FPC stack structure, antenna FPC structure and manufacturing method therefor, and electronic device

Abstract

The present application discloses an FPC stack structure, an antenna FPC structure and a manufacturing method therefor, and an electronic device. The FPC stack structure comprises: a metal layer, a first covering layer, and a second covering layer. The first covering layer is located on a first surface of the metal layer. The first covering layer comprises a first through hole. The second covering layer is located on a second surface of the metal layer. The second covering layer comprises a second through hole. The part of the metal layer opposite to the first through hole and the second through hole is exposed to form a metal pad. The metal pad and a metal middle frame are directly welded together by means of an ultrasonic welding process, a resistance welding process, or a spot welding process so as to form the antenna FPC structure. In this way, a commonly used spring contact can be omitted to avoid problems such as misalignment, lifting-induced false soldering, and PSA adhesive detachment caused by the original spring contact, thereby ensuring an antenna function of the electronic device and reducing costs. In addition, omitting the spring contact can reduce the number of interfaces through which a signal passes during transmission to achieve insertion loss gain, and can reduce the space occupied by the electronic device in the x‑axis direction.

Description

An FPC stacked structure, an antenna FPC structure and its fabrication method, and electronic equipment.

[0001] This application claims priority to Chinese Patent Application No. 202510124898.1, filed on January 24, 2025, entitled "An FPC Stacked Structure, Antenna FPC Structure and Manufacturing Method Thereof, Electronic Device", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of terminal equipment technology, and in particular to an FPC stacked structure, an antenna FPC structure and its manufacturing method, and electronic equipment. Background Technology

[0003] With the trend towards thinner and lighter electronic devices, flexible printed circuit boards (FPCs) are commonly used to implement antenna functions by soldering a mid-frame with spring contacts. The mid-frame serves as either the antenna's feed or ground. However, because existing FPCs contain a PI layer, which cannot be directly soldered to the mid-frame, spring contacts are required on both sides of the FPC.

[0004] However, in order to weld to the mid-frame, the springs need to extend beyond the shape of the FPC, which means that the center of gravity of the springs is not entirely within the shape of the FPC. This can cause problems such as misalignment, warping, and poor soldering of the springs during the welding process, affecting the antenna function. Summary of the Invention

[0005] This application provides an FPC stacked structure, an antenna FPC structure and its manufacturing method, and an electronic device to solve the problem that the springs in existing antenna FPCs are prone to misalignment, warping, and poor soldering during the welding process, which affects the antenna function.

[0006] In a first aspect, this application provides an FPC stack structure, comprising: a metal layer, a first cover layer, and a second cover layer. The metal layer includes a first surface and a second surface facing away from each other; the first cover layer is located on the first surface of the metal layer and includes a first through-hole; the second cover layer is located on the second surface of the metal layer and includes a second through-hole, with the first through-hole and the second through-hole opposite to each other; the portion of the metal layer opposite to the first and second through-holes is exposed to form a metal pad, which is used for soldering to the metal frame of an electronic device.

[0007] The FPC stacked structure provided in this application exposes the metal layer by creating windows in the first and second cover layers, forming metal pads. During subsequent soldering to the metal frame, the metal pads of the metal layer can be directly soldered to the metal frame. This eliminates the need for the spring contacts commonly used for soldering the FPC stacked structure to the metal frame, avoiding problems such as misalignment, warping, poor soldering, and PSA adhesive detachment caused by the original spring contacts. This ensures the antenna function of the electronic device is achieved while simultaneously reducing costs. Furthermore, eliminating the spring contacts not only reduces the number of interfaces through which signal transmission passes, thus improving insertion loss, but also reduces the space occupied by the electronic device in the x-axis direction.

[0008] In some implementations, the second cover layer further includes a third via, which is spaced apart from the second via; the metal layer also includes a metal etched area, which is opposite to and connected to the third via; the size of the third via is larger than the size of the metal etched area. This facilitates the subsequent soldering of components at the metal etched area to achieve antenna functionality.

[0009] In some implementations, the FPC stack structure includes: a first welding area, a second welding area, and a bending area, with the bending area located between the first and second welding areas; one metal pad of the metal layer is located in the first welding area, and the other metal pad and a metal etching area are located in the second welding area; the bending area is bendable so that different metal pads of the metal layer are located on different planes. In this way, the body of the FPC stack structure is bendable and can be applied to welding on different frame surfaces to achieve three-dimensional welding of the FPC stack structure, making it suitable for various scenarios.

[0010] In some implementations, the region of the metal layer opposite the bending area includes a metal comb-shaped line structure; one end of the metal comb-shaped line structure is connected to a metal pad located in the first soldering area, and the other end is connected to the edge of a metal etched area located in the second soldering area. In this way, the metal comb-shaped line structure not only enables bending of the FPC stack structure but also prevents the metal layer from breaking during bending, thus improving reliability.

[0011] In some implementations, the FPC stack structure also includes rounded corner structures formed in the first and second cover layers; the rounded corner structures are located in the bending region and recessed towards the metal comb-shaped line structure. Thus, providing rounded corner structures in the bending region facilitates the bending of the FPC stack structure.

[0012] In some implementations, the rounded corner structure includes a metal protective edge extending to the edge of the bending area at both ends. This metal protective edge covers the edge of the rounded corner structure, preventing the FPC laminate from tearing at the rounded corners during bending.

[0013] In some implementations, a reinforcing component is also included; the reinforcing component is located on the surface of the first cover layer away from the metal layer, and the reinforcing component is opposite to the metal etched area. In this way, the reinforcing component can be used to increase the strength of the FPC stack structure at the metal etched area, preventing breakage.

[0014] In some implementations, the edge of the first through-hole is at a first distance from the edge of the first cover layer; the edge of the second through-hole is at a second distance from the edge of the second cover layer; both the first and second distances are greater than or equal to 0.5 mm. This ensures that the edge widths of the first and second cover layers are at least 0.5 mm wide, guaranteeing the inherent strength of both layers.

[0015] In some implementations, the first cover layer includes a first protective film and a first adhesive layer. The first protective film is bonded to the first surface of the metal layer via the first adhesive layer, and a first through-hole penetrates both the first protective film and the first adhesive layer. The second cover layer includes a second protective film and a second adhesive layer. The second protective film is bonded to the second surface of the metal layer via the second adhesive layer, and a second through-hole penetrates both the second protective film and the second adhesive layer. This allows for a windowing process to be applied to both the first and second cover layers to expose the metal layer itself.

[0016] Secondly, this application provides an FPC stack structure, including: a metal layer, a first cover layer, and a second cover layer. The metal layer includes a first surface and a second surface facing away from each other; the first cover layer is located on the first surface of the metal layer and covers the central region of the metal layer; the second cover layer is located on the second surface of the metal layer and covers the central region of the metal layer; the edge regions of the metal layer not covered by the first cover layer and the second cover layer are exposed to form metal pads, which are used for soldering to the metal frame of an electronic device.

[0017] The FPC stacked structure provided in this application exposes the metal layer by creating windows in the first and second cover layers, forming metal pads. During subsequent soldering to the metal frame, the metal pads of the metal layer can be directly soldered to the metal frame. This eliminates the need for the spring contacts commonly used for soldering the FPC stacked structure to the metal frame, avoiding problems such as misalignment, warping, poor soldering, and PSA adhesive detachment caused by the original spring contacts. This ensures the antenna function of the electronic device is achieved while simultaneously reducing costs. Furthermore, eliminating the spring contacts not only reduces the number of interfaces through which signal transmission passes, thus improving insertion loss, but also reduces the space occupied by the electronic device in the x-axis direction.

[0018] Thirdly, this application provides an antenna FPC structure, including: a device, a metal frame, and an FPC stacked structure provided in the first or second aspect; the device is located in the third via region of the second cover layer, and the device is soldered to the second surface of the metal layer; the metal frame is located on one side of the FPC stacked structure, and the metal pads of the metal layer are soldered to the metal frame.

[0019] The antenna FPC structure provided in this application embodiment can hollow out the cover layer of the FPC stacked structure to expose the bottom metal layer, forming a metal pad. During soldering, the metal pad is directly soldered to the metal frame using ultrasonic welding, spot welding, or resistance welding. This eliminates the need for commonly used spring contacts, avoiding problems such as misalignment, warping, poor soldering, and PSA adhesive detachment caused by the original spring contacts, ensuring the antenna function of the electronic device and simultaneously reducing costs. Furthermore, eliminating the spring contacts not only reduces the number of interfaces through which signal transmission passes, achieving insertion loss benefits, but also reduces the space occupied by the electronic device in the x-axis direction.

[0020] In some implementations, the metal frame includes bosses; the bosses correspond to metal pads on the metal layer, and the metal pads are soldered to the bosses. This facilitates the use of spot welding to solder the metal pads to the bosses of the metal frame.

[0021] In some implementations, the metal frame is located on the side of the FPC stack structure where the components are located; the surface of the metal frame facing the FPC stack structure includes grooves to avoid the components. This provides a method for directly soldering the FPC stack structure to the metal frame, suitable for various scenarios.

[0022] In some implementations, the metal frame is located on the side of the FPC stack structure that has the reinforcing component; the reinforcing component is bonded to the metal frame via a third adhesive layer. This provides another way to directly weld the FPC stack structure to the metal frame, suitable for different scenarios.

[0023] In some implementations, the metal pads of the metal layer are soldered to the same surface of the metal frame. This allows for planar welding of the metal frame and the FPC stack structure.

[0024] In some implementations, the metal frame includes a first welding surface and a second welding surface, with the extension directions of the first and second welding surfaces forming an angle. One metal pad of the metal layer is welded to the first welding surface of the metal frame, and the other metal pad is welded to the second welding surface of the metal frame. In this way, the different metal pads of the metal layer are located in different spaces, allowing the FPC laminate structure to be welded to different planes of the metal frame, achieving three-dimensional welding of the metal frame and the FPC laminate structure.

[0025] Fourthly, this application provides a method for fabricating an FPC stacked structure for fabricating the FPC stacked structure provided in the first aspect. The method includes: providing a metal layer, a first cover layer, and a second cover layer, wherein the first cover layer includes a first through-hole, and the second cover layer includes a second through-hole; pressing the first cover layer onto a first surface of the metal layer; and pressing the second cover layer onto a second surface of the metal layer, wherein the first through-hole and the second through-hole are opposite to each other, so that the portions of the metal layer opposite to the first and second through-holes are exposed to form metal pads, which are used for soldering to the metal frame of an electronic device.

[0026] The method for fabricating an FPC stacked structure provided in this application involves pressing a first cover layer and a second cover layer onto the upper and lower surfaces of a metal layer, respectively, to form a stacked structure with a double cover layer and a metal layer. By creating windows in the double cover layers, the metal layer's pad area is free of cover layers above and below, exposing the metal layer itself and facilitating direct soldering of the metal layer to the metal frame. This eliminates the need for commonly used spring contacts, avoiding problems such as misalignment, warping, poor soldering, and PSA adhesive detachment caused by traditional spring contacts, ensuring the antenna function of the electronic device and further reducing costs. Simultaneously, eliminating spring contacts reduces the number of interfaces through which signal transmission passes, achieving insertion loss gains, and reducing the space occupied by the electronic device in the x-axis direction.

[0027] In some implementations, after laminating the first cover layer onto the first surface of the metal layer, the method further includes etching a metal etched area on the metal layer, the metal etched area penetrating both the first and second surfaces of the metal layer. This facilitates subsequent soldering of devices at the metal etched area to achieve antenna functionality.

[0028] In some implementations, the method further includes: pressing a reinforcing member onto the surface of the first cover layer opposite to the metal layer, with the reinforcing member facing the metal etched area. This allows the reinforcing member to increase the strength of the FPC stack structure at the metal etched area, preventing breakage.

[0029] In some implementations, the method further includes surface treatment of the metal pads in the metal layer to remove surface impurities. This can improve the soldering effect.

[0030] Fifthly, this application provides a method for fabricating an FPC stacked structure for fabricating the FPC stacked structure provided in the second aspect. The method includes: providing a metal layer, a first cover layer, and a second cover layer; pressing the first cover layer onto a first surface of the metal layer, the first cover layer covering a central region of the metal layer; pressing the second cover layer onto a second surface of the metal layer, the second cover layer covering a central region of the metal layer, exposing edge regions of the metal layer not covered by the first and second cover layers to form metal pads, the metal pads being used for soldering to the metal frame of an electronic device.

[0031] The method for fabricating an FPC stacked structure provided in this application involves pressing a first cover layer and a second cover layer onto the upper and lower surfaces of a metal layer, respectively, to form a stacked structure with a double cover layer and a metal layer. By creating windows in the double cover layers, the metal layer's pad area is free of cover layers above and below, exposing the metal layer itself and facilitating direct soldering of the metal layer to the metal frame. This eliminates the need for commonly used spring contacts, avoiding problems such as misalignment, warping, poor soldering, and PSA adhesive detachment caused by traditional spring contacts, ensuring the antenna function of the electronic device and further reducing costs. Simultaneously, eliminating spring contacts reduces the number of interfaces through which signal transmission passes, achieving insertion loss gains, and reducing the space occupied by the electronic device in the x-axis direction.

[0032] In a sixth aspect, this application provides a method for fabricating an antenna FPC structure, used to fabricate the antenna FPC structure as provided in the third aspect. The method includes: fabricating an FPC stacked structure using a fabrication method for an FPC stacked structure as described in the fourth or fifth aspect; soldering a device to the second surface of the metal layer of the FPC stacked structure, wherein the device is located in the third via region of the second cover layer and covers the metal etched area; and using a soldering process to solder the metal pads of the metal layer to the metal frame.

[0033] The antenna FPC structure fabrication method provided in this application involves a metal frame located on one side of the FPC stacked structure. Ultrasonic welding, resistance welding, or spot welding are used to directly weld the metal pads of the FPC stacked structure to the metal frame. This eliminates the need for commonly used spring contacts, avoiding problems such as misalignment, warping, poor soldering, and PSA adhesive detachment associated with them. This ensures the antenna function of the electronic device is realized and simultaneously reduces costs. Furthermore, eliminating the spring contacts reduces the number of interfaces through which signal transmission passes, achieving insertion loss gains, and reducing the space occupied by the electronic device in the x-axis direction.

[0034] In some implementations, a welding process is used to weld the metal pads of the metal layer to the metal frame. This includes: placing the metal frame on one side of the FPC stack structure; and using ultrasonic welding, where pressure from the welding head and the action of high-frequency ultrasonic waves cause the metal pads to deform towards the metal frame and weld them to it. This provides a first method for directly welding the FPC stack structure to the metal frame, suitable for various scenarios.

[0035] In some implementations, the surface of the metal frame facing the FPC stack includes bosses; and a welding process is used to weld metal pads of the metal layer to the metal frame, including: setting the metal frame on one side of the FPC stack, with the bosses corresponding to the metal pads; and using a spot welding process to melt the contact area between the metal pads and the bosses to weld the metal pads to the bosses. This provides a second method for directly welding the FPC stack to the metal frame, suitable for different scenarios.

[0036] In some implementations, the method further includes placing a glass plate on the surface of the FPC laminate structure facing away from the metal frame during the spot welding process, so that the laser spot of the spot weld is focused at the contact point between the metal pads and the bosses. This can improve the welding effect.

[0037] In some implementations, a welding process is used to weld the metal pads of the metal layer to the metal frame. This includes: placing the metal frame on one side of the FPC stack structure; using resistance welding, placing the first and second electrodes required for the resistance welding process on the same side of the metal pads and the metal frame; applying pressure to the first and second electrodes to deform the metal pads towards the metal frame, so as to abut against the metal frame; and energizing the first and second electrodes to melt the contact area between the metal pads and the metal frame, thereby welding the metal pads to the metal frame. This provides a third method for directly welding the FPC stack structure to the metal frame, suitable for different scenarios.

[0038] In a seventh aspect, this application provides an electronic device including a display screen, a rear cover, and an antenna FPC structure as provided in the second aspect, wherein the display screen and the rear cover are located on opposite sides of the antenna FPC structure and are connected to a metal frame.

[0039] The electronic device provided in this application embodiment can directly weld the metal layer in the FPC stacked structure to the metal frame when implementing the antenna function. This eliminates the need for commonly used spring contacts, avoiding problems such as misalignment, warping, poor soldering, and PSA adhesive detachment caused by the original spring contacts, ensuring the antenna function of the electronic device and simultaneously reducing costs. Furthermore, eliminating the spring contacts reduces the number of interfaces through which signal transmission passes, achieving insertion loss gains, and reducing the space occupied by the electronic device in the x-axis direction. Attached Figure Description

[0040] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 is a schematic diagram of the structure of the electronic device provided in an embodiment of this application;

[0042] Figure 2 is a schematic diagram of an FPC structure;

[0043] Figure 3 is a flowchart of the manufacturing process of an FPC;

[0044] Figure 4 is a schematic diagram of an FPC and an inductor;

[0045] Figure 5 is a schematic diagram of an antenna FPC assembly;

[0046] Figure 6 is a schematic diagram of the stacked structure of an antenna FPC assembly;

[0047] Figure 7 is a schematic diagram of a scenario where a reed malfunctions;

[0048] Figure 8 is a schematic diagram of the first structure of the FPC stacked structure provided in the embodiment of this application;

[0049] Figure 9 is a top view of the first FPC stacked structure provided in the embodiment of this application;

[0050] Figure 10 is a second top view of the FPC stacked structure provided in an embodiment of this application;

[0051] Figure 11 is a flowchart of the method for fabricating the FPC stacked structure provided in the embodiment of this application;

[0052] Figure 12 is the first process flow diagram of the manufacturing method of the FPC stacked structure provided in the embodiment of this application;

[0053] Figure 13 is a second structural schematic diagram of the FPC stacked structure provided in an embodiment of this application;

[0054] Figure 14 is a third top view of the FPC stacked structure provided in the embodiment of this application;

[0055] Figure 15 is a second process flow diagram of the manufacturing method of the FPC stacked structure provided in the embodiment of this application;

[0056] Figure 16 is a first structural schematic diagram of the antenna FPC structure provided in the embodiment of this application;

[0057] Figure 17 is a schematic diagram of the FPC stacked structure and device provided in the embodiments of this application;

[0058] Figure 18 is a flowchart of the method for manufacturing the antenna FPC structure provided in the embodiment of this application;

[0059] Figure 19 is a first process flow diagram of the method for manufacturing the antenna FPC structure provided in the embodiment of this application;

[0060] Figure 20 is a second structural schematic diagram of the antenna FPC structure provided in an embodiment of this application;

[0061] Figure 21 is a second process flow diagram of the method for manufacturing the antenna FPC structure provided in the embodiment of this application;

[0062] Figure 22 is the third process flow diagram of the method for manufacturing the antenna FPC structure provided in the embodiment of this application;

[0063] Figure 23 is a schematic diagram of the processing principle of the resistance welding process provided in the embodiments of this application;

[0064] Figure 24 is the fourth process flow diagram of the method for manufacturing the antenna FPC structure provided in the embodiment of this application;

[0065] Figure 25 is a third structural schematic diagram of the antenna FPC structure provided in the embodiment of this application;

[0066] Figure 26 is the fifth process flow diagram of the method for manufacturing the antenna FPC structure provided in the embodiment of this application;

[0067] Figure 27 is a fourth structural schematic diagram of the antenna FPC structure provided in the embodiments of this application;

[0068] Figure 28 is the sixth process flow diagram of the method for manufacturing the antenna FPC structure provided in the embodiment of this application;

[0069] Figure 29 is a fifth structural schematic diagram of the antenna FPC structure provided in the embodiments of this application;

[0070] Figure 30 is a schematic diagram of the first welded structure of the metal frame and FPC stacked structure provided in the embodiment of this application;

[0071] Figure 31 is a schematic diagram of the second welded structure of the metal frame and FPC stacked structure provided in the embodiment of this application;

[0072] Figure 32 is a schematic diagram of the third welded structure of the metal frame and FPC stacked structure provided in the embodiment of this application.

[0073] Illustration:

[0074] Among them, 10-display screen, 20-middle frame, 21-middle plate, 22-middle frame sidewall, 30-FPC, 31-PI layer, 32-copper layer, 321-etched fracture area, 33-CVL layer, 331-protective film layer, 332-adhesive layer, 333-opening, 34-alloy layer, 40-reinforcing sheet, 51-L-shaped spring, 511-PSA backing adhesive, 52-planar spring, 53-solder paste, 60-inductor;

[0075] 100 - Metal layer, 101 - First surface, 102 - Second surface, 103 - Metal pad, 104 - Metal etched area, 105 - Metal comb line structure;

[0076] 200 - First covering layer, 201 - First through hole, 202 - First protective film, 203 - First adhesive layer;

[0077] 300 - Second cover layer, 301 - Second through hole, 302 - Third through hole, 303 - Second protective film, 304 - Second adhesive layer;

[0078] 400 - Reinforcing component;

[0079] 501 - First welding zone, 502 - Second welding zone, 503 - Bending zone, 504 - Rounded corner structure, 505 - Metal protective edge;

[0080] 600-devices;

[0081] 700-Metal frame, 701-Boss, 702-Groove, 703-Third adhesive layer, 700a-First welding surface, 700b-Second welding surface;

[0082] 801a - Ultrasonic welding process, 8021 - Electrode, 8022 - Welded part, 8023 - First electrode, 8024 - Second electrode, 803a - Spot welding process, 804 - Glass sheet. Detailed Implementation

[0083] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are all within the protection scope of this application.

[0084] In the description of this application, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0085] Furthermore, in this application, directional terms such as "upper" and "lower" are defined relative to the indicated placement of the components in the accompanying drawings. It should be understood that these directional terms are relative concepts, used for relative description and clarification, and can change accordingly depending on the placement of the components in the accompanying drawings.

[0086] The following explanations of the technical terms mentioned in the embodiments of this application are provided to facilitate understanding by those skilled in the art.

[0087] Flexible printed circuit boards (FPCs) are highly reliable and extremely flexible printed circuit boards made with polyimide or polyester film as the substrate. FPCs are lightweight, thin, flexible, and adaptable, and are widely used in electronic product manufacturing.

[0088] Flexible copper clad laminate (FCCL) refers to a copper-clad laminate formed by bonding copper foil to one or both sides of a flexible insulating material such as polyester film or polyimide (PI) film through a specific process. FCCL is the substrate material for FPC (Flexible Printed Circuit) and consists of a flexible insulating base film and metal foil.

[0089] Cover Layer (CVL) is the coating layer in FPC. Its main function is to protect the FPC surface from external corrosion, enhance its wear resistance and stain resistance, improve its electrical performance and mechanical strength, thereby increasing the reliability and service life of the FPC.

[0090] Pressure-sensitive adhesive (PSA) is a self-adhesive substance that can form a relatively strong bond under relatively small force. PSA is a type of adhesive that can bond tightly to the substrate with only light finger pressure without the need for solvents, heat or other means.

[0091] Surface Mount Technology (SMT), also known as surface mount technology, is a circuit assembly technology that mounts leadless or short-lead surface mount components onto the surface of an FPC or other substrate, and then assembles them using methods such as reflow soldering or dip soldering.

[0092] Organic solderability preservative (OSP) is an organic coating used to prevent copper from oxidizing before soldering, thus protecting the solderability of FPC pads. The OSP process is a surface treatment method that involves growing an organic film on the bare copper surface to protect it from oxidation and corrosion. Controlling the thickness of this organic film is crucial, as it directly affects soldering performance. If the organic film is too thin, solder strength and heat resistance may be insufficient; conversely, if the organic film is too thick, flux will have difficulty fusing with it, also impacting soldering performance.

[0093] Electroless Nickel / Immersion Gold (ENIG), also known as electroless nickel gold, is produced by chemically displacing palladium on the surface of copper, then chemically plating a nickel-phosphorus alloy layer onto the palladium core, and finally plating a layer of gold onto the nickel surface through a displacement reaction. Electroless Nickel / Immersion Gold is primarily used for surface treatment of circuit boards to prevent oxidation or corrosion of the copper surface, and it is also used for soldering and in contact applications (such as buttons and gold fingers on memory modules).

[0094] The electronic devices described in this application include, but are not limited to, mobile phones, laptops, tablets, personal digital assistants, or wearable devices. The following description uses a mobile phone as an example.

[0095] Figure 1 is a schematic diagram of the structure of the electronic device provided in an embodiment of this application.

[0096] As shown in Figure 1, the electronic device may include a display screen 10, a mid-frame 20, and a rear cover. The display screen 10 and the rear cover are located on opposite sides of the mid-frame 20, and the display screen 10, mid-frame 20, and rear cover are sequentially fastened together to form a complete device cavity. The complete device cavity includes components such as a communication module, circuit board, battery, speaker assembly, and camera assembly, which are not listed here.

[0097] To facilitate the explanation of the positions of various components in the electronic device, this application embodiment exemplarily establishes a three-dimensional coordinate system based on the electronic device, wherein the x-axis direction is the width direction of the electronic device, the y-axis direction is the length direction of the electronic device, and the z-axis direction is the thickness direction of the electronic device.

[0098] Electronic devices incorporate antenna modules to transmit and receive radio frequency (RF) signals. As user demands increase, the number of antenna modules integrated into electronic devices is growing, enabling them to possess excellent RF signal transmission and reception capabilities. Typically, electronic devices utilize a metal area on their casing (such as a metal frame) as the antenna radiator.

[0099] With the trend towards thinner and lighter electronic devices, a design using FPC with spring-loaded contacts to weld the mid-frame 20 is commonly used instead of the more common PCB with spring-loaded contacts to the mid-frame. The antenna module is formed using FPC with spring-loaded contacts to weld the mid-frame 20, which serves as the antenna's receiver feed or ground. This allows for both antenna functionality and increased battery capacity or a narrower device width.

[0100] Figure 2 is a schematic diagram of an FPC structure.

[0101] As shown in Figure 2, the FPC 30 includes a PI layer 31, a copper layer 32, and a CVL layer 33, with the PI layer 31 and CVL layer 33 disposed on two opposite surfaces of the copper layer 32. The CVL layer 33 includes a protective film layer 331 and an adhesive layer 332, with the protective film layer 331 bonded to the surface of the copper layer 32 via the adhesive layer 332.

[0102] Figure 3 is a flowchart of the manufacturing process of an FPC.

[0103] As shown in Figure 3(a), during the fabrication of FPC 30, the PI layer 31 and the copper layer 32 are bonded together to form a single-sided FCCL, with the PI layer 31 supporting the copper layer 32. Furthermore, an etched fracture region 321 is etched onto the copper layer 32.

[0104] As shown in Figure 3(b), a window 333 is first created on the CVL layer 33, and then the CVL layer 33 is laminated onto the surface of the copper layer 32 that is opposite to the PI layer 31. The opening 333 is used for subsequent soldering.

[0105] As shown in Figure 3(c), the exposed copper layer 32 is subjected to chemical nickel-gold treatment to form an alloy layer 34 on the surface of the exposed copper layer 32. This surface treatment is used to prevent the copper layer 32 from being oxidized or corroded.

[0106] As shown in Figure 3(d), a reinforcing sheet 40 is attached to the surface of the PI layer 31 facing away from the copper layer 32 to improve the strength of the FPC 30 at the fracture 321.

[0107] Because FPC 30 adopts a single-sided FCCL structure, it contains a PI layer 31. Due to the material properties of the PI layer 31, its surface cannot be welded or hollowed out. Therefore, FPC 30 cannot be directly welded to the middle frame 20; a spring is needed to achieve the welding between FPC 30 and the middle frame 20.

[0108] Figure 4 is a schematic diagram of an FPC and an inductor; Figure 5 is a schematic diagram of an antenna FPC assembly.

[0109] As shown in Figures 4 and 5, the antenna FPC assembly includes FPC 30, spring, inductor 60 and middle frame 20.

[0110] The spring includes an L-shaped spring 51 and a flat spring 52, which are located on both sides of the FPC 30. The L-shaped spring 51 is used to connect the FPC 30 to different spatial surfaces of the middle frame 20, and the flat spring 52 is used to connect the FPC 30 to the same spatial surface of the middle frame 20.

[0111] Inductor 60 is soldered onto FPC 30 for tuning to enable the antenna function of the antenna FPC assembly.

[0112] The middle frame 20 includes a middle plate 21 and a middle frame sidewall 22 surrounding the edge of the middle plate 21. The middle plate 21 and the middle frame sidewall 22 are perpendicular to each other and are both made of plastic and metal materials.

[0113] Figure 6 is a schematic diagram of the stacked structure of an antenna FPC assembly.

[0114] As shown in Figures 4, 5, and 6, one end of the L-shaped spring 51 is soldered to one end of the FPC 30 via an SMT process. The solder paste 53 required for SMT soldering is located inside one of the openings 333 of the CVL layer 33. Furthermore, this end of the L-shaped spring 51 is also bonded to the side wall 22 of the middle frame 20 via PSA adhesive 511. The other end of the L-shaped spring 51 extends to the outside of the FPC 30 in a bent state and is soldered to the metal part of the middle plate 21 via a spot soldering process.

[0115] One end of the planar spring 52 is soldered to the other end of the FPC 30 via an SMT process. The solder paste 53 required for SMT soldering is located in another opening 333 of the CVL layer 33. The other end of the planar spring 52 extends to the outside of the FPC 30 and is soldered to the metal part of the middle frame sidewall 22 via a spot soldering process.

[0116] Inductor 60 covers the break 321 of copper layer 32 and is soldered to the copper layer 32 at the edge of break 321. In the structure of the antenna FPC assembly, inductor 60 can face the side of the middle frame 20 (as shown in Figure 5) or face away from the middle frame 20 (this state is not shown in the figure).

[0117] As can be seen, the commonly used FPC 30 adopts a stacked structure of single-sided FCCL and CVL layer 33. The FCCL is used to etch patterns, the CVL layer 33 is laminated, and the solder paste 53 is used to solder springs (L-shaped springs 51 and flat springs 52) using SMT process. The springs are then spot-welded to the middle frame 20 to complete the interconnection between the FPC 30 and the middle frame 20.

[0118] However, both the L-shaped spring 51 and the flat spring 52 need to extend beyond the outer side of the FPC 30 in order to spot weld with the metal part of the middle frame 20. This causes the center of gravity of the springs (L-shaped spring 51 and flat spring 52) to be not entirely within the projected area of ​​the FPC 30, resulting in a high proportion of misalignment, lifting, cold solder joints, and PSA adhesive 511 falling off during the SMT soldering process.

[0119] Figure 7 is a schematic diagram of a scenario where the reed malfunctions.

[0120] Taking the planar spring 52 as an example, as shown in Figure 7(a), the planar spring 52 exhibits warping and poor soldering, separating from the FPC 30. As shown in Figure 7(b), the planar spring 52 is misaligned, with its relative position offset from the FPC 30. Furthermore, the PSA adhesive 511 detaches from the surface of the L-shaped spring 51.

[0121] In the structure of the antenna FPC, springs are used to interconnect the FPC 30 and the middle frame 20. During the SMT soldering process, the springs are prone to problems such as misalignment, warping, poor soldering, and PSA backing adhesive 511 falling off. This not only affects the realization of the antenna function of the electronic device, but also leads to production difficulties, increased material loss, and increased costs.

[0122] To address the aforementioned technical issues, this application provides an FPC stacked structure and an antenna FPC structure. This eliminates the spring contacts commonly found in antenna FPCs, and instead uses spot welding, ultrasonic welding, or resistance welding directly between the copper layer of the FPC body and the mid-frame. This avoids problems such as misalignment, warping, and poor soldering caused by spring contact designs, ensuring the antenna function of the electronic device and further reducing costs.

[0123] Figure 8 is a first structural schematic diagram of the FPC stack structure provided in the embodiment of this application; Figure 9 is a first top view schematic diagram of the FPC stack structure provided in the embodiment of this application. The dotted lines in Figure 9 indicate the positions of the subsequent soldered components 600.

[0124] As shown in Figures 8 and 9, in some embodiments, the FPC stack structure provided in this application may include: a metal layer 100, a first cover layer 200, and a second cover layer 300.

[0125] The metal layer 100 includes a first surface 101 and a second surface 102 that are opposite to each other along the x-axis. The metal layer 100 can be a copper layer, for example, rolled copper foil. Exemplarily, the thickness of the metal layer 100 along the x-axis is greater than or equal to 35 micrometers, such as 35 micrometers, 50 micrometers, or 70 micrometers. This avoids the metal layer 100 being too thin and cracking during soldering, thus preventing reliability risks.

[0126] The metal layer 100 includes a metal etched area 104 that penetrates the first surface 101 and the second surface 102. The metal etched area 104 facilitates the fabrication of circuitry during subsequent soldering of the device 600. The device 600 can be soldered using an SMT (Surface Mount Technology) process.

[0127] The first cover layer 200 is located on the first surface 101 of the metal layer 100. The first cover layer 200 includes a first through hole 201, which penetrates the upper and lower surfaces of the first cover layer 200. The number of first through holes 201 can be one or more, and the number of first through holes 201 is not limited in this embodiment. When there are multiple first through holes 201, the multiple first through holes 201 are spaced apart and have a certain distance from the metal etching area 104.

[0128] The edge of the first through-hole 201 and the edge of the first cover layer 200 are at a first distance L1; the first distance L1 is greater than or equal to 0.5 mm. The first through-hole 201 is used for subsequent welding to the metal frame, and the distance between the welding pad and the edge of the first cover layer 200 is greater than or equal to 0.5 mm. This can also be understood as the edge width of the first cover layer 200 being at least 0.5 mm reserved to ensure the strength of the metal layer 100 itself. Here, the metal frame refers to the metal portion of the frame 20.

[0129] In other embodiments, the edge of the first cover layer 200 is not reserved in width, so that the first through hole 201 opens to the edge of the first cover layer 200, allowing the metal pad 103 to be better soldered to the metal frame and avoiding the risk of pad breakage. It should be noted that the specific details of this embodiment can be found in the following content, and will not be repeated here.

[0130] For example, the first cover layer 200 can be a conventional CVL. The first cover layer 200 may include a first protective film 202 and a first adhesive layer 203. The first protective film 202 is bonded to the first surface 101 of the metal layer 100 through the first adhesive layer 203. A first through hole 201 is formed in the first cover layer 200 by punching with a mold or laser engraving. The first through hole 201 penetrates the first protective film 202 and the first adhesive layer 203. The first adhesive layer 203 may be an adhesive layer that provides double-sided adhesion; this is not limited here.

[0131] In other embodiments, the first cover layer 200 may also be made of photosensitive ink (including photosensitive PI ink, LPI), where LPI refers to ordinary photosensitive circuit ink. The photosensitive ink is screen-printed onto the metal layer 100, and then exposed and developed to create windows, forming the first through-hole 201.

[0132] The second cover layer 300 is located on the second surface 102 of the metal layer 100. The second cover layer 300 includes a third through hole 302 and a second through hole 301 spaced apart, both of which penetrate the upper and lower surfaces of the first cover layer 200. The number of second through holes 301 can be one or more; the number of second through holes 301 is not limited in this embodiment. When there are multiple second through holes 301, the multiple second through holes 301 are spaced apart and have a certain distance from the metal etching area 104.

[0133] For example, the second cover layer 300 can be a conventional CVL. The second cover layer 300 may include a second protective film 303 and a second adhesive layer 304. The second protective film 303 is bonded to the second surface 102 of the metal layer 100 through the second adhesive layer 304. The second cover layer 300 is punched with a mold or laser-cut to form a second through hole 301 and a third through hole 302, both of which penetrate the second protective film 303 and the second adhesive layer 304. The second adhesive layer 304 may be an adhesive layer that provides double-sided adhesion; this is not limited here.

[0134] In other embodiments, the second cover layer 300 may also be made of photosensitive ink (including photosensitive PI ink, LPI). The photosensitive ink is screen-printed onto the metal layer 100, and then exposed and developed to create windows, forming the second through-hole 301 and the third through-hole 302.

[0135] The metal etched area 104 is opposite to and connected to the third through hole 302; the size of the third through hole 302 is larger than the size of the metal etched area 104. The third through hole 302 is used to accommodate a device so that the device 600 can cover or span the metal etched area 104 and be soldered to the metal layer 100.

[0136] In some embodiments, the FPC stack structure may further include a reinforcing member 400; the reinforcing member 400 is located on the surface of the first cover layer 200 opposite to the metal layer 100. The reinforcing member 400 is opposite to the metal etched area 104, and the size of the reinforcing member 400 is larger than the size of the metal etched area 104. In this way, the reinforcing member 400 can be used to increase the strength of the FPC stack structure at the metal etched area 104, preventing breakage.

[0137] The edge of the second through-hole 301 and the edge of the second cover layer 300 are at a second distance L2; the second distance L2 is greater than or equal to 0.5mm, and the first distance L1 and the second distance L2 may be equal or unequal. The second through-hole 301 is used for subsequent welding to the metal frame, and the distance between the welding pad and the edge of the second cover layer 300 is greater than or equal to 0.5mm. This can also be understood as the edge width of the second cover layer 300 being at least 0.5mm reserved to ensure the strength of the metal layer 100 itself.

[0138] In other embodiments, the edge of the second cover layer 300 is not reserved in width, so that the second through hole 301 opens to the edge of the second cover layer 300, allowing the metal pad 103 to be better soldered to the metal frame and avoiding the risk of pad breakage. It should be noted that the specific details of this embodiment can be found in the following content, and will not be repeated here.

[0139] The number of second through-holes 301 and first through-holes 201 is the same. The first through-holes 201 and second through-holes 301 correspond one-to-one along the x-axis and are positioned relative to each other during subsequent welding to the metal frame. This exposes portions of the metal layer 100 opposite to the first through-holes 201 and second through-holes 301, forming metal pads 103 for welding to the metal frame of the electronic device. For example, the number of metal pads 103 is the same as the number of first through-holes 201 and second through-holes 301.

[0140] The FPC stacked structure provided in this application exposes the metal layer 100 by creating windows in the first cover layer 200 and the second cover layer 300, forming metal pads 103. During subsequent soldering to the metal frame, the metal pads 103 of the metal layer 100 can be directly soldered to the metal frame. This eliminates the need for the spring contacts commonly used for soldering the FPC stacked structure to the metal frame, avoiding problems such as misalignment, warping, poor soldering, and PSA adhesive 511 detachment caused by the original spring contacts. This ensures the antenna function of the electronic device is realized and simultaneously reduces costs. Furthermore, eliminating the spring contacts not only reduces the number of interfaces through which signal transmission passes, achieving insertion loss benefits, but also reduces the space occupied by the electronic device in the x-axis direction.

[0141] Figure 10 is a second top view of the FPC stack structure provided in an embodiment of this application. In Figure 10, the dotted lines indicate the positions of the subsequent soldered components 600, and the dashed lines indicate the structure of the metal layer 100 located below the second cover layer 300.

[0142] As shown in Figure 10, in some embodiments, depending on the function being implemented, the FPC stack structure may include a soldering area and a bending area 503, with the number of soldering areas being the same as the number of metal pads 103. Taking an FPC stack structure including two metal pads 103 as an example, the soldering area includes a first soldering area 501 and a second soldering area 502. For example, the bending area 503 may be located between the first soldering area 501 and the second soldering area 502.

[0143] One of the metal pads 103 of the metal layer 100 is located in the first soldering area 501, and the other metal pad 103 and the metal etching area 104 are located in the second soldering area 502. The bending area 503 is bendable with a bending radius ≥ 5T, where T represents the thickness of the FPC stack-up structure along the x-axis.

[0144] The bending area 503 can be used to bend the body of the FPC stack structure, thereby changing the relative position of the first welding area 501 and the second welding area 502, so that the first welding area 501 and the second welding area 502 are located in different spaces, and thus the two metal pads 103 of the metal layer 100 are located in different spaces, so as to be welded to different planes of the metal frame.

[0145] In this way, the body of the FPC laminate structure can be bent and can be applied to the welding of different metal frame surfaces to achieve three-dimensional welding of the FPC laminate structure.

[0146] In some embodiments, the region of the metal layer 100 opposite to the bending region 503 includes a metal comb-shaped line structure 105. There are multiple metal comb-shaped line structures 105, which are spaced apart along the y-axis and extend parallel to the z-axis.

[0147] One end of the metal comb-shaped wire structure 105 is connected to the metal pad 103 located in the first welding area 501, and the other end is connected to the metal layer 100 located in the second welding area 502.

[0148] In this way, the metal comb-shaped wire structure 105 can not only realize the bending of the FPC stack structure, but also prevent the metal layer 100 from breaking during bending, thus improving reliability.

[0149] In some embodiments, the FPC stack structure further includes a rounded corner structure 504, which is located in the bending region 503 and is formed on the first cover layer 200 and the second cover layer 300.

[0150] The rounded corner structure 504 is located in the bending area 503 and is recessed toward the metal comb-shaped line structure 105. It can be understood that the rounded corner structure 504 is formed by the inward recess of the edges of the first cover layer 200 and the second cover layer 300.

[0151] Thus, by setting a rounded corner structure 504 in the bending area 503, the bending of the FPC stacked structure can be facilitated.

[0152] In some embodiments, the edge of the rounded corner structure 504 includes a metal protective edge 505, the two ends of which extend to the edge of the bending area 503.

[0153] In this way, the metal protective edge 505 covers the edge of the rounded corner structure 504, which can prevent the FPC stack structure from tearing at the rounded corner structure 504 when bent.

[0154] The FPC stacked structure provided in this application embodiment adopts a stacked structure of a double cover layer (CVL) and a metal layer 100 (copper foil). By opening windows in the double cover layer, the pad area of ​​the metal layer 100 is free of cover layers above and below, exposing the metal layer 100 body, so that the metal layer 100 can be directly soldered to the metal frame. In this way, the commonly used spring clips can be eliminated, avoiding problems such as misalignment, warping, poor soldering, and PSA adhesive 511 detachment caused by the original spring clips, ensuring the antenna function of the electronic device and further reducing costs. At the same time, eliminating the spring clips can also reduce the number of interfaces through which the signal is transmitted, realize insertion loss benefits, and reduce the space occupied by the electronic device in the x-axis direction.

[0155] Figure 11 is a flowchart of the method for manufacturing an FPC stacked structure provided in an embodiment of this application; Figure 12 is the first process flow diagram of the method for manufacturing an FPC stacked structure provided in an embodiment of this application.

[0156] As shown in Figures 11 and 12, in some embodiments, the method for fabricating the FPC stacked structure provided in this application may include the following steps S101 to S103:

[0157] Step S101: Provide a metal layer, a first cover layer, and a second cover layer.

[0158] Step S102: Press a first cover layer onto the first surface of the metal layer.

[0159] Step S103: Press a second cover layer onto the second surface of the metal layer.

[0160] In step S101, as shown in FIG12(a), a first cover layer 200 and a second cover layer 300 are provided. A first through-hole 201 is formed in the first cover layer 200 using a windowing process, and a second through-hole 301 and a third through-hole 302 are formed in the second cover layer 300, with a gap between the third through-hole 302 and the second through-hole 301.

[0161] It should be noted that, depending on the materials of the first covering layer 200 and the second covering layer 300, the corresponding window opening process can be selected. For details, please refer to the aforementioned content, which will not be repeated here.

[0162] In step S102, as shown in FIG12(b), the first cover layer 200 is pressed onto the first surface 101 of the metal layer 100.

[0163] After step S102, as shown in FIG12(c), the fabrication method further includes etching on the metal layer 100 to expose the metal etch area 104.

[0164] The metal layer 100 is etched into a metal etched area 104 through an exposure, development, etching, and stripping process. No metal is present within the metal etched area 104.

[0165] In step S103, as shown in FIG12(d), the second cover layer 300 is pressed onto the second surface 102 of the metal layer 100.

[0166] The first through hole 201 and the second through hole 301 correspond one-to-one so that the portion of the metal layer 100 opposite to the first through hole 201 and the second through hole 301 is exposed, forming a metal pad 103, which is used for soldering to the metal frame of the electronic device.

[0167] In some embodiments, the method for fabricating an FPC stacked structure further includes:

[0168] Step S104: Press a reinforcing component onto the surface of the first cover layer that is away from the metal layer.

[0169] In step S104, as shown in FIG12(d), the reinforcing member 400 is pressed onto the surface of the first cover layer 200 away from the metal layer 100.

[0170] The reinforcing component 400 is opposite to the metal etched area 104. The size of the reinforcing component 400 is larger than that of the metal etched area 104. The reinforcing component 400 can be used to increase the strength of the FPC stack structure at the metal etched area 104 and avoid breakage.

[0171] In some embodiments, the method for fabricating an FPC stacked structure further includes:

[0172] Step S105: Perform surface treatment on the metal pads of the metal layer to remove surface impurities from the metal pads.

[0173] Impurities may include oxide layers or corrosion layers.

[0174] After the FPC stack structure is fabricated and before soldering, the metal pads 103 of the metal layer 100 are surface treated using OSP or ENIG processes to prevent the surface of the copper foil from being affected by oxidation and corrosion, thereby ensuring soldering performance.

[0175] The method for fabricating the FPC stacked structure provided in this application involves pressing a first cover layer 200 and a second cover layer 300 onto the upper and lower surfaces of the metal layer 100, respectively, to form a stacked structure of a double cover layer (CVL) and the metal layer 100 (copper foil). By opening windows in the double cover layer, the pad area of ​​the metal layer 100 is free of cover layers above and below, exposing the body of the metal layer 100, which facilitates direct soldering of the metal layer 100 to the metal frame. This eliminates the need for commonly used spring contacts, avoiding problems such as misalignment, warping, poor soldering, and PSA adhesive 511 detachment caused by the original spring contacts, ensuring the antenna function of the electronic device and further reducing costs. Simultaneously, eliminating the spring contacts also reduces the number of interfaces through which signal transmission passes, achieving insertion loss gains, and reducing the space occupied by the electronic device in the x-axis direction.

[0176] Figure 13 is a second structural schematic diagram of the FPC stack structure provided in an embodiment of this application; Figure 14 is a third top view structural schematic diagram of the FPC stack structure provided in an embodiment of this application. The dotted lines in Figure 14 indicate the positions of the subsequent soldering devices 600.

[0177] As shown in Figures 13 and 14, in some embodiments, the FPC stack structure provided in this application may include: a metal layer 100, a first cover layer 200, and a second cover layer 300. The difference from the FPC stack structure shown in Figure 8 lies in the fact that the first through-hole 201 extends to the edge of the first cover layer 200, and the second through-hole 301 extends to the edge of the second cover layer 300. All other details can be found in the foregoing embodiments and related information, and will not be repeated here.

[0178] The first cover layer 200 is located on the first surface 101 of the metal layer 100 and covers the central region of the metal layer 100; the second cover layer 300 is located on the second surface 102 of the metal layer 100 and covers the central region of the metal layer 100. The edge regions of the metal layer 100 not covered by the first cover layer 200 and the second cover layer 300 are exposed to form metal pads 103.

[0179] When opening a window in the first cover layer 200, all edge areas are removed except for the middle area of ​​the first cover layer 200. That is, no width is reserved at the edges of the first cover layer 200, allowing the first through-hole 201 to open to the edge of the first cover layer 200, with the edge of the first through-hole 201 aligned with the edge of the metal layer 100. Similarly, when opening a window in the second cover layer 300, all edge areas are removed except for the middle area of ​​the second cover layer 300. That is, no width is reserved at the edges of the second cover layer 300, allowing the second through-hole 301 to open to the edge of the second cover layer 300, with the edge of the second through-hole 301 aligned with the edge of the metal layer 100.

[0180] This increases the area of ​​the metal pads 103, allowing them to be better soldered to the metal frame and avoiding the risk of pad breakage.

[0181] The FPC stacked structure provided in this application exposes the metal layer 100 by creating windows in the first cover layer 200 and the second cover layer 300, forming metal pads 103. During subsequent soldering to the metal frame, the metal pads 103 of the metal layer 100 can be directly soldered to the metal frame. This eliminates the need for the spring contacts commonly used for soldering the FPC stacked structure to the metal frame, avoiding problems such as misalignment, warping, poor soldering, and PSA adhesive 511 detachment caused by the original spring contacts. This ensures the antenna function of the electronic device is realized and simultaneously reduces costs. Furthermore, eliminating the spring contacts not only reduces the number of interfaces through which signal transmission passes, achieving insertion loss benefits, but also reduces the space occupied by the electronic device in the x-axis direction.

[0182] Figure 15 is a second process flow diagram of the manufacturing method of the FPC stacked structure provided in the embodiment of this application.

[0183] In some embodiments, the method for fabricating an FPC stacked structure provided in this application is used to fabricate the FPC stacked structure shown in FIG13. The method for fabricating the FPC stacked structure may include steps S101 to S103, which will not be described in detail here.

[0184] In step S101, as shown in FIG15(a), a first cover layer 200 and a second cover layer 300 are provided. A windowing process is used to perform windowing on the first cover layer 200 and the second cover layer 300 respectively, removing the area opposite to the edge of the FPC stack structure, and a third through-hole 302 is formed on the second cover layer 300.

[0185] It should be noted that, depending on the materials of the first covering layer 200 and the second covering layer 300, the corresponding window opening process can be selected. For details, please refer to the aforementioned content, which will not be repeated here.

[0186] In step S102, as shown in FIG15(b), the first cover layer 200 is pressed onto the first surface 101 of the metal layer 100, and the first cover layer 200 covers the central region of the metal layer 100. The area of ​​the first through hole 201 is formed by the edge of the first cover layer 200 and the metal layer 100.

[0187] Following step S102, as shown in Figure 15(c), the fabrication method further includes etching on the metal layer 100 to expose the metal etched area 104. The metal layer 100 is etched to expose the metal etched area 104 through an exposure, development, etching, and stripping process. No metal is present in the area of ​​the metal etched area 104.

[0188] In step S103, as shown in FIG15(d), the second cover layer 300 is pressed onto the second surface 102 of the metal layer 100, and the second cover layer 300 covers the central region of the metal layer 100. The area of ​​the second through hole 301 is formed by the edge of the second cover layer 300 and the metal layer 100.

[0189] The first through hole 201 and the second through hole 301 correspond one-to-one. The edge area of ​​the metal layer 100 that is not covered by the first cover layer 200 and the second cover layer 300 is exposed to form a metal pad 103. The metal pad 103 is used for soldering to the metal frame of the electronic device.

[0190] In some embodiments, the method for manufacturing the FPC stacked structure provided in this application may further include the contents of steps S104 and S105, the specific contents of which can be referred to the foregoing content and will not be repeated here.

[0191] The method for fabricating the FPC stacked structure provided in this application involves pressing a first cover layer 200 and a second cover layer 300 onto the upper and lower surfaces of the metal layer 100, respectively, to form a stacked structure of a double cover layer (CVL) and the metal layer 100 (copper foil). By opening windows in the double cover layer, the pad area of ​​the metal layer 100 is free of cover layers above and below, exposing the body of the metal layer 100, which facilitates direct soldering of the metal layer 100 to the metal frame. This eliminates the need for commonly used spring contacts, avoiding problems such as misalignment, warping, poor soldering, and PSA adhesive 511 detachment caused by the original spring contacts, ensuring the antenna function of the electronic device and further reducing costs. Simultaneously, eliminating the spring contacts also reduces the number of interfaces through which signal transmission passes, achieving insertion loss gains, and reducing the space occupied by the electronic device in the x-axis direction.

[0192] Figure 16 is a first structural schematic diagram of the antenna FPC structure provided in the embodiments of this application.

[0193] As shown in Figure 16, in some embodiments, the first antenna FPC structure provided in this application may include: device 600, metal frame 700 and FPC stacked structure provided in any of the foregoing embodiments.

[0194] The metal frame 700 is the metal part of the frame 20. The metal frame 700 is welded to the metal layer 100 of the FPC stacked structure to realize the antenna function. The device 600 can be an inductor used for tuning to assist in realizing the antenna function of the antenna FPC structure.

[0195] It should be noted that the structural characteristics of the FPC stacked structure can be referred to the content provided in any of the foregoing embodiments, and will not be repeated here.

[0196] Figure 17 is a schematic diagram of the FPC stacked structure and device provided in the embodiments of this application.

[0197] Referring to Figures 16 and 17, taking the FPC stacked structure shown in Figure 8 as an example, device 600 is located in the third via 302 region of the second cover layer 300, device 600 is soldered to the second surface 102 of the metal layer 100, and covers the metal etched area 104.

[0198] The metal frame 700 is located on one side of the FPC stack structure. In this embodiment, the metal frame 700 is located on the side of the FPC stack structure where the device 600 is located.

[0199] The surface of the metal frame 700 facing the FPC stack structure includes a groove 702, which is opposite to the device 600 and is used to avoid the device 600.

[0200] The metal pads 103 of the metal layer 100 deform toward the metal frame 700, causing the metal pads 103 of the metal layer 100 to weld to the metal frame 700, forming an antenna FPC structure to realize the antenna function. The welding method can be ultrasonic welding.

[0201] The antenna FPC structure provided in this application embodiment can hollow out the double-layer cover layer of the FPC stacked structure to expose the metal layer 100 between them, forming a metal pad 103. During welding, the metal pad 103 of the metal layer 100 is directly welded to the metal frame 700 using ultrasonic welding. This eliminates the need for commonly used spring contacts, avoiding problems such as misalignment, warping, poor soldering, and PSA adhesive 511 detachment caused by the original spring contacts, ensuring the antenna function of the electronic device and reducing costs simultaneously. Furthermore, eliminating the spring contacts not only reduces the number of interfaces through which signal transmission passes, achieving insertion loss benefits, but also reduces the space occupied by the electronic device in the x-axis direction.

[0202] Figure 18 is a flowchart of the method for manufacturing the antenna FPC structure provided in the embodiment of this application; Figure 19 is the first process flow diagram of the method for manufacturing the antenna FPC structure provided in the embodiment of this application.

[0203] As shown in Figures 18 and 19, in some embodiments, this application provides a method for manufacturing a first antenna FPC structure, which may include the following steps S201 to S203:

[0204] Step S201: The FPC stack structure is fabricated using the fabrication method of the FPC stack structure shown in Figures 11 and 12.

[0205] Step S202: The device is soldered to the second surface of the metal layer of the FPC stack structure.

[0206] Step S203: Using a welding process, the metal pads of the metal layer are welded to the metal frame.

[0207] As shown in Figure 19(a), in step S201, an FPC stack structure is fabricated. The fabrication of the FPC stack structure can be referred to steps S101 to S105 and related content provided in the aforementioned embodiments, and will not be repeated here.

[0208] In step S202, as shown in FIG19(b), device 600 is located in the region of the third via 302 of the second cover layer 300, device 600 is soldered to the second surface 102 of the metal layer 100, and covers the metal etched area 104.

[0209] As shown in Figure 19(c), step S203 may include the following steps S2031 to S2032:

[0210] Step S2031: The metal frame is placed on the side of the FPC stack structure where the device is located, and the device is embedded in the groove.

[0211] Step S2032: Using ultrasonic welding process, under the pressure of the welding head and the action of high-frequency ultrasonic waves, the metal pads of the metal layer are deformed towards the second through hole of the second cover layer and welded to the metal frame.

[0212] In step S2031, the metal frame 700 is located on the side of the FPC stack structure where the device 600 is located. The groove 702 on the metal frame 700 faces the surface of the FPC stack structure. The device 600 is opposite to the groove 702 and is embedded in the groove 702.

[0213] In step S2032, the welding method adopts ultrasonic welding process 801a. Ultrasonic welding process 801a uses high-frequency vibration waves to transmit to the exposed metal pads 103 (copper foil) and the metal frame 700 of the FPC stacked structure. Under the pressure of the welding head, the two surfaces rub against each other to form the fusion between molecular layers, thereby achieving welding.

[0214] The processing side of ultrasonic welding process 801a is the side of the FPC stack structure facing away from the metal frame 700. The welding head (not shown in the figure) required for ultrasonic welding process 801a is set on the side of the FPC stack structure facing away from the metal frame 700. High-frequency ultrasonic waves are applied to the welding head, causing the welding head to vibrate at high frequency and apply pressure to the metal pads 103 of the metal layer 100. This causes the metal pads 103 to deform toward the second through hole 301 of the second cover layer 300. The two opposing surfaces of the metal pads 103 and the metal frame 700 rub against each other to form a fusion between the molecular layers, thereby achieving welding between the metal pads 103 and the metal frame 700.

[0215] It should be noted that before soldering, the metal pads 103 of the metal layer 100 can be surface treated using OSP or ENIG processes to avoid oxidation and corrosion of the copper foil surface, thus ensuring soldering performance.

[0216] The antenna FPC structure fabrication method provided in this application embodiment involves a metal frame 700 located on the side of the FPC stacked structure where the device 600 is located. Using ultrasonic welding process 801a, the metal pads 103 of the FPC stacked structure deform towards the second through-hole 301 of the second cover layer 300, allowing direct welding to the metal frame 700. This eliminates the need for commonly used spring contacts, avoiding problems such as misalignment, warping, poor soldering, and PSA adhesive 511 detachment caused by the original spring contacts. This ensures the antenna function of the electronic device is realized and simultaneously reduces costs. Furthermore, eliminating the spring contacts reduces the number of interfaces through which signal transmission passes, achieving insertion loss benefits, and reducing the space occupied by the electronic device in the x-axis direction.

[0217] Figure 20 is a second structural schematic diagram of the antenna FPC structure provided in the embodiment of this application.

[0218] As shown in Figure 20, in some embodiments, the second antenna FPC structure provided in this application may include: device 600, metal frame 700, third adhesive layer 703 and the FPC stack structure provided in any of the foregoing embodiments.

[0219] It should be noted that the structural characteristics of the second type of antenna FPC structure differ from those of the first type in that the relative positions of the metal frame 700 and the FPC stacked structure are different. Other details can be found in the corresponding content of the first type of antenna FPC structure, and will not be repeated here.

[0220] In this embodiment, the metal frame 700 is located on the side of the FPC laminate structure where the reinforcing member 400 is located; the reinforcing member 400 is bonded to the metal frame 700 by a third adhesive layer 703. The third adhesive layer 703 can be, but is not limited to, epoxy, acrylic, or other adhesives. Using the third adhesive layer 703 to fix the FPC laminate structure to the metal frame 700 prevents positional misalignment during subsequent welding, thus improving the welding effect.

[0221] When welding the metal frame 700 to the metal pads 103 of the metal layer 100, the metal pads 103 deform in the direction of the metal frame 700 to weld with the metal frame 700, forming an antenna FPC structure to realize the antenna function. The welding method can be ultrasonic welding.

[0222] In this scenario, there is no need to create a groove 702 on the metal frame 700, and the surface of the metal frame 700 facing the FPC stacked structure is a flat surface.

[0223] The antenna FPC structure provided in this application embodiment can hollow out the double-layer cover layer of the FPC stacked structure to expose the metal layer 100 between them, forming a metal pad 103. During welding, the metal pad 103 of the metal layer 100 is directly welded to the metal frame 700 using ultrasonic welding. This eliminates the need for commonly used spring contacts, avoiding problems such as misalignment, warping, poor soldering, and PSA adhesive 511 detachment caused by the original spring contacts, ensuring the antenna function of the electronic device and reducing costs simultaneously. Furthermore, eliminating the spring contacts not only reduces the number of interfaces through which signal transmission passes, achieving insertion loss benefits, but also reduces the space occupied by the electronic device in the x-axis direction.

[0224] Figure 21 is a second process flow diagram of the method for manufacturing the antenna FPC structure provided in the embodiment of this application.

[0225] As shown in Figure 21, in some embodiments, this application provides a method for manufacturing a second antenna FPC structure, which can include the following steps S301 to S303:

[0226] Step S301: The FPC stack structure is fabricated using the fabrication method of the FPC stack structure shown in Figures 11 and 12.

[0227] Step S302: The device is soldered to the second surface of the metal layer of the FPC stack structure.

[0228] Step S303: Using a welding process, the metal pads of the metal layer are welded to the metal frame.

[0229] As shown in Figures 21(a) and (b), the contents of steps S301 to S302 refer to steps S201 to S202 and related contents provided in the aforementioned embodiments, and will not be repeated here.

[0230] As shown in Figure 21(c), step S303 may include the following steps S3031 to S3033:

[0231] Step S3031: Place the metal frame on the side of the FPC stack structure that has the reinforcing component.

[0232] Step S3032: A third adhesive layer is pasted onto the surface of the reinforcing component to bond the FPC laminate structure to the metal frame through the third adhesive layer.

[0233] Step S3033: Using ultrasonic welding process, under the pressure of the welding head and the action of high frequency ultrasonic waves, the metal pads of the metal layer are deformed towards the first through hole of the first cover layer and welded to the metal frame.

[0234] In step S3031, the metal frame 700 is located on the side of the FPC laminate structure where the reinforcing member 400 is located, with the flat surface of the metal frame 700 facing the surface of the FPC laminate structure. The third adhesive layer 703 is bonded to the surface of the reinforcing member 400 that is away from the metal layer 100, and the FPC laminate structure is bonded to the metal frame 700 through the third adhesive layer 703.

[0235] In step S3032, the welding method adopts ultrasonic welding process 801a. The processing side of ultrasonic welding process 801a is the side of the FPC stack structure away from the metal frame 700. The welding head (not shown in the figure) required for ultrasonic welding process 801a is set on the side of the FPC stack structure away from the metal frame 700. High-frequency ultrasonic waves are applied to the welding head, causing the welding head to generate high-frequency vibration and apply pressure to the metal pads 103 of the metal layer 100, so that the metal pads 103 deform toward the first through hole 201 of the first cover layer 200. The two opposite surfaces of the metal pads 103 and the metal frame 700 rub against each other to form a fusion between the molecular layers, thereby realizing the welding of the metal pads 103 and the metal frame 700.

[0236] It should be noted that other process contents of ultrasonic welding process 801a can be referred to the contents of the aforementioned embodiments, and will not be repeated here.

[0237] The antenna FPC structure fabrication method provided in this application embodiment involves a metal frame 700 located on the side of the FPC stacked structure with reinforcing members 400. Using ultrasonic welding process 801a, the metal pads 103 of the FPC stacked structure deform towards the first through-hole 201 of the first cover layer 200, allowing direct welding to the metal frame 700. This eliminates the need for commonly used spring contacts, avoiding problems such as misalignment, warping, poor soldering, and PSA adhesive 511 detachment caused by the original spring contacts. This ensures the antenna function of the electronic device is realized and simultaneously reduces costs. Furthermore, eliminating the spring contacts reduces the number of interfaces through which signal transmission passes, achieving insertion loss benefits, and reducing the space occupied by the electronic device in the x-axis direction.

[0238] In some embodiments, the first antenna FPC structure and the second antenna FPC structure provided in this application can also be manufactured using resistance welding.

[0239] Figure 22 is the third process flow diagram of the method for manufacturing the antenna FPC structure provided in the embodiments of this application.

[0240] As shown in Figure 22, in some embodiments, this application provides a method for fabricating a third antenna FPC structure, used to fabricate the first antenna FPC structure. The method for fabricating the third antenna FPC structure can employ steps S201 to S203 of the method for fabricating the first antenna FPC structure. The difference lies in the content of step S203, where the third antenna FPC structure fabrication method uses resistance welding to weld the metal pad 103 and the metal frame 700. Other details are not elaborated here.

[0241] In step S203, resistance welding is used. Step S203 may include the following steps S2033 to S2036:

[0242] Step S2033: The metal frame is placed on the side of the FPC stack structure where the device is located, and the device is embedded in the groove.

[0243] Step S2034: Using resistance welding, the first electrode and the second electrode required for the resistance welding process are respectively set on the same side of the metal pad and the metal frame.

[0244] In step S2035, pressure is applied to the first electrode and the second electrode to deform the metal pad toward the second through hole of the second cover layer so as to abut against the metal frame.

[0245] In step S2036, energize the first electrode and the second electrode to melt the contact area between the metal pad and the metal frame, so as to weld the metal pad to the metal frame.

[0246] In step S2033, as shown in FIG22(a), the metal frame 700 is located on the side of the FPC stack structure where the device 600 is located. The groove 702 on the metal frame 700 faces the surface of the FPC stack structure. The device 600 is opposite to the groove 702 and is embedded in the groove 702.

[0247] In step S2034, the welding process employs resistance welding. Resistance welding involves pressing the workpieces to be welded between two electrodes and applying current. The resistance heat generated by the current flowing through the contact surface and adjacent areas of the workpieces melts or plastically bondes them together. Resistance welding can be performed using a butt welding method or a same-side welding method.

[0248] Figure 23 is a schematic diagram of the processing principle of the resistance welding process provided in the embodiments of this application.

[0249] As shown in Figure 23(a), in the butt-joint welding method, two electrodes 8021 are located on opposite sides of the two weldment parts 8022, with opposite polarities. When current is applied to both electrodes 8021 (the arrows in the figure indicate the direction of current), the upper electrode 8021 applies downward pressure to the upper weldment part 8022, and the lower electrode 8021 applies upward pressure to the lower weldment part 8022. This causes the two weldment parts 8022 to melt together, forming a weld point, thus achieving welding.

[0250] As shown in Figure 23(b), when using same-side welding, the two electrodes 8021 are located on the same side of the two weldment parts 8022, and the polarities of the two electrodes 8021 are opposite. When current is applied to the two electrodes 8021 (the arrows in the figure indicate the direction of current), the left electrode 8021 applies downward pressure to the weldment part 8022 on the lower side, while the right electrode 8021 applies upward tension to the weldment part 8022 on the lower side. This causes the two weldment parts 8022 to melt together, forming a weld joint, thus achieving welding.

[0251] In this embodiment, the metal pads 103 and the metal frame 700 can be welded using either a butt-on welding method or a same-side welding method. However, to avoid damage to the appearance of the metal frame 700, a same-side welding method is preferred.

[0252] For example, referring again to Figure 22(a), the resistance welding process includes a first electrode 8023 and a second electrode 8024, and the welded part 8022 includes a metal pad 103 and a metal frame 700. The first electrode 8023 and the second electrode 8024 are respectively disposed on the same side of the metal pad 103 and the metal frame 700, and are located on the side away from the metal frame 700.

[0253] In step S2035, as shown in FIG22(b), pressure is applied to the first electrode 8023 and the second electrode 8024, causing the metal pad 103 to deform toward the second through hole 301 of the second cover layer 300, and the metal pad 103 abuts against the metal frame 700.

[0254] In step S2036, the first electrode 8023 and the second electrode 8024 are energized. Under the action of resistance heat, the contact between the metal pad 103 and the metal frame 700 is melted, so as to weld the metal pad 103 to the metal frame 700.

[0255] It should be noted that, to ensure welding quality, different welding positions are welded sequentially, not simultaneously. For example, the metal pads 103 on the left side and the metal frame 700 can be welded first, followed by the metal pads 103 on the right side and the metal frame 700. Furthermore, before welding, the metal pads 103 of the metal layer 100 can be surface-treated using OSP or ENIG processes to prevent oxidation and corrosion of the copper foil surface, thus ensuring welding performance.

[0256] The antenna FPC structure fabrication method provided in this application embodiment involves a metal frame 700 located on the side of the FPC stacked structure where the device 600 is located. Using resistance welding, the metal pads 103 of the FPC stacked structure deform towards the second through-hole 301 of the second cover layer 300, allowing direct welding to the metal frame 700. This eliminates the need for commonly used spring contacts, avoiding problems such as misalignment, warping, poor soldering, and PSA adhesive 511 detachment caused by the original spring contacts. This ensures the antenna function of the electronic device is realized and simultaneously reduces costs. Furthermore, eliminating the spring contacts reduces the number of interfaces through which signal transmission passes, achieving insertion loss benefits, and reducing the space occupied by the electronic device in the x-axis direction.

[0257] Figure 24 is the fourth process flow diagram of the method for manufacturing the antenna FPC structure provided in the embodiments of this application.

[0258] As shown in Figure 24, in some embodiments, this application provides a method for fabricating a fourth antenna FPC structure, used to fabricate the second antenna FPC structure. The method for fabricating the fourth antenna FPC structure can employ steps S301 to S303 of the method for fabricating the second antenna FPC structure. The difference lies in the content of step S303; that is, the fourth antenna FPC structure fabrication method uses resistance welding to weld the metal pad 103 and the metal frame 700. Other details are not elaborated here.

[0259] In step S303, resistance welding is used. Step S303 may include the following steps S3033 to S3036:

[0260] Step S3033: Place the metal frame on the side of the FPC stack structure that has the reinforcing component.

[0261] Step S3034: Using resistance welding, the first electrode and the second electrode required for the resistance welding process are respectively set on the same side of the metal pad and the metal frame.

[0262] In step S3035, pressure is applied to the first electrode and the second electrode to deform the metal pads toward the first through-hole of the first cover layer so as to abut against the metal frame.

[0263] In step S3036, energize the first electrode and the second electrode to melt the contact area between the metal pad and the metal frame, so as to weld the metal pad to the metal frame.

[0264] In step S3033, as shown in FIG24(a), the metal frame 700 is located on the side of the FPC stack structure with the reinforcing member 400, and the flat surface of the metal frame 700 faces the surface of the FPC stack structure. The third adhesive layer 703 is bonded to the surface of the reinforcing member 400 that is opposite to the metal layer 100, and the FPC stack structure is bonded to the metal frame 700 through the third adhesive layer 703.

[0265] In step S3034, the welding process adopts resistance welding process, which includes a first electrode 8023 and a second electrode 8024. The first electrode 8023 and the second electrode 8024 are respectively disposed on the same side of the metal pad 103 and the metal frame 700, and are located on the side away from the metal frame 700.

[0266] In step S3035, as shown in FIG24(b), pressure is applied to the first electrode 8023 and the second electrode 8024, causing the metal pad 103 to deform toward the first through hole 201 of the first cover layer 200, and the metal pad 103 abuts against the metal frame 700.

[0267] In step S3036, the first electrode 8023 and the second electrode 8024 are energized. Under the action of resistance heat, the contact between the metal pad 103 and the metal frame 700 is melted, so as to weld the metal pad 103 to the metal frame 700.

[0268] It should be noted that, to ensure welding quality, different welding positions are welded sequentially, not simultaneously. For example, the metal pads 103 on the left side and the metal frame 700 can be welded first, followed by the metal pads 103 on the right side and the metal frame 700. Furthermore, before welding, the metal pads 103 of the metal layer 100 can be surface-treated using OSP or ENIG processes to prevent oxidation and corrosion of the copper foil surface, thus ensuring welding performance.

[0269] The antenna FPC structure fabrication method provided in this application embodiment involves a metal frame 700 located on the side of the FPC stacked structure with reinforcing members 400. Using resistance welding, the metal pads 103 of the FPC stacked structure deform towards the first through-hole 201 of the first cover layer 200, allowing direct welding to the metal frame 700. This eliminates the need for commonly used spring contacts, avoiding problems such as misalignment, warping, poor soldering, and PSA adhesive 511 detachment caused by the original spring contacts. This ensures the antenna function of the electronic device is realized and simultaneously reduces costs. Furthermore, eliminating the spring contacts reduces the number of interfaces through which signal transmission passes, achieving insertion loss benefits, and reducing the space occupied by the electronic device in the x-axis direction.

[0270] Figure 25 is a third structural schematic diagram of the antenna FPC structure provided in the embodiments of this application.

[0271] As shown in Figure 25, in some embodiments, the third antenna FPC structure provided in this application may include: device 600, metal frame 700 and FPC stacked structure provided in any of the foregoing embodiments.

[0272] It should be noted that the structural characteristics of the third type of antenna FPC structure differ from those of the first type of antenna FPC structure in that the structure of the metal frame 700 is different. Other details can be found in the corresponding content of the first type of antenna FPC structure, and will not be repeated here.

[0273] In this embodiment, the metal frame 700 is located on the side of the FPC stack structure where the device 600 is located. The surface of the metal frame 700 facing the FPC stack structure includes bosses 701, the number of which is the same as the number of metal pads 103. This embodiment uses two bosses 701 and two metal pads 103 as an example, with the two bosses 701 spaced apart along the y-axis. Referring to Figure 8, the two bosses 701 are opposite to the two second through holes 301 on the second cover layer 300. The area enclosed between the two bosses 701 is used to accommodate the device 600, preventing interference between the device 600 and the metal frame 700.

[0274] Two protrusions 701 are embedded one-to-one into the corresponding second through holes 301, and the two protrusions 701 correspond one-to-one with the two metal pads 103 of the metal layer 100. The metal pads 103 are soldered to the corresponding protrusions 701 to form an antenna FPC structure to realize the antenna function. The soldering method can be spot welding.

[0275] The antenna FPC structure provided in this application embodiment can hollow out the double-layer cover layer of the FPC stacked structure to expose the metal layer 100 between them, forming a metal pad 103. During soldering, the metal pad 103 of the metal layer 100 is directly soldered to the boss 701 of the metal frame 700 using a spot welding process. In this way, the commonly used spring can be eliminated, avoiding problems such as misalignment, warping, poor soldering, and PSA adhesive 511 detachment caused by the original spring, ensuring the antenna function of the electronic device, and reducing costs simultaneously. At the same time, eliminating the spring not only reduces the number of interfaces through which the signal is transmitted, realizing insertion loss benefits, but also reduces the space occupied by the electronic device in the x-axis direction.

[0276] Figure 26 is the fifth process flow diagram of the method for manufacturing the antenna FPC structure provided in the embodiments of this application.

[0277] As shown in Figure 26, in some embodiments, this application provides a method for manufacturing a fifth type of antenna FPC structure, used to manufacture the third type of antenna FPC structure. The method for manufacturing the antenna FPC structure may include the following steps S401 to S403:

[0278] Step S401: The FPC stack structure is fabricated using the fabrication method of the FPC stack structure shown in Figures 11 and 12.

[0279] Step S402: The device is soldered to the second surface of the metal layer of the FPC stack structure.

[0280] Step S403: Using a welding process, the metal pads of the metal layer are welded to the metal frame.

[0281] In steps S401 to S402, the content of steps S401 to S402 refers to steps S201 to S202 and related content provided in the foregoing embodiment, and will not be repeated here.

[0282] In step S403, step S403 may include the following steps S4031 to S4032:

[0283] Step S4031: The metal frame is placed on the side of the FPC stack structure where the device is located, and the boss is embedded in the second through hole of the second cover layer.

[0284] Step S4032: A spot welding process is used to melt the contact area between the metal pads and the boss in the metal layer, so as to weld the metal pads to the boss.

[0285] As shown in Figure 26(a), in step S4031, the metal frame 700 is located on the side of the FPC stack structure where the device 600 is located, and the surface of the metal frame 700 facing the FPC stack structure includes bosses 701. Taking two bosses 701 and two through holes 301 as an example, the two bosses 701 are embedded one-to-one into the two second through holes 301 of the second cover layer 300.

[0286] In step S4032, the welding method adopts spot welding process 803a. Spot welding process 803a uses a laser to melt the contact point between the metal pad 103 (hollowed-out copper layer) and the boss 701 of the metal frame, and finally tightly joins to form a weld point.

[0287] The processing side of spot welding process 803a is the side of the FPC laminate structure that is away from the metal frame 700. A glass sheet 804 is placed on the surface of the FPC laminate structure that is away from the metal frame 700. The glass sheet 804 is pressed against the surface of the FPC laminate structure and plays a positioning role for the FPC laminate structure during welding.

[0288] As shown in Figure 26(b), the laser spot of spot welding process 803a is focused at the contact point between the metal pad 103 and the boss 701 of the metal layer 100, so that the contact point between the metal pad 103 and the boss 701 of the metal layer 100 melts and cools down to weld the metal pad 103 to the corresponding boss 701, thereby realizing the direct welding of the metal pad 103 and the metal frame 700.

[0289] After welding is completed using spot welding process 803a, there is a certain gap between the second cover layer 300 and the metal frame 700 along the x-axis direction to avoid problems such as material processing tolerance, and to ensure that the boss 701 of the metal frame 700 and the metal pad 103 can be tightly pressed together.

[0290] It should be noted that before welding, the metal pads 103 of the metal layer 100 can be surface-treated using OSP or ENIG processes to prevent oxidation and corrosion of the copper foil surface, thus ensuring welding performance. Furthermore, when welding the metal frame 700, including the boss 701, to the metal layer 100, ultrasonic welding or resistance welding can also be used. For details, please refer to the embodiments of this application regarding the use of ultrasonic welding or resistance welding, which will not be elaborated here.

[0291] The antenna FPC structure fabrication method provided in this application embodiment involves a metal frame 700 located on the side of the FPC stacked structure where the device 600 is located. Using spot welding process 803a, the metal pads 103 of the FPC stacked structure are directly welded to the bosses 701 of the metal frame 700. This eliminates the need for commonly used spring contacts, avoiding problems such as misalignment, warping, poor soldering, and PSA adhesive 511 detachment caused by the original spring contacts. This ensures the antenna function of the electronic device is realized and simultaneously reduces costs. Furthermore, eliminating the spring contacts reduces the number of interfaces through which signal transmission passes, achieving insertion loss benefits, and reducing the space occupied by the electronic device in the x-axis direction.

[0292] Figure 27 is a fourth structural schematic diagram of the antenna FPC structure provided in the embodiments of this application.

[0293] As shown in Figure 27, in some embodiments, the fourth antenna FPC structure provided in this application may include: device 600, metal frame 700, third adhesive layer 703 and the FPC stack structure provided in any of the foregoing embodiments.

[0294] It should be noted that the structural characteristics of the fourth type of antenna FPC structure differ from those of the third type in that the relative positions of the metal frame 700 and the FPC stacked structure are different. Other details can be found in the corresponding content of the third type of antenna FPC structure, and will not be repeated here.

[0295] In this embodiment, the metal frame 700 is located on the side of the FPC laminate structure where the reinforcing member 400 is located; the reinforcing member 400 is bonded to the metal frame 700 by a third adhesive layer 703. The third adhesive layer 703 can be made of foam adhesive, which can be compressed and thinned under pressure. Using the third adhesive layer 703 to fix the FPC laminate structure to the metal frame 700 prevents positional misalignment during subsequent welding, thus improving the welding effect.

[0296] The surface of the metal frame 700 facing the FPC stack structure includes bosses 701, the number of which is the same as the number of metal pads 103. In this embodiment, two bosses 701 and two metal pads 103 are used as an example, with the two bosses 701 spaced apart along the y-axis. Referring to Figure 8, the two bosses 701 are opposite to the two first through holes 201 on the first cover layer 200.

[0297] Two protrusions 701 are embedded one-to-one into two corresponding first through holes 201. The two protrusions 701 correspond one-to-one with two metal pads 103 of the metal layer 100. The metal pads 103 are soldered to the corresponding protrusions 701 to form an antenna FPC structure to realize the antenna function. The soldering method can be spot welding.

[0298] After welding is completed using spot welding process 803a, there is a certain gap between the first cover layer 200 and the metal middle frame 700 along the x-axis direction to avoid problems such as material processing tolerance, and to ensure that the boss 701 of the metal middle frame 700 and the metal pad 103 can be tightly pressed together.

[0299] The antenna FPC structure provided in this application embodiment can hollow out the double-layer cover layer of the FPC stacked structure to expose the metal layer 100 between them, forming a metal pad 103. During soldering, the metal pad 103 of the metal layer 100 is directly soldered to the boss 701 of the metal frame 700 using a spot welding process. In this way, the commonly used spring can be eliminated, avoiding problems such as misalignment, warping, poor soldering, and PSA adhesive 511 detachment caused by the original spring, ensuring the antenna function of the electronic device, and reducing costs simultaneously. At the same time, eliminating the spring not only reduces the number of interfaces through which the signal is transmitted, realizing insertion loss benefits, but also reduces the space occupied by the electronic device in the x-axis direction.

[0300] Figure 28 is the sixth process flow diagram of the method for manufacturing the antenna FPC structure provided in the embodiments of this application.

[0301] As shown in Figure 28, in some embodiments, this application provides a method for manufacturing a sixth type of antenna FPC structure, used to manufacture a fourth type of antenna FPC structure. The method for manufacturing the antenna FPC structure may include the following steps S501 to S503:

[0302] Step S501: The FPC stack structure is fabricated using the fabrication method of the FPC stack structure shown in Figures 11 and 12.

[0303] Step S502: The device is soldered to the second surface of the metal layer of the FPC stack structure.

[0304] Step S503: Using a welding process, the metal pads of the metal layer are welded to the metal frame.

[0305] In steps S501 to S502, the content of steps S501 to S502 refers to the content of steps S201 to S202 and related content provided in the foregoing embodiment, and will not be repeated here.

[0306] In step S503, step S503 may include the following steps S5031 to S5033:

[0307] Step S5031: The metal frame is placed on the side of the FPC stack structure with the reinforcing member, and the boss is embedded in the first through hole of the first cover layer.

[0308] Step S5032: A third adhesive layer is pasted onto the surface of the reinforcing component, and the FPC laminate structure is bonded to the metal frame through the third adhesive layer.

[0309] Step S5033: A spot welding process is used to melt the contact area between the metal pads and the bosses of the metal layer, so as to weld the metal pads to the corresponding bosses.

[0310] As shown in Figure 28(a), in step S5031, the metal frame 700 is located on the side of the FPC stack structure that has the reinforcing member 400. The surface of the metal frame 700 facing the FPC stack structure includes bosses 701. Taking two bosses 701 and two first through holes 201 as an example, the two bosses 701 are embedded one-to-one into the two first through holes 201 of the first cover layer 200.

[0311] In step S5032, a third adhesive layer 703 is adhered to the surface of the reinforcing component 400, and the FPC laminate structure is bonded to the metal frame 700 through the third adhesive layer 703. This prevents relative displacement between the metal frame 700 and the FPC laminate structure during welding, thereby avoiding affecting the welding effect. Before the spot welding process 803a is performed, the third adhesive layer 703 is not subjected to extrusion pressure and has its initial thickness.

[0312] In step S5033, the welding method adopts spot welding process 803a, and the processing side of spot welding process 803a is the side of the FPC stacked structure that is away from the metal frame 700.

[0313] A glass sheet 804 is placed on the surface of the FPC laminate structure away from the metal frame 700. The glass sheet 804 is pressed against the surface of the FPC laminate structure and plays a positioning role for the FPC laminate structure during welding.

[0314] As shown in Figure 28(b), the laser spot in spot welding process 803a is focused at the contact point between the metal pad 103 and the boss 701 of the metal layer 100, causing the contact point to melt. After cooling, the metal pad 103 is welded to the corresponding boss 701, achieving direct welding between the metal pad 103 and the metal frame 700. After completing spot welding process 803a, the third adhesive layer 703 becomes thinner due to extrusion pressure.

[0315] It should be noted that other processes of spot welding process 803a can be referred to the content of the aforementioned embodiments, and will not be repeated here.

[0316] The antenna FPC structure fabrication method provided in this application embodiment involves a metal frame 700 located on the side of the FPC stacked structure with reinforcing members 400. Using spot welding process 803a, the metal pads 103 of the FPC stacked structure are directly welded to the bosses 701 of the metal frame 700. This eliminates the need for commonly used spring contacts, avoiding problems such as misalignment, warping, poor soldering, and PSA adhesive 511 detachment caused by the original spring contacts. This ensures the antenna function of the electronic device is realized and simultaneously reduces costs. Furthermore, eliminating the spring contacts reduces the number of interfaces through which signal transmission passes, achieving insertion loss benefits, and reducing the space occupied by the electronic device in the x-axis direction.

[0317] Figure 29 is a fifth structural schematic diagram of the antenna FPC structure provided in the embodiments of this application.

[0318] As shown in Figure 29, in some embodiments, the fifth antenna FPC structure provided in this application may include: device 600, metal frame 700, third adhesive layer 703, and the FPC stacked structure provided in any of the foregoing embodiments. Other details can be found in the corresponding content of the antenna FPC structure provided in the foregoing embodiments, and will not be repeated here.

[0319] Taking the FPC stacked structure provided in the embodiment shown in Figure 13 as an example, with the metal frame 700 located on the side of the FPC stacked structure where the device 600 is located, an ultrasonic welding process is used. Under the action of high-frequency ultrasonic waves and the pressure of the welding head, the metal pads 103 of the metal layer 100 deform in the direction of the metal frame 700, so that the metal pads 103 of the metal layer 100 are welded to the metal frame 700 to form an antenna FPC structure to realize the antenna function.

[0320] It should be noted that the specific details of using ultrasonic welding to weld the metal pads 103 and the metal frame 700 can be found in the corresponding descriptions of the foregoing embodiments. Furthermore, the metal frame 700 can also be located on the side of the FPC laminate structure where the reinforcing member 400 is located, and the welding process can also employ spot welding or resistance welding, etc., which will not be elaborated here.

[0321] In some embodiments, the FPC stack structure and the metal frame 700 can be welded using ultrasonic welding, spot welding, or resistance welding, depending on the specific circumstances. The processing requirements for the three welding processes are as follows: To avoid damage to the metal pads 103 (copper foil) due to excessive pressure from the welding head, the applicable pressure range must be assessed beforehand. The bonding force between the metal frame 700 and the metal pads 103 must meet the following requirement: the bonding force between a single metal pad 103 and the metal frame 700 must be greater than 10N. When etching the metal etched area 104 of the metal layer 100 using the exposure, development, etching, and stripping process, the copper layer positions (metal pads 103) exposed due to the cover layer opening need to be protected to avoid damage. Furthermore, before welding, the metal pads 103 of the metal layer 100 undergo surface treatment. The surface treatment method can be ENIG or OSP to prevent surface oxidation of the metal pads 103 from affecting the welding effect. Among these steps, it is necessary to pre-assess whether ENIG meets the requirements for spot welding or ultrasonic welding processes; if OSP process is used for surface treatment, the surface of the pads needs to be evaluated after component assembly, such as oxidation and scrapping treatment.

[0322] Figure 30 is a schematic diagram of the first welded structure of the metal frame and FPC stacked structure provided in the embodiment of this application.

[0323] As shown in Figure 30, the metal frame 700 includes a first welding surface 700a and a second welding surface 700b, the extension direction of the first welding surface 700a and the extension direction of the second welding surface 700b are at an angle. For example, referring to Figure 5, the first welding surface 700a is located on the side wall 22 of the frame 20, and the second welding surface 700b is located on the middle plate 21 of the frame 20. The first welding surface 700a and the second welding surface 700b are perpendicular to each other.

[0324] Taking the FPC stacked structure shown in Figure 9 as an example, multiple metal pads 103 of the metal layer 100 in the FPC stacked structure are welded to the same surface of the metal frame 700. Exemplarily, all the multiple metal pads 103 are welded to the first welding surface 700a of the metal frame 700. The welding method can be ultrasonic welding, resistance welding, or spot welding, and the details can be found in the foregoing embodiments, which will not be repeated here.

[0325] In this way, planar welding of the metal frame 700 and the FPC stack structure can be achieved to obtain an antenna FPC structure.

[0326] Figure 31 is a schematic diagram of the second welded structure of the metal frame and FPC stacked structure provided in the embodiment of this application.

[0327] As shown in Figure 31, taking the FPC stacked structure shown in Figure 10 as an example, the second welding area 502 of the FPC stacked structure is located on the first welding surface 700a of the metal frame 700. The bending area 503 is bent so that the first welding area 501 extends to the second welding surface 700b.

[0328] The metal pads 103 of the metal layer 100 located in the second welding area 502 are welded to the first welding surface 700a of the metal frame 700, and the metal pads 103 located in the first welding area 501 are welded to the second welding surface 700b of the metal frame 700. The welding method can be ultrasonic welding, resistance welding, or spot welding, and the details can be found in the foregoing embodiments, which will not be repeated here.

[0329] In this way, the multiple metal pads 103 of the metal layer 100 are located in different spaces, which can weld the FPC stacked structure to different planes of the metal frame 700, realize the three-dimensional welding of the metal frame 700 and the FPC stacked structure, and obtain another antenna FPC structure.

[0330] Figure 32 is a schematic diagram of the third welded structure of the metal frame and FPC stacked structure provided in the embodiment of this application.

[0331] As shown in Figure 32, the metal frame 700 includes a first welding surface 700a and a second welding surface 700b, the extension direction of the first welding surface 700a and the extension direction of the second welding surface 700b are at an angle. For example, referring to Figure 5, the first welding surface 700a is located on the side wall 22 of the frame 20, and the second welding surface 700b is located on the middle plate 21 of the frame 20. The first welding surface 700a and the second welding surface 700b are perpendicular to each other.

[0332] Taking the FPC stack structure shown in Figure 14 as an example, in the FPC stack structure, multiple metal pads 103 of the metal layer 100 are welded to the same surface of the metal frame 700, and the edges of the multiple metal pads 103 are aligned with the edges of the cover layer. Exemplarily, all the multiple metal pads 103 are welded to the first welding surface 700a of the metal frame 700. The welding method can be ultrasonic welding, resistance welding, or spot welding, and the details can be found in the foregoing corresponding embodiments, which will not be repeated here.

[0333] In this way, planar welding of the metal frame 700 and the FPC stack structure can be achieved to obtain another antenna FPC structure.

[0334] The antenna FPC structure provided in this application embodiment utilizes the excellent flexibility and bendability of the FPC stacked structure to meet the welding requirements of metal frames on different planes, making it suitable for different application scenarios.

[0335] Referring again to Figure 1, this application embodiment also provides an electronic device, including a display screen 10, a rear shell, and an antenna FPC structure provided in any of the foregoing embodiments. The display screen 10 and the rear shell are located on opposite sides of the antenna FPC structure and are connected to the metal frame 700.

[0336] It should be noted that the specific structural details of the electronic device can be found in the corresponding content of the foregoing embodiments, and will not be repeated here.

[0337] The electronic device provided in this application embodiment can directly weld the metal layer in the FPC stacked structure to the metal frame 700 when implementing the antenna function. This eliminates the need for commonly used spring contacts, avoiding problems such as misalignment, warping, poor soldering, and PSA adhesive 511 detachment caused by the original spring contacts, ensuring the antenna function of the electronic device and simultaneously reducing costs. Furthermore, eliminating the spring contacts reduces the number of interfaces through which signal transmission passes, achieving insertion loss benefits, and reducing the space occupied by the electronic device in the x-axis direction.

[0338] It should be noted that those skilled in the art, upon considering the specification and practicing the application disclosed herein, will readily conceive of other embodiments of this application. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and embodiments are to be considered exemplary only, and the true scope of this application is indicated by the following claims.

[0339] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. An FPC stacked structure, characterized in that, include: The metal layer (100) includes a first surface (101) and a second surface (102) facing away from each other; A first cover layer (200) is located on the first surface (101) of the metal layer (100), and the first cover layer (200) includes a first through hole (201); A second cover layer (300) is located on the second surface (102) of the metal layer (100). The second cover layer (300) includes a second through hole (301), and the first through hole (201) is opposite to the second through hole (301). The portion of the metal layer (100) opposite to the first through hole (201) and the second through hole (301) is exposed to form a metal pad (103) for soldering to the metal frame of the electronic device.

2. The FPC stacked structure according to claim 1, characterized in that, The second cover layer (300) further includes a third through hole (302), which is spaced apart from the second through hole (301); The metal layer (100) further includes a metal etching area (104), which is opposite to and connected to the third through hole (302); The size of the third through hole (302) is larger than the size of the metal etching area (104).

3. The FPC stacked structure according to claim 2, characterized in that, The FPC stack structure includes: a first welding area (501), a second welding area (502), and a bending area (503), wherein the bending area (503) is located between the first welding area (501) and the second welding area (502); One of the metal pads (103) of the metal layer (100) is located in the first welding area (501), and the other metal pad (103) and the metal etched area (104) are located in the second welding area (502); The bending area (503) can be bent so that the different metal pads (103) of the metal layer (100) are located on different planes.

4. The FPC stacked structure according to claim 3, characterized in that, The region of the metal layer (100) opposite to the bending region (503) includes a metal comb-shaped line structure (105); One end of the metal comb-shaped wire structure (105) is connected to the metal pad (103) located in the first welding area (501), and the other end is connected to the edge of the metal etching area (104) located in the second welding area (502).

5. The FPC stacked structure according to claim 4, characterized in that, The FPC stack structure further includes a rounded corner structure (504), which is formed on the first cover layer (200) and the second cover layer (300); The rounded corner structure (504) is located in the bending area (503) and is recessed toward the metal comb-shaped line structure (105).

6. The FPC stacked structure according to claim 5, characterized in that, The rounded corner structure (504) includes a metal protective edge (505) at both ends, which extends to the edge of the bending area (503).

7. The FPC stacked structure according to claim 2, characterized in that, Also includes: reinforcing components (400); The reinforcing member (400) is located on the surface of the first cover layer (200) away from the metal layer (100), and the reinforcing member (400) is opposite to the metal etched area (104).

8. The FPC stacked structure according to claim 1, characterized in that, The edge of the first through hole (201) has a first distance from the edge of the first cover layer (200); The edge of the second through hole (301) has a second distance from the edge of the second cover layer (300); Both the first distance and the second distance are greater than or equal to 0.5 mm.

9. The FPC stacked structure according to claim 8, characterized in that, The first cover layer (200) includes a first protective film (202) and a first adhesive layer (203). The first protective film (202) is bonded to the first surface (101) of the metal layer (100) through the first adhesive layer (203). The first through hole (201) penetrates the first protective film (202) and the first adhesive layer (203). The second cover layer (300) includes a second protective film (303) and a second adhesive layer (304). The second protective film (303) is bonded to the second surface (102) of the metal layer (100) through the second adhesive layer (304). The second through hole (301) penetrates the second protective film (303) and the second adhesive layer (304).

10. An FPC stacked structure, characterized in that, include: The metal layer (100) includes a first surface (101) and a second surface (102) facing away from each other; A first cover layer (200) is located on the first surface (101) of the metal layer (100) and covers the central region of the metal layer (100); A second cover layer (300) is located on the second surface (102) of the metal layer (100) and covers the central region of the metal layer (100); The edge regions of the metal layer (100) not covered by the first cover layer (200) and the second cover layer (300) are exposed to form metal pads (103) for soldering to the metal frame of the electronic device.

11. An antenna FPC structure, characterized in that, include: The FPC stack structure as described in any one of claims 1-10; Device (600) is located in the third via (302) region of the second cover layer (300), the device (600) is soldered to the second surface (102) of the metal layer (100) and covers the metal etched area (104); A metal frame (700) is located on one side of the FPC stack structure, and the metal pads (103) of the metal layer (100) are soldered to the metal frame (700).

12. The antenna FPC structure according to claim 11, characterized in that, The metal frame (700) includes a boss (701); The boss (701) corresponds to the metal pad (103) of the metal layer (100), and the metal pad (103) is soldered to the boss (701).

13. The antenna FPC structure according to claim 11 or 12, characterized in that, The metal frame (700) is located on the side of the FPC stack structure where the device (600) is located; The surface of the metal frame (700) facing the FPC stack includes a groove (702) for avoiding the device (600).

14. The antenna FPC structure according to claim 11 or 12, characterized in that, The metal frame (700) is located on the side of the FPC stack structure that has the reinforcing member (400); The reinforcing component (400) is bonded to the metal frame (700) by a third adhesive layer (703).

15. The antenna FPC structure according to claim 11, characterized in that, The metal pads (103) of the metal layer (100) are welded to the same surface of the metal frame (700).

16. The antenna FPC structure according to claim 11, characterized in that, The metal frame (700) includes a first welding surface (700a) and a second welding surface (700b), wherein the extension direction of the first welding surface (700a) and the extension direction of the second welding surface (700b) are at an angle. One of the metal pads (103) of the metal layer (100) is welded to the first welding surface (700a) of the metal frame (700), and the other metal pad (103) is welded to the second welding surface (700b) of the metal frame (700).

17. A method for fabricating an FPC laminated structure, characterized in that, The method for fabricating an FPC stack structure as described in any one of claims 1-9 includes: A metal layer, a first cover layer, and a second cover layer are provided, wherein the first cover layer includes a first through-hole, and the second cover layer includes a second through-hole; The first cover layer is pressed onto the first surface of the metal layer; The second cover layer is pressed onto the second surface of the metal layer, with the first through hole and the second through hole facing each other, so that the portions of the metal layer opposite to the first and second through holes are exposed to form metal pads for soldering to the metal frame of the electronic device.

18. The method according to claim 17, characterized in that, After the first cover layer is pressed onto the first surface of the metal layer, the method further includes: A metal etching region is etched on the metal layer, the metal etching region penetrating the first surface and the second surface of the metal layer.

19. The method according to claim 18, characterized in that, The method further includes: A reinforcing member is pressed onto the surface of the first cover layer opposite to the metal layer, the reinforcing member being opposite to the metal etched area.

20. The method according to claim 17, characterized in that, The method further includes: The metal pads of the metal layer are surface treated to remove surface impurities.

21. A method for fabricating an FPC laminated structure, characterized in that, The method for fabricating the FPC stack structure as described in claim 10 includes: Provides a metal layer, a first cover layer, and a second cover layer; The first cover layer is pressed onto the first surface of the metal layer, and the first cover layer covers the central region of the metal layer; A second cover layer is pressed onto the second surface of the metal layer, the second cover layer covering the central region of the metal layer, and the edge regions of the metal layer not covered by the first cover layer and the second cover layer are exposed to form metal pads for soldering to the metal frame of the electronic device.

22. A method for fabricating an antenna FPC structure, characterized in that, The method for fabricating an antenna FPC structure as described in any one of claims 11-16 includes: The FPC stack structure is fabricated using the fabrication method of the FPC stack structure as described in any one of claims 17-21; The device is soldered to the second surface of the metal layer of the FPC stack structure, the device is located in the third via region of the second cover layer, and covers the metal etched area; The metal pads of the metal layer are welded to the metal frame using a welding process.

23. The method according to claim 22, characterized in that, The process of welding the metal pads of the metal layer to the metal frame includes: The metal frame is disposed on one side of the FPC stacked structure; The ultrasonic welding process is used, in which the metal pads are deformed towards the metal frame under the pressure of the welding head and the action of high-frequency ultrasonic waves, and then welded to the metal frame.

24. The method according to claim 22, characterized in that, The surface of the metal frame facing the FPC stack structure includes bosses; and The process of welding the metal pads of the metal layer to the metal frame includes: The metal frame is disposed on one side of the FPC stack-up structure, and the boss corresponds to the metal pad. A spot welding process is used to melt the contact area between the metal pad and the boss, thereby welding the metal pad to the boss.

25. The method according to claim 24, characterized in that, The method further includes: During the spot welding process, a glass plate is placed on the surface of the FPC stack structure opposite to the metal frame so that the laser spot of the spot welding is focused at the contact point between the metal pad and the boss.

26. The method according to claim 22, characterized in that, The process of welding the metal pads of the metal layer to the metal frame includes: The metal frame is disposed on one side of the FPC stacked structure; Using resistance welding, the first electrode and the second electrode required for the resistance welding process are respectively set on the same side of the metal pad and the metal frame; Pressure is applied to the first electrode and the second electrode to deform the metal pads toward the metal frame so as to abut against the metal frame; When the first electrode and the second electrode are energized, the contact area between the metal pad and the metal frame is melted, thereby welding the metal pad to the metal frame.

27. An electronic device, characterized in that, The device includes a display screen, a rear housing, and an antenna FPC structure as described in any one of claims 11-16, wherein the display screen and the rear housing are located on opposite sides of the antenna FPC structure and are connected to the metal frame.

Images