Abstract: A surface acoustic wave device is disclosed, which comprises a surface acoustic wave element including a lithium tantalate piezoelectric substrate 10 with one principal surface thereof formed with an IDT electrode 11, a connector electrode 12 and a periphery sealing electrode 13, and a base substrate 2 formed with an electrode 21 for connection to the element connected to the connector electrode 12 through a solder bump component 3 and a periphery sealing conductor film 22 joined to the periphery sealing electrode 13 thorough a solder sealing component 4. For the solder bump component 3 and the solder sealing component 4, a Sn—Sb based or Sn—Ag based lead-free solder containing 90% or more Sn is used, and the thermal expansion coefficient of the base substrate 2 is set in the range of 9–20 pm/° C.

Abstract: A surface acoustic wave device is disclosed, which comprises a surface acoustic wave element including a lithium tantalate piezoelectric substrate 10 with one principal surface thereof formed with an IDT electrode 11, a connector electrode 12 and a periphery sealing electrode 13, and a base substrate 2 formed with an electrode 21 for connection to the element connected to the connector electrode 12 through a solder bump component 3 and a periphery sealing conductor film 22 joined to the periphery sealing electrode 13 thorough a solder sealing component 4. For the solder bump component 3 and the solder sealing component 4, a Sn—Sb based or Sn—Ag based lead-free solder containing 90% or more Sn is used, and the thermal expansion coefficient of the base substrate 2 is set in the range of 9-20 pm/° C.

Abstract: A variable capacitance capacitor has a plurality of variable capacitance elements, using a thin-film dielectric layer whose dielectric constant varies with voltage application, connected in series with one another between the high-frequency signal input and output terminals. The first bias lines belonging to a high-potential side and the second bias lines belonging to a low-potential side, in terms of voltage application, are connected, alternately, to electrodes of the variable capacitance elements connected one another and electrodes in the array of the series-connected variable capacitance elements connected respectively to the input terminal and the output terminal.

Abstract: A second substrate 21 composed of a material having a lower dielectric constant than that of a piezoelectric substrate 2 having a transmission-side filter region 12 and a receiving-side filter region 13 formed therein is joined to the other main surface of the piezoelectric substrate 2, and a conductor layer 22 is formed throughout the other main surface of the second substrate 21. The effective dielectric constant of the substrate is reduced, thereby making it possible to reduce a parasitic capacitance formed between an input electrode section 5 in the transmission-side filter region 12 and an output electrode section 6 in the receiving-side filter region 13 and to improve isolation characteristics.

Abstract: A variable capacitance capacitor has a plurality of variable capacitance elements, using a thin-film dielectric layer whose dielectric constant varies with voltage application, connected in series with one another between the high-frequency signal input and output terminals. The first bias lines belonging to a high-potential side and the second bias lines belonging to a low-potential side, in terms of voltage application, are connected, alternately, to electrodes of the variable capacitance elements connected one another and electrodes in the array of the series-connected variable capacitance elements connected respectively to the input terminal and the output terminal.

Abstract: A conductor layer 10 is provided so as to prevent pyroelectric destruction occurring in the steps of manufacturing a surface acoustic wave element 1 on the other surface opposite to an IDT electrode formation surface of a piezoelectric substrate 2. At this time, the conductor layer 10 is formed, except for a region 5a opposed to an input electrode section 5 in a filter region 9 and/or a region 6a opposed to an output electrode section 6. This allows a coupling amount between the input electrode section 5 and the output electrode section 6 due to a parasitic capacitance formed between the input electrode section 5 and the output electrode section 6 in the filter region 9 to be reduced, thereby allowing the out-of-band attenuation characteristics of a surface acoustic wave device to be improved.

Abstract: In a surface acoustic wave device, an excitation electrode 5 in a surface acoustic wave element is provided on a lower surface of a piezoelectric substrate 3, and the lower surface of the piezoelectric substrate 3 is disposed in a state where it is opposed to an upper surface of a mounting base member 2. The surface acoustic wave device comprises a through hole 9 penetrating between the upper surface and a lower surface of the mounting base member 2, a lead electrode 10 closing the through hole 9 and formed so as to extend to the lower surface of the mounting base member 2, and an insulator 11 covering the lead electrode 10 so as to expose its partial area 16.

Abstract: In a surface acoustic wave element 10, in which IDT electrodes 31 and 32, a grounding electrode 37, etc. are formed one main surface of a piezoelectric substrate 20, resistors 40 made of a semiconductor are provided to connection electrodes 38 that interconnect the respective electrodes. By forcing the charges generated in the IDT electrodes to move via the resistors 40, it is possible to provide a compact, highly reliable surface acoustic wave apparatus capable of preventing an electrostatic discharge damage in the IDT electrodes.

Abstract: A surface acoustic wave device is disclosed, which comprises a surface acoustic wave element including a lithium tantalate piezoelectric substrate 10 with one principal surface thereof formed with an IDT electrode 11, a connector electrode 12 and a periphery sealing electrode 13, and a base substrate 2 formed with an electrode 21 for connection to the element connected to the connector electrode 12 through a solder bump component 3 and a periphery sealing conductor film 22 joined to the periphery sealing electrode 13 thorough a solder sealing component 4. For the solder bump component 3 and the solder sealing component 4, a Sn—Sb based or Sn—Ag based lead-free solder containing 90% or more Sn is used, and the thermal expansion coefficient of the base substrate 2 is set in the range of 9-20 pm/° C.

Abstract: A dielectric filter comprises a filtering member made up of resonators, intercoupled through a laminated substrate joined to the filtering member and containing interlaminal patterned conductive platings constituting capacitive and inductive elements. Electric field leakage arising among the conductive platings is reduced, improving the effective dielectric constant of the substrate. The extent of the conductive platings providing desired capacitance and selected electrical length is reducible, to decrease the size of the substrate. Furthermore, the substrate construction prevents foreign matter from becoming lodged on, or even from being brought into contact with, the conductive platings, stabilizing capacitive coupling.

Abstract: A dielectric filter comprises a first resonator and second resonator. Each of the resonators includes a dielectric block having a through-hole, an inner conductive layer placed on the inner surface of the through-hole, and an outer conductive layer placed on the outer surface of the dielectric blocks. The first and second resonators have a coupled hole extending transversely to the through-holes in portions of the resonator couples adjacent to each other. The dielectric filter may further include a frame made of a pair of metal plates covering said coupling hole. The pair of metal plates have legs for earthing and are affixed to the filter body, whereupon the metal plates are located, apart from each other.