Display Partition Wall Exposure Using Visible Alignment Keys
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Solution Overview
Problem
The challenge in manufacturing display devices with quantum dot layers is that the alignment keys formed on the substrate are not recognized during the exposure process due to the presence of a scattering material in the partition wall structure, which affects the formation of openings in the partition wall structure.
Innovation Solution
A method involving the formation of first alignment keys on a mother substrate, rotating it at a preset angle, and using a photoresist that does not overlap these keys, allowing for precise mask alignment and subsequent formation of partition walls without residual films, thereby enhancing luminance and reducing process time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If scattering material is added to the partition wall structure to increase luminance, then luminance is improved, but alignment keys cannot be recognized during exposure process
Solution Approach 1:
The partition wall structure is segmented into two functional zones: a first region containing scattering material (titanium dioxide) for luminance enhancement, and a second region without scattering material for alignment key recognition. This spatial segmentation allows both functions to coexist without interference.
Solution Approach 2:
Different regions of the partition wall structure are assigned different material compositions: the first region has scattering material for light diffusion and luminance improvement, while the second region has transparent material for clear alignment key visibility during exposure. Each region has optimized local quality for its specific function.
2Ease of manufacture
If photoresist overlaps alignment keys to form partition walls, then manufacturing process is simplified, but alignment keys cannot be recognized for mask alignment
Solution Approach 1:
The photoresist coating process is segmented into two sequential steps: first coating the photoresist to cover the alignment keys, then removing the photoresist from the alignment key regions. This segmentation allows the alignment keys to serve their alignment function while still being covered during the coating process.
Solution Approach 2:
The alignment keys are prepared in advance with a specific material composition that prevents photoresist adhesion or allows easy removal. This preliminary preparation ensures that when photoresist is coated, it can be selectively removed from alignment key regions without affecting the coating on the partition wall structure.
3Manufacturing precision
If multiple exposure passes are used to form partition walls without residual films, then manufacturing precision is improved, but process time increases
Solution Approach 1:
The partition wall structure has non-uniform scattering material distribution: higher concentration in the first region for luminance, lower or zero concentration in the second region for clean exposure. This local quality variation enables single-pass exposure to achieve both functional requirements without residual films.
Solution Approach 2:
The scattering material concentration is adjusted as a parameter to achieve different exposure characteristics in different regions. By optimizing the scattering material distribution, the exposure process can complete in a single pass with proper film formation, eliminating the need for multiple passes.
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 method ensures easy recognition of alignment keys, increases luminance by allowing more titanium dioxide in the photoresist, and reduces process time by enabling exposure in a single pass.
Implementation Method 1
A photoresist is formed in a second direction on the first and second light emitting structures by using a coater such that the photoresist does not to overlap the first alignment keys
Implementation Method 2
the partition wall structure may further include a scattering material in order to increase a luminance of the display device
Data Source
AI summary
A method of manufacturing a display device includes providing a mother substrate including a first cell region, a second cell region, and a peripheral region. First alignment keys arranged in a first direction in the peripheral region on the mother substrate is formed such that the first alignment keys are adjacent to a first side portion of each of first and second light emitting structures, while forming the first and second light emitting structures in the first and second cell regions on the mother substrate, respectively. A photoresist is formed in a second direction on the first and second light emitting structures by using a coater such that the photoresist does not to overlap the first alignment keys. The mother substrate is rotated at a preset angle. A light is irradiated to the photoresist by moving an exposer in a direction in which the first alignment keys are arranged.