Electromagnetic Wave Absorbing Sheet Using Conductive Polymer and Mesh Shielding
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Solution Overview
Problem
Conventional electromagnetic-wave absorbing sheets with high frequency capabilities tend to crack when bent, leading to impedance mismatch and reduced electromagnetic-wave absorbing properties, while also lacking light transmittance and flexibility.
Innovation Solution
An electromagnetic-wave absorbing sheet with a conductive organic polymer electric resistance film, a dielectric layer, and an electromagnetic-wave shielding layer, all with light transmittance, are stacked to maintain impedance matching and flexibility, using a conductive mesh for the shielding layer with an aperture ratio of 35% to 85% and a surface electric resistance of 0.3 Ω/sq or less.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional electromagnetic-wave absorbing sheets use metal oxide films formed by sputtering or vacuum evaporation, then electromagnetic-wave absorbing properties are improved, but flexibility deteriorates and light transmittance is reduced
Solution Approach 1:
The patent changes the material parameter from conventional metal oxides (ITO, indium oxide, stannic oxide, zinc oxide) to conductive organic polymers. This material substitution fundamentally alters the physical and chemical properties, enabling flexibility while maintaining electromagnetic-wave absorbing performance through proper conductivity control.
Solution Approach 2:
The patent employs composite material structures by combining conductive organic polymer films with dielectric layers and electromagnetic-wave shielding layers. This multi-layer composite approach allows each layer to contribute specific properties: the conductive polymer provides flexibility and impedance matching, the dielectric layer provides structural support and additional electromagnetic control, and the shielding layer enhances electromagnetic-wave blocking.
2Reliability
If the electromagnetic-wave shielding layer uses a solid continuous film, then electromagnetic-wave shielding performance is improved, but light transmittance deteriorates
Solution Approach 1:
The patent applies porous or mesh-like structures to the electromagnetic-wave shielding layer. This allows electromagnetic waves to be effectively shielded through the conductive network while light can pass through the gaps in the mesh structure, thereby maintaining both shielding performance and light transmittance simultaneously.
Solution Approach 2:
The shielding layer is segmented into a mesh or patterned structure rather than being a continuous solid film. This segmentation creates conductive pathways for electromagnetic-wave blocking while leaving open spaces for light transmission, resolving the contradiction between shielding effectiveness and optical transparency.
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 sheet maintains high electromagnetic-wave absorbing properties and flexibility, with stable surface electric resistance and light transmittance, effectively absorbing electromagnetic waves in high frequency bands without cracking, even when strongly bent.
Implementation Method 1
the electric resistance film has a function of matching the surface impedance of the electromagnetic-wave absorbing sheet to the impedance in the air to enable electromagnetic waves to easily enter the electromagnetic-wave absorbing sheet
Implementation Method 2
an electromagnetic-wave shielding layer that reflects electromagnetic waves is formed on the other surface of the dielectric layer
Implementation Method 3
Electromagnetic waves are absorbed by shifting the phase of reflected waves with respect to the phase of incident waves by 1/2 wavelength to make the incident waves and the reflected waves cancel each other out
Data Source
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AI summary
Provided is an electromagnetic-wave interference type electromagnetic-wave absorbing sheet that can favorably absorb electromagnetic waves in a desired frequency band while having high flexibility and light transmittance and being handled easily. The electromagnetic-wave absorbing sheet having flexibility and light transmittance includes an electric resistance film 1, a dielectric layer 2 and an electromagnetic-wave shielding layer 3 that each have light transmittance and that are stacked. The electric resistance film is formed of a conductive organic polymer, and the electromagnetic-wave shielding layer has an aperture ratio of 35% or more and 85% or less.