JP2004140211A - Multilayer capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce equivalent series inductance of a multilayer capacitor. <P>SOLUTION: First and second extraction electrodes 12-15 and 16-19 are formed in first and second inner electrodes 10 and 11 which face each other for respectively connecting them to first and second external terminal electrodes. In this case, the direction of extension of end edges 28 and 29 which face each other of adjacent electrodes of the first extraction electrodes 12-15 and the second extraction electrodes 16-19 are arranged in such a way that they approach each other as they approach the first and second inner electrodes 10 and 11. <P>COPYRIGHT: (C)2004,JPO

Description

【００３９】
表１に示すように、引出電極３１の端縁に傾斜部分を設けることにより、このような傾斜部分のない試料（ｘ，ｚ＝０μｍ）に比べて、低ＥＳＬ化が図られていることがわかる。特に、寸法ｘの方が、寸法ｚに比べて、低ＥＳＬ化により影響を及ぼし、寸法ｘがより大きくなるほど、ＥＳＬがより低くなっていることがわかる。
【００４０】
以上、この発明を特定的な実施形態について説明したが、この発明の範囲内において、その他、種々の変形例が可能である。
【００４１】
この発明の最も基本的な構成は、図２を参照して説明すると、第１の内部電極１０が引出電極１２のみを形成し、第２の内部電極１１が引出電極１７のみを形成している構成である。したがって、この発明の範囲内において、上述の基本的構成を備える限り、内部電極の引出電極の位置や数を種々に変更したり、それに応じて、外部端子電極の位置や数を種々に変更したりすることができる。
【００４２】
より具体的には、図２を参照して説明すると、引出電極１２のみを備える第１の内部電極１０と引出電極１７のみを備える第２の内部電極１１と引出電極１５のみを備える第１の内部電極１０と引出電極１８のみを備える第２の内部電極１１とを混在させてもよい。また、引出電極１２および１３のみを有する第１の内部電極１０と引出電極１６および１７のみを有する第２の内部電極１１と引出電極１４および１５のみを有する第１の内部電極１０と引出電極１８および１９のみを有する第２の内部電極１１とを混在させてもよい。
【００４３】
また、図２を参照して説明すると、引出電極は、コンデンサ本体２の側面６および／または８にまで引き出されるように形成されてもよい。
【００４４】
また、第１および第２の内部電極ならびにコンデンサ本体は、正方形の平面形状を有していてもよく、あるいは、第１および第２の内部電極が円形の平面形状を有していても、さらには、コンデンサ本体が円形の平面形状を有していてもよい。
【００４５】
【発明の効果】
以上のように、この発明によれば、第１および第２の引出電極が隣り合って位置する箇所において、隣り合う第１および第２の引出電極の各々の互いに向かい合う端縁が、第１および第２の内部電極側に近づくに従って互いに近づくように延びているので、たとえば、第１の引出電極から、第１および第２の内部電極を通って、第２の引出電極へと流れる電流の経路を短くすることができ、また、引出電極の付け根部分での電流の集中を生じにくくでき、それによって、電流の流れを円滑にすることができるので、積層コンデンサの低ＥＳＬ化を有利に図ることができる。
【００４６】
また、引出電極の外部端子電極との接続部分における幅は、これを特に狭くする必要がないので、外部端子電極間のギャップ寸法を所定以上に維持することができ、その結果、ショート不良などの不具合を生じにくくすることができる。
【００４７】
この発明において、各々複数の第１および第２の引出電極ならびに第１および第２の外部端子電極を備え、すべての第１の外部端子電極とすべての第２の外部端子電極とが交互に配置されると、磁束をより効果的に相殺することができるとともに、電流の経路をより短くすることができるので、ＥＳＬをより低くすることが可能になる。
【００４８】
また、この発明において、第１および第２の外部端子電極の少なくとも一方によって並列接続された複数のコンデンサユニットを形成するように、第１の内部電極と第２の内部電極との対向する部分の数が複数とされると、積層コンデンサの小型化かつ高容量化に有効である。
【図面の簡単な説明】
【図１】この発明の一実施形態による積層コンデンサ１の外観を示す斜視図である。
【図２】図１に示した積層コンデンサ１に備えるコンデンサ本体２の内部構造を示すもので、（ａ）は、第１の内部電極１０が通る断面をもって示す平面図であり、（ｂ）は、第２の内部電極１１が通る断面をもって示す平面図である。
【図３】図２（ａ）に示した第１の内部電極１０と図２（ｂ）に示した第２の内部電極１１とを重ねた状態で示す、図２（ａ）に相当する図である。
【図４】図３の一部を拡大して示す図である。
【図５】この発明の他の実施形態を説明するための図４に相当する図である。
【図６】この発明に従って実施した実験例において、引出電極３１の端縁３２の形成態様を説明するための図である。
【符号の説明】
１　積層コンデンサ
２　コンデンサ本体
３，４　主面
５〜８　側面
９　誘電体層
１０　第１の内部電極
１１　第２の内部電極
１２〜１５　第１の引出電極
１６〜１９　第２の引出電極
２０〜２３　第１の外部端子電極
２４〜２７　第２の外部端子電極
２８，２８ａ，２９，２９ａ　端縁[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a multilayer capacitor, and more particularly to a multilayer capacitor that can be advantageously applied in a high-frequency circuit.
[0002]
[Prior art]
A multilayer capacitor of interest to the present invention is described in, for example, Japanese Patent Application Laid-Open No. H11-144996 (Patent Document 1). The multilayer capacitor described in Patent Document 1 is designed to reduce the equivalent series inductance (ESL) so that it can be advantageously used in a high-frequency circuit.
[0003]
More specifically, each of the internal electrodes provided for forming the capacitance in the multilayer capacitor is led out onto the side surface of the capacitor body via a plurality of lead-out electrodes. Then, a plurality of external terminal electrodes are provided on the side surface of the capacitor body so as to be electrically connected to each of the extraction electrodes. Further, the external terminal electrodes are arranged so that those connected to different internal electrodes are alternately adjacent to each other.
[0004]
According to the multilayer capacitor having such a structure, the current flowing through the internal electrodes can be directed in various directions, whereby the magnetic flux generated in association with the current is canceled out, and the ESL can be reduced.
[0005]
[Patent Document 1]
JP-A-11-144996
[Problems to be solved by the invention]
In the multilayer capacitor described in Patent Document 1 described above, in order to further reduce the ESL without increasing the number of extraction electrodes and the number of external terminal electrodes provided correspondingly, the width of the extraction electrode must be increased. It is effective to do.
[0007]
However, increasing the width of the extraction electrode means reducing the gap dimension between the extraction electrodes, and therefore, the gap dimension between the external terminal electrodes must also be reduced. As a result, there is a high possibility that a defect such as a short circuit will occur.
[0008]
Therefore, an object of the present invention is to provide a multilayer capacitor that can achieve a lower ESL without encountering the above-described problem.
[0009]
[Means for Solving the Problems]
A multilayer capacitor according to the present invention includes a capacitor body having two main surfaces facing each other and a side surface connecting the main surfaces. The capacitor body includes a plurality of dielectric layers extending in the direction of the main surface and at least one pair of first and second internal electrodes facing each other via a specific dielectric layer so as to form a capacitor unit; The first and second internal electrodes form first and second extraction electrodes, respectively, extending to the side surface of the capacitor main body, and the first and second internal electrodes are formed on the side surface of the capacitor main body. First and second external terminal electrodes respectively electrically connected to the extraction electrodes are provided. In order to solve the above-mentioned technical problems in the multilayer capacitor having such a basic configuration, the present invention is characterized by including the following configuration.
[0010]
That is, at the places where the above-mentioned first and second extraction electrodes are adjacent to each other, the mutually facing edges of the adjacent first and second extraction electrodes are closer to the first and second internal electrode sides. It is characterized in that it extends so as to approach each other as it approaches.
[0011]
In the present invention, the mutually facing edges of the adjacent first and second extraction electrodes may extend linearly so as to approach each other, or may extend in a curved manner so as to approach each other.
[0012]
A multilayer capacitor according to the present invention includes a plurality of first and second extraction electrodes and first and second external terminal electrodes, wherein all first external terminal electrodes and all second external terminal electrodes are connected to each other. Are preferably arranged alternately.
[0013]
Further, in the multilayer capacitor according to the present invention, the first internal electrode and the second internal electrode are connected so as to form a plurality of capacitor units connected in parallel by at least one of the first and second external terminal electrodes. Preferably, the number of opposing portions is plural.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
FIGS. 1 to 4 illustrate a multilayer capacitor 1 according to an embodiment of the present invention. Here, FIG. 1 is a perspective view showing the appearance of the multilayer capacitor 1.
[0015]
The multilayer capacitor 1 includes a capacitor body 2 as shown in FIG. In this embodiment, the capacitor body 2 has a rectangular parallelepiped shape, and has two opposing main surfaces 3 and 4 and four side surfaces 5, 6, 7 and 8 connecting between the main surfaces 3 and 4. I have.
[0016]
FIG. 2 is a plan view showing the internal structure of the capacitor main body 2 with a cross section parallel to the main surfaces 3 and 4, and shows plan views in cross sections at positions different from each other in (a) and (b). I have.
[0017]
The capacitor body 2 has a plurality of dielectric layers 9 extending in the direction of the main surfaces 3 and 4 and made of, for example, a dielectric ceramic, and at least one dielectric layer 9 opposed to each other via a specific dielectric layer 9 so as to form a capacitor unit. A pair of first and second internal electrodes 10 and 11 are provided.
[0018]
As shown in FIG. 2A, the first internal electrodes 10 form first extraction electrodes 12 and 13 extending to the side surface 5 and first extraction electrodes 14 and 15 extending to the side surface 7. ing.
[0019]
As shown in FIG. 2B, the second internal electrodes 11 form second extraction electrodes 16 and 17 extending to the side surface 5 and second extraction electrodes 18 and 19 extending to the side surface 7. ing.
[0020]
As shown in FIG. 1, on the side surfaces 5 and 7 from which the first extraction electrodes 12 to 15 are drawn, first external terminal electrodes 20 electrically connected to the first extraction electrodes 12 to 15, respectively. , 21, 22 and 23 are provided respectively. On these side surfaces 5 and 7, second external terminal electrodes 24, 25, 26 and 27 are provided, which are electrically connected to the second extraction electrodes 16 to 19, respectively.
[0021]
In this embodiment, the external terminal electrodes 20 to 27 are formed so as to extend from the side surface 5 or 7 to a part of each of the main surfaces 3 and 4.
[0022]
In this manner, a plurality of first and second external terminal electrodes 20 to 23 and 24 to 27 are formed on each of the side surfaces 5 and 7 respectively. Then, on the side surface 5, the first external terminal electrodes 20 and 21 and the second external terminal electrodes 24 and 25 are alternately arranged, while on the side surface 7, the first external terminal electrodes 22 and 23 and the second external terminal electrodes 26 and 27 are alternately arranged.
[0023]
Further, in such a multilayer capacitor 1, in order to obtain a larger capacitance, the number of opposing portions of the first internal electrode 10 and the second internal electrode 11 is plural, and a plurality of capacitor units are formed. To be done. That is, when one of the first and second internal electrodes 10 and 11 is formed in the capacitor body 2, the other of the first and second internal electrodes 10 and 11 sandwiches the other. When two are formed or when a larger capacitance is to be obtained, the number of sets of the first and second internal electrodes 10 and 11 is plural.
[0024]
As described above, when the number of opposing portions of the first internal electrode 10 and the second internal electrode 11 is plural, the plurality of capacitor units include the first external terminal electrodes 20 to 23 and the second They are connected in parallel by at least one of the external terminal electrodes 24-27.
[0025]
In the multilayer capacitor 1 having the above basic configuration, the following characteristic configuration is adopted. FIG. 3 is a plan view corresponding to FIG. 2A, showing a state where the first internal electrode 10 shown in FIG. 2A and the second internal electrode 11 shown in FIG. 2B overlap each other. FIG. In FIG. 3, the second extraction electrodes 16 to 19 extracted from the second internal electrode 11 are indicated by broken lines. FIG. 4 is an enlarged view of a part of FIG. 3, that is, a part where the first extraction electrode 13 and the second extraction electrode 16 are formed.
[0026]
As is well shown in FIGS. 3 and 4, at positions where the first extraction electrodes 12 to 15 and the second extraction electrodes 16 to 19 are adjacent to each other, the first extraction electrodes 12 to 15 Each edge 28 and each edge 29 of the second extraction electrodes 16 to 19 adjacent to the first extraction electrodes 12 to 15 face each other, but these opposite edges 28 and Reference numeral 29 extends so as to approach each other as approaching the first and second internal electrodes 10 and 11. In this embodiment, these opposing edges 28 and 29 extend linearly toward each other.
[0027]
By employing the above-described configuration, the following effects are achieved as compared with the case where the extraction electrode is formed to extend at a constant width. For example, when a current flows from each of the first extraction electrodes 12 to 15 to each of the second extraction electrodes 16 to 19 through the first internal electrode 10 and the second internal electrode 11, this current Path can be made shorter. In addition, it is possible to make it difficult for current to be concentrated at the base of each of the extraction electrodes 12 to 19, so that the flow of current can be made smoother. From these facts, it is possible to effectively reduce the ESL of the multilayer capacitor 1.
[0028]
Note that the width of each of the extraction electrodes 12 to 19 at the connection portion with each of the external terminal electrodes 20 to 27 does not need to be particularly widened. Therefore, it is not necessary to make a design change that tends to cause a short-circuit failure and the like, and the conventional design conditions can be maintained for the arrangement pitch of the external terminal electrodes 20 to 27.
[0029]
FIG. 5 is a diagram corresponding to FIG. 4 for explaining another embodiment of the present invention. 5, elements corresponding to the elements shown in FIG. 4 are denoted by the same reference numerals, and redundant description will be omitted.
[0030]
In the embodiment shown in FIG. 5, adjacent first extraction electrodes 12 to 15 (only the first extraction electrode 13 is shown in FIG. 5) and second extraction electrodes 16 to 19 (FIG. 5). In the drawing, only the second extraction electrode 16 is illustrated.) The mutually adjacent edges 28a and 29a are curved so as to approach each other as approaching the first and second internal electrodes 10 and 11 side. More specifically, it is characterized in that it extends in an arc shape.
[0031]
According to the embodiment shown in FIG. 5, substantially the same effects as those of the embodiment described with reference to FIGS. 1 to 3 can be obtained.
[0032]
Next, an experimental example performed for confirming the effect of the present invention will be described.
[0033]
In this experimental example, a plurality of types of multilayer capacitors serving as samples were manufactured based on the embodiment described with reference to FIGS. The multilayer capacitor according to each sample was designed as follows.
[0034]
First, the capacitor body alternately laminates three layers of first internal electrodes and two layers of second internal electrodes via the respective dielectric layers, and arranges 10 dielectric layers on each of the upper and lower layers. The laminated structure was adopted. Here, the thickness of each dielectric layer was 10 μm, and the thickness of each of the first and second internal electrodes was 1 μm.
[0035]
The dielectric layer was made of a BaTiO ₃ -based dielectric ceramic having a relative dielectric constant of 2000, and the internal electrode was made of a composition containing nickel as a conductive component.
[0036]
The dimensions of the capacitor body, the dimensions of the first and second internal electrodes, and the dimensions of the first and second extraction electrodes will be described with reference to FIG. 3. L = 2000 μm, W = 1200 μm, a = 150 μm, b = 350 μm, c = 200 μm, d = 50 μm, and e = 125 μm.
[0037]
In the multilayer capacitor having such a basic design, samples in which the form of each edge of the first and second extraction electrodes was variously changed were manufactured. That is, in FIG. 6, a representative one of the first and second extraction electrodes is indicated by “31”. However, for all of the first and second extraction electrodes, the inclined portion at the edge 32 of the illustrated extraction electrode 31 is shown. Dimensions x and z were variously changed as shown in Table 1 below to prepare samples. Then, ESL was measured for the multilayer capacitor according to each sample. The results are shown in Table 1.
[0038]
[Table 1]

[0039]
As shown in Table 1, by providing an inclined portion at the edge of the extraction electrode 31, lower ESL can be achieved as compared with a sample without such an inclined portion (x, z = 0 μm). Understand. In particular, it can be seen that the dimension x is more affected by lowering the ESL than the dimension z, and that the larger the dimension x, the lower the ESL.
[0040]
As described above, the present invention has been described with respect to the specific embodiments. However, various other modifications are possible within the scope of the present invention.
[0041]
The most basic configuration of the present invention will be described with reference to FIG. 2. The first internal electrode 10 forms only the extraction electrode 12, and the second internal electrode 11 forms only the extraction electrode 17. Configuration. Therefore, within the scope of the present invention, as long as the above-described basic configuration is provided, the positions and numbers of the extraction electrodes of the internal electrodes are variously changed, and accordingly, the positions and the numbers of the external terminal electrodes are variously changed. Or you can.
[0042]
More specifically, referring to FIG. 2, a first internal electrode 10 having only the extraction electrode 12 and a second internal electrode 11 having only the extraction electrode 17 and a first internal electrode having only the extraction electrode 15 are provided. The internal electrode 10 and the second internal electrode 11 having only the extraction electrode 18 may be mixed. Further, a first internal electrode 10 having only the extraction electrodes 12 and 13, a second internal electrode 11 having only the extraction electrodes 16 and 17, a first internal electrode 10 having only the extraction electrodes 14 and 15, and an extraction electrode 18 are provided. And the second internal electrode 11 having only 19 may be mixed.
[0043]
Referring to FIG. 2, the extraction electrode may be formed so as to be extended to the side surface 6 and / or 8 of the capacitor body 2.
[0044]
The first and second internal electrodes and the capacitor body may have a square planar shape, or the first and second internal electrodes may have a circular planar shape. The capacitor body may have a circular planar shape.
[0045]
【The invention's effect】
As described above, according to the present invention, at locations where the first and second extraction electrodes are adjacent to each other, the mutually facing edges of the adjacent first and second extraction electrodes are the first and second extraction electrodes. The path extends from the first extraction electrode through the first and second internal electrodes to the second extraction electrode, for example, because the second internal electrodes extend so as to approach each other as approaching the second internal electrode side. And the current concentration at the base of the extraction electrode can be made less likely to occur, whereby the current flow can be made smooth. Therefore, it is advantageous to reduce the ESL of the multilayer capacitor. Can be.
[0046]
Further, the width of the extraction electrode at the connection portion with the external terminal electrode does not need to be particularly narrowed, so that the gap size between the external terminal electrodes can be maintained at a predetermined value or more, and as a result, short-circuit failure and the like can be prevented. Inconvenience can be reduced.
[0047]
In the present invention, a plurality of first and second extraction electrodes and first and second external terminal electrodes are provided, and all first external terminal electrodes and all second external terminal electrodes are alternately arranged. Then, the magnetic flux can be more effectively canceled and the current path can be made shorter, so that the ESL can be made lower.
[0048]
Also, in the present invention, the opposing portions of the first internal electrode and the second internal electrode are formed so as to form a plurality of capacitor units connected in parallel by at least one of the first and second external terminal electrodes. When the number is plural, it is effective to reduce the size and increase the capacitance of the multilayer capacitor.
[Brief description of the drawings]
FIG. 1 is a perspective view showing the appearance of a multilayer capacitor 1 according to an embodiment of the present invention.
2A and 2B show an internal structure of a capacitor body 2 provided in the multilayer capacitor 1 shown in FIG. 1, wherein FIG. 2A is a plan view showing a cross section through which a first internal electrode 10 passes, and FIG. FIG. 5 is a plan view showing a cross section through which the second internal electrode 11 passes.
FIG. 3 is a diagram corresponding to FIG. 2A, showing a state in which the first internal electrode 10 shown in FIG. 2A and the second internal electrode 11 shown in FIG. It is.
FIG. 4 is an enlarged view showing a part of FIG. 3;
FIG. 5 is a diagram corresponding to FIG. 4 for explaining another embodiment of the present invention.
FIG. 6 is a diagram for explaining a mode of forming the edge 32 of the extraction electrode 31 in an experimental example implemented according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Multilayer capacitor 2 Capacitor main body 3, 4 Main surface 5-8 Side surface 9 Dielectric layer 10 First internal electrode 11 Second internal electrode 12-15 First extraction electrode 16-19 Second extraction electrode 20-23 First external terminal electrodes 24-27 Second external terminal electrodes 28, 28a, 29, 29a Edge

Claims (5)

A capacitor body having two opposing main surfaces and side surfaces connecting the main surfaces,
The capacitor body includes a plurality of dielectric layers extending in the direction of the main surface, and at least one pair of first and second internal electrodes facing each other via the specific dielectric layer so as to form a capacitor unit. With
The first and second internal electrodes form first and second extraction electrodes that extend to the side surfaces, respectively.
On the side surface, first and second external terminal electrodes respectively electrically connected to the first and second extraction electrodes are provided, respectively.
A multilayer capacitor,
At a location where the first and second extraction electrodes are adjacent to each other, the mutually facing edges of each of the adjacent first and second extraction electrodes approach the first and second internal electrode sides. Characterized in that they extend so as to approach each other in accordance with the following. 2. The multilayer capacitor according to claim 1, wherein mutually facing edges of each of the adjacent first and second extraction electrodes extend linearly so as to approach each other. 2. The multilayer capacitor according to claim 1, wherein the mutually facing edges of each of the adjacent first and second extraction electrodes extend in a curved shape so as to approach each other. Each of the plurality of first and second extraction electrodes and the first and second external terminal electrodes is provided, and all of the first external terminal electrodes and all of the second external terminal electrodes are alternately arranged. The multilayer capacitor according to claim 1, wherein the multilayer capacitor is arranged. The number of opposing portions of the first internal electrode and the second internal electrode is such that a plurality of capacitor units connected in parallel by at least one of the first and second external terminal electrodes are formed. The multilayer capacitor according to any one of claims 1 to 4, wherein the multilayer capacitor is a plurality.

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