Abstract:
An acoustic transducer has a substrate having a cavity that is open at a top of the substrate, a vibration electrode film provided above the substrate so as to cover the cavity, and a fixed electrode film provided a distance above the vibration electrode film. A gap is formed between an upper surface of the substrate and a lower surface of the vibration electrode film around the cavity. In the gap across which the upper surface of the substrate and the lower surface of the vibration electrode film face each other, a narrow portion of the gap that is narrower than another portion of the gap is disposed. The narrow portion of the gap extends linearly.
Abstract:
A microphone has a package, and an acoustic sensor, an under surface of which is fixed to an inner face of the package. The acoustic sensor has a substrate having a plurality of hollows penetrating the substrate from a top surface to an under surface, and a capacitor structure made by a movable electrode plate and a fixed electrode plate disposed above each of the hollows. A package sound hole is opened in the package in a position opposed to the under surface of the acoustic sensor. A dent which is communicated with each of the hollows and open below the under surface side of the substrate is formed below the under surface of the substrate. A height of the dent measured from the under surface of the substrate is equal to or less than half of a height of the hollow.
Abstract:
A capacitance type sensor has a substrate, a vibration electrode plate formed over the substrate, a back plate formed over the substrate so as to cover the vibration electrode plate, and a fixed electrode plate provided on the back plate so as to be opposite to the vibration electrode plate. At least one of the vibration electrode plate and the fixed electrode plate is separated into a plurality of regions, each of the plurality of regions being formed with a sensing section including the vibration electrode plate and the fixed electrode plate. A barrier electrode is provided between respective sensing sections of at least one adjacent pair of regions of the plurality of regions to prevent signal interference between the respective sensing sections.
Abstract:
The present disclosure is directed to an acoustic transducer configured to detect a sound wave according to changes in capacitances between a vibrating electrode and a fixed electrode. At least one of the vibrating electrode and the fixed electrode being divided into a plurality of divided electrodes, and the plurality of divided electrodes outputting electrical signals. The disclosure includes a digital interface circuit coupled to the divided electrodes. The circuit includes a recombination stage, which supplies a mixed signal by combining the first digital processed signal and the second digital processed signal with a respective weight that is a function of a first level value of the first processed signal. An output stage is included, which supplies, selectively and alternatively, a first processed signal, a second processed signal, or a mixed signal.
Abstract:
A capacitive transducer includes a substrate having an opening in a surface thereof, a back plate facing the opening in the substrate, a vibration electrode film facing the back plate across a space, the vibration electrode film being deformable to have a deformation converted into a change in capacitance between the vibration electrode film and the back plate, the vibration electrode film having a through-hole as a pressure relief hole, and a protrusion integral with and formed from the same member as the back plate, the protrusion being placeable in the pressure relief hole before the vibration electrode film deforms. The pressure relief hole and the protrusion have a gap therebetween defining an airflow channel as a pressure relief channel. The protrusion has a through-hole extending from a distal portion of the protrusion to a portion of the back plate opposite to the protrusion.
Abstract:
A capacitive transducer includes a substrate having an opening in a surface thereof, a back plate facing the opening in the substrate, a vibration electrode film facing the back plate across a space, the vibration electrode film being deformable to have a deformation converted into a change in capacitance between the vibration electrode film and the back plate, the vibration electrode film having a through-hole as a pressure relief hole, and a protrusion integral with and formed from the same member as the back plate, the protrusion being placeable in the pressure relief hole before the vibration electrode film deforms. The pressure relief hole and the protrusion have a gap therebetween defining an airflow channel as a pressure relief channel. The protrusion has a through-hole extending from a distal portion of the protrusion to a portion of the back plate opposite to the protrusion.
Abstract:
An acoustic sensor adapted to convert acoustic vibration to a change in an electrostatic capacitance to detect the acoustic vibration is provided. The acoustic sensor includes a semiconductor substrate, a back plate including a fixed plate arranged to face a surface of the semiconductor substrate, and a fixed electrode film arranged on the fixed plate, and a vibrating electrode film arranged to face the back plate with a space formed therebetween. The vibrating electrode film includes a plate-like vibrating member that vibrates in response to sound pressure. The vibrating electrode film is fixed to the back plate with a fixing unit thereof including one or more fixing portions each including a fixing protruding end that is arranged on a protruding end of a leg portion protruding from an edge of the vibrating member. The vibrating member has an edge portion surrounding at least a part of the fixing protruding end.
Abstract:
An acoustic sensor is provided for improving shock resistance performance, along with a method for manufacturing the acoustic sensor. In the acoustic sensor, a fixing plate is provided by a semiconductor manufacturing process, a frame wall has a curved shape in at least a portion of the periphery of the fixing plate, the frame wall being coupled to the semiconductor substrate. A sacrifice layer removed from the inner side of the fixing plate in the manufacturing process remains at least on a portion of the inner side of the frame wall. Roughness of the remaining sacrifice layer is smaller than roughness of a sound shape reflecting structure in which a shape similar to the external shape of sound holes is repeated. Roughness of the sound shape reflecting structure is formed when removing the sacrifice layer using etching liquid supplied from the plurality of sound holes in the semiconductor manufacturing process.
Abstract:
A capacitance type sensor has a substrate, a vibration electrode plate formed over the substrate, a back plate formed over the substrate so as to cover the vibration electrode plate, and a fixed electrode plate provided on the back plate so as to be opposite to the vibration electrode plate. At least one of the vibration electrode plate and the fixed electrode plate is separated into a plurality of regions, each of the plurality of regions being formed with a sensing section including the vibration electrode plate and the fixed electrode plate. A barrier electrode is provided between respective sensing sections of at least one adjacent pair of regions of the plurality of regions to prevent signal interference between the respective sensing sections.
Abstract:
An acoustic transducer has a substrate having an opening in an upper surface thereof, a vibration electrode plate disposed above the substrate, and having an outer edge thereof facing the upper surface of the substrate with a gap therebetween, a fixed electrode plate facing the vibration electrode plate, and a plurality of projections protruding on a lower surface of the outer edge of the vibration electrode plate. The vibration electrode plate covers an upper side of the opening. The plurality of projections are disposed so as to not be positioned along a straight line or a curved line parallel to an edge of the opening in at least a part of one or at least two arrays formed on the lower surface of the outer edge.