Zigzag Inlay Wire Layout for Stable Smart Card Contact Pads
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The production of electronic documents, such as smart cards, faces issues with poor electrical contact and wire dislodgment during machining due to machining depth and material thickness tolerances, leading to connectivity problems and potential short circuits.
Innovation Solution
Incorporating a zigzag metal wire embedded in the substrate with a connection wire to form a connection pad on the surface, allowing for improved contact and reduced risk of wire dislodgment, along with a method of machining that aligns the tool with the wire's width to minimize pulling out during cavity formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the machining depth is increased to ensure good contact between wire ends and module, then electrical contact quality improves, but the risk of wire dislodgment increases
Solution Approach 1:
The wire is pre-embedded in the substrate at a controlled depth before module insertion, creating a stable foundation that prevents dislodgment during subsequent machining operations. This preliminary positioning ensures the wire remains secure regardless of the depth required for electrical contact.
Solution Approach 2:
The substrate acts as a cushioning medium that absorbs mechanical stresses during machining, protecting the embedded wire from dislodgment. The substrate's material properties provide a buffer that allows deeper machining for better electrical contact without compromising wire stability.
2Stability of the object's composition
If the machining depth is reduced to prevent wire dislodgment, then wire stability is maintained, but electrical contact quality deteriorates
Solution Approach 1:
The solution moves from a single-depth dimension to multiple dimensions by creating a multi-layer structure with the substrate, embedded wire, and module. Electrical contact is achieved through vertical connection through the substrate, while wire stability is maintained through lateral embedding, effectively separating the two requirements into different spatial dimensions.
Solution Approach 2:
The substrate serves as an intermediary element between the wire and the module, allowing the wire to be embedded at a stable depth while the module makes contact at a different depth. The substrate transmits electrical connection while protecting the wire from mechanical disruption.
3Device complexity
If a straight wire configuration is used, then the structure is simpler, but the wire is more susceptible to pulling out during machining
Solution Approach 1:
The wire is configured in a zigzag pattern with alternating bends instead of a straight line. This curved configuration increases the wire's resistance to pulling out during machining, as the bends distribute mechanical stresses along the wire path rather than concentrating them at a single point.
Solution Approach 2:
The wire path is segmented into multiple straight sections connected by bends, creating a zigzag pattern. This segmentation increases the effective length of wire within the substrate and distributes the mechanical load across multiple segments, improving overall stability without significantly increasing structural complexity.
4Stability of the object's composition
If the wire is embedded deeply in the substrate, then wire stability improves, but manufacturing precision requirements increase
Solution Approach 1:
The wire embedding depth is optimized to a specific parameter range that provides sufficient stability while remaining achievable with standard manufacturing tolerances. By selecting an optimal depth parameter that balances stability and manufacturability, the design avoids requiring excessive precision without compromising wire security.
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 reliable electrical contact and resistance to wire dislodgment, improving the durability and performance of electronic documents by reducing production tolerances and ensuring consistent connectivity.
Implementation Method 1
The wire is embedded in the substrate by means of ultrasonic vibrations that are transmitted to the wire from the tool
Implementation Method 2
The wire is surrounded, for example, by an insulating sheath which is heated, for example for a very short time, in order to improve the adherence of the sheath to the substrate
Data Source
AI summary
Inlay (40) comprising a substrate (41) and a first zigzag portion (42) formed of a metal wire (421) embedded in an upper face (43) of the substrate (41), the first zigzag portion (42) comprising, alternately, rectilinear segments (422) and bends (423), at least one of the rectilinear segments (422) of the first zigzag portion (42) being disposed, at least in part, in a zone (45) of the upper face (43) of the substrate (41) configured to form a spotface of a cavity of an electronic document, and the inlay (40) comprising a connection wire (47) configured to join together at least the rectilinear segments (422) of the first zigzag portion (42). Method for producing an electronic document (1) comprising such an inlay (40), and electronic document (1).