Flexible printed circuit board

Abstract

The utility model provides a flexible printed circuit board, which belongs to the technical field of printed circuit boards and comprises a soft board, a hard board, a flat-end bonding pad, an extended bonding pad, a graphene sheet and an elastic buffer layer. A plurality of groups of prismatic grids arranged on the surface of the graphene sheet can correspond to the flat-head bonding pad and the extension bonding pad, the graphene sheet conducts heat and can reduce the speed of local temperature rise, and the graphene sheet is connected with the soft board mixed in the inner layer of the copper-clad plate through the via hole, so that the heat dissipation area of the printed circuit board is effectively improved, the long-time working stability is ensured, and the service life of the printed circuit board is prolonged. By coating the elastic buffer layer between the soft board and the hard board, the bending stress of the printed circuit board can be absorbed, the line fatigue can be reduced, a plurality of groups of reinforcing rib wires are formed along the reinforcing rib grids after solidification, and the fiber orientation of the reinforcing rib wires of the elastic buffer layer is consistent with the bending direction between the soft board and the hard board. And the tensile strength of the flexible printed circuit board is effectively improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to printed circuit board technical field, especially relate to a flexible printed circuit board. BACKGROUND

[0002] Flexible circuit board, also known as FPC, is a kind of circuit board made of flexible insulating substrate, which constructs the connection welding point of conductive circuit and various electronic components by printing, etching and other processes on flexible substrate, to realize the transmission of electronic signal and power distribution;

[0003] In smart mobile phones and tablet computers and other mobile electronic devices, FPC is widely used in the connection of display screen, camera, fingerprint identification module and other components, and its flexible feature makes these devices realize more lightweight design, and also improves the reliability and stability of the device;

[0004] Flexible circuit board dense circuit area heat accumulation, its heat dissipation area is relatively small compared with other circuit board area, leading to local temperature rise faster, poor stability in long time work, affecting the service life of device;

[0005] And, the traditional flexible circuit board is poor in bending resistance, PI substrate repeated bending leads to circuit fatigue, easy to produce crack, so that the conductive circuit is broken;

[0006] Therefore, the present application provides flexible printed circuit board to meet the needs. UTILITY MODEL CONTENTS

[0007] The utility model aims at solving the problems in the prior art, and provides a flexible printed circuit board.

[0008] To solve the above technical problems, the utility model provides the following technical scheme:

[0009] A kind of flexible printed circuit board, including: soft board, hard board, flat head pad, extension pad, graphene sheet and elastic buffer layer, the surface of the soft board is provided with several groups of conductive circuit, the left and right ends of the soft board are equipped with hard board, the outer layer of the hard board is provided with copper-clad plate, the surface of the hard board is provided with several groups of via, the hard board is welded with several groups of flat head pad at the outer end point of via, the hard board is welded with extension pad between flat head pad, the inner side of the copper-clad plate is provided with filling groove, the filling groove is provided with reinforcing rib lattice, the side surface of the hard board located in via is equipped with graphene sheet, the filling groove is coated with elastic buffer layer.

[0010] Preferably, the hard board is formed by the outer layer of soft board composite copper-clad plate on both sides, and the flat head pad and extension pad are communicated with the conductive circuit.

[0011] Preferably, the graphene sheet is in the shape of a rectangular strip, and the surface of the graphene sheet is provided with a plurality of groups of prismatic grids.

[0012] Preferably, the graphene sheet is attached to the side of the flat pad and the extended pad, and the graphene sheet is connected to the soft plate mixed in the inner layer of the copper-clad plate through the via hole.

[0013] Preferably, the edge of the copper-clad plate near the soft plate is in the shape of an arc, and the filling groove has a spacing with the soft plate.

[0014] Preferably, a plurality of groups of rectangular strip-shaped reinforcing rib grids are arranged in the filling groove, and the reinforcing rib grids are distributed along the direction of the soft plate.

[0015] Preferably, the elastic buffer layer is made of silica gel, the elastic buffer layer extends from the filling groove to the outer end of the joint between the copper-clad plate and the soft plate, and the elastic buffer layer is wrapped outwardly on the edge of the copper-clad plate.

[0016] Compared with the prior art, the utility model has at least the following beneficial effects:

[0017] In the above scheme, the graphene sheet is installed on the side of the hard plate of the via hole, a plurality of groups of prismatic grids arranged on the surface of the graphene sheet can correspond to the flat pad and the extended pad, the graphene sheet conducts heat, can reduce the speed of local temperature rise, the graphene sheet is connected to the soft plate mixed in the inner layer of the copper-clad plate through the via hole, effectively improves the area of the printed circuit board heat dissipation, and ensures long-time working stability.

[0018] In the above scheme, the elastic buffer layer is coated between the soft plate and the hard plate, the elastic buffer layer extends from the filling groove to the outer end of the joint between the copper-clad plate and the soft plate, and the elastic buffer layer is wrapped outwardly on the edge of the copper-clad plate, the silica gel elastomer in the bending area can absorb the bending stress of the printed circuit board, reduce the circuit fatigue, a plurality of groups of reinforcing filaments are formed along the reinforcing rib grids after solidification, the fiber orientation of the reinforcing filament of the elastic buffer layer is consistent with the bending direction between the soft plate and the hard plate, and the tensile strength of the flexible printed circuit board is effectively improved. BRIEF DESCRIPTION OF DRAWINGS

[0019] The drawings incorporated herein and forming part of the specification illustrate embodiments of the present disclosure and, together with the specification, further serve to explain the principles of the present disclosure and to enable one skilled in the relevant art to practice and use the same.

[0020] Figure 1 It is a whole structure schematic view of the utility model;

[0021] Figure 2 It is a cross-sectional structure schematic view of the utility model;

[0022] Figure 3 The graphene sheet structure schematic diagram of the utility model;

[0023] Figure 4 The copper clad plate sectional structure schematic diagram of the utility model; Figure 2 A enlarged structure schematic diagram.

[0024] Figure 5 The copper clad plate sectional structure schematic diagram of the utility model;

[0025] [Reference signs]

[0026] 1-soft board;2-hard board;3-flat head pad;4-elongated pad;5-graphene sheet;6-elastic buffer layer;101-conductive circuit;201-copper clad plate;202-via hole;203-filling groove;204-reinforcing rib lattice.

[0027] As shown in the drawings, in order to clearly realize the structure of the embodiments of the utility model, specific structures and devices are marked in the drawings, but this is only for the need of illustration, and is not intended to limit the utility model in the specific structure, device and environment, and the ordinary skilled in the art can adjust or modify these devices and environment according to specific needs, and the adjustment or modification still includes in the scope of the appended claims. DETAILED DESCRIPTION

[0028] The technical scheme in the embodiments of the utility model will be described clearly and completely in combination with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the ordinary skilled in the art without creative labor belong to the scope of protection of the utility model.

[0029] In the description of the utility model, it is understood that the orientation or position relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and is not intended to indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, therefore it cannot be understood as a limitation on the utility model.

[0030] As Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5The utility model provides a flexible printed circuit board, the embodiment of the utility model provides, include: soft board 1, hard board 2, flat pad 3, extension pad 4, graphene sheet 5 and elastic buffer layer 6, the surface of soft board 1 is provided with several groups of conductive circuit 101, the left and right ends of soft board 1 are provided with hard board 2, the outer layer of hard board 2 is provided with copper clad plate 201, the surface of hard board 2 is provided with several groups of via hole 202, several groups of flat pad 3 are spot welded to the outer end point of via hole 202 of hard board 2, extension pad 4 is spot welded between flat pad 3 of hard board 2, the inboard of copper clad plate 201 is provided with filling groove 203, the filling groove 203 is provided with reinforcing rib lattice 204, graphene sheet 5 is installed to the side of via hole 202 of hard board 2, and the filling groove 203 is coated with elastic buffer layer 6.

[0031] In the embodiment, the hard board 2 is formed by the outer layer of the soft board 1 being composed of the copper clad plate 201 on both sides, and the flat pad 3 and the extension pad 4 are in communication with the conductive circuit 101.

[0032] In the embodiment, the graphene sheet 5 is in the shape of a rectangular strip, and the surface of the graphene sheet 5 is provided with a plurality of prismatic lattices. The plurality of prismatic lattices on the surface of the graphene sheet 5 can correspond to the flat pad 3 and the extension pad 4, so as to reduce the speed of local temperature rise and ensure the stability of long-time work.

[0033] In the embodiment, the graphene sheet 5 is attached to the side of the flat pad 3 and the extension pad 4, and the graphene sheet 5 is connected to the soft board 1 interlaced in the inner layer of the copper clad plate 201 through the via hole 202. The graphene sheet 5 conducts heat, effectively improving the area of heat dissipation of the printed circuit board.

[0034] In the embodiment, the edge of the copper clad plate 201 close to the side of the soft board 1 is in the shape of an arc, and there is a gap between the filling groove 203 and the soft board 1, so that the connecting surface is softer and the scratching during bending is reduced.

[0035] In the embodiment, the filling groove 203 is provided with a plurality of rectangular strip-shaped reinforcing rib lattices 204, and the reinforcing rib lattices 204 are distributed along the direction of the soft board 1. When the elastic buffer layer 6 is filled in the filling groove 203, a plurality of reinforcing rib filaments are formed along the reinforcing rib lattices 204 after solidification. The fiber orientation of the reinforcing rib filaments of the elastic buffer layer 6 is consistent with the bending direction between the soft board 1 and the hard board 2, effectively improving the tensile strength of the flexible printed circuit board.

[0036] In the embodiment, the elastic buffer layer 6 is made of silica gel. The elastic buffer layer 6 extends from the filling groove 203 to the outer end of the connecting seam between the copper clad plate 201 and the soft board 1, and the elastic buffer layer 6 is coated on the edge of the copper clad plate 201. The silica gel elastomer can absorb the bending stress of the printed circuit board and reduce the circuit fatigue.

[0037] The utility model covers any alternative, modification, equivalent method and scheme which are made on the essence and range of the utility model. In order to make the public have the thorough understanding of the utility model, the specific details are explained in the following preferred embodiment of the utility model, and the utility model can also be completely understood without the description of these details for the person skilled in the art. In addition, in order to avoid unnecessary confusion to the essence of the utility model, the well-known method, process, flow, element and circuit are not explained in detail.

[0038] The above only is the preferred implementation of the utility model, should point out, for the ordinary skill in the art of the present technology, on the premise of not departing from the principle of the utility model, still can make a number of improvement and embellishment, these improvements and embellishment also should be regarded as the protection range of the utility model.

Claims

1. A flexible printed circuit board, characterized in that, include: The system comprises a flexible circuit board (1), a rigid circuit board (2), flat-top pads (3), extended pads (4), a graphene sheet (5), and an elastic buffer layer (6). The surface of the flexible circuit board (1) is provided with several sets of conductive lines (101). Rigid circuit boards (2) are mounted on the left and right ends of the flexible circuit board (1). The outer layer of the rigid circuit board (2) is provided with a copper-clad laminate (201). The surface of the rigid circuit board (2) is provided with several sets of vias (202). The rigid circuit board (2) is located within the vias (202). 02) Several sets of flat-head pads (3) are soldered to the outer end. The rigid board (2) is spot-welded with extension pads (4) between the flat-head pads (3). A filling groove (203) is provided on the inner side of the copper clad board (201). A reinforcing rib grid (204) is provided in the filling groove (203). A graphene sheet (5) is installed on the side of the rigid board (2) near the via (202). An elastic buffer layer (6) is coated and covered in the filling groove (203).

2. The flexible printed circuit board according to claim 1, characterized in that: The rigid board (2) is formed by a composite copper-clad board (201) on both sides of the outer layer of the flexible board (1), and the flat pad (3) and the extended pad (4) are connected to the conductive line (101).

3. The flexible printed circuit board according to claim 1, characterized in that: The graphene sheet (5) is rectangular and has several sets of prisms on its surface.

4. The flexible printed circuit board according to claim 1, characterized in that: The graphene sheet (5) is attached to the side of the flat pad (3) and the extended pad (4), and the graphene sheet (5) is connected to the flexible board (1) sandwiched in the inner layer of the copper clad laminate (201) through the via (202).

5. The flexible printed circuit board according to claim 1, characterized in that: The edge of the copper clad laminate (201) near the flexible board (1) is arc-shaped, and there is a gap between the filling groove (203) and the flexible board (1).

6. The flexible printed circuit board according to claim 1, characterized in that: The filling groove (203) is provided with several sets of rectangular strip-shaped reinforcing ribs (204), and the reinforcing ribs (204) are distributed along the direction of the soft plate (1).

7. The flexible printed circuit board according to claim 1, characterized in that: The elastic buffer layer (6) is made of silicone. The elastic buffer layer (6) overflows from the filling groove (203) and extends to the outer end of the joint between the copper clad laminate (201) and the flexible board (1). The elastic buffer layer (6) covers the outer edge of the copper clad laminate (201).

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