Polymer layer system pressure sensor device, and polymer layer system pressure sensor method

• US 9,766,144 B2
• Filed: 07/03/2012
• Issued: 09/19/2017
• Est. Priority Date: 08/31/2011
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Brettschneider, Thomas, Dorrer, Christian
• Primary Examiner(s): Caputo, Lisa
• Assistant Examiner(s): Tran, Tran M
• Application Number:
  US14/239,802
• Publication Number:
  US 20140290373A1
• Time in Patent Office: 1,904 Days
• Field of Search: 73718
• CPC Class Codes: B01L 2200/146 Employing pressure sensors
• CPC Class Codes: B01L 2300/0663 Whole sensors
• CPC Class Codes: B01L 3/502707 characterised by the manufacture of the container or its components by shaping or joining plastic parts B29C59/00, B29C65/00; by laminating B32B37/00; manufacture of microstructural devices in general B81C
• CPC Class Codes: G01L 7/00 Measuring the steady or quasi-steady pressure of a fluid or a fluent solid material by mechanical or fluid pressure-sensitive elements G01L11/004 takes precedence; transmitting or indicating the displacement of mechanical pressure-sensitive elements by electric , e.g., photoelectric or magnetic means G01L9/00; measuring differences of two or more pressure values G01L13/00; measuring two or more pressure values simultaneously G01L15/00
• CPC Class Codes: G01L 9/0045 Diaphragm associated with a buried cavity
• CPC Class Codes: G01L 9/0052 of piezoresistive elements circuits therefor G01L9/06
• CPC Class Codes: G01L 9/0072 using variations in capacitance

Abstract

A polymer layer system pressure sensor device includes a first polymer substrate having a first cavity and a first polymer membrane stretched over the first cavity. The first polymer membrane is configured to be deflected dependent on a pressure in the first cavity. The device further includes a first membrane metallization layer applied to the first polymer membrane above the first cavity. The first membrane metallization layer is configured to be deflected together with the first polymer membrane dependent on the pressure in the first cavity. The device further includes a second polymer substrate, arranged over the first polymer membrane, a second cavity, arranged over the first cavity, and a second polymer membrane, stretched over the second cavity. The device further includes a second membrane metallization layer applied to the second polymer membrane within the second cavity and includes a third polymer substrate arranged over the second polymer membrane.

Claims

1. A polymer layer system pressure sensor device, comprising:

a first polymer substrate with a first cavity;

a first polymer membrane stretched over the first cavity and configured to be deflected vertically in dependence on a pressure in the first cavity;

a first membrane metallization portion attached on the first polymer membrane above the first cavity and configured to be deflected together with the first polymer membrane in dependence on the pressure in the first cavity;

a second polymer substrate arranged over the first polymer membrane and having a second cavity arranged over the first cavity;

a second polymer membrane stretched over the second cavity;

a second membrane metallization portion attached on the second polymer membrane within the second cavity; and

a third polymer substrate arranged over the second polymer membrane, wherein the second cavity is connected to a first pressure channel, configured to run in the second polymer substrate, wherein the first membrane metallization portion and the second membrane metallization portion are configured to come into contact with one another when there is deflection under pressure.

2. The polymer layer system pressure sensor device as claimed in claim 1, wherein the second polymer membrane is not deflectable.

3. The polymer layer system pressure sensor device as claimed in claim 1, wherein:

the first cavity is connected to a second pressure channel and a third pressure channel, and

the second pressure channel and the third pressure channel are configured to run in the first polymer substrate.

4. The polymer layer system pressure sensor device as claimed in claim 1, wherein the first membrane metallization portion is connected by at least one first conductor track to a side of the second cavity, and the second membrane metallization portion is connected by at least one second conductor track to the side of the second cavity.

5. The polymer layer system pressure sensor device as claimed in claim 1, wherein:

the first membrane metallization portion includes a part-area central metallization region on the first polymer membrane, and the part-area central metallization region is suspended in the first membrane metallization portion by relieving elements.

6. The polymer layer system pressure sensor device as claimed in claim 1, wherein the second membrane metallization portion is configured as a conductor track such that, when is the first membrane metallization portion and the second membrane metallization portion are brought into contact by deflection under pressure, a resistance between two ends of the second membrane metallization portion is dependent on the pressure in the first cavity.

7. The polymer layer system pressure sensor device as claimed in claim 1, wherein the first cavity includes a first part-cavity and a second part-cavity, which are separated by a web, over which the first polymer membrane is stretched.

8. The polymer layer system pressure sensor device of claim 1, further comprising:

a second pressure channel and a third pressure channel extending horizontally from the first cavity within the first polymer substrate.

9. A method of sensing pressure in a polymer layer system, comprising:

sensing the pressure in a first cavity of a first polymer substrate based on a capacitance between a first membrane metallization portion attached on a first polymer membrane above the first cavity and a second membrane metallization portion attached on a second polymer membrane within a second cavity, wherein

the second cavity is connected to a first pressure channel, configured to run in the second polymer substrate.

10. The method of claim 9, comprising:

introducing a pressure into the first cavity through a second pressure channel extending horizontally from the first cavity within the first polymer substrate, wherein

sensing the pressure comprises vertically deflecting at least one of the second membrane metallization layer and the first membrane metallization layer.

11. A method of sensing pressure in a polymer layer system, comprising:

sensing the pressure in a first cavity of a first polymer substrate based on a resistance of a second membrane metallization layer attached on a second polymer membrane above the first cavity,

wherein the second membrane metallization layer and a first membrane metallization layer, attached on the first polymer membrane above the first cavity, are configured to come into contact with one another when there is deflection under pressure.

12. The method of claim 11, comprising:

introducing a pressure into the first cavity through a first pressure channel extending horizontally from the first cavity within the first polymer substrate, wherein

sensing the pressure comprises vertically deflecting at least one of the second membrane metallization layer and the first membrane metallization layer.