PIEZOELECTRIC MEMS MICROPHONE

摘要

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.

主权项

1. A packaged microphone comprising:
a microphone comprising:
a substrate;a transducing element having a first 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; and a casing mounted to the microphone, the casing and microphone cooperatively defining a back cavity having a second acoustic compliance, the casing dimensioned to achieve a predetermined ratio between the first and second acoustic compliances.