Piezoelectric device
AssigneeMurata Manufacturing Co., Ltd.
InventorsYutaka Kishimoto, Shinsuke Ikeuchi, Masashi Omura
Life of this patent
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Abstract
In a piezoelectric device, when viewed in a direction perpendicular to one main surface, an outer shape of a recess is a polygonal shape or a circular shape. When n represents a number of sides of the polygonal shape, r represents a radius of a circumscribed circle of an imaginary regular polygon including n sides with a length identical to a length of a shortest of the sides, and d represents a maximum thickness of a membrane portion, which is located above the recess, of a multilayer portion, r≤197.7 dn−0.6698 when 3≤n≤7, and r≤52.69 d when 8≤n or when the outer shape of the recess is a circular shape.
Claims20
A piezoelectric device comprising:
- a base portion including one main surface and another main surface located on an opposite side from the one main surface, and including a recess in the one main surface;
- and
- a multilayer portion stacked on a side of the base portion where the one main surface is located so as to cover the recess from above;
- wherein
- the multilayer portion includes, at least above the recess, a single-crystal piezoelectric layer and a pair of electrode layers through which a voltage is applied to the single-crystal piezoelectric layer;
- the single-crystal piezoelectric layer curves convexly in the direction perpendicular to the one main surface towards the base portion above the recess;
- an outer shape of the recess is a polygonal shape or a circular shape when viewed in a direction perpendicular to the one main surface;
- and
- when n represents a number of a plurality of sides of the polygonal shape, r represents a radius of a circumscribed circle of an imaginary regular polygon including n sides with a length identical to a length of a shortest side among the plurality of sides, and d represents a maximum thickness of a membrane portion, which is located above the recess, of the multilayer portion:
- r≤197.7 dn−0.6698 is satisfied when 3≤n≤7;
- and
- r≤52.69 d is satisfied when 8≤n or when the outer shape of the recess is a circular shape.
A piezoelectric device comprising:
- a base portion including one main surface and another main surface located on an opposite side from the one main surface, and including a recess in the one main surface;
- and
- a multilayer portion stacked on a side of the base portion where the one main surface is located so as to cover the recess from above;
- wherein
- the multilayer portion includes, at least above the recess, a single-crystal piezoelectric layer and a pair of electrode layers through which a voltage is applied to the single-crystal piezoelectric layer;
- the multilayer portion curves convexly in the direction perpendicular to the one main surface towards the other main surface above the recess;
- an outer shape of the recess is a polygonal shape or a circular shape when viewed in a direction perpendicular to the one main surface;
- and
- when n represents a number of a plurality of sides of the polygonal shape, r represents a radius of a circumscribed circle of an imaginary regular polygon including n sides with a length identical to a length of a shortest side among the plurality of sides, and d represents a maximum thickness of a membrane portion, which is located above the recess, of the multilayer portion:
- r≤197.7 dn−0.6698 is satisfied when 3≤n≤7;
- and
- r≤52.69 d is satisfied when 8≤n or when the outer shape of the recess is a circular shape.
Dependencies are inferred from the claim text.