Electronic device

Abstract

The present application relates to the technical field of electronics. Disclosed is an electronic device, which is used for enabling a plurality of circuit boards to share an FPC so as to reduce the design difficulty of circuit boards. The electronic device comprises a first FPC, a first circuit board, a second circuit board and a third circuit board. The first FPC comprises a first connecting end, a second connecting end and a third connecting end, wherein the first connecting end is electrically connected to the second connecting end, the first connecting end is electrically connected to the third connecting end, the first connecting end is electrically connected to the first circuit board, the second connecting end is electrically connected to the second circuit board, and the third connecting end is electrically connected to the third circuit board.

Description

An electronic device Technical Field

[0001] The embodiments of the present application relate to the field of electronic technology, and in particular to an electronic device. Background Art

[0002] As the internal components of electronic devices like mobile phones become increasingly compact, a single target circuit board (e.g., motherboard) needs to be electrically connected to multiple circuit boards. One approach involves using multiple independent flexible printed circuits (FPCs) to electrically connect multiple connection points on the target circuit board to the multiple circuit boards, resulting in a larger number of connection points on the target circuit board.

[0003] The internal space of electronic equipment is limited, and the available area of ​​the target circuit board is also limited. Too many connection points on the target circuit board will reduce the available area of ​​the target circuit board and increase the design difficulty of the target circuit board.

[0004] Summary of the Invention

[0005] An embodiment of the present application provides an electronic device for reducing the difficulty of designing a circuit board by reducing the number of connection points on the circuit board.

[0006] To achieve the above objectives, the embodiments of the present application adopt the following technical solutions:

[0007] In a first aspect, an electronic device is provided, including a first FPC, a first circuit board, a second circuit board and a third circuit board; the first FPC includes a first connection end, a second connection end and a third connection end, the first connection end is electrically connected to the second connection end, the first connection end is electrically connected to the third connection end, the first connection end is electrically connected to the first circuit board, the second connection end is electrically connected to the second circuit board, and the third connection end is electrically connected to the third circuit board.

[0008] In the electronic device provided by the embodiment of the present application, the first connection end of the first FPC is electrically connected to the first circuit board, the second connection end of the first FPC is electrically connected to the second circuit board, and the third connection end of the first FPC is electrically connected to the third circuit board, so that the first circuit board can be electrically connected to the first FPC through one connection position, and electrically connected to the second circuit board and the third circuit board through the first FPC. Compared with the first circuit board being electrically connected to the second circuit board and the third circuit board respectively through two connection positions and two FPCs, the number of connection positions on the first circuit board can be reduced, the available area of ​​the first circuit board can be increased, and the design difficulty of the first circuit board can be reduced. For example, the placement of components and connection positions on the first circuit board can be more flexible. For another example, when there are new design requirements, there is more available area on the first circuit board for adding new components or connection positions.

[0009] In a possible embodiment, the electronic device further includes a first frame, the first circuit board is located in the first frame, a card slot is provided on a side of the first frame, the second circuit board is inserted into the card slot, and the second connection end is electrically connected to the second circuit board in the card slot.

[0010] A slot is provided on the side of the first frame, into which the second circuit board is inserted. This slot does not occupy the internal space of the first frame, leaving more space for the battery or other circuit boards within the first frame. For the battery, this can increase its volume and improve its battery life. For other circuit boards, this can increase the available area for other circuit boards, reducing the design difficulty of these other circuit boards.

[0011] In one possible embodiment, the second connection end includes at least one conductive contact, the second circuit board includes at least one conductive spring or at least one conductive contact, and the at least one conductive contact of the second connection end is respectively spring-connected with the at least one conductive spring of the second circuit board, or the at least one conductive contact of the second connection end is respectively welded with the at least one conductive contact of the second circuit board.

[0012] The second circuit board and the second connection end are electrically connected using a conductor contact and a metal spring, which simplifies the installation process and improves reliability. The second circuit board and the second connection end are electrically connected via welding (i.e., an FPC-on-board (FOB) connection). This saves space on the second circuit board, allows for a narrower card slot, and allows for a thinner side of the first frame, thereby saving space within the electronic device.

[0013] In one possible embodiment, the first FPC includes a main path, a first branch and a second branch, the first branch and the second branch are arranged at intervals, the first connection end is connected to the second connection end through the main path and the first branch, and the first connection end is also connected to the third connection end through the main path and the second branch.

[0014] There is a certain error when assembling the circuit board onto the first frame, and there is also a certain error when assembling the connection position onto the circuit board. The first branch and the second branch are both connected to the main path, and the first branch and the second branch are spaced apart, which is equivalent to the main path being bifurcated into the first branch and the second branch. The first branch is connected to the second connection end, and the second branch is connected to the third connection end. The position of the first branch can be fine-tuned according to the position of the second connection end, and the position of the second branch can be fine-tuned according to the position of the third connection end, thereby reducing the degree of wrinkling of the first FPC, so that the first FPC remains relatively flat after assembly. If the first FPC is uneven, internal stress will be generated. When the internal stress is too large, the first FPC will break, so keeping the first FPC relatively flat can avoid the first FPC from breaking.

[0015] In one possible embodiment, the main path and the first branch are close to a side edge of the first frame of the electronic device and extend along the length direction of the side edge; the second branch includes a turning area, and the second branch turns toward the side edge in the turning area; the portion of the second branch located between the main path and the turning area is located on the side of the first branch away from the side edge; the portion of the second branch from the turning area to the third connection end is close to the side edge and extends along the length direction of the side edge.

[0016] The main path and first branch of the first FPC are close to the side edge and extend along the length of the side edge. The second branch bends toward the side edge at the bend area, allowing the portion of the second branch from the bend area to the third connection end to also be close to the side edge and extend along the length of the side edge. Therefore, the first FPC as a whole is close to the side edge and extends along the length of the side edge of the first frame, leaving space for other FPCs and preventing the first FPC from overlapping with other FPCs.

[0017] In a possible implementation manner, the length of the first branch extension path is greater than one quarter of the sum of the length of the main passage extension path and the length of the first branch extension path.

[0018] There is a certain error when assembling the circuit board onto the first frame, and there is also a certain error when assembling the connection point onto the circuit board. The length of the first branch has a lower limit, that is, the first branch is long enough to increase the adjustment range of the position of the first branch, so that the second connection end can move within a certain range. Therefore, even if there is an error in the installation position of the second circuit board on the first frame, the position of the second connection end relative to the second circuit board can be flexibly adjusted so that the first FPC remains relatively flat after assembly. If the first FPC is uneven, internal stress will be generated. When the internal stress is too large, the first FPC will break, so keeping the first FPC relatively flat can prevent the first FPC from breaking.

[0019] In a possible embodiment, the first circuit board is provided with a plurality of connection positions in sequence along a direction perpendicular to the side of the first frame body, the plurality of connection positions including a first connection position connected to the first connection end of the first FPC, and the first connection position is a connection position among the plurality of connection positions close to the side of the first frame body.

[0020] The first connection point is located near the side of the first frame, reserving space for other components (e.g., other connection points) on the first circuit board. Furthermore, the first connection point is connected to the first FPC, which is also located near the side of the first frame, reserving space for other FPCs and preventing the first FPC from overlapping with other FPCs.

[0021] In a possible embodiment, the electronic device further includes a second frame, a hinge and a through-axis FPC, the hinge is located between the second frame and the first frame, the second frame and the first frame are hingedly connected by the hinge, and the side is located on the side of the first frame away from the hinge; the multiple connection positions further include a second connection position connected to the through-axis FPC, the second connection position is a connection position away from the side among the multiple connection positions, the first end of the through-axis FPC passes through the hinge and is electrically connected to the circuit board in the second frame, and the second end of the through-axis FPC is electrically connected to the second connection position near the hinge.

[0022] The second connection point is the connection point farthest from the side among the multiple connection points, that is, the second connection point is the connection point closest to the hinge among the multiple connection points, which can reserve space for other devices (such as other connection points) on the first circuit board. In addition, the second connection point is connected to the through-axis FPC, and the second end of the through-axis FPC is close to the hinge and electrically connected to the second connection point. There is no other FPC between the through-axis FPC and the hinge, which facilitates the through-axis FPC to pass through the hinge and electrically connect to the circuit board in the second frame, and prevents the through-axis FPC from overlapping with other FPCs.

[0023] In a possible embodiment, the electronic device further includes a display screen and a display screen FPC, the multiple connection positions further include a third connection position connected to the display screen FPC, the third connection position is located between the first connection position and the second connection position, and the display screen is electrically connected to the third connection position through the display screen FPC.

[0024] The first connection position and the second connection position are connection positions located on both sides among the multiple connection positions, and the third connection position is located between the first connection position and the second connection position. The first connection position is connected to the first FPC, the second connection position is connected to the through-axis FPC, and the third connection position is connected to the display screen FPC, so that the display screen FPC can be located between the first FPC and the through-axis FPC, avoiding overlap of the display screen FPC with the first FPC and the through-axis FPC.

[0025] In one possible embodiment, the electronic device further includes a battery and a battery FPC, and the first circuit board, the battery, and the third circuit board are arranged in sequence along the length direction of the side; the multiple connection positions also include a fourth connection position connected to the battery FPC, the fourth connection position is located between the first connection position and the second connection position, and the battery is electrically connected to the fourth connection position through the battery FPC.

[0026] The first connection position and the second connection position are connection positions located on both sides among the multiple connection positions, and the fourth connection position is located between the first connection position and the second connection position. The first connection position is connected to the first FPC, the second connection position is connected to the through-axis FPC, and the fourth connection position is connected to the battery FPC, so that the battery FPC can be located between the first FPC and the through-axis FPC, avoiding overlap between the battery FPC and the first FPC and the through-axis FPC.

[0027] In a possible implementation, the orthographic projections of the first FPC and the display screen FPC onto the plane where the first frame is located do not overlap, thereby avoiding increasing the thickness of the electronic device.

[0028] In a possible embodiment, the portion between the first connection end and the second connection end on the first FPC, and / or the portion between the first connection end and the third connection end, includes a radio frequency signal line, two isolation ground lines and two non-metallic hollow films; the two isolation ground lines are located on opposite sides of the radio frequency signal line, and the radio frequency signal line and the two isolation ground lines are located between the two non-metallic hollow films.

[0029] Two isolated ground wires are located on opposite sides of the RF signal line. They act as shields against interference from nearby high-frequency signals. Since the RF signal line transmits high-frequency signals, the isolated ground wires can reduce external interference. The RF signal line and the two isolated ground wires are located between two non-metallic membranes, which support them and prevent them from breaking.

[0030] In a possible embodiment, the portion between the first connection end and the second connection end on the first FPC, and / or the portion between the first connection end and the third connection end, further includes a non-RF signal line, and the projection of the non-RF signal line onto the plane where the non-metallic hollow film is located does not overlap with the non-metallic hollow film.

[0031] The RF signal line and two isolated ground lines are located between two non-metallic membranes. The projection of the non-RF signal line onto the plane of the non-metallic membranes does not overlap. Because the RF signal line and the two isolated ground lines are located between the two non-metallic membranes, their projection onto the plane of the non-RF signal line and the two isolated ground lines is far away. The isolated ground lines act as an isolation ground, shielding nearby high-frequency signals from interference. Since the RF signal line transmits high-frequency signals, the isolated ground lines can reduce interference from non-RF signal lines on the RF signal line.

[0032] In one possible embodiment, the projection of the non-RF signal line onto the plane of the non-metallic hollow film is at a distance H1 from the non-metallic hollow film, and H1 is greater than 0.2 mm. When H1 is greater than 0.2 mm, the isolation ground line is more effective in reducing interference from the non-RF signal line on the RF signal line.

[0033] In a possible embodiment, the portion between the first connection end and the second connection end, and / or the portion between the first connection end and the third connection end on the first FPC includes a radio frequency signal line, a non-metallic hollow film, and an isolation ground line stacked in sequence.

[0034] The isolated ground wire acts as an isolation ground, shielding nearby high-frequency signals from interference. The RF signal lines transmit high-frequency signals, so the isolated ground wire reduces external interference. A non-metallic film supports the RF signal lines and the isolated ground wire, preventing them from breaking. Furthermore, the non-metallic film separates the RF signal lines and the isolated ground wire, preventing electrical connection between them.

[0035] In a possible embodiment, the portion between the first connection end and the second connection end on the first FPC, and / or the portion between the first connection end and the third connection end, further includes a non-RF signal line, and the projection of the non-RF signal line onto the plane where the isolation ground line is located does not overlap with the isolation ground line.

[0036] The projection of non-RF signal lines onto the plane of the isolated ground line does not overlap with the isolated ground line. However, the RF signal lines and the isolated ground line are stacked, so the RF signal lines are relatively close to the isolated ground line, while the non-RF signal lines are separated from each other and the isolated ground line. The isolated ground line acts as an isolation ground, shielding high-frequency signals from interference. The RF signal lines transmit high-frequency signals, so the isolated ground line reduces interference from non-RF signal lines on the RF signal lines.

[0037] In one possible implementation, the projection of the non-RF signal line onto the plane where the isolated ground line resides is at a distance H2 from the isolated ground line, and H2 is greater than 0.2 mm. When H2 is greater than 0.2 mm, the isolated ground line is more effective in reducing interference from the non-RF signal line on the RF signal line. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] FIG1 is a schematic diagram of the appearance of a foldable screen mobile phone provided in an embodiment of the present application;

[0039] FIG2 is a schematic diagram of the internal structure of a foldable screen mobile phone provided in an embodiment of the present application;

[0040] FIG3 is a schematic diagram of the internal structure of another foldable screen mobile phone provided in an embodiment of the present application;

[0041] FIG4 is a schematic diagram of a first FPC shape provided in an embodiment of the present application;

[0042] FIG5 is a schematic diagram of another first FPC shape provided in an embodiment of the present application;

[0043] FIG6 is a schematic diagram of another first FPC shape provided in an embodiment of the present application;

[0044] FIG7 is a schematic diagram of a second branch and a second connection end of a first FPC provided in an embodiment of the present application;

[0045] FIG8 is a schematic diagram of an electrical connection method between a first FPC and a second circuit board provided in an embodiment of the present application;

[0046] FIG9 is a schematic diagram of another electrical connection method between a first FPC and a second circuit board provided in an embodiment of the present application;

[0047] FIG10 is a schematic top view of a wiring in a first FPC provided in an embodiment of the present application;

[0048] FIG11 is a cross-sectional schematic diagram of a first FPC provided in an embodiment of the present application;

[0049] FIG12 is a top view of another wiring diagram in a first FPC provided in an embodiment of the present application;

[0050] FIG13 is a schematic cross-sectional view of another first FPC provided in an embodiment of the present application. DETAILED DESCRIPTION

[0051] First, some concepts involved in this application are described.

[0052] The terms "first", "second", etc. involved in the embodiments of the present application are only used to distinguish features of the same type and cannot be understood as indicating relative importance, quantity, order, etc.

[0053] The terms "exemplary" or "for example" in the embodiments of this application are used to indicate examples, illustrations, or descriptions. Any embodiment or design described in this application as "exemplary" or "for example" should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0054] The terms "coupling" and "connection" involved in the embodiments of this application should be understood in a broad sense. For example, they may refer to a physical direct connection, or an indirect connection achieved through electronic devices, such as a connection achieved through resistors, inductors, capacitors or other electronic devices.

[0055] A flexible printed circuit (FPC) is a flexible, soft printed circuit board made of materials such as polyimide or polyester film as a base material. It has the characteristics of light weight, thin thickness, and good bendability. Flexible circuit boards can be used for electrical connections between different circuit boards. The electrical connection between flexible circuit boards and circuit boards can be achieved through board-to-board (BTB) connectors, FPC-on-board (FOB), etc. Among them, FOB refers to welding the conductive contacts on the FPC to the conductive contacts on the circuit board. Compared with BTB, FOB saves more space on the circuit board, thereby saving space inside the electronic device. However, since FOB needs to be assembled through a welding process, the assembly cost of FOB is higher than that of BTB. The conductive contacts of the present application can be made of metals such as copper and gold.

[0056] The electronic device provided in the embodiment of the present application can be mobile or fixed. The electronic device can be deployed on land (for example, indoors or outdoors, handheld or vehicle-mounted, etc.), on water (for example, ships, etc.), or in the air (for example, airplanes, balloons, and satellites, etc.). The electronic device can be referred to as user equipment (UE), access terminal, terminal unit, subscriber unit, terminal station, mobile station (MS), mobile station, terminal agent, or terminal device, etc. For example, the electronic device can be a mobile phone, a tablet computer, a laptop computer, a smart bracelet, a smart screen, a smart watch, a headset, a smart speaker, a terminal in industrial control, a terminal in self-driving, a terminal in remote medical care, a terminal in a smart grid, a terminal in transportation safety, a terminal in a smart city, a terminal in a smart home, etc. The embodiment of the present application takes the electronic device as a folding screen mobile phone as an example for explanation, but does not limit the specific type and structure of the electronic device.

[0057] Figure 1 is a schematic diagram of the appearance of a foldable screen mobile phone provided in an embodiment of the present application. Among them, Figure 1 A is a schematic diagram of the front of the foldable screen mobile phone, and Figure 1 B is a schematic diagram of the back of the foldable screen mobile phone. The front of the foldable screen mobile phone refers to the plane where the largest display screen is located when unfolded, and the back of the foldable screen mobile phone refers to the plane opposite to the front. As shown in Figures A and B in Figures 1, the foldable screen mobile phone includes a first frame 101, a second frame 102 and a hinge 103. The hinge 103 is located between the second frame 102 and the first frame 101. The first frame 101 and the second frame 102 are hinged by the hinge 103, so that the first frame 101 and the second frame 102 can be folded.

[0058] As shown in Figure 1A , the foldable screen phone includes a first camera 104 and a first display screen 105. The first camera 104 can be located on the second frame 102. As shown in Figure 1B , the foldable screen phone also includes a second camera 106, a third camera 107, and a second display screen 108. The third camera 107 can be located on the second frame 102, and the second camera 106 and the second display screen 108 can be located on the first frame 101.

[0059] Since the first display screen 105 occupies most of the front area of ​​the foldable screen phone, for example, the first display screen 105 occupies more than 90% of the front area of ​​the foldable screen phone, that is, the screen-to-body ratio of the first display screen 105 is greater than 90%, the first display screen 105 can also be called the main display screen (referred to as the main screen). The second display screen 108 is smaller than the first display screen 105, so the second display screen 108 can also be called the secondary display screen (referred to as the secondary screen). Since the third camera 107 and the first display screen 105 are located on opposite sides of the foldable screen phone, when the user uses the foldable screen phone, when the first display screen 105 is facing the user, the third camera 107 is facing away from the user, so the third camera 107 can also be called the rear camera. Since the first camera 104 and the first display screen 105 are located on the same side of the foldable screen mobile phone, and the second camera 106 and the second display screen 108 are located on the same side of the foldable screen mobile phone, when the user uses the foldable screen mobile phone, when the first display screen 105 is facing the user, the first camera 104 is also facing the user; when the second display screen 108 is facing the user, the second camera 106 is also facing the user, so the first camera 104 and the second camera 106 can also be called front cameras.

[0060] When the foldable phone is unfolded, the first display screen 105 can be used to display images and receive user touch operations, and the first camera 104 or the third camera 107 can be used to capture images. When the foldable phone is folded, the third camera 107 or the second camera 106 can be used to capture images; the second display screen 108 can be used to display images and receive user touch operations.

[0061] Figure 2 shows a schematic diagram of the internal structure of a foldable screen mobile phone according to an embodiment of the present application. The first frame 101 of the foldable screen mobile phone includes a first circuit board 201, a second circuit board 202, a third circuit board 203, a side FPC 205, a second FPC 206, a through-axis FPC 213, and a battery FPC 215. The first circuit board 201, the battery 204, and the third circuit board 203 are arranged in sequence along the length of the side 217 of the first frame 101. The side FPC 205, the second FPC 206, the battery FPC 215, and the through-axis FPC 213 are arranged in sequence from close to the side 217 to away from the side 217.

[0062] In the embodiment of the present application, the side edge 217 of the first frame body 101 is located on a side of the first frame body 101 away from the hinge 103. For example, in FIG2 , the side edge 217 of the first frame body 101 refers to the rightmost side of the first frame body 101. The bottom edge 218 of the first frame body 101 refers to an edge perpendicular to the side edge 217 and away from the first circuit board 201. For example, in FIG2 , the bottom edge 218 of the first frame body 101 refers to the bottommost side of the first frame body 101.

[0063] In some embodiments, a first antenna switch (not shown) is provided on the second circuit board 202, and a first antenna (i.e., a side antenna) (not shown) is provided on the side 217 of the first frame 101. The first antenna switch is electrically connected to the first antenna and is used to switch the operating frequency band and transmit / receive state of the first antenna. A slot 216 is provided on the side 217 of the first frame 101, and the second circuit board 202 is inserted into the slot 216. This not only facilitates the electrical connection between the second circuit board 20 and the first antenna on the side 217, but also ensures that the second circuit board 202 does not occupy the internal space of the first frame 101, leaving more space for the battery 204 or other circuit boards (e.g., the first circuit board 201 and the third circuit board 203) within the first frame 101. For the battery 204, this can increase its volume, thereby improving its battery life. For other circuit boards, this can increase the available area of ​​other circuit boards, reducing the design difficulty of other circuit boards.

[0064] In some embodiments, a second antenna switch (not shown) and a second speaker 207 and other components are provided on the third circuit board 203, and a second antenna (i.e., a bottom edge antenna) is provided on the bottom edge 218 of the first frame body 101. The second antenna switch is electrically connected to the second antenna, and the second antenna switch is used to switch the operating frequency band and the transmitting and receiving status of the second antenna.

[0065] In some embodiments, the first circuit board 201 is a mainboard in the first frame 101 , and components such as the first speaker 208 and the second camera 106 are disposed on the first circuit board 201 . The first circuit board 201 is sequentially provided with a plurality of connection points along a direction perpendicular to the side 217 .

[0066] The multiple connection points of the first circuit board 201 include a connection point 210 (second connection point) connected to a through-axis FPC 213. Connection point 210 is the connection point farthest from the side 217 among the multiple connection points. The first end of the through-axis FPC 213 passes through the hinge 103 and is electrically connected to the circuit board 214 in the second frame 102. The second end of the through-axis FPC 213 is electrically connected to the connection point 210 near the hinge 103. In some embodiments, the circuit board 214 is the mainboard in the second frame 102. The circuit board 214 includes a system on chip (SoC). The SoC may include control components such as an application processor, a baseband, a graphics processing unit (GPU), and a network processing unit (NPU), thereby playing a control role. The circuit board 214 communicates with the first circuit board 201 through the through-axis FPC 213 to control components on the first circuit board 201, such as controlling the first speaker 208 to produce sound and controlling the second camera 106 to capture images.

[0067] The multiple connection points of the first circuit board 201 also include a connection point 211 for connecting to the side FPC 205. Connection point 211 is the connection point closest to the side 217 among the multiple connection points. The second circuit board 202 is electrically connected to the connection point 211 via the side FPC 205. The circuit board 214 in the second frame 102 communicates with the second circuit board 202 via the through-axis FPC 213, the first circuit board 201, and the side FPC 205. This allows the control of components on the second circuit board 202, such as controlling the first antenna switch on the second circuit board 202 to switch the operating frequency band and transmit and receive status of the first antenna.

[0068] The multiple connection points of the first circuit board 201 also include a connection point 212 for connecting to the second FPC 206. Connection point 212 is located between connection point 211 and connection point 210. The third circuit board 203 is electrically connected to the connection point 212 via the second FPC 206. The circuit board 214 in the second frame 102 communicates with the third circuit board 203 via the through-shaft FPC 213, the first circuit board 201, and the second FPC 206. This allows control of components on the third circuit board 203, such as controlling the second antenna switch on the third circuit board 203 to change the second antenna's operating frequency band and transmit and receive status, and controlling the sound of the second speaker 207.

[0069] The multiple connection points of the first circuit board 201 also include a connection point 209 (fourth connection point) for connecting to a battery FPC 215. Connection point 209 is located between connection points 211 and 210. The battery 204 is electrically connected to connection point 209 via the battery FPC 215 and is used to power the various circuit boards in the first and second frames 101, 102.

[0070] It should be noted that the connection points on the circuit board involved in this application can be board-to-board (BTB) connectors, conductive contacts, etc., and are not specifically limited.

[0071] Due to the limited internal space of electronic devices, the available area of ​​the first circuit board is also limited. First circuit board 201 is not only equipped with components such as speakers and cameras, but also with multiple connection points, which reduces the available area of ​​first circuit board 201. This requires targeted design of the placement of each component and multiple connection points on first circuit board 201, which increases the design difficulty of first circuit board 201. For example, the placement of components and connection points on the target circuit board is difficult to design, leaving less available area for connection points to the second display screen 108. For another example, when design requirements change, it is difficult to add new components or connection points to the target circuit board.

[0072] Furthermore, for small circuit boards such as the second circuit board 202 and the third circuit board 203, which contain relatively few components, the number of pins required for communication with the first circuit board 201 is also small. If the second circuit board 202 is electrically connected to the first circuit board 201 via one FPC, and the third circuit board 203 is electrically connected to the first circuit board 201 via another FPC, two connection points would need to be provided on the first circuit board 201 to electrically connect to the two FPCs, resulting in high costs.

[0073] To this end, in the electronic device provided in the embodiment of the present application, the first circuit board is electrically connected to the second circuit board and the third circuit board respectively through an FPC, and a connection position for connecting the FPC is set on the first circuit board, thereby reducing the number of connection positions on the first circuit board, increasing the available area of ​​the first circuit board, and reducing the design difficulty of the first circuit board.

[0074] Figure 3 is a schematic diagram of the internal structure of another foldable screen mobile phone, where Figure 3B is a schematic diagram of the housing engaged with the first frame, and Figure 3A is a schematic diagram of the internal structure of the foldable screen mobile phone with the housing removed. After flipping the housing 306 in the direction indicated by the arrow, it can be engaged with the first frame.

[0075] The first frame 101 shown in A of FIG3 also includes a first FPC 301, which replaces the side FPC 205 and the second FPC 206 in FIG2 . Accordingly, the first circuit board 201 includes a plurality of connection points arranged in a direction perpendicular to the side 217, and further includes a connection point 302 (first connection point) connected to the first FPC 301. Connection point 302 is the connection point closest to the side 217 among the plurality of connection points and replaces the connection points 211 and 212 in FIG2 . Connection point 302 of the first circuit board 201 is electrically connected to the second circuit board 202 and the third circuit board 203 via the first FPC 301. The circuit board 214 in the second frame 102 communicates with the second circuit board 202 and the third circuit board 203 through the through-axis FPC 213, the first circuit board 201 and the first FPC 301, thereby being able to control the components on the second circuit board 202 and the third circuit board 203, for example, controlling the first antenna switch on the second circuit board 202 to switch the operating frequency band and transceiver status of the first antenna, controlling the antenna switch on the third circuit board 203 to switch the operating frequency band and transceiver status of the second antenna, controlling the sound of the second speaker, etc.

[0076] In addition, the housing 306 shown in FIG3B , which is fastened to the first frame 101, includes the second display screen 108 and the display screen FPC 304. The second display screen 108 is electrically connected to the display screen FPC 304. Accordingly, the multiple connection points of the first circuit board 201 shown in FIG3A also include a connection point 303 (third connection point) for connecting to the display screen FPC 304. Connection point 303 (third connection point) is located between connection point 302 (first connection point) and connection point 210 (second connection point). When the housing 306 is flipped over as shown by the arrow in FIG3 and fastened to the first frame 101, the second display screen 108 can be electrically connected to the connection point 303 via the display screen FPC 304. The circuit board 214 in the second frame 102 communicates with the second display screen 108 via the through-shaft FPC 213, the first circuit board 201, and the display screen FPC 304, for example, to control the second display screen 108 to display images, receive user touch operations from the second display screen 108, etc.

[0077] During the assembly of the housing 306 to the first frame 101, the display FPC 304 bends and bears a portion of the weight of the housing 306, generating internal stress within the display FPC 304. The display FPC 304 is designed to include multiple bends, which disperse the internal stress generated by the display FPC 304. This improves the internal stress tolerance of the display FPC 304 and prevents breakage of the display FPC 304 due to excessive internal stress during assembly.

[0078] It should be noted that the display screen FPC 304 shown in FIG. 3A and the display screen FPC 304 shown in FIG. 3B are the same display screen FPC, wherein the display screen FPC 304 shown in FIG. 3A is connected to the connection position 303, and the display screen FPC 304 shown in FIG. 3B is not connected to the connection position 303.

[0079] Multiple connection points on first circuit board 201, including connection point 210 (second connection point), connection point 209 (fourth connection point), connection point 303 (third connection point), and connection point 302 (first connection point), are arranged on the side of first circuit board 201 near third circuit board 203, in a direction perpendicular to side edge 217. This prevents overlap between the multiple FPCs connected to the multiple connection points and also prevents overlap between the multiple FPCs and components on first circuit board 201, thereby preventing the thickness of the electronic device from increasing.

[0080] Connection point 210 (second connection point) is the connection point of the multiple connection points that is away from the side 217 of the first frame 101. In other words, connection point 210 is the connection point of the multiple connection points that is close to the hinge 103. It can reserve space for other devices (such as other connection points) on the first circuit board 201. In addition, connection point 210 is connected to a through-axis FPC 213. The second end of the through-axis FPC 213 is electrically connected to the second connection point 210 near the hinge 103. There is no other FPC between the through-axis FPC 213 and the hinge 103. This facilitates the through-axis FPC 213 to pass through the hinge 103 and electrically connect to the circuit board 214 in the second frame 102, and avoids the through-axis FPC 213 from overlapping with other FPCs. Therefore, the thickness of the electronic device is not increased.

[0081] Connection point 302 (first connection point) is located near the side 217 of the first housing 101, among the multiple connection points, reserving space for other components (e.g., other connection points) on the first circuit board 201. Furthermore, connection point 305 on the third circuit board 203, which connects to the first flexible printed circuit board (FPC) 301, is also located near the side 217 of the first housing 101. This allows the first flexible printed circuit board 301 to be positioned near the side 217 of the first housing 101, reserving space for other FPCs and preventing overlap between the first FPC 301 and other FPCs (in FIG. 3 , the display FPC 304), thereby preventing the thickness of the electronic device from increasing. Furthermore, connection point 305 on the third circuit board 203 is located on the side of the third circuit board 203 near the first circuit board 201, preventing overlap between the first FPC 301 and components on the third circuit board 203.

[0082] Connection point 302 (first connection point) and connection point 210 (second connection point) are among the multiple connection points located on both sides. Connection point 302 connects to first FPC 301, connection point 210 connects to through-shaft FPC 213, connection point 303 connects to display FPC 304, and connection point 209 connects to battery FPC 215. Connection point 303 (third connection point) and connection point 209 (fourth connection point) are located between connection point 302 (first connection point) and connection point 210 (second connection point), allowing display FPC 304 and battery FPC 215 to be located between first FPC 301 and through-shaft FPC 213, preventing the display FPC 304 from overlapping with the first FPC 301 and through-shaft FPC 213, and preventing the battery FPC 215 from overlapping with the first FPC 301 and through-shaft FPC 213, thereby not increasing the thickness of the electronic device. In addition, the positions of the connection bit 209 and the connection bit 303 can be interchanged.

[0083] Figures 4-6 illustrate several possible shapes for the first FPC 301. The first FPC 301 includes a first connection end E1, a second connection end E2, and a third connection end E3. The first connection end E1 is electrically connected to the first circuit board 201 via a connection position 302, and the third connection end E3 is electrically connected to the third circuit board 203 via a connection position 305. Because the second circuit board 202 is inserted into the slot 216 of the side 217 of the first frame 101, the second connection end E2 is electrically connected to the second circuit board 202 within the slot 216.

[0084] The first FPC 301 further includes a main path 3011, a first branch path 3012, and a second branch path 3013. The first connection end E1 is connected to the second connection end E2 through the main path 3011 and the first branch path 3012, and is further connected to the third connection end E3 through the main path 3011 and the second branch path 3013.

[0085] It should be noted that the present application does not limit the number of branches and the number of connection terminals of the first FPC 301. The first FPC 301 may also include more branches connected to the main path, and connection terminals connected to the branches. The connection terminals can be connected to more circuit boards, thereby electrically connecting the first circuit board 201 to more circuit boards.

[0086] There are certain errors when assembling the circuit board onto the first frame 101, and there are also certain errors when assembling the connector onto the circuit board. The first branch 3012 and the second branch 3013 are both connected to the main path 3011. The first branch 3012 and the second branch 3013 are spaced apart, equivalent to the main path 3011 bifurcating into the first branch 3012 and the second branch 3013. The first branch 3012 connects to the second connection end E2, and the second branch 3013 connects to the third connection end E3. The position of the first branch 3012 can be fine-tuned based on the position of the second connection end E2, and the position of the second branch 3013 can be fine-tuned based on the position of the third connection end E3. This reduces wrinkles on the first FPC 301, ensuring that the first FPC 301 remains relatively flat after assembly. If the first FPC 301 is not flat, internal stress will be generated. When the internal stress is too large, the first FPC 301 will be broken. Therefore, keeping the first FPC 301 relatively flat can prevent the first FPC 301 from breaking.

[0087] The lengths of the first branch 3012 and the second branch 3013 have a lower limit. For example, the length of the extension path of the first branch 3012 is greater than one-quarter the sum of the lengths of the extension path of the main path 3011 and the extension path of the first branch 3012. For another example, the length of the first branch 3012 is at least 1 centimeter. There is a certain degree of error when assembling the circuit board onto the first frame 101, and there is also a certain degree of error when assembling the connector onto the circuit board. The length of the first branch 3012 has a lower limit. In other words, the first branch 3012 is long enough to increase the adjustment range of its position, allowing the second connection end E2 to move within a certain range. Therefore, even if there is an error in the installation position of the second circuit board 202 on the first frame 101, the position of the second connection end E2 relative to the second circuit board 202 can be flexibly adjusted, ensuring that the first FPC 301 remains relatively flat after assembly. If the first FPC 301 is not flat, internal stress will be generated. When the internal stress is too large, the first FPC 301 will be broken. Therefore, keeping the first FPC 301 relatively flat can prevent the first FPC 301 from breaking.

[0088] Since the third circuit board 203 is farther away from the first circuit board 201 than the second circuit board 202, the first branch 3012 connects the second circuit board 202, and the second branch 3013 connects the third circuit board 203, so the length of the second branch 3013 is greater than the length of the first branch 3012, so that the second branch 3013 has sufficient length to connect to the third circuit board 203.

[0089] The connection point 302 (first connection point) on the first circuit board 201, which is connected to the first FPC 301, is the connection point closest to the side 217 of the first frame 101. The main path 3011 and the first branch path 3012 are located near the side 217 of the first frame 101 and extend along the length of the side 217 of the first frame 101. The second branch path 3013 includes a turning area 3014, where the second branch path 3013 turns toward the side 217 of the first frame 101. The portion of the second branch path 3013 located between the main path 3011 and the turning area 3014 is located on the side of the first branch path 3012 away from the side 217 of the first frame 101. The portion of the second branch 3013 between the bend 3014 and the third connection end E3 is adjacent to the side edge 217 of the first frame 101 and extends along the length of the side edge 217 of the first frame 101. The main path 3011 and the first branch 3012 of the first FPC 301 are adjacent to the side edge 217 and extend along the length of the side edge 217. The second branch 3013 bends toward the side edge 217 at the bend 3014, allowing the portion of the second branch 3013 between the bend 3014 and the third connection end E3 to also be adjacent to the side edge 217 and extend along the length of the side edge 217. Therefore, the first FPC 301 as a whole is adjacent to the side edge 217 and extends along the length of the side edge 217, reserving space for other FPCs (such as the display FPC 304) and preventing the first FPC 301 from overlapping with other FPCs.

[0090] The orthographic projections of the first FPC 301 and the display screen FPC 304 onto the plane where the first frame body 101 is located do not overlap, that is, the first FPC 301 and the display screen FPC 304 do not overlap, thereby avoiding increasing the thickness of the electronic device.

[0091] Furthermore, by widening the first FPC 301, sufficient space is provided for the wiring within the first FPC 301 to widen, thereby reducing wiring impedance. The first branch 3012 is located between the second branch 3013 and the side 217 of the first frame 101. Therefore, widening the first branch 3012 away from the side 217 of the first frame 101 is difficult. However, widening the main path 3011 and the second branch 3013 away from the side 217 of the first frame 101 is possible. Therefore, in a direction perpendicular to the side 217 of the first frame 101, the maximum width of the main path 3011 and the maximum width of the second branch 3013 are both greater than or equal to the maximum width of the first branch 3012, thereby reducing wiring impedance within the main path 3011 and the second branch 3013.

[0092] For example, as shown in Figures 4-6 , the maximum width of the first branch 3012 of the first FPC 301 shown in Figure 4 is equal to the maximum width of the second branch 3013. The maximum width of the second branch 3013 of the first FPC 301 shown in Figures 5 and 6 is greater than the maximum width of the first branch 3012, thereby reducing the impedance of the traces in the second branch 3013. In addition, compared with the first FPC 301 shown in Figures 4 and 6 , the first FPC 301 shown in Figure 5 reduces the length of the first branch 3012 (e.g., minimizes the length of the first branch 3012) and increases the length of the main path 3011 (e.g., maximizes the length of the main path 3011), thereby leaving more length for further widening of the main path 3011. Therefore, the maximum width of the main path 3011 shown in Figure 5 is greater than the maximum width of the main path 3011 shown in Figures 4 and 6 , thereby reducing the impedance of the traces in the main path 3011. 4 and 6 is longer than the first branch 3012 shown in FIG. 5 , making it easier to fine-tune the position of the first branch 3012 according to the position of the second connection end E2 , making it easier to install the second connection end E2 .

[0093] As shown in Figure 7, the portion of the second branch 3013 connected to the second connection end E2 is bent toward the slot 216, facilitating the second connection end E2's insertion into the slot 216 on the side 217 of the first frame 101. The portion electrically connects to the second circuit board 202 within the slot 216, thereby positioning the second connection end E2 and the second branch 3013 in different planes. Furthermore, the second connection end E2 includes at least one exposed conductive contact (e.g., T1-T4). The second circuit board 202 can be electrically connected to the at least one conductive contact of the second connection end E2 through the following possible implementations.

[0094] In one possible embodiment, as shown in FIG8 , the second circuit board 202 includes at least one conductive spring (e.g., S1-S4). The conductive spring can be made of metals such as copper and gold, or materials such as conductive plastic. The conductive spring on the second circuit board 202 is electrically connected to a device (e.g., the first antenna switch) on the second circuit board 202. At least one conductive contact (e.g., T1-T4) of the second connection end E2 is electrically connected to the at least one conductive spring (e.g., S1-S4) on the second circuit board 202 via spring connections, thereby electrically connecting the at least one conductive contact (e.g., T1-T4) of the second connection end E2 to the device (e.g., the first antenna switch) on the second circuit board 202.

[0095] When assembling the second connection end E2 and the second circuit board 202 into the card slot 216, first stick the second connection end E2 to the inner wall of the card slot 216, and align the conductive spring sheet of the second circuit board 202 with the conductive contact of the second connection end E2. Insert the second circuit board 202 into the card slot 216 along the inner wall of the card slot 216 so that the conductive spring sheet on the second circuit board 202 is connected to the conductive contact of the second connection end E2, thereby realizing the electrical connection between the conductive spring sheet of the second circuit board 202 and the conductive contact of the second connection end E2.

[0096] In another possible implementation, as shown in FIG9 , the second circuit board 202 includes at least one conductive contact (e.g., T5-T8) for electrically connecting to a component (e.g., the first antenna switch) on the second circuit board 202. At least one conductive contact (e.g., T1-T4) of the second connection terminal E2 is electrically connected to at least one conductive contact on the second circuit board 202 by soldering, i.e., the second connection terminal E2 and the second circuit board 202 are connected using a FOB connection.

[0097] When assembling the second connection end E2 and the second circuit board 202 into the card slot 216, first solder at least one conductive contact of the second connection end E2 to at least one conductive contact on the second circuit board 202, respectively, to achieve electrical connection between the conductive contact of the second circuit board 202 and the conductive contact of the second connection end E2; then insert the second circuit board 202 and the second connection end E2 into the card slot 216 along the inner wall of the card slot 216.

[0098] The second circuit board 202 and the second connection end E2 are electrically connected by means of a spring connection, which simplifies the installation process and has high reliability. The second circuit board 202 and the second connection end E2 are electrically connected by means of a FOB connection, which can save space on the second circuit board 202, allow the slot 216 to be processed narrower, and allow the side 217 of the first frame 101 to be processed thinner, thereby saving space inside the electronic device. Both methods can be applied to scenarios where the number of signals transmitted between the second circuit board 202 and the first circuit board 201 is small. This application is not limited to the above two electrical connection methods, and other electrical connection methods can also be used.

[0099] The first FPC 301 can transmit control signals between the first circuit board 201 and the second and third circuit boards 202 and 203, such as signals for controlling the first and second antenna switches, and signals for controlling the second speaker. These control signals are collectively referred to as non-RF signals. The first FPC 301 can also transmit RF signals for the first and / or second antennas. The traces that transmit RF signals are called RF signal lines, and the traces that transmit non-RF signals are called non-RF signal lines.

[0100] In one possible embodiment, as shown in Figures 10 and 11, Figure 10 is a top view schematic diagram of the routing in the first FPC 301. Projecting along section line AA in Figure 10 in the direction indicated by the arrow yields the cross-sectional schematic diagram of the first FPC 301 shown in Figure 11. The portion between the first connection end E1 and the second connection end E2, and / or the portion between the first connection end E1 and the third connection end E3, on the first FPC 301 includes at least one non-RF signal line 84 and, optionally, may also include at least one multilayer structure 80. The multilayer structure 80 includes at least one RF signal line 81, two isolated ground lines 82, and two non-metallic hollow films 83.

[0101] As shown in Figure 10, the first circuit board 201 can transmit a control signal for controlling the first antenna switch to the second circuit board 202 via a non-RF signal line 84 between the first connection end E1 and the second connection end E2. This non-RF signal line 84 passes through the main path 3011 and the first branch 3012. The first circuit board 201 also transmits a control signal for controlling the second antenna switch and a control signal for controlling the second speaker to the third circuit board 203 via two non-RF signal lines 84 between the first connection end E1 and the third connection end E3. These two non-RF signal lines 84 pass through the main path 3011 and the second branch 3013.

[0102] It should be noted that, as shown in FIG11 , different non-RF signal lines 84 in the main pathway or the same branch pathway can be located on different layers, and the projections of the different non-RF signal lines 84 onto the plane of the non-metallic hollow film 83 can overlap. Therefore, as shown in FIG10 , from a top-down perspective, the three non-RF signal lines 84 in the main pathway 3011 appear as a single line due to their overlap, and the two non-RF signal lines 84 in the second branch pathway 3013 also appear as a single line due to their overlap.

[0103] When the first FPC 301 includes a set of multilayer structures 80, the set of multilayer structures 80 can be located between the first connection end E1 and the second connection end E2, that is, the set of multilayer structures 80 passes through the main path 3011 and the first branch path 3012. The first circuit board 201 transmits RF signals to the second circuit board 202 via the set of multilayer structures 80, reducing external interference with the RF signals, thereby transmitting the RF signals to the first antenna on the side 217 of the first frame 101. Alternatively, the set of multilayer structures 80 can be located between the first connection end E1 and the third connection end E3, that is, the set of multilayer structures 80 passes through the main path 3011 and the second branch path 3013. The first circuit board 201 transmits RF signals to the third circuit board 203 via the set of multilayer structures 80, reducing external interference with the RF signals, thereby transmitting the RF signals to the second antenna on the bottom edge 218 of the first frame 101. When the first FPC 301 includes two sets of multilayer structures 80, a combination of the above two approaches can be used, and the details will not be repeated here.

[0104] As shown in Figure 11, the two isolated ground lines 82 and the RF signal line 81 are located on the same layer. The two isolated ground lines 82 are located on opposite sides of the RF signal line 81. The two isolated ground lines 82 serve as isolation grounds to shield interference from high-frequency signals that are relatively close. The RF signal transmitted by the RF signal line 81 is a high-frequency signal, so the isolated ground line 82 can reduce external interference to the RF signal line 81.

[0105] The RF signal line 81 and the two isolated ground lines 82 are located between two non-metallic hollow films 83. The projections of the RF signal line 81 and the two isolated ground lines 82 onto the plane of any non-metallic hollow film 83 are located within the non-metallic hollow film 83. The two non-metallic hollow films 83 are used to support the RF signal line 81 and the two isolated ground lines 82, preventing them from breaking.

[0106] The non-RF signal line 84 can be located in the same layer as any of the two non-metallic hollow films 83 and the RF signal line 81. The projection of the non-RF signal line 84 onto the plane where any non-metallic hollow film 83 is located is located outside the non-metallic hollow film 83, that is, the projection does not overlap with the non-metallic hollow film 83. Because the RF signal line 81 and the two isolated ground lines 82 are located between the two non-metallic hollow films 83, the projection of the non-RF signal line 84 onto the plane where the RF signal line 81 and the two isolated ground lines 82 are located is far away from the RF signal line 81 and the two isolated ground lines 82. The isolated ground line 82 acts as an isolation ground to shield interference from high-frequency signals that are relatively close. The RF signal transmitted by the RF signal line 81 is a high-frequency signal, so the isolated ground line 82 can reduce the interference of the non-RF signal line 84 on the RF signal line 81. Exemplarily, the distance between the projection of the non-RF signal line 84 onto the plane where any non-metallic hollow film 83 is located and any non-metallic hollow film 83 is H1, and H1 is greater than 0.2 mm. When H1 is greater than 0.2 mm, the effect of the isolated ground line 84 in reducing the interference of the non-RF signal line 84 on the RF signal line 81 is more obvious.

[0107] In another possible embodiment, as shown in Figures 12 and 13, Figure 12 is a top view schematic diagram of the routing in the first FPC 301. Projecting along the section line BB in Figure 12 in the direction indicated by the arrow, a cross-sectional schematic diagram of the first FPC 301 shown in Figure 13 can be obtained. The portion between the first connection end E1 and the second connection end E2, and / or the portion between the first connection end E1 and the third connection end E3 on the first FPC 301 includes at least one non-RF signal line 84, and optionally, may also include at least one group of multilayer structures 80. A group of multilayer structures 80 includes at least one RF signal line 81, an isolated ground line 82, and a non-metallic empty film 83. Regarding the non-RF signal line 84 shown in Figures 12 and 13, refer to the description of the non-RF signal line 84 shown in Figures 10 and 11. Regarding the function of the multilayer structure 80 shown in Figures 12 and 13, refer to the functional description of the multilayer structure 80 shown in Figures 10 and 11, and no further details will be given here.

[0108] As shown in Figure 13, the RF signal line 81, the non-metallic hollow film 83, and the isolated ground line 82 are stacked in sequence. The projection of the RF signal line 81 onto the plane where the isolated ground line 82 is located is located inside the isolated ground line 82. The projection of the RF signal line 81 onto the plane where the non-metallic hollow film 83 is located is located inside the non-metallic hollow film 83. The isolated ground line 82 serves as an isolation ground to shield interference for high-frequency signals that are relatively close. The RF signal transmitted by the RF signal line 81 is a high-frequency signal, so the isolated ground line 82 can reduce external interference to the RF signal line 81. The non-metallic hollow film 83 is used to support the RF signal line 81 and the isolated ground line 82 to prevent the RF signal line 81 and the isolated ground line 82 from breaking, and the non-metallic hollow film 83 separates the RF signal line 81 and the isolated ground line 82 to avoid electrical connection between the RF signal line 81 and the isolated ground line 82.

[0109] The non-RF signal line 84 can be located in the same layer as any one of the non-metallic hollow film 83, the isolated ground line 82, and the RF signal line 81. The projection of the non-RF signal line 84 onto the plane where the isolated ground line 82 is located is located outside the isolated ground line 82, that is, the projection does not overlap with the isolated ground line 82. The RF signal line 81 and the isolated ground line 82 are stacked, so the RF signal line 81 is close to the isolated ground line 82, while the non-RF signal line 84 is at a certain distance from the RF signal line 81 and the isolated ground line 82. As an isolation ground, the isolated ground line 82 shields interference for high-frequency signals that are relatively close, and the RF signal line 81 transmits a high-frequency signal, so the isolated ground line 82 can reduce the interference of the non-RF signal line 84 on the RF signal line 81. Exemplarily, the projection of the non-RF signal line 84 onto the isolated ground line 82 (or the non-metallic hollow film 83) is at a distance H2 from the isolated ground line 82 (or the non-metallic hollow film 83), and H2 is greater than 0.2 mm. When H2 is greater than 0.2 mm, the effect of the isolated ground line 82 in reducing the interference of the non-RF signal line 84 on the RF signal line 81 is more obvious.

[0110] It should be noted that, compared to the embodiment shown in Figures 10 and 11 , the embodiment shown in Figures 12 and 13 has a greater effect on reducing external interference on the RF signal line 81 due to the larger area of ​​the isolated ground line 82. Compared to the embodiment shown in Figures 12 and 13 , the embodiment shown in Figures 10 and 11 has a greater effect on reducing external interference on the RF signal line 81 due to the isolated ground line 82 and the RF signal line 81 being located on the same layer. The non-metallic hollow film 83 can be processed to be thinner without affecting the electrical performance of the isolated ground line 82 and the RF signal line 81. As a result, the first FPC 301 is thinner overall, reducing the thickness of the electronic device.

[0111] In the electronic device provided by the embodiment of the present application, the first connection end of the first FPC is electrically connected to the first circuit board, the second connection end of the first FPC is electrically connected to the second circuit board, and the third connection end of the first FPC is electrically connected to the third circuit board, so that the first circuit board can be electrically connected to the first FPC through one connection position, and electrically connected to the second circuit board and the third circuit board through the first FPC. Compared with the first circuit board being electrically connected to the second circuit board and the third circuit board respectively through two connection positions and two FPCs, the number of connection positions on the first circuit board can be reduced, the available area of ​​the first circuit board can be increased, and the design difficulty of the first circuit board can be reduced. For example, the placement of components and connection positions on the first circuit board can be more flexible. For another example, when there are new design requirements, there is more available area on the first circuit board for adding new components or connection positions.

Claims

1. An electronic device, characterized in that: It includes a first flexible circuit board, a first circuit board, a second circuit board and a third circuit board; the first flexible circuit board includes a first connection end, a second connection end and a third connection end, the first connection end is electrically connected to the first circuit board, the second connection end is electrically connected to the second circuit board, and the third connection end is electrically connected to the third circuit board.

2. The electronic device according to claim 1, wherein The electronic device also includes a first frame, the first circuit board is located in the first frame, a card slot is provided on a side of the first frame, the second circuit board is inserted into the card slot, and the second connection end is electrically connected to the second circuit board in the card slot.

3. The electronic device according to claim 2, wherein: The second connection end includes at least one conductive contact, the second circuit board includes at least one conductive spring or at least one conductive contact, the at least one conductive contact of the second connection end is respectively spring-connected with the at least one conductive spring of the second circuit board, or the at least one conductive contact of the second connection end is respectively welded to the at least one conductive contact of the second circuit board.

4. The electronic device according to any one of claims 1 to 3, characterized in that: The first flexible circuit board includes a main path, a first branch and a second branch, the first branch and the second branch are arranged at intervals, the first connection end is connected to the second connection end through the main path and the first branch, and the first connection end is also connected to the third connection end through the main path and the second branch.

5. The electronic device according to claim 4, characterized in that The main path and the first branch are close to a side edge of a first frame of the electronic device and extend along the length direction of the side edge; the second branch includes a turning area, and the second branch turns toward the side edge at the turning area; the portion of the second branch located between the main path and the turning area is located on a side of the first branch away from the side edge; the portion of the second branch from the turning area to the third connection end is close to the side edge and extends along the length direction of the side edge.

6. The electronic device according to claim 4 or 5, characterized in that: The length of the first branch extension path is greater than one quarter of the sum of the length of the main passage extension path and the length of the first branch extension path.

7. The electronic device according to any one of claims 2 to 6, characterized in that: The first circuit board is sequentially provided with a plurality of connection positions along a direction perpendicular to the side edge, the plurality of connection positions including a first connection position connected to a first connection end of the first flexible circuit board, and the first connection position is a connection position close to the side edge among the plurality of connection positions.

8. The electronic device according to claim 7, wherein: The electronic device also includes a second frame, a hinge and a through-axis flexible circuit board, the hinge is located between the second frame and the first frame, the second frame and the first frame are hinged by the hinge, and the side is located on the side of the first frame away from the hinge; the multiple connection positions also include a second connection position connected to the through-axis flexible circuit board, the second connection position is the connection position among the multiple connection positions away from the side, the first end of the through-axis flexible circuit board passes through the hinge and is electrically connected to the circuit board in the second frame, and the second end of the through-axis flexible circuit board is electrically connected to the second connection position near the hinge.

9. The electronic device according to claim 8, wherein: The electronic device also includes a display screen and a flexible circuit board for the display screen. The multiple connection positions also include a third connection position connected to the flexible circuit board for the display screen. The third connection position is located between the first connection position and the second connection position. The display screen is electrically connected to the third connection position through the flexible circuit board for the display screen.

10. The electronic device according to claim 8 or 9, characterized in that: The electronic device also includes a battery and a battery flexible circuit board, and the first circuit board, the battery, and the third circuit board are arranged in sequence along the length direction of the side; the multiple connection positions also include a fourth connection position connected to the battery flexible circuit board, and the fourth connection position is located between the first connection position and the second connection position, and the battery is electrically connected to the fourth connection position through the battery flexible circuit board.

11. The electronic device according to claim 9, wherein: The orthographic projections of the first flexible circuit board and the display screen flexible circuit board onto the plane where the first frame is located do not overlap.

12. The electronic device according to any one of claims 1 to 11, characterized in that: The portion between the first connection end and the second connection end on the first flexible circuit board, and / or the portion between the first connection end and the third connection end, includes a radio frequency signal line, two isolated ground lines and two non-metallic hollow films; the two isolated ground lines are located on opposite sides of the radio frequency signal line, and the radio frequency signal line and the two isolated ground lines are located between the two non-metallic hollow films.

13. The electronic device according to claim 12, wherein: The portion between the first connection end and the second connection end on the first flexible circuit board, and / or the portion between the first connection end and the third connection end, also includes a non-RF signal line, and the orthographic projection of the non-RF signal line onto the plane where the non-metallic hollow film is located does not overlap with the non-metallic hollow film.

14. The electronic device according to any one of claims 1 to 13, characterized in that: The portion between the first connection end and the second connection end, and / or the portion between the first connection end and the third connection end on the first flexible circuit board includes a radio frequency signal line, a non-metallic hollow film and an isolation ground line stacked in sequence.

15. The electronic device according to claim 14, characterized in that The portion between the first connection end and the second connection end on the first flexible circuit board, and / or the portion between the first connection end and the third connection end, also includes a non-RF signal line, and the orthographic projection of the non-RF signal line onto the plane where the isolated ground line is located does not overlap with the isolated ground line.

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