Multilayer Ceramic Capacitor Cover Portion Thickness Optimization
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Solution Overview
Problem
Multilayer ceramic capacitors face challenges in achieving high warpage strength and moisture resistance reliability, particularly in demanding applications such as vehicles and infotainment systems, where existing dual layer structures with conductive resin layers are insufficient in distributing stress and preventing cracks.
Innovation Solution
A multilayer electronic component design featuring a dielectric layer with alternately layered internal electrodes, upper and lower cover portions, and external electrodes with conductive resin layers, where the thickness of the cover portions (Tp) is optimized in relation to the maximum surface roughness (Rmax) of the conductive resin layers to achieve improved warpage strength and moisture resistance, with Tp/Rmax controlled to be 30 or higher.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a dual layer structure including an electrode layer and a conductive resin layer is used, then reliability is improved by absorbing external impacts and preventing plating solution permeation, but warpage strength is insufficient to meet high reliability standards
Solution Approach 1:
The patent applies parameter changes by optimizing the thickness of the cover portion (Tp) and the maximum surface roughness (Rmax) to satisfy Tp/Rmax ≥ 30. This quantitative parameter optimization resolves the contradiction by adjusting geometric parameters to achieve both adequate warpage strength and moisture resistance reliability simultaneously.
Solution Approach 2:
The patent uses composite materials by combining the cover portion made of dielectric material with the conductive resin layer containing conductive particles. This composite structure provides both mechanical strength to resist warpage and protective functions to prevent moisture permeation, resolving the contradiction between strength and reliability.
2Volume of moving object
If the thickness of cover portions is reduced to achieve miniaturization, then device size is reduced, but warpage strength and stress distribution capability deteriorate
Solution Approach 1:
The patent resolves this contradiction through parameter optimization by establishing the relationship Tp/Rmax ≥ 30. This allows the cover portion thickness (Tp) to be minimized for device miniaturization while maintaining adequate warpage strength by controlling the surface roughness parameter (Rmax) appropriately.
Solution Approach 2:
The patent applies local quality by optimizing specific local parameters (cover portion thickness and surface roughness at the ends of conductive resin layers) rather than uniformly increasing overall dimensions. This enables miniaturization while maintaining local stress distribution capability where it is most needed.
3Strength
If surface roughness of conductive resin layers is increased to improve adhesion, then bonding strength is improved, but stress distribution capability deteriorates leading to increased cracking
Solution Approach 1:
The patent resolves this contradiction through precise parameter optimization by controlling the maximum surface roughness (Rmax) to satisfy Tp/Rmax ≥ 30. This quantitative control balances adhesion strength (improved by some surface roughness) with stress distribution capability (maintained by limiting excessive roughness), preventing crack formation.
Data Source
AI summary
A multilayer electronic component includes a body including dielectric layers and a capacitance forming portion and upper and lower cover portions respectively disposed on and below the capacitance forming portion, and including first and second surfaces opposing each other in a layering direction, an external electrode disposed on the third or fourth surface, connected to the first or second internal electrode, and including an electrode layer extending to a portion of each of the first and second surfaces and a conductive resin layer covering the electrode layer. Tp/Rmax is 30 or higher, in which Rmax is defined as a maximum surface roughness of each of the first and second surfaces on an end of the conductive resin layer, and Tp is defined as a thickness of each of the upper and lower cover portions.