摘要:
A method for manufacturing a Micro-Electro-Mechanical System pressure sensor, including forming a gauge wafer including a diaphragm and a pedestal region. The method includes forming an electrical insulation layer disposed on a second surface of the diaphragm region and forming a plurality of sensing elements patterned on the electrical insulation layer disposed on the second surface in the diaphragm region, forming a cap wafer with a central recess in an inner surface and a plurality of through-wafer embedded vias made of an electrically conductive material in the cap wafer, creating a sealed cavity by coupling the inner recessed surface of the cap wafer to the gauge wafer, such that electrical connections from the sensing elements come out to an outer surface of the cap wafer through the vias, and attaching a spacer wafer with a central aperture to the pedestal region with the central aperture aligned to the diaphragm region.
摘要:
A sensor device and a method of forming thereof comprises a die pad having an inner portion and an outer portion. The outer portion is made of steel, aluminum or other metal and is adapted to mount the die pad to a support structure having a first coefficient of thermal expansion (CTE) value and provide a hermetic seal therewith. The outer portion is made of a material having a CTE value substantially complaint with the first CTE value. The inner portion may be made of Invar, Kovar or ceramic material to receive a MEMS device having a second CTE value. The inner portion is made of a material having a CTE value substantially compliant with the second CTE value. The outer portion has a thickness less than that of the inner portion. The die pad may include a trench between outer edges of the outer and inner portions.
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 method for manufacturing a Micro-Electro-Mechanical System pressure sensor. The method includes forming a gauge wafer including a diaphragm and a pedestal region. The method includes forming an electrical insulation layer disposed on a second surface of the diaphragm region and forming a plurality of sensing elements patterned on the electrical insulation layer disposed on the second surface in the diaphragm region. The method includes forming a cap wafer with a central recess in an inner surface and a plurality of through-wafer embedded vias made of an electrically conductive material in the cap wafer. The method includes creating a sealed cavity by coupling the inner recessed surface of the cap wafer to the gauge wafer, such that electrical connections from the sensing elements come out to an outer surface of the cap wafer through the vias. The method includes attaching a spacer wafer with a central aperture to the pedestal region with the central aperture aligned to the diaphragm region.
摘要:
A low cost micro-electronic package for MEMS applications includes a package substrate, a MEMS device and a buffer insert which is placed between the MEMS device and the package substrate. The buffer insert has a coefficient of thermal expansion (CTE) which is compatible with the material of the MEMS device and is sufficiently rigid to isolate the MEMS device from thermal, mechanical and other physical stresses applied to the package substrate. In an embodiment, the package is formed as an integrated device which includes both the MEMS device and a signal conditioning integrated circuit, potentially found in the same die. The substrate insert may be made of a material having a CTE value compatible with silicon (Si), such as Kovar, Invar, or an appropriate ceramic material or the like.
摘要:
An application specific integrated circuit (ASIC) is disclosed. The ASIC comprises an internal circuit coupled between a power line and ground and an output buffer coupled to the internal circuit; wherein the output buffer provides an output signal. The ASIC includes a fault detection circuit coupled between the power line and ground; and a first protection block configured to receive a first control signal from the fault detection circuit. The first switch is coupled to the power line, the output buffer and the internal circuit. The first protection block prevents current from flowing between the power line and ground when a fault condition is detected. The ASIC further includes a second protection block configured to receive a second control signal from the fault detection circuit, wherein the second protection block is coupled to the output signal, the power line and ground. The second protection block prevents current from flowing between the power line and ground or the power line and the output line when a fault condition is detected.
摘要:
A method for manufacturing a Micro-Electro-Mechanical System pressure sensor, including forming a gauge wafer including a diaphragm and a pedestal region. The method includes forming an electrical insulation layer disposed on a second surface of the diaphragm region and forming a plurality of sensing elements patterned on the electrical insulation layer disposed on the second surface in the diaphragm region, forming a cap wafer with a central recess in an inner surface and a plurality of through-wafer embedded vias made of an electrically conductive material in the cap wafer, creating a sealed cavity by coupling the inner recessed surface of the cap wafer to the gauge wafer, such that electrical connections from the sensing elements come out to an outer surface of the cap wafer through the vias, and attaching a spacer wafer with a central aperture to the pedestal region with the central aperture aligned to the diaphragm region.
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 method for manufacturing a Micro-Electro-Mechanical System pressure sensor. The method includes forming a gauge wafer including a diaphragm and a pedestal region. The method includes forming an electrical insulation layer disposed on a second surface of the diaphragm region and forming a plurality of sensing elements patterned on the electrical insulation layer disposed on the second surface in the diaphragm region. The method includes forming a cap wafer with a central recess in an inner surface and a plurality of through-wafer embedded vias made of an electrically conductive material in the cap wafer. The method includes creating a sealed cavity by coupling the inner recessed surface of the cap wafer to the gauge wafer, such that electrical connections from the sensing elements come out to an outer surface of the cap wafer through the vias. The method includes attaching a spacer wafer with a central aperture to the pedestal region with the central aperture aligned to the diaphragm region.
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.