ACOUSTIC BOUNDARY WAVE DEVICE

• Main Authors: MISHIMA NAOYUKI, YAMAGUCHI MASATSUNE, HASHIMOTO KIYONARI
• Format: Patent
• Language: English
• Published: 31.03.1998
• Edition: 6
• Subjects: BASIC ELECTRONIC CIRCUITRY; ELECTRICITY; IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS

PROBLEM TO BE SOLVED: To provide a device which has a function equivalent to a SAW(surface acoustic wave) device and can be easily miniaturized with reduction of its cost by combining an Si substrate with an LiNbO3 . substrate so as to secure the specific cut face and transmission direction. SOLUTION: A dielectric film 4 having the comb-line grooves 3 is formed on the main side of an Si substrate 2, and these grooves 3 are filled with a conductive material to form a comb-line electrode 5. Then an LiNbO3 a substrate 6 is bonded on the substrate 2 in order to obtain an acoustic boundary wave device. The substrate 2 is combined with the substrate 6 so as to secure a [001] cut face and a transmission direction for the substrate 2 and to secure a 175 deg. rotation cut face and an X transmission direction for the substrate 6 respectively. It's desirable for the substrate 2 to have high resistance of 10Ωcm or more to prevent the DC leakage caused by the electrode 5. The area of the main side of the substrate 6 is smaller than that of the main side of the substrate 2 and includes only an effective area that is necessary at least for transmission of the acoustic boundary wave.