JP2020092129A - Multilayer ceramic capacitor and manufacturing method of multilayer ceramic capacitor - Google Patents

Abstract

To provide a multilayer ceramic capacitor having small ESL and ESR, and large capacitance.SOLUTION: A multilayer ceramic capacitor includes: a ceramic element body 1 including a plurality of ceramic layers 4 and a plurality of inner electrodes and having a first main surface 1A, a second main surface 1B, a first side surface 1C, a second side surface 1D, a first end surface 1E, and a second end surface 1F; a first outer electrode 2; and a second outer electrode 3. The inner electrode includes: a first inner electrode 5 extended only to the first end surface 1E and the first side surface 1C; a second inner electrode 6 extended only to the second end surface 1F and the first side surface 1C; a third inner electrode 7 extended only to the first end surface 1E and the second side surface 1D; and a fourth inner electrode 8 extended only to the second end surface 1F and the second end surface 1D.SELECTED DRAWING: Figure 2

Description

The present invention relates to a laminated ceramic capacitor including a ceramic body in which a ceramic layer and an internal electrode are laminated, and a first outer electrode and a second outer electrode formed on an outer surface of the ceramic body. The present invention also relates to a method for manufacturing a monolithic ceramic capacitor suitable for manufacturing the monolithic 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 cause deterioration of characteristics, are small.

As a method for reducing ESL and ESR in a two-terminal capacitor, for example, as disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 9-260201), the internal electrodes are provided on the end face of the ceramic element body and the three side faces. There is known a method of pulling out in a direction and connecting to an external electrode. FIG. 9 shows a monolithic ceramic capacitor 1000 disclosed in Patent Document 1.

In the monolithic ceramic capacitor 1000, an internal electrode 102 formed between layers of a ceramic layer (dielectric layer) 101 is drawn out in three directions of an end face 103a of a ceramic body 103 and two side faces 103b and 103c to form an external electrode. It is connected to 104. The internal electrode 102 has a portion 102a that mainly forms a capacitance and a wide lead portion 102b for pulling out in three directions.

In the monolithic ceramic capacitor 1000, since the internal electrode 102 is drawn out not only from the end face 103a but also from the side faces 103b and 103c and is connected to the external electrode 104, the internal electrode 102 has a portion 102a that mainly forms a capacitance. The substantial distance from the external electrode 104 is shortened, and the ESL is reduced. Further, in the capacitor 1000, the internal electrode 102 is drawn out not only from the end face 103a but also from the side faces 103b and 103c and connected to the external electrode 104, so that the contact area between the internal electrode 102 and the external electrode 104 is large. And the ESR has become smaller.

JP, 9-260201, A

A general method for manufacturing a monolithic ceramic capacitor that is widely used includes, for example, the following steps. First, a ceramic sheet is produced. Next, a conductive paste is printed on the ceramic sheet to produce a composite 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 one in which a conductive paste is printed on a ceramic sheet to form internal electrodes. Internal electrodes for a plurality of laminated ceramic capacitors are formed on one composite sheet in order to collectively produce a large number of laminated ceramic capacitors.

When the above-mentioned internal electrode 102 is pulled out in three directions to manufacture the multilayer ceramic capacitor 1000, a conductive paste is formed on the composite sheet in order to form the internal electrode, for example, as shown in FIG. 10(A). It is conceivable to print the shape. It should be noted that FIG. 10A is created by the applicant of the present application for the purpose of explanation, and is not described in Patent Document 1.

A plurality of internal electrodes 102 are formed on the composite sheet 110 shown in FIG. In FIG. 10A, each internal electrode 102 has a length direction in a direction indicated by an arrow L and a width direction in a direction indicated by an arrow W. In the composite sheet 110, a pair of two internal electrodes 102 are joined in the lengthwise direction with the lead-out portions 102b back to back. Further, a plurality of pairs of the two joined internal electrodes 102 are continuously joined in the width direction.

In the composite sheet 110, a cut line 112L in the length direction and a cut line 112W in the width direction are assumed as cut lines when the mother block is cut to produce a plurality of ceramic bodies.

The composite sheet 110 shown in FIG. 10A has a problem that unnecessary bleeding of the conductive paste is likely to occur when the conductive paste is printed to form the internal electrodes. That is, the conductive paste is printed by, for example, screen printing or gravure printing from left to right in the length direction, but in the composite sheet 110, from the region P1 in which the wide lead-out portion 102b is formed. As the printing progresses in the region P2 where the portion 102a for forming the capacitance is formed, the pattern width of the printing abruptly narrows, so that unnecessary blurring of the conductive paste is likely to occur in the portion P3 surrounded by the broken line. There was a problem.

When unnecessary bleeding of the conductive paste occurs in the ceramic layer 101 of the monolithic ceramic capacitor 1000, the characteristics may be deteriorated or the electrodes may be short-circuited to cause a failure. Therefore, the composite ceramic capacitor shown in FIG. 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, one shown in FIG. 10B can be considered. It should be noted that FIG. 10B is also prepared by the applicant of the present application for the purpose of explanation, and is not described in Patent Document 1.

A plurality of internal electrodes 102 are formed on the composite sheet 120 shown in FIG. In each internal electrode 102 in FIG. 10B, the direction indicated by arrow L is the length direction, and the direction indicated by arrow W is the width direction. In the composite sheet 120, a pair of two internal electrodes 102 are joined back to back in the length direction. A plurality of pairs of the two joined internal electrodes 102 are arranged in a staggered pattern. When such a conductive paste pattern shape is used, the pattern width for printing does not sharply narrow, so unnecessary bleeding of the conductive paste occurs when the conductive paste is printed to form the internal electrodes. Hard to do.

In the composite sheet 120, a cut line 122L in the length direction and a cut line 122W in the width direction are assumed as cut lines when the mother block is cut to produce a plurality of ceramic bodies.

As described above, in the monolithic ceramic capacitor 1000, in order to draw out the internal electrode 102 in the three directions of the end surface 103a and the side surfaces 103b and 103c of the ceramic body 103, the internal electrode 102 is provided with a wide lead portion 102b. .. Then, in the composite sheet 120, the lead-out portion 102b of the internal electrode 102 is formed wider in the width direction beyond the cut line 122L in the length direction, and the protruding portions 102c are formed on both sides beyond the cut line 122L. There is.

When the plurality of ceramic elements are manufactured by cutting the mother block, the protrusion 102c is cut in the actual length direction from the cut line 122L in the assumed length direction in the width direction (in FIG. 10B). In order to ensure that the lead-out portion 102b of the internal electrode 102 is pulled out from the end face 103a of the ceramic body 103 and the two side faces 103b and 103c even if the lead-out portion 102b is displaced upward or downward. It was installed in. If the protrusion 102c is not provided, and the actual cut in the length direction deviates in the width direction from the cut line 122L in the assumed length direction, the lead-out portion 102b may have one of the side surface 103b and the side surface 103c or There was a risk that they would not be drawn from both. That is, the internal electrode 102 may not be drawn out in three directions of the ceramic body 103, but may be drawn out only in two directions or one direction.

Then, in the monolithic 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 one direction, ESL and ESR are deviated from the designed values, respectively. However, there is a possibility that the product will be a defective product that does not meet the standard.

According to the composite sheet 120, since the protruding portions 102c are formed on both sides of the wide lead-out portion 102b of the internal electrode 102, the actual lengthwise cutting is performed from the assumed lengthwise cutting line 112L. Even if they are deviated in the directions, the internal electrodes 102 are reliably pulled out in the three directions, so that ESL and ESR do not deviate from the designed values.

However, in the composite sheet 110 shown in FIG. 10B, a new problem occurs due to the provision of the protruding portions 102c on both sides of the lead-out portion 102b of the internal electrode 102. That is, in the composite sheet 110, the gap GX must be provided between the portion 102a that forms the capacitance of the internal electrode 102 and the protruding portion 102c of another internal electrode 102 that is adjacent in the width direction for the purpose of preventing a short circuit or the like. It has become obsolete. Then, by providing the gap GX, the widthwise gap GW between the portion 102a forming the capacitance of the internal electrode 102 and both side surfaces of the ceramic body 103 must be made larger than necessary by the gap GX. No longer.

In the monolithic ceramic capacitor 1000, if the width dimension of the ceramic body 103 is constant and the width direction gap GW is increased, the width dimension of the internal electrode 102 must be reduced accordingly. That is, when the pattern shape of the conductive paste of the composite sheet 120 shown in FIG. 10B is adopted, the width dimension of the internal electrode 102 must be reduced, the effective area of the internal electrode is reduced, and the electrostatic capacitance is reduced. There was a problem that it became small.

It should be noted that the reduction rate of the electrostatic capacitance due to the reduction of the width dimension of the internal electrode 102 increases as the outer dimension of the multilayer ceramic capacitor decreases. For example, comparing a large monolithic ceramic capacitor with a microminiature product having 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 electrode 102 is the same, However, even if the size is reduced, the reduction rate of the capacitance of the microminiature product becomes extremely large as compared with that of the monolithic ceramic capacitor having a large outer dimension.

The present invention has been made to solve the above-described conventional problems, and as a means thereof, a monolithic ceramic capacitor according to an 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 orthogonal to the stacking direction, and a length direction orthogonal to both the stacking direction and the width direction. On the outer surface of the ceramic element body having a first end surface and a second end surface facing each other, at least a part or all of the first end surface, a part of the first side surface, and a second side surface. The first external electrode that covers a part of the ceramic body and the outer surface of the ceramic body that covers at least a part or the whole of the second end surface, a part of the first side surface, and a part of the second side surface. A second external electrode, wherein the internal electrode has a first internal electrode drawn out only to the first end surface and the first side surface, a second internal electrode drawn only to the second end surface and the first side surface, It is assumed to have a third internal electrode extended only to the one end face and the second side face, and a fourth internal electrode extended only to the second end face and the second side face.

A laminated ceramic capacitor according to another embodiment of the present invention includes a plurality of laminated ceramic layers and a plurality of internal electrodes, and has a first main surface and a second main surface facing each other in the stacking direction, and a stacking direction. A ceramic body having a first side surface and a second side surface orthogonal to each other in the width direction, and a first end surface and a second end surface opposed to each other in the length direction orthogonal to both the stacking direction and the width direction; A first external electrode covering at least a part or all of the first end surface and a part of the first side surface on the outer surface of the element body, and at least one of the second end surfaces on the outer surface of the ceramic element body. A second external electrode covering the part or the whole and a part of the first side surface, and the internal electrode has a first internal electrode drawn out only to the first end surface and the first side surface, and a second end surface. A second internal electrode that is drawn out only to the first side surface, the first internal electrode and the second internal electrode are each L-shaped, and the first external electrode and the second external electrode are respectively the first external electrode and the first internal electrode. The main surface and the second main surface are not covered.

A method for manufacturing a laminated ceramic capacitor according to an embodiment of the present invention includes a step of producing a ceramic sheet, a step of printing a conductive paste on the ceramic sheet to produce a composite sheet, and laminating the composite sheets. A step of producing a mother block, a first main surface and a second main surface which are cut in the mother block and include a plurality of laminated ceramic layers and a plurality of internal electrodes, respectively, and which face each other in the laminating direction, and a laminating direction. A plurality of ceramic element bodies each having a first side surface and a second side surface that are orthogonal to each other in the width direction, and a first end surface and a second end surface that are opposed to each other in the length direction orthogonal to both the stacking direction and the width direction. The step of producing, the step of firing the ceramic element body, and the step of forming the external electrodes on the ceramic element body, the step of cutting the mother block to produce a plurality of ceramic element bodies, As internal electrodes, a first internal electrode drawn only to the first end surface and the first side surface, a second internal electrode drawn only to the second end surface and the first side surface, and a first end surface and a second side surface. It includes a step of forming a third internal electrode that is drawn out only and a fourth internal electrode that is drawn out only to the second end surface and the second side surface.

The ESL and ESR of the multilayer ceramic capacitor of the present invention are small. Further, the laminated ceramic capacitor of the present invention does not need to reduce the width of the internal electrodes, and thus can obtain a large capacitance.

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

3 is a perspective view of the multilayer ceramic capacitor 100 according to the first embodiment. FIG. 3 is an exploded perspective view of the monolithic ceramic capacitor 100. FIG. FIG. 6 is a plan view of relevant parts of a composite sheet 10 used in an example of a method for manufacturing a monolithic 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 the comparative example. FIG. 6 is an exploded perspective view of a laminated ceramic capacitor 200 according to a second embodiment. FIG. 6 is a perspective view of a laminated ceramic capacitor 300 according to a third embodiment. 3 is an exploded perspective view of a monolithic ceramic capacitor 300. FIG. It is a perspective view of a multilayer ceramic capacitor 400 according to a fourth embodiment. 6 is a cross-sectional view of a monolithic ceramic capacitor 1000 described in Patent Document 1. FIG. FIG. 10A is a plan view of an essential part of a composite sheet 110 that can be used for manufacturing the laminated ceramic capacitor 1000. FIG. 10B is a plan view of relevant parts of a composite sheet 120 that can be used to manufacture the monolithic ceramic capacitor 1000.

Hereinafter, an embodiment for carrying out the present invention will be described with reference to the drawings.

Each embodiment is an exemplification of an embodiment of the present invention, and the present invention is not limited to the contents of the embodiment. It is also possible to combine and implement the contents described in different embodiments, and the contents of implementation in that case are also included in the present invention. In addition, the drawings are for facilitating understanding of the specification and may be schematically drawn, and the drawn components or ratios of dimensions between the components are described in the description. It may not match the ratio of those dimensions. In addition, the constituent elements described in the specification may be omitted in the drawings, or may be drawn with the number omitted.

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

In FIGS. 1 and 2, the length direction of the monolithic ceramic capacitor 100 is indicated by an arrow L, the width direction is indicated by an arrow W, and the height direction is indicated by an arrow T. The same directions are applied to 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. , Length direction, width direction, and height direction.

The monolithic ceramic capacitor 100 includes a ceramic body 1. The ceramic 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 relative length direction. It has a first end face 1E and a second end face 1F.

The ceramic body 1 is formed by stacking a plurality of ceramic layers 4 and a plurality of internal electrodes in the height direction, firing them, and integrating them. The internal electrodes are made up 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-out portion 5b having a width wider than that are connected to each other. The lead-out portion 5b is drawn out only to the first end face 1E and the first side face 1C of the ceramic body 1.

The second internal electrode 6 has an L-shape in which a portion 6a that mainly forms a capacitance and a lead-out portion 6b having a width wider than the portion are connected to each other. The lead-out portion 6b is drawn out only to the second end facet 1F and the first side face 1C of the ceramic body 1.

The third internal electrode 7 has an L-shape in which a portion 7a that mainly forms a capacitance and a lead-out portion 7b having a width wider than the portion 7a are connected to each other. The lead-out portion 7b is drawn out only to the first end face 1E and the second side face 1D of the ceramic body 1.

The fourth inner electrode 8 has an L-shape in which a portion 8a that mainly forms a capacitance and a lead-out portion 8b that is wider than the leading portion 8a are connected to each other. The lead-out portion 8b is drawn out only to the second end surface 1F and the second side surface 1D of the ceramic body 1.

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

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

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

A first outer electrode 2 and a second outer 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 of the ceramic body 1, a portion of the first side face 1C, and a portion of the second side face 1D. 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. 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 face 1F of the ceramic body 1, a portion of the first side face 1C, and a portion of the second side face 1D. 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. The second external electrode 3 may be formed on a part of the second end surface 1F instead of the entire surface.

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

The structure, material, forming 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 respectively provided with a first layer. A Cu plating layer, a second layer was formed into a Ni plating layer, and a third layer was formed into a three-layer structure of an Sn plating layer.

(One Example of Manufacturing Method of Multilayer Ceramic Capacitor 100)
The monolithic ceramic capacitor 100 can be manufactured, for example, by the following manufacturing method.

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

Next, the ceramic slurry is applied on the carrier film in a sheet shape using a die coater, a gravure coater, a microgravure 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 a method such as screen printing or 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 multilayer ceramic capacitors 100. ing.

In the composite sheet 10, the four groups of the first internal electrode 5, the second internal electrode 6, the third internal electrode 7, and the fourth internal electrode 8 constitute one set, and the lead portion 5b, the lead portion 6b, the lead portion 7b, and the lead portion. It is joined at 8b. A plurality of sets of the bonded first internal electrode 5, second internal electrode 6, third internal electrode 7, and fourth internal electrode 8 are arranged side by side 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 longitudinal direction.

In the composite sheet 10, a cut line 10L in the length direction and a cut line 10W in the width direction are assumed as cut lines when the mother block is cut to produce the plurality of ceramic element bodies 1.

The conductive paste is printed, for example, from left to right in the length direction. However, in the composite sheet 10, compared with the composite sheet 110 shown in FIG. Even if printing proceeds from the formed region P1 to the region P2 where the capacitance forming portions 6a and 8a are formed, the pattern width of the printing is gradually narrowed, so that unnecessary blurring of the conductive paste is unlikely to occur. ..

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

Next, the mother block is cut along the cut line 10L in the length direction and the cut line 10W in the width direction to manufacture a plurality of ceramic element bodies 1. At this time, even if the actual cut in the length direction is deviated from the assumed cut line 10L in the length direction in the width direction (upward or downward in FIG. 3) due to stacking deviation of the composite sheet 10 or the like. The lead-out portion 5b of the first internal electrode 5 is always pulled out in two directions, that is, the first end face 1E and the first side face 1C of the ceramic body 1. Similarly, the lead-out portion 6b of the second internal electrode 6 is always pulled out in the two directions of the second end face 1F and the first side face 1C of the ceramic body 1. The lead-out portion 7b of the third internal electrode 7 is always pulled out in the two directions of the first end face 1E and the second side face 1D of the ceramic body 1. The lead-out portion 8b of the fourth internal electrode 8 is always pulled out in the two directions of the second end face 1F and the second side face 1D of the ceramic body 1. Therefore, in the monolithic ceramic capacitor 100 manufactured by the present manufacturing method, even if the cutting position of the mother block is deviated, the lead-out portions 5b to 8b are in one direction of the ceramic body 1 (the first end face 1E or the second end face). It will not be pulled out only from 1F). Therefore, in the monolithic ceramic capacitor 100 manufactured by this manufacturing method, the ESL and ESR do not deviate from the designed values due to the drawn-out portions 5b to 8b being drawn out in only one direction.

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

Next, the first outer electrode 2 and the second outer electrode 3 are formed on the outer surface of the ceramic body 1. More specifically, the first external electrode 2 is formed in the portion of the ceramic body 1 where the lead-out portions 5b and 7b are exposed, and the second external electrode 3 is formed in the portion where the lead-out 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 the Cu plating layer, the second layer is the Ni plating layer, and the third layer is the Sn plating layer.

First, the lead-out 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 electrolytic plating. Next, a second Ni plating layer is formed on the first Cu plating layer by electrolytic plating. Next, the Sn plating layer of the third layer is formed on the Ni plating layer of the second layer by electrolytic plating.

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

(Comparison of Example and Comparative Example)
A monolithic ceramic capacitor according to the example and a monolithic ceramic capacitor according to the comparative example were manufactured, and both were compared.

The monolithic ceramic capacitor according to the example has the structure of the monolithic ceramic capacitor 100 according to the first embodiment. One arbitrarily selected ceramic layer 51 of the monolithic ceramic capacitor according to the example is shown in FIG.

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

Internal electrodes 52 are formed on the upper main surface of the ceramic layer 51. The internal electrode 52 mainly includes a portion 52a that forms a capacitance and a lead portion 52b for leading to the end face and one side face.

The internal electrode 52 has a lengthwise gap GL formed between the opposing end faces of the ceramic body of 0.030 mm, and a widthwise gap GW formed between the opposite side faces of the ceramic body. Each is 0.015 mm. As a result, the effective length EL and the effective width EW of the internal electrode 52, which contributes to forming a capacitance between the adjacent internal electrode and another internal electrode 52, are 0.170 mm and 0.075 mm, respectively. ing. The effective area of the internal electrode 52 that contributes to the formation of electrostatic capacitance between the adjacent internal electrodes and the other internal electrodes is 0.170 mm×0.075 mm=0.01275 mm ² . ..

On the other hand, the multilayer ceramic capacitor according to the comparative example has the structure of the multilayer ceramic capacitor 1000 described in Patent Document 1 shown in FIG. In addition, in manufacturing, 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.

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.

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

The internal electrode 62 has 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 protrusion 63 to prevent a short circuit or the like. Therefore, in the internal electrode 62, it is necessary to increase the widthwise gap GW by the gap GX as compared with the embodiment. The internal electrode 62 has a gap GX of 0.015 mm and a width direction gap GW of 0.030 mm. As a result, in the comparative example, the effective length EL of the internal electrode 62 was 0.170 mm and the effective width EW was 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 .

While the effective area of the internal electrodes 52 according to the embodiment is 0.01275Mm ^2, the effective area of the internal electrodes 62 of the comparative example is 0.00765Mm ^2, examples are compared with the comparative example, 0. 01275mm of ^{2 /0.00765mm 2} ≒ 1.67 times and a valid area. Therefore, the monolithic ceramic capacitor of the example can obtain a large electrostatic capacity of about 1.67 times that of the monolithic ceramic capacitor of the comparative example having the same external dimensions.

In addition, a substantial distance from a portion 52a mainly forming a capacitance of the multilayer ceramic capacitor according to the example to the external electrode, and a portion 62a mainly forming a capacitance of the multilayer ceramic capacitor according to the comparative example to an external electrode. Since the substantial distances are the same, the ESLs are the same in the example and the comparative example.

On the other hand, the lead-out portion 62b of the multilayer ceramic capacitor according to the comparative example is drawn out in three directions of the ceramic body, whereas the lead-out portion 52b of the multilayer ceramic capacitor according to the embodiment is drawn out only in two directions of the ceramic body. Therefore, the ESR of the example is larger than that of the comparative example. However, also in the embodiment, since the pull-out portion 52b is pulled out in two directions, the ESR is sufficiently small.

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

In the laminated ceramic capacitor 200 according to the second embodiment, some of the configurations of the laminated ceramic capacitor 100 according to the first embodiment are modified. Specifically, in the monolithic ceramic capacitor 100, the internal electrodes are arranged in the 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 inside the ceramic body 1. Was laminated to. The monolithic ceramic capacitor 200 is modified so that the internal electrodes are arranged in the interior of the ceramic body 1 from the bottom to 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 monolithic ceramic capacitor 200 also has electrical characteristics (electrostatic capacitance, ESL, ESR, etc.) equivalent to those of the monolithic ceramic capacitor 100.

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

The multilayer ceramic capacitor 300 according to the third embodiment is obtained by modifying a part of the configuration of the multilayer ceramic capacitor 100 according to the first embodiment.

Specifically, first, in the monolithic ceramic capacitor 100, the first outer electrode 2 is formed on the first end face 1E, the first side face 1C, and the second side face 1D of the ceramic body 1, and the second outer electrode 3 is It was formed on the second end face 1F, the first side face 1C, and the second side face 1D of the ceramic body 1. The laminated ceramic capacitor 300 is modified such that the first outer electrode 32 is formed on the first end face 1E and the first side face 1C of the ceramic body 1, and the second outer electrode 33 is formed on the first end face 1C of the ceramic body 1. The two end faces 1F and the first side face 1C are formed.

In the monolithic 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 inside the ceramic body 1 in order from the bottom at least once or more. , Was repeatedly laminated as many times as desired. The laminated ceramic capacitor 300 is modified so that the first internal electrode 5 and the second internal electrode 6 are laminated inside the ceramic body 1 in order from the bottom by repeating at least once or a desired number of times. did. That is, in the monolithic ceramic capacitor 100, four types of internal electrodes including the first internal electrode 5, the second internal electrode 6, the third internal electrode 7, and the fourth internal electrode 8 were used, but in the monolithic ceramic capacitor 300. , Two types of internal electrodes consisting of the first internal electrode 5 and the second internal electrode 6 were used.

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

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

The laminated ceramic capacitor 400 according to the fourth embodiment is obtained by modifying a part of the configuration of the laminated ceramic capacitor 100 according to the first embodiment. Specifically, in the monolithic ceramic capacitor 100, the first outer electrode 2 is formed on the first end face 1E, the first side face 1C, and the second side face 1D of the ceramic body 1, and the second outer electrode 3 is the ceramic body. It was formed on the second end surface 1F, the first side surface 1C, and the second side surface 1D of the body 1. The monolithic ceramic capacitor 400 is modified in such a manner that the first external electrode 42 has 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 body 1. Then, the second external electrode 43 was 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 monolithic ceramic capacitor 400, the first external electrode 42 and the second external electrode 43 were formed on the five surfaces of the ceramic body 1, respectively.

In the monolithic ceramic capacitor 100, the first external electrode 42 and the second external electrode 43 are each a three-layer structure including a first-layer Cu plating layer, a second-layer Ni plating layer, and a third-layer Sn plating layer. It was composed of a plating layer of. In the monolithic ceramic capacitor 400, the Cu plating layer of the first layer was replaced with a Cu thick film layer among these. The Cu thick film layer of the first layer was formed by dipping the five surfaces of the ceramic body 1 into a Cu conductive paste and baking the applied Cu conductive paste. Then, a second Ni plating layer was formed on the first Cu thick film layer by electrolytic plating. Then, the Sn plating layer of the 3rd layer was formed on the Ni plating layer of the 2nd layer by electrolytic plating.

As described above, the formation position, the structure, the material, the formation method, and the like of the first outer electrodes 2 and 42 and the second outer electrodes 3 and 43 can be appropriately selected and adopted.

The multilayer ceramic capacitors 100, 200, 300, 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 according to 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. Further, the structure, material, forming method, etc. of the first external electrode 2 and the second external electrode 3 are arbitrary, and are not limited to the contents described above. Further, the material, pattern shape, and the like 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 above contents.

The monolithic ceramic capacitor according to the embodiment of the present invention is as described in the section “Means for solving the problem”.

In this monolithic 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 sandwiched therebetween. In this case, the laminated internal electrodes are alternately drawn to the first external electrode and the second external electrode, so that a large capacitance can be obtained by utilizing all the internal electrodes.

In addition, the ceramic body may include a region in which the internal electrodes are laminated in this order with the first internal electrode, the second internal electrode, the third internal electrode, and the fourth internal electrode sandwiching the ceramic layer. Alternatively, in the ceramic body, the internal electrodes may include a region in which the first internal electrode, the fourth internal electrode, the third internal electrode, and the second internal electrode are laminated in this order with the ceramic layer interposed therebetween. In these cases as well, the stacked internal electrodes are alternately drawn to the first external electrode and the second external electrode, so that a large capacitance can be obtained by utilizing all the internal electrodes.

Further, the first external electrode and the second external electrode may not cover the first main surface and the second main surface, respectively. In this way, if the first external electrode and the second external electrode are formed only in the necessary portions of the outer surface of the ceramic body and not in the unnecessary portions, the material cost can be reduced. ..

Further, the laminated ceramic capacitor according to another embodiment of the present invention is as described in the section “Means for solving the problem”.

A monolithic ceramic capacitor according to one embodiment of the present invention and a ceramic capacitor according to another embodiment of the present invention, wherein the first external electrode and the second external electrode are each composed of at least one plated metal layer (one layer Alternatively, it may be composed of only two or more plated metal layers). When the first layer and the second outer electrode are the thick metal layer as the first layer and the plated metal layer after the second layer, both the thick film step and the plating step are required, and the manufacturing is complicated. 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 the productivity is improved.

The thickness of each ceramic layer may be 1 μm or less. That is, in a microminiature product having a ceramic layer thickness of 1 μm or less, the height dimension is severely limited, and the ceramic layers cannot be easily increased. Therefore, a sufficiently large internal electrode is effective. This is because the monolithic ceramic capacitor of the present invention which has an area and can obtain a large capacitance becomes particularly useful. Further, when forming the external electrodes by plating on the surface of the element body, the distance between the internal electrodes adjacent to each other in the stacking direction becomes short, so that the external electrodes can be accurately formed.

Further, the thickness (height) of the ceramic body in the stacking direction may be 0.2 mm or less. That is, a microminiature product in which the thickness of the ceramic body in the stacking direction is 0.2 mm or less cannot easily increase the number of ceramic layers, and therefore has a sufficiently large effective area of the internal electrodes and a large electrostatic capacitance. This is because the monolithic ceramic capacitor of the present invention that can obtain the capacitance becomes particularly useful.

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

The method for manufacturing a monolithic ceramic capacitor according to an embodiment of the present invention is as described in the section “Means for Solving the Problem”.

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

1... Ceramic body 1A... 1st main surface 1B... 2nd main surface 1C... 1st side surface 1D... 2nd side surface 1E... 1st end surface 1F... 2nd End face 2, 32, 42... First external electrode 3, 33, 43... Second external electrode 4... Ceramic layer 5... First internal electrode 6... Second internal electrode 7...・Third internal electrode 8... Fourth internal electrode 10... Composite sheet

Claims (12)

A first main surface and a second main surface that include a plurality of laminated ceramic layers and a plurality of internal electrodes and that face each other in the stacking direction, and a first side surface and a second side surface that face each other in the width direction orthogonal to the stacking direction. And a ceramic body having a first end surface and a second end surface facing each other in the length direction orthogonal to both the stacking direction and the width direction,
A first external electrode that covers at least a part or all of the first end surface, a part of the first side surface, and a part of the second side surface on the outer surface of the ceramic body;
A second external electrode that covers at least a part or all of the second end surface, a part of the first side surface, and a part of the second side surface on the outer surface of the ceramic body. ,
The internal electrode is
A first internal electrode extended only to the first end surface and the first side surface;
A second internal electrode extended only to the second end surface and the first side surface;
A third internal electrode extended only to the first end face and the second side face,
A monolithic ceramic capacitor having the second end face and a fourth internal electrode extended only to the second side face. At least 1 of the said 1st internal electrode or the said 3rd internal electrode was each arrange|positioned so that the said 2nd internal electrode and the said 4th internal electrode might be opposed on both sides of the said ceramic layer, respectively. Multilayer ceramic capacitor. The ceramic body includes a region in which the internal electrode is laminated in order of the first internal electrode, the second internal electrode, the third internal electrode, and the fourth internal electrode with the ceramic layer interposed therebetween. Item 1. A multilayer ceramic capacitor as described in Item 1 or 2. The ceramic body includes a region in which the internal electrode is laminated in order of the first internal electrode, the fourth internal electrode, the third internal electrode, and the second internal electrode with the ceramic layer interposed therebetween. Item 1. A multilayer ceramic capacitor as described in Item 1 or 2. The multilayer ceramic capacitor according to claim 1, wherein the first outer electrode and the second outer electrode do not cover the first main surface and the second main surface, respectively. A first main surface and a second main surface that include a plurality of laminated ceramic layers and a plurality of internal electrodes and that face each other in the stacking direction, and a first side surface and a second side surface that face each other in the width direction orthogonal to the stacking direction. And a ceramic body having a first end surface and a second end surface facing each other in a length direction orthogonal to both the stacking direction and the width direction,
A first external electrode that covers at least a part or all of the first end surface and a part of the first side surface on the outer surface of the ceramic body;
A second external electrode that covers at least a part or all of the second end surface and a part of the first side surface on the outer surface of the ceramic body;
The internal electrode is
A first internal electrode extended only to the first end surface and the first side surface;
And a second internal electrode drawn only to the first side surface,
The first internal electrode and the second internal electrode are each L-shaped,
A monolithic ceramic capacitor in which the first external electrode and the second external electrode do not cover the first main surface and the second main surface, respectively. 7. The multilayer ceramic capacitor according to claim 1, wherein each of the first external electrode and the second external electrode is composed of at least one plated metal layer. The multilayer ceramic capacitor according to any one of claims 1 to 7, wherein a thickness of each ceramic layer is 1 µm or less. The multilayer ceramic capacitor according to claim 1, wherein the thickness of the ceramic body in the stacking direction is 0.2 mm or less. 10. The monolithic ceramic capacitor according to claim 1, wherein a size of a gap between each of the internal electrodes and the first side surface and the second side surface is less than 30 μm. A step of producing a ceramic sheet,
A step of producing a composite sheet by printing a conductive paste on the ceramic sheet,
Stacking the composite sheets to produce a mother block,
The mother block is cut and includes a plurality of ceramic layers and a plurality of internal electrodes that are laminated, respectively, and a first main surface and a second main surface facing each other in the stacking direction, and a width direction orthogonal to the stacking direction. A step of producing a plurality of ceramic element bodies each having a first side surface and a second side surface facing each other, and a first end surface and a second end surface facing each other in a length direction orthogonal to both the stacking direction and the width direction; ,
A step of firing the ceramic body,
A method of manufacturing a monolithic ceramic capacitor, comprising the step of forming an external electrode on the ceramic body.
The step of cutting the mother block to produce a plurality of the ceramic bodies is
As the internal electrodes on each of the ceramic bodies,
A first internal electrode extended only to the first end surface and the first side surface;
A second internal electrode extended only to the second end surface and the first side surface;
A third internal electrode extended only to the first end face and the second side face,
A method of manufacturing a monolithic ceramic capacitor, comprising the step of forming the second end face and a fourth internal electrode that is drawn out only to the second side face. The step of printing a conductive paste on the ceramic sheet to produce the composite sheet,
The method of manufacturing a multilayer ceramic capacitor according to claim 11, further comprising a step of printing a conductive paste on the ceramic sheet in an H shape.

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