Deposition Mask Bridge Pattern for Warpage and Pixel Accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wearable devices such as HMDs and AR glasses require high-resolution displays with at least 2000 PPI, but existing deposition masks suffer from warpage due to differences in physical properties between thin films, leading to bending and reduced pixel position accuracy during the deposition process.
Innovation Solution
A deposition mask with a bridge structure where an inorganic layer is patterned to surround the mask membrane, minimizing stress and warpage by forming a bridge pattern around the outer edge, thereby improving pixel position accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple thin films are stacked on the mask substrate, then the mask can perform deposition functions, but stress differences cause warpage and bending
Solution Approach 1:
The mask structure is segmented into multiple functional layers (first inorganic layer, second inorganic layer, organic layer) with distinct stress characteristics. The bridge structure divides the mask into multiple regions (cell regions and mask lip region), allowing differential stress management across segments to prevent overall warpage
Solution Approach 2:
The bridge structure is specifically positioned in the mask lip region surrounding the cell openings, providing localized stress compensation where needed. The first inorganic layer forms a bridge pattern with specific width in this region, creating local structural reinforcement that counteracts stress-induced warpage without affecting the entire mask uniformly
2Manufacturing precision
If the mask membrane is made thin for high-resolution deposition, then pixel position accuracy improves, but stress and warpage increase
Solution Approach 1:
The mask employs a composite structure combining multiple inorganic layers and an organic layer, each with different mechanical properties. This composite architecture allows the thin mask membrane to maintain high pixel position accuracy while the layered structure and bridge regions provide stress distribution and warpage prevention
Data Source
AI summary
A mask and a deposition equipment including the same are provided. The deposition mask comprises a substrate comprising cell regions, a mask lip region dividing the cell regions, and a plurality of cell openings corresponding to the plurality of cell regions, a first inorganic layer disposed on the substrate, and a second inorganic layer disposed on the first inorganic layer, the second inorganic layer is patterned in the cell regions to form a mask membrane, and the first inorganic layer is patterned in the mask lip region to form a bridge pattern having a first width and surrounding an outer edge portion of the mask membrane.