JPH05303913A - Heat resistant small diameter coaxial cable - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a heat-resistant thin coaxial wire that can withstand the heat during soldering while having a thin separator layer formed directly on a foamed insulator. [Structure] In a small-diameter coaxial wire in which a foamed insulator 2 between a coaxially arranged inner conductor 1 and an outer conductor 4 has a degree of foaming of 40% or more, at least 15 is provided immediately above the foamed insulator.
A heat-resistant tape 3 having a thickness of 2 to 10 μm prepared by a resin having a heat resistance of 0 ° C. or more and having an adhesive layer 6 on one surface thereof is wound with the adhesive layer facing inward. is there. 6 is a sheath.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to coaxial lines, and more particularly
The present invention relates to a small-diameter coaxial wire in which an insulator between an inner conductor and an outer conductor coaxially arranged with each other has an outer diameter on the order of several millimeters and a foaming degree of 40% or more.

[0002]

2. Description of the Related Art Conventionally, in this type of small-diameter coaxial cable, 40%
Extruded and coated with polyethylene or fluorine-based resin for the purpose of improving strength directly above the foamed insulator prepared to the above foaming degree, or wound with polyester tape to form a separator layer, and arrange the outer conductor from above Was.

[0003]

As described above, when the foamed insulation having a foaming degree of 40% or more is extrusion-coated with polyethylene or a fluorine-based resin, the extrusion thickness is reduced to 20 μm or less. Very difficult to do. On the other hand, in the case of the polyester tape, the thickness can be reduced, and the outer diameter can be suppressed to be small even when wound on the foamed insulator, but the polyester tape is inferior in heat resistance. , The wrapped polyester tape and the foamed insulator were melted by the heat at the time of soldering or significantly contracted, which made the terminal treatment work extremely difficult.

The present invention solves the above-mentioned problems of the prior art, reduces the thickness of the separator layer formed immediately above the foamed insulator, and can withstand the heat during soldering. The purpose is to provide the lines.

[0005]

The heat-resistant small-diameter coaxial wire of the present invention has a diameter of 2 to 10 μm formed by a resin having a heat resistance of at least 150 ° C. or more immediately above a foamed insulator having a foaming degree of 40% or more. A heat-resistant tape having a thickness adjusted to have an adhesive layer on one side thereof was wrapped around with the adhesive layer facing inward.

The resin used as the material of the tape is a polyimide type, a fluorine type or other heat resistant type, and for example, polyphenylene sulfide is preferable.

By setting the thickness of the tape to 2 to 10 μm, the total outer diameter of the insulator can be suppressed within a predetermined range. If the thickness is less than 2 μm, it becomes difficult to obtain the function as a separator layer. On the other hand, in the case of a tape having a thickness of more than 10 μm, the tape itself becomes hard so that it cannot be successfully wound on a small-diameter foamed insulating material, and the flexibility required as a small-diameter coaxial wire is impaired.

The adhesive layer serves to prevent the tape from coming loose during terminal processing by integrally adhering the tape around the foamed insulation.

[0009]

FIG. 1 shows an embodiment of a heat-resistant small-diameter coaxial wire of the present invention, and FIG. 2 shows an example of a heat-resistant tape used in the coaxial wire.

The coaxial cable of this embodiment has three inner conductors.
6 AWG was used, and the foamed insulation 2 was prepared by extruding polyolefin to have a foaming degree of 60% or more.
It has an outer diameter of 6 mm, a heat-resistant tape 3 according to the present invention is wound directly on it, and a bell-plated annealed copper wire having an outer diameter of 0.05 mm is wound horizontally from thereover to form an outer conductor 4.
The sheath 5 is formed by extrusion coating of C.

The heat-resistant tape 3 is made of polyphenylene sulfide as a resin having a heat resistance of 150 ° C. or higher. The tape 7 is prepared to have a thickness of 4 μm and processed into a width of 2.5 mm. The ethylene-based adhesive layer 6 has a thickness of 1 μm. This heat-resistant tape 3 was wrapped directly above the foamed insulation 2 with the adhesive layer 6 on one side facing inward to form a predetermined separator layer.

According to the thin coaxial wire of this embodiment, the total outer diameter of the insulator could be finished to 2 mm or less. In addition, the sheath 5 and the outer conductor 4 were peeled off one by one at the end to expose the heat-resistant tape 3, but the heat-resistant tape 3 was adhered and integrated with the foamed insulating body 2 to maintain a predetermined winding state and to disperse. I confirmed that there is no. Furthermore, when soldering was performed on such terminals, the foamed insulator and the heat-resistant tape did not melt. Again, 250
There was no problem because the shrinkage length of the heat-resistant tape was 0 to 1 mm when the coaxial wire of this example was dipped in solder of ℃ for 3 seconds.

In the above-mentioned embodiments, the bell-plated annealed copper wire is used as the outer conductor, but a braid or an aluminum polyester tape may be used. Although PVC is used for the sheath, fluororesin or polyethylene may be used, and the heat-resistant tape according to the present invention may be used for winding on the bell-plated annealed copper wire horizontal winding layer.

[0014]

According to the heat-resistant small-diameter coaxial wire of the present invention as described above, it is possible to form a predetermined separator layer directly on a small-diameter foamed insulating material having a foaming degree of 40% or more. Of course, the finished outer diameter of the insulator can be reduced to 2 mm or less, and there is no risk of the insulator and heat-resistant tape melting out due to heat during soldering, which in turn reduces heat resistance and diameter. It is possible to provide this kind of coaxial wire that simultaneously achieves and, and is of great practical value.

[Brief description of drawings]

FIG. 1 is a cross-sectional explanatory view showing an embodiment of a heat-resistant small-diameter coaxial wire according to the present invention.

FIG. 2 is a cross-sectional explanatory view showing an example of a heat-resistant tape used for the coaxial wire.

[Explanation of symbols]

 1 Inner Conductor 2 Foam Insulator 3 Heat Resistant Tape 4 Outer Conductor 5 Sheath 6 Adhesive Layer 7 Tape Body

Claims (1)

[Claims] 1. A small-diameter coaxial wire in which a foamed insulation material between a coaxially arranged inner conductor and an outer conductor has a foaming degree of 40% or more, and at least 150 immediately above the foamed insulation material.
A heat-resistant tape characterized in that a heat-resistant tape having a thickness of 2 to 10 μm prepared by a resin having a heat resistance of ℃ or higher and having an adhesive layer on one side is wound with the adhesive layer facing inward. Thin coaxial cable.