US-20260128228-A1 - THREE-TERMINAL MULTILAYER CERAMIC CAPACITOR

US20260128228A1US 20260128228 A1US20260128228 A1US 20260128228A1US-20260128228-A1

Abstract

In a three-terminal multilayer ceramic capacitor, each of third and fourth external electrodes includes a central portion having a thickness of about 3 μm or more, and first and second convex portions having a thickness greater than that of the central portion and located closer to first and second end surfaces than the central portion, and first and second limit points, adjacent to the first and second end surfaces, where, starting from first and second external electrode end portions on the side of the first and second end surfaces, a thickness is about 3 μm or more. Between the first and second limit points, first and second lead-out end portions, respectively of third and fourth lead-out electrode portions, are located.

Inventors

Kentarou FUJIWARA

Assignees

MURATA MANUFACTURING CO., LTD.

Dates

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

Claims (20)

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 on the first end surface and connected to the plurality of first internal electrode layers; a second external electrode on the second end surface and connected to the plurality of first internal electrode layers; a third external electrode on the first lateral surface and connected to the plurality of second internal electrode layers; and a fourth external electrode 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 external electrode and the fourth external electrode includes a middle portion having a thickness of about 3 μm or more in the width direction with respect to each of the first lateral surface and the second lateral surface and located at a middle in the length direction, a first protruding portion having a thickness in the width direction with respect to each of the first lateral surface and the second lateral surface larger than a thickness in the width direction of the middle portion and located closer to the first end surface than the middle portion, a second protruding portion having a thickness in the width direction with respect to each of the first lateral surface and the second lateral surface larger than a thickness in the width direction of the middle portion and located closer to the second end surface than the middle portion, a first limit point adjacent to the first end surface and having a thickness in the width direction with respect to each of the first lateral surface and the second lateral surface of about 3 μm or more from a first external electrode end portion adjacent to the first end surface, and a second limit point adjacent to the second end surface side and having a thickness in the width direction with respect to each of the first lateral surface and the second lateral surface of about 3 μm or more from a second external electrode end portion adjacent to the second end surface; and a first extension end portion adjacent to the first end surface and a second extension end portion adjacent to the second end surface of each of the third extension electrode portion and the fourth extension electrode portion are located between the first limit point and the second limit point.
2 . 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 each of a distance from the first external electrode end portion to the first limit point and a distance from the second external electrode end portion to the second limit point is defined as f and a width in the length direction of each of the third external electrode and the fourth external electrode is defined as e, a relationship of about 0.01≤f/e≤about 0.09 is satisfied.
3 . 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 each of a distance from the first external electrode end portion to the first protruding portion and a distance from the second external electrode end portion to the second protruding portion is defined as a and a width in the length direction of each of the third external electrode and the fourth external electrode is defined as e, a relationship of about 0.10≤a/e≤about 0.30 is satisfied.
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 a thickness in the width direction of each of the first protruding portion and the second protruding portion with respect to each of the first lateral surface and the second lateral surface is defined as d, and a thickness in the width direction of the middle portion with respect to each of the first lateral surface and the second lateral surface is defined as c, a relationship of about 0.65≤c/d≤about 0.97 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 a thickness in the width direction of the middle portion with respect to each of the first lateral surface and the second lateral surface is defined as c, a relationship of about 8.0 μm≤c≤about 18.0 μm is satisfied.
6 . 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 a thickness in the width direction of each of the first protruding portion and the second protruding portion with respect to each of the first lateral surface and the second lateral surface is defined as d, a relationship of about 10.0 μm≤d≤about 21.0 μm is satisfied.
7 . The three-terminal multilayer ceramic capacitor according to claim 1 , wherein each of the third external electrode and the fourth external electrode includes a base electrode layer and a plated layer covering the base electrode layer; and each of the base electrode layers of the third external electrode and the fourth external electrode includes the middle portion, the first protruding portion, and the second protruding portion, and includes the first limit point and the second limit point.
8 . The three-terminal multilayer ceramic capacitor according to claim 1 , wherein each of the plurality of external electrodes includes a metal component and a glass component; in the cross-sectional view along the first main surface and the second main surface, each of the third external electrode and the fourth external electrode includes a contact region including a contact interface in contact with each of the third extension electrode portion and the fourth extension electrode portion, and a first non-contact region located closer to the first end surface than the contact region and a second non-contact region located closer to the second end surface than to the contact region, and the first non-contact region and the second non-contact region are not in contact with each of the third extension electrode portion and the fourth extension electrode portion; and an out-of-interface region glass ratio, which is a ratio of a glass component to a component of the third external electrode and the fourth external electrode in an out-of-interface region excluding the contact interface in the contact region, is larger than a non-contact region glass ratio, which is a ratio of a glass component to a component of the third external electrode and the fourth external electrode in each of the first non-contact region and the second non-contact region.
9 . The three-terminal multilayer ceramic capacitor according to claim 8 , wherein the out-of-interface region glass ratio is about 1.4 times or more and about 1.7 times or less the non-contact region glass ratio.
10 . The three-terminal multilayer ceramic capacitor according to claim 8 , wherein the middle portion is included in the contact region.
11 . The three-terminal multilayer ceramic capacitor according to claim 1 , further comprising: an external electrode paste of the plurality of external electrodes, the external electrode paste including: 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 H1 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 H1 +about 10° C. or less; a lowest boiling point T L1 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 L1 −about 10)° C., greater than (T Lh +about 10°) C and less than (T H1 −about 10°) C, or greater than (T Hh +about 10°) C; or the metal filler is 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 each of the plurality of ceramic layers includes BaTiO 3 , CaTiO 3 , SrTiO 3 , or CaZrO 3 as a main component.
13 . The three-terminal multilayer ceramic capacitor according to claim 12 , wherein each of the plurality of ceramic layers includes a Mn compound, a Fe compound, a Cr compound, a Co compound, or a Ni compound as a subcomponent.
14 . The three-terminal multilayer ceramic capacitor according to claim 1 , wherein a thickness of each of the plurality of ceramic layers is about 0.3 μm or more and about 5.0 μm or less.
15 . The three-terminal multilayer ceramic capacitor according to claim 1 , wherein a thickness of each of the plurality of internal electrode layers is about 0.30 μm or more and about 1.0 μm or less.
16 . The three-terminal multilayer ceramic capacitor according to claim 7 , wherein the base electrode layer includes a fired layer.
17 . The three-terminal multilayer ceramic capacitor according to claim 16 , wherein the fired layer includes a glass component and a metal component.
18 . The three-terminal multilayer ceramic capacitor according to claim 17 , wherein the glass component includes at least one of B, Si, Ba, Mg, Al, or Li.
19 . The three-terminal multilayer ceramic capacitor according to claim 17 , wherein the metal component includes at least one of Ni, Ag, Pd, an Ag—Pd alloy, or Au.
20 . The three-terminal multilayer ceramic capacitor according to claim 7 , wherein the plated layer includes a lower plated layer including Ni and an upper plated layer including Sn on the lower plated layer.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to Japanese Patent Application No. 2023-112813 filed on Jul. 10, 2023 and is a Continuation Application of PCT Application No. PCT/JP2024/016303 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. 2018-46228 discloses a multilayer feedthrough ceramic capacitor having a general configuration, that is, a three-terminal multilayer ceramic capacitor. 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 an outer surface of the multilayer body. The multilayer body includes a stack of ceramic layers and internal electrode layers. The external electrode includes a pair of end surface electrodes provided on the pair of end surfaces, a portion of the pair of main surfaces, and a portion of the pair of lateral surfaces of the multilayer body, and a pair of lateral surface electrodes provided on a portion of the pair of lateral surfaces and a portion of the pair of main surfaces of the multilayer body. Each of the pair of lateral surface electrodes of Japanese Unexamined Patent Application Publication No. 2018-46228 includes a recessed portion in which the middle on the lateral surface is recessed toward the multilayer body. The recessed portion makes it possible to reduce the height of the swelling when the solder is applied. Therefore, it is possible for the solder fillet to be made small, and the restraining force received by the pair of lateral surface electrodes via the solder fillet is reduced. Therefore, the stress generated in the multilayer body is also reduced, such that it is possible to reduce or prevent the occurrence of cracks in the multilayer body. However, Japanese Unexamined Patent Application Publication No. 2018-46228 does not disclose any positional relationship between the lateral surface electrodes and the internal electrode layers. When the internal electrode layers are provided so as to be misaligned with respect to the lateral surface electrodes, for example, a portion of the internal electrode layers may be positioned outside the lateral surface electrodes. In this case, moisture or the like infiltrates into the multilayer body from a portion of the internal electrode layer that is not covered with the lateral surface electrode, and the moisture resistance reliability of the three-terminal multilayer ceramic capacitor deteriorates. SUMMARY OF THE INVENTION Example embodiments of the present invention provide three-terminal multilayer ceramic capacitors each with improved moisture resistance reliability. An example embodiment of the present invention provides a three-terminal multilayer ceramic capacitor which includes 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. 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 on the first end surface and connected to the plurality of first internal electrode layers, a second external electrode on the second end surface and connected to the plurality of first internal electrode layers, a third external electrode on the first lateral surface and connected to the plurality of second internal electrode layers, and a fourth external electrode 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 lay