Flat Panel Display Inkjet Printing Border Area Surface Energy
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Solution Overview
Problem
Inkjet printing for flat panel displays faces challenges with ink overflow into adjacent areas, leading to color mixing and non-uniform film thickness, which existing methods attempt to address through surface energy modifications and geometrical barriers but often require costly and complex processes.
Innovation Solution
A flat panel display design featuring a substrate with a first electrode layer, an active area, a repellant area with a second organic layer of lower surface energy, and a border area with higher surface energy to prevent ink overflow and ensure uniform film thickness, using a method that avoids vacuum processes and complex surface treatments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If inkjet printing is used to deposit active material, then manufacturing cost is reduced and process simplicity is improved, but ink overflow into adjacent areas occurs leading to color mixing
Solution Approach 1:
The substrate surface is modified to have different wetting properties in different regions: the active area has high surface energy to accept ink, while the border area has low surface energy to repel ink. This local differentiation of surface properties prevents ink overflow into adjacent pixels while maintaining the simplicity of inkjet printing.
Solution Approach 2:
The substrate surface is pre-modified with different wetting properties before inkjet printing occurs. By preparing the surface with appropriate surface energy distribution in advance, the ink naturally confines to the active area during deposition, preventing overflow without requiring additional real-time control mechanisms.
2Manufacturing precision
If substrate surface is modified with different wetting properties to prevent ink overflow, then ink placement precision is improved, but process complexity and manufacturing cost increase
Solution Approach 1:
The patent uses a simple organic coating layer that can be applied through conventional coating methods and then patterned using standard photolithography. This approach replaces complex vacuum-based deposition techniques with simpler, more cost-effective processes that achieve the same surface energy differentiation.
Solution Approach 2:
The patent replaces complex mechanical or vacuum-based surface modification techniques with chemical coating and photolithography methods. By using solution-based coating and standard photoresist patterning, the process becomes simpler and more compatible with existing manufacturing infrastructure.
3Manufacturing precision
If geometrical barriers are formed on substrate surface to prevent ink overflow, then ink placement precision is improved, but manufacturing cost and process complexity increase
Solution Approach 1:
Instead of forming physical geometrical barriers through complex deposition techniques, the patent uses surface energy modification through chemical coating and photolithography. This substitutes mechanical/physical barrier formation with chemical surface property modification, which is simpler and more cost-effective.
Solution Approach 2:
The patent uses photolithography to create a patterned coating that copies the pixel structure. The photoresist is exposed through a mask that defines the active areas, creating a replicated pattern of high and low surface energy regions that matches the display pixel arrangement without requiring complex direct patterning.
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 solution effectively prevents ink overflow and achieves a uniform organic film thickness, enhancing display quality while reducing production costs and avoiding the need for expensive vacuum technologies.
Implementation Method 1
the second organic layer has a surface energy lower than a surface energy of the first organic layer
Implementation Method 2
The wetting property disclosed in this reference is the surface energy across the substrate. A contrast in surface energy across the substrate is produced by an appropriate selection of materials that form the substrate surface.
Implementation Method 3
a border area positioned between the active area and the repellant area and including a second layer, wherein a surface energy of the border area is higher than a surface energy of the repellant area
Data Source
AI summary
A flat panel display and a method of manufacturing the same, which allows the formation of an organic film by inkjet printing while avoiding overflow of ink into adjacent areas, thus increasing the uniformity of thickness of the organic film and decreasing manufacturing costs. The flat panel display includes a substrate, a first electrode layer formed on the substrate, ink with material for a light emission layer formed on an active area of the first electrode layer, a repellant area formed of organic material located around the active area, and a border area also formed of organic material located between the active area and the repellant area. A surface energy of the border area is higher than a surface energy of the repellant area.