Laminated Ceramic Capacitor Electrodes for Fe Diffusion Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Thinner dielectric layers in laminated ceramic capacitors lead to degraded insulation reliability and reduced capacitance due to Fe diffusion, which is mitigated by forming intermediate layers with Fe and Al to enhance the Schottky barrier.
Innovation Solution
A laminated ceramic capacitor design with first and second internal electrode layers containing Ni, Fe, and Al, and intermediate layers with higher Fe concentration between dielectric and internal electrode layers, maintaining a specific Al to Fe ratio to prevent capacitance loss while improving insulation reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If intermediate layers containing Fe are formed between the dielectric layers and the internal electrode layers to increase the Schottky barrier, then insulation reliability is improved, but Fe diffuses into the dielectric layers causing capacitance decrease
Solution Approach 1:
Aluminum (Al) is introduced as an intermediary element that forms Al-Fe alloy compounds at the interface between the Fe-containing intermediate layer and the dielectric layer. This intermediary alloy structure prevents direct Fe diffusion into the dielectric while maintaining the Schottky barrier's insulating function, thus resolving the contradiction between improving insulation reliability and preventing capacitance loss
Solution Approach 2:
The intermediate layer is designed as a composite structure containing both Fe and Al elements, where Fe provides the Schottky barrier effect for insulation and Al forms alloy compounds that prevent Fe diffusion. This composite material approach allows simultaneous achievement of high insulation reliability and capacitance maintenance
2Quantity of substance
If the amount of Fe added to the raw material is reduced to prevent capacitance decrease, then less Fe is present in the dielectric layers, but sufficient intermediate layers are not formed between the dielectric layers and the internal electrode layers
Solution Approach 1:
The invention changes the compositional parameters of the intermediate layer by introducing Al along with Fe, and optimizes the Fe content within a specific range (0.01-5 at%). This parameter optimization ensures sufficient intermediate layer formation for insulation while limiting Fe diffusion that would harm capacitance
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 design achieves excellent capacitance and high insulation reliability by forming a robust Schottky barrier through the use of Fe and Al intermediate layers, preventing Fe diffusion and enhancing leakage current prevention.
Implementation Method 1
intermediate layers containing Fe and Al, and wherein an Al content ratio representing a ratio of a concentration of Al to a concentration of Fe in the first internal electrode layer is from 0.75 to 3.0
Data Source
AI summary
Provided is a laminated ceramic capacitor that can combine excellent capacitance and high insulation reliability. An aspect of the present disclosure includes a laminated ceramic capacitor including a body, a first external electrode, and a second external electrode. The body has a first internal electrode layer containing Ni, Fe and Al, a second internal electrode layer, a dielectric layer and a first intermediate layer. The dielectric layer is disposed between the first internal electrode layer and the second internal electrode layer. The first intermediate layer is disposed between the first internal electrode layer and the dielectric layer, and contains Fe and Al. An Al content ratio representing a ratio of a concentration of Al to a concentration of Fe in the first internal electrode layer is from 0.75 to 3.0.