Coating Apparatus Uniform Film via Squeegee Applicator
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for forming a coating film on substrates, such as semiconductor wafers and glass substrates, face challenges including non-uniform film thickness, excessive liquid supply, and complex equipment adjustments, particularly with slit nozzles, which lead to inefficiencies and space inefficiencies due to separate cleaning and drying stations.
Innovation Solution
A coating apparatus featuring a rotatable tray with a recessed portion to accommodate substrates, a nozzle for supplying coating liquid, and a movable applicator, such as a squeegee, which forms a coating liquid pool and spreads it uniformly across the substrate, allowing for efficient coating, cleaning, and drying without requiring delicate adjustments or separate stations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a slit nozzle is used to supply coating liquid, then coating can be applied to the substrate, but it is difficult to supply coating liquid with uniform thickness and the structure requires delicate adjustment
Solution Approach 1:
The invention extracts the coating liquid supply function from the slit nozzle and relocates it to a reservoir positioned upstream of the applicator. The applicator then distributes the liquid through its width, eliminating the need for delicate nozzle adjustments while achieving uniform coating thickness.
Solution Approach 2:
The invention introduces a reservoir as an intermediary component between the coating liquid source and the substrate. This reservoir holds the liquid and allows the applicator to pick up and distribute it uniformly across the substrate surface, mediating the supply process to eliminate thickness variation.
2Adaptability or versatility
If the recessed portion depth is increased to accommodate substrate variations, then more substrates can be handled, but the apparatus size increases
Solution Approach 1:
The invention makes the tray bottom movable, allowing it to dynamically adjust its position to accommodate substrates of varying thicknesses. This dynamic adjustment enables the apparatus to handle different substrate types without requiring a large fixed recessed portion, thus maintaining compact apparatus size while improving adaptability.
3Reliability
If separate cleaning and drying stations are provided, then thorough cleaning and drying can be achieved, but the apparatus becomes complex and requires multiple transfer devices
Solution Approach 1:
The invention merges the cleaning and drying functions into a single integrated station. The tray is designed to be removable from the coating apparatus and transferred to a combined cleaning-drying station, eliminating the need for separate stations and multiple transfer devices while maintaining effective cleaning and drying through the use of cleaning liquid supply and heating mechanisms.
4Manufacturing precision
If the applicator maintains a certain distance from the substrate surface, then uniform coating can be achieved, but the applicator structure becomes more complex
Solution Approach 1:
The invention designs the applicator to perform multiple functions: it spreads the coating liquid uniformly while maintaining a certain distance from the substrate, and simultaneously serves as a barrier to prevent liquid from reaching the tray. This multi-functionality simplifies the overall structure by eliminating the need for separate components to perform these functions.
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 enables uniform coating film formation without edge beads, reduces waste, simplifies equipment structure, and allows for compact apparatus design, facilitating efficient substrate transfer and reducing the need for multiple transfer devices.
Implementation Method 1
a rotatable tray (1) having a recessed portion (11) for accommodating a substrate (W)
Implementation Method 2
a nozzle for supplying a coating liquid (2), wherein the nozzle for supplying a coating liquid (2) is positioned above a non-recessed portion of the tray (1)
Implementation Method 3
an applicator for spreading the coating liquid, wherein the applicator is relatively movable in a horizontal direction in a state of maintaining a certain distance with respect to the upper surface of the substrate (W) accommodated into the recessed portion (11)
Data Source
AI summary
A coating apparatus is provided in which a coating liquid supplied onto a surface of a substrate such as a semiconductor wafer and a glass substrate can be easily leveled so as to have a uniform thickness without any edge bead. The coating apparatus comprises a tray, a nozzle for supplying a coating liquid, and a squeegee which serves as an applicator for spreading a coating liquid. The tray has a recessed portion into which a substrate is placed, and a spinner chuck is provided in the recessed portion. In the spinner chuck, a chuck for attracting the substrate is attached to the upper end of a spinner shaft which can be lifted and lowered, and the upper surface of the chuck and the bottom surface of the recessed portion are arranged to be in the same plane in a state where the spinner shaft is lowered to the lowest position.