| 摘要 |
<p>To provide a surface acoustic wave device capable of increasing the electromechanical coupling coefficient and reducing the maximum insertion loss in a passband when used as a band-pass filter. A surface acoustic wave device has an electrode (3) and a dielectric layer (10) laminated on a piezoelectric substrate (2), in which the electrode (3) has a first electrode film (3a) containing Pt, Au, Ag, or Cu and a second electrode film (3b) containing Al, the normalized film thickness h/» of the first electrode film (3a) is 0.005 or more and at most 0.015 in the case of Pt, the normalized film thickness h/» of the Al film is 0.06 or more and at most 0.185, and the normalized film thickness h/» of the dielectric layer 10 is 0.2 or less.</p> |
