Wafer aligner

A wafer aligner, comprising:

• a platform;
• a lifting gripper, disposed on the platform to be lifted up or lowered down;
• a rotating gripper, disposed on the platform to be rotated, wherein the lifting gripper and the rotating gripper are coaxial and alternately disposed with each other relative to the platform;
• a rangefinder, disposed next to the platform;
• and
• a control module, electrically connected to the lifting gripper, the rotating gripper, and the rangefinder,
• wherein the control module drives the lifting gripper to lift up relative to the platform, so that the wafer is transferred between the lifting gripper and the rotating gripper, and
• wherein when the wafer is located on the rotating gripper, the control module drives the rotating gripper to rotate relative to the platform, and drives the rangefinder to detect a change in a relative distance along an edge of the wafer to determine a position of a notch of the wafer.