JP2013026586A

JP2013026586A - Metalized film capacitor

Info

Publication number: JP2013026586A
Application number: JP2011162725A
Authority: JP
Inventors: Setsu Tomura; 節戸村; Akira Kikuchi; 朗菊地
Original assignee: Hitachi AIC Inc
Current assignee: Lincstech Circuit Co Ltd
Priority date: 2011-07-26
Filing date: 2011-07-26
Publication date: 2013-02-04

Abstract

PROBLEM TO BE SOLVED: To solve the problem where although the self-healing property of a metalized film capacitor is more reliable in terms of voltage resistance when the film thickness of a vapor-deposited metal is thinner because the film is easily evaporated and/or dispersed with small energy of short circuit, the vapor-deposited metal becomes susceptible to oxidative corrosion and change in capacity reduction easily occurs when the film thickness of the vapor-deposited metal is thinner, and in the case where a dielectric film is made thinner to obtain a high capacity, the film often meanders when being reeled up, making it difficult to have the film layered in a consistent manner, this may prevent excellent electric connection between the vapor-deposited metal and a metallikon electrode, and to provide the metalized film capacitor in which excellent electric connection between the vapor-deposited metal and the metallikon electrode are obtained and change in capacity reduction is decreased.SOLUTION: There is provided a film capacitor having a metal vapor-deposited film on at least one side of a polyetherimide film of 1 μm to 12 μm in thickness, the metal vapor-deposited film being an electrode having a surface electrical resistance of 0.1 Ω/sq. to 5 Ω/sq.

Description

本発明は、金属化フィルムコンデンサに関し、特に金属化フィルムコンデンサの電極に関する。 The present invention relates to a metallized film capacitor, and more particularly to an electrode of a metallized film capacitor.

金属化フィルムコンデンサは、一般的にポリプロピレンやポリエチレンテレフタレートなどの誘電体フィルム上に設けた蒸着金属を電極に用いる金属化したフィルムを使用し、両面を金属化したフィルムとそれより幅を狭めた非金属化したフィルムとで積層するか、または、片面を金属化したフィルムを交互にずらして積層し、その後、積層した上記の方法により生じた端面のはみ出した部分に、金属を溶射しメタリコン電極を設けている。
そして、誘電体フィルムの絶縁欠陥部で短絡が生じた場合に、短絡のエネルギーで絶縁欠陥部周辺の蒸着金属が蒸発・飛散して絶縁化し、コンデンサの機能が回復する自己回復性能（セルフヒーリング）が機能することにより耐電圧に対する信頼性が高いため、従来から広く用いられている。
また、金属化フィルムコンデンサの信頼性をさらに向上させるために、蒸着金属を格子状に分割し、各分割電極を狭幅部分（ヒューズ部分）で並列に接続した分割電極を用いることが提唱されている（特許文献１の従来の技術）。すなわち、短絡電流により絶縁欠陥部のある分割電極の上記ヒューズ部分を溶断することにより、確実に絶縁欠陥部を電気的に切り離すことができる。 A metallized film capacitor generally uses a metallized film that uses a metal deposited on a dielectric film such as polypropylene or polyethylene terephthalate as an electrode, and has a metallized film on both sides and a non-widened film. Laminate with a metallized film, or laminate one side of the metallized film alternately, and then spray metal onto the protruding part of the end face produced by the above-mentioned method and apply the metallicon electrode. Provided.
And when a short circuit occurs in the insulation defect part of the dielectric film, the deposited metal around the insulation defect part is evaporated and scattered by the short circuit energy to insulate and self-healing performance (self healing) Since it has a high reliability with respect to withstand voltage due to its function, it has been widely used.
In order to further improve the reliability of metallized film capacitors, it has been proposed to use divided electrodes in which the deposited metal is divided into a grid and each divided electrode is connected in parallel at a narrow portion (fuse portion). (Conventional technology of Patent Document 1). That is, the insulation defect part can be reliably separated electrically by fusing the fuse part of the divided electrode having the insulation defect part by a short-circuit current.

特開平６−３０２４６８公報JP-A-6-302468

上記のセルフヒーリング性は、蒸着金属の膜厚が薄いほど、低短絡エネルギーで蒸発・飛散しやすく、耐電圧に対する信頼性が得やすいが、蒸着金属の膜厚が薄いほど、蒸着金属が腐食酸化しやすくなり容量減少変化が大きくなりやすい。また、蒸着金属とメタリコン電極との電気的接続が容易ではなくなる。
また、上記分割電極を用いたコンデンサは、分割電極の無いコンデンサに比べて、ヒューズ溶断による失う電極面積が大きく、容量減少変化が大きくなりやすい。
また、高容量を得るために、誘電体フィルムを薄くすると、フィルムが巻き取り中に蛇行しやすくなり、重なり状態を一定に保つことが難しく、蒸着金属とメタリコン電極との良好な電気的接続が得られない場合も生じる。 The self-healing properties mentioned above are easier to evaporate and scatter with a lower short-circuit energy as the deposited metal film thickness is thinner, and it is easier to obtain reliability against withstand voltage. It becomes easy to do, and the decrease in capacity tends to become large. In addition, the electrical connection between the deposited metal and the metallicon electrode is not easy.
Further, a capacitor using the above-mentioned divided electrode has a larger electrode area lost due to fusing of the fuse than a capacitor without the divided electrode, and the capacitance reduction change tends to be large.
In addition, if the dielectric film is thinned in order to obtain a high capacity, the film tends to meander during winding, and it is difficult to keep the overlapping state constant, and a good electrical connection between the deposited metal and the metallicon electrode is achieved. In some cases, it cannot be obtained.

本発明は、蒸着金属とメタリコン電極との良好な電気的接続が得られ、容量減少変化を軽減した金属化フィルムコンデンサを提供することを課題としている。 An object of the present invention is to provide a metallized film capacitor in which a favorable electrical connection between a deposited metal and a metallicon electrode is obtained, and a change in capacitance reduction is reduced.

本発明は、上記の課題を解決するために、厚さが１μｍから１２μｍのポリエーテルイミドフィルムの少なくとも片側に、表面抵抗が０．１Ω／□から５Ω／□の電極となる金属蒸着膜を設けた金属化フィルムコンデンサを提供するものである。 In order to solve the above-mentioned problems, the present invention is provided with a metal vapor deposition film serving as an electrode having a surface resistance of 0.1Ω / □ to 5Ω / □ on at least one side of a polyetherimide film having a thickness of 1 μm to 12 μm. A metallized film capacitor is provided.

本発明によれば、蒸着金属とメタリコン電極との良好な電気的接続が得られ、容量減少変化を軽減した金属化フィルムコンデンサを提供することができる。
According to the present invention, it is possible to provide a metallized film capacitor in which a good electrical connection between a vapor-deposited metal and a metallicon electrode can be obtained, and a change in capacity reduction can be reduced.

金属化フィルムとしては、耐熱性であるポリエーテルイミドフィルムに金属電極として金属を蒸着したものである。そして、金属蒸着後、たとえば、巻回または積層してコンデンサ素子とし、その両端面に、金属の溶射によりメタリコン電極を設ける。そして、このメタリコン電極に外部引き出し電極を溶接又はハンダ付け後、容器に収納し、容器内に絶縁性樹脂を注入し充填するか、または、外部引き出し電極を設けた後、絶縁性樹脂液中に浸漬するディップコーティングなどにより外装を設ける。 As a metallized film, a metal is deposited as a metal electrode on a heat-resistant polyetherimide film. Then, after metal deposition, for example, a capacitor element is formed by winding or stacking, and a metallicon electrode is provided on both end faces by metal spraying. And after welding or soldering the external lead electrode to this metallicon electrode, it is housed in a container and insulative resin is injected and filled into the container, or after the external lead electrode is provided, The exterior is provided by dip coating or the like.

ポリエーテルイミドフィルムとしては、ポリエーテルイミド樹脂単独か、またはポリエーテルイミド樹脂に、ポリイミド樹脂系樹脂、ポリサルホン系樹脂、またはポリサルフィド系樹脂等の公知の樹脂を添加したり、無機または有機の充填剤を必要に応じて添加したりした樹脂をフィルム状に成形したものである。成形厚さは、１μｍから１２μｍのものを使用する。好ましくは２μｍから６μｍのものを使用する。より好ましくは２μｍから４μｍのものを使用する。厚さが１μｍより薄いと取り扱いが困難になりやすくまたフィルム欠陥も増加し、厚いほど厚さ分高容量が得られ難い。
また、ポリエーテルイミドフィルムに微細な凹凸を形成すると、フィルムの走行性が改善される。 As the polyetherimide film, a polyetherimide resin alone, or a known resin such as a polyimide resin resin, a polysulfone resin, or a polysulfide resin may be added to the polyetherimide resin, or an inorganic or organic filler Is formed into a film by adding a resin as necessary. A molding thickness of 1 μm to 12 μm is used. Preferably those having a thickness of 2 to 6 μm are used. More preferably, a film having a thickness of 2 to 4 μm is used. If the thickness is less than 1 μm, handling is likely to be difficult, and film defects also increase. As the thickness increases, it is difficult to obtain a high capacity by the thickness.
Moreover, when the fine unevenness | corrugation is formed in a polyetherimide film, the runnability of a film is improved.

金属蒸着膜の金属としては、アルミニウム、銅、亜鉛またはそれらの合金などが限定なく使用できる。またそれらに添加するものとして、ケイ素、チタンなどが使用できる。一般的には、真空蒸着などにより製膜できる。製膜された薄膜金属の表面抵抗は、０．１Ω／□から５Ω／□が使用でき、０．１Ω／□から０．９Ω／□が好ましく、０．１Ω／□から０．４Ω／□がより好ましい。０．１Ω／□より小さいと金属化フィルムのセルフヒーリングが困難となりやすい。また、その分蒸着速度を増加させると、フィルムが蒸着時、熱負けやたるみが発生しやすくなりやすい。また、逆に表面抵抗が大きいと耐湿性の改善や、蒸着金属とメタリコン電極との接続面積が減り、電気的接続が困難となりやすい。 As a metal of the metal vapor deposition film, aluminum, copper, zinc, or an alloy thereof can be used without limitation. Moreover, silicon, titanium, etc. can be used as what is added to them. In general, the film can be formed by vacuum deposition or the like. The surface resistance of the formed thin film metal can be from 0.1Ω / □ to 5Ω / □, preferably from 0.1Ω / □ to 0.9Ω / □, and from 0.1Ω / □ to 0.4Ω / □. More preferred. If it is less than 0.1Ω / □, self-healing of the metallized film tends to be difficult. Further, when the deposition rate is increased by that amount, heat loss and sagging are likely to occur when the film is deposited. Conversely, if the surface resistance is large, the moisture resistance is improved and the connection area between the vapor-deposited metal and the metallicon electrode is reduced, making electrical connection difficult.

金属蒸着膜の被着体であるポリエーテルイミドフィルムは、通常コンデンサに使用されるポリプロピレンやポリエチレンテレフタレートよりも耐熱性が高く、フィルム厚さを薄くしても、熱負けせず金属蒸着膜を厚く堆積させることができる。フィルム厚さを薄くすることにより高容量化が達成でき、また、金属蒸着膜を厚くしてもフィルムが蒸着時、熱負けによるたるみが発生し難く、そのため、巻き取り中に蛇行しにくく、重なり状態を一定に保つことが容易なためや、端面のはみ出した部分も一定に保つことが容易で、蒸着金属とメタリコン電極との良好な電気的接続が得られやすい。また、金属蒸着膜を厚くすることにより、耐湿性の改善や、蒸着金属とメタリコン電極との接続面積が増え、電気的接続が容易となる。また、金属蒸着膜を厚くすることにより、コンデンサとしての等価直列抵抗が小さくなり、耐リプル電流特性が向上する。 Polyetherimide film, which is a metal vapor deposition film adherence, has higher heat resistance than polypropylene and polyethylene terephthalate, which are usually used for capacitors, and even if the film thickness is reduced, the metal vapor deposition film is thickened without losing heat. Can be deposited. Higher capacity can be achieved by reducing the film thickness, and even if the metal deposition film is thickened, it is difficult for the film to sag due to heat loss during deposition, so it is difficult to meander during winding and overlap. It is easy to keep the state constant, and it is easy to keep the protruding part of the end face constant, and it is easy to obtain a good electrical connection between the deposited metal and the metallicon electrode. Further, by increasing the thickness of the metal vapor deposition film, the moisture resistance is improved, the connection area between the vapor deposition metal and the metallicon electrode is increased, and electrical connection is facilitated. Also, by increasing the thickness of the metal vapor deposition film, the equivalent series resistance as a capacitor is reduced, and the ripple current resistance is improved.

コンデンサ素子の形状は、巻回した場合は断面形状が円形、それをつぶした場合は偏平形、積層した場合は四角形となるが、偏平形や四角形の方が平面となる側面ができ、収納効率、放熱性が向上する。
メタリコン電極は、コンデンサ素子の電極の端部に接続する素子外部電極で、亜鉛、銅またはアルミニウムなどの金属を溶射により付着させたものが使用できる。また、メタリコン電極には、たとえば、外部との接続のための外部引き出し電極を接続し、開放端部を有するケースに収納し、樹脂含侵したり、外部引き出し電極付きコンデンサ素子を樹脂に浸漬して樹脂外装部を設けたりする。
The shape of the capacitor element is circular when it is wound, flat when it is crushed, and square when stacked, but the flat shape or the side of the square is flat, and storage efficiency , Heat dissipation is improved.
The metallicon electrode is an element external electrode connected to the end of the electrode of the capacitor element and can be formed by depositing a metal such as zinc, copper or aluminum by thermal spraying. In addition, for example, an external lead electrode for connection to the outside is connected to the metallicon electrode, and it is housed in a case having an open end and is impregnated with resin, or a capacitor element with an external lead electrode is immersed in resin. A resin exterior is provided.

まず、表１に示すように、所定の厚さのポリエーテルイミドフィルムに、所定の表面抵抗になるように片面にアルミニウムを蒸着して、金属電極を形成した。次に、この蒸着フィルムを２枚重ね合わせて巻回し、端面が円形の柱状体とした。次に、その柱状体の両端面に、銅、その表面に錫の溶射によるメタリコン電極を設けた。
次に、コンデンサ素子のメタリコン電極に、０．３ｍｍ厚の銅箔からなる引き出し電極をはんだ付けする。そして一端が開放したケースにコンデンサ素子を収納し、樹脂封止した。
同様に、比較例を表１に示す条件のポリエーテルイミドフィルムの膜厚と、所定の表面抵抗になるように蒸着する以外実施例と同様に金属化フィルムコンデンサを作成した。
次に、得られた金属化フィルムコンデンサの、絶縁破壊電圧と静電容量変化率を測定した。絶縁破壊電圧は、電圧を１００Ｖ／秒の昇圧速度で印加し、コンデンサが絶縁破壊し、５ｍＡ以上の電流が流れた時点の電圧とした。また、静電容量変化率は、充放電回数１０００回後との比較とし、表１に結果を示した。 First, as shown in Table 1, aluminum was vapor-deposited on one surface of a polyetherimide film having a predetermined thickness so as to have a predetermined surface resistance, thereby forming a metal electrode. Next, two vapor deposited films were overlapped and wound to form a columnar body having a circular end surface. Next, a metallicon electrode by thermal spraying of copper on the both end surfaces of the columnar body and tin on its surface was provided.
Next, a lead electrode made of a copper foil having a thickness of 0.3 mm is soldered to the metallicon electrode of the capacitor element. And the capacitor | condenser element was accommodated in the case where the end was open | released, and resin sealing was carried out.
Similarly, a metallized film capacitor was prepared in the same manner as in Example except that the film thickness of the polyetherimide film under the conditions shown in Table 1 and vapor deposition were performed so as to have a predetermined surface resistance.
Next, the dielectric breakdown voltage and the capacitance change rate of the obtained metallized film capacitor were measured. The dielectric breakdown voltage was a voltage at the time when a voltage was applied at a boosting rate of 100 V / sec, the capacitor was dielectrically broken, and a current of 5 mA or more flowed. The capacitance change rate was compared with that after 1000 charge / discharge cycles, and the results are shown in Table 1.

表１に示す結果の通り、本発明品は、比較例と比べ、絶縁破壊電圧と静電容量変化率のバランスに優れた特性を示した。 As a result shown in Table 1, the product of the present invention exhibited excellent characteristics in balance between dielectric breakdown voltage and capacitance change rate, as compared with the comparative example.

Claims

厚さが１μｍから１２μｍのポリエーテルイミドフィルムの少なくとも片側に、表面抵抗が０．１Ω／□から５Ω／□の電極となる金属蒸着膜を設けた金属化フィルムコンデンサ。 A metallized film capacitor in which a metal vapor deposition film serving as an electrode having a surface resistance of 0.1Ω / □ to 5Ω / □ is provided on at least one side of a polyetherimide film having a thickness of 1 μm to 12 μm.