Flexible Electromagnetic Absorption Sheet for Millimeter-Wave Bending
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Solution Overview
Problem
Conventional electromagnetic-wave absorbing sheets of the interference type face issues with impedance matching and electromagnetic-wave absorbing properties when bent, due to cracking of metal oxide electric resistance films, and lack flexibility and light transmittance.
Innovation Solution
An electromagnetic-wave absorbing sheet with a conductive organic polymer electric resistance film, an adhesive dielectric layer, and a conductive mesh or grid electromagnetic-wave shielding layer, which maintains impedance matching and high absorbing properties even when bent, and provides flexibility and light transmittance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a metal oxide electric resistance film is used in conventional electromagnetic-wave absorbing sheets, then impedance matching can be achieved, but the film cracks when bent and loses electromagnetic-wave absorbing properties
Solution Approach 1:
The patent changes the material parameter from metal oxide to conductive organic polymer, which fundamentally alters the mechanical properties while maintaining electrical conductivity. This allows the electric resistance film to remain flexible and crack-free when bent, while still achieving the required impedance matching for electromagnetic-wave absorption
Solution Approach 2:
The patent uses a composite structure combining conductive organic polymer with plasticizer and crosslinking agent. This composite material provides both the electrical conductivity needed for impedance matching and the mechanical flexibility required to prevent cracking during bending
2Strength
If the dielectric layer is thinned to improve flexibility for high-frequency absorption, then the sheet becomes more flexible, but layer adhesion becomes more difficult
Solution Approach 1:
The patent introduces a crosslinking agent as an intermediary substance that facilitates adhesion between the conductive organic polymer layer and the dielectric layer. This crosslinking mechanism creates strong chemical bonds that ensure proper layer adhesion even when the dielectric layer is thin, while maintaining the required flexibility for high-frequency electromagnetic-wave absorption
3Reliability
If conventional metal oxide films are used, then electromagnetic-wave absorption can be achieved, but the sheets lack light transmittance and user convenience
Solution Approach 1:
The patent changes the material from opaque metal oxide to transparent conductive organic polymer. This parameter change in optical transparency allows light to pass through the electromagnetic-wave absorbing sheet while maintaining the electrical conductivity needed for absorption, thereby significantly improving user convenience and aesthetic appearance
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 solution ensures stable electromagnetic-wave absorption in high-frequency bands, maintains flexibility, and allows for easy adhesion of layers, reducing production costs and enhancing user convenience with light transmittance.
Implementation Method 1
an electric resistance film formed of a conductive organic polymer
Implementation Method 2
a dielectric layer having adhesiveness
Implementation Method 3
an electromagnetic-wave shielding layer that reflects electromagnetic waves
Data Source
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AI summary
The present invention enables the achievement of an electromagnetic interference type electromagnetic wave absorption sheet which is capable of satisfactorily absorbing electromagnetic waves having frequencies in and above the millimeter wave band, and which is able to be produced at low cost. An electromagnetic interference type electromagnetic wave absorption sheet which is obtained by sequentially stacking a resistive film 1 that is formed from a conductive organic polymer, a dielectric layer 2 that has adhesive properties, and an electromagnetic shielding layer 3. The sheet as a whole is flexible; and the dielectric layer is configured to have such a layer thickness that enables absorption of electromagnetic waves that have frequencies in and above the millimeter wave band.