| 摘要 |
PURPOSE:To obtain the circuit having objective performance, by performing the measurement for the characteristics while evaporating dielectric substance on the major plane, through the use of the nature that the phase response and frequency response of the device are dependent on the thickness of the dielectric substance attached to the major plane including the circuit of device. CONSTITUTION:On the major plane 2 of the piezoelectric substrate 1, the elastic surface wave device U including the elastic surface wave circuit Q on which the first and second reed screen type electrodes E1 and E2 are formed respectively, is constituted in advance so that specified object can be obtained. The device U is placed in the vacuum evaporation vessel 11 so that the major plane 2 can be opposed to the boat 10 containing the dielectric substance 9, and the circuit Q is connected to the signal source 14 for frequency and phase response measurement and the display unit 15 located outside the vassel 11. Further, while measuring the performance, the dielectric substance layer is formed on the major plane 2 with vacuum evaporation and the evaporation is stopped when specified performance is obtained. Since the temperature rise at the evaporation is small negligibly, the result of this measurement can be obtained almost equal to the performance at actual usage of device. |
