JP7247559B2 - Multilayer ceramic capacitor and method for manufacturing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a multilayer ceramic capacitor including a ceramic body in which ceramic layers and internal electrodes are laminated, and a first external electrode and a second external electrode formed on the outer surface of the ceramic body. The present invention also relates to a method for manufacturing a multilayer ceramic capacitor suitable for manufacturing the multilayer ceramic capacitor of the present invention.

In a capacitor, it is generally preferable that both ESL (Equivalent Series Inductance) and ESR (Equivalent Series Resistance), which are factors that degrade characteristics, are small.

As a method of reducing the ESL and ESR in a two-terminal capacitor, as disclosed in Patent Document 1 (Japanese Unexamined Patent Publication No. 9-260201), for example, internal electrodes are arranged at the end face and two side faces of a ceramic body. There is known a method of pulling out in a direction and connecting with an external electrode. FIG. 9 shows a laminated ceramic capacitor 1000 disclosed in Patent Document 1. As shown in FIG.

In the laminated ceramic capacitor 1000, internal electrodes 102 formed between ceramic layers (dielectric layers) 101 are drawn out in three directions, that is, an end surface 103a and two side surfaces 103b and 103c of a ceramic body 103, and are connected to external electrodes. 104. The internal electrode 102 has a portion 102a that mainly forms a capacitance and a wide lead portion 102b for leading in three directions.

In the multilayer ceramic capacitor 1000, the internal electrodes 102 are drawn out not only from the end surfaces 103a but also from the side surfaces 103b and 103c and are connected to the external electrodes 104. Therefore, the portions 102a of the internal electrodes 102 that mainly form capacitance The substantial distance to the external electrode 104 is shortened, and the ESL is reduced. In the capacitor 1000, the internal electrodes 102 are drawn out not only from the end surface 103a but also from the side surfaces 103b and 103c and are connected to the external electrodes 104. Therefore, the contact area between the internal electrodes 102 and the external electrodes 104 is large. and the ESR is small.

JP-A-9-260201

A general method for manufacturing a multilayer ceramic capacitor that is widely practiced includes, for example, the following steps. First, a ceramic sheet is produced. Next, a composite sheet is produced by printing a conductive paste on the ceramic sheet. Next, the composite sheets are laminated to produce a mother block. Next, the mother block is cut to produce a plurality of ceramic bodies. Next, the ceramic body is fired. Finally, external electrodes are formed on the ceramic body.

The above composite sheet is obtained by printing a conductive paste on a ceramic sheet to form internal electrodes. In order to collectively produce a large number of laminated ceramic capacitors, internal electrodes for a plurality of laminated ceramic capacitors are formed on one composite sheet.

When manufacturing the laminated ceramic capacitor 1000 with the internal electrodes 102 drawn out in three directions as described above, for example, a conductive paste is applied to the composite sheet in a pattern as shown in FIG. 10A to form the internal electrodes. Printing in shape is conceivable. It should be noted that FIG. 10A was created by the applicant for explanation, and is not described in Patent Document 1. FIG.

A plurality of internal electrodes 102 are formed on the composite sheet 110 shown in FIG. 10(A). In FIG. 10A, each internal electrode 102 has a length direction indicated by an arrow L and a width direction indicated by an arrow W. As shown in FIG. In the composite sheet 110, two internal electrodes 102 are paired and joined in the longitudinal direction with the lead portions 102b facing each other. Further, a plurality of pairs of the two joined internal electrodes 102 are joined continuously in the width direction.

In the composite sheet 110, a lengthwise cutline 112L and a widthwise cutline 112W are assumed as cutlines for producing a plurality of ceramic bodies by cutting the mother block.

The composite sheet 110 shown in FIG. 10(A) has a problem that unnecessary bleeding of the conductive paste tends to occur when the conductive paste is printed to form the internal electrodes. That is, the conductive paste is printed, for example, from left to right in the longitudinal direction by screen printing, gravure printing, or the like. As the printing progresses in the region P2 where the portion 102a forming the capacitor is formed, the width of the printed pattern sharply narrows, so unnecessary bleeding of the conductive paste tends to occur in the portion P3 surrounded by the broken line. I had a problem.

In the multilayer ceramic capacitor 1000, if unnecessary bleeding of the conductive paste occurs in the ceramic layer 101, there is a risk that the characteristics may deteriorate or the electrodes may be short-circuited to cause a failure. It was difficult to adopt the pattern shape of the conductive paste of the sheet 110 .

Therefore, as another pattern shape of the conductive paste, the one shown in FIG. 10B can be considered. It should be noted that FIG. 10B was also created by the applicant for explanation, and is not described in Patent Document 1. FIG.

A plurality of internal electrodes 102 are formed on the composite sheet 120 shown in FIG. 10(B). In FIG. 10B, each internal electrode 102 has a length direction indicated by an arrow L and a width direction indicated by an arrow W. As shown in FIG. In the composite sheet 120, two internal electrodes 102 are joined back-to-back in the length direction as a pair. A plurality of pairs of the two joined internal electrodes 102 are arranged in a zigzag pattern. With such a conductive paste pattern shape, the width of the printed pattern does not suddenly narrow, so when the conductive paste is printed to form the internal electrodes, unnecessary bleeding of the conductive paste occurs. hard to do.

In the composite sheet 120, a lengthwise cutline 122L and a widthwise cutline 122W are assumed as cutlines for producing a plurality of ceramic bodies by cutting the mother block.

As described above, in the multilayer ceramic capacitor 1000, the internal electrodes 102 are provided with wide lead portions 102b in order to lead the internal electrodes 102 in the three directions of the end surface 103a and the side surfaces 103b and 103c of the ceramic body 103. . In the composite sheet 120, the lead portions 102b of the internal electrodes 102 are formed wider in the width direction beyond the cut line 122L in the length direction, and the projecting portions 102c are formed on both sides beyond the cut line 122L. there is

When the mother block is cut to produce a plurality of ceramic bodies, the protrusion 102c is cut in the width direction (in FIG. In order to ensure that the lead-out portion 102b of the internal electrode 102 is led out from the end surface 103a and the two side surfaces 103b and 103c of the ceramic body 103 even if the lead-out portion 102b of the internal electrode 102 is displaced upward or downward). It is provided in If the projecting portion 102c were not provided and the actual cut in the length direction deviated in the width direction from the assumed cut line 122L in the length direction, the lead-out portion 102b would be one of the side surfaces 103b and 103c or There was a fear that it would not be pulled out from both. That is, there is a possibility that the internal electrodes 102 are not pulled out in three directions of the ceramic body 103, but are pulled out in only two or one direction.

In the multilayer ceramic capacitor 1000 designed so that the internal electrodes 102 are drawn out in three directions, if the internal electrodes 102 are drawn out in two directions or in one direction, the ESL and ESR will deviate from the designed values. , there is a risk of becoming a defective product that does not meet the standards.

According to the composite sheet 120, since the projecting portions 102c are formed on both sides of the wide lead-out portion 102b of the internal electrode 102, the actual cutting in the length direction is performed at a width from the assumed length-direction cutting line 112L. Even if there is a deviation in one direction, the internal electrodes 102 are reliably pulled out in three directions, so that the ESL and ESR do not deviate from the design values.

However, in the composite sheet 110 shown in FIG. 10(B), a new problem arises due to the protrusions 102c provided on both sides of the lead-out portions 102b of the internal electrodes 102. FIG. That is, in the composite sheet 110, a gap GX must be provided between the capacitance forming portion 102a of the internal electrode 102 and the projecting portion 102c of the other internal electrode 102 adjacent in the width direction to prevent a short circuit or the like. It has become necessary. By providing the gap GX, the widthwise gap GW between the capacitance-forming portion 102a of the internal electrode 102 and both side surfaces of the ceramic body 103 must be made larger than necessary by the amount of the gap GX. It's gone.

In the multilayer ceramic capacitor 1000, if the width dimension of the ceramic element body 103 is fixed, the width dimension of the internal electrodes 102 must be reduced by that much if the width direction gap GW is increased. That is, if the conductive paste pattern shape of the composite sheet 120 shown in FIG. There was a problem that the .

It should be noted that the smaller the outer dimensions of the multilayer ceramic capacitor, the greater the reduction rate of the capacitance due to the reduction in the width dimension of the internal electrodes 102 . For example, when comparing a large multilayer ceramic capacitor with an ultra-miniature product with a length of 0.250 mm, a width of 0.125 mm, and a height of 0.125 mm, even if the width dimension of the internal electrodes 102 is the same length, Even if the capacitance is reduced by 1, the rate of decrease in the capacitance of a microminiature product is extremely large compared to a monolithic ceramic capacitor with a large outer dimension.

The present invention has been made to solve the above-described conventional problems, and as a means therefor, a multilayer ceramic capacitor according to one embodiment of the present invention includes a plurality of laminated ceramic layers and a plurality of internal electrodes. , a first main surface and a second main surface facing each other in the stacking direction, a first side surface and a second side surface facing each other in the width direction perpendicular to the stacking direction, and a length direction perpendicular to both the stacking direction and the width direction a ceramic body having a first end face and a second end face facing each other; and a first external electrode that covers at least part of, and, on the outer surface of the ceramic body, at least part or all of the second end surface, part of the first side surface, and part of the second side surface. a second external electrode, wherein the internal electrode includes a first internal electrode that extends only to the first end surface and the first side surface, a second internal electrode that extends only to the second end surface and the first side surface, and a second internal electrode that extends only to the second end surface and the first side surface; It has a third internal electrode drawn out only to one end surface and a second side surface, and a fourth internal electrode drawn out only to a second end surface and a second side surface. Each of the third internal electrode and the fourth internal electrode has an L-shape in which a portion that mainly forms a capacitance and a lead portion that is wider than the portion that mainly forms a capacitance are connected to the outside. .

Further, a laminated ceramic capacitor that serves as a reference for the present invention includes a plurality of laminated ceramic layers and a plurality of internal electrodes, a first main surface and a second main surface facing each other in the lamination direction, and a main surface perpendicular to the lamination direction. a ceramic body having first and second side faces facing each other in the width direction and first and second end faces facing each other in the length direction perpendicular to both the stacking direction and the width direction; A first external electrode covering at least part or all of the first end surface and part of the first side surface on the outer surface, and at least part or all of the second end surface on the outer surface of the ceramic body and a part of the first side surface, and a second external electrode covering the first internal electrode, wherein the internal electrode is extended only to the first end surface and the first side surface, and the second end surface and the first side surface. and a second internal electrode that is drawn out only to the first surface and the It is assumed that the second main surface is not covered.

In addition, a method for manufacturing a laminated ceramic capacitor according to an embodiment of the present invention includes steps of producing a ceramic sheet, printing a conductive paste on the ceramic sheet to produce a composite sheet, and laminating the composite sheet. a step of fabricating a mother block; cutting the mother block and including a plurality of laminated ceramic layers and a plurality of internal electrodes, respectively; a plurality of ceramic bodies having first and second side surfaces facing each other in the width direction perpendicular to each other, and first end faces and second end faces facing each other in the length direction perpendicular to both the stacking direction and the width direction; A method for manufacturing a multilayer ceramic capacitor comprising the steps of manufacturing, firing a ceramic element body, and forming external electrodes on the ceramic element body, wherein a mother block is cut to form a plurality of ceramic element bodies. In the process of producing the L-shape, each ceramic element body, as an internal electrode, has a portion that mainly forms a capacitance and an L-shaped lead portion that is wider than the portion that mainly forms a capacitance and is connected to the outside. a first internal electrode extending only to the first end surface and the first side surface; a second internal electrode extending only to the second end surface and the first side surface; and a first internal electrode extending only to the first end surface and the second side surface. and a step of forming a third internal electrode that is extended to the second end surface and a fourth internal electrode that is extended only to the second side surface.

The multilayer ceramic capacitor of the present invention has small ESL and ESR. In addition, since the multilayer ceramic capacitor of the present invention does not need to reduce the width of the internal electrodes, it is possible to obtain a large capacitance.

According to the manufacturing method of the multilayer ceramic capacitor of the present invention, the multilayer ceramic capacitor of the present invention can be manufactured easily.

1 is a perspective view of a laminated ceramic capacitor 100 according to a first embodiment; FIG. 1 is an exploded perspective view of a multilayer ceramic capacitor 100; FIG. FIG. 2 is a plan view of a main part of the composite sheet 10 used in one example of the manufacturing method of the laminated ceramic capacitor 100; FIG. 4A is a plan view showing the ceramic layer 51 of the laminated ceramic capacitor of the example. FIG. 4B is a plan view showing the ceramic layer 61 of the laminated ceramic capacitor of Comparative Example. FIG. 4 is an exploded perspective view of a multilayer ceramic capacitor 200 according to a second embodiment; FIG. 11 is a perspective view of a laminated ceramic capacitor 300 according to a third embodiment; 1 is an exploded perspective view of a multilayer ceramic capacitor 300; FIG. FIG. 11 is a perspective view of a multilayer ceramic capacitor 400 according to a fourth embodiment; 1 is a cross-sectional view of a multilayer ceramic capacitor 1000 described in Patent Document 1; FIG. FIG. 10(A) is a plan view of a main part of composite sheet 110 that can be used to manufacture multilayer ceramic capacitor 1000. FIG. FIG. 10B is a plan view of a main part of a composite sheet 120 that can be used for manufacturing the laminated ceramic capacitor 1000. FIG.

Embodiments for carrying out the present invention will be described below with reference to the drawings.

Each embodiment is an example of an embodiment of the present invention, and the present invention is not limited to the content of the embodiment. Moreover, it is also possible to combine the contents described in different embodiments, and the contents of the implementation in that case are also included in the present invention. In addition, the drawings are intended to aid understanding of the specification, and may be schematically drawn, and the drawn components or the dimensional ratios between the components may not be the same as those described in the specification. The proportions of those dimensions may not match. In addition, there are cases where constituent elements described in the specification are omitted in the drawings, or where the number of constituent elements is omitted.

[First embodiment]
(Structure of Multilayer Ceramic Capacitor 100)
1 and 2 show a multilayer ceramic capacitor 100 according to the first embodiment. 1 is a perspective view of the multilayer ceramic capacitor 100. FIG. FIG. 2 is an exploded perspective view of the multilayer ceramic capacitor 100. FIG.

1 and 2, the length direction of the multilayer ceramic capacitor 100 is indicated by an arrow L, the width direction by an arrow W, and the height direction by an arrow T. As shown in FIG. The ceramic body 1, the ceramic layer 4, the internal electrodes (the first internal electrode 5, the second internal electrode 6, the third internal electrode 7, the fourth internal electrode 8), and the composite sheet 10, which will be described later, are also oriented in the same direction. , the length direction, the width direction, and the height direction, respectively.

A multilayer ceramic capacitor 100 includes a ceramic body 1 . The ceramic element body 1 has a rectangular parallelepiped shape, and has a first main surface 1A and a second main surface 1B facing each other in the height direction, a first side surface 1C and a second side surface 1D facing each other in the width direction, and a side surface 1C and a second side surface 1D facing each other in the length direction. It has a first end face 1E and a second end face 1F.

The ceramic body 1 is formed by laminating a plurality of ceramic layers 4 and a plurality of internal electrodes in the height direction and firing and integrating them. The internal electrodes consist of four types of first internal electrode 5 , second internal electrode 6 , third internal electrode 7 and fourth internal electrode 8 .

The first internal electrode 5 has an L-shape in which a portion 5a that mainly forms a capacitance and a lead portion 5b that is wider than the portion 5a and extends to the outside are connected. The lead-out portion 5b is led out only to the first end surface 1E and the first side surface 1C of the ceramic body 1. As shown in FIG.

The second internal electrode 6 has an L-shape in which a portion 6a that mainly forms a capacitor and a lead portion 6b that is wider than the portion 6b are connected to the outside. The lead-out portion 6b is led out only to the second end face 1F and the first side face 1C of the ceramic body 1. As shown in FIG.

The third internal electrode 7 has an L-shape in which a portion 7a that mainly forms a capacitance and a lead portion 7b that is wider than the portion 7a and extends to the outside are connected. The lead-out portion 7b is led out only to the first end surface 1E and the second side surface 1D of the ceramic body 1. As shown in FIG.

The fourth internal electrode 8 has an L-shape in which a portion 8a that mainly forms a capacitance and a lead portion 8b that is wider than the portion 8a and extends to the outside are connected. The lead-out portion 8b is led out only to the second end face 1F and the second side face 1D of the ceramic body 1. As shown in FIG.

Although the order in which the first internal electrode 5, the second internal electrode 6, the third internal electrode 7, and the fourth internal electrode 8 are stacked is arbitrary, in this embodiment, the first internal electrode 5, the second internal electrode The internal electrode 6, the third internal electrode 7, and the fourth internal electrode 8 are laminated in this order at least once, or a desired number of times.

Although the material of the ceramic layer 4 is arbitrary, dielectric ceramics containing BaTiO ₃ as a main component is used in this embodiment. However, instead of BaTiO ₃ , dielectric ceramics containing other materials as main components such as CaTiO ₃ , SrTiO ₃ and CaZrO ₃ may be used.

Although the material of the internal electrodes (first internal electrode 5, second internal electrode 6, third internal electrode 7, fourth internal electrode 8) is arbitrary, Ni was used as the main component in this embodiment. However, other metals such as Cu and Pd may be used instead of Ni. Also, Ni, Cu, Pd, etc. may be alloys with other metals.

A first external electrode 2 and a second external electrode 3 are formed on the outer surface of the ceramic body 1 .

The first external electrode 2 is formed on the entire first end face 1E, part of the first side face 1C, and part of the second side face 1D of the ceramic body 1. As shown in FIG. The first external electrode 2 is not formed on the first main surface 1A and the second main surface 1B of the ceramic body 1. As shown in FIG. Note that the first external electrode 2 may be formed on a part of the first end surface 1E instead of the entire surface.

The second external electrode 3 is formed on the entire second end surface 1F, part of the first side surface 1C, and part of the second side surface 1D of the ceramic element body 1 . The second external electrode 3 is not formed on the first main surface 1A and the second main surface 1B of the ceramic body 1. As shown in FIG. The second external electrode 3 may be formed on a part of the second end surface 1F instead of the entire surface.

The first external electrode 2 is connected to the first internal electrode 5 and the third internal electrode 7 . The second external electrode 3 is connected to the second internal electrode 6 and the fourth internal electrode 8 .

The structure, material, formation method, etc. of the first external electrode 2 and the second external electrode 3 are arbitrary, but in the present embodiment, the first external electrode 2 and the second external electrode 3 are A Cu-plated layer, a second layer of Ni-plated layer, and a third layer of Sn-plated layer were formed to have a three-layer structure.

(Example of manufacturing method of multilayer ceramic capacitor 100)
Multilayer ceramic capacitor 100 can be manufactured, for example, by the following manufacturing method.

First, a dielectric ceramic powder, a binder resin, a solvent, etc. are prepared, and these are wet-mixed to prepare a ceramic slurry.

Next, the ceramic slurry is coated on the carrier film in a sheet form using a die coater, gravure coater, micro gravure coater, or the like, and dried to produce a ceramic sheet.

Next, a conductive paste prepared in advance is printed on the ceramic sheet in a desired pattern shape, and internal electrodes are formed to produce a composite sheet. The conductive paste can be printed by methods such as screen printing and gravure printing.

FIG. 3 shows a composite sheet 10 as an example of the composite sheet. A plurality of first internal electrodes 5, second internal electrodes 6, third internal electrodes 7, and fourth internal electrodes 8 are formed on the composite sheet 10 in order to collectively produce a large number of laminated ceramic capacitors 100. ing.

In the composite sheet 10, four of the first internal electrode 5, the second internal electrode 6, the third internal electrode 7, and the fourth internal electrode 8 form one set, and the lead portion 5b, the lead portion 6b, the lead portion 7b, the lead portion It is joined at 8b. A plurality of sets of joined first internal electrodes 5, second internal electrodes 6, third internal electrodes 7, and fourth internal electrodes 8 are arranged in a matrix in the length direction and the width direction. As can be seen from FIG. 3, the joined first internal electrode 5, second internal electrode 6, third internal electrode 7, and fourth internal electrode 8 are H-shaped when viewed in the length direction.

In the composite sheet 10, the cut lines 10L in the length direction and the cut lines 10W in the width direction are assumed as the cut lines for producing the plurality of ceramic bodies 1 by cutting the mother block.

The conductive paste is printed, for example, from left to right in the length direction, but composite sheet 10 has wider lead portions 5b to 8b than composite sheet 110 shown in FIG. Even if the printing progresses from the region P1 where the capacitance is formed to the region P2 where the portions 6a and 8a forming the capacitors are formed, the width of the printed pattern gradually narrows, so that unnecessary bleeding of the conductive paste is less likely to occur. .

Next, a plurality of composite sheets 10 are laminated and pressed to produce a mother block. By shifting the stacking positions of the composite sheets 10, in one region inside the mother block, the first internal electrode 5, the second internal electrode 6, the third internal electrode 7, and the fourth internal electrode 8 are arranged from the bottom at least one The layers are repeatedly laminated at least a desired number of times. Further, in another region inside the mother block, the third internal electrode 7, the fourth internal electrode 8, the first internal electrode 5, and the second internal electrode 6 are arranged from the bottom at least once, a desired number of times, Laminated repeatedly. In addition, in yet another region inside the mother block, the fourth internal electrode 8, the third internal electrode 7, the second internal electrode 6, and the first internal electrode 5 are arranged from the bottom at least once, a desired number of times. , repeatedly stacked. In addition, in another region inside the mother block, the second internal electrode 6, the first internal electrode 5, the fourth internal electrode 8, and the third internal electrode 7 are arranged from the bottom at least once or more, a desired number of times. , repeatedly stacked.

Next, the mother block is cut along cut lines 10L in the length direction and cut lines 10W in the width direction to fabricate a plurality of ceramic bodies 1. As shown in FIG. At this time, even if the actual cut in the length direction deviates in the width direction (upward or downward in FIG. 3) from the assumed lengthwise cut line 10L due to stacking deviation of the composite sheet 10, etc. , the lead portions 5b of the first internal electrodes 5 are always led out in two directions, i.e., the first end surface 1E and the first side surface 1C of the ceramic body 1, respectively. Similarly, the lead portions 6b of the second internal electrodes 6 are always led out in two directions, i.e., the second end face 1F and the first side face 1C of the ceramic body 1. As shown in FIG. The lead-out portion 7b of the third internal electrode 7 is always led out in two directions, i.e., the first end surface 1E and the second side surface 1D of the ceramic body 1. As shown in FIG. The lead-out portion 8b of the fourth internal electrode 8 is always led out in two directions of the second end surface 1F and the second side surface 1D of the ceramic body 1. As shown in FIG. Therefore, in the multilayer ceramic capacitor 100 manufactured by this manufacturing method, even if the cut position of the mother block is misaligned, the lead-out portions 5b to 8b are aligned in one direction (the first end face 1E or the second end face) of the ceramic body 1. 1F) will not be pulled out only. Therefore, in the multilayer ceramic capacitor 100 manufactured by this manufacturing method, the ESL and ESR do not deviate from the design values due to the lead portions 5b to 8b being led out in only one direction.

Next, the ceramic body 1 is fired with a predetermined profile.

Next, the first external electrode 2 and the second external electrode 3 are formed on the outer surface of the ceramic body 1 . More specifically, the first external electrode 2 is formed on the portion where the lead portions 5b and 7b of the ceramic body 1 are exposed, and the second external electrode 3 is formed on the portion where the lead portions 6b and 8b are exposed. Form. As described above, each of the first external electrode 2 and the second external electrode 3 has a three-layer structure in which the first layer is a Cu-plated layer, the second layer is a Ni-plated layer, and the third layer is a Sn-plated layer.

First, the lead portions 5b to 8b exposed from the ceramic body 1 are used as a seed layer (conductive substrate) to form a first Cu plating layer by electroplating. Next, a second Ni-plated layer is formed on the first Cu-plated layer by electroplating. Next, a third Sn-plated layer is formed on the second Ni-plated layer by electroplating.

As described above, the multilayer ceramic capacitor 100 according to the first embodiment is completed.

(Comparison between Examples and Comparative Examples)
A laminated ceramic capacitor according to an example and a laminated ceramic capacitor according to a comparative example were produced and compared.

A multilayer ceramic capacitor according to an example has the structure of the multilayer ceramic capacitor 100 according to the first embodiment. One arbitrarily selected ceramic layer 51 of the multilayer ceramic capacitor according to the example is shown in FIG. 4(A).

The ceramic layer 51 has a length of 0.230 mm and a width of 0.105 mm.

An internal electrode 52 is formed on the upper main surface of the ceramic layer 51 . The internal electrode 52 has a portion 52a that mainly forms a capacitance, and a lead portion 52b that leads to an end surface and one side surface.

The internal electrodes 52 have a lengthwise gap GL of 0.030 mm formed between them and the end faces of the opposing ceramic bodies, and a widthwise gap GW formed between the opposing side surfaces of the ceramic bodies. Each is 0.015 mm. As a result, the internal electrode 52 has an effective length EL of 0.170 mm and an effective width EW of 0.075 mm, which contribute to the formation of capacitance between other adjacently laminated internal electrodes. ing. The effective area of the internal electrode 52 that contributes to the formation of capacitance between other adjacently laminated internal electrodes is 0.170 mm×0.075 mm=0.01275 mm ² . .

On the other hand, the laminated ceramic capacitor according to the comparative example had the structure of the laminated ceramic capacitor 1000 described in Patent Document 1 shown in FIG. Moreover, in the production, the internal electrode pattern of the composite sheet 120 shown in FIG. 10B was used.

One arbitrarily selected ceramic layer 61 of the laminated ceramic capacitor according to the comparative example is shown in FIG. 4(B).

The ceramic layer 61 had a length of 0.230 mm and a width of 0.105 mm, like the ceramic layer 51 of the example.

An internal electrode 62 is formed on the upper main surface of the ceramic layer 61 . The internal electrode 62 has a portion 62a that mainly forms a capacitance, and lead portions 62b for leading to the end face and both side faces. Further, two projecting portions 63 are formed on the upper main surface of the ceramic layer 61 so as to face the tip portions of the internal electrodes 62 .

The internal electrodes 62 have a longitudinal gap GL of 0.030 mm, as in the embodiment. In the internal electrode 62, it is necessary to provide a gap GX between the tip portion of the internal electrode 62 and the protruding portion 63 in order to prevent a short circuit or the like. Therefore, the internal electrode 62 needs to increase the width direction gap GW by the gap GX as compared with the embodiment. The internal electrodes 62 have a gap GX of 0.015 mm and a widthwise gap GW of 0.030 mm. As a result, in the comparative example, the internal electrode 62 had an effective length EL of 0.170 mm and an effective width EW of 0.045 mm. As a result, in the comparative example, the effective area of the internal electrode 62 was 0.170 mm×0.045 mm=0.00765 mm ² .

The effective area of the internal electrode 52 according to the example is 0.01275 mm ² , while the effective area of the internal electrode 62 according to the comparative example is 0.00765 mm ² . It has an effective area of 01275 mm ² /0.00765 mm ² ≈1.67 times. Therefore, the laminated ceramic capacitor of the example can obtain a capacitance approximately 1.67 times as large as that of the laminated ceramic capacitor of the comparative example having the same external dimensions.

Note that the actual distance from the portion 52a that mainly forms the capacitance of the laminated ceramic capacitor according to the example to the external electrode and the distance from the portion 62a that mainly forms the capacitance to the external electrode of the laminated ceramic capacitor according to the comparative example Since the practical distances are the same, the ESL is the same between the example and the comparative example.

On the other hand, the lead-out portions 62b of the laminated ceramic capacitor according to the comparative example are led out in three directions of the ceramic body, whereas the lead-out portions 52b of the laminated ceramic capacitor according to the example are led out only in two directions of the ceramic body. Therefore, the ESR of the example is larger than that of the comparative example. However, even in the embodiment, the ESR is sufficiently small because the lead-out portion 52b is led out in two directions.

[Second embodiment]
FIG. 5 shows a multilayer ceramic capacitor 200 according to the second embodiment. 5 is an exploded perspective view of the multilayer ceramic capacitor 200. FIG. The appearance of the laminated ceramic capacitor 200 is the same as that of the laminated ceramic capacitor 100 according to the first embodiment shown in FIG.

A laminated ceramic capacitor 200 according to the second embodiment is obtained by partially modifying the structure of the laminated ceramic capacitor 100 according to the first embodiment. Specifically, in the multilayer ceramic capacitor 100, inside the ceramic body 1, the internal electrodes are arranged in order of the first internal electrode 5, the second internal electrode 6, the third internal electrode 7, and the fourth internal electrode 8 from the bottom. was laminated to In the multilayer ceramic capacitor 200, this is modified so that the internal electrodes inside the ceramic element body 1 are arranged in order from the bottom: the first internal electrode 5, the fourth internal electrode 8, the third internal electrode 7, and the second internal electrode 6. Layered in order.

The laminated ceramic capacitor 200 also has electrical characteristics (capacitance, ESL, ESR, etc.) equivalent to those of the laminated ceramic capacitor 100 .

[Third Embodiment]
6 and 7 show a multilayer ceramic capacitor 300 according to the third embodiment. 6 is a perspective view of the laminated ceramic capacitor 300. FIG. FIG. 7 is an exploded perspective view of the multilayer ceramic capacitor 300. FIG.

A laminated ceramic capacitor 300 according to the third embodiment is obtained by partially modifying the structure of the laminated ceramic capacitor 100 according to the first embodiment.

Specifically, first, in the multilayer ceramic capacitor 100, the first external electrodes 2 are formed on the first end surface 1E, the first side surface 1C, and the second side surface 1D of the ceramic body 1, and the second external electrodes 3 are It was formed on the second end surface 1F, the first side surface 1C, and the second side surface 1D of the ceramic body 1 . The multilayer ceramic capacitor 300 is modified by forming the first external electrodes 32 on the first end face 1E and the first side surface 1C of the ceramic body 1, and forming the second external electrodes 33 on the first end face 1E and the first side face 1C of the ceramic body 1. It is formed on two end faces 1F and a first side face 1C.

In the multilayer ceramic capacitor 100, the first internal electrode 5, the second internal electrode 6, the third internal electrode 7, and the fourth internal electrode 8 are arranged in order from the bottom inside the ceramic body 1 at least once. , was repeatedly laminated a desired number of times. The laminated ceramic capacitor 300 is modified by laminating the first internal electrode 5 and the second internal electrode 6 in order from the bottom inside the ceramic element body 1 at least once or more a desired number of times. bottom. That is, in the multilayer ceramic capacitor 100, four types of internal electrodes consisting of the first internal electrode 5, the second internal electrode 6, the third internal electrode 7, and the fourth internal electrode 8 are used, but in the multilayer ceramic capacitor 300 , a first internal electrode 5 and a second internal electrode 6 were used.

The laminated ceramic capacitor 300 can be used by mounting the first side surface 1C of the ceramic body 1 as a mounting surface, for example.

[Fourth Embodiment]
FIG. 8 shows a multilayer ceramic capacitor 400 according to the fourth embodiment. 8 is a perspective view of the laminated ceramic capacitor 400. FIG. The internal structure of the ceramic body 1 of the multilayer ceramic capacitor 400 is the same as that of the multilayer ceramic capacitor 100 according to the first embodiment shown in FIG.

A multilayer ceramic capacitor 400 according to the fourth embodiment is obtained by partially modifying the configuration of the multilayer ceramic capacitor 100 according to the first embodiment. Specifically, in the multilayer ceramic capacitor 100, the first external electrodes 2 are formed on the first end surface 1E, the first side surface 1C, and the second side surface 1D of the ceramic element body 1, and the second external electrodes 3 are formed on the ceramic element body. It was formed on the second end face 1F of the body 1, the first side face 1C and the second side face 1D. In the multilayer ceramic capacitor 400, the first external electrodes 42 are arranged on the first end surface 1E, the first main surface 1A, the second main surface 1B, the first side surface 1C, and the second side surface 1D of the ceramic element body 1. , and the second external electrodes 43 were formed on the second end surface 1F, the first main surface 1A, the second main surface 1B, the first side surface 1C, and the second side surface 1D of the ceramic body 1 . That is, in the multilayer ceramic capacitor 400, the first external electrodes 42 and the second external electrodes 43 are formed on five surfaces of the ceramic body 1, respectively.

In addition, in the multilayer ceramic capacitor 100, the first external electrode 42 and the second external electrode 43 are three-layered layers each made up of a first layer of Cu plating layer, a second layer of Ni plating layer, and a third layer of Sn plating layer. was composed of a plating layer of In the laminated ceramic capacitor 400, the Cu plating layer of the first layer is replaced with a Cu thick film layer. The Cu thick film layer of the first layer was formed by dipping five surfaces of the ceramic body 1 in a Cu conductive paste and baking the applied Cu conductive paste. Then, on the Cu thick film layer of the first layer, a Ni plating layer of the second layer was formed by electroplating. Subsequently, a third Sn-plated layer was formed on the second Ni-plated layer by electroplating.

In this way, the most suitable one can be appropriately selected and adopted for the formation position, structure, material, formation method, etc. of the first external electrodes 2 and 42 and the second external electrodes 3 and 43 .

The multilayer ceramic capacitors 100, 200, 300, and 400 according to the first to fourth embodiments have been described above. However, the present invention is not limited to the contents described above, and various modifications can be made along the spirit of the invention. For example, the material, the number of layers, the shape, the size, etc. of the ceramic layer 4 of the ceramic body 1 are arbitrary, and are not limited to the contents described above. Moreover, the structure, material, formation method, and the like of the first external electrode 2 and the second external electrode 3 are arbitrary, and are not limited to the contents described above. Moreover, the material, pattern shape, etc. of the first internal electrode 5, the second internal electrode 6, the third internal electrode 7, and the fourth internal electrode 8 are arbitrary, and are not limited to the contents described above.

A laminated ceramic capacitor according to an embodiment of the present invention is as described in the section "Means for Solving the Problems".

In this laminated ceramic capacitor, at least one of the first internal electrode and the third internal electrode may be arranged to face the second internal electrode and the fourth internal electrode with the ceramic layer interposed therebetween. In this case, since the laminated internal electrodes are alternately led out to the first external electrode and the second external electrode, it is possible to obtain a large capacitance by utilizing all the internal electrodes.

Further, the ceramic body may include a region in which the internal electrodes are laminated in order of the first internal electrode, the second internal electrode, the third internal electrode, and the fourth internal electrode with the ceramic layers interposed therebetween. Alternatively, the ceramic body may include a region in which the internal electrodes are laminated in order of a first internal electrode, a fourth internal electrode, a third internal electrode, and a second internal electrode with ceramic layers interposed therebetween. In these cases as well, the laminated internal electrodes are alternately led out to the first external electrode and the second external electrode, so that all the internal electrodes can be used to obtain a large capacitance.

Also, the first external electrode and the second external electrode may not cover the first main surface and the second main surface, respectively. In this manner, the material cost can be reduced by forming the first external electrode and the second external electrode only on the necessary portions of the outer surface of the ceramic body and not forming them on unnecessary portions. .

Further, a laminated ceramic capacitor according to another embodiment of the present invention is as described in the section "Means for Solving the Problems".

In the laminated ceramic capacitor according to one embodiment of the present invention and the ceramic capacitor according to another embodiment, each of the first external electrode and the second external electrode is composed of at least one plated metal layer (one layer Alternatively, it may be composed only of two or more plated metal layers). If the first external electrode and the second external electrode are formed of a thick film metal layer as the first layer and plated metal layers as the second and subsequent layers, both a thick film process and a plating process are required, which complicates the manufacturing process. However, if the first external electrode and the second external electrode are composed of at least one plated metal layer as described above, the thick film process becomes unnecessary and productivity is improved.

Also, the thickness of each ceramic layer may be 1 μm or less. In other words, an ultra-compact product with a thickness of 1 μm or less per ceramic layer has severe limitations on the height dimension, and it is not possible to easily increase the number of ceramic layers. This is because the laminated ceramic capacitor of the present invention, which has a large area and can obtain a large capacitance, is particularly useful. Further, when the external electrodes are formed on the surface of the element body by plating, the distance between the internal electrodes adjacent to each other in the stacking direction becomes short, so the external electrodes can be formed with high accuracy.

Further, the thickness (height) of the ceramic body in the stacking direction may be 0.2 mm or less. In other words, it is not easy to increase the number of ceramic layers in a microminiature product with a thickness of 0.2 mm or less in the lamination direction of the ceramic body. This is because the laminated ceramic capacitor of the present invention, which can obtain capacitance, is particularly useful.

The size of the gap (width direction gap) between the internal electrode and the first and second side surfaces may each be less than 30 μm. In this case, the width of the internal electrodes can be increased and the effective area of the internal electrodes can be increased, so that a large capacitance can be obtained.

A manufacturing method of a laminated ceramic capacitor according to one embodiment of the present invention is as described in the section "Means for Solving the Problems".

In this method for manufacturing a laminated ceramic capacitor, the step of printing the conductive paste on the ceramic sheet to form the composite sheet may include a step of printing the conductive paste on the ceramic sheet in an H-shape. . In this case, the multilayer ceramic capacitor of the present invention can be easily manufactured with high productivity.

REFERENCE SIGNS LIST 1 Ceramic body 1A First main surface 1B Second main surface 1C First side surface 1D Second side surface 1E First end surface 1F Second End faces 2, 32, 42 First external electrodes 3, 33, 43 Second external electrodes 4 Ceramic layers 5 First internal electrodes 6 Second internal electrodes 7・Third internal electrode 8 Fourth internal electrode 10 Composite sheet

Claims (11)

including a plurality of laminated ceramic layers and a plurality of internal electrodes, a first main surface and a second main surface facing each other in the lamination direction, and first side faces and a second side face facing each other in the width direction orthogonal to the lamination direction and a first end surface and a second end surface facing each other in a length direction orthogonal to both the lamination direction and the width direction;
a first external electrode covering at least part or all of the first end surface, part of the first side surface, and part of the second side surface on the outer surface of the ceramic body;
a second external electrode covering at least part or all of the second end surface, part of the first side surface, and part of the second side surface on the outer surface of the ceramic body; ,
The internal electrodes are
a first internal electrode drawn out only to the first end surface and the first side surface;
a second internal electrode drawn out only to the second end surface and the first side surface;
a third internal electrode drawn out only to the first end surface and the second side surface;
having a fourth internal electrode drawn out only to the second end surface and the second side surface;
Each of the first internal electrode, the second internal electrode, the third internal electrode, and the fourth internal electrode has a portion that mainly forms a capacitor and an external portion that is wider than the portion that mainly forms a capacitor. A multilayer ceramic capacitor having an L-shape connected to the lead-out portion to the L-shape . 2. The device according to claim 1, wherein at least one of the first internal electrode and the third internal electrode is arranged to face the second internal electrode and the fourth internal electrode with the ceramic layer interposed therebetween. Multilayer ceramic capacitor. The ceramic body includes a region in which the internal electrodes are laminated in order of the first internal electrode, the second internal electrode, the third internal electrode, and the fourth internal electrode with the ceramic layers interposed therebetween. 3. A multilayer ceramic capacitor according to Item 1 or 2. The ceramic body includes a region in which the internal electrodes are laminated in order of the first internal electrode, the fourth internal electrode, the third internal electrode, and the second internal electrode with the ceramic layers interposed therebetween. 3. A multilayer ceramic capacitor according to Item 1 or 2. 5. The multilayer ceramic capacitor according to claim 1, wherein said first external electrode and said second external electrode do not cover said first main surface and said second main surface, respectively. 6. The multilayer ceramic capacitor according to claim 1, wherein each of said first external electrode and said second external electrode is composed of at least one plated metal layer. 7. The multilayer ceramic capacitor according to claim 1, wherein each ceramic layer has a thickness of 1 [ mu ]m or less. 8. The multilayer ceramic capacitor according to claim 1, wherein said ceramic body has a thickness of 0.2 mm or less in said lamination direction. 9. The multilayer ceramic capacitor according to claim 1, wherein gaps between said internal electrodes and said first side and said second side are each less than 30 [mu]m. a step of making a ceramic sheet;
a step of printing a conductive paste on the ceramic sheet to produce a composite sheet;
a step of laminating the composite sheets to produce a mother block;
The mother block is cut, each including a plurality of laminated ceramic layers and a plurality of internal electrodes, a first main surface and a second main surface facing each other in the lamination direction, and a width direction orthogonal to the lamination direction. a step of fabricating a plurality of ceramic bodies having first and second side surfaces facing each other and first and second end surfaces facing each other in a length direction perpendicular to both the stacking direction and the width direction; ,
firing the ceramic body;
A method for manufacturing a multilayer ceramic capacitor, comprising the step of forming external electrodes on the ceramic body,
The step of cutting the mother block to produce a plurality of the ceramic bodies includes:
In each of the ceramic bodies, as the internal electrode,
Each has an L-shape in which a portion that mainly forms a capacity and a lead-out portion that is wider than the portion that mainly forms a capacity are connected to the outside,
a first internal electrode drawn out only to the first end surface and the first side surface;
a second internal electrode drawn out only to the second end surface and the first side surface;
a third internal electrode drawn out only to the first end surface and the second side surface;
A method of manufacturing a multilayer ceramic capacitor, comprising the step of forming the second end surface and the fourth internal electrode drawn out only to the second side surface. The step of printing a conductive paste on the ceramic sheet to produce the composite sheet,
11. The method of manufacturing a laminated ceramic capacitor according to claim 10 , further comprising the step of printing a conductive paste on said ceramic sheet in an H-shape.

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