MLCC Internal Electrode Alloy Design for Tin Diffusion Control
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Solution Overview
Problem
Multilayer ceramic capacitors face challenges with tin diffusion from internal electrodes to dielectric layers, leading to capacitance degradation due to reactions with oxygen, which affects reliability and performance.
Innovation Solution
Incorporating an alloy metal with nickel, tin, and aluminum in internal electrodes, including a capping internal electrode with specific alloy regions, to improve reliability and prevent oxidation, along with a manufacturing method involving a conductive paste and baking process to form a sintered body with improved connectivity and corrosion resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If tin is added to internal electrode to improve reliability, then high temperature load lifespan and connectivity are improved, but tin diffuses to dielectric layer and reacts with oxygen causing capacitance decrease
Solution Approach 1:
A nickel-aluminum alloy capping internal electrode is introduced as an intermediary layer between the tin-containing core internal electrode and the dielectric layer. This intermediary layer prevents direct contact and reaction between tin and oxygen in the dielectric layer, while still allowing the tin to provide its reliability-enhancing effects in the internal electrode structure.
Solution Approach 2:
The internal electrode is segmented into two distinct parts: a core internal electrode containing tin for improving reliability, and a capping internal electrode made of nickel-aluminum alloy for preventing oxidation. This segmentation allows each part to perform its specific function without interfering with the other.
2Reliability
If tin is added to internal electrode to improve connectivity, then reliability is improved, but tin diffuses from internal electrode to dielectric layer causing capacitance degradation
Solution Approach 1:
The nickel-aluminum alloy capping internal electrode serves as a protective intermediary that prevents tin diffusion into the dielectric layer while maintaining the electrical connectivity benefits of tin in the internal electrode.
Solution Approach 2:
The potential harmful effect of tin diffusion is converted into a benefit by using the tin's presence in the core internal electrode to improve connectivity and reliability, while the capping layer redirects the tin's interaction away from the dielectric layer, preventing capacitance degradation.
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 enhances the reliability and capacitance retention of multilayer ceramic capacitors by preventing tin oxidation and improving connectivity, thus addressing the issue of capacitance degradation and ensuring better performance in high-temperature and high-humidity environments.
Implementation Method 1
tin may diffuse from an internal electrode to a dielectric layer
Implementation Method 2
tin diffused into a dielectric layer may react with oxygen included in a dielectric layer
Implementation Method 3
forming a baked body and an internal electrode by baking the non-sintered body
Data Source
AI summary
An electronic component includes a body including a plurality of dielectric layers, and a plurality of internal electrodes disposed with a corresponding one of the dielectric layers interposed therebetween; and an external electrode disposed on the body and connected to at least one of the plurality of internal electrodes. One of the plurality of internal electrodes includes an alloy metal including nickel, tin and aluminum. One of the plurality of internal electrodes includes a core internal electrode including a first surface and a second surface opposing each other, and a capping internal electrode disposed on the first surface of the core internal electrode and the second surface of the core internal electrode. The capping internal electrode includes a first alloy region including an alloy of nickel and aluminum.