Chip Card Contact Reliability Under Bending Stress

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Solution Overview

Problem

Existing chip cards face contact impairment or interruption due to bending stresses, and existing methods for producing chip cards with contactless data transmission interfaces are either costly or prone to mechanical stress, affecting the reliability of electrical connections.

Innovation Solution

The chip card design features a chip module with contact areas on the top side of a module carrier, connected via conductive media such as solder or hardenable adhesive, allowing for direct local energy supply and stable connections, reducing susceptibility to mechanical stress and improving reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conductive medium (soldering paste or adhesive) is used to establish electrical contact between chip module and antenna, then electrical connection is achieved, but bending stresses cause contact impairment or interruption

Engineering Contradiction:

Improveelectrical connection reliabilityVSAvoidbending stress effect

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent divides the electrical connection path into multiple rigid segments (contact areas on module carrier, connection elements, contact ends of antenna) rather than relying on a single continuous conductive medium. This segmentation allows each component to maintain its structural integrity under bending stress while preserving electrical connectivity through defined rigid contact points.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of using a flexible conductive medium that deforms under stress, the patent inverts the approach by using rigid contact areas and connection elements that maintain their shape. The rigidity is inverted from the traditional flexible adhesive/solder approach, creating connections that resist deformation rather than accommodate it.

Inventive Principle:

Principle #13The other way round (Inversion)

2Reliability

If contact areas are arranged on the underside of module carrier, then electrical connection to antenna is achieved, but access for conductive medium is difficult and reliability is reduced

Engineering Contradiction:

Improveelectrical contact reliabilityVSAvoidaccessibility for conductive medium

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent inverts the conventional arrangement by placing contact areas on the top side of the module carrier instead of the underside. This inversion provides direct access to the contact areas from the top, allowing easy application of conductive medium or direct connection to the contact ends of the antenna, thereby improving both manufacturability and reliability.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent changes the spatial dimension of contact area accessibility by moving from a bottom-side arrangement (requiring access from below) to a top-side arrangement (accessible from above). This dimensional change simplifies the manufacturing process and improves the reliability of electrical connections.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Productivity

If expensive chip is installed first in card body, then complete chip card functionality is achieved, but manufacturing cost increases and reject risk is higher

Engineering Contradiction:

Improvemanufacturing efficiencyVSAvoidmanufacturing cost

Core Design Contradiction:

ProductivityVSQuantity of substance

Solution Approach 1:

The patent performs preliminary actions by installing the antenna and preparing contact areas on the module carrier before installing the expensive chip. This allows the antenna and contact structures to be pre-positioned and tested, reducing the risk of costly rework or rejection after chip installation. The chip is installed last, minimizing exposure to manufacturing defects.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The manufacturing process is segmented into distinct stages: first installing the antenna and preparing contact structures, then finally installing the chip. This segmentation allows independent optimization of each stage and reduces the risk of costly errors affecting the entire assembly.

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

This design enhances the reliability of electrical contacts and reduces the risk of contact impairment under mechanical loads, while simplifying the manufacturing process and maintaining compatibility with ISO 7816-2 standards.

Implementation Method 1

electrically conductively connected to it by means of a conductive medium

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

The chip module is fixed in the recess by means of a module adhesive

Methodology Applied

Scientific EffectAdhesion: Adhesive

Data Source

PatentEP2239692B1Chip card and method for its manufacture

Publication Date: 2013.06.19 CARDAG DEUTLAND

Figure 1~3
Figure 4~5

AI summary

The chip card (1) has a chip module (3) fastened at a recess (6) in a card body (2), and a data transmitting component with two contact ends (8.1, 8.2) attached to contact surfaces (5.1, 5.2) of a module carrier (9). The contact ends are electrically conductively connected with the contact surfaces using conductive medium (15). The contact surfaces are arranged at an upper side of the module carrier such that the contact surfaces form surface area of the chip card. The module carrier has two apertures (12.1, 12.2) for the medium in the contact surfaces, respectively. An independent claim is also included for a method for manufacturing a chip card.