Flexible disposable MEMS pressure sensor

Patent metadata

Field	Value
Publication number	US-10479677-B2
Application number	US-201515535327-A
Country	US
Kind code	B2
Filing date	Dec 10, 2015
Priority date	Dec 15, 2014
Publication date	Nov 19, 2019
Grant date	Nov 19, 2019

Abstract

A MEMS device, e.g., a flexible MEMS pressure sensor, is formed by disposing a sacrificial layer, such as photoresist, on a substrate. A first flexible support layer is disposed on the substrate, and a first conductive layer is disposed over a portion of the first support layer. A liquid or gel separator, e.g., silicone oil, is disposed on an internal region of the first conductive layer. A second flexible support layer encapsulates the first conductive layer and the separator. A second conductive layer disposed over the second support layer at least partially overlaps the first conductive layer and forms a parallel plate capacitor. A third flexible support layer encapsulates the second conductive layer and second support layer. Soaking the sensor in hot water releases the sensor from the sacrificial layer.

First claim

What is claimed is:

1. A MEMS device comprising:
a flexible MEMS sensor element formed by a plurality of layers, the plurality of layers including:
a first flexible support layer; and
a first conducting layer that extends from a first side of the MEMS sensor element and that is configured to operatively connect the MEMS sensor element to an apparatus;
a second flexible support layer disposed over the first flexible support layer and the first conducting layer, such that the first conducting layer is encapsulated by the first flexible support layer and the second flexible support layer, the first conducting layer being disposed on the first flexible support layer, and extending over less than an entirety of the MEMS sensor element toward a second side opposite the first side;
a second conducting layer disposed on the second flexible support layer and including a first end and a second end, the second conducting layer extending from the first end, located at the second side of the MEMS sensor element, over less than an entirety of the MEMS sensor element toward the first side, the second conducting layer at least partially overlaps the first conducting layer, the first and second conducting layers together forming a parallel plate capacitor; and
a third flexible support layer disposed over the second conducting layer and the second flexible support layer such that the second conducting layer is encapsulated between the second flexible support layer and the third flexible support layer from the first end to the second end,

wherein each layer of the MEMS sensor element includes flexible materials such that each layer of the MEMS sensor element is flexible.

2. The MEMS device of claim 1 , the MEMS sensor element being a MEMS pressure sensor.

3. The MEMS device of claim 1 , the MEMS sensor element further including:
a separator encapsulated between the first conducting layer and the second flexible support layer, and configured to space apart the first conductor layer from the second conductor layer.

4. The MEMS device of claim 3 , wherein:
the separator is one of a liquid or a gel; and
the separator has a lower vaper pressure than a deposition pressure of the second flexible support layer.

5. The MEMS device of claim 4 , wherein:
the second flexible support layer includes a Parylene; and
the separator includes a silicone oil.

6. The MEMS device of claim 3 , the MEMS sensor element further including at least one of:
a connecting element that extends from the first conducting layer to the second side of the MEMS sensor element; and
a connecting element that extends from the second conducting layer to the first side of the MEMS sensor element.

7. The MEMS device of claim 1 , further comprising:
at least one apparatus body mount that includes:
at least one electrical component that is configured to removably receive the MEMS sensor element, and that is configured to electrically connect to the MEMS sensor element when the MEMS sensor element is received in the at least one apparatus body mount,

wherein the at least one apparatus body mount is configured to removably receive the MEMS sensor element in such a way that the at least one apparatus body is reusable upon removal of the MEMS sensor element.

8. The MEMS device of claim 7 , the at least one apparatus body mount further including:
a pair of mounting members configured to receive the MEMS sensor element therebetween with an interference fit,
wherein at least one of the mounting members is a spring member that is pivotably mounted on the at least one apparatus body mount, and that is configured to clip the MEMS sensor element into the at least one apparatus body mount along with an opposite mounting member.

9. The MEMS device of claim 1 , wherein third flexible support layer extends from the first side to the second side so as to cover the second conducting layer and a portion of the second flexible support layer not in contact with the second conducting layer such that the first conducting layer, the second flexible support layer, and the second conducting layer are between and encapsulated by the first flexible support layer and the third flexible support layer.

10. A method of producing a MEMS device, comprising:
disposing a layer of photoresist on a substrate;
forming a MEMS sensor element over the layer of photoresist to form an intermediate structure, wherein the MEMS sensor element is at least one of:
encapsulated by material that is insoluble to water; and
configured so as to be unreactive to water; and

soaking the intermediate structure in a water bath having a temperature from about 30 degrees C. to about 90 degrees C. until the MEMS sensor element is released from the layer of photoresist.

11. A method of producing a flexible MEMS pressure sensor, comprising:
forming a sacrificial layer on a substrate;
forming a first flexible support layer on the substrate;
forming a first conducting layer on the first flexible layer that extends from a first side over less than an entirety of the first flexible support layer;
forming a liquid or gel separator on an internal region of the first conducting layer;
forming a second flexible support layer via vapor deposition on the first flexible support layer, on the separator, and on the first conducting layer, extending from the first side to a second side opposite the first side, so as to encapsulate the separator between the first conducting layer and the second flexible support layer, and so as to encapsulate the first conducting layer between the first flexible support layer and the second flexible support layer and separator, wherein the separator has a lower vapor pressure than a vapor pressure that occurs during the vapor deposition of the second flexible support layer;
forming a second conducting layer on the second flexible support layer, the second conducting layer having a first end and a second end, the second conducting layer extending from the first end, located at the second side, over less than an entirety of the second flexible support layer, such that the second conducting layer at least partially overlaps the first conductive layer to form a parallel plate capacitor; and
forming a third flexible support layer over the second conducting layer and the second flexible support layer so as to encapsulate the second conducting layer between the second flexible support layer and the third flexible support layer from the first end to the second end.

12. The method of claim 11 , further comprising:
soaking the MEMS pressure sensor in a water bath having a temperature of about 30 degrees C. to about 90 degrees C. until the MEMS pressure sensor is released from the sacrificial layer.

13. The method of claim 11 , wherein third flexible support layer extends from the first side to the second side so as to cover the second conducting layer and a portion of the second flexible support layer not in contact with the second conducting layer such that the first conducting layer, the second flexible support layer, and the second conducting layer are between and encapsulated by the first flexible support layer and the third flexible support layer.

Assignees

• Bosch Gmbh Robert
• Yee Seow Yuen
• Yama Gary

Inventors

• Yee Seow Yuen
• Yama Gary

Classifications

• G01L19/147

  Details about the mounting of the sensor to support or covering means · CPC title

• B81C99/008 Primary

  separating the processed structure from a mother substrate · CPC title

• B81B2201/0264

  Pressure sensors · CPC title

• G01L19/144

  with dismountable parts, e.g. for maintenance purposes or for ensuring sterile conditions (for detachable interface or adapter between the process medium and the pressure gauge G01L19/003) · CPC title

• B81C2201/056

  Releasing structures at the end of the manufacturing process · CPC title