Capacitive microphone with integrated cavity
AssigneeUniversity of Florida Research Foundation, Inc.
InventorsMark Sheplak, David Patrick Arnold
Life of this patent
Estimating the term…
Abstract
A capacitive microphone and method of fabricating the same are provided. One or more holes can be formed in a first printed circuit board (PCB). A diaphragm can be surface micromachined onto an interior surface of the first PCB at a region having the one or more holes. Interface electronics can also be interconnected to the interior surface of the PCB. One or more spacer PCBs can be attached to a second PCB to the first PCB, such that appropriate interconnections between interconnect vias are made. The second PCB and first PCB with spacers in between can be attached so as to create a cavity in which the diaphragm and interface electronics are located.
Claims38
A method of fabricating a microphone, comprising:
- fabricating a backplate on a portion of a printed circuit board;
- locating a diaphragm relative to the portion of the printed circuit board so as to form a first volume between the diaphragm and the back plate, wherein a front surface of the diaphragm is in contact with the first volume, wherein a back surface is in contact with a second volume, wherein one of the first volume and the second volume is in low acoustic impedance contact with the ambient acoustic environment, and the other of the first volume and second volume is in high acoustical impedance contact with the ambient acoustic environment, wherein the diaphragm flexes in response to acoustic pressure;
- and
- producing an output signal related to the acoustic pressure on the diaphragm,
- wherein the first volume is in high acoustic impedance contact with the ambient acoustic environment the second volume is in low acoustic impedance contact with the ambient acoustic environment,
- further comprising:
- providing an enclosure, wherein the first volume is within the enclosure,
- wherein the enclosure comprises:
- the printed circuit board;
- a bottom printed circuit board;
- and
- one or more spacer printed circuit boards, wherein the printed circuit board, the one or more spacer printed circuit boards, and the bottom printed circuit board are attached to form the enclosure.
A method of fabricating a microphone, comprising:
- depositing a backplate on a portion of a printed circuit board;
- locating a diaphragm relative to the portion of the printed circuit board so as to form a first volume between the diaphragm and the back plate, wherein a front surface of the diaphragm is in contact with the first volume, wherein a back surface is in contact with a second volume, wherein one of the first volume and the second volume is in low acoustic impedance contact with the ambient acoustic environment, and the other of the first volume and second volume is in high acoustical impedance contact with the ambient acoustic environment, wherein the diaphragm flexes in response to acoustic pressure;
- and
- producing an output signal related to the acoustic pressure on the diaphragm,
- wherein the first volume is in high acoustic impedance contact with the ambient acoustic environment the second volume is in low acoustic impedance contact with the ambient acoustic environment,
- further comprising:
- providing an enclosure, wherein the first volume is within the enclosure,
- wherein the enclosure comprises:
- the printed circuit board;
- a bottom printed circuit board;
- and
- one or more spacer printed circuit boards, wherein the printed circuit board, the one or more spacer printed circuit boards, and the bottom printed circuit board are attached to form the enclosure.
Dependencies are inferred from the claim text.