| 摘要 |
The composite substrate 10 is a substrate used to manufacture an acoustic wave device, and includes a support substrate 12, a piezoelectric substrate 14, and a adhesive layer 19 with which the support substrate 12 and the piezoelectric substrate 14 are bonded to each other. In the composite substrate 10, assuming that a surface of the piezoelectric substrate 14 that is bonded to the support substrate 12 is defined as a first surface 15 and a surface at the side opposite to the first surface is defined as a second surface 16, the piezoelectric substrate 14 is formed such that the first surface 15 is inside the second surface 16 when the first surface 15 is projected onto the second surface 16 in a direction perpendicular to the second surface 16. In other words, the composite substrate 10 has an outer peripheral surface that is formed such that the circumference thereof increases toward the top surface of the piezoelectric substrate 14. Thus, the piezoelectric substrate 14 that is larger than a bonding surface 11 of the support substrate 12 is formed above the bonding surface 11. Accordingly, the stress that may be generated at the edge portion of the composite substrate 10 when, for example, the composite substrate 10 is heated may be reduced. |
