Microcircuit Card Pre-Cutouts for 4FF and 3FF Format Adaptability

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Solution Overview

Problem

The challenge lies in manufacturing microcircuit cards in 4FF format that can be adapted to both 4FF and 3FF formats without breaking, while maintaining the standard design rules for contact surfaces, and ensuring mechanical strength, especially when converting a 4FF format card to 3FF format.

Innovation Solution

The solution involves creating a microcircuit card with contact surfaces that are centered on the theoretical zones defined by the standards for both 4FF and 3FF formats, with a specific offset that allows the card to maintain mechanical strength and adaptability, ensuring the contact surfaces cover the theoretical areas even when the 3FF format is offset, and using a card body in 2FF or higher format with pre-cuts that respect the standard contact zones.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If contact surfaces are designed according to standard rules for 4FF format, then communication with 4FF devices is ensured, but the card cannot be adapted to 3FF format without breaking

Engineering Contradiction:
Improveadaptability to multiple formatsVSAvoidmechanical strength of upper strand
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The contact surface is designed to serve multiple functions: it acts as a contact surface for 4FF format devices while simultaneously serving as a structural reinforcement element for 3FF format adaptation. The contact surface extends beyond the theoretical contact zone to provide mechanical strength to the upper strand, enabling the card to be adapted to both 4FF and 3FF formats without breaking.

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

2Adaptability or versatility

If the upper strand width is reduced to enable 3FF format adaptation, then format versatility improves, but mechanical strength decreases leading to breakage

Engineering Contradiction:
Improveformat conversion capabilityVSAvoidupper strand strength
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The contact surface is extended locally beyond the theoretical contact zone specifically in the region where mechanical strength is needed. This local extension provides structural reinforcement to the upper strand without affecting the overall format adaptation capability, allowing the card to withstand mechanical stress during 3FF format conversion.

Inventive Principle:
Principle #3Local quality

3Strength

If contact surfaces are extended beyond theoretical zones, then mechanical strength improves, but standard design rules are compromised

Engineering Contradiction:
Improvecontact surface strengthVSAvoidconformity to standard design rules
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The design parameters of the contact surface are modified by extending it beyond the theoretical contact zone defined in standards. This parameter change increases the contact surface area, providing mechanical strength to the upper strand while maintaining electrical contact functionality. The extension is designed to not interfere with standard compliance for electrical contact while providing structural benefits.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3072087B1Microcircuit card containing multiple pre-cutout cards having one and the same span of contacts
Publication Date: 2020.02.19 IDEMIA FRANCE SAS
  • EP3072087B1 patent drawingFigure 1~3
  • EP3072087B1 patent drawingFigure 4
  • EP3072087B1 patent drawing

AI summary

A microcircuit card comprising an overall span of contacts 15 comprising at least individual contact surfaces C1 to C3, C5 to C7 connected to this microcircuit while defining two parallel columns situated in proximity to two edges of said overall span, in a card body 12 having a format at least equal to the 2FF format, in which there is made a pre-cutout 14 in the 4FF format surrounding the overall span of contacts and a pre-cutout 13 in the 3FF format surrounding the pre-cutout in the 4FF format, these pre-cutouts being such that the individual contact surfaces C1 to C3, C5 to C7 have, with respect to each of the pre-cutouts positions and dimensions such that they encompass the theoretical contact zones defined by the standards defining these 4FF, 3FF and 2FF formats, the upper edge of the pre-cutout in the 3FF format being situated at a distance at least equal to 400 micrometers from the upper edge of the pre-cutout in the 4FF format, the individual surfaces C1 and C5 being, within these columns, symmetric with the individual surfaces C3 and C7 with respect to a midline of the overall span of 3FF and 4FF contact.