摘要:
A single mode VCSEL including a substrate having a lower surface and an upper surface, a bottom electrical contact disposed along the lower surface of the substrate, a lower mirror portion disposed upon the upper surface of the substrate, an active region disposed upon the lower mirror portion, an upper mirror portion disposed upon the active region, an equipotential layer disposed upon the upper mirror portion, an insulating layer interposed between the upper mirror portion and the equipotential layer and adapted to form an aperture therebetween, and an upper contact portion disposed upon the equipotential layer outside the perimeter of the aperture.
摘要:
A sensor apparatus includes a heating element comprising an upstream side and a downstream side. A first heat sensing set is generally configured adjacent to the upstream side of the heating element and comprises a first sensing element and a second sensing element, the first and second sensing elements configured in a serpentine, interdigitated pattern. A second heat sensing set can be configured adjacent to the downstream side of the heating element and comprises a third sensing element and a fourth sensing element, the third and fourth sensing elements configured in a serpentine, interdigitated pattern.
摘要:
A system and method for providing a single mode VCSEL (vertical cavity surface emitting laser). A lower mirror is formed on a substrate. An active region including one or more quantum wells is formed over the lower mirror. The upper mirror formed over the active region can include multiple layers and may be formed to be have substantially isotropic conductivity. The layers in the upper mirror can include a lightly doped DBR layer, a heavily doped second layer including an isolation region, and a third heavily doped DBR layer. The active region may include conduction layers, which may be periodically doped, to improve conductivity and reduce free carrier absorption.
摘要:
A flow sensor apparatus that utilizes a pressure sensor with media isolated electrical connections. A cap can be attached to topside of the pressure sensor over a diaphragm to protect bond pads and wire bonds from a fluid media. A flow channel can be etched on the cap with an opening and exit on the sides of the cap so that liquid can flow through the flow channel. An inlet port and an outlet port can be attached to the channel's opening and exit to allow for fluid flow over the diaphragm. The flow channel creates a larger pressure over portions of the diaphragm that increases the deflection of the diaphragm, which increases an output signal of the pressure sensor. V-grooves can be created on two sides of the pressure sensor and in the cap to create the channel for the fluid in and out of the cap's cavity.
摘要:
A flip-chip flow sensor has electrical components, such as temperature sensors and a heater, on the top of a substrate and has a channel formed in the bottom of the substrate. The channel is separated from the substrate's top by a membrane of substrate material. A fluid flowing through the channel is separated from a heater, upstream temperature sensor, downstream temperature sensor, bond pads, and wire bonds by the membrane. Heat flows through the membrane easily because the membrane is thin. As such, the electrical elements of the flow sensor, the bond pads and the wires are physically separated from a fluid flowing through the channel but can function properly because they are not thermally isolated.
摘要:
A volumetric fluid flow sensor (100) includes a flow channel (120) for flowing a fluid therein; and a diaphragm (110) having an outer surface within the flow channel (120). The diaphragm (110) includes at least one flow disrupting feature mechanically coupled to or emerging from the outer surface of the diaphragm (110). A sensing structure (126) is coupled to the diaphragm (110) for generating a sensing signal responsive to a pressure signal on the diaphragm (110).
摘要:
A Hall-effect device with a merged and/or non-merged complementary structure in order to cancel stress induced offsets includes an n-type epitaxial Hall element and a p-type Hall element. The p-type Hall element can be implanted directly on top of the n-type epitaxial Hall element. The merged Hall elements can be biased in parallel to provide a zero-bias depletion layer throughout for isolation. The output of the p-type Hall element can be connected to the geometrically corresponding output of the n-type epitaxial Hall element through a suitable resistance. The output signal can be taken at the outputs of the n-type element. The Hall-effect device can be constructed utilizing standard processes.
摘要:
A flip-chip flow sensor has electrical components, such as temperature sensors and a heater, on the top of a substrate and has a channel formed in the bottom of the substrate. The channel is separated from the substrate's top by a membrane of substrate material. A fluid flowing through the channel is separated from a heater, upstream temperature sensor, downstream temperature sensor, bond pads, and wire bonds by the membrane. Heat flows through the membrane easily because the membrane is thin. As such, the electrical elements of the flow sensor, the bond pads and the wires are physically separated from a fluid flowing through the channel but can function properly because they are not thermally isolated.
摘要:
A pressure sensor apparatus and method that incorporates a silicon frit bonded cap. The pressure sensor includes a silicon sensor wafer with diaphragms at a bottom surface thereof, a silicon cap wafer mounted on the topside of each sensor wafer, a plurality of silicon sensor die formed on the sensor wafer, a silicon cap wafer etched to create a plurality of reference cavities on the topside of the diaphragm, a thin glass frit to form a wafer-to-wafer bond between the sensor wafer and cap wafer. Sensing devices such as semiconductor die/sensor, peizoresistors, can be used to sense the pressure. The wafer-to-wafer frit bonding improves the output signal drift and the thermal performance of the pressure sensor minimizes the thermal mismatch created by anodic bonded glass wafers.