Multi-Layer Ceramic Capacitor Electrodes Against Sintering Spheroidization
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Solution Overview
Problem
The spheroidization of internal electrode layers in multi-layer ceramic capacitors during high-temperature sintering leads to discontinuity, reducing capacitance characteristics.
Innovation Solution
Form internal electrode layers from metal particles with a nickel core covered by an oxidized metal layer, which are reduced to a nickel alloy during high-temperature sintering, maintaining continuity and forming oxygen vacancies at the interface with ceramic dielectric layers to create a Schottky barrier, suppressing leakage currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high-temperature sintering is applied to form internal electrode layers, then the ceramic body is sintered and formed, but the metal particles spheroidize causing discontinuity in internal electrode layers
Solution Approach 1:
The patent applies a preliminary action by forming a protective oxide layer on the metal particles before sintering. The metal particles are oxidized in advance to create a stable surface layer that prevents spheroidization during the subsequent high-temperature sintering process, thereby maintaining the continuity of internal electrode layers
Solution Approach 2:
The patent changes the chemical state of the metal particle surface by oxidizing it before sintering. This parameter change from metallic state to oxidized state provides thermal stability during sintering, preventing the metal particles from spheroidizing while maintaining electrode layer continuity
2Reliability
If the number of stacked layers of internal electrode layers is increased to meet capacitance requirements, then the capacitance characteristics improve, but the internal electrode layers become finer and more prone to spheroidization defects
Solution Approach 1:
The patent applies preliminary oxidation to metal particles before stacking multiple layers. This pre-treatment ensures that even as layers become finer with increased stacking, the metal particles maintain their shape and continuity during sintering, enabling high capacitance without sacrificing manufacturing precision
Solution Approach 2:
By changing the surface state of metal particles through oxidation, the patent enables the production of finer internal electrode layers with maintained continuity. This parameter change allows increased layer stacking for higher capacitance while preventing the spheroidization that would otherwise occur in finer structures
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
Enhances the continuity of internal electrodes, improving capacitance and reliability of multi-layer ceramic capacitors, meeting the requirements of high-end products.
Implementation Method 1
The oxidized metal layer of each of the metal particles is reduced to a metal layer during the high temperature sintering step
Implementation Method 2
metal particles in the internal electrode layers are easily sphered due to heat energy of high temperature applied during a sintering process
Implementation Method 3
forming oxygen vacancies at the interface with ceramic dielectric layers
Data Source
AI summary
The present application relates to a multi-layer ceramic capacitor and a method for producing the same. Internal electrode layers and ceramic dielectric layers are firstly formed, and the internal electrode layers and the ceramic dielectric layers are alternately laminated to form a laminated stack. The internal electrode layers are formed from specific metal particles. Next, a sintering process is performed to the laminated stack to form a laminated ceramic body, and then end electrodes are formed on two ends of the laminated ceramic body, thereby producing the multi-layer ceramic capacitor of the present application with excellent continuity of the internal electrode and better capacitor properties and reliability.