Acoustic wave device and method for manufacturing same

Abstract

The invention provides an acoustic wave device and a manufacturing method thereof. The acoustic wave device includes a first substrate, a plurality of first electrodes, a second substrate, a plurality of second electrodes, and a coating film. The first substrate comprises a first surface and a second surface. The plurality of first electrodes are arranged on the second surface of the first substrate. The second substrate comprises a third surface and a fourth surface. The plurality of second electrodes are arranged on the third surface of the second substrate, and the second surface of the first substrate faces the third surface of the second substrate, so that the plurality of first electrodes and the plurality of second electrodes are located between the first substrate and the second substrate. The covering film is arranged between the plurality of first electrodes and the plurality of second electrodes.

Description

Technical Field

[0001] The present invention relates to an acoustic wave device, and more particularly to a surface acoustic wave device and a manufacturing method thereof. Background Art

[0002] Surface acoustic wave (SAW) devices are used to convert and transmit electrical and acoustic signals. SAW filters are widely used in many fields. For example, SAW filters can filter noise and retain wireless signals in the required frequency band, provide low transmission loss and immunity to electromagnetic interference, and are compact, so they are widely used in various communication products. In addition, SAW filters can also be used as resonators.

[0003] Due to the development of communication technology, mobile phones and other communication products support more and more frequency bands to increase signal coverage and international roaming capabilities. Therefore, the demand for dual-SAW devices and even multi-SAW devices continues to increase. However, existing dual-SAW devices will increase the circuit area. Summary of the invention

[0004] The present invention discloses an acoustic wave device, comprising a first substrate, a plurality of first electrodes, a second substrate, a plurality of second electrodes, and a first coating. The first substrate comprises a first surface and a second surface. The plurality of first electrodes are arranged on the second surface of the first substrate. The second substrate comprises a third surface and a fourth surface. The plurality of second electrodes are arranged on the third surface of the second substrate, wherein the second surface of the first substrate faces the third surface of the second substrate, so that the plurality of first electrodes and the plurality of second electrodes are located between the first substrate and the second substrate. The first coating is arranged between the plurality of first electrodes and the plurality of second electrodes.

[0005] An embodiment of the present invention further discloses a method for manufacturing an acoustic wave device, comprising providing a first chip, the first chip comprising a first substrate, a first electrode, and a first coating; providing a second chip, the second chip comprising a second substrate and a second electrode; stacking the second chip on the first chip such that the first electrode and the second electrode are located between the first substrate and the second substrate, and the first coating is disposed between the first electrode and the second electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 FIG. 4 is a cross-sectional schematic diagram of an exemplary acoustic wave device in an embodiment of the present invention.

[0007] Figure 2 FIG. 4 is a schematic top view of an exemplary acoustic wave device in an embodiment of the present invention.

[0008] Figure 3FIG. 4 is a flow chart of an exemplary method for manufacturing an acoustic wave device according to an embodiment of the present invention.

[0009] Figure 4 FIG. 4 is a cross-sectional schematic diagram of another exemplary acoustic wave device in an embodiment of the present invention.

[0010] Explanation of symbols:

[0011] 1,4: Sound wave device

[0012] 10A,10B:Substrate

[0013] 20A, 20B: Electrode

[0014] 201A: Input electrode

[0015] 203A: Transducer electrode

[0016] 204A: Transducer electrode

[0017] 205A: Output electrode

[0018] 45A, 45B, 45: Lamination

[0019] 40A, 40B: Side wall

[0020] S1 to S6: Surface

[0021] 30,31: Conductor

[0022] 32A,34A,32B,34B: Contact pad

[0023] 33,35: Connection

[0024] 50: Motherboard

[0025] 60: Sealing element

[0026] 70A, 70B: Cavity

[0027] 300: Manufacturing method

[0028] S301 to S305: Steps

[0029] C1 to C8: Wire

[0030] X,Y,Z: Direction DETAILED DESCRIPTION

[0031] Figure 1Schematic cross-section of an exemplary acoustic wave device 1. In some embodiments, the acoustic wave device 1 can receive a radio frequency signal from an antenna, convert the radio frequency signal into an acoustic wave, process the acoustic wave to generate a filtered signal, and output the filtered signal. The radio frequency signal and the filtered signal can be electrical signals. The acoustic wave device 1 can include two surface acoustic wave (SAW) devices, which can be used for duplexers in the field of communications. For example, two SAW devices can be used to process two filtered signals with different frequencies. The use of the acoustic wave device 1 is only illustrated here, but the present invention is not limited thereto. In other embodiments, the acoustic wave device 1 can also be used for other purposes.

[0032] like Figure 1 As shown, the acoustic wave device 1 may include a substrate 10A, a plurality of electrodes 20A, and a coating 45A, wherein the substrate 10A may have a first surface S1 and a second surface S2, the plurality of electrodes 20A may be disposed on the second surface S2, and the coating 45A covers the plurality of electrodes 20A. The acoustic wave device 1 may also include a substrate 10B, a plurality of electrodes 20B, and a coating 45B, wherein the substrate 10B may have a third surface S3 and a fourth surface S4, the plurality of electrodes 20B may be disposed on the third surface S3, and the coating 45B covers the plurality of electrodes 20B. For example, the width of the substrate 10A along the horizontal direction X may be smaller than the width of the substrate 10B along the horizontal direction X, wherein the horizontal direction X may be parallel to the surface S1 of the substrate 10A. In some embodiments, the substrate 10A, the plurality of electrodes 20A, and the coating 45A may be formed as part of a first wafer, and the substrate 10B, the plurality of electrodes 20B, and the coating 45B may be formed as part of a second wafer.

[0033] In some embodiments, the plurality of electrodes 20A and the plurality of electrodes 20B may each be formed as an interdigital transducer (IDT). For example, the plurality of electrodes 20A disposed on the surface S2 of the substrate 10A may be used to output a first filter signal having a first frequency. The plurality of electrodes 20B disposed on the surface S3 of the substrate 10B may be used to output a second filter signal having a second frequency, wherein the second frequency may be the same as or different from the first frequency. For example, the first frequency may be 900 megahertz (MHz), and the second frequency may be 1800 MHz.

[0034] In such an embodiment, for example, the second chip can be stacked on the first chip to save circuit area, thereby achieving miniaturization of the acoustic wave device 1. For example, the surface S3 of the substrate 10B can face the surface S2 of the substrate 10A, so that the electrode 20A and the electrode 20B are located between the substrate 10A and the substrate 10B, and further, between the surface S2 of the substrate 10A and the surface S3 of the substrate 10B. In some embodiments, the coating 45A and / or 45B can be disposed between the electrode 20A and the electrode 20B to protect the electrode 20A and / or the electrode 20B from contamination or extrusion. For example, the coating 45B can be stacked on the coating 45A and can directly contact the coating 45A. However, the present invention is not limited to this, and in other embodiments, the coating 45B can be separated from the coating 45B. Alternatively, in some other embodiments, the coating 45A or the coating 45B can be omitted.

[0035] In some embodiments, the acoustic wave device 1 may further include a side wall 40A and / or a side wall 40B. For example, the side wall 40A may be disposed on the surface S2 of the substrate 10A and may at least partially surround the plurality of electrodes 20A. On the surface S2, the side wall 40A may completely or partially surround the plurality of electrodes 20A. For example, the side wall 40A may be formed into a complete rectangle to completely surround the plurality of electrodes 20A. In another example, the side wall 40A may be formed into an approximate rectangle, for example, a rectangle with a notch to partially surround the plurality of electrodes 20A. Figure 1 As shown, the coating 45A may be disposed on the sidewall 40A, so that the coating 45A, the sidewall 40A, and the substrate 10A together form a cavity 70A, wherein the plurality of electrodes 20A are located in the cavity 70A. Similarly, the sidewall 40B may be disposed on the surface S3 of the substrate 10B, and may at least partially surround the plurality of electrodes 20B. On the surface S3, the sidewall 40B may completely or partially surround the plurality of electrodes 20B, for example, the sidewall 40B may be formed into a complete rectangle to completely surround the plurality of electrodes 20B. In another example, the sidewall 40B may be formed into an approximate rectangle, for example, a rectangle with a notch to partially surround the plurality of electrodes 20B. As shown in FIG. Figure 1 As shown, the coating 45B may be disposed on the sidewall 40B, so that the coating 45B, the sidewall 40B, and the substrate 10B together form a cavity 70B, wherein a plurality of electrodes 20B are located in the cavity 70B.

[0036] Furthermore, along the vertical direction Y, the sidewall 40A and the sidewall 40B may be at least partially aligned, wherein the vertical direction Y may be a direction perpendicular to the surface S1 of the substrate 10A. Figure 1In the illustrated embodiment, the side wall 40A and the side wall 40B may be substantially completely aligned with each other. However, the present invention is not limited thereto, and in other embodiments, the side wall 40A may not be completely aligned with the side wall 40B, for example, offset along the horizontal direction X by a distance.

[0037] In a further embodiment, in the cavity 70A, a first passivation layer (not shown) may be disposed on the electrode 20A, for example, covering the electrode 20A, to protect the electrode 20A from contamination. In the cavity 70B, a second passivation layer (not shown) may be disposed on the electrode 20B, for example, covering the electrode 20B, to protect the electrode 20B from contamination.

[0038] For example, the material of the substrate 10A and / or 10B includes a piezoelectric material, for example, the substrate 10A may include a first piezoelectric substrate, and / or the substrate 10B may include a second piezoelectric substrate. The piezoelectric material includes, for example, a piezoelectric single crystal, a piezoelectric polycrystal (including piezoelectric ceramics), a piezoelectric polymer and / or a piezoelectric composite material. For example, the piezoelectric material may include zinc oxide (ZnO), aluminum nitride (AlN), lithium niobate (LiTaO3, LT), lithium niobate (LN), quartz (QZ), lead titanate (PTO), lead zirconate titanate (PZT) and the like or a combination thereof. In a further embodiment, for example, the substrate 10A and / or the substrate 10B may include a baseplate and a piezoelectric material layer disposed on the baseplate, wherein the material of the baseplate includes, for example, silicon.

[0039] For example, the material of the electrodes 20A and / or 20B may include molybdenum (Mo), copper (Cu), aluminum (Al), gold (Au), platinum (Pt), tungsten (W), other suitable metals, alloys, and combinations thereof.

[0040] For example, the material of the coating 45A and / or 45B may include a polymer dry film and / or a metal. Taking metal as an example, the conductive coating 45A and / or 45B may be grounded, thereby shielding or reducing undesirable signal coupling or interference, for example, reducing electromagnetic interference (EMI) between the electrode 20A and the electrode 20B. For example, the material of the sidewall 40A and the sidewall 40B may include a polymer dry film and / or a metal. In some embodiments, the sidewall 40A may be formed as a part of the coating 45A, that is, the sidewall 40A and the coating 45A may be formed in the same step.

[0041] For example, the material of the first passivation layer and / or the second passivation layer may include silicon dioxide and silicon nitride.

[0042] In some embodiments, the acoustic wave device 1 may further include a connection portion 33, which may be configured to contact the substrate 10A and the substrate 10B. For example, the connection portion 33 may be configured to contact both the surface S2 of the substrate 10A and the surface S3 of the substrate 10B. Figure 1 As shown, the connection portion 33 may include a contact pad 32A, a conductor portion 30, and a contact pad 32B, wherein the contact pad 32A is disposed on the surface S2 of the substrate 10A, and the contact pad 32B is disposed on the surface S3 of the substrate 10B. In the vertical direction Y, the contact pad 32A and the contact pad 32B may be at least partially aligned. In the present embodiment, the contact pad 32A and the contact pad 32B are substantially completely aligned with each other. The conductor portion 30 may be configured to contact the contact pad 32A and the contact pad 32B. In some embodiments not shown, the connection portion 33 may include a via, and the via may penetrate the substrate 10A and / or the substrate 10B to achieve electrical connection or grounding.

[0043] In a further embodiment, the connection portion 33 may be used to provide electrical connection, buffering, and / or support functions. In detail, the contact pad 32A of the connection portion 33 may be electrically connected to the electrode 20A, and / or the contact pad 32B may be electrically connected to the electrode 20B. The conductor portion 30 may be electrically connected to the electrode 20A via the contact pad 32A, and / or the conductor portion 30 may be electrically connected to the electrode 20B via the contact pad 32B. Therefore, the connection portion 33 (including the contact pad 32A, the conductor portion 30, and the contact pad 32B) may electrically connect the electrode 20A and the electrode 20B together. In this embodiment, the radio frequency signal may be transmitted between the electrode 20A and the electrode 20B via the connection portion 33 in any appropriate direction, for example, the first filter signal and the second filter signal may be output from the electrode 20A and the electrode 20B respectively through the conductor portion 30. In addition, when the second chip (including at least the substrate 10B and the electrode 20B) is stacked on the first chip (including at least the substrate 10A and the electrode 20A), for example, by flip chip bonding technology, the conductor portion 30 of the connecting portion 33 can provide a buffer between the two chips to prevent the electrodes 20A and 20B from being squeezed and deformed or damaged in performance. Furthermore, the conductor portion 30 can make the stacking structure more stable and will not cause tilting, forming a stable support.

[0044] In other embodiments, the connection portion 33 may not be used to provide an electrical connection function. Specifically, the contact pad 32A may not be electrically connected to the electrode 20A, and / or the contact pad 32B may not be electrically connected to the electrode 20B. Alternatively, the conductor portion 30 may not directly contact the contact pad 32A and / or the contact pad 32B. For example, an insulating layer may be additionally provided between the conductor portion 30 and the contact pad 30A so that there is no electrical connection between the contact pad 30A and the contact pad 30B. In this embodiment, the connection portion 33 may be used only for buffering and supporting purposes, and has no electrical connection with the electrode 20A or the electrode 20B.

[0045] In some embodiments, Figure 1 As shown, the connection portion 33 may be disposed on the outside of the side wall 40A and / or the side wall 40B. Specifically, taking the side wall 40A as an example, the electrode 20A located in the cavity 70A may be located on the inside of the side wall 40A, and the connection portion 33 may be located outside the cavity 70A, that is, located on the outside of the side wall 40A. In other words, the inside of the side wall 40A may be defined as a side close to the electrode 20A, and the outside of the side wall 40A may be defined as a side opposite to the inside.

[0046] In some embodiments, the acoustic wave device 1 may further include a mainboard 50, which is disposed on the surface S1 of the substrate 10A. The mainboard 50 may include a surface S5 and a surface S6. The surface S1 of the substrate 10B may be connected to the surface S6 of the mainboard 50 via an adhesive layer (not shown). For example, the mainboard 50 may include a printed circuit board. In such an embodiment, the acoustic wave device 1 may further include a connecting portion 35, which may be configured to contact the substrate 10B and the mainboard 50. For example, the connecting portion 35 may be configured to contact both the surface S3 of the substrate 10B and the surface S6 of the mainboard 50. Figure 1 As shown, the connection portion 35 may include a contact pad 34A, a conductor portion 31, and a contact pad 34B, wherein the contact pad 34A is disposed on the surface S6 of the mainboard 50, and the contact pad 34B is disposed on the surface S3 of the substrate 10B. In the vertical direction Y, the contact pad 34A and the contact pad 34B may be at least partially aligned. In the present embodiment, the contact pad 34A and the contact pad 34B are substantially completely aligned with each other. The conductor portion 31 may be configured to contact the contact pad 34A and the contact pad 34B. The function of the connection portion 35 may be similar to the above-mentioned connection portion 33, and will not be described here for the sake of brevity. In some embodiments, the contact pad 34A on the mainboard 50 may be used for electrical grounding. In some embodiments not shown, the connection portion 35 may include a through hole (via), and the through hole may pass through the substrate 10B and / or the mainboard 50.

[0047] For example, the material of the conductor part 30 and / or the conductor part 31 may include gold or tin. For example, the material of the conductor part 30 may include gold, and the material of the conductor part 31 may include tin. In addition, the conductor part 30 and / or the conductor part 31 may be substantially spherical or cylindrical, wherein the spherical shape includes a shape having an approximately circular cross-section along the vertical direction Y. The material of the contact pads 32A, 32B and / or the contact pads 34A, 34B may include tin.

[0048] In some embodiments, the acoustic wave device 1 may further include a sealing element 60 to fill the gap in the acoustic wave device 1 to ensure airtightness. The sealing element 60 may be formed, for example, by transfer molding or compression molding. For example, transfer molding may use a pressure of 8 to 9 megapascals (Mpa) to form the sealing element 60, and compression molding may use a pressure of 0.5 to 5 Mpa to form the sealing element 60.

[0049] For example, the material of the sealing element 60 may include resin.

[0050] Although in Figure 1 , the acoustic wave device 1 only includes two stacked SAW devices. Those skilled in the art can apply the principles of the present invention to stack other numbers of SAW devices in the acoustic wave device 1 to meet actual needs.

[0051] Figure 2 is a schematic top view of the acoustic wave device 1. For the purpose of clear explanation, the top view schematically omits some elements, or additionally shows some elements that are shielded. As shown in the figure, taking the first chip as an example, the plurality of electrodes 20A can be formed into a forked finger structure, and can be located in the rectangular area formed by the side wall 40A. For example, the plurality of electrodes 20A may include an input electrode 201A, a plurality of transducer electrodes 203A, a plurality of transducer electrodes 204A, and an output electrode 205A. In detail, the input electrode 201A may extend along a horizontal direction X, each of the plurality of transducer electrodes 203A extends from the input electrode 201A along a horizontal direction Z, and each transducer electrode 203A is spaced apart along the horizontal direction X. As shown in FIG. Figure 2 As shown, the end of each transducer electrode 203A away from the input electrode 201A may be separated from the output electrode 205A. Similarly, the output electrode 205A may extend along the horizontal direction X, each of the plurality of transducer electrodes 204A extends from the output electrode 205A along the horizontal direction Z, and each transducer electrode 204A is arranged at intervals along the horizontal direction X. Figure 2As shown, the end of each of the transducer electrodes 204A away from the output electrode 205A may be separated from the input electrode 201A. Further, each of the plurality of transducer electrodes 203A may be separated from any one of the plurality of transducer electrodes 204A, for example, the plurality of transducer electrodes 203A and the plurality of transducer electrodes 204A may be alternately arranged along the horizontal direction X, that is, a transducer electrode 203A may be located between two adjacent ones of the plurality of transducer electrodes 204A. However, the present invention is not limited thereto. For example, in other embodiments, no transducer electrode 203A is located between two adjacent ones of the plurality of transducer electrodes 204A, or two or more transducer electrodes 203A may be located between two adjacent ones of the plurality of transducer electrodes 204A.

[0052] In some embodiments, the input electrodes 201A and / or 205A are also referred to as busbar electrodes or busbar electrodes, and the transducer electrodes 203A or 204A are also referred to as interdigital electrodes. In some embodiments, the horizontal direction Z and the horizontal direction X are both parallel, such as the surface S1 of the substrate 10A, and the horizontal direction Z and the horizontal direction X are perpendicular to each other. However, the present invention is not limited to this, and in other examples, the horizontal direction Z and the horizontal direction X may form an angle other than 90 degrees. It should be noted that the input electrodes and / or output electrodes referred to herein are only used to distinguish different electrodes and are not intended to limit the meaning. In other words, the input electrodes referred to herein may also be used to output signals, and the output electrodes may also be used to input signals.

[0053] In some embodiments, one of the transducer electrodes 203A and / or 204A may have an electrode length L1, an electrode width W1, and an electrode thickness T1 (not shown). Figure 2 In the case where the transducing electrodes 203A and 204A are alternately arranged, there may be an electrode interval g1 therebetween.

[0054] Similarly, the electrode 20B of the second chip can also be formed into a forked finger structure and can be located in the rectangular area formed by the side wall 40B. The arrangement of the plurality of electrodes 20B can be similar to the plurality of electrodes 20A described above, and the details are not repeated here. It should be noted that the second chip can have the following parameters: electrode length L2, electrode width W2, electrode thickness T2, and electrode spacing g2. Further, the first chip and the second chip can be different in at least one of the following aspects: electrode length, electrode width, electrode thickness, and electrode spacing, so that the first chip and the second chip can be used to process sound waves of different wavelengths respectively. Specifically, the electrode length L1 can be different from the electrode length L2, the electrode width W1 can be different from the electrode width W2, the electrode thickness T1 can be different from the electrode thickness T2, and / or the electrode spacing g1 can be different from the electrode spacing g2.

[0055] Also refer to Figure 1 and Figure 2, the wires C1, C5, C3, and / or C7 may be disposed on the surface S2 of the substrate 10A, and may be used to couple the electrode 20A with the contact pad 32A. For example, the input electrode 201A of the electrode 20A is coupled to the contact pad 32A of the connection portion 33 via the wire C3 or C7, and the output electrode 205A of the electrode 20A may be coupled to the contact pad 32A of the connection portion 33 via the wire C1 or C5. In some embodiments, any of the wires C1, C5, C3, and C7 may be omitted as required. In addition, the wires C2, C4, C6, and / or C8 are disposed on the surface S3 of the substrate 10B, and may be used to couple the connection portion 33 with the connection portion 35. For example, the contact pad 32B of the connection portion 33 may be coupled to the contact pad 34B of the connection portion 35 via the wires C2, C4, C6, and / or C8. In this embodiment, for example, a transmission path of the RF signal may at least include the wire C5, the contact pad 32A, the conductor portion 30, the contact pad 32B, the wire C6, the contact pad 34B, the conductor portion 31, and the contact pad 34A.

[0056] Figure 3 Flow chart of the manufacturing method 300 of the acoustic wave device 1. The manufacturing method 300 includes steps S301 to S305, which are used to stack a first chip including a plurality of electrodes 20A and a second chip including a plurality of electrodes 20B using, for example, a flip chip technology to manufacture the acoustic wave device 1. Any reasonable technical changes or step adjustments fall within the scope of the present invention. The details of steps S301 to S305 are as follows:

[0057] Step S301: providing a first wafer, wherein the first wafer comprises a first substrate, a first electrode and a first covering film;

[0058] Step S303: providing a second chip, wherein the second chip includes a second substrate and a second electrode;

[0059] Step S305: stacking the second chip on the first chip, so that the first electrode and the second electrode are located between the first substrate and the second substrate, and the first coating is disposed between the first electrode and the second electrode.

[0060] The following references Figure 1The steps of the manufacturing method 300 are explained. In step S301, the first chip may include a first substrate 10A, a plurality of first electrodes 20A, and a first coating 45A. In step S303, the second chip may include a second substrate 10B, a plurality of second electrodes 20B, and a second coating 45B. In step S305, the second chip is stacked on the first chip, for example, using a flip chip bonding technique, so that the first electrode 20A and the second electrode 20B are located between the first substrate 10A and the second substrate 10B. The first coating 45A is disposed between the first electrode 20A and the second electrode 20B, and the second coating 45B may also be disposed between the first electrode 20A and the second electrode 20B.

[0061] For example, the contact pad 32A and the conductor part 30 may be disposed on the first substrate 10A of the first chip, and the contact pad 32B may be disposed on the second substrate 10B of the second chip. In step S305, when the second chip is stacked on the first chip, the conductor part 30 on the first substrate 10A is bonded to the contact pad 32B on the second substrate 10B. However, the present invention is not limited thereto, and in other embodiments, the conductor part 30 may also be disposed on the second substrate 10B of the second chip before stacking.

[0062] During step S305, the first coating 45A covers and protects the plurality of first electrodes 20A from being contaminated or squeezed, and the second coating 45B covers and protects the plurality of second electrodes 20B from being contaminated or squeezed. By means of the buffering and supporting functions of the connecting portion 33 (which may include the contact pad 32A, the conductor portion 30, and the contact pad 32B), the alignment degree of the second wafer with the first wafer may not be so strict, thereby reducing the difficulty of the process.

[0063] In some embodiments, the first chip and the second chip may be applied to different frequencies, and the second cover film 45B of the second chip may be omitted.

[0064] Furthermore, the contact pad 34B may be disposed on the second substrate 10B of the second chip, and the contact pad 34A and the conductor portion 31 may be disposed on the main board 50. In a subsequent step not shown, for example, the second chip may be bonded to the main board 50 using a flip chip bonding technique, wherein the contact pad 34B on the second substrate 10B is bonded to the conductor portion 31 on the main board 50. However, the present invention is not limited thereto, and in other embodiments, before the second chip is bonded to the main board 50, the conductor portion 31 may also be disposed on the second substrate 10B of the second chip.

[0065] In some embodiments, in a subsequent step not shown, transfer molding or compression molding may be used to form the sealing element 60 , which fills the gap in the acoustic wave device 1 to ensure airtightness.

[0066] Figure 4FIG. 4 is a cross-sectional schematic diagram of another exemplary acoustic wave device 4 in an embodiment of the present invention. The main difference between the acoustic wave device 4 and the acoustic wave device 1 is that the acoustic wave device 1 shows a double-layer coating between the electrode 20A and the electrode 20B, such as the coatings 45A and 45B, while the acoustic wave device 4 shows a single-layer coating between the electrode 20A and the electrode 20B, such as the coating 45. The arrangement and operation of other components in the acoustic wave device 4 are the same as those of the acoustic wave device 1 and will not be described in detail herein.

[0067] In the acoustic wave device and manufacturing method of the embodiment of the present invention, two surface acoustic wave wafers can be stacked to reduce the area occupied by the acoustic wave device. A coating can be provided between two sets of electrodes of the acoustic wave device to protect the electrodes from being squeezed or contaminated, thereby reducing the difficulty of the process.

[0068] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention should fall within the scope of the present invention.

Claims

1. An acoustic wave device, characterized in that: include: A first substrate including a first surface and a second surface; A plurality of first electrodes are disposed on the second surface of the first substrate; A second substrate including a third surface and a fourth surface; a plurality of second electrodes disposed on the third surface of the second substrate, wherein the second surface of the first substrate faces the third surface of the second substrate, so that the plurality of first electrodes and the plurality of second electrodes are located between the first substrate and the second substrate; and A first coating is disposed between the plurality of first electrodes and the plurality of second electrodes.

2. The acoustic wave device according to claim 1, characterized in that The device further comprises a first side wall disposed on the second surface of the first substrate and at least partially surrounding the plurality of first electrodes, wherein The first coating covers the first side wall, and the first substrate, the first side wall and the first coating form a first cavity, and the plurality of first electrodes are located in the first cavity.

3. The acoustic wave device according to claim 2, characterized in that Also includes: A second side wall is disposed on the third surface of the second substrate and at least partially surrounds the plurality of second electrodes.

4. The acoustic wave device according to claim 3, characterized in that Also includes: A second coating covers the second side wall, and the second substrate, the second side wall and the second coating form a second cavity, and the plurality of second electrodes are located in the second cavity.

5. The acoustic wave device according to claim 3, characterized in that Also includes: A first connecting portion is configured to contact the first substrate and the second substrate and is located between the second surface of the first substrate and the third surface of the second substrate.

6. The acoustic wave device according to claim 5, characterized in that in: The first connecting portion includes: A first contact pad is disposed on the second surface of the first substrate; a second contact pad disposed on the third surface of the second substrate, wherein the second contact pad is at least partially aligned with the first contact pad in a vertical direction; and A first conductor portion is configured to contact the first contact pad and the second contact pad.

7. The acoustic wave device according to claim 6, characterized in that The first contact pad is electrically connected to the plurality of first electrodes, and / or the second contact pad is electrically connected to the plurality of second electrodes.

8. The acoustic wave device according to claim 5, characterized in that The invention also comprises a main board which is arranged on the first surface of the first substrate.

9. The acoustic wave device according to claim 8, characterized in that in: The mainboard includes a fifth surface and a sixth surface, and the first surface of the first substrate is connected to the sixth surface of the mainboard via an adhesive layer; and The acoustic wave device further includes a second connecting portion, which is configured to contact the second substrate and the main board and is located between the third surface of the second substrate and the sixth surface of the main board.

10. The acoustic wave device according to claim 9, characterized in that The second connecting portion includes: a third contact pad disposed on the sixth surface of the mainboard; a fourth contact pad disposed on the third surface of the second substrate, wherein the fourth contact pad is at least partially aligned with the third contact pad in a vertical direction; and A second conductor portion is configured to contact the third contact pad and the fourth contact pad.

11. The acoustic wave device according to claim 10, characterized in that The fourth contact pad is electrically connected to the second contact pad, and / or the third contact pad is electrically grounded.

12. The acoustic wave device according to claim 10, characterized in that The material of the second conductor portion includes gold or tin.

13. The acoustic wave device according to claim 3, characterized in that The material of the first side wall includes a polymer dry film, and the material of the second side wall includes a polymer dry film.

14. The acoustic wave device according to claim 3, characterized in that In a vertical direction, the first side wall is at least partially aligned with the second side wall.

15. The acoustic wave device according to claim 5, characterized in that The first connecting portion is disposed on an outer side of the first side wall or the second side wall.

16. The acoustic wave device according to claim 6, characterized in that The material of the first conductor portion includes gold or tin.

17. The acoustic wave device according to claim 1, characterized in that in: The first substrate includes a first piezoelectric substrate; and The second substrate includes a second piezoelectric substrate.

18. The acoustic wave device according to claim 1, characterized in that in: The plurality of first electrodes include a first input electrode, a first transducer electrode, and a first output electrode; and The plurality of second electrodes include a second input electrode, a second transducer electrode, and a second output electrode.

19. The acoustic wave device according to claim 18, characterized in that in: The first transducer electrode and the second transducer electrode are used for sound waves of different wavelengths.

20. The acoustic wave device according to claim 18, characterized in that in: The first transducer electrode is different from the second transducer electrode in at least one of the following aspects: an electrode length, an electrode width, an electrode thickness and an electrode interval.

21. The acoustic wave device according to claim 1, characterized in that in: The material of the first coating includes a polymer dry film and / or metal.

22. A method for manufacturing an acoustic wave device, characterized in that: include: Providing a first chip, the first chip comprising a first substrate, a first electrode and a first covering film; providing a second chip, the second chip comprising a second substrate and a second electrode; and The second chip is stacked on the first chip, so that the first electrode and the second electrode are located between the first substrate and the second substrate, and the first coating is disposed between the first electrode and the second electrode.

23. The method according to claim 22, characterized in that in: The second chip includes a second covering film; and The second coating is disposed between the first electrode and the second electrode.

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