Dual IC Card Coil Layout for Eddy Current Reduction
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Solution Overview
Problem
Electromagnetic-coupling dual IC cards face communication property degradation due to reaction magnetic flux and eddy currents from the interaction of connecting coils with contact terminals, and have limited flexibility in adjusting coil turns and location for impedance matching, which complicates power supply and communication optimization.
Innovation Solution
The design includes a card body with a recess to house the IC module, featuring a non-overlapping configuration of connecting coils with respect to contact terminals, allowing for adjustable coil turns and locations, and a miniaturized IC module with reduced surface area requirements, enabling better impedance matching and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the connecting coil is placed close to contact terminals for compact design, then the IC module size is reduced, but eddy current effects increase causing communication property degradation
Solution Approach 1:
The patent extracts the harmful interaction between the connecting coil and contact terminals by spatially separating them. The connecting coil is positioned on the rear surface of the IC module while contact terminals are on the front surface, eliminating overlap and preventing eddy current generation while maintaining compact overall module dimensions
Solution Approach 2:
The patent utilizes the third dimension (depth/thickness) of the IC module to resolve the spatial conflict. By placing the connecting coil on the rear surface and contact terminals on the front surface, it creates non-overlapping configurations in the planar view while maintaining electromagnetic coupling functionality through the module thickness
2Ease of manufacture
If the connecting coil is fixed in position for simplified manufacturing, then manufacturing complexity is reduced, but impedance matching flexibility is lost
Solution Approach 1:
The patent introduces adjustability in the connecting coil's position and number of turns, transforming a fixed configuration into a dynamic one that can be optimized for different applications. This allows the electromagnetic coupling characteristics to be tuned while maintaining a standardized module structure for manufacturing
3Power
If more turns are added to the connecting coil for better electromagnetic coupling, then power supply efficiency improves, but the coil area increases causing manufacturing complexity
Solution Approach 1:
The patent optimizes the connecting coil's inductance by adjusting the number of turns and spatial configuration rather than simply increasing coil area. This allows achieving the required electromagnetic coupling strength while maintaining a compact and manufacturable coil structure with controlled complexity
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 configuration enhances communication properties by reducing eddy current effects, increases design flexibility, and allows for cost-effective production of durable electromagnetic-coupling dual IC cards with improved durability and design capabilities.
Implementation Method 1
electromagnetic coupling between an antenna coil of an IC module joined to the card body by an insulating adhesive or the like, and an antenna coil embedded in the card body
Implementation Method 2
The coupling coil 48 of the card body 50 is transformer-coupled with the connecting coil 41 of the IC module 40 to enable power supply and communication
Implementation Method 3
reaction magnetic flux, or the like caused by eddy current which is generated by interaction of the connecting coil with the contact terminals
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
An electromagnetic-coupling dual IC card includes an IC module and a plate-like card body. The IC module includes a module substrate having a first surface and a second surface, contact terminals provided on the first surface of the module substrate so as to be contactable with an external contact-type device, an IC chip having a contact communication function and a contactless communication function and disposed on the second surface of the module substrate, and a first connecting coil provided on the first surface of the module substrate. The plate-like card body includes an antenna sheet which is embedded therein and has a recess for holding the IC module, the antenna sheet being provided with a coupling coil to be electromagnetically coupled to the first connecting coil, and a main coil connected to the coupling coil to perform contactless communication with an external contactless-type device. In this IC card, the first connecting coil is disposed so as not to overlap with the contact terminals in plan view.