JP4841311B2 - Substrate mounted surface acoustic wave device, method for manufacturing the same, and communication device - Google Patents

Description

  The present invention includes a substrate-mounted surface acoustic wave device such as a surface acoustic wave filter and a surface acoustic wave resonator used in a mobile communication device such as a mobile phone, a manufacturing method thereof, and a substrate-mounted surface acoustic wave device. The present invention relates to a communication device.

  Conventionally, a surface acoustic wave filter has been widely used as a frequency selection filter used in an RF (radio frequency) stage of a mobile communication device such as a mobile phone or a car phone. In general, characteristics required for a frequency selective filter include various characteristics such as a wide pass band, low loss, and a high attenuation of a non-pass band with respect to the pass band. In recent years, in order to reduce the size, weight, and cost of mobile communication devices, the number of parts used has been reduced, and the addition of new functions to surface acoustic wave filters has been required. One of them is a requirement for dealing with an unbalanced input-balanced output type or a balanced input-unbalanced output type.

  Here, the balanced input or balanced output means that a signal is input or output as a potential difference between two signal lines, and the signals of the signal lines have the same amplitude and the phases are reversed. On the other hand, unbalanced input or unbalanced output means that a signal is input or output as the potential of one line with respect to the ground potential.

  A conventional surface acoustic wave filter is generally an unbalanced input-unbalanced output type surface acoustic wave filter (hereinafter also referred to as an unbalanced surface acoustic wave filter). When the circuit or electronic component to be connected is a balanced input type, a circuit configuration in which an unbalanced-balanced converter (hereinafter also referred to as a balun) is inserted between the unbalanced surface acoustic wave filter and the subsequent stage. I took it. Similarly, when the circuit or electronic component in the previous stage of the unbalanced surface acoustic wave filter is a balanced output type, the circuit configuration is such that a balun is inserted between the previous stage and the unbalanced surface acoustic wave filter.

  Currently, in order to eliminate the balun, the unbalanced surface acoustic wave filter is provided with an unbalanced-balanced conversion function or a balanced-unbalanced conversion function, and the unbalanced input-balanced output type surface acoustic wave filter or balanced input-unbalanced A balanced output surface acoustic wave filter (hereinafter referred to as a balanced surface acoustic wave filter) has been put into practical use, and it has been proposed to improve the balance of the balanced surface acoustic wave filter.

  For example, as shown in FIG. 14, three IDT (Inter Digital Transducer) electrodes 202, 203, 204 are arranged along the propagation direction of the surface acoustic wave, and the central IDT electrode 203 is connected to the unbalanced input terminal 211. The IDT electrodes 202 and 204 on both sides of the central IDT electrode 203 are connected to the balanced output terminals 212 and 213 to increase the impedance, thereby realizing an unbalanced-balanced conversion function. The IDT electrode 203 disposed on the piezoelectric substrate 201 applies an electric field to a pair of comb-like electrodes opposed to each other to excite surface acoustic waves. Therefore, by applying an input signal to the IDT electrode 203, the excited surface acoustic wave is propagated to the output signal IDT electrodes 202 and 204 located on both sides of the IDT electrode 203. A signal is transmitted from one comb-shaped electrode of the IDT electrode 202 to the balanced output terminal 212, and a signal is transmitted from the one comb-shaped electrode of the IDT electrode 204 to the balanced output terminal 213, and these signals are balanced output (for example, (See Patent Document 1).

  Further, as shown in FIG. 15, three IDT electrodes 202, 203, and 204 are arranged close to each other along the propagation direction of the surface acoustic wave, and the central IDT electrode 203 is divided into two, and acoustically connected in cascade. Electrically connected in series and connected to balanced signal terminals 212 and 213, IDT electrodes 202 and 204 having inverted polarities are arranged on both sides of the central IDT electrode 203, and unbalanced signal terminals 211 is connected. With such a configuration, an unbalanced-balanced conversion function can be provided, and the impedance on the balanced signal terminals 212 and 213 side is about four times (200Ω) the impedance (50Ω) on the unbalanced signal terminal 211 side. What can be done has been proposed (see, for example, Patent Document 2).

  Moreover, in the conventional dual mode surface acoustic wave resonator filter, the balance is improved by making the IDT electrodes arranged in the center out of the three IDT electrodes arranged in the propagation direction of the surface acoustic wave. The structure which performs is proposed (for example, refer patent document 3).

  Further, as shown in FIG. 16, three IDT electrodes 202, 203, 204 and 205, 206, 207 are arranged close to each other along the propagation direction of the surface acoustic wave, and the center of the second stage surface acoustic wave element is arranged. The IDT electrode 206 is divided into two parts and connected to balanced signal terminals 222 and 223, respectively, and IDT electrodes 202, 204 and 205, 207 having inverted polarities are arranged on both sides of the central IDT electrodes 203 and 206, respectively. The IDT electrode 203 at the center of the stage is connected to the unbalanced signal terminal 221, and the reactance (capacitance) component 224 is connected to the balanced signal terminal 222 forming the non-electric field region on the piezoelectric substrate 201 or inside or outside the package. The structure which improves a balance degree by forming is proposed (for example, refer patent document 4).

Resonator-type electrodes in which reflector electrodes for efficiently resonating surface acoustic waves are provided at both ends of a surface acoustic wave propagation path of a plurality of IDT electrodes arranged side by side as shown in FIGS. In the pattern, it is required to improve the balance between the amplitude and the phase in the pass band. Here, the amplitude and phase balance means that a signal is input or output as a potential difference between two signal lines, and the amplitude balance is better as the amplitude of the signal on each signal line is equal. Moreover, it can be said that the closer the phase difference of each signal is to 180 °, the better the phase balance.
JP-A-6-204781 JP 11-97966 A JP 2002-84164 A JP 2004-96244 A

  However, in the surface acoustic wave element disclosed in Patent Document 1, in order to reverse the phases of the signals output from the IDT electrodes located on both sides of the central IDT electrode, Since the structure of the IDT electrode positioned such as the electrode finger pitch is changed or the adjacent distance between the center IDT electrode and the IDT electrodes on both sides is changed, the degree of balance deteriorates. There was a problem that it was easy.

  In the surface acoustic wave element disclosed in Patent Document 2, the polarity of the outermost electrode finger of the central IDT electrode and the polarity of the outermost electrode finger of the adjacent IDT electrode are different on the left and right. Since the parasitic capacitance generated at the terminals is different, there is a problem that the balance is poor.

In the surface acoustic wave element disclosed in Patent Document 3, for example, when a LiTaO ₃ single crystal substrate is used as the piezoelectric substrate, the amplitude balance degree is about 1.2 dB (because the better the degree of balance, the closer the amplitude is). The phase balance is only about 11 degrees (the phase difference is closer to 0 degree as the degree of balance is better), and a sufficient degree of balance that satisfies the requirements has not been obtained.

  Furthermore, the effect of the surface acoustic wave device disclosed in Patent Document 4 was verified. FIG. 17 is a diagram (graph) showing frequency characteristics of the surface acoustic wave device shown in FIG. In FIG. 17, the horizontal axis represents frequency (unit: MHz), the vertical axis represents attenuation (unit: dB), the solid characteristic curve shows the result when nothing is added to the balanced signal terminal, and the broken line indicates which The result when a capacitive component is connected in parallel as a reactance component to one of the balanced signal terminals is shown. Since a capacitive component as a reactance component is connected in parallel to one of the balanced signal terminals, the ripple in the passband increases.

  FIG. 18 is a diagram showing a VSWR (Voltage Standing Wave Ratio) in the surface acoustic wave device of FIG. As in FIG. 17, the solid characteristic curve indicates the result when nothing is added to the balanced signal terminal, and the broken line indicates the result when the capacitive component is connected in parallel as a reactance component to one of the balanced signal terminals. . It can be seen that when a capacitive component as a reactance component is connected in parallel to one balanced signal terminal, the VSWR is also degraded.

  In addition, FIG. 19A shows the phase balance in the vicinity of the pass band and FIG. 19B shows the amplitude balance in the surface acoustic wave element of FIG. As in FIG. 17, the solid characteristic curve indicates the result when nothing is added to the balanced signal terminal, and the broken line indicates the result when the capacitive component is connected in parallel as a reactance component to one of the balanced signal terminals. . As is clear from FIG. 19, even when a capacitive component as a reactance component was connected in parallel to one balanced signal terminal, no significant improvement was observed in the phase balance and amplitude balance.

  Therefore, the present invention has been completed to solve the above-mentioned problems in the prior art, and the object thereof is to improve the insertion loss and VSWR without deteriorating the balance of the surface acoustic wave filter. An object of the present invention is to provide a surface acoustic wave device that functions as a high-quality balanced surface acoustic wave filter, a manufacturing method thereof, and a communication device.

The substrate-mounted surface acoustic wave device of the present invention includes: 1) A plurality of electrode fingers that are long in the direction perpendicular to the propagation direction along the propagation direction of the surface acoustic wave propagating on the piezoelectric substrate on the lower surface of the piezoelectric substrate A plurality of odd-numbered IDT electrodes having three or more, and reflector electrodes each provided on both sides of the odd-numbered IDT electrodes and provided with a plurality of long electrode fingers in a direction orthogonal to the propagation direction; A second surface acoustic wave element is formed, and the first and second surface acoustic wave elements have an IDT electrode and a reflector electrode, and an unbalanced signal terminal (unbalanced input terminal or unbalanced output terminal). Are connected in parallel via the surface acoustic wave resonators connected to each other, and each of the first and second surface acoustic wave elements serves as a balanced output unit or a balanced input unit, and the first and second elastic units are connected to each other. Said center of each of the surface wave elements A balanced signal terminal (balanced output terminal or balanced input terminal) is connected to the DT electrode, and a connection pad electrode and a ground electrode connected to the first and second surface acoustic wave elements are arranged. Consisting of
The IDT electrodes located on both sides of the IDT electrode disposed in the center of the first and second surface acoustic wave elements are connected to the unbalanced signal terminal of one of the comb-like electrodes, respectively. A surface acoustic wave device in which the comb-like electrode is connected to the ground electrode,
A lower surface of the piezoelectric substrate and an upper surface of the mounting substrate are opposed to a mounting substrate having a connection pad conductor facing the connection pad electrode and a grounding conductor facing the grounding electrode formed on the upper surface. The connection pad electrode and the ground electrode are respectively bonded and mounted on the connection pad conductor and the ground conductor,
The grounding electrode is formed asymmetrically with respect to a virtual axis provided in a direction orthogonal to the propagation direction at the center between the first and second surface acoustic wave elements.

  Further, the substrate-mounted surface acoustic wave device of the present invention is 2) In the configuration of 1), the grounding conductor joined to the grounding electrode connected to the other comb-shaped electrode is the virtual It is characterized by being arranged asymmetrically with respect to the axis.

  The substrate-mounted surface acoustic wave device according to the present invention is 3) In the configuration of 1), at least one of the grounding electrode connected to the other comb-shaped electrode and the grounding conductor joined thereto. Are different in area so as to be asymmetric with respect to the virtual axis.

  Further, the substrate-mounted surface acoustic wave device of the present invention is 4) In the configuration of 1) above, each of the grounding conductors joined to the grounding electrode connected to the other comb-shaped electrode is through-grounded. Conductors are connected, and these through-ground conductors are arranged asymmetrically with respect to the virtual axis.

  Further, the substrate-mounted surface acoustic wave device of the present invention is 5) In the configuration of 1) above, the grounding conductor joined to the grounding electrode connected to the other comb-shaped electrode is through-grounded. Conductors are connected, and these through-ground conductors are characterized in that at least one diameter is different from the other.

  Further, the substrate-mounted surface acoustic wave device of the present invention is 6) In the configuration of 1) above, each of the grounding conductors joined to the grounding electrode connected to the other comb-shaped electrode is through-grounded. Conductors are connected, and the number of these through-ground conductors is different on both sides of the virtual axis.

  The substrate-mounted surface acoustic wave device according to the present invention includes 7) the grounding electrode connected to the other comb-like electrode and the grounding joint joined thereto in each of the configurations 1) to 3). At least one of the conductors has a portion formed asymmetrically with respect to the virtual axis and a portion formed symmetrically with respect to the virtual axis.

  Further, the substrate-mounted surface acoustic wave device according to the present invention is characterized in that in 8) each of the configurations 1) and 4 to 6), the grounding joined to the grounding electrode connected to the other comb-like electrode. A through-grounding conductor is connected to each of the conductors, and in addition to the group formed asymmetrically with respect to the virtual axis, the through-grounded conductor includes a group formed symmetrically with respect to the virtual axis. It is characterized by having.

  In the substrate-mounted surface acoustic wave device according to the present invention, 9) In each of the above-described configurations 1) to 8), the first and second surface acoustic wave elements may have reflector electrodes at locations where they are adjacent to each other. It consists of one reflector electrode formed integrally.

  Further, in the substrate mounting type surface acoustic wave device of the present invention, 10) in each of the above-mentioned constitutions 1) to 9), the mounting substrate is provided on each side of the upper surface of the rectangular insulating substrate. A first connecting pad conductor electrically connected to the balanced signal terminal; a grounding conductor electrically connected to the other unbalanced signal terminal; and a first conductor electrically connected to the one balanced signal terminal. 2 connection pad conductors and a third connection pad conductor electrically connected to the other balanced signal terminal are formed, and these connection pad conductors and grounding conductors are connected to the virtual axis. It is characterized by being arranged asymmetrically.

  In the substrate-mounted surface acoustic wave device according to the present invention, 11) in the configuration of 10) described above, the first to third connection pad conductors and the grounding conductor extend to the side surface of the insulating substrate. It is characterized by.

  The substrate-mounted surface acoustic wave device according to the present invention is characterized in that in 12) each of the above-mentioned 10) or 11), the first to third connection pad conductors and the grounding conductor are each of the insulating substrate. Adjacent ones are arranged at the end of the side so as not to be close to each other.

  A method for manufacturing a substrate mounted surface acoustic wave device according to the present invention is 13) A method for manufacturing a substrate mounted surface acoustic wave device according to any one of 1) to 12) above, wherein one principal surface of the piezoelectric substrate is provided. A plurality of surface acoustic wave elements each having the IDT electrode and the connection pad electrode connected to the IDT electrode, and the respective elastic surfaces on the connection pad electrode of the piezoelectric substrate or the upper surface of the mounting mother substrate. Forming a conductive bump on a connection pad conductor formed corresponding to the connection pad electrode in a plurality of mounting regions formed corresponding to the wave element region, and the plurality of surface acoustic wave elements. Connecting the connection pad electrode and the connection pad conductor to the plurality of mounting regions of the mounting mother board with the conductive bumps, respectively, and mounting the mounting mother from the other main surface of the piezoelectric substrate. A step of sealing each of the plurality of surface acoustic wave elements by applying a sealing resin over the upper surface of the plate; and the mounting mother board is divided between the surface acoustic wave elements together with the sealing resin for each mounting region A plurality of substrate-mounted surface acoustic wave devices, and in the step of dividing the mounting mother substrate to produce a plurality of substrate-mounted surface acoustic wave devices, the mounting mother substrate The connection pad conductor formed across the dividing line on the upper surface is divided.

  A communication apparatus according to the present invention includes 14) at least one of a reception circuit and a transmission circuit having the substrate-mounted surface acoustic wave device according to any one of 1) to 12) above.

According to the substrate mounted surface acoustic wave device of the present invention, 1) a plurality of electrode fingers that are long in the direction orthogonal to the propagation direction along the propagation direction of the surface acoustic wave propagating on the piezoelectric substrate are formed on the lower surface of the piezoelectric substrate. First and second having three or more odd IDT electrodes provided and reflector electrodes each provided on both sides of the odd IDT electrodes and provided with a plurality of long electrode fingers in a direction orthogonal to the propagation direction The first and second surface acoustic wave elements are connected in parallel via a surface acoustic wave resonator having an IDT electrode and a reflector electrode and connected to an unbalanced signal terminal. Each of the first and second surface acoustic wave elements is used as a balanced output section or a balanced input section, and a balanced signal terminal is connected to the center IDT electrode of each of the first and second surface acoustic wave elements. The first and second Made by disposing the connection pads electrode and the ground electrode connected to sexual surface wave element,
The IDT electrodes positioned on both sides of the IDT electrode disposed in the center of the first and second surface acoustic wave elements have one comb-like electrode connected to the unbalanced signal terminal and the other comb-teeth shape. A surface acoustic wave device in which an electrode is connected to a grounding electrode,
A mounting pad having a connection pad conductor facing the connection pad electrode and a grounding conductor facing the ground electrode formed on the upper surface, with the lower surface of the piezoelectric substrate facing the upper surface of the mounting substrate. The electrode and the grounding electrode are respectively bonded and mounted on the connecting pad conductor and the grounding conductor,
The grounding electrode is formed asymmetrically with respect to a virtual axis provided in the direction perpendicular to the propagation direction at the center between the first and second surface acoustic wave elements, thereby grounding the surface acoustic wave device. This is equivalent to the state in which the inductance component is connected to the terminal, and the same action as in the state in which the matching circuit is connected works, and the insertion loss and VSWR of the surface acoustic wave device can be improved.

  In addition, since the parasitic capacitance is not added to the balanced signal terminal side of the conventional surface acoustic wave device, the balance is not deteriorated. In addition, the insertion loss of the surface acoustic wave device can be greatly improved by the configuration in which the first and second surface acoustic wave elements are connected in parallel to the surface acoustic wave resonator.

  Further, according to the substrate mounted surface acoustic wave device of the present invention, 2) in the configuration of 1), the grounding conductor joined to the grounding electrode connected to the other comb-like electrode is connected to the virtual axis. By being arranged asymmetrically, it becomes possible to add an inductance component to the ground terminal of the surface acoustic wave device and adjust it, and the same action as when the matching circuit is connected works. It is possible to improve the insertion loss and VSWR of the surface acoustic wave device. Further, since the parasitic capacitance is not added to the balanced signal terminal side of the surface acoustic wave device, the balance is not deteriorated. Similarly, the insertion loss of the surface acoustic wave device can be greatly improved by the configuration in which the first and second surface acoustic wave elements are connected in parallel to the surface acoustic wave resonator.

  According to the substrate-mounted surface acoustic wave device of the present invention, 3) in the configuration of 1) above, at least one of the grounding electrode connected to the other comb-shaped electrode and the grounding conductor joined thereto is Since the areas are different so as to be asymmetric with respect to the virtual axis, a large inductance component can be effectively added in the ground wiring path in the same manner as described above, and the insertion loss and VSWR of the surface acoustic wave device are improved. It becomes possible. Further, since the parasitic capacitance is not added to the balanced signal terminal side of the surface acoustic wave device, the balance is not deteriorated. Similarly to the above, the insertion loss of the surface acoustic wave device can be greatly improved by the configuration in which the first and second surface acoustic wave elements are connected in parallel to the surface acoustic wave resonator.

  According to the substrate-mounted surface acoustic wave device of the present invention, 4) In the configuration of 1) above, each of the grounding conductors joined to the grounding electrode connected to the cascaded IDT electrodes is through-grounded. The conductors are connected, and these through-ground conductors are arranged asymmetrically with respect to the virtual axis, so that the inductance value can be adjusted, and parasitic capacitance is added to the balanced terminal side of the surface acoustic wave device. Since it does not become an added form, it becomes possible to improve the insertion loss and VSWR of the surface acoustic wave device without degrading the balance. Similarly to the above, the insertion loss of the surface acoustic wave device can be greatly improved by the configuration in which the first and second surface acoustic wave elements are connected in parallel to the surface acoustic wave resonator.

  Further, according to the substrate-mounted surface acoustic wave device of the present invention, 5) In the configuration of 1) above, the grounding conductor joined to the grounding electrode connected to the other comb-shaped electrode is connected to the through-grounding conductor. Since these through-ground conductors have at least one diameter different from the diameter of the other, it is possible to adjust the inductance value in the same manner as described above, and to the balanced terminal side of the surface acoustic wave device. Since the parasitic capacitance is not added, the insertion loss and VSWR of the surface acoustic wave device can be improved without degrading the balance. Similarly to the above, the insertion loss of the surface acoustic wave device can be greatly improved by the configuration in which the first and second surface acoustic wave elements are connected in parallel to the surface acoustic wave resonator.

  According to the substrate mounted surface acoustic wave device of the present invention, 6) In the configuration of 1) above, each of the grounding conductors connected to the grounding electrode connected to the other comb-shaped electrode has a through-grounding conductor. Even when the numbers of these through grounding conductors are different on both sides of the virtual axis, the same effect as the above can be obtained.

  According to the substrate-mounted surface acoustic wave device of the present invention, 7) in any one of the above-mentioned 1) to 3), the grounding electrode connected to the other comb-shaped electrode and the grounding joined thereto At least one of the conductors has a portion formed asymmetrically with respect to the virtual axis and a portion formed symmetrically with respect to the virtual axis, so that the electrode of the IDT electrode in the balanced surface acoustic wave filter Since the main parts such as the finger arrangement are formed symmetrically with respect to the virtual axis, it is possible to suppress the deterioration of the balance of the surface acoustic wave filter, and the ground wiring path of the surface acoustic wave filter is virtual. Since it is formed asymmetrically with respect to the shaft, a large inductance component can be additionally connected, and the insertion loss and VSWR of the surface acoustic wave device can be improved.Similarly to the above, the insertion loss of the surface acoustic wave device can be greatly improved by the configuration in which the first and second surface acoustic wave elements are connected in parallel to the surface acoustic wave resonator.

  Further, according to the substrate-mounted surface acoustic wave device of the present invention, 8) In any one of the constitutions 1) and 4) to 6), it is bonded to the grounding electrode connected to the other comb-like electrode. A through-ground conductor is connected to each of the grounding conductors, and in addition to a group formed asymmetrically with respect to the virtual axis, these through-ground conductors include a group formed symmetrically with respect to the virtual axis. In addition to suppressing the deterioration of the balance of the surface acoustic wave filter, the ground wiring path of the surface acoustic wave filter is formed asymmetrically with respect to the virtual axis, so that the added inductance component is adjusted. It becomes possible to improve the insertion loss and VSWR of the surface acoustic wave device. Similarly to the above, the insertion loss of the surface acoustic wave device can be greatly improved by the configuration in which the first and second surface acoustic wave elements are connected in parallel to the surface acoustic wave resonator.

  According to the substrate-mounted surface acoustic wave device of the present invention, 9) In any one of the above-mentioned 1) to 8), the first and second surface acoustic wave elements are reflected at locations where they are adjacent to each other. Since the reflector electrode is formed of a single reflector electrode, the deterioration of the balance of the surface acoustic wave filter can be suppressed in the same manner as described above, and the ground wiring path of the surface acoustic wave filter can be further reduced. Since it is formed asymmetrically with respect to the virtual axis, the added inductance component can be adjusted, and the insertion loss and VSWR of the surface acoustic wave device can be improved. In addition, the surface acoustic waves excited by the two surface acoustic wave elements cancel each other on the plus side and the minus side in the integrally formed reflector electrode, and the reflection characteristics are improved. Generation of minute ripples (spikes) in the passband can be suppressed.

  According to the substrate-mounted surface acoustic wave device of the present invention, 10) In any one of the above-mentioned 1) to 9), the mounting substrate is provided on each side of the upper surface of the rectangular insulating substrate. A first connecting pad conductor electrically connected to the unbalanced signal terminal, a grounding conductor electrically connected to the other unbalanced signal terminal, and a first electrically connected to one balanced signal terminal. 2 connection pad conductors and a third connection pad conductor electrically connected to the other balanced signal terminal are formed, and these connection pad conductors and grounding conductors are asymmetric with respect to the virtual axis. By arranging, the arrangement of one balanced signal terminal of the first surface acoustic wave element or the second surface acoustic wave element is close to the grounding conductor, and the arrangement of the other balanced signal terminal is the grounding conductor. And get far away. For this reason, the capacitance added to the balanced signal terminal differs between the first surface acoustic wave element and the second surface acoustic wave device, and it becomes possible to adjust the parasitic capacitance. Since different inductance components can be added due to different ground wiring paths, the insertion loss and VSWR of the surface acoustic wave device can be improved without degrading the balance of the surface acoustic wave device.

  According to the substrate-mounted surface acoustic wave device of the present invention, 11) in the configuration of 10), the first to third connection pad conductors and the grounding conductor extend to the side surface of the insulating substrate. Therefore, when a surface acoustic wave device is mounted on a circuit board such as a mobile communication device, solder can be connected to the side surface of the insulating substrate of the surface acoustic wave device to improve the connection strength of the terminal. Can be made. Therefore, the reliability in the communication device can be improved.

  According to the substrate mounted surface acoustic wave device of the present invention, 12) in the configuration of 10) or 11), the first to third connection pad conductors and the grounding conductor are provided on each side of the insulating substrate. When the surface acoustic wave device is mounted on the circuit board of the communication device, the short circuit between the terminals of the surface acoustic wave device and the solder bridge are prevented by arranging the adjacent parts so as not to be close to each other at the end. It is possible to improve the yield of the mounting process in the communication device.

  According to the method for manufacturing a substrate-mounted surface acoustic wave device of the present invention, 13) the surface acoustic wave device manufacturing method according to any one of 1) to 12) above, wherein the IDT is formed on one principal surface of the piezoelectric substrate. Corresponding to each surface acoustic wave element region on the connection pad electrode of the piezoelectric substrate or the upper surface of the mounting mother board, and a plurality of surface acoustic wave elements formed with electrodes and connection pad electrodes connected thereto. Forming a conductive bump on the connecting pad conductor formed corresponding to the connecting pad electrode in each of the plurality of mounting areas formed, and mounting the plurality of surface acoustic wave elements on the mounting motherboard. A plurality of surface acoustic waves by applying a sealing resin from the other main surface of the piezoelectric substrate to the top surface of the mounting mother board. Each element A step of sealing, and a step of dividing the mounting mother board into a plurality of surface acoustic wave devices by dividing the mounting mother board with the sealing resin between the surface acoustic wave elements for each mounting region. In the step of manufacturing a plurality of substrate-mounted surface acoustic wave devices, the connection-pad conductor formed on the upper surface of the mounting mother board across the dividing line is cut to obtain the substrate-mounted surface acoustic wave device. It is possible to make a batch using an aggregate substrate in which external terminals extend to the side surface of the insulating substrate, and the external terminals on the side surface of the insulating substrate can be formed by a cutting process. The manufacturing process of the device can be simplified.

  In addition, according to the communication device of the present invention, 14) the conventional device includes at least one of the receiving circuit and the transmitting circuit having the substrate-mounted surface acoustic wave device having any one of the above-described configurations 1) to 12). It is possible to obtain a balance that satisfies the required balance, and it is possible to eliminate the balun, and it is possible to increase the mounting area of other components while utilizing the good filter characteristics of the surface acoustic wave device of the present invention. In addition, since the range of component selection is widened, a communication device having high functions can be manufactured. In addition, the reliability of the communication device on which the surface acoustic wave device is mounted can be improved.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a substrate-mounted surface acoustic wave device according to the present invention will be described below in detail with reference to the drawings. In addition, in drawing demonstrated below, the same code | symbol shall be attached | subjected to the same structure. In addition, the number of electrodes and the distance between the electrodes, such as the size of each electrode and the distance between the electrodes, are schematically illustrated for the purpose of explanation.

  FIG. 1 is a plan view showing an electrode pattern such as a surface acoustic wave element formed on the lower surface of a piezoelectric substrate in the substrate-mounted surface acoustic wave device of the present invention. FIG. 2 is a plan view of each layer of a mounting substrate on which a conventional surface acoustic wave device is mounted. FIG. 3 is a plan view of each layer of the mounting substrate on which the surface acoustic wave device of the present invention is mounted.

  The substrate-mounted surface acoustic wave device according to the present invention includes a plurality of electrode fingers that are long in the direction orthogonal to the propagation direction along the propagation direction of the surface acoustic wave propagating on the piezoelectric substrate 1 on the lower surface of the piezoelectric substrate 1. Reflector electrodes 8 and 10 each having three IDT electrodes 2 to 4 and 5 to 7 and IDT electrodes 2 to 4 and 5 to 7, respectively, and having a plurality of long electrode fingers in a direction orthogonal to the propagation direction. , 20 and 21 are formed, and the first and second surface acoustic wave elements 14 and 15 are formed by the IDT electrode 11 and the reflector electrode 12. , 13 and connected in parallel via a surface acoustic wave resonator 16 to which an unbalanced signal terminal (unbalanced input terminal or unbalanced output terminal) 17 is connected, and the first and second surface acoustic wave elements. 14 and 15 are balanced output sections The balanced signal terminals (balanced output terminals or balanced input terminals) 18 and 19 are connected to the IDT electrodes 3 and 6 at the center of the first and second surface acoustic wave elements 14 and 15, respectively. And connecting pad electrodes (also serving as balanced signal terminals) 18 and 19 and first grounding electrodes 29 and 30 connected to the first and second surface acoustic wave elements 14 and 15, respectively. Become.

  Further, the IDT electrodes 2, 4, 5 and 7 positioned on both sides of the IDT electrodes 3 and 6 disposed in the center of the first and second surface acoustic wave elements 14 and 15 are respectively comb-shaped electrodes. Is electrically connected to the unbalanced signal terminal 17 (in FIG. 1, it is connected via the IDT electrode 11 of the surface acoustic wave resonator 16), and the other comb-like electrode is connected to the ground electrode (for grounding). An annular electrode) 28 is mounted, and the connection pad conductors 101 to 103 facing the connection pad electrodes 17 to 19 and the grounding conductors 104 and 105 facing the grounding electrodes 28 to 30 are formed on the upper surface. The connection pad electrodes 17 to 19 and the ground electrodes 28 to 30 are connected to the connection substrate 100 to 103 and the grounding device 104 with the lower surface of the piezoelectric substrate 1 and the upper surface of the mounting substrate 100 facing each other. , 10 The grounding electrodes 29 and 30 are mounted on the virtual axis provided in the direction perpendicular to the propagation direction at the center between the first and second surface acoustic wave elements 14 and 15. And asymmetrically formed.

  As a result, it is possible to add an inductance component to the ground terminal of the surface acoustic wave device and adjust it, and it is not a form in which parasitic capacitance is added to the balanced signal terminal side of the conventional surface acoustic wave device. The same effect as in the state in which the matching circuit is connected operates without degrading the balance, and the insertion loss and VSWR of the surface acoustic wave device can be improved. Further, the configuration in which the first and second surface acoustic wave elements 14 and 15 are connected in parallel to the surface acoustic wave resonator 16 can greatly improve the insertion loss of the surface acoustic wave device.

  FIG. 4 shows a plan view of another example of the embodiment of the substrate mounted surface acoustic wave device of the present invention. The grounding electrodes 29 and 30 connected to the IDT electrodes 3 and 6 of the first and second surface acoustic wave elements 14 and 15 connected in parallel to the surface acoustic wave resonator 16 and the grounding conductor 104 joined thereto. , 105 have different areas so as to be asymmetric with respect to the virtual axis. As a result, a large inductance component can be effectively added to the ground wiring path as described above, and the insertion loss and VSWR of the surface acoustic wave device can be improved. Further, since the parasitic signal is not added to the balanced signal terminal side of the surface acoustic wave device, the balance is not deteriorated. Further, the configuration in which the first and second surface acoustic wave elements 14 and 15 are connected in parallel to the surface acoustic wave resonator 16 can greatly improve the insertion loss of the surface acoustic wave device.

  Further, as shown in FIG. 3, in the substrate-mounted surface acoustic wave device of the present invention, the grounding electrodes 29 and 30 connected to the first and second surface acoustic wave elements 14 and 15 are connected to the virtual axis. In addition to being arranged asymmetrically, through-ground conductors 106 and 107 are respectively connected to ground conductors 104 and 105 joined to ground electrodes 29 and 30 connected to the other comb-like electrode, These through-grounding conductors 106 and 107 are arranged asymmetrically with respect to the virtual axis, so that the inductance value can be adjusted, and parasitic capacitance is provided on the balanced signal terminals 18 and 19 side of the surface acoustic wave device. Since it is not an added form, a surface acoustic wave device with improved insertion loss and VSWR can be provided without degrading the balance.

  FIG. 5 shows a plan view of another example of the embodiment of the substrate mounted surface acoustic wave device of the present invention. A grounding conductor joined to grounding electrodes 29 and 30 connected to the IDT electrodes 3 and 6 in the center of the first and second surface acoustic wave elements 14 and 15 connected in parallel to the surface acoustic wave resonator 16. The through-ground conductors 106 and 107 are connected to 104 and 105, respectively. The through-ground conductors 106 and 107 have at least one diameter different from the diameter of the other. As a result, the inductance value can be adjusted in the same manner as described above, and the parasitic signal is not added to the balanced signal terminals 18 and 19 of the surface acoustic wave device. It becomes possible to improve the insertion loss and VSWR of the surface acoustic wave device. Further, the configuration in which the first and second surface acoustic wave elements 14 and 15 are connected in parallel to the surface acoustic wave resonator 16 can greatly improve the insertion loss of the surface acoustic wave device.

  FIG. 6 shows a plan view of another example of the embodiment of the substrate mounted surface acoustic wave device of the present invention. A grounding conductor joined to grounding electrodes 29 and 30 connected to the IDT electrodes 3 and 6 in the center of the first and second surface acoustic wave elements 14 and 15 connected in parallel to the surface acoustic wave resonator 16. Through-ground conductors 106 and 107 are connected to 104 and 105, respectively, and the number of these through-ground conductors 106 and 107 is different on both sides of the virtual axis, so that the same effect as described above can be obtained.

  FIG. 7 shows a plan view of another example of the embodiment of the substrate mounted surface acoustic wave device of the present invention. A grounding conductor joined to grounding electrodes 29 and 30 connected to the IDT electrodes 3 and 6 in the center of the first and second surface acoustic wave elements 14 and 15 connected in parallel to the surface acoustic wave resonator 16. At least one of 104 and 105 is formed symmetrically with respect to the virtual axis (the ground electrodes 29 and 30 connected to the IDT electrodes 3 and 6) and the virtual axis. By having the portion (the ground electrode 28 connected to the IDT electrodes 2, 4, 5, and 7), it is possible to suppress the deterioration of the balance of the surface acoustic wave device. Further, IDT electrodes 2 to 7, reflector electrodes 8, 10, 20, and 21 and input / output connection pad electrodes 17 to 19 that directly contribute to excitation and propagation of surface acoustic waves in a substrate-mounted surface acoustic wave device, grounding The connection pad conductors 101, 102, 103 and the like to which the electrodes 28 to 30 are connected are preferably arranged symmetrically with respect to the virtual axis.

FIG. 8 shows a plan view of another example of the embodiment of the substrate mounted surface acoustic wave device of the present invention. In each of the above configurations, the first and second surface acoustic wave elements 14 and 15 include two reflector electrodes 31 in which the reflector electrodes 31 are integrally formed at locations where the first and second surface acoustic wave elements 14 and 15 are adjacent to each other. The surface acoustic waves excited by the surface acoustic wave elements 14 and 15 cancel each other on the plus side and the minus side in the integrally formed reflector electrode 31, thereby further improving the reflection characteristics. Generation of minute ripples (spikes) in the passband can be suppressed. Therefore, it is possible to provide a surface acoustic wave filter with improved insertion loss in the passband, which is strictly required in the filter characteristics of the surface acoustic wave filter. FIG. 9 shows the substrate-mounted surface acoustic wave device of the present invention. The top view of the other example of embodiment is shown. FIG. 10A shows a plan view of another example of the embodiment of the substrate mounted surface acoustic wave device of the present invention, and FIG. 10B shows a perspective view of FIG.

  As shown in FIG. 9, the lead-out wiring electrodes 40 and 41 led out from the IDT electrodes 3 and 6 of the first and second surface acoustic wave elements 14 and 15 are connected to signal wiring electrodes via insulators 24 and 25. The three-dimensional wiring intersecting with 22 and 23 is connected to one grounding electrode (grounding annular electrode) 28. As shown in FIGS. 10A and 10B, the grounding electrode 28 is connected to the grounding conductor 34 of the mounting substrate 32 as shown in FIGS. The mounting substrate 32 is electrically connected to the first connection pad conductor 33 and the ground electrode 28 that are electrically connected to one unbalanced signal terminal 17 on each side of the upper surface of the rectangular insulating substrate 32. A grounding conductor 34 connected to the first balanced signal terminal 18, a second connecting pad conductor 35 electrically connected to the one balanced signal terminal 18, and a third connecting pad electrically connected to the other balanced signal terminal 19. A conductor 36 is formed, and the connection pad conductors 33, 35, 36 and the grounding conductor 34 are arranged asymmetrically with respect to the virtual axis, whereby the two surface acoustic wave elements 14, 15 are arranged. Since different inductance components can be added due to different ground wiring paths, the insertion loss and VSWR of the surface acoustic wave device can be improved without degrading the balance of the surface acoustic wave device. It can be.

  As shown in FIG. 10B, the connection pad conductors 33, 35, and 36 and the grounding conductor 34 are formed on the main surface of the insulating substrate 32 and extend from the main surface to the side surface. As a result, when the surface acoustic wave device is mounted on a circuit board such as a mobile communication device, the solder can be connected to the side surface of the insulating substrate 32 of the surface acoustic wave device, and the terminals joined to the solder. It is possible to improve the connection strength. Therefore, the reliability in the communication device can be improved.

  10A and 10B, the first to third connection pad conductors 33, 35, and 36 and the grounding conductor 34 are adjacent to the end of each side of the insulating substrate 32. As shown in FIG. By arranging the matching objects so as not to be close to each other, when mounting the surface acoustic wave device on the circuit board of the communication device, it is possible to prevent a short circuit between the terminals of the surface acoustic wave device and a solder bridge, The yield of the mounting process in the communication device can be improved.

  In addition, the substrate mounted surface acoustic wave device of the present invention can be applied to a communication device. That is, at least one of the receiving circuit and the transmitting circuit is provided, and the substrate-mounted surface acoustic wave device of the present invention is used as a bandpass filter included in these circuits. For example, the transmission signal output from the transmission circuit is put on the carrier frequency by the mixer, the unnecessary signal is attenuated by the band pass filter, and then the transmission signal is amplified by the power amplifier and transmitted from the antenna through the duplexer. Communication device equipped with a transmission circuit capable of receiving the received signal with an antenna, the received signal that passed through the duplexer is amplified with a low noise amplifier, and then the unnecessary signal is attenuated with a band-pass filter, and then the carrier frequency is detected with a mixer. It can be applied to a communication device having a receiving circuit that separates a signal and transmits the signal to a receiving circuit that extracts the signal. By adopting the substrate-mounted surface acoustic wave device of the present invention, excellent sensitivity is improved. A communication device can be provided. In addition, the reliability of the communication device on which the board mounted surface acoustic wave device is mounted can be improved.

  As the piezoelectric substrate 1 for the surface acoustic wave filter, 36 ° ± 3 ° Y-cut X-propagation lithium tantalate single crystal, 42 ° ± 3 ° Y-cut X-propagation lithium tantalate single crystal, 64 ° ± 3 ° Y Cut X Propagation Lithium Niobate Single Crystal, 41 ° ± 3 ° Y Cut X Propagation Lithium Single Crystal, 45 ° ± 3 ° X Cut Z Propagation Lithium Tetraborate Single Crystal has a large electromechanical coupling coefficient and frequency temperature This is preferable because the coefficient is small. Moreover, although these piezoelectric single crystals have pyroelectricity, the piezoelectric substrate 1 with significantly reduced pyroelectricity due to solid solution of oxygen defects, Fe, or the like has good device reliability. The thickness of the piezoelectric substrate 1 is preferably about 0.1 mm to 0.5 mm. If the thickness is less than 0.1 mm, the piezoelectric substrate 1 becomes brittle, and if it exceeds 0.5 mm, the material cost and component dimensions become large and cannot be used.

  The IDT electrodes 2 to 7 are made of Al or an Al alloy (Al—Cu type, Al—Ti type) and are formed by a thin film forming method such as a vapor deposition method, a sputtering method, or a CVD method. The electrode thickness is preferably about 0.1 μm to 0.5 μm for obtaining characteristics as a surface acoustic wave filter.

Further, a protective film made of SiO ₂ , SiN _x , Si, Al ₂ O ₃ is formed on the surface acoustic wave propagation portions of the IDT electrodes 2 to 7 on the piezoelectric substrate 1, thereby causing a short circuit due to adhesion of conductive foreign matters. And the frequency can be adjusted. These protective films may be formed by an ordinary thin film forming method such as a vapor deposition method or a sputtering method after the IDT electrodes 2 to 7 are formed.

  The mounting substrate 100 and the insulating substrate 32 are made of an insulating material and used by stacking a plurality of insulating layers. For these insulating layers, for example, ceramics or glass ceramics are used. A green sheet is produced by molding a slurry in which a metal oxide such as ceramics and an organic binder are homogeneously kneaded with an organic solvent or the like into a sheet shape. After the above pattern is formed, these green sheets are laminated and pressure-bonded so as to be integrally formed and fired.

  The grounding pad conductor, the internal grounding conductor pattern, and the bottom conductor pattern formed on the mounting substrate 100 and the insulating substrate 32 are made of metal conductors such as Au, Cu, Ag, Ag-Pd, and W by screen printing or the like. It is formed by a combination of a film method and etching, or a conductor layer in which W, Ni, and Au are laminated in order from the lower layer is formed in a desired pattern by an electrolytic plating method or an electroless plating method.

  The through-ground conductor is made of, for example, a conductor such as Ag, and a through hole (via hole) is formed at a desired position on the green sheet by micro drilling, punching, laser processing, die punching, photolithography, or the like. For example, it may be formed by filling an Ag-based conductor paste.

  The bonding layer used for bonding the connection pad electrode and the connection pad conductor and bonding the ground electrode and the grounding conductor is formed by forming a solder paste such as an Au-Sn alloy solder paste by a printing method such as screen printing, It is formed by applying with a dispenser. Here, the bonding layer is formed on the mounting substrate 100 or the insulating substrate 32 side. However, the bonding layer may be formed on the surface acoustic wave device side.

  Finally, the substrate-mounted surface acoustic wave device is completed by resin sealing, but the sealing resin prevents the intrusion of high-humidity air into the sealed space, and the mechanical strength of the substrate-mounted surface acoustic wave device. For example, a thermosetting resin such as an epoxy resin or a polyimide resin, a thermoplastic resin such as a polyphenylene sulfide resin, an ultraviolet curable resin, a low melting point glass, or the like can be used. After applying by the method, it may be formed by curing.

  In the case of the substrate mounted surface acoustic wave device of FIG. 1, the substrate mounted surface acoustic wave device manufacturing method (not shown) of the present invention is connected to the IDT electrodes 2 to 7 on one main surface of the piezoelectric substrate 1 and to it. A plurality of surface acoustic wave elements 14 and 15 having connection pad electrodes 17 to 19 formed thereon, and each surface acoustic wave element on the connection pad electrodes 17 to 19 of the piezoelectric substrate 1 or the upper surface of the mounting mother board. Forming a conductive bump on the connection pad conductors 101 to 103 formed corresponding to the connection pad electrodes 17 to 19 in a plurality of mounting regions formed corresponding to the 14 and 15 regions, respectively; A step of mounting the plurality of sets of surface acoustic wave elements 14 and 15 by connecting the connection pad electrodes 17 to 19 and the connection pad conductors 101 to 103 to the plurality of mounting regions of the mounting mother board, respectively, with conductive bumps; , Piezoelectric substrate A step of encapsulating the plurality of surface acoustic wave elements 14 and 15 by applying a sealing resin from the other main surface to the upper surface of the mounting mother board, and mounting the mother board for the surface acoustic wave elements 14 and 15. A plurality of surface acoustic wave devices that are divided into mounting regions together with a sealing resin between the groups, and a plurality of substrate-mounted surface acoustic wave devices are manufactured by dividing the mounting mother board. In this step, the connection pad conductors 101 to 103 formed across the dividing line on the upper surface of the mounting mother board are divided.

  With this configuration, it is possible to manufacture a substrate-mounted surface acoustic wave device in a batch using a collective substrate in which external terminals extend to the side surface of the insulating substrate, and the external terminals on the side surface of the insulating substrate are formed by a cutting process. Therefore, it is possible to simplify the manufacturing process of the board mounted elastic surface wave device.

  Examples of the substrate-mounted surface acoustic wave device of the present invention will be described below.

  An example in which the substrate mounted surface acoustic wave device shown in FIG. 1 is specifically manufactured will be described. A surface acoustic wave filter of PCS (Personal Communication Service) specification having a center frequency in the 1800 MHz band was produced.

  The pattern of each electrode was produced by performing photolithography using a sputtering apparatus, a reduction projection exposure machine (stepper), and an RIE (Reactive Ion Etching) apparatus.

  First, the mother substrate on which a large number of regions to be the individual piezoelectric substrates 1 were formed was ultrasonically cleaned with acetone, IPA (isopropyl alcohol) or the like to remove organic components. Next, after sufficiently drying the mother substrate with a clean oven, a metal film serving as each electrode was formed. A sputtering apparatus was used to form the metal film, and an Al (99 mass%)-Cu (1 mass%) alloy was used as the metal film material. The thickness of the metal film at this time was about 0.16 μm.

  Next, a photoresist layer is spin-coated to a thickness of about 0.5 μm on the metal film, patterned into a desired shape with a reduction projection exposure apparatus, and an unnecessary portion of the photoresist layer is developed with an alkaline developer by a developing apparatus. Dissolve to reveal the desired pattern. Thereafter, the metal film was etched by an RIE apparatus, patterning was completed, and a pattern of each electrode of the surface acoustic wave device of the present invention was obtained.

Next, a protective film was formed on a predetermined region of the electrode. That is, a SiO ₂ film having a thickness of about 0.02 μm was formed on each electrode pattern and the piezoelectric substrate 1 by a CVD (Chemical Vapor Deposition) apparatus.

  Thereafter, a photoresist layer is formed on the lower surface (the surface opposite to the upper surface on which each electrode pattern is formed) of the mother substrate, and a flip chip window opening is formed on the photoresist layer by photolithography. The window opening portion was formed by etching with an RIE apparatus or the like. Thereafter, a sputtering apparatus was used to form a metal film containing Al as a main component on the photoresist layer on the lower surface of the mother substrate. The thickness of the metal film at this time was about 1.0 μm. Thereafter, the photoresist layer and the unnecessary portion of the Al metal film are simultaneously removed by a lift-off method, and an electrode for forming a conductive bump for flip-chip mounting the surface acoustic wave device on an external circuit board or the like in the window opening portion A pad was formed.

  Next, a flip-chip conductor bump made of Au was formed on the electrode pad using a bump bonding apparatus. The conductor bump had a diameter of about 80 μm and a height of about 30 μm.

Next, the mother substrate was diced along the dividing line and divided into surface acoustic wave devices (chips). Thereafter, each chip was accommodated in a package with a flip chip mounting apparatus with the electrode pad forming surface facing down and bonded. Thereafter, baking was performed in an N ₂ atmosphere to complete a substrate-mounted surface acoustic wave device. The package used was a 2.5 × 2.0 mm square laminate structure in which ceramic layers were laminated.

  As a sample of a comparative example, a substrate mounting type elastic surface formed by being arranged symmetrically with respect to a virtual axis provided in the direction orthogonal to the propagation direction at the center of the IDT electrode in which the grounding electrode is disposed in the center A wave device was produced in the same process as described above.

  Next, the characteristics of the substrate-mounted surface acoustic wave device in this example and the comparative example were measured. A signal of 0 dBm was input, and measurement was performed under conditions of a frequency of 1640 to 2140 MHz and a measurement point of 801 points. The number of samples is 30, and the measuring instrument is a multi-port network analyzer (“E5071A” manufactured by Agilent Technologies).

  In this embodiment, the position where the ground electrode is arranged in FIG. 1 of the present invention is adjusted, and the magnitude of the inductance component to be connected to the ground terminal of the surface acoustic wave device is adjusted to a value of 0.2 nH. . FIG. 11 to FIG. 13 show a comparison of the filter characteristics of the substrate-mounted surface acoustic wave device of the example manufactured in this way and the substrate-mounted surface acoustic wave device of the comparative example. The dotted line is the filter characteristic of the comparative example, and the solid line is the filter characteristic of the example of the present invention.

  FIG. 11 shows the pass characteristics of the filter. As shown in FIG. 11, it can be seen that the insertion loss is improved according to the substrate-mounted surface acoustic wave device of the embodiment of the present invention.

  As shown in FIG. 12, according to the substrate-mounted surface acoustic wave device of the embodiment of the present invention, the VSWR in the pass band of the filter characteristics is also improved. This is because by adopting the configuration of the present invention, the inductance component is connected to the GND terminal of the surface acoustic wave device, and the same function as the state in which the matching circuit is connected works.

  FIG. 13A shows the amplitude balance of the substrate-mounted surface acoustic wave device, and FIG. 13B shows the phase balance. Since the substrate-mounted surface acoustic wave device according to the embodiment of the present invention does not have a configuration in which parasitic capacitance is added to the balanced terminal side, the degree of balance does not deteriorate as shown in FIG.

  Further, in the substrate-mounted surface acoustic wave device of the example of the present invention, when the magnitude of the inductance component to be connected to the ground terminal was set to 0.5 nH, the degree of balance was deteriorated as compared with the comparative example. Therefore, in the present invention, it has been found that the magnitude of the inductance component is preferably in the range of 0.1 to 0.3 nH.

It is a top view which shows one example of embodiment about the board | substrate mounting type | mold surface acoustic wave apparatus of this invention. (A)-(f) is a top view which shows each layer of the board | substrate for mounting of the conventional board | substrate mounting type | mold surface acoustic wave apparatus. (A)-(f) is a top view which shows each layer of the board | substrate for mounting of the board | substrate mounting type | mold surface acoustic wave apparatus of this invention. It is a top view which shows the other example of embodiment about the board | substrate mounting type | mold surface acoustic wave apparatus of this invention. (A)-(f) is a top view which shows each layer of the board | substrate for mounting of the board | substrate mounting type | mold surface acoustic wave apparatus of this invention. (A)-(f) is a top view which shows each layer of the board | substrate for mounting of the board | substrate mounting type | mold surface acoustic wave apparatus of this invention. It is a top view which shows the other example of embodiment about the board | substrate mounting type | mold surface acoustic wave apparatus of this invention. It is a top view which shows the other example of embodiment about the board | substrate mounting type | mold surface acoustic wave apparatus of this invention. It is a top view which shows the other example of embodiment about the board | substrate mounting type | mold surface acoustic wave apparatus of this invention. (A), (b) is the top view and perspective view which show the lower layer side of the board | substrate for mounting of the board | substrate mounting type | mold surface acoustic wave apparatus of this invention. It is a diagram which shows the frequency characteristic of the insertion loss in a pass band and its vicinity about the board | substrate mounted surface acoustic wave apparatus of the Example of this invention, and a comparative example. It is a diagram which shows the frequency characteristic of VSWR in a pass band and its vicinity about the board | substrate mounted surface acoustic wave apparatus of the Example of this invention, and a comparative example. (A), (b) is a diagram which shows the frequency dependence of the balance degree in a pass band and its vicinity about the substrate mounted surface acoustic wave apparatus of the Example of this invention, and a comparative example, (a) is amplitude balance. FIG. 4B is a diagram showing the degree of phase balance. It is a top view which shows typically the electrode structure of the conventional surface acoustic wave apparatus. It is a top view which shows typically the electrode structure of the conventional surface acoustic wave apparatus. It is a top view which shows typically the electrode structure of the conventional surface acoustic wave apparatus. It is a diagram which shows the frequency characteristic of the insertion loss in the pass band of the conventional surface acoustic wave apparatus, and its vicinity. It is a diagram which shows the frequency characteristic of VSWR in the pass band of the conventional surface acoustic wave apparatus, and its vicinity. It is a diagram which shows the frequency dependence of the balance degree in the pass band of the conventional surface acoustic wave apparatus and its vicinity, (a) is a diagram which shows an amplitude balance degree, (b) is a diagram which shows a phase balance degree. is there.

Explanation of symbols

1: Piezoelectric substrates 2-7: IDT electrodes 8, 10, 20, 21, 31: Reflectors 17-19: Connection pad electrodes 28-30: Ground electrodes 32: Insulating substrate 100: Mounting substrates 101, 102, 103: connecting pad conductors 104, 105: grounding pad conductors 106, 107: penetrating grounding conductors 14, 15: surface acoustic wave element 16: surface acoustic wave resonator

Claims (8)

Along the propagation direction of the surface acoustic wave, are disposed on both sides of the three or more odd number of IDT electrode and the odd few IDT electrode having a plurality of long electrode fingers in the direction perpendicular to the propagation direction, wherein have a reflector electrodes having a plurality of long electrode fingers in the direction perpendicular to the propagation direction, possess a first and second surface acoustic wave elements connected in parallel to each other, the IDT electrode and reflector electrodes, said A surface acoustic wave resonator connected in series to the first and second surface acoustic wave elements , an unbalanced signal terminal connected to the surface acoustic wave resonator, and the first and second surface acoustic waves The first and second balanced signal terminals connected to one comb-like electrode of the IDT electrode at the center of each element, and the IDT electrode at the center of each of the first and second surface acoustic wave elements For first and second grounding connected to the other comb-like electrode A piezoelectric substrate having an electrode;
A first connecting pad conductor joined to the unbalanced signal terminal; a second connecting pad conductor joined to the first balanced signal terminal; and a third joined to the second balanced signal terminal. The connection pad conductor, the first grounding conductor joined to the first grounding electrode, and the second grounding conductor joined to the second grounding electrode are provided on the top surface. A first bottom electrode pattern connected to the connecting pad conductor via the first through conductor, a second bottom electrode pattern connected to the first balanced signal terminal via the second through conductor, and A mounting board having a third lower surface electrode pattern connected to the second balanced signal terminal via a third through conductor on the lower surface,
The first and second grounding electrodes are formed asymmetrically with respect to a virtual axis provided in the direction perpendicular to the propagation direction at the center between the first and second surface acoustic wave elements , The unbalanced signal terminal is disposed on the imaginary axis and has a line-symmetric shape with respect to the imaginary axis, and the first balanced signal terminal and the second balanced signal terminal are with respect to the imaginary axis. The first lower surface electrode patterns are arranged at equidistant positions and have the same shape, and the first lower surface electrode pattern is arranged on the virtual axis and is symmetrical with respect to the virtual axis. 2. The substrate-mounted surface acoustic wave device according to claim 2, wherein the second lower surface electrode pattern and the third lower surface electrode pattern are arranged at the same distance from the virtual axis and have the same shape. . 2. The substrate-mounted surface acoustic wave device according to claim 1, wherein the first grounding conductor and the second grounding conductor are disposed asymmetrically with respect to the virtual axis. 2. The board mounted surface acoustic wave device according to claim 1, wherein the first grounding conductor and the second grounding conductor have different areas. The mounting board further includes an internal ground conductor pattern provided inside the mounting board,
The first grounding conductor is connected to the internal grounding conductor pattern via a first through-grounding conductor, and the second grounding conductor is connected to the internal grounding conductor pattern via a second through-grounding conductor. Has been
2. The substrate-mounted surface acoustic wave device according to claim 1, wherein the first through-grounding conductor and the second through-grounding conductor are disposed asymmetrically with respect to the virtual axis. The mounting board further includes an internal ground conductor pattern provided inside the mounting board,
The first grounding conductor is connected to the internal grounding conductor pattern via a first through-grounding conductor, and the second grounding conductor is connected to the internal grounding conductor pattern via a second through-grounding conductor. Has been
2. The board-mounted surface acoustic wave device according to claim 1 , wherein a diameter of the first through grounding conductor is different from a diameter of the second through grounding conductor . The said 1st and 2nd surface acoustic wave element consists of one reflector electrode in which the reflector electrode in the location which adjoins them is formed integrally, The any one of Claim 1 thru | or 5 characterized by the above-mentioned. The substrate-mounted surface acoustic wave device according to the item . The piezoelectric substrate further includes a grounding annular electrode formed in an annular shape along an outer periphery of the piezoelectric substrate and connected to the first and second surface acoustic wave elements,
The substrate-mounted surface acoustic wave device according to claim 1, wherein the grounding annular electrode has a line-symmetric shape with respect to the virtual axis . A communication device comprising at least one of a reception circuit and a transmission circuit, comprising the substrate-mounted surface acoustic wave device according to claim 1.

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