| 摘要 |
PURPOSE:To secure easily the frequency-response properties within the allowable range with no variation for along period of time by constituting the roller-screen type electrode with the oxidizable metal and also forming the oxide of the oxidizable metal between adjacent electrode elements. CONSTITUTION:Oxidizable conductive metal layer 22 of Al or the like is formed on priezoelectric substrate 1, and then layer 22 is oxidized via mask layer 23 with electrode E1'' and E2'' formed under layer 23. At the same time, metal oxide 24 constituting E1'' and E2'' is formed between adjacent electrode element e1 and e2 of E1'' and E2'' each. After this, layer 23 is removed on E1'' and E2''. As a result, the frequency-response properties can be secured within the allowable range with no change for a long time of use although the properties may feature the dependency due to the mass effect of electrode E1 and E2 since E1 and E2 are oxidizable metal and the side surfaces of element e1 and e2 are covered with oxide 24 of the same metal. |
