Both-Sides Coating Head With Gas Support for Substrate Flatness
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Solution Overview
Problem
Conventional both-sides coating apparatuses face challenges in maintaining substrate position and flatness while applying coatings to both sides, leading to non-uniform film thickness and potential particle generation due to substrate and nozzle friction during transportation.
Innovation Solution
A both-sides coating apparatus with a conveying mechanism, a first die for applying a first coating material, a second die for applying a second coating material, and a support unit that uses gas transfer to maintain the substrate at a target coating height, preventing substrate deflection and vibration, and reducing particle generation by supporting the substrate with a combination of gas discharge and suction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the substrate is suspended in air during second coating application, then the coating can be applied to both sides, but the substrate position and flatness cannot be maintained
Solution Approach 1:
The patent employs a suction roll with suction holes to create negative pressure between the roll surface and the substrate. This pneumatic mechanism holds the substrate against the roll surface, maintaining its position and flatness during the coating process. The suction force counteracts the substrate's weight and prevents deflection, enabling precise coating while allowing both-sides coating capability.
2Manufacturing precision
If the substrate is supported by the backup roll during first coating application, then the substrate position is maintained, but the second coating cannot be applied when the first coating is undried
Solution Approach 1:
The system dynamically switches the support mechanism for the substrate. During the first coating application, the backup roll supports the substrate. When transitioning to the second coating application, the substrate is transferred to the suction roll which uses pneumatic suction to maintain support. This dynamic transition enables continuous coating operation without requiring the first coating to dry, improving both-sides coating capability.
3Manufacturing precision
If the nozzle portion contacts the substrate for support, then substrate deflection and vibration are suppressed, but particles are generated due to friction
Solution Approach 1:
The suction roll uses pneumatic suction through suction holes to hold the substrate without mechanical contact between the support surface and the substrate. This eliminates friction that would otherwise generate particles. The negative pressure created by the suction mechanism is sufficient to maintain substrate position and flatness, ensuring coating film uniformity while preventing particle generation.
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 apparatus ensures accurate positioning and flatness of the substrate, suppressing deflection and vibration, and preventing particle generation, resulting in a more uniform and higher-quality coating film.
Implementation Method 1
supports the substrate at a target coating height at which the second surface is separated from the second die by a predetermined amount through gas transfer that includes discharge of gas to the second surface and suction of gas interposed between the support unit and the second surface
Data Source
AI summary
A both-sides coating apparatus includes: a conveying mechanism that continuously conveys a substrate having a first surface and a second surface; a first die that applies a first coating material to the first surface; a second die that applies a second coating material to the second surface; and a support unit that is fixed to the outer surface of the second die and that supports the substrate at a target coating height through gas transfer that includes discharge of gas and suction of gas.