KR100820496B1 - Communication cables for emi shielding - Google Patents

Abstract

A communication cable for EMI(Electromagnetic Interference) shielding is provided to prevent deterioration of a mechanical characteristic of the cable while generating an EMI shielding effect by injecting carbon powder into a sheath of the cable. A communication cable includes at least one stranded cable unit(12), and a sheath unit(30). At least one stranded cable is formed by twisting a plurality of insulation-coated lead wires(10,11). The sheath unit wraps the stranded cable unit and is made of polymer resin and conductive particles. A ratio of the conductive particles distributed inside the sheath unit has a uniform gradient along a circumferential direction and is increased or reduced.

Description

Communication cables for electromagnetic shielding {Communication cables for EMI shielding}

The following drawings attached to this specification are illustrative of preferred embodiments of the present invention, and together with the detailed description of the invention to serve to further understand the technical spirit of the present invention, the present invention is a matter described in such drawings It should not be construed as limited to

1 is a perspective view showing a typical wire pair provided in a communication cable.

2 is a cross-sectional view showing the configuration of a communication cable for shielding electromagnetic waves according to an embodiment of the present invention.

3 is an enlarged view of a portion C of FIG. 2.

4 is a graph showing a distribution of conductive particles included in the sheath portion of FIG. 2.

5 is an enlarged cross-sectional view and a graph of a portion of a sheath portion of a communication cable for shielding electromagnetic waves according to a second embodiment of the present invention.

6 is an enlarged cross-sectional view and a graph of a portion of a sheath portion of a communication cable for shielding electromagnetic waves according to a third embodiment of the present invention.

7 is an enlarged cross-sectional view and a graph of a portion of a sheath portion of a communication cable for shielding electromagnetic waves according to a fourth embodiment of the present invention.

8 is an enlarged cross-sectional view and a graph of a portion of a sheath portion of a communication cable for shielding electromagnetic waves according to a fifth embodiment of the present invention.

9 is an enlarged cross-sectional view and a graph of a portion of a sheath portion of a communication cable for shielding electromagnetic waves according to a sixth embodiment of the present invention.

<Description of main reference numerals in the drawings>

10,11 ... wire 12 ... strand

20 ... cross filler 30 ...

The present invention relates to a communication cable, and more particularly, to a UTP (Unshielded Twisted Pair) cable used for high-speed data transmission by suppressing alien crosstalk between cables.

In general, a communication cable forms a pair (Pair, see Fig. 1) by spirally twisting wires made of a conductive wire made of copper or the like and insulates the wires. Unshielded twisted pair cables called Pair cables are commonly used.

These communication cables are classified into categories (Category or Cat.) According to their signal transmission capability. For example, Cat.3 is capable of transmitting signals at 16MHz, Cat.4 is capable of transmitting at 20MHz, and Cat.5 is capable of transmitting at 100MHz. The higher the modulation frequency, the more information can be sent. However, as a higher modulation frequency is used, there is a problem in that signal separation is difficult at a receiver due to crosstalk and interference between adjacent cables. As a result, the information transmission limit of the UTP cable has been limited to about 155Mbps (Megabit per sec).

However, with the development of transmission equipment technology, it is possible to compensate for signal degradation due to interference in the cable by using a method such as compensation (cancellation, cancellation) by equipment such as DSP (Digital Signal Processing), Cat.5e cable The 1000 Mbps (1 Gbps) transmission became possible, and in 1999, the Institute of Electrical and Electronics Engineers (IEEE) Standards Committee officially standardized 1000 Base-T as the Ethernet standard.

On the other hand, the recent trend of moving picture transmission technology is likely to require more information transmission in the near future, and major related companies are conducting R & D in a competitive manner. Accordingly, a lot of high frequencies are used to increase transmission capacity, and as the high frequency is used, there is a problem in that insertion loss and interference between wires increase proportionally. Representative interference phenomena include NEXT (Near End Cross Talk) or FEXT (Far End Cross Talk) .To solve this problem, the compensation method in the transmission system, the twisted pitch of the wire, conductor diameter, insulation diameter, and wire Methods such as cross fillers for suppressing liver contact have been attempted. Moreover, in recent years, attempts have been made to use such high-frequency bands to extend 10 Gbps based on actual transmission capacity of 20 Gbps or more by extending the frequency band above 400 MHz, particularly 500 to 650 MHz. Alien crosstalk, the interference between cables, is the biggest problem.

In order to solve such a problem, conventionally, shielding performance is provided to the UTP cable itself, so that high-speed data transmission of 10 GB band is possible. This is an attempt to shield electromagnetic waves by inserting carbon or the like into the sheath of the UTP cable. This method is an active method compared to the existing method of suppressing electromagnetic interference through inter-conductor gap adjustment and maintenance, and has the advantage of improving data transmission speed while maintaining overall cable specification.

However, this conventional method had to put as much carbon powder as possible into the insulating layer in order to increase electromagnetic shielding performance, and thus these powders adversely affected various mechanical properties, elongation, tensile strength, and ease of extrusion of the sheath. Occurred. By inserting such a large amount of carbon powder into the sheath, the electromagnetic shielding performance is excellent, but there is a high possibility that fatigue breakage occurs when the cable is subjected to a tensile force, and there is a problem that extrusion is not good.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is to provide a communication cable capable of high-speed data transmission by suppressing alien interference between cables without changing existing communication cable types or structures. .

Another object is to provide a communication cable in which carbon powder is inserted into the sheath of the cable to generate an electromagnetic shielding effect and the mechanical properties of the cable are not degraded.

Other objects and advantages of the invention will be described below and will be appreciated by the embodiments of the invention. Furthermore, the objects and advantages of the present invention can be realized by means and combinations indicated in the appended claims.

In order to achieve the above object, a communication cable according to the present invention includes: at least one stranded wire portion formed by twisting a plurality of insulation coated wires; And a sheath part surrounding the stranded part and comprising a polymer resin and conductive particles, wherein a distribution ratio of the conductive particles distributed in the sheath part is not constant.

Preferably, the proportion of the conductive particles distributed inside the sheath portion has a constant gradient along the circumferential direction.

In particular, the sheath portion preferably increases the distribution of the conductive particles in a direction in which the outer diameter of the sheath portion increases.

Alternatively, the sheath portion preferably increases the distribution of the conductive particles in a direction in which the outer diameter of the sheath portion decreases.

Preferably, the proportion of the conductive particles distributed inside the sheath portion is concentrated at a predetermined portion of the sheath portion.

Furthermore, it is preferable that the conductive particles are concentrated on the inner surface of the sheath portion in contact with the stranded portion.

Alternatively, the conductive particles are preferably concentrated on the outer surface of the sheath portion exposed to the outside.

Alternatively, the conductive particles are preferably distributed centrally between the inner surface and the outer surface of the sheath portion.

Alternatively, the conductive particles are preferably concentrated on the inner surface and the outer surface of the sheath portion.

In addition, the conductive particles, preferably made of any one or a combination of conductive polymers, carbon powder, metal fibers, metal powder.

In addition, the polymer resin is preferably made of any one or a combination of polyethylene, PVC, olefin (Olefin) -based polymer material.

Further, the thickness of the sheath portion is 0.3mm to 1.5mm, the stranded portion is composed of four, each stranded portion is preferably in the form of a pair of twisted pair of conductors.

On the other hand, the pitch length of the twisted wire in the stranded portion is preferably 7.0mm to 30mm.

Preferably, the twisted pair includes two or more, and further includes a cross-pillar positioned between each twisted pair to separate the twisted pair.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the specification and claims should not be construed as having a conventional or dictionary meaning, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention. Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiment of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

2 is a cross-sectional view illustrating a configuration of a communication cable for shielding electromagnetic waves according to an embodiment of the present invention, and FIG. 3 is an enlarged view of a portion C of FIG. 2.

2 and 3, a communication cable for shielding electromagnetic waves according to an embodiment of the present invention includes a twisted pair part 12, a cross filler 20, and a sheath part 30.

The twisted pair part 12 has a pair of insulated coated conductors 10 and 11, and the two conductors 10 and 11 forming a pair P are twisted with each other. The pair P wire is twisted at a pitch in the range of 7.0 to 30 mm, more preferably at a pitch in the range of 8.0 to 18 mm. If the pitch length is less than 7.0mm, the material consumption is high and if it is more than 30mm, the structure is not stable and it is difficult to maintain the shape. In addition, although the stranded part 12 is illustrated as two strands of conductors 10 and 11 in the drawing, the present invention is not limited thereto and may be two or more strands. Furthermore, the stranded portion 12 may have a structure covering the outside of the twisted conductors 10 and 11.

3 is an enlarged cross-sectional view of a portion C of the cross section of the sheath portion 30 of FIG. 2. The sheath portion 30 will be described in detail with reference to FIG. 3.

The sheath portion 30 is made of a polymer resin (2) and conductive particles (1), it has a form surrounding the set of the plurality of stranded portion (12). The polymer resin 2 maintains the shape of the sheath portion 30 and exhibits flexible mechanical properties. The polymer resin 2 corresponds to polyethylene, PVC, or an olefin-based polymer material. The conductive particles 1 serves to shield electromagnetic waves. That is, by containing the conductive particles 1 together with the polymer resin 2 in the sheath portion 30, the conductive particles 1 in the sheath portion 30 form a mutual conductive network 3. And it serves to shield the electromagnetic wave of the external cable. As the conductive particles 1, a conductive polymer, carbon powder, metal fiber, metal powder, or the like may be used.

Here, the conductive particles included in the sheath portion 30 are concentrated on the inner surface S1 of the sheath portion 30, which is a portion in contact with the stranded portion 12. That is, a large number of conductive particles are distributed on the inner surface S1, which is the side surface of which the outer diameter of the sheath portion 30 is small, and conductive particles are hardly distributed on the outer surface S2, which is the side surface of which the outer diameter is relatively large. 4 is a graph illustrating a distribution of conductive particles included in the sheath portion 30. Referring to FIG. 4, the vertical axis represents the increase and decrease of the amount PW of the conductive particles, and the horizontal axis represents the length from the inner surface S1 to the outer surface S2 of the sheath portion 30. Therefore, in the graph of FIG. 4, the amount of conductive particles appears high near the inner surface S1 of the sheath portion 30, and then rapidly decreases in the vicinity of the slightly moved to the outer surface S2, and close to the outer surface S2. It can be seen that the amount is very low.

As such, by intensively distributing the polymer resin and the conductive particles constituting the sheath portion 30 to a specific portion of the sheath portion 30, the portion subjected to mechanical force and the portion shielding the electromagnetic wave are functionally separated. can do. That is, the mechanical properties of the sheath portion 30 is responsible for the high distribution of the polymer resin, the electromagnetic wave is responsible for blocking at the high distribution of the conductive particles. Therefore, there is an effect that can be excellent both in the mechanical properties of the cable and the electromagnetic shielding performance.

In addition, the thickness of the sheath portion 30 preferably has a range of 0.3 ~ 1.5mm. In addition, although the number of twisted pairs 12 is shown inside the sheath portion 30 in the drawings, the present invention is not limited to this embodiment and can be variously modified. The plurality of twisted pairs 12 having twisted wires are manufactured to have different pitch conditions because crosstalk between pairs in a cable easily occurs when respective internal pitch conditions are the same or similar. At this time, it is preferable to maintain the pitch difference between the corresponding pair of wire pairs 0.2mm or more in order to prevent electromagnetic interaction.

The cross pillar 20 is located inside the sheath portion 30 and isolates the four stranded wire portions 12 from each other to prevent internal interference between the wire pairs P and maintain the shape of the cable. The material of the cross filler 20 may be PVC or a metal thin film.

Hereinafter, another embodiment of the present invention will be described with reference to FIGS. 5 to 9. In addition, the following other embodiments will be omitted through the embodiment of the present invention will be described only the difference between the structure and the internal configuration of the sheath portion 30. 5 to 9 are enlarged cross-sectional views and graphs of portions of a sheath portion of a communication cable for shielding electromagnetic waves according to embodiments of the present invention.

Referring to FIG. 5, as a second embodiment of the present invention, the conductive particles included in the sheath portion 30 are concentrated on the outer surface S2 of the sheath portion 30, which is a portion exposed to the outside. . That is, a large number of conductive particles are distributed on the outer surface S2, which is a side surface having a large outer diameter of the sheath portion 30, and conductive particles are hardly distributed on the inner surface S1, which is a side surface having a relatively small outer diameter. Let us look at the distribution of the conductive particles contained in the sheath portion 30 in a graph. Referring to FIG. 5, the vertical axis represents the increase and decrease with respect to the amount PW of the conductive particles, and the horizontal axis represents the length from the inner surface S1 to the outer surface S2 of the sheath portion 30. Therefore, in the graph of FIG. 5, the amount of conductive particles appears high near the outer surface S2 of the sheath portion 30, and then rapidly decreases in the vicinity moved slightly to the inner surface S1, and the subsequent inner surface S1. It can be seen that the amount is kept very close to the vicinity.

Referring to FIG. 6, as a third embodiment of the present invention, the conductive particles included in the sheath portion 30 are sheath portions 30 between the inner surface S1 and the outer surface S2 of the sheath portion 30. It is distributed intensively around the center side of). That is, many conductive particles are distributed in the vicinity of the center of the sheath portion 30, and relatively few conductive particles are distributed in the vicinity of the inner surface S1 and the outer surface S2. Let us look at the distribution of the conductive particles contained in the sheath portion 30 in a graph. Referring to FIG. 6, the vertical axis represents the increase and decrease with respect to the amount PW of the conductive particles, and the horizontal axis represents the length from the inner surface S1 to the outer surface S2 of the sheath portion 30. Therefore, in the graph of FIG. 6, the amount of conductive particles appears low near the inner surface S1 of the sheath portion 30, and then rapidly increases in the vicinity moved to the center of the sheath portion 30. In the vicinity moved to S2). And it can be seen that until the vicinity of the outer surface (S2) to maintain a very low amount.

Referring to FIG. 7, as a fourth embodiment of the present invention, the conductive particles included in the sheath portion 30 are concentrated in the vicinity of the inner surface S1 and the outer surface S2 of the sheath portion 30. . That is, a large number of conductive particles are distributed in the vicinity of the inner surface S1 and the outer surface S2 of the sheath portion 30, and relatively few conductive particles are distributed in the vicinity of the center. Let us look at the distribution of the conductive particles contained in the sheath portion 30 in a graph. Referring to FIG. 7, the vertical axis represents the increase and decrease of the amount PW of the conductive particles, and the horizontal axis represents the length from the inner surface S1 to the outer surface S2 of the sheath portion 30. Therefore, in the graph of FIG. 7, the amount of the conductive particles appears high near the inner surface S1 of the sheath portion 30, and then rapidly decreases in the vicinity moved to the center of the sheath portion 30. In the vicinity moved to S2) increases rapidly again. And it can be seen that a very high amount is maintained up to the vicinity of the outer surface S2 thereafter.

Referring to FIG. 8, as a fifth embodiment of the present invention, the conductive particles included in the sheath portion 30 are distributed in the inner surface S1 of the sheath portion 30 gradually and gradually toward the outer surface S2. Its distribution is reduced. That is, the conductive particles are uniformly distributed from the inner surface S1 to the outer surface S2 of the sheath portion 30 while being distributed. Let us look at the distribution of the conductive particles contained in the sheath portion 30 in a graph. Referring to FIG. 8, the vertical axis represents the increase and decrease of the amount PW of the conductive particles, and the horizontal axis represents the length from the inner surface S1 to the outer surface S2 of the sheath portion 30. Therefore, in the graph of FIG. 8, the amount of conductive particles appears near the inner surface S1 of the sheath portion 30, and then passes through the center of the sheath portion 30 and reaches a constant surface until the outer surface S2 is reached. After decreasing, it can be seen that very low amounts of conductive particles are distributed near the outer surface S2.

Referring to FIG. 9, as a sixth embodiment of the present invention, conductive particles included in the sheath portion 30 are hardly present on the inner surface S1 of the sheath portion 30 and then to the outer surface S2. Increasingly, the amount of conductive particles increases. In other words, the conductive particles are uniformly distributed from the inner surface S1 to the outer surface S2 of the sheath portion 30. Let us look at the distribution of the conductive particles contained in the sheath portion 30 in a graph. Referring to FIG. 9, the vertical axis represents the increase and decrease of the amount PW of the conductive particles, and the horizontal axis represents the length from the inner surface S1 to the outer surface S2 of the sheath portion 30. Therefore, in the graph of FIG. 9, the amount of the conductive particles appears in the vicinity of the inner surface S1 of the sheath portion 30, and then passes through the center of the sheath portion 30 and reaches a constant surface until the outer surface S2 is reached. After increasing, it can be seen that very high amounts of conductive particles are distributed near the outer surface S2.

As described above, according to various embodiments of the present invention, rather than uniformly distributing the conductive particles in the sheath portion, by intensively distributed in a specific site or by varying the distribution ratio of the conductive particles along the outer diameter of the sheath portion, Make sure that the part that is energized and the part that shields electromagnetic waves are functionally separated. Therefore, electromagnetic wave shielding and mechanical properties of the communication cable can be satisfied at the same time.

The terms or words used in this specification and claims are not to be construed as limiting in their usual or dictionary meanings, and the inventors may appropriately define the concept of terms in order to best explain their invention in the best way possible. It should be interpreted as meaning and concept corresponding to the technical idea of the present invention based on the principle that the present invention.

Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiment of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

As described above, the communication cable for shielding electromagnetic waves according to the present invention has the following effects.

First, a small amount of shielding material has a large electromagnetic shielding effect.

Second, the electromagnetic shielding performance can be excellent while maintaining the mechanical rigidity.

Third, there is no peeling phenomenon of the insulator material.

Fourth, electromagnetic shielding is easy without increasing the volume of the cable.

Fifthly, when used in conjunction with the gap adjustment method, a higher speed data transmission is possible.

Claims (15)

At least one stranded portion formed by twisting a plurality of insulation coated conductors; And Wrapping the stranded portion, the sheath portion made of a polymer resin and conductive particles; includes; And the proportion of the conductive particles distributed in the sheath portion has a constant gradient along the circumferential direction and increases or decreases. delete The method of claim 1, The sheath portion, the communication cable, characterized in that the distribution of the conductive particles gradually increases in a direction in which the outer diameter of the sheath portion increases. The method of claim 1, The sheath portion of the communication cable, characterized in that the distribution of the conductive particles gradually increases in a direction in which the outer diameter of the sheath portion decreases. delete delete delete delete delete The method according to claim 3 or 4, The conductive particles, A communication cable comprising any one or a combination of conductive polymers, carbon powders, metal fibers, and metal powders. The method of claim 10, The polymer resin, A communication cable comprising any one or a combination of polyethylene, PVC, and olefin-based polymer materials. The method of claim 11, The sheath portion of the communication cable, characterized in that 0.3mm to 1.5mm. The method of claim 12, The twisted pair is composed of four, each twisted pair is a communication cable, characterized in that the pair form a twisted pair of conductors. The method of claim 13, Communication cable, characterized in that the pitch length of the twisted wire in the stranded portion is 7.0mm to 30mm. The method of claim 14, The twisted pair includes two or more, the communication cable further comprises a cross-filler located between each twisted pair to separate the twisted pair.

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