JP2024034458A - Multilayer ceramic capacitors and mounting structures - Google Patents

Abstract

An object of the present invention is to provide a multilayer ceramic capacitor that can reduce noise caused by a substrate.
SOLUTION: A multilayer ceramic capacitor 1 includes a laminate 2 having a first surface 7a and a second surface 7b, a first end surface 8a and a second end surface 8b, and a first side surface 9a and a second side surface 9b; It includes a first side margin portion 3a located on the side surface 9a and having a first outer surface 3aa, a first external electrode 4a, and a second external electrode 4b. The first external electrode 4a and the second external electrode 4b each have a first portion 41 located on the first surface 7a and a second portion 42 located on the first outer surface 3aa. The first portion 41 has a first electrode surface 41a, and the second portion 42 has a second electrode surface 42a. The first outer surface 3aa has an exposed area 3ac that is not covered with the second portion 42. The distance s1 between the second electrode surface 42a and the exposed region 3ac is smaller than the distance s2 between the first electrode surface 41a and the first surface 7a.
[Selection diagram] Figure 2

Description

The present disclosure relates to a multilayer ceramic capacitor and a mounting structure.

A multilayer ceramic capacitor includes a laminate in which dielectric layers and internal electrode layers are alternately stacked. Multilayer ceramic capacitors are normally used mounted on a board, but when the multilayer ceramic capacitor is driven, the dielectric layer expands and contracts due to the electrostrictive effect, which causes the board to bend, causing board noise. Sometimes. In recent years, miniaturization of multilayer ceramic capacitors has been progressing, but even if the multilayer ceramic capacitors are miniaturized, if they are thinner or more laminated, they may cause noise on the board. There is.

Various multilayer ceramic capacitors have been proposed that reduce noise caused by substrates. For example, Patent Document 1 discloses a multilayer ceramic capacitor that reduces the noise of the substrate by making the thickness of the outer layer on the side facing the substrate thicker than the thickness of the outer layer on the side opposite to the side facing the substrate. are doing.

Japanese Patent Application Publication No. 2021-174829

Conventional multilayer ceramic capacitors have room for improvement in reducing board noise.

The multilayer ceramic capacitor of the present disclosure is a substantially rectangular laminate in which dielectric layers and internal electrode layers are alternately stacked, and has first and second surfaces facing each other and first side surfaces facing each other. and a second side surface, and a laminate having a first end surface and a second end surface facing each other,
a first side margin portion located on the first side surface and having a first outer surface opposite to the first side surface side;
a second side margin portion located on the second side surface and having a second outer surface opposite to the second side surface side;
a first external electrode located from the first end surface to the first surface, the second surface, the first outer surface, and the second outer surface;
a second external electrode located from the second end surface to the first surface, the second surface, the first outer surface, and the second outer surface;
The first external electrode and the second external electrode are connected to different internal electrode layers of the internal electrode layer,
The first external electrode and the second external electrode each have a first portion located on the first surface and a second portion located on the first outer surface,
The first portion has a first electrode surface opposite to the first surface side,
The second portion has a second electrode surface opposite to the first outer surface side,
The first outer surface has a covered region covered with the second portion and an exposed region not covered with the second portion,
The distance between the second electrode surface and the exposed region in the direction perpendicular to the first side surface is smaller than the distance between the first electrode surface and the first surface in the direction perpendicular to the first surface.

A mounting structure of the present disclosure includes the above multilayer ceramic capacitor,
A board having a mounting surface;
The multilayer ceramic capacitor is mounted on the substrate so that the first side faces the mounting surface.

According to the multilayer ceramic capacitor and mounting structure of the present disclosure, it is possible to reduce the noise of the substrate.

FIG. 1 is a perspective view showing a multilayer ceramic capacitor according to an embodiment of the present disclosure. 2 is a sectional view taken along section line II-II in FIG. 1. FIG. 2 is a sectional view taken along the section line III-III in FIG. 1. FIG. FIG. 3 is a cross-sectional view showing another example of a multilayer ceramic capacitor according to an embodiment of the present disclosure. FIG. 3 is a cross-sectional view showing another example of a multilayer ceramic capacitor according to an embodiment of the present disclosure. FIG. 3 is a cross-sectional view showing another example of a multilayer ceramic capacitor according to an embodiment of the present disclosure. FIG. 3 is a perspective view showing a process for producing a temporary laminate. FIG. 3 is a perspective view showing a mother laminate. It is a perspective view showing a plurality of laminate precursors obtained by cutting a mother laminate. FIG. 2 is a side view showing the configuration of an apparatus for forming a side margin portion on the side surface of a laminate precursor. It is a side view which shows the process of forming a side margin part on the side surface of a laminated body precursor. It is a side view which shows the process of forming a side margin part on the side surface of a laminated body precursor. FIG. 3 is a perspective view showing the main body. FIG. 1 is a perspective view showing a mounting structure according to an embodiment of the present disclosure. 11 is a sectional view taken along the section line XI-XI in FIG. 10. FIG.

Hereinafter, embodiments of a multilayer ceramic capacitor and a mounting structure of the present disclosure will be described with reference to the drawings. The drawings referred to below are schematic, and the dimensional ratios etc. shown in the drawings are not necessarily accurately illustrated. Further, in this specification, a rectangular coordinate system XYZ is defined for convenience. The X-axis direction is also referred to as the first direction or the length direction. The Y-axis direction is also referred to as the second direction or the width direction. The Z-axis direction is also referred to as the third direction or the height direction.

FIG. 1 is a perspective view showing a multilayer ceramic capacitor according to an embodiment of the present disclosure, FIG. 2 is a cross-sectional view taken from section line II-II in FIG. 1, and FIG. FIG. 3 is a sectional view taken along plane line III-III. 4 to 6 are cross-sectional views showing other examples of multilayer ceramic capacitors according to embodiments of the present disclosure. The cross-sectional views shown in FIGS. 4 and 5 correspond to the cross-sectional view shown in FIG. 2, and the cross-sectional view shown in FIG. 6 corresponds to the cross-sectional view shown in FIG. 3. FIG. 7A is a perspective view showing a process for producing a temporary laminate, FIG. 7B is a perspective view showing a mother laminate, and FIG. 7C is a perspective view showing a plurality of laminate precursors obtained by cutting the mother laminate. FIG. FIG. 8A is a side view showing the configuration of an apparatus for forming a side margin portion on the side surface of the laminate precursor, and FIGS. 8B and 8C show a step of forming the side margin portion on the side surface of the laminate precursor. FIG. FIG. 9 is a perspective view of the main body. FIG. 10 is a perspective view showing a mounting structure according to an embodiment of the present disclosure, and FIG. 11 is a cross-sectional view taken along section line XI-XI in FIG. 10.

As shown in FIGS. 1 to 3, the multilayer ceramic capacitor 1 of this embodiment includes a multilayer body 2, a first side margin part 3a, a second side margin part 3b, a first external electrode 4a, and a second external electrode. and an electrode 4b. Hereinafter, the laminate 2, the first side margin part 3a, and the second side margin part 3b may be collectively referred to as main body parts 2, 3a, and 3b. Further, the first side margin portion 3a and the second side margin portion 3b may be collectively referred to as side margin portions 3a, 3b. Furthermore, the first external electrode 4a and the second external electrode 4b may be collectively referred to as external electrodes 4a and 4b.

The laminate 2 has a substantially rectangular parallelepiped shape. The laminate 2 has a first surface 7a and a second surface 7b facing each other in the third direction, a first end surface 8a and a second end surface 8b facing each other in the first direction, and a first surface 7a and a second surface 7b facing each other in the second direction. It has a side surface 9a and a second side surface 9b. Below, the first surface 7a and the second surface 7b may be collectively referred to as main surfaces 7a, 7b, and the first end surface 8a and second end surface 8b may be collectively referred to as end surfaces 8a, 8b. The first side surface 9a and the second side surface 9b may be collectively referred to as side surfaces 9a and 9b. The main surfaces 7a, 7b may be perpendicular to the third direction, the end surfaces 8a, 8b may be perpendicular to the first direction, and the side surfaces 9a, 9b may be perpendicular to the second direction.

The laminate 2 is constructed by alternately stacking dielectric layers 5 and internal electrode layers 6. The dielectric layer 5 and the internal electrode layer 6 are stacked in the third direction. Internal electrode layer 6 is exposed on first side surface 9a and second side surface 9b. Further, the internal electrode layer 6 is exposed at the first end surface 8a or the second end surface 8b depending on the polarity.

The dielectric layer 5 is made of an insulating material. The dielectric layer 5 is made of a ceramic material whose main components are, for example, BaTiO ₃ (barium titanate), CaTiO ₃ (calcium titanate), SrTiO ₃ (strontium titanate), BaZrO ₃ (barium zirconate), etc. It's okay. In this specification, the term "main component" refers to a component having the highest composition ratio in the material or member of interest. The composition ratio may be the content concentration (mol%).

The internal electrode layer 6 is made of a conductive material. The internal electrode layer 6 may be made of a metal material containing, for example, Ni (nickel), Pd (palladium), Ag (silver), Cu (copper), or the like as a main component.

The thinner the dielectric layer 5 is in the third direction, the more the capacitance (hereinafter also simply referred to as capacitance) of the multilayer ceramic capacitor 1 can be increased. The dielectric layer 5 may have a thickness of, for example, 0.1 μm or more and 10 μm or less. Furthermore, as long as the characteristics as a capacitor can be secured, the thinner the internal electrode layer 6 is in the third direction, the more internal defects caused by internal stress can be suppressed, and the reliability of the multilayer ceramic capacitor 1 can be improved. . The internal electrode layer 6 may have a thickness of, for example, 1.5 μm or less.

Both ends of the laminate 2 in the third direction may be comprised of cover layers. The cover layer is made of an insulating material. The cover layer may be composed of one or more dielectric layers 5, for example.

The first side margin portion 3a is located on the first side surface 9a of the laminate 2, and has a first outer side surface 3aa opposite to the first side surface 9a side. The first side margin portion 3a electrically insulates the internal electrode layers 6 of different polarities exposed on the first side surface 9a. Further, the first side margin portion 3a physically protects the end portion of the internal electrode layer 6 exposed on the first side surface 9a.

The second side margin portion 3b is located on the second side surface 9b of the stacked body 2, and has a second outer side surface 3ba on the opposite side to the second side surface 9b side. The second side margin portion 3b electrically insulates the internal electrode layers 6 of different polarities exposed on the second side surface 9b. Further, the second side margin portion 3b physically protects the end portion of the internal electrode layer 6 exposed on the second side surface 9b. Hereinafter, a component composed of the laminate 2 and the side margin parts 3a, 3b may be referred to as main body parts 2, 3a, 3b.

The side margin portions 3a and 3b are made of an insulating material. The side margin parts 3a and 3b may be made of ceramic material. With this configuration, the side margin parts 3a and 3b can have insulation properties and relatively high mechanical strength. Further, when the side margin parts 3a, 3b are made of a ceramic material, it becomes possible to simultaneously fire the laminate 2 and the side margin parts 3a, 3b. The side margin portions 3a and 3b may be made of a ceramic material containing, for example, BaTiO ₃ , CaTiO ₃ , SrTiO ₃ , BaZrO ₃ or the like as a main component. In FIG. 1, the boundary between the laminate 2 and the side margin parts 3a, 3b is shown by a two-dot chain line, but the actual boundary is not clearly visible.

The thinner the side margin portions 3a, 3b in the second direction, the smaller the multilayer ceramic capacitor 1 and the larger the capacity. The first side margin portion 3a and the second side margin portion 3b may each have a thickness of, for example, about 30 μm or less.

The first external electrode 4a is located from the first end surface 8a to the first surface 7a, the second surface 7b, the first outer surface 3aa, and the second outer surface 3ba. The first external electrode 4a is electrically connected to the internal electrode layer 6 exposed on the first end surface 8a. The second external electrode 4b is located from the second end surface 8b to the first surface 7a, the second surface 7b, the first outer surface 3aa, and the second outer surface 3ba. The second external electrode 4b is electrically connected to the internal electrode layer 6 exposed on the second end surface 8b.

The first external electrode 4a and the second external electrode 4b have a first portion 41 and a second portion 42. The first portion 41 is located on the first surface 7a and covers a portion of the first surface 7a closer to the first end surface 8a and a portion of the first surface 7a closer to the second end surface 8b. The first portion 41 has a first electrode surface 41a on the opposite side to the first surface 7a side. The second portion 42 is located on the first outer surface 3aa and covers a portion of the first outer surface 3aa closer to the first end surface 8a and a portion of the first outer surface 3aa closer to the second end surface 8b. The second portion 42 has a second electrode surface 42a on the opposite side to the first outer surface 3aa side. The first outer surface 3 aa has a covered region 3 ab covered with the second portion 42 and an exposed region 3 ac exposed from the second portion 42 .

The external electrodes 4a, 4b are composed of one or more conductive layers. The external electrodes 4a, 4b may be composed of a first layer 43 and a second layer 44, as shown in FIGS. 2 and 3. The first layer 43 is also called a base layer. The second layer 44 is also referred to as an outer layer. The base layer 43 is in direct contact with the main body portions 2, 3a, and 3b, and is connected to the end portions of the internal electrode layer 6 exposed on the end surfaces 8a, 8b. The outer layer 44 covers the surface of the base layer 43 on the side opposite to the laminate 2 side. By configuring the external electrodes 4a, 4b with a plurality of conductive layers, it is possible to improve the adhesion between the external electrodes 4a, 4b and the main body parts 2, 3a, 3b. Furthermore, the wettability of the external electrodes 4a and 4b with respect to the conductive bonding material used when mounting the multilayer ceramic capacitor 1 on a substrate can be improved. As a result, the reliability of the multilayer ceramic capacitor 1 and the mounting structure including the multilayer ceramic capacitor 1 can be improved.

The base layer 43 is made of a metal material. Examples of the metal material used for the base layer 43 include metals such as Ni, Cu, Ag, Pd, and Au, and alloys made of these metals. The base layer 43 may be formed using a thin film forming technique such as a plating method, a sputtering method, or a vapor deposition method, or may be formed using a thick film forming technique such as a dipping method, a screen printing method, or a gravure printing method. may have been done.

The outer layer 44 is made of a metal material. Examples of the metal material used for the outer layer 44 include metals such as Ni, Cu, Au, and Sn. The outer layer 44 may be formed using a thin film forming technique such as electroless plating or electrolytic plating.

As shown in FIGS. 2 and 3, in the multilayer ceramic capacitor 1, the distance s1 between the second electrode surface 42a and the exposed area 3ac in the direction perpendicular to the first side surface 9a is equal to the distance s1 between the second electrode surface 42a and the exposed region 3ac in the direction perpendicular to the first surface 7a. This configuration is smaller than the spacing s2 between the electrode surface 41a and the first surface 7a. With this configuration, when mounting the multilayer ceramic capacitor 1 on the substrate 10, the first side surface 9a is mounted so as to face the mounting surface 10a of the substrate 10 (see FIGS. 10 and 11), so that the first surface 7a is mounted on the substrate 10. The distance between the multilayer ceramic capacitor 1 and the mounting surface 10a can be made smaller than when mounting the multilayer ceramic capacitor 1 so as to face the surface 10a. As a result, when the multilayer ceramic capacitor 1 is driven, the multilayer ceramic capacitor 1 and the substrate 10 can be brought into substantially surface contact, and the deflection of the substrate 10 can be suppressed. As a result, the vibration of the substrate 10 due to the deflection of the substrate 10 can be reduced, and the noise of the substrate 10 can be reduced. In this specification, the distance between the multilayer ceramic capacitor 1 and the mounting surface 10a refers to the distance between the mounting surface 10a and a portion of the main body portions 2, 3a, 3b that is not covered with the external electrodes 4a, 4b. Further, when the distance between the second electrode surface 42a and the exposed region 3ac is not constant, the average value of the distance between the second electrode surface 42a and the exposed region 3ac may be set as the distance s1. Moreover, when the distance between the first electrode surface 41a and the first surface 7a is not constant, the average value of the distance between the first electrode surface 41a and the first surface 7a may be set as the distance s2.

The multilayer ceramic capacitor 1 may have a configuration in which the second electrode surface 42a and the exposed region 3ac are flush with each other. With this configuration, when mounting the multilayer ceramic capacitor 1 on the substrate 10, the distance between the multilayer ceramic capacitor 1 and the mounting surface 10a can be substantially reduced by mounting the multilayer ceramic capacitor 1 so that the first side surface 9a faces the mounting surface 10a. can be lost. As a result, the deflection of the substrate 10 when the multilayer ceramic capacitor 1 is driven can be effectively reduced, and the noise of the substrate 10 can be effectively reduced.

According to the multilayer ceramic capacitor 1, the visibility when viewed from the first surface 7a side is different from the visibility when viewed from the first outer surface 3aa side because the spacing s1 and the spacing s2 are different. , the first outer surface 3aa can be easily identified. As a result, when mounting the multilayer ceramic capacitor 1 on the substrate 10, it becomes easy to mount the multilayer ceramic capacitor 1 with the first side surface 9a facing the mounting surface 10a.

In the multilayer ceramic capacitor 1 of the present disclosure, the second side margin portion 3b may be configured similarly to the first side margin portion 3a, and the portion of the external electrodes 4a, 4b located on the second outer surface 3ba is It may be configured similarly to the second portion 42 of 4a, 4b. Further, the second surface 7b may be configured similarly to the first surface 7a, and the portions of the external electrodes 4a, 4b located on the second surface 7b are configured similarly to the first portion 41 of the external electrodes 4a, 4b. It's okay to be.

Next, another example of the multilayer ceramic capacitor 1 of the present disclosure will be described.

As shown in FIG. 4, the multilayer ceramic capacitor 1 has a distance s3 (also referred to as a center side margin) between the exposed area 3ac of the first outer surface 3aa and the first side surface 9a in the direction perpendicular to the first side surface 9a. , the distance between the covering region 3ab of the first outer surface 3aa and the first side surface 9a (also referred to as an end surface side margin) s4 may be larger. Since the central side margin s3 is relatively large, the mechanical strength of the first outer surface 3aa side of the main body portions 2, 3a, 3b can be increased. As a result, even if an impact is applied to the exposed region 3ac when mounting the multilayer ceramic capacitor 1 on the substrate 10, for example, the occurrence of cracks starting from the exposed region 3ac can be reduced, so the multilayer ceramic capacitor 1 reliability can be improved. The size of the central side margin s3 may be, for example, about 30 μm or less. Furthermore, even if it is necessary to secure a central side margin s3 of a predetermined size for the multilayer ceramic capacitor 1 of a predetermined size, a wide area of the internal electrode layer 6 when viewed along the third direction can be ensured. can do. As a result, it becomes possible to provide a small-sized and large-capacity multilayer ceramic capacitor 1. Note that when the distance between the exposed region 3ac and the first side surface 9a is not constant, the average value of the distance between the exposed region 3ac and the first side surface 9a may be set as the distance s3. Moreover, when the distance between the covering region 3ab and the first side surface 9a is not constant, the average value of the distance between the covering region 3ab and the first side surface 9a may be set as the distance s4.

The end side margin s4 electrically insulates the first external electrode 4a and the internal electrode layer 6 connected to the second external electrode 4b, and the internal electrode layer 6 connected to the second external electrode 4b and the first external electrode 4a. It may have any size as long as it can electrically insulate it from the electrode layer 6. The size of the end side margin s4 may be about 5% to 80% of the size of the center side side margin s3. The size of the end side side margin s4 may be, for example, about 1 μm or more. Since the covering region 3ab is covered by the external electrodes 4a and 4b, cracks starting from the covering region 3ab are unlikely to occur even if the end face side side margin s4 is relatively small.

As shown in FIG. 4, the multilayer ceramic capacitor 1 has a first outer surface 3aa having at least two bent portions 3ad in a cross section parallel to the first surface 7a, and a first outer electrode 4a and a second outer electrode 4b. may extend to two bent portions 3ad. With this configuration, the contact area between the external electrodes 4a, 4b and the first side margin portion 3a can be increased, and the connection strength between the external electrodes 4a, 4b and the main body portions 2, 3a, 3b can be increased. As a result, the reliability of the multilayer ceramic capacitor 1 can be improved because the possibility that the external electrodes 4a, 4b will peel off from the main body parts 2, 3a, 3b can be reduced.

The first side margin portion 3a has a thickness in the second direction in each of the two bent portions 3ad from the end surfaces 8a, 8b side of the main body portions 2, 3a, 3b in the first direction of the main body portions 2, 3a, 3b. It may become thicker toward the center. Thereby, the first side margin portion 3a and the external electrodes 4a, 4b can form a recess 22, as shown in FIG. As a result, even if a large amount of the conductive bonding material 12 flows between the multilayer ceramic capacitor 1 and the substrate 10 when the multilayer ceramic capacitor 1 is mounted on the substrate 10, the excess conductive bonding material 12 will enter the recess 22. Since it accumulates, it becomes difficult to flow toward the center of the multilayer ceramic capacitor 1 in the first direction (see FIGS. 10 and 11). Furthermore, since the risk of electrical short circuit between the first external electrode 4a and the second external electrode 4b can be reduced, the reliability of the mounting structure including the multilayer ceramic capacitor 1 can be improved.

As shown in FIGS. 5 and 6, in the multilayer ceramic capacitor 1, the distance s5 between the second electrode surface 42a and the exposed area 3ac in the direction perpendicular to the first side surface 9a is the same as the distance s5 between the second electrode surface 42a and the exposed region 3ac in the direction perpendicular to the first surface 7a. The structure may be smaller than the spacing s6 between the electrode surface 41a and the first surface 7a. In other words, the multilayer ceramic capacitor 1 may have a configuration in which the second portions 42 of the external electrodes 4a, 4b are thinner than the first portions 41 of the external electrodes 4a, 4b. With this configuration, when mounting the multilayer ceramic capacitor 1 on the substrate 10, the external electrodes 4a and 4b are mounted so that the first side surface 9a faces the mounting surface 10a of the substrate 10 (see FIGS. 10 and 11). The distance between the electrically connected substrate electrodes 11a, 11b and the internal electrode layer 6 can be shortened. As a result, the equivalent series inductance of the mounting structure including the multilayer ceramic capacitor 1 can be reduced. As a result, it is possible to provide a multilayer ceramic capacitor 1 that can reduce the noise of the substrate 10 and can be used in a high frequency region. Note that when the distance between the second electrode surface 42a and the exposed region 3ac is not constant, the average value of the distance between the second electrode surface 42a and the exposed region 3ac may be set as the distance s5. Further, when the distance between the first electrode surface 41a and the first surface 7a is not constant, the average value of the distance between the first electrode surface 41a and the first surface 7a may be set as the distance s6.

By making the thickness of the second portion 42 thinner than the thickness of the first portion 41, the interval s1 can be made smaller than the interval s2 even when the thickness of the first side margin portion 3a is constant (Fig. (see 2, 3). Therefore, the process of forming the side margin portions 3a, 3b in manufacturing the multilayer ceramic capacitor 1 can be simplified.

Next, an example of a method for manufacturing the multilayer ceramic capacitor 1 will be described.

First, a powder whose main component is a dielectric material such as BaTiO ₃ , CaTiO ₃ , SrTiO ₃ or a mixture thereof is prepared as a material for the dielectric layer 5, and an organic vehicle is added to the powder to prepare a ceramic slurry. do. Next, a ceramic green sheet (hereinafter also simply referred to as a green sheet) 13 is produced using a sheet forming method such as a doctor blade method or a die coater method. The thickness of the green sheet 13 may be, for example, about 0.5 to 10 μm.

Next, as the material for the internal electrode layer 6, a conductive paste is prepared using a powder whose main component is a metal material such as Ni, Cu, Ag, or a mixture thereof. Next, using the adjusted conductive paste, a pattern sheet 14 is formed on the main surface of the green sheet 13 with an electrode pattern that will become an internal electrode layer printed thereon. For printing the electrode pattern, a printing method such as a screen printing method or a gravure printing method can be used, for example.

Next, a predetermined number of patterned sheets 14 are stacked on top of the predetermined number of stacked green sheets 13, and then a predetermined number of green sheets 13 are stacked (see FIG. 7A) to produce a temporary laminate. Next, the temporary laminate is pressed in the stacking direction to obtain a mother laminate 15 (see FIG. 7B). The temporary laminate can be pressed using, for example, a hydrostatic press device. The mother laminate 15 is cut along the virtual dividing line 16 to produce a laminate precursor 2p that will become the laminate 2 (see FIG. 7C). The mother laminate 15 can be cut using, for example, a push cutter, a dicing saw device, or the like. Note that since the laminate precursor 2p has the same structure as the laminate 2, terms such as main surfaces 7a, 7b, end surfaces 8a, 8b, side surfaces 9a, 9b, etc. and reference numerals will be used hereinafter also for the laminate precursor 2p. Use.

Next, ceramic green sheets that will become the side margin parts 3a and 3b are formed on the side surfaces 9a and 9b of the laminate precursor 2p. FIG. 8A shows an example of the configuration of an apparatus for forming green sheets that will become side margin portions 3a and 3b on side surfaces 9a and 9b. The second side surface 9b of the laminate precursor 2p is fixed to the lower surface of the first pedestal 18a via an adhesive and removable support sheet 17. A second pedestal 18b is arranged below the laminate precursor 2p fixed to the first pedestal 18a. The first pedestal 18a and the second pedestal 18b are arranged such that the lower surface of the first pedestal 18a and the upper surface of the second pedestal 18b are substantially parallel. A plurality of band-like members 19 are arranged on the upper surface of the second pedestal 18b. The plurality of strip members 19 are arranged so as to extend in a direction perpendicular to the first surface 7a of the laminate precursor 2p. The interval between adjacent strip members 19 is shorter than the length of the laminate precursor 2p (the distance between the first end surface 8a and the second end surface 8b). A resin sheet 20 made of an elastic material is arranged above the second pedestal 18b so as to cover the plurality of band-shaped members 19. A green sheet 21 serving as the first side margin portion 3a is arranged on the upper surface of the resin sheet 20.

First, as shown in FIG. 8B, the first pedestal 18a is moved downward and the laminate precursor 2p is pressed against the green sheet 21, thereby pressing the green sheet 21 onto the first side surface 9a. At this time, the laminate precursor 2p is pressed with such a pressing force that the resin sheet 20 is deformed according to the shape of the striped steps formed by the second pedestal 18b and the plurality of strip members. Thereby, the green sheet 21 that is pressure-bonded to the first side surface 9a can be made so that the thickness of the center side in the length direction (left-right direction in FIG. 9B) is thicker than the thickness of the end surface side.

Next, as shown in FIG. 8C, the first pedestal 18a is moved upward with the green sheet 21 being pressed onto the first side surface 9a of the laminate precursor 2p. Since the portion of the green sheet 21 that is not in contact with the first side surface 9a remains on the resin sheet 20, the green sheet 21 that becomes the first side margin portion 3a can be formed on the first side surface 9a. Similarly, the green sheet 21 that will become the second side margin part 3b can be formed on the second side surface 9b, and the main body precursor that will become the main body parts 2, 3a, and 3b can be produced.

Next, the main body precursor is degreased in an air atmosphere, an inert gas atmosphere, or a reducing atmosphere at atmospheric pressure or reduced pressure, and then fired in a reducing atmosphere. The firing temperature may be, for example, about 1100°C to 1300°C. Subsequently, the fired main body precursor is subjected to reoxidation treatment in a nitrogen atmosphere. After the re-oxidation treatment, the main body precursor is placed in a pot containing polishing powder, polishing media, etc., and rotated and polished to remove corners and burrs, resulting in a product as shown in Figure 9. The main body parts 2, 3a, 3b are obtained. The multilayer ceramic capacitor 1 can be manufactured by forming external electrodes 4a, 4b on the obtained main body parts 2, 3a, 3b.

As described above, the multilayer ceramic capacitor 1 may have a configuration in which the second portion 42 of the external electrodes 4a, 4b is thinner than the first portion 41 of the external electrodes 4a, 4b (see FIGS. 5 and 6). reference). Such a multilayer ceramic capacitor 1 can be manufactured as follows.

First, the main body portions 2, 3a, and 3b are manufactured by a method similar to the above method. In addition, in the side margin parts 3a and 3b, the center side margin s3 may be larger than the end side side margin s4 (see FIG. 4), and the center side side margin s3 and the end side side margin s4 may be the same size. It's okay. In other words, when forming the ceramic green sheets 21 that will become the side margin parts 3a and 3b on the side surfaces 9a and 9b, the apparatus having the configuration shown in FIG. 9A may be used, and the plurality of strip members 19 are not arranged. , an apparatus may be used in which a ceramic green sheet 21 is disposed on the upper surface of the second pedestal 18b with a resin sheet 20 interposed therebetween.

Next, a conductive paste that will become the base layer 43 is prepared, and the prepared conductive paste is applied to a portion of the main body portions 2, 3a, 3b near the first end surface 8a and a portion near the second end surface 8b with a constant thickness. do. Subsequently, the conductive paste applied to the first outer surface 3aa is subjected to a blot process. The blot process is a process of removing (wiping off) a part of the conductive paste applied to the first outer surface 3aa by pressing the conductive paste applied to the first outer surface 3aa and then pulling it away. be. After firing the main body parts 2, 3a, 3b coated with the conductive paste and forming the base layer 43, the outer layer 44 is formed, so that the thickness of the second part 42 is thinner than the thickness of the first part 41. Electrodes 4a and 4b can be formed.

Next, the mounting structure of the present disclosure will be described.

The mounting structure 100 of this embodiment includes a multilayer ceramic capacitor 1 and a substrate 10, as shown in FIGS. The substrate 10 has a mounting surface 10a. A first substrate electrode 11a and a second substrate electrode 11b are located on the mounting surface 10a. A first external electrode 4a and a second external electrode 4b are electrically connected to the first substrate electrode 11a and the second substrate electrode 11b, respectively. An electric circuit electrically connected to the multilayer ceramic capacitor 1 may be located on the mounting surface 10a.

Multilayer ceramic capacitor 1 is mounted on mounting surface 10a such that first side surface 9a faces mounting surface 10a. The first external electrode 4a and the second external electrode 4b are bonded to the first substrate electrode 11a and the second substrate electrode 11b, respectively, via the conductive bonding material 12. As the conductive bonding material 12, solder, brazing material, etc. can be used.

In the mounting structure 100, since the distance between the multilayer ceramic capacitor 1 and the mounting surface 10a is small, the noise of the substrate 10 when the multilayer ceramic capacitor 1 is driven can be reduced.

Although the embodiments of the present disclosure have been described in detail above, the present disclosure is not limited to the above-described embodiments, and various changes and improvements can be made without departing from the gist of the present disclosure. be.

The multilayer ceramic capacitor and mounting structure of the present disclosure can be implemented in the following configurations (1) to (6).

(1) A substantially rectangular laminate in which dielectric layers and internal electrode layers are alternately stacked, a first surface and a second surface facing each other, a first side surface and a second side surface facing each other, and a laminate having a first end face and a second end face facing each other,
a first side margin portion located on the first side surface and having a first outer surface opposite to the first side surface side;
a second side margin portion located on the second side surface and having a second outer surface opposite to the second side surface side;
a first external electrode located from the first end surface to the first surface, the second surface, the first outer surface, and the second outer surface;
a second external electrode located from the second end surface to the first surface, the second surface, the first outer surface, and the second outer surface;
The first external electrode and the second external electrode are connected to different internal electrode layers of the internal electrode layer,
The first external electrode and the second external electrode each have a first portion located on the first surface and a second portion located on the first outer surface,
The first portion has a first electrode surface opposite to the first surface side,
The second portion has a second electrode surface opposite to the first outer surface side,
The first outer surface has a covered region covered with the second portion and an exposed region not covered with the second portion,
A multilayer ceramic, wherein a distance between the second electrode surface and the exposed region in a direction perpendicular to the first side surface is smaller than a distance between the first electrode surface and the first surface in the direction perpendicular to the first surface. capacitor.

(2) The multilayer ceramic capacitor according to (1) above, wherein the first side surface is positioned to face the substrate when the multilayer ceramic capacitor is mounted on the substrate.

(3) According to (1) or (2) above, the distance between the exposed region and the first side surface is larger than the distance between the covered region and the first side surface in a direction perpendicular to the first side surface. multilayer ceramic capacitor.

(4) The first outer surface has two bent parts, and the first external electrode and the second external electrode each extend to the two bent parts. multilayer ceramic capacitor.

(5) The distance between the second electrode surface and the covered area in the direction perpendicular to the first side surface is smaller than the distance between the first electrode surface and the first surface in the direction perpendicular to the first surface. , the multilayer ceramic capacitor according to any one of (1) to (4) above.

(6) the multilayer ceramic capacitor according to any one of (1) to (5) above;
A board having a mounting surface;
The multilayer ceramic capacitor is a mounting structure mounted on the substrate so that the first side faces the mounting surface.

1 Multilayer Ceramic Capacitor 2 Laminate 2p Laminate Precursor 3a First Side Margin Part 3a Side Margin Part 3aa First Outer Surface 3ab Covered Area 3ac Exposed Area 3ad Bent Part 3b Second Side Margin Part 3ba Second Outer Side 4a First External electrode 4b Second external electrode 41 First portion 41a First electrode surface 42 Second portion 42a Second electrode surface 43 First layer (base layer)
44 Second layer (outer layer)
5 Dielectric layer 6 Internal electrode layer 7a First surface 7b Second surface 8a First end surface 8b Second end surface 9a First side surface 9b Second side surface 10 Substrate 10a Mounting surface 11a First substrate electrode 11b Second substrate electrode 12 Conductivity Bonding material 13 Ceramic green sheet 14 Pattern sheet 15 Mother laminate 16 Virtual dividing line 17 Support sheet 18a First pedestal 18b Second pedestal 19 Band member 20 Resin sheet 21 Ceramic green sheet 22 Recess 100 Mounting structure

Claims (6)

A substantially rectangular laminate in which dielectric layers and internal electrode layers are alternately laminated, the first and second surfaces facing each other, the first and second side surfaces facing each other, and the first and second sides facing each other. a laminate having a first end face and a second end face facing each other;
a first side margin portion located on the first side surface and having a first outer surface opposite to the first side surface side;
a second side margin portion located on the second side surface and having a second outer surface opposite to the second side surface side;
a first external electrode located from the first end surface to the first surface, the second surface, the first outer surface, and the second outer surface;
a second external electrode located from the second end surface to the first surface, the second surface, the first outer surface, and the second outer surface;
The first external electrode and the second external electrode are connected to different internal electrode layers of the internal electrode layer,
The first external electrode and the second external electrode each have a first portion located on the first surface and a second portion located on the first outer surface,
The first portion has a first electrode surface opposite to the first surface side,
The second portion has a second electrode surface opposite to the first outer surface side,
The first outer surface has a covered region covered with the second portion and an exposed region not covered with the second portion,
A multilayer ceramic, wherein the distance between the second electrode surface and the exposed region in the direction perpendicular to the first side surface is smaller than the distance between the first electrode surface and the first surface in the direction perpendicular to the first surface. capacitor. The multilayer ceramic capacitor according to claim 1, wherein the first side surface is positioned to face the substrate when the multilayer ceramic capacitor is mounted on the substrate. 3. The multilayer ceramic capacitor according to claim 1, wherein a distance between the exposed region and the first side surface is larger than a distance between the covered region and the first side surface in a direction perpendicular to the first side surface. The multilayer ceramic capacitor according to claim 3, wherein the first outer surface has two bent portions, and the first external electrode and the second external electrode each extend to the two bent portions. . A distance between the second electrode surface and the covering region in a direction perpendicular to the first side surface is smaller than a distance between the first electrode surface and the first surface in a direction perpendicular to the first surface. 2. The multilayer ceramic capacitor according to 1 or 2. The multilayer ceramic capacitor according to claim 1,
A board having a mounting surface;
The multilayer ceramic capacitor is a mounting structure mounted on the substrate so that the first side faces the mounting surface.