JPH06119815A - Solder corrosion resistant copper wire - Google Patents

Abstract

PURPOSE:To realize a ver small wire diameter without deterioration of mechanical strength and heat resistance and prevent generation of soldering fineness in soldering by coating a copper conductive wire in a predetermined thickness with niobium. CONSTITUTION:A copper conductive wire as a core material is coated in a predetermined thickness with niobium by a depositing or sputtering method, or an ion plating method. The coating thickness preferable ranges from 1.0 to 3.0mum. A tough pitch copper wire or an oxygen free copper wire is used as the copper conductive wire. Although not limited, a diameter of the wire to be used is arbitrarily selected according to miniaturization of electronic equipment and an outer diameter is generally selected within a range from 30 to 100mum. The copper conductive wire is coated with niobium, and then, the entirety is drawn into a given diameter, thus obtaining a wire diameter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solder corrosion resistant copper wire used for an ultra-fine magnet wire, and in particular, it can be made ultra-fine without deteriorating the mechanical strength and prevents solder thinning from occurring. Regarding edible copper wire.

[0002]

2. Description of the Related Art Copper wires have excellent conductivity and workability, and are therefore used in a wide range of applications, such as electric wire materials for transmission and distribution electric wires or magnet wires.

By the way, in recent years, as the miniaturization of communication equipment and electronic equipment has progressed rapidly, there has been an increasing demand for ultra-fine wire diameters such as ten and several μm with respect to the copper wire used for them. In particular, when copper wires are used as electrode lead wires, even with the miniaturization of electronic devices, a printed circuit board is used as an example to insert type parts (types in which terminals are inserted into board holes) to chip type parts (types mounted on the board). ), And the soldering method is becoming more and more surface-mounted, the requirements for solder thermal shock resistance and chip component electrode corrosion resistance are becoming stricter year by year in terms of ease of use by users. It has become to.

Among such demands, the conventional copper wire is TP
A C (tough pitch copper) or OFC (oxygen-free copper) material is used, and is formed to have a predetermined wire diameter according to downsizing of electronic devices and the like.

[0005]

However, according to the conventional copper wire, if the wire diameter is made ultra-fine, there is a disadvantage that conductivity, mechanical strength, heat resistance and the like are deteriorated. Further, when soldering is performed, there is a problem that solder thinning occurs in which the copper conductor is corroded by the solder.

[0006] Therefore, an object of the present invention is to provide a solder corrosion resistant copper wire which can be ultrafine in wire diameter without deteriorating conductivity, mechanical strength and heat resistance.

Another object of the present invention is to provide a solder corrosion resistant copper wire which does not cause solder thinning during soldering.

[0008]

In view of the above problems, the present invention makes it possible to make the wire diameter extremely fine without deteriorating the conductivity, mechanical strength and heat resistance, and at the time of soldering. ,
To prevent solder thinning, a solder corrosion resistant copper wire constituted by coating the outer periphery of a copper conductor wire with niobium at a predetermined thickness is provided.

The above-mentioned niobium is formed on the outer circumference of the copper conductor wire as a core material by vapor deposition or sputtering.
As another method, the ion plating method is also possible. Further, when the coating thickness is 1.0 μm or less, variations in solder corrosion resistance occur, and solder thinning easily occurs in a short time,
If the thickness is 3.0 μm or more, the yield decreases, so the coating thickness is preferably in the range of 1.0 to 3.0 μm. As the copper conductor wire, for example, a tough pitch copper wire, an oxygen-free copper wire or the like is used.

The wire diameter is not particularly limited, but the size to be used is arbitrarily selected in accordance with the miniaturization of electronic equipment and the like, and usually the outer diameter is selected in the range of 30 to 100 μm. The wire diameter can be obtained by coating the outer circumference of the copper conductor wire with niobium and then drawing the whole wire to a predetermined diameter.

Hereinafter, the solder corrosion resistant copper wire of the present invention will be described in detail with reference to the accompanying drawings.

[0012]

Example 1 A core material having a diameter of 1.0 mm and a purity of 99.9.
An oxygen-free copper wire of 96 wt% was used, and this was set on the substrate of a vacuum evaporation apparatus, the substrate temperature was 350 ° C., and the degree of vacuum was 2 × 1.
Niobium having a purity of 99.9 wt% at 0 ^-6 Torr was formed on the surface of the copper wire as a vacuum deposition film having a thickness of 2 μm.

A plurality of niobium-coated copper wires are prepared, and each niobium-coated copper wire has a diameter of 0.1 mm and 0.08 m.
m, 0.05 mm, and 0.03 mm, respectively, and then annealed at 300 ° C. for 30 minutes in an inert gas atmosphere. FIG. 1 shows the surface appearance of the obtained wire and the line analysis result of the cross-section coating layer. The film thickness is about 1 μm.
A niobium layer is formed.

Next, each of the niobium-coated copper wires thus obtained has the same size (diameter of 0.1) as each of the niobium-coated copper wires.
mm, 0.08 mm, 0.05 mm, and 0.03 m
For the conventional copper wire having m), the solder corrosion resistance by immersion in solder was considered. The test conditions are solder composition 60
% Sn-40% Pb, melting temperature: 380 ° C. ± 10 ° C., immersion in a controlled solder melting pot within a range of 1 to 50 seconds, and then withdrawing each to measure the rate of change in conductor diameter with immersion time.

FIG. 2 shows the measurement result. As can be seen from this graph, the niobium-coated copper wire of the present invention has a good solder corrosion resistance as compared with the conventional copper wire, the conductor diameter hardly changes even when the immersion time increases. It is shown that the solder thinning is prevented.

Further, the same experiment as above was carried out for the enamel-coated copper wire having the enamel coating on the outer periphery of the copper conductor wire serving as the core material and the niobium-coated copper wire of the present invention. The obtained niobium-coated copper wire of the present invention had good solder corrosion resistance.

[0017]

As described above, according to the solder corrosion resistant copper wire of the present invention, the outer circumference of the copper conductor wire is coated with niobium to a predetermined thickness, so that the electrical conductivity, mechanical strength and heat resistance are improved. It is possible to make the wire diameter ultra-fine without lowering the wire diameter, and to prevent the solder thinning from occurring when soldering is performed.

[Brief description of drawings]

FIG. 1 is an observation view showing a surface SEM appearance of a solder corrosion resistant copper wire and a line analysis result of a cross-section coating layer according to an embodiment of the present invention.

FIG. 2 is a graph showing measurement results of solder corrosion resistance.

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[Procedure amendment]

[Submission date] October 8, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0001

[Correction method] Change

[Correction content]

[0001]

FIELD OF THE INVENTION The present invention relates to an electrode lead for electronic equipment.
The present invention relates to a solder corrosion resistant copper wire used for a wire , and more particularly to a solder corrosion resistant copper wire that can be made ultra-fine without lowering mechanical strength and prevents solder thinning.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction content]

[0002]

2. Description of the Related Art Copper wires are excellent in conductivity and workability, and are therefore used in a wide range of materials such as transmission / distribution wires, electric wire materials for magnet wires , and electrode lead wires for electronic devices .

[Procedure amendment]

[Submission date] March 15, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

FIG. 1 is a surface appearance scanning electron micrograph of a solder corrosion resistant copper wire according to an embodiment of the present invention, and a photograph showing a line analysis result of a cross-section coating layer.

FIG. 2 is a graph showing measurement results of solder corrosion resistance.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yuji Kajikawa 4-10-1 Kawajiri-cho, Hitachi-shi, Ibaraki Hitachi Cable Ltd. Toyoura factory

Claims (2)

[Claims] 1. A solder corrosion resistant copper wire comprising a copper conductor wire and niobium (Nb) coated on the outer periphery of the copper conductor wire with a predetermined thickness. 2. The niobium is formed on the outer circumference of the copper conductor in an amount of 1 to 1.
The solder corrosion-resistant copper wire according to claim 1, wherein the copper conductor wire coated with a thickness of 3 μm and coated with the niobium is drawn to a predetermined diameter.