Abstract: A surface acoustic wave device configured by forming an oxide layer 2 on a piezoelectric substrate 1 composed of a lithium tantalate single crystal or a lithium niobate single crystal and having weak pyroelectric properties having a lower oxygen content than a stoichiometric composition ratio, and forming thereon an IDT electrode 3. There is no static destruction of a minute electrode due to the pyroelectric effect of the piezoelectric substrate having weak pyroelectric properties, and frequency characteristics are not degraded.

Abstract: To provide a surface elastic wave apparatus that suppresses occurrence of fine ripples within a pass band, improves insertion loss and enhances the degree of balance. First and second surface acoustic wave elements (14, 15) that are parallel-connected to a surface acoustic wave resonator (16) respectively have three or more odd-numbered IDTs (2-4, 5-7), each having a plurality of electrode fingers placed along a propagation direction of a surface acoustic wave that is propagated over a piezoelectric substrate (1), and reflectors (8, 20, 21, 10), each having a plurality of electrode fingers that are placed on the two ends of the IDT row, and among all the electrode fingers respectively possessed by the IDTs and reflectors, the polarities of the electrode fingers placed adjacent to a different IDT or reflector are arranged symmetrically centered on the IDT located in the center.

Abstract: A surface acoustic wave element 1 includes an IDT electrode 11 having an electrode finger 11a on a piezoelectric substrate 10. The electrode finger 11a is formed by laminating an intermediate layer 12 and an electrode layer 13 having a higher coefficient of thermal expansion than that of the intermediate layer 12. The electrode finger 11a has a cross section of a trapezoidal shape that widens nearer to the piezoelectric substrate 10. An angle ?1 formed with a side surface of the intermediate layer 12 is formed larger than an angle ?1 formed with a side surface of the electrode layer 13.

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 surface acoustic wave element 1 includes an IDT electrode 11 having an electrode finger 11a on a piezoelectric substrate 10. The electrode finger 11a is formed by laminating an intermediate layer 12 and an electrode layer 13 having a higher coefficient of thermal expansion than that of the intermediate layer 12. The electrode finger 11a has a cross section of a trapezoidal shape that widens nearer to the piezoelectric substrate 10. An angle ?1 formed with a side surface of the intermediate layer 12 is formed larger than an angle ?1 formed with a side surface of the electrode layer 13.

Abstract: To provide a surface elastic wave apparatus that suppresses occurrence of fine ripples within a pass band, improves insertion loss and enhances the degree of balance. First and second surface acoustic wave elements (14, 15) that are parallel-connected to a surface acoustic wave resonator (16) respectively have three or more odd-numbered IDTs (2-4, 5-7), each having a plurality of electrode fingers placed along a propagation direction of a surface acoustic wave that is propagated over a piezoelectric substrate (1), and reflectors (8, 20, 21, 10), each having a plurality of electrode fingers that are placed on the two ends of the IDT row, and among all the electrode fingers respectively possessed by the IDTs and reflectors, the polarities of the electrode fingers placed adjacent to a different IDT or reflector are arranged symmetrically centered on the IDT located in the center.

Abstract: A surface acoustic wave element 1 comprises a piezoelectric substrate 19, IDT electrodes 3, 4, 5 of an odd number not less than three formed along a propagation direction of surface acoustic waves that propagates on the piezoelectric substrate, wherein IDT electrodes 3, 5 of the odd number of IDT electrodes 3, 4, 5 disposed on both sides of an IDT electrode 4 that is located at the center are connected to first and second reference potential terminals 14, 15, respectively, and the first and second reference potential terminals 14 and 15 are formed asymmetrically with respect to a virtual central axis A that passes through the center of the IDT electrode 4 located at the center and provided in a direction perpendicular to the propagation direction.

Abstract: A plurality of IDT electrodes 2 to 7 each having a large number of electrode fingers extending in a direction perpendicular to a propagation direction of a surface acoustic wave propagating on a piezoelectric substrate 1 are arranged on the piezoelectric substrate 1 along the propagation direction, and each of the two adjacent IDT electrodes out of the plurality of IDT electrodes 2 to 7 comprises a variable pitch section and a fixed pitch section. The electrode finger pitch in the variable pitch section gradually decreases toward the boundary between the two adjacent IDT electrodes, and the minimum electrode finger pitch portion in the two variable pitch sections is on one side spaced apart from the boundary. There can be provided a surface acoustic wave apparatus having a large pass bandwidth, having a low insertion loss, and having improved flatness in a pass band.

Abstract: Disclosed is a surface acoustic wave resonator which comprises, on a piezoelectric substrate 19, an IDT electrode 1 including bus bar electrodes 12a, reflector electrodes 2 disposed to be adjacent to both sides of the IDT electrode 1 in a main propagation direction F of surface acoustic waves at the IDT electrode 1, and auxiliary reflector electrodes 3 that are disposed at four positions external to the reflector electrodes 2 on virtual straight lines extending from the bus bar electrodes 12a of the IDT electrode 1 in an inclined manner so that the periodic direction G of periodically arranged electrodes 14b is oriented toward the IDT electrode 1.

Abstract: A surface acoustic wave apparatus comprises a piezoelectric substrate 17 on the bottom face of which IDT electrodes 3 and 4 and an annular ground electrode 6 which encloses the IDT electrodes 3 and 4 and is connected to the IDT electrode 3, and a base substrate on the top face of which an annular ground conductor 7 is formed and which has an internal ground conductor layer 10a and a bottom face ground conductor layer 11a connected to the annular ground conductor 7 and an internal ground conductor layer 10b and a bottom face ground conductor layer 11b connected to the IDT electrode 4. A first ground conductor composed of the internal ground conductor layer 10a and the bottom face ground conductor layer 11a is electrically separated from a second ground conductor composed of the internal ground conductor layer 10b and the bottom face ground conductor layer 11b. The apparatus has an excellent out-of-band attenuation characteristic.

Abstract: A surface acoustic wave device configured by forming an oxide layer 2 on a piezoelectric substrate 1 composed of a lithium tantalate single crystal or a lithium niobate single crystal and having weak pyroelectric properties having a lower oxygen content than a stoichiometric composition ratio, and forming thereon an IDT electrode 3. There is no static destruction of a minute electrode due to the pyroelectric effect of the piezoelectric substrate having weak pyroelectric properties, and frequency characteristics are not degraded.

Abstract: A surface acoustic wave device configured by forming an oxide layer 2 on a piezoelectric substrate 1 composed of a lithium tantalate single crystal or a lithium niobate single crystal and having weak pyroelectric properties having a lower oxygen content than a stoichiometric composition ratio, and forming thereon an IDT electrode 3. There is no static destruction of a minute electrode due to the pyroelectric effect of the piezoelectric substrate having weak pyroelectric properties, and frequency characteristics are not degraded.

Abstract: After electrode patterning on an electrode forming surface of a piezoelectric substrate 2 (FIG. 1(b)), a conductor layer is formed on an electrode non-forming surface of the piezoelectric substrate 2 (FIG. 1(c)). After forming the conductor layer, the conductor layer formed on the other surface is removed (FIG. 1(f)) after at least one step (FIG. 1(e)), and thereafter, dicing for separation into elements and mounting on a mounting substrate are carried out. By removing all the conductor layer on the other surface of the piezoelectric substrate, the out-of-passband attenuation and isolation performance can be significantly improved.

Abstract: An IDT electrode 2 and an electrode pad 3 are formed on one principal face of a piezoelectric substrate 1 and a circular electrode 4 is formed so as to surround these components. The circular electrode 4 is connected to a radiating conductor 15 formed on a bottom face of a circuit board 11 through a via conductor 14 formed within the circuit board 11. Thus, since heat generated in the IDT electrode 2 is easy to be released to the outside through the circular electrode 4, the via conductor 14 and the radiating conductor 15, adverse effects due to the heat can be prevented, thereby improving high power durability.

Abstract: An IDT electrode 3, and an input electrode section 5 and an output electrode section 6 each connecting with the IDT electrode 3 are formed in a filter region on one main surface of a piezoelectric substrate 2, and a semiconductor layer 22 is formed on the other main surface opposite to the one main surface of the piezoelectric substrate 2. The semiconductor layer 22 makes it possible to prevent pyroelectric destruction in the device manufacturing process as well as to prevent out-of-band attenuation characteristics from being degraded.

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: A plurality of surface acoustic wave elements, with an IDT electrode 2 and a pad electrode 3 formed on the principal surface of a piezoelectric substrate 1, are formed to be flip-chip mounted on a circuit board 5 and sealed using sealing resin 7. The circuit board 5 is diced integrally with the sealing resin 7 applying a rotating dicing blade 8 from the bottom surface side thereof to produce a plurality of surface acoustic wave devices. The side surfaces of the surface acoustic wave devices can be formed perpendicularly with dimensional accuracy without rounding or chipping an edge portion of the sealing resin 7.

Abstract: A surface acoustic wave element 1 comprises a piezoelectric substrate 19, IDT electrodes 3, 4, 5 of an odd number not less than three formed along a propagation direction of surface acoustic waves that propagates on the piezoelectric substrate, wherein IDT electrodes 3, 5 of the odd number of IDT electrodes 3, 4, 5 disposed on both sides of an IDT electrode 4 that is located at the center are connected to first and second reference potential terminals 14, 15, respectively, and the first and second reference potential terminals 14 and 15 are formed asymmetrically with respect to a virtual central axis A that passes through the center of the IDT electrode 4 located at the center and provided in a direction perpendicular to the propagation direction.

Abstract: A surface acoustic wave device includes an excitation electrode formed on a piezoelectric substrate and a binding electrode to be connected with a mounting substrate. The binding electrode is provided with a lower electrode formed on the piezoelectric substrate and an intermediate layer that is made of an adhesion electrode layer and a barrier metal electrode layer. The barrier metal electrode layer includes at least one impurity-containing layer. The binding electrode represents an annular electrode formed to surround the excitation electrode and a wiring electrode connected to the excitation electrode. A surface of at least one of the piezoelectric substrate, the lower electrode and the barrier metal electrode layer is bombarded to make it a rough surface. As a result, a warp due to a film stress caused in each of the layers can be suppressed.

Abstract: A plurality of IDT electrodes 2 to 7 each having a large number of electrode fingers extending in a direction perpendicular to a propagation direction of a surface acoustic wave propagating on a piezoelectric substrate 1 are arranged on the piezoelectric substrate 1 along the propagation direction, and each of the two adjacent IDT electrodes out of the plurality of IDT electrodes 2 to 7 comprises a variable pitch section and a fixed pitch section. The electrode finger pitch in the variable pitch section gradually decreases toward the boundary between the two adjacent IDT electrodes, and the minimum electrode finger pitch portion in the two variable pitch sections is on one side spaced apart from the boundary. There can be provided a surface acoustic wave apparatus having a large pass bandwidth, having a low insertion loss, and having improved flatness in a pass band.