JPH0760337A - Method for drawing wire and device therefor - Google Patents

Abstract

PURPOSE:To provide a wire drawing method being suitable even for an allay of Au-Sn, Au-Si, etc., which is brittle and whose tensile strength is rapidly reduced when it is heated. CONSTITUTION:A die 1 and a blank wire Lp are heated with a heating device 2, and the ductility is increased. On the other, the worked wire Lf immediately after being drawn from the die 1 is cooled in a cooling device and the tensile strength is increased. In such a manner, the working is easily made by increasing the ductility, on the other side, breaking of the wire can be prevented by immediately cooling it after drawing and increasing the tensile strength. Accordingly, the wire drawing of Au-Sn alloy, etc., are made possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for drawing a brittle alloy such as Au-Sn.

[0002]

2. Description of the Related Art Conventionally, a wire drawing method has been widely used as a method for manufacturing a wire rod.

The wire drawing method is a method in which a wire material before processing is drawn through a hole smaller than the diameter of the wire material to reduce the diameter of the wire material to the diameter of the hole. In the present specification,
The wire material before processing by the die is sometimes called "material wire", and the wire material after processing is called "working wire".

[0004]

However, in order to apply the above-mentioned drawing method, the material wire itself has sufficient ductility for drawing, and at the same time, the processed wire has a tensile strength sufficient to withstand the drawing. Must have this is,
In order to pull through the hole, it is necessary to pull with a force corresponding to the ductility, but if the magnitude of this force exceeds the tensile strength, the processing line will be cut.

In principle, even an alloy having a low ductility should be able to be drawn if it is drawn within the above tensile strength range. However, when trying to increase the drawing speed, the tensile load increases, so in order to perform drawing at a speed that is practically sufficient, these (ductility,
The absolute value of the (tensile strength) also needed a certain size.

Therefore, conventionally, a brittle material (for example, Au) has been used.
-Sn, Au-Si, Au-Ge, etc.) could not be drawn. It is possible to increase the ductility by heating, but since the tensile strength of these materials decreases significantly with increasing temperature,
After all, the wire drawing process was difficult. In particular, the difficulty increases as the wire diameter decreases. For example, A
As for the u-Sn wire, at present, no wire rod having a diameter smaller than φ0.25 mm has been obtained.

In spite of the present circumstances, alloys such as Au-Sn which are widely used as a brazing material have been strongly required to have an extremely fine wire material in order to promote automation of the brazing process.

In the present invention, a material which has conventionally been difficult to be drawn due to a problem of balance between ductility and tensile strength (eg, Au-Sn, Au-Si, Au-Ge, etc.).
An object of the present invention is to provide a wire drawing method and apparatus applicable to the above.

The present invention is directed to Au-Sn used for brazing.
It is an object of the present invention to provide a wire rod made of a low melting point alloy such as the above, particularly a wire rod suitable for brazing a fine portion.

[0010]

The present invention has been made in order to achieve the above-mentioned object, and in one aspect thereof, in a wire drawing apparatus for reducing the diameter of a wire rod, a wire rod as a material is sent out. A device, a die having a hole for performing plastic working to reduce the diameter of the wire rod, a wire rod sent from the feed device through the hole at a predetermined speed, and a pulling device. A winding device for winding the wire rod drawn through the hole by means, a first temperature control device for setting a temperature of a portion of the wire rod located in the hole to a predetermined range, Second, to keep the temperature in the part immediately after being drawn from the die below a predetermined value
And a temperature control device of (1) are provided.

The first temperature control device comprises a heating means for heating the die and / or the wire rod located in front of the die, and the second temperature control device includes a heating means for heating the wire rod. It is preferable to provide a cooling means for cooling a portion immediately after being pulled out (hereinafter referred to as "cooled portion").

The cooling means cools the cooled portion to a temperature at which the tensile strength of the cooled portion is at least higher than the tension applied to the cooled portion between the pulling device and the die. It is preferably one.

The cooling means may be a means for cooling by bringing a cooling fluid into contact with the portion to be cooled.

As a second aspect of the present invention, in a wire drawing method for drawing a wire through a hole in a die to reduce the diameter of the wire, the temperature of the wire when passing through the hole is within a predetermined range. And a temperature of the wire rod immediately after being pulled out from the die of the wire rod is set to a value equal to or lower than a predetermined value.

As a third aspect of the present invention, in a wire drawing method of drawing a wire material through a hole of a die to reduce the diameter of the wire material, a fluid is sprayed onto the wire material immediately after being drawn out from the die. A featured drawing method is provided.

[0016]

Operation: The temperature of the wire or die is controlled (heated) by the first temperature control device so that the temperature is within a predetermined temperature range. As a result, the ductility of the wire at the position of the hole of the die can be made suitable for drawing and the processing can be facilitated.

Further, immediately after the plastic working, that is, immediately after coming out of the die, the temperature of the wire is controlled (cooled) by the second temperature control device. In this case, the cooling is performed until the tensile strength of the cooled portion becomes at least higher than the tension applied to the cooled portion. As a result, the tensile strength of the wire is restored, and the wire is not broken. The cooling can be performed, for example, by spraying a fluid.

[0018]

An embodiment of the present invention will be described with reference to the drawings.

In the wire drawing apparatus of the present invention, attention is paid to the fact that the conditions necessary for carrying out wire drawing processing (note: the characteristics required for the material itself here) are not necessarily the same throughout all the processes, and each process is Is characterized in that the condition control is independently performed. That is, control is performed so as to create a state of higher ductility in the portion where the wire drawing is performed, and a state of high tensile strength in the portion immediately after the wire drawing. In practice, this is achieved by independently controlling the temperature before and after drawing.

The present embodiment will be specifically described below.

FIG. 1 shows an outline of the wire drawing apparatus of this embodiment. The device includes a die 1, a heating device 2, and a cooling device 3.
And a feeding device 6, a reel 7, a capstan 8, and a winding device 9.

The die 1 is for performing plastic working (drawing) to reduce the diameter of the wire. In this die 1,
The hole 10 corresponding to the diameter of the target wire is provided, and the raw material wire Lp is made into a wire having a predetermined diameter by passing through the hole 10.

The heating device 2 is for heating the die 1 and the material wire Lp in order to facilitate drawing. By the temperature control (in this case, heating), the material wire L
The temperature of the portion of p located in the hole 10 may be a temperature having ductility suitable for drawing. Although the tensile strength of the material wire Lp is reduced due to the heating, a large amount of tension is not applied to the material wire Lp on the front side of the die 1, so that no breakage or the like occurs.

As shown in FIG. 2, the heating device 2 of this embodiment includes a base 20 having a groove 200 for passing the material wire Lp,
The heater 22 is mounted inside the base 20. Further, the heating device 2 includes a temperature sensor 24.
And a temperature control circuit (not shown).
The inner wall surface of 00 and the temperature of the die 1 can be precisely controlled. As the heater 22 and the temperature control mechanism itself, those which are normally used can be used as they are. The die 1 is installed at one end of the groove 200. The specific configuration of the heating device is not limited to this, and for example, hot air may be blown. The heating device 2 corresponds to the "first temperature control device" in the claims.

Further, in this embodiment, the base 20 is provided with a plurality of grooves 200a to 200c and dies 1a to 1c.
A wire rod can be reciprocated between a capstan 8 and a reel 7, which will be described later, so that a multi-step drawing process can be continuously performed.
In addition, as a result of such a device configuration, heating in each stage is substantially achieved by one heating device 2 and one cooling device 3.
Cooling can be done, equipment cost can be reduced,
In addition, since the temperature can be managed collectively, the control becomes easy. Further, the area occupied by the device can be reduced.

The cooling device 3 is for cooling the processing line Lf immediately after passing through the hole 10 of the die 1. Hole 1
The processing line Lf that has passed 0 is cooled again, and the tensile strength (per unit cross-sectional area) is increased again. Such temperature control (here, cooling) is performed because the tensile load by the capstan 8 is directly applied to the processing line Lf after passing through the die 1, so that the tensile strength that can withstand this is applied. First, it is required. If the cooling by the cooling device 3 is performed on the wire portion that has already been distant from the die 1,
The processing line L on the side closer to the die 1 than the cooled part
There is a risk that f may be cut. Therefore, it is necessary to perform the cooling to the wire portion immediately after coming out from the hole 10 as much as possible. Although the ductility of the processing line Lf decreases as the temperature decreases due to the cooling, it does not become an obstacle because the die 1 has already passed.

In the present embodiment, the cooling device 3 mainly comprises a blower 30 and a nozzle 32 (see FIG. 2). The nozzle 32 is directed to the outlet of the hole 10 and concentrates the air generated by the blower 30 to the portion to immediately cool the wire portion immediately after being pulled out from the hole 10. It is composed. In this embodiment, a nozzle 32 having an inner diameter of the tip opening of 1.5 mm is used. The specific configuration of the cooling device 3 is not limited to this, and for example, if a heat pump is provided and cold air is blown, more efficient cooling is possible. Further, the liquid may be cooled using water, oil, liquid nitrogen or the like. The cooling device 3 corresponds to the "second temperature control device" or the cooling means in the claims. Further, the wind (air), water, oil, liquid nitrogen, etc. referred to here correspond to the cooling fluid in the claims.

The heating and cooling conditions are determined based on the relationship with the tensile strength, tension, etc. of the processing line Lf. This point will be described later in detail using specific data.

The feeding device 6 sequentially feeds the material wire Lp wound around the reel 60 while applying back tension. As described above, the tensile strength of the material wire Lp is lowered by the heating by the heating device 2.
Therefore, the feeding is preferably performed while controlling so that the tension (back tension) applied to the material wire Lp does not become too large.

The capstan 8 draws the processing line Lf to draw the die 1 with respect to the material line Lp connected to it.
The wire drawing process is performed by. The capstan 8 is provided with a driving means such as a motor, and draws the processing line Lf by rotating with its own driving force. Therefore, the drawing speed can be adjusted by controlling (or changing) the rotational speed and the friction coefficient of the capstan 8 surface. The rotational force of the capstan 8 is applied to the processing line Lf as a tensile load as it is. When the drawing speed is high, the tension applied to the processing line Lf becomes large, and the processing line Lf may be cut. Therefore, the processing line Lf must be drawn while controlling so as not to exceed the tensile strength of the processing line Lf after cooling. Further, if the drawing speed fluctuates, the thickness of the machining line Lf becomes non-uniform. Particularly in the present embodiment, the change in the drawing speed has a large effect because it also changes the above-mentioned heating and cooling conditions. Therefore, the capstan 8 needs to be controlled with the highest possible accuracy so as to rotate at a predetermined speed. The degree of heating of the material wire Lp and the degree of cooling of the processing wire Lf change depending on the drawing speed. Therefore, the drawing speed must be determined in consideration of the heating and cooling capacities of the heating device 2 and the cooling device 3. I won't. The capstan 8 corresponds to the pulling device in the claims.

The reel 7 is for re-folding the processing line Lf folded back by the capstan 8 and guiding it to the die 1 of the next stage. The reel 7 itself rotates according to the movement of the machining line Lf, and does not rotate by itself with a driving force.

As described above, in the present embodiment, since the drawing process of three steps is continuously performed, the processing line Lf is folded back by the capstan 8 and the reel 7 and guided to the die 1 of the next step. Therefore, the processing line Lf of the previous stage becomes the material line Lp for the next stage. As described above, it is possible to obtain an effect that work efficiency is improved by continuously performing the multi-stage drawing process. Note that the number of processing steps can be appropriately changed as necessary.

The winding device 9 is for winding the finally completed processing line Lf on the reel 90. Needless to say, the winding by the winding device 9 is also performed while controlling so as not to apply an excessive tension to the processing line Lf after leaving the final stage.

The drawing process will be described.

As a preparatory step, the heater 22 of the heating device 2 is caused to generate heat to heat the inner wall surface of the groove 200 of the base 20 and the die 1 to a predetermined temperature. Also,
The blower 30 of the cooling device 3 is also operated so that it can be cooled no matter when the wire rod comes out of the die 1.

After the above preparations are completed, the capstan 8 starts drawing the wire. At the same time, the material wire Lp wound on the reel 60 is sequentially fed by the feeding device 6.

Material line Lp sent from the reel 60
Is heated to a certain temperature by radiant heat or the like received from the inner wall surface of the heating device 2 when passing through the groove 200. Since the heating device 2 includes the temperature control circuit, the material wire Lp is not heated more than necessary.

The heated material wire Lp is drawn by passing through the similarly heated die 1. Since the material wire Lp has high ductility, drawing is easy.

The processing line Lf drawn from the die 1 is
Immediately after leaving the die 1, the temperature can be lowered to a predetermined temperature or lower by the cooling device 3. As a result, the processing line Lf recovers the tensile strength that can withstand the tension received at this time, and is drawn by the capstan 8 without breaking. Thereafter, the processing line Lf is folded back on the capstan 8 and the reel 7, and the drawing process is performed by the die 1 of the next stage in the same procedure. As a matter of course, the heating of the material wire Lp and the cooling of the processing wire Lf are performed again for each stage.

After the final stage drawing process, the processed line Lf is wound around the reel 90 of the winding device 9 as it is without being folded back by the capstan 8.

Specific conditions for heating and cooling for enabling the above-described wire drawing process will be described.

In order to perform wire drawing, the tensile strength of the wire Lf must be larger than the tension actually applied to the wire Lf.

The tensile strength of Lf of the wire is
It changes depending on its diameter and temperature. φ60um Au
The relationship between the tensile strength of the (80 wt%)-Sn (20 wt%) wire and the temperature is shown in FIG. Even if cooling is performed by the cooling device 3, it is considered that the processing line Lf is weakest in the portion to be cooled (= the portion immediately after passing through the die 1). The data shown in the figures were measured by using a tensile tester, and the measurement was performed by heating the entire test piece instead of heating only a part of the test piece.

On the other hand, the magnitude of the tension actually applied to the processing line Lf is not limited to the diameter and the drawing speed, but the material line Lf.
It depends on the ductility of p (ie temperature). Therefore,
φ62.1um Au (80wt%)-Sn (20wt
%) Wire is drawn at a speed of 1 m / min, and φ6
FIG. 4 shows the result of measurement of the relationship between the tension applied to the processed wire Lf and the temperature of the material wire Lp when the wire material of 0 um is used. In the measurement, the processing line Lf is cooled in order to prevent the processing line Lf from being cut. However, since the cooling is performed only on the rear side of the die, the measurement result is affected. Never give.

By comparing these FIG. 3 and FIG. 4, the heating and cooling conditions can be determined. For example, when the material wire Lp is heated to 200 ° C. by the heating device 2, it is found that a tension of about 30 gf is applied to the processing wire Lf (see FIG. 4). Therefore, the processing line Lf
Has to have a tensile strength of 30 gf or more even in the weakest part, that is, in the part where cooling is performed. And it can be seen from FIG. 3 that the processing line Lf must be cooled to at least about 140 ° C. for that purpose.

Further, for example, when the material wire Lp is heated to 70 ° C. by the heating device 2, it is found that a tension of about 63 gf is applied to the processing wire Lf (see FIG. 4). As can be seen from FIG. 3, the processed line Lf has a tensile strength of 160 gf at 70 ° C. Therefore, in this case, cooling is not necessary.

However, in the actual manufacturing process, in addition to the pulling force, various forces such as a twisting force and a shock due to the start and stop of the apparatus are applied. Therefore, the temperature calculated from FIGS. It is necessary to perform cooling to a lower temperature. The heating temperature can be set to an appropriate value in consideration of the required drawing speed, the cooling capacity of the cooling device 3, and the like. It goes without saying that the heating temperature should not be too close to the melting point. Here, only the data when the drawing speed is 1 m / s is shown. However, as already described, if the other conditions are the same, increasing the drawing speed also increases the tension applied to the machining line Lf (Note: this means that the curve in FIG. 4 shifts to the upper side). Equivalent to). Therefore, in order to increase the drawing speed, it is necessary to increase the cooling.

The degree of heating of the material wire Lp and the cooling of the processing wire Lf vary depending on the sending speed and the winding speed (drawing speed). For example, if the drawing speed becomes faster, the time for receiving heating / cooling becomes shorter, so that it becomes difficult to perform heating / cooling accordingly. Further, the amount of frictional heat generated during drawing also changes depending on the drawing speed and the like. Therefore, the actual drawing speed and temperature control (heating, cooling) must be set after comprehensively judging various conditions.

The inventor of the present application actually performed a wire drawing process using the wire drawing apparatus to which the present invention was applied. As a result, φ1.0 mm
The Au (80 wt%)-Sn (20 wt%) wire can be finally made into an ultrafine wire having a diameter of 18 μm and a length of 200 m, and the wire was not broken during the process. The 20
The length of 0 m is because the length of the material wire used at this time was limited, and was not due to the disconnection. The specific conditions for wire drawing at this time are as follows.

Number of stages of die: 50 stages Heating temperature: 70 to 200 ° C. Cooling method: Blow cooling (20 to 30 ° C. air, 4 to 7 liters / minute, nozzle tip inner diameter 1.5 mm) Drawing speed: 1 to 20 m / In the embodiment described above, the wire is heated to facilitate the drawing. Further, by cooling the wire rod immediately after passing through the die, its tensile strength is increased and wire breakage is prevented. Therefore, it is possible to continuously carry out the wire drawing process without causing the wire breakage while ensuring a practical wire drawing speed.

The explanation so far is Au (80 wt%)-
The description has been made by taking Sn (20 wt%) as an example. However, other than this, a material that is brittle at room temperature and whose ductility increases with temperature rise, but whose tensile strength decreases significantly (for example, Au-Si, Au-Ge, etc.)
It is similarly applicable to the wire drawing process.

In the wire drawing apparatus of the above-mentioned embodiment, only a cooling apparatus and a heating apparatus need to be added to the conventional wire drawing apparatus, so that newly required equipment cost can be reduced. Therefore, the manufacturing cost can be suppressed. The specific configurations and arrangements of the heating device 2, the die 1, and the cooling device 3 are merely examples, and the present invention is not limited thereto.

The Au (80 wt.
%)-Sn (20 wt%) or other low melting point alloy ultrafine wire can be used as a brazing brazing material. If the ultrafine wire of the low melting point alloy is used, the brazing material can be continuously supplied, so that the brazing process can be automated and speeded up.

It should be noted that in the above-mentioned embodiment, the drawing has been described for the material in which the sufficient ductility can be obtained only by increasing the temperature, but the tensile strength is largely lowered. However, the present invention can be applied to a material, such as solder, which has sufficient ductility for wire drawing even at room temperature but cannot be drawn because of insufficient tensile strength. For example, for solder, it suffices to perform cooling immediately after drawing with a die. Since the solder has sufficient ductility even at room temperature, it is not necessary to heat the die or the like.

[0055]

As described above, according to the present invention,
A material whose tensile strength decreases more than the ductility increases with increasing temperature (for example, Au-Sn, A
A low melting point alloy such as u-Si or Au-Ge) can be drawn. In addition, since the device only needs to add a cooling device to the conventional drawing device, the equipment cost and the manufacturing cost can be suppressed.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of a wire drawing apparatus that is an embodiment of the present invention.

FIG. 2 is a perspective view showing details of a heating device 2, a die 1, and a cooling device 3.

FIG. 3 is a graph showing the relationship between the tensile strength of Au—Sn wire and temperature.

FIG. 4 is a graph showing the relationship between the tension applied to the processing line Lf when drawing an Au—Sn wire and the heating temperature of the material wire Lp.

[Explanation of symbols]

1: Dice, 2: Heating device, 3: Cooling device, 6:
Sending device, 7: reel, 8: capstan 9:
Winding device, 10: hole, 20: base, 22: heater, 24: temperature sensor, 30: blower, 32:
Nozzle, 60: reel, 90: reel, 200:
Groove, Lp: Material wire, Lf: Wire material

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shiro Kono 2-10-10 Fukuura, Kanazawa City, Yokohama City, Kanagawa Prefecture Noge Electric Industry Co., Ltd.

Claims (6)

[Claims] 1. A wire drawing apparatus for reducing the diameter of a wire rod, a feed-out device for feeding out a wire rod as a material, a die having a hole for plastic working for reducing the diameter of the wire rod, and the above-mentioned feed-out device. A wire rod sent from the wire rod through the hole at a predetermined speed, a winding device that winds the wire rod drawn through the hole by the pulling means, and inside the hole of the wire rod. A first temperature control device for setting the temperature of a portion to be located in a predetermined range, and a second temperature control device for setting the temperature of a portion of the wire rod immediately after being pulled out from the die to a predetermined value or less. And a wire drawing device. 2. The first temperature control device comprises a heating means for heating the die and / or the wire rod at a position in front of the die, and the second temperature control device comprises the heating means for the wire rod. Immediately after being pulled out from the die (hereinafter referred to as "cooled portion")
The wire drawing apparatus according to claim 1, further comprising: a cooling unit that cools the wire. 3. The cooling means controls the cooled portion to a temperature at which the tensile strength of the cooled portion is at least higher than the tension applied to the cooled portion between the pulling device and the die. The wire drawing apparatus according to claim 2, wherein the wire drawing apparatus is cooled. 4. The wire drawing apparatus according to claim 2, wherein the cooling means cools the portion to be cooled by bringing a cooling fluid into contact with the portion to be cooled. 5. A wire drawing method for reducing the diameter of a wire rod by drawing the wire rod through a hole in a die, wherein the temperature of the wire rod when passing through the hole is set within a predetermined range, and The wire drawing method, wherein the temperature of the wire rod immediately after being drawn out from the die is set to a predetermined value or less. 6. A wire drawing method for drawing a wire through a hole in a die to reduce the diameter of the wire, wherein a fluid is sprayed onto the wire immediately after being drawn out from the die.