US 11,902,727 B2
Inductive acoustic filters for acoustic devices
Anthony D. Minervini, Sunnyvale, CA (US); Peter C. Hrudey, San Mateo, CA (US); and Gokhan Hatipoglu, Santa Clara, CA (US)
Assigned to Apple Inc., Cupertino, CA (US)
Filed by Apple Inc., Cupertino, CA (US)
Filed on Feb. 11, 2022, as Appl. No. 17/670,387.
Prior Publication US 2023/0262370 A1, Aug. 17, 2023
Int. Cl. H04R 1/02 (2006.01); H04R 1/08 (2006.01); H04R 1/28 (2006.01); B81B 7/02 (2006.01)
CPC H04R 1/023 (2013.01) [B81B 7/02 (2013.01); H04R 1/08 (2013.01); H04R 1/2803 (2013.01); H04R 1/2873 (2013.01); B81B 2201/0257 (2013.01); H04R 2499/11 (2013.01)] 26 Claims
OG exemplary drawing
 
1. A microphone module, comprising:
a substrate;
a cover mounted to the substrate and at least partially defining a back volume of the microphone module,
a front volume that is separated from the back volume by a sound-responsive element and that is fluidly coupled to a first opening in the substrate;
a non-porous membrane that defines a sealed volume that is fluidly coupled to the front volume via the first opening, and that provides a liquid-resistant seal between the front volume and a first environment external to the microphone module on a first side of the substrate;
a second opening in the substrate that extends from the sealed volume defined by the non-porous membrane, through the substrate, to a second environment external to the microphone module on an opposing second side of the substrate; and
an inductive filter disposed between at least a portion of the non-porous membrane and at least a portion of the substrate, the inductive filter having a first port coupled to the front volume, a second port coupled to the second opening in the substrate, and a serpentine fluid pathway from the first port to the second port.