| 摘要 |
PURPOSE:To attain the stable loss characteristics in a low frequency band by forming a reflection preventing pattern with a heterometal having a larger reflection coefficient than aluminum at a place right close to the end of a piezoelectric substrate of a short grating. CONSTITUTION:An interlaced electrode 2 and a short grating 3 are formed on a piezoelectric substrate 1 with aluminum electrodes by photolithography. At the same time, a reflection preventing pattern 5 is formed at a position distant from the final end part 4 of the grating 3 by the (wavelength/4 x h)-fold value. Then an Au electrode 6 having a large reflection coefficient is laminated on the pattern 5 only by vapor deposition, plating, etc. Then the substrate 1 is cut into separate chips. In such a way, a piezoelectric surface wave resona tor 7 is obtained with stable loss characteristics. Then the effects given to the loss characteristics owing to the different out width values can be neglected. Thus it is possible to standardize the blade width and to improve the cut effi ciency.
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