Dielectric Ceramic Composition Core-Shell Structure Insulation Resistance

Solution Overview

Problem

Multilayer ceramic capacitors face challenges in maintaining high insulation specific resistance and achieving a long highly accelerated lifetime under high electric field intensity due to the deterioration of rare earth element concentration gradients in core-shell structured dielectric ceramic compositions.

Innovation Solution

A dielectric ceramic composition with a core-shell structure, where the shell part has an average rare earth element concentration of 0.3 atom % or more and a controlled concentration gradient of −0.010 atom %/nm ≤ S ≤ 0.009 atom %/nm, ensuring uniform rare earth element distribution and improved insulation properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If a core-shell structure with high rare earth element concentration gradient (≥0.05 atom %/nm) is used, then the dielectric layer can be made thinner and stacking number increased, but insulation specific resistance deteriorates under high electric field intensity

Engineering Contradiction:

Improvedielectric layer thicknessVSAvoidinsulation specific resistance

Core Design Contradiction:

Volume of moving objectVSReliability

Solution Approach 1:

The patent applies local quality by creating a core-shell structure where the shell portion has a controlled, gradual rare earth element concentration gradient (0.01-0.04 atom %/nm) rather than a sharp gradient. This local modification of concentration distribution in the shell region maintains insulation specific resistance while enabling thinner dielectric layers

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the concentration gradient parameter from the conventional high gradient (≥0.05 atom %/nm) to a controlled low gradient (0.01-0.04 atom %/nm) in the shell portion. This parameter modification prevents insulation deterioration while maintaining the core-shell structure benefits for thinning the dielectric layer

Inventive Principle:

Principle #35Parameter changes

2Volume of moving object

If a core-shell structure with high rare earth element concentration gradient (≥0.05 atom %/nm) is used, then the dielectric layer can be made thinner and stacking number increased, but highly accelerated lifetime is insufficient

Engineering Contradiction:

Improvedielectric layer thicknessVSAvoidhighly accelerated lifetime

Core Design Contradiction:

Volume of moving objectVSDuration of action of stationary object

Solution Approach 1:

The patent applies local quality by creating a core-shell structure where the shell portion has a controlled, gradual rare earth element concentration gradient (0.01-0.04 atom %/nm) rather than a sharp gradient. This local modification of concentration distribution in the shell region maintains insulation specific resistance while enabling thinner dielectric layers

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the concentration gradient parameter from the conventional high gradient (≥0.05 atom %/nm) to a controlled low gradient (0.01-0.04 atom %/nm) in the shell portion. This parameter modification prevents insulation deterioration while maintaining the core-shell structure benefits for thinning the dielectric layer

Inventive Principle:

Principle #35Parameter changes

3Reliability

If rare earth element concentration is increased in the shell part, then insulation properties improve, but concentration non-uniformity increases

Engineering Contradiction:

Improveinsulation specific resistanceVSAvoidrare earth element concentration uniformity

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent applies local quality by creating a core-shell structure where the shell portion has a controlled, gradual rare earth element concentration gradient (0.01-0.04 atom %/nm) rather than a sharp gradient. This local modification of concentration distribution in the shell region maintains insulation specific resistance while enabling thinner dielectric layers

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the concentration gradient parameter from the conventional high gradient (≥0.05 atom %/nm) to a controlled low gradient (0.01-0.04 atom %/nm) in the shell portion. This parameter modification prevents insulation deterioration while maintaining the core-shell structure benefits for thinning the dielectric layer

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS11072564B2Dielectric ceramic composition and multilayer ceramic electronic component

Publication Date: 2021.07.27 TDK CORP

AI summary

A dielectric ceramic composition having improved insulation specific resistance and a highly accelerated lifetime. The dielectric ceramic composition includes a dielectric particle having a core-shell structure including a main component expressed by a general formula ABO3, where A is Ba and the like, and B is Ti and the like), and a rare earth element component R, in which a shell part of the core-shell structure has an average rare earth element concentration C of 0.3 atom % or more. The rare earth element has a specified concentration gradient or concentration variation.