OLED Display Substrate Corner Limit Mark Group for Vapor Deposition Alignment
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Solution Overview
Problem
Existing OLED display devices face challenges in accurately detecting the alignment of organic film layers during vapor deposition, leading to display defects and inaccuracies, especially when the alignment region is positioned outside the display area or becomes separated after slicing the motherboard.
Innovation Solution
A display substrate with a non-display area featuring a limit mark group at the corner part, including rounded chamfers and an epitaxial film layer with through holes, allows for precise detection of vapor deposition offsets by defining theoretical vapor deposition zones and alignment patterns, reducing the influence on signal lines and improving detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the alignment region is disposed on the display substrate at the sides of the display area, then the vapor deposition alignment can be detected, but the displaying effect is deteriorated
Solution Approach 1:
The alignment region is extracted from the display area and relocated to the non-display area, specifically to the corner parts. This separation allows the alignment detection function to be maintained while eliminating the negative impact on the displaying effect, as the alignment region no longer occupies or interferes with the display area.
Solution Approach 2:
The alignment region is moved from a position adjacent to the display area (1D boundary) to the corner parts (2D non-display area), utilizing the non-display area as a new spatial dimension for alignment detection. This dimensional relocation resolves the conflict between detection needs and display quality.
2Area of stationary object
If the alignment region is disposed on the vacant area between adjacent display substrate areas on the motherboard, then space is saved, but the alignment pattern cannot accurately characterize the alignment state after slicing
Solution Approach 1:
The alignment region is preliminarily positioned in the corner parts of the non-display area on each display substrate before slicing. This preliminary positioning ensures that after the motherboard is sliced into separate display substrates, each substrate retains its alignment region with the limit mark group, enabling accurate alignment state characterization without requiring the original motherboard context.
Solution Approach 2:
The alignment detection system is segmented into independent units, with each display substrate containing its own alignment region and limit mark group in the corner parts. This segmentation allows each substrate to function independently with full alignment detection capability, eliminating the dependency on the complete motherboard structure.
3Device complexity
If the limit mark group is disposed in the frame part of the non-display area, then the structure is simple, but the detection accuracy is reduced due to distance from the display area
Solution Approach 1:
Instead of symmetrically distributing alignment regions or placing them in the frame part, the limit mark group is asymmetrically positioned specifically in the corner parts of the non-display area. This asymmetric placement optimizes the detection accuracy by positioning the alignment region closer to the display area while maintaining structural simplicity, leveraging the corner geometry for enhanced precision.
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 enhances the accuracy of pixel position alignment and reduces display defects by minimizing the impact on signal lines and allowing for precise monitoring of vapor deposition effects, thereby improving the quality and display effect of OLED devices.
Implementation Method 1
A light emitting unit is disposed in each of the pixel regions of the Organic Light-Emitting Device (OLED) display device. The light emitting unit includes a plurality of organic film layers which are formed by a vapor deposition process.
Data Source
AI summary
Disclosed is a display substrate, comprising a display area and a non-display area surrounding the display area. At least one limit mark group is disposed in the non-display area; the display area has a plurality of sides, and rounded chamfers are formed between adjacent two sides; the non-display area includes a frame part opposite to the sides of the display area and corner parts opposite to the rounded chamfers; and the limit mark group is located at the corner part. Accordingly, the disclosure also provides an organic light emitting device, a film vapor-deposition detecting method of an organic light emitting device, and a display device. According to the disclosure, it is possible to reduce the display defect and the accuracy of film vapor-deposition detection.