Piezoelectric MEMS microphone
First Claim
1. A packaged microphone comprising:
- a microphone comprising;
a substrate; and
a transducing element having a transducer acoustic compliance, the transducing element comprising a first electrode layer, a piezoelectric layer deposited over the first electrode layer, and a second electrode layer deposited over the piezoelectric material, wherein the first electrode layer is patterned on the substrate, the piezoelectric layer is patterned on the first electrode layer, and the second electrode layer is patterned on the piezoelectric layer; and
a casing mounted to the microphone and having a back wall, wherein a space between the back wall and the transducing element at least partially defines a back cavity having a back cavity acoustic compliance, the casing dimensioned to achieve a predetermined ratio between the transducer and back cavity acoustic compliances.
2 Assignments
0 Petitions
Accused Products
Abstract
A microphone including a casing having a front wall, a back wall, and a side wall joining the front wall to the back wall, a transducer mounted to the front wall, the transducer including a substrate and a transducing element, the transducing element having a transducer acoustic compliance dependent on the transducing element dimensions, a back cavity cooperatively defined between the back wall, the side wall, and the transducer, the back cavity having a back cavity acoustic compliance. The transducing element is dimensioned such that the transducing element length matches a predetermined resonant frequency and the transducing element width, thickness, and elasticity produces a transducer acoustic compliance within a given range of the back cavity acoustic compliance.
43 Citations
12 Claims
-
1. A packaged microphone comprising:
-
a microphone comprising; a substrate; and a transducing element having a transducer acoustic compliance, the transducing element comprising a first electrode layer, a piezoelectric layer deposited over the first electrode layer, and a second electrode layer deposited over the piezoelectric material, wherein the first electrode layer is patterned on the substrate, the piezoelectric layer is patterned on the first electrode layer, and the second electrode layer is patterned on the piezoelectric layer; and a casing mounted to the microphone and having a back wall, wherein a space between the back wall and the transducing element at least partially defines a back cavity having a back cavity acoustic compliance, the casing dimensioned to achieve a predetermined ratio between the transducer and back cavity acoustic compliances. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
-
Specification