A novel radio frequency module, manufacturing method and electronic equipment

Abstract

The present invention discloses a novel radio frequency module, a manufacturing method, and an electronic device, comprising: a substrate wafer; a micro-coaxial structure located on the substrate wafer; a sidewall located on the substrate wafer and arranged around the micro-coaxial structure; a radio frequency chip flipped on the micro-coaxial structure, the signal end of the radio frequency chip being connected to the first port of the micro-coaxial structure; a cover wafer bonded to the substrate wafer, a first through silicon via and a second through silicon via being provided in the cover wafer, the first through silicon via being connected to the second port of the micro-coaxial structure through a conductor post; a grounding device located between the radio frequency chip and the cover wafer, the first end of the grounding device being connected to the ground end of the radio frequency chip, and the second end being connected to the second through silicon via. The radio frequency module not only meets the requirements of high-frequency communication but also has high airtightness. By arranging a grounding device between the radio frequency chip and the cover wafer, the radio frequency chip is grounded through the cover wafer, thereby improving the performance of the radio frequency module.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a novel radio frequency module, a manufacturing method and an electronic device. Background Art

[0002] Electronic communication modules are increasingly moving towards miniaturization and integration. The integration of RF functional modules faces challenges in reducing signal transmission loss, increasing signal isolation, suppressing signal phase distortion, and preventing mutual interference for higher-frequency electromagnetic waves, particularly in the millimeter-wave and terahertz bands.

[0003] Existing technologies employ methods such as fabricating micro-coaxial transmission lines on semiconductor wafers and connecting them to high-frequency devices to form integrated RF functional modules. These modules transmit high-frequency signals and expand in two dimensions to form electronic systems. While this technology has initially achieved the integration of high-frequency signal transmission between RF devices, because the connection and integration are limited to two dimensions, interfaces with external systems (such as PCBs) still require traditional gold bonding wires and SMA connectors. This results in suboptimal RF performance (gold bonding wires have poor RF performance) and integration (SMA connectors cannot be integrated and manufactured). Furthermore, existing technologies do not address backside grounding of the chip, which can severely impact chip performance. Summary of the Invention

[0004] The embodiments of the present application provide a new type of RF module, manufacturing method and electronic device. The RF module not only meets the requirements of high-frequency communication, but also has high airtightness. By arranging a grounding device between the RF chip and the cover wafer, the RF chip is grounded through the cover wafer, thereby improving the performance of the RF module.

[0005] In a first aspect, the present invention provides the following technical solutions through an embodiment of the present invention:

[0006] A novel radio frequency module comprises: a substrate wafer; a micro-coaxial structure located on the substrate wafer; a sidewall located on the substrate wafer and arranged around the micro-coaxial structure; a radio frequency chip flipped on the micro-coaxial structure, the signal end of the radio frequency chip being connected to the first port of the micro-coaxial structure; a cover wafer bonded to the substrate wafer, a first through-silicon via and a second through-silicon via being provided in the cover wafer, the first through-silicon via being connected to the second port of the micro-coaxial structure via a conductor column; and a grounding device located between the radio frequency chip and the cover wafer, the first end of the grounding device being connected to the ground end of the radio frequency chip, and the second end being connected to the second through-silicon via.

[0007] Preferably, the grounding device includes a grounding channel and a grounding backplane connected to each other, the grounding backplane is connected to the RF chip, and the grounding channel is connected to the second through-silicon via.

[0008] Preferably, the ground backplane is attached to the back of the RF chip, and the ground channel includes a first sub-channel, a second sub-channel and a third sub-channel arranged on the substrate wafer. The first sub-channel, the second sub-channel and the third sub-channel are all located on the substrate wafer, the first sub-channel is connected to the second sub-channel, the second sub-channel is connected to the third sub-channel, the ground backplane is connected to the first sub-channel, and the third sub-channel is connected to the second through-silicon via.

[0009] Preferably, the grounding backplane is attached to the lower surface of the cover wafer through the grounding channel, and the grounding channel is connected to the second through-silicon via.

[0010] Preferably, the ground backplane is a panel with one end being wider and the other end being narrower.

[0011] Preferably, the grounding backplane is a panel that is wide in the middle and narrow at both ends.

[0012] In a second aspect, the present invention provides the following technical solution through an embodiment of the present invention:

[0013] A method for manufacturing a novel radio frequency module, comprising:

[0014] A micro-coaxial structure and a side wall surrounding the micro-coaxial structure are formed on a substrate wafer, and a conductor column perpendicular to the substrate wafer is made on the micro-coaxial structure; a radio frequency chip is flipped on the micro-coaxial structure and connected to the first port of the micro-coaxial structure; a cover wafer and a grounding device are provided, wherein the cover wafer is provided with a first through-silicon via, a second through-silicon via, and a first signal port connected to the first through-silicon via, and a second signal port connected to the second through-silicon via, the first signal port being used for signal transmission with the radio frequency chip, and the second signal port being used for grounding the radio frequency chip; the substrate wafer and the cover wafer are bonded, wherein, during the bonding process, the grounding device is provided between the cover wafer and the radio frequency chip of the substrate wafer, so that the first through-silicon via is connected to the second port of the micro-coaxial structure through the conductor column, the first end of the grounding device is connected to the grounding end of the radio frequency chip, and the second end is connected to the second through-silicon via.

[0015] Preferably, the grounding device includes: a grounding channel and a grounding backplane connected to each other, the grounding channel includes a first sub-channel, a second sub-channel and a third sub-channel, the first sub-channel, the second sub-channel and the third sub-channel are all located on the substrate wafer, the first sub-channel is connected to the second sub-channel, the second sub-channel is connected to the third sub-channel, the position of the third sub-channel corresponds to the position of the second silicon through-hole on the cover wafer, and the bonding of the substrate wafer to the cover wafer includes: attaching the grounding backplane to the upper surface of the RF chip and the upper surface of the first sub-channel; bonding the substrate wafer to the cover wafer so that the third sub-channel is connected to the second silicon through-hole.

[0016] Preferably, the grounding device includes: a grounding channel and a grounding backplane connected to each other, the grounding channel is arranged on the lower surface of the cover wafer and is connected to the second silicon through-hole, and the bonding of the substrate wafer to the cover wafer also includes: attaching the grounding backplane to the lower surface of the grounding channel; bonding the substrate wafer to the cover wafer so that the grounding backplane is connected to the RF chip.

[0017] In a third aspect, the present invention provides the following technical solution through an embodiment of the present invention:

[0018] An electronic device comprises a radio frequency module as described in any one of the first aspects above.

[0019] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0020] The embodiment of the present invention provides a new type of radio frequency module, manufacturing method and electronic device, including: a substrate wafer; a micro-coaxial structure, located on the substrate wafer; a side wall, located on the substrate wafer and arranged around the micro-coaxial structure; a radio frequency chip, flipped on the micro-coaxial structure, the signal end of the radio frequency chip is connected to the first port of the micro-coaxial structure, a cover wafer, bonded to the substrate wafer, a first through-silicon via and a second through-silicon via are provided in the cover wafer, the first through-silicon via is connected to the second port of the micro-coaxial structure through a conductor column, a grounding device, located between the radio frequency chip and the cover wafer, and the first end of the grounding device is connected to the ground end of the radio frequency chip, and the second end is connected to the second through-silicon via. The present application prepares side walls and conductor columns on the substrate wafer, and bonds the prepared cover wafer to the substrate wafer containing the side walls and conductor columns, thereby updating the original two-dimensional integration to a three-dimensional integration. By bonding the substrate wafer and the cover wafer together, an excellent airtight packaging structure is provided, which can effectively protect the internal devices. The through-silicon vias integrated on the cover wafer can lead the electrical signals of the RF module out of the cover wafer. In addition, the RF chips are connected with the micro-coaxial structure, and the micro-coaxial technology brings good RF transmission characteristics.

[0021] Furthermore, by providing a grounding device between the RF chip and the cover wafer, the grounding device is connected to the ground terminal of the RF chip, transmitting the signal from the RF chip to the outside of the cover wafer. This facilitates the application of RF chips with power amplification functions when grounding over a large area, thereby improving the performance of the RF chip and further improving the performance of the RF module. Therefore, the three-dimensional integration technology provided by this application improves the integration of RF chips, reduces the transmission loss of RF signals, and extends the service life of RF modules. It has a wide range of applications and is of practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 A schematic structural diagram of a novel radio frequency module provided in an embodiment of the present invention;

[0024] Figure 2 A schematic diagram of a micro-coaxial structure provided by an embodiment of the present invention;

[0025] Figure 3 A schematic cross-sectional view of a micro-coaxial structure provided by an embodiment of the present invention;

[0026] Figure 4A vertical section view of the micro-coaxial structure AA' provided in an embodiment of the present invention;

[0027] Figure 5 A cross-sectional top view of the micro-coaxial structure BB' provided in an embodiment of the present invention;

[0028] Figure 6 A side view of a three-dimensional radio frequency module provided by an embodiment of the present invention;

[0029] Figure 7 A schematic diagram of the structure of a ground backplane provided in an embodiment of the present invention in a radio frequency module;

[0030] Figure 8 A side view of another three-dimensional radio frequency module provided by an embodiment of the present invention;

[0031] Figure 9 A schematic structural diagram of a grounding backplane provided in an embodiment of the present invention;

[0032] Figure 10 A schematic structural diagram of another grounding backplane provided in an embodiment of the present invention;

[0033] Figure 11 A top view of a first through silicon via and an annular hole provided in an embodiment of the present invention;

[0034] Figure 12 Another side view of a three-dimensional radio frequency module from a micro-coaxial vertical section (AA' direction) according to an embodiment of the present invention;

[0035] Figure 13 A top view of a first through silicon via and a third through silicon via provided by an embodiment of the present invention;

[0036] Figure 14 A side view of a three-dimensional radio frequency module with a cavity including a first through-silicon via and an annular hole provided in an embodiment of the present invention;

[0037] Figure 15 A side view of a three-dimensional radio frequency module with a cavity including a first through silicon via and a third through silicon via provided in an embodiment of the present invention;

[0038] Figure 16 A perspective view of the three-dimensional radio frequency module structure provided by an embodiment of the present invention;

[0039] Figure 17 The present invention provides a flowchart of a method for manufacturing a novel radio frequency module. DETAILED DESCRIPTION

[0040] The embodiments of the present application provide a new type of RF module, manufacturing method and electronic device. The RF module not only meets the requirements of high-frequency communication, but also has high airtightness. By arranging a grounding device between the RF chip and the cover wafer, the RF chip is grounded through the cover wafer, thereby improving the performance of the RF module.

[0041] The technical solution of the embodiment of the present application is to solve the above technical problems, and the overall idea is as follows:

[0042] A novel radio frequency module comprises: a substrate wafer; a micro-coaxial structure located on the substrate wafer; a sidewall located on the substrate wafer and arranged around the micro-coaxial structure; a radio frequency chip flipped on the micro-coaxial structure, with a signal end of the radio frequency chip connected to a first port of the micro-coaxial structure; a cover wafer bonded to the substrate wafer, with a first through-silicon via and a second through-silicon via provided in the cover wafer, the first through-silicon via being connected to the second port of the micro-coaxial structure via a conductor column; and a grounding device located between the radio frequency chip and the cover wafer, with a first end of the grounding device connected to a ground end of the radio frequency chip and a second end connected to the second through-silicon via.

[0043] It should be noted that the RF chip mentioned in this application may be a RF power amplifier, a RF low-noise amplifier or a RF switch, etc.

[0044] In order to better understand the above technical solution, the above technical solution will be described in detail below with reference to the accompanying drawings and specific implementation methods.

[0045] In a first aspect, an embodiment of the present invention provides a novel radio frequency module, specifically, Figure 1 As shown, the RF module includes a substrate wafer 100; a micro-coaxial structure located on the substrate wafer 100; a side wall 104 located on the substrate wafer 100 and arranged around the micro-coaxial structure; an RF chip 200 flip-chip mounted on the micro-coaxial structure, and the signal end of the RF chip 200 is connected to the first port 111 of the micro-coaxial structure.

[0046] The cover wafer 300 is bonded to the substrate wafer 100. A first through-silicon via 301 and a second through-silicon via 302 are provided in the cover wafer 300. The first through-silicon via 301 is connected to the second port of the micro-coaxial structure through a conductor post 115 (the outer conductor of the micro-coaxial structure); the grounding device 20 is located between the RF chip 200 and the cover wafer 300, and the first end of the grounding device 20 is connected to the ground end of the RF chip 200, and the second end is connected to the second through-silicon via 302.

[0047] Specifically, the manufacturing process may include: forming a micro-coaxial structure and a side wall 104 surrounding the micro-coaxial structure on a substrate wafer 100, and manufacturing a conductor column 115 perpendicular to the substrate wafer 100 on the micro-coaxial structure; mounting the RF chip 200 on the micro-coaxial structure through the existing flip-chip technology, and connecting it to the first port 111 of the micro-coaxial structure and the port 112 of the lead; providing a cover wafer 300 and a grounding device, and the cover wafer 300 is provided with a first silicon via 301, a second silicon via 302, and a first signal port connected to the first silicon via, and a second signal port connected to the second silicon via. The first signal port is used for signal transmission with the RF chip, and the RF module can be excited by the RF signal through the first signal port. The second signal port is used for grounding the RF chip.

[0048] The cover wafer 300 is bonded to the substrate wafer 100. During the bonding process, a grounding device is set between the cover wafer and the RF chip of the substrate wafer, so that the first silicon via 301 is connected to the second port of the micro-coaxial structure through the conductor post 115, the first end of the grounding device 20 is connected to the ground end of the RF chip, and the second end is connected to the second silicon via 302. After bonding, the silicon via 301 is connected to the conductor post 115.

[0049] In a specific embodiment, before bonding the cover wafer 300 to the substrate wafer 100, the process further includes: forming a first through-silicon via 301 and a second through-silicon via 302 on the cover wafer 300, and forming a metal bonding layer 308 on the lower surface of the cover wafer 300. The position of the metal bonding layer 308 corresponds to the position of the sidewalls 104 and the conductive pillars 115. Wafer-level bonding is then performed on the metal bonding layer 308 on the cover wafer 300 and the sidewalls 104 and conductive pillars 115 formed on the substrate wafer 100.

[0050] Specifically, the substrate wafer and the cover wafer are bonded together, with the bonding position being the metal bonding layer structure and the vertical copper pillars and copper sidewalls. The metal bonding layer structure here can be solder such as titanium / nickel / tin / silver / copper, and the metal bonding layer can be produced using processes such as electroplating.

[0051] As an optional embodiment, the substrate wafer 100 is further provided with leads (ie Figure 1 111 is the first port of the micro-coaxial structure, and 112 is the port of the lead). The RF chip 200 is flip-chip mounted on the first port 111 of the micro-coaxial structure and the port 112 of the lead. The first port of the RF chip 200 is connected to the first port 111 of the micro-coaxial structure, and the second port of the RF chip 200 is connected to the port 112 of the lead.

[0052] The cover wafer 300 is provided with a first through-silicon via 301, a second through-silicon via 302, and a fourth through-silicon via (not shown in the figure), a first signal port connected to the first through-silicon via 301, a second signal port connected to the second through-silicon via 302, and a third signal port connected to the fourth through-silicon via. The second port of the micro-coaxial structure is connected to the first through-silicon via 301 via a first conductor post 115, and the port 112 of the lead is connected to the fourth through-silicon via via a second conductor post (not shown in the figure). The grounding device 20 is connected to the second through-silicon via 302. It should be noted that the third signal port here can be a DC signal port provided on the cover wafer, which is used to bias and control the RF chip.

[0053] Specifically, the manufacturing process may include: forming a micro-coaxial structure, leads, and side walls 104 surrounding the micro-coaxial structure and leads on a substrate wafer 100. A conductor column 115 perpendicular to the substrate wafer is manufactured on the first port of the micro-coaxial structure, and the RF chip 200 is flipped onto the micro-coaxial structure and leads, and connected to the port and leads of the micro-coaxial structure. The first conductor column, the second conductor column, and the side wall 104 are bonded to a cover wafer provided with through-silicon vias 301 / 302. After bonding, the first through-silicon via 301 is connected to the first conductor column 115, the second through-silicon via 302 is connected to the grounding device 20, and the fourth through-silicon via is connected to the second conductor column. Thus, Figure 1 111 and 112 may both be ports of a micro-coaxial structure, or 111 may be a port of a micro-coaxial structure and 112 may be a port of a lead.

[0054] In addition, after the substrate wafer and the cover wafer are bonded, the sidewalls 104 on both sides can be connected to the third through silicon via 303 and the fifth through silicon via 304 respectively, so that the micro-coaxial structure is grounded through the sidewalls, so that the sidewalls and the micro-coaxial structure are at the same level. Figure 1 The left sidewall 104 shown will be connected to the third through silicon via 303, and the right sidewall 104 will be connected to the fifth through silicon via 304. The micro coaxial structure mentioned in this application is described in detail below:

[0055] like Figure 2 As shown in the schematic diagram of the micro-coaxial structure mentioned in this application, its most basic structure consists of an outer conductor, a central conductor and a dielectric strip 117 supporting the central conductor. The high-frequency RF signal is transmitted by the central conductor and the outer conductor is grounded. The micro-coaxial structure has the advantages of low transmission loss and low signal distortion for high-frequency signals.

[0056] like Figure 3The figure shows a cross-section of the basic micro-coaxial structure. The outer and center conductors, along with dielectric strip 117, are fabricated using a five-pass copper electroplating process (which also includes photolithography, chemical mechanical polishing, and other processes). Dielectric strip 117 is fabricated between the second and third copper plating stages to support the center conductor. The space between the center and outer conductors is hollow (which can also be filled with a low-k material). AA' is a vertical section through the micro-coaxial centerline, and BB' is a transverse section through the micro-coaxial centerline.

[0057] Figure 4 It is a vertical side view along the AA' centerline of the basic micro-coaxial structure. Between the lower layer Cu1 and the upper layer Cu5 of the peripheral conductor, the dielectric strip 117 supports the central conductor. Figure 5 It is a cross-sectional top view along the BB' centerline of the micro-coaxial basic structure. The center conductor is supported by a dielectric strip, and the dielectric strip 117 is made on Cu2.

[0058] In a specific embodiment, the grounding device 20 may include a ground channel and a ground backplane connected to each other, the ground backplane is connected to the RF chip, and the ground channel is connected to the second through-silicon via.

[0059] As an optional embodiment, Figure 6 As shown, the ground backplane 202 is attached to the back of the RF chip 200, and the ground channel includes a first sub-channel 204, a second sub-channel 205 and a third sub-channel 206 arranged on the substrate wafer 100. The first sub-channel 204, the second sub-channel 205 and the third sub-channel 206 are all located on the substrate wafer 100, the first sub-channel 204 is connected to the second sub-channel 205, the second sub-channel 205 is connected to the third sub-channel 206, the ground backplane 202 is connected to the first sub-channel 204, and the third sub-channel 206 is connected to the second through-silicon via 302.

[0060] After the RF chip 200 is bonded and integrated into one through the ground backplane 202 and the metal bonding layer structure 203, the back side metallization is completed, and the ground backplane 202 is mounted (welded) on the first sub-channel (vertical metal conductor copper column) 204. The substrate wafer and the cover wafer are bonded so that the ground backplane 202 is connected to the second silicon via in the backplane wafer. The signal in the RF chip will be transmitted from the ground backplane 202 through the first sub-channel 204, the second sub-channel 205, the third sub-channel 206, and the conductor extension structure 307 prepared by photolithography / electroplating and other process methods to the second silicon via 302, and then transmitted to the outside of the cover wafer 300 for grounding.

[0061] Specifically, the manufacturing process may include: forming a first sub-channel, a second sub-channel and a third sub-channel on a substrate wafer, wherein the first sub-channel is connected to the second sub-channel, the second sub-channel is connected to the third sub-channel, and the position of the third sub-channel corresponds to the position of the second through silicon via on the cover wafer.

[0062] Bonding the substrate wafer to the cover wafer includes: attaching the ground backplane 202 to the upper surface of the RF chip 200 and the upper surface of the first sub-channel 204; and bonding the substrate wafer 100 to the cover wafer 300 so that the third sub-channel 206 is connected to the second through-silicon via 302. It should be noted that the second sub-channel 205 here can be a metal copper conductor lead located on the substrate wafer.

[0063] like Figure 7 , which is a top view of the ground backplane, wherein the ground backplane is located above the micro-coaxial structure and the RF chip, and both ends of the ground backplane are connected to the ground channel.

[0064] As another optional embodiment, Figure 8 As shown, the ground backplane 202 is attached to the lower surface of the cover wafer 300 through the ground channel 312, and the ground channel 312 is connected to the ground backplane 202 and the second silicon via 302 respectively. Among them, a metal bonding layer is also provided under the ground backplane 202, and the substrate wafer and the cover wafer are bonded so that the metal bonding layer under the ground backplane 202 is connected to the RF chip 200, thereby realizing the connection between the ground backplane 202 and the RF chip 200. The signal in the RF chip will be transmitted from the ground backplane 202 through the ground channel 312 and the second silicon via 302 to the outside of the cover wafer 300 for grounding. Among them, as Figure 8 As shown, the ground channel 312 can be connected to the third through-silicon via 303 , so that the RF chip can also be grounded through the third through-silicon via 303 .

[0065] The RF chip 200 is flipped and mounted (welded) on the horizontal lead-out end of the micro-coaxial structure (the first port 111 of the micro-coaxial structure) and the port 112 of the metal copper conductor lead (the second port of the metal copper conductor lead) through the solder ball 201 .

[0066] It should be noted that a dielectric passivation layer 108 is formed between all conductors on the substrate wafer for electrical isolation. For example, the dielectric passivation layer can be made of silicon oxide / silicon nitride / polyimide / SU-8 / BCB and other materials.

[0067] In the specific implementation process, Figure 1As shown, before forming a micro-coaxial structure, metal conductor leads, and sidewalls surrounding the micro-coaxial structure and metal conductor leads on a substrate wafer, the following steps are performed: forming a dielectric passivation layer 108 on the substrate wafer; and fabricating an adhesion layer, a barrier layer, and a seed layer on the dielectric passivation layer 108. For example, these layers may be Ti / TiN / Cu or Ta / TaN / Cu. The adhesion layer, barrier layer, and seed layer are shown as 107. Subsequently, processes such as photolithography and electroplating are used to fabricate the outer conductor structure 109 / 114 of the micro-coaxial structure, the port support structure 110 for the inner conductor, the RF signal connection ports 111 / 113 and 115 on the micro-coaxial structure, and the RF signal grounding port 103 on the micro-coaxial transmission line perpendicular to the substrate wafer surface.

[0068] like Figure 6 As shown, 112 / 205 are copper conductor leads fabricated horizontally on the substrate wafer. While fabricating the micro-coaxial structure and metal conductor leads, copper sidewalls 104 are fabricated perpendicular to the substrate wafer around the RF chip, micro-coaxial structure, and metal conductor leads. Following the fabrication of the micro-coaxial structure and metal conductor leads, metal conductor posts 115 are fabricated perpendicular to the substrate wafer on the first ends of the micro-coaxial structure and metal conductor leads.

[0069] As an optional embodiment, Figure 9 As shown in FIG, the ground backplane is a panel with one end being wide and the other end being narrow. Alternatively, it is a panel with a width in the middle and a width at both ends. Figure 10 As shown, of course, the grounding backplane can also adopt other structures suitable for this application, such as: a rectangular structure, etc., and this application does not limit it.

[0070] In a specific embodiment, when the ground backplane is a panel with one end wider than the other, the wide end is connected to the RF chip, while the narrow end is connected to the first sub-channel in the ground channel. This allows the RF chip and the ground channel to be connected together to achieve grounding while occupying a relatively small space on the ground backplane. In other embodiments, when the ground backplane is a panel with a wide center and narrow ends, the wide portion is connected to the RF chip, while the narrow portions are connected to multiple ground channels.

[0071] As an optional embodiment, fabricating a first through-silicon via (TSV) and a second through-silicon via (TSV) on the cover wafer 300 includes: forming a first through-hole and a second through-hole on the cover wafer, wherein the position of the first through-hole on the cover wafer corresponds to the first conductor post, and the position of the second through-hole on the cover wafer corresponds to the second conductor post. Filling the first through-hole and the second through-hole with conductive material, respectively, to obtain a first TSV 301 and a second TSV 302. The first TSV 301 is bonded to the first conductor post 115 for transmitting RF chip signals, and the second TSV 302 is connected to the second conductor post for grounding the RF chip.

[0072] Specifically, when making the first through-silicon via and the second through-silicon via on the cover wafer 300, it also includes: making an annular hole 303 surrounding the first through-hole on the cover wafer, wherein the position of the annular hole 303 on the cover wafer corresponds to the outer conductor 103 part of the micro-coaxial structure, filling the annular hole 303 with conductor material to obtain the annular hole conductor 303, and the annular hole conductor 303 is connected to the outer conductor 109 / 103 of the micro-coaxial structure for grounding the micro-coaxial structure.

[0073] Specifically, the electrical signal generated by the RF chip 200 will be transmitted from the first port 111, the center conductor, and the conductor column 115 of the micro-coaxial structure to the first through-silicon via 301, and then transmitted to the outside of the cover wafer. The ground end of the micro-coaxial structure is transmitted to the annular hole conductor 303 through the outer conductor 109 / 103 for grounding. Figure 11 , which is a top view of the first through silicon via 301 and the annular hole 303 .

[0074] In particular, after forming the through silicon via on the cover wafer, it also includes: forming a dielectric passivation layer 306 on the lower surface of the cover wafer 300, then making a patterned adhesion layer, a barrier layer and a seed layer 305, and continuing to use photolithography / electroplating and other process methods to prepare a conductor extension structure 307 and the aforementioned metal bonding layer structure 308.

[0075] Furthermore, in order to facilitate further integration of the three-dimensional RF module, or to cut it into independent modules and integrate it into a larger electronic system, pads or balls can be made on the upper surface of the cover wafer, such as Figure 6 As shown, 310 on the upper surface of the cover wafer is a bonding pad structure, 311 is a metal implant ball, and a dielectric passivation layer 309 is formed below the bonding pad structure to play an electrical isolation role.

[0076] As another optional embodiment, Figure 12As shown, while forming the first and second TSVs on the cover wafer 300, the process may also include forming a third through-hole on the cover wafer. The position of the third through-hole on the cover wafer corresponds to the position of the outer conductor of the micro-coaxial structure, and the third through-hole is filled with a conductive material to form a third TSV 303. The third TSV 303 is connected to the outer conductor of the micro-coaxial structure to ground the micro-coaxial structure.

[0077] Specifically, if Figure 13 Figure 2 shows a top view of the first and third TSVs. The first TSV connects to the microcoaxial center conductor for RF signal transmission, while the third TSV connects to the microcoaxial outer conductor structure 103 / 109 for grounding the microcoaxial structure. It should be noted that this process for forming the first and third TSVs on the cover wafer is relatively simple to implement and is more suitable for lower-frequency RF signal applications.

[0078] Furthermore, in order to facilitate the setting of RF chips of various structures and thicknesses, a cavity is created between the RF signals of the cover wafer and the substrate wafer. Specifically, by deforming the cover wafer, that is, by setting the thickness of the cover wafer at the position corresponding to the RF signal to be narrower, a certain cavity can be created after the substrate wafer and the cover wafer are bonded. Figure 14 As shown in FIG, it is a deformation of the cover wafer including the first through silicon via and the annular hole conductor. Figure 15 FIG. 3 is a variation of a cover wafer including a first through silicon via and a third through silicon via, wherein a cavity structure with a dielectric passivation layer is fabricated on the cover wafer 300 .

[0079] Furthermore, the height at which the RF chip 200 is flip-chip mounted on the micro-coaxial port is adjustable. Specifically, this is achieved by adjusting the height of the micro-coaxial port and other metal copper conductor ports perpendicular to the substrate wafer. For example, the RF chip can be flip-chip mounted at the height of CU1, CU2, or CU3.

[0080] Furthermore, to prevent uncontrolled microscopic liquid overflow from the metal bonding layer structure (e.g., tin) at the bonding site during the bonding process between the substrate wafer and the cover wafer, which could cause a short circuit between the metal conductor structures, an existing overflow limiting structure for collecting trace amounts of tin liquid can be employed at the location of the metal bonding layer structure. This structure prevents overflow of molten tin liquid during the bonding process between the substrate wafer and the cover wafer, effectively resolving the short circuit problem caused by tin liquid overflow. Of course, this solder current limiting structure can also be used for the solder bonding between flip-chip RF chips and the end of transmission lines.

[0081] It should be noted that, in addition to using a conventional overflow limiting structure, a dielectric strip can also be used as an overflow limiting structure. Specifically, when the RF chip is flipped on the CU2 position, the RF chip can be flipped on the CU2 through the dielectric strip above the CU2, and the port of the RF chip can be welded between the two dielectric strips, so that the overflow liquid generated during welding is blocked by the dielectric strip, thereby achieving the purpose of limiting the overflow of the tin liquid. For example, the dielectric strips are distributed at both ends of the solder ball 201 connected to the RF chip to block the overflow liquid, or the dielectric strips surround the solder ball 201 so that the solder ball 201 is within the surrounding range of the dielectric strips to block the overflow liquid.

[0082] Specifically, if Figure 16 The figure shows a perspective view of the three-dimensional RF module structure provided by an embodiment of the present application. According to a specific circuit design, micro-coaxial transmission lines and copper conductor lines are fabricated on the substrate wafer parallel to the wafer surface, and the RF chip is flip-chip mounted (soldered) on the ports of these micro-coaxial lines and the ports of the copper conductor lines. At the other end of these micro-coaxial transmission lines and copper conductor lines, metal conductor copper pillars are fabricated perpendicular to the substrate wafer direction. Copper sidewalls are also fabricated on the substrate wafer to surround other structures such as the micro-coaxial structure and its ports, the metal copper conductor line structure and its ports, and the RF chip. The copper sidewalls are perpendicular to the substrate wafer surface.

[0083] A metal bonding layer structure is produced at a specific position on the lower surface of the cover wafer, i.e., a position corresponding to the vertically erected metal conductor copper pillars and copper side walls on the substrate wafer. The substrate wafer containing the RF chip, metal copper conductor wires and copper side walls is then bonded to the cover wafer containing the through-silicon via structure, wire bonding pads and metal bonding layer structure to achieve hermetic packaging and fusion of the substrate wafer and the cover wafer.

[0084] Specifically, if Figure 16 As shown, the RF signal input and output port (RF I / O) including the signal port (S) and the ground port (G) provided on the cover wafer is used to excite the RF module (chip); the RF chip is biased and controlled through the DC signal port (DC / Bias) provided on the cover wafer.

[0085] Among them, the silicon via structure of the RF signal port on the cover wafer has two forms. The first is that the middle metal copper cylindrical conductor transmits the RF signal (S), and the surrounding metal copper ring conductor is grounded (G), marked as RF I / O. The second is that the RF signal port (S) and the ground (G) are both silicon vias with metal copper cylindrical conductors, marked as RF I / O*. It should be noted that the DC (DC / Bias) signal on the cover wafer all uses the second form of silicon via, that is, there is no outer metal copper ring, only the metal copper cylindrical conductor.

[0086] The present application provides a novel RF module, which is formed by fabricating a horizontal micro-coaxial structure and its ports, as well as vertical metal conductor copper pillars (for vertical structural support or vertical electrical signal extraction) on the substrate wafer plane, flip-chip soldering the RF chip to the micro-coaxial port, and flip-chip soldering the non-RF functional chip (for operations / control / bias, etc.) to the metal conductor copper leads fabricated horizontally on the substrate wafer plane, thereby forming a RF functional unit module. Copper sidewalls of a certain height are fabricated to completely surround the micro-coaxial structure, RF chip, metal conductor copper pillars and metal conductor copper leads, and other non-RF functional chips. The copper sidewalls surround the space formed by these chips and the metal conductor structure and provide protection for the above structure.

[0087] A cover wafer containing a through-silicon via (TSV) structure is also fabricated, and a metal bonding layer structure is formed at specific locations on the lower surface of the cover wafer. The copper sidewalls and metal conductor copper pillars on the substrate wafer are bonded to the cover wafer with the TSV structure at the wafer level via the metal bonding layer. This achieves electrical connection and structural integration of the two wafers, completing the integration of the 3D RF module. Furthermore, solder pads or implant balls are fabricated on the upper surface of the cover wafer to facilitate further integration of the 3D RF module.

[0088] In summary, the present invention provides a new type of radio frequency module, which adopts the three-dimensional radio frequency integration technology of radio frequency chip, substrate wafer and micro-coaxial structure, side wall, cover wafer and silicon through hole, and solves the problems of poor radio frequency performance with external interface and insufficient manufacturing integration caused by the previous two-dimensional plane expansion. On the basis of meeting the high-frequency communication of the radio frequency module, the radio frequency module also improves the airtightness of the radio frequency module, effectively protects the internal components, and extends the service life of the radio frequency module. And by arranging a grounding device between the radio frequency chip and the cover wafer, the grounding device is connected to the grounding terminal of the radio frequency chip, and the signal is transmitted from the radio frequency chip to the outside of the cover wafer, which is conducive to the application of radio frequency chips with power amplification function when grounding over a large area, and greatly improves the performance of the radio frequency chip.

[0089] In the second aspect, based on the same inventive concept, an embodiment of the present invention provides a method for manufacturing a new type of radio frequency module. Specifically, Figure 17 As shown, the manufacturing method includes the following steps S101 to S104.

[0090] Step S101, forming a micro-coaxial structure and a sidewall surrounding the micro-coaxial structure on a substrate wafer, and fabricating a conductor column perpendicular to the substrate wafer on the micro-coaxial structure;

[0091] Step S102, flip-chipping the radio frequency chip onto the micro-coaxial structure and connecting it to the first port of the micro-coaxial structure;

[0092] Step S103: providing a cover wafer and a grounding device. The cover wafer is provided with a first through-silicon via, a second through-silicon via, a first signal port connected to the first through-silicon via, and a second signal port connected to the second through-silicon via. The first signal port is used for signal transmission with the RF chip, and the second signal port is used for grounding the RF chip.

[0093] Step S104, bonding the substrate wafer and the cover wafer, wherein, during the bonding process, a grounding device is set between the cover wafer and the RF chip of the substrate wafer, so that the first silicon via is connected to the second port of the micro-coaxial structure through the conductor column, the first end of the grounding device is connected to the ground end of the RF chip, and the second end is connected to the second silicon via.

[0094] It should be noted that the specific implementation process of the above steps S101 to S104 can refer to the corresponding description in the RF module embodiment provided in the above first aspect, and will not be repeated here.

[0095] In an optional embodiment, the grounding device includes: a grounding channel and a grounding backplane that are interconnected, the grounding channel includes a first sub-channel, a second sub-channel, and a third sub-channel, the first sub-channel, the second sub-channel, and the third sub-channel are all located on the substrate wafer, the first sub-channel is connected to the second sub-channel, the second sub-channel is connected to the third sub-channel, the position of the third sub-channel corresponds to the position of the second through-silicon via on the cover wafer, and bonding the substrate wafer to the cover wafer includes: attaching the grounding device to the upper surface of the RF chip and the upper surface of the first sub-channel; bonding the substrate wafer to the cover wafer such that the third sub-channel is connected to the second through-silicon via. In an optional embodiment, the grounding device includes: a grounding channel and a grounding backplane that are interconnected, the grounding channel is provided on the lower surface of the cover wafer and is connected to the second through-silicon via, bonding the substrate wafer to the cover wafer also includes: attaching the grounding backplane to the lower surface of the grounding channel; bonding the substrate wafer to the cover wafer such that the grounding backplane is connected to the RF chip.

[0096] An embodiment of the present invention provides a method for manufacturing a new type of RF module, the implementation principle and technical effects of which are the same as those of the embodiment of the RF module described in the first aspect above. For the sake of brief description, for matters not mentioned in the method embodiment, reference can be made to the corresponding content in the aforementioned RF module embodiment.

[0097] In a third aspect, based on the same inventive concept, this embodiment provides an electronic device comprising the radio frequency module described in the first aspect. For example, the electronic device may be a mobile phone, a watch, etc. equipped with the radio frequency module.

[0098] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0099] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A new radio frequency module, characterized in that: include: substrate wafer; A micro-coaxial structure is located on the substrate wafer; A sidewall is located on the substrate wafer and is arranged around the micro-coaxial structure; A radio frequency chip is flip-mounted on the micro-coaxial structure, and a signal end of the radio frequency chip is connected to the first port of the micro-coaxial structure; a cover wafer bonded to the substrate wafer, wherein the cover wafer is provided with a first through-silicon via and a second through-silicon via, and a first signal port connected to the first through-silicon via and a second signal port connected to the second through-silicon via, wherein the first signal port is used for signal transmission with the RF chip and RF signal excitation is performed on the RF chip through the first signal port, the second signal port is used for grounding the RF chip, and the first through-silicon via is connected to the second port of the micro-coaxial structure through a conductor post; a grounding device, located between the RF chip and the cover wafer, with a first end of the grounding device connected to the ground terminal of the RF chip and a second end connected to the second through-silicon via; Among them, a third through-silicon via surrounding the first through-silicon via is also provided on the cover wafer. The position of the third through-silicon via on the cover wafer corresponds to the outer conductor part of the micro-coaxial structure. The third through-silicon via is connected to the outer conductor of the micro-coaxial structure for grounding the micro-coaxial structure.

2. The radio frequency module according to claim 1, wherein: The grounding device includes a grounding channel and a grounding backplane connected to each other, the grounding backplane is connected to the radio frequency chip, and the grounding channel is connected to the second through-silicon via.

3. The radio frequency module according to claim 2, wherein: The ground backplane is attached to the back of the radio frequency chip; The ground channel includes a first sub-channel, a second sub-channel and a third sub-channel arranged on the substrate wafer. The first sub-channel, the second sub-channel and the third sub-channel are all located on the substrate wafer. The first sub-channel is connected to the second sub-channel, the second sub-channel is connected to the third sub-channel, the ground backplane is connected to the first sub-channel, and the third sub-channel is connected to the second through-silicon via.

4. The radio frequency module according to claim 2, wherein: The grounding backplane is attached to the lower surface of the cover wafer through the grounding channel, and the grounding channel is connected to the second through-silicon via.

5. The radio frequency module according to claim 2, wherein: The grounding backplane is a panel with one end being wider and the other end being narrower.

6. The radio frequency module according to claim 2, wherein: The grounding backplane is a panel that is wide in the middle and narrow at both ends.

7. A method for manufacturing a new radio frequency module, characterized in that: include: forming a micro-coaxial structure and a sidewall surrounding the micro-coaxial structure on a substrate wafer, and fabricating a conductor column perpendicular to the substrate wafer on the micro-coaxial structure; Flip-mounting a radio frequency chip on the micro-coaxial structure and connecting the chip to the first port of the micro-coaxial structure; A cover wafer and a grounding device are provided. The cover wafer is provided with a first through-silicon via, a second through-silicon via, and a first signal port connected to the first through-silicon via, and a second signal port connected to the second through-silicon via. The first signal port is used to transmit signals to the RF chip and to excite the RF chip with a RF signal through the first signal port. The second signal port is used to ground the RF chip. Bonding the substrate wafer to the cover wafer, wherein during the bonding process, the grounding device is disposed between the cover wafer and the RF chip of the substrate wafer, so that the first through-silicon via is connected to the second port of the micro-coaxial structure through the conductor post, and the first end of the grounding device is connected to the ground terminal of the RF chip, and the second end is connected to the second through-silicon via; Among them, a third through-silicon via surrounding the first through-silicon via is also provided on the cover wafer. The position of the third through-silicon via on the cover wafer corresponds to the outer conductor part of the micro-coaxial structure. The third through-silicon via is connected to the outer conductor of the micro-coaxial structure for grounding the micro-coaxial structure.

8. The method according to claim 7, wherein The grounding device includes: a grounding channel and a grounding backplane connected to each other, the grounding channel includes a first sub-channel, a second sub-channel, and a third sub-channel, the first sub-channel, the second sub-channel, and the third sub-channel are all located on the substrate wafer, the first sub-channel is connected to the second sub-channel, the second sub-channel is connected to the third sub-channel, and the position of the third sub-channel corresponds to the position of the second through-silicon via on the cover wafer, and bonding the substrate wafer to the cover wafer includes: Attaching the ground backplane to the upper surface of the RF chip and the upper surface of the first sub-channel; The substrate wafer is bonded to the cover wafer so that the third sub-channel is connected to the second through silicon via.

9. The method according to claim 7, wherein: The grounding device includes: a grounding channel and a grounding backplane connected to each other, the grounding channel is provided on the lower surface of the cover wafer and connected to the second through-silicon via, and the bonding of the substrate wafer and the cover wafer further includes: Attaching the grounding back plate to the lower surface of the grounding channel; The substrate wafer is bonded to the cover wafer so that the ground backplane is connected to the radio frequency chip.

10. An electronic device, characterized in that: The method comprises the radio frequency module according to any one of claims 1 to 6.

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