Multilayer Ceramic Capacitor Zr Gradient Inhibitor Layer
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Solution Overview
Problem
Multilayer ceramic capacitors face dielectric property deterioration and insulation resistance decline due to the thermal shrinkage mismatch between dielectric and internal electrode materials, leading to oxygen defects when inhibitors are pushed out during sintering.
Innovation Solution
A multilayer ceramic capacitor design with a dielectric layer and internal electrode layer composition where the Zr concentration gradient is maintained, with higher Zr concentration near the internal electrode layer, preventing oxygen defects and maintaining insulation resistance and high-temperature accelerated lifetime.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an inhibitor is blended in the internal electrode layer to prevent interlayer release, then thermal shrinkage mismatch is relieved, but oxygen defects occur in the dielectric layer and insulation resistance declines
Solution Approach 1:
The patent extracts the inhibitor function from the internal electrode layer by forming a separate inhibitor layer between the dielectric layer and internal electrode layer. This separation prevents the inhibitor from being pushed out into the dielectric layer during sintering, eliminating oxygen defects while maintaining interlayer bonding strength.
Solution Approach 2:
The patent introduces a dedicated inhibitor layer as an intermediary component between the dielectric layer and internal electrode layer. This intermediate layer contains the inhibitor material (such as BaTiO3 with specific particle sizes) that prevents thermal shrinkage mismatch without contaminating the dielectric layer, thus resolving the contradiction between bonding strength and oxygen defect prevention.
2Stability of the object's composition
If barium titanate is blended in the internal electrode layer as inhibitor, then thermal shrinkage difference is compensated, but insulation resistance deteriorates due to oxygen defects
Solution Approach 1:
The patent segments the inhibitor function from the internal electrode layer by creating a distinct inhibitor layer with controlled thickness and composition. This segmentation allows the inhibitor (barium titanate) to perform its thermal shrinkage compensation function without migrating into the dielectric layer, thereby preventing insulation resistance deterioration.
Solution Approach 2:
The patent applies local quality by concentrating the inhibitor material in a specific region (the inhibitor layer adjacent to the internal electrode layer) rather than distributing it throughout the internal electrode layer. This localized placement ensures thermal shrinkage compatibility is achieved at the critical interface without causing oxygen defects in the bulk dielectric layer.
3Reliability
If larger dielectric particles are blended in the internal electrode layer to prevent interlayer release, then dielectric layers are connected and release is prevented, but device complexity increases
Solution Approach 1:
The patent extracts the inhibitor function from the internal electrode layer composition entirely, forming a separate inhibitor layer. This eliminates the need to blend large dielectric particles into the internal electrode layer, simplifying its composition to primarily conductive material while maintaining interlayer connection strength through the dedicated inhibitor layer.
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 Zr concentration gradient in the dielectric layer suppresses oxygen defect formation and insulation resistance deterioration, enhancing the high-temperature accelerated lifetime and insulation resistance of the capacitor.
Implementation Method 1
oxygen defect occurs in barium titanate particle constituting the dielectric layer
Implementation Method 2
As sintering of the internal electrode progresses, the inhibitor which was blended in the internal electrode is pushed out to the dielectric layer
Implementation Method 3
As sintering of the internal electrode progresses, the inhibitor which was blended in the internal electrode is pushed out to the dielectric layer
Implementation Method 4
a dielectric layer and an internal electrode layer may be released from each other due to the difference of a thermal shrinkage of the dielectric material and a thermal shrinkage of the internal electrode material
Data Source
AI summary
The object of the present invention is to provide the multilayer ceramic capacitor having no deterioration of dielectric properties even in case an inhibitor of an internal electrode layer is pushed out to a dielectric layer when sintering. The multilayer ceramic capacitor 1 including a capacitor element body 10 comprising a dielectric layer 2 and an internal electrode layer 3 stacked in an alternating manner, whereinwhen Za represents Zr concentration of an dielectric particle in a center part 6 of the dielectric layer 2 and Zb represents Zr concentration of a dielectric particle near the internal electrode layer, 0<(Za/Zb)<1 is satisfied.