Multilayer Magnetic Sheet Assembly to Limit Flux Leakage

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Solution Overview

Problem

Existing magnetic sheets for contactless charging in electric vehicles are insufficient in size, prone to magnetic flux leakage, and require extensive manual labor for manufacturing multilayer configurations.

Innovation Solution

A multilayer magnetic sheet is constructed by aligning and stacking laminate substrates with overlapping long sides to prevent gaps, using adhesive layers and magnetic strips, reducing manual effort and maintaining high magnetic permeability and Q factor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If multiple alloy strips are stacked to increase width, then the width is increased, but the manufacturing time increases significantly

Engineering Contradiction:

Improvewidth of magnetic sheetVSAvoidmanufacturing time

Core Design Contradiction:

Area of stationary objectVSLoss of time

Solution Approach 1:

The magnetic sheet is divided into multiple laminate substrates that can be manufactured separately and then assembled. Each laminate substrate contains multiple magnetic strips stacked in layers, allowing parallel production and reducing overall manufacturing time while achieving the required width through arrangement of multiple substrates.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Multiple magnetic strips are nested within each laminate substrate in a stacked configuration. This nested structure allows efficient use of space and enables the width requirement to be met by arranging multiple laminate substrates containing nested magnetic strips, rather than stacking single strips sequentially.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Ease of manufacture

If laminate substrates are stacked without overlapping, then manufacturing is simpler, but magnetic gaps form causing deterioration of magnetic characteristics

Engineering Contradiction:

Improveassembly simplicityVSAvoidmagnetic characteristic

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The laminate substrates are designed with overlapping long side portions at specific locations rather than uniform stacking throughout. This local overlapping approach prevents magnetic gaps at critical interfaces while maintaining manufacturing simplicity in other areas, thus preserving magnetic characteristics without excessive complexity.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The laminate substrates are pre-configured with overlapping long side portions before final assembly. This preliminary design of the overlapping structure ensures that when substrates are stacked, magnetic gaps are automatically prevented at the interfaces, maintaining magnetic characteristics without requiring complex real-time adjustment during assembly.

Inventive Principle:

Principle #10Preliminary action

3Area of stationary object

If the magnetic sheet size is increased for electric vehicle applications, then the power transmission capability is improved, but magnetic flux leakage to other devices increases

Engineering Contradiction:

Improvemagnetic sheet sizeVSAvoidmagnetic flux leakage

Core Design Contradiction:

Area of stationary objectVSObject-generated harmful factors

Solution Approach 1:

The large magnetic sheet is segmented into multiple laminate substrates arranged in a plate shape. This segmentation allows better control of magnetic flux distribution across the large area, reducing leakage to surrounding devices while maintaining the required size for electric vehicle power transmission applications.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The magnetic sheet employs a composite structure combining multiple laminate substrates with overlapping long side portions. This composite configuration enhances magnetic flux containment within the desired area while reducing leakage, achieving both large size and reduced harmful electromagnetic interference.

Inventive Principle:

Principle #40Composite materials

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 configuration minimizes manufacturing hours and prevents magnetic characteristic deterioration, achieving a wide, multilayered magnetic sheet with high magnetic permeability and Q factor.

Implementation Method 1

a magnetic flux generated in a primary transmission coil of a power feeding device generates an electromotive force in a secondary transmission coil

Methodology Applied

Scientific EffectMagnetic flux: Magnetic Field

Implementation Method 2

charging is performed by power transmission using electromagnetic induction

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

using adhesive layers and magnetic strips

Methodology Applied

Scientific EffectAdhesion: Adhesive

Data Source

PatentUS12496803B2Multilayer magnetic sheet

Publication Date: 2025.12.16 PROTERIAL LTD

AI summary

A multilayer magnetic sheet comprises laminate substrates. Each of the laminate substrates is formed in a band shape having a short side and a long side and comprises magnetic strips stacked in layers. The laminate substrates are aligned and arranged in a plate shape in a direction, in which the long sides are adjacent to each other and the short sides extend. The laminate substrates aligned and arranged in the plate shape are stacked in layers in a thickness direction of the laminate substrates. Long side portions of the laminate substrates including the long sides and vicinities of the long sides overlap each other.