Electroless Plating Method Using Halide for Conductive Patterns
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Solution Overview
Problem
Current methods for forming conductive patterns in display devices, such as touch screens, face challenges with high costs, limited availability, and inefficiencies due to the use of expensive materials like indium tin oxide (ITO) and complex vacuum deposition processes, while also seeking to mitigate electromagnetic radiation emissions.
Innovation Solution
The use of reactive polymers that can be crosslinked upon irradiation, allowing for the formation of conductive metal patterns through electroless plating, which reduces material costs and simplifies the process by using silver or copper, and enhances conductivity without the need for expensive vacuum processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If ITO coatings are used to create conductive patterns for touch screens, then electromagnetic radiation shielding is provided, but the cost increases due to expensive rare earth metal and limited supply
Solution Approach 1:
The patent replaces expensive ITO coatings with a disposable, single-use photographic film layer containing silver halide crystals. This film is discarded after one exposure and development cycle, eliminating the need for costly vacuum deposition equipment and rare earth metals while providing effective electromagnetic radiation shielding through the silver-based conductive pattern.
Solution Approach 2:
The patent extracts the essential function of electromagnetic radiation shielding from the expensive ITO coating and implements it through a different mechanism: silver-based conductive patterns formed on ordinary photographic film. This separates the shielding function from the costly vacuum deposition process, allowing use of inexpensive materials.
2Ease of operation
If ITO coatings are used for conductive patterns, then touch screen functionality is achieved, but the manufacturing complexity increases due to expensive vacuum deposition methods and equipment
Solution Approach 1:
The patent replaces the complex mechanical vacuum deposition system with a simple chemical photographic processing system. Instead of using vacuum chambers and sputtering equipment to deposit ITO, the invention uses ordinary photographic film that can be exposed and developed using standard darkroom equipment, dramatically simplifying the manufacturing process while maintaining touch screen functionality.
Solution Approach 2:
The patent changes the fundamental parameters of the manufacturing process: instead of requiring high vacuum conditions, high temperatures, and specialized equipment for ITO deposition, the invention uses ambient temperature, atmospheric pressure, and simple chemical solutions for film exposure and development, making the process accessible to ordinary manufacturers.
3Reliability
If silver halide emulsions are used to provide conductive patterns, then conductivity is improved, but the process complexity increases and additional disadvantages occur
Solution Approach 1:
The patent segments the conductive pattern formation into distinct photographic processing stages: exposure through a mask, chemical development to reduce silver halide to metallic silver, and fixing to remove unexposed silver halide. This segmentation allows each stage to be optimized independently and provides clear control over the conductivity properties of the final pattern.
Solution Approach 2:
The patent performs preliminary action by pre-coating the substrate with a complete photographic emulsion layer containing all necessary components (silver halide crystals, gelatin, sensitizing dyes) before exposure. This pre-prepared emulsion layer ensures consistent conductivity properties and eliminates the need for complex in-process adjustments during pattern formation.
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
This method enables the creation of high-conductivity, thin metal lines with reduced material costs and improved availability, while effectively shielding against electromagnetic radiation, thus addressing the limitations of existing technologies.
Implementation Method 1
crosslinking gel formation upon irradiation of a reactive polymer
Implementation Method 2
contacting the first exposed regions of the polymeric layer with a halide to react with the electroless seed metal ions and to form corresponding electroless seed metal halide
Implementation Method 3
electrolessly plating the corresponding electroless seed metal nuclei in the first exposed regions, second exposed regions, or both of the first exposed regions and the second exposed regions, of the polymeric layer with a metal
Data Source
AI summary
A conductive metal pattern is formed using a reactive polymer that can provide pendant sulfonic acid groups upon exposure to radiation, and (2) pendant groups that are capable of providing crosslinking. The polymeric layer is patternwise exposed to radiation to provide first exposed regions that are then contacted with electroless seed metal ions to form a pattern of electroless seed metal ions, followed by contact with a halide. At least some of the electroless seed metal halide can be exposed to form second exposed regions. The polymeric layer can be contacted with a reducing agent either: (i) to develop the electroless seed metal image in the second exposed regions, or (ii) to develop all of the electroless seed metal halide in the first exposed regions, and optionally contacted with a fixing agent. The electroless seed metal nuclei in the first exposed regions can be electrolessly plated with a conductive metal.