Multilayer Ferrite Ceramic Coil with Localized Pore Control
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Solution Overview
Problem
The existing multilayer coil components face issues with reduced strength due to increased pore area ratios outside the side gap portion, leading to internal stress between the internal conductor and magnetic ceramic layers, which affects the coupling and thermal expansion.
Innovation Solution
A multilayer electronic component with a specific pore area ratio configuration, where the side gap pore area ratio is between 9.0% and 20.0%, and the interlayer pore area ratio is 8.0% or less, achieved by stacking insulator layers with ferrite ceramic and connecting coil conductor layers via hole conductors, followed by controlled pressure bonding and firing, allowing an acidic solution to permeate and cut the coupling between the coil and ceramic layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If the pore area ratio of the side gap portion is increased to relax internal stress, then the coupling between internal conductor and magnetic ceramic is cut, but the overall strength of the ceramic multilayer body is reduced
Solution Approach 1:
The patent applies local quality by creating different pore area ratios in different regions of the ceramic multilayer body. Specifically, the side gap portion (between the outer circumferential edge of the annular track and the outer edge of the multilayer body) is designed to have a pore area ratio of 6-20%, while the interlayer portion (between two coil conductor layers) is designed to have a pore area ratio of 0-8%. This localized differentiation allows the side gap to relax internal stress through controlled decoupling of the internal conductor from the magnetic ceramic, while the interlayer portion maintains high strength with minimal pores.
2Strength
If the pore area ratio of the interlayer portion is decreased to enhance strength, then the coupling between coil conductor layers is improved, but the internal stress relaxation is reduced
Solution Approach 1:
The patent applies local quality by creating different pore area ratios in different regions of the ceramic multilayer body. Specifically, the side gap portion (between the outer circumferential edge of the annular track and the outer edge of the multilayer body) is designed to have a pore area ratio of 6-20%, while the interlayer portion (between two coil conductor layers) is designed to have a pore area ratio of 0-8%. This localized differentiation allows the side gap to relax internal stress through controlled decoupling of the internal conductor from the magnetic ceramic, while the interlayer portion maintains high strength with minimal pores.
3Stress or pressure
If the pore area ratio of the side gap portion is within 6-20% to relax internal stress, then the coupling between internal conductor and magnetic ceramic is cut, but the manufacturing precision of the multilayer body is reduced
Solution Approach 1:
The patent applies parameter changes by precisely controlling the pore area ratio within specific ranges (6-20% for side gap, 0-8% for interlayer portion) to achieve the desired balance between stress relaxation and manufacturing precision. By defining these specific parameter ranges, the patent ensures that the multilayer body maintains adequate manufacturing precision while still achieving sufficient internal stress relaxation through the controlled pore structure.
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
This configuration enhances the strength of the multilayer body while relaxing internal stress, maintaining magnetic permeability and inductance values, as demonstrated by experimental results showing improved flexural strength and impedance characteristics.
Implementation Method 1
making an acidic solution permeate into the fired multilayer body
Implementation Method 2
the coupling between the internal conductor and the magnetic ceramic around the internal conductor at the interface is cut
Implementation Method 3
firing each of the multilayer bodies
Implementation Method 4
stacking and pressure bonding the plurality of mother insulator layers
Data Source
AI summary
An electronic component includes a multilayer body having a configuration, in which a plurality of insulator layers containing ferrite ceramic are stacked, and a coil having a configuration, in which a plurality of coil conductor layers containing Ag and being disposed on the insulator layers are connected to at least one via hole conductor penetrating the insulator layers in the stacking direction, and having a spiral shape spiraling in the stacking direction. A first pore area ratio of a side gap interposed between an outer circumferential edge of an annular track formed by stacking the plurality of coil conductor layers and an outer edge of the multilayer body, when viewed in the stacking direction, is 9.0% or more and 20.0% or less, and the second pore area ratio of a portion interposed between two coil conductor layers in the stacking direction is 8.0% or less.