Multilayer Ceramic Capacitor External Electrode Glass Phase Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In electronic components like multilayer ceramic capacitors, reducing the thickness of external electrodes compromises humidity resistance and plating solution resistance, leading to potential structural defects and performance degradation due to glass phase penetration and plating solution intrusion.
Innovation Solution
A conductive paste with a specific composition, including a metal powder with a flat shape and a glass frit containing 36-59% SiO2 by mole, 6-11% volume, and a metal powder aspect ratio of 2.5 or more, ensuring the glass phase is present in the external electrode for improved sealing and plating adhesion without structural defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the thickness of external electrode is decreased, then the size of electronic component is reduced, but humidity resistance and plating solution resistance are degraded
Solution Approach 1:
The patent changes the chemical composition parameters of the glass frit, specifically setting SiO2 content to 36-59% by mole and volume content to 6-11%, which fundamentally alters the glass phase properties to achieve both thin electrode thickness and high resistance to humidity and plating solutions
Solution Approach 2:
The patent uses a composite material system consisting of metal powder with flat shape (aspect ratio ≥2.5) combined with specifically formulated glass frit, creating a composite external electrode that achieves both reduced thickness and enhanced resistance properties that neither material could provide alone
2Volume of moving object
If the thickness of external electrode is decreased, then the size of electronic component is reduced, but structural defects such as peeling and cracks may occur
Solution Approach 1:
The patent optimizes the glass frit composition parameters (SiO2: 36-59% mole%, volume: 6-11%) to control glass phase penetration depth and distribution, ensuring adequate bonding strength and structural integrity even when external electrode thickness is reduced to 7 μm or less
Solution Approach 2:
The patent creates local quality differences within the external electrode by controlling the distribution and penetration of glass phase, ensuring that the region adjacent to the base component has sufficient glass phase for strong bonding while the surface region maintains adequate thickness for structural integrity and resistance properties
3Strength
If glass phase is penetrated into base component to improve bonding strength, then bonding strength and plating adhesion are improved, but glass phase may not be present in surface layer when electrode thickness is decreased
Solution Approach 1:
The patent changes the glass frit composition (SiO2 content and volume percentage) to control the penetration behavior of glass phase, achieving optimal distribution that provides both bonding strength at the interface and sufficient surface presence for resistance properties
Solution Approach 2:
The patent creates different glass phase concentrations at different locations within the external electrode - higher concentration near the base component for bonding strength and adequate concentration at the surface for humidity and plating solution resistance
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 enhanced humidity and plating solution resistance, along with desirable plating adhesion properties, even when the external electrode thickness is reduced, preventing structural defects like peeling and cracks.
Implementation Method 1
the glass phase can be appropriately penetrated into the base component. By this penetration described above, it is intended to improve a bonding strength between the base component and the external electrode
Implementation Method 2
after an external electrode-forming conductive paste is applied onto two end portions of a base component in which internal electrodes are embedded, external electrodes are formed by a firing treatment
Implementation Method 3
in order to improved heat resistance and solder wettability of the external electrodes, plating films of Ni, Sn, solder, and/or the like are formed on the surfaces thereof
Data Source
AI summary
A multilayer ceramic capacitor having an external electrode with a glass phase, where an occupation rate of the glass phase is 30% to 60% on an area ratio, and a maximum length c of the glass phase is 5 μm or less.