COMPOSITE SURFACE ELASTIC WAVE FILTER

摘要

PURPOSE: A composite surface elastic wave filter is provided to be used in analog-digital hand phone by mounting 2 filter chip in one package. CONSTITUTION: The composite surface elastic wave filter comprises: a pair of filter chip(20,20') stacked with a nonconductive resin layer(30) between them; thin membrane type capacitor and inductance devices(23,23'; 24,24') forming impedance matching circuit regarding input and output of respective chip; cutoff grooves(40,40') formed near the IDT electrodes(22,22') of the respective and cutoff surface wave toward the capacitor and inductance; and solder bump(28) supporting the filter chip against the package(10) and cutoff EM wave.