JPH10306358A - Straightened solder-plated beryllium copper wire and method of manufacturing the same - Google Patents

Abstract

(57) [Summary] [PROBLEMS] A long, straight spring for use with good solderability and corrosion resistance, good durability, tensile strength and spring characteristics without being affected by the radius of curvature of the original wire. Provided is a suitable straightened solder-plated beryllium copper wire and a method for manufacturing the same. The average content of beryllium is 1.8 to 2.0 wt.
% Of a beryllium copper wire base material to a beryllium copper wire, a mechanical straightening process F2 for imparting straightness to the beryllium copper wire, and a mechanical straightened beryllium copper wire by heat treatment in a reducing gas atmosphere. Soldering straightening step F3 for increasing the straightness of the solder, a molten solder plating step F4 for forming a molten solder plating film of 59-65wt% of the remaining lead in a beryllium copper wire in a reducing gas atmosphere, and a straightening solder. Curvature radius 2,500mm by winding step F5 of winding plated beryllium copper wire on a bobbin with a body diameter of 250mm or more
A straightened solder-plated beryllium copper wire having the above straightness is manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solder-plated beryllium copper wire and a method for producing the same, and more particularly, to a straightened solder-plated beryllium copper wire used for straight springs and having excellent tensile strength and straightness. The present invention relates to the manufacturing method.

[0002]

2. Description of the Related Art In recent years, as a core of information equipment media,
There is a growing demand for optical pickups that read and write data with light. In order to suspend the objective lens unit of the optical pickup, a suspension wire is required, and for example, a thin copper alloy wire for a straight spring having a diameter of about 0.1 mm is used.

Conventionally, a straightening method for obtaining a high straightness with a fine wire is a mechanical type in which a stationary or rotating straightening die applies repetitive stress of tension and compression to make the residual stress on the surface of the wire uniform and straighten straight. A so-called tension annealing means (hereinafter, abbreviated as annealing means) for removing the residual stress of the wire by heat and tensile force and straightening the wire is used. In addition, the wire after straightening was generally cut to a certain length and commercialized as a short product. Also, the surface of the wire was not plated.

[0004]

The copper alloy thin wire for a straight spring as the suspension wire is required to have high straightness, a constant spring strength, and good corrosion resistance. As described above, the conventional straightening method has some problems because it is either a mechanical means or an annealing means.

First, in the case of a mechanical means, a considerably excellent straightness, for example, a curvature radius of 1,
500mm was obtained. However, since the strain of the wire remains intact, when used for straight springs, reliability over the fatigue of the spring has been concerned for a long period of time.
Further, since there is no heat treatment step, the age hardening treatment of a precipitation hardening type alloy such as beryllium copper cannot be performed, and the wire cannot have the original tensile strength and spring fatigue strength.

Next, the straightening force is weak when only the annealing means is used. For example, only a straightness with a radius of curvature of about 1,000 mm can be obtained. Therefore, in order to obtain a high straightness, it is necessary to use a thin line (original line) having a certain degree of straightness, for example, a radius of curvature of 200 or more before straightening.

[0007] In the case of a thin wire, the wire is normally finished to a predetermined diameter from the bus bar by wire drawing using a diamond die, but it requires a great deal of skill to perform wire drawing while maintaining straightness. In addition, the wire after straightening is generally cut into a certain length, for example, about 40 mm, and is generally commercialized as a short product. Therefore, there are restrictions when using the wire. That is, when performing the injection molding by inserting the wire after the straightening, the wire can be used for the method of setting the wire for each shot, but cannot be used for the method of continuously performing the injection molding. In addition, since the surface of the wire is not plated, there is a problem that deterioration such as surface oxidation progresses in a long period of time. In addition, soldering had to be performed at a high temperature, for example, about 350 ° C., but when set at a high temperature, there was a problem that the wire material was eroded or softened to deteriorate the spring characteristics. Especially,
This problem becomes remarkable when the wire diameter is 0.1 mm or less,
There was a problem that sufficient durability and spring characteristics could not be obtained.

The present invention has been made to solve the above-mentioned various problems of the prior art, and it is possible to obtain good straightness without being affected by the radius of curvature of the original line before straightening. It is another object of the present invention to provide a straightened solder-plated beryllium copper wire which has good solderability, corrosion resistance, good durability, tensile strength and spring characteristics, is suitable for long and straight springs, and a method for producing the same. Aim.

[0009]

According to a first aspect of the present invention, there is provided a beryllium copper wire having an average beryllium content of 1.8 to 2.0 wt%, and a lead of 59 to 65 wt% with tin remaining on the outer peripheral surface. This is a straightened solder-plated beryllium copper wire having a straightness having a radius of curvature of 2,500 mm or more in which a molten solder plating film having a composition is formed.

In a second aspect, the present invention resides in a straightened solder-plated beryllium copper wire in which the diameter of the beryllium copper wire is 70 to 200 μm and the thickness of the molten solder plating is 0.1 to 1.0 μm.

[0011] In a third aspect, the present invention provides a method for drawing a beryllium copper wire base material having an average beryllium content of 1.8 to 2.0 wt% to a beryllium copper wire having a predetermined diameter; A mechanical straightening step (hereinafter abbreviated as a mechanical straightening step) for repeatedly bending a wire to impart straightness to the wire, and applying a tension to the mechanical straightened beryllium copper wire after the straightening step. Performing a heat treatment in a reducing gas atmosphere while adding, and further increasing the straightness of the wire by a tension annealing type straightening process (hereinafter abbreviated as an annealing type straightening process); and a straightening process after the annealing type straightening process. A molten solder plating step of forming a molten solder plating film by passing a beryllium copper wire through a molten solder bath of tin of 59 to 65 wt% in a reducing gas atmosphere; Barrel diameter of straightening solder plated beryllium copper wire is in the manufacturing process of straightening solder plated beryllium copper wire having a radius of curvature 2,500mm above straightness consisting winding step of winding the above bobbin 250mm after.

According to a fourth aspect of the present invention, in the molten solder plating step, after the molten solder is flown horizontally in a raised molten solder jet of a jet-type molten solder bath, excess solder is removed by a drawing tool. And a method for producing a straightened solder-plated beryllium copper wire that forms a uniform molten solder plating film.

In a fifth aspect, the present invention is characterized in that the mechanical straightening step, the tension annealing straightening step, the molten solder plating step and the winding step are continuous steps. Or, there is provided a method for producing a straightened solder-plated beryllium copper wire (hereinafter abbreviated as a straight-plated beryllium copper wire) according to 4.

[0014]

In the straight plated beryllium copper wire of the present invention according to the first aspect, the average content of beryllium is from 1.8 to 1.8.
Since the molten solder plating film is formed on the outer peripheral surface of the beryllium copper wire of 2.0 wt%, good solderability and excellent durability can be obtained. High durability and spring characteristics can be obtained. Further, at the time of soldering, there is no need to use a strong flux or to perform soldering at a high temperature, and there is no danger of damaging the spring property as a straight spring wire. Further, since the composition of the hot-dip solder plating film is 59-65 wt% of tin, the beryllium copper wire is free from solder erosion during hot-dip coating, and good plating can be formed. Also, during soldering work at the time of assembling the optical pickup, excessive solder erosion can be prevented. In addition, in the composition of the molten solder plating film, tin contained 59%
When the value is less than the above, the melting point of the solder is increased. Therefore, if the soldering is performed under the same condition, the solderability is deteriorated, which is not preferable. Further, since it has a straightness with a radius of curvature of 2,500 mm or more, it is particularly preferable for a straight spring.

In the straight plated beryllium copper wire of the present invention according to the second aspect, the thickness of the molten solder plating is 0.1%.
Since the diameter is about 1.0 μm, good solderability can be obtained without impairing the spring property of the straight-plated beryllium copper wire having a diameter of 70 to 200 μm. The reason for limiting the thickness of the molten solder plating film to 0.1 to 1.0 μm is that if the plating film thickness is less than 0.1 μm, sufficient solderability cannot be obtained, and This is because if the thickness is more than 1.0 μm, the spring characteristics deteriorate.

In the method of the present invention for producing a directly plated beryllium copper wire according to the third aspect, the outer peripheral surface of the beryllium copper wire having an average beryllium content of 1.8 to 2.0 wt% has tin of 59 to 65 wt%. A molten solder plating film having a residual lead composition is formed, and a straight plating beryllium copper wire having a straightness of 2,500 mm or more in radius of curvature can be easily manufactured. In particular, since the two-stage straightening process of the mechanical straightening process and the annealing straightening process is performed, the straightening is sufficiently performed. At the time of annealing type straightening process,
For example, by treating at 350 ° C., the precipitation hardening action of beryllium can improve the tensile strength of the wire and the fatigue strength of the spring. Also, in the winding step, the reason why the body diameter of the bobbin is limited to 250 mm or more is that if the body diameter is smaller than that, the wire is wound up in a short time after the wire is wound up, and the initial diameter is reduced. This is because good straightness is lost. In addition, when the body diameter of the bobbin is 250 mm or more, the straight-plated beryllium copper wire of the present invention does not change with time in the reduction of the radius of curvature due to winding until six months have elapsed. Therefore, if used within six months, the straight plated beryllium copper wire that has been fed out will be restored to the initial radius of curvature. In addition, a long wire rod wound on a bobbin is advantageous in a continuous forming step, and is easy to handle such as being transported.

In the method for producing a straight plated beryllium copper wire according to the fourth aspect of the present invention, in the molten solder plating step, the molten solder is made to travel horizontally in a raised molten solder jet of a molten solder bath to perform the molten plating. Since the excess solder is removed by the drawing tool, the solder plating can be performed uniformly, and the straightness of the wire is not affected.

In the method for producing a straight plated beryllium copper wire according to the fifth aspect of the present invention, the mechanical straightening step, the annealing straightening step, the molten solder plating step, and the winding step are continuous steps. A straight-plated beryllium copper wire can be manufactured efficiently without impairing the properties.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the present embodiment. FIG. 1 is a flow chart showing one embodiment of the method for producing a straight plated beryllium copper wire of the present invention. FIG.
(A) is a schematic diagram of a manufacturing apparatus used for the method for manufacturing a straight-plated beryllium copper wire of the present invention, and (b) is a schematic diagram of a straightening portion of the mechanical straightening machine of (a) of FIG. In these figures, 1 is a straightened solder plated beryllium copper wire, 1a is a beryllium copper wire, 1b is a mechanical straightened beryllium copper wire, 1c is a straightened beryllium copper wire, 2 is a storage reel, 2j is a shaft, 3 is a constant tension device, 4 is a feeder,
5 is a machine straightening machine, 5a and 5b are straightening piece heads, 6 is a horizontal pipe, 6i is a horizontal pipe inlet, 6o is a horizontal pipe outlet, and 6g.
Is a reducing gas inlet, 7 is a reducing atmosphere furnace, 8 is a stirrer, 8
a is a blade, 9 is a reducing gas atmosphere, 9g is a reducing gas outlet, 10 is molten solder, 10a is a raised molten solder jet, 11 is a drawing tool (diamond die), 12 is a molten solder bath (jet type melting). Solder bath), 13 is a bobbin having a body diameter of 250 mm or more, 14 is a winder, k is a smooth wheel, and wc is a tungsten carbide die.

Embodiment 1 Embodiment 1 will be described with reference to FIGS. First,
In a drawing step F1, a beryllium copper wire base material having a diameter of 0.25 mm is subjected to a drawing process by a conventional method.
A 10 mm beryllium copper wire 1a was wound around a winding frame 2 for storage (not shown). This beryllium copper wire (original wire)
Had a radius of curvature of R100 mm.

Next, as a wire supplying means to the mechanical straightening step F2, the storage reel 2 is set in the wire supplying device 4, and the reel 2 is rotated about the axis 2j of the reel 2 in the direction of the arrow to remove the spring 2 from the spring. Through the constant tension device 3 and then the smooth wheel k
The beryllium copper wire 1a was pulled out horizontally while applying a tension of 0 gf.

Subsequently, as a mechanical straightening step F2, straightening piece heads 5a and 5b each having five tungsten carbide dies wc provided with bearings as straightening portions and having a length of about 150 mm are respectively arranged in opposite directions. Beryllium copper wire 1 drawn to a straightening machine 5 with a rotatable structure and pulled out
a as shown in the figure and heads 5a and 5b
Bending was repeatedly performed by rotating the RPM, and mechanical straightening was performed. The radius of curvature of the mechanically straightened beryllium copper wire 1b after this step was R2000 mm.

Subsequently, as an annealing type straightening step F3,
The mechanical type straightened beryllium copper wire 1b is guided from the pipe inlet 6i into the horizontal pipe 6 of the reducing atmosphere furnace 7 having a length of 3 m, which is maintained at 350 ° C. by a heater (not shown), and tensioned from 100 to 150 g. , And run at 8 m / min., Led out from the pipeline outlet 6o, and straightened beryllium copper wire 1
c. At this time, hydrogen gas was fed from the reducing gas inlet 6g, and the inside of the horizontal pipeline 6 was set to a hydrogen gas atmosphere with a flow rate of 200 NL / Hr. The radius of curvature of the straightened beryllium copper wire 1c after this step was R2500 mm.

Subsequently, in a molten solder plating step F4, the straightened beryllium copper wire 1c led out from the conduit outlet 6o is communicated with the conduit outlet 6o, and the reducing gas atmosphere 9 and the reducing gas outlet 9g is provided and a stirrer 8
And a molten solder jet 10a of a jet-type molten solder bath 12 provided with a diamond die as a drawing tool 11.
a through a diamond die 11 having a clearance of 1 μm to remove excess molten solder and finish plating to a thickness of 0.15 μm. Wire 1 was produced. The molten solder 10 used was a eutectic solder of 63% tin-residual lead, and a hydrogen gas was used as a reducing gas.

Subsequently, in a winding step F5, the straightened solder-plated beryllium copper wire 1 was wound around a winding frame 13 having a body diameter of 250 mm by a winding machine 14. Note that a smooth pulley was used as a guide pulley for a traveling wire used in an appropriate position of each manufacturing apparatus in the mechanical straightening step F2 to the winding step F5.

COMPARATIVE EXAMPLE The manufacturing apparatus used for manufacturing the solder-plated beryllium copper wire of the following comparative example is not particularly shown because it is partially the same as the above-described embodiment. Comparative Example 1 First, as in Example 1, φ0.25 m was obtained by a conventional method.
m beryllium copper wire base material
A 0.10 mm beryllium copper wire was wound around a storage reel. Next, the wire supplying means was performed in the same manner as in Example 1, and subsequently, the same tension annealing type straightening as in Example 1 was performed to finish the radius of curvature to R1000 mm. Subsequently, the straightened beryllium copper wire was passed through the same eutectic solder bath as in Example 1, and the surface of the copper wire was subjected to solder plating. To a plating having a thickness of 0.15 μm to produce a solder-plated beryllium copper wire, which was wound around a bobbin.

Comparative Example 2 First, in the same manner as in Example 1, φ0.25 m
m beryllium copper wire base material
A 0.10 mm beryllium copper wire was wound around a storage reel. Next, the line supplying means is performed in the same manner as in the first embodiment, and subsequently, the same machine straightening machine as in the first embodiment is used, and the heads 5a and 5b are rotated in the opposite direction by 7000 RPM in the same manner as in the first embodiment, thereby repeating the operation. After bending, mechanical straightening was performed, and the radius of curvature was finished to R1500 mm. continue,
Solder plating was applied to the surface of the straight-corrected beryllium copper wire in the same manner as in Comparative Example 1, and the excess molten solder was removed with a drawing tool to finish the plating to a thickness of 0.15 μm. The wire was manufactured and wound on a bobbin.

Characteristics Test Various characteristics of the solder-plated beryllium copper wires obtained in Example 1 and Comparative Examples 1 and 2 were tested. The results are shown in Table 1 below. In addition, solder wetting time 0sec
Means that the solder is instantaneously wetted.

[0029]

[Table 1]

As is clear from Table 1 above, the straightened solder-plated beryllium copper wire obtained by the present invention has extremely good straightness, a tensile strength superior to that of the mechanical correction alone, or extremely poor wetting. It turns out to be good.

[0031]

The straightened solder-plated beryllium copper wire of the present invention can improve the straightness and tensile strength of a product as a straight spring wire for use in electronic parts and the like.
This greatly contributes to performance improvement, stabilization, and reliability improvement of a CD optical pickup component or the like using a straight spring wire having a diameter of 70 to 200 μm. In addition, a straight spring wire having a long and stable characteristic can be obtained by the manufacturing method of the present invention, thereby enabling automatic production of a suspension unit for an optical pickup and greatly contributing to improvement in productivity. It is. Therefore, the effect of contributing to industry is extremely large.

[Brief description of the drawings]

FIG. 1 is a flowchart showing one embodiment of a method for producing a straightened solder-plated beryllium copper wire of the present invention.

FIG. 2A is a schematic view of a manufacturing apparatus used in the method for manufacturing a straightened solder-plated beryllium copper wire of the present invention.
(B) is a schematic diagram of the straightening part of the machine straightening machine of (a).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Straightened solder plating beryllium copper wire 1a Beryllium copper wire 1b Mechanical straightened beryllium copper wire 1c Straightened beryllium copper wire 2 Storage reel 2j Axis 3 Constant tension device 4 Wire feeding device 5 Mechanical straightening machine 5a, 5b Straightening piece Head 6 Horizontal conduit 6i Horizontal conduit inlet 6o Horizontal conduit outlet 6g Reducing gas inlet 7 Reducing atmosphere furnace 8 Stirrer 8a Blade 9 Reducing gas atmosphere 9g Reducing gas outlet 10 Molten solder 10a Raised molten solder jet 11 Tools (diamond dies) 12 Molten solder bath (jet-type molten solder bath) 13 Reel with a body diameter of 250 mm or more 14 Winding machine k Smooth wheel wc Tungsten carbide die

Continuation of the front page (51) Int.Cl. ⁶ Identification symbol FI C23C 2/38 C23C 2/38 // C22F 1/00 625 C22F 1/00 625 627 627 630 630 630Z 630F 680 680 685 685Z 686 686Z 691 691Z

Claims (5)

[Claims] An average beryllium content of 1.8 to 2.
On the outer peripheral surface of a 0 wt% beryllium copper wire, tin 59-6
A molten solder plating film having a 5% by weight residual lead composition is formed,
A straightened solder-plated beryllium copper wire having a straightness with a radius of curvature of 2,500 mm or more. 2. A beryllium copper wire having a diameter of 70 to 200.
The straightened solder-plated beryllium copper wire according to claim 1, wherein the thickness of the molten solder plating is 0.1 to 1.0 μm. 3. An average beryllium content of 1.8 to 2.
A drawing step of pulling down a 0 wt% beryllium copper wire base material to a beryllium copper wire having a predetermined diameter; a mechanical straightening step of repeatedly bending the beryllium copper wire to impart straightness to the wire; A mechanical annealing straightening beryllium copper wire is subjected to a heat treatment in a reducing gas atmosphere while applying tension to the wire, and a tension annealing straightening straightening process for further increasing the straightness of the wire; and after the annealing straightening straightening process, Molten solder plating step of passing a beryllium copper wire straightened through a molten solder bath of 59-65 wt% tin in a reducing gas atmosphere to form a molten solder plating film, and a straightened solder after the plating step A winding step of winding a plated beryllium copper wire on a bobbin having a body diameter of 250 mm or more, characterized by a radius of curvature of 2,500 mm.
A method for producing a straightened solder-plated beryllium copper wire having the above straightness. 4. In the molten solder plating step, a uniform molten solder plating film is formed by moving a molten solder bath of a jet flow type in a raised molten solder jet in a horizontal state, and then removing excess solder with a drawing tool. The method for producing a straightened solder-plated beryllium copper wire according to claim 3, wherein: 5. The method according to claim 3, wherein the mechanical straightening step, the tension annealing straightening step, the molten solder plating step, and the winding step are continuous steps.
Or the method for producing a straightened solder-plated beryllium copper wire according to 4 above.