Maskless Organic EL Display Apparatus for High-Definition Pixel Formation
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Solution Overview
Problem
The manufacturing of high-definition display apparatuses using organic EL devices faces challenges due to inaccuracies in forming island-shaped light-emitting layers with existing vacuum evaporation methods, leading to deviations in shape and position, reduced aperture ratio, and increased manufacturing costs.
Innovation Solution
A display apparatus structure comprising multiple light-emitting devices with insulating and conductive layers, where island-shaped light-emitting layers are formed without a metal mask, using sacrificial layers and sacrificial films to achieve precise pixel electrode formation and high-definition display without the need for a metal mask, thereby improving dimensional accuracy and reducing manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If vacuum evaporation method using metal mask is used to form island-shaped light-emitting layers, then the light-emitting layers can be formed, but dimensional accuracy deteriorates due to mask position deviation, warp, and vapor scattering
Solution Approach 1:
The patent removes the metal mask from the vacuum evaporation process entirely, extracting the source of dimensional inaccuracy. Instead of using a metal mask to define patterns, the invention forms light-emitting layers directly on pixel electrodes without mask interference, eliminating mask position deviation, warp, and vapor scattering issues that cause poor dimensional accuracy
Solution Approach 2:
The patent performs preliminary patterning of the substrate surface or underlying layers before depositing the light-emitting layer. By pre-forming pixel electrode patterns or using pre-patterned sacrificial layers, the light-emitting layer can be deposited uniformly without requiring mask alignment, ensuring high dimensional and position accuracy from the outset
2Ease of manufacture
If metal mask is used for forming light-emitting layers, then island-shaped layers can be created, but manufacturing cost increases due to mask cleaning and multiple equipment lines
Solution Approach 1:
The patent extracts and eliminates the metal mask component from the manufacturing system. By removing the mask, the complex maintenance routine (cleaning, replacement, alignment calibration) is eliminated entirely, simplifying the manufacturing process and allowing single equipment line operation for continuous production
Solution Approach 2:
The maskless vacuum evaporation method enables continuous deposition without interruption for mask maintenance. The vacuum chamber remains sealed and the deposition process can continue uninterrupted, maintaining continuous productive action without stopping for mask cleaning or replacement
3Area of stationary object
If metal mask is used for vapor deposition, then light-emitting layers can be formed, but aperture ratio decreases due to outline blurring and thickness variation
Solution Approach 1:
By removing the metal mask, the patent eliminates the vapor scattering at mask edges that causes outline blurring. The light-emitting layer is deposited directly without mask interference, maintaining sharp edges and uniform thickness that maximize the effective light-emitting area and aperture ratio
Solution Approach 2:
The patent achieves local control of film thickness and morphology by controlling deposition conditions locally over each pixel electrode area. Without mask shadowing effects, each region receives uniform vapor flux appropriate to its geometry, ensuring consistent edge thickness and maximizing aperture ratio across the entire display
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 enables the production of high-definition display apparatuses with improved aperture ratio and reliability, reducing the need for multiple manufacturing equipment lines and lowering initial investment costs while maintaining high yield and precision.
Implementation Method 1
Light-emitting devices (also referred to as EL devices or EL elements) utilizing electroluminescence (hereinafter referred to as EL)
Data Source
AI summary
A high-definition or high-resolution display apparatus is provided. The display apparatus includes a first insulating layer, a second insulating layer, a first conductive layer, a second conductive layer, a first light-emitting device, and a second light-emitting device. The top surfaces of the first insulating layer, the first conductive layer, and the second conductive layer are level or substantially level with one another. The first light-emitting device includes a first pixel electrode, a first light-emitting layer, and a common electrode over the first conductive layer. The second light-emitting device includes a second pixel electrode, a second light-emitting layer, and the common electrode over the second conductive layer. The second insulating layer covers a side surface of each of the first pixel electrode, the second pixel electrode, the first light-emitting layer, and the second light-emitting layer.