US-20260128227-A1 - THREE-TERMINAL MULTILAYER CERAMIC CAPACITOR

US20260128227A1US 20260128227 A1US20260128227 A1US 20260128227A1US-20260128227-A1

Abstract

A three-terminal multilayer ceramic capacitor includes third and fourth base electrode layers including a joining portion, which is joined to first and second side surfaces, and first and second separated portions, which are spaced farther from the first and second side surfaces toward first and second end surfaces than the joining portion, and third and fourth plating layers including first and second edge portions extending along the first and second separated portions between the first and second separated portions and the first and second side surfaces, and a surface layer portion covering outer surfaces of the third and fourth base electrode layers continuously with the first and second edge portions.

Inventors

Kentarou FUJIWARA

Assignees

MURATA MANUFACTURING CO., LTD.

Dates

Publication Date: 20260507
Application Date: 20260105
Priority Date: 20230710

Claims (18)

1 . A three-terminal multilayer ceramic capacitor comprising: a multilayer body including a plurality of ceramic layers and a plurality of internal electrode layers that are laminated, a first main surface and a second main surface opposed to each other in a height direction, a first end surface and a second end surface opposed to each other in a length direction orthogonal or substantially orthogonal to the height direction, and a first lateral surface and a second lateral surface opposed to each other in a width direction orthogonal or substantially orthogonal to the height direction and the length direction; and a plurality of external electrodes; wherein the plurality of internal electrode layers include: a plurality of first internal electrode layers each extending toward the first end surface and the second end surface; and a plurality of second internal electrode layers each extending toward the first lateral surface and the second lateral surface; the plurality of external electrodes include: a first external electrode including a first base electrode layer and a first plated layer on the first base electrode layer, the first external electrode being provided on the first end surface and connected to the plurality of first internal electrode layers; a second external electrode including a second base electrode layer and a second plated layer on the second base electrode layer, the second external electrode being provided on the second end surface and connected to the plurality of first internal electrode layers; a third external electrode including a third base electrode layer and a third plated layer on the third base electrode layer, the third external electrode being provided on the first lateral surface and connected to the plurality of second internal electrode layers; and a fourth external electrode including a fourth base electrode layer and a fourth plated layer on the fourth base electrode layer, the fourth external electrode being provided on the second lateral surface and connected to the plurality of second internal electrode layers; the plurality of first internal electrode layers each include a first counter electrode portion opposed to a corresponding one of the plurality of second internal electrode layers, a first extension electrode portion extending from the first counter electrode portion toward the first end surface, and a second extension electrode portion extending from the first counter electrode portion toward the second end surface; the plurality of second internal electrode layers each include a second counter electrode portion opposed to a corresponding one of the plurality of first counter electrode portions, a third extension electrode portion extending from the second counter electrode portion toward the first lateral surface, and a fourth extension electrode portion extending from the second counter electrode portion toward the second lateral surface; in a cross-sectional view along the first main surface and the second main surface, each of the third base electrode layer and the fourth base electrode layer includes a bonding portion including a middle portion located at a middle in the length direction and bonded to a corresponding one of the first lateral surface and the second lateral surface, a first separation portion located closer to the first end surface than the bonding portion is and separated from a corresponding one of the first lateral surface and the second lateral surface, and a second separation portion located closer to the second end surface than the bonding portion is and separated from a corresponding one of the first lateral surface and the second lateral surface; in the cross-sectional view along the first main surface and the second main surface, each of the third plated layer and the fourth plated layer includes a first edge portion extending along the first separation portion between the first separation portion and a corresponding one of the first lateral surface and the second lateral surface, a second edge portion extending along the second separation portion between the second separation portion and a corresponding one of the first lateral surface and the second lateral surface, and a surface layer portion covering an outer surface of a corresponding one of the third base electrode layer and the fourth base electrode layer continuously from the first edge portion and the second edge portion.
2 . The three-terminal multilayer ceramic capacitor according to claim 1 , wherein the first external electrode and the second external electrode are in contact with the multilayer body in a portion facing the multilayer body.
3 . The three-terminal multilayer ceramic capacitor according to claim 1 , wherein each of the third extension electrode portion and the fourth extension electrode portion is bonded to the bonding portion of a corresponding one of the third base electrode layer and the fourth base electrode layer.
4 . The three-terminal multilayer ceramic capacitor according to claim 1 , wherein, in the cross-sectional view along the first main surface and the second main surface, when h is defined as a distance in the length direction of the first separation portion and a distance in the length direction of the second separation portion, and when e is defined as a width in the length direction of each of the third base electrode layer and the fourth base electrode layer, a relationship of about 0.01≤h/e≤about 0.20 is satisfied.
5 . The three-terminal multilayer ceramic capacitor according to claim 1 , wherein, in the cross-sectional view along the first main surface and the second main surface, when c is defined as a thickness in the width direction of the middle portion with respect to a corresponding one of the first lateral surface and the second lateral surface, and when d is defined as a separation distance in the width direction of each of a first end surface-side tip portion which is a tip portion closest to the first end surface in the first separation portion and a second end surface-side tip portion which is a tip portion closest to the second end surface in the second separation portion with respect to each of the first lateral surface and the second lateral surface, a relationship of about 0.20≤d/c≤about 0.80 is satisfied.
6 . The three-terminal multilayer ceramic capacitor according to claim 1 , wherein each of the third extension electrode portion and the fourth extension electrode portion includes a first extension end portion adjacent to the first end surface and a second extension end portion adjacent to the second end surface; and when a distance from the first extension end portion to the first separation portion and a distance from the second extension end portion to the second separation portion are respectively defined as P, a relationship of 0<P is satisfied.
7 . The three-terminal multilayer ceramic capacitor according to claim 6 , wherein, when e is defined as a width in the length direction of each of the third base electrode layer and the fourth base electrode layer, a relationship of about 0<P/e≤about 0.20 is satisfied.
8 . The three-terminal multilayer ceramic capacitor according to claim 1 , wherein, in the cross-sectional view along the first main surface and the second main surface, when c is defined as a thickness in the width direction of the middle portion with respect to each of the first lateral surface and the second lateral surface, and when t is defined as a thickness in the width direction of the bonding portion, a relationship of about 0.8≤t/c≤about 1.3 is satisfied.
9 . The three-terminal multilayer ceramic capacitor according to claim 1 , wherein, when e is defined as a width in the length direction of each of the third base electrode layer and the fourth base electrode layer, a relationship of about 270 μm≤e≤about 600 μm is satisfied.
10 . The three-terminal multilayer ceramic capacitor according to claim 1 , wherein, in the cross-sectional view along the first main surface and the second main surface, when c is defined as a thickness in the width direction of the middle portion with respect to each of the first lateral surface and the second lateral surface, a relationship of about 15 μm≤c≤about 30 μm is satisfied.
11 . The three-terminal multilayer ceramic capacitor according to claim 1 , further comprising: an external electrode paste included in the plurality of external electrodes; wherein the external electrode paste includes: a resin; a metal filler; and a solvent; wherein the solvent includes one or more first solvents and one or more second solvents; a ratio of a mass of the first solvent to a mass of the solvent and a ratio of a mass of the second solvent to a mass of the solvent are each about 40% by mass or more; a lowest boiling point T Hl among boiling points of the one or more second solvents under atmospheric pressure is higher by about 10° C. or more than a highest boiling point T Lh among boiling points of the one or more first solvents under atmospheric pressure; a highest boiling point T Hh among the boiling points of the one or more second solvents under atmospheric pressure is T Hl +about 10° C. or less; a lowest boiling point T Ll among the boiling points of the one or more first solvents under atmospheric pressure is T Lh −about 10° C. or more; the solvent includes a sub-solvent in addition to the first solvent and the second solvent; a boiling point of the sub-solvent under atmospheric pressure is less than (T Ll −about 10) ° C., greater than (T Lh +about 10°) C and less than (T Hl −about 10°) C, or greater than (T Hh +about 10°) C; or the metal filler includes a Cu filler; and the resin includes an ethylcellulose-based resin and an acrylic resin, at least a portion of which is copolymerized, and an interfacial tension generated between the resin and the solvent is about 15 mN/m or more.
12 . The three-terminal multilayer ceramic capacitor according to claim 1 , wherein, when e is defined as a width in the length direction of each of the third base electrode layer and the fourth base electrode layer, a relationship of about 280 μm≤e≤about 300 μm is satisfied.
13 . The three-terminal multilayer ceramic capacitor according to claim 1 , wherein, in the cross-sectional view along the first main surface and the second main surface, when h is defined as a distance in the length direction of the first separation portion and a distance in the length direction of the second separation portion, and when e is defined as a width in the length direction of each of the third base electrode layer and the fourth base electrode layer, a relationship of about 0.04≤h/e≤about 0.15 is satisfied.
14 . The three-terminal multilayer ceramic capacitor according to claim 1 , wherein, in the cross-sectional view along the first main surface and the second main surface, when c is defined as a thickness in the width direction of the middle portion with respect to a corresponding one of the first lateral surface and the second lateral surface, and when d is defined as a separation distance in the width direction of each of a first end surface-side tip portion which is a tip portion closest to the first end surface in the first separation portion and a second end surface-side tip portion which is a tip portion closest to the second end surface in the second separation portion with respect to each of the first lateral surface and the second lateral surface, a relationship of about 0.28≤d/c≤about 0.70 is satisfied.
15 . The three-terminal multilayer ceramic capacitor according to claim 1 , wherein, when e is defined as a width in the length direction of each of the third base electrode layer and the fourth base electrode layer, a relationship of about 0.01<P/e≤about 0.18 is satisfied.
16 . The three-terminal multilayer ceramic capacitor according to claim 1 , wherein, in the cross-sectional view along the first main surface and the second main surface, when c is defined as a thickness in the width direction of the middle portion with respect to each of the first lateral surface and the second lateral surface, and when t is defined as a thickness in the width direction of the bonding portion, a relationship of about 0.93≤t/c≤about 1.23 is satisfied.
17 . The three-terminal multilayer ceramic capacitor according to claim 1 , wherein, when c is defined as a thickness in the width direction of the middle portion with respect to each of the first lateral surface and the second lateral surface, about 15 μm≤c≤about 30 μm is satisfied.
18 . The three-terminal multilayer ceramic capacitor according to claim 1 , wherein, when c is defined as a thickness in the width direction of the middle portion with respect to each of the first lateral surface and the second lateral surface, about 19 μm≤c≤about 20 μm is satisfied.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to Japanese Patent Application No. 2023-112815 filed on Jul. 10, 2023 and is a Continuation Application of PCT Application No. PCT/JP2024/016302 filed on Apr. 25, 2024. The entire contents of each application are hereby incorporated herein by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to three-terminal multilayer ceramic capacitors. 2. Description of the Related Art Japanese Unexamined Patent Application Publication No. 2010-109238 discloses a two-terminal multilayer ceramic capacitor including a pair of external electrodes. The two-terminal multilayer ceramic capacitor includes a multilayer body including a pair of main surfaces, a pair of lateral surfaces, and a pair of end surfaces, and a pair of external electrodes each provided on a corresponding one of the pair of end surfaces, a portion of each of the pair of main surfaces, and a portion of each of the pair of lateral surfaces of the multilayer body. Each of the pair of external electrodes includes a proximal-end-side bonding portion bonded to one of the main surfaces and a distal-end-side separation portion separated from the main surface at a distal end of the proximal-end-side bonding portion. Since the external electrode is separated from the multilayer body at the distal-end-side separation portion, it is possible to suppress the strong bonding between the external electrode and the multilayer body. Therefore, it is possible to reduce or prevent cracks in the two-terminal multilayer ceramic capacitor. In addition, a multilayer feedthrough ceramic capacitor having a general configuration, that is, a three-terminal multilayer ceramic capacitor, is also known. The three-terminal multilayer ceramic capacitor includes a multilayer body including a pair of main surfaces, a pair of lateral surfaces, and a pair of end surfaces, and external electrodes provided on outer surfaces of the multilayer body. The external electrodes include a pair of end surface electrodes provided on the pair of end surfaces, a portion of each of the pair of main surfaces, and a portion of each of the pair of lateral surfaces of the multilayer body, and a pair of lateral surface electrodes each provided on a corresponding one of the pair of lateral surfaces and each on a portion of each of the pair of main surfaces of the multilayer body. In each of the lateral surface electrodes, an end portion (an e-dimension end portion) of the lateral surface electrode is provided so as to be in contact with the multilayer body. Specifically, each of the lateral surface electrodes includes a base electrode layer including an e-dimension end portion in contact with the multilayer body, and a plated layer, which functions as an upper layer that covers the base electrode layer. By applying solder to the surface of the plated layer, the three-terminal multilayer ceramic capacitor can be mounted on a board. However, although Japanese Unexamined Patent Application Publication No. 2010-109238 discloses a configuration for suppressing the occurrence of cracks in the end surface electrode, Japanese Unexamined Patent Application Publication No. 2010-109238 discloses only a two-terminal multilayer ceramic capacitor, and therefore, Japanese Unexamined Patent Application Publication No. 2010-109238 does not disclose any configuration for suppressing the occurrence of cracks in the lateral surface electrode. In addition, in a general three-terminal multilayer ceramic capacitor, as described above, the e-dimension end portion of the lateral surface electrode is in contact with the multilayer body, and the lateral surface electrode and the multilayer body are firmly bonded to each other, and therefore, when the three-terminal multilayer ceramic capacitor is bent due to an external factor or the like, for example, cracks occur in the multilayer body from the e-dimension end portion of the lateral surface electrode. Therefore, the reliability of the three-terminal multilayer ceramic capacitor is lowered. In addition, in the lateral surface electrode of the three-terminal multilayer ceramic capacitor, the base electrode layer is formed with the e-dimension end portion in contact with the multilayer body, the plated layer is formed so as to cover the base electrode layer, and the surface area of the plated layer is determined according to the width of the plated layer. In other words, as the width of the plated layer is smaller, the surface area of the plated layer becomes smaller, and the bonding area between the solder and the plated layer also becomes smaller. Therefore, the bonding property between the three-terminal multilayer ceramic capacitor and the board is reduced, and the mountability is reduced. SUMMARY OF THE INVENTION Example embodiments of the present invention provide three-terminal multilayer ceramic capacitors each with an improved bonding property and i