JP2875319B2 - Chemical plating method for fine metal wires - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for chemical plating a fine metal wire.

<Conventional Technology> When chemical plating is performed on a thin metal wire, usually, a thin metal wire is obtained by drawing, and the thin metal wire is immersed in a chemical plating solution.

<Problem to be solved> However, in this method, degreasing and acid cleaning treatments are indispensable as pretreatments before immersion in a chemical plating bath, but due to insufficient treatment, poor adhesion of the chemical plating. And unevenness are often observed. Further, stirring of the plating solution is required, but due to insufficient stirring, gas adheres to the surface of the object to be plated, and uneven plating and non-plated portions are often observed.

By the way, as a method of manufacturing thin metal wires, a cooling diagram is held in a layered shape by the rotating centrifugal force on the inner periphery of the rotating drum, molten metal is jetted from a nozzle in a jet shape, and the jet of the molten metal is incident on the cooling water layer There is known a method of cooling and solidifying. The liquid layer due to the centrifugal force inherently has centrifugal separation properties, but is only used for cooling and solidifying the jet.

The present invention focuses on such centrifugal separability, and aims to eliminate the absurdity of the chemical plating method for thin metal wires by using a chemical plating solution as a liquid for the liquid layer held by the centrifugal force. .

<Means for Solving the Problems> The chemical plating method of a thin metal wire according to the present invention is a method of holding a chemical plating solution in a layer on the inner periphery of a rotating drum by the rotational centrifugal force, and jetting a molten metal jet on the plating solution layer. , And the jet is cooled and solidified with a chemical plating solution, and is also subjected to chemical plating.

<Operation> According to the configuration of the present invention, since the jet of the molten metal is immediately incident on the chemical plating solution, it can be immersed in the chemical plating solution without being stained, and the gas generated during chemical plating can be obtained. Can be centrifuged well, and chemical plating with good adhesion without unevenness and scattered non-plated parts is possible.

<Description of Example> Hereinafter, an example of the present invention will be described with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a rotary drum, which has an inner partition wall 11 as shown in FIG. 2 (a cross section taken along line II-II in FIG. 1). Reference numeral 2 denotes a chemical plating solution, which receives a centrifugal force due to the rotation of the drum 1 and is held in a layered form. Reference numeral 3 denotes a nozzle, which includes a heater 31 and a gas pressurizing tube 32.

In order to carry out the present invention, a metal as a fine wire raw material, for example, an Sn-Pb alloy is contained in the nozzle 3, the metal is melted by a heater, and the molten metal is jet-injected by gas pressure from a gas pressurizing pipe 32. The jet of the molten metal is incident on the chemical plating solution layer 2 in the high-speed rotating drum 1. In this case, if the angle between the jet and the chemical plating solution layer (incident angle) is Θ, the jet speed is V ₁ , and the rotation speed of the plating solution layer is V ₂ , V ₁ cosΘ = V ₂ − is satisfied. V ₁ and V ₂ are set as described above.

And Thus, the jet despite being charged into the chemical plating solution layer in the high-speed rotation in a molten state, shown in the first equation, for alignment with the jet velocity V ₁ and the plating liquid layer rotating speed V ₂ The jet is cooled and solidified by the plating solution without being subjected to tension. Therefore, a thin wire can be continuously obtained without breaking the jet. The fine wire is chemically plated while being immersed in the chemical plating solution. The immersion time required for this chemical plating is usually 5 to 10 minutes. During the chemical plating, the drum is rotated at a high speed to hold the plating liquid layer. Therefore, centrifugal force acts on the plating liquid layer, and the difference in specific gravity between the gas generated during the chemical plating and the plating liquid is generated. It is possible to easily carry out centrifugal separation, to prevent gas from accumulating on the surface of the fine wire, and to well prevent scattered non-plated portions and uneven plating.

A Sn-Pb-based low melting point metal can be used for the fine wire, and a chemical plating solution such as copper, nickel, silver, gold, cobalt, chromium, zinc, iron, and palladium can be used for the chemical plating solution.

The immersion time required for the chemical plating is usually 5 to 10 minutes.

Therefore, even after the molten metal in the nozzle is completely sprayed to complete the production of the fine wire, the drum rotation is continued for 5 to 10 minutes for the chemical plating of the final portion of the fine wire, and the chemical plating solution layer is formed. Need to be retained.

 Next, an embodiment of the present invention will be described.

The metal composition of the used fine wire is a Pb-Sn alloy of 37% by weight of Pb and 63% by weight of Sn. The chemical plating solution used was a copper plating solution, and its composition was copper sulfate 14 g / l, nickel chloride 4 g / l, Rossell salt 45 g / l, formalin 53 g / l, sodium hydroxide 10 g / l, and sodium carbonate 4 g. / l.

The drum is rotated so that the peripheral speed of the plating solution layer is 5 to 6 m / sec, and the ejection speed of the thin wire is 4 to 6 m / sec, and the diameter of the thin wire is 0.15 m.
m, incident angle on the plating solution layer: 10-30 °. After all of the solution metal in the nozzle was sprayed, the drum rotation was continued for 10 minutes to maintain the layer shape of the plating solution. After that, the rotation of the drum was stopped, the plating solution was taken out, and the plating state was examined. The plating thickness was 0.5 μm, and there was no uneven plating or non-plating spots. Pb-Sn fine wire was obtained.

<Effect of the Invention> As described above, the chemical plating method for a thin metal wire according to the present invention is such that the jet of the molten metal jetted from the nozzle is immediately incident on the chemical plating solution, and the fine wire is free from contamination, and the plating solution is Can be chemically plated in the state of heated surface activity without heating, so that a plating film having excellent adhesion can be formed. Also, due to the centrifugal force acting on the chemical plating solution due to the rotation of the drum, the gas generated during chemical plating can be separated well, and a plating film having a good appearance without unevenness and non-plated portions can be coated.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a chemical plating apparatus for thin metal wires used in the present invention, and FIG. 2 is a sectional view taken along the line II-II in FIG. 1 ... drum, 2 ... chemical plating solution layer, 3 ... nozzle.

Claims (1)

(57) [Claims] 1. A chemical plating solution is held in a layered state on the inner periphery of a rotary drum by its rotational centrifugal force, a jet of molten metal is made incident on the plating solution layer, and the jet is cooled and solidified with the chemical plating solution. A chemical plating method for fine metal wires, characterized by plating.