| 摘要 |
PURPOSE: A composite substrate, an elastic surface wave filter using the same, and an elastic surface wave resonator using the same are provided to bond a support substrate with a thermal expansion coefficient smaller than the thermal expansion coefficient of a piezoelectric substrate with the piezoelectric substrate by an organic boding substrate, thereby effectively suppressing a change of a frequency temperature feature of a piezoelectric substrate. CONSTITUTION: A piezoelectric substrate(12) transmits an elastic wave. A metal film and an insulation film are formed on the rear surface of the piezoelectric substrate. A supporting substrate(14) is bonded with the rear surface of the piezoelectric substrate by an organic bonding layer(16). The thermal expansion coefficient difference between the piezoelectric substrate and the supporting substrate is larger than 10 ppm/K. |
