CN211047379U

CN211047379U - Flexible circuit board

Info

Publication number: CN211047379U
Application number: CN201922128011.9U
Authority: CN
Inventors: 陈溪泉
Original assignee: Dongguan Longyi Electronic Technology Co ltd
Current assignee: Dongguan Longyi Electronic Technology Co ltd
Priority date: 2019-11-29
Filing date: 2019-11-29
Publication date: 2020-07-17
Anticipated expiration: 2029-11-29

Abstract

The utility model discloses a flexible line way board, flexible line way board includes from last electromagnetic shielding membrane, first insulation layer, first glue film, signal transmission layer, dielectric layer, reference stratum, second glue film and the second insulating layer to range upon range of setting down, wherein, electromagnetic shielding membrane with local area between the first insulation layer still is equipped with flexible enhancement layer and third glue film. The utility model discloses flexible line way board's simple structure adds flexible enhancement layer and third glue film through the part, effectively increases the interval between electromagnetic shield membrane and the signal line to not only can effectively reduce signal transmission's insertion loss, but also can keep the holistic compliance of flexible line way board, do not influence its bending performance.

Description

Flexible circuit board

Technical Field

The utility model relates to a circuit board technical field especially relates to a flexible line way board with anti-electromagnetic interference function.

Background

With the development demand of electronic products towards high integration, miniaturization and high reliability, flexible circuit boards are more and more widely applied to the fields or products of aerospace, military, mobile communication, portable computers, digital cameras and the like.

In order to shield electromagnetic interference, a shielding film is generally arranged on the surface of the existing flexible circuit board, but on one hand, the impedance is reduced due to the addition of the shielding film, and the impedance line is often required to be thinned to meet the impedance requirement, but the manufacturing difficulty is increased; on the other hand, since the flexible printed circuit board is relatively thin and the cover film is also thin, the distance between the shielding film attached to the cover film and the signal line is small, a close reference ground layer is easily formed, the insertion loss of signal transmission is increased in multiples, and if the thickness of the cover film is increased, the bending property of the whole flexible printed circuit board is reduced.

Therefore, a flexible printed circuit board with simple structure, easy manufacturing, and good transmission performance and bending performance is needed to overcome the above problems.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a simple structure, be convenient for make, transmission performance and the all good flexible line way board of performance of buckling.

In order to achieve the above object, the utility model discloses a flexible circuit board, flexible circuit board includes from last electromagnetic shielding membrane, first insulation layer, first glue film, signal transmission layer, dielectric layer, reference stratum, second glue film and the second insulating layer to range upon range of setting down, wherein, electromagnetic shielding membrane with local area between the first insulation layer still is equipped with flexible enhancement layer and third glue film.

Preferably, the thickness of the electromagnetic shielding film is 1-100 μm.

Preferably, the first insulating layer is at least one of a polyimide film, a polyester film and a polytetrafluoroethylene film, and the thickness of the first insulating layer is 1-100 μm.

Preferably, the first adhesive layer is a thermosetting epoxy adhesive, and the thickness of the first adhesive layer is 1-100 μm.

Preferably, the flexible reinforcing layer is at least one of a PI film, a PEN film, an L CP film, foam and filling glue, and the thickness of the flexible reinforcing layer is 20-1000 μm.

Preferably, the thickness of the signal transmission layer is 1-100 μm, the thickness of the dielectric layer is 1-150 μm, and the thickness of the reference ground layer is 1-100 μm.

Preferably, the signal transmission layer is provided with a signal transmission line, and the signal transmission line is a single-ended transmission line, a differential transmission line or a plurality of pairs of transmission lines.

Preferably, the edge of the flexible reinforcing layer exceeds the transmission area of the signal transmission line by 0.1-10 mm.

Preferably, the electromagnetic shielding film may further be disposed on a lower layer of the second insulating layer, and the third adhesive layer and the flexible reinforcing layer are sequentially disposed in a local area between the lower layer and the second insulating layer.

Compared with the prior art, the utility model discloses flexible line way board includes from last electromagnetic shielding membrane to range upon range of setting down, the first insulation layer, first glue film, signal transmission layer, the dielectric layer, reference stratum, second glue film and second insulation layer, only need set up flexible enhancement layer and third glue film at the local region between electromagnetic shielding membrane and the first insulation layer, can realize only increasing the distance between electromagnetic shielding membrane and the signal transmission layer at local, thereby not only can reduce signal transmission's insertion loss, but also can keep the holistic compliance of flexible line way board, do not influence its bending performance, the utility model discloses flexible line way board simple structure need not to transfer the impedance line thin, thereby reduces the preparation degree of difficulty, the manufacturing of being convenient for, the corresponding manufacturing cost that has reduced.

Drawings

Fig. 1 is a cross-sectional view of the flexible printed circuit of the present invention.

Detailed Description

In order to explain technical contents, structural features, and objects and effects of the present invention in detail, the following description is given in conjunction with the embodiments and the accompanying drawings.

Please refer to fig. 1, the utility model discloses a flexible printed circuit 1, be applicable to on fields or products such as space flight, military affairs, mobile communication equipment, portable computer, digital camera, the utility model discloses flexible printed circuit 1 includes from last to stacking up electromagnetic shielding film 11, first insulating layer 12, first glue film 13, signal transmission layer 14, dielectric layer 15, reference stratum 16, second glue film 17 and second insulating layer 18 of setting down, wherein, the local area between electromagnetic shielding film 11 and the first insulating layer 12 still is equipped with flexible enhancement layer 19 and third glue film 20 to can increase the distance between electromagnetic shielding film 11 and the signal transmission layer 14 locally, and then reduce impedance, reduce transmission loss. Of course, according to actual needs, the electromagnetic shielding film 11 may also be disposed under the second insulating layer 18, and a local area between the two layers is sequentially disposed with the third glue layer 20 and the flexible reinforcing layer 19.

Specifically, in the present embodiment, the thickness of the electromagnetic shielding film 11 is 1 to 100 μm, the first insulating layer 12 and the second insulating layer 18 are both at least one of a polyimide film, a polyester film, and a polytetrafluoroethylene film, the thickness of the two is 1 to 100 μm, the first adhesive layer 13, the second adhesive layer 17, and the third adhesive layer 20 are all thermosetting epoxy resin adhesives, the thickness of the three is 1 to 100 μm, the flexible reinforcing layer 19 is at least one of a PI film, a PEN film, an L CP film, foam, and a filler adhesive, the thickness of the flexible reinforcing layer is 20 to 1000 μm, the thickness of the signal transmission layer 14 is 1 to 100 μm, the thickness of the dielectric layer 15 is 1 to 150 μm, the thickness of the reference ground layer 16 is 1 to 100 μm, and the reference ground layer 16 is generally made of copper foil.

Specifically, the signal transmission layer 14 is provided with a signal transmission line, which is a single-ended transmission line, a differential transmission line, or a plurality of pairs of transmission lines. The flexible reinforcing layer 19 is required to cover the transmission area of the signal transmission line, and specifically, the edge of the flexible reinforcing layer 19 exceeds the transmission area of the signal transmission line by 0.1-10 mm.

Compared with the prior art, the utility model discloses flexible line way board 1 includes from last electromagnetic shielding membrane 11 to range upon range of setting down, first insulation layer 12, first glue film 13, signal transmission layer 14, dielectric layer 15, reference stratum 16, second glue film 17 and second insulating layer 18, only need to set up flexible enhancement layer 19 and third glue film 20 at the local region between electromagnetic shielding membrane 11 and first insulation layer 12, thereby can locally increase the distance between electromagnetic shielding membrane 11 and the signal transmission layer 14, thereby not only can effectively reduce signal transmission's insertion loss, but also can keep the holistic compliance of flexible line way board 1, do not influence its bending performance, the utility model discloses flexible line way board 1 simple structure need not to transfer the impedance line to thin, thereby reduces the preparation degree of difficulty, and the manufacturing of being convenient for has correspondingly reduced manufacturing cost.

The above disclosure is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the scope of the invention, therefore, the invention is not limited thereto.

Claims

1. The utility model provides a flexible circuit board, its characterized in that, flexible circuit board includes from last electromagnetic shielding film, first insulating layer, first glue film, signal transmission layer, dielectric layer, reference stratum, second glue film and the second insulating layer to range upon range of setting down, wherein, electromagnetic shielding film with local area between the first insulating layer still is equipped with flexible enhancement layer and third glue film.

2. The flexible wiring board of claim 1, wherein the electromagnetic shielding film has a thickness of 1 to 100 μm.

3. The flexible wiring board according to claim 1, wherein the first insulating layer is at least one of a polyimide film, a polyester film, and a polytetrafluoroethylene film, and has a thickness of 1 to 100 μm.

4. The flexible circuit board of claim 1, wherein the first adhesive layer is a thermosetting epoxy adhesive and has a thickness of 1-100 μm.

5. The flexible wiring board of claim 1, wherein the flexible reinforcement layer is at least one of a PI film, a PEN film, an L CP film, a foam, and a filler paste, and has a thickness of 20 to 1000 μm.

6. The flexible wiring board of claim 1, wherein the thickness of the signal transmission layer is 1-100 μm, the thickness of the dielectric layer is 1-150 μm, and the thickness of the reference ground layer is 1-100 μm.

7. The flexible wiring board of claim 1, wherein the signal transmission layer is provided with a signal transmission line, and the signal transmission line is a single-ended transmission line, a differential transmission line, or a plurality of pairs of transmission lines.

8. The flexible wiring board of claim 7, wherein the edge of said flexible stiffening layer extends 0.1-10mm beyond the transmission area of said signal transmission line.

9. The flexible printed circuit board of claim 1, wherein the electromagnetic shielding film is further disposed under the second insulating layer, and the third adhesive layer and the flexible reinforcing layer are sequentially disposed in a local area therebetween.