Wafer acceptance test tool and test method using thereof

A method, comprising:

• pressing probes against probe pads arranged in a line over a wafer to form probe marks on the probe pads;
• capturing images including the probe marks on the probe pads;
• recording the captured images in an image inspection machine;
• identifying the probe marks from the probe pads of the captured images using an artificial intelligence-based image analysis through the image inspection machine;
• generating an adjustment parameter based on the identified probe marks through the image inspection machine, wherein the step of generating the adjustment parameter comprises:
• generating, by the image inspection machine, virtual boxes respectively surrounding the identified probe marks of the captured images, each of the virtual boxes having four sides in contact with respective edges of a corresponding one of the probe marks, and determining distances between the sides of the virtual boxes and corresponding edges of the probe pads to calculate the adjustment parameter;
• pressing the probes against the probe pads in response to the adjustment parameter;
• and
• performing a wafer acceptance test to the wafer.

A system, comprising:

• a wafer stage in a wafer acceptance test chamber;
• probes in the wafer acceptance test chamber;
• a controller initiating a relative motion between the wafer stage and the probes, the relative motion allowing the probes to press against probe pads on a wafer held on the wafer stage to form probe marks on the probe pads;
• an image inspection apparatus comprising:
• an image sensor disposed in the wafer acceptance test chamber, wherein the image sensor is configured to capture an image of the probe marks;
• and
• an image processor electrically connected to the image sensor, wherein the image processor is configured to compare areas of the probe marks across multiple probe pads to determine a tilt condition of the probes, and in response to detecting a tilt exceeding a predetermined threshold, to generate an adjustment parameter comprising an adjustment angle for correcting the tilt of the probes relative to the wafer stage;
• and
• a positioning module connected to the wafer stage, wherein the positioning module is configured to adjust a position and an angular orientation of the wafer stage in response to the adjustment parameter.