Laminated Coil Component Non-Magnetic Section Composition
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Solution Overview
Problem
Laminated coil components using copper as an internal conductor face challenges with resistivity decrease and plating growth when fired in a reducing atmosphere, limiting their direct current superimposition characteristics and making it difficult to utilize inexpensive copper effectively.
Innovation Solution
A laminated coil component design with a non-magnetic section comprising 40.0 mol % to 48.5 mol % Fe2O3, 0.5 mol % to 9 mol % Mn2O3, and 0 mol % to 8 mol % CuO, which suppresses resistivity decrease and improves direct current superimposition characteristics by using copper as the internal conductor and employing a heat treatment in an atmosphere with an equilibrium oxygen partial pressure of Cu—Cu2O or less.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If copper is used as an internal conductor and fired in a reducing atmosphere, then cost is reduced and conductivity is improved, but resistivity decreases and plating growth occurs
Solution Approach 1:
The patent changes the chemical composition parameters of the ferrite material by controlling the Fe/Mn ratio and adding specific amounts of CuO (0.1-5.0 wt%). This compositional parameter change allows the material to maintain stability during reducing atmosphere firing, preventing the resistivity decrease and plating growth that normally occur when copper is fired in such conditions.
Solution Approach 2:
The patent introduces CuO as an intermediary substance within the ferrite matrix that acts as a buffer during the firing process. This CuO content (0.1-5.0 wt%) mediates between the copper conductor and the ferrite material, preventing direct harmful interactions while allowing the use of reducing atmosphere firing to maintain copper's low cost and high conductivity.
2Strength
If Fe content is increased to improve magnetic properties, then magnetic permeability improves, but direct current superimposition characteristics degrade
Solution Approach 1:
The patent changes the Fe content parameter to a specific range (40-48.5 mol%) that balances magnetic properties and DC characteristics. This parameter optimization ensures sufficient magnetic permeability while preventing magnetic saturation under DC conditions, thereby maintaining good direct current superimposition characteristics.
Solution Approach 2:
The patent applies local quality by creating a non-magnetic section with reduced Fe content compared to conventional magnetic bodies. This localized reduction in Fe content (to 40-48.5 mol%) in specific regions allows the overall component to maintain good magnetic properties while the non-magnetic sections prevent saturation, improving DC superimposition characteristics.
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 allows for the use of inexpensive copper as an internal conductor while maintaining excellent direct current superimposition characteristics, preventing resistivity decrease and plating growth, thereby enhancing the performance of laminated coil components.
Implementation Method 1
a non-magnetic section of a laminated coil component having a Fe content of 40.0 mol % to 48.5 mol % in terms of Fe2O3, a Mn content of 0.5 mol % to 9 mol % in terms of Mn2O3 and a Cu content of 0 mol % to 8 mol % in terms of CuO can suppress the decrease in resistivity of the non-magnetic section even when using copper as an internal conductor and fired under a reducing atmosphere
Implementation Method 2
employing a heat treatment in an atmosphere with an equilibrium oxygen partial pressure of Cu—Cu2O or less
Data Source
AI summary
A laminated coil component that can use inexpensive copper as an internal conductor, and has excellent direct current superimposition characteristics is provided. In a laminated coil component including: a magnetic section including a ferrite material; a non-magnetic section including a non-magnetic ferrite material; and a coiled conductor section containing copper as a main component embedded inside the magnetic section and the non-magnetic section, the non-magnetic section contains at least Fe, Mn and Zn, and optionally Cu. The non-magnetic section has a Fe content of 40.0 mol % to 48.5 mol % in terms of Fe2O3, a Mn content of 0.5 mol % to 9 mol % in terms of Mn2O3 and a Cu content of 8 mol % or less in terms of CuO.