Abstract:
MEMS force sensors for providing temperature coefficient of offset (TCO) compensation are described herein. An example MEMS force sensor can include a TCO compensation layer to minimize the TCO of the force sensor. The bottom side of the force sensor can be electrically and mechanically mounted on a package substrate while the TCO compensation layer is disposed on the top side of the sensor. It is shown the TCO can be reduced to zero with the appropriate combination of Young's modulus, thickness, and/or thermal coefficient of expansion (TCE) of the TCO compensation layer.
Abstract:
Described herein is a force attenuator for a force sensor. The force attenuator can linearly attenuate the force applied on the force sensor and therefore significantly extend the maximum sensing range of the force sensor. The area ratio of the force attenuator to the force sensor determines the maximum load available in a linear fashion.
Abstract:
Described herein is a ruggedized microelectromechanical (“MEMS”) force sensor including both piezoresistive and piezoelectric sensing elements and integrated with complementary metal-oxide-semiconductor (“CMOS”) circuitry on the same chip. The sensor employs piezoresistive strain gauges for static force and piezoelectric strain gauges for dynamic changes in force. Both piezoresistive and piezoelectric sensing elements are electrically connected to integrated circuits provided on the same substrate as the sensing elements. The integrated circuits can be configured to amplify, digitize, calibrate, store, and/or communicate force values electrical terminals to external circuitry.
Abstract:
Described herein is a ruggedized wafer level microelectromechanical (“MEMS”) force sensor including a base and a cap. The MEMS force sensor includes a flexible membrane and a sensing element. The sensing element is electrically connected to integrated complementary metal-oxide-semiconductor (“CMOS”) circuitry provided on the same substrate as the sensing element. The CMOS circuitry can be configured to amplify, digitize, calibrate, store, and/or communicate force values through electrical terminals to external circuitry.
Abstract:
In one embodiment, a ruggedized wafer level microelectromechanical (“MEMS”) force sensor includes a base and a cap. The MEMS force sensor includes a flexible membrane and a sensing element. The sensing element is electrically connected to integrated complementary metal-oxide-semiconductor (“CMOS”) circuitry provided on the same substrate as the sensing element. The CMOS circuitry can be configured to amplify, digitize, calibrate, store, and/or communicate force values through electrical terminals to external circuitry.
Abstract:
Described herein is a method and system for testing a force or strain sensor in a continuous fashion. The method employs a sensor, a test fixture, a load cell, a mechanical actuator and tester hardware and software to simultaneously record signal outputs from the sensor and load cell as functions of time. The method provides time synchronization events for recording data streams between, for example, a linear ramp of the force on, or displacement of, the sensor and for extracting performance characteristics from the data in post-test processing.
Abstract:
In one embodiment, a ruggedized wafer level microelectromechanical (“MEMS”) force sensor includes a base and a cap. The MEMS force sensor includes a flexible membrane and a sensing element. The sensing element is electrically connected to integrated complementary metal-oxide-semiconductor (“CMOS”) circuitry provided on the same substrate as the sensing element. The CMOS circuitry can be configured to amplify, digitize, calibrate, store, and/or communicate force values through electrical terminals to external circuitry.
Abstract:
Described herein is a ruggedized microelectromechanical (“MEMS”) force sensor including a sensor die and a strain transfer layer. The MEMS force sensor employs piezoresistive or piezoelectric strain gauges for strain sensing where the strain is transferred through the strain transfer layer, which is disposed on the top or bottom side of the sensor die. In the case of the top side strain transfer layer, the MEMS force sensor includes mechanical anchors. In the case of the bottom side strain transfer layer, the protection layer is added on the top side of the sensor die for bond wire protection.
Abstract:
An example MEMS force sensor is described herein. The MEMS force sensor can include a cap for receiving an applied force and a sensor bonded to the cap. A trench and a cavity can be formed in the sensor. The trench can be formed along at least a portion of a peripheral edge of the sensor. The cavity can define an outer wall and a flexible sensing element, and the outer wall can be arranged between the trench and the cavity. The cavity can be sealed between the cap and the sensor. The sensor can also include a sensor element formed on the flexible sensing element. The sensor element can change an electrical characteristic in response to deflection of the flexible sensing element.
Abstract:
MEMS force sensors for providing temperature coefficient of offset (TCO) compensation are described herein. An example MEMS force sensor can include a TCO compensation layer to minimize the TCO of the force sensor. The bottom side of the force sensor can be electrically and mechanically mounted on a package substrate while the TCO compensation layer is disposed on the top side of the sensor. It is shown the TCO can be reduced to zero with the appropriate combination of Young’s modulus, thickness, and/or thermal coefficient of expansion (TCE) of the TCO compensation layer.