Ceramic Electronic Device Electrode Glass Composition
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Solution Overview
Problem
Conventional ceramic electronic devices face challenges in achieving both favorable plating properties of baked electrodes and preventing plating intrusion into the element body, with issues arising from glass frit deposition at high temperatures and void generation at low temperatures.
Innovation Solution
A ceramic electronic device design featuring a baked electrode layer with a first region bonded to the element body using a glass with a low softening point and a second region on the surface with a glass having a high softening point, optimizing the composition of B, Si, and Zn oxides to enhance plating properties and prevent intrusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the baked electrode is formed by applying conductive paste containing glass frit and baking at high temperature, then the electrode structure is formed, but glass frit is deposited on the electrode surface making plating adhesion difficult
Solution Approach 1:
The patent divides the baked electrode into two distinct regions with different glass compositions: the first region (near element body) contains glass with low softening point for good adhesion, while the second region (outer surface) contains glass with high softening point to prevent deposition and ensure plating property. This local differentiation resolves the contradiction between structure formation and plating adhesion.
Solution Approach 2:
The patent changes the chemical composition parameters of the glass frit between two regions: the first region has higher B2O3 content (0.4-0.6 mol ratio) for low softening point and good adhesion, while the second region has higher SiO2 content (0.4-0.6 mol ratio) for high softening point and plating compatibility. This parameter differentiation enables both structure formation and good plating properties.
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 multilayer ceramic capacitor exhibits improved plating properties and reduced intrusion of plating into the element body, maintaining electrical resistance and minimizing crack formation.
Implementation Method 1
The first glass having a low softening point is contained in the first region to be bonded with the end surface of the element body. The first glass has a low softening point. Thus, the inclusion of the first glass improves the sinterability of the baked electrode layer.
Implementation Method 2
The second glass having a high softening point exists on the outer surface of the baked electrode layer to be in contact with the plating electrode. The second glass has a high softening point. It is thus considered that the deposition of the second glass on the outer surface of the baked electrode layer can be prevented.
Data Source
AI summary
A ceramic electronic device includes an element body and an external electrode. The element body is formed by laminating a ceramic layer and an internal electrode layer. The external electrode is electrically connected to at least one end of the internal electrode layer. The external electrode includes a baked electrode layer. The baked electrode layer includes a first region and a second region. The first region is contacted with an end surface of the element body and located near a joint boundary with the element body. The second region is located outside the first region and constituting an outer surface of the baked electrode layer. The first region includes a first glass having a predetermined composition. The second region includes a second glass having a predetermined composition.