CN116867162A

CN116867162A - Soft board, connector and printed circuit board

Info

Publication number: CN116867162A
Application number: CN202310645959.XA
Authority: CN
Inventors: 周进群; 胡忠华; 曾刚
Original assignee: Shennan Circuit Co Ltd
Current assignee: Shennan Circuit Co Ltd
Priority date: 2023-06-01
Filing date: 2023-06-01
Publication date: 2023-10-10

Abstract

The invention discloses a flexible board, a connector and a printed circuit board, wherein the flexible board comprises a substrate, a first cover film and a second cover film, and the substrate comprises a differential line layer, a base layer and a reference layer which are laminated and bonded in sequence; a plurality of differential line pairs which are arranged at intervals are formed on the differential line layer; the first covering film and one side of the differential line layer, which is far away from the base layer, are in fit arrangement, and the second covering film and one side of the reference layer, which is far away from the base layer, are in fit arrangement; wherein, a plurality of connection pads are respectively arranged at the opposite ends of the soft board; opposite ends of each differential line pair are respectively connected with corresponding connecting pads. Through the structure, the flexible board is simple in structure and flexible to install.

Description

Soft board, connector and printed circuit board

Technical Field

The invention is applied to the technical field of electronic components, in particular to a flexible board, a connector and a printed circuit board.

Background

The use of high-speed differential lines to transmit high-speed signals is currently the most widely used high-speed signal transmission scheme.

It is known to use differential signaling to transmit information. Differential signaling uses two complementary signals sent on two pairs of transmission lines. These pairs of transmission lines are referred to as differential pairs, and the complementary signals are referred to as differential signals.

The existing connection structure for high-speed signal data communication and exchange has the problems of complex structure and inconvenient installation.

Disclosure of Invention

The invention provides a flexible board, a connector and a printed circuit board, which are used for solving the problems of complex structure and inconvenient installation of a connection structure for high-speed signal data communication and exchange.

In order to solve the above technical problems, the present invention provides a flexible board, comprising: the substrate comprises a differential line layer, a base layer and a reference layer which are laminated and bonded in sequence; a plurality of differential line pairs which are arranged at intervals are formed on the differential line layer; the first cover film and one side of the differential line layer, which is far away from the base layer, are attached to each other, and the second cover film and one side of the reference layer, which is far away from the base layer, are attached to each other; wherein, a plurality of connection pads are respectively arranged at the opposite ends of the soft board; opposite ends of each differential line pair are respectively connected with corresponding connecting pads.

A shielding piece is arranged between every two adjacent differential line pairs, and the shielding piece and the corresponding two adjacent differential line pairs are respectively arranged at intervals; the width of the differential line pair is a preset width; the distance between every two adjacent differential line pairs is at least 3 times of a preset width; and the distance between the shield and the adjacent differential pair is at least 3 mils.

Wherein each shield is perpendicularly connected with a plurality of shield holes on at least one side near the adjacent differential line pair: one end of each shielding hole is connected with a corresponding shielding piece, and the other end of each shielding hole is connected with a reference layer.

Wherein, a plurality of grounding pads are respectively arranged at the opposite ends of the soft board; each connection pad corresponds to at least one grounding pad, and the at least one grounding pad is arranged around the corresponding connection pad at intervals.

One end of the grounding pad is connected with the corresponding shielding piece, and the other end of the grounding pad is connected with the reference layer; the center of the grounding pad is provided with a through hole, and the through hole penetrates through the substrate.

Wherein, each connecting pad is arranged on the differential line layer; the reference layer is hollowed out in the area corresponding to each connecting pad on the differential line layer.

In order to solve the above technical problems, the present invention further provides a connector, including: a flexible board and two connectors; opposite ends of the soft board are respectively connected with the corresponding connectors; wherein the flexible board comprises any one of the flexible boards described above.

Wherein the connector comprises a male connector or a female connector; one end of the male connector, which is far away from the soft board, is provided with a plurality of first terminals; a plurality of second terminals are arranged at one end of the female connector, which is far away from the soft board; the first terminals and the second terminals are arranged in a one-to-one correspondence manner in number and positions.

Wherein, a shielding cover is arranged around each second terminal of the female connector; at least one grounding terminal is arranged around each first terminal of the male connector; the position of at least one grounding terminal around each first terminal corresponds to the shielding cover of the corresponding second terminal, when the female connector is connected with the male connector, the at least one grounding terminal around each first terminal is contacted with the corresponding shielding cover, and each second terminal and the connecting first terminal are surrounded by the corresponding shielding cover.

In order to solve the technical problem, the invention also provides a printed circuit board, which comprises: a flexible board and at least one circuit board; at least one end of the soft board is connected with the corresponding circuit board; wherein the flexible board comprises any one of the flexible boards described above.

In order to solve the technical problems, the flexible board is simple in structure, two ends of the flexible board can be connected with devices to be connected through the connection pads and the matched connectors or are fixedly connected with the devices to be connected through welding, signal transmission among different devices is achieved, and the flexible board is convenient to install, fast to assemble and use and convenient to detach. And through the arrangement of a plurality of differential line pairs, the signal transmission function among different devices, plates or connectors can be independently realized. And the signal transmission of each differential line pair is relatively independent, so that the modularized design of the signal transmission function of the flexible printed circuit board is realized, the flexible printed circuit board can be rapidly applied to high-speed signal transmission between different communication device products and communication equipment according to actual requirements, and also can be independently applied to short-distance test and communication between local parts in the device, and can adapt to the requirements of short-distance interconnection between the boards and local parts of a high-speed PCB.

Drawings

FIG. 1 is a schematic cross-sectional view of an embodiment of a flexible printed circuit board according to the present invention;

FIG. 2 is a schematic top view of an embodiment of the flexible printed circuit board of FIG. 1;

FIG. 3 is a partial schematic diagram of one embodiment of a differential pair;

FIG. 4 is a partial schematic view of a lateral cross-sectional structure of an embodiment of a flexible board;

FIG. 5 is a schematic view of another embodiment of a flexible printed circuit provided by the present invention;

FIG. 6 is a schematic diagram of an embodiment of a connector according to the present invention;

FIG. 7 is a schematic diagram of an embodiment of a male connector according to the present invention;

FIG. 8 is a schematic diagram of an embodiment of a female connector according to the present invention;

fig. 9 is a schematic structural diagram of an embodiment of a printed circuit board according to the present invention.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, are intended to fall within the scope of the present invention.

It should be noted that, if directional indications (such as up, down, left, right, front, and rear … …) are included in the embodiments of the present invention, the directional indications are merely used to explain the relative positional relationship, movement conditions, etc. between the components in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indications are correspondingly changed.

In addition, if there is a description of "first", "second", etc. in the embodiments of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions of the embodiments may be combined with each other, but it is necessary to base that the technical solutions can be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be considered to be absent and not within the scope of protection claimed in the present invention.

Referring to fig. 1-2, fig. 1 is a schematic cross-sectional structure of a flexible printed circuit board according to an embodiment of the invention. Fig. 2 is a schematic top view of an embodiment of the flexible printed circuit board in the embodiment of fig. 1.

The flexible board 100 of the present embodiment includes a substrate 160, a first cover film 150, and a second cover film 140.

The substrate 160 includes a differential line layer 120, a base layer 110, and a reference layer 130 laminated and bonded in this order. The differential line layer 120 has a plurality of differential line pairs 121 formed thereon and spaced apart from each other.

The differential pair 121 is used to transmit signals, and the differential pairs 121 transmit signals independently of each other. The reference layer 130 is used for grounding and is GND plane. The base layer 110 is a dielectric layer for insulating the differential line layer 120 and the reference layer 130, so that the differential line layer 120 and the reference layer 130 are independent and do not interfere with each other. The base layer 110 may include, but is not limited to, one or more of prepregs, epoxy resins, polyester resins (PET), polyimides, polycarbonates (PC), bismaleimide triazines (Bismaleimide Triazine, BT), ceramic-based insulating materials, and the like.

The flexible board 100 arranges the plurality of differential line pairs 121 side by side on the differential line layer 120 as needed to save space. The arrangement manner of the multiple differential line pairs 121 on the differential line layer 120 may be set based on actual situations, for example: the different positions are spaced apart by different distances and are parallel to each other.

The differential line pairs 121 are respectively and independently transmitted with signals and integrated on one flexible board 100, so that the integration level of the connection device can be improved, and high-density connection can be realized.

The first cover film 150 is attached to a side of the differential line layer 120 away from the base layer 110, and the second cover film 140 is attached to a side of the reference layer 130 away from the base layer 110. The first cover film 150 and the second cover film 140 may be PI films (polyimide films) or other soft cover films to protect opposite sides of the substrate 160 from both sides.

The first cover film 150 and the second cover film 140 may be adhered to opposite sides of the substrate 160 by means of adhesion, vacuum suction, or the like, so as to form a protective layer of the flexible printed circuit board 100, protect the differential pair 121, and improve structural stability and reliability of the flexible printed circuit board 100.

In a specific application scenario, the flexible board 100 may be manufactured by laminating a double-sided copper-clad plate and two PI cover films with back glue. One copper surface of the double-sided copper-clad plate is etched to form a plurality of pairs of differential line pairs 121 with the width of actual requirements in a chemical etching mode, the other copper surface is not moved, and two PI cover films with back glue are respectively bonded on two opposite sides of the double-sided copper-clad plate, so that the soft board 100 is obtained.

The opposite ends of the flexible board 100 are respectively provided with a plurality of connection pads 124; opposite ends of each differential pair 121 are connected to corresponding connection pads 124, respectively. In a specific application scenario, the connection pad 124 is a complete pad, and is used for connecting the corresponding differential line and the external device.

The two ends of the flexible board 100 can be connected with the matched connectors in a contact way through the connecting pads 124 or connected and fixed with devices to be connected in a welding way, so that signal transmission among different devices is realized. At this time, the transmission order is the differential line pair 121, the connection pad 124, and the connector. The flexible board 100 of this embodiment is only required to be in contact with the corresponding connection pads 124 for electrical connection with other devices, has simple structure and flexible installation, can realize rapid assembly and use and convenient disassembly by means of welding and fixing, conductive adhesive bonding and the like, is easy to realize mass production, is favorable for reliable connection in high-speed signal transmission short-distance interconnection, can reduce manufacturing cost, improves assembly efficiency, and is particularly suitable for high-speed signal transmission application on communication module products.

The flexible board 100 of the present embodiment can individually realize the signal transmission function among different devices, boards or connectors by arranging a plurality of differential line pairs 121. And the signal transmission of each pair of differential line pairs 121 is relatively independent, so that the modularized design of the signal transmission function of the flexible printed circuit board 100 is realized, the flexible printed circuit board can be modularized and suitable for rapid plugging test and assembly adaptation between communication module products, can be rapidly applied to high-speed signal transmission between different communication device products and communication equipment, can be independently applied to local parts in devices, can also be suitable for the requirements of interconnection between boards of high-speed PCBs and local short distances, and improves the application scene of the flexible printed circuit board 100.

Through above-mentioned structure, the soft board of this embodiment simple structure, its both ends can be connected or be connected fixedly through welded mode with the device that needs to link to each other through connection pad and mating connector, realize the signal transmission between different devices, simple to operate can realize quick assembly use and convenient dismantlement. And through the arrangement of a plurality of differential line pairs, the signal transmission function among different devices, plates or connectors can be independently realized. And the signal transmission of each differential line pair is relatively independent, so that the modularized design of the signal transmission function of the flexible printed circuit board is realized, the flexible printed circuit board can be rapidly applied to high-speed signal transmission between different communication device products and communication equipment according to actual requirements, and also can be independently applied to short-distance test and communication between local parts in the device, and can adapt to the requirements of short-distance interconnection between the boards and local parts of a high-speed PCB.

In other embodiments, a shielding member 122 is disposed between every two adjacent differential line pairs 121, and the shielding member 122 is spaced from the corresponding two adjacent differential line pairs 121. The shielding piece 122 is arranged between every two adjacent differential line pairs 121, so that the condition that signal transmission between every two adjacent differential line pairs 121 is mutually interfered can be prevented, and independent transmission between the differential line pairs 121 is realized.

The width of the differential line (not labeled in the figure) of the differential line pair 121 is a preset width X; the distance between every two adjacent differential line pairs 121 is at least 3 times of a preset width X, and may specifically be 3 times, 4 times, 5 times, 6 times, 7 times, 8 times, or the like; and the distance between the shield 122 and the adjacent differential pair 121 is at least 3 mils, and may specifically be 3 mils, 4 mils, 5 mils, 7 mils, 8 mils, 10 mils, etc. Through the arrangement of the spacing, the structure spacing can be utilized to further ensure independent transmission between the differential line pairs 121, so that signal interference and other situations are reduced.

The preset width X of the width of each differential line is determined according to the impedance requirement of the device matched with the flexible board 100, and the preset width X is calculated by simulating the actual value of the impedance.

Referring further to fig. 3, fig. 3 is a schematic partial structure of one embodiment of the differential pair.

In other embodiments, the shield 122 of each substrate 160 has a plurality of shield apertures 161 vertically connected on at least one side thereof adjacent the adjacent differential line pair 121. In one particular application scenario, when only one side of the shield 122 is adjacent the differential pair 121, the side is vertically coupled with a plurality of shield apertures 161. In another specific application scenario, when opposite sides of the shielding member 122 are respectively close to the two different differential line pairs 121, a plurality of shielding holes 161 are respectively vertically connected to the opposite sides of the shielding member 122. The arrangement of the shielding holes 161 in other cases of the shielding member 122 is similar to the above application scenario, and will not be repeated.

Through the arrangement, the shielding pieces 122 on the two opposite sides of each differential line pair 121 are correspondingly provided with a plurality of shielding holes 161 for signal shielding, so that a relatively independent shielding structure is generated, and crosstalk is reduced in the high-frequency signal transmission process of each differential line pair 121, so that the high-speed signal transmission requirement is met. And the number and positions of the shielding holes 161 on the opposite sides of each differential line pair 121 may be set based on actual requirements.

One end of each shielding hole 161 is connected to the corresponding shielding member 122, and the other end is connected to the reference layer 130. The shields 122 of the upper and lower layers are connected to the reference layer 130. A relatively independent shielding structure is formed so as to ensure smaller crosstalk in the high-frequency signal transmission process, so that the high-speed signal transmission requirement is met.

In one specific application scenario, the shielding holes 161 may be formed by a metallization copper deposition process after drilling holes in the substrate 160 based on the location of each shielding member 122 near the corresponding differential line pair 121.

The diameter of the shielding hole 161 may be about 0.2mm to ensure structural stability and shielding effect of the shielding hole 161.

In other embodiments, referring further to fig. 4, fig. 4 is a schematic side sectional view of an embodiment of a flexible printed circuit board.

The opposite ends of the flexible board 100 are also provided with a plurality of ground pads 123, respectively; each of the connection pads 124 corresponds to at least one of the ground pads 123, and the at least one ground pad 123 is disposed at intervals around the corresponding connection pad 124. Wherein the center-point spacing of the ground pad 123 from the corresponding connection pad 124 may be between 0.8-1.2 mm.

In a specific application scenario, each connection pad 124 may correspond to 2 ground pads 123, and the 2 ground pads 123 are disposed on opposite sides of the corresponding connection pad 124. In a specific application scenario, each connection pad 124 may correspond to 4 ground pads 123, and the 4 ground pads 123 are respectively disposed around the corresponding connection pad 124. And the like, without limitation.

The coupling of the ground pad 123 can be reduced by arranging the ground pad 123 around the ground pad 123, so that the transmission loss of the ground pad 123 is reduced, the signal integrity is improved, and the impedance of the ground pad 123 can be consistent with the impedance of the differential line pair 121 through reasonable design of the ground pad 123, so that the reflection of signals is reduced, and the signal integrity is improved.

In other embodiments, one end of the ground pad 123 is connected to the corresponding shield 122 and the other end is connected to the reference layer 130. Wherein the shield 122 may extend to the periphery of the connection pad 124 and the ground pad 123 is prepared thereon to achieve a shielding effect of the ground pad 123 on the connection pad 124.

Both sides of the ground pad 123 are connected to the shielding structure formed by the shield 122, the shield hole 161, and the reference layer 130, so that the connection pad 124 is shielded from the shielding structure on the circumferential side by the form of ground.

The ground pad 123 has a through hole (not shown) at the center, and the through hole penetrates the substrate 160. When the flexible board 100 is welded to other devices, the solder can be connected to the bonding pads of other components through the through holes, so that the three-dimensional degree and the firmness of the connection between the flexible board 100 and other devices are improved.

In other embodiments, each connection pad 124 is disposed at the differential line layer 120; the reference layer 130 is hollowed out in a region corresponding to each connection pad 124 on the differential line layer 120. The clearance dimension of the hollowed-out area and the spacing between the sides of the connection pads 124 are required to be more than 6mil, and may be specifically 6mil, 7mil, 8mil, 9mil, 10mil, 15mil or 20mil, etc., so that the impedance consistency of the whole differential pair 121 can be effectively maintained.

Referring to fig. 5, fig. 5 is a schematic structural diagram of another embodiment of a flexible board according to the present invention.

The flexible board of the present embodiment may be the flexible board 100 of any of the above embodiments.

A rigid housing 190 may also be provided around the flexible board to further protect the flexible boards and improve the reliability and stability of the flexible board 100.

Through above-mentioned structure, the soft board of this embodiment is modularized structure design, and the equipment is convenient, is suitable nimble, and the soft board is with other parts can be alone shaping processing and the fixed one set of connector of combination shaping again. The scheme is very suitable for rapid plugging test and assembly adaptation between communication module products. The method can be rapidly applied to high-speed signal transmission between different communication device products and communication equipment, and can also be independently applied to local parts in devices.

Referring to fig. 6, fig. 6 is a schematic structural diagram of an embodiment of a connector according to the present invention.

The connector 200 of the present embodiment includes: a flexible board 210 and two connectors 220; opposite ends of the flexible board 210 are respectively connected with corresponding connectors 220 to be connected with corresponding devices through the connectors 220.

The flexible board 210 of this embodiment may be the flexible board 100 of any of the above embodiments, so that the connector 200 can be assembled into a unit assembly independently and quickly, and can be adapted to short-distance interconnection of high-speed high-frequency devices, and also can be applied to high-speed signal transmission between different communication device products and communication devices.

In other embodiments, the connector 220 comprises a male connector or a female connector. In a specific application scenario, two opposite ends of the flexible board 210 may be male connectors, and corresponding connection devices are provided with female connectors for interconnection. In another specific application scenario, the two opposite ends of the flexible board 210 may be female connectors, and the corresponding connection devices are provided with male connectors for interconnection. In another specific application scenario, the two opposite ends of the flexible board 210 may be a female connector and a male connector, and the connecting device to be connected is correspondingly provided with the male connector and the female connector for connection.

The connection head 220 is electrically connected by connection pads connected to opposite ends of the flexible board 210.

Referring to fig. 7-8, fig. 7 is a schematic structural diagram of an embodiment of a male connector according to the present invention. Fig. 8 is a schematic structural diagram of an embodiment of a female connector provided by the present invention.

The end of the male connector 221 away from the flexible board 210 is provided with a plurality of first terminals 2211; the female connector 222 is provided with a plurality of second terminals 224 at an end thereof remote from the flexible board 210. The first terminals 2211 and the second terminals 224 are arranged in a one-to-one correspondence manner, so that when the male connector 221 and the female connector 222 are correspondingly connected, the first terminals 2211 are in one-to-one correspondence with the second terminals 224.

In other embodiments, a shield can 223 is disposed around each second terminal 224 of the female connector 222; at least one ground terminal 2213 is provided around each first terminal 2211 of the male connector 221.

The position of at least one grounding terminal 2213 around each first terminal 2211 corresponds to the shielding cover 223 of the corresponding second terminal 224, when the female connector 222 is connected with the male connector 221, at least one grounding terminal 2213 around each first terminal 2211 is elastically connected with the corresponding shielding cover 223, and each second terminal 224 and the connected first terminal 2211 are surrounded by the corresponding shielding cover 223, so that a good shielding effect can be achieved at the connection position of the male connector 221 and the female connector 222, and reliable guarantee is provided for realizing low crosstalk transmission of the connector 200.

In other embodiments, the female connector 222 is provided with an anti-releasing device 225 on opposite sides, and the male connector 221 is provided with a fastening base 2212 on opposite sides.

When the female connector 222 is connected with the male connector 221, each anti-trip 225 is buckled with the corresponding buckling platform 2212. The two split connectors are combined together, so that the first terminal 2211 inside the male connector 221 is stably and tightly contacted with the second terminal 224 inside the female connector 222, and the signal conduction and transmission of the high-speed connector are realized.

The connector of the embodiment is suitable for quick plugging test and assembly adaptation between communication module products. The method can be rapidly applied to high-speed signal transmission between different communication device products and communication equipment, and can also be independently applied to local parts in devices.

In other embodiments, the first terminals 2211 of the male connectors 221 include high-speed transmission contact elastic terminals and Y-shaped elastic ground terminals, and the arrangement of the high-speed transmission contact elastic terminals and the ground terminals corresponds to the arrangement of the second terminals 224 in the female connectors 222 mating therewith. The elastic terminal and the grounding terminal of the high-speed transmission contact in the male connector 221 are hardware stamping bending pieces made of high-purity conductive copper, and the male connector 221 is formed by casting and integrating.

The female connector 222 is integrally assembled and formed by a wafer module formed by splicing a plurality of high-speed coaxial cables, and generally, the female connector 222 is arranged at two ends of the high-speed coaxial cables and is inserted and locked with the male connector 221, so that a signal transmission line is conducted, and high-speed signal transmission is realized.

The wafer-like structure with the assembled high-speed cables inside the female connector 222 is also cast. Specifically, the head of the high-speed cable is peeled off to form a wire core with a certain length, a fixed terminal is sleeved on the wire core, the fixed terminal is internally provided with assembled conducting terminal parts and a supporting and fixing insulating plastic block, the plastic block mainly supports, fixes and limits the peeled cable, a spot welder or soldering is utilized to weld and fix the high-speed wire core on the terminal at a specified position, after welding, a shielding terminal at the sheath of the wrapped cable is pressed and fastened, the terminal at the welding position where the shielding terminal is connected with the high-speed wire core is also pressed and fixed together, a second terminal 224 is obtained, the cables of the second terminal 224 after termination are spliced into a specified interval number by utilizing a tool, then casting and secondary molding are carried out, a wafer-shaped component is manufactured, and after the wafer-shaped component is spliced into a specified number of casting and molding, a connector with a female end is manufactured.

Referring to fig. 9, fig. 9 is a schematic structural diagram of an embodiment of a printed circuit board according to the present invention.

The printed circuit board 300 of the present embodiment includes: a flexible board 310 and at least one circuit board 320; at least one end of the flexible board 310 is connected with a corresponding circuit board 320.

One end of the flexible board 310 may be connected to the circuit board 320, and the other end may be connected to other devices through a connector. Or opposite ends of the flexible board 310 may be connected to two circuit boards 320, respectively.

The flexible board 310 of the present embodiment may be the flexible board 100 of any of the above embodiments.

Through above-mentioned structure, the printed circuit board of this embodiment is applicable to quick grafting test and the equipment adaptation between the communication module product. The method can be rapidly applied to high-speed signal transmission between different communication device products and communication equipment, and can also be independently applied to local parts in devices.

The foregoing description is only of embodiments of the present invention, and is not intended to limit the scope of the invention, and all equivalent structures or equivalent processes using the descriptions and the drawings of the present invention or directly or indirectly applied to other related technical fields are included in the scope of the present invention.

Claims

1. A flexible board, characterized in that the flexible board comprises:

the substrate comprises a differential line layer, a base layer and a reference layer which are laminated and bonded in sequence; a plurality of differential line pairs which are arranged at intervals are formed on the differential line layer;

the first cover film and one side of the differential line layer, which is far away from the base layer, are attached, and the second cover film and one side of the reference layer, which is far away from the base layer, are attached;

wherein, a plurality of connection pads are respectively arranged at the opposite ends of the soft board; opposite ends of each differential line pair are respectively connected with corresponding connecting bonding pads.

2. A flexible printed circuit board according to claim 1, wherein,

a shielding piece is arranged between every two adjacent differential line pairs, and the shielding piece and the corresponding two adjacent differential line pairs are respectively arranged at intervals;

the width of the differential line pair is a preset width; the distance between every two adjacent differential line pairs is at least 3 times of a preset width; and the distance between the shield and the adjacent differential pair of wires is at least 3 mils.

3. The flexible printed circuit of claim 2, wherein each of the shields has a plurality of shield holes vertically connected thereto on at least one side adjacent to the differential line pair:

one end of each shielding hole is connected with the corresponding shielding piece, and the other end of each shielding hole is connected with the reference layer.

4. The flexible board according to claim 2, wherein the opposite ends of the flexible board are further provided with a plurality of ground pads, respectively;

each connecting pad corresponds to at least one grounding pad, and at least one grounding pad is arranged around the corresponding connecting pad at intervals.

5. The flexible printed circuit of claim 4, wherein one end of the ground pad is connected to the corresponding shield and the other end is connected to the reference layer;

and a through hole is formed in the center of the grounding pad, and the through hole penetrates through the substrate.

6. The flexible printed circuit of claim 4, wherein each of the connection pads is disposed at the differential line layer;

the reference layer is hollowed out in a region corresponding to each connecting pad on the differential line layer.

7. A connector, the connector comprising: a flexible board and two connectors;

opposite ends of the soft board are respectively connected with the corresponding connectors;

wherein the flexible board comprises the flexible board according to any one of claims 1 to 6.

8. The connector of claim 7, wherein the header comprises a male header or a female header;

a plurality of first terminals are arranged at one end of the male connector, which is far away from the soft board;

a plurality of second terminals are arranged at one end, far away from the soft board, of the female connector;

the first terminals and the second terminals are arranged in a one-to-one correspondence manner.

9. The connector of claim 8, wherein the connector comprises a plurality of pins,

a shielding cover is arranged around each second terminal of the female connector;

at least one grounding terminal is arranged around each first terminal of the male connector;

wherein the position of at least one grounding terminal around each first terminal corresponds to the shielding cover of the corresponding second terminal, when the female connector is connected with the male connector, the at least one grounding terminal around each first terminal is contacted with the corresponding shielding cover, and each second terminal and the connecting first terminal are surrounded by the corresponding shielding cover.

10. A printed circuit board, the printed circuit board comprising: a flexible board and at least one circuit board;

at least one end of the soft board is connected with the corresponding circuit board;