Single-Layer Flexible Circuit for Dual-Interface Smart Card Modules

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Solution Overview

Problem

Dual interface smart cards require cost-effective manufacturing methods that minimize material usage and optimize the design of conductive layers and contacts for both contact and contactless data transmission.

Innovation Solution

A method for manufacturing a flexible circuit for chip card modules using a single conductive layer supported by an insulating substrate, where the conductive layer is etched or laminated, and connection wells are created to facilitate both chip and antenna connections, reducing material usage and enabling miniaturization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a double-sided circuit with conductive layers on both faces of the insulating substrate is used, then both contact and contactless interfaces can be implemented, but the manufacturing cost increases and material usage increases

Engineering Contradiction:
Improvedual interface capabilityVSAvoidmanufacturing cost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent combines both contact and contactless interface functions into a single-sided circuit structure. The conductive layer on one face of the insulating substrate serves dual purposes: forming contacts for card readers and forming conductive pads for antenna connection, eliminating the need for separate conductive layers on both faces of the substrate.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single conductive layer is designed to perform multiple functions simultaneously. It creates both the contact interfaces for magnetic stripe readers and the conductive pads for RFID antennas, making the circuit board universally functional for both contact and contactless operations without requiring additional conductive material layers.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If a double-sided circuit with conductive layers on both faces is used, then both contact and contactless interfaces can be implemented, but the material usage increases

Engineering Contradiction:
Improvedual interface capabilityVSAvoidconductive material usage
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent merges the functions of separate contact and contactless conductive layers into a single conductive layer. This single layer is patterned to form both the contact traces for magnetic stripe readers and the conductive pads for antenna attachment, thereby reducing the total quantity of conductive material required.

Inventive Principle:
Principle #5Merging (Combining)

3Adaptability or versatility

If traditional double-sided circuit design is used, then both interfaces are supported, but the module dimensions and orientation are less optimized

Engineering Contradiction:
Improveinterface supportVSAvoidmodule dimensions
Core Design Contradiction:
Adaptability or versatilityVSShape

Solution Approach 1:

The patent transitions from a three-dimensional double-sided structure to a two-dimensional single-sided configuration. By arranging contacts and conductive pads on the same face of the insulating substrate, the design optimizes the spatial layout and orientation of the module, enabling more efficient use of the card space and improved mechanical integration.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP3567527B1Method of manufacturing a circuit for chip-card module and circuit for chip-card module
Publication Date: 2021.10.13 LINXENS HOLDING SAS
  • EP3567527B1 patent drawingFigure 1~3
  • EP3567527B1 patent drawingFigure 4~7
  • EP3567527B1 patent drawingFigure 8a~10

AI summary

The invention relates to a method for manufacturing a flexible circuit for a smart card module (2). The invention consists of using conductive pads (14) located on the same face of the module (2) as the contacts (6) intended to establish a connection with a card reader, to create an electrical connection between an antenna and an electronic chip (8). The connections to the conductive pads are partly located within an encapsulation zone and partly outside this encapsulation zone, respectively on either side of it. The invention also relates to a flexible circuit for implementing this method.