KR100697764B1 - Surface acoustic wave device - Google Patents

Abstract

A surface acoustic wave device is provided to reduce coupling capacitance between an input and an output of a package, by installing a ground GND pattern between an input pattern and an output pattern. A surface acoustic wave device includes a surface acoustic wave filter where a comb type electrode pattern is formed on a piezoelectric device. An input/output electrode port of the surface acoustic wave filter is connected to a corresponding electrode pattern of a package through a bump. The comb type electrode pattern has a pair of reflection electrodes, and an input comb type electrode and an output comb type electrode arranged between the pair of the reflection electrodes. One electrode port of the input comb type electrode and the output comb type electrode is located at an opposite position to an electrode of another comb type electrode by intervening a ground electrode.

Description

Surface acoustic wave device {SURFACE ACOUSTIC WAVE DEVICE}

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a diagram showing an example of a comb-shaped electrode (IDT: interdigital transducer) pattern of a conventional multi-mode SAW filter.

FIG. 2 is a diagram showing a plan view of a dual mode SAW filter (DMS) connected in three parallel cascades on the basis of the IDT pattern shown in FIG. 1; FIG.

Fig. 3 is a cross-sectional view when a SAW device is formed by accommodating a dual mode SAW filter (DMS) of the IDT pattern shown in Fig. 2 into a package.

FIG. 4 is a cross-sectional view of an example of the configuration where a double mode SAW filter of the IDT pattern shown in FIG. 2 is mounted on a ceramic package by flip chip connection. FIG.

FIG. 5 is a diagram showing a comparison of characteristics when accommodated in a ceramic package by wire bonding and characteristics when accommodated in a ceramic package by flip chip bonding. FIG.

FIG. 6 is a view for explaining the case where a GND pattern is provided without being limited to the surface layer or inner layer of the ceramic package so as to correspond between the IN terminal and the OUT terminal of the IDT pattern.

FIG. 7 shows a terminal pattern on the ceramic package side corresponding to the IDT pattern in FIG. 6; FIG.

8 is a passband characteristic diagram showing an effect of reducing coupling capacity between input and output by a GND pattern.

Fig. 9A is a diagram showing an IDT pattern in the first embodiment.

Fig. 9B is a diagram showing an electrode arrangement on the ceramic package side to be flip chip mounted in the first embodiment.

Fig. 10A is a diagram showing an IDT pattern of the second embodiment.

Fig. 10B is a diagram showing an electrode arrangement on the ceramic package side to be flip chip mounted in the second embodiment.

Fig. 11A is a diagram showing the IDT pattern of the third embodiment.

Fig. 11B is a diagram showing the electrode arrangement on the ceramic package side to be flip chip mounted in the third embodiment.

Fig. 12A is a diagram showing an IDT pattern in the fourth embodiment.

Fig. 12B is a diagram showing the electrode arrangement on the ceramic package side to be flip chip mounted in the fourth embodiment.

Fig. 13A is a diagram showing an IDT pattern of the fifth embodiment.

Fig. 13B is a diagram showing an electrode arrangement on the ceramic package side to be flip chip mounted in the fifth embodiment.

Fig. 14A is a diagram showing an IDT pattern in the sixth embodiment.

Fig. 14B is a diagram showing an electrode arrangement on the ceramic package side to be flip chip mounted in the sixth embodiment.

Fig. 15A is a diagram showing an IDT pattern in the seventh embodiment.

Fig. 15B is a diagram showing an electrode arrangement on the side of a ceramic package on which flip chips are mounted in the seventh embodiment.

Fig. 16A is a diagram showing an IDT pattern in the eighth embodiment.

Fig. 16B is a diagram showing an electrode arrangement on the ceramic package side to be flip chip mounted in the eighth embodiment.

17A corresponds to the sixth embodiment shown in FIGS. 14A and 14B, and shows an IDT pattern of a conventional configuration example in which the present invention is not applied to a multi-mode SAW filter F2 at a later stage.

FIG. 17B is a diagram showing an electrode arrangement on the ceramic package side of a conventional configuration corresponding to the sixth embodiment shown in FIGS. 14A and 14B and in which the present invention is not applied to a multi-mode SAW filter F2 at a later stage.

18A is a diagram illustrating a configuration example of a duplexer.

Fig. 18B is a diagram showing isolation characteristics between transmission and reception when the sixth embodiment according to the present invention and the comparative example of Figs. 17A and 17B are used as a reception (Rx) filter of a PCS duplexer.

19A is a block diagram of a configuration example of a PCS reception filter.

19B is a diagram showing characteristics (Korean PCS receiving filter) in which the values of the ground GND inductance L _{1 to} L ₅ of the ceramic package 10 in the sixth embodiment shown in FIGS. 14A and 14B are changed.

<Explanation of symbols for the main parts of the drawings>

IN: input terminal

OUT: Output terminal

GND: Ground Terminal

5: winding

10: piezoelectric element

11: ceramic package

14 metal cap

15: bump

20: Tx filter

30: Rx filter

[Patent Document 1] Japanese Patent Application Laid-Open No. 2004-194269

The present invention relates to a flip chip mounted surface acoustic wave device that can be miniaturized.

In recent years, wireless devices such as mobile phones are rapidly miniaturized and highly functionalized. A filter is used for the high frequency circuit and plays an important role. Such filters are often constructed using surface acoustic wave (SAW) devices for miniaturization.

For example, in a wireless device such as a personal communications system (PCS) cellular phone, the function of an antenna duplexer having a role of separating a transmission (Tx: 1850 to 1910 MHz) signal and a reception (Rx: 1930 to 1990 MHz) signal is provided. The transmission (Tx) filter and the reception (Rx) filter which are comprised are comprised by a surface acoustic wave device.

The transmission (Tx) filter and the reception (Rx) filter are band pass filters, for example, using a plurality of (two) standing waves generated between reflective electrodes as described in Patent Document 1, for example. It is comprised by combining the multiple (dual) mode SAW filter (DMS) which has several (two) resonance modes.

Dual-mode SAW filter, an example comb-like electrodes as shown in Figure 1 is disclosed, in Patent Document 1 (IDT: Interdigital Transducer) _{pattern, LiTa0 3, LiNb0 3, Li} 2 B 4 0 7, modified, etc. It is formed on the piezoelectric element (piezoelectric substrate) which is not shown in figure.

In the IDT pattern formed in the piezoelectric element, in the example shown in FIG. 1, one input (output) IDT 1 and two output (input) IDTs 2a and 2b are alternately arranged, and on both sides thereof. The grating reflectors 3a and 3b are located in the propagation direction of the surface acoustic wave.

The characteristic of the IDT pattern shown in FIG. 1 is that the terminal IN (OUT) of the input (output) IDT 1 and the common terminal connected OUT (IN) of the two output (input) IDTs 2a, 2b are the same. It is arranged on the side.

In addition, the IDT pattern shown in FIG. 1 is used as a unit, and a plurality of IDT patterns are connected in parallel or in series (cascade) to correspond to the desired filter characteristics as desired.

FIG. 2 is a plan view of a dual mode SAW filter (DMS) cascaded in three parallel cascades on the basis of the IDT pattern shown in FIG. 1, wherein the unit IDT pattern of FIG. 1 is three parallel on the piezoelectric element 10. It is connected by cascade.

FIG. 3 is a cross-sectional view when a surface acoustic wave (SAW) device is formed by accommodating such a double mode SAW filter (DMS) of the IDT pattern shown in FIG. 2 in a package. In this SAW device, the double mode SAW filter DMS is attached to the inner bottom surface of the ceramic package 11 by the conductive paste 12. In the dual mode SAW filter DMS, an IDT pattern is formed on the piezoelectric element 10, and the input terminal IN, the output terminal OUT, and the GND terminal are formed on the ceramic package 11 side by the bonding wire 13. It is connected to the terminal. In addition, the metal cap 14 is bonded to cover the inside of the ceramic package 11 with a space interval of at least a predetermined distance from the IDT pattern.

Here, the surface acoustic wave device has a limitation in miniaturization because the bonding wire 13 requires a predetermined space or more with the metal cap 14 and the IDT pattern. Therefore, instead of the structure which connects the double mode SAW filter DMS to the terminal of the ceramic package side by the bonding wire 13, the structure which connects to the terminal of a ceramic package by flip chip connection is considered.

FIG. 4 is a cross-sectional view of an example of a configuration where a double mode SAW filter of the IDT pattern shown in FIG. 2 is mounted on a ceramic package by flip chip connection.

The ground terminal GND, the input terminal IN, and the output terminal OUT are formed on the ceramic package 11 side.

The IDT pattern side formed on the piezoelectric element 10 of the dual mode SAW filter DMS is turned downward, and the ground terminal GND, the input terminal IN, and the output terminal OUT of the IDT pattern on the IDT pattern side are placed on the ceramic package 11 side. The bump 15 is connected in correspondence with the ground terminal GND, the input terminal IN, and the output terminal OUT. As a result, reduction in the area and height direction when accommodating the double mode SAW filter DMS in the ceramic package 11 can be achieved.

However, when the dual mode SAW filter is accommodated in the ceramic package by flip chip connection as shown in Fig. 4, deterioration in characteristics has been recognized. Fig. 5 shows a terminal IN (OUT) of the same configuration, that is, the terminal IN (OUT) of the input (output) IDT 1 shown in Fig. 1 and the common connection terminal OUT (IN) of the two output (input) IDTs 2a, 2b. Compares the characteristics of a dual mode SAW filter (DMS) having an IDT pattern disposed on the same side with the ceramic package by wire bonding and the characteristics when the ceramic package is accommodated by flip chip bonding. The figure shows.

That is, in FIG. 5, graph (a) of FIG. 5 has shown the passage characteristic of the reception filter for inducing the reception signal in a duplexer from an antenna to a reception circuit. 5B shows the isolation characteristics from the transmitting side to the receiving side in the duplexer.

In general, an attenuation amount of 50 dB or more in the transmission band is required as the reception antenna filter in the PCS duplexer. In addition, the standard value for the isolation of the transmission band is required 55 kHz.

As shown in Fig. 5A, the attenuation characteristic II outside the pass band of the receiving antenna filter when accommodated in the ceramic package by flip chip bonding deteriorates as compared with the case I by wire bonding, and is 50 kHz. It has an area which does not satisfy the above attenuation amount.

In addition, as shown in Fig. 5B, the isolation characteristics II from the transmitting side to the receiving side of the receiving antenna filter when accommodated in the ceramic package by flip chip bonding are compared with the case I by wire bonding. However, there is an area that does not satisfy the standard value 55㏈ for isolation.

The reason for the deterioration of characteristics due to the flip chip bonding is that the flip chip bonding causes the input / output terminals of the ceramic package to be close to each other when accommodated in the ceramic package, thereby increasing the input / output capacity. do.

Based on this estimation, the present inventors widen the IN (OUT) terminal and the OUT (IN) terminal as shown in FIG. 6 with respect to the IDT pattern in FIG. 1, and the IN (OUT) terminal of the IDT pattern. The GND pattern 4 was provided not only in the surface layer or the inner layer of the ceramic package, but the passband characteristic was measured so that it might correspond between and OUT (IN) terminal.

FIG. 7 is a diagram illustrating a terminal pattern on the ceramic package side corresponding to the IDT pattern of FIG. 6. The ground between the IN (OUT) terminal and the OUT (IN) terminal is widened to form a ground GND line.

Thus, since the structure of FIG. 6 divides between an IN (OUT) terminal and an OUT (IN) terminal by the GND pattern 4, the coupling capacity between corresponding input / outputs can be reduced.

FIG. 8 is a passband characteristic diagram showing the effect of reducing the coupling capacitance between the input and output by the GND pattern 4.

As shown in Fig. 8, it can be understood that the amount of out-of-band attenuation can be increased in the direction of the arrow by reducing the coupling capacitance between input and output.

However, in such a configuration, it is necessary to widen the input / output terminals to form the GND pattern 4, as shown in Figs. 6 and 7, and thus the device configuration is enlarged on the plane, thereby achieving miniaturization. To be harmful.

In view of this, it is an object of the present invention to provide a surface acoustic wave device which is characterized by the layout of the input / output terminal arrangement, which avoids the above-mentioned disadvantages to obtain good filter characteristics and which does not increase in device configuration even in plan view.

A first aspect of the present invention, which achieves the object of the present invention, has a surface acoustic wave filter having a comb-shaped electrode pattern formed on a piezoelectric element, and electrode terminals for input / output of the surface acoustic wave filter correspond to packages through bumps. A surface acoustic wave device connected to an electrode pattern, wherein the comb-shaped electrode pattern has a pair of reflection electrodes, an input comb electrode and an output comb electrode disposed between the pair of reflection electrodes. The electrode terminal of any one of the comb-shaped electrode for output and the comb-shaped electrode for output is arrange | positioned so that it may be located on the opposite side to the other electrode terminal with a ground electrode interposed by winding wiring.

The surface acoustic wave filter may be a multi-mode surface acoustic wave filter using surface acoustic waves excited between the reflective electrodes and using a plurality of standing waves generated between the reflective electrodes.

A second aspect of the present invention, which achieves the above object of the present invention, has a comb-shaped electrode pattern formed on a piezoelectric element, and has cascaded first and second surface acoustic wave filters for input / output of the surface acoustic wave filter. A surface acoustic wave device in which an electrode terminal is connected to a corresponding electrode pattern of a package through a bump, wherein the comb-shaped electrode patterns of the first and second surface acoustic wave filters each have a pair of reflective electrodes and the pair of reflections. A comb-shaped electrode for input and an comb-shaped electrode for output disposed between the electrodes, for each of the first and second surface acoustic wave filters, electrode terminals of the comb-shaped electrode for input and output are drawn out from the same side; Electrode terminals of the comb-shaped electrodes for the output (or input) of the first surface acoustic wave filter are rounded with electrode terminals of the comb-shaped electrodes for the input (or output) of the second surface acoustic wave filter. It is connected by wiring, and the electrode terminal of the comb-shaped electrodes for input and output of the said 1st surface acoustic wave filter is opposed to the said 2nd surface acoustic wave filter, between the ground terminals of the said 2nd surface acoustic wave filter. It is characterized by being.

In addition, the third aspect of the present invention, which achieves the above object of the present invention, has a comb-shaped electrode pattern formed on a piezoelectric element and has cascaded first and second surface acoustic wave filters, and input and output of the surface acoustic wave filter. A surface acoustic wave device in which an electrode terminal for a dragon is connected to a corresponding electrode pattern of a package through a bump, wherein the comb-shaped electrode patterns of the first and second surface acoustic wave filters each include a pair of reflective electrodes and the pair A comb-shaped electrode for input and a comb-shaped electrode for output disposed between the reflective electrodes of the electrodes, and for each of the first and second surface acoustic wave filters, electrode terminals of the comb-shaped electrode for input and output are drawn out from the same side. And the electrode terminal of the comb-shaped electrode for the output (or input) of the first surface acoustic wave filter is an electrode terminal of the comb-shaped electrode for the input (or output) of the second surface acoustic wave filter. Connected by a main line and, further characterized in that comprises the first ground terminal of the surface acoustic wave filter and the grounding terminal of the second surface acoustic wave filter it has to be opposed.

In the first aspect, the comb-shaped electrode pattern may be configured to connect two divided filters in series so as to obtain a desired synthesized impedance.

The electrode pattern of at least one surface acoustic wave filter of the first and second surface acoustic wave filters may be configured such that two divided filters are connected in series so as to obtain a desired synthesized impedance.

Moreover, it is also possible to set it as the structure with which the said surface acoustic wave filter is connected in parallel in multiple numbers.

The surface acoustic wave filter may be such that the input (or output) terminal is a balance input (or output).

In addition, the electrode pattern of the said package may be used as an inductance component which comprises a filter.

A fourth aspect of the present invention, which achieves the above object of the present invention, is an antenna duplexer, wherein the surface acoustic wave device is configured as a transmission and / or reception filter.

In the fourth aspect, a ground pattern may be formed in the package between the transmission (Tx) signal electrode pattern connected to the transmission filter and the reception (Rx) signal electrode pattern connected to the reception filter.

<Example>

EMBODIMENT OF THE INVENTION Below, the example of embodiment of this invention is described according to drawing.

9A and 9B are diagrams showing a first embodiment of the basic IDT pattern of the dual mode SAW filter according to the present invention. As described above, this IDT pattern is formed on the piezoelectric element, so that the filter is constructed. In addition, the filter is accommodated in a ceramic package to form a surface acoustic wave device. FIG. 9A shows the IDT pattern of the first embodiment, and FIG. 9B shows the electrode arrangement on the ceramic package side on which flip chips are mounted.

The characteristic of the basic IDT pattern of the dual mode SAW filter shown in FIG. 9A is that the input IN (or output OUT) terminal and the output OUT (or input) terminal are connected between the ground GND terminal in comparison with the IDT pattern of FIG. 1. It is placed on the opposite side. The terminal arrangement on the ceramic package side corresponding to this is shown in Fig. 9B.

As described above, since the input IN terminal and the output OUT terminal are separated by the ground GND terminal, as shown in FIG. 8, the amount of out-of-pass band attenuation can be improved by reducing the coupling capacitance between the input and output. In addition, since the ground GND terminal separating the input IN terminal and the output OUT terminal does not need a space in which an additional GND terminal is provided as the GND terminal of the basic IDT pattern itself, it is possible to avoid an increase in the device configuration in plan.

Here, in the IDT patterns shown in Figs. 9A and 9B, in order to arrange the input IN terminal on the side opposite to the output OUT terminal with the ground GND terminal interposed, it is necessary to form the circumferential wiring 5. At this time, since the resistance value increases in signal transmission due to the length of the winding wire 5, it is preferable to form the winding wire 5 at a thick film to reduce the resistance value.

In addition, an embodiment of the surface acoustic wave device according to the present invention using the extended double mode SAW filter using the basic IDT pattern of the double mode SAW filter shown in Figs. 9A and 9B will be described below.

10A and 10B show a second embodiment, FIG. 10A shows an IDT pattern, and FIG. 10B shows an electrode arrangement on the ceramic package side on which flip chips are mounted.

In the second embodiment shown in Figs. 10A and 10B, the multimode SAW filter F1 at the front end and the multimode SAW filter F2 at the rear end are cascaded. The output terminal of the multimode SAW filter F1 at the front end is connected to the input terminal of the multimode SAW filter F2 at the rear end by the circumferential wiring 5. At this time, the arrangement of the input terminal and the output terminal is inversely related to the first embodiment of FIG. 9 with respect to the multi-mode SAW filter F2 at the rear stage.

In this second embodiment, as shown by the electrode arrangement pattern in the package of Fig. 10B, between the input IN terminal of the front-end multi-mode SAW filter F1 and the output OUT terminal of the rear-end multi-mode SAW filter F2. Since the ground GND terminal of the rear multi-mode SAW filter F2 is disposed, it is possible to arrange the ground GND terminal between input / output terminals in the surface acoustic wave device without expanding the planar space.

11A and 11B show a third embodiment, FIG. 11A shows an IDT pattern, and FIG. 11B shows an electrode arrangement on the ceramic package side on which flip chips are mounted.

11A and 11B, the IDT patterns of the multi-mode SAW filter F1 at the front stage and the multi-mode SAW filter F2 at the rear stage are the same as those in the embodiment of FIG. 9, respectively. The ground terminals GND1 and GND2 are arranged in front and back relationship and are cascaded by the circumferential wiring 5.

Accordingly, the input IN terminal of the front-end multi-mode SAW filter F1 and the output OUT terminal of the rear-end multi-mode SAW filter F2 are more firmly separated by the first ground terminal GND1 and the second ground terminal GND2. Therefore, it is possible to sufficiently avoid deterioration of the filter characteristic due to the capacity between input and output.

12A and 12B show a fourth embodiment, FIG. 12A shows an IDT pattern, and FIG. 12B shows an electrode arrangement on the ceramic package side on which flip chips are mounted.

In this embodiment, the multimode SAW filter Fa and Fb are connected in series so that the desired impedance (for example, 50 Ω) becomes the combined impedance of the first filter Fa and the second filter Fb.

Similarly to the first embodiment shown in FIG. 9A, the output OUT terminal is arranged on the side opposite to the input IN terminal by the circumferential wiring 5. As a result, the coupling capacity between the input and output of the surface acoustic wave device can be reduced.

In the present embodiment, when applied as a reception filter of a duplexer or an antenna filter, as shown in Japanese Patent Application No. 2004-252644 or Japanese Patent Application No. 2005-130988, the voltage applied to the IDT is distributed by multiple stages of serial connection. As the area is enlarged, the excitation intensity of the surface acoustic wave per unit area becomes small, and the intermodulation level can be suppressed. In addition, due to the dispersion of the voltage applied to the IDT, the electrostatic breakdown voltage (ESD) and the electric power resistance can be improved.

13A and 13B show a fifth embodiment, FIG. 13A shows an IDT pattern, and FIG. 13B shows an electrode arrangement on the ceramic package side on which flip chips are mounted.

This embodiment applies the fourth embodiment as a multi-mode SAW filter F1 at the front end in the second embodiment. At this time, the output of the front-end multi-mode SAW filter F1 is connected to the circumferential wiring 5 of the rear-end multi-mode SAW filter F2.

Also in this embodiment, as shown in Fig. 13B, the ground GND terminal of the rear-end multi-mode SAW filter F2 can be arranged between the input IN terminal and the output OUT terminal, thereby reducing the capacity between input and output. In addition, with respect to the front-end multi-mode SAW filter F1, as in the fourth embodiment, the excitation intensity of the surface acoustic wave per unit area is reduced by the expansion of the IDT area, and the effect of suppressing the intermodulation level is possible. Obtained.

14A and 14B show a sixth embodiment, FIG. 14A shows an IDT pattern, and FIG. 14B shows an electrode arrangement on the ceramic package side on which flip chips are mounted.

This embodiment has a configuration in which the structure shown in the fifth embodiment is connected in parallel. As in the other embodiment, the coupling capacity between the input and output of the surface acoustic wave device can be reduced, and the current can be distributed by parallel connection. As a result, an improvement in the power resistance can be expected. In FIG. 14A, although the front multi-mode SAW filter F1 is comprised in 4 parallel, and the rear multi-mode SAW filter F2 is comprised in 3 parallel, different numbers may be the same.

As shown in FIG. 14B, FIG. 14B showing the electrode arrangement on the ceramic package side is the same as FIG. 13B showing the electrode arrangement on the ceramic package side in the fifth embodiment.

15A and 15B show a seventh embodiment, FIG. 15A shows an IDT pattern, and FIG. 15B shows an electrode arrangement on the ceramic package side on which flip chips are mounted.

This embodiment is an example of a configuration in which the multi-mode SAW filters F1 and F2 are cascaded. The rear multi-mode SAW filter F2 is arranged in mirror symmetry, and even if cascaded, the ground GND pattern GND2 can be provided between the input IN terminal and the output OUT terminal pattern (see FIG. 15B) of the ceramic package. However, as described in Patent Document 1 (Japanese Patent Laid-Open No. 2004-194269), however, the insertion loss and the steepness (square) of rise between the transmitting side Tx band and the receiving side Rx band are greatly degraded.

Therefore, like the multi-mode SAW filter F1 at the front end, the input / output IDT is configured to be drawn from the same direction. As a result, insertion loss and square deterioration can be prevented, and the coupling capacitance between the input and output of the surface acoustic wave device can be reduced.

16A and 16B show an eighth embodiment, FIG. 16A shows an IDT pattern, and FIG. 16B shows an electrode arrangement on the ceramic package side for flip chip mounting.

This eighth embodiment is configured to have a balanced output OUT terminal for the multi-mode SAW filter F2 on the rear stage in the seventh embodiment. Since the ground GND terminal GND2 is disposed between the balanced output OUT terminal and the input IN terminal of the multi-mode SAW filter F1 at the front end, the coupling capacitance between the input and output of the surface acoustic wave device can be reduced.

Next, the effect in the application example of the surface acoustic wave device which applied this invention is demonstrated compared with a conventional structure.

17A and 17B correspond to the sixth embodiment shown in FIGS. 14A and 14B, and show a conventional configuration example in which the present invention is not applied to a multi-mode SAW filter F2 at a later stage. 17A shows an IDT pattern, and FIG. 17B shows an electrode arrangement on the ceramic package side on which flip chips are mounted.

Therefore, characteristics are compared between the sixth embodiment shown in FIGS. 14A and 14B and the configuration to which the present invention shown in FIGS. 17A and 17B is not applied.

18A shows a configuration example of the duplexer. Fig. 18B shows the isolation characteristics between transmission and reception when the sixth embodiment according to the present invention and the comparative example of Figs. 17A and 17B are used as the reception (Rx) filter of the PCS duplexer.

In the case of the antenna filter constituting the transmit filter 20 and the receive filter 30 in separate packages, the transmit Tx of the receive SAW filter is reduced by reducing the C _AR of the receive SAW filter Rx according to the present invention. Improving the amount of band attenuation leads to improvement of transmission (Tx) band isolation characteristics.

In the duplexer configured in the same package, the transmission Tx and reception Rx filter 20 and 30, in addition to inhibition of _AR C, a suppression effect on the transmission (Tx) band isolation characteristic C _TR. For this reason, it is desirable to provide a ground GND pattern between transmit Tx-receive Rx in the package.

As described above, as shown in Fig. 18B, the present invention was able to satisfy 55 kHz required for transmission Tx band isolation of the PCS duplexer.

In the sixth embodiment, the ground GND pattern effective for reducing the C _AR is used as the ground GND pattern for the reception (Rx) filter 30. Of course, it is also possible to use it for the transmission (Tx) filter 20, but it does not make it common.

The ground GND pattern provided between the pattern for the transmission (Tx) filter 20 and the pattern for the reception (Rx) filter effective for reducing the C _TR is the ground GND pattern for the reception (Rx) filter 30 and the transmission. The ground GND pattern for the (Tx) filter 20 is provided, and these are not shared.

However, it may be shared (conducted) in order to adjust the ground GND inductance. 19A is a block diagram of a configuration example of a PCS reception filter. Figure 19b is a view 14a, also in the sixth embodiment in which the characteristic variation value of ground GND inductances L ₁ ~L ₅ of the ceramic package 10 in the example shown in 14b (Korean PCS receiving filter). Since the attenuation band can be changed by changing the ground GND inductance, the attenuation amount can be secured even if the transmission Tx-receive Rx interval is changed (even if the system is changed).

According to the present invention, by providing the ground GND pattern between the input and output patterns, not only the surface layer or the inner layer of the package, the coupling capacity between the input and output of the package can be reduced, that is, the coupling capacity between the input and output of the surface acoustic wave device itself can be reduced. .

By this effect, deterioration of characteristics in flip chip mounting can be avoided, and the surface acoustic wave device having low loss and high attenuation characteristics can be provided even when flip chip mounting by the application of the present invention.

Claims (20)

A surface acoustic wave device comprising a surface acoustic wave filter having a comb-shaped electrode pattern formed on a piezoelectric element, wherein an electrode terminal for input / output of the surface acoustic wave filter is connected to a corresponding electrode pattern of a package through bumps, The comb-shaped electrode pattern has a pair of reflective electrodes, an input comb-shaped electrode and an output comb-shaped electrode disposed between the pair of reflective electrodes, The surface acoustic wave device of any one of the said comb-shaped electrode and the said output comb-shaped electrode is arrange | positioned so that it may be located on the opposite side to the electrode terminal of the other comb-shaped electrode with the ground electrode interposed using circumferential wiring. The method of claim 1, The surface acoustic wave device is a surface acoustic wave device which is a multi-mode surface acoustic wave filter using surface acoustic waves excited between the reflective electrodes and using a plurality of standing waves generated between the reflective electrodes. A first electrode and a second surface acoustic wave filter formed on the piezoelectric element and cascaded to each other, and the electrode terminals for input and output of the surface acoustic wave filter are connected to corresponding electrode patterns of the package through bumps. Surface acoustic wave device, The comb-shaped electrode patterns of the first and second surface acoustic wave filters each have a pair of reflection electrodes, an input comb electrode and an output comb electrode disposed between the pair of reflection electrodes, For each of the first and second surface acoustic wave filters, electrode terminals of the input and output comb-shaped electrodes are drawn out from the same side, The electrode terminal of the comb-shaped electrode for output (or input) of the first surface acoustic wave filter is connected to the electrode terminal of the comb-shaped electrode for input (or output) of the second surface acoustic wave filter using a circumferential wiring, 1. The surface acoustic wave device of the surface acoustic wave filter, wherein the electrode terminals of the input and output comb-shaped electrodes face the second surface acoustic wave filter with the ground terminal of the second surface acoustic wave filter interposed therebetween. A surface acoustic wave device comprising first and second surface acoustic wave filters cascaded to each other, wherein the electrode terminals for input and output of the surface acoustic wave filters are connected to corresponding electrode patterns of a package through bumps, The comb-shaped electrode patterns of the first and second surface acoustic wave filters each have a pair of reflection electrodes, an input comb electrode and an output comb electrode disposed between the pair of reflection electrodes, For each of the first and second surface acoustic wave filters, electrode terminals of the input and output comb-shaped electrodes are drawn out from the same side, The electrode terminal of the output of the first surface acoustic wave filter or the comb-shaped electrode for input is connected to the electrode terminal of the comb-shaped electrode of the input or output of the second surface acoustic wave filter using a circumferential wiring, A surface acoustic wave device configured to face a ground terminal and a ground terminal of the second surface acoustic wave filter. The method of claim 1, And the comb-shaped electrode pattern is formed by connecting two divided filters in series so as to obtain a desired impedance. The method of claim 3, And an electrode pattern of at least one surface acoustic wave filter of the first and second surface acoustic wave filters is configured by connecting two divided filters in series so as to obtain a desired impedance. The method of claim 4, wherein And an electrode pattern of at least one surface acoustic wave filter of the first and second surface acoustic wave filters is configured by connecting two divided filters in series so as to obtain a desired impedance. The method of claim 1, The surface acoustic wave device further comprising a plurality of surface acoustic wave filters connected in parallel. The method of claim 3, The surface acoustic wave device further comprising a plurality of surface acoustic wave filters connected in parallel. The method of claim 4, wherein The surface acoustic wave device further comprising a plurality of surface acoustic wave filters connected in parallel. The method of claim 1, A surface acoustic wave device as an input (or output) terminal of the surface acoustic wave filter is a balance input (or output). The method of claim 3, A surface acoustic wave device as an input (or output) terminal of the surface acoustic wave filter is a balance input (or output). The method of claim 4, wherein A surface acoustic wave device as an input (or output) terminal of the surface acoustic wave filter is a balance input (or output). The method of claim 1, The surface acoustic wave device of which the electrode pattern of the said package is an inductance component which comprises the said filter. The method of claim 3, The surface acoustic wave device of which the electrode pattern of the said package is an inductance component which comprises the said filter. The method of claim 4, wherein The surface acoustic wave device of which the electrode pattern of the said package is an inductance component which comprises the said filter. An antenna duplexer comprising the surface acoustic wave device of claim 1 as a transmission filter and / or a reception filter. An antenna duplexer comprising the surface acoustic wave device of claim 3 as a transmission filter and / or a reception filter. An antenna duplexer comprising the surface acoustic wave device of claim 4 as a transmission filter and / or a reception filter. The method of claim 17, And a ground pattern formed in the package between a transmission (Tx) signal electrode pattern connected to the transmission filter and a reception (Rx) signal electrode pattern connected to the reception filter.

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