摘要 |
PURPOSE:To control the central frequency of the pass band by evaporating through sputtering the insulating film on the opposing electrodes of the comb-line electrodes provided on the substrate at the final stage of the manufacturing process. CONSTITUTION:Comb-line electrodes 2 and 2' are provided on substrate 1; piezoelectric substance 3 of 2.5mu thick is evaporated by sputtering on the comb-line electrodes; and furthermore opposing electrodes 4 and 4' are provided on substance 3. Thus a surface wave device is formed. In case the device thus manufactured in out of the standard, the insulator is evaporated by sputtering about 1000Angstrom on the device. As a result, the sound speed can be changed within the device, and the central frequency of the device is controlled to obtain the standardized products. |