Recirculation Spin Coater with Optical Controls
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Solution Overview
Problem
Existing spin coaters fail to effectively minimize coating material loss and adequately address work piece positioning and spin coater controls, particularly in a closed environment, which is crucial for manufacturing optical lenses.
Innovation Solution
A recirculation spin coater system with a substantially closed spin coating bowl, a recirculation drain for material recovery, and a vision system for optical controls, along with an annular array of light sources and a wetting fluid chamber to maintain a solvent-rich environment and prevent material loss, is developed. The system includes a coating nozzle with operable positions for dispensing and purging, and a rotating work piece holding chuck for precise alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If a closed spin coating bowl is used to maintain solvent-rich environment, then coating material loss is reduced, but illumination for optical controls becomes difficult
Solution Approach 1:
A translucent barrier (such as a translucent cap or wall) is introduced as an intermediary between the closed bowl environment and the external light sources. This barrier allows light to pass through while maintaining the closed solvent-rich environment, enabling both material loss reduction and adequate illumination for optical controls
2Loss of substance
If recirculation system is implemented to recover coating material, then material loss is minimized, but device complexity increases
Solution Approach 1:
The system implements a recirculation mechanism that captures coating material mist and solvent vapor, condenses it back to liquid form, and returns it to the coating material reservoir. This recovery process minimizes material loss while the integrated design keeps the added complexity manageable
3Loss of substance
If substantially closed bowl structure is used to prevent material loss, then coating material loss is reduced, but work piece access and positioning becomes more difficult
Solution Approach 1:
The closed bowl structure is segmented with a removable or movable access port that allows work piece insertion and removal. The access port can be opened only when needed for loading/unloading, and remains closed during the coating process to maintain the solvent-rich environment and minimize material loss
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 system significantly reduces coating material loss, ensures consistent coating application, and provides precise work piece alignment, enhancing the efficiency and cost-effectiveness of the spin coating process while maintaining a solvent-rich environment.
Implementation Method 1
an annular array of light sources surrounding sides of the spin coating bowl and configured to illuminate the interior of the spin coating bowl for optical controls
Implementation Method 2
The spin coating bowl has a recirculation drain that is configured to allow coating material to be recovered from the spin coating bowl and return the recovered coating material to the source of coating material
Implementation Method 3
a wetting fluid chamber associated with an upper end of the inner side walls and configured to dispense a side wall wetting fluid to the inner side walls of the spin coating bowl at least during operation of the nozzle
Implementation Method 4
Spin coating processes and associated spin coating machines are well known for efficiently providing a uniform coating to a substrate work piece
Data Source
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AI summary
A recirculation spin coater system includes a spin coating bowl with a having a recirculation drain and a wetting fluid chamber associated with the upper end of the inner side walls wherein the wetting fluid chamber is configured to dispense a side wall wetting fluid to inner side walls of the spin coating bowl. A vision system configured to capture images of the work piece within the spin coating bowl for quality control and work piece positioning. An annular array of light sources are surrounding sides of the spin coating bowl and are configured to illuminate the interior of the spin coating bowl for optical controls. The vision system may be utilized for both quality control and work piece positioning. The coating nozzle is configured to move between a first coating position vertically aligned with the work piece, and a second purge position vertically aligned with the recirculation drain.