Card-Type Information Substrate Frame with Eddy-Current Restriction

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Solution Overview

Problem

Conventional card-type information substrates face challenges in achieving superior external appearance and weight while maintaining flexibility in wireless connectivity, with metal-based designs limiting lifetime due to wear and tear and lacking wireless connectivity.

Innovation Solution

Incorporating a frame made of a different material, such as plastic, with embedded metal components and an antenna, and using eddy current restriction components to minimize RF interference, allowing for increased weight and appearance without compromising wireless connectivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If metal components are added to increase weight and superior appearance, then external appearance and weight are improved, but wireless connectivity is compromised due to RF interference

Engineering Contradiction:
Improveexternal appearanceVSAvoidwireless connectivity
Core Design Contradiction:
ShapeVSReliability

Solution Approach 1:

The card is divided into distinct functional zones: a non-conductive plastic frame forming the outer boundary, and a central area containing conductive elements (antenna, electronic module, metal slug) isolated from the frame. This segmentation prevents RF interference while maintaining aesthetic metal components and wireless connectivity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A non-conductive plastic frame acts as an intermediary barrier between the metal components (slug, antenna) and the outer boundary of the card. This intermediary material blocks eddy current paths that would otherwise form through continuous metal, thereby preventing RF interference while allowing the metal components to contribute to weight and appearance.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Shape

If metal-based card material is used to achieve heavy weight and superior appearance, then external appearance and weight are improved, but lifetime is reduced due to wear and tear of contacts

Engineering Contradiction:
Improveexternal appearanceVSAvoidlifetime
Core Design Contradiction:
ShapeVSDuration of action of moving object

Solution Approach 1:

The card combines plastic frame material with metal components (slug, antenna, contact pads) to create a composite structure. The plastic frame provides mechanical robustness and wear resistance, while metal components contribute to weight, appearance, and electrical functionality. This composite approach resolves the contradiction between durability and aesthetic/heavy material preferences.

Inventive Principle:
Principle #40Composite materials

3Shape

If continuous metal frame is used to maximize weight and appearance, then external appearance is improved, but eddy currents are generated that interfere with RF performance

Engineering Contradiction:
Improveexternal appearanceVSAvoideddy currents
Core Design Contradiction:
ShapeVSObject-generated harmful factors

Solution Approach 1:

The continuous metal frame is segmented by introducing non-conductive plastic sections or breaks in the metal continuity. This segmentation interrupts eddy current paths, preventing the formation of large circulating currents that would interfere with RF performance, while still maintaining the aesthetic appearance of a metal frame.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different sections of the frame have different electrical properties: metal sections provide aesthetic appearance and structural strength, while non-conductive plastic sections strategically placed in the frame break eddy current paths. This local differentiation of material properties resolves the contradiction between continuous metal appearance and eddy current prevention.

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 provides card-type information substrates with enhanced weight and appearance while ensuring robust wireless connectivity and RF performance, maintaining mechanical integrity and reducing manufacturing complexity.

Implementation Method 1

an antenna (130) that is positioned within an outline of the frame (110) and that is operatively connected to the electronic module (120) to perform wireless communication

Methodology Applied
Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Implementation Method 2

An eddy current restriction component (150) is provided in the frame (110), wherein the eddy current restriction component (150) is configured and arranged to restrict eddy currents in the frame (110)

Methodology Applied
Scientific EffectEddy currents: Eddy Currents

Data Source

PatentEP4046074B1Card-type information substrate including a frame and a pre-form thereof
Publication Date: 2025.07.02 LINXENS HOLDING SAS
  • EP4046074B1 patent drawingFigure 1A~2C
  • EP4046074B1 patent drawingFigure 3A~3E
  • EP4046074B1 patent drawingFigure 4A~4C

AI summary

The present invention relates to card-type information substrates, such as payment cards, and a pre-form thereof, in which a frame, in some embodiments in combination with a metal containing plate, is implemented so as to impart increased weight and/or superior appearance to the card-type substrates, wherein the influence of the frame and the metal containing plate, if provided, on the RF performance of the card-type substrate is taken into consideration. For example, in illustrative embodiments the influence of a conductive material in the frame and/or the plate is reduced by selecting one or more appropriate features countering the negative effect on the RF performance.