TWI775668B - Flat data transmission cable - Google Patents

Abstract

The present invention relates to a flat data transmission cable. The data transmission cable includes a number of wires, a plastic layer enclosing all wires and a metal layer enclosing the plastic layer. The metal layer is formed by a metal strip spirally wound on the outside of the plastic layer. The metal layer has an aluminum foil layer and a bonding layer attached on one side of the aluminum foil layer. The metal layer is bonded to the plastic layer by melted bonding layer.

Description

Flat data transmission cable

The invention relates to a flat data transmission cable, in particular to a flat data transmission cable with better high-frequency transmission performance.

In the 3C industry, the transmission cable can be used as a medium for electrical connection between two electronic devices and can stably perform the expected signal transmission operation. Therefore, the transmission cable is widely used in various electronic devices. Among them, the transmission cables connected with USB, HDMI, DVI, Displayport and other interfaces are favored by the public because of their high transmission rate, long distance and high quality, and the number of them is also increasing. The transmission cables have a plurality of metal wires inside, including differential signal wires and ground wires. The plurality of metal wires are usually fixed only by the Mylar layer and the metal layer on the outside. After fixing, there will be air between the metal layer and the wires, thereby affecting the high-frequency transmission performance of the wires. In addition, with the development of computer technology, the data transmission speed of electronic products such as computer hard disks and motherboards is getting faster and faster, and the transmission frequency is getting higher and higher. In the field of high-frequency and ultra-high-frequency data transmission, control differential signal lines The differential impedance is very important to the integrity of the high-speed digital signal, and the conventional wire arrangement can no longer meet the requirements.

In view of this, it is necessary to further improve the conventional data transmission cable to solve the above problems.

The purpose of the present invention is to provide a flat data transmission with better high-frequency transmission performance cable.

In order to achieve the above purpose, the present invention provides a flat data transmission cable, which includes a plurality of wires arranged side by side, a plastic layer covering the plurality of wires, and a metal tape formed by spirally winding a metal tape and arranged on the outside of the plastic layer. The metal layer at least has an aluminum foil layer and an adhesive layer disposed on the side of the aluminum foil layer facing the plastic layer, and the metal layer is hot-melted and fixed to the outside of the plastic layer by the adhesive layer.

As a further improvement of the present invention, the wires are arranged at equal intervals.

As a further improvement of the present invention, the metal layer further has an insulating layer disposed on the surface of the aluminum foil layer away from the plastic layer.

As a further improvement of the present invention, the width of the metal strip is 0.5 to 3 times the line width of the flat data transmission cable.

As a further improvement of the present invention, an overlapping area is formed when the metal strip is spirally wound on the outside of the plastic layer.

The wrapping overlap ratio of the metal strip is 15% to 50% of the width of the metal strip.

As a further improvement of the present invention, the width of the overlapping area is at least 0.8 mm.

As a further improvement of the present invention, the winding angle of the metal strip in the width direction of the flat data transmission cable is 40° to 55°.

As a further improvement of the present invention, the distance between the conductor and the metal layer of the flat data transmission cable is 0.1 mm to 0.45 mm.

As a further improvement of the present invention, the wires include at least a pair of differential signal wires, each wire has a conductor located at a central position, the outer diameter of the conductors of the differential signal wires is the same, and the center distance of the differential signal wires is the same as that of the differential signal wires. The ratio between the conductor outer diameters of the wire is 1.5 to 2.8.

In the present invention, by arranging the metal layer to be disposed on the outside of the plastic layer by spiral winding through the metal strip, the tight winding and bonding between the metal layer and the plastic layer can be achieved; and, on the side of the metal layer facing the plastic layer Setting the adhesive layer can not only directly fix the metal layer to the outside of the plastic layer by bonding, without the intervention and fixation of the Mylar layer, so that the entire cable can be made thinner and more flexible; The air can be discharged, and because of the bonding and fixing, the discharged air cannot enter, achieving the effect of compactness, and then achieving the effect of tight wrapping, good high-frequency transmission performance, and softness and thinness.

100: Flat data transmission cable

1: Wire

2: Differential signal line

3: Ground wire

11: Conductor

12: The first cladding layer

13: Second cladding layer

4: plastic layer

5: Metal layer

51: Aluminum foil layer

52: Adhesive layer

53: Insulation layer

54: Overlap

The first figure is a partial perspective view of a preferred embodiment of the flat data transmission cable of the present invention.

The second figure is a front view of the flat data transmission cable shown in the first figure.

The third figure is a top view of the flat data transmission cable shown in the first figure.

Please refer to the first figure to the third figure together to show the first preferred embodiment of the flat data transmission cable 100 of the present invention. The flat data transmission cable 100 includes a plurality of wires 1 arranged side by side. The wires 1 at least include a pair of differential signal wires 2 and a ground wire 3 . The ground wires 3 can be used to suppress signal interference on the side of the differential signal pair. The arrangement of the wires 1 is a loop arrangement of the ground wires 3 and the differential signal wires 2 side by side, and the number of the wires 1 arranged side by side is between 3 and 50. Each wire 1 has a conductor 11 at the center position, and at least the outer diameters of the conductors 11 of each pair of differential signal lines 2 are the same. In the present invention, the outer diameters of the conductors 11 of all the wires 1 are the same, and the spacing is also the same.

Each wire 1 also has a first cladding layer 12 surrounding the conductor 11 and a second cladding layer 13 surrounding the first cladding layer 12 , respectively.

In the present invention, the dielectric coefficient of the first cladding layer 12 is set to be lower than that of the second cladding layer The dielectric constant of layer 13.

Specifically, in the present invention, the first cladding layer 12 is made of an insulating material with a relatively low dielectric coefficient, which is mainly used to provide a better signal transmission environment for each conductor 11 and reduce signal transmission. Delay, to ensure high-speed and effective signal transmission, reduce signal attenuation. The second cladding layer 13 is set to have a relatively high dielectric coefficient, mainly to suppress the interference of external electromagnetic waves, so as to effectively isolate each conductor 11 from the outside world and ensure the transmission of internal high-frequency and ultra-high-frequency signals; The second cladding layer 13 is preferably configured as a wave absorbing layer.

Further, the flat data transmission cable 100 in the present invention further includes a plastic layer 4 covering the plurality of wires 1 , and a metal layer 5 formed by spirally winding a metal material tape on the outside of the plastic layer 4 . In the present invention, the metal layer 5 at least has an aluminum foil layer 51 and an adhesive layer 52 disposed on the side of the aluminum foil layer 51 facing the plastic layer 4 , so that the metal layer 5 can be thermally fused through the adhesive layer 52 . Then, it is bonded and fixed on the outer surface of the plastic layer 4 .

On the one hand, in the present invention, the metal layer 5 is arranged on the outside of the plastic layer 4 in a spiral winding manner by means of a metal material tape, so that the tight winding and bonding between the metal layer 5 and the plastic layer 4 can be realized; on the other hand, on the metal layer 5. The adhesive layer 52 is provided on the side facing the plastic layer 4, not only can the metal layer 5 be directly fixed to the outside of the plastic layer 4 by bonding, without the intervention and fixation of the Mylar layer, so that the entire cable can be made more flexible. It is thinner and softer; it can also discharge air during bonding, and because the bonding is fixed, the discharged air cannot enter, so as to prevent the air from affecting the transmission of high-frequency signals, and achieve a dense effect, thereby achieving tight wrapping and high Excellent frequency transmission performance and soft and thin effect.

Combined with the above-mentioned settings of the first cladding layer 12 , the second cladding layer 13 , the plastic layer 4 and the metal layer 5 , the ratio between the center distance of each pair of the differential signal lines 2 and the outer diameter of the conductor 11 can be guaranteed. When it is 1.5 to 2.8, the differential impedance of each pair of differential signal lines 2 can be effectively reduced, effectively controlling the generally required In the range of 75Ω to 110Ω, the coupling effect is enhanced to ensure long-distance transmission of high-frequency signals.

Specifically, the above arrangement of the present invention can ensure that when the ratio between the center distance of each pair of the differential signal lines 2 and the outer diameter of the conductor 11 thereof is 1.5 to 2.8, the distance between each pair of the differential signal lines 2 can be guaranteed. Differential impedance is 79Ω to 106Ω.

In the present invention, the plastic layer 4 is wrapped around the wire 1, and the overall thickness after wrapping is between 0.3 mm and 1 mm, preferably between 0.3 mm and 0.55 mm. The thickness of the plastic layer 4 can be set as thin as possible, at least to ensure that the relative positions of all the wires 1 are fixed. And the above-mentioned plastic layer 4 can be set to be made of a plastic material with a dielectric coefficient close to that of air, so that the impedance of the plastic layer 4 can be reduced, so as to further provide a better signal transmission environment for the differential signal line 2 and reduce the signal transmission rate. Propagation delay and interference ensure high-speed and effective signal transmission and reduce signal attenuation.

Further, in the present invention, the distance between the outer edge of the conductor 11 in the flat data transmission cable 100 and the outer edge of the plastic layer 4 is preferably between 0.1 mm and 0.45 mm, preferably between 0.15 mm and 0.35 mm. between. The above distance is also the distance between the conductor 11 and the metal layer 5. Because the metal layer 5 is used to shield the external signal interference and ensure the transmission of high frequency and ultra-high frequency signals, the above distance also affects the height of the wire 1. It is one of the elements of high frequency data transmission. The smaller the distance, the smaller the impedance and the better the high frequency performance. At the same time, the thickness of the entire flat data transmission cable 100 is also smaller, which is softer and thinner. However, if the thickness is too small, the metal layer 5 will affect the signal transmission of the conductor 11 , and the above-mentioned interval of the present invention can better meet the needs of various aspects.

In addition, as shown in the second figure, the arrangement of the aluminum foil layer 51 in the metal layer 5 can effectively shield the external electromagnetic interference, that is, the differential signal line 2 can be effectively isolated from the outside world, so as to ensure the transmission of high-frequency and ultra-high-frequency signals. . In addition, the metal layer 5 also has a fireproof function.

In combination with the above, the cladding layer on the outer side of the conductor 11 in the present invention can make the differential signal The conductor 11 of the line 2 has a better signal transmission environment during information transmission, reduces the propagation delay of the signal, ensures the high-speed and effective transmission of the signal, reduces the signal attenuation, and avoids external interference. The metal layer 5 is disposed on the outside of the plastic layer 4 by a metal material tape in a spiral winding manner, so that the metal layer 5 and the plastic layer 4 can be tightly wound and adhered; furthermore, the metal layer 5 faces the plastic layer 4 The bonding layer 52 is provided on one side of the cable, which can not only directly fix the metal layer 5 to the outside of the plastic layer 4 by bonding, without the intervention and fixation of the Mylar layer, so that the entire cable can be made thinner and more flexible; In addition, the air can be discharged during bonding, and because of the bonding and fixing, the discharged air cannot enter, so as to prevent the air from affecting the transmission of high-frequency signals, and achieve the effect of compaction, thereby achieving tight wrapping, good high-frequency transmission performance and Soft and lightweight effect.

Specifically, when the ratio between the center distance of each pair of the differential signal lines 2 and the outer diameter of the conductor 11 is 1.55 to 2.31, the differential impedance between each pair of the differential signal lines 2 can be 79Ω to 91Ω.

In order to further ensure the flexibility and thinness of the flat data transmission cable 100, the outer diameter of the conductor 11 in the present invention is 31AWG or 32AWG or 33AWG. The differential impedance between each pair of the differential signal lines 2 can be guaranteed to be 79Ω to 91Ω. When the center-to-center distance is o.01mm, the differential impedance differs by 1.5Ω.

Wherein, when the outer diameter of the conductor 11 is 31AWG, the center-to-center spacing of each pair of the differential signal lines 2 is set to 0.44 to 0.52 mm, which can ensure that the differential impedance between each pair of the differential signal lines 2 is 79Ω to 91Ω; Specifically, when the center-to-center distance is 0.48 mm, the differential impedance between each pair of the differential signal lines 2 can be controlled at 85Ω.

When the outer diameter of the conductor 11 is 32AWG, the center-to-center spacing of each pair of the differential signal lines 2 is set to 0.36 to 0.44 mm, which can ensure that the differential impedance between each pair of the differential signal lines 2 is 79Ω to 91Ω. Specifically, when the center-to-center distance is 0.40mm, the difference between each pair of the differential signal lines 2 can be Impedance is controlled at 85Ω.

When the outer diameter of the conductor 11 is 33AWG, the center-to-center spacing of each pair of the differential signal lines 2 is set to 0.28 to 0.36 mm, which can ensure that the differential impedance between each pair of the differential signal lines 2 is 79Ω to 91Ω. Specifically, when the center-to-center distance is 0.32 mm, the differential impedance between the differential signal lines 2 can be controlled at 85Ω.

In addition, when the ratio between the center distance of each pair of the differential signal lines 2 and the outer diameter of the conductor 11 thereof is 2.18 to 2.84, the differential impedance between each pair of the differential signal lines 2 is 94Ω to 106Ω.

In order to further ensure the softness and thinness of the flat data transmission cable 100, the outer diameter of the conductor 11 in the present invention is 33AWG or 34AWG; at this time, the center distance of each pair of the differential signal lines 2 is set to 0.35mm to 0.51mm, which can ensure The differential impedance of each pair of the differential signal lines 2 is 94Ω to 106Ω. The differential impedance differs by 1.5Ω for every 0.01mm difference in center-to-center spacing.

Wherein, in the present invention, when the outer diameter of the conductor 11 is 33AWG, the center-to-center spacing of each pair of the differential signal lines 2 is set to 0.43 to 0.51 mm, which can ensure that the differential impedance of each pair of the differential signal lines 2 is 94Ω to 94Ω to 0.51mm. Specifically, when the center-to-center distance is 0.47mm, the differential impedance between each pair of the differential signal lines 2 can be controlled to be 100Ω.

When the outer diameter of the conductor 11 is 34AWG, the center spacing of each pair of the differential signal lines 2 is set to 0.35 to 0.43mm, which can ensure that the differential impedance of each pair of the differential signal lines 2 is 94Ω to 106Ω; When the center-to-center distance is 0.39mm, the differential impedance between each pair of the differential signal lines 2 can be controlled to be 100Ω.

In addition, in the present invention, the metal layer 5 also has an insulating layer 53 disposed on the surface of the aluminum foil layer 51 away from the plastic layer 4. The insulating layer 53 can replace the Mylar layer in the prior art and is insulated from the outside. The aluminum foil layer 51 can also be protected.

Further, in the metal layer 5, the sum of the thicknesses of the aluminum foil layer 51 and the insulating layer 53 is 0.010mm to 0.055mm, preferably 0.015mm to 0.025mm, so as to reduce the thickness as much as possible when realizing the external mask The thickness of the entire cable.

In addition, for the selection of the above-mentioned spirally wound metal strip, in the present invention, the width is 0.5 to 3 times the width of the flat data transmission cable 100 , preferably 0.5 to 2 times. In this width range, the winding is more It is convenient and convenient to grasp the tightness of the winding, and can also ensure the softness of the entire data transmission cable after winding.

Further, when the metal strip is spirally wound to form the metal layer 5, the metal layer 5 is formed with an overlapping area 54; preferably, the winding overlap ratio of the metal strip is 15% to 50% of the width of the metal strip. %, that is, the overlapping area 54 accounts for 15% to 50% of the width of the metal strip; the width of the overlapping area 54 is at least 0.8 mm, preferably at least 1 mm, which can be easily controlled, ensure the effectiveness of the winding, and avoid the Adjacent metal strips are collapsed and separated from each other, thereby causing mask leakage. In addition, the winding angle of the metal strip in the width direction of the flat data transmission cable 100 is 40° to 55°, preferably 45° to 53°.

It should be particularly pointed out that, for those of ordinary skill in the art, the equivalent changes to the present invention made under the teaching of the present invention should still be included in the claimed scope of the patentable scope of the present invention.

100: Flat data transmission cable

1: Wire

2: Differential signal line

3: Ground wire

11: Conductor

12: The first cladding layer

13: Second cladding layer

4: plastic layer

5: Metal layer

51: Aluminum foil layer

52: Adhesive layer

53: Insulation layer

Claims (10)

A flat data transmission cable, comprising a plurality of wires arranged side by side; wherein, the data transmission cable further comprises a plastic layer covering a plurality of the wires, a metal tape formed by spirally winding a metal tape and arranged on the outside of the plastic layer. The metal layer at least has an aluminum foil layer and an adhesive layer disposed on the side of the aluminum foil layer facing the plastic layer, and the metal layer is hot-melted and fixed to the outside of the plastic layer by the adhesive layer. The data transmission cable as described in item 1 of the scope of application, wherein the wires are arranged at equal intervals. The data transmission cable according to claim 1, wherein the metal layer further has an insulating layer disposed on the surface of the aluminum foil layer on the side facing away from the plastic layer. The data transmission cable according to claim 1, wherein the width of the metal strip is 0.5 to 3 times the line width of the flat data transmission cable. The data transmission cable as described in claim 4, wherein the metal strip forms an overlapping area when helically wound on the outside of the plastic layer. The data transmission cable according to item 5 of the claimed scope, wherein the wrapping overlap ratio of the metal strip is 15% to 50% of the width of the metal strip. The data transmission cable as described in claim 6, wherein the width of the overlapping region is at least 0.8mm. The data transmission cable according to claim 7, wherein a winding angle of the metal strip in the width direction of the flat data transmission cable is 40° to 55°. The data transmission cable according to item 1 of the claimed scope, wherein the distance between the conductor and the metal layer of the flat data transmission cable is 0.1 mm to 0.45 mm. The data transmission cable as described in claim 1, wherein the conducting wires include at least a pair of differential signal wires, each conducting wire has a conductor located at a central position, the outer diameters of the conductors of the differential signal wires are the same, and the differential signal wires have the same outer diameter. The ratio between the center-to-center distance of the signal lines and the outer diameter of the conductors of the differential signal lines is 1.5 to 2.8.

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