摘要:
A pressure sensor is described with sensing elements electrically and physically isolated from a pressurized medium. An absolute pressure sensor has a reference cavity, which can be at a vacuum or zero pressure, enclosing the sensing elements. The reference cavity is formed by bonding a recessed cap wafer with a gauge wafer having a micromachined diaphragm. Sensing elements are disposed on a first side of the diaphragm. The pressurized medium accesses a second side of the diaphragm opposite to the first side where the sensing elements are disposed. A spacer wafer may be used for structural support and stress relief of the gauge wafer. In one embodiment, vertical through-wafer conductive vias are used to bring out electrical connections from the sensing elements to outside the reference cavity. In an alternative embodiment, peripheral bond pads on the gauge wafer are used to bring out electrical connections from the sensing elements to outside the reference cavity
摘要:
The invention provides a submersible, electrically-powered sensor assembly that incorporates a flexible seal assembly having operative and non-operative electrical traces of a uniform vertical height for carrying clamping loads and avoiding signal loss along a signal carrying trace due to compression of the flex seal, minimizing fluid leak paths between two flange surfaces, providing stability in compression, and enabling electrical communication in an environment having an operating fluid.
摘要:
A temperature compensated CMOS RC oscillator circuit changes the source- bulk voltage to stabilize the MOSFET's threshold voltage variation over temperature using a resistor and temperature-correlated bias current. The MOSFET's source is connected to ground through a resistor. This temperature-correlated bias current also runs through this resistor. When temperature increases, the bias current also increases, which increases the MOSFET's source-bulk voltage. The increased source-bulk voltage helps to stabilize the threshold voltage of MOSFET at high temperature. A power saving logic is also embedded in this oscillator to achieve higher frequency at lower power consumption. In the present invention, there is no high gain op amp or high speed comparator, which makes the resultant oscillator to be low power design and which can be integrated into a single chip with other system.
摘要:
A sensor device and a method of forming comprises a die pad receives a sensor device, such as a MEMS device. The MEMS device has a first coefficient of thermal expansion (CTE). The die pad is made of a material having a second CTE compliant with the first CTE. The die pad includes a base and a support structure with a CTE compliant with the first and second CTE. The die pad has a support structure that protrudes from a base. The support structure has a height and wall thickness which minimize forces felt by the die pad and MEMS device when the base undergoes thermal expansion or contraction forces from a header.
摘要:
The present invention disclosed provides for a rugged, compact sensing device for various implementations including those of automotive, marine, and other combustion technologies that require low cost accurate pressure sensing during internal combustion engine process. In one or more aspects of the present invention, a MEMS sensor connection with a flexible circuit is presented and the communication of which is preferably achieved through the use of wire bond technology.
摘要:
The present invention disclosed provides for a rugged, compact sensing device for various implementations including those of automotive, marine, and other combustion technologies that require low cost accurate pressure sensing during internal combustion engine process. In one or more aspects of the present invention, a MEMS sensor connection with a flexible circuit is presented and the communication of which is preferably achieved through the use of wire bond technology.
摘要:
A method for separating a plurality of dies on a Micro-Electro-Mechanical System (MEMS) wafer comprising scribing a notch on a first side of the wafer between at least two of the plurality of dies on a first surface and depositing a metal on the first surface of the plurality of dies. The method further comprises scribing a second side of the wafer between at least two of the plurality of dies from a second surface thereof through the notch. The first side and second side are substantially parallel and opposite each other and the first surface and the second surface are substantially parallel and opposite each other. In a process in accordance with the present invention, a method to minimize chipping of the bonding portion of a MEMs device during sawing of the wafer is provided, which minimally affects the process steps associated with separating the die on a wafer.