Elastic wave device and manufacturing method therefor
AssigneeMurata Manufacturing Co., Ltd.
InventorsYutaka Kishimoto, Masashi Omura
Life of this patent
Estimating the term…
Abstract
An elastic wave device in which an IDT electrode defines an excitation electrode on a piezoelectric layer, an acoustic reflection layer is laminated on a first main surface of the piezoelectric layer, the acoustic reflection layer includes high acoustic impedance layers with a relatively high acoustic impedance and low acoustic impedance layers with a relatively low acoustic impedance, and the acoustic reflection layer has an unwanted wave reflection suppression structure in which reflection of unwanted waves toward the piezoelectric layer side is significantly reduced or prevented.
Claims14
An elastic wave device comprising:
- a piezoelectric layer that includes a first main surface and a second main surface opposite to the first main surface;
- a first excitation electrode and a second excitation electrode that are in contact with the piezoelectric layer;
- and
- an acoustic reflection layer that is provided on the first main surface of the piezoelectric layer;
- wherein
- the acoustic reflection layer includes a high acoustic impedance layer including a pair of opposing main surfaces and with a relatively high acoustic impedance and a low acoustic impedance layer including a pair of opposing main surfaces and with a relatively low acoustic impedance;
- and
- in the acoustic reflection layer, outer peripheral edges of individual main surfaces of the pair of main surfaces of at least one of the low acoustic impedance layer and the high acoustic impedance layer are curved so as not to be located within surfaces where the individual main surfaces at a center of the at least one of the low acoustic impedance layer and the high acoustic impedance layer are extended in an outer peripheral edge direction.
An elastic wave device comprising:
- a piezoelectric layer that includes a first main surface and a second main surface opposite to the first main surface;
- a first excitation electrode and a second excitation electrode that are in contact with the piezoelectric layer;
- and
- an acoustic reflection layer that is provided on the first main surface of the piezoelectric layer;
- wherein
- the acoustic reflection layer includes a high acoustic impedance layer with a relatively high acoustic impedance and a low acoustic impedance layer with a relatively low acoustic impedance;
- and
- on an outer peripheral side surface of the acoustic reflection layer, an outer peripheral side surface of at least one of the high acoustic impedance layer and the low acoustic impedance layer is separate from outer peripheral side surfaces of other layers with a step therebetween.
Dependencies are inferred from the claim text.