Fine Metal Mask Alignment Holes for Precise OLED Evaporation
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Solution Overview
Problem
Current evaporation technologies face challenges in achieving precise alignment between fine metal masks and OLED substrates during the formation of organic material layers, leading to inaccuracies in pixel position alignment, which affects the yield and quality of OLED display panels.
Innovation Solution
The use of three fine metal masks with alignment holes outside the pattern region, matching the arrangement and shape of the openings, allows for accurate tensioning and alignment with corresponding alignment marks on the OLED substrate, enhancing the alignment accuracy and stability of the masks on the mesh frame.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If alignment holes are not provided on the mask, then the pattern region remains clean and simple, but alignment accuracy between mask and substrate deteriorates
Solution Approach 1:
The mask is segmented into two functional regions: the pattern region for pixel formation and the alignment region with separate alignment holes. This segmentation allows the alignment holes to be positioned outside the pattern region, preventing interference with pixel patterns while providing dedicated alignment features for accurate positioning on the substrate.
Solution Approach 2:
Alignment holes serve as intermediary features between the mask and substrate. These holes provide reference points that facilitate precise alignment without directly interfering with the pixel pattern formation process. The alignment holes act as mediators that enable accurate positioning while maintaining the integrity of both mask and substrate patterns.
2Reliability
If multiple mask tensioning positions are provided, then tensioning accuracy and mask stability improve, but mask structure complexity increases
Solution Approach 1:
The alignment holes serve multiple functions: they provide alignment references for positioning the mask on the substrate, and simultaneously serve as tensioning positions for securing the mask. This multi-functionality reduces the need for separate tensioning features, maintaining structural simplicity while improving tensioning accuracy and stability.
Solution Approach 2:
The alignment region and tensioning function are merged into a unified structure. The alignment holes that provide positioning references are also used as tensioning points, combining alignment and securing functions into a single set of features rather than requiring separate mechanisms.
3Ease of operation
If alignment holes are placed inside the pattern region, then alignment marks are easily accessible, but pixel pattern accuracy deteriorates due to interference
Solution Approach 1:
The mask surface is segmented into distinct functional zones: the pattern region for pixel formation and the alignment region for positioning. By placing alignment holes in the alignment region outside the pattern region, the design ensures that alignment operations can be performed easily without the holes interfering with or complicating the pixel pattern structure.
Solution Approach 2:
The alignment features (alignment holes) are extracted from the pattern region and placed in a separate alignment region. This extraction removes potential sources of interference from the pixel pattern area while maintaining easy accessibility for alignment operations, as the alignment holes remain clearly visible and accessible on the mask surface.
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 improves the alignment accuracy and product yield by allowing easy identification and precise positioning of alignment holes with alignment marks, ensuring correct alignment and stable tensioning of the fine metal masks on the mesh frame, thereby improving the overall evaporation process.
Implementation Method 1
the organic material layer with required patterns is formed on the OLED substrate masked by a mask plate with patterns by vacuum evaporation
Data Source
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AI summary
A fine metal mask (100) comprises a pattern region (110) comprising a plurality of openings; and a plurality of alignment holes (120) located outside the pattern region (110). Also disclosed are a display substrate (200) and an alignment method for the fine metal mask (100) for evaporation.