668 results about "Condenser microphone" patented technology

A silicon condenser microphone package is disclosed. The silicon condenser microphone package comprises a transducer unit, substrate, and a cover. The substrate includes an upper surface having a recess formed therein. The transducer unit is attached to the upper surface of the substrate and overlaps at least a portion of the recess wherein a back volume of the transducer unit is formed between the transducer unit and the substrate. The cover is placed over the transducer unit and includes an aperture.

MEMS microphone packages and fabrication methods thereof are disclosed. A MEMS microphone package includes a cavity that houses a MEMS sensing element, an IC chip and other passive elements supported by a common substrate. The cavity is formed by a top cover member, a housing wall surrounds and supports the top cover member and the common substrate supports the housing wall. A conductive casing encloses and surrounds the cavity, and is electrically connected to a common analog ground lead on a PCB board. The top cover member and the housing wall are non-conductive. And the conductive casing is not connected directly to the ground leads of the package. An acoustic absorption layer is sandwiched between the conductive casing and the cavity which is formed by the top cover member, the housing wall and the substrate.

A condenser microphone includes a support, a plate having a fixed electrode bridged across the supports, a diaphragm, which has a moving electrode at a center portion thereof and which vibrates due to sound waves applied thereto, and a spacer, in which a first end is fixed to the plate, and a second end is fixed to the near-end portion of the diaphragm so as to surround the center portion of the diaphragm, wherein an air gap is formed between the plate and the diaphragm. This reduces the tensile stress of the diaphragm so as to increase the amplitude of vibration of the diaphragm. Hence, it is possible to increase the sensitivity of the condenser microphone. A structure constituted of the plate, the diaphragm, and the spacer is bridged across the support by means of the bridges, which absorb the residual stress of the diaphragm due to the deformation thereof.

A microphone element having a diaphragm and a fixed electrode disposed opposite to each other on a silicon board having a central opening portion is mounted and fixed onto a base board having a sound hole. A perimeter-shaped side board and a cover board are mounted and fixed onto the board, thereby forming a back cavity on an upper side of the microphone element. The diaphragm and the fixed electrode are conducted to conductive layers of the cover board through conductive layers of the base board, and a conductive layer and a coiled spring in the side board respectively, and mounting on a surface of a printed board of an external apparatus can be carried out in a conductive layer on an upper surface thereof.

The present invention relates to a preamplifier suitable for use with Electret Condenser Microphones such as used within telecommunication equipment. More particularly the invention relates to a preamplifier specially suited for the demands to such a preamplifier within telecommunication equipment: low input capacitance, gain and a combined terminal for output and supply voltage, thus making the preamplifier suitable for two terminal microphone assemblies. These features are obtained with a two stage amplifier with a first stage optimised for low input capacitance and the second stage being able to provide gain. The preamplifier may be implemented using an ASIC, thus making the preamplifier suitable for applications with very limited space available, such as for integration within microphone assemblies.

A preamplifier having extremely high input impedance amplifies the electrical signal output from an electret condenser microphone (ECM) without suffering from the effects of a DC leakage current at the input. The preamplifier circuit includes a pair of cross-coupled PN junction diodes setting the input impedance, a PMOS device, and a load resistor configured similarly to a conventional preamplifier. A capacitor is placed between the input and the cross-coupled diodes such that a DC path no longer exists to bias the cross-coupled diodes. Therefore, leakage currents are prevented from upsetting the DC operating point of the preamplifier and biasing the cross-coupled diodes. Consequently, small signal gain distortion, excessive demodulation products and increased noise can be avoided.

A condenser microphone is provided having a transducer element. A diaphragm has an electrically conductive portion. A back-plate has an electrically conductive portion. A DC bias voltage element is operatively coupled to the diaphragm and the back-plate. A collapse detection element is adapted to determine a physical parameter value related to a separation between the diaphragm and the back-plate. A collapse control element is adapted to control the DC bias voltage element based on the determined physical parameter value.

Methods and apparatus automatically cancel or attenuate an unwanted signal (such as low frequencies from wind buffets) from, and/or control frequency response of, a condenser microphone, or control the effective condenser microphone sensitivity before the signal reaches an ASIC or other processing circuit. As a result, the maximum amplitude signal seen by the processing circuit is limited, thereby preventing overloading the input of the processing circuit. Remaining (wanted) frequencies can be appropriately amplified to reduce the noise burden on further processing circuits. A corrective signal is applied to a bias terminal of the condenser microphone to cancel the unwanted signal. Optionally or alternatively, a controllable impedance is connected to a line that carries the signal generated by the MEMS microphone, so as to attenuate unwanted portions of the signal.

A vibration transducer (e.g. a condenser microphone) having a high sensitivity is constituted of a housing composed of an airtight material having a through-hole, a vibration conversion die (e.g. a microphone die) which is attached to the interior surface of the housing at the prescribed position embracing the through-hole in plan view, and a barrier diaphragm composed of an airtight material whose external periphery is attached to the exterior surface of the housing in an airtight manner oppositely to the prescribed position. The barrier diaphragm has a vibration area which is larger than the sectional area of the through-hole. A space allowing the barrier diaphragm to vibrate is formed between the barrier diaphragm and the exterior surface of the housing, wherein the distance between the barrier diaphragm and the exterior surface of the housing can be gradually reduced from the vibration axis to the external periphery.

A capacitor microphone is constituted by a plate having a fixed electrode, a diaphragm including a center portion and at least one near-end portion that is fixed to the outer periphery, in which the center portion having a vibrating electrode, which is positioned relative to the fixed electrode and which vibrates in response to sound waves, is increased in rigidity in comparison with the near-end portion; and a spacer that is fixed to the plate and the near-end portion of the diaphragm and that has an air gap formed between the plate and the diaphragm. Alternatively, a diaphragm electrode is horizontally supported by extension arms extended from a circular plate thereof and is vertically held in a hanging state being apart from a fixed electrode with a controlled distance therebetween.

A silicon condenser microphone is described. The silicon condenser microphone of the present invention comprises a perforated backplate comprising a portion of a single crystal silicon substrate, a support structure formed on the single crystal silicon substrate, and a floating silicon diaphragm supported at its edge by the support structure and lying parallel to the perforated backplate and separated from the perforated backplate by an air gap.

An electrostatic pressure transducer (e.g., a condenser microphone) includes a plate having a plurality of holes and forming a fixed electrode, a diaphragm forming a vibrating electrode, at lease one spacer that is positioned between the plate and the diaphragm in the ring-shaped internal area internally of the peripheral end of the diaphragm, and a stopper plate having an opening, which is positioned opposite to the plate with respect to the diaphragm. The diaphragm vibrates relative to the plate in such a way that, due to electrostatic attraction, the internal portion thereof moves close to the plate while the external portion thereof moves opposite to the plate, wherein the peripheral end thereof partially comes in contact with the opening edge of the stopper plate. Thus, it is possible to realize flat frequency characteristics while improving the sensitivity in low-frequency ranges.

An electroacoustic transducer includes a condenser microphone, which includes a package having a cavity and a through-hole, a plate whose thickness is thinner than the length of the through-hole and which has a sound hole overlapping with the through-hole in plan view, and an electroacoustic transducer die, which is stored in the cavity of the package. The electroacoustic transducer die includes a fixed electrode and a diaphragm electrode, which are positioned opposite to each other and which are supported by and enclosed inside of a support. The sound hole of the plate is reduced in dimensions realizing a small sectional area and a small depth, thus realizing a high resonance frequency higher than the audio frequency range.

This invention mainly provides a SMT-type structure of the minimized and low-power silicon-based electret condenser microphone. Primarily integrates with the electret, silicon-based, MEMS and microphone techniques to implement the minimized and low-power silicon-based electret condenser microphone. The Silicon-based bi-diaphragm of the composite diaphragm-chip was coated with the low-dielectric macromolecule material to allow the microphone acquires the sufficient electrical charges. Moreover, the impedance matching element of the microphone that MOSFET was implemented by the MEMS technology. Conclusively, this silicon-based electret condenser microphone gains several achievements as the smallest volume, a lower bias voltage, a SMT-type structure, a lower residue stress and a lower assembly cost.

In order to automate a microphone assembly process including a dust-proof treatment, an object of the present invention is to provide a dust-proof microphone having a configuration suitable for automated assembly.

According to the present invention, a microphone has a plate-like or film-like dust-proof section that is disposed in a conductive housing (capsule) having a sound aperture and covers the sound aperture. The dust-proof section has a plurality of pores at least in a region corresponding to the sound aperture, and the dust-proof section further has a nonporous region. In the case of an electret condenser microphone, from the viewpoint of performance of the microphone, the dust-proof section is conductive. In addition, taking into account a soldering in a reflow furnace, the dust-proof section is heat-resistant. Each pore is desirably designed taking into account the environment for the usage of the microphone. However, if it is supposed that the microphone is used near one's mouth, each pore has an area of 0.01 mm² or less. In addition, to enhance the dust-proof effect, the pores may be subjected to a water-repellent treatment.

An electret condenser microphone includes: a substrate 13 in which an opening 25 is formed; an electret condenser 50 connected to one face of the substrate 13 so as to close the opening 25 and having an acoustic hole 12 and a cavity 2; a drive circuit element 15 connected to the one face of the substrate 13; and a case 17 mounted over the substrate 13 so as to cover the electret condenser 50 and the drive circuit element 15. Electric contact is established at a joint part between the electret condenser 50 and the substrate 13. The acoustic hole 12 communicates with an external space through the opening 25. The cavity 2 and an internal region of the case 17 serve as a back air chamber for the electret condenser 50.

An air gap is formed between a first film having a first electrode film and a second film having a second electrode film. The first film has a stopper protruding toward the second film, and a recess communicating with the air gap is provided in the center of the stopper.