Multilayer electronic device

Patent metadata

Field	Value
Publication number	US-12374490-B2
Application number	US-202318357505-A
Country	US
Kind code	B2
Filing date	Jul 24, 2023
Priority date	Aug 4, 2022
Publication date	Jul 29, 2025
Grant date	Jul 29, 2025

Abstract

A multilayer electronic device includes an element body and a pair of external electrodes. The element body includes an interior region in which inner dielectric layers and internal electrode layers are alternately laminated and an exterior region located outside the interior region in its lamination direction. The pair of external electrodes exists on surfaces of the element body. Main-phase particles in the inner dielectric layers and outer dielectric layers of the exterior region include a main component having a perovskite crystal structure represented by a general formula of ABO 3 . r1<r2<r1×4.0 is satisfied, in which r1 is an average particle size of the main-phase particles constituting the inner dielectric layers, and r2 is an average particle size of the main-phase particles constituting the outer dielectric layers.

First claim

What is claimed is:

1. A multilayer electronic device comprising:
an element body including:
an interior region in which inner dielectric layers and internal electrode layers are alternately laminated; and
an exterior region located outside the interior region in its lamination direction; and

a pair of external electrodes existing on surfaces of the element body to connect with the internal electrode layers
wherein
main-phase particles in the inner dielectric layers and outer dielectric layers of the exterior region include a main component having a perovskite crystal structure represented by a general formula of ABO 3 , in which
A is at least one selected from Ba, Sr, and Ca, and
B is at least one selected from Ti, Zr, and Hf,

the inner dielectric layers and the outer dielectric layers include subcomponents containing RE, M, and Si, in which
RE is at least one selected from Yb, Y, Ho, Dy, Tb, Gd, and Eu, and
M is at least two selected from Mg, Mn, V, and Cr,

an RE content C RE in terms of RE 2 O 3 is 0.90 parts by mol or more and 3.60 parts by mol or less with respect to 100 parts by mol of the main component in the inner dielectric layers and the outer dielectric layers,
an M content C M in terms of MO is 0.20 parts by mol or more and 1.20 parts by mol or less with respect to 100 parts by mol of the main component in the inner dielectric layers and the outer dielectric layers,
a Si content C Si in terms of SiO 2 is 0.60 parts by mol or more and 1.80 parts by mol or less with respect to 100 parts by mol of the main component in the inner dielectric layers and the outer dielectric layers, and
r1 and r2 satisfy a relation of r1<r2<r1×4.0, in which
r1 is an average particle size of the main-phase particles constituting the inner dielectric layers, and

r2 is an average particle size of the main-phase particles constituting the outer dielectric layers,
and wherein L, ra, rb, and rc satisfy relations of (rb−ra)/L>0.00008 and (rc−rb)/L>0.00008, in which
2×L is a distance from an outer surface of an outermost layer of the internal electrode layers to an outer surface of the element body,
ra is an average particle size of the main-phase particles in the exterior region near the internal electrode layers,
rb is an average particle size of the main-phase particles in the exterior region at an intermediate point between the outer surface of the outermost layer of the internal electrode layers and the outer surface of the element body, and
rc is an average particle size of the main-phase particles in the exterior region near the outer surface of the element body.

2. The multilayer electronic device according to claim 1 , wherein SNR, SNRa, SNRb, and SNRc satisfy relations of SNR>SNRa, SNR>SNRb, and SNR>SNRc, in which
SNR is a SN ratio of particle sizes of the main-phase particles constituting the inner dielectric layers,
SNRa is a SN ratio of particle sizes of the main-phase particles in the exterior region near the internal electrode layers,
SNRb is a SN ratio of particle sizes of the main-phase particles in the exterior region at an intermediate point between an outer surface of an outermost layer of the internal electrode layers and an outer surface of the element body, and
SNRc is a SN ratio of particle sizes of the main-phase particles in the exterior region near the outer surface of the element body.

3. The multilayer electronic device according to claim 1 , wherein an area ratio of a solid-solution region of RE of the main-phase particles constituting the inner dielectric layers is 12% or more and 50% or less.

4. The multilayer electronic device according to claim 1 , wherein
at least a part of the main-phase particles constituting the inner dielectric layers has a core-shell structure including:
a core portion; and
a shell portion surrounding the core portion and containing RE in solid solution,

the main-phase particles constituting the inner dielectric layers and having an average thickness of 5 nm or more in the shell portion are defined as specific main-phase particles, and
a number ratio of the specific main-phase particles to the main-phase particles in the inner dielectric layers is 90% or more.

5. The multilayer electronic device according to claim 1 , wherein
M1 is an element of M with the highest content in the inner dielectric layers and the outer dielectric layers, and
a M1 content C M1 in terms of M1O is 0.40 parts by mol or more and 0.90 parts by mol or less with respect to 100 parts by mol of the main component in the inner dielectric layers and the outer dielectric layers.

6. The multilayer electronic device according to claim 1 , wherein a relation of 180 nm<r1<240 nm is satisfied,
in which r1 is an average particle size of the main-phase particles constituting the inner dielectric layers.

7. A multilayer electronic device comprising:
an element body including:
an interior region in which inner dielectric layers and internal electrode layers are alternately laminated; and
an exterior region located outside the interior region in its lamination direction; and

a pair of external electrodes existing on surfaces of the element body to connect with the internal electrode layers
wherein
main-phase particles in the inner dielectric layers and outer dielectric layers of the exterior region include a main component having a perovskite crystal structure represented by a general formula of ABO 3 , in which
A is at least one selected from Ba, Sr, and Ca, and
B is at least one selected from Ti, Zr, and Hf,

the inner dielectric layers and the outer dielectric layers include subcomponents containing RE, M, and Si, in which
RE is at least one selected from Yb, Y, Ho, Dy, Tb, Gd, and Eu, and
M is at least two selected from Mg, Mn, V, and Cr,

an RE content C RE in terms of RE 2 O 3 is 0.90 parts by mol or more and 3.60 parts by mol or less with respect to 100 parts by mol of the main component in the inner dielectric layers and the outer dielectric layers,
an M content C M in terms of MO is 0.20 parts by mol or more and 1.20 parts by mol or less with respect to 100 parts by mol of the main component in the inner dielectric layers and the outer dielectric layers,
a Si content C Si in terms of SiO 2 is 0.60 parts by mol or more and 1.80 parts by mol or less with respect to 100 parts by mol of the main component in the inner dielectric layers and the outer dielectric layers, and
r1 and r2 satisfy a relation of r1<r2<r1×4.0, in which
r1 is an average particle size of the main-phase particles constituting the inner dielectric layers, and
r2 is an average particle size of the main-phase particles constituting the outer dielectric layers,

and wherein SNR, SNRa, SNRb, and SNRc satisfy relations of SNR>SNRa, SNR>SNRb, and SNR>SNRc, in which
SNR is a SN ratio of particle sizes of the main-phase particles constituting the inner dielectric layers,
SNRa is a SN ratio of particle sizes of the main-phase particles in the exterior region near the internal electrode layers,
SNRb is a SN ratio of particle sizes of the main-phase particles in the exterior region at an intermediate point between an outer surface of an outermost layer of the internal electrode layers and an outer surface of the element body, and
SNRc is a SN ratio of particle sizes of the main-phase particles in the exterior region near the outer surface of the element body.

8. A multilayer electronic device comprising:
an element body including:
an interior region in which inner dielectric layers and internal electrode layers are alternately laminated; and
an exterior region located outside the interior region in its lamination direction; and

a pair of external electrodes existing on surfaces of the element

Assignees

• Tdk Corp

Inventors

• Murakami Taku
• Morigasaki Nobuto
• Ariizumi Takuma
• Nagashima Yoshitaka
• Kimura Masato

Classifications

• H01G4/30 Primary

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

• H01G4/224

  Housing; Encapsulation · CPC title

• H01G4/1245

  containing also titanates · CPC title

• H01G4/1227

  based on alkaline earth titanates · CPC title

• H01G4/1209 Primary

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