JPS61140366A - Production of extrafine solder coating wire - Google Patents

Abstract

PURPOSE:To obtain a extrafine solder coating wire at low cost and with good efficiency by making a base wire with the extrusion coating of a solder on a core wire and by performing a wire drawing work without the heat treatment of this base wire. CONSTITUTION:The solder coated wire 5 consisting of a core wire 2 and the solder 1A coating the core wire 2 is obtained by passing the core wire 2 through a die 4 with applying a tension on the core wire 2 with preheating and pressing a solder billet 1. A wire drawing is performed with more than 85% reduction with this solder coated wire 5 as the base wire without subjecting to a heat treatment on the way. With this method the extrafine solder coated wire of high strength having sufficient hardening work is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing ultrafine solder-coated wires used as lead wires for electronic components.

[Conventional technology and its problems]

Traditionally, it has been widely used as lead wire for electronic components.
Solder-coated wires, which are made by coating the surface of a core wire such as a copper wire with solder, are generally manufactured by either a hot-dip solder plating method or an electric solder plating method. Therefore, such solder coated wire is generally known by the name solder plated wire rather than by that name.

Now, regarding this solder-plated wire, recently there has been a demand from manufacturers of electronic components for thicker solder-plated wire than the previous solder-plated wire, and therefore the manufacturing method of such solder-plated wire has been changed. This is currently being considered. Here, with the molten solder plating method, thick plating cannot be obtained because there is a limit to the plating thickness.

The electric solder plating method has the problem of slow production speed and high cost.

On the other hand, in contrast to such plating methods, there is a method for manufacturing composite metal wires in which the core wire is inserted into a coated metal pipe and integrated, the entire bus bar is manufactured, and this bus bar is drawn to finish it to a predetermined wire diameter. There is a co-pulling method, and a method of manufacturing solder-coated wire using this co-pulling method is being studied. However, with this co-pulling method, it is possible to obtain solder sheaths with a thickness of 10 μm or more, just as with the electro-solder plating method, but it is not possible to obtain a solder sheath with a thickness of 10 μm or more, but it is difficult to obtain a solder sheath with a thickness of 10 μm or more, because it takes time to manufacture the bus bar. The problem is that the cost is several times higher than that of plated wire.

An object of the present invention is to solve these problems and provide a method for manufacturing ultra-fine solder-coated wires inexpensively and efficiently.

[Failure to solve the problem]

In other words, the gist of the present invention is that 8
To manufacture a bus bar by extrusion coating the circumference of a core wire with solder capable of giving a workability of 5% or more, and to wire-draw the busbar at a workability of 85% or more without performing heat treatment on the way.

[Effect]

In the present invention, in order to improve the strength of the composite wire, it is necessary to apply processing 1f' to the core wire by 85% or more. However, materials that undergo significant work hardening when subjected to a working degree of 85% or more and refuse to be processed further without heat treatment cannot be used as the core wire in the present invention.

This is because in the case of solder-covered wire, the softening temperature of the solder is extremely low, so if you try to soften the core wire by heat treatment, the solder will usually melt before that, so heat treatment is practically impossible. This is because.

Here, as core wires that can be processed to a degree of workability of 85% or more without heat treatment, for example, brass wire can be worked to a degree of up to 99%, and steel wire can be worked to a degree of around 90%.

Usually 150 to 250 for industrial extrusion coating of solder.
It requires a hot extrusion temperature of By preheating the wire as well, a diffusion layer or an intermetallic compound can be formed at the interface between the core wire and the solder to improve adhesion.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The method of the present invention for producing a solder-coated wire having a wire diameter of 0.2 μm and a coating thickness of 10 μm will be explained below with reference to the drawings.

FIG. 1 is a structural sectional view of an extruder that extrudes and coats a core wire with solder in order to carry out the manufacturing method of the present invention. In the figure, 1 is a solder billet, 70φX20(l
Preheat to 150°C using the same size. Reference numeral 2 denotes a core wire, which is made of a completely annealed material such as copper wire.

3.4 is the core wire 2. The nipple and die hold the entire manufactured solder coated wire 5, and are maintained at around 150°C. Now, by applying tension to the core wire 2 while pressurizing the solder billet 1, the core wire 2 is passed through a 5.6H die 4, and the solder-coated wire 5 shown in FIG. 2 is manufactured. This solder-covered wire 5 consists of a core wire 2 and a solder IA coated with the core wire 2'tl. In order to improve the adhesion between the core wire 2 and the solder IA, the core wire 2 is preheated to about 100° C. before being supplied. When solder-covered wire 5 (core wire diameter is 5-1) with a wire diameter of 5.6 mm is drawn to a processing degree of approximately 99.87%, it becomes 0.211 (core wire 0.181). Become. Also,
High strength solder coated wire 5 can be obtained by sufficient work hardening.

Furthermore, in order to improve workability during wire drawing, it is necessary to improve adhesion at the interface, and the means to achieve this are (1) increasing the temperature during extrusion to diffuse both the core wire and solder materials; (2) performing a diffusion heat treatment after extrusion and before wire drawing; and (3) melt-plating the core wire in advance and extruding and covering the core with solder for more reliable adhesion.

〔Effect of the invention〕

According to the present invention, a bus bar is manufactured by extrusion coating solder on the periphery of a core wire that can provide a workability of 85% or more without heat treatment,
Since this generatrix wire is drawn at a processing rate of 85% or more without being heat-treated midway, it has become an industrially advantageous extrusion wire drawing method, and can extremely thick solder-covered wire without deteriorating its properties. It has the effect of being able to be manufactured at low cost and efficiently.

[Brief explanation of drawings]

FIG. 1 is a structural cross-sectional view of an extruder for carrying out the method of the present invention, and FIG. 2 is a cross-sectional view of a solder-coated wire manufactured by the method of the present invention. 1... Solder billet, 2... Core wire, 5
...-Solder coated wire, IA...Solder.

Claims (1)

[Claims] (1) Produce a bus bar by extruding and coating the circumference of the core wire with solder that can give a workability of 85% or more without heat treatment, and draw this busbar with a workability of 85% or more without heat treatment midway. A method of manufacturing an ultra-fine solder-coated wire, which is characterized by processing.