Exposure Mask Inspection Patterns for Shot Boundary Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In the manufacturing of large display devices, alignment errors such as shift, rotation, and distortion occur at the boundaries of divided shot areas during the exposure process, leading to deteriorated electrical characteristics and display quality issues.
Innovation Solution
An exposure mask with a base layer featuring first and second inspection transmission patterns arranged in ring and polygonal or circular shapes, respectively, allowing for the formation of inspection resist patterns that facilitate detection of alignment errors, preventing process defects like island patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the substrate is divided into multiple shot areas for exposure, then the manufacturing of large display devices becomes feasible, but alignment errors occur at the boundaries between shot areas
Solution Approach 1:
The patent applies preliminary action by pre-defining inspection patterns (ring-shaped and polygonal/circular patterns) on the exposure mask before the actual exposure process. These patterns are positioned at the boundaries between shot areas to proactively detect alignment errors. By preparing these reference patterns in advance, the system can verify alignment accuracy at stitch areas before producing the final display device patterns, thus preventing alignment errors from affecting manufacturing precision.
2Reliability
If alignment errors occur at shot area boundaries, then electrical characteristics deteriorate, but adding inspection patterns increases device complexity
Solution Approach 1:
The patent applies segmentation by dividing the inspection functionality into distinct pattern types: ring-shaped inspection patterns and polygonal/circular inspection patterns. These segmented patterns are strategically placed at different locations on the exposure mask to independently verify alignment in various regions. This segmentation allows for targeted alignment verification without requiring a complete redesign of the entire exposure mask structure, thus maintaining reliability while managing complexity.
Solution Approach 2:
The patent uses copying by creating simplified reference patterns (ring-shaped and polygonal patterns) that replicate the essential geometric features needed for alignment verification. These copied patterns serve as reference copies of the expected alignment geometry, allowing the system to detect deviations without incorporating complex electrical testing structures directly into the exposure mask.
3Ease of manufacture
If traditional exposure masks are used without inspection patterns, then the exposure process is simple, but alignment errors cause stains and display quality deterioration
Solution Approach 1:
The patent applies self-service by enabling the exposure mask to perform its own alignment verification function through the integrated inspection patterns. The ring-shaped and polygonal patterns on the mask allow the system to self-check alignment accuracy at stitch areas during the exposure process. This self-verification capability is built into the mask structure itself, eliminating the need for separate, complex external alignment verification systems while maintaining ease of manufacture.
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 exposure mask enables accurate alignment verification, ensuring high-quality display manufacturing by preventing alignment errors and process defects, thereby maintaining electrical characteristics and display quality.
Implementation Method 1
matching an exposure mask on the first shot area of the substrate and exposing the first photoresist layer using the exposure mask
Implementation Method 2
exposing the first photoresist layer using the exposure mask, developing the first photoresist layer to form a first inspection resist pattern
Data Source
AI summary
An exposure mask includes a base layer including a first area and a second area spaced apart from a first area in a first direction, a first inspection transmission pattern defined in a first area of a base layer and arranged in a ring shape having at least one connection part in plan view, and a second inspection transmission pattern defined in a second area of a base layer and arranged in a polygonal shape or a circular shape in plan view.