IC Card Substrate Thickness via Screen-Printing Coating
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Solution Overview
Problem
Integrated-circuit cards with integrated circuits in substrates face production complexity and cost issues due to difficulties in precisely removing sectors in 2FF, 3FF, and 4FF formats, often resulting in defective products and high rejection rates.
Innovation Solution
A substrate with a thickness equal to or less than the 4FF format is used, with a screen-printing coating process to increase thickness selectively for 2FF or 3FF sectors, avoiding structural damage and enabling precise sector removal without complex machining or molding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If scraping is used to reduce substrate thickness for 4FF format, then the required thickness is achieved, but manufacturing precision deteriorates due to difficulty in precise scraping and pre-cut line formation
Solution Approach 1:
The patent applies preliminary action by forming pre-cut lines in the substrate before performing the scraping operation. The pre-cut lines are created while the substrate maintains its original thickness, ensuring precise line formation. Only after the pre-cut lines are established does the scraping process reduce the substrate thickness to the required 4FF format thickness. This sequence prevents breakage of pre-cut lines during scraping and ensures both precision and correct thickness.
2Length of stationary object
If injection-moulding is used to create thinner 4FF sector, then the required thickness is achieved, but device complexity and manufacturing cost increase due to complex moulding process
Solution Approach 1:
The patent applies segmentation by dividing the substrate into distinct sectors (4FF sector, 3FF sector, 2FF sector) with different thickness requirements. Each sector is independently processed: the 4FF sector is scraped to the required thinness, while the 3FF and 2FF sectors retain their original thickness. This segmented approach eliminates the need for complex injection-moulding processes that would be required to create varying thicknesses across different sectors, thereby reducing device complexity and manufacturing cost.
3Ease of manufacture
If pre-cut lines are formed before scraping, then sector delimitation is established, but reliability deteriorates due to breakage of pre-cut lines during scraping
Solution Approach 1:
The patent applies preliminary action by forming pre-cut lines in the substrate before performing the scraping operation. The pre-cut lines are created while the substrate maintains its original thickness, ensuring precise line formation. Only after the pre-cut lines are established does the scraping process reduce the substrate thickness to the required 4FF format thickness. This sequence prevents breakage of pre-cut lines during scraping and ensures both precision and correct thickness.
4Ease of manufacture
If a single substrate thickness is used for all formats, then manufacturing is simplified, but adaptability deteriorates because different formats require different thicknesses
Solution Approach 1:
The patent applies segmentation by dividing the substrate into distinct sectors (4FF sector, 3FF sector, 2FF sector) with different thickness requirements. Each sector is independently processed: the 4FF sector is scraped to the required thinness, while the 3FF and 2FF sectors retain their original thickness. This segmented approach eliminates the need for complex injection-moulding processes that would be required to create varying thicknesses across different sectors, thereby reducing device complexity and manufacturing cost.
Solution Approach 2:
The patent applies local quality by applying different thickness characteristics to different regions of the substrate. The 4FF sector is locally modified through scraping to achieve the required thinness, while the 3FF and 2FF sectors maintain their original thickness. This localized modification allows each sector to have the specific thickness quality needed for its format, thereby achieving multi-format compatibility without complicating the overall manufacturing process.
Data Source
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AI summary
An integrated-circuit card (1) is described, said card comprising a substrate (2) and a circuit (3) integrated in the substrate (2), with the pads of the circuit (3) substantially coplanar with a surface (S) of the substrate (2). The substrate (2) comprises a first area defining a first sector (5) comprising the circuit (3) and able to be separated from the card (1), said first sector (5) having a form and size equivalent to a 4FF format of integrated-circuit cards and being intended to be separated from the card owing to a first pre-cut or weakening line (4) delimiting said first sector (5) with 4FF format; the card further comprises at least one area defining a second sector (7) around the first sector (5) and able to be separated from card (1) owing to a second pre-cut or weakening line (6), said second sector (7) having a form or size equivalent to a 2FF or 3FF format of integrated-circuit cards, and a screen-printed coating (8) on the surface (SC) opposite to the surface (S) of the substrate (2), in the region of at least the second sector (7), the screen-printed coating (8) having, along the second sector (7), a thickness (B) which is equal to the difference between a predefined thickness (X) of the 2FF or 3FF format and a thickness (A) of the first sector ( 5 ).