Surface-Mounted Reactor with Segmented Ferrite Core
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing surface mountable reactors face issues with misalignment leading to reduced inductance values and increased heat generation due to their complex magnetic core structure, which complicates material selection and assembly, causing magnetic noise interference with other components on circuit boards.
Innovation Solution
A surface mountable reactor design featuring a first magnetic core with an axial portion and flange portions, a second magnetic core composed of separable components, and a resin mount that surrounds the coil, allowing for easy assembly and reduced misalignment effects, with the second magnetic core being made of ferrite material for low core loss and high permeability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a closed magnetic circuit structure with EP-form magnetic cores is used, then magnetic shielding is achieved, but misalignment easily reduces the butt-contact surface area and causes inductance variation
Solution Approach 1:
The magnetic core is divided into multiple independent pieces (first magnetic core with axial and flange portions, second magnetic core with connecting portions) that can be separately manufactured and assembled. This segmentation allows for easier manufacturing of each component while maintaining the overall closed magnetic circuit structure, reducing the impact of misalignment on total assembly precision.
Solution Approach 2:
The magnetic core components are designed with asymmetric features including protruding portions and recessed portions that mate together. This asymmetric design provides self-alignment during assembly, ensuring that the butt-contact surfaces align properly even with some manufacturing tolerances, thereby maintaining stable inductance values.
2Reliability
If the middle leg portions are inserted into the coil air core, then the magnetic circuit is closed, but leakage magnetic flux intersects with the coil causing eddy current loss and heat generation
Solution Approach 1:
The design extracts the problematic middle leg portions from the coil air core region by positioning them outside the coil winding. The first magnetic core's axial portion and flange portions, along with the second magnetic core's connecting portions, are arranged so that the butt-contact surfaces are located outside the coil, preventing leakage magnetic flux from intersecting with the coil turns and eliminating eddy current losses.
Solution Approach 2:
The magnetic core structure is designed with three-dimensional arrangement where the connecting portions extend in multiple directions. This spatial arrangement allows the magnetic circuit to be closed while positioning the butt-contact surfaces in a different spatial dimension (outside the coil plane), avoiding interference with the magnetic flux path through the coil.
3Reliability
If the magnetic core has a complicated EP-form shape, then a closed magnetic circuit is formed, but material selection is limited and molding difficulty increases
Solution Approach 1:
The complex EP-form magnetic core is segmented into multiple simpler components (first magnetic core with axial and flange portions, second magnetic core with connecting portions) that can be manufactured using standard molding processes. Each segment has a simpler geometry that is easier to mold with various magnetic materials, while the segments are designed to assemble into the complete closed magnetic circuit structure.
Solution Approach 2:
Multiple separately manufactured magnetic core pieces are combined through assembly to form the complete closed magnetic circuit. The first magnetic core's flange portions connect with the second magnetic core's connecting portions via butt-contact surfaces, merging the individual components into a functional unified structure that achieves the desired magnetic circuit closure.
4Ease of manufacture
If the outer leg portion butt-contact surfaces are perpendicular to magnetic flux, then the structure is simple, but magnetic flux leakage causes noise interference with adjacent parts
Solution Approach 1:
The magnetic core components are designed with different local geometries optimized for their specific functions. The connecting portions have butt-contact surfaces with specific orientations and shapes that minimize magnetic flux leakage in critical areas. By varying the local quality of different portions of the magnetic core, the design achieves both structural simplicity and reduced magnetic noise interference with adjacent circuit board components.
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 design enhances the formability of magnetic core components, reduces inductance variations due to misalignment, and minimizes magnetic noise interference, providing a stable and efficient magnetic shield structure for surface mounting.
Implementation Method 1
the second magnetic core being made of ferrite material for low core loss and high permeability
Implementation Method 2
a coil; a first magnetic core comprising an axial portion around which the coil is disposed
Data Source
AI summary
The invention is directed to a surface mountable reactor including: a coil 60; a first magnetic core 5 including an axial portion 5a around which the coil 60 is disposed and flange portions 5b and 5c at both ends thereof; a second magnetic core 10 disposed outside the coil 60 to connect the flange portions of the first magnetic core 5; and a resin mount 30 disposed outside the coil 60, wherein the second magnetic core 10 includes a plurality of components 10a and 10b separable toward outside the coil 60, the circumference of the coil 60 is surrounded by the second magnetic core 10 and the resin mount 30, and the coil 60 has end portions 65 disposed outside the resin mount 30, and to a method for fabrication thereof.