TWM530461U - Flexible flat cable structure - Google Patents

Description

Flexible cable structure

The present invention relates to a flexible cable structure, and more particularly to a flexible cable structure that can be applied to high-frequency signal transmission.

Flexible Flat Cable (Flexible Flat Cable), referred to as flexible cable or FFC, is a data cable structure that is made of PET insulation material and a plurality of tinned flat copper wires pressed through a high-tech automation equipment production line. The flexible cable is a signal transmission component, which has the advantages of arbitrary deflection and high signal transmission capability, and thus is widely used in many electronic products.

Generally, the conventional flexible cable is subdivided into a three-layer structure, which is formed by stacking the upper insulating layer, the wiring layer and the lower insulating layer in order from top to bottom. The upper and lower insulating layers are made of PET material, and the wires are made. The layer comprises a plurality of flat copper wires arranged in parallel with each other, and the ends thereof are exposed at both ends of the flexible cable to form a conductive contact, and the conductive contacts of the flexible cable can be directly connected to the cable connector. Alternatively, the conductive contacts of the flexible cable are attached to the insulative housing, and then the upper and lower iron shells are assembled on the insulative housing, so that the connector structure with the flexible contact wires as the terminals can be formed.

As people's demand for electronic communication is increasing, the signal transmission speed requirements of electronic devices are becoming higher and higher, and the development of electronic technology tends to be high-frequency signals and high-current transmission. Therefore, the requirements for the electrical characteristics of the transmission line have also been improved. Although coaxial cables have been developed for use in electronic products for high-frequency signal transmission, their production costs and high prices do not meet the low-cost requirements of consumers. Therefore, some operators have tried to replace the coaxial cable with a soft flat cable, but the electrical characteristics of today's soft flat cable cannot meet the requirements of high frequency use. Therefore, how to develop a transmission line that is cheaper and can meet the signal transmission requirements for high-frequency use is a problem to be solved by the present invention.

Although the soft flexible cable has the advantages of arbitrarily flexing and high signal transmission capability, it is widely used in many electronic products. However, in today's electronic technology development tends to use high-frequency signal transmission environment, the conventional soft cable The signal transmission cannot meet the characteristics of the high-frequency use, so it cannot meet the market demand.

The present invention provides a flexible cable structure comprising a first insulating layer, a first adhesive layer, a wire layer, a second adhesive layer and a second insulating layer. The first adhesive layer is disposed on the first insulating layer, and the wire layer is disposed on the first adhesive layer, the conductive layer comprises a plurality of flat metal wires arranged in parallel with each other, wherein at least one of the flat metal wires is covered with an insulating film The second adhesive layer is disposed on the wire layer and the second insulating layer is disposed on the second adhesive layer.

The flexible wiring structure provided by the present invention is covered with an insulating film on the periphery of the flat metal wire, and the insulating film can reduce the dielectric constant of the flexible cable, so that the flexible cable meets the high frequency use. The electrical characteristics requirements can solve the problem that the conventional flexible cable cannot meet the requirements of high frequency use and can not meet the market demand.

1‧‧‧Flexible cable structure

11‧‧‧First insulation

12‧‧‧First layer

13‧‧‧Wire layer

131‧‧‧flat metal wire

132‧‧‧Signal line

133‧‧‧ Grounding wire

134‧‧‧Insulation film

135‧‧‧Contacts

14‧‧‧Second layer

15‧‧‧Second insulation

16‧‧‧Acrylic adhesive layer

17‧‧‧Metal shielding

The first figure is a three-dimensional schematic diagram of the flexible cable structure of the present invention.

The second figure is a partial cross-sectional view of the flexible cable structure of the first figure.

The first embodiment of the present invention is a preferred embodiment of the flexible cable structure. The flexible cable structure 1 includes a first insulating layer 11 and a first adhesive layer 12. A wire layer 13, a second adhesive layer 14 and a second insulating layer 15, an acrylic adhesive layer 16 and a metal shielding layer 17.

The first adhesive layer 12 is formed on the first insulating layer 11. In the embodiment, the first adhesive layer 12 is made of insulating glue, and the first insulating layer 11 is polyethylene terephthalate (PET). The layer, the wire layer 13 is disposed on the first adhesive layer 12, and the wire layer 13 includes a plurality of flat metal wires 131 arranged in parallel with each other, wherein the flat metal wires 131 comprise a plurality of signal lines for transmitting signals. 132 and a plurality of grounding wires 133 for grounding. Since the signal wires 132 are used to transmit high frequency signals in the present embodiment, the insulating film 134 is coated on the periphery of the signal wires 132 to protect the high frequency signals. The layer 14 is disposed on the wire layer 13, the second insulating layer 15 is disposed on the second adhesive layer 14, the second adhesive layer 14 is composed of an insulating glue, and the second insulating layer 15 is polyethylene terephthalate. (PET) layer.

In the present embodiment, the insulating film 134 is made of a material having a low dielectric constant, such as a foamed insulating material, and the dielectric constant is usually between 1 and 3.5. The film 134 is wrapped around the periphery of the signal line 132 in the flat metal wire 131, thereby reducing the dielectric constant of the flexible wire structure 1, so that the electrical characteristics of the high-frequency use can be met, so that the conventional soft row can be solved. The line cannot meet the requirements of high frequency use and the problem of not meeting market demand.

In this embodiment, the width of each of the flat metal wires 131 after processing is substantially between 0.25 mm and 0.7 mm, and the height is between 0.022 mm and 0.1 mm, and the insulating film is matched. The thickness of 134 is between 50 μm and 100 μm, so as to obtain better low dielectric properties. It can be understood that the manufacturing method of the insulating film 134 on the periphery of the signal line 132 can be achieved by various different coating methods such as extrusion molding, coating method or immersion coating method, and thus in this creation. The manufacturing method in which the insulating film 134 is coated on the periphery of the signal line 132 is not limited.

It is to be noted that, in this embodiment, the ends of the plurality of flat metal wires 131 of the wire layer 13 of the flexible cable structure 1 are exposed to the second insulating layer 15 and the second adhesive layer 14 to form a plurality of The contacts 135 have flat contact faces, so as to facilitate subsequent use with the connector (not shown). That is, in the embodiment, the insulating film 134 covering the periphery of the signal line 132 in the flat metal wire 131 is not exposed to the second insulating layer 15 and the second adhesive layer 14, so that the conductive effect can be formed. Point 135, in other words, the insulating film 134 is not completely covered to the end of the flat metal wire 131.

In addition, in this embodiment, the widths of the signal lines 132 for transmitting signals in the plurality of flat metal wires 131 and the ground lines 133 for grounding are substantially equal, but are not limited thereto, and another option is The width of the ground line 133 may also be different from the width of the signal line 132, so that it can be applied to the use requirements of different electrical characteristics. Similarly, in this embodiment, the periphery of each of the signal lines 132 for transmitting signals is covered with an insulating film 134. However, the present invention is not limited thereto. Alternatively, only the periphery of the signal line 132 for transmitting high frequency signals is used. The insulating film 134 needs to be covered, and the periphery of the signal line 132 for transmitting the general signal does not need to be covered with the insulating film 134. This design can reduce the manufacturing cost.

In this embodiment, in order to prevent the high-frequency signal transmission of the flexible cable structure 1 from being disturbed by external electromagnetic waves, a metal shielding layer 17 is additionally disposed on the upper side of the second insulating layer 15 by using the acrylic adhesive layer 16, so that The signal transmission effect of the protective flexible cable structure 1 is not limited thereto. Alternatively, another metal shielding layer 17 may be attached on the lower side of the first insulating layer 11, so that the flexible cable structure 1 is Both the upper and lower sides can be protected by the metal shielding layer 17.

It is to be noted that, in the present embodiment, since the thickness of the insulating film 134 of the present invention is thin and conformally covers the flat signal line 132, the outer shape of the insulating film 134 is substantially hollow and flat. Therefore, it is advantageous to adhere to the thermal compression of the first insulating layer 11 and the second insulating layer 15 without causing voids, and the electrical characteristics such as the impedance of the flexible wiring structure 1 are preferably improved. In the example, the thickness of the insulating film 134 must be smaller than the width of the signal line 132. In addition, its appearance size is almost the same as the conventional flexible cable, but its electrical characteristics suitable for high-frequency signal transmission are far superior to the conventional flexible cable, so the flexible cable structure 1 of this creation can achieve no Increase the advantages of using space.

In summary, the flexible cable structure provided by the present invention is coated with an insulating film on the periphery of the flat metal wire, and the insulating film can reduce the dielectric constant of the flexible wire, so that the flexible wire meets the requirements. The electrical characteristics required for high-frequency use can solve the problem that the conventional flexible cable cannot meet the requirements of high-frequency use and can not meet the market demand.

The above detailed description is intended to be illustrative of a preferred embodiment of the present invention, which is not intended to limit the scope of the present invention, and other equivalents and modifications may be made without departing from the spirit of the invention. Changes are to be included in the scope of patents covered by this new model.

1‧‧‧Flexible cable structure

11‧‧‧First insulation

12‧‧‧First layer

13‧‧‧Wire layer

131‧‧‧flat metal wire

132‧‧‧Signal line

133‧‧‧ Grounding wire

134‧‧‧Insulation film

14‧‧‧Second layer

15‧‧‧Second insulation

16‧‧‧Acrylic adhesive layer

17‧‧‧Metal shielding

Claims (10)

A flexible cable structure comprising: a first insulating layer; a first adhesive layer disposed on the first insulating layer; a wire layer disposed on the first adhesive layer, the wire layers including parallel to each other Separating a plurality of flat metal wires, wherein at least one of the flat metal wires is covered with an insulating film; a second adhesive layer is disposed on the wire layer; and a second insulating layer is disposed on the second adhesive layer on. The flexible wiring structure according to claim 1, wherein the insulating film is made of a foamed insulating material. The flexible wiring structure according to claim 1, wherein the insulating film has a thickness of between 50 μm and 100 μm. The flexible cable structure of claim 1, wherein the flat metal wire has a width of between 0.25 mm and 0.7 mm. The flexible cable structure of claim 1, wherein the flat metal wire has a height between 0.022 mm and 0.1 mm. The flexible cable structure of claim 1, wherein the flat metal wires comprise a plurality of signal lines, at least one of the signal lines peripherally covering the insulating film. The flexible cable structure of claim 6, wherein the insulating film has a thickness smaller than a width of the signal line, and the insulating film conformally covers the periphery of the signal line. The flexible cable structure of claim 1, wherein the end of each of the flat metal wires of the wire layer is exposed to the second insulating layer and the second adhesive layer to form a joint, the insulating film is Not exposed to the second insulating layer and the second adhesive layer. The flexible wiring structure according to any one of claims 1 to 8, wherein the insulating film is made of a material having a low dielectric constant. The flexible wiring structure according to any one of claims 1 to 8, wherein the insulating film has a dielectric constant of between 1 and 3.5.