Ceramic electronic device

Patent metadata

Field	Value
Publication number	US-11710599-B2
Application number	US-202217684944-A
Country	US
Kind code	B2
Filing date	Mar 2, 2022
Priority date	Mar 8, 2021
Publication date	Jul 25, 2023
Grant date	Jul 25, 2023

Abstract

A ceramic electronic device includes an element body and an external electrode. The element body is formed by laminating a ceramic layer and an internal electrode layer. The external electrode is electrically connected to at least one end of the internal electrode layer. The external electrode includes a baked electrode layer. The baked electrode layer includes a first region and a second region. The first region is contacted with an end surface of the element body and located near a joint boundary with the element body. The second region is located outside the first region and constituting an outer surface of the baked electrode layer. The first region includes a first glass having a predetermined composition. The second region includes a second glass having a predetermined composition.

First claim

What is claimed is:

1. A ceramic electronic device comprising:
an element body formed by laminating a ceramic layer and an internal electrode layer; and
an external electrode electrically connected to at least one end of the internal electrode layer,
wherein
the external electrode includes a baked electrode layer,
the baked electrode layer includes:
a first region contacted with an end surface of the element body and located near a joint boundary with the element body; and
a second region located outside the first region and constituting an outer surface of the baked electrode layer,

the first region includes a first glass,
the second region includes a second glass,
a molar content rate of B in terms of oxide to a total molar content of B, Si, and Zn in terms of oxide in the first glass is higher than a molar content rate of B in terms of oxide to a total molar content of B, Si, and Zn in terms of oxide in the second glass,
a molar content rate of Si in terms of oxide to a total molar content of B, Si, and Zn in terms of oxide in the first glass is lower than a molar content rate of Si in terms of oxide to a total molar content of B, Si, and Zn in terms of oxide in the second glass, and
an oxide of B is B 2 O 3 , an oxide of Si is SiO 2 , and an oxide of Zn is ZnO, in terms of oxide.

2. The ceramic electronic device according to claim 1 , wherein the ceramic layer comprises a perovskite compound represented by ABO 3 as a main component.

3. The ceramic electronic device according to claim 1 , wherein the perovskite compound represented by ABO 3 is represented by (Ba 1-a-b Sr a Ca b ) m (Ti 1-c-d Zr c Hf d )O 3 and satisfies 0.94<m<1.1, 0≤a≤1, 0≤b≤1, 0≤c≤1, and 0≤d≤1.

4. The ceramic electronic device according to claim 1 , wherein a conductor of the baked electrode layer includes at least one of Cu and Cu alloys as a main component.

5. The ceramic electronic device according to claim 1 , wherein
a B content in terms of oxide in the second glass is 0.25-0.4 parts by mol,
a Si content in terms of oxide in the second glass is 0.4-0.6 parts by mol, and
a Zn content in terms of oxide in the second glass is 0.1-0.35 parts by mol,
provided that a total content of B, Si, and Zn in terms of oxide in the second glass is 1 part by mol.

6. The ceramic electronic device according to claim 1 , wherein
a B content in terms of oxide in the first glass is 0.4-0.6 parts by mol,
a Si content in terms of oxide in the first glass is 0.15-0.35 parts by mol, and
a Zn content in terms of oxide in the first glass is 0.1-0.35 parts by mol,
provided that a total content of B, Si, and Zn in terms of oxide in the first glass is 1 part by mol.

7. The ceramic electronic device according to claim 1 , wherein a ratio of an average thickness of the second region to an average thickness of the baked electrode layer is 0.22 to 0.78.

8. The ceramic electronic device according to claim 1 , wherein
an average of a ratio of a total area of non-metal components and voids to a unit cross-sectional area of the baked electrode layer is 0.10 to 0.45, and
the non-metal components include the first glass and the second glass.

Assignees

• Tdk Corp

Inventors

• Iguchi Toshihiro
• Sueda Yuichiro
• Namiki Ryota
• Okui Yasuhiro
• Watanabe Atsushi

Classifications

• H01G4/1209 Primary

  characterised by the ceramic dielectric material (H01G4/1272, H01G4/1281 take precedence) · CPC title

• H01G4/2325

  characterised by the material of the terminals · CPC title

• H01G4/30

  Stacked capacitors (H01G4/33 takes precedence) · CPC title

• H01G4/0085 Primary

  Fried electrodes · CPC title

• H01G4/1245

  containing also titanates · CPC title