Multilayer Capacitor Side Portions Acicular Mullite Phase

Solution Overview

Problem

Multilayer capacitors with exposed internal electrodes suffer from degradation in moisture resistance reliability and toughness due to shrinkage after sintering, which affects their performance and longevity.

Innovation Solution

Incorporating acicular mullite second phases with a glass composition of aluminum (Al), silicon (Si), manganese (Mn), and phosphorus (P) in the side portions, which are densified through chemical low-temperature sintering, to enhance the capacitor's moisture resistance and toughness, while maintaining a thin structure for increased capacitance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the internal electrode is exposed in the width direction to increase electrode area, then capacitance is improved, but moisture resistance reliability and toughness degrade due to shrinkage after sintering

Engineering Contradiction:

Improvemoisture resistance reliabilityVSAvoidtoughness

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The patent changes the chemical composition parameters of the side portions by incorporating specific glass components (Al, Si, Mn, P) in controlled amounts. This compositional parameter change enables the side portions to resist shrinkage during sintering while maintaining moisture resistance reliability and toughness, directly resolving the contradiction between reliability and strength

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite material structure where side portions contain a matrix phase with embedded acicular second phases. This composite structure combines the moisture resistance properties of the matrix with the structural reinforcement of acicular phases, achieving both improved reliability and strength simultaneously

Inventive Principle:

Principle #40Composite materials

2Volume of moving object

If the capacitor structure is thinned to enable miniaturization, then device size is reduced, but moisture resistance reliability and toughness deteriorate

Engineering Contradiction:

Improvecapacitor sizeVSAvoidmoisture resistance reliability

Core Design Contradiction:

Volume of moving objectVSReliability

Solution Approach 1:

The patent modifies the chemical composition parameters of side portions by incorporating specific glass components (Al, Si, Mn, P) in controlled amounts. This compositional parameter change enables the side portions to resist shrinkage during sintering while maintaining moisture resistance reliability and toughness, directly resolving the contradiction between reliability and strength

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite material structure where side portions contain a matrix phase with embedded acicular second phases. This composite structure combines the moisture resistance properties of the matrix with the structural reinforcement of acicular phases, achieving both improved reliability and strength simultaneously

Inventive Principle:

Principle #40Composite materials

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

The solution effectively improves the moisture resistance reliability and toughness of multilayer capacitors, preventing degradation even with reduced thickness, thus enhancing their performance and lifespan while allowing for miniaturization and reduced manufacturing costs.

Implementation Method 1

the first and second side portions comprise an acicular second phase including a glass comprising aluminum (Al) and silicon (Si), manganese (Mn), and phosphorus (P), and a volume of the second phase is 30% or more with respect to the entire first and second side portions

Methodology Applied

Scientific EffectSintering: Sintering

Implementation Method 2

Incorporating acicular mullite second phases with a glass composition of aluminum (Al), silicon (Si), manganese (Mn), and phosphorus (P) in the side portions, which are densified through chemical low-temperature sintering

Methodology Applied

Scientific EffectChemical low-temperature sintering:

Data Source

PatentUS11694847B2Multilayer capacitor and board having the same mounted thereon

Publication Date: 2023.07.04 SAMSUNG ELECTRO MECHANICS CO LTD

AI summary

A multilayer capacitor includes a capacitor body including dielectric layers and first and second internal electrodes, the capacitor body having first to sixth surfaces, the first internal electrode being exposed through the third, fifth, and sixth surfaces, and the second internal electrode being exposed through the fourth, fifth, and sixth surfaces, a first side portion and a second side portion, respectively disposed on the fifth surface and the sixth surface of the capacitor body, and a first external electrode and a second external electrode, respectively be connected to the first internal electrode and the second internal electrode. The first and second side portions comprise an acicular second phase including a glass comprising aluminum (Al) and silicon (Si), manganese (Mn), and phosphorus (P), and a volume of the second phase is 30% or more with respect to the entire first and second side portions.