JP2004095605A - Metallized film capacitor, manufacturing method thereof, and inverter device using metallized film capacitor - Google Patents

Abstract

An object of the present invention is to provide a metallized film capacitor realizing low heat generation and a high self-protection function in high voltage and high ripple current applications.
A divided electrode (3, 4) of a substantially rhombic and substantially triangular vapor-deposited metal surrounded by a non-vapor-deposited slit (2) is disposed at at least one position on each side of the divided electrode to connect the divided electrodes. A single-sided metallized polypropylene film 8 having a pattern shape composed of a fuse portion 5 and a single-sided metallized polypropylene film 9 having a vapor-deposited metal on substantially one side thereof are superposed and wound, and a metallicon electrode 10 is provided on both side end surfaces. The part is provided near the vertex of the rhombus. Thus, a metallized film capacitor having a low temperature rise and a high-performance inverter device can be obtained.
[Selection] Fig. 2

Description

【００５８】
（実施の形態２）
図３は本実施の形態２で説明する金属化フィルムコンデンサに使用する蒸着フィルム表面の模式図である。本実施の形態は、ヒューズ部の構成が実施の形態１における発明のヒューズ部５と異なるだけで、それ以外の同一構成ならびに作用効果を奏する部分には同じ符号を付して詳細な説明を省略し、異なるところを中心に説明する。
【００５９】
本実施の形態では、図３に示すように実施の形態１における図１のヒューズ部５を、ヒューズ部１２に置き換えたこと以外は実施の形態１と同じにした。図３においてヒューズ部１２は、その非金属部分である非蒸着スリット２との境界線１２ａの方向がメタリコン電極１０の面の方向と垂直にしたことである。ヒューズ部１２の幅は０．３ｍｍとした。
【００６０】
この図３のようなパターン蒸着フィルムを、実施の形態１における蒸着フィルムである片面金属化ポリプロピレンフィルム８と置き換えて、実施の形態１と同様な方法で本実施の形態２の金属化フィルムコンデンサを製造した。
【００６１】
上記（表１）に、本実施の形態２のコンデンサを８５℃において直流電圧６００Ｖを印加し、リップル電流を１０ｋＨｚで３０Ａ印加した際の加速寿命試験２０００時間後の容量減少率（ΔＣ／Ｃ）、および上記の条件における９０分間通電後のコンデンサの温度上昇値（５個の平均値）、および８５℃において直流電圧６００Ｖから２時間おきに５０Ｖずつ電圧を上昇させたステップアップ試験によって保安性を確認した結果を示す。この結果に基づく、本実施の形態の特徴ならびに作用効果は比較例との対比で後述する。
【００６２】
（実施の形態３）
本実施の形態は、ヒューズ部の配置が実施の形態１における発明のヒューズ部５と異なるだけで、それ以外は同一構成ならびに作用効果を奏するので詳細な説明を省略し、図１を利用して異なるところを中心に説明する。
【００６３】
本実施の形態では、実施の形態１における蒸着パターンの図１でヒューズ部５を、分割電極３の菱形状の頂点から辺の長さにおける３分の１の距離に配置したこと以外は、実施の形態１と同様な方法でコンデンサを製造した。
【００６４】
上記（表１）に、本実施の形態のコンデンサを８５℃において直流電圧６００Ｖを印加し、リップル電流を１０ｋＨｚで３０Ａ印加した際の加速寿命試験２０００時間後の容量減少率（ΔＣ／Ｃ）、および上記の条件における９０分間通電後のコンデンサの温度上昇値（５個の平均値）、および８５℃において直流電圧６００Ｖから２時間おきに５０Ｖずつ電圧を上昇させたステップアップ試験によって保安性を確認した結果を示す。この結果に基づく、本実施の形態の特徴ならびに作用効果は比較例との対比で後述する。
【００６５】
（実施の形態４）
図４は本実施の形態で説明する金属化フィルムコンデンサに使用する蒸着フィルム表面のヒューズ部の拡大模式図である。本実施の形態は、ヒューズ部の構成が実施の形態１における発明のヒューズ部５と異なるだけで、それ以外は同一構成ならびに作用効果を奏するので詳細な説明を省略し、異なるところを中心に説明する。
【００６６】
本実施の形態では、ヒューズ部１３の形状を、図４に示すように分割電極３に接続されるところである部分１３ａを、ヒューズ幅が広がるように曲率を設けたものに変更したこと以外は、実施の形態１と同様な方法でコンデンサを製造した。本実施の形態において、ヒューズ部１３はその最も細い部分の幅は０．２ｍｍとした。
【００６７】
上記（表１）に、本実施の形態のコンデンサを８５℃において直流電圧６００Ｖを印加し、リップル電流を１０ｋＨｚで３０Ａ印加した際の加速寿命試験２０００時間後の容量減少率（ΔＣ／Ｃ）、および上記の条件における９０分間通電後のコンデンサの温度上昇値（５個の平均値）、および８５℃において直流電圧６００Ｖから２時間おきに５０Ｖずつ電圧を上昇させたステップアップ試験によって保安性を確認した結果を示す。この結果に基づく、本実施の形態の特徴ならびに作用効果は比較例との対比で後述する。
【００６８】
なお、実施の形態１から４では、巻回型の金属化フィルムコンデンサについて記載したが、本発明は巻回型のコンデンサに限定されるものではなく、積層型の金属化フィルムコンデンサに適用しても良い。
【００６９】
また、実施の形態１から４では、ポリプロピレンフィルムの全面に均一厚みのアルミニウムを蒸着したが、本発明は蒸着膜厚によって何ら限定されるものではない。例えば、メタリコンに接する付近の蒸着金属の膜厚を厚くしたヘビーエッジ蒸着を用いると、メタリコンとの接触抵抗が向上するので好適である。
【００７０】
また、本実施の形態１から４では、蒸着金属としてアルミニウムを用いたが、本発明ではアルミニウムに限定されるものではなく他の蒸着した金属であっても良いことは言うまでもない。例えば、アルミニウムと亜鉛の合金、亜鉛などでも良い。
【００７１】
また、本実施の形態１から４では、片面蒸着したポリプロピレンフィルムについて記載したが、本発明ではポリプロピレンフィルムの片面に蒸着したパターンに限定されるものではなく、両面蒸着したポリプロピレンフィルムと蒸着していないポリプロピレンフィルムの２枚を１対として巻回や積層した場合のコンデンサでも良いことは言うまでもない。
【００７２】
また、誘電体フィルムとしてもポリプロピレンに限定されるものではなく、ポリエチレンテレフタレートなどのポリエステルフィルム、ポリフェニレンサルファイドフィルム、ポリスチレンフィルムなどの他の高分子フィルムでも良い。
【００７３】
（比較例１）
比較例１で用いた蒸着パターンを有する金属化フィルムを図５（ｂ）に示す。比較例１では、実施の形態１において、ヒューズ部５を菱形状の分割電極３と三角形状の分割電極４の辺の中央に配置したヒューズ部１５に置き換えたこと以外は、実施の形態１と同様な方法でコンデンサを製造した。
【００７４】
上記（表１）に、比較例１のコンデンサを８５℃において直流電圧６００Ｖを印加し、リップル電流を１０ｋＨｚで３０Ａ印加した際の加速寿命試験２０００時間後の容量減少率（ΔＣ／Ｃ）、および上記の条件における９０分間通電後のコンデンサの温度上昇値（５個の平均値）、および８５℃において直流電圧６００Ｖから２時間おきに５０Ｖずつ電圧を上昇させたステップアップ試験によって保安性を確認した結果を示す。
【００７５】
（比較例２）
比較例２では、実施の形態１のヒューズ位置を、図６に示すように菱形状の１つの頂点に２つのヒューズ部１４が近接するように配置したこと以外は、実施の形態１と同様な方法でコンデンサを製造した。
【００７６】
上記（表１）に、比較例２のコンデンサを８５℃において直流電圧６００Ｖを印加し、リップル電流を１０ｋＨｚで３０Ａ印加した際の加速寿命試験２０００時間後の容量減少率（ΔＣ／Ｃ）、および上記の条件における９０分間通電後のコンデンサの温度上昇値（５個の平均値）、および８５℃において直流電圧６００Ｖから２時間おきに５０Ｖずつ電圧を上昇させたステップアップ試験によって保安性を確認した結果を示す。
【００７７】
（比較例３）
比較例３では、実施の形態１における菱形状の分割電極３の長い方の対角線を半分の長さにし、短い方の対角線を２倍にしたこと以外は、実施の形態１と同様な方法でコンデンサを製造した。このようにすると、金属化フィルム幅方向のヒューズ本数が２倍になる。
【００７８】
上記（表１）に、比較例３のコンデンサを８５℃において直流電圧６００Ｖを印加し、リップル電流を１０ｋＨｚで３０Ａ印加した際の加速寿命試験２０００時間後の容量減少率（ΔＣ／Ｃ）、および上記の条件における９０分間通電後のコンデンサの温度上昇値（５個の平均値）、および８５℃において直流電圧６００Ｖから２時間おきに５０Ｖずつ電圧を上昇させたステップアップ試験によって保安性を確認した結果を示す。
【００７９】
（性能比較）
実施の形態１は、比較例１と比較してコンデンサの温度上昇が小さかった。この理由を図５（ａ）、（ｂ）を用いて説明する。
【００８０】
図５の（ａ）（ｂ）は、実施の形態１および比較例１における金属化フィルムの蒸着パターン面上で１０ｋＨｚのある位相における水平方向の電流の流れを矢印で模式的に示した図である。本発明者らは、フォトン社製電場シミュレーションソフト（ＶＯＬＴ）を用いて、有限要素法によって蒸着した分割電極のパターン内の電流密度分布や発熱分布解析を実施した結果を基に図５（ａ）（ｂ）のような模式図を描いている。
【００８１】
実施の形態１では、ヒューズ部５を菱形状と三角形状の頂点付近に配置し、頂点には１つのヒューズ部のみが近接するようにしたことから、分割電極内の電流の流れは図５（ａ）の矢印のようになっている。一方、ヒューズ部１５を分割電極の辺の真中に配置した比較例１では、図５（ｂ）のような電流の流れになっている。
【００８２】
この二つの例を比較すると、比較例１における図５（ｂ）の方が点線楕円で示した電流密度の小さい部分が存在することがわかる。ヒューズ部を菱形状の辺の真中に配置した比較例１では、ヒューズ部の位置よりも菱形状や三角形状の先端に相当する点線楕円部では電流の出口がないため蒸着膜平面方向では電流密度が小さくなる。
【００８３】
従って、比較例１よりも実施の形態１の方が蒸着パターンの電極全体において、電流密度分布が均一であり、ヒューズ部５における発熱量も小さくなる。そのため、（表１）に示したように実施の形態１の方が比較例１よりもコンデンサの温度上昇が小さくなった。このことは、電場シミュレーションによる計算を行っても同じ傾向となった。
【００８４】
次に、実施の形態１と比較例２の結果について図５（ａ）および図７を用いて説明する。比較例２のコンデンサは、実施の形態１よりも図７で示すように点線楕円で示した電流密度が小さい部分が生じる。従って、比較例２よりも実施の形態１の方が蒸着パターンの電極全体において、電流密度分布が均一であり、ヒューズ部５における発熱量も小さくなる。そのため、（表１）に示したように実施の形態１の方が比較例２よりもコンデンサの温度上昇が小さくなった。このことは、電場シミュレーションによる計算を行っても同じ傾向となった。
【００８５】
実施の形態１は、比較例１および２よりもパターン電極内の電流密度分布が均一であるため、分割電極内のどこで短絡が起こっても周りのヒューズ部から電流がスムーズに流れ込んで効率的に自己回復性を発揮することができる。そのため、異常時の保安機能も比較例１や２よりも優れている。
【００８６】
また、実施の形態１の図１で示した蒸着フィルムはヒューズ部の位置が隣合う辺において離れるように配置しているため、比較例１の図５（ｂ）や比較例２の図６で示した蒸着フィルムよりも巻回し複数枚のフィルムが重なり合った時に、発熱要因となるヒューズ部の重なりが少ない。従って、実施の形態１におけるコンデンサのヒューズ部の発熱の放熱性は比較例１や２のコンデンサよりも高くなっている。前述の電流密度の均一性が高いということに加えて、ヒューズ部の重なりを少なくしたことも実施の形態１におけるコンデンサの温度上昇が小さくなった要因である。
【００８７】
次に、実施の形態１と比較例３の結果について説明する。実施の形態１と比較例３を比べると、実施の形態１の方が比較例３よりも金属化フィルムの幅方向のヒューズ本数が２分の１になっているため、温度上昇が小さくなっている。このように、金属化フィルムの幅方向においてヒューズ本数を少なくするには、細長い菱形を長い方の対角線がメタリコンと垂直になる向きに配置し、なおかつ長い方の対角線が短い方の対角線の２倍以上であるのが好ましい。
【００８８】
次に、実施の形態２における発明について図３および図８（ａ）、（ｂ）を用いて詳細に説明する。
【００８９】
実施の形態２では、図３および図８（ａ）に示すようにヒューズ部１２の向きをメタリコンと垂直になるように構成した。すなわち、ヒューズ部１２の非金属部分である非蒸着スリット２との境界線１２ａの方向が前記メタリコン面の方向と略垂直に形成する。このようにすると、図８（ｂ）に示した分割電極の辺と垂直になるように接続した比較例３のヒューズ部１５の場合よりも、ヒューズ部と分割電極との境界エッジ部における局所的な電界集中を緩和することができる。図８（ａ）、（ｂ）において、点線丸印で示したところが電界が集中し、発熱がヒューズ部内で最も高くなるヒューズ部と分割電極３との境界エッジ部１６、１７である。
【００９０】
実施の形態２である図８（ａ）では電界集中部が２箇所であることに対して、比較例３を示す図８（ｂ）では４箇所となりヒューズ部１５内の発熱も大きくなる。さらに、図８（ａ）の方が通電面であるメタリコン面と垂直になっているため電流の流れがスムーズとなり、図８（ｂ）よりもエッジ部に電界集中しにくい。電場シミュレーションによる計算結果においても、ここで述べた結果と同様の傾向が得られた。
【００９１】
従って、本実施の形態２の発明は、低発熱化には大きな効果があり、コンデンサのリップル電流通電時の温度上昇を低下させることができる。そのため、（表１）において、実施の形態２のコンデンサは温度上昇値が小さい。
【００９２】
なお本発明では、実施の形態１や実施の形態２という単独の方法だけに限定されるものではなく、本実施の形態２のようにヒューズ部の向きをメタリコン面と垂直にし、なおかつヒューズの位置を実施の形態１のように頂点付近に設けて、実施の形態１および２における両者の効果を複合させた実施の形態にしても良い。
【００９３】
次に、実施の形態３における発明を比較例１と比べて詳細に説明する。ヒューズ部の位置を、分割電極の菱形状の頂点から辺における長さの３分の１の距離にした実施の形態３では、温度上昇値が４．９℃、辺の中心部にヒューズ部を配置した比較例１では温度上昇値が７．３℃であり、実施の形態３の方が温度上昇値が小さい。比較例１のようにヒューズ部の位置が頂点から辺の長さにおける３分の１以上の距離に配置されると温度上昇値が５℃以上となり、周囲温度が８５℃以上の場合ＰＰフィルムを用いたコンデンサの温度が９０℃を越えるため好ましくない。ＰＰフィルムを用いたコンデンサは１００℃以下で使用するのが望ましく、好ましくは９０℃以下で使用するのが良い。
【００９４】
上記のような理由から、本発明においては実施の形態１や３のように分割電極の頂点から辺の長さにおける３分の１以下のところにヒューズ部を配置している。
【００９５】
本実施の形態１では、ヒューズ部５の位置を各分割電極の頂点から２ｍｍの位置にしたが、本発明はこの位置に限定されるものではなく、頂点付近に配置されていれば効果が得られる。実施の形態３のように各頂点から分割電極を構成する菱形や三角形の各辺の長さにおける３分の１以下の距離以内にヒューズ部を配置すれば、大きく発熱を増大させるほどパターン内の電流密度分布が不均一になることはない。３分の１以上の距離になると、発熱に影響する電流密度の不均一さが増大する。本発明者らは、ここで述べたヒューズ部の位置と発熱の関係についても、電場シミュレーションによって検証を行ない確認している。
【００９６】
次に、本実施の形態４の発明について図４および図８（ｂ）を用いて詳細に説明する。
【００９７】
本実施の形態４では、図４に示したようにヒューズ部１３の分割電極３との接続部分１３ａとなる境界部分を幅広になるようにしたため、図８（ｂ）で示した電界集中部の発熱を減少させる効果がある。本実施の形態４では、最もヒューズ部１３の細い幅を０．２ｍｍと実施の形態１よりも狭くしたにもかかわらず、実施の形態１よりも若干温度上昇値が小さかった。
【００９８】
なお本発明では、実施の形態４で述べたヒューズ部の形状の効果と実施の形態１〜３で述べたヒューズの位置や向きに関する発明を組み合わせた実施の形態にしても良く、実施の形態１から４に記載の発明を組み合わせると、より低発熱の効果が期待できる。
【００９９】
（実施の形態５）
図９は、本発明の実施の形態１から４のいずれかにおける金属化フィルムコンデンサを搭載したインバータ装置の回路の概略図である。４０は実施の形態１から４で説明したいずれかの金属化フィルムコンデンサの単品を４個並列にして８００μＦとしたコンデンサである。
【０１００】
インバータ４２のスイッチング周波数は１０ｋＨｚでリップル電流として８０Ａ（実効値）がコンデンサ４０に流れるインバータ装置である。バッテリー４１等でコンデンサ４０に印加される最大電圧は７００Ｖである。このような状態でインバータ装置を運転し、車輌駆動用のモータ４３を駆動させた。
【０１０１】
コンデンサ４０の形としては、金属化フィルムを巻回後、扁平形にしたコンデンサ４個をケースに入れて樹脂モールドした。このようにして得たコンデンサの体積は、８００ｃｍ^３である。
【０１０２】
同じリップル電流を流そうとして市販の電解コンデンサ（定格電圧５００Ｖ）を用いる場合は、低温域における直列抵抗成分の増大も考慮すると、容量を大きくして等価直列抵抗を小さくする必要がある。静電容量としては、少なくとも５００μＦ×５＝２５００μＦ程度必要であり、体積として１２５０ｃｍ^３コンデンサ部分として占有した。
【０１０３】
次の（表２）に、実施の形態５における上記条件で運転させた場合の定常状態のコンデンサ４０の温度上昇値および８５℃で２０００時間運転後の容量減少率を示す。比較のために、市販の電解コンデンサを組み合わせた２５００μＦの場合の値も（表２）に示す。
【０１０４】
【表２】

【０１０５】
（表２）の結果から、実施の形態１から４における金属化フィルムコンデンサを用いれば、電解コンデンサを用いる場合よりも小型で低発熱なインバータ装置を製造することができる。また、適切な蒸着パターンを有する金属化フィルムを用いたコンデンサを使用しているため、長期使用における容量減少が少なく、長寿命のインバータ装置にできる。
【０１０６】
本実施の形態５のように最大電圧が６００Ｖ以上になると電解コンデンサでは、（表２）のように単品では容量減少が大きくなる。直列接続して耐圧を持たそうとすると更に体積増加につながるので、定格６００Ｖ以上では、本実施の形態１から４における金属化フィルムコンデンサを用いると、低コストで、なおかつ低発熱、小型化、長寿命化が図れる。
【０１０７】
【発明の効果】
以上のように本発明の請求項１に記載の発明は、ヒューズ部を残して非金属部分に囲まれた金属部からなる略菱形状および略三角形状の分割電極と、その各辺上の少なくとも１箇所に配置して前記分割電極同士を接続するヒューズ部を備えたパターン形状を有する蒸着金属電極が形成してある金属化フィルムを巻回または積層し、両側端面にメタリコン部を有する金属化フィルムコンデンサであって、前記ヒューズ部は、前記菱形状の頂点付近に設けたことから、耐リップル電流性能が優れ、温度上昇が低く、保安性の優れたコンデンサを得ることができる。
【０１０８】
本発明の請求項２に記載の発明は、ヒューズ部を残して非金属部分に囲まれた金属部からなる略菱形状および略三角形状の分割電極と、その各辺上の少なくとも１箇所に配置して前記分割電極同士を接続するヒューズ部を備えたパターン形状を有する蒸着金属電極が形成してある金属化フィルムを巻回または積層し、両側端面にメタリコン部を備えた金属化フィルムコンデンサであって、前記ヒューズ部は前記非金属部分との境界線の方向が前記メタリコン面の方向と略垂直に形成していることから、耐リップル電流性能が優れ、温度上昇の低いコンデンサを得ることができる。
【０１０９】
本発明の請求項３に記載の発明は、ヒューズ部を残して非金属部分に囲まれた金属部からなる略菱形状および略三角形状の分割電極と、その各辺上の少なくとも１箇所に配置して前記分割電極を接続するヒューズ部を備えたパターン形状を有する蒸着金属電極が形成してある金属化フィルムを巻回または積層し、両側端面にメタリコン部を有する金属化フィルムコンデンサであって、前記ヒューズ部を前記菱形状の頂点付近に設け、かつ前記ヒューズ部の前記非金属部分との境界線の方向が前記メタリコン面の方向と略垂直に形成していることから、耐リップル電流性能が優れ、温度上昇が低く、保安性の優れたコンデンサを得ることができる。
【０１１０】
本発明の請求項４に記載の発明は、ヒューズ部を分割電極の頂点から辺の長さにおける３分の１以下の距離に設けたことから、耐リップル電流性能が優れ、温度上昇が低く、保安性の優れたコンデンサを得ることができる。
【０１１１】
本発明の請求項５に記載の発明は、菱形は対角線の長い方が短い方の２倍以上の形状で、長い方の対角線が金属化フィルムの幅方向を向くように配置されており、三角形状は前記菱形状を短い方の対角線で２等分した形の二等辺三角形であり、その底辺をメタリコンと近接する位置に配置したことから、耐リップル電流性能が優れ、温度上昇の低いコンデンサを得ることができる。
【０１１２】
本発明の請求項６に記載の発明は、　パターン電極中で菱形状および三角形状の１辺には１個所のみヒューズ部が存在し、１つの頂点には１本のヒューズ部のみが近接するように配置したことから、耐リップル電流性能が優れ、温度上昇が低く、保安性の優れたコンデンサを得ることができる。
【０１１３】
本発明の請求項７に記載の発明は、ヒューズ部が、分割電極に接続される部分のヒューズ幅が広がるように設けたものであることから、耐リップル電流性能が優れ、温度上昇の低いコンデンサを得ることができる。
【０１１４】
本発明の請求項８に記載の発明は、請求項１から７に記載のいずれかのパターン形状を形成して金属化フィルムコンデンサを製造することから、６００Ｖ以上の高電圧用途に適し、耐リップル電流性能が優れ、温度上昇の低いコンデンサを得ることができる。
【０１１５】
本発明の請求項９に記載の発明は、請求項１から７のいずれかに記載の金属化フィルムコンデンサを車輌駆動用モータの駆動回路の平滑用に用いたことから、インバータ装置の効率を向上させ、機器の省エネ化を図ることができる。
【０１１６】
本発明の請求項１０に記載の発明は、車輌用の駆動回路においてコンデンサに印加される最大電圧が６００Ｖ以上であることから、本発明の請求項１から７のいずれかに記載の金属化フィルムコンデンサを用いれば、小型で長寿命で安全性に優れたインバータ装置が得ることができる。
【０１１７】
本発明の請求項１１に記載の発明は、請求項１から７のいずれかに記載の金属化フィルムコンデンサを車輌駆動用モータの駆動回路の平滑用コンデンサとして用いたインバータ装置であることから、小型で長寿命で安全性に優れたインバータ装置にできる。
【図面の簡単な説明】
【図１】本発明の実施の形態１および３における金属化フィルムコンデンサに使用した蒸着フィルムの表面の模式図
【図２】同実施の形態１における金属化フィルムコンデンサの要部分解の模式図
【図３】同実施の形態２における金属化フィルムコンデンサに使用した蒸着フィルムの表面の模式図
【図４】同実施の形態４における金属化フィルムコンデンサに使用した蒸着フィルムのヒューズ部付近の模式図
【図５】（ａ）同実施の形態１における金属化フィルムコンデンサに使用した蒸着フィルム内の電流の流れ模式図
（ｂ）比較例１における金属化フィルムコンデンサに使用した蒸着フィルム内の電流の流れ模式図
【図６】比較例２における金属化フィルムコンデンサに使用した蒸着フィルムの表面の模式図
【図７】比較例２における金属化フィルムコンデンサに使用した蒸着フィルム内の電流の流れ模式図
【図８】（ａ）本発明の実施の形態２における金属化フィルムコンデンサのヒューズ部内の電流流れと電界集中部を示す模式図
（ｂ）金属化フィルムコンデンサのヒューズ部が分割電極の辺と垂直になる向きに接続された場合のヒューズ部内の電流流れと電界集中を示す模式図
【図９】本発明の実施の形態５におけるインバータ装置の回路図
【図１０】従来の金属化フィルムコンデンサに使用した四角形の分割電極にした蒸着フィルムの表面の模式図
【図１１】従来の金属化フィルムコンデンサに使用した三角形と菱形の分割電極にした蒸着フィルムの表面の模式図
【符号の説明】
１　　非蒸着部
２　　非蒸着スリット（非金属部分）
３　　菱形状の分割電極（金属部）
４　　三角形状の分割電極（金属部）
５、１２、１３　　ヒューズ部
８、９　片面金属化ポリプロピレンフィルム（金属化フィルム）
１０　引き出し電極（メタリコン部）
１２ａ　境界線
１３ａ　接続部分
４０　コンデンサ（平滑用コンデンサ）[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a metallized film capacitor having a self-security mechanism for electric equipment, industrial use, electric power, and the like, a method for manufacturing the same, and an inverter device using the capacitor.
[0002]
[Prior art]
Generally, a metallized film capacitor using a vapor-deposited metal for an electrode has excellent electrical characteristics, such as low loss, high withstand voltage, non-polarity, long life, and good temperature characteristics, compared to an aluminum electrolytic capacitor. However, there has been a problem that the size of the dielectric film has to be increased when trying to obtain the same capacitance as that of an electrolytic capacitor, because there has been a limit to thinning the dielectric film and the dielectric constant of the film is small. Was.
[0003]
However, in recent years, there has been a movement to use metallized film capacitors instead of electrolytic capacitors in order to save energy, prolong the service life, and improve safety of electric devices equipped with an inverter circuit. .
[0004]
The life of an aluminum electrolytic capacitor is shorter than that of a metallized film capacitor because it is difficult to avoid dry-up of the driving electrolyte. Therefore, in an electric device using an aluminum electrolytic capacitor, the life of the electrolytic capacitor determines the life of the device. Therefore, when the electric device is used for a long time, it is necessary to replace the capacitor in a fixed period. Further, since the electrolyte is an organic solvent, there is a problem regarding safety. In addition, it is difficult for aluminum electrolytic capacitors to be used at a rated voltage of 600 V or higher because it is difficult to increase the withstand voltage of the oxide film, which is a dielectric. For high voltage applications, multiple capacitors are connected in series. Needed to use.
[0005]
Further, the electrolytic capacitor has a higher electric resistance of the electrolytic solution than the metal, and the resistance further increases particularly in a low temperature range, so that a large amount of heat is generated by a ripple current. Therefore, in a circuit in which a relatively large ripple current of several tens of amperes or more flows in a smoothing application, the capacitance is increased (electrode area is increased), the series resistance component is reduced, and the ripple resistance is often improved. . As described above, when the area of the electrode foil is increased, the size of the electrolytic capacitor is increased. Therefore, the size performance is reduced in a smoothing application in which a high ripple current flows.
[0006]
On the other hand, since the metallized film capacitor has an extremely long life, there is no need to replace it during long-term use, thereby facilitating maintenance of electric equipment. Further, since the metalized film capacitor has a high withstand voltage of the dielectric film, it can be used alone as an inverter circuit having a high voltage of 600 V or more. Therefore, if a metalized film capacitor is used, the voltage of the inverter can be increased and the efficiency can be improved, and the energy saving of the device can be achieved. Further, the metallized film capacitor uses a metal having a small electric resistance for the electrode and has a small dielectric loss due to the dielectric itself, so that the loss as the capacitor is small and the ripple resistance is excellent.
[0007]
In order to meet the needs of the market by taking advantage of such advantages, metallized film capacitors must be made as thin as an aluminum electrolytic capacitor by using a thinner dielectric film to achieve reliability and safety. Needs to be further enhanced.
[0008]
In order to reduce the size of metallized film capacitors, it is necessary to use a thinner dielectric film than in the conventional example, so it is necessary to increase the potential gradient (withstand voltage per 1 μm) of the dielectric film deposited with metal. It becomes. In order to further enhance the reliability and safety, the quality of the deposited metal is an important point.
[0009]
As the dielectric film is made thinner, the probability that an electric weak point exists in the film increases. In order to function normally as a capacitor even if there is such an electric weak point, the following two methods are generally used.
[0010]
One is to improve the self-healing property by reducing the thickness of the deposited film. The self-healing property is a phenomenon in which, when an excessive current flows through an electric weak point due to a short circuit or the like, heat is generated, and a vapor deposited film around the weak point evaporates and scatters, thereby instantaneously recovering insulation. When this property works sharply and the clearing energy at the time of self-healing is relatively small, dielectric breakdown does not easily progress from the electrical weak point, so it can be used in a normal state without causing significant damage to the capacitor .
[0011]
The other is a pattern deposition electrode consisting of a large number of divided metal deposition electrodes and a fuse section connecting them by providing a large number of non-deposition slits in a grid pattern using an oil printing method when forming the deposition metal electrodes. (For example, see Japanese Patent Application Laid-Open No. 10-154631).
[0012]
FIGS. 10 and 11 show a conventional example of a vapor-deposited film having patterned metal electrodes. FIG. 10 shows a vapor deposition pattern in which the shape of the divided electrodes is quadrangular, and FIG. 11 shows a vapor deposition pattern using diamonds and triangles. In the drawing, reference numerals 20 and 30 denote non-evaporated portions provided at one end edge in the length direction, reference numerals 21 and 31 denote non-evaporated slits, reference numerals 22 and 32 denote divided electrodes, and reference numerals 23 and 33 denote fuses for connecting divided electrodes in the film width direction. , 24 and 34 are fuse portions closest to the lead electrode, 25 is a fuse portion connecting the divided electrodes in the film length direction, and 26 and 35 are portions that come into contact with a metallikon which is a lead electrode when a metallized film capacitor is formed. .
[0013]
When a metallized film capacitor employs a patterned vapor deposition electrode as shown in FIGS. 10 and 11 for a dielectric film, an excessive current flows from a surrounding divided electrode through a fuse portion toward a short-circuited electrical weak point. The large current cuts the fuse connecting the divided electrodes, thereby separating the divided capacitor having the electric weak point from the entire capacitor.
[0014]
When the split electrodes are configured in this way, even if the self-healing action described above does not work sharply, the split capacitor having the weak point is instantaneously electrically disconnected by the fusing of the fuse, which slightly reduces the capacitance. However, it can be used normally as a capacitor. Therefore, the smaller the area of the split electrode is, the smaller the capacity decrease during long-term use at the same working voltage is. That is, since the potential gradient of the dielectric film can be increased by reducing the size of the divided electrodes, the life of the capacitor can be extended.
[0015]
Furthermore, if the divided electrodes are formed by pattern evaporation, even if an abnormality occurs in the capacitor, the fuse part will be cut in a chain and the capacitance will be lost, so the self-protection function will work, so there is no risk of ignition or smoke and safety , A capacitor having a high capacitance can be obtained.
[0016]
However, in the case of a metallized film capacitor, the shape of the divided electrodes and the pattern of the fuse portion at the time of vapor deposition greatly affect the heat generation of the capacitor when used in a steady state. The fuse portion has a higher resistance value than each of the divided electrodes and generates heat due to the current, and blows when the current amount is too large. For this reason, suppressing heat generation and enhancing the self-security function are mutually contradictory. Therefore, it is necessary to design a vapor deposition pattern so as to generate as little heat as possible when used in a steady state and to ensure that the self-protection function works when a local short circuit occurs in the divided electrodes.
[0017]
There have been disclosed several inventions in which fuse portions are arranged at the sides and vertices of a polygon such as a quadrangle, a triangle, and a rhombus as shown in FIGS. 10 and 11 (for example, Japanese Patent Application Laid-Open No. 7-865088, See JP-A-11-144995). However, the prior art does not disclose in detail how to minimize the heat generation by designing the shapes of the divided electrodes, the arrangement of the fuse portions, and the orientation of the fuse portions.
[0018]
The present inventors have been working diligently on the development of a vapor deposition film pattern with low heat generation. In order to reduce heat generation, the number of fuse portions serving as a resistance component in the width direction of the dielectric film may be reduced as much as possible. However, if the divided electrodes are enlarged in the width direction of the film to increase the area in order to reduce the number of fuse portions, the potential gradient is reduced and the life is shortened.
[0019]
In order to prevent the potential gradient from decreasing, the width of the rectangular or rhombic split electrode is reduced in the length direction of the dielectric film and is increased in the width direction of the film. With such a configuration, the number of fuse portions in the film width direction can be reduced without increasing the area of the divided electrodes, so that heat generation can be reduced while maintaining a high potential gradient.
[0020]
When the elongated rectangular divided electrodes are arranged in the width direction of the dielectric film, the ratio of the non-deposited portion surrounding the divided electrodes is larger than that in the case where the diamond is arranged, so that it is not suitable for miniaturization. Therefore, it is more advantageous to reduce the size of the film than to employ a rectangular pattern in which elongated diamonds are arranged in the width direction of the film.
[0021]
When adopting a diamond shape as a split electrode in a dielectric film in this way, in order to minimize heat generation, where in the diamond shape should the fuse part be placed and in what direction should the fuse part be connected? I did not know clearly. Further, it has not been known in detail how the position and the shape of the fuse portion are optimized to reliably operate the security function in the pattern having the rhombic divided electrodes.
[0022]
[Problems to be solved by the invention]
In view of the above-mentioned problems of the conventional technology, the problem to be solved by the present invention is to provide a metallized film capacitor that realizes low heat generation and a high self-protection function in high voltage and high ripple current applications, and the metallized film capacitor. It is to provide a manufacturing method and an inverter device using the capacitor.
[0023]
[Means for Solving the Problems]
In order to achieve the above object, a metallized film capacitor according to claim 1 of the present invention has a substantially rhombus-shaped and a substantially triangular divided electrode composed of a metal portion surrounded by a non-metal portion except for a fuse portion. Winding or laminating a metallized film on which a vapor-deposited metal electrode having a pattern shape provided with a fuse portion arranged at at least one position on each side of the divided electrode and connecting the divided electrodes, A metallized film capacitor having metallikon portions on both side end surfaces, wherein the fuse portion is provided near a vertex of the rhombus.
[0024]
The metallized film capacitor according to claim 2 of the present invention has a substantially rhombus-shaped and a substantially triangular-shaped divided electrode made of a metal part surrounded by a non-metal part except for a fuse part, Winding or laminating a metallized film on which a vapor-deposited metal electrode having a pattern shape provided with a fuse portion arranged at at least one place and connecting the divided electrodes is formed, and metallized portions having metallikon portions on both end surfaces In the film capacitor, the fuse portion is formed such that a direction of a boundary line with the non-metal portion is substantially perpendicular to a direction of a surface of the metallikon portion.
[0025]
The metallized film capacitor according to claim 3 of the present invention has a substantially rhombus-shaped and a substantially triangular-shaped divided electrode made of a metal portion surrounded by a non-metal portion except for a fuse portion, A metallized film having a metallized portion formed by winding or laminating a metallized film on which a vapor-deposited metal electrode having a pattern shape provided with a fuse portion disposed at at least one place and connecting the split electrode is formed, and having metallicon portions on both side end surfaces. The capacitor is characterized in that the fuse portion is provided near a vertex of the rhombus, and a direction of a boundary line with the non-metal portion is formed substantially perpendicular to a surface direction of the metallikon portion.
[0026]
Further, the metallized film capacitor according to claim 4 of the present invention is characterized in that the fuse portion is provided at a distance of one third or less of the side length from the vertex of the divided electrode.
[0027]
In the metallized film capacitor according to claim 5 of the present invention, the rhombus has a shape in which the longer diagonal line is twice or more than the shorter diagonal line, and the longer diagonal line faces the width direction of the metallized film. The triangular shape is characterized in that the rhombus is an isosceles triangle obtained by bisecting the rhombus with a shorter diagonal line, and the base is arranged at a position close to the metallikon portion.
[0028]
Further, in the metallized film capacitor according to claim 6 of the present invention, only one fuse portion exists on one side of the diamond shape and the triangular shape in the pattern-shaped divided electrode, and only one vertex of the divided electrode has Is characterized in that only one fuse portion is arranged close to the fuse portion.
[0029]
Further, the metallized film capacitor according to claim 7 of the present invention is characterized in that the fuse portion is formed so as to be wider at a portion connected to the split electrode.
[0030]
Further, a method of manufacturing a metallized film capacitor according to claim 8 of the present invention is characterized in that a metallized film capacitor is manufactured by forming the pattern shape according to any one of claims 1 to 7.
[0031]
A metallized film capacitor according to a ninth aspect of the present invention is characterized in that the metallized film capacitor according to any one of the first to seventh aspects is used for smoothing a drive circuit of a motor for driving a vehicle. I have.
[0032]
The metallized film capacitor according to claim 10 of the present invention is characterized in that the maximum voltage applied to the capacitor in the drive circuit of the vehicle drive motor is 600 V or more.
[0033]
Further, an inverter device according to claim 11 of the present invention is characterized in that the metallized film capacitor according to any one of claims 1 to 7 is used as a smoothing capacitor of a drive circuit of a motor for driving a vehicle. .
[0034]
BEST MODE FOR CARRYING OUT THE INVENTION
Since the above-mentioned object of the present invention can be achieved by implementing the configurations described in the claims as embodiments, the operation and effect of the configurations will be described together with the configurations of the claims, and the description of the claims will be described below. Specific terms that need explanation in the configuration will be described in the embodiments of the present invention with a detailed explanation.
[0035]
According to the first aspect of the present invention, a substantially rhombus-shaped and substantially triangular-shaped divided electrode made of a metal part surrounded by a non-metal part except for a fuse part, and arranged at at least one position on each side thereof A metallized film capacitor having a metallized film formed by winding or laminating a metallized film on which a pattern-shaped vapor-deposited metal electrode having a fuse portion connecting the divided electrodes is formed, and having a metallikon portion on both side end surfaces, Since the fuse portion is provided near the vertex of the rhombus, the current density distribution in the pattern-shaped divided electrode becomes uniform.
[0036]
According to a second aspect of the present invention, a substantially rhombus-shaped and substantially triangular-shaped divided electrode made of a metal part surrounded by a non-metal part except for a fuse part is arranged at at least one position on each side thereof. A metallized film capacitor comprising a metallized film formed by winding or laminating a metallized film on which a pattern-shaped vapor-deposited metal electrode having a fuse portion connecting the divided electrodes is formed, and having a metallikon portion on both end surfaces. Since the direction of the boundary between the fuse portion and the non-metal portion is substantially perpendicular to the direction of the surface of the metallicon portion, local current concentration in the fuse portion is reduced.
[0037]
According to a third aspect of the present invention, a substantially rhombus-shaped and substantially triangular-shaped divided electrode made of a metal part surrounded by a non-metal part except for a fuse part is disposed at at least one position on each side thereof. A metallized film capacitor having a metallized portion wound or laminated with a metallized film on which a patterned metal electrode having a fuse portion connecting the divided electrodes is formed, and having a metallikon portion on both side end faces, Since the fuse portion is provided near the apex of the rhombus and the direction of the boundary line with the non-metal portion is formed substantially perpendicular to the direction of the surface of the metallikon portion, the current in the pattern-shaped divided electrode is The density distribution becomes uniform, and local current concentration is reduced in the fuse portion.
[0038]
In the invention according to claim 4 of the present invention, since the position of the fuse portion is provided at a distance of one-third or less of the side length from the vertex of the rhombus of the divided electrode, the current density in the divided electrode is reduced. The distribution becomes uniform.
[0039]
In the invention according to claim 5 of the present invention, the rhombus of the divided electrode has a shape in which the longer diagonal line is twice or more as long as the shorter diagonal line, and is arranged such that the longer diagonal line faces the width direction of the metallized film. The triangular shape is an isosceles triangle obtained by bisecting the rhombus with a shorter diagonal line.Since the base is disposed at a position close to the metallikon portion, the metallization is performed without lowering the potential gradient. The number of fuse portions in the width direction of the film is reduced.
[0040]
According to a sixth aspect of the present invention, in the pattern-shaped divided electrode, only one fuse portion exists on one side of the diamond shape and the triangular shape, and one fuse is provided at one vertex of the divided electrode. Since only the portions are arranged close to each other, the current density distribution can be made uniform within the divided electrodes.
[0041]
According to the invention described in claim 7 of the present invention, the portion of the fuse portion connected to the split electrode is formed so as to be wider, so that local current concentration in the fuse portion can be reduced.
[0042]
According to the invention described in claim 8 of the present invention, since the metallized film capacitor is manufactured by forming the pattern shape according to any one of claims 1 to 7, a capacitor with low heat generation can be obtained.
[0043]
According to a ninth aspect of the present invention, the metallized film capacitor according to any one of the first to seventh aspects is used for smoothing a drive circuit of a motor for driving a vehicle. Inverter circuit can be realized.
[0044]
According to the tenth aspect of the present invention, the maximum voltage applied to the capacitor in the drive circuit of the vehicle drive motor is 600 V or more, so that the inverter device is more compact and has a longer life than using an electrolytic capacitor. Can be achieved.
[0045]
The invention according to claim 11 of the present invention is an inverter device using the metallized film capacitor according to any one of claims 1 to 7 for smoothing a drive circuit of a motor for driving a vehicle. Can be smaller.
[0046]
Hereinafter, a metallized film capacitor of the present invention, a method for manufacturing the same, and an inverter device equipped with the metalized film capacitor will be described with reference to the drawings.
[0047]
(Embodiment 1)
FIG. 1 is a schematic diagram of the surface of a vapor-deposited film used for the metallized film capacitor of the present invention, and FIG. 2 is a schematic diagram of a metallized film capacitor using the vapor-deposited film of FIG.
[0048]
In FIG. 1, reference numeral 1 denotes a non-evaporated portion provided at one longitudinal edge of a polypropylene (PP) film which is a dielectric film, and 2 denotes a non-evaporated slit which is a non-metal portion formed by oil transfer. Reference numeral 3 denotes a diamond-shaped divided electrode made of a vapor-deposited metal, which is a metal part divided into a large number by the non-vapor-deposited slit 2, and 4 denotes a triangular-shaped divided electrode. The length of the diagonal line in the diamond-shaped divided electrode 3 was 18 mm for the longer one and 5 mm for the shorter one. Therefore, the area of one diamond-shaped divided electrode 3 is 45 mm. ² It is. The triangular divided electrode 4 is an isosceles triangle that is divided into two by the shorter diagonal line of the diamond-shaped divided electrode 3. In the first embodiment, aluminum is used as the vapor deposition metal.
[0049]
Reference numeral 5 denotes a fuse portion connecting the diamond-shaped divided electrode 3 and the triangular-shaped divided electrode 4, having a fuse width of 0.3 mm and a fuse length of 0.4 mm. The position of the fuse portion 5 was set at 2 mm along each side from the top of the divided electrode 3 and the divided electrode 4. As shown in FIG. 1, only one fuse part was arranged so as to be always adjacent to one vertex of each divided electrode.
[0050]
Reference numeral 6 denotes a deposition electrode portion which comes into contact with a metallikon as an extraction electrode. Reference numeral 7 denotes a fuse portion connecting the deposition electrode portion 6 and the divided electrode 4, and has a fuse width of 0.5 mm and a fuse length of 0.4 mm. In FIG. 1, a vapor-deposited metal is formed only on one side of the polypropylene film. In FIG. 1, the pattern-deposited metal part is shown in gray.
[0051]
Next, the structure of the metallized film capacitor according to the first embodiment manufactured using the metallized film of FIG. 1 will be described with reference to FIG.
[0052]
In FIG. 2, reference numeral 8 denotes a single-sided metal which is a metallized film having a pattern-shaped vapor-deposited metal electrode provided with the divided electrodes 3 and 4 described in FIG. 1 and the fuse portions 5 and 7 connecting the divided electrodes 3 and 4 to each other. Reference numeral 9 denotes a single-sided metallized polypropylene film which is a metallized film in which the entire surface other than the non-deposited portion 1 which is the edge is vapor-deposited. In FIG. 2, the non-deposited portions are shown in gray.
[0053]
As shown in FIG. 2, two sheets of a single-sided metallized polypropylene film 8 having a vapor-deposited metal pattern and a single-sided metallized polypropylene film 9 having no pattern are overlapped so that the non-deposited portion 1 at one edge of the metallized film does not overlap. The metallicon electrode 10 is formed by spraying zinc onto the two end surfaces of the wound material, thereby forming a metallicon portion serving as a lead electrode. 11 is an electrode lead.
[0054]
The thickness of the polypropylene film as the dielectric used in the first embodiment by the micrometer method is 3.3 μm, and the capacitance of the prototype capacitor is 200 μF.
[0055]
In the following (Table 1), when the capacitor of Embodiment 1 is applied with a DC voltage of 600 V at 85 ° C. and a ripple current of 30 A at 10 kHz, a capacity reduction rate (ΔC / C) after 2,000 hours of an accelerated life test is applied. ), And the temperature rise value (average value of five capacitors) of the capacitor after energization for 90 minutes under the above-described conditions, and the security by a step-up test in which the voltage is increased by 50 V every two hours from a DC voltage of 600 V at 85 ° C. The result of confirming is shown.
[0056]
In the step-up test, when the capacity began to decrease from about 800 V and did not ignite or smoke until 1300 V, and the fuse section was blown and the capacity decreased by 97% or more, it was evaluated as ◎ (pass). The features and effects of this embodiment based on the results will be described later in comparison with a comparative example.
[0057]
[Table 1]

[0058]
(Embodiment 2)
FIG. 3 is a schematic view of the surface of a vapor-deposited film used for the metallized film capacitor described in the second embodiment. In the present embodiment, only the configuration of the fuse portion is different from the fuse portion 5 of the invention in the first embodiment, and the other portions having the same configuration and operation and effect are denoted by the same reference numerals, and detailed description is omitted. The following description focuses on the differences.
[0059]
In the present embodiment, the configuration is the same as that of the first embodiment except that the fuse unit 5 of FIG. 1 in the first embodiment is replaced with a fuse unit 12 as shown in FIG. In FIG. 3, the direction of the boundary line 12 a of the fuse portion 12 with the non-evaporated slit 2, which is a non-metal portion, is perpendicular to the surface of the metallikon electrode 10. The width of the fuse part 12 was 0.3 mm.
[0060]
3 is replaced with the single-sided metallized polypropylene film 8 which is the vapor deposition film in the first embodiment, and the metallized film capacitor of the second embodiment is manufactured in the same manner as in the first embodiment. Manufactured.
[0061]
In the above (Table 1), when the DC voltage of 600 V is applied to the capacitor of the second embodiment at 85 ° C. and the ripple current is applied at 30 A at 10 kHz, the capacity reduction rate (ΔC / C) after 2,000 hours of the accelerated life test is obtained. And the temperature rise value (average value of five capacitors) of the capacitor after energization for 90 minutes under the above conditions, and the security by a step-up test in which the voltage was increased by 50 V every two hours from a DC voltage of 600 V at 85 ° C. The results are shown below. The features and effects of this embodiment based on the results will be described later in comparison with a comparative example.
[0062]
(Embodiment 3)
The present embodiment differs from the fuse section 5 of the first embodiment only in the arrangement of the fuse section, and otherwise has the same configuration and operation and effect. Therefore, detailed description is omitted, and FIG. The different points will be mainly described.
[0063]
In the present embodiment, except that the fuse portion 5 in FIG. 1 of the vapor deposition pattern in the first embodiment is arranged at a distance of one third of the side length from the vertex of the rhombus of the divided electrode 3. A capacitor was manufactured in the same manner as in Embodiment 1.
[0064]
In Table 1 above, when the capacitor of the present embodiment is applied with a DC voltage of 600 V at 85 ° C. and a ripple current of 30 A at 10 kHz, a capacity reduction rate (ΔC / C) after 2000 hours of an accelerated life test, And the temperature rise value of the capacitor after 90 minutes of energization under the above conditions (average value of 5 capacitors), and the security was confirmed by a step-up test in which the voltage was increased by 50 V every 2 hours from a DC voltage of 600 V at 85 ° C. The results obtained are shown. The features and effects of this embodiment based on the results will be described later in comparison with a comparative example.
[0065]
(Embodiment 4)
FIG. 4 is an enlarged schematic diagram of a fuse portion on the surface of a vapor-deposited film used for the metallized film capacitor described in the present embodiment. The present embodiment differs from the fuse section 5 of the first embodiment only in the configuration of the fuse section, and otherwise has the same configuration and operation and effect. Therefore, detailed description will be omitted, and different points will be mainly described. I do.
[0066]
In the present embodiment, except that the shape of the fuse portion 13 is changed from a portion 13a, which is connected to the divided electrode 3 as shown in FIG. A capacitor was manufactured in the same manner as in the first embodiment. In the present embodiment, the width of the thinnest portion of the fuse portion 13 is 0.2 mm.
[0067]
In Table 1 above, when the capacitor of the present embodiment is applied with a DC voltage of 600 V at 85 ° C. and a ripple current of 30 A at 10 kHz, a capacity reduction rate (ΔC / C) after 2000 hours of an accelerated life test, And the temperature rise value of the capacitor after 90 minutes of energization under the above conditions (average value of 5 capacitors), and the security was confirmed by a step-up test in which the voltage was increased by 50 V every 2 hours from a DC voltage of 600 V at 85 ° C. The results obtained are shown. The features and effects of this embodiment based on the results will be described later in comparison with a comparative example.
[0068]
In the first to fourth embodiments, the wound type metallized film capacitor is described. However, the present invention is not limited to the wound type metallized film capacitor, and is applied to a laminated type metallized film capacitor. Is also good.
[0069]
In Embodiments 1 to 4, aluminum having a uniform thickness is deposited on the entire surface of the polypropylene film. However, the present invention is not limited by the thickness of the deposited film. For example, it is preferable to use heavy-edge deposition in which the thickness of the deposited metal near the metallikon is increased because the contact resistance with the metallikon is improved.
[0070]
Further, in Embodiments 1 to 4, aluminum is used as the metal to be deposited. However, it is needless to say that the present invention is not limited to aluminum but may be another metal to be deposited. For example, an alloy of aluminum and zinc, zinc, or the like may be used.
[0071]
Further, in the first to fourth embodiments, the polypropylene film deposited on one side is described. However, the present invention is not limited to the pattern deposited on one side of the polypropylene film, and the polypropylene film deposited on both sides is not deposited. It goes without saying that a capacitor in which two polypropylene films are wound or laminated as a pair may be used.
[0072]
Also, the dielectric film is not limited to polypropylene, but may be another polymer film such as a polyester film such as polyethylene terephthalate, a polyphenylene sulfide film, or a polystyrene film.
[0073]
(Comparative Example 1)
FIG. 5B shows a metallized film having a vapor deposition pattern used in Comparative Example 1. Comparative Example 1 differs from the first embodiment in that the fuse part 5 is replaced with a fuse part 15 arranged at the center of the sides of the diamond-shaped divided electrode 3 and the triangular divided electrode 4 in the first embodiment. A capacitor was manufactured in a similar manner.
[0074]
In the above (Table 1), when the DC voltage of 600 V is applied to the capacitor of Comparative Example 1 at 85 ° C. and the ripple current is applied at 30 A at 10 kHz, the capacity reduction rate (ΔC / C) after 2000 hours of the accelerated life test, and The security was confirmed by a temperature rise value (average value of five capacitors) of the capacitor after energization for 90 minutes under the above conditions and a step-up test in which the voltage was increased by 50 V every two hours from a DC voltage of 600 V at 85 ° C. The results are shown.
[0075]
(Comparative Example 2)
Comparative Example 2 is the same as Embodiment 1 except that the fuse position of Embodiment 1 is arranged such that two fuse portions 14 are located close to one vertex of a diamond shape as shown in FIG. The capacitor was manufactured by the method.
[0076]
In Table 1 above, when the capacitor of Comparative Example 2 was applied with a DC voltage of 600 V at 85 ° C. and a ripple current of 30 A at 10 kHz, a capacity reduction rate (ΔC / C) after 2000 hours of an accelerated life test, and The security was confirmed by a temperature rise value (average value of five capacitors) of the capacitor after energization for 90 minutes under the above conditions and a step-up test in which the voltage was increased by 50 V every two hours from a DC voltage of 600 V at 85 ° C. The results are shown.
[0077]
(Comparative Example 3)
In Comparative Example 3, a method similar to that of Embodiment 1 was used, except that the longer diagonal of the diamond-shaped divided electrode 3 in Embodiment 1 was set to half the length, and the shorter diagonal was doubled. A capacitor was manufactured. This doubles the number of fuses in the width direction of the metallized film.
[0078]
In the above (Table 1), when the DC voltage of 600 V is applied to the capacitor of Comparative Example 3 at 85 ° C. and the ripple current is applied at 30 A at 10 kHz, the capacity reduction rate (ΔC / C) after 2000 hours of the accelerated life test, and The security was confirmed by a temperature rise value (average value of five capacitors) of the capacitor after energization for 90 minutes under the above conditions and a step-up test in which the voltage was increased by 50 V every two hours from a DC voltage of 600 V at 85 ° C. The results are shown.
[0079]
(Performance comparison)
In the first embodiment, the temperature rise of the capacitor is smaller than that of the first comparative example. The reason will be described with reference to FIGS.
[0080]
FIGS. 5A and 5B are diagrams schematically showing the flow of current in the horizontal direction at a certain phase of 10 kHz on the vapor deposition pattern surface of the metallized film in Embodiment 1 and Comparative Example 1 by arrows. is there. The present inventors performed analysis of the current density distribution and the heat generation distribution in the pattern of the divided electrodes deposited by the finite element method using the electric field simulation software (VOLT) manufactured by Photon, and based on the results of FIG. A schematic diagram as shown in (b) is drawn.
[0081]
In the first embodiment, the fuse portion 5 is arranged near the apex of the rhombus and the triangular shape, and only one fuse portion is close to the apex. It is like the arrow of a). On the other hand, in Comparative Example 1 in which the fuse portion 15 is disposed in the middle of the side of the divided electrode, the current flows as shown in FIG.
[0082]
Comparing these two examples, it can be seen that FIG. 5B in Comparative Example 1 has a portion with a smaller current density indicated by a dotted ellipse. In Comparative Example 1 in which the fuse portion was disposed in the middle of the rhombus side, there was no current outlet in the dotted elliptical portion corresponding to the rhombus or triangular tip than the fuse portion position. Becomes smaller.
[0083]
Therefore, in the first embodiment, the current density distribution is uniform over the entire electrode of the vapor deposition pattern, and the amount of heat generated in the fuse portion 5 is smaller than in the first comparative example. Therefore, as shown in (Table 1), the temperature rise of the capacitor was smaller in the first embodiment than in the first comparative example. This is the same tendency even when the calculation is performed by the electric field simulation.
[0084]
Next, the results of Embodiment 1 and Comparative Example 2 will be described with reference to FIGS. In the capacitor of Comparative Example 2, a portion having a smaller current density indicated by a dotted ellipse occurs as shown in FIG. 7 than in Embodiment 1. Therefore, in the first embodiment, the current density distribution is uniform over the entire electrode of the vapor deposition pattern, and the amount of heat generated in the fuse portion 5 is smaller than in the comparative example 2. Therefore, as shown in (Table 1), the temperature rise of the capacitor was smaller in the first embodiment than in the second comparative example. This is the same tendency even when the calculation is performed by the electric field simulation.
[0085]
In the first embodiment, since the current density distribution in the pattern electrode is more uniform than in the comparative examples 1 and 2, even if a short circuit occurs in the divided electrode, the current flows from the surrounding fuse portion smoothly and efficiently. It can exhibit self-healing properties. Therefore, the security function at the time of abnormality is also superior to Comparative Examples 1 and 2.
[0086]
Further, since the deposited films shown in FIG. 1 of the first embodiment are arranged so that the positions of the fuse portions are separated from each other on adjacent sides, the vapor deposition films shown in FIG. 5B of Comparative Example 1 and FIG. When a plurality of films are wound around each other and overlapped with each other, the overlapping of the fuse portions, which causes heat generation, is smaller than that of the vapor-deposited film shown. Therefore, the heat dissipation of the heat generated by the fuse portion of the capacitor in the first embodiment is higher than those of the capacitors of Comparative Examples 1 and 2. In addition to the above-mentioned high uniformity of the current density, the reduction of the overlapping of the fuse portions is also a factor of reducing the temperature rise of the capacitor in the first embodiment.
[0087]
Next, the results of Embodiment 1 and Comparative Example 3 will be described. Comparing the first embodiment with the comparative example 3, since the number of fuses in the width direction of the metallized film in the first embodiment is half that in the comparative example 3, the temperature rise is small. I have. Thus, in order to reduce the number of fuses in the width direction of the metallized film, an elongated diamond is arranged so that the longer diagonal line is perpendicular to the metallikon, and the longer diagonal line is twice the shorter diagonal line. The above is preferable.
[0088]
Next, the invention in the second embodiment will be described in detail with reference to FIGS. 3 and 8A and 8B.
[0089]
In the second embodiment, as shown in FIG. 3 and FIG. 8A, the direction of the fuse unit 12 is configured to be perpendicular to the metallicon. That is, the direction of the boundary line 12a between the non-metallic portion of the fuse portion 12 and the non-evaporated slit 2 is formed substantially perpendicular to the direction of the metallicon surface. By doing so, the locality at the boundary edge portion between the fuse portion and the divided electrode is larger than that in the case of the fuse portion 15 of Comparative Example 3 connected so as to be perpendicular to the side of the divided electrode shown in FIG. It is possible to alleviate the electric field concentration. 8A and 8B, the portions indicated by the dotted circles are the boundary edge portions 16 and 17 between the fuse portion and the divided electrode 3 where the electric field is concentrated and heat generation is highest in the fuse portion.
[0090]
In FIG. 8A of the second embodiment, the number of electric field concentrating portions is two, whereas in FIG. 8B showing Comparative Example 3, the number of electric field concentrating portions is four, and heat generation in the fuse portion 15 increases. Furthermore, since the current in FIG. 8A is perpendicular to the metallicon surface, which is the current-carrying surface, the current flows smoothly, and the electric field is less likely to be concentrated on the edge than in FIG. 8B. The same tendency as the result described here was obtained also in the calculation result by the electric field simulation.
[0091]
Therefore, the invention of the second embodiment has a great effect on lowering the heat generation, and it is possible to reduce the temperature rise when the ripple current flows through the capacitor. Therefore, in Table 1, the capacitor according to the second embodiment has a small temperature rise value.
[0092]
It should be noted that the present invention is not limited to the single method of the first or second embodiment, but the direction of the fuse portion is perpendicular to the metallicon surface as in the second embodiment, and the position of the fuse is different. May be provided in the vicinity of the vertex as in the first embodiment to combine the effects of both the first and second embodiments.
[0093]
Next, the invention in the third embodiment will be described in detail in comparison with the first comparative example. In the third embodiment in which the position of the fuse portion is set to a distance of one third of the length of the side from the vertex of the rhombus of the divided electrode, the temperature rise value is 4.9 ° C., and the fuse portion is located at the center of the side. In Comparative Example 1, the temperature rise value is 7.3 ° C., and the temperature rise value is smaller in the third embodiment. When the position of the fuse portion is arranged at a distance of one third or more of the length of the side from the vertex as in Comparative Example 1, the temperature rise value becomes 5 ° C. or more, and when the ambient temperature is 85 ° C. or more, the PP film is used. The temperature of the used capacitor exceeds 90 ° C., which is not preferable. A capacitor using a PP film is desirably used at a temperature of 100 ° C. or less, and preferably at a temperature of 90 ° C. or less.
[0094]
For the above-described reasons, in the present invention, the fuse portion is arranged at a position not more than one third of the length of the side from the vertex of the divided electrode as in the first and third embodiments.
[0095]
In the first embodiment, the position of the fuse portion 5 is set to a position 2 mm from the vertex of each divided electrode. However, the present invention is not limited to this position, and an effect can be obtained if it is arranged near the vertex. Can be If the fuse portion is arranged within a distance of not more than one third of the length of each side of the rhombus or the triangle constituting the divided electrode from each vertex as in the third embodiment, the larger the heat generation, the more the pattern in the pattern becomes. The current density distribution does not become non-uniform. When the distance is one third or more, the unevenness of the current density affecting the heat generation increases. The present inventors have also verified and confirmed the relationship between the position of the fuse section and the heat generation described above by electric field simulation.
[0096]
Next, the invention of the fourth embodiment will be described in detail with reference to FIG. 4 and FIG.
[0097]
In the fourth embodiment, as shown in FIG. 4, the boundary portion that is the connection portion 13 a of the fuse portion 13 with the divided electrode 3 is made wider, so that the electric field concentration portion shown in FIG. It has the effect of reducing heat generation. In the fourth embodiment, the temperature rise value is slightly smaller than that of the first embodiment, despite the narrowest width of the fuse portion 13 being 0.2 mm, which is narrower than that of the first embodiment.
[0098]
In the present invention, an embodiment in which the effect of the shape of the fuse section described in the fourth embodiment and the invention relating to the position and orientation of the fuse described in the first to third embodiments may be combined. By combining the inventions described in (1) to (4), an effect of lower heat generation can be expected.
[0099]
(Embodiment 5)
FIG. 9 is a schematic diagram of a circuit of an inverter device equipped with a metallized film capacitor according to any of the first to fourth embodiments of the present invention. Reference numeral 40 denotes a capacitor of 800 μF in which four single metalized film capacitors described in the first to fourth embodiments are arranged in parallel.
[0100]
The switching frequency of the inverter 42 is 10 kHz, and the inverter device is such that a ripple current of 80 A (effective value) flows through the capacitor 40. The maximum voltage applied to the capacitor 40 in the battery 41 or the like is 700 V. The inverter device was operated in such a state, and the motor 43 for driving the vehicle was driven.
[0101]
As for the shape of the capacitor 40, after flattening a metallized film, four flat capacitors were put in a case and resin-molded. The volume of the capacitor thus obtained is 800 cm ³ It is.
[0102]
When a commercially available electrolytic capacitor (rated voltage: 500 V) is used to allow the same ripple current to flow, it is necessary to increase the capacitance and reduce the equivalent series resistance in consideration of an increase in the series resistance component in a low temperature range. The capacitance needs to be at least about 500 μF × 5 = about 2500 μF, and the volume is 1250 cm. ³ Occupied as a capacitor part.
[0103]
The following (Table 2) shows the steady-state temperature rise value of the capacitor 40 and the rate of capacity decrease after operation at 85 ° C. for 2000 hours when the capacitor is operated under the above conditions in the fifth embodiment. For comparison, the values in the case of 2500 μF combined with a commercially available electrolytic capacitor are also shown in (Table 2).
[0104]
[Table 2]

[0105]
From the results shown in Table 2, it is possible to manufacture an inverter device that is smaller and generates less heat by using the metalized film capacitor according to Embodiments 1 to 4 than by using the electrolytic capacitor. Further, since a capacitor using a metallized film having an appropriate vapor deposition pattern is used, a long-life inverter device with little reduction in capacity during long-term use can be obtained.
[0106]
When the maximum voltage is 600 V or more as in the fifth embodiment, the capacitance of the electrolytic capacitor alone decreases greatly as shown in (Table 2). If the withstand voltage is increased by connecting in series, the volume is further increased. Therefore, when the metallized film capacitor according to the first to fourth embodiments is used at a rated voltage of 600 V or more, low cost, low heat generation, small size, and long Life can be extended.
[0107]
【The invention's effect】
As described above, the invention according to claim 1 of the present invention provides a substantially rhombus-shaped and substantially triangular-shaped divided electrode composed of a metal portion surrounded by a non-metal portion except for a fuse portion, and at least a portion on each side thereof. A metallized film having a metallized film formed by winding or laminating a metallized film having a patterned metal electrode formed in a pattern and having a fuse portion arranged at one place and connecting the divided electrodes, and having metallikon portions on both side end surfaces Since the fuse portion is provided near the apex of the rhombus, a capacitor having excellent ripple current resistance, low temperature rise, and excellent security can be obtained.
[0108]
According to a second aspect of the present invention, a substantially rhombus-shaped and substantially triangular-shaped divided electrode made of a metal portion surrounded by a non-metal portion except for a fuse portion, and arranged at at least one position on each side thereof A metallized film capacitor having a metallized film on which a vapor-deposited metal electrode having a pattern shape provided with a fuse portion connecting the divided electrodes is wound or laminated, and having a metallikon portion on both side end surfaces. Since the direction of the boundary between the fuse portion and the non-metal portion is substantially perpendicular to the direction of the metallicon surface, a capacitor having excellent ripple current resistance and low temperature rise can be obtained. .
[0109]
According to a third aspect of the present invention, a substantially rhombus-shaped and substantially triangular-shaped divided electrode made of a metal part surrounded by a non-metal part except for a fuse part is disposed at at least one position on each side thereof. A metallized film capacitor having a metallized film formed by winding or laminating a metallized film on which a vapor-deposited metal electrode having a pattern shape provided with a fuse portion connecting the divided electrodes is formed, and having a metallikon portion on both side end surfaces, Since the fuse portion is provided near the apex of the rhombus, and the direction of the boundary line between the fuse portion and the non-metal portion is formed substantially perpendicular to the direction of the metallikon surface, ripple current resistance is reduced. It is possible to obtain a capacitor which is excellent, has a low temperature rise, and has excellent security.
[0110]
In the invention according to claim 4 of the present invention, since the fuse portion is provided at a distance of one third or less of the length of the side from the top of the divided electrode, the ripple current resistance is excellent, the temperature rise is low, A capacitor with excellent security can be obtained.
[0111]
In the invention according to claim 5 of the present invention, the rhombus has a shape in which the longer diagonal line is twice as long as the shorter diagonal line, and the longer diagonal line is arranged so as to face the width direction of the metallized film. The shape is an isosceles triangle of a shape obtained by bisecting the rhombus with a shorter diagonal line.Since the base is arranged at a position close to the metallikon, a capacitor having excellent ripple current resistance and low temperature rise is provided. Obtainable.
[0112]
According to a sixth aspect of the present invention, in the pattern electrode, only one fuse portion exists on one side of the rhombus and the triangle, and only one fuse portion is close to one vertex. Therefore, a capacitor having excellent ripple current resistance, low temperature rise, and excellent security can be obtained.
[0113]
According to a seventh aspect of the present invention, since the fuse portion is provided so that the fuse width at the portion connected to the split electrode is widened, the capacitor has excellent ripple current resistance and low temperature rise. Can be obtained.
[0114]
Since the invention described in claim 8 of the present invention forms a metallized film capacitor by forming any one of the pattern shapes according to claims 1 to 7, it is suitable for high-voltage applications of 600 V or more, and has ripple resistance. A capacitor with excellent current performance and low temperature rise can be obtained.
[0115]
According to a ninth aspect of the present invention, since the metallized film capacitor according to any one of the first to seventh aspects is used for smoothing a drive circuit of a vehicle drive motor, the efficiency of the inverter device is improved. As a result, energy saving of the device can be achieved.
[0116]
According to the tenth aspect of the present invention, the metallized film according to any one of the first to seventh aspects of the present invention, wherein the maximum voltage applied to the capacitor in the vehicle drive circuit is 600 V or more. If a capacitor is used, a small-sized inverter device having a long life and excellent safety can be obtained.
[0117]
The invention according to claim 11 of the present invention is an inverter device using the metallized film capacitor according to any one of claims 1 to 7 as a smoothing capacitor of a drive circuit of a motor for driving a vehicle. In this way, a long-life inverter device with excellent safety can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic view of the surface of a vapor-deposited film used for a metallized film capacitor according to Embodiments 1 and 3 of the present invention.
FIG. 2 is a schematic diagram of an essential part of the metallized film capacitor according to the first embodiment.
FIG. 3 is a schematic view of a surface of a vapor-deposited film used for a metalized film capacitor according to the second embodiment.
FIG. 4 is a schematic diagram showing a vicinity of a fuse portion of a vapor-deposited film used for a metallized film capacitor according to the fourth embodiment.
FIG. 5 (a) is a schematic diagram of the flow of current in a vapor-deposited film used for a metallized film capacitor according to the first embodiment.
(B) Schematic diagram of the current flow in the deposited film used for the metallized film capacitor in Comparative Example 1.
FIG. 6 is a schematic view of the surface of a vapor-deposited film used for a metallized film capacitor in Comparative Example 2.
FIG. 7 is a schematic diagram of a current flow in a vapor-deposited film used for a metalized film capacitor in Comparative Example 2.
FIG. 8A is a schematic diagram showing a current flow and an electric field concentration portion in a fuse portion of a metallized film capacitor according to a second embodiment of the present invention.
(B) Schematic diagram showing current flow and electric field concentration in the fuse portion when the fuse portion of the metallized film capacitor is connected in a direction perpendicular to the sides of the divided electrodes.
FIG. 9 is a circuit diagram of an inverter device according to a fifth embodiment of the present invention.
FIG. 10 is a schematic view of the surface of a vapor-deposited film formed into a rectangular split electrode used in a conventional metallized film capacitor.
FIG. 11 is a schematic view of the surface of a vapor-deposited film formed into triangular and rhombic split electrodes used in a conventional metallized film capacitor.
[Explanation of symbols]
1 Non-evaporated part
2 Non-evaporated slit (non-metallic part)
3 Diamond-shaped split electrode (metal part)
4 Triangular split electrode (metal part)
5, 12, 13 fuse section
8, 9 Single-sided metallized polypropylene film (metallized film)
10 Leader electrode (metallicon part)
12a border
13a Connection part
40 capacitor (smoothing capacitor)

Claims (11)

A substantially rhombic and substantially triangular split electrode made of a metal part surrounded by a non-metal part except for a fuse part, and a fuse part arranged at at least one position on each side to connect the split electrodes to each other. A metallized film on which a vapor-deposited metal electrode having a provided pattern shape is formed by winding or laminating, and having a metallicon portion on both side end surfaces, wherein the fuse portion is provided near a vertex of the rhombus. A metallized film capacitor characterized by the following. A substantially rhombic and substantially triangular split electrode made of a metal part surrounded by a non-metal part except for a fuse part, and a fuse part arranged at at least one position on each side to connect the split electrodes to each other. Winding or laminating a metallized film on which a vapor-deposited metal electrode having a provided pattern shape is formed, and having a metallikon portion on both side end surfaces, wherein the fuse portion has a boundary line with the non-metal portion. A metallized film capacitor having a direction substantially perpendicular to the direction of the surface of the metallikon portion. A substantially rhombus-shaped and substantially triangular-shaped divided electrode made of a metal part surrounded by a non-metal part except for a fuse part, and a fuse part arranged at at least one position on each side to connect the divided electrode is provided. Winding or laminating a metallized film on which a vapor-deposited metal electrode having a patterned shape is formed, and having a metallikon portion on both side end surfaces, wherein the fuse portion is provided near a vertex of the rhombus, and A metallized film capacitor, wherein a direction of a boundary line between the fuse portion and the non-metal portion is formed substantially perpendicular to a direction of a surface of the metallicon portion. The metallized film capacitor according to any one of claims 1 to 3, wherein the fuse portion is provided at a distance from the apex of the split electrode to one third or less of the length of the side. The rhombus of the divided electrode is shaped so that the longer diagonal line is twice or more than the shorter diagonal line, and the longer diagonal line is oriented in the width direction of the metallized film. The metallized film capacitor according to any one of claims 1 to 4, wherein is a isosceles triangle having a shape that is bisected by a shorter diagonal line, and a bottom side thereof is arranged at a position close to the metallikon portion. 5. The method according to claim 1, wherein only one fuse portion exists on one side of the diamond-shaped or triangular shape of the divided electrode, and only one fuse portion is arranged near one vertex of the divided electrode. The metallized film capacitor according to any one of claims 1 to 5. The metallized film capacitor according to any one of claims 1 to 6, wherein the fuse portion is formed so that a fuse width of a portion connected to the divided electrode is widened. A method for manufacturing a metallized film capacitor, comprising forming a pattern shape according to any one of claims 1 to 7 to manufacture a metallized film capacitor. 8. A metallized film capacitor comprising the metallized film capacitor according to claim 1 used for smoothing a drive circuit of a motor for driving a vehicle. The metallized film capacitor according to claim 9, wherein the maximum voltage applied to the capacitor is 600V or more. An inverter device using the metallized film capacitor according to any one of claims 1 to 7 as a smoothing capacitor of a drive circuit of a vehicle drive motor.

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