Multilayer Ceramic Capacitor End-Layer Structure for Field Relief

Solution Overview

Problem

Existing multilayer ceramic capacitors face reliability issues due to electric field concentration at the ends of internal electrodes, which is exacerbated by the concentration of electric field at the ends of the internal electrodes in close proximity to the dielectric ceramic layer with ceramic paste for level difference elimination.

Innovation Solution

The multilayer ceramic capacitor design includes a multilayer body with dielectric ceramic layers and internal electrode layers, where the second internal electrode layer is opposed to the first internal electrode layer with a dielectric ceramic layer in between, and a second dielectric ceramic layer is positioned to overlap the first dielectric ceramic layer, reducing electric field concentration at the ends of the internal electrodes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the thickness of the side margin is reduced to increase the area of internal electrode layers, then the capacitance is improved, but the electric field concentration at the ends of internal electrodes is exacerbated, degrading reliability

Engineering Contradiction:

ImprovecapacitanceVSAvoidreliability

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent applies local quality by introducing a second dielectric ceramic layer with different composition and properties specifically at the end portions of the multilayer body, while maintaining the original dielectric ceramic layer composition in the central capacitance-forming regions. This localized modification addresses electric field concentration at electrode ends without affecting the overall capacitance performance.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The second dielectric ceramic layer acts as an intermediary between the internal electrode layers at the end portions, modifying the electric field distribution in this critical region. This intermediate layer prevents direct electric field concentration between adjacent internal electrodes by providing a compositional buffer zone.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Manufacturing precision

If ceramic paste for level difference elimination is applied to suppress level difference between overlapping and non-overlapping internal electrode portions, then the manufacturing precision is improved, but the electric field concentration at the ends of internal electrodes is increased, degrading reliability

Engineering Contradiction:

Improvelevel difference eliminationVSAvoidreliability

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent changes the compositional parameters of the dielectric ceramic layer at the end portions by introducing a second dielectric ceramic layer with different material composition. This parameter change modifies the electrical properties in the end region, reducing electric field concentration while maintaining the level difference elimination function achieved by the ceramic paste.

Inventive Principle:

Principle #35Parameter changes

3Area of stationary object

If the area of internal electrode layers is increased by reducing side margin thickness, then the capacitance is improved, but the electric field concentration at internal electrode ends occurs more severely

Engineering Contradiction:

Improvearea of internal electrode layersVSAvoidelectric field concentration

Core Design Contradiction:

Area of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by introducing a second dielectric ceramic layer with different composition and properties specifically at the end portions of the multilayer body, while maintaining the original dielectric ceramic layer composition in the central capacitance-forming regions. This localized modification addresses electric field concentration at electrode ends without affecting the overall capacitance performance.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The second dielectric ceramic layer acts as an intermediary between the internal electrode layers at the end portions, modifying the electric field distribution in this critical region. This intermediate layer prevents direct electric field concentration between adjacent internal electrodes by providing a compositional buffer zone.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS12237114B2Multilayer ceramic capacitor

Publication Date: 2025.02.25 MURATA MFG CO LTD

AI summary

A multilayer ceramic capacitor includes a second alloy portion including one metal element provided in a greatest amount among metal elements of an internal electrode layer, and one or more metal elements among a metal group including Sn, In, Ga, Zn, Bi, Pb, Cu, Ag, Pd, Pt, Ph, Ir, Ru, Os, Fe, V, and Y is provided between a second dielectric ceramic layer and a first internal electrode layer, and between a second dielectric ceramic layer and a second internal electrode layer, respectively.