Semiconductor device with hybrid waveguide and method thereof

Abstract

A method of forming a hybrid waveguide semiconductor device is provided. The method includes forming a packaged radio frequency (RF) device and attaching a waveguide structure on the packaged RF device. The waveguide structure includes a non-conductive substrate and an aerated waveguide formed in the substrate. A radiating element of the packaged RF device includes a pin structure and a cap structure connected to a die pad of a semiconductor die. The pin structure is embedded in an encapsulant of the packaged RF semiconductor device, and the cap structure is exposed within the inflated waveguide.

Description

Technical Field

[0001] This disclosure generally relates to semiconductor device packaging, and more specifically, to semiconductor devices having hybrid waveguides and methods of forming them. Background Technology

[0002] Today, there is an increasing trend to include complex semiconductor devices in everyday products and systems. These complex devices may include application-specific features that can influence the semiconductor device package configuration. For some high-performance characteristics and applications, the semiconductor device package configuration may be susceptible to performance constraints and higher product or system costs. Therefore, it presents a considerable challenge to enable semiconductor devices to enhance performance without significant cost impact while accommodating these high-performance characteristics and applications. Summary of the Invention

[0003] According to one aspect of this application, a method is provided comprising: forming a packaged radio frequency (RF) device, the packaged RF device comprising: a semiconductor die, a radiating element connected to a first die pad of the semiconductor die, the radiating element including a pin structure and a cap structure, and an encapsulation encapsulating at least a portion of the semiconductor die, the pin structure being embedded in the encapsulation; and attaching a waveguide structure to a first main side of the packaged RF device, the waveguide structure comprising: a non-conductive waveguide substrate, and an inflatable waveguide formed in the non-conductive waveguide substrate, the cap structure being exposed within the inflatable waveguide.

[0004] According to one or more embodiments, the method further includes: applying a redistribution structure over a second main side of the packaged RF device, the redistribution structure including a non-conductive redistribution substrate and a plurality of conductive traces embedded in the non-conductive redistribution substrate.

[0005] According to one or more embodiments, the packaged RF device further includes: a conductive trace formed over a portion of the active side of the semiconductor die, the conductive trace being embedded in the encapsulation and configured as a signal reflector of the radiating element.

[0006] According to one or more embodiments, the waveguide structure further includes a conductive fence formed by one or more of the plurality of conductive traces and one or more vias interconnecting the one or more conductive traces, the conductive fence being at least partially embedded in the non-conductive waveguide substrate and configured to substantially surround the gas-filled waveguide.

[0007] According to one or more embodiments, the waveguide structure is configured to propagate RF signals through the top portion of the non-conductive waveguide substrate.

[0008] According to one or more embodiments, the waveguide structure further includes an opening formed through a top portion of the non-conductive waveguide substrate, wherein the gas-filled waveguide of the waveguide structure is configured to propagate RF signals through the opening.

[0009] According to one or more embodiments, the inflatable waveguide of the waveguide structure includes a first chamber portion and a second chamber portion adjacent to the first chamber portion, with the cap structure exposed within the first chamber portion.

[0010] According to one or more embodiments, the second chamber portion is vertically offset from the first chamber portion.

[0011] According to one or more embodiments, the gas-filled waveguide of the waveguide structure is configured for the TE10 propagation mode of RF signals.

[0012] According to a second aspect of this application, a semiconductor device is provided, comprising: a packaged radio frequency (RF) device, the packaged RF device including: a semiconductor die, a radiating element connected to a first die pad of the semiconductor die, the radiating element including a pin structure and a cap structure, and an encapsulation encapsulating at least a portion of the semiconductor die, the pin structure being embedded in the encapsulation; and a waveguide structure attached to a first main side of the packaged RF device, the waveguide structure including: a non-conductive waveguide substrate, and an inflated waveguide formed in the non-conductive waveguide substrate, the cap structure being exposed within the inflated waveguide.

[0013] According to one or more embodiments, the semiconductor device further includes a redistribution structure applied over a second main side of the packaged RF device, the redistribution structure including a non-conductive redistribution substrate and a plurality of conductive traces embedded in the non-conductive redistribution substrate.

[0014] According to one or more embodiments, the packaged RF device further includes a conductive trace formed over a portion of the active side of the semiconductor die, the conductive trace being embedded in the encapsulation and configured as a signal reflector of the radiating element.

[0015] According to one or more embodiments, the waveguide structure further includes a conductive fence formed by one or more conductive traces of the plurality of conductive traces and one or more vias interconnecting the one or more conductive traces, the conductive fence being at least partially embedded in the non-conductive waveguide substrate and configured to substantially surround the gas-filled waveguide.

[0016] According to one or more embodiments, the inflatable waveguide of the waveguide structure includes a first rectangular chamber portion and a second rectangular chamber portion adjacent to the first rectangular chamber portion, the cap structure being exposed within the first rectangular chamber portion.

[0017] According to one or more embodiments, the second rectangular chamber portion is vertically offset from the first rectangular chamber portion.

[0018] According to a third aspect of this application, a method is provided comprising: forming a packaged radio frequency (RF) device, the packaged RF device comprising: a semiconductor die having a first die pad on an active side; a radiating element directly connected to the first die pad of the semiconductor die; the radiating element including a pin structure and a cap structure; and an encapsulation encapsulating at least a portion of the semiconductor die, the pin structure being embedded in the encapsulation; and attaching a waveguide structure to a first main side of the packaged RF device, the waveguide structure comprising: a non-conductive laminated waveguide substrate; and an inflated waveguide formed in the non-conductive laminated waveguide substrate, the cap structure being exposed within the inflated waveguide.

[0019] According to one or more embodiments, the packaged RF device further includes: a conductive trace formed over a portion of the active side of the semiconductor die and configured as a signal reflector of the radiating element, the conductive trace being interconnected with a second die pad of the semiconductor die.

[0020] According to one or more embodiments, the waveguide structure further includes a conductive fence formed by one or more of the plurality of conductive traces and one or more vias interconnecting the one or more conductive traces, the conductive fence being at least partially embedded in the non-conductive waveguide substrate and configured to substantially surround the gas-filled waveguide.

[0021] According to one or more embodiments, the waveguide structure further includes an opening formed through a top portion of the non-conductive laminated waveguide substrate, wherein the gas-filled waveguide of the waveguide structure is configured to propagate RF signals through the opening.

[0022] According to one or more embodiments, the inflatable waveguide of the waveguide structure includes a first rectangular chamber portion and a second rectangular chamber portion adjacent to the first rectangular chamber portion. Attached Figure Description

[0023] This invention is illustrated by way of example and is not limited to the accompanying drawings, in which similar reference numerals indicate similar elements. The elements in the drawings are shown for simplicity and clarity and are not necessarily drawn to scale.

[0024] Figures 1 to 3 An example packaged radio frequency (RF) device in the manufacturing stage according to an embodiment is shown in a simplified cross-sectional view.

[0025] Figures 4 to 6A simplified cross-sectional view is shown of an example semiconductor device, including a packaged RF device, in the manufacturing stage according to an embodiment.

[0026] Figure 7 An alternative example semiconductor device, including a packaged RF device, is shown in a simplified cross-sectional view according to an embodiment during the manufacturing stage.

[0027] Figure 8 and Figure 9 A simplified cross-sectional view illustrates an alternative example packaged RF device in the manufacturing stage according to an embodiment.

[0028] Figure 10 An example semiconductor device, including an alternative packaged RF device, is shown in a simplified cross-sectional view according to an embodiment during the manufacturing stage.

[0029] Figure 11 A simplified cross-sectional view illustrates an alternative example packaged RF device in the manufacturing stage according to an embodiment.

[0030] Figures 12 to 14 An example semiconductor device, including an alternative packaged RF device, is shown in a simplified cross-sectional view according to an embodiment during the manufacturing stage. Detailed Implementation

[0031] Generally, a semiconductor device with a hybrid waveguide is provided. The semiconductor device includes a waveguide structure mounted on a packaged RF device. The packaged RF device includes a semiconductor die encapsulated in an encapsulant. A radiating element is formed as a die pad directly connected to the semiconductor die. The radiating element includes a "pin" structure portion embedded in the encapsulant and a "cap" structure formed on the encapsulant and directly connected to the pin structure. A signal reflector surrounding the radiating element is embedded in the encapsulant at the surface of the semiconductor. The waveguide structure of the semiconductor device includes a gas-filled waveguide embedded in a waveguide substrate of the waveguide structure. The waveguide structure is attached above the active side of the encapsulated semiconductor die, such that the cap structure of the radiating element is exposed within the waveguide. The portion of the encapsulant containing the signal reflector and pin structure, together with the gas-filled waveguide of the waveguide structure, forms a hybrid waveguide. By forming a semiconductor device with a hybrid waveguide in this manner, TE10 mode excitation can be achieved with minimal package size and reduced signal loss.

[0032] Figure 1A simplified cross-sectional view illustrates an example packaged RF device 100 in the manufacturing stage according to an embodiment. In this manufacturing stage, the packaged RF device 100 includes a semiconductor die 102 placed on a carrier substrate 118. For example, the semiconductor die 102 is temporarily attached to the carrier substrate 118 by means of a releasable adhesive (not shown) at the top side of the carrier substrate. In some embodiments, the semiconductor die 102 is placed on the carrier substrate 118 in wafer form.

[0033] Semiconductor die 102 has an active side (e.g., a main side having a circuit system) and a back side (e.g., a main side opposite to the active side). Semiconductor die 102 includes die pads 104 and 106 of a circuit system formed on the active side and connected to the semiconductor die. Figure 1 As depicted, semiconductor die 102 is configured with its active side facing upward, wherein the back side of the semiconductor die is bonded to a carrier substrate 118. Semiconductor die 102 may be formed from any suitable semiconductor material, such as silicon, germanium, gallium arsenide, gallium nitride, etc. Semiconductor die 102 may also include RF circuitry, digital circuitry, analog circuitry, power supply circuitry, memory, processor, sensor, etc., and combinations thereof, located on the active side. In this embodiment, semiconductor die 102 is characterized as an RF semiconductor die configured to transmit and / or receive RF signals at die pad 106.

[0034] In this embodiment, a conductive layer (e.g., copper) is formed over the active side of semiconductor die 102 and patterned to form conductive traces 108 and 110. Unless otherwise specified, the term "conductive" as used herein generally refers to electrical properties. Portions of conductive traces 108 and 110 are directly connected to corresponding die pads 104 and 106 of semiconductor die 102. Conductive trace 108 is dielectrically isolated from conductive trace 110 and is configured to substantially surround a signal reflector 112 around conductive trace 110. For example, signal reflector 112 may be interconnected to a ground power supply in a subsequent stage. In this embodiment, conductive die connectors 114 and 116 (e.g., copper pillars, gold bumps, plated dielectric pillars) are formed directly over corresponding die pads 104 and 106 of semiconductor die 102 and are conductively connected to corresponding traces 108 and 110. In this embodiment, conductive die connector 116 is configured as a "pin" structure portion of a radiating element. The conductive die connector 116 may also be referred to as pin structure 116 in this document.

[0035] Figure 2A simplified cross-sectional view illustrates an example packaged RF device 100 in a subsequent manufacturing stage according to an embodiment. In this manufacturing stage, the packaged RF device 100 includes an encapsulation 202 (e.g., epoxy molding compound) formed over the active side of a semiconductor die 102 and patterned conductive traces 204 and 206 (e.g., copper) formed over a portion of the encapsulation. In this embodiment, the semiconductor die 102 is molded using the encapsulation 202 via a molding process such as thin-film assisted molding (FAM). For example, a FAM tool using a conformal film can engage predetermined portions of die connectors 114 and 116 during the molding process to keep the top surfaces of die connectors 114 and 116 free of the encapsulation 202. In this way, the top surfaces of die connectors 114 and 116 can be exposed at the top of the encapsulation 202. Alternatively, the semiconductor die 102 may be encapsulated using an encapsulant 202 during injection molding operations, for example, by exposing the top surfaces of die connectors 114 and 116 on top of the encapsulant 202 subsequently by means of a polishing process. In some embodiments, in wafer form, the encapsulant 202 may be formed over the active side of the semiconductor die 102 and then detached.

[0036] After the encapsulation 202 is formed over the semiconductor die 102, conductive traces 204 and 206 are formed. In this embodiment, trace 204 is formed over a portion of the encapsulation 202 and over the sidewall of the semiconductor die 102. Trace 204 is configured to directly connect to the exposed top surface of the embedded die connector 114. Trace 206 is formed to directly connect to the exposed top surface of the embedded pin structure 116. In this embodiment, the encapsulation 202 directly contacts the sidewall of the pin structure 116. In this embodiment, conductive trace 206 is configured as a “cap” structure portion of the radiating element. Conductive trace 206 may also be referred to herein as cap structure 206. For example, cap structure 206 may be formed with a suitable shape (e.g., circular, straight), material (e.g., solder, metal), and size that facilitates the propagation of high-frequency RF signals. In this embodiment, cap structure 206, together with pin structure 116, forms a radiating element 208 configured to transmit and / or receive RF signals. In this embodiment, the signal reflector 112 embedded in the encapsulation 202 is configured to substantially surround the radiating element 208.

[0037] Figure 3A simplified cross-sectional view illustrates an example packaged RF device 100 in a subsequent manufacturing stage according to an embodiment. In this manufacturing stage, the packaged RF device 100 includes a metal trace 304 formed on the back side of an encapsulated semiconductor die 102. In this embodiment, the encapsulated semiconductor die 102 is separated from a carrier substrate 118, reoriented (e.g., flipped), and placed on the carrier substrate 302 such that the back side of the semiconductor die 102 is exposed for further processing. In this embodiment, a conductive layer (e.g., copper) is formed over the back side of the semiconductor die 102 and patterned to form the conductive trace 304. In this embodiment, at least a portion of the trace 304 is connected to a trace 204. The trace 304 may be configured, for example, for heat dissipation, shielding, and / or back-side grounding.

[0038] Figure 4 A simplified cross-sectional view illustrates an example semiconductor device 400 including a packaged RF device 100 during the manufacturing stage according to an embodiment. During this manufacturing stage, the semiconductor device 400 includes a redistribution structure 402 applied over the back side of the packaged RF device 100. In this embodiment, the redistribution structure 402 is provided as a pre-formed package substrate. The redistribution structure 402 (also referred to herein as “package substrate 402”) includes conductive features (e.g., patterned copper traces 410 and 412, vias 414) substantially embedded in a non-conductive redistribution substrate material (e.g., dielectric layers 404, 406, 408). The redistribution structure 402 may be characterized as a redistribution layer (RDL) substrate having, for example, exposed portions of traces 410 and vias 414 at a top surface and exposed portions of traces 412 at a bottom surface. In this embodiment, for example, the exposed portion of via 414 is configured for attaching the packaged RF device 100, and the exposed portion of trace 412 is configured for attaching a conductive connector (in a subsequent manufacturing stage). The exposed portion of trace 412 may be characterized as a conductive connector pad 412. The packaged RF device 100 may be attached to the redistribution structure 402, for example, by means of solder, conductive adhesive, or nanofilaments (not shown). In this embodiment, the non-conductive redistribution substrate of the redistribution structure 402 is formed as a laminate having a core dielectric layer 404 (e.g., FR4) sandwiched between dielectric layers 406 and 408 (e.g., prepreg).

[0039] In some embodiments, the redistribution structure 402 may be formed as a build-up packaging substrate in a subsequent manufacturing stage. For example, after a packaging operation, a patterned dielectric layer and a conductive layer may be sequentially applied to the exposed pads of a semiconductor device, thereby allowing the conductive features of the redistribution structure to interconnect with the exposed pads in a built-up manner.

[0040] Figure 5A simplified cross-sectional view illustrates an example semiconductor device 400 including a packaged RF device 100 in a subsequent manufacturing stage according to an embodiment. In this manufacturing stage, the semiconductor device 400 includes a second encapsulant 502 (e.g., epoxy molding compound) formed over a portion of a reel structure 402 and adjacent to the outer periphery of the packaged RF device 100 attached to the reel structure 402. In this embodiment, the exposed portion of the reel structure 402 surrounding the outer periphery of the packaged RF device 100 is molded using the encapsulant 502 by means of a second molding process, such as a second FAM process. For example, a FAM tool using a conformal film can engage with a predetermined top portion of the packaged RF device 100 during the molding process to keep the top surface of the packaged RF device 100 free of the encapsulant 502. In this way, the top surfaces of the conductive traces 204 and 206 can remain exposed after the second molding process.

[0041] After the encapsulation 502 is formed above the exposed portion of the re-lay structure 402 surrounding the outer periphery of the packaged RF device 100, conductive through-holes (TMVs) 504 and conductive traces 506 are formed. In this embodiment, an opening (e.g., a hole) is formed through the encapsulation 502, extending from the top surface of the encapsulation to the underside of the trace 410 formed on the top side of the re-lay structure 402. The opening may be formed by means of a suitable process (e.g., etching, laser drilling) and subsequently filled with a conductive material (e.g., copper) to form the TMV 504. Alternatively, the conductive through-holes 504 may be placed in the re-lay structure 402 before the encapsulation 502 is formed above the exposed portion of the re-lay structure 402 surrounding the outer periphery of the packaged RF device 100. After the TMVs 504 are formed, the top surface portion of each TMV 504 is exposed at the top surface of the encapsulation 502. Patterned traces 506 are formed over portions of the encapsulation 502 and the exposed portions of the TMV 504. The traces 506 are configured to connect directly to the top surface of the TMV 504. In this embodiment, at least one continuous conductive path is formed via the TMV 504 from the conductive traces 506 to the connector pads 412 of the relay structure 402.

[0042] Figure 6A simplified cross-sectional view illustrates an example semiconductor device 400 including a packaged RF device 100 in a subsequent manufacturing stage according to an embodiment. In this manufacturing stage, the semiconductor device 400 includes a waveguide structure 600 electrically attached to the top main side of the encapsulated redistribution structure 402 and the packaged RF device 100. In this embodiment, patterned conductive traces 610 and vias 612 formed on the bottom side of the waveguide structure 600 are electrically connected to exposed portions of traces 506 and 204. The waveguide structure 600 may be attached and interconnected to the packaged RF device 100 and the redistribution structure 402, for example, by means of solder, conductive adhesive, or nanowires (not shown).

[0043] In this embodiment, the waveguide structure 600 includes conductive features (e.g., patterned copper traces 610, vias 612) substantially surrounded by a non-conductive waveguide substrate (e.g., dielectric layers 602, 604, 606, 608), and a gas-filled waveguide 614 substantially embedded in the non-conductive waveguide substrate. The waveguide substrate of the waveguide structure 600 may be formed as follows: Figure 6 The laminated structure depicted has a first core dielectric layer 602 (e.g., FR4) sandwiched between dielectric layers 604 and 606 (e.g., prepreg) and a second core dielectric layer 608 (e.g., FR4).

[0044] In this embodiment, an inflatable waveguide 614 (also referred to herein as "waveguide 614") is formed as a rectangular chamber within a non-conductive waveguide substrate of the waveguide structure 600. Waveguide 614 is open at the bottom side of the waveguide structure 600, exposing the cap structure 206 of the radiating element 208 within the inflatable waveguide. A conductive enclosure 616, formed by portions of the trace 610 of the waveguide structure 600 and the via 612, is configured to substantially surround the sidewalls of waveguide 614. Alternatively, a conductive liner (e.g., a copper layer) may be formed on the sidewalls of waveguide 614. In this embodiment, a waveguide opening 618 is formed in the conductive trace 610 formed above waveguide 614, thereby allowing RF signals to propagate into or out of the waveguide. A dielectric layer 608 encloses the top of waveguide 614. In this embodiment, a portion of the encapsulation 202 of the packaged RF device 100, between the signal reflector 112 and the top surface of the encapsulation 202 in which the pin structure 116 is embedded, together with the inflated waveguide 614 of the waveguide structure 600, forms a hybrid waveguide configured to excite the TE10 mode with minimal package size and reduced signal loss. In this embodiment, a conductive fence 616 is directly connected to a trace 204 that substantially surrounds the outer periphery of the packaged RF device 100 and interconnects with conductive features of the signal reflector 112 and the redistribution structure 402. For example, the conductive fence 616 and the signal reflector 112 may be interconnected with a ground power supply via the redistribution structure 402.

[0045] In this embodiment, a plurality of conductive package connectors 620 (e.g., solder balls) are attached to the bottom conductive connector pads 412 of the reflow structure 402. For example, the conductive package connectors 620 are configured and arranged to provide a conductive connection between the reflow structure 402 and the PCB. The conductive package connectors 620 may be in the form of suitable conductive structures such as solder balls, gold pillars, copper pillars, etc., to connect the conductive features of the example semiconductor device 400 to the PCB.

[0046] Figure 7 An alternative example semiconductor device 700, including a packaged RF device 100, is shown in a simplified cross-sectional view according to an embodiment during the manufacturing stage. In this embodiment, Figures 1 to 5 The manufacturing stages depicted are substantially similar to those of the packaged RF device 100 and the second encapsulation 502 formed above the redistribution structure 402 adjacent to the packaged RF device 100. At this stage, the semiconductor device 700 includes an alternative waveguide structure 702 attached in an electrically conductive manner to the top main side of the encapsulated redistribution structure 402 and the packaged RF device 100. In this embodiment, patterned conductive traces 714 and vias 716 formed on the bottom side of the waveguide structure 702 are conductively connected to exposed portions of traces 506 and 204. The waveguide structure 702 may be attached and interconnected to the packaged RF device 100 and the redistribution structure 402, for example, by means of solder, conductive adhesive, or nanowires (not shown).

[0047] In this embodiment, waveguide structure 702 includes conductive features (e.g., patterned copper traces 714, vias 716) surrounded substantially by a non-conductive waveguide substrate (e.g., dielectric layers 704, 706, 708, 710, 712), and a gas-filled waveguide 736 substantially embedded in the non-conductive waveguide substrate. The waveguide substrate of waveguide structure 702 may be formed as follows: Figure 7 The laminated structure depicted has a first core dielectric layer 706 (e.g., FR4) sandwiched between dielectric layers 704 and 708 (e.g., prepreg), and a second core dielectric layer 710 and a third core dielectric layer 712 (e.g., FR4).

[0048] In this embodiment, the inflatable waveguide 736 (also referred to herein as "waveguide 736") includes a first rectangular chamber portion 718 (also referred to herein as "chamber 718") formed in the waveguide substrate and a second rectangular chamber portion 720 (also referred to herein as "chamber 720") formed adjacent to the first chamber portion of the waveguide substrate. Waveguide 736 is open at the bottom side of waveguide structure 702, such that the cap structure 206 of radiating element 208 is exposed within the first chamber 718 of the inflatable waveguide. A conductive fence is formed by portions of trace 714 of waveguide structure 702 and via 716. The conductive fence includes a first conductive fence portion 722 adjacent to a portion of the first chamber 718, a second conductive fence portion 724 adjacent to a portion of the second chamber 720, and a third conductive fence portion 726. The first conductive fence portion 722, the second conductive fence portion 724, and the third conductive fence portion 726 are configured together to substantially surround the sidewalls of waveguide 736. In this embodiment, the waveguide opening 728 is formed through a conductive trace 714 formed above the second chamber 720 of the waveguide 736, thereby allowing RF signals to propagate into or out of the waveguide.

[0049] A first chamber 718 includes a top conductive trace 714 forming a conductive liner on the top side of the first chamber 718, and a signal reflector 112 on the bottom side of the first chamber. A first conductive enclosure portion 722 interconnects the top conductive trace 714 with the signal reflector 112 and laterally surrounds a sidewall portion of the first chamber 718. The first chamber 718 has a first height dimension 732 measured from the top conductive trace 714 to the signal reflector 112. A second chamber 720 includes a dielectric layer 712 and a portion of the topmost conductive trace 714 forming a partial conductive liner on the top side of the second chamber 720, and a second signal reflector formed by trace 204 on the bottom side of the second chamber. In this embodiment, the dielectric layer 712 forms a continuous seal above the top of the second chamber 720 of the waveguide 736. The second conductive enclosure portion 724 laterally surrounds a sidewall portion of the second chamber 720. The second chamber 720 has a second height dimension 734 measured from the topmost conductive trace 714 to the second signal reflector formed by trace 204. In this embodiment, the first height dimension 732 and the second height dimension 734 are substantially similar. In some embodiments, the first height dimension 732 and the second height dimension 734 may be different. In this embodiment, the second chamber 720 is vertically offset from the first chamber 718.

[0050] In this embodiment, a portion of the encapsulation 202 of the packaged RF device 100, between the signal reflector 112 and the top surface of the encapsulation 202 in which the pin structure 116 is embedded, together with the inflated waveguide 736 of the waveguide structure 702, forms a hybrid waveguide configured to excite the TE10 mode with minimal package size and reduced signal loss. In this embodiment, conductive fence portions 722, 724, 726 are interconnected with the signal reflector 112 at the bottom of the first chamber 718 and with a second signal reflector formed by trace 204 on the bottom side of the second chamber 720, and may be interconnected with a ground power supply terminal, for example by means of a redistribution structure 402.

[0051] In this embodiment, a plurality of conductive package connectors 730 (e.g., solder balls) are attached to the bottom conductive connector pads 412 of the reflow structure 402. For example, the conductive package connectors 730 are configured and arranged to provide a conductive connection between the reflow structure 402 and the PCB. The conductive package connectors 730 may be in the form of suitable conductive structures such as solder balls, gold pillars, copper pillars, etc., to connect the conductive features of the example semiconductor device 700 to the PCB.

[0052] Figure 8 A simplified cross-sectional view illustrates an alternative example packaged RF device 800 during the manufacturing stage according to an embodiment. During this manufacturing stage, the packaged RF device 800 includes a semiconductor die 802 placed on a carrier substrate 824 and encapsulated with an encapsulant 818 (e.g., epoxy molding compound). For example, the semiconductor die 802 is temporarily attached to the carrier substrate 824 by means of a releasable adhesive (not shown) at the top side of the carrier substrate.

[0053] Semiconductor die 802 has an active side (e.g., a main side having a circuit system) and a back side (e.g., a main side opposite to the active side). Semiconductor die 802 includes die pads 804 and 806 formed on the active side and connected to the circuit system of the semiconductor die. Figure 8 As depicted, semiconductor die 802 is configured with its active side facing upward, wherein the back side of the semiconductor die is bonded to a carrier substrate 824. Semiconductor die 802 can be formed from any suitable semiconductor material, such as silicon, germanium, gallium arsenide, gallium nitride, etc. Semiconductor die 802 may also include RF circuitry, digital circuitry, analog circuitry, power supply circuitry, memory, processor, etc., and combinations thereof, on the active side. In this embodiment, semiconductor die 802 is characterized as an RF semiconductor die configured to transmit and / or receive RF signals at die pad 806.

[0054] In this embodiment, a conformal conductive layer (e.g., copper) is formed over the active side of the semiconductor die 802 and patterned to form a conductive trace 808. A portion of the patterned conductive trace 808 is directly connected to a corresponding die pad 804 of the semiconductor die 802 and is formed over a portion of the sidewalls of the semiconductor die 802 and the carrier substrate 824. The conductive trace 808 is dielectrically isolated from the die pad 806 and is configured as a signal reflector 810 substantially surrounding the die pad 806. For example, the signal reflector 810 may be interconnected with a ground power supply in a subsequent stage. Conductive die connectors 812 and 814 (e.g., copper pillars, gold bumps) are formed directly over the corresponding die pads 804 and 806 of the semiconductor die 802. Conductive die connector 812 is, for example, directly connected to the conductive trace 808. In this embodiment, conductive die connector 814 is configured as a “pin” structure portion of the radiating element 826. Conductive die connector 814 may also be referred to herein as pin structure 814.

[0055] Encapsulation 818 is formed on the active side of semiconductor die 102, above patterned conductive traces 808, and a portion of the carrier substrate 824 surrounding the semiconductor die. In this embodiment, the molded semiconductor die 102 can be encapsulated with encapsulation 818 using a FAM molding process to, for example, keep the top surfaces of die connectors 812 and 814 free of encapsulation 818. In this way, the top surfaces of die connectors 812 and 814 can be exposed on top of encapsulation 818.

[0056] After the encapsulation 818 is formed, conductive TMVs 816 are formed. In this embodiment, an opening (e.g., a hole) is formed through the encapsulation 818, extending from the top surface of the encapsulation to the underlying carrier substrate 824. The opening may be formed by means of a suitable process (e.g., etching, laser drilling) and subsequently filled with a conductive material (e.g., copper) to form the TMV 816. After the TMV 816 is formed, a portion of the top surface of each TMV 816 is exposed at the top surface of the encapsulation 818. Patterned conductive traces 820 and 822 are then formed over portions of the encapsulation 818 and the exposed top surface portions of the TMVs 816 and die connectors 812 and 814. Conductive traces 820 are configured to interconnect the TMVs 816 with the corresponding die connectors 812, and traces 822 are configured to connect directly to the embedded lead structure 814. In this embodiment, the encapsulation 818 directly contacts the sidewalls of the lead structure 814. In this embodiment, the conductive trace 822 is configured as a “cap” structure portion of the radiating element 826. The conductive trace 822 may also be referred to herein as cap structure 822. For example, cap structure 822 may be formed with a suitable shape (e.g., circular, straight), material (e.g., solder, metal), and size that facilitates the propagation of high-frequency RF signals. In this embodiment, cap structure 822, together with pin structure 814, forms the radiating element 826 configured to transmit and / or receive RF signals. In this embodiment, signal reflector 810 embedded in encapsulation 818 is configured to substantially surround the radiating element 826.

[0057] Figure 9 A simplified cross-sectional view illustrates an alternative example packaged RF device 800 in a subsequent manufacturing stage according to an embodiment. In this manufacturing stage, the packaged RF device 800 includes an encapsulated semiconductor die 802 separated from a carrier substrate and interconnected with a redistribution structure 900. After the encapsulated semiconductor die 802 is separated from the carrier substrate, portions of trace 808 and TMV 816, along with the back side of the semiconductor die 802, are exposed through encapsulation 818.

[0058] In this embodiment, the redistribution structure 900 forms a multilayer RDL package substrate over the back side of the encapsulated semiconductor die 802 of the packaged RF device 800. The redistribution structure 900 (also referred to herein as “package substrate 900”) includes conductive features (e.g., patterned copper traces 904 and 906) substantially embedded in a non-conductive redistribution substrate material (e.g., dielectric 902). For example, a patterned dielectric layer (not shown separately) and a patterned conductive layer (e.g., traces 904 and 906) of the dielectric material 902 may be sequentially applied over the back side of the encapsulated semiconductor die 802 to interconnect exposed portions of trace 808 and TMV 816 with traces 904 and 906 in a multilayer manner. Exposed portions of trace 906 of the package substrate 900 are configured for attaching conductive connectors, for example (in a subsequent manufacturing stage).

[0059] Figure 10 A simplified cross-sectional view illustrates an example semiconductor device 1000, including an alternative packaged RF device 800, in the manufacturing stage according to an embodiment. In this manufacturing stage, the semiconductor device 1000 includes a waveguide structure 1024 attached to the top main side of the packaged RF device 800. In this embodiment, patterned conductive traces 1010 and vias 1012 formed on the bottom side of the waveguide structure 1024 are conductively connected to exposed portions of traces 820 of the packaged RF device 800. The waveguide structure 1024 may be attached and interconnected to the packaged RF device 800, for example, by means of solder, conductive adhesive, or nanowires (not shown).

[0060] In this embodiment, the waveguide structure 1024 includes conductive features (e.g., patterned copper traces 1010, vias 1012) surrounded substantially by a non-conductive waveguide substrate (e.g., dielectric layers 1002, 1004, 1006, 1008), and a gas-filled waveguide 1014 substantially embedded in the non-conductive waveguide substrate. The waveguide substrate of the waveguide structure 1024 may be formed as follows: Figure 10 The laminated structure depicted has a first core dielectric layer 1002 (e.g., FR4) sandwiched between dielectric layers 1004 and 1006 (e.g., prepreg) and a second core dielectric layer 1008 (e.g., FR4).

[0061] In this embodiment, an inflatable waveguide 1014 (also referred to herein as "waveguide 1014") is formed as a rectangular chamber within a non-conductive waveguide substrate of waveguide structure 1024. Waveguide 1014 is open at the bottom side of waveguide structure 1024, exposing the cap structure 822 of radiating element 826 within the inflatable waveguide. A conductive fence 1016, formed by portions of trace 1010 of waveguide structure 1024 and via 1012, is configured to substantially surround the sidewalls of waveguide 1014. In this embodiment, a waveguide opening 1020 is formed through the conductive trace 1010 and dielectric layer 1008 at the top portion of the waveguide. A conductive liner 1018 (e.g., copper) is formed to surround opening 1020. The opening 1020 formed at the top portion of waveguide 1014 allows RF signals to propagate into or out of the waveguide. In this embodiment, a portion of the encapsulation 818 of the packaged RF device 800, between the signal reflector 810 and the top surface of the encapsulation 818 in which the pin structure 814 is embedded, together with the gas-filled waveguide 1014 of the waveguide structure 1024, forms a hybrid waveguide configured to excite the TE10 mode with minimal package size and reduced signal loss. In this embodiment, the conductive fence 1016 interconnects with conductive features of the trace 808, the signal reflector 810, and the redistribution structure 900, which substantially surround the outer periphery of the semiconductor die 802. For example, the conductive fence 1016 and the signal reflector 810 may be interconnected with a ground power supply via the redistribution structure 900.

[0062] In this embodiment, a plurality of conductive package connectors 1022 (e.g., solder balls) are attached to the bottom conductive connector pads 906 of the reflow structure 900. For example, the conductive package connectors 1022 are configured and arranged to provide a conductive connection between the reflow structure 900 and the PCB. The conductive package connectors 1022 may be in the form of suitable conductive structures such as solder balls, gold pillars, copper pillars, etc., to connect the conductive features of the example semiconductor device 1000 to the PCB.

[0063] Figure 11 A simplified cross-sectional view illustrates an alternative example packaged RF device 1100 during the manufacturing stage according to an embodiment. During this manufacturing stage, the packaged RF device 1100 includes a semiconductor die 1102 disposed on a carrier substrate 1124 and an encapsulation 1116 (e.g., epoxy molding compound) formed over the active side of the semiconductor die 1102. For example, the semiconductor die 1102 is temporarily attached to the carrier substrate 1124 by means of a releasable adhesive (not shown) at the top side of the carrier substrate.

[0064] Semiconductor die 1102 has an active side (e.g., a main side having a circuit system) and a back side (e.g., a main side opposite to the active side). Semiconductor die 1102 includes die pads 1104 and 1106 of a circuit system formed on the active side and connected to the semiconductor die. Figure 11 As depicted, semiconductor die 1102 is configured with its active side facing upward, wherein the back side of the semiconductor die is bonded to carrier substrate 1124. Semiconductor die 1102 can be formed from any suitable semiconductor material, such as silicon, germanium, gallium arsenide, gallium nitride, etc. Semiconductor die 1102 may also include RF circuitry, digital circuitry, analog circuitry, power supply circuitry, memory, processor, etc., and combinations thereof, located on the active side. In this embodiment, semiconductor die 1102 is characterized as an RF semiconductor die configured to transmit and / or receive RF signals at die pad 1106.

[0065] In this embodiment, a conductive layer (e.g., copper) is formed over the active side of the semiconductor die 102 and patterned to form a conductive trace 1108. A portion of the patterned conductive trace 1108 is directly connected to a corresponding die pad 1104 of the semiconductor die 1102. The conductive trace 1108 is dielectrically isolated from the die pad 1106 and is configured to substantially surround a signal reflector 1110 around the die pad 1106. For example, the signal reflector 1110 may be interconnected with a ground power supply in a subsequent stage. Conductive die connectors 1112 and 1114 (e.g., copper pillars, gold bumps) are formed directly over the corresponding die pads 1104 and 1106 of the semiconductor die 1102. Conductive die connector 1112 is, for example, directly connected to the conductive trace 1108. In this embodiment, conductive die connector 1114 is configured as a “pin” structure portion of the radiating element 1126. Conductive die connector 1114 may also be referred to herein as pin structure 1114.

[0066] Encapsulation 1116 is formed on the active side of semiconductor die 1102 and over patterned conductive traces 1108 configured as signal reflectors 1110. In this embodiment, the molded semiconductor die 1102 can be covered with encapsulation 1116 using a FAM molding process to, for example, keep the top surfaces of die connectors 1112 and 1114 free of encapsulation 1116. In this way, the top surfaces of die connectors 1112 and 1114 can be exposed at the top surface of encapsulation 1116.

[0067] After the encapsulation 1116 is formed over the semiconductor die 1102, patterned conformal conductive traces 1118 and 1120 are formed. In this embodiment, trace 1118 is formed over a portion of the encapsulation 1116, the exposed top surfaces of the respective die connectors 1112 and 1114, and the sidewalls of the semiconductor die 1102. Trace 1118 is configured to directly connect to the exposed top surface of the embedded die connector 1112, and trace 1120 is formed to directly connect to the exposed top surface of the embedded lead structure 1114. In this embodiment, the encapsulation 1116 directly contacts the sidewalls of the lead structure 1114. In this embodiment, conductive trace 1120 is configured as a “cap” structure portion of the radiating element 1126. Conductive trace 1120 may also be referred to herein as cap structure 1120. For example, cap structure 1120 may be formed with a suitable shape (e.g., circular, straight), material (e.g., solder, metal), and size that facilitates the propagation of high-frequency RF signals. In this embodiment, the cap structure 1120, together with the pin structure 1114, forms a radiating element 1126 configured to transmit and / or receive RF signals. In this embodiment, a signal reflector 1110 embedded in the encapsulation 1116 is configured to substantially surround the radiating element 1120.

[0068] Figure 12 A simplified cross-sectional view illustrates an example semiconductor device 1200, including an alternative packaged RF device 1100, in the manufacturing stage according to an embodiment. In this manufacturing stage, the semiconductor device 1200 includes the packaged RF device 1100 positioned above a redistribution structure 1220. In this embodiment, the redistribution structure 1220 is provided as a pre-formed package substrate. The redistribution structure 1220 (also referred to herein as "package substrate 1220") includes conductive features (e.g., patterned copper traces 1210, 1212, 1216, vias 1214) substantially embedded in a non-conductive redistribution substrate material (e.g., dielectric layers 1202, 1204, 1206, 1208). In this embodiment, the redistribution structure 1220 also includes a cavity 1218 configured for (in a later stage) placement and attachment of the packaged RF device 1100. The redistribution structure 1220 can be characterized as, for example, a redistribution layer (RDL) package substrate having an exposed portion of trace 1210 within cavity 1218 and an exposed portion of trace 1212 at its bottom surface. In this embodiment, for example, the exposed portion of trace 1210 is configured for interconnecting a packaged RF device 1100, and the exposed portion of trace 1212 is configured for attaching a conductive connector (in a subsequent manufacturing stage). The exposed portion of trace 1212 can be characterized as a conductive connector pad 1212.

[0069] In this embodiment, the non-conductive redistributed substrate of the redistributed structure 1220 is formed as a laminated structure having a core dielectric layer 1202 (e.g., FR4) and a second core dielectric layer 1208 (e.g., FR4) sandwiched between dielectric layers 1204 and 1206 (e.g., prepreg). The dielectric layer 1208 may be formed as a homogeneous single dielectric layer or a laminate having multiple dielectric layers. In this embodiment, a cavity 1218 is formed in the dielectric layer 1208. For example, a through-hole 1214 is formed to interconnect traces 1210 and 1216. In some embodiments, for example, the dielectric layer 1208 may be formed as an encapsulation (e.g., epoxy molding compound) on the underlying portion of the non-conductive redistributed substrate, the encapsulation having a TMV formed through the encapsulation to interconnect traces 1210 and 1216.

[0070] Figure 13 A simplified cross-sectional view illustrates an example semiconductor device 1200, including an alternative packaged RF device 1100, in a subsequent manufacturing stage according to an embodiment. In this manufacturing stage, the semiconductor device 1200 includes a packaged RF device 1100 mounted within a cavity of a reflow structure 1220. In this embodiment, the packaged RF device 1100 may be attached to the reflow structure 1220 by means of a conductive adhesive 1302. Figure 12 The bottom of cavity 1218. For example, conductive adhesive 1302 is configured to provide a conductive connection between the exposed portion of trace 1210 (within the cavity) and trace 1118 of packaged RF device 1100. In other embodiments, other materials (solder, solder paste, nanowires) may be used to form a conductive connection between the exposed portion of trace 1210 and trace 1118. The sidewalls of packaged RF device 1100 and the re-layout structure 1220 ( Figure 12 The gap between the sidewalls of cavity 1218 may be filled with a conductive or non-conductive material 1304 (e.g., glue, paste, gel, epoxy resin), thereby allowing the subsequently formed conductive trace segment 1306 to interconnect the trace 1118 at the top of the packaged RF device 1100 with the trace 1216 at the top of the re-layout structure 1220.

[0071] After the packaged RF device 1100 is installed in the cavity of the redistribution structure 1220, the top surface of the encapsulation 1116 is substantially coplanar with the top surface of the dielectric layer 1208. Similarly, the top surface of the trace 1118 at the top of the packaged RF device 1100 is substantially coplanar with the top surface of the trace 1216 of the redistribution structure 1220.

[0072] Figure 14A simplified cross-sectional view illustrates an example semiconductor device 1200, including an alternative packaged RF device 1100, in a subsequent manufacturing stage according to an embodiment. In this manufacturing stage, the semiconductor device 1200 includes a waveguide structure 1400 attached to the top main side of the packaged RF device 1100, mounted within a cavity of the redistribution structure 1220. In this embodiment, exposed vias 1414 formed on the bottom side of the waveguide structure 1400 are conductively connected to portions of exposed traces 1216 and 1118. The waveguide structure 1400 may be attached and interconnected to the packaged RF device 1100 and the redistribution structure 1220, for example, by means of solder, conductive adhesive, or nanowires (not shown).

[0073] In this embodiment, the waveguide structure 1400 includes conductive features (e.g., patterned copper traces 1412, vias 1414) surrounded substantially by a non-conductive waveguide substrate (e.g., dielectric layers 1402, 1404, 1406, 1408, 1410), and a gas-filled waveguide substantially embedded in the non-conductive waveguide substrate. The waveguide substrate of the waveguide structure 1400 may be formed as follows: Figure 14 The laminated structure depicted has a first core dielectric layer 1402 (e.g., FR4) sandwiched between dielectric layers 1404 and 1406 (e.g., prepreg), and a second core dielectric layer 1408 and a third core dielectric layer 1410 (e.g., FR4).

[0074] In this embodiment, the gas-filled waveguide of the waveguide structure 1400 includes a first rectangular chamber portion 1416 (also referred to herein as “chamber 1416”) formed in the waveguide substrate and a second rectangular chamber portion 1418 (also referred to herein as “chamber 1418”) formed adjacent to the first chamber portion of the waveguide substrate. The waveguide is open at the bottom side of the waveguide structure 1400, such that the cap structure 1120 of the radiating element 1126 is exposed within the first chamber 1416 of the gas-filled waveguide. A conductive fence is formed by portions of the trace 1412 of the waveguide structure 1400 and vias 1414. The conductive fence includes a first conductive fence portion 1422 adjacent to a portion of the first chamber 1416, a second conductive fence portion 1424 adjacent to a portion of the second chamber 1418, and a third conductive fence portion 1426. The first conductive fence portion 1422, the second conductive fence portion 1424, and the third conductive fence portion 1426 are configured together to substantially surround the sidewalls of the gas-filled waveguide of the waveguide structure 1400. In this embodiment, a waveguide opening 1420 is formed through a conductive trace 1412 and a dielectric layer 1410 at the top portion of the second chamber 1418 of the waveguide. A conductive liner 1428 (e.g., copper) is formed to surround the opening 1420. For example, the opening 1420 formed at the top portion of the waveguide allows RF signals to propagate into or out of the waveguide.

[0075] The first chamber 1416 includes a top conductive trace 1412 forming a conductive liner on the top side of the first chamber 1416, and a signal reflector 1110 embedded in an encapsulation 1116 on the bottom side of the first chamber. A first conductive fence portion 1422 interconnects the top conductive trace 1412 with the signal reflector 1110 and laterally surrounds a portion of the sidewall of the first chamber 1416. The second chamber 1418 includes a portion of the topmost conductive trace 1412 forming a partial conductive liner on the top side of the second chamber 1418 surrounding an opening 1420, and a second signal reflector formed by the trace 1118 exposed on the bottom side of the second chamber. A second conductive fence portion 1424 laterally surrounds a portion of the sidewall of the second chamber 1418. In this embodiment, the second chamber 1418 is vertically offset from the first chamber 1416.

[0076] In this embodiment, a portion of the encapsulation 1116 of the packaged RF device 1100, between the signal reflector 1110 and the top surface of the encapsulation 1116 with embedded pin structure 1120, together with the gas-filled waveguide of the waveguide structure 1400, forms a hybrid waveguide configured to excite the TE10 mode with minimal package size and reduced signal loss. In this embodiment, conductive fence portions 1422, 1424, 1426 are interconnected with the signal reflector 1110 at the bottom of the first chamber 1416 and with a second signal reflector formed by trace 1118 on the bottom side of the second chamber 1418, and may be interconnected with a ground power supply terminal, for example by means of the redistribution structure 1220.

[0077] In this embodiment, a plurality of conductive package connectors 1430 (e.g., solder balls) are attached to the bottom conductive connector pads 1212 of the reflow structure 1220. For example, the conductive package connectors 1430 are configured and arranged to provide a conductive connection between the reflow structure 1220 and the PCB. The conductive package connectors 1430 may be in the form of suitable conductive structures such as solder balls, gold pillars, copper pillars, etc., to connect the conductive features of the example semiconductor device 1200 to the PCB.

[0078] Generally, a method is provided, the method comprising: forming a packaged radio frequency (RF) device including a semiconductor die, a radiating element connected to a first die pad of the semiconductor die, and an encapsulation encapsulating at least a portion of the semiconductor die, the radiating element including a pin structure and a cap structure, the pin structure being embedded in the encapsulation; and attaching a waveguide structure to a first main side of the packaged RF device, the waveguide structure including a non-conductive waveguide substrate and a gas-filled waveguide formed in the non-conductive waveguide substrate, the cap structure being exposed within the gas-filled waveguide. The method may further include applying a redistribution structure over a second main side of the packaged RF device, the redistribution structure including a non-conductive redistribution substrate and a plurality of conductive traces embedded in the non-conductive redistribution substrate. The packaged RF device may further include conductive traces formed over a portion of the active side of the semiconductor die, the conductive traces being embedded in the encapsulation and configured as a signal reflector of the radiating element. The waveguide structure may further include a conductive fence formed by one or more conductive traces of the plurality of conductive traces and one or more vias interconnecting the one or more conductive traces. The conductive fence is at least partially embedded in the non-conductive waveguide substrate and configured to substantially surround the gas-filled waveguide. The waveguide structure may be configured to propagate RF signals through a top portion of the non-conductive waveguide substrate. According to the method of claim 1, the waveguide structure may further include an opening formed through the top portion of the non-conductive waveguide substrate, and the gas-filled waveguide of the waveguide structure is configured to propagate RF signals through the opening. The gas-filled waveguide of the waveguide structure may include a first chamber portion and a second chamber portion adjacent to the first chamber portion, with the cap structure exposed within the first chamber portion. The second chamber portion may be vertically offset from the first chamber portion. The gas-filled waveguide of the waveguide structure may be configured for a TE10 propagation mode of the RF signal.

[0079] In another embodiment, a semiconductor device is provided, the semiconductor device comprising: a packaged radio frequency (RF) device including a semiconductor die, a radiating element connected to a first die pad of the semiconductor die, and an encapsulation encapsulating at least a portion of the semiconductor die, the radiating element including a lead structure and a cap structure, the lead structure being embedded in the encapsulation; and a waveguide structure attached to a first main side of the packaged RF device, the waveguide structure including a non-conductive waveguide substrate and a gas-filled waveguide formed in the non-conductive waveguide substrate, the cap structure being exposed within the gas-filled waveguide. The semiconductor device may further include a redistribution structure applied over a second main side of the packaged RF device, the redistribution structure including a non-conductive redistribution substrate and a plurality of conductive traces embedded in the non-conductive redistribution substrate. The packaged RF device may further include conductive traces formed over a portion of the active side of the semiconductor die, the conductive traces being embedded in the encapsulation and configured as a signal reflector of the radiating element. The waveguide structure may further include a conductive fence formed by one or more conductive traces of the plurality of conductive traces and one or more vias interconnecting the one or more conductive traces. The conductive fence is at least partially embedded in the non-conductive waveguide substrate and configured to substantially surround the gas-filled waveguide. The gas-filled waveguide of the waveguide structure may include a first rectangular chamber portion and a second rectangular chamber portion adjacent to the first rectangular chamber portion, with the cap structure exposed within the first rectangular chamber portion. The second rectangular chamber portion may be vertically offset from the first rectangular chamber portion.

[0080] In another embodiment, a method is provided, the method comprising: forming a packaged radio frequency (RF) device, the packaged RF device including a semiconductor die having a first die pad at an active side, a radiating element directly connected to the first die pad of the semiconductor die, and an encapsulation encapsulating at least a portion of the semiconductor die, the radiating element including a pin structure and a cap structure, the pin structure being embedded in the encapsulation; and attaching a waveguide structure to a first main side of the packaged RF device, the waveguide structure including a non-conductive laminated waveguide substrate and a gas-filled waveguide, the gas-filled waveguide being formed in the non-conductive laminated waveguide substrate, the cap structure being exposed within the gas-filled waveguide. According to the method of claim 16, the packaged RF device may further include a conductive trace formed above a portion of the active side of the semiconductor die and configured as a signal reflector of the radiating element, the conductive trace being interconnected with a second die pad of the semiconductor die. The waveguide structure may further include a conductive fence formed by one or more conductive traces of the plurality of conductive traces and one or more vias interconnecting the one or more conductive traces, the conductive fence being at least partially embedded in the non-conductive waveguide substrate and configured to substantially surround the gas-filled waveguide. The waveguide structure may also include an opening formed through a top portion of the non-conductive laminated waveguide substrate, the gas-filled waveguide of the waveguide structure being configured to propagate RF signals through the opening. The gas-filled waveguide of the waveguide structure may include a first rectangular chamber portion and a second rectangular chamber portion adjacent to the first rectangular chamber portion.

[0081] It is now understood that a semiconductor device with a hybrid waveguide has been provided. The semiconductor device includes a waveguide structure mounted on a packaged RF device. The packaged RF device includes a semiconductor die encapsulated in an encapsulant. A radiating element is formed as a die pad directly connected to the semiconductor die. The radiating element includes a “pin” structure portion embedded in the encapsulant and a “cap” structure formed on the encapsulant and directly connected to the pin structure. A signal reflector surrounding the radiating element is embedded in the encapsulant at the surface of the semiconductor. The waveguide structure of the semiconductor device includes a gas-filled waveguide embedded in a waveguide substrate of the waveguide structure. The waveguide structure is attached above the active side of the encapsulated semiconductor die, such that the cap structure of the radiating element is exposed within the waveguide. The portion of the encapsulant containing the signal reflector and pin structure, together with the gas-filled waveguide of the waveguide structure, forms a hybrid waveguide. By forming a semiconductor device with a hybrid waveguide in this manner, TE10 mode excitation can be achieved with minimal package size and reduced signal loss.

[0082] The terms “front,” “rear,” “top,” “bottom,” “above,” “below,” etc., used in the specification and claims, if present, are for descriptive purposes and are not necessarily used to describe permanent relative positions. It should be understood that such terms are interchangeable where appropriate, such that embodiments of the invention described herein can operate, for example, in orientations different from those shown or described herein.

[0083] While the invention has been described herein with reference to specific embodiments, various modifications and alterations may be made without departing from the scope of the invention as set forth in the appended claims. Therefore, this specification and figures should be viewed in an illustrative rather than restrictive sense, and all such modifications are intended to be included within the scope of the invention. It is not intended that any benefit, advantage, or solution to a problem described herein with respect to specific embodiments be construed as a key, necessary, or essential feature or element of any or all claims.

[0084] Furthermore, as used herein, the term "a" is defined as one or more. Additionally, the use of introductory phrases such as "at least one" and "one or more" in the claims should not be construed as implying that another claim element introduced by the indefinite article "a" limits any particular claim containing such an element to an invention containing only one such element, even when the same claim includes the introductory phrase "one or more" or "at least one" and an indefinite article such as "a". The same applies to the use of definite articles.

[0085] Unless otherwise stated, terms such as “first” and “second” are used to arbitrarily distinguish the elements described by such terms. Therefore, these terms are not necessarily intended to indicate the temporal or other priority order of such elements.

Claims

1. A method, characterized in that, include: A packaged radio frequency (RF) device is formed, the packaged RF device comprising: Semiconductor die, A radiating element, connected to a first die pad of the semiconductor die, the radiating element comprising a pin structure and a cap structure, and An encapsulation that encapsulates at least a portion of the semiconductor die, wherein the lead structure is embedded in the encapsulation; and A waveguide structure is attached to the first main side of the packaged RF device, the waveguide structure comprising: Non-conductive waveguide substrate, and An inflatable waveguide is formed in the non-conductive waveguide substrate, and the cap structure is exposed within the inflatable waveguide.

2. The method according to claim 1, characterized in that, In addition, including: A redistribution structure is applied above the second main side of the packaged RF device. The redistribution structure includes a non-conductive redistribution substrate and a plurality of conductive traces embedded in the non-conductive redistribution substrate.

3. The method according to claim 1, characterized in that, The packaged RF device further includes: A conductive trace is formed above a portion of the active side of the semiconductor die, the conductive trace is embedded in the encapsulation, and is configured as a signal reflector of the radiating element.

4. The method according to claim 1, characterized in that, The waveguide structure further includes: A conductive fence, formed by one or more conductive traces of the plurality of conductive traces and one or more through-holes interconnecting the one or more conductive traces, the conductive fence being at least partially embedded in the non-conductive waveguide substrate and configured to substantially surround the gas-filled waveguide.

5. The method according to claim 1, characterized in that, The waveguide structure is configured to propagate RF signals through the top portion of the non-conductive waveguide substrate.

6. The method according to claim 1, characterized in that, The waveguide structure further includes: An opening is formed through the top portion of the non-conductive waveguide substrate, and the gas-filled waveguide of the waveguide structure is configured to propagate RF signals through the opening.

7. The method according to claim 1, characterized in that, The inflatable waveguide of the waveguide structure includes a first chamber portion and a second chamber portion adjacent to the first chamber portion, with the cap structure exposed within the first chamber portion.

8. The method according to claim 7, characterized in that, The second chamber portion is vertically offset from the first chamber portion.

9. A semiconductor device, characterized in that, include: Packaged radio frequency (RF) device, the packaged RF device comprising: Semiconductor die, A radiating element, connected to a first die pad of the semiconductor die, the radiating element comprising a pin structure and a cap structure, and An encapsulation that encapsulates at least a portion of the semiconductor die, wherein the lead structure is embedded in the encapsulation; and A waveguide structure, attached to a first main side of the packaged RF device, the waveguide structure comprising: Non-conductive waveguide substrate, and An inflatable waveguide is formed in the non-conductive waveguide substrate, and the cap structure is exposed within the inflatable waveguide.

10. A method, characterized in that, include: A packaged radio frequency (RF) device is formed, the packaged RF device comprising: A semiconductor die having a first die pad on the active side. A radiating element, which is directly connected to the first die pad of the semiconductor die, the radiating element comprising a pin structure and a cap structure, and An encapsulation that encapsulates at least a portion of the semiconductor die, wherein the lead structure is embedded in the encapsulation; and A waveguide structure is attached to the first main side of the packaged RF device, the waveguide structure comprising: Non-conductive laminated waveguide substrate, and An inflatable waveguide is formed in the non-conductive laminated waveguide substrate, and the cap structure is exposed within the inflatable waveguide.

Images