Deposition Mask Structure for Low-Warpage Display Patterning
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Solution Overview
Problem
Wearable devices such as HMDs and AR glasses require high-resolution displays with at least 2000 pixels per inch, but existing deposition masks suffer from stress and warpage issues due to differences in physical properties between the mask substrate and thin films, leading to damage during deposition and cleaning processes.
Innovation Solution
A deposition mask design with a substrate, mask membrane, and dummy inorganic film patterns that include lip openings and outer frame regions, reducing stress and warpage by allowing controlled exposure of the substrate surface, and a manufacturing method that uses this mask to form display panel patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a deposition mask uses a substrate with thin films stacked on it, then the mask can support high-resolution display patterns, but stress and warpage occur due to physical property differences between the substrate and thin films
Solution Approach 1:
The mask structure is divided into multiple functional regions: a mask membrane region containing the actual deposition patterns, a dummy inorganic film pattern region for stress compensation, and a lip opening region for substrate exposure. This segmentation allows each region to serve its specific function while collectively reducing overall stress and warpage.
Solution Approach 2:
Different regions of the mask are assigned different properties and functions. The mask membrane region provides high-resolution patterning capability, while the dummy inorganic film pattern region provides stress compensation. The lip opening region provides substrate exposure. This local differentiation allows the mask to simultaneously achieve high resolution and reduced stress.
2Reliability
If the mask structure is made more complex to reduce stress and warpage, then mask reliability improves, but device complexity increases
Solution Approach 1:
The dummy inorganic film pattern region serves itself by providing stress compensation through its inherent physical properties. The structure automatically compensates for stress without requiring external control mechanisms or complex active components, thereby improving reliability while maintaining relatively simple construction.
Solution Approach 2:
The mask design utilizes changes in physical parameters (such as the presence of dummy inorganic film patterns with different thermal and mechanical properties) to achieve stress compensation. By carefully selecting and arranging these dummy patterns, the mask achieves improved durability without requiring complex active control systems.
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
Reduces stress and warpage in the deposition mask, minimizing damage during the deposition and cleaning processes, thereby improving the reliability and longevity of high-resolution display panel production.
Implementation Method 1
a deposition mask capable of reducing stress caused by a difference in physical properties between a substrate of the mask and a thin film stacked on the substrate, and reducing warpage, which is a bending characteristic of the mask
Data Source
AI summary
A deposition mask includes a substrate including a plurality of cell regions, a mask lip region partitioning the plurality of cell regions, and an outer frame region disposed at an outer edge of the plurality of cell regions; a mask membrane defined by an inorganic film pattern which is a portion of an inorganic film formed on the substrate and disposed to correspond to the plurality of cell regions; and a dummy inorganic film pattern which is a remaining portion of the inorganic film except for the inorganic film pattern, where the dummy inorganic film pattern includes a first dummy inorganic film pattern disposed in the mask lip region, and a second dummy inorganic film pattern disposed in a portion of the outer frame region, and the first dummy inorganic film pattern includes a lip opening exposing a surface of the substrate in the mask lip region.