Elastic wave device

Abstract

This invention provides an elastic wave device capable of improving heat dissipation. The elastic wave device includes: an encapsulation substrate having first and second main surfaces; an elastic wave element disposed on the first main surface; a sealing resin layer configured to cover at least a portion of the elastic wave element; and a shielding film configured to cover the sealing resin layer, and is a metal film. The encapsulation substrate includes: a ground connection electrode disposed within the encapsulation substrate, electrically connected to the elastic wave element, and connected to a ground potential. The encapsulation substrate has: a side surface; and a connecting portion connected to at least a portion of the end edge of the second main surface side and at least a portion of the outer periphery of the second main surface. The shielding film reaches the side surface of the encapsulation substrate but does not reach the connecting portion, and the shielding film is connected to the ground connection electrode.

Description

Technical Field

[0001] This invention relates to elastic wave devices. Background Technology

[0002] Previously, elastic wave devices were widely used in filters for portable telephones, etc. Patent Document 1 discloses an example of a filter having a piezoelectric thin-film resonator utilizing elastic waves. In this filter, a filter chip is flip-chip mounted on a substrate. A sealing portion is provided on the substrate. The filter chip is surrounded by the sealing portion. The sealing portion is covered by a protective film. The protective film is a metal film or an insulating film. Through-hole wiring and a metal layer are provided within the substrate. The filter is electrically connected to the outside via the through-hole wiring and the metal layer.

[0003] Prior art literature

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2018-093388

[0006] In the filter described in Patent Document 1, via wiring and metal layers within the substrate serve as heat dissipation paths for heat generated within the filter. However, the heat dissipation in this filter is insufficient. Summary of the Invention

[0007] The problem the invention aims to solve

[0008] The purpose of this invention is to provide an elastic wave device that can improve heat dissipation.

[0009] Technical solutions for solving the problem

[0010] In a broad aspect of the elastic wave device of the present invention, a package substrate is provided, comprising: an encapsulation substrate having a first main surface and a second main surface opposed to each other; an elastic wave element disposed on the first main surface of the encapsulation substrate; a sealing resin layer disposed on the first main surface of the encapsulation substrate such that it covers at least a portion of the elastic wave element; and a shielding film disposed to cover the sealing resin layer and being a metal film. The encapsulation substrate includes: a ground connection electrode disposed within the encapsulation substrate, electrically connected to the elastic wave element, and connected to a ground potential. The encapsulation substrate has: a side surface connected to the first main surface; and a connecting portion connected to at least a portion of the end edge of the second main surface side of the side surface and at least a portion of the outer periphery of the second main surface, the connecting portion being located inside the portion surrounded by an imaginary surface extending the second main surface and an imaginary surface extending the side surface. The shielding film reaches the side surface of the encapsulation substrate but does not reach the connecting portion, and the shielding film is connected to the ground connection electrode.

[0011] In other broad aspects of the elastic wave device of the present invention, it comprises: an encapsulation substrate having a first main surface and a second main surface opposite to each other; an elastic wave element disposed on the first main surface of the encapsulation substrate; a sealing resin layer disposed on the first main surface of the encapsulation substrate such that it covers at least a portion of the elastic wave element; and a shielding film disposed to cover the sealing resin layer and being a non-metallic film. The encapsulation substrate includes: a ground connection electrode disposed within the encapsulation substrate, electrically connected to the elastic wave element and connected to a ground potential; and a signal connection electrode disposed on the encapsulation substrate. The package substrate is electrically connected to the elastic wave element and to a signal potential. It has: a side surface connected to the first main surface; and a connecting portion connected to at least a portion of the end edge of the second main surface side of the side surface and at least a portion of the outer periphery of the second main surface. The connecting portion is located inside the portion surrounded by an imaginary surface extending the second main surface and an imaginary surface extending the side surface. The shielding film reaches the side surface of the package substrate but not the connecting portion. The shielding film is connected to at least one of the ground connection electrode and the signal connection electrode.

[0012] Invention Effects

[0013] The elastic wave device according to the present invention can improve heat dissipation. Attached Figure Description

[0014] Figure 1 This is a schematic circuit diagram of the elastic wave element in the first embodiment of the present invention.

[0015] Figure 2 This is a schematic front sectional view of the elastic wave device according to the first embodiment of the present invention.

[0016] Figure 3 This is a graph showing the relationship between input power and output power in the first embodiment and comparative example of the present invention.

[0017] Figure 4 (a) to (d) are schematic front sectional views illustrating an example of the elastic wave element mounting process, sealing resin layer formation process, sealing resin layer slitting process, encapsulation substrate half-cutting process, and shielding film formation process in a method for manufacturing an elastic wave device according to the first embodiment of the present invention.

[0018] Figure 5 This is a bottom view of the packaging substrate dicing process in an example of a method for manufacturing an elastic wave device according to the first embodiment of the present invention.

[0019] Figure 6This is a bottom view showing the electrode structure of the series arm resonator in the transmitting filter according to the first embodiment of the present invention.

[0020] Figure 7 This is a bottom view showing the electrode structure of a longitudinally coupled resonator type elastic wave filter in a receiving filter according to the first embodiment of the present invention.

[0021] Figure 8 This is a schematic front sectional view of an elastic wave device according to a first variation of the first embodiment of the present invention.

[0022] Figure 9 This is a schematic front sectional view of an elastic wave device according to a second variation of the first embodiment of the present invention.

[0023] Figure 10 This is a schematic front sectional view of the elastic wave device according to the third variation of the first embodiment of the present invention.

[0024] Figure 11 This is a schematic front sectional view of the elastic wave device according to the second embodiment of the present invention.

[0025] Figure 12 This is a schematic front sectional view of the elastic wave device according to the third embodiment of the present invention.

[0026] Figure 13 This is a schematic front sectional view of the elastic wave device according to the fourth embodiment of the present invention.

[0027] Explanation of reference numerals in the attached figures

[0028] 1: Elastic wave element;

[0029] 1A: Transmit filter;

[0030] 1B: Receiver filter;

[0031] 2: Common connection terminal;

[0032] 3A, 3B: Longitudinal-coupled resonator type elastic wave filter;

[0033] 4: Packaging substrate;

[0034] 4a, 4b: 1st and 2nd main surfaces;

[0035] 4c: Side view;

[0036] 4d: Connecting part;

[0037] 5: Piezoelectric substrate;

[0038] 5a, 5b: The 3rd and 4th main faces;

[0039] 6: Sealing resin layer;

[0040] 7: Shielding film;

[0041] 8A, 8B: Signal terminals 1 and 2;

[0042] 9: Bumps;

[0043] 10: Elastic wave device;

[0044] 12A: Grounding connection terminal;

[0045] 12B: Grounding connection via electrode;

[0046] 12C: Grounding connection electrode;

[0047] 12D: Ground connection to external electrode;

[0048] 13A: Signal connection terminal;

[0049] 13B: Signal connection via electrode;

[0050] 13D: Signal connection to external electrodes;

[0051] 14, 14A: Packaging substrate;

[0052] 14a, 14b: 1st and 2nd main surfaces;

[0053] 14e: Groove section;

[0054] 14f: Bottom;

[0055] 15, 15A~15C: IDT electrodes;

[0056] 16A~16D: Reflectors;

[0057] 17a, 17b: Busbar 1 and Busbar 2;

[0058] 18a, 18b: The first and second electrodes refer to;

[0059] 19: Grounding connection electrode pad;

[0060] 21A: Transmitting filter;

[0061] 21B: Receiver filter;

[0062] 24: Packaging substrate;

[0063] 25, 25A, 25B: Piezoelectric substrates;

[0064] 26: Support base plate;

[0065] 27: High-speed acoustic membrane;

[0066] 28: Low-velocity membrane;

[0067] 29: Piezoelectric layer;

[0068] 31: Elastic wave element;

[0069] 32A, 32B: First and second support members;

[0070] 32a: Opening;

[0071] 33: Covering component;

[0072] 34A, 34B: Through electrodes;

[0073] 46: Install the substrate;

[0074] 46a, 46b: 5th and 6th main surfaces;

[0075] 47: Grounding electrode;

[0076] 48: Signal electrode;

[0077] 49: Bumps;

[0078] 50: Elastic wave device;

[0079] 53C: Signal connection electrode;

[0080] 54: Packaging substrate;

[0081] 57: Shielding film;

[0082] C: Capacitor element;

[0083] P1~P3、P11: Parallel arm resonators;

[0084] S1, S2, S3a, S3b, S4, S11: Series arm resonators. Detailed Implementation

[0085] Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings, thereby clarifying the present invention.

[0086] In addition, it should be noted that the embodiments described in this specification are illustrative and that partial substitutions or combinations of structures can be made between different embodiments.

[0087] Figure 1 This is a schematic circuit diagram of the elastic wave element in the first embodiment of the present invention.

[0088] The elastic wave device of this embodiment includes an elastic wave element 1. The elastic wave element 1 is a duplexer. More specifically, the elastic wave element 1 has a common connection terminal 2, a transmitting filter 1A, and a receiving filter 1B. The transmitting filter 1A and the receiving filter 1B are commonly connected to the common connection terminal 2. In this embodiment, the common connection terminal 2 is an antenna terminal. The antenna terminal is connected to an antenna. The common connection terminal 2 can be configured as wiring, or it can be configured as an electrode pad.

[0089] Transmitting filter 1A is a trapezoidal filter. Transmitting filter 1A has multiple series-arm resonators and multiple parallel-arm resonators. All of the multiple series-arm resonators and multiple parallel-arm resonators in transmitting filter 1A are elastic wave resonators. On the other hand, receiving filter 1B has a longitudinally coupled resonator type elastic wave filter 3A and a longitudinally coupled resonator type elastic wave filter 3B, and a series-arm resonator S11 and a parallel-arm resonator P11. The series-arm resonator S11 and the parallel-arm resonator P11 are elastic wave resonators used for characteristic adjustment. Furthermore, hereinafter, each elastic wave resonator and each longitudinally coupled resonator type elastic wave filter may sometimes be referred to simply as a resonator.

[0090] The elastic wave element is a duplexer for Band 1. More specifically, the passband of the transmitting filter 1A is 1920–1980 MHz. The passband of the receiving filter 1B is 2110–2170 MHz. However, the passband of the elastic wave element 1 is not limited to the above. Hereinafter, the specific structure of the elastic wave device of this embodiment will be described.

[0091] Figure 2 This is a schematic front sectional view of the elastic wave device according to the first embodiment. Figure 2 In the diagram, a portion of the electrode construction of the transmitting filter 1A and the receiving filter 1B is shown by adding two diagonal lines to a rectangle.

[0092] The elastic wave device 10 has a packaging substrate 4. The packaging substrate 4 has a first main surface 4a and a second main surface 4b. The first main surface 4a and the second main surface 4b are opposite to each other. The aforementioned elastic wave element 1 is disposed on the first main surface 4a. More specifically, the multiple resonators of the transmitting filter 1A and the receiving filter 1B share the same piezoelectric substrate 5. Thus, the transmitting filter 1A and the receiving filter 1B are made into a single component chip. The elastic wave element 1, as this component chip, is flip-chip mounted on the first main surface 4a of the packaging substrate 4. Specifically, the elastic wave element 1 is bonded to the packaging substrate 4 by a plurality of bumps 9. In this embodiment, the elastic wave device 10 is a CSP (Chip Size Package) structure. However, the elastic wave device 10 may also be constructed in a WLP (Wafer Level Package) structure, where the elastic wave element 1 is mounted on the packaging substrate 4.

[0093] A sealing resin layer 6 is provided on the first main surface 4a of the packaging substrate 4, covering the elastic wave element 1. Furthermore, a shielding film 7 is provided, covering the sealing resin layer 6. In this embodiment, the shielding film 7 is a metal film. The shielding film 7 functions as an electromagnetic shield. Therefore, it is possible to suppress the deterioration of the electrical characteristics of the elastic wave element 1 caused by unwanted external electrical signals, etc.

[0094] The packaging substrate 4 also has a side surface 4c and a connecting portion 4d. The side surface 4c is connected to the first main surface 4a. The connecting portion 4d is connected to the entire end edge of the side surface 4c on the side of the second main surface 4b, and the entire outer peripheral edge of the second main surface 4b. More specifically, in the packaging substrate 4 of this embodiment, a recess is provided in the entire portion facing the outer peripheral edge of the second main surface 4b. This recess also faces the entire end edge of the side surface 4c on the side of the second main surface 4b. The portion constituting this recess is the aforementioned connecting portion 4d. Therefore, the connecting portion 4d is located inside the portion surrounded by the imaginary surface A after extending the second main surface 4b and the imaginary surface B after extending the side surface 4c.

[0095] More specifically, the first main surface 4a and the second main surface 4b of the packaging substrate 4 have a rectangular shape. The packaging substrate 4 has four side surfaces 4c. In the elastic wave device 10, all four sides at the outer periphery of the second main surface 4b are connected to the connecting portion 4d. However, the connecting portion 4d only needs to be connected to at least a portion of the end edge of the side surface 4b on the second main surface 4b side surface 4c and at least a portion of the outer periphery of the second main surface 4b. It is sufficient to connect only a portion of the side surface 4c and a portion of the second main surface 4b. For example, at least one of the plurality of sides at the outer periphery of the second main surface 4b may be connected to the connecting portion 4d, and at least one of the plurality of sides may be connected to the side surface 4c. In addition, the shapes of the first main surface 4a and the second main surface 4b are not limited to rectangles.

[0096] The package substrate 4 has at least one ground connection terminal 12A, multiple signal connection terminals 13A, multiple ground connection via electrodes 12B, multiple signal connection via electrodes 13B, at least one ground connection electrode 12C, at least one ground connection external electrode 12D, and multiple signal connection external electrodes 13D. The ground connection terminal 12A and the signal connection terminal 13A are disposed on a first main surface 4a of the package substrate 4. The ground connection via electrodes 12B, the signal connection via electrodes 13B, and the ground connection electrode 12C are disposed within the package substrate 4. The ground connection external electrode 12D and the signal connection external electrode 13D are disposed on a second main surface 4b. A portion of the multiple ground connection via electrodes 12B connects the ground connection terminal 12A and the ground connection electrode 12C. Another portion of the multiple ground connection via electrodes 12B connects the ground connection electrode 12C and the ground connection external electrode 12D. Conversely, the signal connection via electrode 13B connects the signal connection terminal 13A and the signal connection external electrode 13D.

[0097] The elastic wave element 1 is connected to an external ground potential via bump 9, ground connection terminal 12A, ground connection via electrode 12B, ground connection electrode 12C, and ground connection external electrode 12D. On the other hand, the elastic wave element 1 is connected to an external signal potential via bump 9, signal connection terminal 13A, signal connection via electrode 13B, and signal connection external electrode 13D. Additionally, a portion of the plurality of ground connection via electrodes 12B can also connect the ground connection terminal 12A and the ground connection external electrode 12D.

[0098] The feature of this embodiment is that the packaging substrate 4 has the aforementioned connecting portion 4d, the shielding film 7 reaches the side surface 4c of the packaging substrate 4 but does not reach the connecting portion 4d, and the shielding film 7 is connected to the ground connection electrode 12C. More specifically, the end of the ground connection electrode 12C is located on the side surface 4c of the packaging substrate 4. The shielding film 7 is connected to this end. The heat dissipation path of the heat generated in the elastic wave element 1 is, for example, a path via the ground connection via electrode 12B and the ground connection external electrode 12D. This heat dissipation path is a path from the first main surface 4a of the packaging substrate 4 through the second main surface 4b. In addition, in this embodiment, a heat dissipation path is also provided via the ground connection via electrode 12B, the ground connection electrode 12C, and the shielding film 7. In this way, the elastic wave device 10 also has a heat dissipation path from the first main surface 4a of the packaging substrate 4 through the side surface 4c. As a result, the heat dissipation path can be effectively increased. Therefore, heat dissipation performance can be effectively improved.

[0099] In this embodiment, improved heat dissipation leads to improved power handling capacity. The details of this effect are shown below by comparing this embodiment with a comparative example. Furthermore, the comparative example differs from this embodiment in that the grounding connection electrode is not connected to the shielding film. Power application tests were conducted in the elastic wave devices of this embodiment and the comparative example. The results are shown below. Figure 3 .

[0100] Figure 3 This is a graph showing the relationship between input power and output power in the first embodiment and the comparative example.

[0101] like Figure 3 As can be seen, in the first embodiment, the output power is higher than that in the comparative example under any input power. Furthermore, in the comparative example, when the input power is 30.5 dBm or higher, the increase in output power is small even when the input power is increased. In contrast, in the first embodiment, even when the input power is 30.5 dBm or higher, the increase in output power is large when the input power is increased.

[0102] Generally, in regions with low input power, the output power increases with increasing input power. However, in regions with high input power, the temperature of each resonator rises due to heat generation. Consequently, the frequency bands with low insertion loss in the receiving and transmitting filters shift continuously. Therefore, even assuming an increase in the input power of the same frequency signal, the signal becomes difficult to pass through the receiving and transmitting filters due to the temperature rise. As a result, even with increased input power, the increase in output power is smaller.

[0103] In contrast, in the first embodiment, heat dissipation is improved in the elastic wave device 10. This suppresses the temperature rise of each elastic wave resonator and each longitudinally coupled resonator-type elastic wave filter, and suppresses changes in frequency characteristics. Therefore, even with increased input power, the output power can be increased. In this way, power handling characteristics are improved.

[0104] Return to Figure 2 In the small-scale elastic wave device 10, the area of ​​the second main surface 4b of the packaging substrate 4 is small. Therefore, the heat dissipation path is also limited. In contrast, in the first embodiment, the side surface 4c can also be used as a heat dissipation path. Therefore, the present invention is particularly suitable for cases where the elastic wave device 10 is small-scale.

[0105] Furthermore, in the first embodiment, a connecting portion 4d is provided on the packaging substrate 4. This allows for a more reliable reduction in the size of the elastic wave device 10 and improves productivity. This will be described below along with an example of the manufacturing method of the elastic wave device according to the first embodiment.

[0106] Figure 4 (a)~ Figure 4 (d) is a schematic front sectional view illustrating an example of the manufacturing method of the elastic wave device according to the first embodiment, including the elastic wave element mounting process, the sealing resin layer forming process, the sealing resin layer dividing process, the encapsulation substrate half-cutting process, and the shielding film forming process. Figure 5 This is a bottom view showing the packaging substrate cutting process in an example of the manufacturing method of the elastic wave device according to the first embodiment. Furthermore, in this specification, [the following will be discussed...] Figure 2 The downward direction observed in the image is considered an upward view. From... Figure 2 The direction of observation from above in the image is taken as a bird's-eye view.

[0107] like Figure 4 As shown in (a), a packaging substrate 14 having a first main surface 14a and a second main surface 14b is prepared. Next, a plurality of elastic wave elements 1 are provided on the first main surface 14a of the packaging substrate 14. Specifically, the plurality of elastic wave elements 1 are respectively bonded to the packaging substrate 14 by a plurality of bumps 9. In addition, an electrode structure corresponding to the plurality of elastic wave elements 1 is provided on the packaging substrate 14.

[0108] Next, as Figure 4 As shown in (b), a sealing resin layer 6 is provided on the packaging substrate 14, covering a plurality of elastic wave elements 1. Next, the sealing resin layer 6 is cut from the first main surface 14a side, for example, by cutting, and the packaging substrate 14 is half-cut. Thus, as Figure 4 As shown in (c), the sealing resin layer 6 is divided. Then, a groove 14e is formed on the encapsulation substrate 14A. At this time, the groove 14e is formed such that the end of the ground connection electrode 12C is exposed in the groove 14e. Additionally, the groove 14e includes a bottom 14f. This half-cut is formed in relation to... Figure 5 The line that overlaps with line II and line II-II.

[0109] Next, as Figure 4 As shown in (d), a shielding film 7 is formed, covering the sealing resin layer 6 and the groove 14e. As described above, the end of the grounding connection electrode 12C is exposed in the groove 14e. Therefore, in this shielding film forming process, the shielding film 7 is connected to the grounding connection electrode 12C. The shielding film 7 can be formed, for example, by sputtering or vacuum evaporation.

[0110] Next, as Figure 5 As shown, the package substrate 14A is cut along line II and line II-II. More specifically, the package substrate 14A is cut such that the package substrate 14A reaches the package substrate 14A. Figure 4 The bottom 14f of the groove 14e shown in (c). At this time, in comparison Figure 4 In the encapsulation substrate half-cutting process shown in (c), the encapsulation substrate 14A is cut from the second main surface 14b side with a wider groove width. More specifically, the encapsulation substrate 14A is cut such that the portion where the shielding film 7 and the ground connection electrode 12C are connected is not reached. Thus, a... Figure 2 The connecting portion 4d of the packaging substrate 4 shown. Through the above, the packaging substrate 14A can be monolithically processed to obtain multiple elastic wave devices 10.

[0111] exist Figure 5 In the packaging substrate dicing process shown, as described above, in the ratio Figure 4 The packaging substrate half-cutting process shown in (c) is performed with a wider groove width. Therefore, even assuming a positional offset in the cutting of the packaging substrate 14A, a smaller packaging substrate 4 can be obtained more reliably. Consequently, the elastic wave device 10 can be made smaller more reliably, and productivity can be improved.

[0112] In the above-mentioned packaging substrate cutting process, a portion of the electrodes on the main surface of the packaging substrate 14A may also be removed. Figure 2 A portion of the ground connection external electrode 12D and a portion of the signal connection external electrode 13D shown are removed in this process. Therefore, the ground connection external electrode 12D and the signal connection external electrode 13D are in contact with the boundary of the connection portion 4d and the second main surface 4b of the package substrate 4. Preferably, at least one of the ground connection external electrode 12D and the signal connection external electrode 13D is in contact with the boundary of the connection portion 4d and the second main surface 4b. In this case, the area of ​​the electrode connected to the outside can be increased more reliably. Therefore, heat dissipation can be improved more reliably. However, it is also possible that neither the ground connection external electrode 12D nor the signal connection external electrode 13D is in contact with the boundary of the connection portion 4d and the second main surface 4b.

[0113] The connection portion 4d of the package substrate 4 is formed after the shielding film 7 is formed. Therefore, the shielding film 7 does not reach the connection portion 4d of the package substrate 4. As a result, the shielding film 7 and the signal connection external electrode 13D are less likely to short-circuit.

[0114] The circuit structure of the elastic wave element 1 according to the first embodiment will be described below.

[0115] like Figure 1As shown, the transmitting filter 1A has a first signal terminal 8A, multiple series-arm resonators and multiple parallel-arm resonators, and a capacitor element C. More specifically, the multiple series-arm resonators are series-arm resonators S1, S2, S3a, S3b, and S4. The multiple parallel-arm resonators are parallel-arm resonators P1, P2, and P3. The first signal terminal 8A is an input terminal.

[0116] Between signal terminal 8A and common connection terminal 2, series arm resonators S1, S2, S3a, S3b, and S4 are connected in series. A parallel arm resonator P1 is connected between the connection point of series arm resonators S1 and S2 and the ground potential. A parallel arm resonator P2 is connected between the connection point of series arm resonators S2 and S3a and the ground potential. A parallel arm resonator P3 is connected between the connection point of series arm resonators S3b and S4 and the ground potential. Additionally, a capacitor C is connected in parallel with series arm resonator S3b.

[0117] On the other hand, as described above, the receiving filter 1B includes a longitudinally coupled resonator type elastic wave filter 3A and a longitudinally coupled resonator type elastic wave filter 3B, a series arm resonator S11, and a parallel arm resonator P11. The receiving filter 1B also includes a second signal terminal 8B. The second signal terminal 8B is an output terminal. The second signal terminal 8B can be configured as wiring, for example, or it can be configured as an electrode pad. The same applies to the first signal terminal 8A described above.

[0118] Between the common connection terminal 2 and the second signal terminal 8B, longitudinally coupled resonator type elastic wave filter 3A and longitudinally coupled resonator type elastic wave filter 3B are connected in parallel. A series arm resonator S11 is connected between the common connection terminal 2 and the longitudinally coupled resonator type elastic wave filter 3A and longitudinally coupled resonator type elastic wave filter 3B. A parallel arm resonator P11 is connected between the connection point between the series arm resonator S11 and the longitudinally coupled resonator type elastic wave filter 3A and longitudinally coupled resonator type elastic wave filter 3B and the ground potential. The parallel arm resonator P11 of the receiving filter 1B and the parallel arm resonators P2 and P3 of the transmitting filter 1A are commonly connected to the ground potential.

[0119] Furthermore, the circuit structure of the elastic wave element 1 is not limited to the above. Moreover, the elastic wave element 1 is not limited to a duplexer. The elastic wave element 1 can be, for example, a transmitting filter, a receiving filter, or a multiplexer. Furthermore, the elastic wave element 1 can also be, for example, a single-port type elastic wave resonator.

[0120] The following shows the specific structure of the elastic wave resonator and the longitudinally coupled resonator type elastic wave filter in the first embodiment.

[0121] Figure 6 This is a bottom view showing the electrode structure of the series arm resonator in the transmitting filter of the first embodiment. Figure 6 The wiring connecting to the series arm resonator S1 is omitted in the text.

[0122] The series arm resonator S1 has a piezoelectric substrate 5. As described above, the multiple resonators of the transmitting filter 1A and the receiving filter 1B share the same piezoelectric substrate 5. In this embodiment, the piezoelectric substrate 5 is a substrate that only contains a piezoelectric layer. The piezoelectric layer contains lithium tantalate. In this specification, the term "a component contains a material" includes trace amounts of impurities that do not degrade the electrical characteristics of the elastic wave device. However, the material of the piezoelectric layer is not limited to the above; for example, lithium niobate, zinc oxide, aluminum nitride, quartz, or PZT (lead zirconate titanate) can also be used. In addition, the piezoelectric substrate 5 may also be a laminated substrate containing a piezoelectric layer.

[0123] The piezoelectric substrate 5 has a third main surface 5a and a fourth main surface 5b. The third main surface 5a and the fourth main surface 5b are opposite to each other. Of the third main surface 5a and the fourth main surface 5b, the third main surface 5a is located on the side of the packaging substrate 4. An IDT (Interdigital Transducer) electrode 15 is provided on the third main surface 5a. An elastic wave is excited by applying an alternating voltage to the IDT electrode 15. A pair of reflectors 16A and reflectors 16B are provided on both sides of the elastic wave propagation direction of the IDT electrode 15 on the third main surface 5a.

[0124] The IDT electrode 15 has a first busbar 17a and a second busbar 17b, and a plurality of first electrode fingers 18a and a plurality of second electrode fingers 18b. The first busbar 17a and the second busbar 17b are opposite to each other. One end of each of the plurality of first electrode fingers 18a is connected to the first busbar 17a. One end of each of the plurality of second electrode fingers 18b is connected to the second busbar 17b. The plurality of first electrode fingers 18a and the plurality of second electrode fingers 18b are interleaved with each other. Hereinafter, the first electrode fingers 18a and the second electrode fingers 18b will sometimes be referred to simply as electrode fingers. When the direction in which the plurality of electrode fingers extend is defined as the electrode finger extension direction, in the first embodiment, the electrode finger extension direction and the elastic wave propagation direction are orthogonal to each other.

[0125] Each elastic wave resonator other than the series arm resonator S1 also has an IDT electrode and a reflector, just like the series arm resonator S1. In the first embodiment, both the multiple series arm resonators and the multiple parallel arm resonators are surface acoustic wave resonators.

[0126] Figure 7 This is a bottom view showing the electrode structure of the longitudinally coupled resonator type elastic wave filter in the receiving filter of the first embodiment. Figure 7 The wiring connecting to the longitudinally coupled resonator type elastic wave filter 3A is omitted in the text.

[0127] The longitudinally coupled resonator type elastic wave filter 3A has the piezoelectric substrate 5 described above. IDT electrodes 15A, 15B, and 15C are provided on the third main surface 5a of the piezoelectric substrate 5. The IDT electrodes 15A, 15B, and 15C are arranged along the elastic wave propagation direction. A pair of reflectors 16C and 16D are provided on both sides of the elastic wave propagation direction of the IDT electrodes 15A, 15B, and 15C on the third main surface 5a. The longitudinally coupled resonator type elastic wave filter 3A is a 3IDT type. However, the number of IDT electrodes in the longitudinally coupled resonator type elastic wave filter 3A is not limited to the above. For example, the longitudinally coupled resonator type elastic wave filter 3A can also be a 5IDT type or a 7IDT type, etc. The longitudinally coupled resonator type elastic wave filter 3B also similarly has multiple IDT electrodes and reflectors.

[0128] Return to Figure 2 A plurality of external connection terminals are provided on the third main surface 5a of the piezoelectric substrate 5. In this embodiment, the external connection terminals are configured as electrode pads. Bumps 9 are respectively bonded to the plurality of external connection terminals. The plurality of external connection terminals include a ground connection electrode pad 19. The ground connection electrode pad 19 is electrically connected to the ground connection terminal 12A via the bumps 9. Furthermore, the plurality of external connection terminals also include... Figure 1 The first signal terminal 8A, the second signal terminal 8B, and the common connection terminal 2 are shown. The first signal terminal 8A, the second signal terminal 8B, and the common connection terminal 2 are electrically connected to their respective signal connection terminals 13A via bumps 9.

[0129] As described above, the piezoelectric substrate 5 in the first embodiment only includes a piezoelectric layer. However, the piezoelectric substrate 5 may also be a multilayer substrate including a piezoelectric layer. For example, in Figure 8In the first variation of the first embodiment shown, the piezoelectric substrate 25 includes a support substrate 26, a high-velocity film 27 as a high-velocity material layer, a low-velocity film 28, and a piezoelectric layer 29. More specifically, the support substrate 26, the high-velocity film 27, the low-velocity film 28, and the piezoelectric layer 29 are stacked sequentially. In this variation, similar to the first embodiment, the shielding film 7 is connected to the ground connection electrode 12C. This improves heat dissipation.

[0130] Furthermore, the low-velocity film 28 is a film with relatively low sound speeds. More specifically, the sound speed of bulk waves propagating in the low-velocity film 28 is lower than the sound speed of bulk waves propagating in the piezoelectric layer 29. As a material for the low-velocity film 28, for example, materials mainly composed of glass, silicon oxide, silicon oxynitride, lithium oxide, tantalum pentoxide, or compounds in which fluorine, carbon, and boron are added to silicon oxide can be used.

[0131] The hypersonic material layer is a layer with relatively high sound speed. In this modified example, the hypersonic material layer is a hypersonic film 27. The sound speed of the bulk wave propagating in the hypersonic material layer is higher than the sound speed of the elastic wave propagating in the piezoelectric layer 29. As the material for the hypersonic material layer, for example, silicon, alumina, silicon carbide, silicon nitride, silicon oxynitride, sapphire, lithium tantalate, lithium niobate, quartz, bauxite, zirconium oxide, cordierite, mullite, block talc, forsterite, magnesium oxide, DLC (diamond-like carbon) film, or diamond, etc., and media with the above materials as the main components can be used.

[0132] The material used as the support substrate 26 can be, for example, various ceramics such as alumina, lithium tantalate, lithium niobate, piezoelectric materials such as quartz, bauxite, sapphire, magnesium oxide, silicon nitride, aluminum nitride, silicon carbide, zirconium oxide, cordierite, mullite, block talc, magnesium olivine, diamond, glass and other dielectrics, silicon, gallium nitride and other semiconductors, or resins.

[0133] In this modified example, a high-velocity film 27, a low-velocity film 28, and a piezoelectric layer 29, which are high-velocity material layers, are sequentially stacked in the piezoelectric substrate 25. As a result, the energy of the elastic wave can be effectively contained on the piezoelectric layer 29 side.

[0134] Furthermore, the laminated structure of the piezoelectric substrate is not limited to the above. For example, the piezoelectric substrate may also be a laminated substrate of a support substrate, a hypersonic film, and a piezoelectric layer. Furthermore, the hypersonic material layer may also be a hypersonic support substrate. In this case, the piezoelectric substrate may be a laminated substrate of a hypersonic support substrate, a low-velocity film, and a piezoelectric layer, or it may be a laminated substrate of a hypersonic support substrate and a piezoelectric layer. In these cases, the energy of the elastic wave can be effectively contained on the piezoelectric layer side. Furthermore, similar to the first modification, heat dissipation can be improved.

[0135] In the first embodiment, the sealing resin layer 6 covers the fourth main surface 5b of the piezoelectric substrate 5. However, the sealing resin layer 6 only needs to be provided on the first main surface 4a of the encapsulation substrate 4 such that it covers at least a portion of the elastic wave element 1. For example, in Figure 9 In the second variation of the first embodiment shown, the sealing resin layer 6 covers the side surface of the piezoelectric substrate 5 but does not cover the fourth main surface 5b. The sealing resin layer 6 becomes flush with the fourth main surface 5b. In this variation, the shielding film 7 covers both the sealing resin layer 6 and the fourth main surface 5b. In this case, similar to the first embodiment, heat dissipation can be improved.

[0136] In the elastic wave device 10, all resonators share the same piezoelectric substrate 5. The elastic wave element 1 is flip-chip mounted on the package substrate 4 as a single component chip. However, this is not a limitation. For example, as Figure 10 As shown in the third variation, the transmitting filter 21A and the receiving filter 21B can also have different piezoelectric substrates. In this variation, all the resonators of the transmitting filter 21A share the piezoelectric substrate 25A. All the resonators of the receiving filter 21B share the piezoelectric substrate 25B. The transmitting filter 21A and the receiving filter 21B are each configured as a single chip. Furthermore, the elastic wave element in this variation is flip-chip mounted as two chip components on the packaging substrate 24. The packaging substrate 24 has a wiring structure corresponding to the number of chip components. A sealing resin layer 6 is provided to cover each chip component. However, in this variation, similar to the first embodiment, the shielding film 7 is connected to the ground connection electrode 12C. This improves heat dissipation.

[0137] Furthermore, the number of piezoelectric substrates is not particularly limited; for example, each resonator may have its own piezoelectric substrate. Alternatively, three or more component chips may be flip-chip mounted on the package substrate 24. In this case, similar to the third modification, heat dissipation can be improved.

[0138] Return to Figure 2 In the first embodiment, the connecting portion 4d of the packaging substrate 4 has a curved shape. However, the connecting portion 4d may also have a shape that connects multiple planes, for example. The multiple planes have different inclination angles relative to the second main surface 4b.

[0139] Figure 11 This is a schematic front sectional view of the elastic wave device according to the second embodiment.

[0140] The difference between this embodiment and the first embodiment is that the elastic wave element 31 is a WLP (Wave-Lift) structure. Apart from the points mentioned above, this embodiment has the same structure as the elastic wave device 10 of the first embodiment.

[0141] On the third main surface 5a of the piezoelectric substrate 5, a first support member 32A and a second support member 32B are provided. The first support member 32A is the support member of this invention. The first support member 32A is configured to surround multiple IDT electrodes of the multiple resonators. The first support member 32A has a frame-like shape. More specifically, the first support member 32A has an opening 32a. The multiple IDT electrodes are located within the opening 32a. On the third main surface 5a, similar to the first embodiment, a multiple external connection terminals are provided. The first support member 32A covers at least a portion of the multiple external connection terminals.

[0142] On the other hand, the second support member 32B is located within the opening 32a of the first support member 32A. The second support member 32B has a columnar shape. However, the second support member 32B may also have a wall-like shape. The second support member 32B covers at least a portion of the external connection terminal. A covering member 33 is provided on the first support member 32A and the second support member 32B. The covering member 33 is configured to block the opening 32a of the first support member 32A. A plurality of IDT electrodes are surrounded by the piezoelectric substrate 5, the first support member 32A, and the covering member 33.

[0143] Multiple through electrodes 34A are provided, penetrating the covering member 33 and the first support member 32A. Similarly, through electrodes 34B are provided, penetrating the covering member 33 and the second support member 32B. One end of each through electrode 34A and through electrode 34B is connected to an external connection terminal. A bump 9 is respectively attached to the other end of each through electrode 34A and through electrode 34B. Furthermore, the elastic wave element 31 is connected to the packaging substrate 4 via the multiple bumps 9.

[0144] In this embodiment, similarly to the first embodiment, the shielding film 7 is connected to the grounding connection electrode 12C. This improves heat dissipation.

[0145] Figure 12 This is a schematic front sectional view of the elastic wave device according to the third embodiment.

[0146] The difference between this embodiment and the first embodiment is that it includes a mounting substrate 46. An encapsulation substrate 4 is disposed on the mounting substrate 46. Apart from the points mentioned above, the elastic wave device of this embodiment has the same structure as the elastic wave device 10 of the first embodiment.

[0147] The mounting substrate 46 has a fifth main surface 46a and a sixth main surface 46b. The fifth main surface 46a and the sixth main surface 46b are opposite to each other. Of the fifth main surface 46a and the sixth main surface 46b, the fifth main surface 46a is located on the side of the package substrate 4. The mounting substrate 46 has at least one ground electrode 47 and a plurality of signal electrodes 48. The ground electrode 47 and the signal electrodes 48 are disposed on the fifth main surface 46a.

[0148] The package substrate 4 is engaged with the mounting substrate 46 via a plurality of bumps 49. More specifically, the ground connection external electrode 12D of the package substrate 4 is engaged with the ground electrode 47 via bumps 49. The signal connection external electrode 13D is engaged with the signal electrode 48 via bumps 49. The elastic wave element 1 is electrically connected to the mounting substrate 46 via the package substrate 4.

[0149] In this embodiment, similarly to the first embodiment, the shielding film 7 is connected to the grounding connection electrode 12C. This improves heat dissipation.

[0150] Figure 13 This is a schematic front sectional view of the elastic wave device according to the fourth embodiment.

[0151] The difference between this embodiment and the first embodiment is that the shielding film 57 is a non-metallic film. Another difference is that a signal connection electrode 53C is provided within the packaging substrate 54, and the shielding film 57 is connected to the signal connection electrode 53C. Apart from the points mentioned above, the elastic wave device 50 of this embodiment has the same structure as the elastic wave device 10 of the first embodiment.

[0152] The signal connection electrode 53C is connected to the signal connection terminal 13A through a portion of the plurality of signal connection via electrodes 13B. Furthermore, the signal connection electrode 53C is connected to the external signal connection electrode 13D through another portion of the plurality of signal connection via electrodes 13B. The end of the signal connection electrode 53C is located on the side 4c of the package substrate 54. A shielding film 57 is connected to this end. Since the shielding film 57 is a non-metallic film, the electrical characteristics of the elastic wave device 50 are not easily degraded even when the shielding film 57 is connected to the signal connection electrode 53C.

[0153] The heat dissipation path for the heat generated in the elastic wave element 1 is, for example, a path via the signal connection via electrode 13B and the signal connection external electrode 13D. This heat dissipation path extends from the first main surface 4a of the package substrate 54 through the second main surface 4b. In addition, in this embodiment, a heat dissipation path is also provided via the signal connection via electrode 13B, the signal connection electrode 53C, and the shielding film 57. Thus, the elastic wave device 50 also has a heat dissipation path extending from the first main surface 4a of the package substrate 54 through the side surface 4c. This effectively increases the number of heat dissipation paths, thereby effectively improving heat dissipation performance.

[0154] Similar to the first embodiment, the shielding film 57 is also connected to the ground connection electrode 12C. However, the shielding film 57 is a non-metallic film with low resistance. Therefore, the shielding film 57 does not electrically connect the ground connection electrode 12C and the signal connection electrode 53C. Consequently, the electrical characteristics of the elastic wave device 50 are less prone to degradation.

[0155] In this embodiment, the shielding film 57 is connected to both the ground connection electrode 12C and the signal connection electrode 53C. Therefore, heat dissipation can be further improved. Furthermore, the shielding film 57 only needs to be connected to at least one of the ground connection electrode 12C and the signal connection electrode 53C. This effectively improves heat dissipation.

[0156] As the material for the shielding film 57, a non-metal with high heat dissipation properties, such as silicon nitride, is preferably used. In this case, heat dissipation can be improved more reliably.

Claims

1. An elastic wave device, comprising: The packaging substrate has a first main surface and a second main surface that are opposite to each other; An elastic wave element is disposed on the first main surface of the packaging substrate; A sealing resin layer is disposed on the first main surface of the encapsulation substrate, such that it covers at least a portion of the elastic wave element; and The shielding film is configured to cover the sealing resin layer and is a metal film. The packaging substrate includes: a ground connection electrode disposed within the packaging substrate, electrically connected to the elastic wave element, and connected to a ground potential. The packaging substrate has: a side surface connected to the first main surface; and a connecting portion connected to at least a portion of the end edge of the second main surface side of the side surface and at least a portion of the outer periphery of the second main surface, the connecting portion being located inside the portion surrounded by an imaginary surface extending the second main surface and an imaginary surface extending the side surface. The shielding film reaches the side of the packaging substrate but not the connection portion, and the shielding film is connected to the ground connection electrode.

2. An elastic wave device, comprising: The packaging substrate has a first main surface and a second main surface that are opposite to each other; An elastic wave element is disposed on the first main surface of the packaging substrate; A sealing resin layer is disposed on the first main surface of the encapsulation substrate, such that it covers at least a portion of the elastic wave element; and The shielding film is configured to cover the sealing resin layer and is a non-metallic film. The packaging substrate includes: a ground connection electrode disposed within the packaging substrate, electrically connected to the elastic wave element and connected to a ground potential; and a signal connection electrode disposed within the packaging substrate, electrically connected to the elastic wave element and connected to a signal potential. The packaging substrate has: a side surface connected to the first main surface; and a connecting portion connected to at least a portion of the end edge of the second main surface side of the side surface and at least a portion of the outer periphery of the second main surface, the connecting portion being located inside the portion surrounded by an imaginary surface extending the second main surface and an imaginary surface extending the side surface. The shielding film reaches the side of the packaging substrate but not the connection portion, and the shielding film is connected to at least one of the ground connection electrode and the signal connection electrode.

3. The elastic wave device according to claim 2, wherein, The end of the signal connection electrode is located on the side of the packaging substrate, and the shielding film is connected to this end.

4. The elastic wave device according to any one of claims 1 to 3, wherein, The end of the grounding connection electrode is located on the side of the packaging substrate, and the shielding film is connected to this end.

5. The elastic wave device according to any one of claims 1 to 4, wherein, The entire end edge of the second main surface side of the side surface of the packaging substrate and the entire outer peripheral edge of the second main surface are connected to the connecting portion.

6. The elastic wave device according to any one of claims 1 to 5, wherein, It also has a mounting base plate. The encapsulation substrate is disposed on the mounting substrate, and the elastic wave element is electrically connected to the mounting substrate via the encapsulation substrate.

7. The elastic wave device according to any one of claims 1 to 6, wherein, The elastic wave element comprises: a piezoelectric substrate; at least one elastic wave resonator configured on the piezoelectric substrate; an external connection terminal electrically connected to the at least one elastic wave resonator; and a bump engaging with the external connection terminal. The elastic wave element is bonded to the packaging substrate via the bump.

8. The elastic wave device according to any one of claims 1 to 6, wherein, The elastic wave element comprises: a piezoelectric substrate; at least one elastic wave resonator formed on the piezoelectric substrate; an external connection terminal electrically connected to the at least one elastic wave resonator; a support member including an opening surrounding the at least one elastic wave resonator and disposed on the piezoelectric substrate such that it covers at least a portion of the external connection terminal; a cover member disposed on the support member such that it blocks the opening; a through electrode penetrating the cover member and the support member and connected to the external connection terminal; and a bump engaging with the through electrode. The elastic wave element is bonded to the packaging substrate via the bump.

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