JP2006307277A - Method for manufacturing plated extra-fine wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a plated extra-fine wire, which hardly breaks the wire and has superior production efficiency. <P>SOLUTION: This manufacturing method comprises the steps of: firstly forming an Ag-plated layer which is harder than a rod material made from copper or a copper alloy and has a Vickers hardness (Hv) of 100 to 150, on the surface of the rod material by using a cyan plating bath containing selenium of 20 to 40 ppm; and then wire-drawing the rod material having the Ag-plated layer formed thereon into the plated extra-fine wire having the diameter of less than 50 μm. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method of manufacturing an ultrafine plated wire having a diameter of less than 50 μm used for an ultrafine coaxial cable of a small electronic device such as a mobile phone.

  Recently, with the miniaturization and weight reduction of electronic devices, the demand for ultra-fine coaxial cables with excellent electrical characteristics has increased. In particular, in order to support high-speed signal transmission, the strands of copper or copper alloy There is an increasing demand for extra fine wires having a plating layer formed on the surface. Conventionally, when manufacturing such an ultra-fine plated wire, after forming a plating layer made of silver (Ag) or the like having a purity of 99.9% by mass or more on the surface of a wire made of copper or a copper alloy, the wire is stretched. Line processing is given.

  However, when copper or copper alloy wire with a plated layer is drawn, metal powder derived from the plated layer is clogged in the die hole, and copper or copper alloy wire with no plated layer is drawn The frequency of breakage increases compared to, and production efficiency decreases. In particular, when manufacturing an extra fine wire having a diameter of less than 50 μm, the wire diameter is thin and the strength is low. Therefore, conventionally, in order to prevent disconnection at the time of wire drawing, a method has been proposed in which a plating layer is formed on the surface of a copper or copper alloy ultrafine wire that has been previously drawn to form an ultrafine plated wire ( For example, see Patent Documents 1 and 2.) For example, in the method of manufacturing an ultrafine plated wire described in Patent Document 2, in order to improve the surface quality of the strand and improve the adhesion between the plating layer and the strand, the drawn wire is further chemically dissolved or After reducing the diameter by electrochemical dissolution, a plating layer is formed on the surface.

Japanese Patent No. 2714922 JP 2002-140935 A

  However, the conventional techniques described above have the following problems. That is, when the plating layer is formed on the surface of the drawn wire as in the manufacturing method of the fine wire described in Patent Documents 1 and 2, the frequency of wire breakage during wire drawing decreases, There is a problem in that it is difficult to control the tension when the processed wire is plated, and the production efficiency is lowered.

  This invention is made | formed in view of this problem, Comprising: It aims at providing the manufacturing method of the ultra fine plating wire which was hard to generate | occur | produce a disconnection and was excellent in production efficiency.

  The method for producing an ultrafine plated wire according to the present invention is the method for producing an ultrafine plated wire having a diameter of less than 50 μm in which a plating layer containing silver is formed on the surface of a wire made of copper or a copper alloy. A step of forming a plating layer containing silver on the surface of the wire material that is harder than the wire material, and a step of drawing the wire material on which the plating layer is formed to make the diameter less than 50 μm. Features.

  In the present invention, since the plating layer is harder than copper or copper alloy wire, even if the wire having the plating layer formed on the surface is drawn, metal powder derived from the plating layer is hardly generated. It is possible to prevent disconnection during wire drawing. In addition, since the wire rod on which the plating layer is formed is drawn, the production efficiency is improved as compared with the case where the plating layer is formed on the surface of the ultrafine wire previously drawn to a predetermined diameter.

  In the step of forming the plating layer, a plating bath containing potassium selenium cyanide may be used. Thereby, the hardness of a plating layer can be easily adjusted by changing the addition amount of potassium selenium cyanide.

  In that case, the selenium concentration in the plating bath can be 20 to 40 ppm. Thereby, the plating layer which is hard to disconnect and has excellent gloss can be formed.

  The plating layer has a Vickers hardness of 100 to 150, for example.

  According to the present invention, since the Ag plating layer is harder than the copper or copper alloy wire, even if the wire having the Ag plating layer formed on the surface is drawn, the metal powder derived from the Ag plating layer is not present. It is less likely to occur, can prevent disconnection during wire drawing, and is excellent in production efficiency because the wire with the Ag plating layer formed thereon is wire drawn.

  Hereinafter, the ultrafine plated wire according to the embodiment of the present invention will be specifically described. The ultra fine plated wire of the present embodiment has a diameter of less than 50 μm, and has a thickness of, for example, 1 to 3 μm and a plated layer containing Ag on the surface of a wire made of copper or a copper alloy. In addition, an element for hardening the Ag plating layer, such as selenium (Se) and antimony (Sb), is added to the plating layer in the ultra fine plating wire. It is higher than that.

  Next, the manufacturing method of the ultra fine plated wire of this embodiment is demonstrated. First, a plating layer having a thickness of, for example, 6 μm and containing Ag is formed on the surface of a wire made of copper or a copper alloy and having a diameter of, for example, 120 μm. At this time, a plating bath containing silver cyanide, potassium cyanide and potassium selenium cyanide and further added with a brightening agent such as carbon disulfide if necessary is used. The amount of potassium selenium cyanide added in this plating bath is By adjusting, the plating layer is made harder than the copper or copper alloy wire. Thereafter, the copper or copper alloy wire having a plating layer formed on the surface is drawn by a wire drawing machine so that the diameter is less than 50 μm to obtain an ultra fine plated wire.

  In addition, it is desirable that the Vickers hardness (Hv) of the plating layer in the ultra fine plating wire of this embodiment is 100 to 150. When the Vickers hardness (Hv) of the plating layer is less than 100, the wire drawing property is lowered, and breakage may occur frequently during wire drawing. On the other hand, when the Vickers hardness (Hv) of the plating layer exceeds 150, the glossiness of the plating layer may be lowered. In addition, what is necessary is just to make Se density | concentration of a plating bath into the range of 20-40 ppm, for example, in order to make the hardness of a plating layer into the above-mentioned range.

  The reason why metal powder is generated when a copper or copper alloy wire having a plating layer formed on the surface is drawn is that the plating layer is softer than copper or copper alloy wire. Therefore, in the manufacturing method of the ultra fine plated wire of this embodiment, a trace amount of an element that has an effect of hardening the Ag plated layer such as Se and Sb is added to the plated layer, and the plated layer is made harder than the copper or copper alloy wire. ing. Thereby, even if a wire having a plating layer formed on the surface is drawn, metal powder derived from the plating layer is hardly generated, and disconnection during the drawing can be prevented.

  Moreover, in the manufacturing method of the ultra fine plated wire of this embodiment, since the wire in which the plating layer was formed is drawn, the manufacturing method of the ultra fine plated wire described in Patent Documents 1 and 2 described above is used. Thus, the production efficiency is superior to the case where the plating layer is formed on the surface of the ultrafine wire drawn to a predetermined diameter.

  Hereinafter, the effect of the present invention will be described in comparison with a comparative example that is out of the scope of the present invention. First, 5 bobbins of a copper alloy wire made of a copper alloy containing 1.0% by mass of Ag, having a diameter of 120 μm, a length of 1000 m, and a Vickers hardness (Hv) of 105 are prepared on the surface of each copper alloy wire. In addition, a plating layer having a thickness of 6 μm, Vickers hardness (Hv) of 40, 75, 100, 125, and 150 and mainly composed of Ag was formed, and Comparative Examples 1 to 3 and Example 1 and 2 plating wire was produced. At this time, a plating bath containing 30 g / liter of silver cyanide, 35 g / liter of potassium cyanide, 35 g / liter of potassium carbonate, 100 g / liter of potassium nitrate and selenium potassium cyanide was used, and the amount of potassium selenium cyanide added was adjusted. By changing, the Se concentration in the plating bath was adjusted in the range of 0 to 40 ppm, and the hardness of the plating layer formed on each wire was adjusted.

  Further, in the same manner, a copper alloy wire comprising a copper alloy containing 1.0% by mass of Ag, having a diameter of 120 μm and a length of 1000 m, and having a Vickers hardness (Hv) of 60 by heat treatment or processing method. A plating layer having a thickness of 6 μm, a Vickers hardness (Hv) of 100, and Ag as a main component was formed on the surface, and the plating wire of Example 3 was produced. Furthermore, it is made of a copper alloy containing 1.0% by mass of Ag, the diameter is 120 μm, the length is 1000 m, and the thickness of the copper alloy wire rod having a Vickers hardness (Hv) of 130 by heat treatment or processing method is set on the surface. A plated wire of Comparative Example 4 was produced by forming a plating layer having a Vickers hardness (Hv) of 100 μm and a main component of Ag at 6 μm.

  Next, the plated wires of Examples 1 to 3 and Comparative Examples 1 to 4 described above were drawn using a wire drawing machine so that the diameter was 50 μm, and then further drawn so that the diameter was 25 μm. The number of wire breaks in each wire drawing process was examined. The results are shown in Table 1 below.

  As shown in Table 1 above, in the plated wires of Examples 1 to 3 in which the plated layer was harder than the copper alloy wire, no breakage occurred during the wire drawing. On the other hand, in the plated wires of Comparative Examples 1 to 4 where the plating layer is softer than the copper alloy wire, breakage occurs during the wire drawing process, and in particular, the number of occurrences of breakage is large in the process of changing the diameter from 50 μm to 25 μm. It was. Therefore, the surface of the broken wire was observed by SEM (Scanning Electron Microscope) and the cause of the wire breakage was investigated. As a result, metal powder derived from the plating layer was generated during wire drawing. The metal powder was clogged in the die, and disconnection occurred.

Claims (4)

In the method for producing an ultrafine plated wire having a diameter of less than 50 μm in which a plating layer containing silver is formed on the surface of a wire made of copper or copper alloy, the wire contains silver on the surface of the wire made of copper or copper alloy A method for producing an ultrafine plated wire, comprising: forming a harder plating layer; and drawing the wire on which the plating layer is formed to reduce the diameter to less than 50 μm. The method for producing an ultrafine plated wire according to claim 1, wherein a plating bath containing potassium selenium cyanide is used in the step of forming the plating layer. The method for producing an ultrafine plated wire according to claim 2, wherein the selenium concentration in the plating bath is 20 to 40 ppm. The method of manufacturing an ultra fine plated wire according to any one of claims 1 to 3, wherein the plating layer has a Vickers hardness of 100 to 150.