Multi-level stacked acoustic wave (AW) filter package and related manufacturing method

Abstract

A multilevel stacked AW filter package (200) including a first acoustic wave AW filter (208) stacked on a second AW filter (204) employs a semiconductor fabrication method and structure, including a metallization layer with an interconnect for coupling the contact surface to the second AW filter. Each AW filter includes an AW filter circuit on a semiconductor substrate. A second substrate (206) disposed on a frame (218) on the substrate protects the AW filter circuit. In the multilevel AW filter package, the second substrate of the first AW filter comprises a glass substrate having a similar expansion coefficient to the semiconductor substrate. The interconnect connecting the second AW filter and the contact surface is disposed on an insulator on the sidewall surface of the semiconductor substrate of the first AW filter for isolation. In a stacked AW filter package with a single AW filter, the interconnect couples the contact surface to the AW filter.

Description

[Technical field]

[0001] I. Field of Disclosure The field of the disclosure relates to an acoustic wave (AW) filter package including an AW filter having an AW filter circuit on a substrate and a laminate substrate having the AW filter circuit. [Background technology]

[0002] II. Background technology

[0002] Mobile wireless device manufacturers can make new devices attractive to buyers by increasing the functional capabilities of the devices with each new generation. Increasing the capabilities of a device typically requires more circuits to be added, which occupies more space, but the device size of a handheld device, for example, is based on the size of a human hand, which remains the same. Methods for achieving increased functionality without increasing device size include reducing the dimensions of the circuits that provide the functional capabilities so that more circuits fit into the internal space of the device. Reducing the area of ​​transistors and wires can increase circuit density, reducing the size of a semiconductor chip, or allowing more circuits to be placed on a semiconductor chip of a given size. Another method for increasing the number of integrated circuits (ICs) in a package is three-dimensional (3D) IC stacking. With this method, the area previously occupied by two ICs placed side-by-side is reduced (e.g., cut in half) by vertically stacking one IC on top of another IC in the same horizontal area, which may result in only a slight increase in package height. The active circuitry in stacked ICs is encapsulated in layers of metal, dielectric material, insulators, and / or molding compound, and stacking the ICs within a package may not significantly interfere with the operation of the ICs.

[0003]

[0003] The handheld device also includes a wireless device including a radio frequency (RF) circuit. The RF circuit includes an analog filter that is conventionally formed as an acoustic wave (AW) device including an AW filter circuit. Examples of AW filter circuits include a surface acoustic wave (SAW) filter circuit and a bulk acoustic wave (BAW) filter circuit. The AW filter circuit converts an electrical input signal into an acoustic wave in a piezoelectric material. In one example, the SAW filter circuit includes a first interdigital transducer (IDT) on the surface of the piezoelectric material configured to receive an RF signal and a second IDT on the surface configured to generate a filtered RF signal. The RF signal is converted into an acoustic wave that propagates through the surface of the piezoelectric material from the first IDT to the second IDT. The acoustic wave in the SAW filter circuit needs to be protected from physical contact, which would interfere with the wave propagation. The protection is done by providing a cavity or air space above the surface of the substrate. Such a cavity is necessary to protect the AW filter circuitry, and since stacked ICs do not require such a cavity, AW filter devices are not stacked by traditional methods used in 3D IC stacking. Summary of the Invention

[0004]

[0004] Exemplary aspects disclosed in the detailed description include a multi-level stacked acoustic wave (AW) filter package including a structure for supporting stacked AW filters. Related manufacturing methods are also disclosed. The specific structures and manufacturing methods disclosed herein that support a multi-level stacked AW filter package may also be employed in an AW filter package that includes only a single AW filter. In this regard, the AW filter package disclosed herein includes one or more AW filters, each including a first substrate having a first surface (e.g., a piezoelectric material) on which at least one AW filter circuit is disposed. Each AW filter circuit includes first and second interdigital transducers (IDTs) for providing radio frequency (RF) signal filtering. Each AW filter also includes a frame coupled to the first substrate and surrounding the at least one AW filter circuit. A second substrate (e.g., a cap substrate) disposed on the frame encloses an air cavity inside the frame between the first substrate and the second substrate. In one exemplary embodiment, the AW filter package includes a multi-level AW filter package including a plurality of AW filters stacked vertically in a stacked arrangement to include a plurality of filter circuits for filtering a plurality of frequencies or frequency bands. The multi-level AW filter package includes a first upper AW filter including at least a first AW filter circuit disposed on the first substrate, and a second substrate disposed on a first frame disposed on the first substrate. The first substrate disposed on a second frame disposed on a third substrate encloses a second lower AW filter including at least a second AW filter circuit to form a multi-level AW filter package. The first substrate and the third substrate can be formed from semiconductor materials as semiconductor substrates. Fabricating the first substrate and the third substrate as semiconductor substrates can allow the AW filter package to be manufactured using semiconductor manufacturing processes and techniques used in manufacturing semiconductor die packages.

[0005]

[0005] In a first exemplary embodiment of the multi-level AW filter package, the metal interconnects provided on the first AW filter are separate from the metal interconnects provided on the second AW filter to provide separate signal paths for receiving RF signals in the respective AW filter circuits from contact pads on the contact surface of the second substrate and providing the respective filtered RF signals to the contact pads on the contact surface. In this regard, a first metal interconnect in the form of a metallized vertical interconnect access (via) is disposed through the second substrate to the surface of the first substrate to provide an interconnect path for the first upper AW filter. Furthermore, a metallization layer including a second metal interconnect is formed on the perimeter wall of the stacked AW filter to provide an interconnect path for the AW filter circuit of the second lower AW filter that is physically and electrically separated from the interconnect path of the first upper AW filter. The second metal interconnect of the metallization layer provides an interconnect path between the second lower AW filter circuit and the first contact pads on the contact surface of the second substrate of the first upper AW filter. For example, forming the interconnection paths of the AW filters in the AW filter package as metal interconnects in a metallization layer, such as a redistribution layer (RDL), allows a metallization layer fabrication process (e.g., an RDL fabrication process) to be adopted to fabricate the AW filter package. Even in an AW filter package that includes only a single AW filter and does not include a stacked AW filter, the metal interconnects in the metallization layer can be adopted to provide metal interconnects for the interconnection paths of the AW filters. Also, in an example of a multi-level AW filter package, the sidewall surfaces of the second substrate, the first substrate, and the third substrate can be staggered horizontally to support the formation of a metallization layer on the perimeter wall of the stacked AW filter to provide interconnection paths from the contact pads on the contact surface of the second substrate to the second lower AW filter circuit.The alternating sidewall surfaces form a shoulder region on the first substrate that extends outwardly from the second substrate, and in a multi-level AW filter package, a lower shoulder region on the third substrate that extends from the first substrate of the AW filter package. The alternating sidewall surfaces provide support for forming metal interconnects on the perimeter walls of the stacked AW filter and avoid overlaps that create "negative exposure" regions where metal interconnects may not be formed.

[0006] In another exemplary embodiment of the multi-level AW filter package, metal interconnects (e.g., RDL interconnects) are formed on the outer periphery wall of the stacked AW filter to provide an interconnection path from the contact surface of the second substrate to the second lower AW filter, which necessarily extends on the outer wall of the first substrate of the first upper AW filter before extending downward to the third substrate of the second lower AW filter. The first substrate of the first upper AW filter is disposed between the second substrate and the third substrate of the second lower AW filter. Thus, an electrical signal carried in the second metal interconnect in the interconnection path from the contact pad on the second substrate to the third substrate of the second AW filter may electrically contact the first substrate of the first upper AW filter, causing a leakage current path between the second metal interconnect and at least one AW filter circuit of the first upper AW filter. The leakage current may interfere with the performance of the AW filter circuits on the first substrate and the third substrate. In this regard, in another exemplary embodiment, one or more insulating layers are disposed on the perimeter wall of the laminated AW filter between the first substrate and the second metal interconnect. The second metal interconnect is formed on the one or more insulating layers disposed on the perimeter wall of the laminated AW filter. In this manner, the electrical signal carried by the second metal interconnect is separated and insulated from the first substrate of the first upper AW filter.

[0007]

[0007] In another exemplary aspect of the AW filter package, the second substrate of the first upper AW filter can be made of a glass material that can be laser machined to allow precision openings to be formed in the second substrate to form metallized vias for the first metal interconnects to the first AW filter circuit. The glass second substrate can also advantageously provide mechanical robustness and stability to the AW filter package. The coefficient of thermal expansion (CTE) of glass is higher than the CTE of polymeric materials that have traditionally been used to form the second substrate, for example. Particularly in stacked multi-level AW filter packages where multiple AW filter cavities are formed on each substrate in a stacked arrangement, it is important to provide mechanical stability to the AW filter package to avoid breakage of the second substrate or the first substrate due to deflection in the filter cavity. Also, employing a glass second substrate can provide mechanical stability to the reduced thickness substrates employed to maintain the overall height of the AW filter package within a desired height budget.

[0008]

[0008] In one exemplary embodiment, a laminated AW filter package is disclosed. The laminated AW filter package includes a first substrate having a first surface, an AW filter circuit on the first substrate's first surface, a frame disposed on the first substrate's first surface, a second substrate having a contact surface and a sidewall surface, the second substrate being disposed on the frame to form a cavity between the AW filter circuit and the second substrate, and a metallization layer having at least one metal interconnect bonded to the contact surface of the second substrate and the first substrate's first surface, the at least one metal interconnect being disposed on the sidewall surface of the second substrate.

[0009]

[0009] In another exemplary aspect, a method for manufacturing a laminated AW filter package is disclosed, the method includes forming a first substrate with a first surface, forming an AW filter circuit on the first substrate surface, forming a frame on the first substrate surface, forming a second substrate with a contact surface and a sidewall surface, disposing the second substrate on the frame to form a cavity between the AW filter circuit and the second substrate, and forming a metallization layer with at least one metal interconnect coupled to the contact surface of the second substrate and the first substrate surface, the at least one metal interconnect disposed on the sidewall surface of the second substrate.

[0010]

[0010] In another exemplary aspect, a laminated AW filter package is disclosed. The laminated AW filter package includes a first substrate having a first surface and a sidewall surface, a first AW filter circuit on the first surface of the first substrate, a first frame disposed on the first surface of the first substrate, a second substrate having a contact surface and a sidewall surface, the second substrate being laminated on the first frame to form a cavity between the first AW filter circuit and the second substrate, a third substrate having a second AW filter circuit on the second surface of the third substrate, and a second frame disposed on the second surface of the third substrate, The first substrate comprises a second frame disposed on the second frame to form a second cavity between the second AW filter circuit and the first substrate; a metallization layer having at least one metal interconnect bonded to a contact surface of the second substrate and a second surface of the third substrate, the at least one metal interconnect disposed on a sidewall surface of the first substrate; and an insulator disposed on the sidewall surface of the first substrate between the sidewall surface of the first substrate and the at least one metal interconnect.

[0011]

[0011] In another exemplary aspect, a method of manufacturing a laminated AW filter package is disclosed, the method includes forming a first substrate with a first surface and a sidewall surface, forming a first AW filter circuit on the first surface of the first substrate, forming a first frame on the first surface of the first substrate, forming a second substrate with a contact surface and a sidewall surface, disposing the second substrate on the first frame to form a first cavity between the first AW filter circuit and the second substrate, forming a third substrate with the second AW filter circuit on a second surface of the third substrate, and disposing the third substrate on the first frame to form a first cavity between the first AW filter circuit and the second substrate. forming a second frame on a second surface of the plate; disposing the first substrate on the second frame to form a second cavity between the second AW filter circuit and the first substrate; forming an insulator on a sidewall surface of the first substrate; and forming a metallization layer having at least one metal interconnect coupled to the contact surface of the second substrate and the second surface of the third substrate, the at least one metal interconnect being disposed on the insulator on the sidewall surface of the first substrate. [Brief description of the drawings]

[0012] [Figure 1]

[0012] FIG. 1 is a diagram of an example of a surface acoustic wave (SAW) device that may be employed in a laminate acoustic wave (AW) filter package. [Figure 2A]

[0013] 1 is a side cross-sectional view of a multi-level stacked AW filter package including a first substrate of a first upper AW filter, a second substrate stacked on the first substrate, the first substrate being stacked on a third substrate of a second lower AW filter, and metal interconnects in a metallization layer on an outer perimeter wall of the stacked AW filter coupling the second lower AW filter to contact pads on the second substrate. [Figure 2B]1 is a side cross-sectional view of a multi-level stacked AW filter package including a first substrate of a first upper AW filter, a second substrate stacked on the first substrate, the first substrate being stacked on a third substrate of a second lower AW filter, and metal interconnects in a metallization layer on an outer perimeter wall of the stacked AW filter coupling the second lower AW filter to contact pads on the second substrate. [Figure 2C] 1 is a side cross-sectional view of a multi-level stacked AW filter package including a first substrate of a first upper AW filter, a second substrate stacked on the first substrate, the first substrate being stacked on a third substrate of a second lower AW filter, and metal interconnects in a metallization layer on an outer perimeter wall of the stacked AW filter coupling the second lower AW filter to contact pads on the second substrate. [Diagram 3]

[0014] FIG. 1 is a diagram of an AW filter in a laminated AW filter package that includes a second substrate laminated onto a frame on a first surface of the substrate to form a cavity above the AW filter circuitry on the substrate. [Figure 4]

[0015] FIG. 4 is a flowchart illustrating a process for manufacturing the laminated AW filter package of FIG. 3, including laminating a second substrate onto a first frame on the first substrate to form a cavity above the AW filter circuit on the first substrate. [Figure 5A]

[0016] FIG. 2C is a flowchart showing a process for manufacturing the laminated AW filter package of FIGS. 2A-2C, including forming an insulator between an outer peripheral wall of the laminated AW filter and a metal interconnect extending between a third substrate and contact pads on a second substrate to avoid leakage current. [Figure 5B] FIG. 2C is a flowchart showing a process for manufacturing the laminated AW filter package of FIGS. 2A-2C, including forming an insulator between an outer peripheral wall of the laminated AW filter and a metal interconnect extending between a third substrate and contact pads on a second substrate to avoid leakage current. [Figure 6]

[0017] 4 is a top view of a frame on a surface of a substrate in the AW filter package of FIGS. 2A to 2C and 3. FIG. [Figure 7]

[0018] FIG. 2C is a top perspective view of the example of the AW filter circuit shown in FIGS. 2A to 2C. [Figure 8]

[0019] 2A-2C, 3, and 7, a block diagram of an exemplary wireless communication device including a radio frequency (RF) module including an AW filter package including a first AW filter circuit on a first substrate protected in a cavity by a second substrate stacked on a frame on the first substrate, and also including an insulator between the first substrate and a metal interconnect extending from a contact pad on the second substrate to a third substrate stacked on the back side of the first substrate. [Figure 9]

[0020] FIG. 2A is a block diagram of an exemplary processor-based system that may include an AW filter package that includes a first AW filter circuit on a first substrate protected in a cavity by a second substrate stacked on a frame on the substrate, and also includes an insulator between the first substrate and metal interconnects extending from contact pads on the second substrate to a third substrate stacked on the back side of the substrate, according to any of the embodiments disclosed herein, as shown in FIGS. 2A-2C, 3, and 7. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013]

[0021] Some exemplary aspects of the present disclosure will now be described with reference to the drawings. The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any aspect described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects.

[0014]

[0022] Before describing an exemplary embodiment of a stacked acoustic wave (AW) filter package of one or more AW filters, each including at least one AW filter circuit on a first substrate and a second substrate (e.g., a cap substrate) disposed on a frame to provide a protective cavity on the AW filter circuit, as shown in FIGS. 2A-2C, FIG. 1 is described. FIG. 1 is a diagram of a surface acoustic wave (SAW) filter circuit 100 on a first substrate 102 that may be employed in an AW filter 104 in a stacked AW filter package. Although not shown here, the AW filter 104 includes a second substrate disposed on a frame on the first substrate 102 to form a cavity to protect the AW filter circuit 100 from acoustic interference, as disclosed herein. In this regard, FIG. 1 is a perspective view of an AW filter 104 configured to pass a particular frequency range while blocking other frequencies of an input radio frequency (RF) signal. The AW filter 104 may be included in another integrated circuit (IC) package that includes RF transmit / receive circuitry and an antenna, and the SAW filter circuit 100 is employed to filter the transmitted and / or received RF signals. The first substrate 102 includes a piezoelectric material 106 that forms a first surface 108 in this example. A first interdigital transducer (IDT) 110(1) is disposed on the first surface 108 of the first substrate 102 as an input circuit. A second IDT 110(2) is also disposed on the first surface 108 of the first substrate 102 as an output circuit adjacent to the first IDT 110(1). The first IDT 110(1) is configured to receive an input RF signal 112 via first metal interconnects 114A, 114B that are coupled to first metal contacts 116A, 116B, respectively. The first metal contacts 116A, 116B (e.g., solder bumps, solder balls) on the first substrate 102 connect to the first IDT 110(1). The first IDT 110(1) includes interdigitated metal interconnects 118A, 118B (e.g., metal lines, metal traces) and is configured to convert a received electrical input RF signal 112 into an acoustic wave that propagates on the first surface 108 of the substrate 102 from the first IDT 110(1) to the second IDT 110(2).The first IDT 110(1) is configured to radiate an acoustic wave onto the first surface 108, and the second IDT 110(2) is configured to receive the filtered acoustic wave and convert the filtered acoustic wave into a filtered RF signal 120. The second IDT 110(2) includes interdigitated metal interconnects 122A, 122B coupled to second metal contacts 124A, 124B, respectively, and provides the filtered RF signal 120 to the second metal interconnects 126A, 126B. In some examples, a SAW substrate corresponding to the first substrate 102 may include multiple SAW filter circuits 100. Similarly, a bulk acoustic wave (BAW) substrate may include multiple BAW filter circuits.

[0015]

[0023] Exemplary embodiments disclosed herein support a multi-level stacked AW filter package 200 as shown in cross-sectional side views in FIGS. 2A-2C, which includes a first upper AW filter 202 ("first AW filter 202") and a second lower AW filter 204 ("second AW filter 204"), each including a first substrate 206 with at least one first AW filter circuit 208 disposed on a first surface 210 and a third substrate 212 with at least one second AW filter circuit 214 disposed on a second surface 216. The first substrate 206 and the third substrate 212 have the first AW filter circuit 208 and the second AW filter circuit 214 disposed thereon, respectively. The multi-level stacked AW filter package 200 may also be referred to herein as "stacked AW filter package 200" or "AW filter package 200".

[0016]

[0024] The first AW filter circuit 208 and the second AW filter circuit 214 each provide RF signal filtering. The first AW filter 202 includes a first frame 218 coupled to the first substrate 206 and surrounding at least one first AW filter circuit 208. A second substrate 220 disposed on the first frame 218 encloses a first cavity 222 (e.g., an air cavity) above the first AW filter circuit 208, inside the first frame 218, and between the first substrate 206 and the cap substrate 220. The second substrate 220 is disposed on the first frame 218 to form a cap structure, which may also be referred to herein as a "cap substrate 220." The second AW filter 204 includes a second frame 224 coupled to the third substrate 212 and surrounding at least one second AW filter circuit 214. The first substrate 206 of the first AW filter 202 is disposed on the second frame 224 to provide a cap structure enclosing a second cavity 226 (e.g., an air cavity) within the second frame 224 between the first substrate 206 and the third substrate 212. In this regard, the multi-level AW filter package 200 includes multiple AW filters vertically stacked in a stacked arrangement to include multiple filter circuits for filtering multiple frequencies or frequency bands.

[0017]

[0025] The first substrate 206 and the third substrate 212 may be formed from a semiconductor material, as the semiconductor substrate 213, to utilize semiconductor manufacturing processes and techniques used in manufacturing semiconductor die packages that may be less expensive than conventional processes in which the substrates are formed from piezoelectric materials. Manufacturing the first substrate 206 and the third substrate 212 includes forming a semiconductor substrate 213, such as a silicon substrate, having a first surface 210 and a second surface 216 that include a piezoelectric material 228. The piezoelectric material 228 may be any suitable piezoelectric material, including, but not limited to, quartz, lithium tantalate (LiTaO3), lithium niobate (LiNbO3), aluminum nitride (AlN), scandium doped AlN (AlNSc), barium titanate (BaTiO3), and zinc oxide (ZnO), disposed on the first substrate 206 and the third substrate 212.

[0018]

[0026] In the multi-level AW filter package 200, the first metal interconnect 230 provides an interconnect path ("signal path") 232 for the first AW filter 202 to receive an RF signal and transmit a filtered RF signal to a contact surface 234 of the cap substrate 220. The first metal interconnect 230 is separated from at least one second metal interconnect 236 and provides a signal path 238 for the second AW filter 204. In this regard, the first metal interconnect 230 is in the form of a metallized vertical interconnect access (via) 240 disposed through the cap substrate 220 to the first surface 210 of the first substrate 206 to provide the signal path 232 to the first AW filter circuit 208. Furthermore, at least one second metal interconnect 236 ("metal interconnect 236") in the metallization layer 243 is formed on the perimeter wall 244 of the stacked AW filters 202, 204 to provide a signal path 238 for the second AW filter circuit 214 of the second AW filter 204 that is physically and electrically isolated from the signal path 232 of the first AW filter 202. The metal interconnect 236 provides the signal path 238 between the second AW filter circuit 214 and a contact pad 246 disposed on the contact surface 234 of the cap substrate 220 of the first AW filter 202. The contact pad 246 includes a metal or metal alloy (e.g., solder) that may be formed into a pad or bump and configured to conduct an electrical signal. In this example, the metal interconnect 236 formed in the metallization layer 243 is configured to distribute a signal from the contact pad 246 to the first surface 210 of the first substrate 206. As a non-limiting example, the metal interconnect 236 may be a redistribution layer (RDL) interconnect formed in one or more RDL layers coupled to the contact pads 246, where the RDL interconnect is configured to redistribute signals from the contact pads 246 to the first surface 210 of the first substrate 206. Forming the signal path 238 of the second AW filter 204 in the AW filter package 200 as a second metal interconnect 236 of the metallization layer 243 can enable, for example, a metallization layer manufacturing process to be employed to manufacture the AW filter package 200.For example, if the metallization layer 243 is an RDL, an RDL manufacturing process may be employed.

[0019]

[0027] Surfaces on which metal interconnects 236 may be formed in a metallization layer fabrication process (e.g., RDL fabrication process) include surfaces on a first side (e.g., top) of the substrate that are parallel (e.g., horizontal) to the substrate, surfaces perpendicular (e.g., vertical) to the substrate, or inclined surfaces on the first side of the substrate. However, metal interconnects 236 may not be successfully formed on inclined or horizontal surfaces on the second side (e.g., downward-facing side) of the substrate that are not exposed perpendicular to the substrate on the first side of the substrate. For example, a metallization layer may be formed on upward-facing surfaces and continuous sidewall surfaces, but not on downward-facing surfaces or sidewall surfaces that are shadowed by the upper substrate. In this regard, to successfully fabricate a continuous metal interconnect 236 on the perimeter wall 244 of the AW filters 202, 204, a "negatively exposed" area, such as an area where an upper structure overhangs an underlying structure (e.g., shadows the underlying structure from a first side), may result in unreliable results in the formation of the metallization layer 243. In an example with respect to a stacked structure, a metal interconnect may be formed on the perimeter wall of a stack of substrates with the substrate sides aligned in the Z-axis direction. However, this requires that each perimeter wall of the stack on which the metal interconnect is located is aligned in the Z-axis direction. However, in practice, due to manufacturing tolerances of the substrates, the substrate width may vary and the overlay of the substrates may vary. An upper substrate in a stack that has a larger width than a lower substrate in the stack and that overhangs the lower substrate on at least one side of the stack forms a shadowed area (e.g., a negatively exposed area) on a second side (e.g., in the Z-axis direction) of the overhanging upper substrate. Such shadowed areas may not have a metallization layer properly formed therein because the shadowed areas are not exposed in a direction perpendicular to the first side of the upper substrate (eg, in the Z-axis direction).

[0020]

[0028] In this regard, in another exemplary embodiment, in the example multi-level AW filter package 200, the sidewall surface 250 of the cap substrate 220, the sidewall surface 252 of the first substrate 206, and the sidewall surface 254 of the third substrate 212 may be staggered relative to one another in the horizontal direction to support the formation of metal interconnects 236 on the perimeter wall 244 of the stacked AW filters 202, 204 to provide a signal path 238 to the second AW filter circuit 214. Here, "staggered" means that the first substrate 206 extends further in the X-axis direction than the sidewall surface 250 of the cap substrate 220, the third substrate 212 extends further in the X-axis direction than the sidewall surface 252 of the first substrate 206, and the sidewall surface 252 of the first substrate 206 is between the sidewall surface 250 of the cap substrate 220 and the sidewall surface 254 of the third substrate 212 in the X-axis direction. The alternating sidewall surfaces 250, 252 form a shoulder region 256 of the first substrate 206 that extends beyond the sidewall surface 250 (see FIG. 2B ) of the cap substrate 220 in a direction perpendicular to the sidewall surface 250 of the cap substrate 220 (e.g., in the X-axis direction). The alternating sidewall surfaces 252, 254 also form a lower shoulder region 258 on the third substrate 212 of the multi-level AW filter package 200 that extends beyond the sidewall surface 252 of the first substrate 206 of the AW filter package 200 (e.g., in the X-axis direction). The shoulder region 256 and the lower shoulder region 258 provide support for forming the metal interconnect 236 on the perimeter wall 244 of the stacked AW filters 202, 204, for example, using an RDL manufacturing process, and avoid overlaps that form negative exposed areas where the metal interconnect 236 may not be formed.

[0021]

[0029] 2A-2C, the metal interconnect 236 is disposed on the contact surface 234 of the cap substrate 220 and electrically coupled to the contact pad 246. The contact pad 246 is configured to couple to an external circuit to receive an RF signal or to provide a filtered RF signal. A signal received or generated on the contact pad 246 can be electrically coupled to one of the second AW filter circuits 214 on the third substrate 212 via the metal interconnect 236. In this regard, the metal interconnect 236 continues from the contact surface 234 (e.g., the top surface of the AW filter package 200) onto a sidewall surface 250 of the cap substrate 220. The sidewall surface 250 of the cap substrate 220 extends in a vertical direction (e.g., a Z-axis direction) perpendicular to the contact surface 234. The first frame 218 is disposed between the cap substrate 220 and the first surface 210 of the first substrate 206. The sidewall surface 260 of the first frame 218 may extend alongside the sidewall surface 250 of the cap substrate 220 (e.g., in the Z-axis direction) without being offset in a direction perpendicular to the sidewall surface 250 of the cap substrate 220 (e.g., in the X-axis direction). In this manner, the sidewall surface 250 of the cap substrate 220 and the sidewall surface 260 of the first frame 218 may enable the metal interconnect 236 to be formed, for example, by an RDL fabrication process or other metallization layer fabrication process. The metal interconnect 236 extends from the sidewall surface 250 of the cap substrate 220 onto the sidewall surface 260 of the first frame 218 between the cap substrate 220 and the first substrate 206. The first frame 218 extends in a direction perpendicular to the sidewall surface 250 of the cap substrate 220 (X-axis direction) from the sidewall surface 250 of the cap substrate 220 at the first side S1 of the sidewall surface 250 of the cap substrate 220 (i.e., into the first cavity 222) to support the cap substrate 220. The first frame 218 includes a material different from the cap substrate 220. In some examples, the first frame 218 is a polymer material formed on one of the cap substrates 220 and the first substrate 206 before the cap substrate 220 is laminated on the first substrate 206. The cap substrate 220 may be formed of, for example, glass.

[0022]

[0030] In some examples, the first frame 218 extends onto a shoulder region 256 on the first surface 210 of the first substrate 206 at the second side S2 of the sidewall surface 250 of the cap substrate 220 in a direction perpendicular to the sidewall surface 250 of the cap substrate 220. In this regard, the sidewall surface 260 of the first frame 218 is not aligned with the sidewall surface 250 of the cap substrate 220 such that the sidewall surface 260 of the first frame 218 is staggered relative to the sidewall surface 250 of the cap substrate 220, which also allows for the formation of the metal interconnect 236. In such examples, the metal interconnect 236 is also disposed on the top surface 262 of the first frame 218. Thus, the metal interconnects 236 extend, in such an example, from the sidewall surface 250 of the cap substrate 220 onto the top surface 262 of the first frame 218 and onto the sidewall surface 260 of the first frame 218 .

[0023]

[0031] Following the metal interconnect 236 along the perimeter wall 244 in the Z-axis direction toward the third substrate 212, the metal interconnect 236 is disposed on the shoulder region 256 of the first substrate 206 and onto the sidewall surface 252 of the first substrate 206. The sidewall surface 252 of the first substrate 206 may be perpendicular to the first surface 210 of the first substrate 206. The second frame 224 is disposed between the first substrate 206 and the third substrate 212. The sidewall surface 264 of the second frame 224 may be aligned with the sidewall surface 252 of the first substrate 206, thereby forming the metal interconnect 236 extending from the sidewall surface 252 of the first substrate 206 and continuing onto the sidewall surface 264 of the second frame 224. The second frame 224 extends from the side wall surface 252 of the first substrate 206 in a direction perpendicular to the side wall surface 252 of the first substrate 206 (e.g., in the X-axis direction) to the first side S1 (i.e., into the second cavity 226) to support the first substrate 206.

[0024]

[0032] In some examples, the second frame 224 extends in a direction perpendicular to the sidewall surface 252 of the first substrate 206 to the second side S2 of the sidewall surface 252 of the first substrate 206 so as to be staggered with respect to the sidewall surface 252 of the first substrate 206 (i.e., the sidewall surface 264 of the second frame 224 extends in the X-axis direction to the side S2 of the sidewall surface 252 of the first substrate 206). In such examples, the metal interconnects 236 are disposed on the top surface 266 of the second frame 224, continue onto the sidewall surface 264 of the second frame 224, and are also disposed on the lower shoulder region 258 of the third substrate 212, which is also on the second side S2 of the sidewall surface 264 of the second frame 224.

[0025]

[0033] The metal interconnect 236 coupled to the contact pad 246 is also coupled to the surface interconnect 268 to electrically couple the contact pad 246 to the second AW filter circuit 214 on the second surface 216 via the metal interconnect 236. The surface interconnect 268 is disposed on the second surface 216 of the third substrate 212 and extends from inside the second cavity 226 to the lower shoulder region 258 (outside the cavity). The surface interconnect 268 is coupled to both the second AW filter circuit 214 and the metal interconnect 236. The second frame 224 is disposed onto a portion of the surface interconnect 268 between the second AW filter circuit 214 in the second cavity 226 and the metal interconnect 236 on the lower shoulder region 254. In this manner, the metal interconnect 236 electrically couples the second AW filter circuit 214 to the contact pad 246.

[0026]

[0034] In another exemplary embodiment, in a multi-level stacked AW filter package 200 in which the metal interconnects 236 provide signal paths 238 between the contact pads 246 on the third substrate 212 and the second AW filter circuit(s) 214, and the metal interconnects 236 extend across the first substrate 206 that includes the first AW filter circuit 208, the insulator 270 is disposed on the sidewall surface 252 of the first substrate 206 between the sidewall surface 252 of the first substrate 206 and the metal interconnects 236. The first substrate 206 comprises one of the semiconductor substrates 213 having a piezoelectric material 228 on the first surface 210. The piezoelectric material 228 protects the semiconductor substrate 213, which is a semiconductor, from electrical signals in the metal interconnects 236. During manufacturing, the semiconductor substrate 213 is diced from the wafer, and the sidewall surface 252 of the first substrate 206 is exposed (e.g., not protected from electrical signals). Thus, disposing the metal interconnects 236 directly onto the sidewall surface 252 of the first substrate 206 on which at least one first AW filter circuit(s) 208 is formed electrically couples the first AW filter circuit 208 to the metal interconnects 236 and thus to the second AW filter circuit 214 and the contact pads 246. As a result of such electrical coupling, current may leak through the semiconductor substrate 213 between the first AW filter circuit 208 and the second AW filter circuit 214, which may cause interference with the operation of the first and second AW filter circuits 208, 214 and may also cause power loss in the AW filter package 200. In this regard, an insulator 270 is disposed on the sidewall surface 252 of the first substrate 206 between the sidewall surface 252 of the first substrate 206 and the metal interconnects 236 to insulate and separate the first AW filter circuit 208 from the second AW filter circuit 214. During manufacture, the insulator 270 is disposed on the peripheral walls 244 of the stacked AW filters 202, 204, including the sidewall surface 250 of the cap substrate 220, the sidewall surface 260 of the first frame 218, and the first surface 210 of the first substrate 206, before the metal interconnects 236 are disposed thereon.Thus, the insulator 270 is disposed between the sidewall surface 250 of the cap substrate 220 and the metal interconnect 236, between the sidewall surface 260 of the first frame 218 and the metal interconnect 236, and between the first surface 210 of the first substrate 206 and the metal interconnect 236.

[0027]

[0035] In another aspect, the first metal interconnect 230 (i.e., the via 240) and the second metal interconnect 236 also provide separate thermal paths for dissipating heat away from the first AW filter circuit 208 and the second AW filter circuit 214 to the contact surface 234 of the cap substrate 220 for dissipation from the AW filter package 200. Forming the via 240 in the cap substrate 220 may include, for example, laser drilling holes in the cap substrate 220 and filling the holes with a metal to provide both electrical and thermal conductivity. The via 240 may be formed from copper, aluminum, or one or more other metals that provide electrical and thermal conductivity.

[0028]

[0036] In another aspect, the purpose of the multi-level stacked AW filter package 200 is to conserve area within an electronic device, but the area savings are not beneficial unless the resulting increased height is acceptable for use within the electronic device. In this regard, by forming the first substrate 206 and the third substrate 212 of a semiconductor substrate 213 that may be processed by IC processing methods, the first substrate 206 and the third substrate 212 may be thinned to reduce the package height. Furthermore, forming the cap substrate 220 from glass provides the AW filter package 200 with additional structural integrity not provided by more flexible capping materials such as polymers. By way of example, the third substrate 212 may have a thickness T in a range of 60 microns (μm) to 130 (130) μm in a first direction perpendicular to the second surface 216. 212 and the first substrate 206 may have a thickness T in the first direction in the range of 30 μm to 70 μm. 206 and the cap substrate 220 may have a thickness T in the range of 30 μm to 70 μm. 220In some examples, the third substrate 212 may have a thickness T 212 is less than 85 μm, and the thickness T 206 is less than 55 μm, and the thickness T 220 is less than 55 μm.

[0029]

[0037] Exemplary embodiments disclosed herein supporting a multi-level stacked AW filter package 200 as shown in FIGS. 2A-2C can also be employed in a stacked AW filter package 300 as shown in FIG. 3 including only a single AW filter 302, including a first substrate 304, an AW filter circuit 306 on a first surface 308 of the first substrate 304, a frame 310 disposed on the first surface 308, and a second substrate 312 disposed (e.g., stacked) on the frame 310. The second substrate 312 is disposed on the frame 310 to form a cap structure, which may also be referred to herein as a “cap substrate 312.” In this regard, a metallization manufacturing process may be used to fabricate a metallization layer 313 comprising at least one metal interconnect 314 (“metal interconnect 314”). As a non-limiting example, the metallization layer 312 can be an RDL having an RDL interconnect therein, providing a signal path 316 for the AW filter 302 even in an AW filter package 300 that does not include a stacked AW filter. The metal interconnect 314 provides the signal path 316 (and a thermal path) from the first substrate 304 to a contact pad 318 on a contact surface 320 of the cap substrate 312. The metal interconnect 314 is disposed on the contact surface 320 and is electrically coupled to the contact pad 318, which is also coupled to the first surface 308 of the first substrate 304.

[0030]

[0038] To employ a metallization manufacturing process, such as a non-limiting example of an RDL manufacturing method, the sidewall surface 322 of the first substrate 304 is staggered relative to the sidewall surface 324 of the cap substrate 312, as in the multi-level AW filter package 200 described above. Thus, the first surface 308 includes a shoulder region 326 extending in a direction perpendicular to the sidewall surface 324 of the cap substrate 312. The metal interconnect 314 extends onto the sidewall surface 324 of the cap substrate 312. In an example in which the sidewall surface 328 of the frame 310 is aligned with the sidewall surface 324 of the cap substrate 312 (e.g., along the Y-axis), the metal interconnect 314 extends from the sidewall surface 324 of the cap substrate 312 onto the sidewall surface 328 of the frame 310. The frame 310 extends from a sidewall surface 324 of the cap substrate 312 to a first side S1 between the cap substrate 312 and the first substrate 304 to support the cap substrate 312 and provide a cavity 330. In some examples, the frame 310 is not aligned with the sidewall surface 324 of the cap substrate 312. Instead, the frame 310 extends beyond the sidewall surface 324 of the cap substrate 312 in a direction perpendicular to the sidewall surface 324 of the cap substrate 312 to a second side S2 of the sidewall surface 324 of the cap substrate 312 and onto a shoulder region 326 of the first substrate 304, such that a sidewall surface 328 of the frame 310 is staggered relative to the sidewall surface 324 of the cap substrate 312. In this example, the metal interconnect 314 extends from a sidewall surface 324 of the cap substrate 312 onto a top surface 332 of the frame 310 and onto a sidewall surface 328 of the frame 310. The metal interconnect 314 is disposed onto a first surface 308 of the first substrate 304. A surface interconnect 334 disposed on the first surface 308 extends from within the cavity 330, where the surface interconnect 334 is electrically coupled to the AW filter circuit 306, over the frame 310 into the shoulder region 326. The metal interconnect 314 is electrically coupled to the surface interconnect 334 in the shoulder region 326 to electrically couple the AW filter circuit 306 to the contact pad 318.

[0031]

[0039] 4 is a flow chart of a process 400 for manufacturing a laminated AW filter package 300. The process 400 includes forming a first substrate 304 with a first surface 308 (block 402) and forming an AW filter circuit 306 on the first surface 308 of the first substrate 304 (block 404). The process 400 includes forming a frame 310 on the first surface 308 of the first substrate 304 (block 406) and forming a second substrate (e.g., cap substrate) 312 with a contact surface 320 and a sidewall surface 324 (block 408). The process 400 includes placing a cap substrate 312 on a frame 310 to form a cavity 330 between the AW filter circuit 306 and the cap substrate 312 (block 410), and forming a metallization layer 313 having at least one metal interconnect 314 coupled to a contact surface 320 of the cap substrate 312 and a first surface 308 of the first substrate 304, the at least one metal interconnect 314 being disposed on a sidewall surface 324 of the cap substrate 312 (block 412).

[0032]

[0040] 5A and 5B are a flow chart of a process 500 for manufacturing the laminated AW filter package 200. The process 500 includes forming a first substrate 206 having a first surface 210 and a sidewall surface 252 (block 502) and forming a first AW filter circuit 208 on the first surface 210 of the first substrate 206 (block 504). The process 500 includes forming a first frame 218 on the first surface 210 of the first substrate 206 (block 506) and forming a cap substrate 220 having a contact surface 234 and a sidewall surface 250 (block 508). The process 500 includes disposing the cap substrate 220 on the first frame 218 to form a first cavity 222 between the first AW filter circuit 208 and the cap substrate 220 (block 510) and forming a third substrate 212 with a second AW filter circuit 214 on a second surface 216 of the third substrate 212 (block 512). The process 500 includes forming a second frame 224 on the second surface 216 of the third substrate 212 (block 514) and disposing the first substrate 206 on the second frame 224 to form a second cavity 226 between the second AW filter circuit 214 and the first substrate 206 (block 516). The process 500 includes forming an insulator 268 on the sidewall surface 256 of the first substrate 206 (block 518) and forming a metallization layer 243 having at least one metal interconnect (236) coupled to the contact surface 234 of the cap substrate 220 and the second surface 216 of the third substrate 212, where the at least one metal interconnect (236) is disposed on the insulator 270 on the sidewall surface 252 of the first substrate 206 (block 520).

[0033]

[0041] FIG. 6 is a top view of an example of a frame 600 supporting the fabrication of the laminated AW filter packages 200 and 300. The frame 600 may correspond to the frames 218 and 224 of FIGS. 2A-2C and the frame 310 of FIG. 3. The frame 600 includes a perimeter frame 602 that extends along the perimeter 604 of a larger first substrate 606 in the X-axis and Y-axis directions, such that the first substrate 606 includes shoulder regions 608 that are staggered widthwise relative to the frame 600. In some examples, the dimensions of the frame 600 may be the same size as the second substrate (e.g., a cap substrate) or slightly larger in area than the second substrate to avoid "negative exposure" regions where metal interconnects may not be formed. The perimeter frame 602 in this example is rectangular, but may also be square or another shape that corresponds to the perimeter of the second substrate to be supported. The frame 600 includes a frame member 610 for supporting the second substrate against pressure on the contact surface by providing additional support, so the size of the cavity 612 can be increased to include more AW filter circuits 614 on the first substrate 606. The frame member 610 extends across the cavity 612 from the surrounding frame 602. The frame member 610 may be linear and has a first end 616 that contacts and extends from the surrounding frame 602. The frame member 610 includes a second end 618 that is within the cavity and is not in contact with the surrounding frame 602. The cavity 612 is continuous (i.e., uninterrupted) around the second end 618 from a first cavity portion 620A on a first side of the frame member 610 to a second cavity portion 620B on a second side of the frame member 610. An AW filter circuit 614 may be disposed in the first cavity portion 620A. In some examples, another AW filter circuit 624 may be disposed in the second cavity portion 620B. As shown, the frame 600 includes a plurality of frame members 610 extending from a perimeter frame 602 into a cavity 612 to support a second substrate.

[0034]

[0042] The perimeter frame 602 and frame member 610 are in contact with the second substrate (not shown) and the first substrate 606. The frame member 610 supports the laminated AW filter package by providing more support in the cavity 612 against pressure on the contact surface of the first substrate. Pressure applied to the first substrate, which may be a glass substrate, may cause inward deflection of the glass and top substrate in the laminated AW filter package. In areas of the cavity 612 where the frame member 610 is excluded (i.e., the frame member 610 is not present), the glass may deflect to a breaking point under pressure if such unsupported area is too large. However, due to the structural rigidity of the glass second substrate, the cavity 612 of the AW filter package may include a circular region 626 having a diameter of up to 400 μm, as disclosed herein, where the perimeter frame 602 and frame member 610 are excluded. In some examples, the circular region 626 has a diameter (D1) in the range of 360 μm to 400 μm.

[0035]

[0043] FIG. 7 is a top perspective view of a laminated AW filter package 700. The laminated AW filter package 700 includes a second substrate 702 laminated above a first substrate 704 to form a first AW filter 706. The second substrate 702 is disposed on the first substrate 704 to form a cap structure, which may also be referred to herein as a "cap substrate 702". The first AW filter 706 also provides a cap structure to be laminated on a third substrate 708 to form a second AW filter 710. The laminated AW filter package 700 includes contact pads 712 on the cap substrate 702. The contact pads 712 couple to first metal interconnects 714 with vias 716 extending through the cap substrate 702 to couple to a first AW filter circuit (not shown) on the first substrate 704. A second metal interconnect 718 (which may be an RDL interconnect) extends from the contact pad 712 along a perimeter wall 720 to the second AW filter 710. The second metal interconnect 718 is disposed on an insulator 722 on a sidewall surface 724 of the first substrate 704 to couple the contact pad 712 to a second AW filter circuit (not shown) on the third substrate 708 without electrically coupling to the semiconductor material of the first substrate 704.

[0036]

[0044] FIG. 8 illustrates an exemplary wireless communication device 800 that includes RF components formed from one or more ICs 802 and may include a stacked AW filter package 803. The stacked AW filter package 803 includes a first AW filter circuit disposed on a first substrate, a second substrate disposed on a first frame disposed on the first substrate, and a first substrate disposed on a second frame disposed on a third substrate to enclose a second lower AW filter circuit, and as shown in FIGS. 2A-2C, 3, and 7, according to any of the aspects disclosed herein, contact pads on the second substrate are electrically coupled to the second AW filter circuit by metal interconnects disposed on an insulator to protect against leakage current to the first substrate. The wireless communication device 800 may include any of the above devices, or may be provided within any of the above devices, as an example. As shown in FIG. 8, the wireless communication device 800 includes a transceiver 804 and a data processor 806. The data processor 806 may include a memory for storing data and program codes. The transceiver 804 includes a transmitter 808 and a receiver 810 supporting bidirectional communication. In general, the wireless communication device 800 may include any number of transmitters 808 and / or receivers 810 for any number of communication systems and frequency bands. All or a portion of the transceiver 804 may be implemented on one or more analog ICs, RFICs, mixed-signal ICs, etc.

[0037]

[0045] The transmitter 808 or the receiver 810 may be implemented by a super-heterodyne architecture or a direct-conversion architecture. In the super-heterodyne architecture, the signal is frequency converted between RF and baseband in multiple stages, for example, from RF to intermediate frequency (IF) in one stage and then from IF to baseband in another stage. In the direct-conversion architecture, the signal is frequency converted between RF and baseband in one stage. The super-heterodyne architecture and the direct-conversion architecture may use different circuit blocks and / or have different requirements. In the wireless communication device 800 in FIG. 8, the transmitter 808 and the receiver 810 are implemented by a direct-conversion architecture.

[0038]

[0046] In the transmit path, a data processor 806 processes data to be transmitted and provides I and Q analog output signals to a transmitter 808. In the exemplary wireless communication device 800, the data processor 806 includes digital-to-analog converters (DACs) 812(1) and 812(2) to convert digital signals generated by the data processor 806 into I and Q analog output signals, e.g., I and Q output currents, for further processing.

[0039]

[0047] Within the transmitter 808, low-pass filters 814(1) and 814(2) filter the I and Q analog output signals, respectively, to remove unwanted signals caused by previous digital-to-analog conversion. The low-pass filters 814(1), 814(2) may be implemented as an AW filter package 803. Amplifiers (AMP) 816(1), 816(2) amplify the signals from the low-pass filters 814(1), 814(2), respectively, and provide the I and Q baseband signals. An upconverter 818 upconverts the I and Q baseband signals with an ITX LO signal and a Q TX LO signal from a transmit (TX) local oscillator (LO) signal generator 822 via mixers 820(1), 820(2) to provide an upconverted signal 824. A filter 826 filters the upconverted signal 824 to remove unwanted signals caused by frequency upconversion as well as noise in the receive frequency band. A power amplifier (PA) 828 amplifies the upconverted signal 824 from the filter 826 to obtain a desired output power level and provides a transmit RF signal. The transmit RF signal is routed through a duplexer or switch 830 and transmitted via an antenna 832. Either of the low pass filters 814(1) and 814(2), or the filter 826, may be an acoustic wave filter (AW filter) package 803.

[0040]

[0048] In the receive path, an antenna 832 receives a signal transmitted by a base station and provides a received RF signal, which is routed through a duplexer or switch 830 and provided to a low noise amplifier (LNA) 834. The duplexer or switch 830 is designed to operate at a particular RX to TX duplexer frequency separation such that the receive (RX) signal is separated from the TX signal. The received RF signal is amplified by the LNA 834 and filtered by a filter 836 to obtain a desired RF input signal. Downconversion mixers 838(1), 838(2) mix the output of the filter 836 with I and Q RX LO signals (i.e., LO_I and LO_Q) from a RX LO signal generator 840 to generate I and Q baseband signals. The I and Q baseband signals are amplified by AMPs 842(1), 842(2) and further filtered by low pass filters 844(1), 844(2) to obtain I and Q analog input signals, which are provided to data processor 806. Either filter 836 or low pass filters 844(1), 844(2) may be AW filter package 803. In this example, data processor 806 includes analog-to-digital converters (ADCs) 846(1), 846(2) to convert the analog input signals to digital signals for further processing by data processor 806.

[0041]

[0049] In the wireless communication device 800 of FIG. 8, a TX LO signal generator 822 generates I and Q TX LO signals used for frequency up-conversion, and a RX LO signal generator 840 generates I RX LO signals and Q RX LO signals used for frequency down-conversion. Each LO signal is a periodic signal having a particular fundamental frequency. A TX phase-locked loop (PLL) circuit 848 receives timing information from the data processor 806 and generates a control signal used to adjust the frequency and / or phase of the TX LO signal from the TX LO signal generator 822. Similarly, a RX PLL circuit 850 receives timing information from the data processor 806 and generates a control signal used to adjust the frequency and / or phase of the RX LO signal from the RX LO signal generator 840.

[0042]

[0050] A wireless communication device 800 may each include a stacked AW filter package 803 including a second substrate stacked on a first substrate including a first AW filter circuit, which is further stacked on a third substrate including a second AW filter circuit, and according to any of the embodiments disclosed herein, as shown in Figures 2A-2C, 3 and 7, contact pads on the second substrate are electrically coupled to the second AW filter circuit by metal interconnects disposed on an insulator to protect against leakage current to the first substrate, and may be provided or integrated within any processor-based device. Examples include, but are not limited to, a set-top box, an entertainment unit, a navigation device, a communication device, a fixed location data unit, a mobile location data unit, a global positioning system (GPS) device, a mobile phone, a cellular phone, a smartphone, a session initiation protocol (SIP) phone, a tablet, a phablet, a server, a computer, a portable computer, a mobile computing device, a wearable computing device (e.g., a smart watch, a health or fitness tracker, eyewear, etc.), a desktop computer, a personal digital assistant (PDA), a monitor, a computer monitor, a television, a tuner, a radio, a satellite radio, a music player, a digital music player, a portable music player, a digital video player, a video player, a digital video disc (DVD) player, a portable digital video player, an automobile, a vehicle component, an avionics system, a drone, and a multicopter.

[0043]

[0051] In this regard, FIG. 9 illustrates an example of a processor-based system 900 including a stacked AW filter package 901 including an RF circuit. The stacked AW filter package 901 includes a first AW filter circuit disposed on a first substrate, a second substrate disposed on a first frame disposed on the first substrate, and the first substrate disposed on a second frame disposed on a third substrate to enclose the second lower AW filter circuit, with contact pads on the second substrate electrically coupled to the second AW filter circuit by metal interconnects disposed on an insulator to protect against leakage current to the first substrate according to any embodiment disclosed herein, as shown in FIGS. 2A-2C, 3, and 7. In this example, the processor-based system 900 includes one or more central processing units (CPUs) 902, sometimes referred to as CPUs or processor cores, each including one or more processors 904. The CPU(s) 902 may have a cache memory 906 coupled to the processor(s) 904 for quick access to temporarily stored data. The CPU(s) 902 may be coupled to a system bus 908, which may interconnect master and slave devices included in the processor-based system 900. As is well known, the CPU(s) 902 communicate with these other devices by exchanging address, control, and data information via the system bus 908. For example, the CPU(s) 902 may communicate bus transaction requests to a memory controller 910, as an example of a slave device. Although not shown in FIG. 9, multiple system buses 908 may be provided, where each system bus 908 constitutes a different fabric.

[0044]

[0052] 9, these devices can include, by way of example, a memory system 912 including a memory controller 910 and one or more memory arrays 914, one or more input devices 916, one or more output devices 918, one or more network interface devices 920, and one or more display controllers 922. Each of the memory system 912, the one or more input devices 916, the one or more output devices 918, the one or more network interface devices 920, and the one or more display controllers 922 can include RF circuitry that includes the laminated AW filter package 901. The laminated AW filter package 901 includes a first AW filter circuit disposed on a first substrate, a second substrate disposed on a first frame disposed on the first substrate, and the first substrate disposed on a second frame disposed on a third substrate to enclose the second lower AW filter circuit, and the contact pads on the second substrate are electrically coupled to the second AW filter circuit by metal interconnects disposed on an insulator according to any of the embodiments disclosed herein as shown in FIGS. 2A-2C, 3 and 7 to protect against leakage current to the first substrate. The input device(s) 916 may include any type of input device including, but not limited to, input keys, switches, voice processors, etc. The output device(s) 918 may include any type of output device including, but not limited to, audio, video, other visual indicators, etc. The network interface device(s) 920 may be any device configured to enable the exchange of data to and from the network 924.The network 924 can be any type of network, including, but not limited to, a wired or wireless network, a private or public network, a local area network (LAN), a wireless local area network (WLAN), a wide area network (WAN), a BLUETOOTH network, and the Internet. The network interface device(s) 920 can be configured to support any type of communication protocol desired.

[0045]

[0053] The CPU 902 may also be configured to access a display controller(s) 922 via the system bus 908 to control information sent to one or more displays 926. The display controller(s) 922 send information to the display(s) 926 for display via one or more video processors 928, which process the information to be displayed into a format suitable for the display(s) 926. The display(s) 926 may include any type of display, including, but not limited to, a cathode ray tube (CRT), a liquid crystal display (LCD), a plasma display, a light emitting diode (LED) display, and the like. The display controller(s) 922, the display(s) 926, and / or the video processor(s) 928 may include RF circuitry including the stacked AW filter package 901. The stacked AW filter package 901 includes a first AW filter circuit disposed on a first substrate, a second substrate disposed on a first frame disposed on the first substrate, and the first substrate disposed on a second frame disposed on a third substrate to enclose the second lower AW filter circuit, and contact pads on the second substrate are electrically coupled to the second AW filter circuit by metal interconnects disposed on an insulator according to any of the embodiments disclosed herein, as shown in FIGS. 2A-2C, 3 and 7, to protect against leakage current to the first substrate.

[0046]

[0054] Those skilled in the art will further appreciate that the various exemplary logic blocks, modules, circuits, and algorithms described with respect to the aspects disclosed herein may be implemented as electronic hardware, instructions stored in a memory or another computer-readable medium and executed by a processor or other processing device, or a combination of both. The master and slave devices described herein may be employed in any circuit, hardware component, IC, or IC chip, as examples. The memories disclosed herein may be any type and size of memory and may be configured to store any type of information desired. To clearly illustrate this interchangeability, the various exemplary components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. How such functionality is implemented depends on the particular application, design choices, and / or design constraints imposed on the overall system. Those skilled in the art may implement the described functionality in various ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.

[0047]

[0055] The various example logic blocks, modules, and circuits described in connection with the aspects disclosed herein may be implemented or performed using a processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The processor may be a microprocessor, but alternatively the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

[0048]

[0056] Aspects disclosed herein may be embodied in hardware and instructions stored in the hardware and may reside in, for example, a Random Access Memory (RAM), a flash memory, a Read-Only Memory (ROM), an Electrically Programmable ROM (EPROM), an Electrically Erasable Programmable ROM (EEPROM), a register, a hard disk, a removable disk, a CD-ROM, or any other form of computer readable medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. Alternatively, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a remote station. Alternatively, the processor and the storage medium may reside as discrete components in a remote station, base station, or server.

[0049]

[0057] It should also be noted that the operational steps described in any of the exemplary aspects herein are described to provide examples and explanations. The described operations may be performed in many different sequences other than the sequence shown. Furthermore, an operation described in a single operational step may actually be performed in several different steps. In addition, one or more operational steps discussed in the exemplary aspects may be combined. It should be understood that many different modifications may be made to the operational steps shown in the flowchart diagrams, as would be readily apparent to one of ordinary skill in the art. Those skilled in the art will also understand that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, optical fields or optical particles, or any combination thereof.

[0050]

[0058] The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other examples. Thus, the disclosure is not intended to be limited to the examples and designs described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0051]

[0059] The following numbered clauses describe example implementations. 1. A laminated acoustic wave (AW) filter package comprising: a first substrate having a first surface; an AW filter circuit on a first surface of a first substrate; a frame disposed on a first surface of the first substrate; a second substrate having a contact surface and a sidewall surface, the second substrate being disposed on the frame to form a cavity between the AW filter circuit and the second substrate; a metallization layer comprising at least one metal interconnect coupled to the contact surface of the second substrate and the first surface of the first substrate, the at least one metal interconnect disposed on a sidewall surface of the second substrate; 1. A laminated AW filter package comprising:

[0052] 2. Further comprising a contact pad coupled to the contact surface; at least one metal interconnect configured to redistribute signals from the contact pads to the first surface of the first substrate; 2. A laminated AW filter package as defined in clause 1.

[0053] 3. a frame is disposed between the second substrate and the first surface of the first substrate, and extends from the sidewall surface of the second substrate in a direction perpendicular to the sidewall surface of the second substrate on a first side of the sidewall surface of the second substrate; the first surface of the first substrate has a shoulder region on a second side of the sidewall surface of the second substrate in a direction perpendicular to the sidewall surface of the second substrate; 2. A laminated AW filter package according to claim 1 or 2.

[0054] 4. 4. The laminated AW filter package of claim 3, wherein at least one metal interconnect is disposed on a shoulder region of the first surface of the first substrate.

[0055] 5. A laminated AW filter package as described in any of clauses 1 to 4, further comprising contact pads on the contact surface, the contact pads configured to couple to an external circuit, and at least one metal interconnect electrically coupled to the contact pads.

[0056] 6. A laminated AW filter package as described in any of clauses 2 to 5, further comprising a surface interconnect on a first surface of the first substrate extending from inside the cavity to the shoulder region, the surface interconnect being electrically coupled to the AW filter circuit and to at least one metal interconnect of the metallization layer on the shoulder region.

[0057] 7. A laminated AW filter package as described in any of clauses 1 to 6, wherein at least one metal interconnect of the metallization layer is disposed on a side of the frame between the second substrate and the first substrate.

[0058] 8. the frame extends into a shoulder region on a second side of the sidewall of the second substrate in a direction perpendicular to the sidewall of the second substrate; At least one metal interconnect of the metallization layer is disposed on the top surface of the frame; 8. The laminated AW filter package according to any one of clauses 2 to 7.

[0059] 9. The laminated AW filter package of any of clauses 1-8, wherein the frame comprises a first material and the second substrate comprises a second material different from the first material.

[0060] 10. the frame comprises a polymeric material; the second substrate comprises glass; the first substrate comprises a semiconductor material; 10. The laminated AW filter package according to any one of clauses 1 to 9.

[0061] 11. the frame further comprises a perimeter frame disposed along a perimeter of the second substrate; The cavity is surrounded by a peripheral frame. 11. The laminated AW filter package according to any one of clauses 1 to 10.

[0062] 12. The laminated AW filter package of claim 11, wherein the frame further comprises a frame member extending orthogonally to at least a portion of the perimeter frame and into the cavity.

[0063] 13. The laminated AW filter package of claim 12, wherein the frame member comprises one of a plurality of frame members of a frame.

[0064] 14. The laminated AW filter package of claim 12 or 13, wherein the frame member further comprises a linear frame member having a first end coupled to the perimeter frame.

[0065] 15. A laminated AW filter package as described in clause 14, wherein the cavity comprises a continuous cavity extending from a first cavity portion on a first side of the linear frame member, around a second end of the linear frame member, to a second cavity portion on a second side of the linear frame member.

[0066] 16. the AW filter circuit on the first surface of the first substrate is a first AW filter circuit; a first AW filter circuit disposed within the first cavity portion on the first side of the linear frame member; the laminated AW filter package further comprising another AW filter circuit on a second side of the linear frame member; 16. The laminated AW filter package according to clause 15.

[0067] 17. A laminated AW filter package as described in any of clauses 1-16, wherein the cavity comprises a continuous circular area having a diameter of up to 400 micrometers (μm), excluding the frame.

[0068] 18. A laminated AW filter package according to any one of clauses 1 to 17, wherein the diameter of the continuous circular area is greater than 360 μm.

[0069] 19. a third substrate comprising a second AW filter circuit on a second surface of the third substrate; a second frame disposed on the second surface of the third substrate; Further comprising: a first substrate is disposed on the second frame to form a second cavity between the second AW filter circuit and the first substrate; 6. A laminated AW filter package as claimed in clause 5.

[0070] 20. the first substrate further comprising a sidewall surface perpendicular to the first surface of the first substrate; a second frame is disposed between the first substrate and the second surface of the third substrate, and extends from the sidewall surface of the first substrate in a direction perpendicular to the sidewall surface of the first substrate on a first side of the sidewall surface of the first substrate; the second surface of the third substrate includes a lower shoulder region on a second side of the sidewall surface of the first substrate in a direction perpendicular to the first sidewall surface of the first substrate; 20. The laminated AW filter package according to clause 19.

[0071] twenty one. At least one metal interconnect comprises: On a sidewall surface of the first substrate, and on a lower shoulder region of the second surface of the third substrate 21. The laminated AW filter package of claim 20,

[0072] 22. The laminated AW filter package described in clause 21, further comprising a surface interconnect on a second surface of the third substrate extending from inside the second cavity to the lower shoulder region, the surface interconnect being electrically coupled to the second AW filter circuit and to at least one metal interconnect on the lower shoulder region.

[0073] 23. A laminated AW filter package as described in any of clauses 19-22, wherein at least one metal interconnect is disposed on a side of the second frame between the first substrate and the third substrate.

[0074] twenty four. a second frame extending onto a lower shoulder region of a second side of the sidewall of the first substrate in a direction perpendicular to the sidewall of the first substrate; At least one metal interconnect is disposed on the top surface of the second frame. 24. The laminated AW filter package according to any one of clauses 20 to 23.

[0075] 25. A method for manufacturing a laminated acoustic wave (AW) filter package, comprising: Providing a first substrate having a first surface; forming an AW filter circuit on a first surface of a first substrate; forming a frame on a first surface of a first substrate; providing a second substrate having a contact surface and a sidewall surface; disposing a second substrate on the frame to form a cavity between the AW filter circuit and the second substrate; forming a metallization layer comprising at least one metal interconnect coupled to a contact surface of a second substrate and a first surface of the first substrate, the at least one metal interconnect being disposed on a sidewall surface of the second substrate; A method comprising:

[0076] 26. disposing a frame between the second substrate and a first surface of the first substrate, the frame extending from the sidewall surface of the second substrate in a direction perpendicular to the sidewall surface of the second substrate on a first side of the sidewall surface of the second substrate; forming a shoulder region of the first surface of the first substrate on a second side of the sidewall surface of the second substrate in a direction perpendicular to the sidewall surface of the second substrate; 26. The method of claim 25, further comprising:

[0077] 27. A laminated acoustic wave (AW) filter package comprising: a first substrate having a first surface and a sidewall surface; a first AW filter circuit on a first surface of a first substrate; a first frame disposed on a first surface of a first substrate; a second substrate having a contact surface and a sidewall surface, the second substrate being disposed on the first frame to form a first cavity between the first AW filter circuit and the second substrate; a third substrate comprising a second AW filter circuit on a second surface of the third substrate; a second frame disposed on the second surface of the third substrate, a second frame, the first substrate being disposed on the second frame to form a second cavity between the second AW filter circuit and the first substrate; a metallization layer comprising at least one metal interconnect coupled to the contact surface of the second substrate and to the second surface of the third substrate, the at least one metal interconnect disposed on a sidewall surface of the first substrate; an insulator disposed on the sidewall surface of the first substrate between the sidewall surface of the first substrate and the at least one metal interconnect; 1. A laminated AW filter package comprising:

[0078] 28. The laminated AW filter package of claim 27, wherein an insulator is disposed between the at least one metal interconnect and the first frame.

[0079] 29. The laminated AW filter package of claim 27 or 28, wherein an insulator is disposed between at least one metal interconnect and the first surface of the first substrate.

[0080] 30. A laminated AW filter package as described in any of clauses 27-29, wherein an insulator is disposed between at least one metal interconnect and a sidewall surface of the second substrate.

[0081] 31. The laminated AW filter package of any of clauses 27-30, further comprising a via extending through the second substrate from the contact surface to the first surface of the first substrate.

[0082] 32. Further comprising a contact on the contact surface; the contact pads are configured to conduct electrical signals; the via is configured to electrically couple the first AW circuit to the contact pad; 32. The laminated AW filter package according to claim 31.

[0083] 33. the thickness of the third substrate in a first direction perpendicular to the second surface is in the range of 60 to 130 micrometers (μm); The thickness of the first substrate in the first direction is in the range of 30 to 70 μm; The thickness of the second substrate in the first direction is in the range of 30 to 70 μm. 33. The laminated AW filter package according to any one of clauses 27 to 32.

[0084] 34. The first substrate has a thickness of less than 85 μm; The third substrate has a thickness of less than 55 μm; The thickness of the second substrate is less than 55 μm; 34. The laminated AW filter package according to any one of clauses 27 to 33.

[0085] 35. A method of forming a laminated acoustic wave filter (AW filter) package, comprising: providing a first substrate having a first surface and a sidewall surface; forming a first AW filter circuit on a first surface of a first substrate; forming a first frame on a first surface of a first substrate; providing a second substrate having a contact surface and a sidewall surface; disposing a second substrate on the first frame to form a first cavity between the first AW filter circuit and the second substrate; forming a third substrate comprising a second AW filter circuit on a second surface of the third substrate; forming a second frame on a second surface of a third substrate; disposing the first substrate on a second frame to form a second cavity between the second AW filter circuit and the first substrate; forming an insulator on a sidewall surface of a first substrate; forming a metallization layer comprising at least one metal interconnect coupled to the contact surface of the second substrate and the second surface of the third substrate, the at least one metal interconnect disposed on an insulator on a sidewall surface of the first substrate; A method comprising:

Claims

1. A stacked acoustic wave (AW) filter package, comprising: a first substrate having a first surface; an AW filter circuit on the first surface of the first substrate; a frame disposed on the first surface of the first substrate; a second substrate having a contact surface and side wall surfaces, the second substrate being disposed on the frame to form a cavity between the AW filter circuit and the second substrate; a metallization layer having at least one metal interconnect coupled to the contact surface of the second substrate and the first surface of the first substrate, the at least one metal interconnect being disposed on the side wall surfaces of the second substrate; A stacked AW filter package.

2. Further comprising contact pads coupled to the contact surface, wherein the at least one metal interconnect is configured to redistribute signals from the contact pads to the first surface of the first substrate. The stacked AW filter package according to claim 1.

3. The frame is disposed between the second substrate and the first surface of the first substrate, and extends in a direction perpendicular to the side wall surface of the second substrate at a first side of the side wall surface of the second substrate. The first surface of the first substrate has a shoulder region on a second side of the side wall surface of the second substrate in a direction perpendicular to the side wall surface of the second substrate. The at least one metal interconnect is disposed on the shoulder region of the first surface of the first substrate. The stacked AW filter package according to claim 1.

4. Further comprising contact pads on the contact surface, the contact pads being configured to be coupled to an external circuit, and the at least one metal interconnect being electrically coupled to the contact pads. The stacked AW filter package according to claim 3.

5. Further comprising surface interconnects on the first surface of the first substrate extending from inside the cavity to the shoulder region, the surface interconnects being electrically coupled to the AW filter circuit and the at least one metal interconnect of the metallization layer on the shoulder region. The at least one metal interconnect of the metallization layer is disposed on a side surface of the frame between the second substrate and the first substrate. The frame extends in a direction orthogonal to the side wall surface of the second substrate into a shoulder region on the second side of the side wall surface of the second substrate. At least one metal interconnect of the metallization layer is disposed on the upper surface of the frame. The stacked AW filter package according to claim 3.

6. The frame includes a first material, and the second substrate includes a second material different from the first material. The frame includes a polymer material. The second substrate includes glass. The first substrate includes a semiconductor material. The stacked AW filter package according to claim 1.

7. The frame further includes a peripheral frame disposed along the periphery of the second substrate. The cavity is surrounded by the peripheral frame. The frame further includes a frame member extending into the cavity orthogonally to at least a part of the peripheral frame. The stacked AW filter package according to claim 1.

8. The stacked AW filter package according to claim 7, wherein the frame member comprises one of a plurality of frame members of the frame.

9. The stacked AW filter package according to claim 7, wherein the frame member further comprises a linear frame member having a first end coupled to the peripheral frame.

10. The cavity comprises a continuous cavity extending from a first cavity portion on a first side of the linear frame member, through around a second end of the linear frame member, to a second cavity portion on a second side of the linear frame member. The AW filter circuit on the first surface of the first substrate is a first AW filter circuit. The first AW filter circuit is disposed in the first cavity portion on the first side of the linear frame member. The stacked AW filter package further comprises another AW filter circuit on the second side of the linear frame member. The stacked AW filter package according to claim 9.

11. A method of manufacturing a stacked acoustic wave (AW) filter package, comprising: forming a first substrate having a first surface; forming an AW filter circuit on the first surface of the first substrate; forming a frame on the first surface of the first substrate; forming a second substrate having a contact surface and a side wall surface. Placing the second substrate on the frame to form a cavity between the AW filter circuit and the second substrate; Forming a metallization layer comprising at least one metal interconnect coupled to the contact surface of the second substrate and the first surface of the first substrate, wherein the at least one metal interconnect is disposed on the side wall surface of the second substrate; A method comprising. **Claim 12** A laminated acoustic wave (AW) filter package, comprising: A first substrate having a first surface and side wall surfaces; A first AW filter circuit on the first surface of the first substrate; A first frame disposed on the first surface of the first substrate; A second substrate having a contact surface and side wall surfaces, the second substrate being disposed on the first frame to form a first cavity between the first AW filter circuit and the second substrate; A third substrate having a second AW filter circuit on a second surface of the third substrate; A second frame disposed on the second surface of the third substrate; The first substrate being disposed on the second frame to form a second cavity between the second AW filter circuit and the first substrate; A metallization layer comprising at least one metal interconnect coupled to the contact surface of the second substrate and the second surface of the third substrate, the at least one metal interconnect being disposed on the side wall surface of the first substrate; An insulator disposed on the side wall surface of the first substrate between the side wall surface of the first substrate and the at least one metal interconnect; A laminated AW filter package comprising. **Claim 13** The laminated AW filter package according to claim 12, wherein the insulator is disposed between the at least one metal interconnect and the first frame. **Claim 14** The laminated AW filter package according to claim 13, further comprising a via extending through the second substrate from the contact surface to the first surface of the first substrate, The laminated AW filter package according to claim 13, further comprising a contact pad in contact with the contact surface, The contact pad being configured to conduct an electrical signal, The via being configured to electrically couple the first AW circuit to the contact pad. The laminated AW filter package according to claim 13. **Claim 15** A method of forming a laminated acoustic wave filter (AW filter) package, comprising: Forming a first substrate having a first surface and side wall surfaces; Forming a first AW filter circuit on the first surface of the first substrate; Forming a first frame on the first surface of the first substrate; Forming a second substrate having a contact surface and a side wall surface; Placing the second substrate on the first frame to form a first cavity between the first AW filter circuit and the second substrate; Forming a third substrate having a second AW filter circuit on a second surface of the third substrate; Forming a second frame on the second surface of the third substrate; Placing the first substrate on the second frame to form a second cavity between the second AW filter circuit and the first substrate; Forming an insulator on the side wall surface of the first substrate; Forming a metallization layer having at least one metal interconnect coupled to the contact surface of the second substrate and the second surface of the third substrate, the at least one metal interconnect being disposed on the insulator on the side wall surface of the first substrate; A method comprising.

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