Multilayer Ceramic Capacitor Electrodes with Ceramic Grains
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Solution Overview
Problem
The reduction in thickness of dielectric and internal electrode layers in multilayer ceramic capacitors leads to a lower continuity modulus due to differences in sintering temperatures between metal and ceramic components, making it difficult to maintain high dielectric properties and capacity.
Innovation Solution
Incorporating ceramic grains into the internal electrode layers with a specific area ratio of 10% or more in the cross-section, and using a manufacturing method involving a metal conductive paste with controlled grain size distribution to prevent excessive sintering and diffusion of co-materials into dielectric layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the thicknesses of dielectric layers and internal electrode layers are reduced to downsize the capacitor, then the chip size is reduced, but the continuity modulus of the internal electrode layers becomes lower
Solution Approach 1:
The internal electrode layer is formed as a composite material containing both metal particles (conductive component) and ceramic particles (sintering control component). This composite structure allows the layer to maintain low thickness while preserving high continuity modulus, as the ceramic particles control sintering behavior to prevent metal particle aggregation and maintain conductive network integrity.
Solution Approach 2:
The invention changes the particle size parameters of both metal and ceramic particles to nanometer scale (10-100 nm). This parameter change enables the internal electrode layer to achieve high continuity modulus even at reduced thickness, as nanoscale particles provide better packing density and more uniform distribution, maintaining conductive pathways despite thinner layer geometry.
2Stability of the object's composition
If a ceramic co-material is added to the internal electrode layers to delay contraction, then the sintering control is improved, but the co-material diffuses to the dielectric layers during sintering
Solution Approach 1:
The ceramic co-material particle size is controlled to be in the nanometer range (10-100 nm), which significantly reduces its diffusion distance and mobility during sintering. This parameter control allows the ceramic particles to remain confined within the internal electrode layer, preventing unwanted diffusion into dielectric layers while still providing effective sintering control.
Solution Approach 2:
The internal electrode layer is designed as a composite with specifically sized metal and ceramic particles in controlled proportions. This composite structure creates a system where the nanoscale ceramic particles effectively control sintering contraction without excessive diffusion, as their small size limits their mobility while maintaining uniform distribution within the metal matrix.
3Volume of moving object
If the thickness of internal electrode layers is reduced, then the chip size is reduced, but the continuity modulus is further reduced
Solution Approach 1:
The invention changes the particle size parameters to nanometer scale and controls the particle size distribution (standard deviation ≤ 1.5 for metal particles). This parameter optimization enables thin layers to maintain high continuity modulus by ensuring uniform particle distribution and preventing aggregation, which would otherwise be problematic in thinner geometries.
Solution Approach 2:
The internal electrode layer uses a composite formulation with nanoscale metal and ceramic particles. The ceramic component acts as a sintering aid that maintains the conductive network integrity during sintering, allowing thin layers to achieve and maintain high continuity modulus despite reduced thickness that would normally compromise the conductive pathways.
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 enhances the continuity modulus of internal electrode layers, maintains high dielectric properties, and achieves a larger capacity by suppressing excessive sintering and diffusion, thereby ensuring desirable dielectric performance.
Implementation Method 1
a second step of forming internal electrode layers by sintering the metal powders and forming dielectric layers by sintering the ceramic powders of the green sheet
Implementation Method 2
forming dielectric layers by sintering the ceramic powders of the green sheet
Implementation Method 3
by baking a ceramic multilayer structure obtained by stacking a plurality of layer units obtained by the first step
Data Source
AI summary
A multilayer ceramic capacitor includes: a multilayer structure in which each of dielectric layers and each of internal electrode layers are alternately stacked, a main component of the dielectric layers being ceramic, a main component of the internal electrode layers being a metal, wherein: at least one of the internal electrode layers includes grains of which a main component is ceramic; and an area ratio of a total area of the grains in a cross section of the at least one of the internal electrode layers in a stacking direction of the dielectric layers and the internal electrode layers is 10% or more.