MLCC Electrode Hole Sizing for High-Voltage Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multilayer ceramic capacitors face challenges in maintaining high reliability under high voltage applications due to electric field concentration, which existing technologies fail to adequately address, particularly considering the influence of holes in internal electrode layers.
Innovation Solution
The design incorporates internal electrode layers with holes of varying area equivalent diameters, where the cumulative distribution's 99% value (D99) and dielectric layer thickness satisfy the condition (D99) < 0.0879×exp(2.86×t), with t being 0.5 μm or more, to reduce or prevent electric field concentration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the distance between internal electrode layers is increased to achieve high breakdown voltage, then reliability under high voltage is improved, but the capacitance decreases due to increased layer spacing
Solution Approach 1:
The patent changes the geometric parameters of holes in internal electrode layers, specifically controlling the area equivalent diameter D99 to satisfy D99 < 0.0879×exp(2.86×t) where t is dielectric layer thickness. This parameter optimization allows maintaining appropriate electric field distribution while using thinner dielectric layers, thus preserving capacitance without sacrificing breakdown voltage reliability
2Quantity of substance
If dielectric layer thickness is reduced to increase capacitance, then capacitance increases, but electric field concentration increases leading to dielectric breakdown
Solution Approach 1:
The patent applies local quality by creating non-uniform hole distributions in internal electrode layers. The holes have varying area equivalent diameters with their cumulative distribution controlled by the D99 parameter. This local structural variation modifies the electric field distribution specifically in regions prone to concentration, allowing thin dielectric layers to be used without causing breakdown
Solution Approach 2:
The patent optimizes the geometric parameters of holes (area equivalent diameter D99) as a function of dielectric layer thickness t, establishing the relationship D99 < 0.0879×exp(2.86×t). This parameter change allows systematic design of internal electrode structures that prevent electric field concentration while maintaining thin dielectric layers for high capacitance
3Reliability
If auxiliary electrodes are added to reduce electric field concentration, then breakdown voltage increases, but device complexity increases
Solution Approach 1:
The patent extracts the electric field management function from separate auxiliary electrodes and integrates it into the internal electrode layers themselves. By incorporating holes directly into the internal electrode structure with controlled D99 parameters, the patent eliminates the need for additional auxiliary electrodes while achieving the same electric field distribution benefits
Solution Approach 2:
The internal electrode layers are given multiple functions: they serve as both the capacitive elements and the electric field management structures. The holes in the internal electrodes perform the dual role of maintaining electrical connectivity while controlling electric field distribution, eliminating the need for separate auxiliary electrodes
Data Source
AI summary
A multilayer ceramic capacitor includes a multilayer body including dielectric layers and internal electrode layers laminated on each other, and first and second external electrodes. The internal electrode layers include first and second internal electrode layers each respectively electrically connected to the first and second external electrodes. The first and second internal electrode layers include holes having different area equivalent diameters. A thickness of each of the dielectric layers is about 0.5 μm or more and (area equivalent diameter D99)<about 0.0879×exp(2.86×t) is satisfied.