Multilayer Ceramic Capacitor Electrode Design for ESL Reduction

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Solution Overview

Problem

Multilayer ceramic capacitors face challenges with high equivalent serial inductance (ESL), low adhesion strength between external electrodes and the ceramic body, and acoustic noise issues due to piezoelectric phenomena, which affect the reliability and noise levels in high-frequency applications.

Innovation Solution

The design includes three external electrodes spaced apart on the ceramic body with specific height-to-thickness ratios to reduce ESL, enhance adhesion strength, and minimize acoustic noise by optimizing the structure of internal and external electrodes and their connections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the external electrode is extended to both side surfaces of the ceramic body, then the adhesion strength is improved, but the equivalent serial inductance increases

Engineering Contradiction:

Improveadhesion strengthVSAvoidequivalent serial inductance

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The external electrode is selectively extended to only one side surface of the ceramic body rather than both sides, creating an asymmetric configuration. This local modification optimizes the balance between adhesion strength and equivalent serial inductance by concentrating the electrode extension where it provides maximum benefit while minimizing the negative impact on inductance

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The electrode configuration transitions from a two-dimensional planar extension to a three-dimensional structure with controlled height d on one side surface. By defining the height parameter d and establishing the ratio d/T ≥ 0.10, the invention adds a vertical dimension to optimize both mechanical adhesion and electrical performance simultaneously

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Strength

If the height-to-thickness ratio d/T is increased, then the adhesion strength is improved, but the acoustic noise increases

Engineering Contradiction:

Improveadhesion strengthVSAvoidacoustic noise

Core Design Contradiction:

StrengthVSObject-generated harmful factors

Solution Approach 1:

The invention establishes a specific parameter range for the height-to-thickness ratio d/T ≥ 0.10, optimizing the geometric parameters of the external electrode. This parameter optimization ensures sufficient adhesion strength while controlling the piezoelectric effect that generates acoustic noise during operation

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The piezoelectric effect that causes acoustic noise is managed by optimizing the electrode geometry. By carefully controlling the d/T ratio, the design converts the potentially harmful piezoelectric vibration into a controlled phenomenon that maintains adhesion strength while minimizing noise generation

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This configuration effectively decreases ESL, improves adhesion strength, and reduces acoustic noise, enhancing the reliability and performance of multilayer ceramic capacitors in high-frequency applications.

Implementation Method 1

since the dielectric layers of the multilayer ceramic capacitor have piezoelectricity and electrostriction, when a direct current (DC) voltage or an alternating current (AC) voltage is applied to the multilayer ceramic capacitor, a piezoelectric phenomenon may occur between internal electrodes, causing the occurrence of vibrations

Methodology Applied

Scientific EffectPiezoelectric phenomenon: Piezoelectric Effect

Implementation Method 2

Methodology Applied

Scientific EffectElectrostriction: Electrostriction

Data Source

PatentUS9728334B2Multilayer ceramic capacitor and board for mounting thereof

Publication Date: 2017.08.08 SAMSUNG ELECTRO MECHANICS CO LTD

AI summary

A multilayer ceramic capacitor may include three external electrodes disposed on a mounting surface of a ceramic body so as to be spaced apart from each other. When a height of at least one portion of the external electrode formed on one side surface of the ceramic body in a width direction is defined as d, and a thickness of the ceramic body is defined as T, a ratio of d/T satisfies 0.10≦d/T.