Dielectric ceramic composition and multilayer ceramic capacitor

Patent metadata

Field	Value
Publication number	US-2017287635-A1
Application number	US-201715466224-A
Country	US
Kind code	A1
Filing date	Mar 22, 2017
Priority date	Mar 30, 2016
Publication date	Oct 5, 2017
Grant date	—

Abstract

A dielectric ceramic composition having good characteristic even under high electric field intensity, and particularly good IR characteristic and high temperature accelerated lifetime. The present invention is a dielectric ceramic composition comprising,
a main component comprising a perovskite type compound shown by a compositional formula (Ba1-x-ySrxCay)m(Ti1-zZrz)O3, a first sub component comprising oxides of a rare earth element, a second sub component as a sintering agent, wherein said dielectric ceramic composition is a complete solid solution particle wherein the rare earth element is solid dissolved to entire dielectric particle, or a core-shell particle having high ratio of the diffusion phase, and comprises the dielectric particle having 5 to 20 atom % of the average concentration of the rare earth element in the diffusion phase, and having uniform concentration distribution of the rare earth element in the diffusion phase.

First claim

1 . A dielectric ceramic composition comprising,
a main component comprising a perovskite type compound shown by a compositional formula (Ba1-x-ySrxCay)m(Ti1-zZrZ)O3 and “z” all show a mol ratio, and each satisfies 0.94<m<1.1, 0<x<1.0, 0<y<1.0, 0<(x+y)<1.0, 0.06<z<0.2), a first sub component comprising oxides of a rare earth element R (note that, R is at least one selected from the group consisting of Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu), a second sub component as a sintering agent, wherein said dielectric ceramic composition comprises a dielectric particle and a particle boundary, said dielectric particle comprises a complete solid solution particle wherein the rare earth element R is solid dissolved to entire dielectric particle, when a concentration of Ti atom in said complete solid solution particle is 100 atom %, then an average concentration Ra of the rare earth element R in said complete solid solution particle is 5 to 20 atom %, when the rare earth element concentration (atom %) is measured at a part excluding an area 20 nm or less from the particle boundary of said complete solid solution particle, then a standard deviation and an average value of a measured values satisfies (standard deviation/average value)<0.25.

2 . The dielectric ceramic composition as set forth in claim 1 , wherein said (standard deviation/average value) satisfies (standard deviation/average value)<0.10.

3 . A dielectric ceramic composition comprising,
a main component comprising a perovskite type compound shown by a compositional formula (Ba1-x-ySrxCay)m(Ti1-zZrz)O3 (note that, said “m”, “x”, “y” and “z” all show a mol ratio, and each satisfies 0.94<m<1.1, 0<x<1.0, 0<y<1.0, 0<(x+y)<1.0, 0.06<z<0.2), a first sub component comprising oxides of a rare earth element R (note that, R is at least one selected from the group consisting of Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu), a second sub component as a sintering agent, wherein said dielectric ceramic composition comprises a dielectric particle and a particle boundary, said dielectric particles comprises a main component phase made of said main component, and a diffusion phase wherein said first sub component is diffused in said main component, a ratio of area occupied by said diffusion phase is 95% or more and less than 100% in average with respect to a total area of said main component phase and said diffusion phase, when a concentration of Ti atom in said diffusion phase is 100 atom %, then an average concentration Ra of the rare earth element R in the diffusion phase is 5 to 20 atom %, when the rare earth element concentration (atom %) is measured at a part excluding an area 20 nm or less from the particle boundary of said complete solid solution particle and at the diffusion phase excluding the area 20 nm or less from the boundary between the main component phase and the diffusion phase, then a standard deviation and an average value of a measured values satisfies (standard deviation/average value)<0.25.

4 . The dielectric ceramic composition as set forth in claim 3 , wherein said (standard deviation/average value) satisfies (standard deviation/average value)<0.10.

5 . The dielectric ceramic composition as set forth in claim 3 , the ratio of area occupied by said diffusion phase is 98% or more and less than 100% in average with respect to the total area of said main component phase and said diffusion phase.

6 . The dielectric ceramic composition as set forth in claim 4 , the ratio of area occupied by said diffusion phase is 98% or more and less than 100% in average with respect to the total area of said main component phase and said diffusion phase.

7 . An electronic component including the dielectric ceramic composition as set forth in claim 1 .

8 . A multilayer ceramic capacitor comprising a dielectric layer including the dielectric ceramic composition as set forth in claim 1 , and an internal electrode layer.

Assignees

• Tdk Corp

Inventors

• Sakurai Dan
• Morigasaki Nobuto
• Ishii Tatsuya
• Ariizumi Takuma
• Hashimoto Shinsuke
• Ito Yasuhiro

Classifications

• H01G4/1227

  based on alkaline earth titanates · CPC title

• H01G4/1245 Primary

  containing also titanates · CPC title

• C04B2235/6567

  Treatment time · CPC title

• C04B2235/658

  Atmosphere during thermal treatment · CPC title

• C04B2235/768

  Perovskite structure ABO3 · CPC title