Bulk acoustic wave resonator and filter

Abstract

The utility model belongs to the technical field of impedance networks, and particularly relates to a bulk acoustic wave resonator and a filter, and the bulk acoustic wave resonator comprises a resonator body and a heat conduction assembly. Wherein the resonator body is internally provided with a heat conduction channel communicated with the external environment, and the heat conduction assembly is located in the heat conduction channel; the heat conduction assembly is suitable for conducting heat of the resonator body to the external environment. According to the utility model, the heat conduction channel communicated with the external environment is arranged in the resonator body, and the heat conduction assembly is additionally arranged in the heat conduction channel, so that the heat generated by the work of the resonator body can be quickly guided to the external environment, and the conduction efficiency of the heat from the interior of the resonator body to the external environment is enhanced; and the stability and the reliability of the resonator body under long-time high-power operation are ensured, the temperature rise of the bulk acoustic wave resonator is remarkably reduced, and the bearable maximum power and the stability of the acoustic wave resonator are improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of impedance networks, and specifically relates to a resonator, and in particular to a bulk acoustic wave resonator and a filter. Background Art

[0002] In terms of high-frequency and high-power development, thin film bulk acoustic resonator (FBAR) has some shortcomings. Although FBAR technology is constantly improving, its performance may be limited when faced with extremely high frequency and high power requirements, such as large insertion loss, thermal stability issues, and insufficient material tolerance.

[0003] An FBAR filter is a device that utilizes the piezoelectric effect. When an AC electric field is applied, the piezoelectric material vibrates mechanically, consuming electrical energy and converting it into mechanical energy. Simultaneously, due to internal damping and friction, some of this mechanical energy is converted into heat. In an FBAR filter, sound waves propagate through the thickness of the piezoelectric film and are reflected at the interface between the upper and lower electrodes and the air, generating oscillations. This process also involves energy loss and conversion, with some energy being converted into heat. Metal electrodes exhibit a certain resistance when current flows through them, consuming electrical energy and generating heat. Although the resistance of metal electrodes is relatively low, high-frequency signals generate significant heat due to this resistance effect.

[0004] The core structure of a film bulk acoustic wave resonator consists of a piezoelectric film, a metal bottom electrode, a metal top electrode, and an air cavity between them. Although this closed cavity structure helps to reflect sound waves inside the resonator, it also limits the dissipation of heat. Since the thermal conductivity of air is relatively low and the sound wave energy in the cavity structure is mainly confined to the inside of the piezoelectric film, the generated heat is difficult to be effectively transferred to the external environment through the cavity. Under high power and high frequency operating conditions, the film bulk acoustic wave resonator will generate more heat. If the heat dissipation performance is poor, this heat will accumulate inside the film bulk acoustic wave resonator, causing the temperature to rise, which will affect the performance and stability of the film bulk acoustic wave resonator and even burn the device.

[0005] Therefore, there is an urgent need to develop a new bulk acoustic wave resonator and filter to solve the technical problem that traditional thin film bulk acoustic wave resonators are difficult to dissipate heat due to internal cavity limitations.

[0006] It should be noted that the above information disclosed in this background technology section is only used to understand the background technology of the present application concept, and therefore, the above description is not considered to constitute information of the prior art. Utility Model Content

[0007] The embodiments of the present disclosure at least provide a bulk acoustic wave resonator and a filter.

[0008] In a first aspect, an embodiment of the present disclosure provides a bulk acoustic wave resonator, comprising: a resonator body and a heat-conducting component; wherein a heat-conducting channel connected to the external environment is opened inside the resonator body, and the heat-conducting component is located in the heat-conducting channel; the heat-conducting component is suitable for conducting heat from the resonator body to the external environment.

[0009] In an optional embodiment, the heat-conducting component includes: a heat-conducting layer; the heat-conducting layer is attached to the inner wall of the heat-conducting channel.

[0010] In an optional embodiment, the resonator body includes: a bottom electrode, a gold connection layer, a support layer, a silicon dioxide layer and a silicon substrate layer; the bottom electrode, the gold connection layer, the support layer, the silicon dioxide layer and the silicon substrate layer are sequentially arranged from top to bottom, and corresponding through holes are provided on the gold connection layer, the support layer and the silicon dioxide layer, and a heat conduction port connected to the external environment is provided on the silicon substrate layer, and each of the through holes is connected to the heat conduction port to form a heat conduction channel.

[0011] In an optional embodiment, the resonator body further includes: a top electrode and a piezoelectric layer; the top electrode and the piezoelectric layer are bonded together, and the piezoelectric layer and the bottom electrode are bonded together.

[0012] In an optional embodiment, the heat conduction port includes: a longitudinal heat conduction branch port and a transverse heat conduction branch port; the top of the longitudinal heat conduction branch port is connected to the through hole on the silicon dioxide layer, the bottom of the longitudinal heat conduction branch port is connected to the transverse heat conduction branch port, and the transverse heat conduction branch port is connected to the external environment.

[0013] In an optional embodiment, the heat-conducting component is interference-fitted with the transverse heat-conducting branch.

[0014] In an optional embodiment, the cross-section of the longitudinal heat-conducting branch opening is trapezoidal.

[0015] In an optional embodiment, the distance between the transverse heat conduction branch and the bottom electrode is not less than 150 μm.

[0016] In an optional embodiment, the resonator body further includes: a sealing layer; the sealing layer is located on the outer side wall of the silicon substrate layer to block the lateral heat conduction branch opening.

[0017] In a second aspect, an embodiment of the present disclosure further provides a filter, which includes: the bulk acoustic wave resonator as described above.

[0018] The beneficial effect of the present invention is that, by opening a heat conduction channel connected to the external environment in the resonator body and adding a heat conduction component in the heat conduction channel, the present invention can quickly conduct the heat generated by the resonator body during operation to the external environment, which not only enhances the efficiency of heat conduction from the inside of the resonator body to the external environment, but also ensures the stability and reliability of the resonator body under long-term high-power operation, significantly reduces the temperature rise of the bulk acoustic wave resonator, and improves the maximum power and stability that the acoustic wave resonator can withstand.

[0019] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or understood by practicing the present invention. The objectives and other advantages of the present invention are realized and obtained by the structures particularly pointed out in the description, claims and drawings.

[0020] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are specifically cited herein and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 A structural diagram of a bulk acoustic wave resonator provided in an embodiment of the present disclosure;

[0023] Figure 2 A structural diagram of a gold connection layer provided in an embodiment of the present disclosure;

[0024] Figure 3 A structural diagram of a support layer provided in an embodiment of the present disclosure;

[0025] Figure 4 A structural diagram of a silicon dioxide layer provided in an embodiment of the present disclosure;

[0026] Figure 5 A structural diagram of a silicon substrate layer provided in an embodiment of the present disclosure;

[0027] Figure 6 A semi-finished product of a bulk acoustic wave resonator provided in an embodiment of the present disclosure Figure 1 ;

[0028] Figure 7 A semi-finished product of a bulk acoustic wave resonator provided in an embodiment of the present disclosure Figure 2 ;

[0029] Figure 8 A semi-finished product of a bulk acoustic wave resonator provided in an embodiment of the present disclosure Figure 3 ;

[0030] Figure 9 A semi-finished product of a bulk acoustic wave resonator provided in an embodiment of the present disclosure Figure 4 ;

[0031] Figure 10 A semi-finished product of a bulk acoustic wave resonator provided in an embodiment of the present disclosure Figure 5 ;

[0032] Figure 11 A semi-finished product of a bulk acoustic wave resonator provided in an embodiment of the present disclosure Figure 6 ;

[0033] Figure 12 A semi-finished product of a bulk acoustic wave resonator provided in an embodiment of the present disclosure Figure 7 .

[0034] In the picture:

[0035] 1. Resonator body; 11. Thermal conduction channel; 111. Through hole; 12. Bottom electrode; 13. Gold connection layer; 14. Support layer; 15. Silicon dioxide layer; 16. Silicon substrate layer; 161. Thermal port; 1611. Longitudinal thermal branch port; 1612. Transverse thermal branch port; 17. Top electrode; 18. Piezoelectric layer;

[0036] 2. Thermal conductive component; 21. Thermal conductive layer. DETAILED DESCRIPTION

[0037] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0038] In this document, when it is mentioned that a first component is located on a second component, this may mean that the first component may be directly formed on the second component, or that a third component may be interposed between the first component and the second component. In addition, in the drawings, the thickness of components may be exaggerated or reduced in order to effectively describe technical content.

[0039] As used herein, when an element or layer is referred to as being "located on," "engaged to," "connected to," "attached to," or "coupled to" another element or layer, it may be directly located on, engaged, connected, attached to, or coupled to the other element or layer, or there may be intervening elements or layers. Conversely, when an element is referred to as being "directly on," "directly engaged to," "directly connected to," "directly attached to," or "directly coupled to" another element or layer, there may be no intervening elements or layers. Other words used to describe the relationship between elements should be interpreted in a similar manner (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," etc.). As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0040] The terms used herein are intended only to describe specific exemplary configurations and are not intended to be limiting. As used herein, the singular articles "a," "an," and "the" may also be intended to include the plural forms, unless the context clearly indicates otherwise. The terms "include," "comprise," and "have" are inclusive and thus specify the presence of features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof.

[0041] As used herein, the phrases "in one embodiment," "according to one embodiment," "in some embodiments," and the like generally refer to the fact that the particular feature, structure, or characteristic following the phrase may be included in at least one embodiment of the present disclosure. Thus, a particular feature, structure, or characteristic may be included in more than one embodiment of the present disclosure, such that these phrases do not necessarily refer to the same embodiment. As used herein, the terms "example," "exemplary," and the like are used to "serve as an example, instance, or illustration." Any implementation, aspect, or design described herein as "example" or "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations, aspects, or designs. Instead, the use of the terms "example," "exemplary," and the like is intended to present concepts in a concrete manner.

[0042] FBAR refers to thin film bulk acoustic resonator.

[0043] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not require further definition or explanation in subsequent drawings.

[0044] The following embodiments of the present invention are described in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments may be combined with each other.

[0045] like Figures 1 to 5As shown, at least one embodiment provides a bulk acoustic wave resonator, which includes: a resonator body 1 and a heat-conducting component 2; wherein a heat-conducting channel 11 connected to the external environment is opened inside the resonator body 1, and the heat-conducting component 2 is located in the heat-conducting channel 11; the heat-conducting component 2 is suitable for conducting the heat of the resonator body 1 to the external environment.

[0046] In at least one embodiment, by opening a heat conduction channel 11 connected to the external environment in the resonator body 1 and installing a heat conduction component 2 in the heat conduction channel 11, the heat generated by the resonator body 1 during operation can be quickly conducted to the external environment, which not only enhances the efficiency of heat conduction from the inside of the resonator body 1 to the external environment, but also ensures the stability and reliability of the resonator body 1 under long-term high-power operation, significantly reduces the temperature rise of the bulk acoustic wave resonator, and improves the maximum power and stability that the acoustic wave resonator can withstand.

[0047] In at least one embodiment, the heat conducting component 2 includes: a heat conducting layer 21 ; the heat conducting layer 21 is attached to the inner wall of the heat conducting channel 11 .

[0048] Specifically, the heat-conducting layer 21 can guide the heat generated by the functional components to the external environment through the heat-conducting channel 11 .

[0049] Specifically, the heat-conducting layer 21 can be made of a metal material or a non-metal material with good heat dissipation rate, for example, one or a mixture of gold, silver, aluminum, copper and graphene.

[0050] In at least one embodiment, see Figures 1 to 5 The resonator body 1 includes: a bottom electrode 12, a gold connection layer 13, a support layer 14, a silicon dioxide layer 15 and a silicon substrate layer 16; the bottom electrode 12, the gold connection layer 13, the support layer 14, the silicon dioxide layer 15 and the silicon substrate layer 16 are sequentially arranged from top to bottom, and corresponding through holes 111 are opened on the gold connection layer 13, the support layer 14 and the silicon dioxide layer 15, and a heat conduction port 161 connected to the external environment is opened on the silicon substrate layer 16, and each of the through holes 111 is connected to the heat conduction port 161 to form a heat conduction channel 11.

[0051] In at least one embodiment, the resonator body 1 further includes: a top electrode 17 and a piezoelectric layer 18 ; the top electrode 17 and the piezoelectric layer 18 are bonded together, and the piezoelectric layer 18 and the bottom electrode 12 are bonded together.

[0052] Specifically, the top electrode 17 , the piezoelectric layer 18 , and the bottom electrode 12 are functional devices that generate heat during operation.

[0053] In at least one embodiment, see Figure 5The heat conduction port 161 includes: a longitudinal heat conduction branch port 1611 and a transverse heat conduction branch port 1612; the top of the longitudinal heat conduction branch port 1611 is connected to the through hole 111 on the silicon dioxide layer 15, and the bottom of the longitudinal heat conduction branch port 1611 is connected to the transverse heat conduction branch port 1612, and the transverse heat conduction branch port 1612 is connected to the external environment.

[0054] Specifically, the longitudinal heat conduction branch 1611 is used to ensure that there is a cavity in the resonator body 1 to ensure the normal operation of the BAW resonator, while the transverse heat conduction branch 1612 can conduct heat to the external environment.

[0055] In at least one embodiment, the heat conducting component 2 is interference fit with the transverse heat conducting branch 1612, achieving a good sealing effect, and is in full contact with the silicon substrate layer 16, thereby improving the heat dissipation effect.

[0056] In at least one embodiment, the cross-section of the longitudinal heat-conducting branch 1611 is trapezoidal.

[0057] Specifically, the cross section of the longitudinal heat conduction branch 1611 is set to be trapezoidal, which increases the heat conduction area and thus improves the heat dissipation efficiency.

[0058] In at least one embodiment, the distance between the transverse heat conduction branch 1612 and the bottom electrode 12 is not less than 150 μm.

[0059] Specifically, the heat-conducting layer 21 is distributed on the inner wall of the longitudinal heat-conducting branch 1611 and in the longitudinal heat-conducting branch 1611. The heat-conducting layer 21 in the longitudinal heat-conducting branch 1611 is more than 150 μm away from the bottom electrode 12. The parasitic capacitance introduced thereby is very small and has almost no effect on the performance of the bulk acoustic wave resonator itself.

[0060] In at least one embodiment, the resonator body 1 further includes: a sealing layer; the sealing layer is located on the outer side wall of the silicon substrate layer 16 to block the transverse heat conduction branch opening 1612 .

[0061] Specifically, the sealing layer cooperates with the heat-conducting layer 21 to seal the transverse heat-conducting branch opening 1612 , thereby preventing impurities or water vapor from entering the BAW resonator.

[0062] Specifically, see Figure 6 The resonator body 1, which has completed the previous part of the process but has not yet undergone cavity etching, includes, from top to bottom, a top electrode 17, a piezoelectric layer 18, a bottom electrode 12, a gold connection layer 13, a support layer 14, a silicon dioxide layer 15, and a silicon substrate layer 16.

[0063] Specifically, see Figure 7 , the silicon substrate layer 16 is thinned to 150 μm.

[0064] Specifically, see Figure 8 , a longitudinal heat conduction branch 1611 is etched on the silicon substrate layer 16 .

[0065] Specifically, see Figure 9 , a heat conducting layer 21 is grown on the back side of the silicon substrate layer 16 .

[0066] Specifically, see Figure 10 , etching the gold connection layer 13, the support layer 14, and the silicon dioxide layer 15 under the bottom electrode 12.

[0067] Specifically, see Figure 11 A heat conducting layer 21 is also grown on another silicon substrate layer 16 for sealing the longitudinal heat conducting branch opening 1611 .

[0068] Specifically, see Figure 12 , bonding the two layers of heat conducting layers 21 to complete the sealing of the transverse heat conducting branch port 1612.

[0069] Based on the same concept, at least one embodiment further provides a filter, which includes: the bulk acoustic wave resonator as described above.

[0070] To sum up, the utility model can quickly conduct the heat generated by the operation of the resonator body to the external environment by opening a heat conduction channel connected to the external environment in the resonator body and installing a heat conduction component in the heat conduction channel. It not only enhances the efficiency of heat conduction from the inside of the resonator body to the external environment, but also ensures the stability and reliability of the resonator body under long-term high-power operation, significantly reduces the temperature rise of the bulk acoustic wave resonator, and improves the maximum power and stability that the acoustic wave resonator can withstand.

[0071] In the description of the embodiments of the present invention, unless otherwise specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0072] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, terms such as "first", "second" and other numerical terms do not imply an order or sequence when used herein unless expressly indicated above. Therefore, without departing from the teachings of the example embodiments, the first element, component, region, layer or section discussed above may be referred to as a second element, component, region, layer or section.

[0073] Spatially relative terms, such as "inside," "outside," "below," "beneath," "down," "above," "on," etc., may be used herein to describe the relationship of one element or feature to another element or feature as illustrated in the figures. In addition to the orientations depicted in the figures, spatially relative terms may be intended to encompass different orientations of the device in use or operation. For example, if the device in the figures is flipped, an element described as being "below" or "below" other elements or features will be oriented to be "above" the other elements or features. Thus, the example term "below" may encompass both above and below orientations. The device may be oriented otherwise (rotated 90 degrees or in other orientations), and the spatially relative descriptors used herein are interpreted accordingly.

[0074] In the above discussion, unless otherwise indicated, the terms "about," "approximately," "substantially," etc., when used to describe a numerical value, mean a variation of + / - 10% of the value.

[0075] Based on the above-mentioned ideal embodiment of the present invention, and in accordance with the above description, relevant personnel can make various changes and modifications without departing from the technical scope of the present invention. The technical scope of the present invention is not limited to the content of the specification, but must be determined according to the scope of the claims.

Claims

1. A bulk acoustic wave resonator, characterized in that: include: A resonator body (1) and a heat conducting component (2); in A heat conduction channel (11) communicating with the external environment is provided inside the resonator body (1), and the heat conduction component (2) is located inside the heat conduction channel (11); The heat-conducting component (2) is suitable for conducting the heat of the resonator body (1) to the external environment.

2. The bulk acoustic wave resonator according to claim 1, wherein The heat-conducting component (2) comprises: a heat-conducting layer (21); The heat-conducting layer (21) is attached to the inner side wall of the heat-conducting channel (11).

3. The bulk acoustic wave resonator according to claim 1, wherein The resonator body (1) comprises: a bottom electrode (12), a gold connection layer (13), a support layer (14), a silicon dioxide layer (15) and a silicon substrate layer (16); The bottom electrode (12), the gold connection layer (13), the support layer (14), the silicon dioxide layer (15), and the silicon substrate layer (16) are sequentially laminated from top to bottom. The gold connection layer (13), the support layer (14), and the silicon dioxide layer (15) are each provided with corresponding through holes (111), and the silicon substrate layer (16) is provided with a heat conduction port (161) connected to the external environment. Each of the through holes (111) is connected to the heat conduction port (161) to form a heat conduction channel (11).

4. The bulk acoustic wave resonator according to claim 3, wherein The resonator body (1) further includes: a top electrode (17) and a piezoelectric layer (18); The top electrode (17) is bonded to the piezoelectric layer (18), and the piezoelectric layer (18) is bonded to the bottom electrode (12).

5. The bulk acoustic wave resonator according to claim 3, wherein The heat conduction port (161) comprises: a longitudinal heat conduction branch port (1611) and a transverse heat conduction branch port (1612); The top of the longitudinal heat-conducting branch opening (1611) is connected to the through hole (111) on the silicon dioxide layer (15), the bottom of the longitudinal heat-conducting branch opening (1611) is connected to the transverse heat-conducting branch opening (1612), and the transverse heat-conducting branch opening (1612) is connected to the external environment.

6. The bulk acoustic wave resonator according to claim 5, wherein The heat-conducting component (2) is interference-fitted with the transverse heat-conducting branch opening (1612).

7. The bulk acoustic wave resonator according to claim 5, wherein The cross section of the longitudinal heat-conducting branch opening (1611) is arranged in a trapezoidal shape.

8. The bulk acoustic wave resonator according to claim 5, wherein The distance between the transverse heat conduction branch (1612) and the bottom electrode (12) is not less than 150 μm.

9. The bulk acoustic wave resonator according to claim 5, wherein The resonator body (1) further comprises: a sealing layer; The sealing layer is located on the outer side wall of the silicon substrate layer (16) to block the transverse heat conduction branch opening (1612).

10. A filter, characterized in that: include: The bulk acoustic wave resonator according to any one of claims 1 to 9.

Images