Fine Metal Mask Plate Buffer-Hole Layout for Wrinkle-Free Stretching
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Solution Overview
Problem
In the semiconductor manufacturing process, particularly during the photolithography step for fabricating OLED displays, fine metal mask plates often develop wrinkles when stretched, affecting the flatness of the evaporation area and subsequently the quality of the deposited organic light emitting material.
Innovation Solution
A mask plate design featuring two opening areas with buffer holes and welding areas, where the buffer holes are significantly larger than the evaporation holes and arranged in a specific pattern to alleviate stress and prevent wrinkles, combined with a method of fabricating the mask plate using electroplating and laser cutting processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the mask plate is stretched to fit the substrate, then the mask plate can be mounted and used, but wrinkles appear on the mask plate surface affecting flatness
Solution Approach 1:
The mask plate is divided into multiple regions with different hole patterns: a first region with evaporation holes for patterning, and a second region with larger buffer holes for stress relief. This segmentation allows different parts of the mask plate to serve different functions - the evaporation holes maintain the mask pattern while the buffer holes accommodate stretching without causing wrinkles.
Solution Approach 2:
Different regions of the mask plate are given different local properties through varying hole sizes and distributions. The first region has smaller evaporation holes optimized for precise patterning, while the second region has larger buffer holes optimized for stress distribution. This local differentiation allows the mask plate to maintain flatness in the patterning region while accommodating stretching in the buffer region.
2Ease of manufacture
If the mask plate structure is simplified, then manufacturing is easier, but stress distribution during stretching becomes uneven causing wrinkles
Solution Approach 1:
Buffer holes are pre-designed and pre-positioned in the mask plate structure before the stretching process occurs. These holes are strategically located in regions that will experience stress during mounting and stretching, allowing the stress to be distributed evenly from the beginning rather than requiring complex real-time adjustments during the stretching process.
3Stress or pressure
If buffer holes are made larger to improve stress distribution, then wrinkle formation is reduced, but the ratio of buffer hole size to evaporation hole size becomes excessively large
Solution Approach 1:
The invention optimizes the size parameters of both evaporation holes and buffer holes to achieve a balanced ratio. The buffer holes are made sufficiently large to provide effective stress distribution (with a diameter of 0.5-5 mm), while evaporation holes are maintained at appropriate sizes for precise patterning (with a diameter of 1-100 μm). The ratio is controlled to be between 10:1 and 100:1, which is sufficiently large to provide stress relief but not so large as to create unnecessary structural complexity or waste material.
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 design ensures a smooth stress transition and reduces wrinkle defects in the mask plate, maintaining the flatness of the evaporation area and enhancing the quality of the deposited material, thereby improving the semiconductor manufacturing process.
Implementation Method 1
a ratio of a maximum dimension of each of the buffer holes in any direction in a plane where the mask plate is located to a maximum dimension of each of the plurality of evaporation holes in the direction is greater than 100, the plurality of buffer holes are distributed at equal intervals along a second direction
Implementation Method 2
a method for fabricating the mask plate using electroplating and laser cutting processes
Implementation Method 3
a method for fabricating the mask plate using electroplating and laser cutting processes
Data Source
AI summary
The present application provides mask plate, fabrication method thereof, and mask plate assembly. The mask plate includes two opening areas being respectively on different sides of mask pattern area along first direction, and two welding areas. One welding area is on a side of one opening area away from the mask pattern area along first direction, and the other welding area is on a side of the other opening area away from mask pattern area along first direction. Evaporation holes are arranged in mask unit, buffer holes are arranged in each opening area, and ratio of maximum dimension of buffer hole in any direction in plane where the mask plate is located to maximum dimension of evaporation hole in the direction is greater than 100. Buffer holes are distributed at equal intervals along a second direction, and second direction is in the plane and is perpendicular to first direction.