| 摘要 |
PROBLEM TO BE SOLVED: To improve anti-moldability and heat resistance of a surface mounting type surface acoustic wave device mainly used for a mobile communication apparatus. SOLUTION: This surface acoustic wave device includes: am interdigital electrode 2 and a pad electrode 3 which are provided on the surface of a piezoelectric substrate 1 having anisotropicity; side walls 7 disposed on the piezoelectric substrate 1 and surrounding the interdigital electrode 2; a top plate 8 disposed on the side walls and covering an excitation space of the interdigital electrode 2; and a filler-containing sealing resin 5 for covering the top plate 8 and the surface of the piezoelectlic substrate 1. The top plate 8 is made of a metal foil 8a for covering an opening portion of the side walls 7, and a plating layer 8b provided on the metal foil 8a and having a thickness thicker than that of the metal foil 8a, wherein the plating layer 8b is separated in a direction where the difference in linear thermal expansion ratio between the piezoelectric substrate 1 and the plating layer 8b becomes large. COPYRIGHT: (C)2010,JPO&INPIT
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