Abstract:
A composite wafer level MEMS force dies including a spacer coupled to a sensor is described herein. The sensor includes at least one flexible sensing element, such as a beam or diaphragm, which have one or more sensor elements formed thereon. Bonding pads connected to the sensor elements are placed on the outer periphery of the sensor. The spacer, which protects the flexible sensing element and the wire bonding pads, is bonded to the sensor. For the beam version, the bond is implemented at the outer edges of the die. For the diaphragm version, the bond is implemented in the center of the die. An interior gap between the spacer and the sensor allows the flexible sensing element to deflect. The gap can also be used to limit the amount of deflection of the flexible sensing element in order to provide overload protection.
Abstract:
Described herein are ruggedized wafer level MEMS force dies composed of a platform and a silicon sensor. The silicon sensor employs multiple flexible sensing elements containing Piezoresistive strain gages and wire bonds.
Abstract:
A microelectromechanical (“MEMS”) load sensor device for measuring a force applied by a human user is described herein. In one aspect, the load sensor device has a contact surface in communication with a touch surface which communicates forces originating on the touch surface to a deformable membrane, on which load sensor elements are arranged, such that the load sensor device produces a signal proportional to forces imparted by a human user along the touch surface. In another aspect, the load sensor device has an overload protection ring to protect the load sensor device from excessive forces. In another aspect, the load sensor device has embedded logic circuitry to allow a microcontroller to individually address load sensor devices organized into an array. In another aspect, the load sensor device has electrical and mechanical connectors such as solder bumps designed to minimize cost of final component manufacturing.
Abstract:
An interface device for measuring forces applied to the interface device. The interface device has a flexible contact surface suspended above a rigid substrate. The interface device has at least one sensor in communication with the contact surface. The interface device has processing circuitry for receiving signals from the sensors and substantially instantaneously producing an output signal corresponding to the location and force applied in multiple locations across the contact surface.
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 sensor in chip scale package form factor. For example, a non-vacuum packaged sensor chip described herein includes a substrate, and a sensing element arranged on the substrate. The sensing element is configured to change resistance with temperature. Additionally, the non-vacuum packaged sensor chip includes an absorbing layer configured to absorb middle infrared (“MIR”) radiation.
Abstract:
Described herein is a ruggedized microelectromechanical (“MEMS”) force sensor. The sensor employs piezoresistive or piezoelectric sensing elements for force sensing where the force is converted to strain and converted to electrical signal. In one aspect, both the piezoresistive and the piezoelectric sensing elements are formed on one substrate and later bonded to another substrate on which the integrated circuitry is formed. In another aspect, the piezoelectric sensing element is formed on one substrate and later bonded to another substrate on which both the piezoresistive sensing element and the integrated circuitry are formed.
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 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 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.