Abstract: The present invention relates to a flow-modifying device for a compressor of a charging apparatus. The flow-modifying device comprises a cylindrical housing portion, which defines an inner lateral surface and in the axial direction comprises a downstream end region and an upstream end region. The flow-modifying device furthermore comprises a plurality of pockets, which are arranged on the inner lateral surface, spaced-apart from one another in the peripheral direction. Each pocket is defined here by a longitudinal projection line and a depth projection line. In an orientation plane, which is formed by the longitudinal projection line and the depth projection line, there is arranged a downstream angle of entry ? of the pocket relative to the inner lateral surface and an upstream angle of entry ? of the pocket relative to the inner lateral surface. The downstream angle of entry ? defines a downstream opening region of the pocket and the upstream angle of entry ? defines an upstream opening region of the pocket.

Abstract: A differential pressure sensor comprises a membrane arranged over a cavity on a semiconductor substrate. A lid layer is arranged at the top side of the device and comprises an access opening for providing access to the top side of the membrane. A channel extends laterally from the cavity and intersects with a bore. The bore is formed by laser drilling from the bottom side of the substrate and provides access to the bottom side of the membrane. The bore extends all through the substrate and optionally into the lid layer.

Abstract: A pressure sensor is manufactured by joining two wafers, the first wafer comprising CMOS circuitry and the second being an SOI wafer. A recess is formed in the top material layer of the first wafer, which is covered by the silicon layer of the second wafer to form a cavity. Part or all of the substrate of the second wafer is removed to forming a membrane from the silicon layer. Alternatively, the cavity can be formed in the second wafer. The second wafer is electrically connected to the circuitry on the first wafer. This design allows to use standard CMOS processes for integrating circuitry on the first wafer.

Abstract: A differential pressure sensor comprises a membrane arranged over a cavity on a semiconductor substrate. A lid layer is arranged at the top side of the device and comprises an access opening for providing access to the top side of the membrane. A channel extends laterally from the cavity and intersects with a bore. The bore is formed by laser drilling from the bottom side of the substrate and provides access to the bottom side of the membrane. The bore extends all through the substrate and optionally into the lid layer.