Surface acoustic wave device and mobile radio terminal using same

PURPOSE: To attain the making of a device into a module and the miniaturization of a mobile radio terminal using the same by placing a surface acoustic wave element chip on the back plane of a sub substrate on which a peripheral circuit is packaged, and mounting the sub substrate on a package substrate. CONSTITUTION: A transmission side final stage surface acoustic wave filter chip T1 and a reception side initial stage surface acoustic wave filter chip R1 are placed on the metallic film 15 on the back plane of the sub substrate 3. Pads on the hot sides of the chips T1, R1 are wire-bonded with corresponding pads for wire-bonding on the back plane of the substrate 3, respectively, and pads on the ground sides of the chips T1, R1 are wire-bonded with the film 15. The substrate 3 is placed by coming in contact with the back plane on the step of the package substrate 1, and the wiring pattern of the substrate is connected to a corresponding pad for connection on the step with a conductive adhesive or by soldering. A metallic cap 5 is welded and sealed hermetically on a frame 6 with a seam welding ring 13 on the pad, which forms the module of a branching filter. COPYRIGHT: (C)1993,JPO&Japio