JPH04209413A - Conductor for extra fine coil - Google Patents

Abstract

PURPOSE:To obtain an extra fine conductor which is excellently insoluble in solder by using a copper wire or a copper alloy wire as the core material, and coating thereon with Fe or Co at a specified thickness, and furthermore, coating thereon with Ag or Cu at a specified thickness. CONSTITUTION:In an extra fine conductor having a wire diameter 0.05mm or less, a copper wire or a copper alloy wire is used as the core material, and it is coated with Fe or Co at a thickness of 0.05-2.0mum. Insoluble characteristic of the conductor in solder is thereby improved. Furthermore, it is coated with Ag or Cu at a thickness of 0.05-1.5mum. Solder wettability is thereby improved. As a result, a conductor for an extra fine coil which has an excellent solderability and the excellently insoluble in solder is obtained.

Description

[Detailed description of the invention]

[00011

[Industrial Field of Application] The present invention relates to a conductor for ultra-fine winding that has excellent resistance to solder thinning and solder wettability. [0002] Conventionally, winding wires use copper or copper alloy wire as a conductor, which is coated with enamel. When used, the enamel film on the terminal is removed and soldering is performed. Currently, the diameter of such winding wires is also becoming smaller, and the demand for ultra-fine winding wires with a diameter of 0.05 mm or less is increasing, and it is expected that the diameter will become even smaller in the future. [0003] When it comes to ultra-fine windings with a diameter of 0.05 mm or less, it becomes difficult to peel off the enamel film, and from the point of view of automating terminal processing, ultra-fine windings are soldered directly onto the enamel film. became. [0004]

[Problems to be Solved by the Invention] When soldering is performed directly on the enamel film as described above, the soldering temperature is kept quite high in order to remove the enamel with the solder. However, in the case of ultra-fine winding wire or ultra-fine winding wire with a wire diameter of 0.05 mm or less,
The surface area/volume ratio per unit length is quite large, and the conductor becomes thinner during the soldering process, which frequently causes the conductor to break away from the soldered part. Moreover, even if it does not break, the reliability after soldering is considerably poor. [0005]

[Means for Solving the Problems] In view of this, as a result of various studies, the present invention has a so-called solder melt resistance, which has good solderability and almost no thinning of the conductor even when soldered directly over the enamel film. We have developed an excellent ultra-fine winding conductor. [0006] That is, the present invention provides a conductor having a wire diameter of 0.05 mm or less, with a copper or steel alloy wire as a core material, and an F
It is characterized in that it is coated with e or Co to a thickness of 0.05 to 2.0 μm, and further coated with Ag or Cu to a thickness of 0.05 to 1.5 μm. [0007]

[Function] The conductor of the present invention has copper or copper alloy wire as the core material and coats Fe or Co to a thickness of 0.05 to 2.0 μm to improve the solder melting resistance of the conductor. Solder wettability and wire drawability are improved by coating Ag or Cu to a thickness of 0.05 to 1.5 μm. Therefore, in the present invention, the thickness of the Fe or Co film is limited to 0.05 to 2.01 tm, and the thickness of the Ag or Cu film is limited to 0.05 to 1.5 μm for the following reason. [0008] The Fe or Co coating increases the solder melting resistance, and the reason why the film thickness is set to 0.05 to 2.0 μm is because if it is less than 0.05 μm, the effect on the solder melting resistance is small. If it exceeds 0 μm, wire drawability will deteriorate.
This is because not only is it difficult to wire-draw a conductor with a wire diameter of 0.05 mm or less, but no further effect can be expected, and the cost simply increases. [0009] The Ag or Cu coating improves solder wettability and wire drawability, and the coating thickness is 0.05 to 1.5.
The reason why it is set as μm is that if it is less than 0405 μm, the effect on solder wettability and wire drawability is small, and if it exceeds 145 μm, no further improvement in solder wettability or wire drawability can be expected, which increases cost. be. [00101 The reason why the wire diameter of the conductor was limited to 0.05 mm or less is as follows. In other words, the wire diameter is 0
．． This is because when the wire diameter is larger than 0.05 mm, thinning due to soldering hardly becomes a problem, but when the wire diameter is 0.05 mm or less, thinning due to soldering suddenly becomes a problem. [00111 For the core material, copper wire such as tough pitch steel (TPC) or oxygen-free copper (OFC) is used, and other materials include Ag.
The use of copper alloy wires such as copper alloy wires, Sn alloy wires, Indium copper alloy wires, etc. are effective in improving strength and heat resistance. Also Fe or Co coating,
Electroplating is suitable for Ag or Cu coating. [0012]

[Example] A copper or copper alloy wire with a diameter of 0.2 mm shown in Table 1 was electroplated with Fe or CO to a diameter of 0.025 mm and a desired plating thickness, and then Ag or Cu
was electroplated. This is drawn by a continuous wire drawing machine to a diameter of 0.
The conductor was made into a conductor of 0.025 mm, and the surface was coated with polyurethane to make an ultra-fine winding wire. In addition to examining the wire drawability of the conductor of the winding thus produced, the conductor's solder wettability and conductor melting time were measured using the winding as a test material, and the strength of the conductor on hard wood was also measured. The manufacturing costs of windings were compared. These results are shown in Table 2 in comparison with a conventional ultrafine winding using TPC, which is a conventional conductor. (00131 solder wettability and conductor dissolution time are 50%
Figure 1: 5N-50% PB alloy solder bath kept at 380°C
Using the testing machine shown in Figure 1, the winding (
2) was immersed in a solder bath (3), and the solder wetting time and solder wetting load of the conductor were determined. Immersion speed is 25mm/sec
The immersion depth was 12 degrees, and the immersion time was 1 second. In addition, melting time is the time until the conductor melts and disappears. Good wire drawability is marked with ◎, and poor wire drawing property is marked with Those with higher values are indicated with an O mark, higher ones with a Δ mark, and even higher ones with an X mark. [0014]

[Table 1] [00161 As is clear from Table 2, the present invention conductor No.
1 to 18 have solder wettability compared to conventional conductor No. 26,
It can be seen that the solder wetting load is excellent, the melting time of the conductor is long, and the melting resistance is excellent. [0017] On the other hand, comparative conductor No. 19 with a thin Fe coating thickness had no improvement in solder melting resistance at all. Comparative conductor No. 21, which has a thin coating of Ag, and comparative conductor No. 23, which has a thin coating of Cu, have poor wire drawability, cracks, etc. are observed on the surface, and the solder wetting time and solder wetting load are also poor. bad. Comparative conductor No. 20, which had a thick Fe coating, had extremely poor wire drawability, and it was difficult to draw the wire to a diameter of 0.05 mm or less. Moreover, the cost is also considerably high. Comparative conductors No. 22 and C with thick Ag coating thickness
Comparison conductor N0624 with thick coating thickness of u is Ag and C
There is no effect of improving the solder wetting time and solder wetting load by increasing the thickness of u, and only the cost increases. Comparative conductor No. without coating with Ag or Cu after coating with Fe
, No. 25 had extremely poor solder wettability and was also poor in wire drawability, making long wire drawing impossible. [0018] (Effects of the Invention) As described above, according to the present invention, it is possible to obtain a conductor for ultra-fine winding that has good solderability and excellent solder melting resistance, and has a remarkable effect industrially. It is.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of a testing machine for testing the solderability of the conductor of the present invention.

[Explanation of symbols]

1 Chuck 2 windings 3 Solder bathtub

Claims (1)

[Claims] Claim 1: A conductor with a wire diameter of 0.05 mm or less,
Copper or copper alloy wire is used as the core material, and 0 Fe or Co is added on top of it.
．． Coated with a thickness of 05 to 2.0 μm, and further coated with Ag
Or a conductor for ultrafine winding characterized by being coated with Cu to a thickness of 0.05 to 1.5 μm.