Ultrathin Transparent EMI Shielding Filter for Optical Displays
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Solution Overview
Problem
Existing optical filters for electronic display devices are costly, bulky, and require multiple components to achieve desired performance characteristics, including EMI shielding, visible reflection adjustment, and transmission optimization, which increases production costs and device complexity.
Innovation Solution
A multi-component optical display filter with a transparent polymeric substrate, a three-layer construction comprising an electrically-conductive layer, a nucleation layer, and a barrier layer, along with a transparent dielectric layer, which provides EMI shielding, antireflective properties, and high transmission of visible light, all integrated into a single lightweight and cost-effective film.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple optical filters and EMI shielding films are used in combination, then EMI shielding performance is improved, but device complexity and production cost increase
Solution Approach 1:
The patent combines EMI shielding function and optical filtering function into a single integrated film structure. The film includes a conductive layer (silver, aluminum, or copper) for EMI shielding, coupled with dielectric layers (metal oxides or organic polymers) that provide optical filtering. This merging eliminates the need for separate EMI shielding films and optical filters, reducing component count while maintaining both functions.
Solution Approach 2:
The integrated film serves multiple functions simultaneously: EMI shielding through the conductive layer, optical wavelength filtering through dielectric layers, and potential antireflective properties. This multi-functionality allows a single component to replace what would traditionally require multiple separate components, simplifying the overall device structure.
2Illumination intensity
If multiple optical filters are used to adjust performance characteristics, then optical performance is improved, but transmission loss of desired images increases
Solution Approach 1:
The dielectric layers are designed with specific refractive indices and thicknesses to target particular wavelength ranges. By optimizing the local optical properties of each layer, the film achieves high transmission in the visible range while blocking specific unwanted wavelengths, minimizing overall transmission loss of desired light.
Solution Approach 2:
The patent optimizes parameters such as dielectric layer thickness, refractive index, and material composition to maximize visible light transmission while maintaining EMI shielding effectiveness. By carefully controlling these parameters, the film achieves high transmission (>80% in some embodiments) while still providing the required optical filtering and EMI protection.
3Reliability
If interference stacks of alternating conductors and dielectrics are used, then EMI shielding and optical adjustment are achieved, but production cost increases due to slow deposition rate
Solution Approach 1:
The patent employs organic polymer dielectric layers that can be deposited more rapidly than traditional metal oxide layers. These organic materials offer sufficient dielectric properties for optical filtering and can be applied using faster deposition techniques, improving production speed and reducing manufacturing costs.
Solution Approach 2:
The integrated film uses composite structures combining conductive metals with dielectric materials (metal oxides or organic polymers). This composite approach allows optimization of each layer's properties for its specific function while enabling more efficient deposition processes compared to traditional multi-layer interference stacks, thereby improving productivity.
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 offers lightweight, low-cost optical filters that can be easily applied to electronic devices, providing effective EMI shielding, high transmission of visible light, and adjustable reflection properties, suitable for use in handheld devices such as mobile phones and liquid crystal display panels.
Implementation Method 1
The filter can also provide EMI shielding when included in or placed on a display panel, touch panel, or an electronic device
Implementation Method 2
a discontinuous nucleation layer in contact with the first surface
Implementation Method 3
a barrier layer for preventing or retarding the diffusion of moisture or corrosive agents
Implementation Method 4
The provided filter can have antireflective layers and components built into it to increase transmission of visible light
Implementation Method 5
high transmission of visible light
Data Source
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Figure 7A~7B
AI summary
Provided are multi-component films useful as optical display filters. The films include a transparent substrate, a nucleation layer, an electrically-conductive layer, a barrier layer, and a dielectric layer. The films can provide high visible transmission, are corrosion-resistant, and can provide shielding from electromagnetic interference (EMI shielding). The optical display filters are useful as components of active optical devices such as display panels including liquid crystal display panels such as those used on mobile hand-held phones.