Quadrangular Contact Pads for IC Card Index Error Tolerance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Integrated circuit cards face manufacturing challenges due to index errors in x and y directions during the production process, leading to potential misalignment of contact pads and increased complexity in maintaining conductivity, especially when multiple pads are required in a small area.
Innovation Solution
The use of quadrangular-shaped contact pads allows for increased tolerance in index errors by ensuring sectors overlap contact pads even when errors reach limits in both directions, while maintaining close pad positioning through a specific substrate and coating configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the size of contact pads is increased to accommodate index errors, then manufacturing tolerance is improved, but the card size increases and the ability to fit many contact pads in a small area is worsened
Solution Approach 1:
The contact pads are designed with an asymmetric quadrangular shape rather than a symmetric circular shape. This asymmetry allows the pads to be positioned more efficiently within the limited card area while providing extended coverage in the directions where index errors occur during manufacturing, thereby accommodating larger tolerances without increasing overall card size.
2Area of stationary object
If multiple contact pads are positioned closely together to reduce card size, then card area is reduced, but the risk of misalignment due to index errors increases
Solution Approach 1:
The quadrangular shape of contact pads provides asymmetric coverage that extends further in the directions where index errors are most likely to occur. This asymmetric design ensures that even when multiple pads are positioned closely together, the extended coverage areas overlap sufficiently to maintain reliable electrical contact despite manufacturing variations.
3Ease of manufacture
If circular sectors are used to uncover contact pads, then manufacturing is simplified, but the sectors may not overlap contact pads when index errors reach limits
Solution Approach 1:
By designing contact pads with a quadrangular shape rather than a circular shape, the patent ensures that the sectors formed during manufacturing will overlap the contact pads even when index errors reach their limits. The asymmetric quadrangular geometry provides extended coverage in the critical directions where manufacturing variations occur.
Solution Approach 2:
The patent changes the geometric parameters of the contact pads from circular to quadrangular shape. This parameter change fundamentally alters how the pads interact with the manufacturing processes, allowing for reliable coverage despite variations in sector formation while maintaining ease of manufacture.
Data Source
AI summary
A circuit layer for an integrated circuit card comprising an electronic circuit embedded in a substrate and a coating covering the substrate and circuit. To enable larger tolerances of the position of the circuit in the substrate, the electronic circuit has contact pads with a quadrangular shape and the contact pads are exposed through the coating by holes having a circular shape.