Title:
ACOUSTIC WAVE DEVICE
Document Type and Number:
WIPO Patent Application WO/2022/085581
Kind Code:
A1
Abstract:
Provided is an acoustic wave device with which it is possible to suppress the occurrence of cracks in a dielectric film, and to suppress sticking of a piezoelectric layer to the dielectric film. An acoustic wave device 10 is provided with a support substrate 12, a dielectric film 13, a piezoelectric layer 14, and an IDT electrode 15 (excitation electrode). The piezoelectric layer 14 has first and second main surfaces 14a, 14b. The second main surface 14b is positioned on the dielectric film 13 side. A void portion 11a is provided in the dielectric film 13. The void portion 11a overlaps at least a portion of the IDT electrode 15 in a plan view. The dielectric film 13 includes a sidewall surface 13a which faces the void portion 11a. The sidewall surface 13a has an inclined portion 13c which is inclined in such a way that the width of the void portion 11a decreases with increasing distance from the piezoelectric layer 14. The inclined portion 13c includes at least an end portion of the sidewall surface 13c on the piezoelectric layer 14 side. If the angle between the inclined portion 13c and the second main surface 14b of the piezoelectric layer 14 is an angle of inclination α, the angle of inclination α is from 40° to 80° inclusive.
Inventors:
KIMURA TETSUYA (JP)
KUBO SHINTAROU (JP)
KISHIMOTO YUTAKA (JP)
OMURA MASASHI (JP)
YAMADA HAJIME (JP)
KUBO SHINTAROU (JP)
KISHIMOTO YUTAKA (JP)
OMURA MASASHI (JP)
YAMADA HAJIME (JP)
Application Number:
PCT/JP2021/038195
Publication Date:
April 28, 2022
Filing Date:
October 15, 2021
Export Citation:
Assignee:
MURATA MANUFACTURING CO (JP)
International Classes:
H03H9/25
Domestic Patent References:
| WO2016068003A1 | 2016-05-06 | |||
| WO2016147687A1 | 2016-09-22 | |||
| WO2018198654A1 | 2018-11-01 | |||
| WO2012073871A1 | 2012-06-07 |
Foreign References:
| US20190020328A1 | 2019-01-17 |
Attorney, Agent or Firm:
MIYAZAKI & METSUGI (JP)
Download PDF: