NFC Antenna Module with Composite Magnetic Shielding

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Solution Overview

Problem

Existing NFC antenna modules face performance degradation due to electromagnetic interference and have limitations in flexibility and permeability, particularly with ferrite substrates that can be stressed and inflexible.

Innovation Solution

An NFC antenna module is designed with a loop coil antenna sheet and a hybrid magnetic shielding sheet made of a metal sheet and ferrite-based material, where the metal sheet is embedded with ferrite powder and fired to enhance flexibility and permeability, and an adhesive film is used to bond the sheets, minimizing stress and warpage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a ferrite substrate is used to absorb electromagnetic waves, then electromagnetic interference is reduced, but flexibility and permeability deteriorate due to stress during forming and firing processes

Engineering Contradiction:

Improveelectromagnetic interferenceVSAvoidflexibility and permeability

Core Design Contradiction:

Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The patent uses a composite magnetic shielding sheet combining ferrite-based material and metal material, where the ferrite absorbs electromagnetic waves while the metal provides flexibility and stress resistance. This composite structure resolves the contradiction by integrating materials with complementary properties.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The magnetic shielding sheet is divided into multiple layers: a ferrite-based material layer for electromagnetic wave absorption and a metal layer for structural flexibility. This segmentation allows each layer to perform its specialized function without compromising the other.

Inventive Principle:

Principle #1Segmentation

2Adaptability or versatility

If a metal sheet is used for the magnetic shielding sheet, then flexibility is improved, but electromagnetic wave absorption capability deteriorates

Engineering Contradiction:

ImproveflexibilityVSAvoidelectromagnetic wave absorption

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent combines metal material with ferrite-based material in a composite magnetic shielding sheet. The metal provides flexibility while the ferrite maintains electromagnetic wave absorption capability, resolving the trade-off between these properties.

Inventive Principle:

Principle #40Composite materials

3Object-affected harmful factors

If ferrite-based material is used alone, then electromagnetic wave absorption is improved, but stress and warpage increase during forming process

Engineering Contradiction:

Improveelectromagnetic wave absorptionVSAvoidstress resistance

Core Design Contradiction:

Object-affected harmful factorsVSStrength

Solution Approach 1:

The composite magnetic shielding sheet uses ferrite-based material for electromagnetic wave absorption combined with metal material that has high stress resistance. The metal layer compensates for the brittleness of ferrite during forming processes.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

Different regions of the magnetic shielding sheet have different material compositions optimized for their specific functions: ferrite-rich regions for maximum electromagnetic absorption and metal-rich regions for structural integrity and stress resistance.

Inventive Principle:

Principle #3Local quality

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 effectively absorbs electromagnetic interference, improves flexibility and permeability, and enhances the durability of the NFC antenna module, reducing electromagnetic interference and extending communication range while maintaining a thin and flexible form.

Implementation Method 1

the ferrite substrate solves a problem of a reduction in a communication range due to a loss which is caused by generation of eddy current of metal, thereby increasing the communication range of NFC

Methodology Applied

Scientific EffectElectromagnetic wave absorption: Absorption (EM radiation)

Implementation Method 2

the magnetic shielding sheet is made by stacking a ferrite based material on the metal sheet and integrally firing the metal sheet

Methodology Applied

Scientific EffectSintering: Sintering

Implementation Method 3

an adhesive film interposed between the antenna sheet and the magnetic shielding sheet

Methodology Applied

Scientific EffectAdhesion: Adhesive

Data Source

PatentUS9653797B2Antenna module for near field communication

Publication Date: 2017.05.16 WITS CO LTD

AI summary

Embodiments of the invention provide an antenna module for NFC. According to at least one embodiment, the antenna module includes an antenna sheet patterned with a loop coil of a conductive metal material, a magnetic shielding sheet comprising a metal sheet, which is embedded in a magnetic sheet, and an adhesive film interposed between the antenna sheet and the magnetic shielding sheet.