Akustisches Oberflächenwellenelement und Herstellungsverfahren

摘要

In a surface acoustic wave element according to an embodiment of this invention, raised electrodes 20 formed on thin film electrodes 18 are provided with throughholes 31. Additionally, bumps 26 arranged on the raised electrodes 20 reach the thin film electrode 18 by going through an oxide film 18a of the thin film electrodes 18 after part of the bumps enters the throughholes 31 of the raised electrodes 20. By doing this, conduction is achieved between the thin film electrodes 18 and the bumps 26 formed on a piezoelectric monocrystal substrate 28. Thus, a solid oxide film 18a is formed on the surface of the thin film electrodes 18 formed from monocrystal aluminum, but part of the bumps 26 which enters the throughholes 31 of the raised electrodes 20 goes through this oxide film 18a, so conduction between the thin film electrode 18 and the bump 26 is achieved with higher accuracy.