EP-4738406-A1 - MULTILAYER CERAMIC CAPACITOR

EP4738406A1EP 4738406 A1EP4738406 A1EP 4738406A1EP-4738406-A1

Abstract

Provided is a multilayer ceramic capacitor that can be reduced in size with increased capacity and also has high reliability. In a laminate 10 of the multilayer ceramic capacitor, when a region in which internal electrode layers 30 overlap with one another when viewed from a lamination direction T is defined as an effective part 11, facing regions which sandwich the effective part 11 from the width direction W are respectively defined as a first side surface-side outer layer portion WG1 and a second side surface-side outer layer portion WG2, and facing regions which sandwich the effective part 11, the first side surface-side outer layer portion WG1, and the second side surface-side outer layer portion WG2 from the lamination direction T are respectively defined as a first main surface-side outer layer portion TG1 and a second main surface-side outer layer portion TG2, the porosity Pw (%) of the first side surface-side outer layer portion or the second side surface-side outer layer portion, and the porosity Pwt (%) of the first main surface-side outer layer portion TG1 or the second main surface-side outer layer portion TG2 satisfy the relational formula (1). 1.6 ≤ Pwt − Pw ≤ 3.1

Inventors

IWATA SHUN
SHIMADA YASUYUKI

Assignees

Murata Manufacturing Co., Ltd.

Dates

Publication Date: 20260506
Application Date: 20240628

Claims (4)

A multilayer ceramic capacitor comprising: a multilayer body including a plurality of dielectric layers and a plurality of internal electrode layers that are laminated; and external electrodes each provided to be electrically conductive with the internal electrode layers, wherein the multilayer body includes a first main surface and a second main surface opposed to each other in a lamination direction in which the plurality of dielectric layers and the plurality of internal electrode layers are laminated, a first lateral surface and a second lateral surface opposed to each other in a width direction that intersects both the lamination direction and a length direction in which each of the plurality of internal electrode layers extends toward a corresponding one of the external electrodes, and a first end surface and a second end surface opposed to each other in the length direction that intersects the lamination direction and the width direction, each of the external electrodes is on one of the first end surface or the second end surface, in the multilayer body, when a region where the plurality of internal electrode layers overlap each other when viewed in the lamination direction is defined as an effective portion, opposing regions sandwiching the effective portion in the width direction are defined as a first lateral surface-side outer layer portion and a second lateral surface-side outer layer portion, opposing regions sandwiching the effective portion in the length direction are defined as a first end surface-side outer layer portion and a second end surface-side outer layer portion, and opposing regions sandwiching the effective portion, the first lateral surface-side outer layer portion, the second lateral surface-side outer layer portion, the first end surface-side outer layer portion, and the second end surface-side outer layer portion in the lamination direction are defined as a first main surface-side outer layer portion and a second main surface-side outer layer portion, a pore ratio Pw (%) of the first lateral surface-side outer layer portion or the second lateral surface-side outer layer portion and a pore ratio Pwt (%) of the first main surface-side outer layer portion or the second main surface-side outer layer portion satisfy the following relational expression (1): 1.6 ≤ Pwt − Pw ≤ 3.1
A multilayer ceramic capacitor comprising: a multilayer body including a plurality of dielectric layers and a plurality of internal electrode layers that are laminated; and external electrodes each provided to be electrically conductive with the internal electrode layers, wherein the multilayer body includes a first main surface and a second main surface opposed to each other in a lamination direction in which the plurality of dielectric layers and the plurality of internal electrode layers are laminated, a first lateral surface and a second lateral surface opposed to each other in a width direction that intersects both the lamination direction and a length direction in which each of the plurality of internal electrode layers extends toward a corresponding one of the external electrodes, and a first end surface and a second end surface opposed to each other in the length direction that intersects the lamination direction and the width direction, each of the external electrodes is on one of the first end surface or the second end surface, in the multilayer body, when a region where the plurality of internal electrode layers overlap each other when viewed in the lamination direction is defined as an effective portion, opposing regions sandwiching the effective portion in the width direction are defined as a first lateral surface-side outer layer portion and a second lateral surface-side outer layer portion, opposing regions sandwiching the effective portion in the length direction are defined as a first end surface-side outer layer portion and a second end surface-side outer layer portion, and opposing regions sandwiching the effective portion, the first lateral surface-side outer layer portion, the second lateral surface-side outer layer portion, the first end surface-side outer layer portion, and the second end surface-side outer layer portion in the lamination direction are defined as a first main surface-side outer layer portion and a second main surface-side outer layer portion, a pore ratio Pl (%) of the first end surface-side outer layer portion or the second end surface-side outer layer portion and a pore ratio Plt (%) of the first main surface-side outer layer portion or the second main surface-side outer layer portion satisfy the following relational expression (2): 1.6 ≤ Plt − Pl ≤ 3.1
The multilayer ceramic capacitor according to claim 1 or 2, wherein when the multilayer body is viewed in a cross section parallel to the width direction and the lamination direction at a middle portion in the length direction, a length in the width direction of a range where respective one-side ends of the plurality of internal electrode layers in the width direction are aligned is 1 µm or more and 15 µm or less.
The multilayer ceramic capacitor according to claim 1 or 2, wherein when the multilayer body is viewed in a cross section parallel to the width direction and the lamination direction at a middle portion in the length direction, a length Ew in the width direction of one of the plurality of internal electrode layers at a middle portion in the lamination direction and a length Es in the width direction of one of the plurality of internal electrode layers closest to the first main surface or the second main surface satisfy the following relational expression (3): 95 ≤ Es / Ew × 100 ≤ 101

Description

TECHNICAL FIELD The present invention relates to a multilayer ceramic capacitor. BACKGROUND ART Conventionally, multilayer ceramic capacitors widely used in electronic devices such as mobile phones and portable music players each include an inner layer portion that includes a stack of a plurality of dielectric layers made of ceramic material and a plurality of internal electrode layers to generate capacitance, outer layer portions provided on both sides of the inner layer portion in the lamination direction, and side margin portions provided on both sides of the inner layer portion in the width direction. With the recent reduction in size and improvement in performance of electronic devices, multilayer ceramic capacitors are also required to be reduced in size and increased in capacity. In order to achieve a reduction in size and increase in capacity in multilayer ceramic capacitors, means such as for reducing the thickness of the side margin portions and increasing the area of the internal electrode layers can be considered. However, when the thickness of the side margin portions is reduced, resistance to moisture penetrating between the lateral surfaces of the multilayer body and the external electrodes and reaches the internal electrode layers at the end surfaces of the multilayer body, that is, moisture resistance, is lowered, and as a result, the reliability may be lowered. Therefore, there is a need to develop multilayer ceramic capacitors that have high reliability while achieving a reduction in size and increase in capacity. Citation List Patent Document Patent Document 1: Japanese Unexamined Patent Application, Publication No. 2014-150240 DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention It is an object for the present invention to provide multilayer ceramic capacitors each having high reliability while achieving a reduction in size and increase in capacity. Means for Solving the Problems The present inventors have found that, in a multilayer ceramic capacitor including a multilayer body including a plurality of dielectric layers and a plurality of internal electrode layers that are laminated, and external electrodes provided to be electrically conductive with the internal electrode layers, when the pore ratio Pw of the first lateral surface-side outer layer portion or the second lateral surface-side outer layer portion and the pore ratio Pwt of the first main surface-side outer layer portion or the second main surface-side outer layer portion are adjusted to have a predetermined relationship, moisture resistance is improved and high reliability can be obtained, while achieving a reduction in size and increase in capacity, and thereby completed the present invention. An embodiment of the present invention provides a multilayer ceramic capacitor which includes a multilayer body including a plurality of dielectric layers and a plurality of internal electrode layers that are laminated, and external electrodes each provided to be electrically conductive with the internal electrode layers. The multilayer body includes a first main surface and a second main surface opposed to each other in a lamination direction in which the plurality of dielectric layers and the plurality of internal electrode layers are laminated, a first lateral surface and a second lateral surface opposed to each other in a width direction that intersects both the lamination direction and a length direction in which each of the plurality of internal electrode layers extends toward a corresponding one of the external electrodes, and a first end surface and a second end surface opposed to each other in the length direction that intersects the lamination direction and the width direction. Each of the external electrodes is on one of the first end surface or the second end surface. In the multilayer body, when a region where the plurality of internal electrode layers overlap each other when viewed in the lamination direction is defined as an effective portion, opposing regions sandwiching the effective portion in the width direction are defined as a first lateral surface-side outer layer portion and a second lateral surface-side outer layer portion, opposing regions sandwiching the effective portion in the length direction are defined as a first end surface-side outer layer portion and a second end surface-side outer layer portion, and opposing regions sandwiching the effective portion, the first lateral surface-side outer layer portion, the second lateral surface-side outer layer portion, the first end surface-side outer layer portion, and the second end surface-side outer layer portion in the lamination direction are defined as a first main surface-side outer layer portion and a second main surface-side outer layer portion, a pore ratio Pw (%) of the first lateral surface-side outer layer portion or the second lateral surface-side outer layer portion and a pore ratio Pwt (%) of the first main surface-side outer layer p