SURFACE ACOUSTIC WAVE FILTER

摘要

PURPOSE: A surface acoustic wave(SAW) filter is provided to improve surface acoustic wave speed of a single crystal substrate and to directly mount the surface acoustic wave filter on a printed circuit board without mounting on a package. CONSTITUTION: A piezoelectric single crystal substrate(100) converts an electric signal into a mechanical surface acoustic wave and converts the surface acoustic wave into the electric signal. An input converter is formed on one side of the piezoelectric single crystal substrate(100) and transmits the electric signal to the piezoelectric single crystal substrate(100). An output converter is formed on the other side of the piezoelectric single crystal substrate(100) and transmits the electric signal converted at the piezoelectric single crystal substrate(100) to the outside. A carbon thin film of diamond nature or diamond thin film(300) is formed on the input and the output converter to expose the top of the piezoelectric single crystal substrate(100) and a part of the input and the output converter, and increases speed of the surface acoustic wave.