Composite Ferrite Sheet Magnetic Shielding

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Solution Overview

Problem

Thinned ferrite sheets in portable devices fail to effectively contain magnetic fields, leading to increased magnetic field leakage, necessitating a solution for maintaining shielding performance while maintaining thinness.

Innovation Solution

A composite ferrite sheet is manufactured by attaching insulating composite sheets with flake-shaped metal powder particles to both surfaces of a ferrite sheet, using a resin-based slurry applied and rolled onto the ferrite sheet, which are then integrated and thermally compressed, allowing for efficient magnetic field containment without the need for an adhesive.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If ferrite sheets are thinned to meet portable device requirements, then device thickness is reduced, but magnetic field containment capability deteriorates

Engineering Contradiction:
Improveferrite sheet thicknessVSAvoidmagnetic field containment capability
Core Design Contradiction:
Length of moving objectVSReliability

Solution Approach 1:

The patent applies composite materials by combining ferrite particles with a resin matrix to create a composite ferrite sheet. This composite structure maintains thin thickness while achieving effective magnetic field containment through the distributed ferrite particles within the resin, resolving the contradiction between reduced thickness and maintained shielding capability

Inventive Principle:
Principle #40Composite materials

2Strength

If composite sheets are attached using adhesive, then bonding strength is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvebonding strengthVSAvoidmanufacturing process complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent merges the bonding function into the composite sheet structure itself by using a resin-based slurry that acts as both the composite material matrix and the bonding agent. This eliminates the need for separate adhesive layers and simplifies the manufacturing process while maintaining strong bonding between the composite sheet and ferrite sheet

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If multiple manufacturing steps are used to attach composite sheets, then bonding reliability is improved, but production time increases

Engineering Contradiction:
Improvebonding reliabilityVSAvoidproduction time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by pre-mixing the resin slurry with ferrite particles to create a ready-to-use composite material that can be directly applied and bonded in a single step. This pre-prepared composite slurry eliminates the need for multiple sequential steps of applying adhesive, attaching sheets, and curing, thereby reducing production time while maintaining bonding reliability

Inventive Principle:
Principle #10Preliminary action

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 composite ferrite sheet effectively enhances magnetic field containment, improving shielding efficiency and maintaining a relatively thin thickness, thus reducing magnetic field leakage and enhancing the performance of wireless charging apparatuses.

Implementation Method 1

forming composite sheets having insulating properties on both surfaces of the ferrite sheet, respectively... applying the slurry to both surfaces of the ferrite sheet; and rolling the ferrite sheet and the slurry, to press and bond the slurry to both surfaces of the ferrite sheet

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

integrating the composite sheets with the ferrite sheet by compressing the composite sheets... applying heat to the composite sheets to thermally compress the composite sheets

Methodology Applied
Scientific EffectThermal compression: Heat Treatment

Implementation Method 3

The composite sheet may be formed of a resin containing metal powder particles... The metal powder particles may include at least any one of a sendust-based metal, a Permalloy-based metal, and an amorphous metal... effectively enhances magnetic field containment

Methodology Applied
Scientific EffectMagnetic field containment: Magnetism

Data Source

PatentEP2897139B1Method of manufacturing a composite ferrite sheet.
Publication Date: 2017.10.11 SAMSUNG ELECTRO MECHANICS CO LTD
  • EP2897139B1 patent drawingFigure 1
  • EP2897139B1 patent drawingFigure 2~3
  • EP2897139B1 patent drawingFigure 4

AI summary

A composite ferrite sheet may include a ferrite sheet, and composite sheets attached to both surfaces of the ferrite sheet, respectively, and having insulating properties. The composite sheet may be formed of a resin containing metal powder particles. The composite ferrite sheet may be easily manufactured and have improved shielding performance.