Surface wave filter manufacturing method

Abstract

Abstract PURPOSE:To improve the accuracy and to prevent a fault such as short-circuiting by providing a com bline electrode onto the major plane of a piezoelectric substance such as single crystal, and forming a layer of the piezoelectric substance such as zinc oxide on the comb line electrode, thereby suppressing the variance in the center frequency. CONSTITUTION:Comb line electrodes 3, 3' are provided on the major plane of the piezoelectric substrate 1 such as single crystal and zinc oxide is sputtered to the electrodes 3, 3' to form a zinc oxide thin film 5. In supplying an electric signal to an input lead electrode 9', the signal reaches the electrode 3' via a wire 8 and a pad electrode 4 and converted into mechanical vibration through the piezoelectric effect. Then the vibration causes a surface wave, which is propagated toward the electrode 3 and converted into an electric signal and an output signal is obtained from the output side lead electrode 9 via the electrode 4 and the wire 8. In such a case, in providing an optional characteristic to the input/output electrodes 3, 3', the output signal has a frequency characteristic subject to filtering as the set characteristic. Thus, the dispersion in the center frequency is suppressed to improve the accuracy and a fault such as shortcircuiting due to the adhesion of a metal between the electrodes is prevented.

Inventors

• 👤 Junichi Inohara
• 👤 猪原　淳一
• 👤 Tomohiko Shinkawa
• 👤 新川　友彦
• 👤 Akio Nishino
• 👤 西野　明夫

Bibliographic Details