CPC H03H 9/08 (2013.01) [H03H 9/02559 (2013.01); H03H 9/02574 (2013.01); H03H 9/145 (2013.01); H03H 9/25 (2013.01)] | 8 Claims |
1. A layered body comprising:
a ceramic substrate formed of polycrystalline ceramic and having a supporting main surface; and
a piezoelectric substrate formed of a piezoelectric material and having a bonding main surface in contact with the supporting main surface of the ceramic substrate,
wherein at the supporting main surface, a mean of grain sizes of the polycrystalline ceramic is 15 μm or more and less than 40 μm, and
a standard deviation of the grain sizes is less than 1.5 times the mean.
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