Multilayer Ceramic Capacitor Rare Earth Concentration Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multilayer ceramic capacitors face degradation in sintering characteristics due to differences in composition between active and protective regions, leading to inadequate densification and humidity resistance, especially when firing temperatures are elevated to promote sintering.
Innovation Solution
The use of a rare earth element with a concentration equal to or greater in the active region compared to the protective region, and an average ionic radius in the protective region equal to or less than that in the active region, to enhance sintering characteristics without increasing firing temperatures, thereby improving reliability and humidity resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the firing temperature is increased to promote densification of the protective region, then the sintering characteristic of the protective region is improved, but the characteristic degradation occurs and the continuity modulus is affected
Solution Approach 1:
The patent applies different rare earth element concentrations to different regions of the multilayer ceramic capacitor. The active region contains a first concentration of rare earth elements while the protective region contains a second concentration, creating local compositional differences that optimize each region's properties for its specific function during firing and operation
Solution Approach 2:
The patent changes the compositional parameters by controlling the concentration of rare earth elements in the green sheets. By adjusting the rare earth element content in the active region versus the protective region, the patent modifies the sintering behavior and densification characteristics of each region, allowing the protective region to densify properly without causing characteristic degradation
2Volume of stationary object
If the firing temperature is increased to improve sintering of the protective region, then the density of the protective region is improved, but the optimal firing temperature of the active region is exceeded
Solution Approach 1:
Different rare earth element concentrations are introduced into the active region and protective region respectively, creating localized compositional variations that result in different sintering temperatures and densification behaviors for each region, allowing simultaneous optimization at a single firing temperature
Solution Approach 2:
The patent modifies the chemical composition parameters of the green sheets by controlling rare earth element concentrations. This compositional adjustment changes the thermal and sintering properties of each region, enabling the protective region to achieve adequate density at a lower firing temperature that still optimizes the active region
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 approach allows for balanced densification of both active and protective regions, suppressing characteristic degradation and maintaining continuity modulus, thus enhancing the overall performance and reliability of the multilayer ceramic capacitors.
Implementation Method 1
Densifying of the protective region in a firing process may be slower than that of the active region... in order to promote the densifying of the protective region, the active region is fired in a temperature higher than an optimal firing temperature
Data Source
AI summary
A multilayer ceramic capacitor includes: a multilayer structure in which each of a plurality of dielectric layers and each of a plurality of internal electrode layers are alternately stacked, wherein a concentration of a rare earth element in an active region with respect to a main component ceramic of the active region is equal to or more than a concentration of a rare earth element in at least a part of a protective region with respect to a main component ceramic of the protective region, wherein an average ionic radius of the rare earth element of the at least a part of the protective region is equal to or less than an average ionic radius of the rare earth element in the active region.