Smart Card Manufacturing Thickness Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for manufacturing SIM cards struggle to reduce thickness below 0.80 mm due to surface irregularities and excessive plastic usage, leading to increased costs and limited component integration, especially with the transition to 3FF and 4FF formats.
Innovation Solution
A smart card manufacturing method involving a dielectric carrier film with electronic components, a first protective resin coat, and a second protective coat made of epoxy glass or thermoplastic, which allows for precise thickness control and even surface finish, enabling reduced thickness without costly equipment investment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the standard embedding method is used to protect electronic components, then the components are protected, but the surface irregularities and height differences prevent thickness reduction below 0.80 mm
Solution Approach 1:
The method applies a planarizing layer of resin over the encapsulated electronic component assembly before inserting it into the card body. This preliminary action creates a flat surface that eliminates height differences and surface irregularities, allowing the final card thickness to be reduced below 0.80 mm while maintaining component protection.
Solution Approach 2:
The planarizing layer of resin acts as an intermediary between the irregular surface of the encapsulated components and the final card surface. This intermediate layer smooths out surface irregularities and enables precise thickness control without compromising the protective encapsulation of the electronic components.
2Ease of manufacture
If the card body is made with extended format to accommodate embedding, then components can be integrated, but the useful surface area for electronics is limited
Solution Approach 1:
The method changes the dimensional approach by applying the planarizing layer in the thickness dimension rather than extending the card body in the planar dimensions. This allows the useful surface area to be maximized for the final card format without compromising component integration capabilities.
Solution Approach 2:
The invention changes the parameter of card body format from extended to final format, and compensates for the manufacturing ease by introducing the planarizing layer. This parameter change increases the useful surface area while the planarizing layer maintains the protective function.
3Strength
If hot melt adhesive and card body cavity are used to secure the module, then the module is fixed, but at least 0.15 mm thickness is added
Solution Approach 1:
The planarizing layer is applied preliminarily to the encapsulated assembly before insertion into the card body. This preliminary layer fills gaps and provides a flat bonding surface, allowing the module to be securely fixed with minimal additional thickness from the adhesive and cavity.
Solution Approach 2:
The method changes the thickness parameter contribution from the fixation system by using the planarizing layer to minimize gap filling requirements. This reduces the cumulative thickness from adhesive, gap, and cavity bottom to approach the theoretical minimum of 0.15 mm.
4Reliability
If a large quantity of plastic is used for the extended card body, then the card structure is complete, but the manufacturing cost increases
Solution Approach 1:
The method extracts the planarizing function from the card body structure itself and implements it as a separate resin layer applied only where needed over the electronic component assembly. This extraction reduces the total quantity of plastic required in the card body while maintaining structural reliability.
Solution Approach 2:
Instead of making the entire card body with extended format, the planarizing layer is applied locally only to the area containing the electronic component assembly. This local application of the planarizing function reduces overall plastic consumption while maintaining the necessary structural quality where components are located.
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 method enables significant thickness reduction while ensuring mechanical and thermal reliability, compliance with stricter tolerances, and maximizing component integration, all while maintaining cost-effectiveness and using conventional industry equipment.
Implementation Method 1
the first protective coat (11) made of resin is located on the second side of the dielectric carrier film (4) and covers the electronic component assembly (2)
Implementation Method 2
a second protective coat (12) made of epoxy glass or thermoplastic material is located on the first protective coat (11)
Implementation Method 3
a second protective coat (12) made of epoxy glass or thermoplastic material is located on the first protective coat (11)
Data Source
Figure 1~2
Figure 3~4
Figure 5a~5d
AI summary
This invention relates to a smart card (1) manufacturing method that makes it possible to reduce the thickness of the said smart card and directly obtain a final 3FF or 4FF format. The smart card manufacturing method comprises steps for depositing resin forming a first protective coat (11) over the electronic element assembly with a surface greater than the required smart card format and depositing a second protective coat with a format larger than the required card format on the first protective coat. The second protective coat is fixed to the first protective coat by curing the first protective coat, and then the assembly obtained in that way is cut to the required format.