Precision dispensing pump and method of dispensing

• US 6,250,502 B1
• Filed: 09/20/1999
• Issued: 06/26/2001
• Est. Priority Date: 09/20/1999
• Status: Expired due to Fees

• Current Assignee: Daniel A. Cote, Hofmeister, Christopher A., Jayanth Prabharkar
• Original Assignee: Daniel A. Cote, Hofmeister, Christopher A., Jayanth Prabharkar
• Inventors: Hofmeister, Christopher A., Prabharkar, Jayanth, Cote, Daniel A.
• Primary Examiner(s): Morris, Lesley D.
• Application Number:
  US09/398,683
• Time in Patent Office: 645 Days
• Field of Search: 222/1, 222/380, 222/334, 417/383, 417/389
• US Class Current: 222/1
• CPC Class Codes: A61M 2005/14513 with secondary fluid driving or regulating the infusion
• CPC Class Codes: A61M 5/14224 Diaphragm type
• CPC Class Codes: A61M 5/14593 the diaphragm being actuated by fluid pressure
• CPC Class Codes: B05C 11/10 Storage, supply or control of liquid or other fluent material; Recovery of excess liquid or other fluent material B05C1/0813, B05C5/0225, B05C17/002 and B05C19/06 take precedence
• CPC Class Codes: F04B 13/00 Pumps specially modified to deliver fixed or variable measured quantities
• CPC Class Codes: F04B 43/067 the fluid being actuated directly by a piston

Abstract

A precision dispensing pump for dispensing fluids and method of dispensing for use in semiconductor packaging and/or semiconductor assembly. The precision dispensing pump employs a working fluid displacement drive for volumetric displacement of a working fluid, a dispensing reservoir for containment of dispensing fluid and a isolation diaphragm for isolating the working fluid from dispensing fluid in the dispensing reservoir. Volumetric displacement of dispensing fluid in the dispensing reservoir is proportional to volumetric displacement of working fluid in the working fluid displacement drive.

Claims

1. A precision dispensing pump for dispensing a dispensing fluid, comprising:

a working fluid displacement drive having a bellows for containment of a working fluid;

the working fluid displacement drive for volumetric displacement of said working fluid;

a dispensing reservoir for containment of dispensing fluid;

a isolation diaphragm for isolating said working fluid in said working fluid displacement drive from dispensing fluid in said dispensing reservoir;

wherein volumetric displacement of dispensing fluid in said dispensing reservoir is proportional to volumetric displacement of said working fluid in said working fluid displacement drive.

2. The precision dispensing pump according to claim 1 wherein said working fluid displacement drive further comprises:

a linear drive coupled to said bellows;

wherein linear displacement of said linear drive effects volumetric displacement of said working fluid.

3. The precision dispensing pump according to claim 2 wherein said linear drive comprises:

a motor driven lead screw; and

a bushing guided housing for linear constraint of said bellows.

4. The precision dispensing pump according to claim 2 wherein said linear drive comprises a motor driven lead screw.

5. The precision dispensing pump according to claim 1 further comprising:

a inlet valve having a supply port and a inlet port;

said supply port connected to a dispensing fluid container;

said inlet port connected to said dispensing reservoir;

a outlet valve having a outlet port and a dispense port;

said outlet port connected to said dispensing reservoir.

6. The precision dispensing pump according to claim 5 wherein said working fluid displacement drive further comprises:

a linear drive coupled to said bellows;

wherein linear displacement of said linear drive effects volumetric displacement of said working fluid.

7. The precision dispensing pump according to claim 6 wherein said linear drive comprises:

a motor driven lead screw; and

a bushing guided housing for linear constraint of said bellows.

8. The precision dispensing pump according to claim 1 further comprising:

a switching valve having a supply port, a reservoir port and a dispense port;

said supply port connected to a dispensing fluid container;

said reservoir port connected to said dispensing reservoir;

said switching valve having a charging position and a dispensing position

wherein said supply port is connected to said reservoir port when said switching valve is in said charging position;

wherein said reservoir port is connected to said dispense port when said switching valve is in said dispensing position.

9. The precision dispensing pump according to claim 8 wherein said working fluid displacement drive further comprises:

a linear drive coupled to said bellows;

wherein linear displacement of said linear drive effects volumetric displacement of said working fluid.

10. The precision dispensing pump according to claim 9 wherein said linear drive comprises:

a motor driven lead screw; and

a bushing guided housing for linear constraint of said bellows.

11. A precision dispensing pump for dispensing a dispensing fluid, comprising:

a working fluid displacement drive for volumetric displacement of a working fluid

a dispensing reservoir for containment of dispensing fluid;

a isolation diaphragm for isolating said working fluid in said working fluid displacement drive from dispensing fluid in said dispensing reservoir;

said isolation diaphragm having a primary diaphragm and a secondary diaphragm;

said primary diaphragm having a primary working side and a primary interfacing side;

said primary working side sealed to said working fluid displacement drive;

said secondary diaphragm having a secondary interfacing side and a secondary dispensing side;

said secondary dispensing side sealed to said dispensing reservoir;

said primary interfacing side mating with said secondary interfacing side;

wherein volumetric displacement of dispensing fluid in said dispensing reservoir is proportional to volumetric displacement of working fluid in said working fluid displacement drive.

12. The precision dispensing pump according to claim 11 wherein said working fluid displacement drive comprises:

a bellows for containment of said working fluid;

a linear drive coupled to said bellows;

wherein linear displacement of said linear drive effects volumetric displacement of said working fluid.

13. The precision dispensing pump according to claim 12 wherein said linear drive comprises:

a motor driven lead screw; and

a bushing guided housing for linear constraint of said bellows.

14. The precision dispensing pump according to claim 11 wherein said working fluid displacement drive comprises:

a piston for containment of said working fluid;

a linear drive coupled to said piston

wherein linear displacement of said linear drive effects volumetric displacement of said working fluid.

15. The precision dispensing pump according to claim 14 wherein said linear drive comprises a motor driven lead screw.

16. The precision dispensing pump according to claim 11 further comprising:

a inlet valve having a supply port and a inlet port;

said supply port connected to a dispensing fluid container;

said inlet port connected to said dispensing reservoir;

a outlet valve having a outlet port and a dispense port;

said outlet port connected to said dispensing reservoir.

17. The precision dispensing pump according to claim 16 wherein said working fluid displacement drive comprises:

a piston for containment of said working fluid;

a linear drive coupled to said piston;

wherein linear displacement of said linear drive effects volumetric displacement of said working fluid.

18. The precision dispensing pump according to claim 17 wherein said linear drive comprises a motor driven lead screw.

19. The precision dispensing pump according to claim 16 wherein said working fluid displacement drive comprises:

a bellows for containment of said working fluid;

a linear drive coupled to said bellows;

wherein linear displacement of said linear drive effects volumetric displacement of said working fluid.

20. The precision dispensing pump according to claim 19 wherein said linear drive comprises:

a motor driven lead screw; and

a bushing guided housing for linear constraint of said bellows.

21. The precision dispensing pump according to claim 11 further comprising:

a switching valve having a supply port, a reservoir port and a dispense port;

said supply port connected to a dispensing fluid container;

said reservoir port connected to said dispensing reservoir;

said switching valve having a charging position and a dispensing position;

wherein said supply port is connected to said reservoir port when said switching valve is in said charging position;

wherein said reservoir port is connected to said dispense port when said switching valve is in said dispensing position.

22. The precision dispensing pump according to claim 21 wherein said working fluid displacement drive comprises:

a bellows for containment of said working fluid;

a linear drive coupled to said bellows;

wherein linear displacement of said linear drive effects volumetric displacement of said working fluid.

23. The precision dispensing pump according to claim 22 wherein said linear drive comprises:

a motor driven lead screw; and

a bushing guided housing for linear constraint of said bellows.

24. The precision dispensing pump according to claim 21 wherein said working fluid displacement drive comprises:

a piston for containment of said working fluid;

a linear drive coupled to said piston;

wherein linear displacement of said linear drive effects volumetric displacement of said working fluid.

25. The precision dispensing pump according to claim 24 wherein said linear drive comprises a motor driven lead screw.

26. A method of dispensing a dispensing fluid, comprising the steps of:

providing a bellows for volumetric displacement of a working fluid;

providing a dispensing reservoir for containment of dispensing fluid in a dispensing volume;

providing a isolation diaphragm for isolating said working fluid in said bellows from dispensing fluid in said dispensing reservoir;

connecting said dispensing volume to a dispensing fluid container;

drawing dispensing fluid from said dispensing fluid container into said dispensing volume by expanding said dispensing volume;

isolating said dispensing volume from said dispensing fluid container;

connecting said dispensing volume to a dispensing outlet;

exhausting dispensing fluid from said dispensing volume through said dispensing outlet by contracting said dispensing volume.