Rotary Drum Substrate Apparatus Scale Alignment
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Solution Overview
Problem
Existing substrate processing apparatuses face challenges in accurately measuring the position of cylindrical masks and substrates, leading to potential misalignment and errors in pattern exposure, particularly when the optical reading head and scale disk are not aligned optimally, affecting the precision of pattern transfer and alignment processes.
Innovation Solution
The apparatus includes a rotary cylindrical member with a scale member that rotates with the cylindrical member, featuring a ring-shaped scale portion and a reading mechanism positioned to accurately read the scale portion, ensuring high-precision position measurement and alignment by minimizing calculation load and Abbe errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the optical reading head and scale disk are not aligned optimally (with gap changes), then the encoder system cannot measure misalignment, but the cylindrical mask and substrate cause relative misalignment leading to pattern exposure errors
Solution Approach 1:
The patent introduces a second reading head arranged in a different dimensional orientation (radial direction) compared to the first reading head (axial direction). This multi-dimensional measurement approach allows the system to detect misalignment in directions that a single reading head cannot capture, thereby resolving the measurement blind spot caused by suboptimal alignment between the optical reading head and scale disk.
Solution Approach 2:
The scale disk serves as an intermediary measurement element that rotates with the cylindrical mask. By reading the scale disk from multiple directions using multiple reading heads, the system indirectly measures the positional relationship between the mask and substrate, converting the complex alignment problem into a measurable scale disk rotation and position problem.
2Measurement precision
If multiple reading heads are used to measure position from different directions, then measurement accuracy improves, but device complexity increases
Solution Approach 1:
The scale disk is designed to serve multiple functions simultaneously: it provides measurement references for multiple reading heads, rotates with the cylindrical mask to enable dynamic measurement, and maintains a fixed radial position that allows both axial and radial reading heads to access it. This multi-functionality reduces the need for separate measurement systems for each reading head, thereby controlling device complexity while achieving high measurement precision.
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
This configuration enables high-accuracy processing and pattern transfer on substrates by accurately detecting the target position, reducing positional errors and enhancing processing precision while maintaining a low calculation load.
Implementation Method 1
a reading mechanism that is arranged to face the scale portion, that is disposed in substantially a same direction as the specific position when viewed from the center line, and that is configured to read the scale portion
Data Source
AI summary
A pattern forming apparatus comprising: a rotary drum that includes a cylindrical outer circumferential surface which is curved at a predetermined radius from a predetermined center line, that rotates about the center line in a state in which a part of a sheet substrate is supported in a length direction of the sheet substrate along the outer circumferential surface; a pattern forming part that forms the pattern on the sheet substrate at a first specific position; a scale disk that is fixed to an end portion of the rotary drum in a direction in which the center line extends while being coaxial with the center line and that includes a circular scale; and a first reading mechanism that is arranged to oppose with the scale formed at the outer circumferential surface of the scale disk, that is arranged at substantially same azimuth as an azimuth.