TWI753756B - Transmission cable and method of manufacturing the same - Google Patents

Abstract

A transmission cable includes a conductor and a composite layer. The composite layer is composed of an inner surface of an outer wrap layer adhered to an outer surface of an inner wrap layer by a glue material; wherein the composite layer wraps the conductor, and an inner surface of the inner wrap layer is in contact with an outer surface of the conductor; wherein the inner wrap layer is made of polytetrafluoroethylene with a foaming degree by 65~77% and the outer wrap layer is made of polyimide; and wherein during the wrapping process, the composite layer has a wire drawing rate of 0.1~0.5m/min and a overlap rate of 32%~37%.

Description

Transmission cable and method of making the same

The present invention relates to a cable structure and method, and more particularly, to a high-speed/high-frequency transmission cable and a method of manufacturing the same.

In the production process of current cables, an insulating layer is directly extruded on the conductor to achieve the effect of protection and insulation. As shown in FIG. 1 , the conductor 10 in the transmission cable 1 is covered with an insulating layer 11 . However, the dielectric constant of the insulating layer has a great influence on the performance of high-frequency/high-speed transmission, so foamed materials are usually used to reduce the dielectric constant, but the foamed materials are not easy to meet the standard of distribution and yield in the process , and the outer diameter of the foam material is relatively large, which limits the choice of the size of the mechanism.

Therefore, using the wrapping process to improve the above problems, the transmission loss of the cable produced by the wrapping process at high frequency/high speed is lower than that of the foaming process cable, but the mechanical properties of the wrapping cable such as bending resistance, tensile strength and elongation rate are lower. Insufficient properties, it is easy to be bent during the wire management and manufacturing process, resulting in breakage of the wire core, which reduces the yield.

Therefore, there is a need to propose a cable structure that can improve bending resistance, tensile strength and elongation.

The present invention provides a transmission cable, which includes a conductor and a composite layer. The composite layer is formed by attaching an inner surface of an outer cladding layer to an outer surface of an inner cladding layer through a glue material; wherein the composite layer is wrapped around the conductor and an inner surface of the inner cladding layer is attached. The inner surface contacts an outer surface of the conductor; wherein, the inner wrapping layer is composed of polytetrafluoroethylene with a foaming degree of 65% to 77%, and the outer wrapping layer is The layer is composed of polyimide; and wherein, the composite layer is produced using a wire drawing speed of 0.1-0.5 m/min and a wrapping overlap rate of between 32% and 37% during the wrapping process.

The invention provides a manufacturing method of a transmission cable, comprising the following steps: an inner surface of an outer wrapping layer is attached to an outer surface of an inner wrapping layer by a glue material to form a composite layer; and the composite layer is wrapped around It is wrapped around a conductor to form a transmission cable, and an inner surface of the inner wrapping layer contacts an outer surface of the conductor; wherein, the inner wrapping layer is made of polytetrafluoroethylene with a foaming degree of 65% to 77%. composition, the outer wrapping layer is composed of polyimide; and wherein, the composite layer uses a wire drawing speed of 0.1~0.5m/min and a wrapping overlap between 32% and 37% during the wrapping process rate production.

Those skilled in the art will understand that the effects that can be achieved through the disclosure of the present invention are not limited to the above specific description, and the advantages of the present invention will be more clearly understood from the above detailed description in conjunction with the accompanying drawings.

1,2,2': Transmission cable

10: Conductor

11: Insulation layer

12: Outer cladding

121: The first wrapping layer

122: The second wrapping layer

123: The third wrapping layer

13: Inner cladding

14: Composite layer

15: Glue

20: Transmission cable module

Figure 1 is an example of a transmission cable made using existing wrapping techniques.

Figure 2 is an example of a transmission cable according to an embodiment of the present invention.

3A is an example of a transmission cable according to another embodiment of the present invention.

FIG. 3B is a partial structural example of the transmission cable of FIG. 3A .

Figure 4 is an example of a transmission cable based on the embodiment of Figure 3A.

FIG. 5 is a time domain reflectometry graph according to an embodiment of the present invention.

FIG. 6 is a graph of a feed loss measurement according to an embodiment of the present invention.

Please refer to FIGS. 2 , 3A and 3B. FIG. 2 is an example of a transmission cable according to an embodiment of the present invention. The transmission cable 2 includes a conductor 10 , an inner cladding 13 , and an outer cladding 12 in sequence from the inside out. Fig. 3A is an example of a transmission cable 2' according to another embodiment of the present invention, and Fig. 3B is a partial structural example of the transmission cable of Fig. 3A. As shown in FIG. 3B , the present embodiment is different from the embodiment of FIG. 2 in that an inner surface of the outer cladding layer 12 is attached to an outer surface of the inner cladding layer 13 through an adhesive material 15 to form A composite layer 14, so that the outer wrapping layer 12 and the inner wrapping layer 13 can be wrapped around the conductor 10 and the inner wrapping layer 13 can be wrapped by only one wrapping procedure of the composite layer 14. An inner surface contacts an outer surface of the conductor 10 to achieve a double-layer protection effect. It should be noted that, in this embodiment, the outer cladding layer 12 and the inner cladding layer 13 are respectively composed of at least two layers of high molecular polymers through the adhesive material 15 .

Please refer to FIG. 4, which is an example of a transmission cable based on the embodiment of FIG. 3A. As shown in FIG. 4 , two transmission cables 2 ′ of the structure of FIG. 3A and a conductor 10 are coated with a first cladding layer 121 , a second cladding layer 122 and a third cladding layer 123 to form a Transmission cable module 20 . The first cladding layer 121 is mainly composed of the above-mentioned material of the outer cladding layer 12 and is covered on the outer surface of the composite layer 14 by the adhesive material 15 . Similarly, the second wrapping layer 122 is composed of the material of the above-mentioned outer wrapping layer 12 and covers a part of the outer surface of the outer wrapping layer 121 and the first conductor 10 of the two transmission cables 2 ′ through the glue material 15 . and the third wrapping layer 123 is composed of the material of the above-mentioned outer wrapping layer 12 and covers the outer surface of the second wrapping layer 122 through the adhesive material 15 . It should be noted that, preferably, the first wrapping layer 121 , such as the outer wrapping layer 12 and the inner wrapping layer 13 , is also composed of at least two layers of high molecular polymers through the adhesive material 15 . In addition, in a preferred embodiment of the present invention, the outer cladding layer 12 included in the composite layer 14 has a thickness of 0.012-0.024 mm, and is made of polyimide (ie, PI or Kapton) material; the composite layer 14 also includes a glue material 15 with a thickness of 0.01~0.02mm; and the inner wrapping layer 13 has a thickness of 0.15mm and is made of polytetrafluoroethylene with a foaming degree of 65%~77% (the dielectric constant before foaming is 2.1, 1.25~1.39 after foaming); the composite layer 14 is produced using a wire drawing speed of 0.1~0.5m/min and a wrapping overlap rate between 32% and 37% during the wrapping process. The above-mentioned material, thickness, wire drawing rate and wrapping rate are only preferred examples and are not intended to limit the present invention.

In this way, through the composite layer of the present invention, such as the aforementioned composite layer of PTFE material, compared with the prior art using double PTFE layers, higher roundness, higher impedance and lower feed rate can be achieved. input loss. The prior art compared here uses a double PTFE layer, made of 65% expanded polytetrafluoroethylene, but uses a wire draw rate of 0.3 m/min and a 50% wrapping overlap during the wrapping process rate production. Preferably, the embodiment of the present invention can achieve a roundness higher than 93%, while the prior art can only achieve a roundness of 80-85%, and at the same time achieve a differential mode impedance of 105 ohms, which is higher than the 99 ohms of the prior art. , and the insertion loss (I/L) is lower than that of the prior art. Preferably, the input loss value that can be achieved by the embodiment of the present invention is -2.97dB, and the prior art is -3.4dB.

Please refer to FIG. 5 , which is a time-domain reflectometry curve diagram according to an embodiment of the present invention. As shown in Figure 5, the numerical curve obtained by time domain reflectometry (TDR) of the transmission cable 2' made with the above-mentioned preferred values includes m1 (0.8045, 104.7784) and m2 (1.5914, 105.9300 ) two points, can fall within the differential impedance range of 100~110ohm, while the previous technology can only be below 100ohm.

Please refer to FIG. 6 . FIG. 6 is a graph illustrating an insertion loss (IL) measurement curve according to an embodiment of the present invention. As shown in FIG. 6 , the values of the transmission cable 2 ′ produced by using the above-mentioned preferred values are the dotted curve. Compared with the solid-line feed-in loss critical value curve, some of the curve values in the embodiment of the present invention can reach the critical value. below, and the prior art all exceed the critical value.

It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit of the invention. Therefore, the above description should not be construed in a limiting sense, but rather in an illustrative sense in all respects.

The scope of the invention should be determined by reasonable interpretation of the appended claims and all changes that come within the scope of the equivalents of the invention are included in the scope of the invention.

2': Transmission cable

10: Conductor

14: Composite layer

Claims (2)

A transmission cable, comprising: a conductor; and a composite layer formed by attaching an inner surface of an outer cladding layer to an outer surface of an inner cladding layer through a glue material; wherein, the composite layer is wound around Wrapped on the conductor and an inner surface of the inner wrapping layer contacts an outer surface of the conductor; wherein, the inner wrapping layer is composed of polytetrafluoroethylene with a foaming degree of 65% to 77%, and the outer wrapping layer The layer is composed of polyimide; and wherein, the composite layer is produced using a wire drawing speed of 0.1-0.5 m/min and a wrapping overlap rate of between 32% and 37% during the wrapping process. A manufacturing method of a transmission cable, comprising the following steps: an inner surface of an outer wrapping layer is attached to an outer surface of an inner wrapping layer by a glue material to form a composite layer; and the composite layer is wrapped around a A conductor is formed to form a transmission cable, and an inner surface of the inner wrapping layer contacts an outer surface of the conductor; wherein, the inner wrapping layer is composed of polytetrafluoroethylene with a foaming degree of 65% to 77%. The outer wrapping layer is composed of polyimide; and wherein, the composite layer is produced using a wire drawing speed of 0.1-0.5 m/min and a wrapping tape overlap rate between 32% and 37% during the wrapping process.

Images