Touchdown Monitoring for Individual Dies of a Semiconductor Wafer

A method of counting wafer touchdowns at a prober system, the method comprising:

• loading a semiconductor wafer having a plurality of semiconductor dies onto a chuck of the prober system;
• controlling horizontal movement of the chuck to position a selected group of the dies for parallel testing and vertical movement of the chuck to press the selected group of dies in contact with probes of a tester probe card;
• measuring the vertical movement of the chuck when the wafer is on the chuck;
• determining a total number of touchdowns between the wafer and the probes based on the vertical movement measured for the chuck;
• and
• associating each of the touchdowns with a location of the wafer contacted by the probes during that touchdown.

A test data analysis system, comprising:

• an input/output (I/O) interface configured to retrieve tester data and prober data for a semiconductor wafer having a plurality of semiconductor dies, the tester data including test data collected for the wafer by one or more testers having a probe card for contacting the wafer, the prober data including a total number of touchdowns between the wafer and each probe card that tested the wafer and a location of the wafer contacted by one of the probe cards during each of the touchdowns;
• and
• a processing circuit configured to:
• determine a total number of touchdowns for each of the dies based on the total number of touchdowns for the wafer and the location of the wafer contacted by one of the probe cards during each of the touchdowns;
• and
• compare the total number of touchdowns determined for each of the dies to a maximum touchdown limit to determine whether any of the dies exceeds the maximum touchdown limit.

A method of analyzing test data, the method comprising:

• retrieving tester data and prober data for a semiconductor wafer having a plurality of semiconductor dies, the tester data including test data collected for the wafer by one or more testers having a probe card for contacting the wafer, the prober data including a total number of touchdowns between the wafer and each probe card that tested the wafer and a location of the wafer contacted by one of the probe cards during each of the touchdowns;
• determining a total number of touchdowns for each of the dies based on the total number of touchdowns for the wafer and the location of the wafer contacted by one of the probe cards during each of the touchdowns;
• and
• comparing the total number of touchdowns determined for each of the dies to a maximum touchdown limit to determine whether any of the dies exceeds the maximum touchdown limit.