| 摘要 |
PROBLEM TO BE SOLVED: To stabilize frequency characteristics by joining the cover of a second member to a substrate by a joining member and pulling out an electrode to the outside while being in contact with the joining member in a surface acoustic wave element for which the electrode is formed on the substrate composed of the piezoelectric body of a first member. SOLUTION: The electrode 5 for generating surface acoustic waves is provided on a piezoelectric body substrate 1 and the electrode 5 is connected to an external circuit by a pad electrode 3. In this case, the substrate 1 is crystal and the cover 2 is joined through the joining member 4 onto the electrode for connecting a part of the electrode 3 or the electrode 5 and the pad electrode 3. The cover 2 uses quartz glass. The joining member 4 is formed so as to vacuum-deposit a glass material whose fusing point is around 450 deg.C to the cover 2 and recess a part facing the electrode 5 including the cover 2 thereafter. Thereafter, the cover 2 is piled up on the substrate 1 so as to make the joining member 2 face each other, the glass is fused under a high temperature and joining is performed. Thus, the cover of a wafer state similarly is joined altogether to the piezoelectric substrate of the wafer state and the frequency is stabilized. |
