Control system for non-contact edge coating apparatus for solar cell substrates
View Patent ↗A non-contact edge coating apparatus includes an applicator for applying a coating material on an edge of a solar cell substrate and a control system configured to drive the applicator. The control system may drive the applicator along an axis to maintain a distance with an edge of the substrate as the substrate is rotated to have the edge coated with a coating material. The applicator may include a recessed portion into which the edge of the substrate is received for edge coating. For example, the applicator may be a roller with a groove. Coating material may be introduced into the groove for application onto the edge of the substrate. A variety of coating materials may be employed with the apparatus including hot melt ink and UV curable plating resist.
1. A method of coating an edge of a wafer, the method comprising:
locating points on an edge of a substrate prior to rotating the substrate;
identifying coordinates of a center about which the substrate is rotated;
tracking locations of the points on the edge of the substrate during rotation of the substrate;
moving an applicator along a single axis to maintain a coating distance between the edge of the substrate and the applicator; and
coating the edge of the substrate with a coating material from the applicator during rotation of the substrate without the applicator physically contacting the edge of the substrate.
2. The method of claim 1 wherein locating the points on the edge of the substrate comprises:
taking an image of the substrate before rotating the substrate.
3. The method of claim 1 wherein tracking locations of the points on the edge of the substrate during rotation of the substrate comprises:
receiving an updated image of the substrate from a camera as the substrate is rotated.
4. The method of claim 1 wherein moving the applicator along the single axis to maintain the coating distance between the edge of the substrate and the applicator comprises:
moving a slider assembly that supports the substrate while the substrate is rotated.
5. The method of claim 1 wherein the substrate is rotated on a substrate support.
6. The method of claim 5 further comprising:
curing the coating material while the substrate is on the substrate support.
7. The method of claim 1 wherein coating the edge of the substrate with the coating material from the applicator during rotation of the substrate without the applicator physically contacting the edge of the substrate comprises:
applying the coating material from a roller to the edge of the substrate.
8. A non-transitory computer-readable storage medium storing program instructions, wherein the program instructions are executable by at least one processor to perform:
receiving an indication of locations of points on an edge of a substrate;
identifying coordinates of a center about which the substrate is rotated;
receiving an updated indication of the locations of the points on the edge of the substrate; and
based on the updated indication of the points, providing an instruction to an applicator to:
move along a single axis to maintain a coating distance between the edge of the substrate and the applicator, and
coat the edge of the substrate with a coating material from the applicator during rotation of the substrate without the applicator physically contacting the edge of the substrate.