Conductive Ink Composition for Offset Printing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing conductive ink compositions for offset or reverse-offset printing face challenges in achieving excellent coatability and transferability onto substrates, particularly with polydimethylsiloxane (PDMS) blankets, due to issues like swelling and pinhole formation, which affect the precision and quality of ultra-fine metal patterns.
Innovation Solution
A conductive ink composition utilizing tert-butyl alcohol as the main solvent, combined with high boiling point and dispersion assistant solvents, along with metal particles and additives like binders and dispersants, to enhance coatability, prevent swelling, and ensure stable transferability, forming uniform and high-conductivity patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional solvents are used in conductive ink composition, then coatability onto blanket may be achieved, but blanket swelling occurs and transferability deteriorates
Solution Approach 1:
The patent changes the chemical parameters of the solvent system by selecting tert-butyl alcohol with specific solubility parameter (10.6) and controlling its content (40-65 wt%), combined with high boiling point solvents (180-250°C) and dispersion assistant solvents (50-150°C). This parameter optimization resolves the contradiction by achieving both good coatability and preventing blanket swelling, thereby ensuring reliable transferability without the harmful swelling effect.
Solution Approach 2:
The patent employs a composite solvent system consisting of three types of solvents: tert-butyl alcohol as main solvent, high boiling point solvents, and dispersion assistant solvents. This composite approach allows each component to contribute different properties - tert-butyl alcohol provides good coatability and prevents swelling, while high boiling point solvents ensure proper drying and dispersion assistant solvents enhance metal particle distribution, collectively achieving reliable transferability without blanket swelling.
2Manufacturing precision
If optical patterning method is used to form high-definition wiring patterns, then pattern definition is improved, but material waste increases and process complexity increases
Solution Approach 1:
The patent replaces the optical patterning method (which uses photoresist, exposing, developing, and etching) with a direct printing method using conductive ink. This substitution eliminates the need for photoresist materials, developing liquids, and etching solutions, thereby preventing material waste while maintaining the ability to form precise wiring patterns through direct deposition of metal particles onto the substrate.
Solution Approach 2:
The patent extracts and eliminates the unnecessary intermediate materials and processes from the optical patterning method. By removing photoresist, developing liquids, and etching solutions from the process flow, the invention achieves direct pattern formation through printing, thereby preventing material waste while maintaining manufacturing precision for wiring patterns.
3Manufacturing precision
If blanket swelling is prevented through solvent selection, then transfer precision is improved, but coatability may deteriorate
Solution Approach 1:
The patent optimizes the solubility parameter of the main solvent to match the blanket material properties. By selecting tert-butyl alcohol with solubility parameter of 10.6 and controlling its content (40-65 wt%), the ink achieves good coatability onto the blanket while preventing swelling. The balanced formulation ensures both ease of operation (coatability) and manufacturing precision (transfer precision) are achieved simultaneously.
Solution Approach 2:
The patent applies different solvent functions to different aspects of the coating process: tert-butyl alcohol specifically addresses coatability and swelling prevention, high boiling point solvents (180-250°C) handle drying and film formation, and dispersion assistant solvents (50-150°C) ensure uniform metal particle distribution. This local optimization of solvent properties ensures both good coatability and high transfer precision without compromise.
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 ink composition achieves excellent coatability and transferability, prevents blanket swelling, secures a waiting time of 30 seconds or longer, forms ultra-fine metal patterns with high electric conductivity, and maintains dispersion stability, preventing nozzle blockages and pinholes.
Implementation Method 1
The tert-butyl alcohol constitutes a medium of the ink composition together with the high boiling point solvent and the dispersion assistant solvent, which will be described later, and thus, provides excellent coatability onto a material of the blanket and prevents swelling of the blanket
Implementation Method 2
contains a high boiling point solvent having a boiling point of 180 to 250°C and a dispersion assistant solvent having a boiling point of 50 to 150°C, together with metal particles and tert-butyl alcohol
Data Source
Figure 1(a)~2(b)
Figure 3(a)~3(b)
Figure 4(a)~4(b)
AI summary
There is provided a conductive ink composition for offset or reverse-offset printing, the conductive ink composition including a high boiling point solvent having a boiling point of 180 to 250°C and a dispersion assistant solvent having a boiling point of 50 to 150°C, together with metal particles and tert-butyl alcohol as a main solvent.