Carbon Nanotube Composite for Precise Inkjet Semiconductor Coating
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Solution Overview
Problem
Carbon nanotube dispersion liquids used in inkjet techniques for forming semiconductor layers in RFID tags suffer from poor coating properties, leading to satellite formation and inaccurate positioning, which results in variations in transistor characteristics.
Innovation Solution
A carbon nanotube composite is developed where a conjugated polymer with a specific side chain is attached to the surface of carbon nanotubes, enhancing their dispersibility in solvents suitable for inkjet coating, allowing for precise application and maintaining high electrical characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If low-viscosity solvents such as toluene or N-methylpyrrolidone are used for carbon nanotube dispersion, then the dispersion can be easily prepared, but the coating properties by inkjet deteriorate, causing satellite formation and inaccurate positioning
Solution Approach 1:
The patent changes the viscosity parameter of the solvent from low-viscosity (toluene: 1.5 cP, N-methylpyrrolidone: 1.9 cP) to medium-viscosity range (3-20 cP) to resolve the contradiction between ease of preparation and coating accuracy. This parameter change eliminates satellite formation and improves positioning accuracy while maintaining dispersibility through the specific conjugated polymer structure.
2Device complexity
If conventional carbon nanotube dispersion liquids are used for inkjet coating, then the preparation process is simple, but the coating properties are poor, leading to large variations in transistor characteristics
Solution Approach 1:
The patent creates a composite material system where carbon nanotubes are dispersed in a medium-viscosity solvent with a specifically designed conjugated polymer (having side chains with carbonyl or carboxyl groups). This composite approach improves transistor characteristic consistency while maintaining a relatively simple preparation process, resolving the contradiction between process simplicity and device reliability.
3Manufacturing precision
If additives such as thickeners are added to improve viscosity for inkjet coating, then the coating properties improve, but the conductivity of the semiconductor material is inhibited
Solution Approach 1:
Instead of adding thickeners that would inhibit conductivity, the patent changes the fundamental parameter of the solvent itself to have medium viscosity (3-20 cP). This intrinsic viscosity adjustment improves coating uniformity and eliminates satellite formation without introducing substances that would compromise the electrical conductivity of the carbon nanotube semiconductor material.
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 carbon nanotube composite enables accurate inkjet application and uniform film formation, improving semiconductor device performance and reducing transistor characteristic variations.
Implementation Method 1
a conjugated polymer is attached to at least a part of the surface of a carbon nanotube
Data Source
AI summary
A carbon nanotube composite is described that can be accurately applied to a desired position by inkjet and a dispersion liquid using the same, where a main object is a carbon nanotube composite in which a conjugated polymer is attached to at least a part of the surface of a carbon nanotube, the conjugated polymer having a side chain represented by general formula (1):wherein R, X and A are defined as described.