Multilayer Ceramic Capacitor Electrode Design for Low ESR
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multilayer ceramic capacitors with thermosetting electroconductive resin layers in the outer electrodes face high equivalent series resistance (ESR) and large end-face thickness, which limits their performance and capacitance.
Innovation Solution
The design includes a multilayer ceramic capacitor with a base electrode layer only on the surface of the end surfaces and an electroconductive resin layer extending to cover the primary and lateral surfaces, avoiding coverage of the base electrode layer by the resin, thus reducing ESR and allowing for larger design dimensions and increased capacitance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an epoxy-based thermosetting resin layer is formed to cover the entire electrode layer, then the multilayer body is protected from cracking in harsh environments, but the equivalent series resistance (ESR) increases and the end-face thickness becomes large
Solution Approach 1:
The patent applies different properties to different parts of the electrode structure. The resin layer is selectively positioned to cover only specific regions (lateral surfaces and portions of primary surfaces) while leaving the end-face electrode regions exposed. This local differentiation allows the resin to provide crack protection where needed while maintaining low ESR by avoiding coverage of the end-face electrode areas that contribute to electrical conductivity.
Solution Approach 2:
The electrode structure is segmented into distinct regions with different functions. The end-face regions are kept as pure electroconductive material for optimal electrical contact and low resistance, while the lateral and primary surface regions are covered with the resin layer for mechanical protection and stress absorption. This segmentation resolves the contradiction between protection and conductivity.
2Reliability
If an epoxy-based thermosetting resin layer is formed to cover the entire electrode layer, then the multilayer body is protected from cracking in harsh environments, but the end-face thickness becomes large
Solution Approach 1:
The resin layer thickness is locally controlled by restricting its formation to specific regions. The end-face thickness is kept small by preventing resin coverage on the end surfaces, while the lateral surfaces receive the full protective benefit of the resin layer. This local quality approach allows the component to meet both the protection requirement and the thickness constraint.
Solution Approach 2:
The protective resin coating is segmented to cover only the lateral surfaces and portions of primary surfaces, deliberately excluding the end-face regions. This segmentation ensures that the end-face thickness remains small for proper electrical contact while the lateral surfaces gain crack protection from the resin layer.
3Reliability
If the electroconductive resin layer covers the base electrode layer, then the anti-cracking performance is improved, but the ESR increases
Solution Approach 1:
The patent implements local quality by controlling the resin layer to cover only specific regions (lateral surfaces and portions of primary surfaces) while deliberately leaving the base electrode layer on the end surfaces exposed. This selective coverage maintains low ESR by preserving direct electrical contact at the end faces while still providing anti-cracking protection through resin coverage on the lateral surfaces where mechanical stress is most critical.
Solution Approach 2:
The electrode structure is segmented into functionally distinct zones: end-face regions with pure electroconductive base electrode material for optimal electrical performance, and lateral/primary surface regions with resin coverage for mechanical protection. This segmentation resolves the contradiction by assigning different protective qualities to different spatial regions.
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 significantly reduces ESR, allows for larger design dimensions, and enhances the anti-cracking performance by absorbing flexural stress, leading to improved capacitance and reliability under thermal cycles.
Implementation Method 1
the electroconductive resin layer extending over a wide area from the first end surface of the multilayer ceramic capacitor to portions of the surfaces of the first and second primary surfaces and portions of the surfaces of the first and second lateral surfaces, and by the second electroconductive resin layer... the anti-cracking performance is further improved
Data Source
AI summary
A multilayer ceramic capacitor includes a multilayer body and first and second outer electrodes that include first and second base electrode layers, respectively, first and second electroconductive resin layers, respectively, and first and second plating layers, respectively. The first and second base electrode layers are only located on the end surfaces of the multilayer body. The first and second electroconductive resin layers reach portions of the surfaces of the primary surfaces and portions of the surfaces of the lateral surfaces of the multilayer body. The first and second plating layers cover at least a portion of the base electrode layers and at least a portion of the electroconductive resin layers.