Smartcard Milling With Electromagnetic Contact-Pad Detection
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Solution Overview
Problem
Existing methods for manufacturing biometrically-authorisable smartcards face challenges in exposing contact pads during milling when manufacturing tolerances are low, leading to inadequate electrical connections between smartcard modules.
Innovation Solution
A method involving milling smartcard bodies to expose contact pads by using a longer embedded wire, allowing for precise depth exposure and separate wires, and utilizing an electromagnetic field to detect optimal milling depth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a fixed depth milling method is used, then the manufacturing process is simple, but the contact pads are not sufficiently exposed when manufacturing tolerances are low
Solution Approach 1:
The patent replaces the traditional mechanical fixed-depth milling method with an electromagnetic field-based detection system. An electromagnetic field is generated adjacent to the smartcard body during milling, and a sensor detects the induced voltage to determine when contact pads are properly exposed. This substitution of mechanical measurement with electromagnetic detection resolves the contradiction by achieving high precision contact pad exposure without increasing mechanical process complexity.
2Manufacturing precision
If separate wires are used in the final smartcard, then the electrical connection is reliable, but the milling process cannot precisely expose contact pads due to wire placement tolerance
Solution Approach 1:
The patent applies preliminary action by using a longer embedded wire during the milling process that extends beyond the final required configuration. This longer wire allows the electromagnetic field detection system to accurately determine the milling depth for exposing contact pads. After milling, the wire is cut to its final length, achieving both precise contact pad exposure during manufacturing and reliable electrical connection in the final product.
Solution Approach 2:
The patent changes the wire length parameter during different stages of manufacturing. Initially, a longer wire is used that spans across cavity regions, enabling electromagnetic detection during milling. Subsequently, the wire length is reduced by cutting to the final configuration after milling is complete. This parameter change resolves the contradiction by allowing precise exposure detection with a longer wire while maintaining reliable connection with the final shorter wire.
3Manufacturing precision
If a longer embedded wire is used during milling, then the contact pad exposure is more precise, but the wire may be damaged during the milling process
Solution Approach 1:
The patent applies beforehand cushioning by generating the electromagnetic field and detecting the induced voltage before the milling process completes. This allows the optimal milling depth to be determined in advance, preventing over-milling that could damage the wire. The detection system provides early warning of the correct exposure point, cushioning against the risk of wire damage while maintaining precise contact pad exposure.
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
Ensures reliable electrical connections between smartcard modules by accurately exposing contact pads, enhancing manufacturing precision and reducing the risk of wire damage during the milling process.
Implementation Method 1
generating an electromagnetic field adjacent to the smartcard body, wherein the electromagnetic field induces an induced voltage in the wire
Data Source
AI summary
A method for use in manufacturing a smartcard. The method includes the steps of providing a smartcard body having a first cavity region and a second cavity region, wherein a wire is embedded within the smartcard body, the wire extending from a first contact pad in the first cavity region, continuously through first and second contact pads in the second cavity region, and to a second contact pad in the first cavity region; milling a first cavity within one of the first cavity region and the second cavity region to a first depth that exposes the first and second contact pads in the respective cavity region; and after milling the first cavity, milling a second cavity within the second cavity region to a second depth that cuts the wire between the first and second contact pads of the second cavity region.