JPS62287516A - Cable - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a cable used as internal wiring of electronic equipment, and particularly to a cable useful for high-speed signal transmission.

[Prior Art] In recent years, cables used for internal wiring of electronic devices such as computers are required to transmit signals at high speed.

Therefore, as an insulator for this type of cable, it is being considered to foam a fluororesin with a low dielectric constant, particularly a fluororesin at a high rate.

[Problems to be Solved by the Invention] By the way, in a highly foamed fluororesin insulated cable, when the thickness of the insulator is thin (t = 0.3 mm or less) and the foaming ratio is ultra-high foamed with a foaming rate of 70% or more, It becomes a foam with an extremely fine diameter, making the insulator extremely soft.

Therefore, the adhesion strength between the conductor and the insulator is also weakened.

(The force with which the insulator presses the conductor is very weak. In other words, the harder the insulator, the greater the force with which the insulator presses the conductor.) Therefore, when a single wire conductor is used, the adhesion strength with the conductor is very weak, and the terminal treatment process The disadvantage was that the conductor would move.

In order to maintain the specified dimensions constant, it is necessary to use special jigs and tools, which is inefficient and requires a large number of man-hours for terminal processing, resulting in an expensive product.

Generally, when the above problem occurs with single line,
It is conceivable to use twisted wires.

It is true that when using stranded wires, even if the insulator is soft, the unevenness on the surface of the strands increases the adhesion strength, which appears to be better than that of solid wires, and the conductor moves during the terminal processing process. The problem was solved.

However, because the wires are stranded, when soldering them to the board, preliminary soldering is required in advance to prevent the wires from coming loose.
The disadvantage of inefficient and extremely expensive terminal processing work also arises depending on the intended use and terminal processing method.

[Means for Solving the Problems] An object of the present invention is to eliminate the drawbacks of the prior art described above and to provide a new cable that does not require preliminary soldering even when the conductor is in the form of a stranded wire. .

That is, the gist of the present invention is to apply a temperature that allows the silver plating layer of each strand to be fused after the wire-twisting operation as a conductor for an ultra-highly foamed (70% or more) fluororesin insulated cable. The plated layers in between are fused together to form so-called rod-shaped stranded wires, and by using this, preliminary soldering work to the stranded wires that is performed at the time of terminal processing is omitted, and the workability of terminal processing is greatly improved. It is something that

As for the material of the stranded wire in the above, materials commonly used for electrical wires such as general copper conductors and copper alloy conductors are used.

Especially when heated, there is a risk of wire breakage if the wire is thin, so steel alloys are useful.

Silver is used as the plating material because the insulating fluororesin is extruded and coated at high temperature.

Materials commonly used for electric wires, such as tin and solder plating, cannot be used. (It will melt due to the heat of high-temperature fluororesin extrusion.) Highly foamed fluororesin, which is a melt extrusion type of fluororesin, is used as the material for the insulator.

In the present invention, the insulator is limited to a highly foamed extruded type of fluororesin, but if the technology of the present invention is applied, other materials such as porous fluororesin tape wrapped or polyolefin-based melt extrusion can be used. It can also be applied to types.

[Embodiment] Next, an embodiment of the cable of the present invention will be described with reference to the accompanying drawings. The attached drawing shows the characteristic impedance, Zo-65
±5 (Ω) at TDR, delay time, Td-3,8
±0. 1 (nsec/m) a tTDR1 signal line pitch: 1. 27 (IIIG) shows a specific example of a 25-core coaxial cable in which only the jacket surfaces of the terminal portions are heat-sealed.

The diameter of conductor 3 is determined by the characteristic impedance and the pitch between signal lines +
1. In order to satisfy 27 (mm), it will be 0.26φ or less according to the theoretical calculation, but considering workability etc., it will be 0.2φ
~0.25φ is preferable. In other words, if you make it too thin, the insulator 4 will also become thinner, and if you make it too thick, the pitch between the signal lines: 1. 27 (am), and this time the jacket 8 becomes thinner, which poses a problem.

Single wire conductor conventionally used as a reference example: 0.2
We manufactured a 25-core coaxial cable using 3φ silver-plated wire with only the flattened terminal portion, but there were no problems other than the conductor moving during terminal processing.

In addition, as another conventional reference example, a stranded wire conductor (710,08
Silver plating (outer diameter: 0.24φ) had stranded wires with "hikkari" and no problem with conductor movement, but preliminary soldering is required for soldering to a board.

Figure 1 shows the conductor used in the present invention, 710
．． 08 silver-plated wire (plating thickness: approx. 2μ), right-handed twist P =
After twisting the wires at 5 am, a temperature of about 400° C. was applied so that the silver-plated wires 1 were fused and almost integrated into a rod-shaped conductor.

However, since the wire is as thin as 0.08φ, an alloy material containing approximately 0.3% tin was used in order to withstand the working tension of the high-temperature heating of the wire as a conductor on the bar.

On this conductor, as shown in Figure 2, ultra-high foaming P F A4 is applied.
(foaming rate near 5±5%) to thickness t-0,235ma (
Extruded to a diameter of 0.71φ) and E-TF as the reinforcing layer 5.
Apply an E-skin (full) layer with a thickness of t-0,045c+a+, add one 0.23φ silver plated wire 6 vertically, wrap it with aluminum/polyester tube 7, and use FEP as the jacket 8.
was extruded into a rectangular shape and made into a coaxial cable.

This cable is arranged in parallel with 25 cores as shown in Figure 3.
Only the ends of the jacket surfaces were heat-sealed (9).

This cable has satisfactory results both in terms of characteristics and terminal processing.

In this embodiment, the general twisted wire is 7 or more twisted wires, but from the viewpoint of the present purpose, it can be applied to 2 to 6 wires without any problem.

Furthermore, if the technology of the present invention is applied, even if the materials and plating of each strand are different, it can be applied without any problems as long as it meets the purpose of forming a rod-shaped stranded wire and does not require preliminary soldering.

From the point of view of "preventing loose wires" on the outer periphery, it is possible that the inner cable wire can be applied without plating.

Even with a single wire, if the surface is made uneven in the same way as a stranded wire, it can of course be applied without any problem.

It is also conceivable to strand the plated wireless wires and overcoat them.

[Effects of the Invention] According to the present invention, even rod-shaped twisted wires are more flexible than single wires, and the surface unevenness can be controlled to some extent by adjusting the number of twisted wires, the wire diameter, the twisting pitch, etc. This makes it possible to provide ultra-high foamed fluororesin insulated cables that have a strong adhesive strength between conductors and insulators, and can also control the degree of hiccups. It has great value.

[Brief explanation of drawings]

Fig. 1 is an explanatory cross-sectional view showing a rod-shaped stranded wire conductor structure used in the cable of the present invention, Fig. 2 is an explanatory cross-sectional view showing an embodiment of the coaxial core constituting the cable of the present invention, and Fig. FIG. 2 is an explanatory cross-sectional view showing an embodiment of the end-fused flat portion of the cable of the present invention. 1: Stranded conductor strands (outer diameter: 0.08φ), 2: Fusion plating layer (material: silver plating), 3: Rod-shaped stranded conductor (710
, 08), 4: Highly foamed insulator (material: PFA), 5: Solid skin layer (material: E-TFE), 6: Drain wire (outer diameter: 0.23φ), 7: Shield tape (aluminum/polyester tube) ), 8: Fluororesin jacket (material: FEP), 9: Surface adhesive layer,

Claims (1)

[Claims] (1) Consists of a conductor and an insulator provided around its outer periphery.The conductor is made by twisting a plurality of silver-plated wires and then applying a temperature high enough to fuse the plating layer of each wire. 1. A cable comprising a rod-shaped stranded wire, wherein the insulator is a highly foamed fluororesin insulator with a foaming rate of 70% or more.