Knowles Electronics, Inc.

Sung Bok Lee

Michael Kuntzman

Vahid Naderyan

Peter V Loeppert

Wade Conklin

Bing Yu

Michael Pedersen

Yunfei Ma

Sagnik Pal

John Szczech

Sandra Vos

Venkataraman Chandrasekaran

John J Albers

Peter Van Kessel

Daniel Giesecke

Ryan McCall

Claus Erdmann Fürst

Mohammad Shajaan

Kim Spetzler Berthelsen

Eric J Lautenschlager

Yenhao Chen

Jeremy Hui

Jonathan Reeg

Brandon Harrington

Alyssa Kueffner

Ankur Sharma

Nick Wakefield

Yaoyang Guo

Josh Watson

A method of forming a micro electro mechanical system (MEMS) assembly comprises providing a substrate having an electrically conductive layer disposed thereon. The method also comprises depositing, on the substrate over the electrically conductive layer, a bonding material having an elastic modulus of less than 500 MPa so as to form a bond layer. The bond layer is completely cured, and a MEMS die is attached to the completely cured bond layer.

MEMS assembly substrates including a bond layer

A method of forming an acoustic transducer comprises providing a substrate and depositing a first structural layer on the substrate. The first structural layer is selectively etched to form at least one of an enclosed trench or an enclosed pillar thereon. A second structural layer is deposited on the first structural layer and includes a depression or a bump corresponding to the enclosed trench or pillar, respectively. At least the second structural layer is heated to a temperature above a glass transition temperature of the second structural layer causing the second structural layer to reflow. A diaphragm layer is deposited on the second structural layer such that the diaphragm layer includes at least one of a downward facing corrugation corresponding to the depression or an upward facing corrugation corresponding to the bump. The diaphragm layer is released, thereby forming a diaphragm suspended over the substrate.

Methods of forming MEMS diaphragms including corrugations

A MEMS die includes a substrate having an opening formed therein, a diaphragm having a first surface attached around a periphery thereof to the substrate and over the opening, and a backplate separated from a second surface of the diaphragm. The diaphragm includes at least one passage disposed between the first and second surfaces, and the at least one passage has a smaller cross-sectional area at the first surface than at the second surface.

MEMS die with a diaphragm having a stepped or tapered passage for ingress protection

A microphone device includes a base and a microelectromechanical system (MEMS) transducer and an integrated circuit (IC) disposed on the base. The microphone device also includes a cover mounted on the base and covering the MEMS transducer and the IC. The MEMS transducer includes a diaphragm attached to a surface of the substrate and a back plate mounted on the substrate and in a spaced apart relationship with the diaphragm. The diaphragm is attached to the surface of the substrate along at least a portion of a periphery of the diaphragm. The diaphragm can include a silicon nitride insulating layer, and a conductive layer, that faces a conductive layer of the back plate. The MEMS transducer can include a peripheral support structure that is disposed between at least a portion of the diaphragm and the substrate. The diaphragm can include one or more pressure equalizing apertures.

Microphone device with ingress protection

An acoustic transducer for generating electrical signals in response to acoustic signals, comprises a first diaphragm having a first corrugation formed therein. A second diaphragm has a second corrugation formed therein, and is spaced apart from the first diaphragm such that a cavity having a pressure lower than atmospheric pressure is formed therebetween. A back plate is disposed between the first diaphragm and the second diaphragm. One or more posts extend from at least one of the first diaphragm or the second diaphragm towards the other through the back plate. The one or more posts prevent each of the first diaphragm and the second diaphragm from contacting the back plate due to movement of the first diaphragm and/or the second diaphragm towards the back plate. Each of the first corrugation and the second corrugation protrude outwardly from the first diaphragm and the second diaphragm, respectively, away from the back plate.

Acoustic transducers with a low pressure zone and diaphragms having enhanced compliance

An acoustic transducer comprises a transducer substrate having an aperture defined therethrough. At least one diaphragm is disposed on the transducer substrate over the aperture. A back plate is disposed on the transducer substrate and axially spaced apart from the at least one diaphragm. A perimetral support structure is disposed circumferentially between the at least one diaphragm and the back plate at a radially outer perimeter of the back plate. A plurality of perimetral release holes are defined circumferentially through at least one of the at least one diaphragm or the back plate proximate to and radially inwards of the perimetral support structure, at least a portion of the plurality of perimetral release holes defining a non-circular shape.

Acoustic transducers having non-circular perimetral release holes

An acoustic transducer for generating electrical signals in response to acoustic signals includes a transducer substrate, a back plate, and a diaphragm assembly. The diaphragm assembly includes a first diaphragm and a second diaphragm coupled thereto. The second diaphragm is positioned closer to the back plate than the first diaphragm. The second diaphragm includes a plurality of diaphragm apertures configured to allow air to pass through the second diaphragm. Each of the back plate and the first diaphragm are coupled to the transducer substrate at their periphery. In an embodiment, the transducer includes a post coupled to the first diaphragm and the second diaphragm, the post configured to prevent movement of the second diaphragm relative to the first diaphragm in a direction substantially perpendicular to the second diaphragm.

Acoustic transducer with reduced damping

Acoustic transducers for generating electrical signals in response to acoustic signals are disclosed. In some embodiments, an acoustic transducer includes an at least partially evacuated hermetically sealed cavity defined in part by a first diaphragm. The acoustic transducer also includes a backplate disposed at least partially within the cavity. The cavity having a pressure lower than atmospheric pressure. The acoustic transducer further includes a pressure sensor coupled to the backplate and configured to sense the pressure in the cavity.

Acoustic transducers with a low pressure zone and diaphragms having a pressure sensor

A microelectromechanical system (MEMS) motor includes a substrate, a backplate, and a diaphragm. The substrate has a first surface and a second surface. The second surface has a slot that extends at least partially into the substrate. A port extends through the substrate. The backplate is mounted to the first surface of the substrate, and the backplate covers at least a portion of the port. The diaphragm is between the backplate and the substrate. The diaphragm moves with respect to the backplate in response to acoustic energy that passes through the port.

Acoustic relief in MEMS

A microphone assembly includes an acoustic transducer having a back plate and a diaphragm, such that a surface of the back plate includes a plurality of holes. At least a portion of the plurality of holes are arranged in a non-uniform pattern. The non-uniform pattern includes holes of varying sizes spaced apart from neighboring holes by varying distances. The microphone assembly further includes an audio signal electrical circuit configured to receive an acoustic signal from the acoustic transducer.

Systems and methods for acoustic hole optimization

An acoustic transducer comprises a transducer substrate defining an aperture therein. A diaphragm is disposed on the transducer substrate. The diaphragm comprises a diaphragm inner portion disposed over the aperture such that an outer edge of the diaphragm inner portion is located radially inwards of a rim of the aperture, the diaphragm inner portion having a first stress. A diaphragm outer portion extends radially from the outer edge of the diaphragm inner portion to at least the rim of the aperture, the diaphragm outer portion having a second stress different from the first stress.

Composite diaphragms having balanced stress

An acoustic apparatus includes a back plate, a diaphragm, and at least one pillar. The diaphragm and the back plate are disposed in spaced relation to each other. At least one pillar is configured to at least temporarily connect the back plate and the diaphragm across the distance. The diaphragm stiffness is increased as compared to a diaphragm stiffness in absence of the pillar. The at least one pillar provides a clamped boundary condition when the diaphragm is electrically biased and the clamped boundary is provided at locations where the diaphragm is supported by the at least one pillar.

Acoustic apparatus with diaphragm supported at a discrete number of locations

A microphone assembly includes an acoustic transducer and an audio signal electrical circuit configured to receive an output signal from the acoustic transducer. The output signal includes an audio signal component and a tracking signal component. The audio signal component is representative of an acoustic signal detected by the acoustic transducer and the tracking signal component is based on an input tracking signal applied to the acoustic transducer. The audio signal electrical circuit includes an analog to digital converter configured to convert the output signal into a digital signal, an extraction circuit configured to separate the tracking signal component and the audio signal component from the digital signal, an envelope estimation circuit configured to estimate a tracking signal envelope from the tracking signal component, and a signal correction circuit configured to reduce distortion in the audio signal component using the tracking signal envelope.

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Chicago, IL, United States of America

Sung Bok Lee