Title:
COMPOSITE SUBSTRATE, PIEZOELECTRIC ELEMENT, AND METHOD FOR MANUFACTURING COMPOSITE SUBSTRATE
Document Type and Number:
WIPO Patent Application WO/2020/067013
Kind Code:
A1
Abstract:
A composite substrate of the present disclosure comprises: a piezoelectric substrate having a first surface, which is an element forming surface, and a second surface, which is a back surface thereof; a sapphire substrate having a third surface, which is disposed to face the second surface, and a fourth surface, which is a back surface thereof; and an alumina layer that has a fifth surface facing the second surface, and a sixth surface facing the third surface, and joins the second surface and the third surface, wherein the arithmetic average roughness Ra of the third surface is 0.1 μm or more and 0.5 μm or less, and the arithmetic average roughness Ra of the fifth surface is not more than 0.1 μm and smaller than the arithmetic average roughness Ra of the third surface.
Inventors:
UMEHARA MOTOHIRO (JP)
MITSUDA KUNIAKI (JP)
FUJIMOTO KAZUYOSHI (JP)
MITSUDA KUNIAKI (JP)
FUJIMOTO KAZUYOSHI (JP)
Application Number:
PCT/JP2019/037272
Publication Date:
April 02, 2020
Filing Date:
September 24, 2019
Export Citation:
Assignee:
KYOCERA CORP (JP)
International Classes:
H03H9/25; H01L41/09; H01L41/113; H01L41/187; H01L41/312; H01L41/337; H03H3/08
Domestic Patent References:
| WO2017163722A1 | 2017-09-28 | |||
| WO2018016169A1 | 2018-01-25 |
Foreign References:
| JP2005252550A | 2005-09-15 | |||
| JP2018026695A | 2018-02-15 | |||
| JP2014147054A | 2014-08-14 | |||
| JP2018061226A | 2018-04-12 |
Other References:
See also references of EP 3859971A4
Attorney, Agent or Firm:
BUNA PATENT ATTORNEYS (JP)
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