Title:
COMPOSITE SUBSTRATE FOR ELASTIC WAVE DEVICE
Document Type and Number:
WIPO Patent Application WO/2022/054372
Kind Code:
A1
Abstract:
[Problem] To improve the bonding strength between a piezoelectric material substrate and a support substrate, effectively reduce the reflection of bulk waves, and suppress spurious emissions. [Solution] This composite substrate 7A for an elastic wave device comprises a piezoelectric material layer PZ, a support substrate S, and x layers (x is an integer of 3 or more) of intermediate layers 1, 2, X between the piezoelectric material layer and the support substrate. The piezoelectric material layer, the support substrate, and the intermediate layers satisfy formula (1), formula (2) is satisfied when x is an even number, and formula (3) is satisfied when x is an odd number. Formula (1): Rn < Rn+1 (n represents all integers from 1 to x, Rn is the arithmetic mean roughness of the surface of the n-th intermediate layer on the piezoelectric material layer side when viewed from the piezoelectric material layer, and Rx+1 is the arithmetic mean roughness of the surface of the support substrate on the piezoelectric material layer side). Formula (2): Vn-1 < Vn (n is 2 or more and represents all even numbers equal to or less than x, and Vn is the acoustic velocity of the n-th intermediate layer when viewed from the piezoelectric material layer). Formula (3): Vn-1 > Vn (n is 1 or more and represents all odd numbers equal to or less than x, Vn is the acoustic velocity of the n-th intermediate layer when viewed from the piezoelectric material layer, and V0 represents the acoustic velocity of the piezoelectric material layer).
Inventors:
HORI YUJI (JP)
YAMADERA TAKAHIRO (JP)
YAMADERA TAKAHIRO (JP)
Application Number:
PCT/JP2021/023918
Publication Date:
March 17, 2022
Filing Date:
June 24, 2021
Export Citation:
Assignee:
NGK INSULATORS LTD (JP)
International Classes:
H03H3/08; H03H9/25
Domestic Patent References:
| WO2020130128A1 | 2020-06-25 | |||
| WO2018154950A1 | 2018-08-30 | |||
| WO2017163729A1 | 2017-09-28 |
Foreign References:
| JP2018061226A | 2018-04-12 | |||
| JP2001053579A | 2001-02-23 | |||
| JPH0563500A | 1993-03-12 | |||
| JPS6250856B2 | 1987-10-27 | |||
| US20170063333A1 | 2017-03-02 | |||
| JP2014086400A | 2014-05-12 |
Other References:
"Acoustic wave device technology"
See also references of EP 4047819A4
See also references of EP 4047819A4
Attorney, Agent or Firm:
HOSODA Masutoshi et al. (JP)
Download PDF:
Previous Patent: ACOUSTIC PROCESSING DEVICE
Next Patent: MEDICAL IMAGE DEVICE AND METHOD FOR OPERATING SAME
Next Patent: MEDICAL IMAGE DEVICE AND METHOD FOR OPERATING SAME