Bulk acoustic wave components and methods of plasma dicing the same

Abstract

The present invention relates to a method for manufacturing bulk acoustic wave (BAW) components. This method includes plasma cutting to monolithically form individual BAW components. A buffer layer may be formed over a substrate of the BAW component, exposing separation channels. The BAW component may be plasma-cut along the exposed separation channels to monolithically form the BAW component. Related BAW components are disclosed.

Description

Bulk acoustic wave device and method for plasma cutting the same Embodiments of the present invention relate to acoustic wave devices, and more particularly, to bulk acoustic wave devices. Acoustic wave filters can be implemented in radio frequency electronic systems. For example, a filter in a radio frequency front end of a mobile phone may include an acoustic wave filter. An acoustic wave filter can filter a radio frequency signal. An acoustic wave filter can be a bandpass filter. Multiple acoustic wave filters can be configured as a multiplexer. For example, two acoustic wave filters can be configured as a duplexer. An acoustic wave filter may include a plurality of acoustic wave resonators configured to filter a radio frequency signal. Example acoustic wave filters include surface acoustic wave (SAW) filters and bulk acoustic wave (BAW) filters. BAW filters include BAW resonators. Example BAW resonators include film bulk acoustic wave resonators (FBARs) and solid-mount resonators (SMRs). In a BAW resonator, acoustic waves propagate through a bulk of a piezoelectric layer. A BAW device may include a packaged BAW resonator enclosed within a sealed portion. The packaging structure increases the size of the BAW device. It is desirable to reduce the size of the BAW device without sacrificing reliability and performance. The innovations described in the technical solutions each have several aspects, no single one of which is solely responsible for its intended properties. Without limiting the scope of the technical solutions, some of the salient features of the present invention will now be briefly described. One aspect of the present invention is a method for fabricating singulated BAW devices. The method includes forming a buffer layer over a substrate of an array of BAW devices to form exposed streets between the individual BAW devices. The method also includes plasma dicing the BAW devices along the exposed streets to thereby singulate the BAW devices. Each of the singulated BAW components may include an integral BAW resonator and a cover enclosing the BAW resonator. The cover may include a sidewall that is 5 micrometers or less from an edge of the substrate of the respective singulated BAW component. The sidewall may be at least 1 micrometer from the edge of the respective singulated BAW component. The sidewall may comprise copper. The plasma cutting may include etching through both the substrate and a cover substrate. The BAW component may include a BAW resonator positioned above the substrate and below the cover substrate. The substrate and the cover substrate may be silicon substrates. The method may further include forming a conductor over the substrate. The conductor may extend laterally from a through-hole extending through the substrate. The conductor may be electrically connected to a conductive layer in the through-hole. Forming the buffer layer may be performed such that the buffer layer is over at least a portion of the conductor. The method may further include forming solder over the conductor such that the solder does not overlap the through-hole. The substrate may be a silicon substrate. The buffer layer may be a material that etches at least 30 times slower than silicon during the plasma dicing. The buffer layer may include a resin. Forming the buffer layer may include forming the exposed isolation streets by a photolithography process. The BAW components may each include a thin film bulk acoustic wave resonator. Another aspect of the present invention is a method for manufacturing a BAW component. The method includes providing a first wafer bonded to a second wafer. The first wafer has BAW resonators thereon. The second wafer is above and equally spaced from the BAW resonators. The method includes forming a buffer layer on a side of the first wafer opposite the BAW resonators, exposing separation lanes. The method includes plasma dicing through the first and second wafers along the exposed separation lanes to form singulated BAW components. The first wafer and the second wafer may be silicon wafers. Each of the singulated BAW devices may include a BAW resonator and a lid enclosing the BAW resonator. The lid may include a sidewall. The sidewall may be within a range of 1 micron to 5 microns from an edge of a substrate of the respective singulated BAW device, wherein the substrate corresponds to a portion of the first wafer before plasma dicing. Another aspect of the present invention is a method for manufacturing a BAW component. The method includes forming a buffer layer above a silicon substrate of the BAW component, exposing separation lanes. The method also includes plasma dicing the BAW components along the exposed separation lanes to thereby singulate the BAW components. Each of the singulated BAW components includes a bulk acoustic wave resonator and a cap enclosing the BAW resonator. The cap includes a silicon cap substrate and a sidewall spaced apart from an edge of the silicon substrate of each singulated BAW component by a distance in a range from 1 micron to 5 microns. The sidewall may include copper. The buffer layer may include a resin. The bulk acoustic wave resonator may be a thin film bulk acoustic wave resonator. Another aspect of the present invention is a BAW device comprising: a substrate; at least one BAW resonator on the substrate; and a cover enclosing the at least one BAW resonator. The cover includes a sidewall spaced apart from an edge of the substrate. The sidewall is 5 microns or less from the edge of the substrate. The sidewall may be 3 microns or less from the edge of the substrate. The sidewall may be at least 1 micron from the edge of the substrate. The BAW component may further include a through hole extending through the substrate, a conductive layer in the through hole, and a buffer layer in the through hole. The BAW component may further include a through hole extending through the substrate, a conductor extending laterally from the through hole and electrically connected to the conductive layer in the through hole, and solder on the conductor and located laterally from the through hole. The at least one BAW resonator may include a thin film BAW resonator. The at least one BAW resonator may include a solid-mount resonator. The substrate may be a silicon substrate. A top portion of the cover may include a silicon cover substrate. The sidewalls may comprise copper. The at least one BAW resonator may include a plurality of BAW resonators included in a filter configured to filter a radio frequency signal. The plurality of BAW resonators may include at least 10 BAW resonators. Another aspect of the present invention is a BAW device comprising a silicon substrate; at least one BAW resonator on the silicon substrate; and a lid enclosing the at least one BAW resonator. The lid comprises a lid substrate and a sidewall. The lid substrate comprises silicon. The sidewall is spaced apart from an edge of the silicon substrate by a distance in a range from 1 micron to 5 microns. The BAW component may further include a through hole extending through the silicon substrate, a conductive layer in the through hole, and a buffer layer in the through hole. The BAW component may further include a through hole extending through the substrate, a conductor extending laterally from the through hole and electrically connected to the conductive layer in the through hole, and solder on the conductor and located laterally from the through hole. The sidewall may comprise copper.The at least one BAW resonator may comprise at least 10 BAW resonators included in an acoustic wave filter configured to filter a radio frequency signal. Another aspect of the present invention is a wireless communication device comprising an antenna and an integrated BAW component. The BAW component comprises: a substrate, BAW resonators (BAW resonators) on the substrate; and a cover enclosing the BAW resonators. The cover includes a sidewall spaced 5 microns or less from an edge of the substrate. The BAW resonators are incorporated into a filter in communication with the antenna. The wireless communication device may be a mobile phone. The wireless communication device may further include a radio frequency amplifier in communication with the filter and a switch coupled between the filter and the antenna. For the purpose of summarizing the present invention, certain aspects, advantages, and novel features of the present invention have been described herein. It should be understood that not all such advantages may be achieved according to any particular embodiment. Thus, the present invention may be embodied or performed in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein. Cross-reference to priority application This application claims priority to U.S. Provisional Patent Application No. 62 / 747,486, filed on October 18, 2018, and entitled “BULK ACOUSTIC WAVE COMPONENTS AND METHODS OF PLASMA DICING THE SAME,” the entire disclosure of which is incorporated herein by reference. The following description of specific embodiments presents various descriptions of specific embodiments. However, the invention described herein can be embodied in a variety of different ways (e.g., as defined and encompassed by the scope of the invention claims). In this description, reference is made to the drawings in which similar element numbers may indicate identical or functionally similar elements. It should be understood that the elements shown in the drawings are not necessarily drawn to scale. Furthermore, it will be understood that a specific embodiment may include more elements than the elements shown in a drawing and / or a subset of the elements shown in a drawing. In addition, some embodiments may incorporate any appropriate combination of features from two or more drawings. Acoustic wave filters can filter radio frequency (RF) signals in various applications, such as the RF front end of a mobile phone. An acoustic wave filter may comprise a bulk acoustic wave (BAW) device. The BAW device may comprise a single die. The BAW device may include one or more BAW resonators on a substrate, such as a silicon substrate. The one or more BAW resonators may be enclosed by a lid of the BAW device. The lid may comprise another silicon substrate and sidewalls. The lid may form a hermetic seal around the one or more BAW resonators. The sidewalls may comprise, for example, copper. BAW components can be manufactured by cutting bonded wafers using a hollow portion between the wafers. Cracking has occurred in a portion of a BAW component facing the hollow portion. When a relatively large wafer is present, an airtight seal around the BAW resonator can be damaged. To reduce and / or eliminate the risk of cracking, the BAW component can include a gap between an edge of the BAW component and the sealing portion. The gap can, for example, be about 15 to 20 microns from a side wall of a cover to a cut edge of a BAW component. The gap can consume the area of ​​the BAW component. Aspects of the present invention relate to a method for plasma cutting of bulk acoustic wave components. A buffer layer may be formed above the bulk acoustic wave component to cover a redistribution layer. The buffer layer may be formed so that separation lanes for cutting are exposed. The buffer layer may serve as a mask layer for plasma cutting. BAW components may be singulated by plasma cutting. Plasma cutting may result in fewer BAW component cracks relative to other cutting techniques (such as blade cutting or laser cutting). With plasma cutting, a sidewall of a cover enclosing one or more BAW resonators may be closer to a cut edge of the BAW component than with other cutting techniques without increasing the risk of cracking of the BAW component. Plasma cutting may involve cutting through an upper wafer and a lower wafer across a hollow portion. The upper wafer and the lower wafer may be silicon wafers. With plasma dicing, the size of BAW devices can be reduced. With a smaller gap between a cap sidewall and a BAW device edge, more BAW devices can be included on a wafer. Furthermore, BAW devices consume less area in the module. Blade dicing techniques typically cut sharp edges and can create side stresses when the blade cuts a wafer. This can lead to cracks and / or chipping at a sharp edge of a blade-cut component. With plasma dicing, a pattern can be formed using a photolithographic process used for dicing, and during plasma dicing, there can be no significant mechanical side stresses. Thus, plasma dicing can maintain a sharp edge while reducing and / or eliminating damage that can result from mechanical cracking. In certain instances, plasma dicing can result in rounded corners on a BAW component, providing more reliable performance compared to mechanical dicing techniques. Rounded corners can reduce and / or eliminate the risk of cracks and / or chipping in BAW components. Using the manufacturing techniques disclosed herein, the yield of BAW devices from a single wafer can be improved by approximately 10% to 18% in certain examples compared to a previous manufacturing method. This improved yield can reduce manufacturing costs. Even with increased costs due to additional processing operations and / or facility investment, the improved yield can still reduce manufacturing costs. A method for fabricating BAW devices using plasma dicing is disclosed. FIG1 is a flow chart of an example process 10 for fabricating a BAW device according to one embodiment. Process 10 will be described with reference to the cross-sectional views shown in FIG2A through FIG2E. Any of the methods discussed herein may include more or fewer operations and the operations may be performed in any order, as appropriate. Process 10 includes providing a substrate with one or more BAW resonators enclosed in a lid at block 12. The substrate may be a silicon substrate. The lid may include sidewalls and a second substrate that together enclose the one or more BAW resonators. The second substrate may be a silicon substrate. The one or more BAW resonators may include a film bulk acoustic resonator (FBAR) and / or a solid-mount resonator (SMR). At block 14, a redistribution layer is formed over the substrate. The redistribution layer includes a conductor extending laterally from a through substrate via. The redistribution layer may be referred to as a wiring layer. The redistribution layer may be formed during the same processing operation(s) as forming a conductive layer in one or more through substrate vias of a BAW component. The redistribution layer and the conductive layer may be, for example, approximately 5 microns thick. Solder may be formed over a portion of the redistribution layer. The redistribution layer may provide an electrical connection from the conductive layer in a through substrate via to the solder of the BAW component. Solder may be formed over any suitable portion of a substrate by means of the redistribution layer. For example, solder may be formed laterally from a through substrate via. In certain instances, the solder and the through substrate via are non-overlapping. FIG2A illustrates a cross-section of a plurality of BAW devices having a redistribution layer formed in block 14 of process 10. As shown in FIG2A, the plurality of BAW devices have not yet been singulated. FIG2A illustrates a lid substrate 21, a substrate 22, sidewalls 23, BAW resonators 24, air cavities 25, through-substrate vias 26, a conductive layer 27 in each of the through-substrate vias 26, a redistribution layer 28, and electrodes 29. Prior to singulating the individual BAW devices, a first wafer includes the substrate 22 for each of the individual BAW devices, and a second wafer includes the lid substrate 21 for each of the individual BAW devices. As shown, the first wafer is bonded to the second wafer. The BAW resonator 24 is enclosed within a lid comprising a lid substrate 21 and sidewalls 23. Prior to forming the redistribution layer 28, the BAW resonator 24 is enclosed within the lid. As shown, a bonding layer 30 and a capping layer 31 may be positioned between the substrate 22 and the sidewalls 23. The bonding layer 30 may be a gold layer. The capping layer 31 may be a tin capping layer. The lid forms an airtight seal around the BAW resonator 24. Thus, an air cavity 25 may be contained within the lid around the BAW resonator 24. In some examples, a BAW component may include 10 to 50 BAW resonators 24 enclosed within a lid. The BAW resonator 24 may include one or more FBARs. Alternatively or in addition, the BAW resonator 24 may include one or more SMRs. The BAW resonator 24 may be included in one or more filters. The substrate 21 may be a silicon substrate. The sidewalls 23 may include copper. The BAW resonator 24 is on a substrate 22 and enclosed by a cover. The substrate 22 can be a silicon substrate. A conductive layer 27 in a through-substrate via 26 can provide an electrical connection from one or more of the BAW resonators 24 to an element on an opposite side of the substrate 22. As shown, a redistribution layer 28 formed in block 14 is above the substrate 22 and extends laterally from the through-substrate via 26. Therefore, an electrode 29 can be formed laterally from the through-substrate via 26 above the redistribution layer 28. The redistribution layer 28 is on a side of the substrate 22 opposite the BAW resonator 24. The electrode 29 provides a terminal for external connection to the BAW component. With the help of the redistribution layer 28, the electrode 29 can be positioned at any appropriate location of a BAW component. The redistribution layer 28 can provide shielding. The redistribution layer 28 can shield the BAW resonator 24 from external components and / or shield external components from the BAW resonator 24. Referring back to FIG. 1 , at block 16 , a buffer layer is formed over the substrate, exposing the lanes. The buffer layer may be formed by a photolithography process. Forming the buffer layer may include depositing a layer of buffer material, masking specific areas above the buffer material, and applying light to remove the buffer material above the lanes. A surface of the substrate may be exposed along the lanes. The buffer layer may provide encapsulation of the BAW device on the side opposite the cover substrate. The buffer layer may be formed over the redistribution layer formed in block 14 . FIG2B illustrates a cross-section of a BAW device including a buffer layer 32 formed in block 16 of process 10. The buffer layer 32 is over the substrate 22. The buffer layer 32 is on a side of the substrate 22 opposite the BAW resonator 24. A portion of the buffer layer 32 is within the through-substrate via 26. The buffer layer 32 is also over a portion of the redistribution layer 28. As shown in FIG2B , the buffer layer 32 is formed so that the electrode 29 remains exposed. The buffer layer 32 comprises a material that acts as a mask to resist etching when the substrate 22 is plasma-diced. For example, the buffer layer 32 may be a material that is etched less than silicon when etching silicon for a substrate 22 that is a silicon substrate. Typically, the etch rate of the buffer layer 32 is more than 30 times slower than the etch rate of silicon. Therefore, a typical buffer layer thickness is sufficient for plasma dicing of wafer silicon. The buffer layer 32 may be a polyimide layer, a phenolic resin layer (such as a phenolic resin layer with a rubber filler), or any other suitable buffer layer. The separation streets 34 facilitate the cutting of the BAW device. FIG2C shows an enlarged view of a portion 35 of the BAW device shown in FIG2B. As shown, the separation lanes 34 may have a width D S Width D S Suitable for plasma cutting, as shown. The width D of the separation lane 34 SThe width D of the separation lane 34 may be in a range from about 10 microns to 20 microns, such as in a range from 10 microns to 15 microns. As an example, the width D of the separation lane 34 may be in a range from about 10 microns to 20 microns, such as in a range from 10 microns to 15 microns. S 2C also shows that a bonding layer 30 and a capping layer 31 may be included between the substrate 22 and the sidewalls 23 . Referring back to FIG. 1 , at block 18 , the BAW components are plasma cut along the exposed separation lanes. This singulates the BAW components. In other words, the BAW components are separated from each other into individual BAW components by plasma cutting. Plasma cutting may involve dry etching through a substrate on which the BAW resonator is positioned and through a cover substrate. During this etching, a hollow portion may exist between the substrate and the cover substrate below the separation lanes (e.g., as shown in FIG. 2B ). As an example, both the substrate and the cover substrate may be silicon substrates that are etched at a rate of approximately 20 microns per minute. In this example, the substrate and the cover substrate may be approximately 200 microns thick together and it may take approximately 10 minutes to etch through approximately 200 microns of silicon. With plasma cutting, cracking of the singulated BAW components may be reduced relative to other cutting methods (such as blade cutting or laser cutting). For plasma cutting, a photolithography process may pattern any appropriate pattern of the separation lanes. In specific instances, this may result in rounded corners of the singulated BAW components. These rounded corners can reduce the risk of cracking and / or breaking of the BAW device, thereby increasing the reliability of the BAW device. FIG2D illustrates a cross-section of a BAW device after plasma dicing at block 18 of process 10. Plasma dicing along the separation streets removes portions of substrate 22 and cover substrate 21, thereby separating the individual BAW devices. FIG2D shows a plurality of singulated BAW devices 36. A tape 37 holds the singulated BAW devices 36 together. Prior to plasma dicing, the tape 37 may be laminated to the BAW device. FIG2E is an enlarged view of a portion 38 of the singulated BAW device 36 shown in FIG2D. As shown, a distance D from a sidewall 23 to an edge of a substrate 22 of a singulated BAW device 36 is E is relatively small. Using a buffer layer as a mask for plasma cutting, a photolithography process can be used. Therefore, plasma cutting has a greater accuracy than other cutting methods, such as blade cutting or laser cutting, which have a mechanical system accuracy. For example, plasma cutting can be performed within an accuracy of + / - 2 microns. However, in the case of blade cutting, the mechanical accuracy is + / - 10 microns and there can be cracks of 5 to 10 microns. With the increased accuracy and reduced risk of cracking of plasma cutting, the distance D from the side wall 23 to the edge of the substrate 22 of the singulated BAW component 36 is EThe distance D from the sidewall 23 to the edge of the substrate 22 of the singulated BAW device 36 can be reduced. E Can be less than 5 microns. Distance D E As an example, the distance D E The distance D may be about 2.5 microns. E is greater than zero, as shown. In some examples, the distance D E It may be in a range from 1 micron to 5 microns, such as in a range from 1 micron to 3 microns. In certain embodiments, the sidewalls 23 and the edges of the substrate 22 may be substantially flush in a singulated BAW device. Therefore, by plasma dicing, there can be less spacing between the sidewalls 23 of adjacent BAW devices on a wafer. In FIG2E , a distance D from the sidewalls 23 of each adjacent singulated BAW device is SW Corresponding to the width of the separation lane D S and distance D E The sum of twice the distance D SW The distance D may be, for example, in a range from about 10 microns to 30 microns. SW It can be in a range from about 10 microns to 20 microns. As an example, the separation lane width D S It can be about 15 microns and the distance D E can be about 2.5 microns, which would make the distance D SW In the cross section shown in FIG. 2E , it is approximately 20 microns. FIG3A is a cross-sectional view of a BAW device 40 according to one embodiment. The BAW device 40 can be fabricated by a process including plasma dicing. For example, the BAW device 40 can correspond to a singulated BAW device fabricated by process 10 of FIG1 . As shown in FIG. 3A , the distance D from a sidewall 23 to an edge of the substrate 22 of a singulated BAW device 36 is E The distance D can be relatively small due to plasma cutting. E2E . In the illustrated BAW component 40 , the BAW resonator 24 is enclosed within a lid comprising a lid substrate 21 and sidewalls 23 . The BAW resonator 24 may form some or all of the resonators of one or more acoustic wave filters. There may be any suitable number of BAW resonators 24 enclosed within the lid of the BAW component 40 . For example, there may be 10 to 50 BAW resonators 24 enclosed within the lid of the BAW component 40 . The BAW resonator 24 may be electrically connected to an electrode 29 via a conductive layer 27 and a redistribution layer 28 in a through-substrate via 26 . The buffer layer 32 extends over the redistribution layer 28 and is included in the through-substrate via 26 in the BAW component 40 . FIG3B is a cross-sectional view of a bulk acoustic wave (BAW) component 42 according to one embodiment. BAW component 42 can be fabricated by a process including plasma dicing. For example, BAW component 42 can correspond to a singulated BAW component fabricated by process 10 of FIG1 . BAW component 42 is similar to BAW component 40 of FIG3A , except that BAW component 42 includes a via 26 filled with a conformal conductive layer 43 rather than a conductive layer 27 . Conformal conductive layer 43 can be, for example, a copper layer. BAW component 42 illustrates that a conformal layer 43 can be used to fill via 26 . One or more BAW resonators of a BAW component including any suitable combination of features disclosed herein may be included in a filter configured to filter a radio frequency signal in a fifth generation (5G) new radio (NR) operating band within frequency range 1 (FR1). A filter configured to filter a radio frequency signal in a 5G NR operating band may include one or more BAW resonators of any BAW component disclosed herein. FR1 may, for example, be from 410 megahertz (MHz) to 7.125 gigahertz (GHz), as specified in current 5G NR specifications. One or more BAW resonators of a BAW component according to any suitable principles and advantages disclosed herein may be included in a filter configured to filter a radio frequency signal in a fourth generation (4G) long term evolution (LTE) operating band and / or a filter having a passband spanning at least one 4G LTE operating band and at least one 5G NR operating band. FIG4 is a schematic diagram of a transmission filter 45 including a bulk acoustic wave resonator (BAW) component according to one embodiment. Transmission filter 45 may be a bandpass filter. The illustrated transmission filter 45 is configured to filter a radio frequency (RF) signal received at a transmission port TX and provide a filtered output signal to an antenna port ANT. Transmission filter 45 includes series BAW resonators TS1, TS2, TS3, TS4, TS5, TS6, and TS7, parallel BAW resonators TP1, TP2, TP3, TP4, and TP5, a series input inductor L1, and a parallel inductor L2. Some or all of BAW resonators TS1 through TS7 and / or TP1 through TP5 may be included in a BAW component according to any suitable principles and advantages disclosed herein. For example, BAW component 40 of FIG3A or BAW component 42 of FIG3B may include all of the BAW resonators of transmission filter 45. In certain embodiments, a BAW device according to any suitable principles and advantages disclosed herein may include two or more BAW resonators of an acoustic wave filter. Any number of series BAW resonators and parallel BAW resonators may be included in a transmission filter 45. FIG5 is a schematic diagram of a receive filter 50 including a bulk acoustic wave resonator (BAW) component according to one embodiment. Receive filter 50 may be a bandpass filter. The illustrated receive filter 50 is configured to filter a radio frequency (RF) signal received at an antenna port ANT and provide a filtered output signal to a receive port RX. Receive filter 50 includes series BAW resonators RS1, RS2, RS3, RS4, RS5, RS6, RS7, and RS8; parallel BAW resonators RP1, RP2, RP3, RP4, RP5, and RP6; a parallel inductor L2; and a series output inductor L3. Some or all of BAW resonators RS1 to RS8 and / or RP1 to RP6 may be included in a BAW component according to any suitable principles and advantages disclosed herein. For example, BAW component 40 of FIG3A or BAW component 42 of FIG3B may include all BAW resonators of receive filter 50. Any suitable number of series BAW resonators and parallel BAW resonators may be included in a receive filter 50 . FIG6 is a schematic diagram of a radio frequency system 60 including an integrated acoustic wave component according to one embodiment. As shown, radio frequency system 60 includes an antenna 62, an antenna switch 64, multiplexers 65 and 66, filters 67 and 68, power amplifiers 70, 72, and 74, and a selector switch 73. Power amplifiers 70, 72, and 74 are each configured to amplify a radio frequency signal. Selector switch 73 electrically connects an output of power amplifier 72 to a selected filter. Multiplexer 65 and / or one or more filters of multiplexer 66 may include one or more BAW resonators of a BAW component according to any suitable principles and advantages discussed herein. In a specific example, a BAW component may include one or more filters of a multiplexer. Although the multiplexer shown in FIG6 includes a quadplexer and a duplexer, one or more BAW resonators of a BAW component may be included in any other suitable multiplexer, such as a triplexer, a hexaplexer, an octaplexer, or the like. The antenna switch may selectively electrically connect one or more filters and / or one or more multiplexers to the antenna 62 . The BAW components discussed herein can be implemented in various packaging modules. Such BAW components can consume less area in the packaging module than similar modules cut using laser cutting. A packaging module configured to process an RF signal can be referred to as an RF module. Some RF modules are front-end modules. An RF module that includes a BAW component according to any appropriate principles and advantages disclosed herein may also include one or more RF amplifiers (for example, one or more power amplifiers and / or one or more low-noise amplifiers), one or more RF switches, the like, or any appropriate combination thereof. Example packaging modules will now be discussed in which any appropriate principles and advantages of the BAW components discussed herein can be implemented. Figures 7 and 8 are schematic block diagrams of illustrative packaging modules according to specific embodiments. Any appropriate combination of the features of these embodiments may be combined with each other. FIG7 is a schematic diagram of an RF module 75 including an integrated BAW component 76 according to one embodiment. RF module 75 is shown including BAW component 76 and other circuitry 77. BAW component 76 can include any suitable combination of features of the BAW components disclosed herein. BAW component 76 can include a BAW die that includes a BAW resonator. The BAW component 76 shown in FIG7 includes a filter 78 and terminals 79A and 79B. The filter 78 includes a BAW resonator. Terminals 79A and 79B can, for example, serve as an input contact and an output contact. In FIG7, the BAW component 76 and other circuits 77 are on a common package substrate 80. The package substrate 80 can be a laminate substrate. Terminals 79A and 79B can be electrically connected to contacts 81A and 81B on the package substrate 80 via electrical connectors 82A and 82B, respectively. Electrical connectors 82A and 82B can, for example, be bumps or wire bonds. The other circuits 77 can include any suitable additional circuits. For example, the other circuits can include one or more power amplifiers, one or more RF switches, one or more additional filters, one or more low-noise amplifiers, the like, or any suitable combination thereof. The RF module 75 can include one or more packaging structures to, for example, provide protection for the RF module 75 and / or facilitate easier handling of the RF module 75. Such a packaging structure may include an overmold structure formed on the packaging substrate 75. The overmold structure may encapsulate some or all components of the RF module 75. Figure 8 is a schematic diagram of a radio frequency module 84 including an integrated acoustic wave component according to one embodiment. As shown, radio frequency module 84 includes duplexers 85A through 85N, each including transmit filters 86A1 through 86N1 and receive filters 86A2 through 86N2; a power amplifier 87; a selector switch 88; and an antenna switch 89. Radio frequency module 84 may include a package enclosing the illustrated components. The illustrated components may be mounted on a common package substrate 80. The package substrate may be, for example, a build-up substrate. Each of the duplexers 85A to 85N may include two acoustic wave filters coupled to a common node. The two acoustic wave filters may be a transmission filter and a reception filter. As shown, the transmission filter and the reception filter may each be a bandpass filter configured to filter a radio frequency signal. One or more transmission filters 86A1 to 86N1 may include one or more BAW resonators of a BAW component according to any appropriate principles and advantages disclosed herein. Similarly, one or more reception filters 86A2 to 86N2 may include one or more BAW resonators of a BAW component according to any appropriate principles and advantages disclosed herein. Although FIG. 8 illustrates a duplexer, any appropriate principles and advantages disclosed herein may be implemented in other multiplexers (e.g., a quadplexer, a hexaplexer, an octaplexer, etc.) and / or in a switch multiplexer. Power amplifier 87 can amplify a radio frequency signal. The illustrated switch 88 is a multi-throw radio frequency switch. Switch 88 can electrically couple an output of power amplifier 87 to a selected one of transmission filters 86A1 through 86N1. In some examples, switch 88 can electrically connect the output of power amplifier 87 to more than one of transmission filters 86A1 through 86N1. Antenna switch 89 can selectively couple a signal from one or more duplexers 85A through 85N to an antenna port ANT. Duplexers 85A through 85N can be associated with different frequency bands and / or different operating modes (e.g., different power modes, different signaling modes, etc.). FIG9A is a schematic diagram of a wireless communication device 90 including a filter 93 in an RF front end 92 according to one embodiment. Filter 93 may include a BAW resonator of a BAW component according to any suitable principles and advantages discussed herein. Wireless communication device 90 may be any suitable wireless communication device. For example, wireless communication device 90 may be a mobile phone (such as a smartphone). As shown, wireless communication device 90 includes an antenna 91, an RF front end 92, a transceiver 94, a processor 95, a memory 96, and a user interface 97. Antenna 91 may transmit RF signals provided by RF front end 92. These RF signals may include carrier aggregation signals. RF front end 92 may include one or more power amplifiers, one or more low-noise amplifiers, one or more RF switches, one or more receive filters, one or more transmit filters, one or more duplex filters, one or more multiplexers, one or more frequency multiplexing circuits, the like, or any suitable combination thereof. RF front end 92 may transmit and receive RF signals associated with any suitable communication standard. Filter 93 may include a BAW resonator comprising a BAW component including any suitable combination of the features discussed with reference to any of the embodiments discussed above. Transceiver 94 can provide RF signals to RF front end 92 for amplification and / or other processing. Transceiver 94 can also process an RF signal provided by a low-noise amplifier of RF front end 92. Transceiver 94 communicates with processor 95. Processor 95 can be a baseband processor. Processor 95 can provide any appropriate baseband processing functions for wireless communication device 90. Memory 96 can be accessed by processor 95. Memory 96 can store any appropriate data for wireless communication device 90. User interface 97 can be any appropriate user interface, such as a display with touch screen capabilities. FIG9B is a schematic diagram of a wireless communication device 100 including a filter 93 in an RF front end 92 and a second filter 103 in a diversity receive module 102. Wireless communication device 100 is similar to wireless communication device 90 of FIG9A , except that wireless communication device 100 also includes diversity receive features. As shown in FIG9B , wireless communication device 100 includes: a diversity antenna 101; a diversity module 102 configured to process signals received by diversity antenna 101 and including filter 103; and a transceiver 104 in communication with both RF front end 92 and diversity receive module 102. Filter 103 may include a BAW resonator including a BAW component comprising any suitable combination of the features discussed with reference to any of the embodiments discussed above. Any of the embodiments described above may be implemented in association with a mobile device, such as a cellular phone. The principles and advantages of the embodiments may be applied to any system or device that may benefit from any of the embodiments described herein, such as any uplink cellular device. The teachings herein may be applied to a variety of systems. While the present invention includes some example embodiments, the teachings described herein may be applied to a variety of structures. Any of the principles and advantages discussed herein may be implemented in association with RF circuits configured to process signals having a frequency in a range from approximately 30 kilohertz (kHz) to 300 GHz, such as a frequency in a range from approximately 450 MHz to 8.5 GHz. Aspects of the present invention may be implemented in a variety of electronic devices. Examples of electronic devices include, but are not limited to, consumer electronic products, portions of consumer electronic products (such as die and / or acoustic wave filter assemblies) and / or packages, radio frequency modules, uplink wireless communication devices, wireless communication infrastructure, electronic test equipment, and the like. Examples of electronic devices include, but are not limited to, a mobile phone (such as a smartphone), a wearable computing device (such as a smartwatch or a headset), a phone, a television, a computer monitor, a computer, a modem, a handheld computer, a laptop computer, a tablet computer, a personal digital assistant (PDA), a microwave oven, a refrigerator, a car, a stereo system, a DVD player, a CD player, a digital music player (such as an MP3 player), a radio, a camcorder, a video camera, a digital video camera, a portable memory chip, a washing machine, a dryer, a washer / dryer, a copier, a fax machine, a scanner, a multi-function peripheral device, a wristwatch, a clock, and the like. Furthermore, the electronic device may include an unfinished product. Unless the context clearly requires otherwise, throughout the description and claims, the words "comprise," "comprising," "include," "including," and the like should be interpreted in an inclusive sense, rather than an exclusive or exhaustive sense; that is, in the sense of "including but not limited to." The word "coupled," as generally used herein, refers to two or more elements that can be connected directly or through one or more intermediate elements. Similarly, the word "connected," as generally used herein, refers to two or more elements that can be connected directly or through one or more intermediate elements. In addition, the words "herein," "above," "hereafter," and words of similar meaning, when used in this application, shall refer to this application as a whole and not to any particular parts of this application. Where the context permits, words used in the singular or plural number in the above embodiments shall also include the plural or singular number, respectively. The word "or" in reference to a list of two or more items includes all of the following interpretations of the word: any item in the list, all items in the list and any combination of the items in the list. Furthermore, unless expressly stated otherwise or understood otherwise within the context of their use, conditional language used herein (especially terms such as "may," "could," "would," "might," "for example," "for example," "such as," and the like) is generally intended to convey that some embodiments include and other embodiments do not include certain features, elements, and / or states. Thus, such conditional language is generally not intended to imply that features, elements, and / or states are in any way required for one or more embodiments. Although specific embodiments have been described, these embodiments have been presented by way of example only, and these embodiments are not intended to limit the scope of the invention. Indeed, the novel devices, methods, and systems described herein may be embodied in a variety of other forms; in addition, various omissions, substitutions, and changes may be made in the form of the methods and systems described herein without departing from the spirit of the invention. For example, although blocks are presented in a given configuration, alternative embodiments may perform similar functions with different components and / or circuit topologies, and some blocks may be deleted, moved, added, subdivided, combined, and / or modified. Each of these blocks may be implemented in a variety of different ways. Any appropriate combination of the elements and actions of the various embodiments described above may be combined to provide further embodiments. The accompanying patent claims and their equivalents are intended to cover such forms or modifications that would fall within the scope and spirit of the invention. 10: Program 12: Block 14: Block 16: Block 18: Block 21: Cover Substrate 22: Substrate 23: Sidewall 24: BAW Resonator 25: Air Cavity 26: Through-Substrate Via 27: Conductive Layer 28: Redistributed Layer 29: Electrode 30: Bonding Layer 31: Cover Layer 32: Buffer Layer 34: Separator 35: Portion 36: Singled BAW Component 37: Strip 38: Portion 40: Bulk Acoustic Wave Component 42: Bulk Acoustic Wave Component 43: Conformal Conductive Layer 45: Transmit Filter 50: Receive Filter 60: RF System 62: Antenna 64: Antenna Switch 65: Multiplexer 66: Multiplexer 67: Filter 68: Filter 70: Power Amplifier 72: Power Amplifier 73: Selector Switch 74: Power Amplifier 75: RF module 76: BAW component 77: Other circuits 78: Filter 79A: Terminal 79B: Terminal 80: Common package substrate 81A: Contact 81B: Contact 82A: Electrical connector 82B: Electrical connector 84: RF module 85A-85N: Duplexer 86A1-86N1: Transmit filter 86A2-86N2: Receive filter 87: Power amplifier 88: Selector switch 89: Antenna switch 90: Wireless communication device 91: Antenna 92: RF front end 93: Filter 94: Transceiver 95: Processor 96: Memory 97: User interface 100: Wireless communication device 101: Diversity antenna 102: Diversity receive module 103: Filter ANT: Antenna port D E: Distance D S: Divider width D SW: Distance L1: Series input inductor L2: Parallel inductor L3: Series output inductor TS1-TS7: Series BAW resonators TP1-TP5: Parallel BAW resonators TX: Transmission port RS1-RS8: Series BAW resonators RP1-RP6: Parallel BAW resonators RX: Receive port Embodiments of the invention will now be described, by way of non-limiting examples, with reference to the accompanying drawings. FIG1 is a flow chart of an example process for fabricating a BAW component according to one embodiment. 2A to 2E are cross-sectional views illustrating a process of manufacturing a BAW component according to an embodiment. 3A is a cross-sectional view of a BAW component according to one embodiment. 3B is a cross-sectional view of a BAW component according to another embodiment. FIG. 4 is a schematic diagram of a transmission filter including a bulk acoustic wave resonator with an integral acoustic wave element according to one embodiment. FIG. 5 is a schematic diagram of a receive filter including a bulk acoustic wave resonator with an integral acoustic wave element according to an embodiment. FIG6 is a schematic diagram of a radio frequency system including an integrated acoustic wave component according to one embodiment. FIG. 7 is a schematic diagram of a radio frequency module including an integrated acoustic wave component according to an embodiment. FIG8 is a schematic diagram of a radio frequency module including an integrated acoustic wave component according to an embodiment. 9A is a schematic block diagram of a wireless communication device including a filter according to one or more embodiments. FIG9B is a schematic block diagram of another wireless communication device including a filter according to one or more embodiments. 21: Cover substrate 22:Substrate 23: Sidewall 24:BAW resonator 25: Air cavity 26: Through-substrate through-hole 27: Conductive layer 28: Heavy cloth layer 29: Electrode 30: Bonding layer 31: Covering layer 32: buffer layer 36: Single-granular BAW components 37: belt 38: Part

Claims

1. A bulk acoustic wave assembly, comprising: A substrate having a via extending through it; at least one integral acoustic resonator on the substrate; a cap enclosing the at least one integral acoustic resonator, the cap including a sidewall spaced apart from an edge of the substrate, the sidewall being 5 micrometers or less from the edge of the substrate; a conductor extending laterally from the via and electrically connected to a conductive layer in the via, the conductor being on a side of the substrate opposite to the at least one integral acoustic resonator, the conductor having solder thereon, the solder not overlapping the via; and a buffer layer on the side of the substrate opposite to the at least one integral acoustic resonator, the buffer layer being over a portion of the conductor.

2. The bulk acoustic wave assembly of claim 1, wherein the sidewall is 3 micrometers or less from the edge of the substrate.

3. The bulk acoustic wave assembly of claim 1, wherein the sidewall is at least 1 micrometer from the edge of the substrate.

4. The bulk acoustic wave assembly of claim 1, wherein a portion of the buffer layer is in the via.

5. The bulk acoustic wave assembly of claim 1, wherein the buffer layer comprises a phenol resin.

6. The bulk acoustic wave assembly of claim 1, wherein the buffer layer comprises a polyimide.

7. The bulk acoustic wave assembly of claim 1, wherein the buffer layer has an etching rate at least 30 times slower than that of plasma dicing silicon.

8. The bulk acoustic wave assembly as claimed in claim 1, wherein the sidewall comprises copper.

9. The bulk acoustic component of claim 1, wherein the at least one acoustic resonator comprises a plurality of individual acoustic resonators, the plurality of individual acoustic resonators being included in a filter configured to filter a radio frequency signal.

10. The bulk acoustic wave assembly of claim 1, further comprising a plurality of additional conductors extending laterally from a plurality of additional vias extending through the substrate, each of the plurality of additional vias having solder thereon.

11. A radio frequency module, comprising: The package includes an integral acoustic wave assembly comprising at least one integral acoustic wave resonator on a substrate, a cap enclosing the at least one integral acoustic wave resonator and a cap including a sidewall spaced 5 micrometers or less from an edge of the substrate, a conductor extending laterally through a via of the substrate, and a buffer layer on a side of the substrate opposite to the at least one integral acoustic wave resonator, the buffer layer being above a portion of the conductor, the conductor being electrically connected to a conductive layer in the via, and the conductor having solder on it such that the solder does not overlap with the via; an RF switch connected to a filter comprising the at least one integral acoustic wave resonator; and a package enclosing the integral acoustic wave assembly and the RF switch.

12. The radio frequency module of claim 11, further comprising a power amplifier configured to output a radio frequency signal, the filter configured to filter the radio frequency signal.

13. The RF module of claim 11 further includes an RF amplifier, wherein the RF on / off relationship is located in a signal path between the RF amplifier and the filter.

14. The radio frequency module of claim 11 further includes a multiplexer that contains the filter.

15. A wireless communication device comprising: An antenna; and a bulk acoustic wave assembly comprising bulk acoustic wave resonators on a substrate, a cover enclosing the bulk acoustic wave resonators and a cover comprising a sidewall spaced 5 micrometers or less from an edge of the substrate, a conductor extending laterally through a via of the substrate, and a buffer layer on a side of the substrate opposite to the bulk acoustic wave resonators, the buffer layer being on a portion of the conductor and the conductor being electrically connected to a conductive layer in the via, the conductor having solder thereon such that the solder does not overlap with the via, the bulk acoustic wave resonators being included in a filter communicating with the antenna.

16. The wireless communication device of claim 15, comprising a radio frequency front end and a baseband processor communicating with the radio frequency front end, wherein the filter is included in the radio frequency front end.

17. The wireless communication device of claim 15, wherein the wireless communication device is a mobile device.

18. A bulk acoustic wave assembly, comprising: A substrate having a through-hole extending therethrough; at least one integral acoustic resonator on the substrate; a cover enclosing the at least one integral acoustic resonator, the cover including a sidewall spaced apart from an edge of the substrate, the sidewall being 5 micrometers or less from the edge of the substrate; and a conductor extending laterally from the through-hole and electrically connected to a conductive layer in the through-hole, the conductor being on a side of the substrate opposite to the at least one integral acoustic resonator, the conductor having solder thereon, and the solder not overlapping the through-hole, the cover including a silicon cover substrate, and the substrate being a silicon substrate.

19. A bulk acoustic wave assembly, comprising: A substrate having a through-hole extending therethrough; at least one integral acoustic resonator on the substrate; a cover enclosing the at least one integral acoustic resonator, the cover including a sidewall spaced apart from an edge of the substrate, the sidewall being 5 micrometers or less from the edge of the substrate; and a conductor extending laterally from the through-hole and electrically connected to a conductive layer in the through-hole, the conductor being on a side of the substrate opposite to the at least one integral acoustic resonator, the conductor having solder thereon, the solder not overlapping the through-hole, the conductive layer in the through-hole being a conformal layer.

Images