Field Emission Display Barrier Array via Photolithography
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Solution Overview
Problem
Conventional methods for manufacturing barrier arrays in field emission displays face challenges such as difficulty in achieving high precision, uniformity, and cost-effectiveness, particularly due to issues with screen printing and sandblasting methods, which limit mass production and environmental sustainability.
Innovation Solution
A field emission display with a barrier array formed using a shadow mask and an insulative layer, where the shadow mask is created through photolithographic etching and the insulative layer is deposited using electrophoretic deposition, allowing for precise and cost-effective production, suitable for mass production and environmentally friendly processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If screen printing method is used to manufacture barrier array, then production cost is reduced, but manufacturing precision and uniformity deteriorate
Solution Approach 1:
The patent replaces the mechanical screen printing process with a photolithography-based patterning process. The barrier array pattern is transferred using photomasks and chemical etching, eliminating the need for repeated mechanical printing and drying cycles. This substitution enables high-precision fabrication while maintaining cost-effectiveness through standard semiconductor manufacturing techniques.
Solution Approach 2:
The patent changes the manufacturing parameters from screen printing (mechanical deposition) to photolithography (optical patterning followed by chemical etching). This parameter change enables precise control of barrier array dimensions, uniform thickness, and accurate positioning, directly improving manufacturing precision while using established, cost-effective processes.
2Ease of manufacture
If sandblasting method is used to manufacture barrier array, then barrier array can be formed, but production time increases and reliability deteriorates
Solution Approach 1:
The patent replaces the sandblasting mechanical erosion process with photolithographic patterning and chemical etching. The barrier array is formed by depositing material and then selectively removing it through chemically controlled etching based on photomask patterns. This eliminates the time-consuming sand injection and masking steps while improving process reliability through better control.
Solution Approach 2:
The patent uses photomasks to copy the desired barrier array pattern onto the substrate. The photomask contains the precise pattern that is transferred through photolithography and etching, enabling rapid and reliable reproduction of the barrier array structure without the need for time-consuming mechanical masking and sandblasting operations.
3Ease of manufacture
If conventional barrier array methods are used, then manufacturing can proceed, but environmental contamination increases
Solution Approach 1:
The patent replaces sandblasting (which generates airborne sand particles and contamination) with photolithography and wet chemical etching. The pattern transfer is achieved through optical exposure and controlled chemical reactions in liquid etchants, eliminating the generation of airborne contaminants while maintaining manufacturing feasibility through standard cleanroom processes.
Solution Approach 2:
The patent employs photolithography and chemical etching processes that can be conducted in controlled, enclosed environments. The photolithography step uses UV light exposure in a mask aligner, and the etching uses liquid chemicals in contained vessels, both of which prevent environmental contamination compared to open sandblasting operations.
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 enables the production of high-precision barrier arrays with reduced production costs and environmental impact, facilitating mass production while ensuring the barrier arrays are non-porous and have a flat upper surface, enhancing display quality.
Implementation Method 1
the shadow mask is created through photolithographic etching
Implementation Method 2
the insulative layer is deposited using electrophoretic deposition
Data Source
AI summary
A field emission display includes: a substrate (11); cathode electrodes (21) formed on the substrate; a plurality of emitters formed on the cathode electrodes; a barrier array (41) defining a plurality of openings (42) therethrough according to a pixel pattern, the barrier array comprising a shadow mask with an insulative layer (43) formed thereon, the barrier array being fixed to the substrate; gate electrodes (51) formed on the barrier array; and a phosphor screen (70) spaced from the substrate. This field emission display employs the known technology for making a shadow mask in the field of CRTs. In addition, the thickness and the material of the insulative layer can be determined according to the insulative performance required for the field emission display. In summary, the present invention provides a field emission display having a high precision, and low production cost barrier array.