JP2006101550A - Surface acoustic wave device, communication apparatus using the same, and antenna duplexer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make compact and highly reliable a surface acoustic wave device mounting, on a package, a piezoelectric element in which a surface acoustic wave element is formed by flip-chip bonding. <P>SOLUTION: The surface acoustic wave device includes a package having a linear expansion coefficient, and a piezoelectric element in which a surface acoustic wave element is formed, and which is mounted on the package by flip-chip bonding. The piezoelectric element is cut out of a single crystal having X, Y, Z crystallographic axes at a predetermined angle, has different linear expansion coefficients in the direction of advancement of a surface acoustic wave that is generated by the interdigital electrode of the surface acoustic wave element, and in a direction vertical thereto, and has, as a long side, the direction having a linear expansion coefficient close to the linear expansion coefficient of the package. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a surface acoustic wave device and a communication apparatus using the same. In particular, the present invention relates to a surface acoustic wave device that uses flip-chip bonding technology to reduce the size of the device and further increases the reliability of the device, and a communication device using the surface acoustic wave device.

  In recent years, there has been a remarkable downsizing of communication devices including mobile phones. In response to the trend toward miniaturization of such devices, there is an increasing demand for miniaturization and low profile of components used in the apparatus.

  In particular, filters, resonators, and delay line devices are indispensable components in communication apparatuses, and these miniaturizations are realized by SAW (Surface Acoustic Wave) devices using flip chip bonding technology. .

  FIG. 1 is a schematic cross-sectional view showing a method for mounting such a surface acoustic wave device on a package.

  FIG. 1A shows a method of mounting a surface acoustic wave device on a package by wire bonding technology. A surface acoustic wave element is formed on the piezoelectric element (chip) 1.

  The piezoelectric element 1 is mounted on a package 2 having a recess formed of a dielectric material such as ceramic, and is fixedly attached by a conductive adhesive 3. The package 2 is sealed with a cap 5 after mounting the piezoelectric element 1. Further, the outer surface of the package 2 including the cap 5 is formed of a conductive metal plate or metal plating connected to the ground terminal 4 on the back surface.

  Here, Al wires 6 are connected between appropriate electrodes on the piezoelectric element 1 and corresponding electrodes of the package 2. Therefore, the Al wire 6 needs a predetermined size in the height direction.

  As described above, in the case of the wire bonding technique shown in FIG. FIG. 1B shows an example in which a flip chip bonding technique is used as a technique for solving this problem.

  In comparison with FIG. 1A, in the flip chip bonding technique of FIG. 1B, the connection between an appropriate electrode on the piezoelectric element 1 and the corresponding electrode of the package 2 is made via an Au bump 7. Done. Therefore, the height direction can be reduced as compared with the case of using the Al wire 6.

  Here, in the flip chip bonding technique of FIG. 1B, the connection surface between the piezoelectric element 1 and the package 2 is determined by the size of the Au bump 7 and is smaller than that in the case of the wire bonding technique. On the other hand, there is a difference in linear expansion coefficient between the piezoelectric element 1 and the package 2 that are generally used.

  For this reason, the stress load applied to the bump 7 at the time of a temperature cycle given in the test stage becomes large. This has been a factor that decreases the reliability of the device (connection disconnection, etc.), and has been an obstacle to adopting the flip chip bonding technology for miniaturization.

As a prior art, Patent Document 1 describes an invention that refers to an expansion coefficient of a ceramic package. Another patent document 2 discloses the thermal expansion coefficient of LiTaO ₃ that is a piezoelectric element.
Japanese Patent Laid-Open No. 07-111438 JP 11-055070 A

  However, none of the above-described prior arts discloses a solution to the problems such as disconnection in the piezoelectric element 1 and the package 2 caused by the temperature cycle given in the test stage based on the difference in linear expansion coefficient.

  Accordingly, it is an object of the present invention to provide a surface acoustic wave device and a communication apparatus using the surface acoustic wave device that can solve such problems and can be downsized and highly reliable.

  A first aspect of the present invention that solves the above problems is a surface acoustic wave device in which a package having a linear expansion coefficient and a surface acoustic wave element are formed and mounted on the package by flip chip bonding. The piezoelectric element is cut out from a single crystal having X, Y, and Z crystal axes at a predetermined angle, and the traveling direction of the surface acoustic wave generated by the comb-shaped electrode of the surface acoustic wave element And a direction having a linear expansion coefficient close to the linear expansion coefficient of the package as a long side.

  In the first aspect, the piezoelectric element may further include an electrode pattern, and a position of the bump connecting the electrode pattern and the package may be arranged symmetrically with respect to the center of the piezoelectric element.

  The surface acoustic wave element can be configured to have an electrode pattern constituting a ladder filter.

  Furthermore, all the positions of the bumps connecting the electrode pattern and the package can be arranged closer to the center of the piezoelectric element than the resonator arranged on the short side of the ladder filter.

  A second aspect of the present invention that solves the above problems is a surface acoustic wave device, in which a package having a linear expansion coefficient and a surface acoustic wave element are formed and mounted on the package by flip chip bonding. Each of the two piezoelectric elements is cut from a single crystal having X, Y, and Z crystal axes at a predetermined angle, and is generated by a comb-shaped electrode of the surface acoustic wave element. The surface expansion direction of the surface acoustic wave is different from the direction perpendicular to the linear expansion coefficient, and the direction having the linear expansion coefficient close to the linear expansion coefficient of the package is a long side, and the center frequency of each is different. It is characterized by being.

  In the second aspect, the ground electrode of the surface acoustic wave element formed on each of the two piezoelectric elements can be made common on the package.

  Furthermore, the ground electrode of the surface acoustic wave element formed on each of the two piezoelectric elements can be made independent on the package.

  Furthermore, in the side surface 1, the surface acoustic wave element is a double mode filter, and the input side ground electrode and the output side ground electrode of the filter can be separated on the package.

  The surface acoustic wave element formed on one of the two piezoelectric elements is a cascade-connected double mode filter, and the input side ground electrode and the output side ground electrode of the filter include: It can be configured to be separated on the package.

  In the above aspect, the piezoelectric element may be cut out from a single crystal having X, Y, and Z crystal axes so that the X crystal axis coincides with the propagation direction of the surface acoustic wave.

  Further, the piezoelectric element can be cut from a LiTaO3 single crystal at a Y-axis rotation angle of 40 to 44 degrees.

  Further, the piezoelectric element may be cut from a LiNbO3 single crystal at a predetermined angle.

  A third aspect of the present invention that solves the above problems is a communication device having a surface acoustic wave filter, in which a package having a linear expansion coefficient and a surface acoustic wave element are formed, and the package is flip-chip bonded. An elastic surface produced by a comb-shaped electrode of the surface acoustic wave element, the piezoelectric element being cut at a predetermined angle from a single crystal having X, Y, and Z crystal axes. The long side has a direction having a linear expansion coefficient that is different from the linear expansion coefficient of the package in a direction perpendicular to the traveling direction of the wave and that has a linear expansion coefficient close to the linear expansion coefficient of the package.

  Furthermore, a fourth aspect of the present invention that solves the above-described problem is an antenna duplexer, which has two piezoelectric elements each formed with a surface acoustic wave filter and mounted on the package by flip chip bonding. Each of the two piezoelectric elements is cut from a single crystal having X, Y, and Z crystal axes at a predetermined angle, and the traveling direction of the surface acoustic wave generated by the comb-shaped electrode of the surface acoustic wave filter The surface acoustic wave filter of the surface acoustic wave filter formed in the two piezoelectric elements has a direction having a linear expansion coefficient different from that of the package and a direction having a linear expansion coefficient close to the linear expansion coefficient of the package as a long side. Each center frequency is different.

  Further features of the present invention will become apparent from the following embodiments described in conjunction with the drawings.

  According to the present invention, it is possible to reduce the size and increase the reliability of a surface acoustic wave device in which a piezoelectric element having a surface acoustic wave element formed by flip chip bonding technology is mounted on a package.

  Embodiments of the present invention will be described below. In the drawings, the same or similar items are denoted by the same reference numerals or reference symbols.

  FIG. 2 is a top view of a piezoelectric element 1 on which a conventional surface acoustic wave element is formed.

Here, the piezoelectric element 1 is a single crystal having X, Y, and Z crystal axes, for example, LiTaO _3.
The piezoelectric substrate (wafer) cut out at a predetermined angle from the substrate is further divided into a plurality of rectangular parallelepiped chips. The piezoelectric element 1 has a side along the crystal axis. In the example of FIG. 2, the long side Lx is a side along the X axis, and the short side Lz is a side along the Z axis.

The surface acoustic wave element formed on the piezoelectric element 1 has comb-shaped electrodes 10, 12, and 11. The comb-shaped electrodes 10 and 12 are parallel resonators, and the comb-shaped electrode 11 is an input electrode pad so as to configure a series resonator. P ₁ , output electrode pad P ₂ and ground electrode pad P ₃ are connected to form a ladder type filter. FIG. 3 is an equivalent circuit of a ladder type filter using the surface acoustic wave element shown in FIG. 2, and has two stages of series resonance circuits and three stages of parallel resonance circuits.

  Here, in FIG. 2, the long side Lx of the piezoelectric element 1 coincides with the propagation direction of the surface acoustic wave (SAW) by the comb electrode of the surface acoustic wave element. Furthermore, the piezoelectric element 1 has a different linear expansion coefficient in the long side Lx direction and a linear expansion coefficient in the short side Lz direction.

  The crystal axis that is the propagation direction of these surface acoustic waves (SAW) and the linear expansion coefficient in each side direction are unambiguous depending on the type of single crystal from which the piezoelectric substrate is cut and the cutting angle.

For example, a piezoelectric substrate cut out at a LiTaO ₃ single crystal Y-axis rotation angle of 42 degrees has a coefficient of linear expansion αx = 16.1 ppm in the direction of surface acoustic wave propagation (direction along the X-axis), the vertical direction (Z-axis) The linear expansion coefficient in the direction along (α) is αz = 9.5 ppm.

On the other hand, when the piezoelectric element 1 shown in FIG. 2 is mounted on a package by the flip chip bonding technique, the bumps 7 are formed at positions corresponding to the respective electrode pads P ₁ , P ₂ , P ₃ as shown in FIG. Is connected to the electrode on the package 2.

  However, the package 2 itself also has a linear expansion coefficient. For example, when a ceramic package is used, the linear expansion coefficient is approximately α = 7 to 8 ppm.

  Therefore, the piezoelectric element 1 shown in FIG. 2 has a large difference between the linear expansion coefficient of the side of the surface acoustic wave propagation direction, that is, the long side Lx, and the linear expansion coefficient of the package 2. A large stress acts, causing a problem in connection reliability.

  The present invention solves such a problem, and FIG. 4 shows the configuration of one embodiment thereof, and is a view of the piezoelectric element 1 as viewed from above as in FIG. In the embodiment of FIG. 4, the long side and the short side of the piezoelectric element 1 are opposite in comparison with the example of FIG. 2. That is, the long side Lz is a side along the Z axis, and the short side Lx is a side along the X axis.

  Thus, according to the present invention, the side Lz closer to the linear expansion coefficient of the package 2 is configured to be the long side. As a result, the stress on the bump 7 can be reduced as compared with the conventional example shown in FIG.

By the way, in the piezoelectric substrate cut out at the LiTaO ₃ single crystal Y axis rotation angles of 40 degrees, 42 degrees and 44 degrees, the linear expansion coefficient along the X axis is αx = 16.1 ppm, Since the linear expansion coefficient along the direction is αz = 9.1 ppm, 9.5 ppm, and 9.9 ppm, the linear expansion coefficient α of the ceramic package is 7 to 8 ppm compared to the direction along the X axis when cut at any rotation angle. Close to.

As another example, when LiNbO ₃ is used, when the Y-axis rotation angle is 41 degrees, the linear expansion coefficient αx = 15.4 ppm in the X-axis direction, and in the Z-direction αz = 10.9 ppm, 64 degrees, the X-axis The linear expansion coefficient αx in the direction is 15.4 ppm, and in the Z direction is αz = 13.9 ppm. Also in this case, the linear expansion coefficient in the direction along the Z axis is closer to the linear expansion coefficient α = 7 to 8 ppm of the ceramic package than the linear expansion coefficient in the X axis direction.

  In any of the above cases, it is possible to reduce the stress load on the bumps by setting the long side in the direction along the Z-axis having a linear expansion coefficient close to that of the ceramic package. As described above, the present invention uses the piezoelectric element 1 having a long side in the direction along the crystal axis having a linear expansion coefficient close to the linear expansion coefficient of the package 2, and the piezoelectric element 1 is attached to the ceramic package 2 as shown in FIG. It is mounted and connected to the corresponding electrode of the package 2 via the bump 7. Thereby, a highly reliable surface acoustic wave device can be obtained.

  Returning to FIG. 4, another feature of the present invention will be described. That is, in FIG. 4, the electrode pads A, A′B, B′C, and C ′ are arranged point-symmetrically with respect to the center of the piezoelectric element 1.

  As described above, by arranging the electrode pads symmetrically with respect to the center of the piezoelectric element 1, it is possible to disperse the stress load applied to the bumps corresponding to the electrode pad positions and to distribute the stress.

  The application of the present invention described above is not limited to the surface acoustic wave element formed on the piezoelectric element 1 having the ladder-type comb electrode structure shown in FIG. 4, but an elastic surface having another comb electrode structure. Naturally, a case where a wave element is formed is also included.

For example, FIGS. 6 to 8 show examples of surface acoustic wave elements having other comb electrode structures. In particular, the example shown in FIG. 6 is an example of an IIDT (Interdigitated Interdigital Transducer) type filter, the side along the Z axis is the long side Lz, and the relationship between the input / output electrode pads P ₁ and P ₂ and the ground electrode in relation between the pads P _3, they are arranged symmetrically.

  FIG. 7 shows an example of a cascade-connected double mode filter, in which the long side is in the direction along the Z axis. In FIG. 7, a first double-mode filter 101 and a second double-mode filter 102 are cascade-connected by connecting electrodes 103 and 104, and a two-stage double-mode filter forms a filter with higher selectivity. ing.

  Further, also in FIG. 7, the electrode pads are arranged point-symmetrically with respect to the center point of the piezoelectric element 1.

FIG. 8 is a top view of the piezoelectric element 1 in which another surface acoustic wave filter of a double mode type is further formed. In particular, this is an example in which two double-mode filters 101 and 102 are connected in cascade and the output is taken from two output electrode pads P ₄ .

FIG. 9 is a diagram showing an embodiment for explaining still another feature of the present invention. In the ladder type filter shown in FIG. 9A, the ground electrode pad P ₆ of the series resonator R1 and the ground electrode pad P ₇ of the series resonator R2 are outside the series resonators R1 and R2, respectively. As shown in FIG. 9B, the pads P ₆ and P ₇ are arranged inside the series resonators R 1 and R 2, respectively.

As a result, the distance of the ground electrode pads P ₆ and P ₇ from the center of the piezoelectric element 1 can be reduced, and therefore the stress load applied to the bumps corresponding to the ground electrode pads P ₆ and P ₇ can be reduced.

  Here, the application of the filter in the communication apparatus will be considered. FIG. 10 is a block diagram centering on a high-frequency circuit of a wireless communication apparatus, for example, a mobile phone. The antenna duplexer 21 connected to the antenna 20 includes a transmission filter 210 and a reception filter 211. Each of the transmission filter 210 and the reception filter 211 has a predetermined pass band and has a different center frequency.

  On the transmission side, the modulator 22 modulates the carrier wave with the audio signal. The modulated carrier wave is multiplied by a multiplier 24 into a transmission frequency band signal from the local oscillator 23. Next, the power is amplified by the power amplifier 26 through the interstage filter 25, and transmitted from the antenna 20 through the transmission filter 210 of the antenna duplexer 21.

  On the other hand, the reception signal received by the antenna 20 passes through the reception filter 211 of the antenna duplexer 21 and is amplified by the preamplifier 27. The output of the preamplifier 27 passes through the interstage filter 28 and is led to the frequency reducer 29.

  A frequency signal different from the transmission frequency is extracted from the frequency signal output from the local oscillator 23 by the filter 30, and thereby the received signal is converted into an IF signal by the reducer 29. The converted IF signal has its harmonic components removed by the IF filter 31 and guided to the demodulator 32 where it is demodulated.

  FIG. 11 is a block diagram centering on a high-frequency circuit of still another mobile phone. In particular, it is a schematic configuration of a high-frequency circuit unit of a mobile phone used in Europe. That is, one telephone is configured to support two systems. This corresponds to an EGSM system having a frequency band of 900 MHz and a DCS system having a frequency band of 1.8 GHz.

  For this purpose, transmission / reception dual filters 40 and 41 for each system are provided. In some cases, a SAW filter is further mounted between the diplexer module 30 and the amplifiers 31 and 32 for separating the system connected to the antenna 20 and the transmission / reception signal.

  The subsequent stages of the interstage filters 40 and 41 are connected to the modulation / demodulation circuit in the same manner as in the configuration of FIG. 10. However, in the description of the present invention, since they are not directly related, further description is omitted.

  As can be easily understood from the description of FIG. 10 and FIG. 11, when a plurality of filters are used in the communication device and miniaturization is required like a mobile phone, these filters are realized. A small surface acoustic wave device is required.

  FIG. 12 is a diagram for explaining an example of mounting a surface acoustic wave device according to the present invention that meets such a requirement, and FIG. 13 is a diagram showing a state after mounting. In this embodiment, two piezoelectric elements 1 having the features of the present invention described above are mounted on the package 2 in common and sealed with a cap 5. The package 2 has a recess, and is connected and fixed to the corresponding electrode pad of the piezoelectric element 1 through the ground terminal, the input / output terminal, and the Au bump 7.

  Here, as described above, the long side of the piezoelectric element 1 is selected in the axial direction close to the linear expansion coefficient of the package 2, and the arrangement of the electrode pads is symmetric with respect to the center of the piezoelectric element 1. is there. Therefore, in FIG. 13, the stress on the bump 7 is reduced.

  The example of FIG. 13 is an example in which the ground electrode pads of the two piezoelectric elements 1 are commonly connected to the ground terminal 4 of the package 2.

  FIG. 14 shows still another example in which the ground electrode pads of the two piezoelectric elements 1 mounted on the common package 2 are separated and connected to the ground terminal 4 of the package 2. Thereby, it is possible to prevent interference between the two piezoelectric elements 1.

  FIG. 15 shows still another example. The input and output ground electrode pads of two surface acoustic wave elements formed on one piezoelectric element 1 are separated from each other and connected to the ground terminal 4 of the package 2. This is an example. As a result, it is possible to prevent interference between input and output.

  Such an example is applicable to a two-stage double mode filter or a one-stage double mode filter cascade-connected with the connection electrodes 103 and 104 described above with reference to FIG.

  Here, in FIG. 12 to FIG. 15, the example in which the two piezoelectric elements are mounted on the common package has been described. However, the application of the present invention is not limited to such an example. When two piezoelectric elements are mounted in a common package, for example, the antenna duplexer 21 in FIG. 10 or the dual filters 40 and 41 in FIG. 11 can be configured.

  Further, when two or more piezoelectric elements are mounted in a common package, for example, in FIG. 10, an interstage filter, an IF filter, or a filter for another system can be included.

  In the above description of the embodiment, the case where one filter is configured on one piezoelectric element has been described. However, the present invention is not limited to this, and two or more filters are provided on one piezoelectric element. You can configure it.

It is a schematic sectional drawing which shows the mounting method to the package of a surface acoustic wave device. It is the figure which looked at the piezoelectric element 1 in which the conventional surface acoustic wave element was formed from the upper surface. 3 is an equivalent circuit of a ladder type filter using the surface acoustic wave element of FIG. 2. 2 is a diagram showing a configuration of an embodiment according to the present invention that solves the problem of the configuration. It is a figure explaining mounting to a ceramic package of a piezoelectric element. It is an example of a surface acoustic wave device having a comb electrode structure according to the present invention, and is a diagram showing an example of an IIDT (Interdigitated Interdigital Transducer) type filter. 2 is an example of a cascaded double mode filter according to the present invention. It is a top view of the piezoelectric element 1 in which another surface acoustic wave filter of a double mode type is formed. It is a figure which shows the Example explaining another characteristic of this invention. It is a block diagram centering on the high frequency circuit of a radio | wireless communication apparatus, for example, a mobile telephone. It is a block diagram centering on the high frequency circuit of another mobile telephone. It is a figure explaining the Example in mounting of the surface acoustic wave device according to this invention which responds to the request | requirement of a small surface acoustic wave device. It is a figure which shows the state after mounting of the Example of FIG. It is a figure which shows the state after mounting. In another example, the ground electrode pads of the two piezoelectric elements 1 mounted on the common package 2 are separated and connected to the ground terminal 4 of the package 2. Further, in another example, the input / output ground electrode pads of the double mode filter formed on one piezoelectric element 1 are separated from each other and connected to the ground terminal 4 of the package 2.

Explanation of symbols

1 Piezoelectric element 2 Package 4 Ground terminal 5 Cap 7 Au bump

Claims (14)

A package having a linear expansion coefficient;
A surface acoustic wave element is formed, and has a piezoelectric element mounted on the package by flip chip bonding,
The piezoelectric element is cut from a single crystal having X, Y, and Z crystal axes at a predetermined angle, and is perpendicular to the traveling direction of the surface acoustic wave generated by the comb-shaped electrode of the surface acoustic wave element. A surface acoustic wave device having a direction having a linear expansion coefficient different from each other and having a linear expansion coefficient close to that of the package as a long side. In claim 1,
Furthermore, the surface acoustic wave device is characterized in that the piezoelectric element has an electrode pattern, and the bumps connecting the electrode pattern and the package are arranged symmetrically with respect to the center of the piezoelectric element. In claim 1,
The surface acoustic wave device has an electrode pattern that constitutes a ladder-type filter. In claim 3,
A surface acoustic wave characterized in that all the positions of the bumps connecting the electrode pattern and the package are arranged closer to the center of the piezoelectric element than the resonator arranged on the short side of the ladder filter. device. A package having a linear expansion coefficient;
A surface acoustic wave element is formed and has two piezoelectric elements mounted on the package by flip chip bonding,
Each of the two piezoelectric elements is cut out at a predetermined angle from a single crystal having X, Y, and Z crystal axes, and the traveling direction of the surface acoustic wave generated by the comb-shaped electrode of the surface acoustic wave element is Elasticity characterized in that the linear expansion coefficient in the direction perpendicular to this is different and has a direction having a linear expansion coefficient close to the linear expansion coefficient of the package as a long side, and each center frequency is different. Surface wave device. In claim 5,
A surface acoustic wave device, wherein a ground electrode of a surface acoustic wave element formed on each of the two piezoelectric elements is shared on the package. In claim 5,
A surface acoustic wave device, wherein ground electrodes of surface acoustic wave elements formed on each of the two piezoelectric elements are made independent on the package. In claim 1,
The surface acoustic wave device is a double mode filter, and an input side ground electrode and an output side ground electrode of the filter are separated on the package. In claim 5,
The surface acoustic wave element formed on one of the two piezoelectric elements is a cascade-connected double mode filter, and the input side ground electrode and the output side ground electrode of the filter are connected to the package. A surface acoustic wave device characterized by being separated above. In any one of Claims 1 thru | or 9,
The surface acoustic wave device, wherein the piezoelectric element is cut from a single crystal having X, Y, and Z crystal axes, and the X crystal axis coincides with a propagation direction of the surface acoustic wave. In claim 10,
The surface acoustic wave device according to claim 1, wherein the piezoelectric element is cut from a LiTaO3 single crystal at a Y-axis rotation angle of 40 to 44 degrees. In claim 10,
2. The surface acoustic wave device according to claim 1, wherein the piezoelectric element is cut from a LiNbO3 single crystal at a predetermined angle. A package having a linear expansion coefficient;
A surface acoustic wave element is formed, and has a piezoelectric element mounted on the package by flip chip bonding,
The piezoelectric element is cut from a single crystal having X, Y, and Z crystal axes at a predetermined angle, and is perpendicular to the traveling direction of the surface acoustic wave generated by the comb-shaped electrode of the surface acoustic wave element. A communication device having a surface acoustic wave filter having a direction whose linear expansion coefficient is different and whose direction has a linear expansion coefficient close to the linear expansion coefficient of the package. A package having a linear expansion coefficient;
Each has a surface acoustic wave filter, and has two piezoelectric elements mounted on the package by flip chip bonding,
Each of the two piezoelectric elements is cut at a predetermined angle from a single crystal having X, Y, and Z crystal axes, and the traveling direction of the surface acoustic wave generated by the comb-shaped electrode of the surface acoustic wave filter The direction of the linear expansion coefficient in the direction perpendicular to this is different, and has a direction having a linear expansion coefficient close to the linear expansion coefficient of the package as a long side,
The antenna duplexer is characterized in that the surface frequencies of the surface acoustic wave filters formed on the two piezoelectric elements are different from each other.

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