residual zinc and copper.
[0012]
The plate terminal 11 of the second external electrode is provided with a C-shaped, U-shaped, or four rectangular or drum-shaped windows.
Then, the side surface of the plate-like terminal 11 of the second external electrode is formed in a trapezoidal shape (without an upper bottom) or a letter shape, The ratio is set to 0.05 to 0.35.
[0013]
Further, after the first external electrode 9 is provided on the above-described belt-shaped resin sheathed cured product, the resin sheathed cured product is impregnated with an epoxy resin having a viscosity of 250 cps or less and a surface tension of 30 dyne / cm ² or less, and an excess epoxy The resin is removed, heat-cured, the external electrode surface 9 is cut and polished, the resin portion 10 between the capacitor elements is cut, and then the cut and polished first external electrode surface 9 is connected to the plate-like terminal of the second external electrode. 11 are joined and heat-treated at 150 to 250 ° C.
[0014]
【Example】
Next, an embodiment of the present invention will be described with reference to FIGS.
[0015]
[1] Examination of composition of first metallicon layer FIG. 1 is a cross-sectional view of a film capacitor (before mounting of the second external electrode) according to an embodiment of the present invention, in which aluminum is deposited on a dielectric film PPS, PET, PEN or the like. A pair of metallized films are overlapped and wound, and a plastic film 3 for subsequent winding is wound thereon to form a capacitor element 7, and a first metallicon layer is formed as an electrode lead portion on each end face of the capacitor element 7. 4 and the second metallicon layer 5 formed thereon are configured as a first external electrode 9. The conventional example has the configuration disclosed in the example of Japanese Patent Laid-Open No. 2000-58369.
[0016]
The first metallikon layer 4 above, as shown in Table 1, (Example) using alloy (brass) consisting of 65% copper and 35% zinc, the second metallikon layer 5 tin 89% residual zinc The one made of copper was used. The results of conducting a current resistance test on the first external electrode composed of the first and second metallicon layers are the results of the first metallicon layer 4: (conventional example): aluminum 88% and silicon 12%, the second metallicon layer 5 : It shows in [Table 1] compared with the thing by 89% tin remaining zinc and copper. This result example it can be seen that excellent withstand current characteristic as compared with the conventional example.
[0017]
[Table 1]

[0018]
[2] Examination of window part area / metallicon surface side area of second external electrode plate terminal The capacitor element 7 is placed on a thermosetting resin sheet 6a made of a thermosetting epoxy resin prepreg sheet having substantially the same width. The liquid thermosetting epoxy resin 8 having a viscosity ratio of about 3 is arranged between the capacitor elements (FIG. 2), and the same as the above thermosetting epoxy resin prepreg sheet 6a. The sheet 6b was placed and cured by heating and pressurizing to obtain a belt-shaped resin exterior cured product (FIG. 4).
The first metallicon layer 4 made of 44% aluminum, 6% silicon, and 50% zinc, and the second metallicon made of 89% residual zinc and copper as electrode lead portions on both end faces of the belt-shaped resin sheathed cured product, respectively. After providing the first external electrode 9 composed of the layer 5 (FIG. 5), the belt-shaped resin sheathed cured product is vacuum-impregnated with an epoxy resin having a viscosity of about 230 cps and a surface tension of 25 dyne / cm ² , and an excess epoxy After removing the resin and heat-curing, the first external electrode surface was cut and polished.
Here, as described above, the first external electrode 9 is composed of the first metallicon layer 4 made of 44% aluminum, 6% silicon and 50% zinc, and the second metallicon layer 5 made of 89% tin zinc and copper. However, as long as the window shape of the plate-like terminal is the same, the same effect as above can be obtained even if the composition of the first metallicon layer is composed of an alloy composed of 60% to 70% copper. Can do.
In addition, when the above-mentioned epoxy resin has a viscosity of more than 250 cps and a surface tension of more than 30 dyne / cm ² , the impregnation property is lowered, and moisture absorption cannot be suppressed, so that there is a problem in terms of corrosion resistance.
After performing the said process, the resin part 10 between the capacitor | condenser elements of strip | belt-shaped resin exterior cured | curing material was cut | disconnected.
[0019]
Thereafter, a plate-like terminal of the second electrode having the C-shaped window portion 11a shown in FIG. 10 on the cut and polished first external electrode surface and having a trapezoidal shape (no upper bottom) as shown in FIG. (Fe / Ni42 alloy alloy thin plate, about 0.1 mmt) was attached by resistance welding (FIG. 9). At this time, what changed the ratio of the opening area of the plate-like terminal and the area on the metallicon surface side was designated as Examples 1-1a to 1-1g in [Table 2], during reflow soldering and manual soldering. Then, the film was heat treated at 160 ° C. for 2 hours to produce 10 film capacitors having the films fixed to each other.
When the heat treatment temperature is lower than 150 ° C., the films are not sufficiently fixed to each other and easily absorb moisture. When the heat treatment temperature exceeds 200 ° C., product characteristics are deteriorated.
The liquid thermosetting epoxy resin 8 disposed between the capacitor elements 7 has good dimensional accuracy and does not cause resin dripping if the viscosity ratio is in the range of 2 to 7. If the viscosity ratio is less than 2, resin sag occurs, and if the viscosity exceeds 7, the dimensional accuracy may be reduced and the appearance may be poor.
In the film capacitors of Examples 1-1a to 1-1g, ΔC / C and tan δ characteristics before and after manual soldering are attached to the second external electrode plate terminals (window portion: two square shapes) shown in FIG. The results compared with the conventional example are shown in [Table 2].
[0020]
[Table 2]

[0021]
Next, Table 3 shows the results of comparing the ΔC / C, tan δ characteristics, insulation resistance, and breakdown voltage before and after reflow of the film capacitors of Examples 1-1a to 1-1g with those of the conventional example of FIG. .
[0022]
[Table 3]

[0023]
As apparent from [Table 2] and [Table 3], the plate-like terminal having the C-shaped window portion of the second external electrode 1 on the first external electrode 5 of Examples 1-1a to 1-1g. which was installed, conventional second compared Noto also provided with two square-shaped window as the external electrodes of the hand soldering, excellent solder heat resistance at any reflow soldering (heat radiation It can be seen that this indicates
[0024]
Here, the ratio of the area of the opening of the second external electrode plate-like terminal according to the above embodiment and the area of the first external electrode surface side is optimally 0.05 to 0.35, and less than 0.05 This is inappropriate because there is no escape path for the gas generated during soldering. If it exceeds 0.35, the heat conduction of the plate-like terminal will be poor, the heat will be difficult to disperse, the heat dissipation will be reduced, and the characteristics will be poor. This is inappropriate.
[0025]
As another embodiment , the first external electrode of the embodiment and the U-shaped window shown in FIG. 11 or the four rectangular (or drum-shaped) windows shown in FIG. A combination with a trapezoidal (without upper bottom, FIG. 13) second external electrode, or a second external electrode having the above-mentioned window portion or C-shaped window portion and having a laterally-shaped side shape. Even with the combined film capacitor, almost the same results as in [Table 2] and [Table 3] were obtained in the characteristics during reflow soldering and manual soldering.
[0027]
【The invention's effect】
The chip-type film capacitor according to the present invention is provided with a C-shaped, U-shaped, or four rectangular or drum-shaped window portions as the second external electrode, and the area of the window portion and the area of the metallicon surface side. By using a plate-shaped terminal having a ratio of 0.05 to 0.35, an excellent heat dissipation effect is exhibited at the time of reflow soldering and manual soldering, solder heat resistance is improved, and the first external electrode is It consists of 1 metallicon layer and 2nd metallicon layer, and since the 1st metallicon layer is composed of an alloy composed of 60-70% copper, it is excellent in mechanical and electrical joining with aluminum of the internal electrode, especially Excellent current resistance.
Furthermore, since the capacitor element is impregnated with a highly impregnated epoxy resin, moisture absorption is suppressed and corrosion resistance is improved, so that a highly reliable film capacitor can be obtained at a low cost and has a great industrial effect. .
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a chip-type film capacitor (before attaching a second external electrode) according to an embodiment of the present invention.
FIG. 2 is a perspective view of a state in which capacitor elements are juxtaposed on a thermosetting resin sheet at substantially equal intervals.
3 is a perspective view of a state in which a liquid thermosetting resin is filled between the capacitor elements of FIG. 2. FIG.
4 is a perspective view showing a state in which a thermosetting resin sheet is disposed on the capacitor element of FIG. 3 and a liquid thermosetting resin to form a belt-shaped resin exterior cured product. FIG.
5 is a perspective view showing a state in which a first external electrode is provided on the belt-shaped resin-cured cured product of FIG. 4. FIG.
FIG. 6 is a plan view of a completed capacitor according to an embodiment of the present invention.
FIG. 7 is a side view of a completed capacitor according to an embodiment of the present invention.
FIG. 8 is a front view of a completed capacitor according to an embodiment of the present invention.
FIG. 9 is a perspective view of a completed capacitor according to an embodiment of the present invention.
FIG. 10 is a front view of a plate-like terminal of a second external electrode according to an embodiment of the present invention, in which a window is formed in a C shape.
FIG. 11 is a front view of a plate-like terminal of a second external electrode according to another embodiment of the present invention, in which a window is formed in a U shape.
FIG. 12 is a front view of a plate-like terminal of a second external electrode according to another embodiment of the present invention, in which a window portion is formed into four rectangular shapes (drum shape).
FIG. 13 shows a plate-like structure terminal of a second external electrode according to an embodiment of the present invention, the side surface of which is formed in a trapezoidal shape (without an upper bottom).
FIG. 14 shows a plate-like structure terminal of a second external electrode according to another embodiment of the present invention, wherein the side surface is formed in a letter shape.
FIG. 15 is a cross-sectional view of a chip-type film capacitor (before attaching a second external electrode) according to a conventional example.
FIG. 16 shows a conventional example in which a first external electrode made of a metallicon layer and a second external electrode of a plate-like terminal provided with a convex portion are integrally joined and juxtaposed at substantially equal intervals on a thermosetting resin sheet. FIG. 6 is a perspective view of a state in which a liquid thermosetting resin is disposed between capacitor elements.
17 is a perspective view of a state in which a thermosetting resin sheet is disposed on the capacitor element and the liquid thermosetting resin of FIG.
18 is a perspective view of a chip-type film capacitor produced by cutting the resin portion between the capacitor elements from the cured resin exterior of FIG.
FIG. 19 is a front view of a plate-like terminal of a second external electrode according to another conventional example, in which a window portion is formed in two rectangular shapes.
20 is a front view showing a state in which the plate-like terminal of the second external electrode (window portion: two rectangular shapes) of FIG. 19 is attached to the capacitor element.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Deposition metal 2 Dielectric plastic film 3 Plastic film 4 for back rolls 1st metallicon layer 5

2nd metallicon layer

6a, 6b Thermosetting resin sheet 7 Capacitor element 8 Thermosetting resin 9 1st external electrode 10 Between capacitor elements Resin portion 11 Plate terminal 11a of second external electrode Window portion (C-shaped)
11b Window (U-shaped)
11c Window (square shape, drum shape)
11d Window (square shape, drum shape)
12 Convex 13 Resistance Weld

Claims

A capacitor element is formed by winding a plastic film for subsequent winding on a pair of metallized films, or elements wound with a double-sided metallized film and a film,
The capacitor elements are juxtaposed on a thermosetting resin sheet made of a strip-shaped epoxy resin prepreg sheet having substantially the same width, and a liquid thermosetting resin having a viscosity ratio of 2 to 7 is filled between the capacitor elements.
Put the same sheet as the thermosetting resin sheet on it, heat and pressurize to make a belt-shaped resin exterior cured product,
In each electrode lead portion on both end faces of the resin sheathed cured product ,
A first metallikon layer constituted with alloy of copper 60% to 70% residual zinc, 80% tin remaining zinc, a first external electrode and a second metallikon layer was made of copper is formed,
After impregnating the resin sheathed cured product with an epoxy resin, removing excess epoxy resin and heating and curing, the first external electrode surface is cut and polished, and after cutting the resin portion filled between the capacitor elements,
Said first outer electrode surface, C-shaped, have a shape, or four square-shaped or drum-shaped window portion co, 0.05 is the ratio of the area of the window portion area and metallikon surface A method of manufacturing a film capacitor , wherein a plate-like terminal of 0.35 is joined as a second external electrode and heat treatment is performed .

^{2. The} method for producing a film capacitor according to claim 1, wherein the resin-covered cured product is impregnated with an epoxy resin having a viscosity of 250 cps or less and a surface tension of 30 dyne / cm ² or less.

The method for manufacturing a film capacitor, wherein the heat treatment temperature according to claim 1 is 150 to 250 ° C.