Mask Assembly for Thin Film Deposition Alignment
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Solution Overview
Problem
In thin film deposition for display apparatuses, existing mask assemblies often deform under pressure, leading to misalignment with substrates and imprecise patterning due to the need for a mask frame, which causes alignment issues during the deposition process.
Innovation Solution
A mask assembly comprising a glass mask with patterned metal layers on both surfaces, featuring deposition areas with slits and a support structure to maintain alignment, eliminating the need for a mask frame and allowing precise deposition patterns without thermal deformation-induced positional changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mask frame is used to hold the mask, then the mask can be mounted and maintained, but the mask deforms under pressure causing misalignment
Solution Approach 1:
The invention removes the mask frame structure entirely and directly mounts the mask onto the substrate. This extraction of the frame eliminates the source of deformation while maintaining the necessary mounting function through direct contact between the mask and substrate edge.
Solution Approach 2:
Instead of mounting the mask on a frame and then positioning the frame on the substrate, the invention inverts the approach by directly mounting the mask on the substrate edge. This reversal eliminates the intermediate frame structure that causes alignment issues.
2Strength
If pressure is applied to mount the mask, then the mask is secured to the substrate, but the mask deforms and becomes misaligned
Solution Approach 1:
The invention removes the frame structure that distributes mounting pressure across the mask, instead applying pressure directly at the mask-substrate interface. This eliminates the deformation pathway while maintaining secure mounting through direct contact.
Solution Approach 2:
The invention applies mounting pressure locally at the mask edge where it contacts the substrate, rather than distributing pressure across a frame structure. This localized pressure application secures the mask without causing deformation of the deposition pattern areas.
3Ease of operation
If a mask frame structure is used, then the mask can be handled and positioned, but thermal deformation causes positional changes
Solution Approach 1:
The invention removes the frame structure that is susceptible to thermal expansion and contraction, eliminating the source of thermally-induced positional changes. The mask is handled and positioned directly on the substrate without the intermediate frame structure.
4Productivity
If openings are made larger on the deposition surface, then deposition material can be deposited, but the mask structure becomes weaker
Solution Approach 1:
The invention creates localized openings only in the deposition areas where material needs to pass through, while maintaining the mask structure in non-deposition areas. This localized approach ensures adequate deposition material flow where needed while preserving structural integrity in the surrounding areas.
Solution Approach 2:
The invention transitions from a two-dimensional planar mask structure to a three-dimensional structure with varying thickness, having thicker portions in non-deposition areas for strength and thinner portions with openings in deposition areas for material flow.
Data Source
AI summary
A mask assembly for thin film deposition and a method of manufacturing the same. The mask assembly includes a glass mask having a first surface and a second surface opposite the first surface, a first metal layer patterned above the first surface of the glass mask, and a second metal layer patterned below the second surface of the glass mask. A plurality of deposition areas are arranged on the glass mask, and a plurality of deposition pattern portions each having a plurality of slits are patterned in the plurality of deposition areas.