| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a composite substrate in which occurrence of cracking in grinding of a piezoelectric substrate can be suppressed and occurrence of cracking in handling can also be suppressed. <P>SOLUTION: In the composite substrate 10, a piezoelectric substrate 12 capable of propagating an elastic wave and a supporting substrate 14 having a smaller thermal expansion coefficient than that of the piezoelectric substrate 12 are stuck to each other via an organic adhesive layer 16. On a surface of the piezoelectric substrate 12, a groove 18 is formed over the entire circumference on an inner side than the outer circumferential edge. In the groove 18, a longitudinal cross section is approximately V-shaped, and a bottom part of the groove 18 reaches the supporting substrate 14, but since longitudinal cross-sectional shape of the groove 18 becomes gradually thinner from an opening toward the bottom part, the supporting substrate 14 is merely shaved just a little. <P>COPYRIGHT: (C)2011,JPO&INPIT |
