Acoustic wave element and acoustic wave device
AssigneeKYOCERA Corporation
InventorHiroyuki Tanaka
Life of this patent
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Abstract
An acoustic wave element of the present invention includes a substrate; and an IDT electrode on an upper surface of the substrate, including a first bus bar, a second bus bar arranged with a space in a first direction from the first bus bar, a plurality of first electrode fingers connected to the first bus bar, a plurality of second electrode fingers connected to the second bus bar, and a second dummy electrode finger facing a tip end of one of the first electrode fingers through a gap. In at least one of the second electrode fingers, a width in a region on the side closer to the second bus bar than a first virtual line connecting the tip ends of the plurality of first electrode fingers is wider than a width in a region on the side closer to the first bus bar than the first virtual line.
Claims8
An acoustic wave element, comprising:
- a substrate configured by a piezoelectric crystal;
- an IDT electrode on an upper surface of the substrate, comprising
- a first bus bar connected to a first potential,
- a second bus bar connected to a second potential and arranged with a space in a first direction from the first bus bar,
- a plurality of first electrode fingers connected to the first bus bar and extending toward a side of the second bus bar,
- a plurality of second electrode fingers connected to the second bus bar and extending toward a side of the first bus bar,
- a first dummy electrode finger connected to the first bus bar and facing a tip end of one of the second electrode fingers through a gap, and
- a second dummy electrode finger connected to the second bus bar and facing a tip end of one of the first electrode fingers through a gap;
- and
- a support substrate which is joined to a lower surface of the substrate, comprising a larger thickness than the substrate, and is made of a material having a smaller thermal expansion coefficient than the substrate, wherein
- a width of at least one of the first electrode fingers, the second electrode fingers, the first dummy electrode finger, and the second dummy electrode finger outside of an intersection area surrounded by a first virtual line connecting the tip ends of the plurality of first electrode fingers and by a second virtual line connecting the tip ends of the plurality of second electrode fingers is wider than widths of the first electrode fingers and the second electrode fingers in the intersection area, in at least one of the second electrode fingers, the width at all positions in a region from the first virtual line to the second bus bar is wider than the width in the intersection area, and at least one of the second electrode fingers extends lineally.
Dependencies are inferred from the claim text.