Laminated semiconductor sensor with overpressure protection

• US 5,062,302 A
• Filed: 08/27/1990
• Issued: 11/05/1991
• Est. Priority Date: 04/29/1988
• Status: Expired due to Fees

• Current Assignee: Schlumberger Industries Incorporated (SLB)
• Original Assignee: Schlumberger Industries Incorporated (SLB)
• Inventors: Petersen, Kurt E., Barth, Phillip W., Bryzek, Janusz, Mallon, Joseph R. Jr.
• Primary Examiner(s): Orsino, Joseph A.
• Assistant Examiner(s): SWARTHOUT, BRENT
• Application Number:
  US07/574,387
• Time in Patent Office: 435 Days
• Field of Search: 73/715, 73/716, 73/718, 73/719, 73/721, 73/754, 73/706, 73/DIG. 4, 73/727, 73/720, 338/4, 338/42
• US Class Current: 73/754
• CPC Class Codes: G01L 19/0618 Overload protection
• CPC Class Codes: G01L 19/0636 using particle filters
• CPC Class Codes: G01L 9/0042 Constructional details associated with semiconductive diaphragm sensors, e.g. etching, or constructional details of non-semiconductive diaphragms details about the integration or bonding of piezoresistor in or on the diaphragm G01L9/0052 and G01L9/0057 respectively
• CPC Class Codes: G01L 9/0054 integral with a semiconducting diaphragm
• CPC Class Codes: G01L 9/0073 using a semiconductive diaphragm
• CPC Class Codes: Y10S 73/04 Piezoelectric

Abstract

An electromechanical sensor is provided which comprises: first semiconductor wafer including a first stop surface residing in a first shallow recessed region of the first wafer; a second semiconductor wafer; wherein the first and second semiconductor wafers are laminated together such that the first recessed region of the first wafer and the second wafer define a first chamber in which the first stop surface and the second wafer are disposed close enough together such that the first stop surface restrains the second wafer from deflecting beyond the first stop surface; and an apparatus for measuring deflection of the second wafer.

Claims

1. An electromechanical sensor comprising:

a first semiconductor wafer including a first stop surface residing in a first shallow recessed region of said first wafer;

a second semiconductor wafer;

wherein said first and second semiconductor wafers are laminated together such that said first recessed region of said first wafer and said second wafer define a first chamber in which said first stop surface and said second wafer are disposed close enough together such that said first stop surface restrains said second wafer from deflecting beyond said first stop surface;

means for measuring deflection of said second wafer;

wherein said second wafer includes a first contact surface residing in a second shallow recessed region of said second wafer;

wherein said first stop surface and said first contact surface are disposed substantially opposite each other in said first chamber; and

wherein said second shallow recessed region includes a center section and a thinner perimeter section which substantially surrounds said center section.

2. An electromechanical sensor comprising:

a first semiconductor wafer including a first stop surface residing in a first shallow recessed region of said first wafer;

a second semiconductor wafer;

wherein said first and second semiconductor wafers are laminated together such that said first recessed region of said first wafer and said second wafer define a first chamber in which said first stop surface and said second wafer are disposed close enough together such that said first stop surface restrains said second wafer from deflecting beyond said first stop surface;

means for measuring deflection of said second wafer;

a first fluid feedthrough port to provide fluid communication with said first chamber;

wherein said first fluid feedthrough port is disposed in laterally spaced relation to said first chamber;

wherein said first and second wafers together define at least one tubular conduit extending laterally between said first and second wafers for providing fluid coupling between said first fluid feedthrough port and said first chamber; and

means for preventing said first wafer from adhering to said first stop surface.

3. The sensor of claim 2 wherein said means for preventing includes a plurality of upstanding members formed in said first stop surface such that one or more of said plurality of upstanding members abuts against said second wafer when said first stop surface restrains said second wafer.

4. The sensor of claim 2 wherein said means for preventing includes a plurality of upstanding members formed in said second wafer such that one or more of said plurality of upstanding members abuts against said first stop surface when said first stop surface restrains said second wafer.

5. The sensor of claim 3 wherein said upstanding members are spaced apart such that fluid provided to said first port can flow within spaces between said upstanding members one or more of said plurality of upstanding members abuts against said second wafer.

6. The sensor of claim 4 wherein said upstanding members are spaced apart such that fluid provided to said first port can flow within spaces between said upstanding members one or more of said plurality of upstanding members abuts against said first stop surface.

7. The sensor of claim 3 or 4 wherein said upstanding members are short relative to spacing between said first stop surface and said second wafer.

8. An electromechanical sensor comprising:

a first semiconductor wafer including a first stop surface residing in a first shallow recessed region of said first wafer;

a second semiconductor wafer;

wherein said first and second semiconductor wafers are laminated together such that said first recessed region of said first wafer and said second wafer define a first chamber in which said first stop surface and said second wafer are disposed close enough together such that said first stop surface restrains said second wafer from deflecting beyond said first stop surface;

means for measuring deflection of said second wafer;

wherein said means for measuring comprises a plurality of piezoresistive elements formed in said second wafer;

a plurality of respective electrical feedthroughs formed in said first wafer to provide electrical communication between a laminated surface of said first wafer and an unlaminated surface of said first wafer;

means for coupling electrical signals between respective ones of said plurality of feedthroughs and said means for measuring, said means for coupling including a plurality of respective conductive regions formed in a laminated surface of said second wafer; and

a plurality of respective metallized regions, each formed in a different respective electrical feedthroughs such that each respective metallized region is electrically coupled to said means for coupling.

9. An electromechanical sensor comprising:

a first semiconductor wafer including a first stop surface residing in a first shallow recessed region of said first wafer;

a second semiconductor wafer;

wherein said first and second semiconductor wafers are laminated together such that said first recessed region of said first wafer and said second wafer define a first chamber in which said first stop surface and said second wafer are disposed close enough together such that said first stop surface restrains said second wafer from deflecting beyond said first stop surface;

means for measuring deflection of said second wafer;

a third semiconductor wafer including a second stop surface residing in a third shallow recessed region of said third wafer;

wherein said second and third semiconductor wafers are laminated together such that said third recessed region of said third wafer and said second wafer define a second chamber in which said second stop surface and said second wafer are disposed close enough together such that said second stop surface restrains said second wafer from deflecting beyond said second stop surface.

10. An electromechanical sensor comprising:

a first silicon wafer including a first stop surface residing in a first shallow recessed region of said first wafer;

a second silicon wafer including a diaphragm including first and second contact surfaces, said diaphragm being suitable to withstand at least a prescribed amount of deflection without sustaining damage;

a third silicon wafer including a second stop surface residing in a second shallow recessed region of said third wafer;

wherein said first, second and third wafers are laminated together with said second wafer sandwiched between said first and third wafers such that said first recessed region and said first contact surface define a first chamber and said second recessed region and said second contact surface define a second chamber;

wherein said first contact surface and said first stop surface are disposed opposite each other in said first chamber and are separated by a predetermined distance selected such that said first contact surface abuts against said first stop surface before said diaphragm reaches said prescribed amount of deflection;

wherein said second contact surface and said second stop surface are disposed opposite each other in said second chamber and are separated by a prescribed distance selected such that said second contact surface abuts against said second stop surface before said diaphragm reaches said prescribed amount of deflection;

means for measuring deflection of said diaphragm;

a first fluid feedthrough port formed in said first wafer to provide fluid communication with said first chamber;

a second fluid feedthrough port formed in said third wafer to provide fluid communication with said second chamber;

first means for preventing said first stop surface and said first contact surface from adhering together; and

second means for preventing said second stop surface and said second contact surface from adhering together.

11. The sensor of claim 10 wherein said first and second contact surfaces reside in respective recessed regions on opposite sides of said diaphragm.

12. The sensor of claim 10 wherein:

said first and second fluid feedthrough ports are respectively disposed in laterally spaced relation to said respective first and second chambers;

said first and second wafers together define at least one first tubular conduit for providing fluid coupling between said first fluid feedthrough port and said first chamber; and

said second and third wafers together define at least one second tubular conduit for providing fluid coupling between said second fluid feedthrough port and said second chamber.

13. The sensor of claim 12 and further comprising:

first means for filtering fluid provided to said at least one first tubular conduit by said first fluid feedthrough port; and

second means for filtering fluid provided to said at least one second tubular conduit by said second fluid feedthrough port.

14. The sensor of claim 13 wherein said diaphragm comprises a center section and thinner, perimeter section which substantially surrounds said center section.

15. The sensor of claim 10 wherein said first and second wafers are bonded directly to one another;

and wherein said second and third wafers are bonded directly to one another.

16. An electromechanical sensor comprising:

a first semiconductor wafer including a first stop surface residing in a first shallow recessed region of said first wafer;

a second semiconductor wafer;

wherein said first and second semiconductor wafers are laminated together such that said first recessed region of said first wafer and said second wafer define a first chamber in which said first stop surface and said second wafer are disposed close enough together such that said first stop surface restrains said second wafer from deflecting beyond said first stop surface;

wherein said first and second wafers are bonded directly to one another;

a first fluid feedthrough port formed in said first wafer to provide fluid communication with said first chamber, said first fluid feedthrough port being disposed in laterally spaced relation to said first chamber;

at least one tubular conduit extending laterally between said first and second wafers for providing fluid coupling between said first fluid feedthrough port and said first chamber;

means for measuring deflection of said second wafer; and

a plurality of upstanding members formed in said first stop surface such that one or more of said plurality of upstanding members abut against said second wafer when said first stop surface restrains said second wafer.

18. The sensor of claim 16 or 17 and further comprising:

means for filtering fluid provided to said at least one tubular conduit.

19. The sensor of claims 16 or 17 and further comprising:

means for filtering fluid provided to said at least one first tubular conduit, said means for filtering including a plurality of channels each having narrower lateral dimensions than said at least one first tubular conduit.

17. An electromechanical sensor comprising:

a first semiconductor wafer including a first stop surface residing in a first shallow recessed region of said first wafer;

a second semiconductor wafer;

wherein said first and second semiconductor wafers are laminated together such that said first recessed region of said first wafer and said second wafer define a first chamber in which said first stop surface and said second wafer are disposed close enough together such that said first stop surface restrains said second wafer from deflecting beyond said first stop surface;

wherein said first and second wafers are bonded directly to one another;

a first fluid feedthrough port formed in said first wafer to provide fluid communication with said first chamber, said first fluid feedthrough port being disposed in laterally spaced relation to said first chamber;

at least one tubular conduit extending laterally between said first and second wafers for providing fluid coupling between said first fluid feedthrough port and said first chamber;

means for measuring deflection of said second wafer; and

a plurality of upstanding members formed in said second wafer such that one or more of said plurality of upstanding members abuts against said first stop surface when said first stop surface restrains said second wafer.

20. An electromechanical sensor comprising:

a first semiconductor wafer including a first stop surface residing in a first shallow recessed region of said first wafer;

a second semiconductor wafer;

wherein said first and second semiconductor wafers are laminated together such that said first recessed region of said first wafer and said second wafer define a first chamber in which said first stop surface and said second wafer are disposed close enough together such that said first stop surface restrains said second wafer from deflecting beyond said first stop surface; and

a third semiconductor wafer including a second stop surface residing in a third shallow recessed region of said third wafer;

wherein said second and third semiconductor wafers are laminated together such that said third recessed region of said third wafer and said second wafer define a second chamber in which said second stop surface and said second wafer are disposed close enough together such that said second stop surface retrains said second wafer from deflecting beyond said second stop surface;

means for measuring deflection of said second wafer;

a first fluid feedthrough port to provide fluid communication with said first chamber, said first fluid feedthrough port being disposed in laterally spaced relation to said first chamber;

a second fluid feedthrough port to provide fluid communication with said second chamber, said second fluid feedthrough port being disposed in laterally spaced relation to said second chamber;

at least one first tubular conduit extending laterally between said first and second wafers for providing fluid coupling between said first fluid feedthrough port and said first chamber;

at least one second tubular conduit extending laterally between said second and third wafers for providing fluid coupling between said second fluid feedthrough port and said second chamber.

21. The sensor of claim 20 and further comprising:

a first plurality of upstanding members formed in at least one of, the first stop surface and a portion of said second wafer opposite said first stop surface, for preventing said second wafer from adhering to said first stop surface when said first stop surface restrains said second wafer; and

a second plurality of upstanding members formed in at least one of, the second stop surface and a portion of said second wafer opposite said second stop surface, for preventing said second wafer from adhering to said second stop surface when said second stop surface restrains said second wafer.

22. The sensor of claim 20 and further comprising:

first means for filtering fluid provided to said at least one first tubular conduit, said first means for filtering including a plurality of channels each having narrower lateral dimensions than said at least one first tubular conduit; and

second filtering means for filtering fluid provided to said at least one second tubular conduit, said means for filtering including a plurality of channels each having narrower lateral dimensions than said at least one second tubular conduit.

23. The sensor of claim 20, 21 or 22 wherein said first and second wafers are bonded directly to one another;

and wherein said second and third wafers are bonded directly to one another.