Sealed force sensor with etch stop layer
AssigneeNextInput, Inc.
InventorsJulius Minglin Tsai, Ryan Diestelhorst, Dan Benjamin
Life of this patent
Estimating the term…
Abstract
An example microelectromechanical system (MEMS) force sensor is described herein. The MEMS force sensor can include a sensor die configured to receive an applied force. The sensor die can include a first substrate and a second substrate, where a cavity is formed in the first substrate, and where at least a portion of the second substrate defines a deformable membrane. The MEMS force sensor can also include an etch stop layer arranged between the first substrate and the second substrate, and a sensing element arranged on a surface of the second substrate. The sensing element can be configured to convert a strain on the surface of the membrane substrate to an analog electrical signal that is proportional to the strain.
Claims20
A microelectromechanical system (MEMS) device, comprising:
- a substrate;
- and
- a MEMS force sensor mounted on the substrate, the MEMS force sensor comprising:
- a sensor die configured to receive an applied force, the sensor die comprising a first substrate and a second substrate, wherein at least a portion of the second substrate defines a deformable membrane;
- a cavity formed in the first substrate;
- a sensing element on a surface of the second substrate, the sensing element operable to convert a strain on the surface of the second substrate to an analog electrical signal that is proportional to the strain;
- a protective layer at least partially covering the surface of the second substrate;
- and
- a conductive pad on the protective layer and electrically coupled to the sensing element, wherein:
- the MEMS force sensor is mounted on the substrate using an under bump metal (UBM) layer that is on the conductive pad and an electrical connector that is between the UBM layer and the substrate;
- and
- the conductive pad is electrically coupled to the substrate through the UBM layer and the electrical connector.
A method of manufacturing a microelectromechanical system (MEMS) device, the method comprising:
- providing an etch stop layer between a first substrate and a deformable membrane of a second substrate;
- etching the first substrate to remove a portion of the first substrate to form a cavity in the first substrate;
- providing a sensing element on a surface of the deformable membrane;
- providing a conductive pad over the surface of the second substrate and electrically coupling the conductive pad to the sensing element;
- providing an under bump metal (UBM) layer on the conductive pad;
- providing an electrical connector on the UBM layer;
- and
- mounting a substrate on the electrical connector, wherein the conductive pad is electrically coupled to the substrate through the UBM layer and the electrical connector.
A microelectromechanical system (MEMS) force sensor, comprising:
- a sensor die configured to receive an applied force, the sensor die comprising a first substrate bonded to a second substrate, wherein at least a portion of the second substrate defines a deformable membrane;
- a cavity in the first substrate;
- an etch stop layer between the first substrate and the second substrate, wherein the etch stop layer at least partially covers the deformable membrane of the second substrate;
- a sensing element on a surface of the second substrate, the sensing element operable to convert a strain on the surface of the second substrate to an analog electrical signal that is proportional to the strain;
- a protective layer at least partially over the surface of the second substrate;
- and
- a conductive pad on the protective layer and electrically coupled to the sensing element.
Dependencies are inferred from the claim text.