Coil Component Magnetic Flux Leakage Shielding

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Solution Overview

Problem

In coil components using a drum-shaped core, the variation in magnetic material characteristics often leads to parameter deviations, such as inductance value, exceeding specified tolerances, causing magnetic flux leakage that can affect other electronic components.

Innovation Solution

A coil component design featuring a drum-shaped core with a winding core part divided by a magnetic gap, where the gap is formed within the core itself, and a plate-like core is fixed to the flange parts to shield the leaking magnetic flux, with optional non-magnetic material filling and surface application to enhance winding and reduce flux leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a magnetic gap is formed between the drum-shaped core and the plate-like core to reduce tolerance variation, then the inductance value stability is improved, but the magnetic flux leakage increases and affects other electronic components

Engineering Contradiction:

Improveinductance value toleranceVSAvoidmagnetic flux leakage

Core Design Contradiction:

Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The magnetic gap is repositioned from the interface between the drum-shaped core and plate-like core to the axial direction within the drum-shaped core itself. This dimensional relocation allows the gap to control inductance while the plate-like core shields the leakage flux, resolving the contradiction between tolerance control and flux leakage reduction.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The plate-like core acts as a magnetic shield (intermediary) that blocks the leakage flux generated by the magnetic gap. By positioning the gap inside the drum-shaped core and using the plate-like core as a shield, the system achieves both tolerance control and leakage reduction.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the magnetic gap is significantly increased to control parameter variation, then the inductance stability is improved, but the leakage magnetic flux increases and interferes with other components

Engineering Contradiction:

Improveparameter consistencyVSAvoidinterference with other electronic components

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The plate-like core serves as a magnetic shield that intercepts and redirects the leakage flux from the enlarged magnetic gap. This allows the gap to be sufficiently large for parameter control while the shield prevents interference with surrounding components.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The leakage flux that would normally be harmful is redirected by the plate-like core shield to follow a controlled path through the magnetic circuit, converting potential interference into a contained magnetic field that maintains reliability without affecting other components.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Manufacturing precision

If the drum-shaped core is divided by a magnetic gap in the axial direction, then the inductance tolerance is controlled, but the manufacturing complexity increases

Engineering Contradiction:

Improveinductance value controlVSAvoidcore structure complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The drum-shaped core is segmented into two sections along the axial direction with a magnetic gap between them. This segmentation enables precise control of the magnetic path length and inductance value while maintaining a relatively simple cylindrical structure that is easy to manufacture.

Inventive Principle:

Principle #1Segmentation

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 effectively reduces magnetic flux leakage, maintaining tolerance within specified limits while minimizing impact on adjacent electronic components, and allows for precise control of gap dimensions for improved handling and performance.

Implementation Method 1

the magnetic gap is formed in the drum-shaped core itself, so that magnetic flux leaking from the magnetic gap can be shielded by the plate-like core

Methodology Applied

Scientific EffectMagnetic shielding: Magnetic Field

Implementation Method 2

a wire wound around the winding core part and having one end connected to the first terminal electrode and the other end connected to the second terminal electrode

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS11515081B2Coil component

Publication Date: 2022.11.29 TDK CORP

AI summary

An object of the present invention is to provide a coil component in which leakage of magnetic flux from a magnetic gap is reduced. A coil component includes: a drum-shaped core 20 having a winding core part 30 with a gap G formed therein and first and second flange parts 31 and 32; a plate-like core 40 fixed to the first and second flange parts 31 and 32; and wires W1 to W3 wound around the winding core part 30 and each having one end connected to a terminal electrode provided on the first flange part 31 and the other end connected to a terminal electrode provided on the second flange part 32. According to the present invention, the gap G formed in the winding core part 30 functions as a magnetic gap, and magnetic flux leaking from the magnetic gap is shielded by the plate-like core 40. Thus, even when the magnetic gap is provided to reduce a tolerance due to characteristic variation of a magnetic material, it is possible to solve the problem that other electronic components are affected by the leakage magnetic flux.