Metal Chip Card With Segmented Transponder Coil

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Solution Overview

Problem

Current metal chip cards with transponder coils face communication disruptions due to the metal layer, particularly when trying to receive radio signals from both sides, as the metal layer can hinder or prevent RFID transmission.

Innovation Solution

A chip card design featuring a self-supporting metal layer that extends over the entire card, with turns of the transponder coil formed by the metal layer itself and spaces filled with insulating material to prevent capacitive coupling, and an optional insulating layer covering the metal surface to enhance signal reception and aesthetic appeal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a metal layer is used in chip cards to increase exclusivity and aesthetic appeal, then the visual appearance and perceived value are improved, but the metal layer interferes with or prevents RFID communication

Engineering Contradiction:
Improveaesthetic appealVSAvoidRFID communication
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The patent segments the metal layer into multiple conductive layers (first conductive layer and second conductive layer) separated by an insulating layer. This segmentation allows each layer to serve specific functions: the first layer provides aesthetic appearance while the second layer enables RFID communication, resolving the conflict between visual appeal and communication reliability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an insulating layer as an intermediary between the first conductive layer and second conductive layer. This insulating layer prevents direct electrical contact between the layers while allowing electromagnetic signals to pass through, enabling both aesthetic and communication functions to coexist without interference

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If a transponder coil is placed between the metal layer and plastic layer to enable contactless communication, then RFID functionality is added, but the metal layer still shields the coil and prevents bidirectional communication

Engineering Contradiction:
Improvecontactless communicationVSAvoidbidirectional RFID transmission
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent divides the traditional single-layer metal structure into multiple conductive layers with insulating material between them. This segmentation creates separate functional zones: the first conductive layer optimized for aesthetic appearance and the second conductive layer optimized for RFID signal transmission, eliminating the shielding effect that prevented bidirectional communication

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent creates a composite structure combining conductive layers, insulating layers, and plastic materials. This composite design allows the card to simultaneously achieve aesthetic appeal from the metal-like appearance and reliable bidirectional RFID communication through the optimized conductive layer structure

Inventive Principle:
Principle #40Composite materials

3Area of stationary object

If the metal layer is extended to cover the entire card surface for full-surface metal card design, then aesthetic exclusivity is maximized, but signal reception from both sides is hindered

Engineering Contradiction:
Improvemetal layer coverageVSAvoidsignal reception
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The patent segments the extensive metal layer into multiple separated conductive layers with insulating material between them. This allows the full-surface metal appearance to be maintained while the insulating layers prevent capacitive coupling and shielding effects, enabling signal reception from both sides of the card

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

Enables high signal yield from both sides and allows for full-surface metal card designs, improving RFID signal reception while maintaining an exclusive metallic appearance.

Implementation Method 1

The spaces between the windings are filled with insulating material

Methodology Applied
Scientific EffectCapacitive coupling: Capacitance

Implementation Method 2

a transponder coil coupled to the chip... in the case of chip cards equipped with a transponder coil for inductive coupling

Methodology Applied
Scientific EffectInductive coupling: Electromagnetic Induction

Data Source

PatentEP4018373B1Chip card
Publication Date: 2025.01.01 GIESECKE & DEVRIENT EPAYMENTS GMBH
  • EP4018373B1 patent drawingFigure 1~2
  • EP4018373B1 patent drawingFigure 3A~3B
  • EP4018373B1 patent drawingFigure 4~5

AI summary

The invention relates to a chip card (1) which is designed as a metal card and has RFID capability on both sides, wherein the windings (4a, 4b, 4c) of the transponder coil (4) are formed by the metal layer (2) itself. Interspaces (5a, 5b) between the windings (4a, 4b, 4c) of the transponder coil (4) are filled with insulating material. A chip module (3) is arranged above the ends of the transponder coil (4) such that these ends are not visible for an observer.