Piezoelectric accelerometer with wake function
AssigneeQUALCOMM Technologies, Inc.
InventorRobert J. Littrell
Life of this patent
Estimating the term…
Abstract
A sensor device that senses proper acceleration. The sensor device includes a substrate, a spacer layer supported over a first surface of the substrate, at least a first tapered cantilever beam element having a base and a tip, the base attached to the spacer layer, and which is supported over and spaced from the substrate by the spacer layer. The at least first tapered cantilever beam element tapers in width from the base portion to the tip portion. The at least first cantilever beam element further including at least a first layer comprised of a piezoelectric material, a pair of electrically conductive layers disposed on opposing surfaces of the first layer, and a mass supported at the tip portion of the at least first tapered cantilever beam element.
Claims20
A packaged micro electromechanical system (MEMS) device comprising:
- a package having a compartment;
- and
- a MEMS die disposed in the compartment, the MEMS die supporting a MEMS accelerometer formed by a first structure and a MEMS microphone formed by a second structure different from the first structure;
- wherein the MEMS accelerometer comprises:
- a spacer layer;
- at least a first tapered cantilever beam element having a base portion and a tip portion, the base portion attached to the spacer layer, wherein at least the first tapered cantilever beam element is supported over and spaced from a substrate of the MEMS die by the spacer layer, with at least the first tapered cantilever beam element tapering in width from the base portion, and with at least the first tapered cantilever beam element further comprising:
- at least a first layer comprised of a piezoelectric material;
- a pair of electrically conductive layers disposed on opposing surfaces of the first layer, wherein at least one conductive layer of the pair of electrically conductive layers has an electrical discontinuity to provide an electrically active portion of at least the first tapered cantilever beam element and an electrically inactive portion of at least the first tapered cantilever beam element;
- and
- a mass element supported at the tip portion of at least the first tapered cantilever beam element.
A packaged micro electromechanical system (MEMS) device comprising:
- a package having a compartment;
- and
- a MEMS die disposed in the compartment, the MEMS die supporting a MEMS accelerometer formed by a first structure and a MEMS microphone formed by a second structure different from the first structure;
- wherein the MEMS accelerometer, comprises:
- a spacer layer;
- at least a first tapered cantilever beam element having a base portion and a tip portion, the base portion attached to the spacer layer, wherein at least the first tapered cantilever beam element is supported over and spaced from a substrate of the MEMS die by the spacer layer, with at least the first tapered cantilever beam element tapering in width from the base portion, and with at least the first tapered cantilever beam element further comprising:
- at least a first layer comprised of a piezoelectric material;
- and
- a pair of electrically conductive layers disposed on opposing surfaces of the first layer;
- wherein at least the first tapered cantilever beam element is configured to have the base portion taper to an intermediate neck region, from the intermediate neck region expand to a wide intermediate region, and from the wide intermediate region taper to the tip portion, and wherein at least one conductive layer of the pair of electrically conductive layers has an electrical discontinuity to provide an electrically active portion of at least the first tapered cantilever beam element and an electrically inactive portion of at least the first tapered cantilever beam element.
Dependencies are inferred from the claim text.