JP6769059B2 - Multilayer capacitor - Google Patents

Description

The present invention relates to a multilayer capacitor.

Conventionally, various laminated capacitors having a laminated structure having a plurality of internal electrodes have been known. Patent Document 1 describes a two-terminal vertically stacked capacitor (that is, a capacitor having two capacitor terminals in which stacked internal electrodes in the capacitor are arranged perpendicular to the mounting surface of the circuit board and connected to the circuit board. ) Is disclosed.

In the multilayer capacitor disclosed in Patent Document 1, a pair of external electrodes and an insulating layer that completely covers the region between the pair of external electrodes are provided on the surface facing the circuit board.

Japanese Unexamined Patent Publication No. 2013-46052

In the above-mentioned multilayer capacitor, if a short circuit occurs between a pair of external electrodes, it causes a malfunction of the component, and it is important to prevent such a short circuit. At the same time, reduction of equivalent series inductance (ESL) is also required.

An object of the present disclosure is to provide a multilayer capacitor in which ESL is reduced while suppressing a short circuit.

The multilayer capacitor according to the present disclosure is provided on the element body, an internal electrode having a lead-out electrode located inside the element body and having an end surface exposed from the first surface of the element body, and a first surface of the element body. The internal electrode is provided with an electrode layer in contact with the end surface of the extraction electrode exposed on the first surface of the element body and an insulating layer provided on the first surface of the element body so as to cover a part of the electrode layer. When viewed from the normal direction of, the width of the lead-out electrode in the pull-out direction is W1, the width of the region where the electrode layer is exposed from the insulating layer is W2, the width of the electrode layer is W3, and the width of the element body is W4. Then, the equation of W2 <W3 ≦ W1 holds, and the formula of W3 / W4 ≧ 0.25 holds.

In the multilayer capacitor, the width (W2) of the region where the electrode layer is exposed from the insulating layer is narrower than the width (W3) of the electrode layer (that is, W2 <W3), so that a short circuit during mounting is suppressed. In addition, in the multilayer capacitor, the width of the extraction electrode (W1) is the same as or larger than the width of the electrode layer (W3), and the width of the electrode layer / the width of the element body (W3 / W4) is large. Since it is 0.25 or more, the ESL is also reduced.

Further, a plurality of internal electrodes having different polarities laminated in parallel with each other are provided, and the end surface of the extraction electrode of the internal electrode having one polarity is in contact with the first electrode layer provided on the first surface of the element body. The end face of the extraction electrode of the internal electrode of the other polarity is in contact with the second electrode layer provided on the first surface of the element body and different from the first electrode layer, and is viewed from the stacking direction of the plurality of internal electrodes. W1 / Y, where Y is the length of the region where neither the end face of the lead-out electrode of the internal electrode of one polarity and the end face of the lead-out electrode of the internal electrode of the other polarity are exposed on the first surface. The mode may be such that the equation of ≧ 1.00 holds. In this case, the ESL can be reduced while suppressing a short circuit at the time of mounting between the first electrode layer and the second electrode layer provided on the first surface.

Further, a plurality of internal electrodes having different polarities laminated in parallel with each other are provided, and the end surface of the extraction electrode of the internal electrode having one polarity is in contact with the first electrode layer provided on the first surface of the element body. A second electrode layer provided on a second surface different from the first surface of the element body and different from the first electrode layer is in contact with the end face of the extraction electrode of the internal electrode of the other polarity, and a plurality of internal surfaces are provided. When the width of the element body is W4 when viewed from the stacking direction of the electrodes, the equation W1 / W4 ≥ 0.25 may hold. In this case, it is possible to reduce ESL while suppressing a short circuit at the time of mounting between the first electrode layer provided on the first surface and the second electrode layer provided on the second surface. it can.

Further, the plating layer may be formed in the region where the electrode layer is exposed from the insulating layer. In this case, it can be mounted in the region where the plating layer is formed.

Further, a plurality of insulating layers are provided on the first surface of the element body, and both ends of the end faces of the extraction electrodes are exposed from the electrode layer when viewed from the normal direction of the internal electrode, and the exposed extraction electrodes are exposed. Both ends of the end face of the above surface may be covered with a plurality of insulating layers. In this case, the length of contact between the electrode layer and the end face of the extraction electrode is the same as the width of the electrode layer, so that the variation in ESL is suppressed.

According to the present disclosure, a multilayer capacitor in which ESL is reduced while suppressing a short circuit is provided.

FIG. 1 is a schematic perspective view of a multilayer capacitor according to an embodiment. FIG. 2 is a sectional view taken along line II-II of the multilayer capacitor shown in FIG. FIG. 3 is a sectional view taken along line III-III of the multilayer capacitor shown in FIG. FIG. 4 is a diagram showing the dimensions of each element of the multilayer capacitor shown in FIG. FIG. 5 is a table showing the results of Examples and Comparative Examples. FIG. 6 is a diagram showing a modified example of the multilayer capacitor shown in FIG. FIG. 7 is a schematic perspective view showing a multilayer capacitor having a mode different from that shown in FIG. FIG. 8 is a diagram showing the dimensions of each element of the multilayer capacitor shown in FIG. 7. FIG. 9 is a schematic perspective view showing a multilayer capacitor having a mode different from that shown in FIGS. 1 and 7. FIG. 10 is a diagram showing the dimensions of each element of the multilayer capacitor shown in FIG. FIG. 11 is a table showing the results of Examples and Comparative Examples.

Hereinafter, the multilayer capacitor according to the embodiment will be described in detail with reference to the accompanying drawings. In the description, the same reference numerals are used for the same elements or elements having the same function, and duplicate description will be omitted.

FIG. 1 shows the multilayer capacitor 10 according to the embodiment. As shown in FIG. 1, the multilayer capacitor 10 includes a body 20 having a substantially rectangular parallelepiped outer shape. The element body 20 has a pair of end faces 20a and 20b facing each other, extends so as to be orthogonal to both end faces 20a and 20b, and has a bottom surface (first face) 20c connecting both end faces 20a and 20b. Has. As an example, the dimensions of the element body 20 are such that the length in the longitudinal direction (distance between both end faces 20a and 20b) is 600 μm and the length in the lateral direction (opposite directions of both end faces 20a and 20b and the normal direction of the bottom surface 20c). The length in the orthogonal direction) is 300 μm, and the height is 300 μm, but the present invention is not limited to this. The dimensions of the element body 20 are preferably such that the length in the longitudinal direction is 1000 μm or less, the length in the lateral direction is 500 μm or less, and the height is 500 μm or less.

A plurality of internal electrodes 22 and 24 are formed inside the element body 20. Each of the internal electrodes 22 and 24 is in an upright posture with respect to the bottom surface 20c of the element body 20 and extends along the opposite direction of the end faces 20a and 20b. The plurality of internal electrodes 22 and 24 are separated from each other by a predetermined distance and are laminated in parallel with each other. That is, the plurality of internal electrodes 22 and 24 are laminated so as to be orthogonal to the facing direction of the end faces 20a and 20b of the element body 20 and the normal direction of the bottom surface 20c.

The plurality of internal electrodes 22 and 24 are composed of a positive electrode internal electrode 22 and a negative electrode internal electrode 24, and the positive electrode internal electrode 22 and the negative electrode internal electrode 24 are alternately arranged. Each of the internal electrodes 22 and 24 has integrally formed capacitive electrodes 22a and 24a mainly for forming a capacitance, and lead-out electrodes 22b and 24b mainly for drawing the electrodes out of the element body. .. Specifically, as shown in FIG. 2, the internal electrodes 24 are a rectangular capacitive electrode 24a extending in the opposite direction (left-right direction in FIG. 2) of the element body end faces 20a and 20b, and a bottom surface 20c of the capacitive electrode 24a. It has a rectangular lead-out electrode 24b provided on the side and exposed on the bottom surface 20c. The extraction electrode 24b extends from the vicinity of the end surface 20b to the vicinity of the center of the bottom surface 20c along the bottom surface 20c. The other internal electrode 22 also includes a capacitance electrode 22a having substantially the same dimensions as the capacitance electrode 24a of the internal electrode 24, and a rectangular lead-out electrode 22b provided on the bottom surface 20c side of the capacitance electrode 22a and exposed on the bottom surface 20c. Has.

The dimensions of the capacitive electrodes 22a and 24a are, for example, 500 μm in length, 200 μm in height, and 1 μm in thickness. The dimensions of the extraction electrodes 22b and 24b are, for example, 200 μm in length, 50 μm in height, and 1 μm in thickness.

An electrode layer 30A (first electrode layer), an electrode layer 30B (second electrode layer), and three insulating layers 40, 40A, and 40B are formed on the bottom surface 20c (first surface) of the element body 20. Has been done. As shown in FIGS. 1 to 3, the pair of electrode layers 30A and 30B and the three insulating layers 40, 40A and 40B extend over the entire length in the lateral direction of the bottom surface 20c (that is, the stacking direction of the internal electrodes 22 and 24). Is formed.

The pair of electrode layers 30A and 30B are connected to the above-mentioned internal electrodes 22 and 24. Specifically, the electrode layer 30A of the positive electrode is provided in the bottom surface region on the end surface 20a side, and is in contact with a part of the end surface 23 of the extraction electrode 22b of each internal electrode 22 exposed on the bottom surface 20c, whereby the electrode layer 30A And each internal electrode 22 are electrically connected. The electrode layer 30B of the negative electrode is provided in the bottom surface region on the end surface 20b side, and is in contact with a part of the end surface 25 of the extraction electrode 24b of each internal electrode 24 exposed on the bottom surface 20c, whereby the electrode layer 30B and each internal electrode 24 And are electrically connected.

The insulating layer 40 is provided in the central region of the bottom surface 20c so as to integrally cover the region between the pair of electrode layers 30A and 30B and a part of each of the electrode layers 30A and 30B. More specifically, as shown in FIG. 2, the insulating layer 40 covers the central end portion of the electrode layer 30A (that is, the end portion on the electrode layer 30B side) by a predetermined length. Similarly, the insulating layer 40 also covers the central end portion of the electrode layer 30B (that is, the end portion on the electrode layer 30A side) by the same length as the electrode layer 30A. Therefore, the insulating layer 40 exhibits a line-symmetrical cross-sectional shape in FIG.

Further, the insulating layer 40 fills the space between the pair of electrode layers 30A and 30B and rides on the electrode layers 30A and 30B, and the thickness of the insulating layer 40 is thicker than the thickness of the electrode layers 30A and 30B. It is designed to be. It can also be said that the electrode layers 30A and 30B in contact with the insulating layer 40 are submerged in the lower side (bottom surface 20c side) of the insulating layer 40.

The insulating layer 40A extends from the vicinity of the end face 20a to a position covering a part of the electrode layer 30A along the bottom surface 20c. The insulating layer 40A covers a portion of the end surface 23 of the extraction electrode 22b of each internal electrode 22 exposed on the bottom surface 20c, which is exposed from the electrode layer 30A. Further, the insulating layer 40B extends from the vicinity of the end surface 2b to a position covering a part of the electrode layer 30B along the bottom surface 20c. The insulating layer 40B covers the portion of the end surface 25 of the extraction electrode 24b of each internal electrode 24 exposed on the bottom surface 20c that is exposed from the electrode layer 30B. The insulating layers 40A and 40B are all mounted on the electrode layers 30A and 30B, and are designed to be thicker than the thickness of the electrode layers 30A and 30B.

The insulating layers 40, 40A, and 40B are made of an insulating material such as glass or resin, and are formed by a forming method such as printing.

As shown in FIG. 2, the plating layer 50 can be formed in each of the regions where the electrode layers 30A and 30B are exposed from the insulating layers 40, 40A and 40B. It can be mounted on the circuit board 51 in the region where the plating layer 50 is formed.

Here, with reference to FIG. 4, the positional relationship and the magnitude relationship of the dimensions of the extraction electrodes 22b and 24b, the electrode layers 30A and 30B, and the insulating layers 40, 40A and 40B will be described in more detail.

As shown in FIG. 4, for convenience of explanation, the width of the internal electrode 22 with respect to the drawing direction of the drawing electrode 22b is set to W1 when viewed from the stacking direction of the internal electrodes 22 and 24, and the electrode layer 30A is exposed from the insulating layers 40 and 40A. The width of the region is W2, and the width of the electrode layer 30A is W3. Further, the width of the bottom surface 20c of the element body 20 is W4, and the total length of the regions where none of the end faces 23 and 25 of the extraction electrodes 22b and 24b of the internal electrodes 22 and 24 is exposed on the bottom surface 20c is Y (Y). = Y1 + y2 + y3). Note that y1 indicates the length of the region where the end surface 20a of the element body 20 and the end surface 23 of the extraction electrode 22b exposed on the bottom surface 20c are separated from each other, and y2 is near the center of the bottom surface 20c of the element body 20. The length of the region where the end surface 23 of the extraction electrode 22b and the end surface 25 of the extraction electrode 24b are separated is shown, and y3 is the end surface 20b of the element body 20 and the end surface 25 of the extraction electrode 24b exposed on the bottom surface 20c. Indicates the length of the separated regions. The above widths W1, W2, W3, and W4 are all widths related to the pull-out direction of the lead-out electrode when viewed from the normal direction of the internal electrode as shown in FIG. 4, that is, the length in the direction orthogonal to the pull-out direction. That's right.

At this time, in the multilayer capacitor 10, the equation W2 <W3 ≦ W1 (hereinafter, also referred to as the first equation) holds, and the equation W3 / W4 ≧ 0.25 (hereinafter, also referred to as the second equation). ), And the equation of W1 / Y ≧ 1.00 (hereinafter, also referred to as the third equation) is established.

The number of the insulating layers 40, 40A, and 40B provided on the bottom surface 20c of the element body 20 is not limited to three, and even if it is one (only the insulating layer 40), the first equation and the second The equation and the third equation can hold.

The first equation means that the width (W2) of the region where the electrode layer 30A is exposed from the insulating layer 40 is narrower than the width (W3) of the electrode layer 30A (that is, W2 <W3). As shown in 2, it means that the central end of the electrode layer 30A is covered with the insulating layer 40. In this case, since the exposed portion of the electrode layer 30A is separated from the other electrode layer 30B by the insulating layer 40, both electrode layers 30A are mounted when a voltage is applied between the electrode layer 30A and the electrode layer 30B. , The situation where a short circuit occurs between 30B is suppressed.

Further, the first equation means that the width (W1) of the extraction electrode 22b is the same as or larger than the width (W3) of the electrode layer 30A (that is, W3 ≦ W1), and the second equation. Means that the width (W3) of the electrode layer 30A is 0.25 times or more the width (W4) of the element body 20, and when these equations hold, the ESL of the multilayer capacitor 10 is reduced. It was found by the experiments shown below by the inventors.

In the experiment, as shown in FIG. 5, a sample according to a comparative example and four samples according to Examples 1 to 4 were prepared, and the S parameter was converted into impedance using a network analyzer, and the ESL (pH) of each sample was converted. ) Was measured. In each sample, the width (W4) of the element body 20 when viewed from the stacking direction of the internal electrodes 22 and 24 is unified to 600 μm.

Specifically, in the sample according to the comparative example, the widths of the electrode layers 30A and 30B are both 200 μm, and W3 is 0.33 times that of W4. That is, in the sample according to the comparative example, the relationship of W3 ≦ W1 does not hold, and the relationship of the second equation does not hold either.

Then, when ESL was measured for the sample according to the comparative example, it was 230 pH, which was a high value.

Regarding Examples 1 to 4, in the sample according to Example 1, the widths of the electrode layers 30A and 30B are both 150 μm, and W3 is 0.25 times that of W4. Further, in the sample according to Example 2, the widths of the electrode layers 30A and 30B are both 150 μm, and W3 is 0.25 times that of W4. Further, in the sample according to Example 3, the widths of the electrode layers 30A and 30B are both 150 μm, and W3 is 0.25 times that of W4. Further, in the sample according to Example 4, the widths of the electrode layers 30A and 30B are both 200 μm, and W3 is 0.33 times that of W4. That is, in all of the samples according to Examples 1 to 4, W3 is 0.25 times or more that of W4, and the relationship of the second equation holds.

When the ESL was measured for each of the samples according to Examples 1 to 4, it was 155 pH for the sample of Example 1, 140 pH for the sample of Example 2, 110 pH for the sample of Example 3, and 100 pH for the sample of Example 4. Also showed a lower value than Comparative Examples 1 to 3. In this experiment, if the ESL is 155 pH or less, the value is sufficiently low for practical use, and if the ESL is 110 pH or less, the value is more practical.

From the above experimental results, the inventors have found that when the relationship of W3 ≦ W1 holds and W3 is 0.25 times or more of W4 (that is, the second equation holds), it is practically sufficient. It was found that a low ESL value can be obtained.

Regarding the internal electrode 24 and the electrode layer 30B, the width of the extraction electrode 24b is W1 and the width of the region where the electrode layer 30B is exposed from the insulating layer 40 is W2 when viewed from the stacking direction of the internal electrodes 22 and 24. Therefore, even when the width of the electrode layer 30B is W3, the above-mentioned first equation and second equation hold.

Further, the third equation means that W1 is 1.00 times or more of Y, and when this equation holds, the ESL of the multilayer capacitor 10 can be reduced as the result of the above-mentioned experiment. .. That is, as shown in the experimental results shown in FIG. 5, a low ESL value cannot be obtained in the sample according to the comparative example in which W1 is less than 1.00 times Y, but W1 is 1.00 times or more of Y. Low ESL values are obtained for the samples according to Examples 1-4.

As shown in FIG. 2, in the multilayer capacitor 10, the internal electrodes 22 and 24, the electrode layers 30A and 30B, and the insulating layer 40 have symmetry. Therefore, from the above experimental results, the width of the extraction electrode 24b of the internal electrode 24 is set to W1. It is considered that a low ESL value can be obtained even when W1 / Y ≧ 1.00 holds.

The multilayer capacitor 10 described above can have the configuration shown in FIG. That is, in FIG. 6, when viewed from the stacking direction of the internal electrodes 22 and 24, both ends 23a and 23b of the end surface 23 of the extraction electrode 22b of the internal electrode 22 are exposed from the electrode layer 30A, and the exposed extraction electrode 22b Both ends 23a and 23b of the end surface 23 are covered with two insulating layers 40 and 40A, respectively.

In the configuration shown in FIG. 6, the extraction electrodes 22b and the electrode layer 30A that are in contact with each other have a constant length of contact even when the relative positions are displaced along the bottom surface 20c of the element body 20, and the electrodes are in contact with each other. It is the same as the width of the layer 30A. Therefore, even if the relative position shift occurs during manufacturing or the like, the variation in ESL is suppressed.

When only one of both ends 23a and 23b of the end surface 23 of the lead-out electrode 22b of the internal electrode 22 is exposed from the electrode layer 30A, the pull-out electrode 22b and the electrode layer 30A come into contact with each other when the relative positional deviation occurs. The length changes and the ESL varies.

In the configuration shown in FIG. 6, also for the internal electrode 24, both ends 25a and 25b of the end surface 25 of the extraction electrode 24b are exposed from the electrode layer 30B, and both ends 25a and 25b are two insulating layers 40 and 40B. Since each of them is covered, the variation of ESL is suppressed for the reason described above.

FIG. 7 shows a multilayer capacitor 10A having a mode different from that of the multilayer capacitor 10 described above.

The multilayer capacitor 10A has the same element body 20A as the element body 20 of the laminated capacitor 10 described above, and a plurality of internal electrodes 26 and 28 are formed inside the element body 20A. The internal electrodes 26 and 28 extend along the opposite directions of the end faces 20a and 20b in a posture parallel to the bottom surface 20c of the element body 20A. The plurality of internal electrodes 26, 28 are separated from each other by a predetermined distance and are laminated in parallel with each other.

The plurality of internal electrodes 26 and 28 are composed of a positive electrode internal electrode 26 and a negative electrode internal electrode 28, and the positive electrode internal electrode 26 and the negative electrode internal electrode 28 are alternately arranged. Each of the internal electrodes 26 and 28 has an integrally formed capacitive electrodes 26a and 28a mainly for forming a capacitance, and pull-out electrodes 26b and 28b mainly for pulling the electrodes out of the element body. .. Specifically, as shown in FIG. 8, the internal electrodes 26 are a rectangular capacitive electrode 26a extending in the opposite direction (left-right direction in FIG. 8) of the element body end faces 20a and 20b, and an element body from the capacitive electrode 26a. It has a pair of rectangular lead-out electrodes 26b that extend to and expose both side surfaces 20d and 20e of 20A. The pair of drawer electrodes 26b are a drawer electrode 26b extending from the vicinity of the end surface 20a to the vicinity of the center of the side surface 20d along the side surface 20d, and a extraction electrode 26b extending from the vicinity of the end surface 20b to the vicinity of the center of the side surface 20e along the side surface 20e. It is composed of 26b. As for the other internal electrode 28, the capacitance electrode 28a having substantially the same dimensions as the capacitance electrode 26a of the internal electrode 26 and a pair of rectangular shapes extending from the capacitance electrode 28a to the side surfaces 20d and 20e of the element body 20A are exposed. It has a lead-out electrode 28b. The pair of drawer electrodes 28b are a drawer electrode 28b extending from the vicinity of the end surface 20a to the vicinity of the center of the side surface 20e along the side surface 20e, and a extraction electrode 28b extending from the vicinity of the end surface 20b to the vicinity of the center of the side surface 20d along the side surface 20d. It is composed of 28b. The shape of the internal electrode 26 and the shape of the internal electrode 28 have a rotationally symmetric relationship or a mirror image relationship that overlap when rotated by 180 degrees.

The dimensions of the capacitive electrodes 26a and 28a are, for example, 500 μm in length, 200 μm in height, and 1 μm in thickness. The dimensions of the lead-out electrodes 26b and 28b are, for example, 200 μm in length, 50 μm in height, and 1 μm in thickness.

Four electrode layers 30A to 30D and six insulating layers 40, 40A, and 40B are formed on both side surfaces 20d and 20e of the element body 20A. That is, on one side surface 20d (first surface) of the element body 20A, an electrode layer 30A (first electrode layer), an electrode layer 30B (second electrode layer), and three insulating layers 40, 40A, 40B Is formed, and a pair of electrode layers 30C and 30D and insulating layers 40, 40A and 40B are formed on the other side surface 20e.

Also in the multilayer capacitor 10A, a plating layer 50 for mounting on the circuit board 51 can be formed in each of the regions where the electrode layers 30A to 30D are exposed from the insulating layers 40, 40A, and 40B.

In the laminated capacitor 10A, the lead-out electrodes 26b and 28b, the electrode layers 30A to 30D, and the insulating layer when viewed from the stacking direction of the internal electrodes 26 and 28 on each side of the side surfaces 20d and 20e of the element body 20A. The positional relationship and the size relationship of the 40, 40A, and 40B are the same as the positional relationship and the size relationship of the lead-out electrodes 22b, 24b, the electrode layers 30A, 30B and the insulating layers 40, 40A, 40B of the multilayer capacitor 10 described above. It has become.

That is, as shown in FIG. 8, when viewed from the stacking direction of the internal electrodes 26 and 28, the width of the internal electrode 26 with respect to the drawing direction of the drawing electrode 26b is set to W1, and the electrode layer 30A is exposed from the insulating layers 40 and 40A. The width of the region is W2, and the width of the electrode layer 30A is W3. Further, the width of the side surface 20d of the element body 20A is W4, and the total length of the regions where none of the end faces 27 and 29 of the extraction electrodes 26b and 28b of the internal electrodes 26 and 28 are exposed on the side surface 20d is Y (Y). = Y1 + y2 + y3). Note that y1 indicates the length of the region where the end surface 20a of the element body 20A and the end surface 27 of the extraction electrode 26b exposed on the side surface 20d are separated from each other, and y2 is near the center of the side surface 20d of the element body 20A. The length of the region where the end surface 27 of the extraction electrode 26b and the end surface 29 of the extraction electrode 28b are separated is shown. In y3, the end surface 20b of the element body 20A and the end surface 29 of the extraction electrode 28b exposed on the side surface 20d are formed. Indicates the length of the separated regions. The above widths W1, W2, W3, and W4 are all widths related to the pull-out direction of the lead-out electrode when viewed from the normal direction of the internal electrode as shown in FIG. 8, that is, the length in the direction orthogonal to the pull-out direction. That's right.

At this time, in the multilayer capacitor 10A, the above-mentioned first equation (W2 <W3 ≦ W1), second equation (W3 / W4 ≧ 0.25) and third equation (W1 / Y ≧ 1.00) Are all true.

The number of the insulating layers 40, 40A, and 40B provided on one side surface 20d (or the side surface 20e) of the element body 20A is not limited to three, and may be one (only the insulating layer 40). The first equation, the second equation, and the third equation can hold.

Therefore, also in the multilayer capacitor 10A, as in the above-mentioned multilayer capacitor 10, when a voltage is applied between the electrode layer 30A and the electrode layer 30B and between the electrode layer 30C and the electrode layer 30D, the electrode layer 30A, The situation where a short circuit occurs between 30B and between the electrode layers 30C and 30D is suppressed, and ESL is reduced.

FIG. 9 shows a multilayer capacitor 10B having a mode different from that of the multilayer capacitors 10 and 10A described above.

The multilayer capacitor 10B has the same element body 20B as the element bodies 20 and 20A of the laminated capacitor 10 and 10A described above, and a plurality of internal electrodes 52 and 54 are formed inside the element body 20B. Each of the internal electrodes 52 and 54 extends along the opposite direction of the end faces 20a and 20b in a posture parallel to the bottom surface 20c of the element body 20B. The plurality of internal electrodes 52, 54 are separated from each other by a predetermined distance and are laminated in parallel with each other.

The plurality of internal electrodes 52 and 54 are composed of the internal electrodes 52 of the positive electrode and the internal electrodes 54 of the negative electrode, and the internal electrodes 52 of the positive electrode and the internal electrodes 54 of the negative electrode are alternately arranged. Each of the internal electrodes 52, 54 has an integrally formed capacitance electrode 52a, 54a mainly for forming a capacitance, and an extraction electrode 52b, 54b mainly for drawing the electrode out of the element body. .. Specifically, as shown in FIG. 10, the internal electrodes 52 are a rectangular capacitive electrode 52a that extends long in the opposite direction (left-right direction in FIG. 10) of the element body end faces 20a and 20b, and an element body from the capacitive electrode 52a. It has a pair of rectangular lead-out electrodes 52b extending to and exposing both side surfaces 20d and 20e of 20B. The pair of drawer electrodes 52b is composed of a drawer electrode 52b formed near the center on the side surface 20d side and a drawer electrode 52b formed near the center on the side surface 20e side. The other internal electrode 54 is a capacitance electrode 54a having substantially the same dimensions as the capacitance electrode 52a of the internal electrode 52, and a pair of rectangular drawers extending from the capacitance electrode 54a to both end faces 20a and 20b of the element body 20B and exposed. It has an electrode 54b. The pair of pull-out electrodes 54b is composed of a pull-out electrode 54b formed near the center on the end face 20a side and a pull-out electrode 54b formed near the center on the end face 20b side.

The dimensions of the capacitive electrodes 52a and 54a are, for example, 500 μm in length, 200 μm in height, and 1 μm in thickness. The dimensions of the lead-out electrodes 52b and 54b are, for example, 200 μm in length, 50 μm in height, and 1 μm in thickness.

Four electrode layers 30A to 30D and four insulating layers 40 are formed on both end faces 20a and 20b and both side surfaces 20d and 20e of the element body 20B. That is, an electrode layer 30A (first electrode layer) and two insulating layers 40 are formed on one side surface 20d (first surface) of the element body 20B, and an electrode layer 40 on the other side surface 20e. 30C and two insulating layers 40 are formed, an electrode layer 30B (second electrode layer) is formed on one end surface 20a (second surface), and an electrode layer 30D is formed on the other end surface 20b. Is formed.

The electrode layers 30A and 30C are connected to the internal electrode 52. Specifically, the positive electrode layers 30A and 30C are provided in the central region of the side surfaces 20d and 20e, and are in contact with a part of the end surface 53 of the extraction electrode 52b of each internal electrode 52 exposed on the side surfaces 20d and 20e. As a result, the electrode layers 30A and 30C and each internal electrode 52 are electrically connected. The electrode layers 30B and 30D of the negative electrode are provided in the central region of the end faces 20a and 20b, and are in contact with a part of the end face 55 of the extraction electrode 54b of each internal electrode 54 exposed on each end face 20a and 20b, whereby the electrode layer. 30B and 30D and each internal electrode 54 are electrically connected.

Two of the four insulating layers 40 are provided on both side surfaces 20d and 20e so as to cover between the positive electrode layers 30A and 30C and the negative electrode layers 30B and 30D, respectively. Specifically, each insulating layer 40 is provided so as to integrally cover the region between the electrode layers and a part of the electrode layers 30A and 30C. More specifically, as shown in FIG. 10, the two insulating layers 40 on the side surfaces 20d and 20e cover both ends of the electrode layers 30A and 30C by the same length and are exposed on the side surfaces 20d and 20e. Of the end faces 53 of the lead-out electrodes 52b of each of the internal electrodes 52, the portions exposed from the electrode layers 30A and 30C are covered. Therefore, the electrode layers 30A and 30C and the insulating layer 40 exhibit a line-symmetrical planar shape in FIG.

Further, the insulating layer 40 covers between the electrode layers 30A to 30D, and rides on the electrode layers 30A and 30C. It can also be said that the electrode layers 30A and 30C in contact with the insulating layer 40 are submerged in the lower side (side surfaces 20d and 20e side) of the insulating layer 40.

Also in the multilayer capacitor 10B, a plating layer 50 for mounting on the circuit board 51 can be formed in each of the regions where the electrode layers 30A to 30D are exposed from the insulating layer 40.

Then, in the laminated capacitor 10B, on each side of the side surfaces 20d and 20e of the element body 20B, the lead-out electrodes 52b, the electrode layers 30A and 30C and the insulating layer 40 when viewed from the stacking direction of the internal electrodes 52 and 54. The positional relationship and the magnitude relationship of the dimensions satisfy the first formula (W2 <W3 ≦ W1) and the second formula (W3 / W4 ≧ 0.25) described above.

That is, as shown in FIG. 10, the width of the internal electrode 52 with respect to the drawing direction of the drawing electrode 52b when viewed from the stacking direction of the internal electrodes 52 and 54 is W1, and the region where the electrode layer 30A is exposed from the insulating layer 40. The width of is W2, the width of the electrode layer 30A is W3, and the width of the side surface 20d of the element body 20B is W4.

Therefore, in the laminated capacitor 10B as well, when the voltage is applied between the electrode layer 30A and the electrode layers 30B and 30D and between the electrode layer 30C and the electrode layers 30B and 30D, as in the case of the laminated capacitors 10 and 10A described above. In the above, the situation where a short circuit occurs between these electrode layers is suppressed, and the ESL is reduced.

Further, in the multilayer capacitor 10B, the equation of W1 / W4 ≧ 0.25 (hereinafter, also referred to as the fourth equation) holds.

The fourth equation means that W1 is 0.25 times or more that of W4, and is an equation found by the following experiments by the inventors.

In the experiment, as shown in FIG. 11, three samples according to Comparative Examples 1 to 3 and four samples according to Examples 1 to 4 were prepared, and S-parameters were converted into impedance using a network analyzer. The ESL (pH) of the sample was measured. In each sample, the width (W4) of the element body 20B seen from the stacking direction of the internal electrodes 52 and 54 is unified to 1000 μm.

Specifically, in the sample according to Comparative Example 1, the width of the extraction electrode 52b is 80 μm, and W1 is 0.08 times that of W4. Further, in each of the samples according to Comparative Examples 2 and 3, the width of the extraction electrode 52b is 200 μm, and W1 is 0.20 times that of W4. That is, W1 is less than 0.25 times that of Y in all of the samples according to Comparative Examples 1 to 3, and the relationship of the fourth equation does not hold.

When the ESL of the samples according to Comparative Examples 1 to 3 was measured, it was 34 pH in the sample of Comparative Example 1, 20 pH in the sample of Comparative Example 2, and 22 pH in the sample of Comparative Example 3, all showing high values.

Regarding Examples 1 to 4, in the sample according to Example 1, the width of the extraction electrode 52b is 250 μm, and W1 is 0.25 times that of W4. Further, in the sample according to Example 2, the width of the extraction electrode 52b is 350 μm, and W1 is 0.35 times that of W4. In the sample according to Example 3, the width of the extraction electrode 52b is 450 μm, and W1 is 0.45 times that of W4. In the sample according to Example 4, the width of the extraction electrode 52b is 500 μm, and W1 is 0.50 times that of W4. That is, in all of the samples according to Examples 1 to 4, W1 is 0.25 times or more of Y, and the relationship of the fourth equation holds.

When the ESL was measured for each of the samples according to Examples 1 to 4, it was 17 pH for the sample of Example 1, 13 pH for the sample of Example 2, 12 pH for the sample of Example 3, and 12 pH for the sample of Example 4. Also showed a lower value than Comparative Examples 1 to 3. In this experiment, if ESL is 17 pH or less, it is a sufficiently low value for practical use, and if it is 12 pH or less, it is a more practical value.

From the above experimental results, the inventors can obtain a practically sufficiently low ESL value when W1 is 0.25 times or more that of W4, that is, when the above-mentioned fourth equation holds. I got the knowledge of.

The present invention is not limited to the above embodiment, and various modifications can be made. For example, the shapes of internal electrodes such as capacitive electrodes and lead-out electrodes can be changed as appropriate. Further, along with such a change, the shape and number of the electrode layers can be appropriately changed.

10, 10A, 10B ... Multilayer capacitor, 20, 20A, 20B ... Elementary body, 20a, 20b ... End face, 20c ... Bottom surface, 20d, 20e ... Side surface, 22, 24, 26, 28, 52, 54 ... Internal electrode, 22b , 24b, 26b, 52b, 54b ... Lead-out electrode, 23, 25, 27, 29, 53, 55 ... End face, 30A to 30D ... Electrode layer, 40, 40A, 40B ... Insulation layer, 50 ... Plating layer.

Claims (5)

With the body
A plurality of internal electrodes having different polarities, which are located inside the element body and are laminated in parallel with each other, and have an internal electrode having a lead-out electrode whose end surface is exposed from the first surface of the element body. Includes an internal electrode of one polarity that is exposed from the element body and has an internal electrode of the other polarity that is separated from the extraction electrode of the internal electrode of one polarity when viewed from the stacking direction of the plurality of internal electrodes. , With multiple internal electrodes,
A first electrode layer provided on the first surface of the element body and exposed on the first surface of the element body and in contact with an end surface of a lead-out electrode of an internal electrode having one of the polarities.
A second electrode layer provided on the surface of the element body to which the extraction electrode of the other polarity internal electrode is exposed and in contact with the end surface of the extraction electrode of the other polarity internal electrode exposed on the surface.
The first surface of the element body covers between the first electrode layer and the second electrode layer, and a part of the first electrode layer on the second electrode layer side and the second electrode layer. It is provided with a plurality of insulating layers provided so as to cover a part of the side opposite to the electrode layer side of 2.
When viewed from the stacking direction of the plurality of internal electrodes, the width of the pull-out electrode of the one-polarity internal electrode is defined as W1, and the width of the region where the first electrode layer is exposed from the insulating layer is defined as W1. When W2 is used, the width of the first electrode layer is W3, and the width of the element body is W4, the formula W2 <W3 ≦ W1 holds, and the formula W3 / W4 ≧ 0.25 holds. , Multilayer capacitor. The extraction electrode of the internal electrode having the other polarity is exposed from the first surface of the element body, and the second electrode layer is provided on the first surface of the element body.
When viewed from the stacking direction of the plurality of internal electrodes, neither the end surface of the extraction electrode of the internal electrode of one polarity nor the end surface of the extraction electrode of the internal electrode of the other polarity is exposed on the first surface. The multilayer capacitor according to claim 1, wherein the equation W1 / Y ≥ 1.00 holds when the length of the region is Y. The extraction electrode of the internal electrode having the other polarity is exposed from a second surface different from the first surface of the element body, and the second electrode layer is provided on the second surface of the element body. Has been
The multilayer capacitor according to claim 1, wherein the equation W1 / W4 ≥ 0.25 holds. The multilayer capacitor according to any one of claims 1 to 3, wherein a plating layer is formed in a region where the first electrode layer and the second electrode layer are exposed from the insulating layer. When viewed from the stacking direction of the plurality of internal electrodes, both ends of the end faces of the extraction electrodes of the one-polarity internal electrode are exposed from the first electrode layer, and the exposed internal electrode of one polarity is exposed. The multilayer capacitor according to any one of claims 1 to 4, wherein both ends of an end surface of the lead-out electrode are covered with a plurality of the insulating layers.

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