Multilayer Ceramic Capacitor Electrode Polarity Materials for Thin Dielectrics
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multilayer ceramic capacitors with Ni as a main component in the inner electrode face reliability issues under high electric field intensity due to insufficient insulation degradation during voltage application, hindering miniaturization and higher capacitance requirements.
Innovation Solution
The use of Cu and Sn in the first inner electrodes as positive electrodes and Cu with noble metals as additives in the second inner electrodes as negative electrodes, based on differing standard electrode potentials, reduces negative electrode segregation of oxygen ions, thereby enhancing insulation and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If dielectric layers are made thinner to achieve smaller size and higher capacitance, then miniaturization and capacitance requirements are met, but electric field intensity increases and reliability during voltage application deteriorates
Solution Approach 1:
The patent applies different metal compositions to different inner electrodes based on their polarity. First inner electrodes (positive polarity) use a first metal composition while second inner electrodes (negative polarity) use a second metal composition. This local differentiation addresses the reliability issue by optimizing each electrode's material properties for its specific electrical role, preventing insulation degradation at critical interfaces under high electric field conditions.
Solution Approach 2:
The patent employs composite metal compositions for the inner electrodes, where the first metal composition and second metal composition are distinct from each other. These composite materials are designed to resist insulation degradation when thin dielectric layers are used, thereby maintaining reliability even as capacitor size is reduced and electric field intensity increases.
2Ease of manufacture
If Ni is used as the main component of inner electrodes, then manufacturing is simplified, but insulation degradation occurs during voltage application and reliability is insufficient
Solution Approach 1:
The patent changes the material composition parameters of the inner electrodes by specifying distinct first and second metal compositions instead of using uniform Ni-based material. This parameter change optimizes the electrochemical stability and interface properties of the electrodes, preventing insulation degradation during voltage application while maintaining manufacturing feasibility through established ceramic capacitor fabrication processes.
3Reliability
If first inner electrodes include Cu and Sn with specific composition, then insulation degradation is reduced and reliability is improved, but device complexity increases due to different metal compositions
Solution Approach 1:
The patent implements local quality by assigning different metal compositions to inner electrodes based on their polarity function. First inner electrodes use a first metal composition optimized for positive polarity, while second inner electrodes use a second metal composition optimized for negative polarity. This targeted approach improves reliability by addressing insulation degradation at electrode-dielectric interfaces without requiring complete redesign of the entire capacitor structure.
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 configuration prevents insulation degradation and improves reliability of multilayer ceramic capacitors under high electric field conditions, ensuring excellent performance even with thinner dielectric layers.
Implementation Method 1
The first inner electrodes have a first metal composition including Cu and Sn, and the second inner electrodes have a second metal composition including Cu. The first metal composition and the second metal composition are different from each other in terms of at least one of the types and contents of the constituent elements.
Implementation Method 2
the reliability of the multilayer ceramic capacitor during voltage application is further improved... reduces negative electrode segregation of oxygen ions
Data Source
AI summary
In a multilayer ceramic capacitor including first and second inner electrodes alternately arranged with respect to a stacking direction of a multilayer body, a polarity based on a direction of voltage applied between a first outer electrode and a second outer electrode is determined such that the first inner electrodes function as positive electrodes and the second inner electrodes function as negative electrodes. The first inner electrodes have a first metal composition including Cu and Sn, and the second inner electrodes have a second metal composition including Cu. The second metal composition of the second inner electrodes includes Cu as a main component, and at least one metal element selected from Au, Pt, Ir, Pd, Os, Ag, Rh, and Ru, which have standard electrode potentials higher than that of Cu, as an additive component.