Smart seals for monitoring and analysis of seal properties useful in semiconductor valves

Patent metadata

Field	Value
Publication number	US-11860059-B2
Application number	US-202016888726-A
Country	US
Kind code	B2
Filing date	May 30, 2020
Priority date	May 31, 2019
Publication date	Jan 2, 2024
Grant date	Jan 2, 2024

Abstract

Methods, systems and a self-sensing valve assembly are described for monitoring seal life. The method includes providing a valve assembly movable from an open position to a closed position and including a seal seated within the valve and in contact with a surface of the valve assembly, wherein when the seal is in operation it is subject to degradation. At least one sensor is placed for measuring micro strain on a surface of the valve assembly or within the valve assembly. The valve assembly is placed in an operation wherein the seal is subject to degradation and the operation of the valve assembly is initiated. At a time after the operation is initiated, micro strain data is recorded and at least one other property related to a condition selected from an ambient condition of operation and a condition related to degradation of the seal is recorded; and the recorded data is analyzed against baseline data associated with 100% seal life to evaluate seal life at the time after the operation is initiated as a percentage of seal life less than 100%.

First claim

We claim:

1. A method for monitoring seal life comprising:
providing a valve assembly movable from an open position to a closed position and comprising a door configured for covering an opening in a process chamber, a valve for operating the door from the open position to the closed position, and a seal having elastomeric properties seated within the valve in contact with a surface of the valve assembly, wherein the valve operates the door from the open position to a closed position, and when the seal is in operation it is subject to degradation;
placing at least one sensor for measuring micro strain on an exterior surface of the door of the valve assembly or within the valve assembly;
placing the valve assembly in an operation wherein the seal is subject to degradation and initiating the operation of the valve assembly;
at a time after the operation is initiated, recording micro strain data and at least one other property related to a condition selected from an ambient condition of operation and a condition related to degradation of the seal; and
analyzing the recorded data against baseline data associated with 100% seal life to evaluate seal life at the time after the operation is initiated as a percentage of seal life less than 100%.

2. The method according to claim 1 , wherein the valve assembly is one of a valve assembly with a door, a pendulum valve assembly, and an isolation valve assembly.

3. The method according to claim 1 , wherein initiating operation of the valve assembly comprises initiating a vacuum process when the door is in the closed position.

4. The method according to claim 3 , further comprising evaluating the seal life at the time after the vacuum process is initiated as a percentage of seal life less than 100%.

5. The method according to claim 1 , wherein the movable valve door is a bonded slit valve or gate valve.

6. The method according to claim 5 , wherein the moveable valve door is a bonded slit valve.

7. The method according to claim 1 , wherein the seal is mechanically affixed to a surface of the door.

8. The method according to claim 1 , wherein there are two or more sensors for measuring micro strain that are each positioned at different locations on the door.

9. The method according to claim 8 , wherein the sensors are bonded to an exterior surface of the door.

10. The method according to claim 8 , wherein one or more strain gage rosette pattern is positioned on the door.

11. The method according to claim 10 , wherein there are two or more strain gage rosette patterns and they are positioned in different locations.

12. The method according to claim 1 , wherein the baseline data is measured after calibrating the door.

13. The method according to claim 1 , wherein the baseline data is measured when a load is applied to the door and then removed, based at least in part on initial micro strain data.

14. The method according to claim 13 , wherein the baseline data is created by measuring initial micro strain data at 100% seal life and again at one or more percentages of seal life to create an adjusted range of baseline data.

15. The method according to claim 14 , wherein the baseline data is saved and incorporated into a database for predicting seal life for a type of door and seal in a specific process.

16. The method according to claim 1 , wherein the at least one sensor is a strain gage.

17. The method according to claim 1 , wherein the at least one other property is related to an ambient condition of operation and is selected from one or more of temperature, humidity, and vibration, and monitoring of such condition of operation is used to compensate for ambient noise.

18. The method according to claim 1 , wherein at least one sensor is placed to measure each of the at least one other property.

19. The method according to claim 1 , wherein the strain gage micro strain data is converted to a digital signal through use of a circuit including a Wheatstone bridge to convert micro strain to data to a change in voltage, conditioning an analog signal from the measured change in voltage, and converting the analog signal to the digital signal.

20. The method according to claim 19 , wherein the circuit is incorporated into a printed circuit board.

21. The method according to claim 19 , wherein the Wheatstone bridge incorporates high precision resistors having a tolerance of no greater than 0.25%.

22. The method according to claim 21 , wherein the high precision resistors have a tolerance of no greater than 0.1%.

23. The method according to claim 19 , wherein the circuit comprises an amplifier.

24. The method according to claim 1 , wherein the baseline data is measured after calibrating the valve assembly.

25. The method according to claim 1 , wherein the baseline data is measured after the valve assembly is in operation and the valve is under pressure, based in part on initial micro strain data.

26. The method according to claim 1 , wherein the baseline data is measured when a load is applied to the valve and then removed, based at least in part on initial micro strain data.

27. The method according to claim 26 , wherein the baseline data is created by measuring initial micro strain data at 100% seal life and again at one or more percentages of seal life to create an adjusted range of baseline data.

28. The method according to claim 27 , wherein the baseline data is saved and incorporated into a database for predicting seal life for a type of door and seal in a specific process.

29. A system for analyzing seal life, comprising:
at least one memory for storing computer-executable instructions; and
at least one processing unit for executing the instructions stored in the memory, wherein execution of the instructions programs the at least one processing unit to perform operations comprising:
engaging a valve assembly movable from an open position to a closed position, to place the valve assembly in operation, wherein the valve assembly comprises a seal having elastomeric properties, a door configured for covering an opening in a process chamber and a valve for operating the door from the open position to the closed position and the seal contacts the door, wherein the seal is seated within the valve and in contact with a surface of the valve assembly, and wherein pressure is applied to the valve assembly in operation and the seal is subject to degradation;
receiving from a circuit a signal from a change in voltage, wherein the circuit is in communication with at least one sensor for measuring micro strain on an exterior surface of the door of the valve assembly or within the valve assembly;
recording micro strain data and at least one other property related to a condition selected from an ambient condition of operation and a condition related to degradation of the seal after operation of the valve assembly is initiated; and
analyzing the recorded data against baseline data associated with 100% seal life to evaluate seal life at the time after the operation of the valve assembly is initiated as a percentage of seal life less than 100%.

30. The system according to claim 29 , wherein the valve assembly is one of a valve assembly with a door, a pendulum valve assembly, and an isolation valve assembly.

31. The system according to claim 29 , wherein operation of the valve assembly is

Assignees

• Greene Tweed Tech Inc
• Univ Of Rhode Island Board Of Trustees

Inventors

• Quartapella Carmen J
• Periyasamy Mookkan
• Sassano Elizabeth
• Gregory Otto J
• Fischer Godi
• Wei Tao
• Kinzel Zakary
• Burke Noah A

Classifications

• F16K37/0041

  for measuring valve parameters (F16K37/0033 takes precedence) · CPC title

• G01M13/005 Primary

  Sealing rings · CPC title

• G01M13/003

  Machine valves (testing valves for fluid tightness G01M3/00) · CPC title

• H01J37/32513 Primary

  Sealing means, e.g. sealing between different parts of the vessel · CPC title

• G01L1/22

  using resistance strain gauges · CPC title