JPH0715139B2 - Method for manufacturing conductor for image display device and audio device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to the production of conductors used in wiring of electronic devices that require signal transmission circuits such as TVs, VTRs, CRTs (Cathod Ray Tubes) and audio devices. It is about law.

(Background Art) In these electronic devices, if signals are not accurately transmitted without causing a phase difference, an image or sound may be blurred or sound may not be clear.

Conventionally, tough pitch copper (pure copper containing about 200 to 500 PPm oxygen) or oxygen-free copper (pure copper containing almost no oxygen) is cold-worked, then annealed and softened to recrystallize annealed copper wire or sometimes as cold-worked. The hard copper wire of the above, or the wire to which tin or the like is plated has been used for these applications.

However, these lines have not always been convenient for the accurate transmission of signals for the following reasons.

In the case of annealed copper wire, crystal grains are usually distributed in a shape close to equiaxed due to recrystallization by annealing, so when the current flows in the longitudinal direction of the conductor, the number of crystal grain boundaries that will cross will increase, and Is considered to act significantly as a cause of generation of a phase difference, especially for high frequency component signals.

In the case of a hard copper wire, since it has a shape of a crystal that extends in the longitudinal direction in a fibrous shape compared to an annealed copper wire, when an electric current flows in the longitudinal direction, the crystal grain boundaries that will cross are apparently less than the point.
Although it is not easily affected by crystal grain boundaries, the density of atomic vacancies (point defects) and dislocations (linear crystal defects) is much higher than that of annealed copper wire, and the electron density is unsuitable for electrical conduction. There are many homogeneity, etc., and this is also considered to cause the phase difference for the high frequency component signal.

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a signal current flows through a conductor accurately without causing a phase difference,
An object of the present invention is to provide a method of manufacturing an image display device and a conductor for an audio device, in which images and sounds are clear.

The present invention, after the casting or hot working of oxygen-free copper, in a temperature range in which the crystal does not recrystallize, and an image display device, characterized by performing a heat treatment of heating and holding in a temperature range of 500 ℃ or more, acoustic equipment It is a manufacturing method of a conductor for use.

The conductor to be the subject of the present invention is, for example, a conductor used for wiring an image display device such as a TV, a VTR, a CRT or an audio device such as a stereo, but is not limited to a high-frequency signal transmission circuit, It is used in the state of a single wire, a single wire plated with tin, solder or the like, or a twisted wire formed by twisting a plurality of these wires. The cross-sectional shape of the conductor may be circular, elliptical, quadrangular, or any other irregular shape.

In the present invention, oxygen-free copper is used as a raw material because oxygen and impurity elements or oxygen and copper compounds having semiconductor characteristics are not distributed in the conductor.

Hereinafter, the present invention will be described by way of examples with reference to the drawings. The drawings show the manufacturing process of a typical embodiment of the method of the present invention. In the figure, after hot rolling, the special heat treatment according to the present invention is performed. Further, this heat treatment may be performed after other hot working (eg, extrusion, swaging, wire drawing, etc.) or casting (eg, continuous casting, deep forming, chill mold casting, etc.).

This special heat treatment is performed by heating and holding in a temperature range in which crystals do not recrystallize and in a temperature range of 500 ° C. or higher. When continuously performing casting or hot working, stop cooling at a predetermined temperature of 500 ° C or higher in the cooling process of the ingot after casting or in the cooling process of the material after hot working. The temperature is maintained at that temperature, or is gradually cooled in a predetermined temperature range of 500 ° C. or higher at a cooling rate of 100 ° C./hour or less. Cooling rate is 100
When the temperature exceeds ° C / hour, the time for existence at the desired temperature of 500 ° C or higher is insufficient. By carrying out continuously in this way, energy required for reheating is omitted, which is economical.

If the temperature of the heat treatment is less than 500 ° C, it takes a long time to obtain a desired clear image or sound, which is industrially inappropriate or the effect is not sufficient. Also, at the temperature at which recrystallization occurs, impurities are likely to form a solid solution, and it is also difficult to obtain a clear image and sound.

Although the mechanism of the special heat treatment in the present invention is not clear, the presence state of impurities unavoidably contained in industrially produced oxygen-free copper changes from a solid solution state to a precipitation state, It is considered that the irregularity of the electron distribution of is reduced and the phase of the high frequency signal current is less likely to shift. As a result, when the high-frequency signal current flows as a conductor after the final processing, the high-frequency signal current flows accurately with no phase difference, and the image and sound become clear. The reason for performing this heat treatment after casting or after hot working is 500 when the cold working degree is high.
When heated above ℃, it recrystallizes to coarsen the crystal grains and impairs the mechanical properties of the conductor.In addition, heating at high temperature may cause oxidation of the surface, but if it is close to the product size, peeling or pickling may occur. Is also not industrially advantageous.

In the method of the present invention, after the above-mentioned special heat treatment, cold working, peeling if necessary, intermediate softening, and twisted wire are applied in order to finish to the final size.

Further, finish softening may be carried out at the final wire diameter or the twisted wire stage.

(Example 1) Using electrolytic copper as a raw material, an oxygen-free copper rod was formed by a deep forming method, hot-rolled into a wire having a diameter of 9.5 mm, and then heat-treated at 550 ° C for 12 hours. There was no change in crystal grains due to this heat treatment.

The surface of this wire was peeled off, cold-drawn to 1.6 mmφ, then softened for 2 hours at 300 ° C. in a non-oxidizing atmosphere, and then cold-drawn to 0.12 mmφ.

This wire is passed through a tunnel furnace in a non-oxidizing atmosphere maintained at a temperature of 400 ° C to make annealed copper wire, and these 19 pieces are twisted to form a stranded wire, which is then braided and shielded (No.
1) was created.

For comparison, the above-mentioned heat treatment after hot rolling is not performed, and the other conditions are the same, and the electric wire of the comparative example (No. 2) and the electric wire of the conventional example using the tough pitch copper wire prepared by the conventional method ( N
o.3) was prepared.

The obtained electric wire is used as an electric wire for a speaker, and the result of sound evaluation is shown in Table 1.

From Table 1, it can be seen that the one according to the present invention has a clearer sound and no distortion as compared with the comparative example and the conventional example.

(Example 2) An oxygen-free copper billet was hot extruded, then heat-treated under the conditions shown in Table 2, peeled off, and then cold drawn to a wire of 0.18 mmφ, and 11 wires of the softened wire were twisted. A stranded wire was put together, and insulation coating was performed to make a cord.

Table 2 shows the results of evaluation of TV sound and images using this cord as a TV wiring conductor.

From Table 2, it can be seen that the one according to the present invention has a clearer sound and image than the comparative example.

In Tables 1 and 2, the evaluations of "acoustic and image were clear" and "acoustic and image were clear" in the acoustic evaluation result section and the acoustic and image evaluation section ,Ten
The evaluation is based on the evaluation results of 0 people and at least 88 people.

(Effects of the Invention) The image display device and audio device conductor of the present invention configured as described above have the following effects.

(B) After casting or hot working of oxygen-free copper, heat treatment is performed by heating and holding in a temperature range where crystals do not recrystallize, and in a temperature range of 500 ° C or higher. Changes so as not to cause the irregularity of the electron distribution in the conductor, so that the image and acoustic signal currents flow accurately without phase difference, so that a conductor with clear image and acoustic can be manufactured.

(B) The raw material may be ordinary electrolytic copper, and the manufacturing process is merely the addition of a heat treatment process to the conventional method, so that it can be industrially easily manufactured at low cost.

[Brief description of drawings]

The drawings show the manufacturing process of a typical embodiment of the method of the present invention.

Claims (3)

[Claims] Claims: 1. After casting or hot working of oxygen-free copper, heat-treat it by heating and holding it in a temperature range where crystals do not recrystallize and in a temperature range of 500 ° C or more, cold work, and wire drawing. A method for manufacturing a conductor for an image display device and an audio device, characterized by. 2. In the cooling process of the ingot after casting or the cooling process of the material after hot working, the heat treatment is stopped at a predetermined temperature of 500 ° C. or higher and kept at that temperature. The method for producing a conductor for an image display device and an audio device according to claim 1, which is carried out by gradually cooling a predetermined temperature range of 500 ° C. or more at a cooling rate of 100 ° C./hour or less. . 3. The method for producing a conductor for an image display device and an audio device according to claim 1 or 2, wherein the casting is performed by a dip forming method.