Calibration process for an automated test system

Patent metadata

Field	Value
Publication number	US-11226390-B2
Application number	US-201715688112-A
Country	US
Kind code	B2
Filing date	Aug 28, 2017
Priority date	Aug 28, 2017
Publication date	Jan 18, 2022
Grant date	Jan 18, 2022

Abstract

An example method, such as a calibration method, includes: determining a geometry of an arrangement of cells that is perceived by a robot configured to move devices into, and out of, the cells; determining an expected location of a target cell among the cells; determining an offset from the expected location that is based on the geometry that is perceived by the robot; and calibrating the robot based on the offset.

First claim

What is claimed is:

1. A method comprising:
determining a first geometry of an arrangement of cells that is perceived by a robot configured to move devices into, and out of, the cells, the first geometry comprising a distortion of an expected geometry of the arrangement of cells, the first geometry being determined by moving the robot to predefined locations on a calibration device having a same geometry as a tray containing the arrangement of cells and recording coordinates of the predefined locations;
determining an expected location of a target cell among the cells based on the expected geometry stored in computer memory;
determining an offset from the expected location that is based on the first geometry and the expected geometry; and
calibrating the robot based on the offset to compensate for the distortion;
wherein the expected geometry is a second geometry, and wherein determining the offset comprises:
calculating a first dimension error based on a difference in the first dimension between the first geometry and the second geometry; and
calculating a second dimension error based on a difference in the second dimension between the first geometry and the second geometry, the offset comprising a combination of the first dimension error and the second dimension error.

2. The method of claim 1 , wherein the first dimension error and the second dimension error are calculated relative to the expected location of the target cell.

3. The method of claim 1 , wherein calibrating the robot comprises incorporating the first dimension error and the second dimension error into a movement of the robot to reach the target cell.

4. The method of claim 1 , wherein the robot comprises multiple heads, and the offset is determined with respect to a first head among the multiple heads; and
wherein calibrating the robot comprises calibrating a second head among the multiple heads that is different than the first head, the second head being calibrated based on both the offset and a second offset corresponding to a difference in locations between the first head and the second head.

5. The method of claim 1 , wherein the robot is calibrated to reach the expected location of the target cell by combining the offset with a perceived location of the target cell.

6. The method of claim 1 , wherein the cells are on one or more trays for holding devices that have been tested or devices that have not been tested.

7. The method of claim 1 , wherein the cells comprises one or more receptacles on one or more shuttles configured to move devices between different stages of a test system.

8. The method of claim 1 , wherein the robot is calibrated to a sub-millimeter accuracy.

9. The method of claim 1 , wherein the robot is calibrated to an accuracy of at least 0.1 millimeters.

10. One or more non-transitory machine-readable storage devices storing instructions that are executable to perform operations comprising:
determining a first geometry of an arrangement of cells that is perceived by a robot configured to move devices into, and out of, the cells, the first geometry comprising a distortion of an expected geometry of the arrangement of cells, the first geometry being determined by moving the robot to predefined locations on a calibration device having a same geometry as a tray containing the arrangement of cells and recording coordinates of the predefined locations;
determining an expected location of a target cell among the cells based on the expected geometry stored in computer memory;
determining an offset from the expected location that is based on the first geometry and the expected geometry; and
calibrating the robot based on the offset to compensate for the distortion;
wherein the expected geometry is a second geometry, and wherein determining the offset comprises:
calculating a first dimension error based on a difference in the first dimension between the first geometry and the second geometry; and
calculating a second dimension error based on a difference in the second dimension between the first geometry and the second geometry, the offset comprising a combination of the first dimension error and the second dimension error.

11. The one or more non-transitory machine-readable storage devices of claim 10 , wherein the first dimension error and the second dimension error are calculated relative to the expected location of the target cell.

12. The one or more non-transitory machine-readable storage devices of claim 10 , wherein calibrating the robot comprises incorporating the first dimension error and the second dimension error into a movement of the robot to reach the target cell.

13. The one or more non-transitory machine-readable storage devices of claim 10 , wherein the robot comprises multiple heads, and the offset is determined with respect to a first head among the multiple heads; and
wherein calibrating the robot comprises calibrating a second head among the multiple heads that is different than the first head, the second head being calibrated based on both the offset and a second offset corresponding to a difference in locations between the first head and the second head.

14. The one or more non-transitory machine-readable storage devices of claim 10 , wherein the robot is calibrated to reach the expected location of the target cell by combining the offset with a perceived location of the target cell.

15. The one or more non-transitory machine-readable storage devices of claim 10 , wherein the cells are on one or more trays for holding devices that have been tested or devices that have not been tested.

16. The one or more non-transitory machine-readable storage devices of claim 10 , wherein the cells comprises one or more receptacles on one or more shuttles configured to move devices between different stages of a test system.

17. The one or more non-transitory machine-readable storage devices of claim 10 , wherein the robot is calibrated to a sub-millimeter accuracy.

18. The one or more non-transitory machine-readable storage devices of claim 10 , wherein the robot is calibrated to an accuracy of at least 0.1 millimeters.

Assignees

• Teradyne Inc

Inventors

• Khalid Adnan

Classifications

• G01R31/2834

  Automated test systems [ATE]; using microprocessors or computers (G01R31/317 takes precedence; ATE for detection of defective computer hardware G06F11/2736) · CPC title

• G01R35/00 Primary

  Testing or calibrating of apparatus covered by the other groups of this subclass · CPC title

• G05B19/402

  characterised by control arrangements for positioning, e.g. centring a tool relative to a hole in the workpiece, additional detection means to correct position (G05B19/19 takes precedence) · CPC title

• G01R31/2893

  Handling, conveying or loading, e.g. belts, boats, vacuum fingers (G01R31/2867 takes precedence; handling semiconductor devices or wafers during manufacture or treatment H10P72/00) · CPC title

• B25J9/1692

  Calibration of manipulator · CPC title