System and Method for a Variable Home Position Dispense System

• US 20090132094A1
• Filed: 11/21/2005
• Published: 05/21/2009
• Est. Priority Date: 11/23/2004
• Status: Active Grant

• Current Assignee: Entegris Incorporated
• Original Assignee: Entegris Incorporated
• Inventors: King, Timothy J., Cedrone, James, Gonnella, George, Magoon, Paul, Gashgaee, Iraj, Laverdiere, Marc
• Granted Patent: US 8,292,598 B2
• Time in Patent Office: Days
• US Class Current: 700/283
• CPC Class Codes: F04B 13/00 Pumps specially modified to deliver fixed or variable measured quantities
• CPC Class Codes: F04B 2201/0201 Position of the piston
• CPC Class Codes: F04B 2205/09 Flow through the pump
• CPC Class Codes: F04B 43/02 having plate-like flexible members, e.g. diaphragms F04B43/14 takes precedence
• CPC Class Codes: F04B 49/065 and making use of computers

Abstract

Embodiments of the present, invention provide a system and method for reducing the hold-up volume of a pump. More particularly, embodiments of the present invention provide a system and method for determining a home position to reduce hold-up volume at a dispense pump and/or a feed pump. The home position for the diaphragm can be selected such that the volume of the chamber at the dispense pump and/or feed pump contains sufficient fluid to perform the various steps of a dispense cycle while minimizing the hold-up volume. Additionally, the home position of the diaphragm can be selected to optimize the effective range of positive displacement.

Claims

1. A pumping system comprising:

a dispense pump, wherein the dispense pump has a maximum available volume, the dispense pump further comprising a dispense diaphragm movable within a dispense chamber; and

a pump controller coupled to the dispense pump, the pump controller operable to;

control the dispense pump to move the dispense diaphragm in the dispense chamber to reach a dispense pump home position to partially fill the dispense pump, wherein an available volume corresponding to the dispense pump home position is less than the maximum available volume of the dispense pump and is the greatest available volume for the dispense pump in a dispense cycle and wherein the dispense pump home position is selected based on one or more parameters for the dispense operation;

control the dispense pump to dispense the process fluid from the dispense pump.

2. The system of claim 1, further comprising:

a filter downstream of the dispense pump;

an inlet valve upstream of the dispense pump;

a purge valve downstream of the filter; and

an outlet valve downstream of the filter.

3. The system of claim 1, further comprising:

a filter downstream of the feed pump and upstream of the dispense pump;

an inlet valve upstream of the feed pump;

an isolation valve between the feed pump and the filter;

a barrier valve between the filter and the dispense pump;

a purge valve downstream of the dispense pump; and

an outlet valve downstream of the dispense pump.

4. The system of claim 1, wherein the controller is further operable to control the dispense pump to purge a purge volume of fluid and wherein the available volume corresponding to the dispense pump home position is at least a dispense volume plus the purge volume.

5. The system of claim 1, wherein the dispense pump further comprises a dispense motor to move the dispense diaphragm and wherein the controller is further operable to:

control the dispense pump to move the dispense diaphragm to a hard stop prior to partially filling the dispense pump;

control the dispense pump to move the dispense diaphragm from the hard stop position to the dispense pump home position by reversing the stepper motor a corresponding number of steps.

6. The system of claim 1, wherein the dispense pump further comprises:

a dispense motor to move the dispense diaphragm;

a position sensor to indicate the position of the dispense motor.

7. The system of claim 6, wherein the position sensor is a linear encoder.

8. The system of claim 6, wherein the position sensor is a rotary encoder.

9. The system of claim 6, wherein the controller is further operable to control the dispense motor to move the dispense diaphragm from a first position to the dispense pump home position.

10. The system of claim 9, wherein the controller is further operable to stop the dispense diaphragm at the home position based on feedback from the position sensor.

11. The system of claim 1, further comprising:

a feed pump comprising a feed diaphragm movable within a feed chamber; and

wherein the pump controller is connected to the feed pump and operable to control the feed pump to assert a pressure on the process fluid to provide the process fluid to the dispense pump.

12. The system of claim 11, wherein the controller is further operable to control the feed pump to move the feed diaphragm to a feed pump home position to partially fill the feed pump.

13. The system of claim 12, wherein the controller is further operable to control the feed pump to vent a vent volume of fluid.

14. The system of claim 13, wherein an available volume of the feed pump when the feed diaphragm is at the feed pump home position is at least equal to a dispense volume, the vent volume and a purge volume.

15. The system of claim 1, wherein the available volume of the dispense pump corresponding to the dispense pump home position is at least equal to a user specified volume.

16. The system of claim 15, wherein the controller is further operable to:

receive a user specified volume; and

add an error volume to the user specified volume to determine the available volume of the dispense pump corresponding to the dispense pump home position.

17. The system of claim 1, further comprising:

a feed pump comprising a feed diaphragm movable within a feed chamber; and

wherein the pump controller is connected to the feed pump and operable to;

control the feed pump to assert a pressure on the process fluid to provide the process fluid to the dispense pump;

receive a user specified volume for the feed pump;

add an error volume to the user specified volume to determine the available volume of the feed pump corresponding to the feed pump home position.

18. The system of claim 1, wherein the dispense pump home position is selected to utilize the effective region of the dispense diaphragm.

19. A method for reducing hold-up volume of a process fluid in a pump system comprising:

providing a process fluid to a dispense pump;

selecting a dispense pump home position for the dispense pump based on one or more parameters for the dispense operation;

partially filling a dispense pump to a dispense pump home position for a dispense cycle, wherein the dispense pump has an available volume corresponding to the dispense pump home position that is less than the maximum available volume of the dispense pump and is the greatest available volume at the dispense pump for the dispense cycle;

dispensing the process fluid from the dispense pump to a wafer, wherein a dispense volume of process fluid is dispensed from the dispense pump with at least a portion of the dispense volume being dispensed to the wafer, and wherein the available volume corresponding to the dispense pump home position of the dispense pump is at least the dispense volume.

20. The method of claim 19, further comprising purging a purge volume of fluid from the dispense pump.

21. The method of claim 20, wherein the available volume of the dispense pump corresponding to the dispense pump home position is at least the dispense volume plus the purge volume.

22. The method of claim 21, wherein purging occurs in the dispense cycle prior to dispensing.

23. The method of claim 19, wherein purging occurs in the dispense cycle subsequent to dispensing.

24. The method of claim 19, further comprising:

partially filling a feed pump to a feed pump home position, wherein the feed pump has an available volume corresponding to the feed pump home position that is less than the maximum available volume of the feed pump and the greatest available volume for the feed pump during the dispense cycle and wherein the available volume corresponding to the feed pump home position is at least the dispense volume.

25. The method of claim 24, further comprising venting a vent volume of process fluid, wherein the available volume corresponding to the feed pump home position is at least the vent volume plus the dispense volume.

26. The method of claim 25, further comprising purging a purge volume of process fluid from the dispense pump, wherein the available volume corresponding to the feed pump home position is at least the vent volume plus the dispense volume plus the purge volume.

27. The method of claim 26, further comprising sucking back a suckback volume of process fluid at the dispense pump, wherein the available volume at the feed pump corresponding to the feed pump home position is at least the vent volume plus the dispense volume plus the purge volume minus the suckback volume.

28. The method of claim 19, further comprising selecting the dispense pump home position based on the effective range of the dispense diaphragm.

29. A computer program product comprising a set of computer instructions stored a computer readable medium, the computer instructions comprising instructions executable by a processor to:

receive one or more parameters for a dispense operation;

select a dispense pump home position for a dispense pump based on the one or more parameters;

direct a dispense pump to move a dispense diaphragm to reach the dispense pump home position to partially fill the dispense pump with a process fluid, wherein an available volume corresponding to the dispense pump home position is less than the maximum available volume of the dispense pump and is the greatest available volume for the dispense pump in a dispense cycle;

direct the dispense pump to dispense the process fluid from the dispense pump.

30. The computer program product of claim 29, wherein the set of computer instructions further comprise instructions executable to direct the dispense pump to purge a purge volume of fluid, wherein the available volume of the dispense pump corresponding to the dispense pump home position is at least a dispense volume plus the purge volume.

31. The computer program product of claim 29, wherein the set of computer instructions further comprise instructions executable to:

direct the dispense pump to move the dispense diaphragm to a hard stop prior to partially filling the dispense pump;

direct the dispense pump to move the dispense diaphragm from the hard stop position to the dispense pump home position by reversing the stepper motor a corresponding number of steps.

32. The computer program product of claim 29, wherein the set of computer instructions further comprise instructions executable to control the dispense motor to move the dispense diaphragm from a first position to the dispense diaphragm home position.

33. The computer program product of claim 32, wherein the set of computer instructions further comprise instructions executable to:

receive feedback from a position sensor at the dispense pump; and

stop the dispense diaphragm at the home position based on the feedback from the position sensor.

34. The computer program product of claim 29, wherein the set of computer instructions further comprise instructions executable to:

direct a feed pump to assert pressure on the process fluid to provide the process fluid to the dispense pump;

direct the feed pump to move a feed diaphragm to a feed stage home position to partially fill the feed pump.

35. The computer program product of claim 34, wherein the set of computer instructions further comprise instructions executable to direct the feed pump to vent a vent volume of fluid.

36. The computer program product of claim 35, wherein an available volume of the feed pump when the feed diaphragm is at the feed stage home position is at least equal to the dispense volume plus the vent volume plus a purge volume.

37. The computer program product of claim 29, wherein the available volume of the dispense pump when the dispense diaphragm is at the dispense pump home position is at least equal to a user specified dispense pump volume.

38. The computer program product of claim 37, wherein the one or more parameters for the dispense operation include user specified dispense pump volume and wherein the set of computer instructions further comprise instructions executable to:

add an error volume to the user specified dispense pump volume to determine the available volume corresponding to the dispense diaphragm home position.

39. The computer program product of claim 29, wherein an available volume of the feed pump when the feed pump is at the feed pump home position is at least equal to a user specified feed pump volume.

40. The computer program product of claim 38, wherein the one or more parameters for the dispense operation include the user specified feed pump volume and wherein the set of computer instructions further comprise instructions executable to:

add an error volume to the user specified feed pump volume to determine the available volume corresponding to the dispense diaphragm home position.

41. The computer program product of claim 29, wherein the set of computer instructions further comprise instructions executable to select the dispense pump home position to utilize the effective range of the dispense diaphragm.