| 摘要 |
The present invention provides a surface-mount SAW device configured to prevent sealing resin layer coated all over the top surface of a piezoelectric substrate from becoming charged even if the piezoelectric substrate forming the SAW device is made of a pyroelectric material. The SAW device is composed of: a mounting substrate 2; a SAW chip 15 provided with a piezoelectric substrate 18, an IDT electrode 17 formed on one surface of said piezoelectric substrate, and connection pads 16 connected via conductor bumps 10 to conductor traces 5; and a sealing resin layer 21 coated all over the outer surface of the SAW chip flip-chip mounted on the mounting substrate and extended down to the top surface of the mounting substrate to define an airtight space S between the IDT electrode and the mounting substrate; wherein the crystal structure of the piezoelectric substrate belongs to any one of point groups C 1 , C 2 , C S , C 2V , C 4 , C 4V , C 3 , C 3V , C 6 and C 6V in terms of Schoenflies symbols; characterized in that the conductivity of the piezoelectric substrate is increased to suppress charging of the sealing resin layer.
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