A pad structure of a surface acoustic wave device and a surface acoustic wave filter

Abstract

The utility model relates to surface acoustic wave device technical field provides a kind of pad structure and surface acoustic wave filter of surface acoustic wave device, wherein the pad structure of surface acoustic wave device includes: base layer structure, is provided with pad area;First adhesive layer, is set on the base layer structure and is located in the pad area;Enhancement layer group, is set on the first adhesive layer, the enhancement layer group includes at least one layer of enhancement layer and at least one layer of second adhesive layer of staggered lamination, the lowermost layer of the enhancement layer group is the enhancement layer, the uppermost layer of the enhancement layer group is the second adhesive layer;Bonding layer, is set on the enhancement layer group. Enhancement layer group can enhance the supporting effect to bonding layer, it is favorable to limit the occurrence of grain boundary slip when bonding, so that the plastic deformation caused by bonding is more controllable, to make the contact area at bonding interface more stable, reach the effect of improving bonding binding force and making pad connection more stable and reliable.

Description

Technical Field

[0001] This utility model relates to the field of surface acoustic wave (SAW) device technology, and in particular to a pad structure for a SAW device and a SAW filter. Background Technology

[0002] Surface acoustic wave (SAW) devices are electronic devices that utilize sound waves propagating on the surface of piezoelectric materials for signal processing. They are widely used in key functions such as filtering and resonance in wireless communication. The structure of a SAW device typically includes a piezoelectric substrate, interdigital transducers fabricated on the piezoelectric substrate, and metal pads for external electrical connections. During packaging, the metal pads need to be connected to external circuits via gold ball bonding to achieve mechanical fixation and electrical interconnection. Therefore, the bonding strength between the metal pads and the gold balls is crucial to the reliability of the structure.

[0003] However, in existing technologies, the metal pads of surface acoustic wave (SAW) devices generally employ a stacked structure of titanium and aluminum layers, with the aluminum layer bonded to gold balls. However, under the ultrasonic energy and pressure applied during the bonding process, the aluminum layer is prone to grain boundary slip, leading to uncontrollable plastic deformation. This results in unstable actual contact area at the bonding interface, causing insufficient bonding force, which in turn affects the reliability of the pad connection and restricts the device's packaging yield. Utility Model Content

[0004] This invention provides a pad structure for a surface acoustic wave (SAW) device and a SAW device, which solves the defect of insufficient bonding force in the pads of existing SAW devices.

[0005] This utility model provides a pad structure for a surface acoustic wave device, comprising: The base structure includes a solder pad area. A first adhesive layer is disposed on the base structure and located in the pad area; A reinforcing layer group is disposed on the first adhesive layer. The reinforcing layer group includes at least one reinforcing layer and at least one second adhesive layer that are stacked in an alternating manner. The bottom layer of the reinforcing layer group is the reinforcing layer, and the top layer of the reinforcing layer group is the second adhesive layer. A bonding layer is disposed on the enhancement layer group.

[0006] According to the present invention, a surface acoustic wave device has a pad structure, wherein the reinforcement layer group includes two reinforcement layers and two second adhesive layers.

[0007] According to the present invention, the pad structure of a surface acoustic wave device is provided, wherein the reinforcing layer is an aluminum alloy layer.

[0008] According to the pad structure of the surface acoustic wave device provided by this utility model, both of the reinforcing layers are aluminum-copper alloy layers. And / or, both of the reinforcing layers are aluminum-titanium alloy layers; And / or, one of the two reinforcing layers is an aluminum-copper alloy layer and the other is an aluminum-titanium alloy layer.

[0009] According to the present invention, the bonding layer of a surface acoustic wave device is an aluminum layer.

[0010] According to the pad structure of the surface acoustic wave device provided by this utility model, the first adhesive layer is a titanium layer, a chromium layer, or a nickel-chromium alloy layer.

[0011] According to the pad structure of the surface acoustic wave device provided by this utility model, the second adhesive layer is a titanium layer, a chromium layer, or a nickel-chromium alloy layer.

[0012] According to the present invention, a pad structure for a surface acoustic wave device is provided, wherein the base structure includes a piezoelectric substrate, an interdigital transducer layer, a dielectric layer and a wiring layer stacked from bottom to top, and the pad area is disposed on the wiring layer.

[0013] According to the present invention, a surface acoustic wave device pad structure further includes a passivation layer disposed on the trace layer, wherein the passivation layer has a window portion in the pad area for exposing the bonding layer.

[0014] This invention also provides a surface acoustic wave filter, including the pad structure of the surface acoustic wave device described above.

[0015] This invention provides a surface acoustic wave (SAW) device pad structure and SAW filter, which has at least the following beneficial effects: In the pad region of the base structure, a reinforcement layer group is provided between a first adhesive layer and a bonding layer. The reinforcement layer group includes at least one reinforcement layer and at least one second adhesive layer. When multiple reinforcement layers and multiple second adhesive layers are provided, they are stacked in a staggered manner. The bottom layer of the reinforcement layer group is the reinforcement layer, i.e., the reinforcement layer is placed on the first adhesive layer, and the top layer of the reinforcement layer group is the second adhesive layer, i.e., the bonding layer is placed on the second adhesive layer. With this structure, the reinforcement layer group located between the first adhesive layer and the bonding layer can enhance the support of the bonding layer, which is beneficial for limiting the occurrence of grain boundary slip during bonding, making the plastic deformation caused by bonding more controllable, and thus making the contact area at the bonding interface more stable, thereby improving the bonding force and making the pad connection more stable and reliable. Meanwhile, the structure of the interleaved reinforcing layer and the second adhesive layer in the reinforcing layer group can disperse the stress generated by bonding in the multilayer structure, avoid local stress concentration, prevent crack propagation and grain boundary slip, and further improve the stability and reliability of bonding forces. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this utility model or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of one embodiment of the pad structure of a surface acoustic wave device provided by this utility model.

[0018] Figure 2 This is a schematic diagram of another embodiment of the pad structure of a surface acoustic wave device provided by this utility model.

[0019] Figure 3 This is a frequency response test diagram of one embodiment of a surface acoustic wave filter provided by this utility model.

[0020] Figure 4 This is a frequency response test diagram of another embodiment of the surface acoustic wave filter provided by this utility model.

[0021] Figure label: 100: Base layer structure; 101: Pad area; 110: Piezoelectric substrate; 120: Interdigitated transducer layer; 130: Dielectric layer; 140: Wiring layer; 200: First adhesive layer; 300: Reinforcement layer group; 310: Reinforcement layer; 320: Second adhesive layer; 400: Bonding layer; 500: Passivation layer; 510: Window. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0023] The following is combined Figure 1 and Figure 2 The present invention describes a pad structure for a surface acoustic wave (SAW) device, comprising: The base structure 100 has a pad area 101; A first adhesive layer 200 is disposed on the base structure 100 and located in the pad area 101; A reinforcing layer group 300 is disposed on the first adhesive layer 200. The reinforcing layer group 300 includes at least one reinforcing layer 310 and at least one second adhesive layer 320 that are stacked in an alternating manner. The bottom layer of the reinforcing layer group 300 is the reinforcing layer 310, and the top layer of the reinforcing layer group 300 is the second adhesive layer 320. A bonding layer 400 is disposed on the reinforcement layer group 300.

[0024] In the pad area 101 of the base structure 100, a reinforcement layer group 300 is provided between the first adhesive layer 200 and the bonding layer 400. The reinforcement layer group 300 includes at least one reinforcement layer 310 and at least one second adhesive layer 320. When multiple reinforcement layers 310 and multiple second adhesive layers 320 are provided, they are stacked in a cross-layer manner. The bottom layer of the reinforcement layer group 300 is the reinforcement layer 310, that is, the reinforcement layer 310 is provided on the first adhesive layer 200. The top layer of the reinforcement layer group 300 is the second adhesive layer 320, that is, the bonding layer 400 is provided on the second adhesive layer 320.

[0025] With this structure, the reinforcing layer group 300 located between the first adhesive layer 200 and the bonding layer 400 can enhance the support of the bonding layer 400, which helps to limit the occurrence of grain boundary slip during bonding, making the plastic deformation caused by bonding more controllable, thereby making the contact area at the bonding interface more stable, achieving the effect of improving the bonding force and making the pad connection more stable and reliable.

[0026] Meanwhile, the structure of the interleaved reinforcing layer 310 and the second adhesive layer 320 in the reinforcing layer group 300 can disperse the stress generated by bonding in the multilayer structure, avoid local stress concentration, prevent crack propagation and grain boundary slip, and further improve the stability and reliability of bonding forces.

[0027] It is important to emphasize that the hardness of the reinforcing layer 310 is higher than that of the bonding layer 400. During bonding, under the action of bonding ultrasound and pressure, the bonding layer 400 undergoes plastic deformation and atomic diffusion to form a strong intermetallic compound with the bonding wire. In this process, the higher hardness of the reinforcing layer 310 requires greater bonding energy to undergo plastic deformation. Therefore, the reinforcing layer 310 can provide structural support for the bonding layer 400, restrict the occurrence of grain boundary slip, and make the plastic deformation of the bonding layer 400 more controllable and stable, thereby improving the bonding force.

[0028] It should be noted that, compared to the common structure of titanium and aluminum layers, where a single aluminum layer is responsible for both structural support and surface bonding, by introducing the reinforcing layer group 300, the functions of structural support and surface bonding are separated into different layers, achieving the effect of functional separation. In this way, the reliability of structural support can be guaranteed by the reinforcing layer group 300, avoiding the performance limitations of a single aluminum layer, and improving the stability and reliability of the bonding process.

[0029] For bonding strength, quantitative evaluation is usually based on push force testing. Specifically, a testing tool is used to apply a force perpendicular to the pad surface or at a certain angle to separate the gold ball bonding point from the pad until the connection between the gold ball and the pad breaks. The force value at the moment of bond breakage, i.e., the push force, is recorded to quantify the bonding strength and to assess the reliability between the bonded wire and the pad. This invention, by adding a reinforcing layer group 300 between the first adhesive layer 200 and the bonding layer 400, can verify, based on push force testing, that adding the reinforcing layer 310 can stably improve the push force.

[0030] It is understood that the base structure 100 may include structures such as a piezoelectric layer and an interdigital transducer layer 120 to realize the function of a surface acoustic wave device. Multiple pad areas 101 may be provided on the base structure 100.

[0031] refer to Figure 1 and Figure 2 In some embodiments of the pad structure of a surface acoustic wave device according to the present invention, the reinforcement layer group 300 includes two reinforcement layers 310 and two second adhesive layers 320.

[0032] The more reinforcing layers 310 and second adhesive layers 320 there are in the reinforcing layer group 300, the more significant the supporting effect on the bonding layer 400, and the more layers are stacked, the better they are at dispersing bonding stress throughout the multilayer structure. However, more layers also make the structure and processing more complex. Therefore, a structure with two reinforcing layers 310 and two second adhesive layers 320 stacked alternately can achieve a better balance between structural performance and structural complexity. That is, compared to a structure with only one reinforcing layer 310 and one second adhesive layer 320, it can more effectively hinder dislocation movement and grain boundary slip, which is beneficial for further enhancing the bonding force, while avoiding excessive structural complexity.

[0033] It is understood that the number of reinforcing layer 310 and second adhesive layer 320 may be adjusted according to the needs of actual application scenarios, that is, according to different requirements for bonding strength and cost control. In some embodiments, the reinforcing layer group 300 may include only one reinforcing layer 310 and one second adhesive layer 320; in some embodiments, the reinforcing layer group 300 may include three or more layers of reinforcing layer 310 and second adhesive layer 320.

[0034] In some embodiments of the pad structure of the surface acoustic wave device of this utility model, the reinforcing layer 310 is an aluminum alloy layer.

[0035] The reinforcing layer 310 is made of aluminum alloy. Under the ultrasonic energy and pressure applied during bonding, the aluminum alloy layer itself is not prone to plastic deformation, thus providing reliable support for the bonding layer 400 above, which helps to avoid collapse and uncontrollable plastic deformation. In this way, the stability of the bonding interface is ensured, thereby improving the bonding force.

[0036] The aluminum alloy layer is formed by adding other metallic or non-metallic elements to pure aluminum. Due to the presence of the added elements, lattice distortion is introduced into the aluminum alloy layer, forming second-phase precipitates or refining the grains. This can effectively hinder grain boundary slip, thereby improving hardness and yield strength, and providing a basis for the aluminum alloy layer to perform the structural support function as a reinforcing layer 310.

[0037] In some embodiments of this invention, when the bonding layer 400 is an aluminum layer, using an aluminum alloy layer as the reinforcing layer 310 can also achieve the effect of matching the coefficients of thermal expansion. Since the coefficients of thermal expansion of the aluminum layer and the aluminum alloy layer are close, the thermal stress generated by thermal expansion can be reduced at different temperatures, avoiding excessive internal thermal stress and cracking due to a large difference in the coefficients of thermal expansion, thus improving the overall structural reliability.

[0038] In some embodiments of the pad structure of the surface acoustic wave device of this utility model, both reinforcing layers 310 are aluminum-copper alloy layers. And / or, both of the reinforcing layers 310 are aluminum-titanium alloy layers; And / or, one of the two reinforcing layers 310 is an aluminum-copper alloy layer and the other is an aluminum-titanium alloy layer.

[0039] In the aluminum-copper alloy layer (AlCu), copper atoms effectively inhibit the electromigration of aluminum and increase hardness; in the aluminum-titanium alloy layer (AlTi), titanium atoms significantly improve the material's hardness and strength. The reinforcing layer 310, employing either an aluminum-copper alloy layer or an aluminum-titanium alloy layer, can provide structural support and achieve the goal of improving bonding strength.

[0040] Both reinforcing layers 310 are made of aluminum-copper alloy, which not only enhances structural support but also improves electromigration resistance, thus improving the long-term operational stability and current carrying capacity of the device. Both reinforcing layers 310 are also made of aluminum-titanium alloy, providing even more reliable structural support. Furthermore, with the second adhesive layer 320 being a titanium layer, the compatibility between the aluminum-titanium alloy and titanium layers is higher, further improving overall structural reliability. Alternatively, one reinforcing layer 310 may be an aluminum-copper alloy, and the other an aluminum-titanium alloy, combining the advantages of both to achieve both good electromigration resistance and reliable structural support.

[0041] In the case where one of the two reinforcing layers 310 is an aluminum-copper alloy layer and the other is an aluminum-titanium alloy layer, the lower layer may be an aluminum-copper alloy layer (AlCu) and the upper layer may be an aluminum-titanium alloy layer (AlTi), or the lower layer may be an aluminum-titanium alloy layer (AlTi) and the upper layer may be an aluminum-copper alloy layer (AlCu).

[0042] In some embodiments of this utility model, the copper content in the aluminum-copper alloy layer can be between 1% and 5%, and the titanium content in the aluminum-titanium alloy layer can be between 1% and 5%.

[0043] In some embodiments of this utility model, in addition to aluminum-copper alloys and aluminum-titanium alloys, the reinforcing layer 310 can also be made of other types of aluminum alloys, such as aluminum-silicon (AlSi) alloy layers, which are aluminum alloy types that can achieve structural support functions.

[0044] In some embodiments of the pad structure of the surface acoustic wave device of this utility model, the bonding layer 400 is an aluminum layer.

[0045] An aluminum layer (Al) is used as the bonding layer 400. When naturally exposed, the surface of the aluminum layer forms a thin and dense layer of aluminum oxide. Under the ultrasonic energy of bonding, the aluminum oxide is broken down, exposing the pure aluminum underneath. Pure aluminum is relatively soft and has excellent ductility, easily undergoing plastic deformation and atomic diffusion. This allows it to bond with the gold wire to form a strong intermetallic compound, achieving a stable connection between the pad and the bonded gold wire. Therefore, by using an aluminum layer as the bonding layer 400, the excellent ductility of aluminum ensures a large-area, high-quality metallurgical bond with the gold ball during bonding. This, combined with the structural integration of the reinforcing layer group 300, provides structural support to prevent grain boundary slip in the aluminum layer, making the plastic deformation of the aluminum layer more stable, thereby improving the bonding strength.

[0046] It is understandable that when the bonding layer 400 is made of aluminum and the reinforcing layer 310 is made of aluminum alloy, the thermal expansion coefficients of aluminum and aluminum alloy are similar, which helps to reduce the thermal stress caused by temperature changes, and thus helps to make the structure of the pad more stable and reliable.

[0047] In some embodiments of this utility model, the bonding layer 400 may be made of aluminum, copper, silver, or other materials.

[0048] In some embodiments of the pad structure of the surface acoustic wave device of this utility model, the first adhesive layer 200 is a titanium layer, a chromium layer, or a nickel-chromium alloy layer. In some embodiments of the pad structure of the surface acoustic wave device of this utility model, the second adhesive layer 320 is a titanium layer, a chromium layer, or a nickel-chromium alloy layer.

[0049] The first adhesive layer 200 and the second adhesive layer 320 are made of titanium (Ti), chromium (Cr), or nickel-chromium alloy (NiCr), which have excellent wettability and chemical affinity, facilitating the formation of a strong bonding interface and tight connection with adjacent layers to achieve adhesion. The first adhesive layer 200 ensures that the overall multilayer structure can be firmly attached to the base structure 100; the second adhesive layer 320, located between the reinforcing layers 310, ensures reliable bonding between reinforcing layers 310 and between reinforcing layers 310 and bonding layers 400, preventing delamination or peeling, and improving the stability and reliability of the overall pad structure.

[0050] refer to Figure 2 In some embodiments of the pad structure of a surface acoustic wave device of the present invention, the base structure 100 includes a piezoelectric substrate 110, an interdigital transducer layer 120, a dielectric layer 130 and a wiring layer 140 stacked from bottom to top, and the pad area 101 is disposed on the wiring layer 140.

[0051] An interdigital transducer layer 120 is disposed on a piezoelectric substrate 110. The interdigital transducer layer 120 is used to realize the electroacoustic conversion function of the surface acoustic wave device. The dielectric layer 130 between the interdigital transducer layer 120 and the wiring layer 140 is used for electrical isolation and protection. The wiring layer 140 is used for wiring and for leading out through pads so that the interdigital transducer layer 120 can be electrically connected to pins or other devices.

[0052] In the pad region 101 of the trace layer 140, a reinforcement layer group 300 is provided between the first adhesive layer 200 and the bonding layer 400. This enhances the support for the bonding layer 400, helps to limit grain boundary slip during bonding, makes the plastic deformation caused by bonding more controllable, and thus makes the contact area at the bonding interface more stable. This improves the bonding force and makes the pad connection more stable and reliable. At the same time, the structure of the interleaved reinforcement layer 310 and the second adhesive layer 320 in the reinforcement layer group 300 can disperse the stress generated by bonding in the multilayer structure, avoid local stress concentration, prevent crack propagation and grain boundary slip, and further improve the stability and reliability of the bonding force.

[0053] It is understood that the first adhesive layer 200 and the trace layer 140 are partially connected in the pad area 101; the interdigitated transducer layer may include implementations of structures such as interdigitated electrodes and reflective grids.

[0054] In some embodiments of this utility model, the piezoelectric substrate 110 may include a structure in which a support layer, a low-velocity layer and a piezoelectric layer are stacked sequentially from bottom to top, or it may include a structure in which a support layer, a low-velocity layer, a high-velocity layer and a piezoelectric layer are stacked sequentially from bottom to top. The piezoelectric substrate 110 may also be other commonly used substrate structures.

[0055] refer to Figure 2 In some embodiments of the pad structure of the surface acoustic wave device of this utility model, a passivation layer 500 is further included. The passivation layer 500 is disposed on the trace layer 140. The passivation layer 500 has a window portion 510 in the pad area 101, and the window portion 510 is used to expose the bonding layer 400.

[0056] By covering the trace layer 140 with a passivation layer 500, the passivation layer 500 serves as an insulating protective layer to protect the traces and structure of the trace layer 140, preventing environmental factors such as moisture and impurity particle contamination, and avoiding damage from impacts and scratches, thus improving the reliability of the structure. The passivation layer 500 has an opening 510 at the pad area 101 to expose the bonding layer 400 of the pad area 101, facilitating bonding connections. During the bonding process, the passivation layer 500 protects the trace layer 140.

[0057] In some embodiments of this utility model, the passivation layer 500 can be implemented as a silicon nitride layer (SiN) or a silicon dioxide layer (SiO2), or it can be an organic polymer material, such as polyimide.

[0058] The following describes a surface acoustic wave filter provided by this utility model. The surface acoustic wave filter described below and the pad structure of the surface acoustic wave device described above can be referred to and correspond to each other.

[0059] refer to Figure 1 and Figure 2 This utility model also provides a surface acoustic wave filter, including the pad structure of the surface acoustic wave device described above.

[0060] Within the surface acoustic wave (SAW) filter, the base layer structure 100 performs the SAW filtering function. The pad area 101 on the base layer structure 100 is connected to pins or other devices to achieve electrical connection, thus bringing out the SAW filtering function. In the pad area 101 of the base layer structure 100, a reinforcement layer group 300 is provided between the first adhesive layer 200 and the bonding layer 400. The reinforcement layer group 300 includes at least one reinforcement layer 310 and at least one second adhesive layer 320. When multiple reinforcement layers 310 and multiple second adhesive layers 320 are provided, they are stacked in a staggered manner. The bottom layer of the reinforcement layer group 300 is the reinforcement layer 310, i.e., the reinforcement layer 310 is disposed on the first adhesive layer 200, and the top layer of the reinforcement layer group 300 is the second adhesive layer 320, i.e., the bonding layer 400 is disposed on the second adhesive layer 320.

[0061] With this structure, the reinforcing layer group 300 located between the first adhesive layer 200 and the bonding layer 400 can enhance the support of the bonding layer 400, which helps to limit the occurrence of grain boundary slip during bonding, making the plastic deformation caused by bonding more controllable, thereby making the contact area at the bonding interface more stable, achieving the effect of improving the bonding force and making the pad connection more stable and reliable.

[0062] Meanwhile, the structure of the interleaved reinforcing layer 310 and the second adhesive layer 320 in the reinforcing layer group 300 can disperse the stress generated by bonding in the multilayer structure, avoid local stress concentration, prevent crack propagation and grain boundary slip, and further improve the stability and reliability of bonding forces.

[0063] It is understandable that after the pads are bonded, the base structure 100, the pads, and the bonding wires are encapsulated for protection.

[0064] This invention adds a reinforcing layer group 300 between the first adhesive layer 200 and the bonding layer 400, which improves the bonding strength without degrading the frequency response. For a more intuitive explanation, refer to... Figure 3 and Figure 4 , Figure 3The measured frequency response curves are shown for the embodiment in which the structure of the first adhesive layer 200, the reinforcing layer group 300 and the bonding layer 400 includes, from bottom to top, a titanium layer, an aluminum-copper alloy layer, a titanium layer, an aluminum-copper alloy layer, a titanium layer and an aluminum layer, i.e., Ti / AlCu / Ti / AlCu / Ti / Al. Figure 4 The measured frequency response curves are shown for an embodiment where the structure of the first adhesive layer 200, the reinforcing layer group 300, and the bonding layer 400, from bottom to top, includes a titanium layer, an aluminum-titanium alloy layer, a titanium layer, an aluminum-titanium alloy layer, a titanium layer, and an aluminum layer, i.e., Ti / AlTi / Ti / AlTi / Ti / Al. The red curve is the frequency response curve corresponding to the above structure, and the black curve is the frequency response curve corresponding to the titanium layer and aluminum layer structure. Figure 3 The left and right figures in the middle represent the frequency response curves corresponding to different S-parameters, i.e., different transmission characteristics; Figure 4 The left and right figures represent the frequency response curves corresponding to different S-parameters, i.e., different transmission characteristics.

[0065] It can be seen that the structure of adding a reinforcing layer group 300 between the first adhesive layer 200 and the bonding layer 400 provided by this utility model is basically similar to the structure of commonly used titanium and aluminum layers. In fact, the structure provided by this utility model is even better in the part of the frequency response where the red curve is above the black curve in a local area. Therefore, the structure of adding a reinforcing layer group 300 between the first adhesive layer 200 and the bonding layer 400 of this utility model will not cause a deterioration effect on the frequency response while improving the bonding force.

[0066] In the description of this utility model, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0067] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A pad structure for a surface acoustic wave device, characterized in that, include: The base structure (100) has a pad area (101). A first adhesive layer (200) is disposed on the base structure (100) and located in the pad area (101). A reinforcing layer group (300) is disposed on the first adhesive layer (200). The reinforcing layer group (300) includes at least one reinforcing layer (310) and at least one second adhesive layer (320) that are stacked in an alternating manner. The bottom layer of the reinforcing layer group (300) is the reinforcing layer (310), and the top layer of the reinforcing layer group (300) is the second adhesive layer (320). A bonding layer (400) is disposed on the reinforcement layer group (300).

2. The pad structure of a surface acoustic wave device according to claim 1, characterized in that, The reinforcing layer group (300) includes two reinforcing layers (310) and two second adhesive layers (320).

3. The pad structure of a surface acoustic wave device according to claim 2, characterized in that, The reinforcing layer (310) is an aluminum alloy layer.

4. The pad structure of a surface acoustic wave device according to claim 2, characterized in that, Both of the aforementioned reinforcing layers (310) are aluminum-copper alloy layers; And / or, both of the reinforcing layers (310) are aluminum-titanium alloy layers; And / or, one of the two reinforcing layers (310) is an aluminum-copper alloy layer and the other is an aluminum-titanium alloy layer.

5. The pad structure of a surface acoustic wave device according to claim 4, characterized in that, The bonding layer (400) is an aluminum layer.

6. The pad structure of a surface acoustic wave device according to any one of claims 1 to 5, characterized in that, The first adhesive layer (200) is a titanium layer, a chromium layer, or a nickel-chromium alloy layer.

7. The pad structure of a surface acoustic wave device according to any one of claims 1 to 5, characterized in that, The second adhesive layer (320) is a titanium layer, a chromium layer, or a nickel-chromium alloy layer.

8. The pad structure of a surface acoustic wave device according to any one of claims 1 to 5, characterized in that, The base structure (100) includes a piezoelectric substrate (110), an interdigital transducer layer (120), a dielectric layer (130), and a wiring layer (140) stacked from bottom to top, and the pad area (101) is disposed on the wiring layer (140).

9. The pad structure of a surface acoustic wave device according to claim 8, characterized in that, It also includes a passivation layer (500) disposed on the trace layer (140), the passivation layer (500) having a window (510) in the pad area (101) for exposing the bonding layer (400).

10. A surface acoustic wave filter, characterized in that, Includes the pad structure of a surface acoustic wave device as described in any one of claims 1 to 9.

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