JPH0414811Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is applicable to coaxial cables used as internal wiring of electronic equipment such as computers, and more specifically, to various properties such as heat resistance, weather resistance, and heat resistance. The present invention relates to the improvement of a coaxial cable that has excellent wiring workability, electrical properties, and terminal processing workability.

[Prior Art] Internal wiring materials for electronic devices such as computers are required to have excellent electrical properties such as low loss and low dielectric constant.

As one cable structure for satisfying this requirement, a coaxial cable using fluororesin as an insulator has previously been proposed.

In other words, this cable consists of a central conductor, a fluororesin insulator provided around its outer periphery, a drain wire attached vertically to this, a shield layer provided around the outer periphery of these, and a fluororesin jacket layer provided around the outer periphery. It depends on this.

This cable uses fluororesin as an insulator, so it has a low dielectric constant, and since the drain wire is in contact with the shield, it has good terminal processing and easy wiring work. It is achieving the desired results.

[Problems that the invention aims to solve] However, this cable had the drawback of poor noise resistance.

That is, when a coaxial cable is bent, friction occurs between the insulator and the shield, causing noise.

One possible measure to improve the noise resistance is to coat a fluororesin insulator with a conductive fluororesin, but the material is hard and lacks flexibility.

The conductive layer is hard and the terminal processing properties are poor.

There was a drawback.

[Means for Solving the Problems] The purpose of the present invention is to eliminate the drawbacks of the prior art described above, and to provide a coaxial cable for electronic equipment that has good terminal processing operations and excellent crosstalk characteristics and electrical characteristics. There is a particular thing.

In other words, its gist is that: a central conductor, a highly foamed fluororesin insulating layer with a foaming degree of 60% or more extruded around the center conductor, and a conductive layer with a thickness of 0.3 mm or less around the center conductor. The drain wire is characterized by being composed of a core made of a polyvinyl chloride layer, a drain wire attached vertically to the core, a shield layer provided on the outer periphery of these, and further a vinyl chloride jacket extruded on the outer periphery of the drain wire. There is a coaxial cable.

[Function] This invention improves transmission speed by using highly foamed fluororesin as an insulator, and has excellent flexibility by using conductive vinyl chloride as a conductive layer. It also has excellent properties.

[Embodiment of the invention] Next, an embodiment of the coaxial cable of the invention will be further described with reference to the accompanying drawings.

Reference numeral 1 denotes a central conductor, and on its outer periphery, a highly foamed fluororesin insulator 2 and a conductive vinyl chloride layer 3 are sequentially formed.
is provided.

Reference numeral 4 denotes a drain wire attached vertically in contact with the conductive vinyl chloride layer, and a shield tape 5 is further provided around the outer periphery of the drain wire.

Reference numeral 6 denotes a vinyl chloride jacket provided on the outer periphery of these, and constitutes a coaxial cable.

Here, as the center conductor 1 and the drain wire 4, silver-plated annealed copper stranded wires of 7/0.127 mm (outer diameter 0.38 mm) are used.

That is, the coaxial cable of the present invention uses fluororesin as an insulator, and is silver-plated to prevent the conductor from discoloring at the high temperatures during extrusion of the fluororesin.

The foamed insulator 2 has a foaming degree of 60% or more.
PFA is used and is extruded to an outer diameter of 1.36 mm.

Other fluororesin layers include FEP or E
- TFE is used.

As the conductive layer 3, vinyl chloride is used, and its thickness is about 0.2 mm.

As the shield tape 5, a laminate tape of polyester and aluminum is used.
A thickness of 9μ and polyester of 4μ are used.

Here, the laminate tape is used with the aluminum side facing inside.

Polyester tape is used to reinforce aluminum tape.

As a shield, in addition to shield tape wrapping, a braided shield and a horizontally wound shield can be considered.

The jacket 6 is made of extruded vinyl chloride and has a thickness of about 0.2 mm.

According to the coaxial cable of the present example formed in this way, characteristics of characteristic impedance Z _O =75±8 (Ω) and transmission speed T _d =4.05±0.15 (nsec/m) were obtained.

[Effects of the invention] As explained above, according to the invention, it is possible to provide a coaxial cable for internal wiring of electronic devices that has the following advantages, and its practical value is extremely great. be.

It has excellent electrical properties (transmission speed) because it uses highly foamed fluororesin with a foaming degree of over 60% for the insulator.

Excellent flexibility.

Excellent terminal processing performance.

The conductive vinyl chloride layer itself has good cutting properties, and since the bottom layer is made of fluororesin and the surface is inactive, it does not stick to the conductive vinyl chloride layer, and the conductive layer can be easily peeled off.

The noise resistance characteristics are also sufficient.

According to experiments (by striking the coaxial cable and applying vibrations), the spike voltage generated is approximately 1/6th that of a coaxial cable of the same structure without the conductive PVC layer.

[Brief explanation of drawings]

The accompanying drawing is a cross-sectional explanatory view showing one embodiment of the coaxial cable of the present invention. DESCRIPTION OF SYMBOLS 1... Center conductor, 2... Highly expanded fluororesin insulation layer, 3... Conductive vinyl chloride layer, 4... Drain wire, 5... Shield tape layer, 6... Vinyl chloride jacket.

Claims (1)

[Scope of utility model registration request] A core consisting of a central conductor, a highly foamed fluororesin insulation layer with a foaming degree of 60% or more extruded around the center conductor, and a conductive vinyl chloride layer with a thickness of 0.3 mm or less around the outside. A coaxial cable comprising: a drain wire vertically attached to the core; a shield layer provided around the outer periphery of the drain wire; and a vinyl chloride jacket extruded around the outer periphery of the drain wire.