OLED Planarization Member for Uniform Light Emission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Top-emission type OLED displays face challenges in achieving a uniform light emission layer due to non-uniform thickness caused by height differences between regions with TFTs and wiring, especially when using soluble materials.
Innovation Solution
The implementation of a planarization member and insulating layer on the substrate, along with a method involving chemical mechanical polishing or thermal reflow to ensure a uniform surface, combined with the use of a sealing member to prevent moisture ingress, helps in maintaining a flat passivation layer and uniform light emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a top-emission type OLED structure is used to increase aperture ratio, then the aperture ratio is improved, but the light emitting layer thickness becomes non-uniform due to height differences between TFT/wiring regions and other regions
Solution Approach 1:
A planarization member is formed in advance on the substrate before forming the light emitting layer. This preliminary planarization step creates a flat surface that compensates for the height differences caused by TFTs and wiring, ensuring uniform thickness of the subsequent light emitting layer while maintaining the top-emission structure's high aperture ratio
Solution Approach 2:
The planarization member acts as an intermediary layer between the uneven substrate (with TFTs and wiring) and the light emitting layer. It mediates the height differences by providing a flat surface, allowing the light emitting layer to be deposited uniformly without direct contact with the underlying structural variations
2Manufacturing precision
If chemical mechanical polishing or thermal reflow is used to planarize the surface, then the surface uniformity is improved, but the manufacturing process complexity increases
Solution Approach 1:
The patent replaces complex mechanical planarization processes (chemical mechanical polishing) or thermal processes (thermal reflow) with a simpler approach of forming a planarization member through standard thin film deposition techniques. This substitution maintains surface uniformity while significantly reducing manufacturing process complexity
Solution Approach 2:
Instead of using complex planarization processes that require precise control of mechanical or thermal parameters, the patent changes the approach by controlling the deposition parameters of the planarization member to achieve the desired surface uniformity through material selection and deposition conditions rather than post-formation processing
3Ease of manufacture
If the light emitting layer is made of soluble materials to simplify manufacturing, then the ease of manufacture is improved, but the non-uniform thickness problem is exacerbated due to surface height differences
Solution Approach 1:
The planarization member is formed in advance to create a flat surface before depositing the soluble light emitting materials. This preliminary action eliminates the surface height differences that would otherwise cause non-uniform thickness, allowing soluble materials to be applied using simple solution-based techniques while maintaining uniform film formation
Solution Approach 2:
The planarization member serves as an intermediary flat surface that enables the uniform application of soluble light emitting materials. It mediates between the uneven substrate and the solution-based deposition process, ensuring that the soluble materials form a uniform layer despite the underlying structural variations
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 ensures a uniform light emission layer, enhances the aperture ratio, and increases the luminance of the OLED display while preventing degradation and extending its lifespan.
Implementation Method 1
a method involving chemical mechanical polishing or thermal reflow to ensure a uniform surface
Implementation Method 2
a method involving chemical mechanical polishing or thermal reflow to ensure a uniform surface
Implementation Method 3
combined with the use of a sealing member to prevent moisture ingress
Implementation Method 4
The injected electrons and holes are combined to form excitons, and the excitons emit light as discharge energy upon changing its energy state
Data Source
AI summary
An organic light emitting diode display with enhanced luminance and light uniformity is presented, along with a method of manufacturing the display. The display including: a substrate, a first signal line formed on the substrate and a second signal line extending perpendicularly to the first signal line, and thin film transistors formed on the substrate and electrically coupled to the first signal line and the second signal line. A planarization member is formed on the same layer as the first signal line and/or the second signal line, such that it does not overlap the first signal line, the second signal line, and the thin film transistors. An insulating layer is formed on the first signal line, the second signal line, the thin film transistors, and the planarization member. Two electrodes are formed on the insulating layer connected to one of the thin film transistors and sandwiching a light emitting member.