Electromagnetic Shielding Sheet with Filled Through Holes

Solution Overview

Problem

Existing wireless power charging systems face inefficiencies due to eddy currents generated in magnetic materials, leading to power loss and increased temperature, which degrade charging efficiency and require separate shielding sheets for different frequency bands.

Innovation Solution

A novel electromagnetic wave shielding sheet comprising a first magnetic material with through holes filled with a second magnetic material, allowing for blocking of different frequency bands and reducing eddy current influence, thereby enhancing charging efficiency and heating characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a magnetic material is used for electromagnetic wave shielding, then shielding function is provided, but eddy current is generated causing power loss and temperature increase

Engineering Contradiction:

Improveelectromagnetic wave shieldingVSAvoidpower loss

Core Design Contradiction:

Object-affected harmful factorsVSLoss of energy

Solution Approach 1:

The magnetic material is segmented into a composite structure consisting of a magnetic material layer and an insulating material layer alternately arranged. This segmentation divides the continuous magnetic path into discrete segments, interrupting eddy current flow while preserving magnetic shielding functionality. The insulating layers act as barriers that break the eddy current loops without significantly affecting the magnetic field blocking capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention uses a composite material structure combining magnetic material and insulating material in alternating layers. This composite approach allows the magnetic material to provide shielding function while the insulating material suppresses eddy current generation. The synergistic combination resolves the contradiction between achieving effective shielding and minimizing energy loss from eddy currents.

Inventive Principle:

Principle #40Composite materials

2Object-affected harmful factors

If a magnetic material is used for electromagnetic wave shielding, then shielding function is provided, but temperature of the magnetic material increases

Engineering Contradiction:

Improveelectromagnetic wave shieldingVSAvoidtemperature of magnetic material

Core Design Contradiction:

Object-affected harmful factorsVSTemperature

Solution Approach 1:

The magnetic material is segmented into a composite structure consisting of a magnetic material layer and an insulating material layer alternately arranged. This segmentation divides the continuous magnetic path into discrete segments, interrupting eddy current flow while preserving magnetic shielding functionality. The insulating layers act as barriers that break the eddy current loops without significantly affecting the magnetic field blocking capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The insulating material layers, which inherently have high electrical resistance, are strategically positioned to convert the harmful eddy current effect into a beneficial temperature reduction. The insulating layers block eddy current paths, preventing excessive heat generation, while the magnetic material layers continue to provide shielding. This transforms the potential harm of heat generation into a benefit by using the insulating material's natural property to reduce temperature.

Inventive Principle:

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

3Object-affected harmful factors

If a magnetic material is used for electromagnetic wave shielding, then shielding function is provided, but magnetic field generated by eddy current degrades power charging efficiency

Engineering Contradiction:

Improveelectromagnetic wave shieldingVSAvoidpower charging efficiency

Core Design Contradiction:

Object-affected harmful factorsVSProductivity

Solution Approach 1:

The magnetic material is segmented into a composite structure consisting of a magnetic material layer and an insulating material layer alternately arranged. This segmentation divides the continuous magnetic path into discrete segments, interrupting eddy current flow while preserving magnetic shielding functionality. The insulating layers act as barriers that break the eddy current loops without significantly affecting the magnetic field blocking capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention uses a composite material structure combining magnetic material and insulating material in alternating layers. This composite approach allows the magnetic material to provide shielding function while the insulating material suppresses eddy current generation. The synergistic combination resolves the contradiction between achieving effective shielding and minimizing energy loss from eddy currents.

Inventive Principle:

Principle #40Composite materials

4Object-affected harmful factors

If separate shielding sheets are used for different frequency bands, then each frequency band is blocked effectively, but device complexity and thickness increase

Engineering Contradiction:

Improvefrequency band blockingVSAvoidshielding sheet structure

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The alternating layer structure of magnetic material and insulating material creates a multi-functional shielding sheet that can effectively block multiple frequency bands simultaneously. Different combinations of layer materials, thicknesses, and numbers of layers can be designed to target specific frequency ranges (e.g., 100-300 KHz for inductive coupling and 6-7 MHz for resonant magnetic coupling). This universal design eliminates the need for separate shielding sheets for different wireless charging standards.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The invention merges the functions of multiple frequency-specific shielding sheets into a single composite structure. By combining magnetic material layers (which block low frequencies) and insulating material layers (which suppress eddy currents across frequencies) in an alternating pattern, the single shielding sheet achieves the cumulative effect of multiple separate sheets, reducing overall device complexity and thickness.

Inventive Principle:

Principle #5Merging (Combining)

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 enables efficient wireless power charging across multiple frequency bands with reduced thickness, improved heating characteristics, and enhanced power charging efficiency by utilizing a dual-layer magnetic structure with specific electrical conductivity and insulation properties.

Implementation Method 1

a first magnetic material blocking a first frequency band of electromagnetic waves

Methodology Applied

Scientific EffectMagnetic shielding: Magnetic Field

Implementation Method 2

a second magnetic material blocking a second frequency band of electromagnetic waves

Methodology Applied

Scientific EffectMagnetic shielding: Magnetic Field

Implementation Method 3

The second magnetic material may have a lower electrical conductivity than the first magnetic material

Methodology Applied

Scientific EffectEddy current reduction: Eddy Currents

Data Source

PatentUS10028420B2Sheet for shielding against electromagnetic waves and wireless power charging device

Publication Date: 2018.07.17 WITS CO LTD

AI summary

A sheet for shielding against electromagnetic waves includes a first magnetic material having a plurality of through holes formed in a thickness direction, and a second magnetic material filling the plurality of through holes and blocking a frequency band different from that of electromagnetic waves blocked by the first magnetic material.