| 摘要 |
PURPOSE:To decrease the number of components and to improve the mass-productivity with small size, by providing a case so as to form a space between input/output transducers provided on a piezoelectric substrate. CONSTITUTION:On the piezoelectric substrate 12, the input/output transducers 13, 14 comprising comb-type electrodes, and leadout electrodes 15-18 leading to the rear side of the substrate 12 from the input/output transducers 13, 14 respectively are provided. Further, a space is provided to the input/output transducers 13, 14 and a part where a surface acoustic wave between the transducers 13, 14 is propagated so as not to interfere the propagation of the surface acoustic wave, and moreover, in order to protect said comb-type electrodes formed with a thin film of Al or the like for the assurance of the reliability, a case 19 made of an insulator 19 or the like is bonded on the surface of the substrate 12 with an adhesive 20 so as to avoid short-circuit. Thus, the constituting components are reduced, the miniaturization is attained and the mass-productivity is improved. |
