Imprint Apparatus Position-Load Control for Mold Pressing
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Solution Overview
Problem
The nano-imprinting technique faces challenges in reducing the time required for the mold pressing step while maintaining dimensional accuracy and preventing mold damage from shocks, especially when using UV-curable resins and glass molds that are vulnerable to shocks.
Innovation Solution
An imprint apparatus with a driving device, measuring device, and controller that controls the mold movement using position control initially and load control after contact to achieve faster and controlled mold pressing, ensuring precise force application and reducing the risk of mold damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the moving speed of the mold or substrate is increased to quicken the mold pressing step, then the time for mold pressing is reduced, but a large shock is generated at contact which may destroy the mold
Solution Approach 1:
The mold pressing step is divided into two distinct phases: a rapid movement phase to minimize time loss, and a controlled contact phase to prevent shock. The controller switches between position control during rapid movement and load control during contact, effectively segmenting the process to achieve both speed and safety.
Solution Approach 2:
The control method dynamically adjusts the control parameter based on the pressing stage. Initially, position is the controlled variable for fast movement, then automatically switches to load control when contact is detected. This dynamic adaptation allows the system to optimize for speed when safe and for protection when needed.
2Reliability
If the mold is slowly brought close to the resin to prevent shock, then mold damage is prevented, but the time necessary for mold pressing step increases
Solution Approach 1:
The pressing motion is segmented into a fast approach phase and a controlled contact phase. The controller detects contact and switches from position control to load control, ensuring that only the necessary portion of the movement is slowed down, while the majority can proceed at high speed.
Solution Approach 2:
The load sensor provides real-time feedback on the pressing force. When the sensor detects contact between mold and resin, it triggers a switch in control mode from position-based to load-based control, enabling automatic adaptation that prevents shock without requiring manual intervention or complete speed reduction.
3Device complexity
If position control is used throughout the mold pressing step, then the control is simple, but the pressing force cannot be maintained constant which reduces pattern dimensional accuracy
Solution Approach 1:
The control system dynamically switches between position control and load control based on the pressing stage. During the approach phase, position control maintains simplicity and speed. Upon contact detection, the system transitions to load control to maintain constant pressing force, ensuring pattern dimensional accuracy without requiring complex control throughout the entire process.
Solution Approach 2:
The load sensor provides feedback that triggers a switch in control strategy. This feedback mechanism allows the system to maintain constant pressing force during the critical contact phase, improving manufacturing precision while keeping the overall control system relatively simple by using automatic detection rather than continuous complex control.
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 approach allows for a significant reduction in the time needed for the mold pressing step while maintaining the accuracy of the resin pattern transfer and preventing damage to the mold, enhancing the throughput and reliability of the nano-imprinting process.
Implementation Method 1
a measuring device configured to measure a position of at least one of the mold and the substrate
Implementation Method 2
a detector configured to detect the pressing force
Implementation Method 3
The optical curing method irradiates an ultraviolet (UV)-curable resin with ultraviolet (UV) light through a transparent mold in a pressed state of the mold to cure the UV-curable resin
Implementation Method 4
The thermal cycle method heats a resin (thermoplastic resin) to a glass transition temperature or more to increase fluidity of the resin
Implementation Method 5
Japanese Patent Laid-Open No. 2004-288811 discloses a technique for increasing fluidity of a resin by ultrasonically vibrating a mold to lower viscosity of the resin
Data Source
AI summary
The imprint apparatus presses resin disposed on a substrate and a mold to each other to form a resin pattern on the substrate. The apparatus includes a driving device configured to move the mold and the substrate relatively to apply a pressing force between the mold and the resin, a measuring device configured to measure a position of at least one of the mold and the substrate, a detector configured to detect the pressing force, and a controller configured to control the driving device. The controller is configured to control the driving device using the position as a controlled variable in a first period, and to control the driving device using the pressing force as a controlled variable in a second period after the first period.