Elastic wave device and method for manufacturing the same
AssigneeMurata Manufacturing Co., Ltd.
InventorYutaka Kishimoto
Life of this patent
Estimating the term…
Abstract
An elastic wave device includes a piezoelectric layer including a first main surface and a second main surface facing the first main surface, an acoustically reflective layer stacked on the first main surface of the piezoelectric layer, an excitation electrode disposed on the piezoelectric layer, and a support layer. The acoustically reflective layer overlaps at least the excitation electrode in a plan view of the piezoelectric layer from the side of the second main surface. The support layer surrounds the acoustically reflective layer in a plan view of the piezoelectric layer from the side of the second main surface.
Claims19
An elastic wave device, comprising:
- a piezoelectric layer including a first main surface and a second main surface facing the first main surface;
- an acoustically reflective layer stacked on the first main surface of the piezoelectric layer;
- an excitation electrode disposed on the piezoelectric layer;
- and
- a support layer;
- wherein
- the acoustically reflective layer overlaps at least the excitation electrode in a plan view of the piezoelectric layer from a second main surface side;
- the support layer surrounds at least the acoustically reflective layer in the plan view of the piezoelectric layer from the second main surface side;
- the acoustically reflective layer includes a plurality of acoustic impedance layers;
- and
- a gap is provided outside at least one of the plurality of acoustic impedance layers.
A method for manufacturing an elastic wave device, comprising:
- stacking an acoustically reflective layer on a first main surface of a motherboard that includes the first main surface and a second main surface facing the first main surface and that is formed of a piezoelectric layer;
- performing patterning on the acoustically reflective layer to divide the acoustically reflective layer into a plurality of acoustically reflective layers;
- forming a support layer on the first main surface of the motherboard and the plurality of acoustically reflective layers;
- disposing a plurality of excitation electrodes on the motherboard;
- and
- cutting the support layer with a dicing machine to obtain a divided individual elastic wave device;
- wherein
- the step of forming the support layer includes forming the support layer such that the support layer surrounds the plurality of acoustically reflective layers in a plan view of the piezoelectric layer from a second main surface side;
- and
- the step of stacking the acoustically reflective layer includes forming the acoustically reflective layer at a position at which the acoustically reflective layer overlaps at least the plurality of excitation electrodes in the plan view of the piezoelectric layer from the second main surface side.
Dependencies are inferred from the claim text.