JP2008130858A

JP2008130858A - Chip-shaped solid-state electrolytic capacitor

Info

Publication number: JP2008130858A
Application number: JP2006314936A
Authority: JP
Inventors: Yuichi Igawa; 祐一井川
Original assignee: Nichicon Corp
Current assignee: Nichicon Corp
Priority date: 2006-11-22
Filing date: 2006-11-22
Publication date: 2008-06-05
Anticipated expiration: 2026-11-22
Also published as: JP4875468B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chip-shaped solid-sate electrolytic capacitor reduced in ESR (equivalent series resistance) through lead frameless chip type. <P>SOLUTION: The chip-shaped solid-state electrolytic capacitor is constituted, such that the outer peripheral surface excluding an anode lead-out line for a capacitor element, consisting of an oxide film layer provided on the surface of an anode body formed of metallic powder for valve effect through pressurizing formation and anode lead-out line is planted on the surface of the anode body; a solid-state electrolytic layer and a cathode lead-out layer are coated by insulating resin; and more than one layer of conductor layers are formed on an anode lead-out unit consisting of the anode lead-out line that is not applied with the resin coating, and the peripheral part thereof, as well as, the cathode lead-out unit on a surface opposed to the anode lead-out line to employ as electrodes. Furthermore, the cathode lead-out unit is provided on a surface, facing the planting surface of anode lead-out lines of the capacitor element and at a position facing the substrate mounting part of at least the cathode. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

本発明は固体電解コンデンサに関するものであり、特に、ＥＳＲを低減したチップ状固体電解コンデンサの構造に関するものである。 The present invention relates to a solid electrolytic capacitor, and more particularly to a structure of a chip-shaped solid electrolytic capacitor with reduced ESR.

従来の固体電解コンデンサは、次の方法によって製造されている。
まず、タンタル、ニオブ等の弁作用金属粉末を加圧成形し、陽極導出線を植立した陽極体表面に酸化皮膜層、固体電解質層、陰極引出層を順次形成してコンデンサ素子を作製する。
その後、コンデンサ素子の陽極導出部および陽極導出部と対向する面を除く外周面を絶縁樹脂で外装し、該樹脂外装が施されていない陽極導出線とその周辺部（陽極導出部）、および底面（陰極導出部）にそれぞれ１層以上の導電体層を形成して電極とし、チップ状固体電解コンデンサを作製する(例えば、特許文献１参照)。
特開平７−２２２９３号公報 A conventional solid electrolytic capacitor is manufactured by the following method.
First, a valve action metal powder such as tantalum or niobium is pressure-molded, and an oxide film layer, a solid electrolyte layer, and a cathode lead layer are sequentially formed on the surface of the anode body on which the anode lead-out line is planted to produce a capacitor element.
Then, the outer peripheral surface excluding the anode lead-out portion and the surface facing the anode lead-out portion of the capacitor element is sheathed with an insulating resin, and the anode lead-out line not provided with the resin sheath, its peripheral portion (anode lead-out portion), and the bottom surface At least one conductor layer is formed on each (cathode lead-out portion) to form an electrode to produce a chip-shaped solid electrolytic capacitor (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 7-22293

しかしながら、上記特許文献１の方法で製造された固体電解コンデンサでは、陰極導出部が底面に限定され、充放電時の電流の導出、導入部分の面積が狭いため、ＥＳＲ値が高くなる問題がある。 However, in the solid electrolytic capacitor manufactured by the method of Patent Document 1, the cathode lead-out portion is limited to the bottom surface, and there is a problem that the ESR value becomes high because the area of the lead-out and introduction portion of current during charge / discharge is small. .

また、近年の製品の低背化に対応してコンデンサ素子の薄型化が進んでおり、それに伴い、コンデンサ素子の陰極導出面積がさらに小さくなっているため、充放電時の電流の導入、導出の効率の低下がより顕著になってきている。また、コンデンサが使用される回路が高周波化されると、さらに効率の低下が顕著になる。 In addition, the capacitor element has become thinner in response to the recent reduction in the height of products, and the cathode lead area of the capacitor element has been further reduced accordingly. The decrease in efficiency is becoming more pronounced. Further, when the circuit in which the capacitor is used is increased in frequency, the efficiency is further lowered.

本発明は、上記課題を解決するもので、弁作用金属粉末を加圧成形し、陽極導出線を植立した陽極体表面に酸化皮膜層、固体電解質層、陰極引出層を形成してなるコンデンサ素子の陽極導出線および陰極引出層の一部に設けた陰極導出部を除く外周面を絶縁樹脂で外装し、該樹脂外装が施されていない陽極導出線とその周辺部からなる陽極導出部および陽極導出線の植立面と対向する面の陰極導出部にそれぞれ１層以上の導電体層を形成して電極とするチップ状固体電解コンデンサにおいて、
上記陰極導出部が、コンデンサ素子の陽極導出線の植立面に対向する面と、少なくとも陰極の基板実装部に対応する位置とに設けられたことを特徴とするチップ状固体電解コンデンサである。 The present invention solves the above-mentioned problems, and is a capacitor formed by pressure forming a valve action metal powder and forming an oxide film layer, a solid electrolyte layer, and a cathode lead layer on the surface of an anode body on which an anode lead-out line is implanted. An outer peripheral surface excluding the anode lead-out line of the device and the cathode lead-out part provided in a part of the cathode lead-out layer is sheathed with an insulating resin, an anode lead-out line not provided with the resin sheath and an anode lead-out part composed of the peripheral part, and In a chip-shaped solid electrolytic capacitor in which one or more conductor layers are formed on the cathode lead-out portion on the surface opposite to the planting surface of the anode lead-out wire to form an electrode,
A chip-shaped solid electrolytic capacitor in which the cathode lead-out portion is provided on a surface facing the planting surface of the anode lead-out line of the capacitor element and at least a position corresponding to the substrate mounting portion of the cathode.

本発明によると、従来より陰極導出部の電流の導出、導入面積を拡大できることから充放電時の電流の導出、導入の効率が改善されるため、ＥＳＲを低減することができる。 According to the present invention, since the current derivation and introduction area of the cathode lead-out portion can be expanded conventionally, the efficiency of derivation and introduction of current during charge / discharge is improved, so that ESR can be reduced.

以下に、本発明の実施例を図面を参照しながら説明する。
［実施例１］
まず、タンタルの弁作用金属粉末を加圧成形し、図１に示すように、陽極導出線２を植立した陽極体１の表面に誘電体となる酸化皮膜層３を形成し、固体電解質（二酸化マンガン）層４と、カーボン層５および銀層６の陰極引出層とを順次積層してコンデンサ素子７を形成した。 Embodiments of the present invention will be described below with reference to the drawings.
[Example 1]
First, a tantalum valve action metal powder is pressure-molded, and as shown in FIG. 1, an oxide film layer 3 serving as a dielectric is formed on the surface of the anode body 1 on which the anode lead-out wire 2 is planted, and a solid electrolyte ( The capacitor element 7 was formed by sequentially laminating the manganese dioxide layer 4 and the cathode lead layer of the carbon layer 5 and the silver layer 6.

続けて、陽極導出線が植立された面と対向する面（底面）および図１、図１（ａ）に示すような陰極形状とほぼ同一形状とした陰極導出部を除く全外周面上にエポキシ系の絶縁樹脂８を被覆、硬化して樹脂外装し、該樹脂外装が施されていない陽極導出線とその周縁部（陽極導出部）と陰極導出部にそれぞれ銀電極９および１２、金属メッキ層１０および１３、はんだ層１１および１４を形成して電極とし、チップ状固体電解コンデンサを作製した。
なお、定格は６．３Ｖ−１００μＦと６．３Ｖ−４７μＦの２種類とし、さらに各々の定格において低背化（実装時の製品高さを低くした製品）した製品を作製した。 Subsequently, on the entire outer peripheral surface excluding the surface (bottom surface) opposite to the surface where the anode lead-out line is planted and the cathode lead-out portion having substantially the same shape as the cathode shape as shown in FIG. 1 and FIG. An epoxy insulating resin 8 is coated and cured to coat the resin, and the anode lead-out line and its peripheral portion (anode lead-out portion) and the cathode lead-out portion, which are not coated with the resin sheath, are respectively silver-plated 9 and 12, and metal plated Layers 10 and 13 and solder layers 11 and 14 were formed as electrodes to produce a chip-shaped solid electrolytic capacitor.
The ratings were two types of 6.3 V-100 μF and 6.3 V-47 μF, and a product with a reduced profile (product with a reduced product height at the time of mounting) was produced.

［実施例２］
実施例１と同様にコンデンサ素子を形成し、続けて底面および図２、図２（ｂ）に示すような底面と、陰極の基板実装部とほぼ同一形状の部位からなる陰極導出部を除く全外周面上とに絶縁樹脂を被覆した以外は、実施例１と同様にして、チップ状固体電解コンデンサを作製した。 [Example 2]
A capacitor element is formed in the same manner as in Example 1, and then all except the bottom surface and the bottom surface as shown in FIGS. 2 and 2B and the cathode lead-out portion having the same shape as the substrate mounting portion of the cathode. A chip-shaped solid electrolytic capacitor was produced in the same manner as in Example 1 except that the outer peripheral surface was coated with an insulating resin.

（従来例）
実施例１と同様にコンデンサ素子を形成し、続けて図３に示すように底面を除く全外周面上に絶縁樹脂を被覆した以外は実施例１と同様にして、チップ状固体電解コンデンサを作製した。 (Conventional example)
A capacitor element was formed in the same manner as in Example 1, and then a chip-shaped solid electrolytic capacitor was produced in the same manner as in Example 1 except that an insulating resin was coated on the entire outer peripheral surface except the bottom as shown in FIG. did.

次に、本発明の実施例について、従来例とともに、ＥＳＲを測定した。それぞれ１００個の測定結果の平均値を表１に示す。 Next, ESR was measured for the examples of the present invention together with the conventional example. Table 1 shows the average value of 100 measurement results.

表１より明らかなように、本発明による実施例１、２とも従来例と比較し、ＥＳＲ値を大幅に低減することができた。 As is apparent from Table 1, the ESR values of Examples 1 and 2 according to the present invention were significantly reduced as compared with the conventional example.

また、製品を薄くしたことによるＥＳＲ値の悪化が実施例１、２とも従来例と比較し、軽減されていることが分かる。 Moreover, it turns out that the deterioration of the ESR value by making the product thinner is reduced in both Examples 1 and 2 as compared with the conventional example.

これは、本発明により陰極導出部の面積を拡大でき、充放電時の電流の導出、導入の効率が改善されたためと考えられる。
なお、ＥＳＲ低減の効果は、陰極導出部の面積を最も広くした実施例１が最も大きいことが分かる。 This is considered to be because the area of the cathode lead-out portion can be enlarged by the present invention, and the efficiency of derivation and introduction of current during charge / discharge is improved.
It can be seen that the effect of ESR reduction is greatest in Example 1 in which the area of the cathode lead-out portion is the largest.

なお、従来より拡大する陰極導出部の形状、大きさは上記実施例に限られるものではなく、底面と底面につながる１〜４面を陰極とほぼ同一形状としてもよい。 It should be noted that the shape and size of the cathode lead-out portion that is larger than the conventional one is not limited to the above embodiment, and the bottom surface and the first to fourth surfaces connected to the bottom surface may be substantially the same shape as the cathode.

また、高周波領域でのインピーダンスは製品のＥＳＬが影響するが、ＥＳＬはコンデンサ素子から電極の実装部分までの電気の通り道の長さに影響されるものであることから、陰極導出部を実装面側に拡大した場合、高周波でのインピーダンスが低減することは明らかである。 The impedance in the high frequency range is affected by the ESL of the product, but since the ESL is affected by the length of the electrical path from the capacitor element to the mounting portion of the electrode, Obviously, the impedance at high frequencies is reduced when expanded to.

さらに、図３に示すように実装面側の陰極導出部に関して、コンデンサ素子の陰極側のエッジ部に外装樹脂を存在させると、チップ状固体電解コンデンサのコプラナリティー（平坦度）がより安定するため、エッジ部に外装樹脂を存在させた形状としてもよい。 Furthermore, as shown in FIG. 3, regarding the cathode lead-out portion on the mounting surface side, if an exterior resin is present at the edge portion on the cathode side of the capacitor element, the coplanarity (flatness) of the chip-shaped solid electrolytic capacitor becomes more stable. The shape may be such that the exterior resin is present in the edge portion.

また、本発明の実施例では、弁作用金属粉末としてタンタルを用いたが、ニオブを用いても同様の効果が得られる。 In the examples of the present invention, tantalum was used as the valve action metal powder, but the same effect can be obtained by using niobium.

実施例１のチップ状固体電解コンデンサの断面図であり、（ａ）は絶縁樹脂被覆後の陰極側斜め上方より見た陰極導出部の図、（ｂ）は絶縁樹脂被覆後の基板実装面側より見た陰極導出部の図である。BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing of the chip-shaped solid electrolytic capacitor of Example 1, (a) is the figure of the cathode derivation | leading-out part seen from the cathode side diagonally upper side after insulation resin coating, (b) is the board | substrate mounting surface side after insulation resin coating It is the figure of the cathode derivation | leading-out part seen more. 本発明の実施例２のチップ状固体電解コンデンサの断面図であり、（ａ）は絶縁樹脂被覆後の陰極側斜め上方より見た陰極導出部の図、（ｂ）は絶縁樹脂被覆後の下方より見た陰極導出部の図である。It is sectional drawing of the chip-shaped solid electrolytic capacitor of Example 2 of this invention, (a) is the figure of the cathode derivation | leading-out part seen from the cathode side diagonally upper direction after insulation resin coating, (b) is the downward direction after insulation resin coating It is the figure of the cathode derivation | leading-out part seen more. 本発明の他の実施例のチップ状固体電解コンデンサの断面図であり、（ａ）は絶縁樹脂被覆後の陰極側斜め上方より見た陰極導出部の図、（ｂ）は絶縁樹脂被覆後の下方より見た陰極導出部の図である。It is sectional drawing of the chip-shaped solid electrolytic capacitor of the other Example of this invention, (a) is the figure of the cathode derivation | leading-out part seen from the cathode side diagonally upper direction after insulation resin coating, (b) is after insulation resin coating It is a figure of the cathode derivation part seen from the lower part. 従来例のチップ状固体電解コンデンサの断面図であり、（ａ）は絶縁樹脂被覆後の陰極側斜め上方より見た陰極導出部の図、（ｂ）は絶縁樹脂被覆後の基板実装面側より見た陰極導出部の図である。It is sectional drawing of the chip-shaped solid electrolytic capacitor of a prior art example, (a) is the figure of the cathode derivation | leading-out part seen from the cathode side diagonally upper side after insulation resin coating, (b) is from the board | substrate mounting surface side after insulation resin coating It is the figure of the cathode derivation | leading-out part seen.

符号の説明Explanation of symbols

１陽極体
２陽極導出線
３酸化皮膜層
４導電性層
５カーボン層
６銀層
７コンデンサ素子
８外装樹脂
９銀電極（陽極）
１０金属メッキ層（陽極）
１１はんだ層（陽極）
１２銀電極（陰極）
１３金属メッキ層（陰極）
１４はんだ層（陰極）
１５陰極導出部（絶縁樹脂被覆直後）
１６絶縁樹脂 DESCRIPTION OF SYMBOLS 1 Anode body 2 Anode lead-out line 3 Oxide film layer 4 Conductive layer 5 Carbon layer 6 Silver layer 7 Capacitor element 8 Exterior resin 9 Silver electrode (anode)
10 Metal plating layer (anode)
11 Solder layer (anode)
12 Silver electrode (cathode)
13 Metal plating layer (cathode)
14 Solder layer (cathode)
15 Cathode lead-out part (immediately after insulating resin coating)
16 Insulating resin

Claims

弁作用金属粉末を加圧成形し、陽極導出線を植立した陽極体表面に酸化皮膜層、固体電解質層、陰極引出層を形成してなるコンデンサ素子の陽極導出線および陰極引出層の一部に設けた陰極導出部を除く外周面を絶縁樹脂で外装し、該樹脂外装が施されていない陽極導出線とその周辺部からなる陽極導出部および陽極導出線と対向する面の陰極導出部にそれぞれ１層以上の導電体層を形成して電極とするチップ状固体電解コンデンサにおいて、
上記陰極導出部が、コンデンサ素子の陽極導出線の植立面に対向する面と、少なくとも陰極の基板実装部に対応する位置とに設けられたことを特徴とするチップ状固体電解コンデンサ。 Part of the anode lead-out line and cathode lead-out layer of a capacitor element formed by pressure-molding valve action metal powder and forming an oxide film layer, solid electrolyte layer, and cathode lead-out layer on the surface of the anode body on which the anode lead-out line is planted The outer peripheral surface excluding the cathode lead-out portion provided on the outer surface is covered with an insulating resin, and the anode lead-out line not provided with the resin sheath, the anode lead-out portion composed of the peripheral portion, and the cathode lead-out portion on the surface facing the anode lead-out line In a chip-shaped solid electrolytic capacitor in which one or more conductor layers are formed and used as electrodes,
A chip-shaped solid electrolytic capacitor, wherein the cathode lead-out portion is provided on a surface facing the planting surface of the anode lead-out line of the capacitor element and at a position corresponding to at least the substrate mounting portion of the cathode.