Abstract:
Tire sensor packaging capable of being installed on a standard snap-in tire valve stem is provided. The sensor package includes an attachment member capable of being disposed in the flexible bore of a snap-in tire valve stem, and of securely engaging with the inner wall of the flexible bore. The attachment member can be an integral part of the sensor package, or it can be a separate part that acts as an expansion device when engaged with the sensor package. Preferably, the attachment member includes features, such as barbs, to provide more secure engagement with the tire valve stem. Packages according to embodiments of the invention include a package passage to permit the flow of air past the sensor, so that the tire can be inflated or deflated. Sensors can be attached to the tire valve stem before or after the tire valve stem is installed in the wheel.
Abstract:
Improved sensor packaging is provided with a hybrid integration approach. In one example, an application specific integrated circuit (ASIC) for sensor signal conditioning is packaged. The ASIC package has an aperture in it that exposes a chip to chip bonding interface of the ASIC chip. The rest of the ASIC chip is surrounded by the package, including the connections between the external package leads and the ASIC chip. A sensor^ chip, also having a chip to chip bonding interface, is disposed in the package aperture and bonded to the ASIC chip. such that the two chip to chip bonding interfaces are connected. Flip chip bonding of the sensor chip to the ASIC chip is a preferred approach for chip to chip bonding. The vertical gap between the two chips can be filled in by an underfill process. The lateral gap between the sensor chip and the package can also be filled.
Abstract:
Improved sensor packaging is provided with a hybrid integration approach. In one example, an application specific integrated circuit (ASIC) for sensor signal conditioning is packaged. The ASIC package has an aperture in it that exposes a chip to chip bonding interface of the ASIC chip. The rest of the ASIC chip is surrounded by the package, including the connections between the external package leads and the ASIC chip. A sensor^ chip, also having a chip to chip bonding interface, is disposed in the package aperture and bonded to the ASIC chip. such that the two chip to chip bonding interfaces are connected. Flip chip bonding of the sensor chip to the ASIC chip is a preferred approach for chip to chip bonding. The vertical gap between the two chips can be filled in by an underfill process. The lateral gap between the sensor chip and the package can also be filled.
Abstract:
A tire pressure monitoring system is provided that includes a switched capacitor circuit having a clock with two non-overlapping clock phases that control a state of analog switches of the switched capacitor circuit. The system uses tire pressure sensor MEMS capacitors that are measured differentially. A capacitance-to-voltage converter is connected to the MEMS sense capacitor, and a sigma-delta converter having a comparator with a first digital output state and a second digital output state is used. The first output state is a sum of reference voltages and the second output state is a difference of the reference voltages. An average value of the capacitance-to-voltage converter output is driven to a zero value and a digital output is provided of the average output states that is equal to a difference between the MEMS capacitors divided by their sum multiplied by a ratio of the reference voltages.
Abstract:
The present invention provides an inertial energy scavenger that includes at least one piezoelectric element held by a housing, a proof mass that is movable within the housing in a direction parallel to the piezoelectric element, and a mechanical assembly disposed between the proof mass and the piezoelectric element. The mechanical assembly transfers work from the proof mass to the piezoelectric element, where the work from the proof mass is a first force along a first distance and the work to the piezoelectric element is a second force along a second distance. The first distance is greater than the second distance and the first force is smaller than the second force. Force amplification is determined by the geometry of the mechanical transfer assembly and can range anywhere from just above 1 to at least 10, where some embodiments include a bi-lever configuration, a tube-shaped configuration and a reverse actuation configuration.
Abstract:
The present invention provides a tire pressure sensor system that has multiple functions and is integrated into a small package. The system includes one or more Micro Electro Mechanical System (MEMS)-based sensors, including a MEMS-based pressure sensor; a MEMS-oscillator-based wireless signal transmitter; and a microcontroller, where the microcontroller processes the data generated by at least one of the MEMS-based sensors, controls at least one of the MEMS-based sensors, and controls the encoding and timing of transmission of data from the wireless signal transmitter. Preferably, the MEMS-based sensors, MEMS-oscillator-based wireless signal transmitter, and microcontroller are integrated onto one or more chips in one or more packages. The system also preferably includes a MEMS-based motion sensor, a low frequency (LF) receiver, an IC-based voltage sensor, a voltage regulator, a temperature sensor and a polarization voltage generator. Thus, the disclosed tire pressure sensor system is high in functionality, yet small in size.
Abstract:
A method of powering one or more electronic devices in a tire monitoring system using a tire pressure based energy scavenger is provided. With this method, a tire is rotated on a surface to generate pressure changes within the tire. These pressure changes are then converted into electrical energy with a transducer and the energy is stored. The electrical energy or stored electrical energy can then be used to power one or more electronic devices in a tire monitoring system, such as a tire pressure sensor, temperature sensor, acceleration profile sensor, and/or a tire wear monitor. A tire monitoring system with a tire pressure based energy scavenger is also provided.
Abstract:
The devices presented herein are capacitive sensors with single crysta silicon on all key stress points. Isolating trenches are formed by trench and refill forning dielectrically isolated conductive silicon electrodes for drive, sense and guards, For pressure sensing devices according to the invention, the pressure port is opposed to the e ectrical wire bond pads for ease of packaging. Dual-axis accelerometers measuring in plane acceleration and out of plane acceleration are also described. A third axis in plane is i easy to achieve by duplicating and rotating the accelerometer 90 degrees about its out of plane axis Creating resonant structures, angular rate sensors, bolometers, and many other structures are possible with this process technology. Key advantages are hermeti ity, vertical vias, vertical and horizontal gap capability, single crystal materials, wafejr level packaging, small size, high performance and low cost.
Abstract:
The devices presented herein are capacitive sensors with single crysta silicon on all key stress points. Isolating trenches are formed by trench and refill forning dielectrically isolated conductive silicon electrodes for drive, sense and guards, For pressure sensing devices according to the invention, the pressure port is opposed to the e ectrical wire bond pads for ease of packaging. Dual-axis accelerometers measuring in plane acceleration and out of plane acceleration are also described. A third axis in plane is i easy to achieve by duplicating and rotating the accelerometer 90 degrees about its out of plane axis Creating resonant structures, angular rate sensors, bolometers, and many other structures are possible with this process technology. Key advantages are hermeti ity, vertical vias, vertical and horizontal gap capability, single crystal materials, wafejr level packaging, small size, high performance and low cost.
Abstract:
The present invention provides a tire pressure sensor system that has multiple functions and is integrated into a small package. The system includes one or more Micro Electro Mechanical System (MEMS)-based sensors, including a MEMS-based pressure sensor; a MEMS-oscillator-based wireless signal transmitter; and a microcontroller, where the microcontroller processes the data generated by at least one of the MEMS-based sensors, controls at least one of the MEMS-based sensors, and controls the encoding and timing of transmission of data from the wireless signal transmitter. Preferably, the MEMS-based sensors, MEMS-oscillator-based wireless signal transmitter, and microcontroller are integrated onto one or more chips in one or more packages. The system also preferably includes a MEMS-based motion sensor, a low frequency (LF) receiver, an IC-based voltage sensor, a voltage regulator, a temperature sensor and a polarization voltage generator. Thus, the disclosed tire pressure sensor system is high in functionality, yet small in size.