Multilayer ceramic electronic component

Abstract

Provided is a multilayer ceramic electronic component with which flexural strength can be improved while suppressing whining noise. A multilayer ceramic electronic component 1 comprises a capacitor body 1A comprising a stacked body 2 and two external electrodes that are disposed on each of two end surfaces of the stacked body, are connected to an internal electrode layer 15, and cover a portion of a main surface, and two spacers arranged respectively on one end surface side and the other end surface side of one main surface side of the capacitor body 1A, sandwiching the external electrodes 3, and a reinforcing material 5, wherein: the reinforcing material 5 has a spacer-side covering portion 52 covering at least 4.9% of each of the two spacers in a stacking direction and a capacitor-side covering portion 51 which continues from the spacer-side covering portion 52 and covers the spacer side of an outer periphery of the capacitor body 1A; and the spacer-side covering portion continuously covers opposing spacer end surfaces, among end surfaces of the two spacers, that oppose one other between the two spacers, and two spacer side surfaces.

Description

Multilayer ceramic electronic components

[0001] The present invention relates to a multilayer ceramic electronic component such as a multilayer ceramic capacitor.

[0002] Multilayer ceramic electronic components such as multilayer ceramic capacitors are widely used in various electronic devices, such as mobile terminal devices such as mobile phones and personal computers. A multilayer ceramic capacitor comprises a rectangular parallelepiped laminate in which dielectric layers and internal electrode layers are alternately stacked, and external electrodes formed on both opposing ends of the laminate.

[0003] A multilayer ceramic capacitor has an inner layer portion in which dielectric layers and internal electrodes are alternately stacked, and dielectric layers are disposed on the top and bottom of the inner layer portion as outer layers to form a rectangular parallelepiped laminate, and external electrodes are provided on both longitudinal end faces of the laminate to form a capacitor body.

[0004] Furthermore, in order to suppress the occurrence of so-called "squeak noise," a multilayer ceramic capacitor is known that includes a spacer formed on the side of the capacitor body that is mounted on the substrate so as to cover part of the external electrodes.

[0005] Japanese Patent Application Laid-Open No. 2015-216337

[0006] The multilayer ceramic electronic component described in Patent Document 1 uses a conductive resin as the spacer material and is plated on top of it. However, the conductive resin layer has poor conductivity, which increases the ESR (equivalent series resistance) of the multilayer ceramic electronic component. For this reason, some multilayer ceramic capacitors use metal spacers to ensure conductivity and suppress acoustic noise, but metal spacers have poor resistance to flexure strength.

[0007] An object of the present invention is to provide a multilayer ceramic electronic component that can suppress acoustic noise while improving flexural strength.

[0008] In order to solve the above problems, the present invention provides a capacitor body including: a laminate in which dielectric layers and internal electrode layers are alternately laminated, the laminate having two main surfaces opposing each other in a lamination direction, two end surfaces opposing each other in a length direction intersecting the lamination direction, and two side surfaces opposing each other in a width direction intersecting the lamination direction and the length direction; and two external electrodes arranged on each of the two end surfaces, connected to the internal electrode layers, and extending to the two main surfaces to cover a part of the main surfaces or a part of the opposing side surfaces or both of the main surfaces; and two external electrodes arranged on one end surface side and the other end surface side of one of the main surfaces or one side surface side of the capacitor body, each of which is arranged on one end surface side and the other end surface side of the capacitor body, and ... and a reinforcing material, wherein the reinforcing material has a spacer-side covering portion that covers 4.9% or more of the length of each of the two spacers in the stacking direction or the width direction, and a capacitor-side covering portion that is continuous with the spacer-side covering portion and covers the spacer side of the outer periphery of the capacitor body, and the spacer-side covering portion continuously covers the opposing spacer end faces of the two spacers that are opposed to each other, and the two spacer side faces.

[0009] According to the present invention, it is possible to provide a multilayer ceramic electronic component that can suppress acoustic noise and improve flexural strength.

[0010] 1 is a schematic perspective view of a multilayer ceramic capacitor 1. FIG. 2 is a cross-sectional view of the multilayer ceramic capacitor 1 taken along line II-II in FIG. 1. FIG. 3 is a cross-sectional view of the multilayer ceramic capacitor 1 taken along line III-III in FIG. 1. FIG. 4 is an enlarged view of a spacer 4 portion in the cross-sectional view of the multilayer ceramic capacitor 1 in FIG. 2. FIG. 5 is a diagram illustrating a covering state of a spacer-side covering portion 52 in a reinforcing material 5, with (a), (b), and (c) being an embodiment and (d) and (e) being a comparative embodiment. FIG. 6 is a diagram illustrating a covering state of a capacitor body 1A with a capacitor-side covering portion 51 of a reinforcing material 5. FIG. 7 is a flowchart illustrating a method for manufacturing a multilayer ceramic capacitor 1. FIG. 8 is a diagram illustrating a laminate manufacturing step S1 and an external electrode forming step S2. FIG. 9 is a diagram illustrating a spacer arranging step S3. FIG. 10 is a diagram illustrating a reinforcing material arranging step S4. FIG. 11 is a table showing the results of evaluations 1 and 2 performed on a multilayer ceramic capacitor 1 provided with a reinforcing material 5 of an embodiment.

[0011] Hereinafter, a multilayer ceramic capacitor 1 will be described as an embodiment of the multilayer ceramic electronic component of the present invention, but the present invention is not limited thereto. Furthermore, the drawings may be drawn in a simplified and schematic manner to explain the contents of the invention, and the dimensional ratios of the depicted components or between the components may not match the dimensional ratios of those components described in the specification. Furthermore, components described in the specification may be omitted in the drawings, or the number of components may be omitted.

[0012] Fig. 1 is a schematic perspective view of a multilayer ceramic capacitor 1 according to an embodiment. Fig. 2 is a cross-sectional view of the multilayer ceramic capacitor 1 according to an embodiment taken along line II-II in Fig. 1. Fig. 3 is a cross-sectional view of the multilayer ceramic capacitor 1 according to an embodiment taken along line III-III in Fig. 1.

[0013] The multilayer ceramic capacitor 1 has a substantially rectangular parallelepiped shape and comprises a capacitor body 1A including a laminate 2 and a pair of external electrodes 3 provided on both ends of the laminate 2, a spacer 4 attached to the capacitor body 1A, and a reinforcing material 5 covering the spacer 4 and a portion of the capacitor body 1A. The laminate 2 also includes an inner layer portion 11 in which dielectric layers 14 and internal electrode layers 15 are laminated.

[0014] In the following description, the terms used to represent the orientation of the multilayer ceramic capacitor 1 are: a length direction L, which is the direction in which a pair of external electrodes 3 are provided in the multilayer ceramic capacitor 1; a stacking direction T, which is the direction in which the dielectric layers 14 and the internal electrode layers 15 are stacked; and a width direction W, which is the direction intersecting both the length direction L and the stacking direction T. In the embodiment, the width direction W is perpendicular to both the length direction L and the stacking direction T.

[0015] (Outer Surfaces of Laminate 2) Of the six outer surfaces of the laminate 2, a pair of outer surfaces facing each other in the stacking direction T will be referred to as the first main surface A1 and the second main surface A2, a pair of outer surfaces facing each other in the width direction W will be referred to as the first side surface B1 and the second side surface B2, and a pair of outer surfaces facing each other in the length direction L will be referred to as the first end surface C1 and the second end surface C2. Note that when there is no need to particularly distinguish between the first main surface A1 and the second main surface A2, they will be collectively referred to as the main surface A; when there is no need to particularly distinguish between the first side surface B1 and the second side surface B2, they will be collectively referred to as the side surface B; and when there is no need to particularly distinguish between the first end surface C1 and the second end surface C2, they will be collectively referred to as the end surface C.

[0016] The laminate 2 preferably has rounded ridges R1 including corners. The ridges R1 are the portions where two surfaces of the laminate 2, i.e., the main surface A and the side surface B, the main surface A and the end surface C, or the side surface B and the end surface C, intersect.

[0017] (Laminate 2) The laminate 2 includes an inner layer portion 11 that forms capacitance, an outer layer portion 12 that is arranged to sandwich the inner layer portion 11 in the stacking direction T, and a side gap portion 16 that is arranged to sandwich the inner layer portion 11 and the outer layer portion 12 in the width direction W.

[0018] (Inner Layer Portion 11) The inner layer portion 11 includes dielectric layers 14 and internal electrode layers 15 alternately stacked along the stacking direction T.

[0019] (Dielectric Layer 14) The dielectric layer 14 is made of a ceramic material, such as BaTiO ３ A dielectric ceramic containing the above as its main component is used.

[0020] (Internal Electrode Layer 15) The internal electrode layer 15 includes a plurality of first internal electrode layers 15a and a plurality of second internal electrode layers 15b. The first internal electrode layers 15a and the second internal electrode layers 15b are alternately arranged. The first internal electrode layer 15a includes a first opposing portion 152a opposing the second internal electrode layer 15b and a first lead portion 151a extending from the first opposing portion 152a toward the first end face C1. An end of the first lead portion 151a is exposed at the first end face C1 and electrically connected to the first external electrode 3a described below. The second internal electrode layer 15b includes a second opposing portion 152b opposing the first internal electrode layer 15a and a second lead portion 151b extending from the second opposing portion 152b to the second end face C2. An end of the second lead portion 151b is electrically connected to the second external electrode 3b described below. Charges are stored in the first opposing portions 152a of the first internal electrode layers 15a and the second opposing portions 152b of the second internal electrode layers 15b.

[0021] The internal electrode layers 15 are preferably formed from a metal material such as nickel (Ni), copper (Cu), silver (Ag), palladium (Pd), a silver-palladium (Ag-Pd) alloy, or gold (Au).

[0022] (Outer Layer Portion 12) The outer layer portion 12 can be formed from the same material as the dielectric layer 14 of the inner layer portion 11.

[0023] (Side gap portion 16) The side gap portion 16 is arranged to sandwich the inner layer portion 11 and the outer layer portion 12 in the width direction W, and includes a first side gap portion 16a that forms the first side surface B1 of the multilayer ceramic capacitor 1, and a second side gap portion 16b that forms the second side surface B2 of the multilayer ceramic capacitor 1. The side gap portion 16 can be formed from the same material as the dielectric layer 14.

[0024] (External electrode 3) The external electrode 3 includes a first external electrode 3a provided on the first end face C1 and a second external electrode 3b provided on the second end face C2. The external electrode 3 covers not only the end face C but also a part of the main face A and the side face B that are continuous with the end face C.

[0025] As described above, the end of the first lead portion 151a of the first internal electrode layer 15a is exposed at the first end face C1 and is electrically connected to the first external electrode 3a. Also, the end of the second lead portion 151b of the second internal electrode layer 15b is exposed at the second end face C2 and is electrically connected to the second external electrode 3b. This results in a structure in which multiple capacitor elements are electrically connected in parallel between the first external electrode 3a and the second external electrode 3b.

[0026] The external electrode 3 includes, for example, a base electrode layer 30 and a plating layer 31. However, it is not always necessary for the external electrode 3 to have such a layered structure.

[0027] The base electrode layer 30 is formed by, for example, applying and baking a conductive paste containing copper (Cu). The base electrode layer 30 may also contain glass or a ceramic material. However, the configuration of the base electrode layer 30 is not limited to this.

[0028] The plating layer 31 includes a nickel (Ni) plating layer 31 a disposed on the surface of the base electrode layer 30, and a tin (Sn) plating layer 31 b disposed on the surface of the nickel (Ni) plating layer 31 a. Note that the configuration of the plating layer 31 is not limited to this.

[0029] (Spacer 4) The spacer 4 includes a pair of first and second spacers 4a and 4b. The first spacer 4a is disposed on one end face C1 in the longitudinal direction L of the second main surface A2, which is the mounting surface of the capacitor body 1A, and the second spacer 4b is disposed on the other end face C2. Each spacer 4 is disposed so as to connect to a portion of the external electrode 3 disposed on the second main surface A2. When the mounting surface of the capacitor body 1A is the first side face B1, the first spacer 4a is disposed on one end face C1 in the longitudinal direction L of the first side face B1, which is the mounting surface of the capacitor body 1A, and the second spacer 4b is disposed on the other end face C2.

[0030] In the following, the two surfaces of each spacer 4 facing in the stacking direction T will be referred to as the spacer main surfaces SA, the two surfaces facing in the length direction L as the spacer end surfaces SC, and the two surfaces facing in the width direction W as the spacer side surfaces SB.

[0031] Furthermore, of the two spacer end faces SC, the spacer end face SC closer to the center of the longitudinal direction L of the capacitor body 1A will be described as the central spacer end face SC1, and the spacer end face SC on the outside of the longitudinal direction L of the laminate 2 will be described as the outer spacer end face SC2.

[0032] Of the two spacer main surfaces SA, the spacer main surface SA on the capacitor body 1A side will be referred to as the body-side spacer main surface SA1, and the spacer main surface SA on the other side will be referred to as the mounting-side spacer main surface SA2. When the substrate mounting surface of the capacitor body 1A is the first side surface B1, of the two spacer side surfaces SB, the spacer side surface SB on the capacitor body 1A side will be referred to as the body-side spacer side surface SB1, and the spacer side surface SB on the other side will be referred to as the mounting-side spacer side surface SB2.

[0033] In the embodiment, the length in the longitudinal direction L of each spacer 4 is longer than the external electrode 3 arranged on the second main surface A2. That is, the center-side spacer end face SC1 of each spacer 4 is arranged beyond the external electrode 3, and there is a portion where the body-side spacer main surface SA1 of the spacer 4 directly contacts the second main surface A2 of the laminate 2. However, this is not limited thereto, and the length in the longitudinal direction L of each spacer 4 may be shorter than the external electrode arranged on the second main surface A2. The same applies when the substrate mounting surface of the capacitor body 1A is the first side surface B1.

[0034] In the embodiment, the external electrode 3 is configured by the base electrode layer 30 and the plating layer 31 covering it, and the spacer 4 is disposed on the surface of the plating layer 31. However, for example, the spacer 4 may be disposed on the surface of the base electrode layer 30, and a second plating layer may be disposed so as to cover the spacer 4 and the base electrode layer 30. By disposing the second plating layer, the adhesive strength between the spacer 4 and the base electrode layer 30 is improved.

[0035] (Material of Spacer 4) The spacer 4 contains either copper (Cu) or nickel (Ni) and tin (Sn) as metal powder. The copper (Cu) and nickel (Ni) may be coated with silver (Ag). Furthermore, the spacer 4 may further contain silver (Ag) as a metal constituting an intermetallic compound.

[0036] Intermetallic compounds formed by adding tin (Sn) to either copper (Cu) or nickel (Ni) have a melting point that does not melt, even when soldering is performed when mounting the multilayer ceramic capacitor 1 on a wiring board, and do not deform due to heat. Therefore, the shape of the spacer 4 can be reliably maintained, and it is possible to arrange it while maintaining the desired shape even during soldering. In particular, intermetallic compounds formed by adding tin (Sn) to an alloy of copper (Cu) and nickel (Ni) are preferred as components for forming the spacer 4.

[0037] A phenolic resin may be contained in the metal region MP formed by the metal powder. The phenolic resin coats the particles of the intermetallic compound and is scattered so as to fill the gaps between the particles. The phenolic resin may not completely coat the particles of the intermetallic compound. Furthermore, by using a phenolic resin, the amount of gas generated during the heat treatment for forming the spacer 4 can be reduced, thereby reducing voids within the spacer 4. The phenolic resin may be exposed to the surface of the spacer 4 and coat at least a portion of the surface of the spacer 4. By coating the surface of the spacer 4 with the phenolic resin, the smoothness of the surface of the spacer 4 can be improved, and the mechanical strength of the spacer 4 can be increased.

[0038] Examples of the phenol resin include novolac-type phenol resins such as phenol novolac resin, phenol aralkyl resin, cresol novolac resin, Tcrt-butylphenol novolac resin, and nonylphenol novolac resin; resol-type phenol resin; and polyoxystyrene such as polyparaoxystyrene.

[0039] The area ratio of the phenolic resin in the spacer 4 is preferably 1% to 20% and particularly preferably 5% to 15% in the LT cross section perpendicular to the width direction W of the spacer 4. If it is less than 1%, the effect of the phenolic resin cannot be fully exerted, and if it exceeds 20%, the adhesive strength of the spacer to the external electrode may decrease.

[0040] The percentage (%) of the area occupied by the phenolic resin in the spacer 4 can be calculated, for example, by polishing the spacer 4 in the width direction W up to the center of the width direction W, and then photographing the polished surface with a microscope (BX-51) at a total magnification of 50x using a digital camera for microscopes (DP22 manufactured by Olympus). The obtained photographed image is binarized to separate it into metal regions MP and resin regions RP, and the percentage (%) of the area occupied by the phenolic resin can be calculated from the areas of the metal regions MP, metal powder MF, resin regions RP, and voids P using the formula: (area of ​​resin regions RP) / (area of ​​metal regions MP + area of ​​metal powder MF + area of ​​resin regions RP + area of ​​voids P) × 100.

[0041] Fig. 4 is an enlarged view of the spacer 4 in the cross-sectional view of the multilayer ceramic capacitor 1 in Fig. 2. As shown in Fig. 4, metal powder MF may be contained in the resin region RP formed by the phenolic resin. The metal powder MF inhibits the shrinkage of the phenolic resin, thereby alleviating the shrinkage stress caused by the phenolic resin.

[0042] The spacer 4 preferably has a porosity of 20% or less in a region Z extending from the interface with the external electrode 3 to a depth of 5 μm. By keeping the porosity low, the bonding area of ​​the spacer 4 that is bonded to the external electrode 3 increases, improving the bonding strength with the external electrode 3.

[0043] A void P is formed inside the spacer 4, and the maximum diameter of the void P is preferably ½ or less of the maximum dimension of the thickness of the spacer 4 in the stacking direction T. If the diameter is greater than ½, cracks are more likely to occur starting from the void P, reducing the strength of the spacer 4. When the substrate mounting surface of the capacitor body 1A is the first side surface B1, the maximum diameter of the void P formed inside the spacer 4 is preferably ½ or less of the maximum dimension of the thickness of the spacer 4 in the width direction W.

[0044] The porosity (%) can be calculated, for example, by polishing the spacer 4 in the width direction W up to the center of the width direction W, and then photographing the polished surface with a microscope (BX-51) at a total magnification of 50 times and a digital camera for microscopes (DP22 manufactured by Olympus). The obtained photographed image is binarized to separate it into metal regions MP and voids P, and the porosity (%) can be calculated from the areas of the metal regions MP, metal powder MF, resin regions RP, and voids P using the formula: (area of ​​voids P) / (area of ​​metal regions MP + area of ​​metal powder MF + area of ​​resin regions RP + area of ​​voids P) × 100.

[0045] Although the spacer material described above includes an intermetallic compound and a phenolic resin, the present invention is not limited to this and may include other metal components, or may include a resin other than phenolic resin, such as an epoxy resin or rosin, or a glass component. The spacer may also be formed without including resin. The spacer may be manufactured from a material containing copper or a copper alloy, and may be arranged to be connected via Ni plating and solder.

[0046] When the spacer 4 is smaller than the external electrodes 3 in a plan view from the surface on which the spacer 4 is provided to the surface opposite the surface, it is preferable to provide an orientation discriminator on at least a portion of the spacer 4. The orientation discriminator indicates the orientation for facing the second main surface A2 or the first side surface B1 on which the spacer 4 is provided to the wiring board when mounting the multilayer ceramic capacitor 1 on the wiring board. The orientation discriminator can be implemented by coloring the spacer 4 in a color different from the external electrodes 3, printing an orientation discriminator mark for discriminating the orientation, such as a QR code (registered trademark), or providing a recess in a portion of the laminate. As a coloring method, a phenolic resin contained in the spacer 4 may be exposed on the surface of the spacer 4, so that the spacer 4 has a color different from that of the external electrodes 3. The orientation discriminator may also be provided on the laminate 2, not just the spacer 4. The orientation discriminator may also be provided even when the spacer 4 is larger than the external electrodes 3.

[0047] For example, if the spacers 4 and the external electrodes 3 have the same color, it may be difficult to tell which side the spacers 4 are attached to when viewed from above, which could lead to errors in image processing. However, providing a direction identification mark can prevent such errors in image processing.

[0048] 1 , the reinforcing material 5 includes a capacitor-side covering portion 51 that covers a predetermined length of the capacitor body 1A in the stacking direction T, and a spacer-side covering portion 52 that is continuous with the capacitor-side covering portion 51 and is arranged on the spacer 4 side. When the board mounting surface of the capacitor body 1A is the first side surface B1, the reinforcing material 5 includes the capacitor-side covering portion 51 that covers a predetermined length of the capacitor body 1A in the width direction W, and the spacer-side covering portion 52 that is continuous with the capacitor-side covering portion 51 and is arranged on the spacer 4 side.

[0049] (Material of Reinforcing Material 5) The reinforcing material 5 includes an insulating resin, and in this embodiment, the reinforcing material 5 is primarily made of insulating resin. The surface of the insulating resin may be coated with an insulating water-repellent agent. Forming the reinforcing material 5 from an insulating resin improves flexural strength, and further coating it with an insulating water-repellent agent improves moisture resistance. The insulating resin may contain ceramics, glass, etc. Furthermore, the reinforcing material 5 preferably has a stronger adhesive strength with the laminate 2 than an intermetallic compound. For example, the reinforcing material 5 may be primarily composed of epoxy resin, combined with a phenolic resin as a curing agent. Other curing agents that can be used include acid anhydride-based, amine-based, and ester-based curing agents. A curing accelerator may also be added to the epoxy resin. The reinforcing material 5 may be formed solely from a water-repellent agent.

[0050] (Shape of reinforcing material 5) (Spacer-side covering portion 52) The spacer-side covering portion 52 includes side portions 52a that cover the two spacer side surfaces SB of each of the two spacers 4, and a central portion 52b that is disposed between the center-side spacer end face SC1 of one spacer 4 and the center-side spacer end face SC1 of the other spacer 4 and covers the second main surface A2 of the capacitor body 1A (laminate 2). The central portion 52b covers the center-side spacer end face SC1 of each of the two spacers 4.

[0051] As shown in Figure 2, in this embodiment, when the length of the central portion 52b in the stacking direction T at the center of the longitudinal direction L of the capacitor body 1A (laminated body 2) is Tm and the length in the stacking direction T at the central spacer end face SC1 is Tc, Tm < Tc.

[0052] In the embodiment, the central portion 52b connects the central spacer end face SC1 of one spacer 4 to the central spacer end face SC1 of the other spacer 4. However, the central portion 52b does not necessarily have to be continuous between the first spacer 4a and the second spacer 4b. For example, the central portion 52b may be divided into two portions, one covering the central spacer end face SC1 of the first spacer 4a and a portion on the side of the second main surface A2 of the capacitor body 1A (laminate 2), and the other covering the central spacer end face SC1 of the second spacer 4b and a portion on the side of the second main surface A2 of the capacitor body 1A (laminate 2), and the other portion may be arranged discontinuously.

[0053] In the embodiment, the spacer side covering portion 52 also covers the outer spacer end face SC2, but is not limited to this and does not have to cover the outer spacer end face SC2.

[0054] 5A, 5B, and 5C are diagrams illustrating the covering state of the spacer-side covering portion 52 on the reinforcing material 5, with FIGS. 5A, 5B, and 5C illustrating an embodiment and FIGS. 5D and 5E illustrating a comparative embodiment. In this embodiment, when the stacking direction length (total length) of the spacer 4 is Ts and the stacking direction length of the side surface 52a of the spacer-side covering portion 52 on the reinforcing material 5 is T1, the stacking direction length T1 of the side surface 52a is 4.9% or more of the stacking direction length Ts of the spacer 4. As will be described later, the side surface 52a does not cover the mounting-side spacer principal surface SA2 of the spacer principal surface SA of the spacer 4, and therefore, is less than 100%. That is, 0.049≦T1 / Ts<1.

[0055] FIG. 5(a) shows the case where T1 / Ts is about 0.5, and FIG. 5(b) shows the case where T1 / Ts is about 0.95.

[0056] 5C shows a case where the mounting-side spacer main surface SA2 is inclined with respect to the body-side spacer main surface SA1. In FIG. 5C, T1 / Ts is approximately 0.7 at the portion of the mounting-side spacer main surface SA2 farthest from the body-side spacer main surface SA1, but T1 / Ts is approximately 1 at the portion of the mounting-side spacer main surface SA2 closest to the body-side spacer main surface SA1. However, even at the portion of the mounting-side spacer main surface SA2 closest to the body-side spacer main surface SA1, the reinforcing material 5 does not extend to the mounting-side spacer main surface SA2, and no reinforcing material 5 is disposed on the mounting-side spacer main surface SA2.

[0057] FIG. 5D shows a comparative example in which T1 / Ts is greater than 1 and the reinforcing material 5 is also disposed on the mounting-side spacer main surface SA2.

[0058] 5(e) shows a comparative example in which the mounting-side spacer main surface SA2 is inclined relative to the body-side spacer main surface SA1. Unlike the case of FIG. 5(c), T1 / Ts is approximately 0.9 at the portion of the mounting-side spacer main surface SA2 that is farthest from the body-side spacer main surface SA1, but T1 / Ts is 1 or greater at the portion of the mounting-side spacer main surface SA2 that is closest to the body-side spacer main surface SA1. Furthermore, in the portion of the mounting-side spacer main surface SA2 that is closest to the body-side spacer main surface SA1, the reinforcing material 5 is present on the mounting-side spacer main surface SA2.

[0059] 5(d) and 5(e), which are comparative examples, the reinforcing material 5 extends to the mounting-side spacer main surface SA2, so when the multilayer ceramic capacitor 1 is mounted on a substrate, the presence of the reinforcing material 5 hinders electrical continuity between the spacer 4 and the substrate. Furthermore, if the reinforcing material 5 covers the mounting-side spacer main surface SA2 of the spacer 4, the solder will not bond to the spacer 4 during mounting, which may increase the risk of mounting defects.

[0060] 5(a) to 5(c), however, the reinforcing material 5 is not present on the mounting-side spacer main surface SA2, ensuring good electrical continuity between the spacer 4 and the substrate, i.e., good electrical continuity between the substrate and the external electrodes 3. Furthermore, the solder and spacer 4 are fixed together during mounting, reducing the possibility of mounting defects.

[0061] It is preferable that the reinforcing material 5 is not disposed between the external electrode 3 and the spacer 4 on the main body-side spacer main surface SA1 of the spacer 4. Since the reinforcing material 5 is not disposed between the external electrode 3 and the spacer 4, electrical connection between the external electrode 3 and the spacer 4 can be ensured.

[0062] However, if there is a gap between the spacer 4 and a portion of the second main surface A2 of the laminate 2 where the external electrode 3 is not arranged, the reinforcing material 5 may be arranged so as to fill the gap. If the reinforcing material 5 fills the gap, the bonding area between the reinforcing material 5 and the spacer 4 increases, thereby increasing the bonding strength. Note that if the gap is not completely filled with the reinforcing material 5, the gap can mitigate the propagation of vibration.

[0063] It is preferable that the reinforcing material 5 covers a larger area of ​​the surfaces other than the spacer main surface SA, since this improves the reinforcing effect.

[0064] (Capacitor side covering portion 51) Figure 6 is a diagram illustrating the state in which the capacitor body 1A is covered by the capacitor side covering portion 51 of the reinforcing material 5. The capacitor side covering portion 51 covers a predetermined length range in the stacking direction on the second main surface A2 side of the capacitor body 1A. If the length in the stacking direction of the capacitor body 1A is Tc and the length in the stacking direction of the capacitor side covering portion 51 is T2, T2 / Tc is approximately 0.05 in Figure 6(a), approximately 0.5 in Figure 6(b), and approximately 1.1 in Figure 6(c).

[0065] As long as the capacitor-side covering portion 51 of the reinforcing material 5 covers the capacitor body 1A, the coverage may be partial as in Figures 6(a) and 6(a), but it is preferable that the reinforcing material 5 covers the entire capacitor body 1A as in Figure 6(c). In other words, it is preferable that the reinforcing material 5 covers a portion of the spacer 4 and the entire capacitor body 1A. By having the reinforcing material 5 cover the entire capacitor body 1A, the cushioning properties of the reinforcing material 5 are enhanced, and the impact resistance when an impact is applied to the multilayer ceramic capacitor 1 can be improved.

[0066] (Measurement Method) As explained above, the measurement of the length of the reinforcing material 5 in the lamination direction T can be performed, for example, as follows. When the wiring board and the multilayer ceramic capacitor 1 are joined by solder, the multilayer ceramic capacitor 1 joined to the wiring board by solder is polished in the width direction W to an LT cross-sectional position where the multilayer ceramic capacitor 1 and the reinforcing material 5 can be seen. Next, using a microscope (e.g., BX-51, manufactured by Olympus) connected to a digital camera for a microscope (e.g., DP22, manufactured by Olympus), the length of the reinforcing material 5 in the lamination direction T is measured with an appropriate adjustment of the total magnification, such as 10 to 50 times.

[0067] (Effects of Reinforcing Material 5) According to the embodiment, the reinforcing material 5 includes a spacer-side covering portion 52 that covers 4.9% or more of each of the two spacers in the stacking direction T, and a capacitor-side covering portion 51 that is continuous with the spacer-side covering portion 52 and covers the spacer side of the outer periphery of the capacitor body 1A. This makes it possible to ensure substrate bending resistance while maintaining the effect of suppressing acoustic noise.

[0068] Furthermore, in each spacer 4, the spacer-side covering portion 52 of the reinforcing material 5 continuously covers the central spacer end face SC1 and the two spacer side faces SB of the two spacer end faces SC, thereby increasing the area of ​​the spacer 4 covered by the reinforcing material 5, thereby making it possible to further strengthen the substrate bending resistance.

[0069] Furthermore, when the reinforcing material 5 covers the entire capacitor body 1A, it can further strengthen the bending resistance of the substrate.

[0070] (Method of Manufacturing Multilayer Ceramic Capacitor 1) Fig. 7 is a flowchart illustrating a method of manufacturing the multilayer ceramic capacitor 1. The method of manufacturing the multilayer ceramic capacitor 1 includes a laminate manufacturing step S1, an external electrode forming step S2, a spacer arranging step S3, and a reinforcing material arranging step S4. Fig. 8 is a diagram illustrating the laminate manufacturing step S1 and the external electrode forming step S2. Fig. 9 is a diagram illustrating the spacer arranging step S3. Fig. 10 is a diagram illustrating the reinforcing material arranging step S4.

[0071] (Laminate manufacturing process S1) A ceramic slurry containing ceramic powder, a binder, and a solvent is formed into a sheet on the surface of a carrier film using a die coater, gravure coater, microgravure coater, or the like to prepare a ceramic green sheet 101 for lamination that will become the dielectric layer 14. Next, a conductive paste is printed in strips on the ceramic green sheet 101 for lamination by screen printing, inkjet printing, gravure printing, or the like, and a conductive pattern 102 that will become the internal electrode layer 15 is printed on the surface of the ceramic green sheet 101 for lamination to prepare a material sheet 103.

[0072] 8( a), a plurality of material sheets 103 are stacked such that the conductive patterns 102 face the same direction and are offset, for example, by half a pitch, between adjacent material sheets 103 in the length direction L. Furthermore, outer layer ceramic green sheets 112 that will become the outer layer portions 12 are stacked on both sides of the plurality of stacked material sheets 103.

[0073] The stacked material sheets 103 and the outer layer ceramic green sheets 112 are pressed together by a hydrostatic press or the like to form a mother block 110 shown in FIG. 8(b).

[0074] Next, the mother block 110 is cut along cutting lines X and Y intersecting with cutting line X shown in FIG. 8(b) to produce a plurality of laminates 2 shown in FIG. 8(c).

[0075] (External electrode forming process S2) Subsequently, a conductive paste containing copper (Cu) is applied to and baked on the end surface C of the laminate 2 to form a base electrode layer 30. The base electrode layer 30 is formed not only on both end surfaces C of the laminate 2 but also extends to the main surface A and side surface B of the laminate 2, covering a portion of the end surface C side of the main surface A. Next, a nickel (Ni) plating layer 31a and a tin (Sn) plating layer 31b disposed on the surface of the nickel (Ni) plating layer 31a are formed as plating layers 31 on the surface of the base electrode layer 30, thereby producing the capacitor body 1A shown in FIG. 8( d ).

[0076] (Spacer Arrangement Step S3) A spacer manufacturing paste 41 used for manufacturing spacers is prepared. The spacer manufacturing paste 41 contains metals made of copper (Cu), nickel (Ni), tin (Sn), and silver (Ag), a phenolic resin, a solvent, and an additive. In this case, rosin may be contained instead of the phenolic resin.

[0077] Examples of the phenol resin include novolac-type phenol resins such as phenol novolac resin, phenol aralkyl resin, cresol novolac resin, t-butylphenol novolac resin, and nonylphenol novolac resin; resol-type phenol resin; and polyoxystyrene such as polyparaoxystyrene.

[0078] 9A and 9B are diagrams illustrating the spacer arranging step S3. As shown in Fig. 9A, first, a spacer manufacturing paste 41 is arranged on a holding substrate 40 by screen printing, dispensing, or the like.

[0079] 9(b), the capacitor body 1A is mounted on the upper surface of the holding substrate 40 with the second main surface A2 facing the holding substrate 40. At this time, the external electrodes 3 of the capacitor body 1A and the spacer-producing paste 41 are aligned, and the spacer-producing paste 41 adheres to the capacitor body 1A.

[0080] In this state, a heating step is carried out. When at least a portion of the metal in the paste generates an intermetallic compound to form the metal region MP, some of the phenolic resin is taken into the metal region MP and some is expelled from the metal region MP while hardening, forming the spacer 4 bonded to the capacitor body 1A.

[0081] Although the spacer material described above includes an intermetallic compound and a phenolic resin, the present invention is not limited to this and may include other metal components, or may include a resin other than the phenolic resin, such as an epoxy resin or rosin, or a glass component. The spacer may also be formed without including a resin.

[0082] 9(c), the capacitor body 1A is separated from the holding substrate 40 together with the spacer 4. The manufacturing method is not limited to this, and the spacer may be formed by applying a spacer manufacturing paste in a desired shape directly on the surface of the capacitor body 1A and performing a heat treatment.

[0083] (Reinforcing Material Arrangement Step S4) Figure 10 is a diagram illustrating the reinforcing material arrangement step S4. First, the surface of the capacitor body 1A on which the spacers 4 are arranged is cleaned with a solvent. After cleaning is completed, as shown in Figure 10(a), the capacitor body 1A on which the spacers 4 are arranged is aligned so that the spacers 4 face upward.

[0084] 10(b), a dispenser or squeegee printing is used to form an insulating resin layer between the first spacer 4a and the second spacer 4b on the capacitor body 1A on which the spacers 4 have been placed, which will become the central portion 52b of the reinforcing material 5. The amount of insulating resin that wets onto the central spacer end face SC1 can be changed by adjusting the amount of insulating resin.

[0085] When the insulating resin is to be allowed to penetrate into the interface between the spacer 4 and the laminate 2, the insulating resin can be placed and then evacuated. The amount of penetration can be controlled by changing the time and pressure of the evacuation.

[0086] 10(c), an insulating resin is applied so as to straddle the outer periphery of the capacitor body 1A and the outer periphery of the spacer 4. The applied insulating resin is then heated at 100 to 200°C for 20 to 80 minutes, whereby the insulating resin hardens to form a capacitor-side covering portion 51 on the outer periphery of the capacitor body 1A and a spacer-side covering portion 52 on the outer periphery of the spacer 4. Through the above steps, the multilayer ceramic capacitor 1 is manufactured.

[0087] (Evaluation of the embodiment) Next, the results of evaluation 1 and evaluation 2 performed on the multilayer ceramic capacitor 1 including the reinforcing material 5 of the embodiment will be described.

[0088] (Multilayer ceramic capacitor 1 used for evaluation) The following capacitor body 1A was used: Length direction L: 1.6 mm Width direction W: 0.8 mm Lamination direction T: 0.8 mm Main component of internal electrode: Ni Dielectric layer: BaTiO ３ Main component of base electrode layer: Cu First plating layer: Ni Second plating layer: Sn

[0089] The spacer 4 is composed of the following components: 31.5 wt% Cu-10 wt% Ni powder with a D50 (median diameter) of 5 μm, 58.5 wt% solder powder with a D50 of 5 μm consisting of 3 wt% Sn, 0.5 wt% Ag, and Cu, and 10 wt% rosin, solvent, and additive components.

[0090] The reinforcing material 5 is an insulating resin containing epoxy resin as a main component and phenol resin as a hardener.

[0091] (Evaluation 1) (1) Five types of multilayer ceramic capacitors 1 were prepared, each having a length of the spacer-side covering portion 52 that was 0%, 1.2%, 3.6%, 4.9%, and 13.5% of the length of the spacer 4 in the stacking direction T. Ten pieces of each type of multilayer ceramic capacitor 1 were prepared.

[0092] Next, the multilayer ceramic capacitor 1 was mounted on a JIS substrate having a thickness of 1.6 mm using lead-free solder, and was held at a bending amount of 4 mm for 5 seconds.

[0093] Next, in order to check whether or not the multilayer ceramic capacitor 1 had any cracks, the multilayer ceramic capacitor 1 was cut down to half its original width in the width direction W.

[0094] The multilayer ceramic capacitor near the mounting surface was observed using a microscope (BX-51, Olympus) connected to a digital camera for microscope (DP22, Olympus) with the total magnification adjusted appropriately, such as 10 times.

[0095] The presence or absence of cracks in the multilayer ceramic capacitors 1 was checked, and a crack occurrence rate (number of multilayer ceramic capacitors 1 with cracks / number of confirmed multilayer ceramic capacitors 1) of 50% or more was marked as ×, and a rate of less than 50% was marked as ◯.

[0096] (Evaluation 2) The multilayer ceramic capacitor was mounted on the same multilayer ceramic capacitor mounting substrate as that used in Evaluation 1, and placed in an anechoic box.

[0097] A sound-collecting microphone was placed so as to face the mounting substrate portion on which the multilayer ceramic capacitor 1 was placed.

[0098] An alternating current having a frequency of 3 kHz and a voltage of 1 Vpp was applied to the multilayer ceramic capacitor 1, and the acoustic noise level of the multilayer ceramic capacitor 1 was measured by a sound collecting microphone. The acoustic noise of the multilayer ceramic capacitor 1 was collected by the sound collecting microphone, and the output of the sound collecting microphone was input to an FFT (Fast Fourier Transform) analyzer via a sound collection meter, where the sound pressure level was analyzed.

[0099] With the sound pressure level of the multilayer ceramic capacitor 1 as the standard, an improvement of less than 10% was evaluated as △, and an improvement of 10% or more was evaluated as ◯.

[0100] 11 is a table showing the results of evaluations 1 and 2 performed on the multilayer ceramic capacitor 1 including the reinforcing material 5 of the embodiment. As shown in evaluation 1, in the embodiments in which the length of the spacer-side covering portion 52 relative to the spacer length in the stacking direction T was 4.9% and 13.5%, the crack occurrence rate was less than 50%, while in the comparative embodiments in which the length was 0%, 1.2%, and 3.6%, the crack occurrence rate was 50% or more.

[0101] As shown in Evaluation 2, the provision of the reinforcing material 5 had an effect of improving the sound pressure level. In particular, the sound pressure level improved by 10% or more when the length of the spacer-side covering portion relative to the spacer length in the stacking direction was 1.2% or more, including 4.9% or more in the embodiment.

[0102] As shown by the above evaluation results, it was verified that the multilayer ceramic capacitor 1 of the embodiment reduces the rate of crack occurrence and also reduces the occurrence of squealing noise.

[0103] In the above, an example of the spacer material contains an intermetallic compound and rosin, but the present invention is not limited to this and may contain other metal components, or may contain resins other than rosin, such as epoxy resins or phenolic resins, or glass components. Furthermore, the spacer may be formed without containing resin.

[0104] Although the embodiments of the present invention have been described above, the present invention is not limited to the embodiments and can be embodied in various forms without departing from the spirit of the present invention. The present invention includes the following combinations.

[0105] <1> A capacitor body including: a laminate in which dielectric layers and internal electrode layers are alternately stacked, the laminate having two main surfaces opposing each other in a stacking direction, two end surfaces opposing each other in a length direction intersecting the stacking direction, and two side surfaces opposing each other in a width direction intersecting the stacking direction and the length direction; and two external electrodes disposed on each of the two end surfaces, connected to the internal electrode layers, and extending to the two main surfaces to cover parts of the main surfaces; and two external electrodes disposed on one end surface side and the other end surface side of one of the main surfaces of the capacitor body, with the external electrodes covering the parts of the main surfaces sandwiched therebetween, the external electrodes being disposed on one end surface side and the other end surface side, and each of the external electrodes being arranged on one end surface side and the other end surface side of the laminate in the stacking direction. a spacer-side covering portion covering 5.0% or more of each of the two spacers in the stacking direction; and a capacitor-side covering portion continuing from the spacer-side covering portion and covering the spacer side of the outer periphery of the capacitor body, wherein the spacer-side covering portion is a reinforcing material continuously covering opposing spacer end faces of the two spacers that face each other and the two spacer side faces.

[0106] <2> A multilayer ceramic electronic component according to <1> or <2>, wherein each of the spacers has two spacer main surfaces opposing each other in the stacking direction, two spacer end faces opposing each other in the length direction, and two spacer side surfaces opposing each other in the width direction, and in each of the spacers, the spacer-side covering portion of the reinforcing material covers one of the two spacer end faces, an outer spacer end face that is on the outer side in the length direction of the laminate.

[0107] <3> The multilayer ceramic electronic component according to <1> or <2>, wherein the reinforcing material covers the entire capacitor body.

[0108] <4> The multilayer ceramic electronic component according to any one of <1> to <3>, wherein an orientation identification mark is arranged on the laminate.

[0109] <5> The multilayer ceramic electronic component according to any one of <1> to <4>, wherein the spacer has an orientation identification mark arranged thereon.

[0110] SA: Spacer main surface SA1: Body-side spacer main surface SA2: Mounting-side spacer main surface SB: Spacer side surface SC: Spacer end surface SC1: Center-side spacer end surface SC2: Outer spacer end surface 1: Multilayer ceramic capacitor 1A: Capacitor body 2: Laminate 3: External electrode 3a: First external electrode 3b: Second external electrode 4: Spacer 4a: First spacer 4b: Second spacer 5: Reinforcing material 51: Capacitor-side covering portion 52: Spacer-side covering portion 52a: Side portion 52b: Center portion

Claims

1. a laminate in which dielectric layers and internal electrode layers are laminated, the laminate having two main surfaces opposing each other in a lamination direction, two end faces opposing each other in a length direction intersecting the lamination direction, and two side surfaces opposing each other in a width direction intersecting the lamination direction and the length direction; a capacitor body including two external electrodes disposed on the two end faces, respectively, connected to the internal electrode layers, and extending to the two main surfaces to cover parts of the main surfaces; two spacers arranged on one end face side and the other end face side of one main surface side of the capacitor body, each having two spacer main faces opposing each other in the stacking direction, two spacer end faces opposing each other in the length direction, and two spacer side faces opposing each other in the width direction; and a reinforcing material; the reinforcing material has a spacer-side covering portion that covers 4.9% or more of the length of the spacer in the stacking direction, and a capacitor-side covering portion that is continuous with the spacer-side covering portion and covers the spacer side of the outer periphery of the capacitor body, The spacer-side covering portion continuously covers opposing spacer end faces of the two spacers and two spacer side faces.

2. each of the spacers has two spacer main surfaces opposing each other in the stacking direction, two spacer end surfaces opposing each other in the length direction, and two spacer side surfaces opposing each other in the width direction; The spacer side covering portion of the reinforcing material is covering the outer spacer end faces on the outer sides of the laminate in the longitudinal direction; The multilayer ceramic electronic component according to claim 1 .

3. The reinforcing material covers the entire capacitor body. The multilayer ceramic electronic component according to claim 1 or 2.

4. An orientation identification mark is arranged on the laminate. The multilayer ceramic electronic component according to claim 1 or 2.

5. A direction identification mark is arranged on the spacer. The multilayer ceramic electronic component according to claim 1 or 2.

6. A laminate in which dielectric layers and internal electrode layers are stacked, and which has two main surfaces facing each other in the stacking direction, two end faces facing each other in a length direction intersecting the stacking direction, and two side surfaces facing each other in a width direction intersecting the stacking direction and the length direction; and a capacitor body including two external electrodes disposed on the two end faces, respectively, connected to the internal electrode layers, and extending to the two main faces to cover parts of the side faces; two spacers arranged on one end face side and the other end face side of one side surface of the capacitor body, each spacer having two spacer main faces opposing each other in the stacking direction, two spacer end faces opposing each other in the length direction, and two spacer side faces opposing each other in the width direction; and a reinforcing material; the reinforcing material has a spacer-side covering portion that covers 4.9% or more of the length of the spacer in the width direction, and a capacitor-side covering portion that is continuous with the spacer-side covering portion and covers the spacer side of the outer periphery of the capacitor body, The spacer-side covering portion continuously covers opposing spacer end faces of the two spacers and two spacer side faces.

7. each of the spacers has two spacer main surfaces opposing each other in the stacking direction, two spacer end surfaces opposing each other in the length direction, and two spacer side surfaces opposing each other in the width direction; The spacer side covering portion of the reinforcing material is covering the outer spacer end faces on the outer sides of the laminate in the longitudinal direction; The multilayer ceramic electronic component according to claim 1 .