Smart Card Prelam Layout for Even Flip-Chip Adhesive Support
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Solution Overview
Problem
Conventional smart card prelam bodies face issues with uneven distribution of adhesive material between the chip and the substrate, leading to potential mechanical stress on the chip and unreliable bonding during flip-chip bonding, which can cause fabrication problems.
Innovation Solution
Incorporating dummy islands and contact pads in the IC landing area of the prelam body substrate to evenly distribute adhesive material and provide additional support, allowing for improved bonding without mechanical stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional separate lamination processes are used for forming prelam bodies, then manufacturing complexity increases and production time is extended, but manufacturing precision and reliability of smart cards are compromised
Solution Approach 1:
The patent combines multiple separate lamination processes into a single integrated lamination step where the substrate, first intermediate layer, second intermediate layer, and coating layer are laminated together in one operation. This merging of processes eliminates the need for separate lamination steps, reducing manufacturing complexity while maintaining high lamination precision through unified process control.
Solution Approach 2:
The patent applies a release coat to the substrate before lamination and uses release papers on the adhesive layers. These preliminary actions prepare the surfaces for precise lamination by controlling adhesion characteristics in advance, ensuring that layers bond correctly during the single lamination step while facilitating easy separation during later processing.
2Productivity
If multiple separate lamination processes are used, then production efficiency decreases, but quality control becomes more difficult
Solution Approach 1:
By consolidating multiple lamination operations into one integrated process, the patent eliminates repeated handling, alignment, and bonding cycles. This single-step lamination approach directly increases production efficiency while improving reliability by reducing the number of potential failure points and ensuring consistent quality across all layers through unified process parameters.
3Strength
If adhesive layers are exposed to air during storage, then adhesive strength decreases due to contamination, but protective measures increase process complexity
Solution Approach 1:
The patent uses release papers as protective thin films that cover the adhesive layers during storage and handling. These release papers prevent air exposure and contamination while maintaining adhesive strength. The release papers are designed to be easily removed during the lamination process, providing protection without significantly increasing process complexity.
Solution Approach 2:
The release coat applied to the substrate serves as a preliminary protective measure that prevents adhesive contamination before lamination occurs. This preliminary action ensures that the adhesive layers remain clean and effective throughout storage and handling, maintaining bond strength without requiring complex protective systems.
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 use of dummy islands and contact pads ensures a more even distribution of adhesive material, enhancing the bonding force and reducing the risk of mechanical stress on the chip, resulting in a stable and reliable connection during the fabrication process.
Implementation Method 1
an adhesive layer, in which a substrate, a first intermediate layer, a second intermediate layer and a coating layer are laminated in this order
Data Source
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AI summary
The present disclosure provides in various aspects for a prelam body of a smart card, a method of forming a prelam body of a smart card, and a smart card having a card body with such a prelam body. According to some embodiments herein, a prelam body of a smart card comprises a prelam body substrate having an IC landing area provided on a first main surface of the prelam body substrate, the IC landing area having at least one contact pad and at least one dummy island, wherein the at least one contact pad is electrically coupled with at least one conductive line routed in or on the prelam body substrate, and a chip having at least one contact element arranged on a second main surface of the chip, wherein the at least one contact element is in electric connection with the at least one contact pad. The chip is flip-chip bonded to the prelam body substrate such that the first main surface and the second main surface face each other and that the chip at least partially overlies the at least one contact pad. Herein, the at least one dummy island and the at least one contact pad each represent a support for the chip on the prelam body substrate.