System for detecting warped carriers and associated methods

• US 20050247541A1
• Filed: 05/04/2004
• Published: 11/10/2005
• Est. Priority Date: 05/04/2004
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Casallo, Romulo D. Jr., Partosa, Raymond M., Alviar, Melvin B., Viluan, Ramil A.
• Granted Patent: US 7,326,025 B2
• Time in Patent Office: Days
• US Class Current: 198/346.100
• CPC Class Codes: H01L 21/67288 Monitoring of warpage, curvature, damage, defects or the like

Abstract

Disclosed herein is a warp detection system (200) for determining warping in a carrier (110) configured to carry substrates (120) for processing. In one embodiment, the system (200) includes a guide plate (210) configured to guide a path of the carrier (110) during the processing, where the guide plate (210) is positioned underneath the carrier (110). In addition, the system (220) includes a plurality of sensors (230) positioned within the guide plate (210), wherein each of the plurality of sensors (230) is configured to measure a distance of a respective area of the carrier (110) from the guide plate (210). Also in this embodiment, the system (200) includes a processing device (310) configured to receive the measured distances and determine warping in the carrier (110) based on differences between the measured distances. Also disclosed are a method of determining warping in a carrier (110) configured to carry substrates (120) for processing, and a method of manufacturing a warp detection system (200) for determining warping in a carrier (110) configured to carry substrates (120) for processing.

Claims

1. A warp detection system for determining warping in a carrier configured to carry substrates for processing, the system comprising:

a guide plate configured to guide a path of the carrier during the processing, the guide plate positioned underneath the carrier;

a plurality of sensors positioned within the guide plate, each of the plurality of sensors configured to measure a distance of a respective area of the carrier from the guide plate; and

a processing device configured to receive the measured distances and determine warping in the carrier based on differences between the measured distances.

2. A system according to claim 1, wherein the plurality of sensors comprise a plurality of height sensors.

3. A system according to claim 1, wherein the carrier is rectangular and the plurality of sensors comprises sensors positioned to measure a distance proximate each corner of the carrier.

4. A system according to claim 3, wherein the plurality of sensors further comprises sensors positioned to measure a distance proximate a longitudinal center of the carrier.

5. A system according to claim 1, further comprising a jig configured to perform the processing on the substrates, the jig having a calibration surface oriented towards the guide plate for calibrating the plurality of sensors.

6. A system according to claim 5, wherein the calibration surface comprises a recessed gap, the plurality of sensors further configured to measure a distance of the calibration surface and a distance of the recessed gap from the guide plate to accomplish the calibrating.

7. A system according to claim 1, further comprising a calibration carrier predetermined to be substantially free of warping and having a calibration surface oriented towards the guide plate for calibrating the plurality of sensors.

8. A system according to claim 1, wherein the plurality of sensors is configured to measure a distance of a respective area of the carrier from the guide plate as the carrier is moving across the guide plate.

9. A method of determining warping in a carrier configured to carry substrates for processing, the method comprising:

guiding a path of the carrier over a guide plate during the processing;

measuring a distance of a respective area of the carrier from the guide plate using a plurality of sensors positioned within the guide plate; and

determining warping in the carrier based on differences between the measured distances.

10. A method according to claim 9, wherein the plurality of sensors comprises a plurality of height sensors.

11. A method according to claim 9, further comprising measuring a distance proximate each corner of a rectangular carrier from the guide plate.

12. A method according to claim 11, wherein the measuring still further comprises measuring a distance proximate a longitudinal center of the rectangular carrier from the guide plate.

13. A method according to claim 9, further comprising calibrating the plurality of sensors by measuring a distance from the guide plate to a calibration surface of a jig configured to perform the processing on the substrates, the calibration surface oriented towards the guide plate.

14. A method according to claim 13, wherein the calibrating further comprises calibrating the plurality of sensors by measuring a distance of a recessed gap in the calibration surface from the guide plate to accomplish the calibrating.

15. A system according to claim 9, further comprising calibrating the plurality of sensors by measuring a distance of a calibration surface of a calibration carrier from the guide plate, the calibration surface oriented towards the guide plate and the calibration carrier predetermined to be substantially free of warping.

16. A method according to claim 9, further comprising measuring a distance of a respective area of the carrier from the guide plate as the carrier is moving across the guide plate.

17. A method of manufacturing a warp detection system for determining warping in a carrier configured to carry substrates for processing, the method comprising:

providing a guide plate configured to guide a path of the carrier during the processing, the guide plate positioned underneath the carrier;

locating a plurality of sensors within the guide plate, each of the plurality of sensors configured to measure a distance of a respective area of the carrier from the guide plate; and

providing a processing device configured to receive the measured distances and determine warping in the carrier based on differences between the measured distances.

18. A method according to claim 17, wherein locating comprises located a plurality of height sensors within the guide plate.

19. A method according to claim 17, wherein the carrier is rectangular and the locating comprises locating a plurality of sensors to measure a distance proximate each corner of the carrier.

20. A method according to claim 19, wherein the locating further comprises locating others of the plurality of sensors to measure a distance proximate a longitudinal center of the carrier.

21. A method according to claim 17, further comprising providing a jig configured to perform the processing on the substrates and having a calibration surface oriented towards the guide plate for calibrating the plurality of sensors.

22. A method according to claim 21, further comprising providing a recessed gap in the calibration surface, the plurality of sensors further configured to measure a distance of the calibration surface and a distance of the recessed gap from the guide plate to accomplish the calibrating.

23. A method according to claim 17, further comprising providing a calibration carrier predetermined to be substantially free of warping and having a calibration surface oriented towards the guide plate for calibrating the plurality of sensors.

24. A system according to claim 17, wherein the plurality of sensors is configured to measure a distance of a respective area of the carrier from the guide plate as the carrier is moving across the guide plate.