Multilayer Ceramic Capacitor Electrode Insulation for Short-Circuit Prevention
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Solution Overview
Problem
The demand for miniaturized multilayer ceramic capacitors with high capacitance has increased due to the miniaturization and multi-functionalization of electronic products, but existing technologies face challenges in achieving optimal insulation and preventing short-circuits and defects during manufacturing and mounting.
Innovation Solution
A multilayer ceramic capacitor design featuring internal electrodes with different reactivity metals and insulating parts formed by oxidation, along with a manufacturing method that includes preparing ceramic green sheets, forming internal electrode patterns, and sintering, to create a ceramic body with exposed insulating parts that prevent short-circuits and enhance capacitance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If internal electrodes are exposed at both end surfaces to increase capacitance, then capacitance is improved, but short-circuit risk increases due to lack of insulation
Solution Approach 1:
The patent applies different treatments to different parts of the internal electrodes. The first internal electrode is oxidized at its exposed surface to form an insulating oxide layer, while the second internal electrode is plated with a protective metal layer. This local differentiation allows both electrodes to be exposed for capacitance while preventing short-circuits through targeted insulation and protection at critical locations.
Solution Approach 2:
The patent uses composite material structures for the internal electrodes. The first internal electrode consists of a base metal (Ni, Pd, or Pt) combined with an oxidized surface layer. The second internal electrode uses a base metal (Cu, Ag, or Al) combined with a protective plating layer. These composite structures provide both electrical conductivity for capacitance and insulating/pro protective properties for reliability.
2Reliability
If metal materials are used for internal electrodes to ensure conductivity, then electrical conductivity is improved, but oxidation resistance deteriorates
Solution Approach 1:
The patent employs composite material structures where a conductive base metal is combined with protective surface layers. The first internal electrode uses Ni/Pd/Pt as base metal with an oxidized surface layer that provides both insulation and protection. The second internal electrode uses Cu/Ag/Al as base metal with a protective plating layer. This composite approach maintains electrical conductivity through the base metal while the surface layers provide oxidation resistance.
Solution Approach 2:
The patent changes the chemical state of the metal surfaces through oxidation and plating processes. By controlling the oxidation state of the first internal electrode and applying protective plating to the second, the patent transforms the surface properties of the metals to achieve both conductivity and oxidation resistance simultaneously.
3Ease of manufacture
If asymmetric electrode configuration is used to simplify manufacturing, then manufacturing complexity is reduced, but mounting reliability deteriorates due to tombstone defects
Solution Approach 1:
The patent intentionally uses asymmetric electrode configuration where the first and second internal electrodes have different materials and different protective treatments. This asymmetry is designed to create different wetting characteristics on each end surface, which balances the thermal and mechanical stresses during reflow soldering, thereby preventing tombstone defects and improving mounting reliability.
Solution Approach 2:
The patent applies preliminary protective treatments (oxidation and plating) to the internal electrodes before mounting to prevent potential problems. By pre-forming the insulating oxide layer on the first electrode and the protective plating on the second electrode, the patent anticipates and prevents short-circuits and mounting defects before they occur during the mounting process.
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
The solution provides a high capacitance multilayer ceramic capacitor with improved reliability and reduced defects, such as short-circuits and tombstone defects, by effectively insulating internal electrodes and maintaining symmetry during mounting on printed circuit boards.
Implementation Method 1
oxidizing the edge of the first internal electrode exposed to the second end surface to form a first insulating part
Implementation Method 2
oxidizing the plating part to form a second insulating part
Implementation Method 3
preparing a laminate by stacking the ceramic green sheets in such a manner that the first and second internal electrode patterns face each other, having the ceramic green sheets interposed therebetween; and sintering the cut laminate
Data Source
AI summary
There is provided a multilayer ceramic capacitor including: a ceramic body having a plurality of dielectric layers and having first and second end surfaces opposing each other; a first internal electrode formed on each of the dielectric layers, including a first insulating part exposed to the second end surface, and exposed to the first end surface; a second internal electrode disposed to face the first internal electrode, having the dielectric layer interposed therebetween, and exposed to the first and second end surfaces; and a second insulating part formed on an edge of the second internal electrode exposed to the first end surface.