JP2020155967A - Filter and multiplexer - Google Patents

Abstract

To allow for miniaturization.SOLUTION: A filter is provided that comprises: a first substrate having a first surface; a second substrate having a second surface opposite to the first surface with a gap interposed between the surfaces; a first series resonator which is provided in the first surface and in a first path between a first node and a second node; a first parallel resonator which is provided in the first surface, and in which one end is connected to the first path and the other end is connected to a ground; a second series resonator which is provided in the second surface, and in a second path connected to the first path in parallel between the first node and the second node, and which is at least partially overlapped with at least a part of the first series resonator in a plan view; and a second parallel resonator which is provided in the second surface, and in which one end is connected to the second path and the other end is connected to the ground, and which is at least partially overlapped with at least a part of the first parallel resonator in a plan view.SELECTED DRAWING: Figure 4

Description

The present invention relates to filters and multiplexers, for example, multiplexers having filters provided on a plurality of substrates.

It is known that two substrates on which filters are formed are mounted so that surfaces on which filters are formed face each other with a gap in between (for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2007-67617

If the two filters are provided so as to overlap each other in a plan view, the filters interfere with each other and the isolation characteristics deteriorate. If the two filters are provided so as not to overlap in a plan view, it becomes difficult to reduce the size. As described above, it is difficult to miniaturize the filter and the multiplexer.

The present invention has been made in view of the above problems, and an object of the present invention is to enable miniaturization.

The present invention includes a first substrate having a first surface, a second substrate having a second surface facing the first surface with a gap interposed therebetween, and a first node and a second node provided on the first surface. A first series resonator provided in the first path between the two, a first parallel resonator provided on the first surface, one end connected to the first path and the other end connected to the ground, and the above. The first series resonator is provided on the second surface and is provided in the second path connected in parallel to the first path between the first node and the second node, and at least a part thereof is provided in a plan view. A second series resonator that overlaps at least a part of the above, and a second series resonator provided on the second surface, one end connected to the second path and the other end connected to the ground, and at least a part of the first parallel resonance in a plan view. A filter comprising a second parallel resonator that overlaps at least a portion of the instrument.

In the above configuration, the first series resonator and the second series resonator are provided in the same number as one or more, respectively, and at least a part of the first or more second series resonators correspond to the corresponding first series. It overlaps with at least a part of the resonator in a plan view, and one or more of the first parallel resonator and the second parallel resonator are provided in the same number, respectively, and at least one of the one or more second parallel resonators. Each unit may be configured to overlap at least a part of the corresponding first parallel resonator in a plan view.

In the above configuration, the capacitance of the one or more second series resonators is substantially equal to the capacitance of the corresponding first series resonators, respectively, and the capacitance of the one or more second parallel resonators. Can be configured to be substantially equal to the capacitance of the corresponding first parallel resonator.

In the above configuration, the resonator is not connected between the first node and the input terminal, and the resonator is not connected between the second node and the output terminal.

The present invention includes a first substrate having a first surface, a second substrate having a second surface facing the first surface with a gap interposed therebetween, and a first node and a second node provided on the first surface. A first elastic wave resonator connected between the above and a first elastic wave resonator provided on the second surface and connected in parallel with the first elastic wave resonator between the first node and the second node in a plan view. A filter including at least a second elastic wave resonator that overlaps at least a part of the first elastic wave resonator.

In the above configuration, the capacitance of the first elastic wave resonator can be substantially equal to the capacitance of the second elastic wave resonator.

In the above configuration, a third elastic wave resonator provided on the first surface and connected between the third node and the fourth node, and the third node and the fourth node provided on the second surface. A fourth elastic wave resonator connected in parallel with the third elastic wave resonator between the nodes and at least a part of which overlaps with at least a part of the third elastic wave resonator in a plan view, the first node and The second node is provided in a series path between an input terminal and an output terminal, and the third node and the fourth node are connected in parallel with one end connected to the series path and the other end connected to the ground. It can be configured to be provided on the route.

The present invention is a multiplexer including the above filter.

The present invention comprises a first substrate having a first surface, a second substrate having a second surface facing the first surface with a gap interposed therebetween, and a common terminal and a first terminal provided on the first surface. A first series resonator provided in the first path between them, a first parallel resonator provided on the first surface, one end connected to the first path and the other end connected to the ground, and the first. It is provided on two surfaces, is provided on a second path connected in parallel to the first path between the common terminal and the first terminal, and at least a part of the first series resonator in a plan view is at least. A second series resonator that overlaps a part, and one end that is provided on the second surface and one end that is connected to the second path and the other end that is connected to the ground, and at least a part of the first parallel resonator in a plan view. A first filter including a second parallel resonator that overlaps at least a part, and a third series resonator provided on the first surface and provided in a third path between the common terminal and the second terminal. A third parallel resonator provided on the first surface, one end connected to the third path and the other end connected to the ground, and the common terminal and the second terminal provided on the second surface. A fourth series resonator provided in a fourth path connected in parallel with the third path and at least a part of which overlaps with at least a part of the third series resonator in a plan view, and the second. A fourth parallel resonator provided on the surface, one end of which is connected to the fourth path and the other end of which is connected to the ground, and at least a part of which overlaps with at least a part of the third parallel resonator in a plan view. , A multiplexer comprising a second filter having a pass band that does not overlap with the pass band of the first filter.

The present invention includes a first substrate having a first surface, a second substrate having a second surface facing the first surface with a gap interposed therebetween, and a first node and a second node provided on the first surface. The first elastic wave resonator connected between the two, and the first elastic wave resonator provided on the second surface and connected in parallel between the first node and the second node in a plan view. A first filter including at least a second elastic wave resonator that overlaps at least a part of the first elastic wave resonator, and a first filter connected between a common terminal and the first terminal, and the first surface. A third elastic wave resonator provided between the third node and the fourth node, and the third elastic wave resonator provided on the second surface between the third node and the fourth node. A fourth elastic wave resonator, which is connected in parallel with the elastic wave resonator and at least a part of which overlaps with at least a part of the third elastic wave resonator in a plan view, is provided between the common terminal and the second terminal. It is a multiplexer provided with a second filter which is connected to and has a passing band which does not overlap with the passing band of the first filter.

According to the present invention, miniaturization can be made possible.

FIG. 1 is a circuit diagram of a multiplexer according to the first embodiment. FIG. 2 is a cross-sectional view of the multiplexer according to the first embodiment. FIG. 3A is a plan view of the elastic wave resonator, and FIG. 3B is a cross-sectional view of the elastic wave resonator. 4 (a) and 4 (b) are plan views of the substrates 10 and 20, respectively, in the first embodiment. FIG. 5 is a circuit diagram of the multiplexer according to Comparative Example 1. FIG. 6 is a plan view of the substrate in Comparative Example 1. FIG. 7 is a circuit diagram of the multiplexer according to the second embodiment. FIG. 8 is a cross-sectional view of the multiplexer according to the second embodiment. 9 (a) and 9 (b) are plan views of the substrates 10 and 20, respectively, in the second embodiment. FIG. 10 is a circuit diagram of the filter according to the third embodiment. 11 (a) and 11 (b) are plan views of the substrates 10 and 20, respectively, in the third embodiment. FIG. 12 is a circuit diagram of the filter according to the fourth embodiment. 13 (a) and 13 (b) are plan views of the substrates 10 and 20, respectively, in the fourth embodiment. FIG. 14 is a circuit diagram of the filter according to the fifth embodiment.

Hereinafter, examples of the present invention will be described with reference to the drawings.

FIG. 1 is a circuit diagram of a multiplexer according to the first embodiment. As shown in FIG. 1, a transmission filter 50 is connected between the common terminal Ant and the transmission terminal Tx. A reception filter 52 is connected between the common terminal Ant and the reception terminal Rx. The pass band of the transmission filter 50 and the pass band of the reception filter 52 do not overlap. The transmission filter 50 outputs a signal in the transmission band among the high frequency signals input to the transmission terminal Tx to the common terminal Ant, and suppresses signals in other frequency bands. The reception filter 52 outputs a signal in the reception band among the high frequency signals input to the common terminal Ant to the reception terminal Rx, and suppresses signals of other frequencies.

The transmission filter 50 is a ladder type filter. In the transmission filter 50, nodes N1 and N2a are provided in a series path between the common terminal Ant and the transmission terminal Tx. Subfilters 50a and 50b are connected in parallel between the nodes N1 and N2a. The sub-filter 50a includes series resonators S11a to S14a connected in series between the nodes N1 and N2a, and parallel resonators P11a to P14a connected in parallel between the nodes N1 and N2a. The sub-filter 50b includes series resonators S11b to S14b connected in series between the nodes N1 and N2a, and parallel resonators P11b to P14b connected in parallel between the nodes N1 and N2a. Two resonators are connected in series in the series resonators S11a to S14a, S11b to S14b, and the parallel resonators P14a and P14b, respectively.

The sub-filters 50a and 50b are provided mirror-symmetrically with respect to the nodes N1, N2a and the ground terminal Tg. That is, the series resonators S11a to S14a and the parallel resonators P11a to P14a, the series resonators S11b to S14b, and the parallel resonators P11b and P14b are provided in the same number, and the corresponding resonators have substantially the same characteristics. For example, the corresponding resonators have substantially the same capacitance, approximately the same resonance frequency, and approximately the same antiresonance frequency.

The reception filter 52 is a ladder type filter. In the reception filter 52, nodes N1 and N2b are provided in a series path between the common terminal Ant and the reception terminal Rx. Subfilters 52a and 52b are connected in parallel between the nodes N1 and N2b. The sub-filter 52a includes series resonators S21a to S24a connected in series between the nodes N1 and N2b, and parallel resonators P21a to P24a connected in parallel between the nodes N1 and N2b. The sub-filter 52b includes series resonators S21b to S24b connected in series between the nodes N1 and N2b, and parallel resonators P21b to P24b connected in parallel between the nodes N1 and N2b. In the series resonators S21a to S24a, S21b to S24b, and the parallel resonators P24a and P24b, two resonators are connected in series. The sub-filters 52a and 52b are provided mirror-symmetrically with respect to the nodes N1 and N2b and the ground terminal Tg.

The input / output impedance of the sub-filters 50a and 50b is twice the input / output impedance of the transmission filter 50. The input / output impedance of the sub-filters 52a and 52b is twice the input / output impedance of the reception filter 52. For example, when the input / output impedance of the transmission filter 50 is 50Ω, the input / output impedance of the subfilters 50a and 50b is 100Ω.

FIG. 2 is a cross-sectional view of the multiplexer according to the first embodiment. As shown in FIG. 2, the substrate 20 is mounted on the substrate 10. The substrate 10 has a support substrate 10a and a piezoelectric substrate 10b bonded onto the support substrate 10a. The substrate 20 has a support substrate 20a and a piezoelectric substrate 20b bonded onto the support substrate 20a. The support substrates 10a and 20a are, for example, a sapphire substrate, a spinel substrate, an alumina substrate, a crystal substrate, or a silicon substrate. The piezoelectric substrates 10b and 20b are, for example, a lithium tantalate substrate or a lithium niobate substrate.

An elastic wave resonator 12 and a wiring 14 are provided on the upper surface of the substrate 10. A terminal 18 is provided on the lower surface of the substrate 10. The terminal 18 is a foot pad for connecting the elastic wave resonators 12 and 22 to the outside. The via wiring 16 is provided so as to penetrate the substrate 10. The via wiring 16 electrically connects the wiring 14 and the terminal 18. The wiring 14, the via wiring 16, and the terminal 18 are metal layers such as a copper layer, an aluminum layer, or a gold layer. The terminal 18 includes a common terminal Ant, a transmission terminal Tx, a reception terminal Rx, and a ground terminal Tg.

An elastic wave resonator 22 and wiring 24 are provided on the lower surface of the substrate 20. The wiring 24 is a metal layer such as a copper layer, an aluminum layer or a gold layer. The wiring 14 of the substrate 10 and the wiring 24 of the substrate 20 are joined via bumps 26. The upper surface of the substrate 10 and the lower surface of the substrate 20 face each other through the gap 28. A sealing portion 30 is provided between the substrates 10 and 20 so as to surround the elastic wave resonators 12, 22 and the wirings 14 and 24. The sealing portion 30 seals the elastic wave resonators 12 and 22 in the gap 28.

Examples of elastic wave resonators 12 and 22 will be described. FIG. 3A is a plan view of the elastic wave resonator, and is an example of the elastic surface wave resonator as the elastic wave resonators 12 and 22. As shown in FIG. 3A, an IDT (Interdigital Transducer) 42 and a reflector 41 are formed on the piezoelectric substrates 10b and 20b of the substrates 10 and 20. The IDT 42 has a pair of comb-shaped electrodes 42d facing each other. The comb-shaped electrode 42d has a plurality of electrode fingers 42a and a bus bar 42c connecting the plurality of electrode fingers 42a. Reflectors 41 are provided on both sides of the IDT 42. IDT42 excites surface acoustic waves on the substrate 10. The IDT 42 and the reflector 41 are formed of, for example, an aluminum film or a copper film. As shown in FIG. 2, the piezoelectric substrates 10b and 20b may be bonded to the support substrates 10a and 20a, respectively, or the support substrates 10a and 20a are not provided, and the substrates 10 and 20 are the piezoelectric substrates 10b and 20b, respectively. May be a single unit. An insulating film such as a silicon oxide film or an aluminum oxide film may be provided between the support substrates 10a and 20a and the piezoelectric substrates 10b and 20b, respectively. A protective film or a temperature compensation film may be provided on the substrates 10 and 20 so as to cover the IDT 42 and the reflector 41.

FIG. 3B is a cross-sectional view of the elastic wave resonator, and is an example of the piezoelectric thin film resonator as the elastic wave resonators 12 and 22. As shown in FIG. 3B, the elastic wave resonators 12 and 22 are piezoelectric thin film resonators. Piezoelectric films 46 are provided on the substrates 10 and 20. The lower electrode 45 and the upper electrode 47 are provided so as to sandwich the piezoelectric film 46. A gap 49 is formed between the lower electrode 45 and the substrates 10 and 20. The region where the lower electrode 45 and the upper electrode 47 face each other with at least a part of the piezoelectric film 46 sandwiched is the resonance region 48. The lower electrode 45 and the upper electrode 47 in the resonance region 48 excite elastic waves in the thickness longitudinal vibration mode in the piezoelectric film 46. The substrates 10 and 20 are, for example, a sapphire substrate, a spinel substrate, an alumina substrate, a glass substrate, a crystal substrate, or a silicon substrate. The lower electrode 45 and the upper electrode 47 are metal films such as a ruthenium film. The piezoelectric film 46 is, for example, an aluminum nitride film. An acoustic reflection film that reflects elastic waves may be provided instead of the void 49.

Elastic wave resonators 12 and 22 include electrodes that excite elastic waves. Therefore, the elastic wave resonators 12 and 22 are covered with the gap 28 so as not to hinder the excitation of the elastic wave.

4 (a) and 4 (b) are plan views of the substrates 10 and 20, respectively, in the first embodiment. FIG. 4B is a perspective view of the lower surface of the substrate 20 from above. As shown in FIG. 4A, an elastic wave resonator 12 and wiring 14 are provided on the upper surface of the substrate 10. The surface acoustic wave resonator 12 is an elastic surface wave resonator having an IDT 42 and a reflector 41. The wiring 14 is connected to the elastic wave resonator 12. A sealing portion 30 is provided on the peripheral edge of the substrate 10. The elastic wave resonator 12 includes series resonators S11a to S14a, S21a to S24a, parallel resonators P11a to P14a, and P21a to P24a. The wiring 14 includes pads Pa1, Pt1, Pr1 and Pg1. The pads Pa1, Pt1, Pr1 and Pg1 are electrically connected to the common terminal Ant, the transmission terminal Tx, the reception terminal Rx and the ground terminal Tg, respectively, via the via wiring 16.

As shown in FIG. 4B, an elastic wave resonator 22 and a wiring 24 are provided on the upper surface of the substrate 20. The surface acoustic wave resonator 22 is an elastic surface wave resonator having an IDT 42 and a reflector 41. The wiring 24 is connected to the elastic wave resonator 22. A sealing portion 30 is provided on the peripheral edge of the substrate 20. The elastic wave resonator 22 includes series resonators S11b to S14b, S21b to S24b, parallel resonators P11b to P14b, and P21b to P24b. The wiring 24 includes pads Pa2, Pt2, Pr2 and Pg2. The pads Pa2, Pt2, Pr2 and Pg2 are electrically connected to the pads Pa1, Pt1, Pr1 and Pg1 via bumps 26, respectively. Pads Pa1 and Pa2 correspond to node N1, pads Pt1 and Pt2 correspond to node N2a, and pads Pr1 and Pr2 correspond to node N2b.

The series resonators S11a to S14a, S21a to S24a, the parallel resonators P11a to P14a and P21a to P24a overlap with the series resonators S11b to S14b, S21b to S24b, and the parallel resonators P11b to P14b and P21b to P24b, respectively. ing.

[Comparative Example 1]
FIG. 5 is a circuit diagram of the multiplexer according to Comparative Example 1. As shown in FIG. 5, the transmitting filter 50 includes series resonators S11 to S14 and parallel resonators P11 to P14, and the receiving filter 52 includes series resonators S21 to S24 and parallel resonators P21 to P24. The transmission filter 50 and the reception filter 52 do not include a sub-filter as in the first embodiment. Other configurations are the same as in the first embodiment.

FIG. 6 is a plan view of the substrate in Comparative Example 1. The elastic wave resonator 12 includes series resonators S11 to S14, S21 to S24, parallel resonators P11 to P14, and P21 to P24. Wiring 14 includes pads Pa, Pt, Pr and Pg. The pads Pa, Pt, Pr and Pg are electrically connected to the common terminal Ant, the transmission terminal Tx, the reception terminal Rx and the ground terminal Tg, respectively, via the via wiring 16.

When the pass bands of the transmission filter 50 and the reception filter 52 do not overlap, if the transmission filter 50 and the reception filter 52 face each other via the gap 28, a high frequency signal is generated between the transmission filter 50 and the reception filter 52 via the gap 28. Isolation characteristics deteriorate due to leakage. Therefore, if the transmission filter 50 and the reception filter 52 are provided on the same substrate 10 as in Comparative Example 1, the chip size of the substrate 10 becomes large.

As in the first embodiment, the transmission filter 50 is divided into the sub-filters 50a and 50b in parallel, and the reception filter 52 is divided into the sub-filters 52a and 52b in parallel. The corresponding resonators face each other via the gap 28. Almost the same voltage is applied to the corresponding resonators. Therefore, even if the corresponding resonators are overlapped with each other, leakage of the high frequency signal can be suppressed, and the size can be reduced without deteriorating the isolation characteristics. In one example, the size of the substrate 10 of Comparative Example 1 is 1.5 mm × 0.9 mm, and the size of the substrate 10 of Example 1 is 1.2 mm × 0.7 mm.

According to the transmission filter 50 (first filter) of the first embodiment, as shown in FIG. 1, the node N1 (first) is located between the common terminal Ant (output terminal) and the transmission terminal Tx (input terminal, first terminal). Node) and N2a (second node) are provided. The series resonators S11a to S14a (first series resonator) are provided in the series path (first path) between the nodes N1 and N2a, and the parallel resonators P11a and P14a (first parallel resonator) have one end in series. It is connected to the path and the other end is connected to the ground. The series resonators S11b to S14b (second series resonator) are provided in the series path between the nodes N1 and N2a (the second path connected in parallel with the first path), and the parallel resonators P11b and P14b (the first). The two parallel resonators) have one end connected to the series path and the other end connected to the ground.

As shown in FIGS. 4A and 4B, the series resonators S11a to S14a and the parallel resonators P11a and P14a are provided on the upper surface (first surface) of the substrate 10 (first substrate). The series resonators S11b to S14b and the parallel resonators P11b and P14b are provided on the lower surface (second surface) of the substrate 20 (second substrate).

At least a part of each of the series resonators S11a to S14a overlaps with at least a part of each of the series resonators S11b to S14b in a plan view, and at least a part of each of the parallel resonators P11a to P14a is a parallel resonator P11b to P14b. It overlaps with at least a part of each of the above in a plan view. As a result, interference of high-frequency signals in the transmission filter 50 is suppressed, and miniaturization becomes possible.

The overlap of the surface acoustic wave resonators 12 and 22 means that at least a part of the IDT 42 and the reflector 41 of FIG. 3 (a) overlap each other in the case of the surface acoustic wave resonator, and in the case of the piezoelectric thin film resonator. , At least a part of the resonance region 48 of FIG. 3B overlaps.

One or more series resonators S11a to S14a and series resonators S11b to S14b are provided in the same number, respectively, and at least a part of the series resonators S11b to S14b and at least a part of the corresponding series resonators S11a to S14a, respectively. Overlap in plan view. One or more parallel resonators P11a to P14a and parallel resonators P11b to P14b are provided in the same number, respectively, and at least a part of the parallel resonators P11b to P14b and at least a part of the corresponding parallel resonators P11a to P14a. Overlap in plan view. As a result, the voltage applied to the corresponding resonator becomes almost the same, and the interference of the high frequency signal in the filter is suppressed.

The capacitance of each of the one or more series resonators S11a to S14a is substantially equal to the capacitance of the corresponding series resonators S11b to S14b to a degree of manufacturing error. The capacitance of each of the one or more parallel resonators P11a to P14a is substantially equal to the capacitance of the corresponding parallel resonators P11b to P14b to a degree of manufacturing error. As a result, the voltage applied to the corresponding resonator becomes almost the same, and the interference of the high frequency signal in the filter is suppressed.

No resonator is connected between the node N1 and the common terminal Ant, and no resonator is connected between the node 2a and the transmission terminal Tx. This makes it possible to further reduce the size.

In the reception filter 52 (second filter), nodes N1 (third node) and N2b (fourth node) are provided between the common terminal Ant and the reception terminal Rx (second terminal). The series resonators S21a to S24a (third series resonator) are provided in the series path (third path) between the nodes N1 and N2b, and the parallel resonators P21a and P24a (third parallel resonator) are in series at one end. It is connected to the path and the other end is connected to the ground. The series resonators S21b to S24b (fourth series resonator) are provided in the series path (fourth path connected in parallel to the third path) between the nodes N1 and N2b, and the parallel resonators P21b and P24b (third). The four parallel resonators) have one end connected to the series path and the other end connected to the ground.

The series resonators S21a to S24a and the parallel resonators P21a and P24a are provided on the upper surface of the substrate 10. The series resonators S21b to S24b and the parallel resonators P21b and P24b are provided on the lower surface of the substrate 20. At least a part of each of the series resonators S21a to S24a overlaps with at least a part of each of the series resonators S21b to S24b in a plan view, and at least a part of each of the parallel resonators P21a to P24a is a parallel resonator P21b to P24b. It overlaps with at least a part of each of the above in a plan view. As a result, the isolation between the transmission filter 50 and the reception filter 52 can be suppressed and the size can be reduced.

FIG. 7 is a circuit diagram of the multiplexer according to the second embodiment. As shown in FIG. 7, in the transmission filter 50, nodes N11 and N12 are provided in a series path between the common terminal Ant and the transmission terminal Tx. The series resonators S11a and S11b are connected in parallel between the nodes N11 and N12. Nodes N13 and N14 are provided in a parallel path in which one end is connected to a series path and the other end is connected to the ground. The parallel resonators P11a and P11b are connected in parallel between the nodes N13 and N14. Similarly, the series resonators S12a to S14a and S12b to S14b are connected in parallel between the nodes provided in the series path. The parallel resonators P12a to P14a and P12b to P14b are connected in parallel between the nodes provided in the parallel path.

In the reception filter 52, nodes N21 and N22 are provided in a series path between the common terminal Ant and the reception terminal Rx. The series resonators S21a and S21b are connected in parallel between the nodes N21 and N22. Nodes N23 and N24 are provided in a parallel path in which one end is connected to a series path and the other end is connected to the ground. The parallel resonators P21a and P21b are connected in parallel between the nodes N23 and N24. Similarly, the series resonators S22a to S24a and S22b to S24b are connected in parallel between the nodes provided in the series path. The parallel resonators P22a to P24a and P22b to P24b are connected in parallel between the nodes provided in the parallel path. Other configurations are the same as those in FIG. 1 of the first embodiment, and the description thereof will be omitted.

FIG. 8 is a cross-sectional view of the multiplexer according to the second embodiment. As shown in FIG. 8, the bump 26 is not provided, and the wirings 14 and 24 are joined. Other configurations are the same as those in FIG. 2 of the first embodiment, and the description thereof will be omitted.

9 (a) and 9 (b) are plan views of the substrates 10 and 20, respectively, in the second embodiment. FIG. 9B is a perspective view of the lower surface of the substrate 20 from above. As shown in FIGS. 9A and 9B, the bump 26 is not provided, and the wirings 14 and 24 are connected. As a result, as shown in FIG. 7, the corresponding resonators are connected in parallel. Other configurations are the same as those in FIGS. 4 (a) and 4 (b) of the first embodiment, and the description thereof will be omitted.

According to the transmission filter 50 (first filter) of the second embodiment, as shown in FIG. 7, the series resonator S11a (first elastic wave resonator) has a transmission terminal Tx (input terminal) and a common terminal Ant (output terminal). ) Is connected between the nodes N11 and N12 provided in the series path, and the series resonator S11b (second elastic wave resonator) is connected in parallel with the series resonator S11a between the nodes N11 and N12. Has been done. As shown in FIGS. 9 (a) and 9 (b), the series resonator S11a is provided on the upper surface (first surface) of the substrate 10 (first substrate), and the series resonator S11b is the substrate 20 (second substrate). It is provided on the lower surface (second surface) of the. At least a portion of the series resonator S11b overlaps at least a portion of the series resonator S11a in plan view. As a result, interference of high-frequency signals in the transmission filter 50 is suppressed, and miniaturization becomes possible.

The capacitance of the series resonator S11a is substantially equal to the capacitance of the series resonator S11b and the manufacturing error. As a result, the voltage applied to the corresponding resonator becomes almost the same, and the interference of the high frequency signal in the filter is suppressed.

The parallel resonator P11a (third elastic wave resonator) is connected between the nodes N13 and N14 provided in the parallel path, and the parallel resonator P11b (fourth elastic wave resonator) is connected to the nodes N13 and N14. It is connected in parallel with the parallel resonator P11a between them. The parallel resonator P11a is provided on the upper surface of the substrate 10, and the parallel resonator P11b is provided on the lower surface of the substrate 20. At least a portion of the parallel resonator P11b overlaps at least a portion of the parallel resonator P11a in plan view. As a result, the interference of the high frequency signal in the transmission filter 50 is further suppressed, and the size can be further reduced.

In the receiving filter 52 (second filter), the series resonator S21a (third elastic wave resonator) is connected between the nodes N21 (third node) and N22 (fourth node), and the series resonator S21b ( The second elastic wave resonator) is connected in parallel with the series resonator S21a between the nodes N21 and N22. The series resonator S21a is provided on the upper surface of the substrate 10, and the series resonator S21b is provided on the lower surface of the substrate 20. At least a portion of the series resonator S21b overlaps at least a portion of the series resonator S21a in plan view. As a result, the isolation between the transmission filter 50 and the reception filter 52 can be suppressed and the size can be reduced.

FIG. 10 is a circuit diagram of the filter according to the third embodiment. As shown in FIG. 10, in the filter 54, nodes N1 and N2 are provided in a series path between the input terminal Tin and the output terminal Tout. The subfilters 54a and 54b are connected in parallel between the nodes N1 and N2. The sub-filter 54a includes series resonators S1a to S6a and parallel resonators P1a to P6a. The subfilter 54b includes series resonators S1b to S6b and parallel resonators P1b to P6b. The sub-filters 54a and 54b are provided mirror-symmetrically with respect to the nodes N1, N2 and the ground terminal Tg. Other configurations are the same as those in FIG. 1 of the first embodiment, and the description thereof will be omitted.

11 (a) and 11 (b) are plan views of the substrates 10 and 20, respectively, in the third embodiment. FIG. 11B is a perspective view of the lower surface of the substrate 20 from above. As shown in FIG. 11A, the elastic wave resonator 12 includes series resonators S1a to S6a and parallel resonators P1a to P6a. Wiring 14 includes pads Pin1, Pout1 and Pg1. The pads Pin1, Pout1 and Pg1 are electrically connected to the input terminal Tin, the output terminal Tout and the ground terminal Tg via the via wiring 16, respectively.

As shown in FIG. 11B, the elastic wave resonator 22 includes series resonators S1b to S6b and parallel resonators P1b to P6b. The wiring 24 includes pads Pin2, Pin2 and Pg2. The pads Pin2, Pout2 and Pg2 are electrically connected to the pads Pin1, Pout1 and Pg1 via bumps 26, respectively. The series resonators S1a to S6a and the parallel resonators P1a to P6a overlap the series resonators S1b to S6b and the parallel resonators P1b to P6b in a plan view, respectively. Other configurations are the same as those in FIGS. 4 (a) and 4 (b) of the first embodiment.

As in the third embodiment, the filter 54 may be divided into sub-filters 54a and 54b in parallel, and the corresponding resonators may be overlapped in a plan view. As a result, interference of high frequency signals in the filter 54 can be suppressed and the filter 54 can be miniaturized.

FIG. 12 is a circuit diagram of the filter according to the fourth embodiment. As shown in FIG. 12, in the filter 56, the node N1 is provided in the middle of the series path between the input terminal Tin and the output terminal Tout. The subfilters 56a and 56b are connected in parallel between the nodes N1 and N2. The series resonators S1 and S2 and the parallel resonators P1 and P2 are connected between the input terminal Tin and the node N1. The subfilter 56a includes series resonators S3a and S4a and parallel resonators P3a and P4a. The subfilter 56b includes series resonators S3b and S4b and parallel resonators P3b and P4b. The sub-filters 56a and 56b are provided mirror-symmetrically with respect to the nodes N1, N2 and the ground terminal Tg. Other configurations are the same as those in FIG. 10 of the third embodiment, and the description thereof will be omitted.

13 (a) and 13 (b) are plan views of the substrates 10 and 20, respectively, in the fourth embodiment. FIG. 13B is a perspective view of the lower surface of the substrate 20 from above. As shown in FIG. 13A, the elastic wave resonator 12 includes series resonators S1, S2, S3a, S4a and parallel resonators P1, P2, P3a and P4a. The wiring 14 includes pads Pin1, Pout1, Pn1 and Pg1. The pads Pin1, Pout1 and Pg1 are electrically connected to the input terminal Tin, the output terminal Tout and the ground terminal Tg via the via wiring 16, respectively.

As shown in FIG. 13B, the elastic wave resonator 22 includes series resonators S3b and S4b and parallel resonators P3b and P4b. The wiring 24 includes pads Pin2, Pout2, Pn2 and Pg2. The pads Pin2, Pout2, Pn2 and Pg2 are electrically connected to the pads Pin1, Pout1, Pn1 and Pg1 via bumps 26, respectively. The series resonators S3a and S4a and the parallel resonators P3a and P4a overlap in plan view with the series resonators S3b and S4b and the parallel resonators P3b and P4b, respectively. Other configurations are the same as those in FIGS. 11 (a) and 11 (b) of the third embodiment, and the description thereof will be omitted.

As in the fourth embodiment, a part of the filter 56 may be divided in parallel into the sub-filters 56a and 56b, and the corresponding resonators may be overlapped in a plan view. As a result, the filter 54 can be miniaturized. Also in the multiplexer, a part of at least one of the transmission filter 50 and the reception filter 52 may be divided in parallel into the sub-filter, and the corresponding resonators may be superimposed.

FIG. 14 is a circuit diagram of the filter according to the fifth embodiment. As shown in FIG. 14, the series resonators S1 and S2 and the parallel resonators P1 and P2 are connected between the input terminal Tin and the node N1. The series resonators S3a and S3b are connected in parallel, the series resonators S4a and S4b are connected in parallel, the parallel resonators P3a and P3b are connected in parallel, and the parallel resonators P4a and P4b are connected in parallel. The series resonators S3a and S4a and the parallel resonators P3a and P4a overlap in plan view with the series resonators S3b and S4b and the parallel resonators P3b and P4b, respectively. Other configurations are the same as in Examples 2 and 4.

As in the fifth embodiment, at least a part of the filter 56 may be connected in parallel for each resonator, and the remaining resonators may not be connected in parallel. This enables miniaturization.

As in the fifth embodiment, in the filter, each resonator may be connected in parallel and the corresponding resonators may be overlapped. In the multiplexer, at least one of the resonators of the transmission filter 50 and the reception filter 52 may be connected in parallel and the corresponding resonators may be superposed.

The number of series resonators and parallel resonators of each filter in Examples 1 to 5 can be appropriately set. At least a part of the filter may be a multiple mode filter. The elastic wave resonators 12 and 22 may be piezoelectric thin film resonators as shown in FIG. 3 (b). Although the duplexer has been described as an example in Examples 1 and 2, the multiplexer may be a triplexer or a quadplexer.

Although the examples of the present invention have been described in detail above, the present invention is not limited to such specific examples, and various modifications and modifications are made within the scope of the gist of the present invention described in the claims. It can be changed.

10, 20 Substrate 12, 22 Elastic wave resonator 14, 24 Wiring 26 Bump 28 Void 50 Transmission filter 50a, 50b, 52a, 52b, 54a, 54b Subfilter 52 Reception filter 54, 56 filter

Claims (10)

A first substrate having a first surface and
A second substrate having a second surface facing the first surface with a gap in between,
A first series resonator provided on the first surface and provided in the first path between the first node and the second node,
A first parallel resonator provided on the first surface, one end connected to the first path and the other end connected to the ground.
It is provided on the second surface and is provided on the second path connected in parallel to the first path between the first node and the second node, and at least a part thereof is the first series resonance in a plan view. A second series resonator that overlaps at least part of the instrument,
A second parallel resonator provided on the second surface, one end connected to the second path and the other end connected to the ground, and at least part of which overlaps at least part of the first parallel resonator in a plan view. ,
Filter with. The first series resonator and the second series resonator are provided in the same number as one or more, respectively, and at least a part of the one or more second series resonators is at least one of the corresponding first series resonators. It overlaps with a part in a plan view,
The first parallel resonator and the second parallel resonator are provided in the same number as one or more, respectively, and at least a part of the one or more second parallel resonators is at least one of the corresponding first parallel resonators. The filter according to claim 1, which overlaps a part in a plan view. The capacitance of the one or more second series resonators is approximately equal to the capacitance of the corresponding first series resonator, respectively.
The filter according to claim 2, wherein the capacitance of the one or a plurality of second parallel resonators is substantially equal to the capacitance of the corresponding first parallel resonator. The invention according to any one of claims 1 to 3, wherein the resonator is not connected between the first node and the input terminal, and the resonator is not connected between the second node and the output terminal. Filter. A first substrate having a first surface and
A second substrate having a second surface facing the first surface with a gap in between,
A first elastic wave resonator provided on the first surface and connected between the first node and the second node,
It is provided on the second surface and is connected in parallel with the first elastic wave resonator between the first node and the second node, and at least a part of the first elastic wave resonator in a plan view is at least one of the first elastic wave resonators. The second elastic wave resonator that overlaps the part,
Filter with. The filter according to claim 5, wherein the capacitance of the first elastic wave resonator is substantially equal to the capacitance of the second elastic wave resonator. A third elastic wave resonator provided on the first surface and connected between the third node and the fourth node,
It is provided on the second surface and is connected in parallel with the third elastic wave resonator between the third node and the fourth node, and at least a part of the third elastic wave resonator in a plan view is at least one of the third elastic wave resonators. The fourth elastic wave resonator that overlaps the part,
The first node and the second node are provided in a series path between an input terminal and an output terminal.
The filter according to claim 5 or 6, wherein the third node and the fourth node are provided in a parallel path in which one end is connected to the series path and the other end is connected to the ground. A multiplexer including the filter according to any one of claims 1 to 7. A first substrate having a first surface and
A second substrate having a second surface facing the first surface with a gap in between,
A first series resonator provided on the first surface and provided in the first path between the common terminal and the first terminal,
A first parallel resonator provided on the first surface, one end connected to the first path and the other end connected to the ground.
The first series resonator is provided on the second surface and is provided in a second path connected in parallel to the first path between the common terminal and the first terminal, and at least a part thereof is provided in a plan view. A second series resonator that overlaps at least part of
A second parallel resonator provided on the second surface, one end connected to the second path and the other end connected to the ground, and at least part of which overlaps at least part of the first parallel resonator in a plan view. The first filter with, and
A third series resonator provided on the first surface and provided in the third path between the common terminal and the second terminal,
A third parallel resonator provided on the first surface, one end connected to the third path and the other end connected to the ground.
The third series resonator is provided on the second surface and is provided in a fourth path connected in parallel to the third path between the common terminal and the second terminal, and at least a part thereof is provided in a plan view. With a fourth series resonator that overlaps at least part of
A fourth parallel resonator provided on the second surface, one end connected to the fourth path and the other end connected to the ground, and at least part of which overlaps at least part of the third parallel resonator in a plan view. A second filter having a pass band that does not overlap with the pass band of the first filter.
A multiplexer equipped with. A first substrate having a first surface and
A second substrate having a second surface facing the first surface with a gap in between,
Between the first elastic wave resonator provided on the first surface and connected between the first node and the second node, and between the first node and the second node provided on the second surface. A second elastic wave resonator, which is connected in parallel with the first elastic wave resonator and at least partially overlaps with at least a part of the first elastic wave resonator in a plan view, is provided with a common terminal and a first terminal. The first filter connected between and
A third elastic wave resonator provided on the first surface and connected between the third node and the fourth node, and between the third node and the fourth node provided on the second surface. A fourth elastic wave resonator, which is connected in parallel with the third elastic wave resonator and at least partially overlaps with at least a part of the third elastic wave resonator in a plan view, is provided with the common terminal and a second elastic wave resonator. A second filter connected between the terminals and having a pass band that does not overlap with the pass band of the first filter,
A multiplexer equipped with.

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