JPH0715138B2 - Method for manufacturing conductors for image display equipment and audio equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a conductor used for wiring a high-frequency transmission circuit of a conductor for image display equipment and audio equipment.

(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 soft 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 inhomogeneous, which is inappropriate for electrical conduction. It is considered that this also causes a phase difference for a high frequency component signal.

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a method for manufacturing a conductor for an image display device and an audio device having excellent signal transfer characteristics.

As a result of various studies on the signal transmission characteristics of the conductor, the inventors of the present invention have found that the crystal structure remains the fibrous structure in the longitudinal direction of the conductor and the density of point defects and dislocations is reduced to obtain a high-frequency signal current. It has been found that no phase difference is generated when the is passed.

That is, the present invention, after cold working pure copper 99.95% or more of purity, without recrystallization, and the point defects, the density of dislocations at 120 ~ 200 ℃ below the recrystallization temperature reduced compared to after cold working. In addition, the method for producing a conductor for an image display device and an audio device is characterized by performing heat treatment so that the tensile strength becomes 80 to 98% of the tensile strength immediately after cold working.

The conductor to be the subject of the present invention is, for example, a conductor used for wiring of electronic devices that require a high-frequency signal transmission circuit such as TV, CRT, and audio equipment, but is not limited to signal transmission circuits. 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 (for example, 10 or more). The cross-sectional shape of the conductor may be circular, elliptical, quadrangular, or any other irregular shape.

In the present invention, as pure copper having a purity of 99.95% or more, oxygen-free copper, tough pitch copper (oxygen 200 to 500 ppm) or the like is used, and the purity of 99.95% or more is defined as the density of point defects or dislocations at less than 99.95%. Is difficult to reduce, and impurities existing in a solid solution state are likely to cause nonuniformity of the electron density distribution.

In the present invention, the condition of the heat treatment after the cold working is a temperature condition in which the fibrous structure by the cold working does not recrystallize and the density of point defects and dislocations decreases as compared with that after the cold working. The time is appropriately selected depending on the material, size, processing conditions, crystal structure, etc. of the conductor. 120 to 200 below normal recrystallization temperature
C is preferred.

The tensile strength after this heat treatment is 80% of that immediately after cold working.
It is preferable to treat it under the condition of ~ 98%.
If it is less than 100%, recrystallized grains are generated, and if it exceeds 98%, the dislocation density and the vacancy density remain high.

A conductor that has been subjected to such heat treatment (although it is difficult to detect the difference from a normal conductor with normal measurement equipment), the sharpness and There is a clear difference in transparency.

The conductor of the present invention is usually used as a twisted wire in which 10 or more wires are twisted, and a conductor composed of such a large number of strands is more advantageous in terms of the skin effect of high frequency signal current.

Since it is expected that crystal defects will be introduced during the twisting process, it is preferable that the above heat treatment is performed after the twisting process. In addition, this has the advantage that the shape of the stranded wire of the final product tends to be stable and is stable during use, so that the sound is less likely to be disturbed.

(Example) Using various copper materials shown in Table 1, ordinary casting, hot rolling,
After peeling and cold drawing to create a 0.1mmφ hard copper wire,
This was heat-treated under the conditions shown in Table 1 to prepare a conductor of 0.1 mmφ.

Twisted wires of 19 of this conductor are applied with an insulation coating of polyvinyl chloride and used as electric wires for wiring inside and outside the TV,
The results of investigation of sound and image sharpness are shown in Table 1.

In the table, the tensile strength ratio indicates the ratio of the tensile strength of the conductor after heat treatment to that immediately after cold drawing. No. 1 of the comparative example
1 used a stranded wire formed by twisting five 0.2 mmφ conductors.

From Table 1, the conductor according to the present invention is more acoustic than the comparative example.
It can be seen that both images have excellent sharpness.

(Effects of the Invention) The electronic device conductor of the present invention configured as described above has the following effects.

(B) After cold working of pure copper with a purity of 99.95% or more, it is not recrystallized, and the heat treatment is performed under the temperature conditions in which the density of point defects and dislocations is reduced compared to after cold working, so the crystals are longitudinal. Since it has the same fibrous structure as in (1), there are fewer crystal grain boundaries that must cross in the direction of electric signal current than annealed copper, and the electron density distribution in the crystal is inhomogeneous. Point defects and line defects (dislocations) Since the existence density of is less than that of hard copper, the electric signal current flows accurately without phase difference, so
It is possible to manufacture a conductor for an electronic device in which the image of a CRT or the like becomes clear and the sound becomes beautiful.

(B) Since the manufacturing process is simple and easy, the conductor for electronic equipment can be industrially manufactured at low cost.

Claims (3)

[Claims] 1. Pure copper having a purity of 99.95% or more is not recrystallized after cold working, and the density of point defects and dislocations is 120 to 200 ° C., which is lower than the recrystallization temperature at which it is reduced as compared with after cold working, and A method for producing a conductor for an image display device and an audio device, which is characterized by performing a heat treatment so that the tensile strength becomes 80 to 98% of the tensile strength immediately after cold working. 2. The method for producing a conductor for an image display device and an audio device according to claim 1, wherein the conductor is formed by twisting 10 or more element wires. 3. The method for producing a conductor for an image display device and an audio device according to claim 2, wherein the heat treatment is performed after twisting the strands.