Patent ID: 7411334
Filing Date: 2008-08-12
Classification: H03H,Y10T

Abstract:
1. A surface acoustic wave apparatus comprising: a piezoelectric substrate; at least one electrode provided on the piezoelectric substrate and including one of a metal and an alloy; a protective metal film provided on said at least one electrode and including a metal or an alloy having higher erosion-resistant characteristics than the metal or the alloy of the at least one electrode; a first insulating layer provided on the piezoelectric substrate in an area other than an area in which said at least one electrode is provided and having a thickness substantially equal to a total thickness of said at least one electrode and said protective metal film; and a second insulating layer arranged to cover said protective metal film and said first insulating layer; wherein the first and second insulating layers are made of SiO the average density of a laminated structure of said at least one electrode and said protective metal film is about 1.5 times or greater than a density of said first insulating layer; and a thickness of the second insulating layer is greater than the thickness of the first insulating layer.