US-12626865-B2 - Method of manufacturing electronic component

US12626865B2US 12626865 B2US12626865 B2US 12626865B2US-12626865-B2

Abstract

A method of manufacturing an electronic component including a multilayer body including a multilayer main body including end surfaces at which internal nickel electrode layers are exposed, side gap portions, external nickel layers on the end surfaces of the multilayer body, and external copper electrode layers covering the end surfaces on which the external nickel layers are provided. Forming at least one of a nickel-based oxide and a silicon-based oxide between the external nickel layer and the external copper electrode layer. Forming a nickel layer and a tin layer outside the external copper electrode layer. In a cross section passing through a middle of the electronic component in the width direction and extending in the length direction and the lamination direction, a relationship of about 0.2≤Tea/Tem≤about 1.1 is satisfied.

Inventors

Yasuhiro NISHISAKA
Mitsuru Ikeda

Assignees

MURATA MANUFACTURING CO., LTD.

Dates

Publication Date: 20260512
Application Date: 20230309
Priority Date: 20200707

Claims (10)

1 . A method of manufacturing an electronic component, the method comprising steps of: laminating dielectric layers and internal nickel electrode layers alternately to form a multilayer body; attaching a nickel sheet to an end surface of the multilayer body; firing the multilayer body and the nickel sheet to form an external nickel layer; immersing the end surface on which the external nickel layer is formed in a copper paste to form a copper film; firing the multilayer body with the external nickel layer, and the copper film in a reducing atmosphere, to form an external copper electrode layer from the copper film; and forming at least one of a nickel-based oxide and a silicon-based oxide between the external nickel layer and the external copper electrode layer.
2 . The method of manufacturing an electronic component according to claim 1 , wherein the firing the multilayer body with the external nickel layer and the copper film is performed at conditions of an oxygen partial pressure of about 10 −9 Pa≤PO 2 ≤about 10 −13 Pa and a firing temperature of about 700° C.≤TY≤about 950° C.
3 . The method of manufacturing the electronic component according to claim 1 , further comprising a step of forming a fluorine layer on the multilayer body between the attaching the nickel sheet and the firing the multilayer body and the nickel sheet.
4 . The method of manufacturing an electronic component according to claim 1 , wherein the immersing the end surface on which the external nickel layer is formed in the copper paste further includes steps of: immersing the end surface in the copper paste to form a first copper film; removing the copper paste attached to the end surface in the immersing the end surface in the copper paste to form the first copper film; and forming a second copper film outside the first copper film after the removing the copper paste.
5 . The method of manufacturing the electronic component according to claim 1 , wherein, after the firing the multilayer body and the nickel sheet, in a cross section passing through a middle of the electronic component in a width direction and extending in a length direction and a lamination direction, when the external nickel layer is divided into four equal portions in the lamination direction by three linear lines extending in the length direction, an average value of a thickness of the external nickel layer on a center linear line among the three linear lines is defined as Tem, and an average value of a thickness of the external nickel layer on all of the three linear lines is defined as Tea, a relationship of about 0.2≤Tea/Tem≤about 1.1 is satisfied.
6 . The method of manufacturing the electronic component according to claim 5 , wherein a relationship of about 0.33≤Tea/Tem≤about 1.1 is satisfied.
7 . The method of manufacturing the electronic component according to claim 5 , wherein a relationship of about 0.8 μm≤Tea≤about 15 μm, and a relationship of about 2 μm≤Tem≤about 7 μm are satisfied.
8 . The method of manufacturing the electronic component according to claim 1 , wherein, after the firing of the multilayer body with the external nickel layer and the copper film, the dielectric layers each have a thickness tu of about 0.40 μm≤tu≤about 0.50 μm.
9 . The method of manufacturing the electronic component according to claim 1 , wherein, after the firing of the multilayer body with the external nickel layer and the copper film, the internal nickel electrode layers each have a thickness tn of about 0.25 μm≤tn≤about 0.33 μm.
10 . The method of manufacturing the electronic component according to claim 1 , wherein, after the firing of the multilayer body with the external nickel layer and the copper film, the side gap portions each have a thickness ts of about 5 μm≤ts≤about 12 μm.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is based on and claims the benefit of priority from Japanese Patent Application No. 2020-116885, filed on Jul. 7, 2020, the entire contents of which are incorporated herein by reference, and is a Divisional Application of U.S. application Ser. No. 17/366,136, which has matured into U.S. Pat. No. 11,626,252. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component and a method of manufacturing an electronic component. 2. Description of the Related Art Recently, with the miniaturization and increased capacitance of electronic components such as multilayer ceramic capacitors, the number of the internal electrode layers is increasing, and the side gap portions have been minimized. In such a small multilayer ceramic capacitor, copper used for the external electrode layers is diffused into the interior of nickel which is used for the internal electrode layers, such that the thickness of each of the internal electrode layers increases, and cracks may occur. On the other hand, when using nickel for the external electrode layer, it is not possible to ensure moisture resistance sufficiently with only the external electrode layers, and there may be a case in which water enters the internal electrode layers beyond the external electrode layers. Therefore, a method is used which forms nickel layers on end surfaces where the internal electrode layers are exposed, and applies copper for external electrode layers so as to cover the end surfaces where the nickel layers are formed (refer to Japanese Unexamined Patent Application Publication No. 2020-21819). However, due to the shrinkage stress of the nickel layers, there is a possibility that cracks occur in the multilayer ceramic capacitor. SUMMARY OF THE INVENTION Preferred embodiments of the present invention provide electronic components and methods of manufacturing electronic components which are resistant to cracking and can be miniaturized. An electronic component according to a preferred embodiment according to the present invention includes a multilayer body including a multilayer main body and side gap portions, the multilayer main body including an inner layer portion that includes dielectric layers and internal nickel electrode layers laminated alternately therein, and including end surfaces on both sides in a length direction intersecting a lamination direction, wherein the internal nickel electrode layers are exposed at the end surfaces, the side gap portions being provided on both sides of the multilayer main body in a width direction intersecting the lamination direction and the length direction; external nickel layers provided on the end surfaces of the multilayer body; and external copper electrode layers covering the end surfaces on which the external nickel layers are provided, a nickel-based oxide and/or a silicon-based oxide are provided between the external nickel layer and the external copper electrode layer, a nickel layer and tin layer are provided outside the external copper electrode layer, and in a cross-section passing through a middle of the electronic component in the width direction and extending in the length direction and the lamination direction, when the external nickel layer is divided into four equal or substantially equal portions in the lamination direction by three linear lines extending in the length direction, an average value of a thickness of the external nickel layer on a center linear line among the three linear lines is defined as Tem, and an average value of a thickness of the external nickel layer on all of the three linear lines is defined as Tea, about 0.2≤Tea/Tem≤about 1.1 is satisfied. According to preferred embodiments of the present invention, it is possible to provide electronic components and methods of manufacturing electronic components which are resistant to cracking and can be miniaturized. The above and other elements, features, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic perspective view of a multilayer ceramic capacitor according to a first preferred embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1 of the multilayer ceramic capacitor of the first preferred embodiment of the present invention. FIG. 3A is a cross-sectional view taken along the line III-III in FIG. 1 of the multilayer ceramic capacitor 1 of the first preferred embodiment of the present invention. FIG. 3B is a partially enlarged view of FIG. 3A. FIG. 4A is a cross-sectional view taken along the line IV-IV in FIG. 1 of the multilayer ceramic capacitor of the first preferred embodiment of the present invention. FIG. 4B is a partially enlarged view of FIG. 4A. FIG. 5 is a schem