Antenna Sheet Laser Welding for Contact Resistance
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Solution Overview
Problem
Existing antenna sheet connection methods, such as crimping and through-hole conductivity, suffer from weak bonding strength, unreliable electrical connections, and manufacturing inefficiencies due to mechanical pressure and oxidation risks, as well as complexity in achieving stable contact resistance and resistance to thermal expansion differences.
Innovation Solution
A method involving a pressing step where an antenna coil and connection pattern on a thermoplastic resin substrate are pressed and welded using a heated pressing unit, followed by laser welding to securely connect the antenna coil and conductive member, ensuring stable and reliable electrical connections without mechanical contact, thereby improving manufacturability and reducing oxidation risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If connection by crimping is used to connect antenna and bridge pattern, then manufacturing process is simple, but bonding strength is weak and electrical connection reliability is low
Solution Approach 1:
The patent replaces the mechanical crimping connection system with a welding system. The welding unit welds the antenna and bridge pattern to each other, substituting mechanical pressure-based connection with thermal fusion-based connection. This resolves the contradiction by providing strong bonding strength through welding while maintaining manufacturing simplicity through automated welding processes.
Solution Approach 2:
The patent changes the connection parameter from mechanical pressure (crimping) to thermal energy (welding). By using a welding unit that applies heat and fusion to join the antenna and bridge pattern, the connection strength and electrical reliability are significantly improved while the process remains manufacturable through controlled welding parameters.
2Stability of the object's composition
If heat treating is done after crimping connection, then material properties are improved, but warping occurs due to thermal expansion difference causing open wires
Solution Approach 1:
The patent performs the welding connection between antenna and bridge pattern before heat treating the substrate. By establishing the electrical connection in advance through welding, subsequent heat treating processes can be performed without causing warping-induced open wires, as the welded joints are more resistant to thermal expansion stresses than crimped connections.
Solution Approach 2:
The patent replaces mechanical crimping with welding to create a more robust connection that can withstand subsequent heat treating processes. The welded joint provides stronger mechanical and electrical integrity compared to crimping, preventing open wires during thermal processing.
3Reliability
If through hole plating or filling is used to achieve conductivity, then electrical connection is achieved, but manufacturing process becomes complicated and efficiency decreases
Solution Approach 1:
The patent extracts and eliminates the through-hole plating or filling step from the manufacturing process. By using surface-level welding to connect the antenna and bridge pattern, the need for through-holes is removed entirely, simplifying the manufacturing process while maintaining electrical conductivity through the welded joint.
Solution Approach 2:
The patent replaces the through-hole conduction method with surface welding. Instead of creating holes through the substrate and plating/filling them, the welding unit directly joins the antenna and bridge pattern on the surface, achieving electrical conductivity without the complex through-hole processing steps.
4Ease of manufacture
If crimping connection is used, then manufacturing is simple, but oxidation or corrosion of contact surfaces occurs reducing reliability
Solution Approach 1:
The patent replaces mechanical crimping with welding to eliminate exposure of contact surfaces to oxidation and corrosion. The welding process fuses the antenna and bridge pattern together, creating a unified structure without separate contact surfaces that would be susceptible to environmental degradation.
Solution Approach 2:
The patent merges the antenna and bridge pattern into a unified structure through welding. By fusing these components together, the separate contact surfaces that would otherwise be exposed to oxidation and corrosion are eliminated, creating a single integrated structure with improved durability.
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
The method enhances the reliability and stability of antenna sheet connections by reducing electrical resistance and preventing open wires, while improving manufacturing efficiency and preventing oxidation, resulting in a high-reliability antenna sheet for data carriers with non-contact ICs.
Implementation Method 1
a pressing step in which an overlapped portion of an antenna coil and/or a connection pattern formed from a metal material and provided on one surface of a substrate formed from a thermoplastic resin, and a conductive member formed from a metal material and provided on the other surface of the substrate is pressed using a pressing unit at least from the surface of one side of the substrate; and a welding steps in which the overlapped portion of the antenna coil and/or the connection pattern and the conductive member is welded
Implementation Method 2
the pressing unit that is heated to at least the softening temperature of the material that forms the substrate
Implementation Method 3
the welding steps, a laser beam may strike a part pressed by the pressing unit to weld the antenna coil and/or the connection pattern to the conductive member
Implementation Method 4
the antenna of an antenna sheet, in addition to functioning as an antenna for data communication, functions as a coil to generate electrical power by electromagnetic induction for driving the integrated circuit
Data Source
Figure 1A~1B
Figure 2
Figure 3A~3B
AI summary
A method for manufacturing an antenna sheet which comprises: a pressing step in which an overlapped portion of an antenna coil and/or a connection pattern formed from a first metal material and provided on one surface of a substrate formed from a thermoplastic resin, and a conductive member formed from a second metal material and provided on the other surface of the substrate is pressed; and a welding step in which a welded part is formed at the overlapped portion where the at least one of the antenna coil and the connection pattern, and the conductive member are in contact with each other, the conductive member and one end of the at least one of the antenna coil and the connection pattern are welded in the welded part, wherein the welding step is performed using a laser.