Flexible circuit boards and electronic devices

Abstract

The present application discloses a flexible circuit board and an electronic device, belonging to the technical field of flexible circuit boards. The flexible circuit board is applied to electronic devices, and the flexible circuit board includes: a flexible carrier part, a pad part is provided on the first side of the flexible carrier part; a transmission line part, the transmission line part is provided on the flexible carrier part, and the transmission line part includes a wiring group; a reinforcement part, the reinforcement part is installed on the second side of the flexible carrier part, the position of the reinforcement part corresponds to the position of the pad part, and a clearance is provided on the reinforcement part, the position of the clearance corresponds to the position of the wiring group passing through the pad part, and is used to make way for the wiring group passing through the pad part; wherein the first side of the flexible carrier part is opposite to the second side of the flexible carrier part. By making way for the wiring group passing through the pad part, the transmission line is prevented from changing from a microstrip line to a strip line, the impedance discontinuity phenomenon is eliminated, and the signal quality and system performance are improved.

Description

Technical Field

[0001] The present application relates to the technical field of flexible circuit boards, and in particular to a flexible circuit board and an electronic device. Background Art

[0002] FPC (Flexible Printed Circuit) is a flexible printed circuit board made of flexible substrates such as polyimide (PI) or polyester (PET) as a carrier, on which circuit patterns are printed. It has the characteristics of light weight, small size, and flexibility, and is widely used in electronic products.

[0003] refer to Figure 1 As shown, in some electronic products, it is necessary to attach devices on the FPC, such as LCD (Liquid Crystal Display) and other display devices. In order to ensure the connection reliability between the display device and the FPC, it is necessary to press the steel sheet 1 on the FPC to make the surface of the FPC flat and prevent the device on the pad from falling off.

[0004] However, laminating the steel sheet 1 on the FPC will cause the transmission line 2 on the FPC to change in shape from a microstrip line to a stripline. Microstrip line is a transmission line structure with a metal conductor strip printed on a planar dielectric layer, which has the characteristics of continuous impedance, low loss, and wide frequency response. Stripline is a transmission line structure with a dielectric layer sandwiched between two metal planes, which has the characteristics of stable impedance and strong anti-interference. Due to the different impedance characteristics of microstrip line and stripline, when the transmission line changes from microstrip line to stripline, impedance discontinuity will occur, resulting in problems such as signal reflection, attenuation or distortion.

[0005] Especially for high-speed signal transmission lines, such as MIPI (Mobile Industry Processor Interface) routing, impedance discontinuity will seriously affect signal quality and system performance. MIPI is a high-speed serial interface standard designed for mobile devices, used to connect components such as processors, cameras, and displays. Summary of the invention

[0006] The present application provides a flexible circuit board and an electronic device, wherein the flexible circuit board is used to reduce the difficulty of sealing the sound outlet and reduce the manufacturing cost.

[0007] To achieve the above purpose, the embodiment of the present application adopts the following technical solution:

[0008] In a first aspect, a flexible circuit board is provided. The flexible circuit board is applied to electronic equipment. The flexible circuit board comprises: a flexible carrier portion, a first side surface of the flexible carrier portion is provided with a pad portion; a transmission line portion, the transmission line portion is provided on the flexible carrier portion, and the transmission line portion comprises a wiring group; a reinforcement portion, the reinforcement portion is mounted on a second side surface of the flexible carrier portion, the position of the reinforcement portion corresponds to the position of the pad portion, a clearance is provided on the reinforcement portion, the position of the clearance corresponds to the position of the wiring group passing through the pad portion, and the reinforcement portion is used to make way for the wiring group passing through the pad portion; wherein the first side surface of the flexible carrier portion is opposite to the second side surface of the flexible carrier portion.

[0009] The flexible circuit board provided in the embodiment of the present application avoids the transmission line from being changed from a microstrip line to a strip line by giving way to the routing group passing through the pad part, eliminates the impedance discontinuity phenomenon, and improves the signal quality and system performance. This can reduce problems such as signal reflection, attenuation or distortion, improve the transmission speed and accuracy of the signal, reduce signal interference and noise, and improve the operating efficiency and reliability of the system. Especially for high-speed signal transmission lines, such as MIPI routing, the effect of this technology is more significant.

[0010] In one embodiment, if the clearance gap is only provided in a local area near the pad portion, there will still be a certain degree of impedance discontinuity, because the transmission line will still undergo a shape change when entering and leaving the clearance gap. The clearance gap extends along the length direction of the routing group passing through the pad portion. By extending the clearance gap along the length direction of the routing group passing through the pad portion, the clearance range of the routing group is increased, and the influence of the impedance discontinuity is further reduced.

[0011] In one embodiment, there are multiple routing groups and multiple clearance gaps, and multiple routing groups are set in one-to-one correspondence with multiple clearance gaps. By setting multiple clearance gaps and multiple routing groups in one-to-one correspondence, it is ensured that each routing group has a corresponding clearance gap to make way, avoiding the transmission line from microstrip line to strip line, eliminating impedance discontinuity, and improving signal quality and system performance. In this way, problems such as signal reflection, attenuation or distortion can be reduced, the transmission speed and accuracy of the signal can be improved, the interference and noise of the signal can be reduced, and the operating efficiency and reliability of the system can be improved.

[0012] In one embodiment, the pad portion includes a plurality of pad areas, the reinforcement portion includes a plurality of reinforcement plates, and a clearance gap is formed between every two adjacent reinforcement plates, and the position of the reinforcement plate corresponds to the position of at least one pad area. By forming a clearance gap between two adjacent reinforcement plates, the routing group passing through the pad area is given way, thereby avoiding the transmission line from a microstrip line to a strip line, eliminating impedance discontinuity, and improving signal quality and system performance. By providing a plurality of reinforcement plates, the flexible circuit board can also have a certain degree of bendability, so that the flexible circuit board can adapt to different installation spaces and shapes, and improve the applicability and flexibility of the flexible circuit board. In this way, the application scope of the flexible circuit board in electronic products can be expanded to meet the needs of different users and occasions. The flexible carrier portion can also have different rigidity and flexibility in different areas, thereby realizing local bending control of the flexible carrier portion.

[0013] In one embodiment, the pad area is provided with a plurality of pads, the plurality of pads are arranged at intervals, the reinforcing plate includes an outer frame and a hollow space located inside the outer frame, and the reinforcing plate also includes a supporting structure, the position of the supporting structure corresponds to at least the position of one pad to support the pad. By the position of the supporting structure corresponding to at least the position of one pad, the reinforcing plate is guaranteed to reinforce and support each pad while meeting the lightweight requirement, thereby preventing the device from falling off during the welding process.

[0014] In one embodiment, the support structure includes a connecting section and a supporting protrusion, at least one end of the connecting section is connected to the inner wall of the outer frame, and the supporting protrusion is arranged on the connecting section. By arranging the connecting section on the reinforcing plate, the supporting protrusion is effectively fixed, and the stability and reliability of the supporting structure are improved. By arranging the supporting protrusion on the connecting section, the pad is effectively supported, the rigidity and flatness of the pad are improved, and the connection reliability between the display device and the pad is ensured. In this way, the stability and life of the display device can be improved, and the maintenance cost and risk can be reduced.

[0015] In one embodiment, a weight-reducing hole is provided inside the reinforcing plate. By providing the weight-reducing hole, the weight of the reinforcing plate can be reduced, the portability of the reinforcing plate can be improved, and the flexibility of the reinforcing plate can be increased to a certain extent, so that the reinforcing plate can adapt to different shapes and bending degrees of the flexible carrier part, thereby improving the applicability and flexibility of the reinforcing plate.

[0016] In one embodiment, there are multiple weight-reducing holes, and the multiple weight-reducing holes are arranged at intervals. By arranging multiple weight-reducing holes, the weight of the parts can be greatly reduced and the portability of the parts can be improved. By arranging multiple weight-reducing holes at intervals, effective support for the pad can also be achieved, that is, the pad is supported by the interval area between the weight-reducing holes.

[0017] In one embodiment, the pad area is provided with a plurality of pads, the plurality of pads are arranged at intervals, and the positions of the weight-reducing holes and the pads are not arranged relative to each other. By making the positions of the weight-reducing holes and the pads not arranged relative to each other, effective protection and support of the pad area is achieved.

[0018] In one embodiment, the pad portion includes a plurality of pad areas, the reinforcement portion includes a plurality of reinforcement plates, a gap is provided between two adjacent reinforcement plates, the plurality of gaps include a clearance gap, and the position of the reinforcement plate corresponds to the position of at least one pad area. By providing a plurality of reinforcement plates, the plurality of pad areas can be reinforced separately, the rigidity and flatness of the pad areas can be improved, and the connection reliability between the display device and the pad areas can be ensured. By providing a gap between the plurality of reinforcement plates, the bendability of the flexible circuit board can also be increased, so that the flexible circuit board can adapt to different installation spaces and shapes, and the applicability and flexibility of the flexible circuit board can be improved.

[0019] In one embodiment, the transmission line portion is a MIPI transmission line portion.

[0020] A second aspect of the present application provides an electronic device, the electronic device comprising a flexible circuit board, and the flexible circuit board is the above-mentioned flexible circuit board.

[0021] Through the above technical solution, since the electronic device includes the above flexible circuit board, it at least has all the beneficial effects of the flexible circuit board, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of a flexible circuit board in the prior art;

[0023] Figure 2 A schematic structural diagram of a second side surface of a flexible carrier portion provided in an embodiment of the present application;

[0024] Figure 3 A schematic structural diagram of a first side surface of a flexible carrier portion provided in an embodiment of the present application;

[0025] Figure 4 A schematic diagram of the structure of a reinforcement plate with supporting protrusions provided in an embodiment of the present application;

[0026] Figure 5 A schematic structural diagram of another reinforcement plate with supporting protrusions provided in an embodiment of the present application;

[0027] Figure 6 A schematic diagram of the structure of a reinforcement plate with weight-reducing holes provided in an embodiment of the present application;

[0028] Figure 7 A schematic structural diagram of another reinforcement plate with weight-reducing holes provided in an embodiment of the present application;

[0029] Figure 8 It is the measured eye diagram of MIPI routing of flexible circuit board in the prior art;

[0030] Fig. 9 The corresponding eye diagram of the MIPI routing of the flexible circuit board in the embodiment of the present application;

[0031] The meanings of the figures are as follows:

[0032] 1. Steel sheet; 2. Transmission line;

[0033] 10. flexible carrier portion; 11. pad area; 12. pad;

[0034] 20. Transmission line part; 30. Reinforcement part;

[0035] 31. reinforcing plate; 311. outer frame; 312. hollow space; 313. connecting section; 314. supporting protrusion;

[0036] 321. Weight reduction hole. DETAILED DESCRIPTION

[0037] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below in conjunction with the accompanying drawings.

[0038] It should be understood that in the description of the present application, it should be understood that the terms "length", "width", "thickness", "top", "bottom", "inside", "outside", "up", "down", "left", "right", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0039] The terms "first", "second", "third", "fourth", etc. are only used to distinguish the descriptions and shall not be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features.

[0040] For example, the first pushing part and the second pushing part are only used to distinguish different pushing parts, and the order thereof is not limited. The first pushing part may also be named as the second pushing part, and the second pushing part may also be named as the first pushing part, without departing from the scope of the various described embodiments. Moreover, the terms "first", "second", "third", "fourth" and the like do not necessarily limit the characteristics indicated to be different.

[0041] In the embodiments of the present application, unless otherwise clearly specified and limited, the terms "connected", "connection" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0042] In the description of the embodiments of the present application, “plurality” means two or more than two, unless otherwise clearly and specifically defined.

[0043] In the embodiments of the present application, "and / or" is only a description of the association relationship of the associated objects, indicating that three relationships can exist; for example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0044] It should be noted that, in the embodiments of the present application, words such as "in one embodiment", "exemplarily", "for example", etc. are used to indicate examples, illustrations or descriptions. Any embodiment or design described in the embodiments of the present application as "in one embodiment", "exemplarily", "for example" should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "in one embodiment", "exemplarily", "for example", etc. is intended to present related concepts in a specific way.

[0045] In order to make the objectives, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0046] In the related art, FPC (Flexible Printed Circuit) is a flexible printed circuit board made of a flexible substrate such as polyimide (PI) or polyester (PET) as a carrier, on which a circuit pattern is printed. It has the characteristics of light weight, small size, and flexibility, and is widely used in electronic products. In some electronic products, it is necessary to attach devices to FPC, such as LCD (Liquid Crystal Display) and other display devices. Figure 1 As shown, in order to ensure the connection reliability between the display device and the FPC, it is necessary to press the steel sheet 1 on the FPC to make the surface of the FPC flat and prevent the pad from bending or falling off.

[0047] However, laminating the steel sheet 1 on the FPC will cause the transmission line 2 on the FPC to change in shape from a microstrip line to a stripline. Microstrip line is a transmission line structure with a metal conductor strip printed on a planar dielectric layer, which has the characteristics of continuous impedance, low loss, and wide frequency response. Stripline is a transmission line structure with a dielectric layer sandwiched between two metal planes, which has the characteristics of stable impedance and strong anti-interference. Due to the different impedance characteristics of microstrip line and stripline, when the transmission line changes from microstrip line to stripline, impedance discontinuity will occur, resulting in problems such as signal reflection, attenuation or distortion.

[0048] Specifically, a transmission line is a conductor used to transmit electrical signals. It has two important parameters: characteristic impedance and transmission speed. Characteristic impedance refers to the constant value of the ratio of voltage to current in a transmission line in a steady state. Transmission speed refers to the speed at which electrical signals propagate on a transmission line, which depends on the dielectric material of the transmission line. In order to ensure the integrity and quality of the signal, the characteristic impedance of the transmission line must match the impedance of the signal source and the signal terminal, otherwise reflection, distortion, interference, etc. will occur. Therefore, when designing and making FPC, it is necessary to consider the impedance control of the transmission line.

[0049] The steel sheet of FPC is a reinforcing material used to strengthen the FPC structure or provide grounding function. It can be stainless steel or other metal materials. The steel sheet of FPC adds a conductive plane, which means that a reference plane is added to the original single-sided or double-sided FPC, thus changing the definition of the transmission line.

[0050] According to different reference planes and wire arrangements, transmission lines can be divided into microstrip lines, strip lines, coplanar waveguides, etc. Different types of transmission lines have different impedance calculation formulas and design requirements.

[0051] The steel sheet of FPC not only changes the type of transmission line, but also affects the distributed parameters of the transmission line. Distributed parameters refer to the physical quantities such as capacitance, inductance, resistance and conductance of the transmission line per unit length. Distributed parameters determine the characteristic impedance and transmission speed of the transmission line.

[0052] The steel sheet of FPC adds a conductive plane, which reduces the distance between transmission lines and between transmission lines and reference plane, thus increasing distributed capacitance; at the same time, since the steel sheet itself has a certain thickness and conductivity, it also increases distributed inductance. These changes will affect the characteristic impedance of the transmission line.

[0053] Therefore, if you want to add a steel sheet to the FPC, you need to redesign and optimize the structure and parameters of the transmission line to meet the requirements of impedance matching and signal integrity. This is a relatively complex and professional engineering problem that requires the use of relevant software and instruments for simulation and testing.

[0054] In addition, the electromagnetic field is a physical phenomenon generated by electric charge and current, which includes two parts: electric field and magnetic field. The distribution of the electromagnetic field in space depends on the distribution of charge and current, as well as the properties of the medium. The medium refers to the material that can propagate electromagnetic waves, which can be vacuum, air, water, metal, semiconductor, etc. Different media have different effects on the electromagnetic field, which are mainly manifested in the following aspects:

[0055] Dielectric constant: Dielectric constant is a physical quantity that reflects the degree of response of a medium to an electric field. It determines the relationship between the electric displacement vector in the medium and the external electric field. The larger the dielectric constant, the stronger the medium's response to the electric field, and the weaker the effect of the external electric field in the medium.

[0056] Magnetic permeability: Magnetic permeability is a physical quantity that reflects the degree of medium's response to the magnetic field. It determines the relationship between the magnetic induction intensity in the medium and the external magnetic field. The larger the magnetic permeability, the stronger the medium's response to the magnetic field, and the weaker the effect of the external magnetic field in the medium.

[0057] Conductivity: Conductivity is a physical quantity that reflects the ability of free charges to flow in a medium. It determines the relationship between the current density in the medium and the applied electric field. The greater the conductivity, the more free charges there are in the medium, and the applied electric field will generate a larger current in the medium.

[0058] When there is an alternating signal on the transmission line, an alternating electromagnetic field will be generated around the transmission line. This alternating electromagnetic field will interact with the medium in which the transmission line is located, thereby affecting the transmission characteristics of the signal on the transmission line.

[0059] Adding a steel sheet is equivalent to adding a layer of metal material to the FPC, which changes the dielectric environment around the transmission line. Metal materials have high conductivity and low dielectric constant and magnetic permeability, which means that metal materials have a strong shielding effect on both alternating electric and magnetic fields.

[0060] Therefore, adding steel sheets will change the distribution form and strength of the alternating electromagnetic field around the transmission line, thereby changing the distribution parameters of the signal on the transmission line. Specifically, adding steel sheets will cause more electrostatic coupling and magnetostatic coupling between the transmission lines and between the transmission lines and the reference plane, thus increasing the distributed capacitance and distributed inductance.

[0061] Distributed capacitance and distributed inductance are important factors that affect the characteristic impedance and transmission speed of the transmission line. When the distributed capacitance increases, the characteristic impedance decreases; when the distributed inductance increases, the characteristic impedance increases. Therefore, adding steel sheets will cause the characteristic impedance to change.

[0062] Especially for high-speed signal transmission lines, such as MIPI (Mobile Industry Processor Interface) routing, impedance discontinuity will seriously affect signal quality and system performance. MIPI is a high-speed serial interface standard designed for mobile devices, used to connect components such as processors, cameras, and displays. An embodiment of the present application provides a flexible circuit board, which is applied to an electronic device, wherein the electronic device includes a screen assembly and a cover plate covering the screen assembly, and the flexible circuit board has an inner cavity sealing portion, a first colloid portion, and a second colloid portion, which can improve the above technical problems.

[0063] It should be noted that electronic equipment refers to devices that use electronic technology to achieve information processing, transmission, storage, display and other functions, such as smart phones, tablet computers, laptops, etc.

[0064] Specifically, please refer to Figures 2 to 7 As shown, the flexible circuit board of the embodiment of the present application includes: a flexible carrier part 10, a transmission line part 20, and a reinforcement part 30. The first side of the flexible carrier part 10 is provided with a pad part; the transmission line part 20 is provided on the flexible carrier part 10, and the transmission line part 20 includes a wiring group; the reinforcement part 30 is installed on the second side of the flexible carrier part 10, and the position of the reinforcement part 30 corresponds to the position of the pad part. A clearance is provided on the reinforcement part 30, and the position of the clearance corresponds to the position of the wiring group passing through the pad part, which is used to make way for the wiring group passing through the pad part. Among them, the first side of the flexible carrier part 10 is opposite to the second side of the flexible carrier part 10.

[0065] It should be noted that the flexible circuit board is a circuit board assembly consisting of a flexible carrier part 10, a transmission line part 20 and a reinforcement part 30, which has the characteristics of light weight, small size, and flexibility, and can be bonded to devices such as display devices and used in electronic products. The flexible carrier part 10 is a flexible printed circuit board made of a flexible substrate such as polyimide (PI) or polyester (PET) as a carrier, on which a circuit pattern is printed, and is the main part of the flexible circuit board.

[0066] The pad portion is a metal conductor area disposed on the first side of the flexible carrier portion 10, which is used for welding or connecting with a display device or the like, and is an important interface of the flexible circuit board. The transmission line portion 20 is a metal conductor line disposed on the flexible carrier portion 10, which is used for transmitting signals or currents, and is an important functional part of the flexible circuit board.

[0067] The routing group is a line combination composed of multiple transmission lines, which is used to transmit signals or currents of different types or frequencies, and is the basic unit of the transmission line part 20. The reinforcement part 30 is a metal plate installed on the second side of the flexible carrier part 10, which is used to enhance the rigidity and flatness of the flexible carrier part 10 and ensure the connection reliability between the display device and the pad part. It is an important auxiliary part of the flexible circuit board. The clearance is a gap area set on the reinforcement part 30, which is used to make way for the routing group passing through the pad part, avoid the transmission line from microstrip line to strip line, eliminate impedance discontinuity, and improve signal quality and system performance.

[0068] Among them, the pad part is used to connect the device, and the device can be a direct plug component, a surface mount component, a conductive rubber button, etc. The direct plug component is a component that directly inserts the pin of the component into the through-hole pad 12 on the printed board, such as a resistor, a capacitor, an inductor, a diode, a triode, an integrated circuit, etc. The direct plug component usually adopts a wave soldering process, and it is necessary to ensure the matching and spacing between the pad 12 and the pin. The surface mount component is a component that attaches the pin or terminal of the component to the surface mount pad 12 on the printed board, such as a chip resistor, a chip capacitor, a chip inductor, a chip diode, a chip triode, a chip integrated circuit, etc. The surface mount component usually adopts a reflow soldering process, and it is necessary to ensure the alignment and coverage between the pad 12 and the pin or terminal. The plug-in component is a component that inserts the plug or socket of the component into the plug-in pad 12 on the printed board, such as a connector, a socket, a switch, a button, etc. The plug-in component usually adopts a manual soldering process, and it is necessary to ensure the stability and reliability between the pad 12 and the plug or socket. Conductive rubber keys are components that contact the conductive rubber keys with the gold finger pads 12 on the printed circuit board, such as keys commonly found in remote controls, calculators, etc. Conductive rubber keys are usually crimped, and the matching and gold plating thickness between the gold finger pads 12 and the conductive rubber keys must be ensured.

[0069] For example, in some electronic products, it is necessary to attach devices such as LCD (Liquid Crystal Display) and other display devices to the FPC. In order to ensure the connection reliability between the display device and the FPC, the embodiment of the present application installs a reinforcement part 30 on the flexible carrier part 10 to make the surface of the FPC flat and prevent the device to be soldered by the pad 12 from falling off. The traditional method of pressing a steel sheet on the FPC will cause the transmission line on the FPC to change from a microstrip line to a strip line.

[0070] It should be noted that microstrip line is a transmission line structure with metal conductor strips printed on a planar dielectric layer, which has the characteristics of continuous impedance, low loss, and wide frequency response. Stripline is a transmission line structure with a dielectric layer sandwiched between two metal planes, which has the characteristics of stable impedance and strong anti-interference. Due to the different impedance characteristics of microstrip line and stripline, when the transmission line changes from microstrip line to stripline, impedance discontinuity will occur, leading to problems such as signal reflection, attenuation or distortion.

[0071] Especially for high-speed signal transmission lines, such as MIPI (Mobile Industry Processor Interface) routing, impedance discontinuity will seriously affect signal quality and system performance. MIPI is a high-speed serial interface standard designed for mobile devices, used to connect components such as processors, cameras, and displays.

[0072] The embodiments of the present application avoid the transmission line from changing from a microstrip line to a stripline by giving way to the routing group passing through the pad portion, eliminating impedance discontinuity, and improving signal quality and system performance. This can reduce problems such as signal reflection, attenuation or distortion, improve signal transmission speed and accuracy, reduce signal interference and noise, and improve system operation efficiency and reliability. This technology is particularly effective for high-speed signal transmission lines, such as MIPI routing.

[0073] The routing group passing through the pad portion is given way to avoid the transmission line from changing from a microstrip line to a stripline, and the impedance discontinuity phenomenon is eliminated. However, if the giving way gap is only set in a local area near the pad portion, there will still be a certain degree of impedance discontinuity, because the transmission line will still undergo a morphological change when entering and leaving the giving way gap. In order to further eliminate the impedance discontinuity phenomenon, the giving way gap in the embodiment of the present application extends along the length direction of the routing group passing through the pad portion. By extending the giving way gap along the length direction of the routing group passing through the pad portion, the giving way range of the routing group is increased, and the impact of impedance discontinuity is further reduced. More effectively eliminate problems such as signal reflection, attenuation or distortion, improve the transmission speed and accuracy of the signal, reduce signal interference and noise, and improve the operating efficiency and reliability of the system. Especially for high-speed signal transmission lines, such as MIPI routing, this technical effect is more significant.

[0074] Please refer to Figure 2 and Figure 3Since many transmission line parts 20 have multiple routing groups, there are multiple routing groups and multiple clearance gaps in the embodiment of the present application, and multiple routing groups are set in a one-to-one correspondence with multiple clearance gaps. By setting multiple clearance gaps and multiple routing groups, the transmission of signals or currents of various types or frequencies can be achieved, and the functionality and complexity of the flexible circuit board can be improved. In this way, different design requirements and conditions can be met, and the application scope of flexible circuit boards in electronic products can be expanded. By setting multiple clearance gaps and multiple routing groups in a one-to-one correspondence, it is ensured that each routing group has a corresponding clearance gap to make way, avoiding the transmission line from a microstrip line to a strip line, eliminating impedance discontinuity, and improving signal quality and system performance. In this way, problems such as signal reflection, attenuation or distortion can be reduced, the transmission speed and accuracy of the signal can be improved, the interference and noise of the signal can be reduced, and the operating efficiency and reliability of the system can be improved.

[0075] Please refer to Figure 2 and Figure 3 The pad portion in the embodiment of the present application includes a plurality of pad areas 11, and the reinforcement portion 30 includes a plurality of reinforcement plates 31. A clearance gap is formed between every two adjacent reinforcement plates 31, and the position of the reinforcement plate 31 corresponds to the position of at least one pad area 11. By dividing the reinforcement portion 30 into a plurality of reinforcement plates 31, the plurality of pad areas 11 can be reinforced separately, the rigidity and flatness of the pad area 11 can be improved, and the connection reliability between the display device and the pad area 11 can be ensured. In this way, the stability and life of the display device can be improved, and the maintenance cost and risk can be reduced.

[0076] By forming a clearance gap between two adjacent reinforcing plates 31, the routing group passing through the pad area 11 is made to make way, so as to avoid the transmission line from microstrip line to strip line, eliminate impedance discontinuity, and improve signal quality and system performance. In this way, problems such as signal reflection, attenuation or distortion can be reduced. By making the position of the reinforcing plate 31 correspond to the position of at least one pad area 11, it is ensured that each pad area 11 has a corresponding reinforcing plate 31 to be reinforced, and deformation or falling off of the pad area 11 can be avoided. The integrity and stability of the pad area 11 are protected, the service life of the pad area 11 is extended, and the failure rate and the number of repairs are reduced.

[0077] In addition, by providing a plurality of reinforcing plates 31, the flexible circuit board can also have a certain degree of bendability, so that the flexible circuit board can adapt to different installation spaces and shapes, and improve the applicability and flexibility of the flexible circuit board. In this way, the application scope of the flexible circuit board in electronic products can be expanded to meet the needs of different users and occasions. The flexible carrier part 10 can also have different rigidity and flexibility in different areas, thereby realizing local bending control of the flexible carrier part 10. When the flexible carrier part 10 needs to be bent, it only needs to be bent in the area without the reinforcing plate 31, and remain flat in the area with the reinforcing plate 31. In this way, excessive pressure or damage to devices such as the pad area 11, the wiring group and the display device can be avoided, and the integrity and stability of the device can be protected.

[0078] Please refer to Figure 4 and Figure 5 As shown, as electronic devices move towards lightweight, the lightweight of each component of the electronic device is crucial to the lightweight of the electronic device. In order to ensure the lightweight of the flexible circuit board in the embodiment of the present application, the pad area 11 in the embodiment of the present application is provided with a plurality of pads 12, and the plurality of pads 12 are arranged at intervals. The reinforcing plate 31 includes an outer frame 311 and a hollow space 312 located inside the outer frame 311. The reinforcing plate 31 also includes a supporting structure, and the position of the supporting structure corresponds to the position of at least one pad 12 to support the pad 12. By arranging a plurality of pads 12 in the pad area 11, multiple devices can be connected, and the functionality and complexity of the flexible circuit board can be improved. By arranging the outer frame 311, the hollow space 312 and the supporting structure, the pad area 11 can be effectively reinforced and supported, the rigidity and flatness of the pad area 11 can be improved, and the connection reliability between the device and the pad area 11 can be ensured. By setting the reinforcing plate 31 as a hollow structure, the weight of the reinforcing plate 31 can be reduced, thereby achieving lightweighting of the flexible circuit board. In addition, by having the position of the support structure correspond to at least the position of one pad 12, while meeting the lightweight requirement, the reinforcing plate 31 is guaranteed to reinforce and support each pad 12, thereby preventing the device from falling off during the welding process. In this way, the integrity and stability of the pad 12 can be protected, the service life of the pad 12 can be extended, and the failure rate and the number of repairs can be reduced.

[0079] Since there are multiple reinforcing plates 31, the weight of the flexible circuit board can be further reduced, the portability and energy saving of the flexible circuit board can be improved, and the burden and energy consumption of the flexible circuit board during transportation and use can be reduced.

[0080] By providing a plurality of reinforcing plates 31, the flexible carrier part 10 can have different rigidity and flexibility in different areas, thereby realizing local bending control of the flexible carrier part 10. When the flexible carrier part 10 needs to be bent, it only needs to be bent in the area without the reinforcing plates 31, and remains flat in the area with the reinforcing plates 31. In this way, excessive pressure or damage to devices such as the pad area 11, the wiring group and the display device can be avoided, and the integrity and stability of the device can be protected.

[0081] refer to Figure 3 and Figure 4 As shown, specifically, the support structure in the embodiment of the present application includes a connecting section 313 and a supporting protrusion 314, at least one end of the connecting section 313 is connected to the inner wall of the outer frame 311, and the supporting protrusion 314 is arranged on the connecting section 313. By arranging the connecting section 313 on the reinforcing plate 31, the supporting protrusion 314 is effectively fixed, and the stability and reliability of the supporting structure are improved. In this way, it can be ensured that the supporting structure can effectively support the pad 12 to avoid deformation or falling off of the pad 12. Among them, the connecting section 313 is a structure arranged on the reinforcing plate 31, and the material is the same as that of the reinforcing plate 31, which is used to connect the outer frame 311 and the supporting protrusion 314 to fix the position of the supporting structure on the reinforcing plate 31. The connecting section 313 can have different shapes and sizes, such as straight lines, curves, L-shaped, U-shaped, etc., to adapt to different design requirements and conditions.

[0082] By arranging the support protrusion 314 on the connecting section 313, effective support for the pad 12 is achieved, the rigidity and flatness of the pad 12 are improved, and the connection reliability between the display device and the pad 12 is ensured. In this way, the stability and life of the display device can be improved, and the maintenance cost and risk can be reduced. The support protrusion 314 is a structure arranged on the connecting section 313, and the material is consistent with the reinforcing plate 31, and is used to support the pad 12 of the pad area 11 to prevent the deformation or falling off of the pad 12. The support protrusion 314 can have different shapes and sizes, such as round, square, oval, etc., to adapt to different shapes and sizes of pads 12. By making the position of the support protrusion 314 correspond to the position of the pad 12, it is ensured that each pad 12 has a corresponding support protrusion 314 to support it, and the deformation or falling off of the pad 12 can be avoided. In this way, the integrity and stability of the pad 12 can be protected, the service life of the pad 12 can be extended, and the failure rate and the number of repairs can be reduced.

[0083] Please refer to Figure 6 and Figure 7In order to ensure the lightweight of the flexible circuit board of the embodiment of the present application, other methods may also be used. In another embodiment, a weight-reducing hole 321 is provided inside the reinforcing plate 31 in the embodiment of the present application. The reinforcing plate 31 is a plate used to strengthen the mechanical strength of the flexible circuit board, and is usually welded or connected to the flexible carrier part 10 for subsequent installation or assembly. The thickness of the reinforcing plate 31 is generally the same as or slightly larger than that of the flexible carrier part 10, but should not exceed 1.5 times the thickness of the flexible carrier part 10.

[0084] In the embodiment of the present application, a weight-reducing hole 321 is provided inside the reinforcing plate 31, which can achieve the following technical effects: By providing the weight-reducing hole 321, the weight of the reinforcing plate 31 can be reduced, and the lightness of the reinforcing plate 31 can be improved. In this way, the burden and energy consumption of the reinforcing plate 31 during transportation and use can be reduced, and the cost and environmental impact can be reduced. By providing the weight-reducing hole 321, the flexibility of the reinforcing plate 31 can also be increased to a certain extent, so that the reinforcing plate 31 can adapt to the different shapes and bending degrees of the flexible carrier part 10, and the applicability and flexibility of the reinforcing plate 31 can be improved. In this way, the application scope of the reinforcing plate 31 in electronic products can be expanded to meet the needs of different users and occasions.

[0085] There are multiple weight-reducing holes 321 in the embodiment of the present application, and the multiple weight-reducing holes 321 are arranged at intervals. The weight-reducing holes 321 are a design method for reducing the weight of parts, and are usually arranged in non-load-bearing areas or areas with less force on the parts to improve the lightness and energy efficiency of the parts. The shape and size of the weight-reducing holes 321 can be selected according to different design requirements and conditions. Common ones are circular, triangular, quadrilateral, polygonal, etc. It is preferably circular to avoid stress concentration and ensure the overall strength of the reinforcement plate 31. By setting multiple weight-reducing holes 321, the weight of the parts can be greatly reduced and the lightness of the parts can be improved.

[0086] This can reduce the burden and energy consumption of parts during transportation and use, and reduce costs and environmental impact. By setting multiple weight-reducing holes 321 at intervals, a certain material strength and rigidity can be retained to avoid deformation or breakage of parts. This can ensure the functionality and reliability of parts and extend the service life of parts. By setting multiple weight-reducing holes 321 at intervals, effective support for the pad 12 can also be achieved, that is, the pad 12 is supported by the interval area between the weight-reducing holes 321. Specifically, the pad area 11 in the embodiment of the present application is provided with multiple pads 12, and the multiple pads 12 are arranged at intervals, and the positions of the weight-reducing holes 321 and the positions of the pads 12 are not arranged relative to each other. By making the positions of the weight-reducing holes 321 and the positions of the pads 12 not arranged relative to each other, effective protection and support of the pad area 11 can be achieved, and the integrity and stability of the pad area 11 can also be guaranteed, and problems such as copper foil breakage or copper peeling can be prevented.

[0087] In another embodiment, the gap between two adjacent reinforcing plates 31 is not necessarily a clearance gap, but may be a normal gap. Specifically, the pad portion in the embodiment of the present application includes a plurality of pad areas 11, the reinforcing portion 30 includes a plurality of reinforcing plates 31, there is a gap between two adjacent reinforcing plates 31, the plurality of gaps include a clearance gap, and the position of the reinforcing plate 31 corresponds to the position of at least one pad area 11. By providing a plurality of reinforcing plates 31, it is possible to reinforce the plurality of pad areas 11 separately, improve the rigidity and flatness of the pad areas 11, and ensure the connection reliability between the display device and the pad area 11. By providing a gap between the plurality of reinforcing plates 31, it is also possible to increase the bendability of the flexible circuit board, so that the flexible circuit board can adapt to different installation spaces and shapes, and improve the applicability and flexibility of the flexible circuit board.

[0088] In this way, the application scope of the flexible circuit board in electronic products can be expanded to meet the needs of different users and occasions. By setting gaps between multiple reinforcement plates 31, the flexible carrier part 10 can have different rigidity and flexibility in different areas, thereby realizing local bending control of the flexible carrier part 10. When the flexible carrier part 10 needs to be bent, it only needs to be bent in the area without the reinforcement plate 31, and the area with the reinforcement plate 31 remains flat. In this way, excessive pressure or damage to the pad area 11, the wiring group and the device can be avoided, and the integrity and stability of the device can be protected.

[0089] The reinforcing plate 31 in the embodiment of the present application is a stainless steel reinforcing plate. The stainless steel reinforcing plate is a metal plate made of stainless steel, which has the advantages of high strength, high hardness, wear resistance, corrosion resistance, etc. The thickness of the stainless steel reinforcing plate is generally 0.1mm~0.3mm, and the shape can be processed by etching or stamping. In other implementations, the reinforcing plate can be an aluminum foil reinforcing plate. The aluminum foil reinforcing plate is a metal plate made of aluminum foil, which has the advantages of light weight, low cost, and conductivity. The aluminum foil reinforcing plate is mainly used for conductive and inductive functions, such as antennas, touch screens, etc. The thickness of the aluminum foil reinforcing plate is generally 0.05mm~0.2mm, and the shape can be processed by etching or stamping. The reinforcing plate can be a polyester reinforcing plate. The polyester reinforcing plate is a plastic plate made of polyester film, which has the advantages of softness, transparency, and heat resistance. The polyester reinforcing plate is mainly used to protect circuit insulation, such as covering films, protective films, etc. The thickness of the polyester reinforcement plate is generally 0.05mm to 0.25mm, and the shape can be processed by cutting or molding. The reinforcement plate can be a polyimide reinforcement plate. The polyimide reinforcement plate is a plastic plate made of polyimide film, which has the advantages of high temperature resistance, acid and alkali resistance, and low temperature resistance. The thickness of the polyimide reinforcement plate is generally 0.05mm to 0.25mm, and the shape can be processed by cutting or molding. The reinforcement plate can be a glass fiber reinforcement plate, which is a composite material plate made of glass fiber cloth impregnated with resin, and has the advantages of high rigidity, high stability, and flame resistance. The thickness of the glass fiber reinforcement plate is generally 0.1mm to 0.5mm, and the shape can be processed by CNC drilling or laser cutting. The reinforcement plate can be a polytetrafluoroethylene reinforcement plate, which is a plastic plate made of polytetrafluoroethylene, which has the advantages of low friction coefficient, high temperature resistance, and chemical resistance. The polytetrafluoroethylene reinforcement plate is mainly used to reduce friction and wear, such as sliding areas, folding areas, etc. The thickness of the polytetrafluoroethylene reinforcement plate is generally 0.05mm to 0.2mm, and the shape can be processed by cutting or molding. The reinforcement plate can be a polycarbonate reinforcement plate, which is a plastic plate made of polycarbonate, with the advantages of high transparency, high toughness, and impact resistance.

[0090] For high-speed signal transmission lines, impedance discontinuity will seriously affect signal quality and system performance. The transmission line part in the embodiment of the present application is a MIPI transmission line part. MIPI is the abbreviation of Mobile Industry Processor Interface, which is an open standard initiated by the MIPI Alliance for mobile application processors. MIPI includes a set of protocols and standards to meet the unique requirements of various subsystems. MIPI can be divided into three types: D-PHY, C-PHY, and M-PHY according to the physical layer. D-PHY is one of the most commonly used physical layer standards in MIPI, mainly used for purposes such as camera interface CSI and display interface DSI. D-PHY adopts differential signal transmission, and each lane consists of 2 signal lines, namely P and N. D-PHY supports two operating modes: high-speed mode and low-power mode.

[0091] In addition to MIPI and the above-mentioned transmission line parts, there are some other common transmission line parts, such as: HDMI: High Definition Multimedia Interface is a digital video / audio interface technology, mainly used to connect high-definition video source devices and display devices. HDMI supports two working modes: high-speed mode and low-power mode. EDP: Embedded DisplayPort is a digital video / audio interface technology, mainly used to connect built-in displays and graphics processors. EDP adopts differential signal transmission, and each lane consists of 2 signal lines. EDP supports two working modes: high-speed mode and low-power mode. RGB: Red Green Blue is an analog video / audio interface technology, mainly used to connect displays and video source devices. RGB adopts single-ended signal transmission, and each lane consists of 1 signal line, namely R, G, and B. RGB only supports high-speed mode and does not support low-power mode.

[0092] The flexible carrier part of the embodiment of the present application adopts a material used to make flexible circuit boards, which needs to have a certain flexibility.

[0093] The eye diagram is a tool for analyzing the transmission quality of high-speed digital signals. The eye height is an important parameter of the eye diagram, which reflects the noise tolerance of the signal, that is, the ability of the signal to resist noise interference. The larger the eye height, the higher the noise tolerance and the better the signal quality.

[0094] Figure 8 This is the measured eye diagram of the MIPI routing of the flexible circuit board in the prior art. Fig. 9 The corresponding eye diagram of the MIPI routing of the flexible circuit board in the embodiment of the present application;

[0095] Please refer to Figure 8 Shown and Fig. 9 As shown, except for setting the clearance gap, other parameters are exactly the same. It can be seen that by adopting the solution of the present application, the eye height is significantly increased.

[0096] According to a second aspect of the present application, an electronic device is provided, the electronic device comprising a flexible circuit board, wherein the flexible circuit board is the above-mentioned flexible circuit board.

[0097] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A flexible circuit board, characterized in that: The flexible circuit board comprises: A flexible carrier portion, wherein a pad portion is disposed on a first side surface of the flexible carrier portion; A transmission line portion, the transmission line portion is arranged on the flexible carrier portion, and the transmission line portion includes a routing group; A reinforcement portion, the reinforcement portion is mounted on the second side surface of the flexible carrier portion, the position of the reinforcement portion corresponds to the position of the pad portion, a clearance gap is provided on the reinforcement portion, the position of the clearance gap corresponds to the position of the wiring group passing through the pad portion, and is used to make way for the wiring group passing through the pad portion; wherein the first side surface of the flexible carrier portion is opposite to the second side surface of the flexible carrier portion; The pad portion includes a plurality of pad areas, the reinforcement portion includes a plurality of reinforcement plates, a clearance gap is formed between every two adjacent reinforcement plates, and the position of the reinforcement plate corresponds to the position of at least one of the pad areas; The pad area is provided with a plurality of pads, and the plurality of pads are arranged at intervals. The reinforcement plate includes an outer frame and a hollow space located inside the outer frame. The reinforcement plate also includes a support structure, and the position of the support structure corresponds to the position of at least one of the pads to support the pad.

2. The flexible circuit board according to claim 1, characterized in that: The clearance gap extends along the length direction of the wiring group passing through the pad portion.

3. The flexible circuit board according to claim 1, characterized in that: There are multiple routing groups and multiple giving way gaps, and the multiple routing groups and the multiple giving way gaps are arranged in a one-to-one correspondence.

4. The flexible circuit board according to claim 1, characterized in that: The support structure comprises a connecting section and a supporting protrusion, at least one end of the connecting section is connected to the inner wall of the outer frame, and the supporting protrusion is arranged on the connecting section.

5. The flexible circuit board according to claim 1, characterized in that: The reinforcing plate is provided with weight-reducing holes inside.

6. The flexible circuit board according to claim 5, characterized in that: There are multiple weight-reducing holes, and the multiple weight-reducing holes are arranged at intervals.

7. The flexible circuit board according to claim 6, characterized in that: The pad area is provided with a plurality of pads, the plurality of pads are arranged at intervals, and the positions of the weight-reducing holes and the positions of the pads are not arranged relative to each other.

8. The flexible circuit board according to claim 1, characterized in that: The pad portion includes a plurality of pad areas, the reinforcement portion includes a plurality of reinforcement plates, a gap is provided between two adjacent reinforcement plates, the plurality of gaps include a clearance gap, and the position of the reinforcement plate corresponds to the position of at least one of the pad areas.

9. The flexible circuit board according to any one of claims 1 to 8, characterized in that: The transmission line portion is a MIPI transmission line portion.

10. An electronic device, characterized in that: The electronic device includes a flexible circuit board, and the flexible circuit board is the flexible circuit board according to any one of claims 1 to 9.

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