Method and system for positioning center of V-type notch of wafer, and computer storage medium

A positioning system for a center of a V-type notch of a wafer, comprising:

• a first determining portion, a judging portion, a second determining portion and a rotating portion;
• wherein
• the first determining portion is configured to determine, based on collected edge data of the V-type notch of the wafer, a center of a concentric circle corresponding to edges of the V-type notch;
• wherein determining, based on the collected edge data of the V-type notch of the wafer, the center of the concentric circle corresponding to the edges of the V-type notch comprises:
• rotating the wafer until the V-type notch is rotated to below a line laser contour detection sensor;
• using the line laser contour detection sensor to collect coordinates of each edge point of the V-type notch;
• obtaining, based on the coordinates of each edge point, coordinate (XO, YO) of the center O of the concentric circle corresponding to the edge of the V-type notch by using least squares;
• the judging portion is configured to judge, based on a position relation between the center and a set reference scale line, whether the V-type notch is at a preset target center position;
• wherein the judging, based on the position relation between the center and the set reference scale line, whether the V-type notch is at a preset target center position comprises:
• obtaining a distance L between the center O and the preset reference scale line;
• determining that the V-type notch is at the preset target center position when the distance L=0 or the distance L is within a preset range;
• determining that the V-type notch is out of the preset target center position and continuing positioning the center of the V-type notch, when the distance L is without a preset range;
• wherein the preset range is the distance L=0±0.001 mm between the center O of the concentric circle and the set reference scale line;
• the second determining portion is configured to determine, based on the position relation between the center and the set reference scale line, a rotation direction and rotation angle of the wafer when the V-type notch is out of the preset target center position;
• the rotating portion is configured to drive, according to the rotation direction and rotation angle of the wafer, the wafer to rotate until the V-type notch is rotated to the preset target center position.

A system for positioning a center of a V-type notch of a wafer, comprising:

• a positioning back plate for positioning a wafer with the center of the V-type notch, a vacuum suction cup, a line laser contour detection sensor, a data processing device, and a servo motor;
• wherein
• the positioning back plate is provided with a circular hole that cooperates with the vacuum suction cup, and the vacuum suction cup is embedded in the circular hole;
• the vacuum suction cup is used to adsorb the wafer with a back of the wafer tightly attached to the positioning back plate;
• the line laser contour detection sensor is used to collect edge data of the V-type notch;
• the data processing device is configured to:
• determine, based on collected edge data of the V-type notch of the wafer, a center of a concentric circle corresponding to edges of the V-type notch;
• wherein the determining, based on the collected edge data of the V-type notch of the wafer, the center of the concentric circle corresponding to the edges of the V-type notch comprises:
• rotating the wafer until the V-type notch is rotated to below a line laser contour detection sensor;
• using the line laser contour detection sensor to collect coordinates of each edge point of the V-type notch;
• obtaining, based on the coordinates of each edge point, coordinate (XO, YO) of the center O of the concentric circle corresponding to the edges of the V-type notch by using least squares;
• judge, based on a position relation between the center and a set reference scale line, whether the V-type notch is at a preset target center position;
• wherein the judging, based on the position relation between the center and the set reference scale line, whether the V-type notch is at a preset target center position comprises:
• obtaining a distance L between the center O and the preset reference scale line;
• determining that the V-type notch is at the preset target center position when the distance L=0 or the distance L is within a preset range;
• determining that the V-type notch is out of the preset target center position and continuing positioning the center of the V-type notch, when the distance L is without a preset range;
• wherein the preset range is the distance L=0±0.001 mm between the center O of the concentric circle and the set reference scale line;
• determining, based on the position relation between the center and the set reference scale line, a rotation direction and rotation angle of the wafer when the V-type notch is out of the preset target center position;
• and,
• outputting, according to the rotation direction and rotation angle of the wafer, a control signal;
• the servo motor is configured to drive the wafer to rotate clockwise or counterclockwise until the V-type notch is located below the line laser contour detection sensor;
• and drive, based on the control signal, the wafer to rotate according to the rotation direction and rotation angle of the wafer, until the V-type notch is rotated to the preset target center position.