| 摘要 |
A composite substrate (10) is obtained by bonding a supporting substrate (12) and a piezoelectric substrate (14) with each other, and the supporting substrate (12) and the piezoelectric substrate (14) are bonded with each other by an adhesive layer (16) in an embodiment of the present invention. Since the supporting substrate (12) of this composite substrate (10) is formed of a light-transmitting alumina ceramic, alignment during FCB can be easily done in comparison to the cases where a supporting substrate is formed of an opaque ceramic. In addition, it is preferable that the linear transmittance and the total forward light transmittance of the supporting substrate (12) in the visible light region (360-750 nm) are 10% or more and 70% or more, respectively. |
