TW202001934A - Flat data transmission cable - Google Patents

Abstract

The present invention relates to a flat data transmission cable. The data transmission cable includes a plurality of wires, an insulative layer enclosing all wires and a metal shielding film covering the insulative layer. In the length direction of the data transmission cable, the data transmission cable has at least a bending portion, a first part and a second part at two sides of the bending portion. The bending portion is formed with a stable angle.

Description

Flat data transmission cable

The invention relates to a data transmission cable, in particular to a flat data transmission cable which can have a stable bending angle without auxiliary bending tools, so as to facilitate installation and connection.

In the 3C industry, the transmission cable can be used as a medium for the electrical connection between two electronic devices, and can stably perform the expected signal transmission operation, thereby the transmission cable is commonly used in various electronic devices. Among them, the transmission cables connected with interfaces such as USB, HDMI, DVI, Displayport, SAS and others have high transmission rate, long distance, high quality and are popular among the public, and the number of uses is also increasing. The transmission cables have a plurality of metal wires inside. The plurality of metal wires are usually fixed by the outer Mylar layer and the metal layer. In most conventional terminal devices, in order to facilitate the connection of two electronic devices at different locations, the transmission cable needs to be bent. However, when performing bending operations on site, due to the large number of internal cables in the equipment, various bending methods need to be considered, which leads to a significant reduction in the assembly efficiency of the terminal equipment; in addition, the thickness of the conventional wire is large, and it is easy to rebound after bending Then, additional auxiliary tools such as clips are needed to fix the bends. When there are many bends, it is found that the inside of the equipment is covered with clips, which increases the assembly process and the cost of the equipment.

In view of this, it is indeed 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 cable that can have a stable bending angle without the need for an auxiliary bending tool to facilitate installation and connection.

In order to achieve the above object, the present invention provides a flat data transmission cable including a plurality of conductors arranged side by side, a plastic layer integrally covering the periphery of the plurality of conductors, and a spirally wrapped metal material tape The metal layer formed outside the plastic layer has at least one bend in the length direction of the data transmission cable, so that the data transmission cable is formed with first Segment and second segment, a stable bending angle is formed between the first segment and the second segment.

As a further improvement of the present invention, the bending point has a predetermined bending angle, and the difference between the stable bending angle and the predetermined bending angle is less than 10 degrees.

As a further improvement of the present invention, the mean impedance at the bend of the aforementioned at least one bend differs from the preset impedance of the data transmission cable by no more than 2 ohms.

As a further improvement of the present invention, the impedance of the data transmission cable at each bend is different from the preset impedance of the data transmission cable by no more than 2 ohms.

As a further improvement of the present invention, the signal delay of the data transmission cable per unit length is not greater than 5 picoseconds.

As a further improvement of the present invention, the difference between the insertion loss of the data transmission cable after bending and when the bend is flattened is less than 10%.

As a further improvement of the present invention, the difference between the reflection loss of the data transmission cable after bending and when the bend is flattened is less than 10%.

As a further improvement of the present invention, in the arrangement direction of the plurality of conductors, the plurality of conductors have a plurality of ground conductors and a pair of signal conductors disposed between each adjacent two ground conductors, the aforementioned pair of signal conductors constituting Differential signal wire set.

As a further improvement of the present invention, the plurality of wires are arranged at equal intervals, and the conductor diameters of the plurality of wires are the same.

As a further improvement of the present invention, the metal layer has at least an aluminum foil layer and an adhesive layer provided on the side of the aluminum foil layer facing the plastic layer, and the metal layer is bonded and fixed to the outside of the plastic layer by hot melting of the adhesive layer.

The flat data transmission cable of the invention, on the one hand, by arranging the wires side by side, and integrally overmolding the plastic layer on the outside of the plural wires, so that the thickness of the entire data transmission cable can be made thin; on the other hand, the metal material tape is spirally wound It is arranged on the outside of the plastic layer, which can achieve tight winding and bonding between the metal layer and the plastic layer, making the metal layer more tightly covered, and making the data transmission cable of the present invention on the premise of a metal layer with shielding interference, It is made thinner and softer; combining the above two points, it can further enable the data transmission cable of the present invention to achieve a stable bending operation in advance, and achieve a stable bending angle without the aid of auxiliary tools, thereby providing a stable Bending angle data transmission cable is convenient for installation and connection in subsequent equipment.

The invention relates to a flat-type data transmission cable. The data transmission cable includes at least a plurality of wires arranged side by side and a plastic layer integrally covering the plurality of wires. The following is a detailed example with several preferred embodiments.

Please refer to FIG. 1 to FIG. 7 together to show the first preferred embodiment of the data transmission cable 100 of the present invention. Among them, FIG. 1 and FIG. 2 show the state diagram before the data transmission cable 100 of the present invention is bent, and FIGS. 4 to 5 are schematic diagrams of the actual state of the data transmission cable 100 of the present invention with a bend.

1 to 7, the data transmission cable 100 of the present invention includes a plurality of conductors 1 arranged side by side, a plastic layer 2 integrally covering the plurality of conductors 1 and a spirally wound metal material tape disposed on the plastic Metal layer 3 formed outside layer 2.

With reference to FIGS. 1 to 5, in this embodiment, each of the wires 1 has a conductor 11 and a cladding layer 12 surrounding each of the conductors 11. The central axis of the conductor 11 is on the same plane. The plastic layer 2 is jointly formed outside the cladding layer 12 of the plurality of conductors 11 to form a common single insulating layer; and the plastic layer 2 is formed parallel to the plane where the central axis of the conductor 11 is located Upper and lower surfaces. The arrangement of the upper and lower surfaces of the plastic layer 2 in parallel can effectively maintain the arrangement of the wires 1 and prevent twisting or folding; furthermore, it can further facilitate the winding of the metal layer 3 to avoid An air interlayer appears between the plastic layer 2 and the metal layer 3.

The cladding layer 12 can protect the conductor 11 well, and prevent problems such as short circuit caused by contact between adjacent conductors 11 during the molding of the plastic layer 2. Furthermore, with the design of the cladding layer 12, the thickness of the plastic layer 2 can also be set to be as thin and light as possible to ensure that the relative positions of all the wires 1 are fixed, thereby reducing the thickness of the entire line and making the data of the present invention The transmission cable 100 is softer and thinner.

The materials of the cladding layer 12 and the plastic layer 2 are the same or similar; they are preferably made of similar materials, so that the plastic layer 2 and the cladding layer 12 can be combined when the data transmission cable 100 of the present invention is formed Good performance, can achieve a good fusion, minimize delamination problems or air intrusion, molding effect is better.

Further, the homogeneous materials are polyhydrocarbon compounds. Further, the polyhydrocarbon compounds are preferably high-density polyethylene.

In addition, the above-mentioned cladding layer 12 and the plastic layer 2 can be set to be preferably made of a plastic material having a dielectric coefficient close to air, thereby making the cladding layer 12 and the plastic layer 2 have a smaller impedance, thereby providing the conductor 11 A good signal transmission environment reduces the propagation delay of signals, reduces crosstalk between signals, ensures high-speed and effective transmission of signals, and reduces signal attenuation.

The above embodiment of the wire 1 with the cladding layer 12 is preferably such that the distance between the outer edge of the conductor 11 and the outer edge of the plastic layer 2 is 0.1 mm to 0.45 in the thickness direction of the data transmission cable 100 Between mm, preferably between 0.15mm and 0.25mm. The above distance is also the distance between the conductor 11 and the metal layer 3, which is one of the factors that affect the stable signal transmission of the wire 1 and is particularly a high-frequency data transmission. The smaller the distance, the lower the impedance and the higher the high-frequency performance. Good, at the same time the smaller the thickness of the entire data transmission cable 100, the more flexible and thin. However, when the thickness is too small, the metal layer 3 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.

Of course, as shown in FIG. 8, which is the second preferred embodiment of the present invention, the wire 1 may also only include the conductor 11, that is, no separate coating layer 12 is provided, and the plastic layer 2 is used directly. The overall cladding and insulation can also achieve the purpose of the invention, and with this arrangement, the thickness of the plastic layer 2 can be further reduced, so that the overall thickness of the data transmission cable 100 is further reduced.

Further, in this embodiment, the conductive wires 1 are arranged at equal intervals, and the number of the conductive wires 1 is between 3 and 50 in the arrangement direction of the conductive wires 1. The plurality of wires 1 has at least two ground wires and a signal wire disposed between the two ground wires. In this way, it is possible to eliminate the interference around the signal conductor between them by the grounding conductor, ensure the signal transmission environment of the signal conductor, and thereby improve the signal transmission efficiency and stability.

As a preferred embodiment of the present invention, in order to meet the development needs of high-speed signal transmission, the number of the signal conductors between two adjacent ground conductors is preferably set to two, and the two signal conductors constitute a differential transmission The signal wire set of the signal. That is, the ground wire is used for signal wire group protection to ensure high-frequency transmission performance.

Further, as shown in FIG. 5, all the wires 1 in the first preferred embodiment of the present invention include only the ground wire g and the signal wire group s, and the number of the ground wire g is one more than the number of the signal wire group s. Preferably, in the arrangement direction of the conductors 1, the two conductors 1 located on both sides are grounding conductors g, and there is a pair of signal conductor groups s between two adjacent grounding conductors g. In this way, each group of signal conductors can be protected by grounding conductors on both sides, further improving the high-frequency transmission characteristics of the entire data transmission cable.

Of course, as another preferred embodiment of the present invention, in order to cooperate with other single-ended signal transmission, the signal wire may also have a single-ended signal wire. For example, to adapt to the Mini SAS (Mini Serial Attached Small Computer System Interface, Mini Serial Serial SCSI) product design, the number of the signal wires is twice the number of ground wires; at this time, in the direction of the arrangement of the wires 1, The single-ended signal conductor may be disposed outside the ground conductor, that is, on both sides of the entire data transmission cable 100. Between the two single-ended signal conductors, a ground conductor and a signal conductor group are sequentially arranged.

Furthermore, as another embodiment of the present invention, the data transmission cable 100 may also be provided with only a plurality of ground conductors and single-ended signal conductors; if it is suitable for narrow Mini SAS products, the number of the ground conductors is greater than the number of signal conductors One more, the specific arrangement method is that the conductors 1 located on both sides of the edge are grounding conductors, and the entire data transmission cable 100 is shielded and protected from both sides of the edge; and in the arrangement direction, the grounding conductor and the signal conductor are alternately arranged in sequence cloth.

In the present invention, the outer diameters of the conductors 11 of the plurality of wires 1 are the same, and it is preferably set such that the ratio between the center distance between adjacent wires 1 and the outer diameter of the conductors 11 is 1.4 to 2.8; This kind of setting relationship makes it possible to effectively reduce the differential impedance of each pair of differential signal wire groups when the wire 1 is set to have a differential signal wire group, and effectively control the coupling within the generally required range of 75Ω to 110Ω. The effect is enhanced to ensure long-distance transmission of high-frequency signals.

As a preferred embodiment of the present invention, the wire 1 has a differential signal wire group, and the above-mentioned plastic layer 2 and metal layer 3 are arranged so that the center distance between the adjacent wires 1 of each differential signal wire group is different from the conductor 11 When the ratio between the diameters is 1.4 to 2.8, the differential impedance of the differential signal wire set is 79Ω to 106Ω.

Specifically, when the ratio between the center distance in each pair of the aforementioned signal conductor groups and the outer diameter of its conductor 11 is 1.55 to 2.31, the differential impedance between the conductors 1 in each pair of the signal conductor groups can be controlled to 79Ω To 91Ω.

As a preferred embodiment of the present invention, in order to further ensure the softness and thinness of the data transmission cable 100, in this embodiment, the outer diameter of the conductor 11 is 31AWG or 32AWG or 33AWG, at this time, each pair of the signal wire group The center distance of the inner conductor 1 is set to 0.28mm to 0.52mm, which can ensure that the differential impedance between the conductors 1 in each pair of the signal conductor group is 79Ω to 91Ω.

Among them, when the outer diameter of the conductor 11 is 31 AWG, the center distance of the wires 1 in each pair of the signal wire group is set to 0.44mm to 0.52mm, which can ensure the differential impedance between the wires 1 in each pair of the signal wire group It is 79Ω to 91Ω; specifically, when the center-to-center spacing is 0.48mm, the differential impedance between the wires 1 in each pair of the signal wire group can be controlled to 85Ω.

When the outer diameter of the conductor 11 is 32 AWG, the center distance of the wires 1 in each pair of signal wire groups is set to 0.36mm to 0.44mm, which can ensure that the differential impedance between the wires 1 in each pair of signal wire groups is 79Ω To 91Ω. Specifically, when the center-to-center distance is 0.40 mm, the differential impedance between the wires 1 in each pair of the signal wire groups can be controlled to 85Ω.

When the outer diameter of the conductor 11 is 33AWG, the center distance of the wires 1 in each pair of signal wire groups is set to 0.28mm to 0.36mm, which can ensure that the differential impedance between the wires 1 in each pair of signal wire groups is 79Ω To 91Ω. Specifically, when the center distance is 0.32 mm, the differential impedance between the wires 1 in the signal wire group can be controlled to 85Ω.

In addition, when the ratio between the center distance of the wire 1 in each pair of the signal wire group and the outer diameter of the conductor 11 is 2.18 to 2.84, the differential impedance between the wire 1 in each pair of the signal wire group is 94Ω To 106Ω.

As a preferred embodiment of the present invention, in order to further ensure the softness and thinness of the data transmission cable 100, the outer diameter of the conductor 11 in the present invention adopts 33AWG or 34AWG; at this time, the center distance of the conductor 1 in each pair of the signal conductor group The setting is 0.35mm to 0.51mm, which can ensure that the differential impedance of the wire 1 in each pair of the signal wire group is 94Ω to 106Ω.

In the present invention, when the outer diameter of the conductor 11 is 33 AWG, the center distance of the wire 1 in each pair of the signal wire group is set to 0.43mm to 0.51mm, which can ensure that the wire 1 in each pair of the signal wire group The differential impedance is from 94Ω to 106Ω; specifically, when the center-to-center spacing is 0.48mm, the differential impedance between the wires 1 in each pair of the signal wire group can be controlled to 100Ω.

When the outer diameter of the conductor 11 is 34 AWG, the center distance of the wire 1 in each pair of the signal wire set is set to 0.35mm to 0.43mm, which can ensure that the differential impedance of the wire 1 in each pair of the signal wire set is 94Ω to 106Ω ; Specifically, when the center distance is 0.4 mm, the differential impedance between the wires 1 in each pair of the signal wire group can be controlled to 100 Ω.

Preferably, in the present invention, the wire 1 has a conductor 11 and a cladding layer 12, and the data transmission cable 100 is arranged such that the center distance between the wires 1 is equal to the outer diameter of the wire 1, that is, the adjacent The wire 1 is placed against the arrangement. In this way, the overall shaping control of the data transmission cable 100 is facilitated.

As mentioned above, the plastic layer 2 is integrally wrapped around the outer side of the plurality of wires 1, and the metal layer 3 is spirally wound on the outer side of the plastic layer 2 using a metal tape, which can realize the gap between the metal layer 3 and the plastic layer 2 The tight winding and bonding make the coating of the metal layer 3 more compact and make the data transmission cable 100 of the present invention thinner and softer under the premise of the metal layer 3 with shielding interference, and the overall thickness is controlled at In the range of 0.3mm to 1mm.

Wherein, in combination with the two embodiments in which the wire 1 may or may not have the aforementioned coating layer 12, after a plurality of the wire 1 is entirely covered by the plastic layer 2, the overall thickness of the wire 1 and the plastic layer 2 d2 can be controlled from 0.25mm to 0.8mm. The conductor 11 combined with the above-mentioned wire 1 is set at about 31 AWG to 34 AWG specifications, and the overall thickness d2 of the wire 1 and the plastic layer 2 can be further controlled to 0.3 mm to 0.6 mm. Further, for example, when the conductor 11 uses 32 AWG, when the cladding layer 12 is provided, the cladding layer 12 can be set to a thickness of about 0.1 mm, and the single-sided plastic layer 2 outside the conductor 11 can be set to about 0.07, so that the wire 1 and The overall thickness of the plastic layer 2 is about 0.54. Of course, the thickness of the cladding layer 12 and the plastic layer 2 can also be adjusted according to actual needs and technical capabilities, and is not limited to the specific setting of the embodiment in which the conductor 11 is 32 AWG.

Further, referring to FIGS. 1 to 5, in this embodiment, the metal layer 3 has at least an aluminum foil layer 31 and a bonding layer 32 disposed on the side of the aluminum foil layer 31 facing the plastic layer 2, so that the metal layer 3 It can be fixed on the outer surface of the plastic layer 2 by the adhesive layer 32. The arrangement of the aluminum foil layer 31 in the metal layer 3 can effectively shield the external electromagnetic interference, that is, effectively isolate the conductor 11 of the signal wire set from the outside, and ensure the transmission of high frequency and ultra high frequency signals. In addition, the metal layer 3 also has a fireproof function, which can enable the data transmission cable 100 to reach a horizontal flame retardant level FT-2 and a vertical flame retardant level VW-1.

Furthermore, in one aspect of the present invention, the metal layer 3 is arranged on the outer side of the plastic layer 2 by a spiral winding method of the metal strip, so that the metal layer 3 and the plastic layer 2 can be tightly wound and bonded to ensure the shield On the premise of fire resistance and other performance, the overall volume of the data transmission cable 100 is reduced as much as possible; on the other hand, the adhesive layer 32 is provided on the side of the metal layer 3 facing the plastic layer 2, not only by direct bonding The metal layer 3 is fixed to the outside of the plastic layer 2 without the intervention of the Mylar layer, so that the entire cable can be made thinner and softer; and the air can be discharged during bonding, and the air is discharged because of the bonding. Can not enter, to achieve a compact effect, and then to achieve a tight coating, high-frequency transmission performance, soft and thin effect.

Preferably, the adhesive layer 32 is configured to fix the plastic layer 2 and the aluminum foil layer 31 by hot melt to facilitate the setting of the adhesive layer 32 and the winding of the metal layer 3, while increasing the number of the metal layer 3 and the plastic layer 2 Combining strength and closeness. In the present invention, the metal layer 3 further has an insulating layer (not shown) disposed on the surface of the aluminum foil layer 31 facing away from the plastic layer 2. This insulating layer can replace the Mylar layer in the conventional art to insulate from the outside ， While protecting the aluminum foil layer 31.

Further, combining the above two embodiments with or without an insulating layer, the overall thickness d1 of the metal layer 3 can be set to 0.010 mm to 0.055 mm, so as to minimize the entire data transmission line on the basis of external shielding The thickness of the cable 100. Preferably, the overall thickness d1 of the metal layer 3 is set to 0.015 mm to 0.025 mm.

The overall thickness of the data transmission cable 100 of the present invention can be further controlled to 0.35 mm to 0.65 mm by combining the overall arrangement of the conductor 11, the cladding layer 12 and the plastic layer 2 and the thickness setting of the metal layer 3. For example, when the conductor 11 uses 32 AWG, the overall thickness of the wire 1 and the plastic layer 2 is about 0.54, and when the thickness of the combined metal layer 3 is set to 0.045 mm, the thickness of the entire data transmission cable 100 can be 0.63 mm. Of course, the thickness of the cladding layer 12, the plastic layer 2 and the metal layer 3 can also be adjusted according to actual needs and technical capabilities, and is not limited to the specific settings of the foregoing embodiments.

In addition, regarding the selection of the spirally wound metal tape in the present invention, the width of the metal tape is set to W, and in the length direction of the data transmission cable 100, the metal tape is wound with N turns, the The data transmission cable 100 has a length L, then the metal strip satisfies such that L<N*W; with this arrangement, in addition to the above-mentioned winding arrangement, the data transmission cable 100 can be guaranteed to be dense and compact, and In addition to reducing the size as much as possible and achieving the fireproof effect, it can also effectively reduce the impedance discontinuity that is easily generated when the cable is bent, thereby ensuring the stability of signal transmission, especially high-frequency signal transmission.

Preferably, an overlapping cladding area 35 is formed between two adjacent metal strips, and the width of the overlapping cladding area 35 in the width direction of the metal strip is w, which occupies the width W of the metal strip 5% to 50%. The w is at least 0.5mm; preferably not less than 0.8mm, and of course it is best to set it to at least 1mm, thereby effectively ensuring the continuity of the winding of the metal layer 3, and performing bending and other operations on the data transmission cable 100 of the present invention At this time, the phenomenon of cracking and the like of the metal layer 3 can be effectively avoided, and thus the phenomenon of impedance discontinuity can be effectively avoided, and the stability of signal transmission, especially high-frequency signal transmission, can be more guaranteed.

Further, the winding angle of the metal strip compared to the width direction of the data transmission cable 100 is 40° to 55°, preferably 45° to 53°; with this arrangement, the data transmission cable 100 of the present invention can be made The flexibility in the longitudinal direction is relatively uniform, and cracks are less likely to occur during bending.

In addition, in the present invention, the width W of the metal strip is set to not less than half of the overall line width of the data transmission cable 100, preferably not less than 0.75 times the line width, and preferably not less than one time the line width Width, under this kind of width setting, the winding of the metal material strip is more convenient and convenient to grasp the tightness of the winding, and also can ensure the softness of the entire data transmission cable 100 after winding; in addition, this kind of width setting can also make There are relatively few overlapping parts of the entire data transmission cable 100 per unit length, thereby further reducing the possibility of scattering when bending.

Furthermore, assuming that there is a center distance d0 between adjacent wires 1 in the present invention, the number of the wires 1 is n, and the overall line width of the data transmission cable 100 is set between d0*n and d0*(n+2 ); further, the overall line width of the data transmission cable divided by n is 1 to 1.25 times d0; that is to ensure that there is still a certain width of plastic on the outside of the wires 1 on both sides of the data transmission cable 100 in the width direction The layer 2 is provided, but the plastic layers 2 on both sides in the width direction of the data transmission cable 100 are not too much to increase the overall line width, thereby enabling effective protection of the wire 1 in as few cases as possible.

With the above settings, the weight of the data transmission cable 100 of the present invention is between 0.015g and 0.30g at 1 cm unit length; further, the weight of the data transmission cable 100 at 1 cm unit length The ratio to the number of wires 1 is between 0.0080 and 0.0020. It can be seen from this that the data transmission cable 100 of the present invention is not only flexible, high-frequency stable, but also lighter.

Please refer to FIG. 9, which shows a third preferred embodiment of the data transmission cable 100 ′ of the present invention before bending. The state after bending is the same as that shown in FIGS. 3 to 5, compared with the first embodiment described above In this embodiment, the data transmission cable 100' further includes a Mylar layer 4 coated on the outside of the metal layer 3'.

Under this arrangement, the metal layer 3'may include only the aforementioned aluminum foil layer, or it may include the aluminum foil layer and the bonding layer at the same time as the metal layer 3'in the first preferred embodiment described above, or both Insulation layer; thus, the Mylar layer 4 can again provide a guarantee for the tightness of the coating of the metal layer 3'.

Further, in this embodiment, the Mylar layer 4 is also spirally wound, and the Mylar layer 4 is also provided with adhesive on the side facing the metal layer 3 ′, the adhesive can be hot melted Afterwards, the Mylar layer 4 is fixed to the outside of the metal layer 3', so that the coating effect of the Mylar layer 4 is also as tight as the metal layer 3'. Preferably, the Mylar layer 4 and the metal layer 3'are arranged in a cross winding manner, thereby further providing protection for the winding of the metal layer 3', further reducing or avoiding the phenomenon of impedance discontinuity, and stabilizing signal transmission Sex provides further protection.

In addition, as in the embodiment shown in FIG. 8, as another preferred embodiment of the present invention, the aforementioned coating layer 12 ′ can also be removed on the basis of the embodiment shown in FIG. 9, that is, directly performed by the plastic layer 2 ′ The insulation coating of the conductor 1 and the conductor 11 is fixed, which can also achieve the purpose of the invention.

3a, 3b, and 4, further, in the length direction of the data transmission cable 100 of the present invention, the data transmission cable 100 has at least one bend 101, so that the data transmission cable 100 A first section 102 and a second section 103 are formed on both sides of the bend, and a stable bending angle is formed between the first section 102 and the second section 103.

As described above, on the one hand, the data transmission cable 100 of the present invention is formed by arranging the wires 1 side by side, and the plastic layer 2 is integrally overmolded on the outside of the plurality of wires 1, so that the thickness of the entire data transmission cable can be made thin; The metal strip is spirally wound outside the plastic layer 2, which can realize the tight winding and bonding between the metal layer 3 and the plastic layer 2, making the metal layer 3 more tightly wrapped, and making the data transmission cable 100 of the present invention Under the premise of the interference-shielding metal layer 3, it can be made thinner and softer; combining the above two points, it can further enable the data transmission cable 100 of the present invention to achieve a pre-stable bending operation without the premise of using auxiliary tools Realize a stable bending angle, and then provide a data transmission cable 100 with a stable bending angle to facilitate installation and connection in subsequent devices

The bending position of the data transmission cable 100 of the present invention has a predetermined bending angle, and the above-mentioned plastic layer 2 and metal layer 3 of the present invention are arranged to enable the stable bending angle and predetermined bending of the present invention after bending The difference between the angles is less than 10 degrees. As shown in the comparative example of FIG. 3a and FIG. 3b, when the predetermined bending angle is 90 degrees, the actual bending angle shown in FIG. 3b is greater than the predetermined bending angle of FIG. 3a by 5 degrees. The figure only shows a simple example of a bend and a 90 degree bend. In actual use, multiple angles and/or multiple bends can be made according to requirements.

In addition, as shown in FIG. 6a, the impedance of the conventional data transmission cable is tested after being bent. It can be seen that the impedance change at the bend is about 13 ohms; and FIG. 6b shows the data with bending of the present invention. A test schematic diagram of a preferred embodiment of the transmission cable 100. In this embodiment, the data transmission cable 100 is bent in multiple places. As can be seen from FIG. 6b, when testing, it is found that there are slight fluctuations at some positions. The fluctuation position is the bending position of the data transmission cable 100. However, it can be seen that the average impedance change at the bending point of the aforementioned at least one bending of the data transmission cable 100 of the present invention, or the prediction with the data transmission cable Set the impedance difference to no more than 2 ohms. Specifically, the impedance change of the data transmission cable 100 at each bend, or the difference from the preset impedance is not greater than 2 ohms.

Furthermore, after testing, the signal delay of the data transmission cable 100 with a bend per unit length according to the present invention is not greater than 5 picoseconds.

Please refer to FIG. 7, which mainly shows the insertion loss of the data transmission cable 100 with bending according to the present invention when performing signal transmission, where curve a is the signal transmission loss of the data transmission cable when flattened, and curve b is The present invention has the signal transmission loss of the bent data transmission cable 100. As can be seen from the comparison of the figures, at the same frequency, the data transmission cable 100 of the present invention after bending and flattening the bend Compared with the insertion loss, the difference is less than 10%. In addition, the difference between the reflection loss of the data transmission cable 100 of the present invention after bending and when the bend is flattened is less than 10%.

In particular, it should be pointed out that for those of ordinary skill in the art, equivalent changes made to the present invention under the teaching of the present invention should still be included in the scope claimed by the patent application scope of the present invention.

100 、100’‧‧‧Data transmission cable 1, 1’‧‧‧ wire 11, 11’‧‧‧ conductor 12、12’‧‧‧ coating 2, 2’‧‧‧ Plastic layer 3. 3’‧‧‧ metal layer 31‧‧‧Aluminum foil layer 32‧‧‧adhesive layer 35‧‧‧ Overlapping cladding area g‧‧‧Ground wire s‧‧‧Signal wire set 4‧‧‧Mylar 101‧‧‧Bending 102‧‧‧ First paragraph 103‧‧‧Second paragraph d0‧‧‧Center distance d1‧‧‧ Overall thickness of metal layer d2‧‧‧Overall thickness of wire and plastic layer

FIG. 1 is a partial perspective view of the first preferred embodiment of the flat data transmission cable of the present invention before bending, which shows the spiral winding of the metal layer. FIG. 2 is a schematic top view of the data transmission cable shown in FIG. 1. 3a and 3b are schematic side views of a part of the structure of the data transmission cable of the present invention, which shows the comparison between the predetermined bending angle and the actual bending angle of the data transmission cable of the present invention. Figure 4 is a front view of the data transmission cable shown in Figure 3b. 5 is an enlarged schematic view of the end surface of the data transmission cable shown in FIG. 4 to clearly show the structural configuration of the data transmission cable of the present invention. Fig. 6a is a graph of impedance changes when a conventional data transmission cable is bent. FIG. 6b is a graph of the impedance variation of the data transmission cable of the present invention shown in FIG. 3b. Fig. 7 is a graph showing the insertion loss of the data transmission cable and bending and flattening shown in Fig. 3b. 8 is a schematic end view of a second preferred embodiment of the data transmission cable of the present invention. FIG. 9 is a partial perspective view of the third preferred embodiment of the data transmission cable of the present invention before bending, which can show the spiral winding of the metal layer and the Mylar layer.

100‧‧‧flat data transmission cable

1‧‧‧ Lead

101‧‧‧Bending

102‧‧‧ First paragraph

103‧‧‧Second paragraph

Claims (10)

A flat data transmission cable, comprising: a plurality of conductors arranged side by side; wherein, the data transmission cable further comprises a plastic layer integrally covering the periphery of the plurality of conductors and a metal material tape spirally wrapped around the outer side of the plastic layer The formed metal layer has at least one bend in the length direction of the data transmission cable, so that the data transmission cable is formed with a first section and a second section on both sides of the bend Segment, a stable bending angle is formed between the first segment and the second segment. The data transmission cable as described in item 1 of the patent application range, wherein the bending point has a predetermined bending angle, and the difference between the stable bending angle and the predetermined bending angle is less than 10 degrees. The data transmission cable as described in item 1 of the patent application range, wherein the mean impedance at the bend of the at least one bend is different from the preset impedance of the data transmission cable by no more than 2 ohms. The data transmission cable as described in item 3 of the patent application scope, wherein the impedance of the data transmission cable at each bend is different from the preset impedance of the data transmission cable by no more than 2 ohms. The data transmission cable as described in item 1 of the patent application scope, wherein the signal delay of the data transmission cable per unit length is not more than 5 picoseconds. The data transmission cable as described in item 1 of the patent application scope, wherein the difference between the insertion loss of the data transmission cable after bending and the flattening of the bend is less than 10%. The data transmission cable as described in item 6 of the patent application scope, wherein the difference between the reflection loss of the data transmission cable after bending and when the bend is flattened is less than 10%. The data transmission cable according to item 1 of the patent application scope, wherein in the arrangement direction of the plurality of conductors, the plurality of conductors have a plurality of ground conductors and a pair of signals disposed between each adjacent two ground conductors Conductors, the aforementioned pair of signal conductors constitute a differential signal conductor group. The data transmission cable as described in item 8 of the patent application, wherein the plurality of conductors are arranged at equal intervals, and the conductor diameters of the plurality of conductors are the same. The data transmission cable according to item 1 of the patent application scope, wherein the metal layer has at least an aluminum foil layer and a bonding layer provided on the side of the aluminum foil layer facing the plastic layer, and the metal layer is melted by the bonding layer The adhesive is fixed outside the plastic layer.

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