Transparent Conductive Metal Pattern for Antenna Transparency
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Solution Overview
Problem
Existing electrically-conductive thin-film articles, such as those used in thin-film antennas, face a challenge in achieving both high optical transparency and low surface resistance, with commercially available materials like copper and ITO exhibiting either low transparency or high surface resistance, leading to reduced antenna performance.
Innovation Solution
The development of an article comprising a transparent laminating film with an electrically-conductive metal-containing pattern, where the pattern is transferred from a first substrate to a second transparent laminating film, allowing for improved registration and reduced visibility of the substrate edges in composite articles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If copper films are used to achieve low surface resistance, then electrical conductivity is improved, but optical transparency deteriorates (below 70%)
Solution Approach 1:
The patent applies parameter changes by varying the thickness of the copper film and adjusting the mesh density of the conductive pattern. By optimizing these parameters, the patent achieves a balance between electrical conductivity (surface resistance of about 1 ohm/square) and optical transparency (greater than 70%), resolving the contradiction between these two properties.
Solution Approach 2:
The patent uses composite materials by combining copper film with a mesh pattern structure and potentially incorporating darkening agents. This composite approach allows the material to exhibit both high electrical conductivity through the copper and high optical transparency through the mesh design, while the darkening agent reduces reflectivity without compromising conductivity.
2Illumination intensity
If ITO films are used to achieve high optical transparency, then optical transparency is improved (greater than 75%), but surface resistance increases (4-8 ohms/square)
Solution Approach 1:
The patent changes the material parameter from ITO to copper film, and adjusts the geometric parameters of the mesh pattern (density and thickness) to achieve both high optical transparency and low surface resistance. The copper mesh pattern with optimized parameters provides surface resistance of about 1 ohm/square while maintaining greater than 70% optical transparency.
3Illumination intensity
If metallic patterns are darkened to reduce light reflectivity, then optical appearance is improved, but manufacturing complexity increases
Solution Approach 1:
The patent applies color changes by using darkening agents that modify the optical appearance of the copper mesh pattern. These agents reduce light reflectivity from the metallic pattern, making it less visible from the exterior. The darkening process is integrated into the manufacturing sequence, adding minimal complexity while achieving the desired optical appearance.
Data Source
AI summary
A transparent article has a transparent laminating film; and an electrically-conductive, metal-containing pattern disposed over a surface of the transparent laminating film. The electrically-conductive, metal-containing pattern has a metallic pattern comprising a first surface facing the transparent laminating film and an opposing second surface. Such articles can be prepared using steps A) and B′), in order: A) providing a metallic pattern on a surface of a first substrate; and B′) transferring the metallic pattern to a surface of a second substrate, thereby providing an electrically-conductive metal-containing pattern on the surface of the second substrate, wherein the second substrate is a transparent laminating film.