Abstract:
A method for fabricating a micromechanical device and a semiconductor circuit on a substrate includes the steps of forming the micromechanical device on a device area of the substrate, the micromechanical device being embedded in a sacrificial material, selectively depositing a planarization layer on the substrate in a circuit area thereof, forming the semiconductor circuit on the planarization layer in the circuit area and removing the sacrificial material from the embedded micromechanical device. In a preferred embodiment, the planarization layer is an epitaxial silicon layer. A protective cap may be formed over the micromechanical device, so that it is completely encapsulated and is thereby protected against particulate contamination.
Abstract:
Improved microelectromechanical systems (MEMS), processes and apparatus using thermocompression bonding are disclosed. For example, process embodiments are disclosed in which wafer-scale as well as die-scale thermocompression bonding is utilized to encapsulate MEMS and/or to provide electrical interconnections with MEMS. Apparatus embodiments include apparatus for performing thermocompression bonding and bonded hybrid structures manufactured in accordance with the process embodiments. Devices having various substrate bonding and/or sealing configurations variously offer the advantage of reduced size, higher manufacturing yields, reduced costs, improved reliability, improved compatibility with existing semiconductor manufacturing process and/or greater versatility of applications.
Abstract:
Improved microelectromechanical systems (MEMS), processes and apparatus using thermocompression bonding are disclosed. For example, process embodiments are disclosed in which wafer-scale as well as die-scale thermocompression bonding is utilized to encapsulate MEMS and/or to provide electrical interconnections with MEMS. Apparatus embodiments include apparatus for performing thermocompression bonding and bonded hybrid structures manufactured in accordance with the process embodiments. Devices having various substrate bonding and/or sealing configurations variously offer the advantage of reduced size, higher manufacturing yields, reduced costs, improved reliability, improved compatibility with existing semiconductor manufacturing process and/or greater versatility of applications.
Abstract:
Improved microelectromechanical systems (MEMS), processes and apparatus using thermocompression bonding are disclosed. For example, process embodiments are disclosed in which wafer-scale as well as die-scale thermocompression bonding is utilized to encapsulate MEMS and/or to provide electrical interconnections with MEMS. Apparatus embodiments include apparatus for performing thermocompression bonding and bonded hybrid structures manufactured in accordance with the process embodiments. Devices having various substrate bonding and/or sealing configurations variously offer the advantage of reduced size, higher manufacturing yields, reduced costs, improved reliability, improved compatibility with existing semiconductor manufacturing process and/or greater versatility of applications.
Abstract:
The present invention comprises a circuit for measuring the capacitive differences of small capacitors. The circuit comprises a reference capacitor and a sensor capacitor. Connected to one of the plates of each capacitor is a switch which connects the capacitors to one of two reference voltages. The other plate of the capacitors are connected to an input terminal of a voltage comparator. The comparator compares the input voltage with a third reference voltage. Differences in voltages detected by the comparator are applied to a feedback loop for generating an offset voltage at the input terminal. The offset voltage applied at the input terminal is proportional to the capacitive difference between the reference capacitor and the sensor capacitor. The feedback loop comprises a successive approximation register for digitizing the offset voltages and a digital to analog converter for converting the digitized voltages into analog voltages which are applied at the input terminal. Digitized offset voltages can be measured at the output of the successive approximation register.
Abstract:
Lightning protection means for aircraft structural components includes thin, perforated, dielectric and metallic layers applied to the ordinarily lightning-accessible surfaces of composite structures. Where the outer metallic layer of the lightning protection means is formed from sprayed metal, ground connection means to the metallic layer preferably comprises a section of wire screen fused with the sprayed metal on the dielectric layer, a thin metal plate brazed to the wire screen, and a metal attachment connecting the metal plate to adjacent ground structure. Composite-to-metal or composite-to-composite structural joints are protected by making the entire bonded and bolted interface areas conductive for transfer of lightning current, or by isolating the bonded interface area to control the transfer path of the lightning current through the bolted interface area only.