Substrate Coating Bead Removal via Underflow Gas Flow
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Solution Overview
Problem
The existing methods for coating substrates using rotation methods often result in a bead formation at the edge of the substrate due to centrifugal forces, which requires manual removal or solvent use, increasing production costs and risk of impurities.
Innovation Solution
A method involving a gas flow directed from the underside to the upper side of the substrate to prevent or remove the bead, utilizing a gas flow that generates a negative pressure to draw the coating material away from the edge, ensuring a homogeneous coating without directly impairing the coated surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a rotation method is used to apply coating material to the substrate, then the coating material is distributed evenly on the surface of the substrate, but a bead of coating material forms on the edge of the upper side of the substrate due to centrifugal force
Solution Approach 1:
A gas flow is introduced as an intermediary substance between the coating material and the substrate edge. The gas flow acts as a mediator that prevents the coating material from accumulating at the edge by exerting a counteracting force, thereby eliminating bead formation without interfering with the overall coating uniformity achieved by rotation
Solution Approach 2:
The invention utilizes a gas flow (pneumatic approach) directed at the coating material or substrate edge to counteract the centrifugal force causing bead formation. The gas flow creates a pressure differential that prevents coating material accumulation at the periphery while maintaining central coating uniformity
2Object-generated harmful factors
If manual removal or solvent is used to remove the coating bead, then the bead is removed from the substrate, but the production cost increases and impurities may be introduced
Solution Approach 1:
The gas flow is applied during the coating process itself to prevent bead formation before it becomes a problem requiring removal. This preliminary preventive action eliminates the need for subsequent removal steps, simplifying the production process and avoiding contamination from solvents or manual handling
Solution Approach 2:
The invention converts the harmful centrifugal force that causes bead formation into a beneficial process by using a gas flow to counteract it in real-time. The gas flow transforms the potential defect into an opportunity for process optimization, eliminating the need for additional removal operations and reducing overall process complexity
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 effectively prevents bead formation during the coating process, eliminating the need for subsequent removal steps and maintaining a homogeneous, defect-free surface, thereby reducing production costs and ensuring consistent coating quality.
Implementation Method 1
the gas flow generates a pressure on the coating material to prevent the formation of a bead and to push away the coating material of a bead already formed
Implementation Method 2
a gas flow is generated that is directed from the underside of the substrate to the upper side of the substrate
Implementation Method 3
the coating is pushed radially outwards as a result of the centrifugal force when rotating the substrate
Data Source
AI summary
Method for coating a substrate with a coating material is described, in particular with a coating or photoresist, wherein said substrate is provided in said method. Said coating material is applied to said upper side of said substrate. A gas flow is generated, said gas flow being directed from said underside of said substrate to said upper side of said substrate, wherein said gas flow prevents a bead of said coating material forming on said edge of said upper side of said substrate or a previously existing bead is removed by means of said gas flow. In addition, a coating system is described.