Inductance Element With Composite Magnetic Core
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inductance elements with closed magnetic path structures experience magnetic saturation and reduced inductance values when direct current is applied, leading to poor direct current superimposition characteristics and temperature coefficient mismatch between magnetic materials.
Innovation Solution
A ferrite sintered body with a positive temperature coefficient and a soft magnetic resin with a negative temperature coefficient of -30 ppm/°C or less are used to form an inductance element, where the soft magnetic resin covers the coil and fills the space between flange sections, allowing for increased magnetic permeability and reduced magnetic saturation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a closed magnetic path structure is used, then magnetic shielding effect and interference reduction are improved, but magnetic saturation occurs and inductance value decreases when direct current is applied
Solution Approach 1:
The patent uses a composite magnetic path structure combining ferrite sintered body (with positive temperature coefficient) and soft magnetic resin (with negative temperature coefficient of -30 ppm/°C or less). This composite structure allows the ferrite core to provide magnetic shielding while the soft magnetic resin compensates for magnetic saturation effects, maintaining inductance value under direct current conditions.
Solution Approach 2:
The patent changes the temperature coefficient parameter of the magnetic materials by selecting ferrite with positive temperature coefficient and soft magnetic resin with negative temperature coefficient of -30 ppm/°C or less. This parameter selection enables the materials to compensate for each other's temperature-dependent magnetic permeability changes, improving direct current superimposition characteristics while maintaining the closed magnetic path structure.
2Object-affected harmful factors
If ferrite material is used for magnetic core, then magnetic shielding effect is improved, but temperature coefficient mismatch with soft magnetic materials occurs
Solution Approach 1:
The patent deliberately selects materials with specific temperature coefficient parameters: ferrite sintered body with positive temperature coefficient and soft magnetic resin with negative temperature coefficient of -30 ppm/°C or less. This parameter matching allows the temperature-dependent magnetic permeability changes of different materials to compensate each other, achieving temperature stability in the overall magnetic path.
Solution Approach 2:
The patent creates a composite magnetic path system combining ferrite (positive temperature coefficient) and soft magnetic resin (negative temperature coefficient). This composite approach allows the inherent temperature coefficient mismatch between ferrite and soft magnetic materials to be converted into a compensatory mechanism, where one material's temperature drift counteracts the other's, achieving overall temperature stability.
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 effectively suppresses the decrease in inductance value due to direct current superimposition, especially in high current regions, and improves direct current superimposition characteristics by maintaining magnetic flux concentration and reducing magnetic saturation.
Implementation Method 1
A temperature coefficient of a magnetic permeability of the ferrite sintered body is positive, and a temperature coefficient of a magnetic permeability of the soft magnetic resin is −30 ppm/° C. or less
Implementation Method 2
The solution effectively suppresses the decrease in inductance value due to direct current superimposition, especially in high current regions, and improves direct current superimposition characteristics by maintaining magnetic flux concentration and reducing magnetic saturation
Data Source
AI summary
An inductance element is not interfered by peripheral circuits when mounted on a wiring board by forming a closed magnetic path. The inductance element has a small reduction of an inductance value when a direct current is superimposed, and thus has excellent direct current superimposition characteristics. The temperature coefficient of the magnetic permeability of a ferrite sintered body which constitutes a magnetic core can be positive. The temperature coefficient of the magnetic permeability of a soft magnetic resin provided as an external covering to cover a coil and to fill a space between flange sections of the magnetic core is permitted to be −30 ppm/° C. or less.