摘要:
A method of bonding a first silicon wafer to a second silicon wafer comprises the steps of diffusing a high conductivity pattern into a surface of a first semiconductor wafer, etching a portion of the surface to raise at least a portion of the pattern, providing a second semiconductor wafer having an insulating layer of a silicon compound disposed thereon, contacting the surface of the pattern to the insulating layer, and bonding the first and second semiconductor wafers at an elevated temperature.
摘要:
There is disclosed a method of mounting a pressure transducer on a convoluted three-dimensional structure as for example a turbine blade. The method first forms a groove on a surface of a blade. The groove is formed at a given length and depth in order to accommodate a plurality of components. The groove is then filled with a ceramic material so that the top of the groove is aligned with the top surface of the structure. The entire structure is then coated with a first layer of a ceramic material which layer also covers the filled groove. Suitable conductors are then placed on the coated surface so that they span and overlie the groove. The structure is then coated with a second layer of ceramic material and the coating covers the conductors thereby serving to embed the conductors between the first and second layers. A second groove is then formed in the first and second layers which second groove overlies the first groove and which extends into the first groove. The formation of the second groove operates to separate or cut the conductors as overlying the first groove. Then ceramic material from the second layer is removed on each side of the second groove to expose the separated end surfaces of the conductors. The pressure transducer which is an integrated circuit is then placed into the second groove, and one now bonds the component terminals of the pressure transducer to the exposed conductor surfaces. In this manner both the wires leading from the transducer and the transducer itself are beneath the surface of the structure and do not interfere with the surface contours of the structure while further allowing testing of the same in all operating environments.
摘要:
There is disclosed a gas leak detector employing pressure transducers. In one embodiment the pressure in a vessel is monitored by means of a pressure transducer. The output of the pressure transducer is coupled to an operational amplifier whereby the amplifier has a gain which is proportional to 1/T absolute. In this manner, since the gain is inversely proportional to temperature, the amplifier will produce an output which is independent of temperature but which is capable of providing a pressure indication when there is a gas leak in the container.
摘要:
A transducer or accelerometer employs at least one slot or gap located in a seismic mass of a block-like configuration. The relative displacement of the opposing faces of the block, due to the slot, is monitored by means of a shim or similar metallic member, which spans the slot. Secured to the shim is a piezoresistive strain gage whose size and dimensions become relatively independent of the dimension of the slot, therefore enabling accurate and reliable strain detection without attendant temperature problems.
摘要:
A system for measuring a multiplicity of pressures as those experienced by a model in a wind tunnel is depicted. The system includes individual sensor devices which are connected to an electronics module. The sensors may be connected to the electronics module via a cable in a first embodiment. In an alternate embodiment, the sensors may be connected to the electronics module via a mating connector located therebetween. A memory component which stores compensation coefficients associated with each of the sensors may also be included in the system to correct errors associated with each sensor. The advantage of the various embodiments is that each sensor does not have any compensation stored thereon and thus, the sensors can be made very small to operate at very high temperatures without any loss of accuracy.
摘要:
A semiconductor filter is provided to operate in conjunction with a differential pressure transducer. The filter receives a high and very low frequency static pressure attendant with a high frequency low dynamic pressure at one end, the filter operates to filter said high frequency dynamic pressure to provide only the static pressure at the other filter end. A differential transducer receives both dynamic and static pressure at one input port and receives said filtered static pressure at the other port where said transducer provides an output solely indicative of dynamic pressure. The filter in one embodiment has a series of etched channels directed from an input end to an output end. The channels are etched pores of extremely small diameter and operate to attenuate or filter the dynamic pressure. In another embodiment, a spiral tubular groove is found between a silicon wafer and a glass cover wafer, an input port of the groove receives both the static and dynamic pressure with an output port of the groove providing only static pressure. The groove filters attenuate dynamic pressure to enable the differential transducer to provide an output only indicative of dynamic pressure by cancellation of the static pressure.
摘要:
A two or three axis load cell capable of measuring axial and one or more shear forces is disclosed. The load cell can comprise a force collector connected by one or more connecting rods to one or more cross pieces. The load cell can comprise a single cross piece and can measure an axial force applied to the load cell and at least one component of shear force applied to the load cell. In other embodiments, the load cell can comprise two cross pieces, disposed at disparate angles, to enable the measurement of an axial force and both components of shear force applied to the force collector. The cross pieces are equipped with a means, such as piezoresistive elements to measure their deflection due to the applied forces on the force collector. The connecting rods can be fitted with additional piezoresistors to measure the axial forces on the force collector.
摘要:
A pressure transducer comprising a corrosion resistant metal diaphragm, having an active region, and capable of deflecting when a force is applied to the diaphragm; and a piezoresistive silicon-on-insulator sensor array disposed on a single substrate, the substrate secured to the diaphragm, the sensor array having a first outer sensor near an edge of the diaphragm at a first location and on the active region, a second outer sensor near an edge of the diaphragm at a second location and on the active region, and at least one center sensor substantially overlying a center of the diaphragm, the sensors connected in a bridge array to provide an output voltage proportional to the force applied to the diaphragm. The sensors are dielectrically isolated from the substrate.
摘要:
An oil-filled pressure transducer having reduced back pressure, comprising an alignment plate having a sensor accommodating aperture, a sensor module inserted into the sensor accommodating aperture, a header surrounding the alignment plate, the header having a protruding top surface, and a diaphragm disposed on the protruding top surface to create a relatively small oil accommodating region between the diaphragm and the sensor. This configuration reduces the oil volume required for operation, which ultimately reduces the back pressure applied against the diaphragm.
摘要:
A pressure transducer assembly for measuring pressures in high temperature environments employing an elongated tube which is terminated at one end by an acoustic micro-filter. The micro-filter is operative to absorb acoustic waves impinging on it with limited or no reflection. To improve the absorption of acoustic waves, the elongated tube may be tapered and/or mounted to a support block and further convoluted to reduce the overall size and mass of the device. A pressure transducer with a diaphragm flush may be mounted to the elongated tube and extend through to the inner wall of the tube. Hot gases propagate through the elongated tube and their corresponding pressures are measured by the transducer. The acoustic filter operates to absorb acoustic waves resultant from the hot gases, therefore enabling the pressure transducer to be mainly responsive to high frequency waves associated with the gas turbine operation.