Metal Nanowire Patterning via Pulsed Light Sintering

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for manufacturing conductive patterns in touch panels, such as electrostatic capacitance touch panels, face challenges in minimizing pattern visibility due to the need for narrow gaps between conductive and non-conductive regions, which is difficult to achieve with current photolithography techniques that require multiple steps and generate significant waste.

Innovation Solution

A method involving the formation of a metal nanowire layer on a substrate, where metal nanowires are sintered in specific patterns using pulsed light through a mask to create conductive regions and unsintered regions for non-conductivity, reducing the number of processing steps and waste, while maintaining low surface resistance for conductive areas and high insulation for non-conductive areas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If photolithography is used to form narrow gaps between electrode patterns, then pattern visibility is prevented, but the number of processing steps increases and manufacturing complexity increases

Engineering Contradiction:
Improvepattern visibilityVSAvoidprocessing steps
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the photosensitive layer and its associated processing steps (coating, developing, etching) from the conventional photolithography process. By directly patterning the conductive material without these intermediate layers, the method maintains narrow gap precision while significantly reducing processing steps and manufacturing complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical/chemical photolithography system with a direct patterning approach that eliminates the need for photosensitive materials and chemical development processes. This substitution reduces the number of processing steps while maintaining the ability to achieve narrow gaps between conductive patterns.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If photolithography with photosensitive layer is used, then narrow pitch patterns can be formed, but chemical waste and processing time increase

Engineering Contradiction:
ImprovepitchVSAvoidchemical waste
Core Design Contradiction:
Manufacturing precisionVSLoss of substance

Solution Approach 1:

The patent removes the photosensitive layer and associated chemical processing steps from the fabrication process. By directly forming conductive patterns without photosensitive materials, the method achieves narrow pitch precision while eliminating the generation of chemical waste from resist coatings, developers, and etchants.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent eliminates the use of disposable photosensitive materials that generate waste. Instead, the method uses a direct patterning approach on the conductive material itself, avoiding the need for single-use resist layers and chemical processing agents that must be disposed of.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Manufacturing precision

If multiple photolithography steps are used for pattern formation, then conductive patterns can be created, but productivity decreases

Engineering Contradiction:
Improvepattern formationVSAvoidmanufacturing efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent merges multiple separate photolithography steps (photosensitive layer coating, patterning, etching, and removal) into a single direct patterning step. This consolidation maintains the precision of pattern formation while significantly improving manufacturing efficiency by reducing the total number of processing steps and cycle time.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent enables continuous patterning of conductive materials without the intermittent steps required in photolithography (coating, drying, developing, etching, stripping). The direct patterning method allows for uninterrupted processing, improving productivity while maintaining pattern formation precision.

Inventive Principle:
Principle #20Continuity of useful action

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 approach allows for the creation of conductive patterns with reduced pattern visibility by minimizing the optical difference between conductive and non-conductive regions, achieved through simple steps and efficient use of resources, resulting in effective conductivity and insulation properties.

Implementation Method 1

a step for irradiating light to the metal nanowire layer in a predetermined pattern to sinter the metal nanowires in the metal nanowire layer in a region of the predetermined pattern

Methodology Applied
Scientific EffectLight sintering: Sintering

Implementation Method 2

irradiating light to the metal nanowire layer in a predetermined pattern to sinter the metal nanowires

Methodology Applied
Scientific EffectPhotothermal effect: Absorption (EM radiation)

Data Source

PatentEP2991083B1Method for manufacturing electroconductive pattern and electroconductive pattern-formed substrate
Publication Date: 2021.06.09 RESONAC HOLDINGS CORP
  • EP2991083B1 patent drawingFigure 1(a)~2
  • EP2991083B1 patent drawingFigure 3(a)~4
  • EP2991083B1 patent drawingFigure 5~6(b)

AI summary

Provided are a conductive pattern manufacturing method and a conductive pattern formed substrate, capable of easily achieving a narrow pitch. A metal nanowire layer 12 is formed on the entirety of a part of at least one of the main faces of a substrate 10, pulsed light is irradiated thereto through a mask 14 provided with a light transmission portion 14a formed in a predetermined pattern, and the metal nanowires in the metal nanowire layer 12 at the region having the above predetermined pattern were sintered, to thereby obtain conductivity at the predetermined patterned region. Accordingly, a substrate provided with a conductive pattern having any selected pattern can be produced by simple steps.