CN113539562B

CN113539562B - Transmission cable and method for manufacturing the same

Info

Publication number: CN113539562B
Application number: CN202110086836.8A
Authority: CN
Inventors: 李政
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-04-20
Filing date: 2021-01-22
Publication date: 2023-03-14
Anticipated expiration: 2041-01-22
Also published as: TW202141541A; CN113539562A; TWI753756B

Abstract

The invention provides a transmission cable, which comprises a conductor and a composite layer. The composite layer is formed by attaching an inner surface of a wrapping layer to an outer surface of an inner wrapping layer through a gluing material; the composite layer is wrapped on the conductor, and an inner surface of the inner wrapping layer is contacted with an outer surface of the conductor; the lapping layer is composed of polytetrafluoroethylene with the foaming degree of 65% -77%, and the inner lapping layer is composed of polyether imide; and the composite layer is manufactured by using a drawing speed of 0.1 to 0.5m/min and a tape overlapping rate of between 32 and 37 percent in a wrapping process.

Description

Transmission cable and method for manufacturing the same

Technical Field

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

Background

In the present cable manufacturing process, an insulating layer is directly pressed on the conductor to achieve the protection and insulation effects, 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 that the dielectric constant is usually reduced by using a foaming material, but the foaming material cannot easily reach the distribution and yield standards in the manufacturing process, and the outer diameter of the insulating layer manufactured by using the foaming material is relatively large, which limits the size selection in the mechanism.

Therefore, the wrapping process is used to improve the above problems, the transmission loss of the cable manufactured by the wrapping process under high frequency/high speed is lower than that of the cable manufactured by the foaming process, but the mechanical properties of the wrapped cable, such as bending resistance, tensile strength and elongation, are insufficient, and the cable is easy to be bent in the wire arranging and manufacturing processes to cause the core to break, so that the yield is reduced.

Therefore, it is desirable to provide a cable structure that improves bending resistance, tensile strength and elongation.

Disclosure of Invention

The invention provides a transmission cable, which comprises a conductor and a composite layer. The composite layer is formed by adhering an inner surface of a wrapping layer to an outer surface of an inner wrapping layer through a gluing material; the composite layer is wrapped on the conductor, and an inner surface of the inner wrapping layer is contacted with an outer surface of the conductor; the wrapping layer is composed of polytetrafluoroethylene with the foaming degree of 65% -77%, and the inner wrapping layer is composed of polyether imide; and the composite layer is manufactured by using a drawing speed of 0.1 to 0.5m/min and a tape overlapping rate of between 32 and 37 percent in a wrapping process.

The invention provides a manufacturing method of a transmission cable, which comprises the following steps: one inner surface of the wrapping layer is attached to one outer surface of the inner wrapping layer through a gluing material to form a composite layer; the composite layer is wrapped on a conductor to form a transmission cable, and an inner surface of the inner wrapping layer is contacted with an outer surface of the conductor; the wrapping layer is composed of polytetrafluoroethylene with the foaming degree of 65% -77%, and the inner wrapping layer is composed of polyether imide; and the composite layer is manufactured by using a drawing speed of 0.1 to 0.5m/min and a tape overlapping rate of between 32 and 37 percent in a wrapping process.

Those skilled in the art will appreciate that the effects that can be achieved through the present disclosure are not limited to what has been particularly described hereinabove, and that the advantages of the present invention will be more clearly understood from the foregoing detailed description taken in conjunction with the accompanying drawings.

Drawings

Fig. 1 is an example of a transmission cable made using existing lapping technology.

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

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

Fig. 3B is a partial structure example in the transmission cable of fig. 3A.

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

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

Fig. 6 is a graph of feed loss measurements according to an embodiment of the present invention.

Description of the reference numerals

1, 2' transmission cable

10: conductor

11 insulating layer

12, wrapping layer

121: first wrapping layer

122 second wrapping layer

123 third lapping layer

13, inner wrapping layer

14 composite layer

15 adhesive material

20: transmission cable module

Detailed Description

Referring to fig. 2, fig. 3A and 3B, fig. 2 is an example of a transmission cable according to an embodiment of the invention. The transmission cable 2 comprises, in order from inside to outside: a conductor 10, an inner wrapping 13, and a wrapping 12. Fig. 3A is an example of a transmission cable 2' according to another embodiment of the present invention, and fig. 3B is a partial structure example in the transmission cable of fig. 3A. As shown in fig. 3B, the present embodiment is different from the embodiment shown in fig. 2 in that the wrapping layer 12 has an inner surface adhered to an outer surface of the inner wrapping layer 13 by a bonding material 15 to form a composite layer 14, so that the wrapping layer 12 and the inner wrapping layer 13 can be wrapped around the conductor 10 by only one wrapping process of the composite layer 14 and an inner surface of the inner wrapping layer 13 contacts an outer surface of the conductor 10 to achieve a double protection effect. It should be noted that, in this embodiment, the wrapping layer 12 and the inner wrapping layer 13 are each composed of at least two layers of polymer through the adhesive material 15.

Referring to fig. 4, fig. 4 is an example of a transmission cable based on the embodiment of fig. 3A. As shown in fig. 4, two transmission cables 2' and a conductor 10 of the structure of fig. 3A are wrapped with a first wrapping layer 121, a second wrapping layer 122 and a third wrapping layer 123 to form a transmission cable module 20. The first wrapping layer 121 is mainly composed of the above-mentioned material of the wrapping layer 12 and covers the outer surface of the composite layer 14 with the adhesive material 15. Similarly, the second wrapping layer 122 is made of the above-mentioned material of the wrapping layer 12 and covers a portion of the outer surface of the first wrapping layer 121 and a portion of the outer surface of the first conductor 10 of the two transmission cables 2' with the adhesive material 15, and the third wrapping layer 123 is made of the above-mentioned material of the wrapping layer 12 and covers the outer surface of the second wrapping layer 122 with the adhesive material 15. It should be noted that, preferably, the first wrapping layer 121, such as the wrapping layer 12 and the inner wrapping layer 13, is also composed of at least two layers of high molecular polymer through the adhesive material 15. In addition, in the preferred embodiment of the present invention, the inner wrapping layer 13 included in the composite layer 14 has a thickness of 0.012 to 0.024mm, and is made of a polyether imide (PI or Kapton) material; the composite layer 14 also contains a gluing material 15 with the thickness of 0.01 to 0.02mm; the lapping layer 12 is 0.15mm thick and made of polytetrafluoroethylene with the foaming degree of 65-77% (dielectric constant is 2.1 before foaming and 1.25-1.39 after foaming); the composite layer 14 is manufactured by using a drawing speed of 0.1 to 0.5m/min and a tape overlapping rate of between 32 and 37 percent in a wrapping process. The above materials, thickness, drawing rate and tape overlapping rate are only preferred examples and are not intended to limit the present invention.

Thus, the composite layer of the present invention, such as the composite layer of PTFE, can achieve higher roundness, higher impedance and lower feeding loss compared to the prior art using dual PTFE layers. The prior art compared here is to use a double PTFE layer made of 65% expanded PTFE but made with a 0.3m/min draw rate and 50% tape overlap during the lapping process. Preferably, the roundness of the present invention is higher than 93%, while the roundness of the prior art can only reach 80-85%, and the differential mode impedance of 105 ohms is higher than 99 ohms and the feed loss (I/L) is lower than that of the prior art, and preferably, the feed loss value of the present invention is-2.97 dB, and the feed loss value of the prior art is-3.4 dB.

Referring to fig. 5, fig. 5 is a graph illustrating time domain reflectometry according to an embodiment of the invention. As shown in fig. 5, a numerical curve obtained by performing Time Domain Reflectometry (TDR) on the transmission cable 2' manufactured by using the above preferred values includes two points m1 (0.8045, 104.7784) and m2 (1.5914, 105.9300), which can fall within a differential impedance range of 100 to 110ohm, but the prior art can only fall below 100 ohm.

Referring to fig. 6, fig. 6 is a graph illustrating a measurement curve of the loss in feeding (IL) according to an embodiment of the present invention. As shown in fig. 6, by using the transmission cable 2' manufactured by the above preferred values, which is a dashed curve, the values of the partial curves of the embodiment of the present invention can reach below the threshold value compared to the feed loss threshold curve of the solid line, which is over the threshold value in the prior art.

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. The description is thus not to be construed in a limiting sense in all respects, but rather as illustrative.

The scope of the invention should be determined by reasonable interpretation of the appended claims and all changes which come within the range of equivalents of the invention are intended to be embraced therein.

Claims

1. A transmission cable, characterized in that it comprises:

a conductor; and

the composite layer is formed by adhering one inner surface of a wrapping layer to one outer surface of an inner wrapping layer through a gluing material;

the composite layer is wrapped on the conductor, and an inner surface of the inner wrapping layer is contacted with an outer surface of the conductor;

the lapping layer is composed of polytetrafluoroethylene with the foaming degree of 65% -77%, and the inner lapping layer is composed of polyether imide; and

the composite layer is manufactured by using a drawing speed of 0.1-0.5 m/min and a tape overlapping rate of 32-37% in a wrapping process.

2. A method of manufacturing a transmission cable, comprising the steps of:

an inner surface of a wrapping layer is attached to an outer surface of an inner wrapping layer through a gluing material to form a composite layer; and

the composite layer is wrapped on a conductor to form a transmission cable, and an inner surface of the inner wrapping layer is contacted with an outer surface of the conductor;