Piezoelectric MEMS valve for an electronic device
A micro-electromechanical systems (MEMS) package comprising: a MEMS package comprising a substate and a lid coupled to the substrate; a piezoelectric valve coupled to the substrate and comprising a number of movable members operable to be deformed in opposite directions upon application of a voltage to modify an acoustic resistance of an acoustic port; and a first stopper defined by the substrate and a second stopper defined by the lid, the first stopper and the second stopper being aligned with the number of movable members and operable to prevent an undesirable deflection of the number of movable members.
1 . A micro-electromechanical systems (MEMS) package comprising:
a MEMS package comprising a substrate and a lid coupled to the substrate;
a piezoelectric valve coupled to the substrate and enclosed by the lid, and the piezoelectric valve comprising a first set of cantilevers having a number of cantilevers in a stacked arrangement and a second set of cantilevers having a number of cantilevers in a stacked arrangement, the first set and the second set of cantilevers extend from opposites sides of an acoustic port and the first set of cantilevers are operable to be deformed in an opposite direction than the second set of cantilevers to modify an acoustic resistance of the acoustic port; and
a first stopper defined by the substrate and a second stopper defined by the lid, the first stopper and the second stopper arranged below or above the number of cantilevers and having different dimensions operable to prevent an undesirable deflection of the number of cantilevers.
2 . The MEMS package of claim 1 wherein adjacent cantilevers are deformed in opposite directions.
3 . The MEMS package of claim 1 wherein each of the cantilevers comprises a polygon shape.
4 . The MEMS package of claim 1 wherein the first set and the second set of cantilevers each comprise more than two cantilevers that extend toward a center of the acoustic port between a first side opposite a second side.
5 . The MEMS package of claim 1 wherein the stacked arrangement of the number of cantilevers comprises a stack up of a first inactive material layer and a second inactive material layer separated by a first active material layer and a second active material layer.
6 . The MEMS package of claim 1 wherein each cantilever of the first set and the second set of cantilevers comprises a stack up of an inactive material layer, a first electrode layer, a piezoelectric layer and a second electrode layer covering only a portion of the inactive material layer, and the piezoelectric layer comprises a piezoelectric material operable to drive the deformation of each of the cantilevers upon application of a voltage.
7 . The MEMS package of claim 1 wherein an application of a voltage deforms the cantilevers to an out of plane open position that uncovers the acoustic port and decreases the acoustic resistance.
8 . The MEMS package of claim 1 wherein the cantilevers comprise an anisotropic stress that deforms the cantilevers out of plane to an open position in an absence of any voltage, and an application of the voltage deforms the cantilevers to an in plane closed position.
9 . The MEMS package of claim 1 wherein a contrast ratio of the acoustic resistance between the cantilevers in a deformed configuration in which the acoustic port is open and a non-deformed configuration in which the acoustic port is closed is 1000 times or more.
10 . The MEMS package of claim 1 wherein the first stopper is positioned above the cantilevers to prevent an undesirable upward deformation of the cantilevers and the second stopper is positioned below the cantilevers to prevent an undesirable downward deformation of the cantilevers.
11 . The MEMS package of claim 1 further comprising an earpiece enclosure that encloses the MEMS package and a transducer coupled to an interior chamber and the acoustic port defined by the earpiece enclosure.
12 . A portable electronic device comprising:
an enclosure having an enclosure wall that forms an interior chamber and a port to an ambient environment;
a piezoelectric valve coupled to the port and comprising a first set of cantilevers having a number of cantilevers in a stacked arrangement and a second set of cantilevers having a number of cantilevers in a stacked arrangement, the first set and the second set of cantilevers extend from opposites sides of the port, and the first set of cantilevers are operable to be deformed in an opposite direction than the second set of cantilevers to modify an acoustic resistance of the port; and
a first stopper defined by a substrate and a second stopper defined by a lid coupled to the substrate and enclosing the piezoelectric valve, and the first stopper and the second stopper having different dimensions operable to prevent an undesirable downward deflection and an undesirable upward deflection of the first set and the second set of cantilevers.
13 . The portable electronic device of claim 12 wherein adjacent cantilevers are deformed in opposite directions.
14 . The portable electronic device of claim 12 wherein each cantilever comprises a polygon shape.
15 . The portable electronic device of claim 12 wherein the first set and the second set of cantilevers each comprise more than two cantilevers that extend toward a center of the port between a first side opposite a second side.
16 . The portable electronic device of claim 12 wherein the stacked arrangement of cantilevers of the number of cantilevers comprises a stack up of a first inactive material layer and a second inactive material layer separated by a first active material layer and a second active layer.
17 . The portable electronic device of claim 12 wherein each cantilever of the first set and the second set of cantilevers comprises a stack up of an inactive material layer, a first electrode layer, a piezoelectric layer and a second electrode layer covering only a portion of the inactive material layer, and the piezoelectric layer comprises a piezoelectric material operable to drive the deformation of each cantilever upon application of a voltage.
18 . The portable electronic device of claim 12 wherein an application of a voltage deforms the cantilevers to an out of plane open position that uncovers the port and decreases the acoustic resistance.
19 . The portable electronic device of claim 12 wherein each of the cantilevers comprises an anisotropic stress that deforms the cantilevers out of plane to an open position in an absence of any voltage, and an application of the voltage deforms the cantilevers to an in plane closed position.
20 . The portable electronic device of claim 12 wherein a contrast ratio of the acoustic resistance between the cantilevers in a deformed configuration in which the port is open and a non-deformed configuration in which the port is closed is 1000 times or more.
21 . The portable electronic device of claim 12 wherein the enclosure comprises an earpiece enclosure that encloses a transducer coupled to the interior chamber.