Venturi Gap Turntable for Substrate Back Side Protection
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Solution Overview
Problem
Existing substrate processing devices, particularly spin coaters, often damage or contaminate the back side of double-sided wafers during etching and developing due to the penetration of processing media.
Innovation Solution
A device with a turntable featuring a Venturi gap that uses compressed air to securely hold substrates in place, preventing media from reaching the back side, combined with a gripper system and diffuser for precise positioning and controlled pressure distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a spin coater is used to apply processing medium to substrates, then the substrate can be coated and processed, but the processing medium penetrates the back of the substrate and damages it
Solution Approach 1:
Instead of trying to prevent processing medium from reaching the back side through conventional means, the invention inverts the approach by using suction through the back side to hold the substrate against the turntable. This creates a pressure differential that prevents medium penetration while maintaining secure substrate holding during rotation and processing.
Solution Approach 2:
The invention employs pneumatic principles by using a vacuum or suction system applied to the back side of the substrate through the turntable. This pneumatic holding mechanism creates sufficient adhesion to prevent substrate ejection during rotation while simultaneously preventing processing medium from penetrating to the back side, thus protecting the substrate.
2Stability of the object's composition
If the substrate is held firmly on the turntable during rotation, then the substrate remains stable, but the processing medium can still penetrate and contaminate the back
Solution Approach 1:
The invention uses pneumatic suction applied through the turntable to the back side of the substrate to achieve stable holding during rotation. This pneumatic mechanism creates a pressure differential that both secures the substrate firmly and prevents processing medium from penetrating through to the back side, thus eliminating contamination while maintaining stability.
Solution Approach 2:
The suction force applied to the back side of the substrate acts as a counterbalancing force that prevents both substrate ejection during rotation and medium penetration. This counteracting pneumatic force simultaneously addresses both requirements: stable substrate holding and back side protection from contamination.
3Reliability
If compressed air is delivered through the Venturi gap, then the substrate is held securely and back side is protected, but the device complexity increases
Solution Approach 1:
The invention extracts the substrate holding function from mechanical clamping mechanisms and implements it through pneumatic suction delivered via the Venturi gap in the turntable. This extraction of the holding mechanism into the turntable structure itself, rather than requiring separate complex clamping devices, actually simplifies the overall device while improving reliability of substrate holding and back side protection.
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 solution effectively prevents damage and contamination of the back side of substrates by ensuring the processing medium does not penetrate, while maintaining substrate stability during rotation, leading to improved coating application and drying results.
Implementation Method 1
The turntable has a Venturi gap. Compressed air or another medium is preferably delivered through the Venturi gap. The first advantage is that the substrate is sucked in according to the Venturi principle, is held on the turntable
Implementation Method 2
Another advantage is that the back remains clean and the treatment medium cannot run onto the back and dirty or damage it
Implementation Method 3
the at least one hole is arranged in a central region of the turntable, which faces a substrate. Several holes are preferably arranged in the surface. This has the advantage that a negative pressure or a vacuum is prevented from developing between the turntable and a central region of the substrate. This is advantageous because it prevents the substrate from bending or otherwise deforming in the central region.
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The device has a tray-shaped turntable (1) comprising a Venturi gap (3), and a hole (13) for discharging pressure medium i.e. air. A diffuser (5) is inserted into a tray-shaped bottom part (4) of the turntable such that the Venturi gap is formed between the diffuser and the turntable. An outer edge of the turntable is provided with multiple grooves. A gripper comprises multiple lifting pins, and the turntable is provided with a chamfer. The chamfer has width of about 0.5 mm to 10 mm preferably 3 mm, and height of about 0.5 mm to 10 mm preferably 3 mm.