JPH0947919A - Apparatus and process for manufacturing fine metal wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus and process for manufacturing metal fine metal wire, which is able to shorten processing time, fine a wire, and heighten precision in shape. SOLUTION: This fine metal wire manufacturing apparatus comprises a metal wire feeding mechanism 2 for feeding a metallic wire raw material to be processed into a fine wire, an electrode portion for applying plasma etching processing to the metallic wire raw material 1a fed out from the metal wire feeding mechanism 2, a metal wire winding mechanism 4 for winding a metal fine wire 1b processed and fined at the electrode portion 3 into a fine wire, and a reaction vessel 5 for containing the metal wire feeding mechanism 2, the electrode portion 3, and the metal wire winding mechanism 4. Near the electrode portion 3, a reacting gas is flowed to transform it into plasma by applying a high frequency electric field so as to etch the metallic wire material 1a by reacting with it, performing the manufacture of the fine wire 1b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal wire manufacturing apparatus and a manufacturing method thereof, which utilize plasma etching.

[0002]

2. Description of the Related Art Generally, thin metal wires used for bonding wires for ICs and electrode wires for wire electric discharge machining are
It is manufactured using the drawing method. The drawing method is
This is a method of manufacturing a wire rod, a rod or a pipe having a cross-sectional shape equal to that of a die hole by pulling a metal material through a tool having a hole called a die and pulling the metal material. This drawing process includes a cold drawing method and a hot drawing method.For example, a material that is difficult to deform at room temperature, such as tungsten, is drawn hot, but in many materials, a cold drawing method is used. Pull out between. In such drawing, wire drawing is performed by passing the material through a die, and thus the final finished diameter dimension is determined by the size of the die. Therefore, it is necessary to replace the die every time the setting of the diameter of the processed product changes. The cross-sectional reduction rate that can be changed by one drawing process is about 10 to 15%, although it depends on the material. Therefore, the larger the difference between the diameter of the material before being drawn and the diameter of the material at the time of final finishing, the more it is necessary to repeat the drawing process. Further, in a typical drawing process, a lubricant is used to reduce drawing stress when drawing a material from a die. For example, in the case of tungsten or molybdenum, a lubricant is applied to the material and then heated together with the material to form a lubricating coating on the surface of the material. Therefore, depending on the application, it is necessary to remove this coating in the final finishing step. Further, in the case of other metal materials, since an oil-based lubricant is used, the surface of the processed product at the time of finishing is contaminated by the lubricant. Therefore, a cleaning process is required to remove this dirt. Furthermore, in the drawing process, strain due to plastic deformation occurs during the process. Therefore, heat treatment for releasing the strain is necessary.

On the other hand, as a method of processing an electric conductor using plasma etching, as described in Japanese Patent Laid-Open No. 3-222210, the surface of the electric conductor is undulated by using plasma etching. There is disclosed a method of forming the uneven portion having In this method, only the surface layer of the electric conductor is processed by plasma etching.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention As mentioned above,
In the conventional apparatus and method for manufacturing a thin metal wire by the drawing method, it is necessary to replace the die every time the setting of the diameter of the processed product changes. Further, the larger the difference between the diameter of the material before being drawn and the diameter of the final finished material, the more it is necessary to repeat the drawing process. Furthermore, since a lubricant is used to reduce the drawing stress when the material is drawn from the die, a cleaning step for removing the lubricant is required in the final finishing step. Furthermore, in the drawing process, strain occurs due to plastic deformation during the process, and therefore heat treatment for releasing the strain is required. Therefore, a die replacement step, a cleaning step, a heat treatment step, and the like are required, and the number of steps increases, which causes a problem that the time required for processing becomes long.

On the other hand, for example, thin metal wires used for bonding wires for ICs have been required to be finer with the high integration of IC chips. In addition, when a metal thin wire is used as an electrode wire for wire electric discharge machining, an electrode wire with a smaller wire diameter than the conventional one is used due to the demand for miniaturization of the work piece and miniaturization of the tool diameter due to high precision. Is becoming popular. As described above, the thin metal wire obtained as a processed product is required to be thin and highly accurate.

Therefore, the object of the present invention is made in view of the above-mentioned circumstances, and a metal thin wire manufacturing apparatus capable of shortening the processing time, thinning the wire, and improving the accuracy of the shape. And to provide a manufacturing method thereof.

[0007]

SUMMARY OF THE INVENTION The present invention has been made based on the above-mentioned problems, and provides an apparatus for producing a fine metal wire having a minute diameter by reacting a rod-shaped metal member with a reaction gas which has been turned into plasma. A plasma generating means for generating a reaction gas that has been turned into plasma for plasma-processing the rod-shaped metal member, a moving mechanism for moving the rod-shaped metal member in its longitudinal direction, the plasma generating means, and a moving mechanism. A metal thin wire manufacturing apparatus, comprising: a reaction container that houses at least a plasma generating means.

Further, according to the present invention, the rod-shaped metal member is reacted with any one of atoms and molecules to generate a plasma reaction gas for generating a volatile compound, and the rod-shaped metal member. In a metal thin wire manufacturing apparatus having a moving mechanism for moving a metal member in a longitudinal direction thereof, a plasma generating means, and a reaction container accommodating at least the plasma generating means of the moving mechanism, the rod-shaped metal member is provided. The metal thin wire manufacturing method comprises manufacturing a metal thin wire having a minute diameter by moving the rod-shaped metal member by the plasma generating means at a predetermined speed by the moving mechanism and reacting the reaction gas turned into plasma.

According to the present invention, the metal thin wire is manufactured by plasma-etching the rod-shaped metal member with the plasma-generated reaction gas generated by the plasma generation means while moving the rod-shaped metal member by the moving mechanism. Therefore, the die replacement step, the cleaning step for removing dirt, and the heat treatment step for releasing processing strain can be eliminated. Therefore, the processing time is shortened.

Further, according to the present invention, there are provided a wire diameter measuring means for measuring the diameter dimension of the rod-shaped metal member, and a control means for controlling the feeding speed for feeding the rod-shaped metal member and the winding speed for winding the thin metal wire. Depending on the target size of the thin metal wire to be manufactured, the feeding speed of the feeding means and the winding speed of the winding means are controlled, and the rod-shaped metal member is moved at a predetermined speed to perform plasma etching, so that one plasma The fine metal wire having a desired diameter can be manufactured by etching. Therefore, the number of processing steps can be significantly reduced.

Further, according to the present invention, the shape of the discharge electrode is ring-shaped or cylindrical, and the rod-shaped metal member is passed near the axis of the hollow space of the discharge electrode, whereby the rod-shaped metal member is isotropic. Plasma-etched. Therefore, it is possible to manufacture a fine metal wire having a good shape accuracy.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a diagram schematically showing a thin metal wire manufacturing apparatus according to a first embodiment of the present invention. That is, the thin metal wire manufacturing apparatus includes a metal wire feeding mechanism 2 for feeding the metal wire material 1a before the thin wire processing, and an electrode portion for performing plasma etching processing on the metal wire material 1a fed from the metal wire feeding mechanism 2. 3, a metal wire winding mechanism 4 for winding the thin metal wire 1b processed by the electrode portion 3, and a reaction for accommodating the metal wire feeding mechanism 2, the electrode portion 3, and the metal wire winding mechanism 4. It has a container 5.

The metal wire feeding mechanism 2 includes a metal wire material 1a.
Has a motor 6 as a drive source for applying a driving force for transferring the toner in the longitudinal direction, and a pair of rollers 7a, 7b mounted directly to the rotation shaft of the motor 6 or via a gear (not shown) or the like. The rotation speed of the motor 6 can be changed according to the set value. A pair of rollers 7
The a and 7b are arranged so as to face each other at an interval substantially equal to the diameter dimension of the cross section orthogonal to the longitudinal direction of the metal wire blank 1a. The distance between the rollers 7a and 7b can be appropriately changed according to the diameter of the metal material. Further, at least one of the rollers 7a and 7b may be provided with an elastic member such as a spring so as to urge the rollers 7a and 7b against the metal wire material so that they are pressed against each other. By providing such an elastic member, the roller 7 for the metal wire material 1a
The pressure contact force between a and 7b is improved, and the metal wire material 1a can be reliably sent out. Such a metal wire feeding mechanism 2 drives the motor 6 to drive the rollers 7a,
7b rotates to feed the metal wire material 1a downward in the figure, that is, to the electrode portion 8.

FIG. 2 and FIG. 3 are schematic views showing an electrode portion provided in the metal thin wire manufacturing apparatus of the present invention. As shown in FIG. 2, the electrode portion 3 has a ring-shaped or cylindrical electrode 8 and a high-frequency power source 9 connected to the electrode 8. At this time, the metal wire material 1a is connected to the ground 10. In the electrode part 3, the metal wire material 1a sent from the metal wire sending mechanism 2 is subjected to plasma etching using glow discharge by a reaction gas sealed in a reaction container 5 described later and a high frequency electric field generated from the electrode 8. Is thinned. Since the metal wire material 1a passes through substantially the center position of the ring-shaped or cylindrical electrode 8, the metal wire material 1a is isotropically etched and the shape of the metal thin wire 1b is processed accurately.

Further, the electrode portion 3 having the structure shown in FIG.
2 has the same configuration as the electrode part 3 shown in FIG. 2, but the high frequency power source 9 is connected to the metal wire material 1a and the electrode 8 is connected to the ground. Even in the case of such a configuration, the metal wire material 1a is isotropically plasma-etched to be thinned.

The thin metal wire 1b thinned by passing through the electrode portion 3 is supplied to the metal wire winding mechanism 4. The metal wire winding mechanism 4 is a motor 11 as a drive source that applies a driving force for winding the metal thin wire 1b that has been plasma-processed into a thin wire, directly to a rotation shaft of the motor 11, or a gear (not shown) or the like. A take-up roller 12 attached via a roller, and a torque measuring machine 13 for measuring the torque applied to the motor 11 when the thin metal wire 1b is taken up.
Having. The rotation speed of the motor 11 is changed according to the torque measurement value measured by the torque measuring machine 13, and the metal wire can be wound with a constant force. Take-up roller 12
By providing a moving mechanism for moving the winding roller 12 in parallel along the rotation axis of the roller, it is possible to uniformly wind the thin metal wire 1b on the rotation axis of the winding roller 12. .

As shown in FIG. 1, the reaction vessel 5 includes a metal wire feeding mechanism 2, an electrode portion 3, and a metal wire feeding mechanism 2 in this embodiment.
Also, the metal wire winding mechanism 4 is accommodated, but at least only the electrode portion 3 may be accommodated. That is, the metal wire feeding mechanism 2 and the metal wire winding mechanism 4 can be arranged outside the reaction container 5. In this case, a seal or a differential evacuation system is provided at a portion where the metal wire material 1a is inserted into the reaction container 5 and a portion where the processed metal thin wire 1b is discharged to the outside of the reaction container 5. In this way, by disposing the metal wire feeding mechanism 2 and the metal wire winding mechanism 4 outside the reaction vessel 5, the metal wire feeding by the reaction gas in the reaction vessel 5 and the performance of the winding mechanisms 2 and 4 are performed. Of the reaction vessel 5
Can be downsized.

Further, the reaction container 5 has a gas inlet 14 for injecting a reaction gas having a predetermined composition corresponding to the metal wire material as the object to be etched, and a gas exhaust port 15 for exhausting the gas after the reaction. It is provided. Carbon halide is mainly used as the reaction gas supplied to the reaction vessel 5, but it may be used as a reaction gas mixed with oxygen, nitrogen, hydrogen, helium, argon gas or the like in order to increase the etching rate. . For example, when the metal wire material is molybdenum or tungsten, fluorocarbon (CF ₄ ) is used as the reaction gas.
Is used. Here, by applying a high frequency electric field to the electrode 8, the reaction gas is turned into plasma and the metal wire material 1a is formed.
And the surface portion of the material 1a is removed as a volatile substance.

The metal wire raw material 1a before being processed by using the thin metal wire manufacturing apparatus is subjected to a predetermined pretreatment such as pressing and sintering to have a predetermined diameter. Next, the method for manufacturing a thin metal wire of the present invention will be described.

First, a metal wire material 1a that has been subjected to a predetermined pretreatment is prepared, and the tip thereof is passed between a pair of rollers 7a and 7b of the metal wire feeding mechanism 2 and is clamped. Further, the tip of the metal wire material 1a is passed through substantially the center of the electrode portion 3 to take up the winding roller 1 of the metal wire winding mechanism 4.
Wrapped around 2. Therefore, the metal wire material 1a is stretched between the metal wire feeding and winding mechanisms 2 and 4 without slack. At this time, in the case of the electrode portion 3 having the structure as shown in FIG. 2, the electrode 8 is connected to the high frequency power source 9 and the metal wire material 1a is connected to the ground. Further, in the case of the electrode portion 3 having the structure as shown in FIG. 3, the electrode 8 is connected to the ground, and the metal wire material 1a is connected to the high frequency power supply 9.

Next, the motor 6 of the metal wire feeding mechanism 2,
Also, the motor 11 of the metal wire winding mechanism 4 is driven to move the metal wire material 1a at a constant speed. At this time, the torque of the motor 11 is controlled based on the torque measurement value applied to the motor 11 measured by the torque measuring machine 13, and the thin metal wire 1b can be wound with a constant force.

On the other hand, a reaction gas synthesized in advance with a predetermined composition is supplied into the reaction vessel 5. When a high frequency electric field is applied to the electrode part 3, the electrode 8 and the metal wire material 1
The reaction gas is turned into plasma between a and the metal wire material 1a.
Is plasma etched. That is, when a high frequency electric field is applied to the reaction gas sealed in the reaction container 5 from the electrode part 3, radicals or ions are generated and the metal wire material 1a
Reacts with. The reaction between the reaction gas turned into plasma and the metal wire produces a volatile substance, whereby the etching reaction proceeds. A gas flow is formed so that the volatile substance generated here is promptly removed from the vicinity of the electrode 8 where the reaction proceeds. During this reaction, metal wire material 1
a is moved at a constant speed, and the thin metal wire 1b plasma-etched to a desired diameter dimension is wound around the winding roller 12 of the metal wire winding mechanism 4.

At this time, since the etching amount of the metal wire depends on the moving speed of the metal wire material 1a, that is, the time it takes to pass through the electrode portion 3, various moving speeds can be set to obtain a fine metal wire having a desired diameter. Can be manufactured by a single plasma etching. Therefore, the number of processing steps can be reduced, and a processing step such as a cleaning step for removing stains on the thin metal wires and a heat treatment step for releasing processing strains are not required, so that processing time can be shortened. Further, since the metal wire material 1a passes near the center of the electrode 8 and isotropically plasma-etched, the processing accuracy is improved. Further, by adjusting the etching amount, it is possible to make the line thinner.

Next, a thin metal wire manufacturing apparatus according to a second embodiment of the present invention will be described with reference to the drawings.
In addition, regarding the same components as those of the first embodiment,
The same reference numerals are given and the detailed description is omitted.

FIG. 4 is a diagram schematically showing a thin metal wire manufacturing apparatus according to the second embodiment of the present invention. This thin metal wire manufacturing apparatus is provided with a wire diameter measuring mechanism 20 for measuring the diameter dimension of the metal wire material 1 a sent from the metal wire sending mechanism 2.

As the wire diameter measuring mechanism 20, for example, a non-contact measuring mechanism for optically measuring the diameter dimension of the metal wire raw material 1a using a laser beam is used. Further, although the wire diameter measuring mechanism 20 is arranged at a position between the metal wire feeding mechanism 2 and the electrode portion 3 in this embodiment, the diameter dimension of the metal wire raw material 1a before being processed is If it can be measured, it may be arranged in front of the metal wire feeding mechanism 2. The wire diameter measuring mechanism 20 can also be arranged outside the reaction container 5.

Next, the method for manufacturing the thin metal wire of the present invention will be described. In the second embodiment, the metal wire material 1a is based on the control block diagram as shown in FIG.
The passing time of the electrode portion of the metal wire feeding mechanism 2,
Also, the motor rotation speed of the metal wire winding mechanism 4 is controlled.

That is, the control unit 30 for controlling the moving speed of the metal wire is input with the wire diameter measuring mechanism 20 for measuring the diameter of the unprocessed metal material 1a and the target value of the desired diameter of the thin metal wire. The input device 40 is connected. The control unit 30 calculates the electrode portion transit time of the metal wire blank 1a based on the measurement value measured by the wire diameter measuring mechanism 20 and the target value input by the input device 40. As described above, the etching amount of the metal wire depends on the passage time of the electrode portion. For example, the larger the difference between the measured value and the target value, the longer the electrode wire passage time of the metal wire is set, and the slower the moving speed of the metal wire is.

Next, the control unit 30 transmits a motor rotation signal based on the electrode passage time calculated for the metal wire feeding mechanism 2 and the metal wire winding mechanism 4. Based on the motor transmission signal, the motor 6 of the metal wire feeding mechanism 2 and the motor 11 of the metal wire winding mechanism 4 are respectively driven to move the metal wire material 1a at a predetermined speed.
At this time, the torque measurement value applied to the metal wire winding mechanism 4 measured by the torque measuring machine 13 is fed back and transmitted to the metal wire winding mechanism 4 as a fine adjustment signal. The fine adjustment signal and the motor rotation signal are combined, and the motor 11 of the metal wire winding mechanism 4 is based on both signals.
Is controlled, and the thin metal wire 1b is wound with a constant force.

As described above, the wire diameter measuring mechanism 20 is provided, the electrode portion passing time is calculated based on the measured value of the diameter dimension of the metal wire and the target value after processing, and the metal wire feeding mechanism 2 and the metal wire are measured. By controlling the motor rotation speed of the winding mechanism 3, the adjustment of the moving speed of the metal wire is automated, and the thin metal wire having a desired diameter can be manufactured by one plasma etching. Therefore, the number of processing steps can be reduced and the processing time can be shortened because steps such as a die replacement step, a cleaning step, and a heat treatment step are unnecessary. Further, since the metal wire material 1a passes near the center of the electrode 8 and isotropically plasma-etched, the processing accuracy is improved.
Further, by adjusting the etching amount, it is possible to make the line thinner.

By measuring the diameter of the thin metal wire that has passed through the electrode portion 3 to find the deviation from the target value, and feeding back the moving speed of the metal wire, the voltage applied to the electrode 8, the gas flow rate, etc., It is also possible to achieve a more precise thinning.

[0032]

As described above, according to the apparatus and method for manufacturing a thin metal wire of the present invention, a thin metal wire having a desired diameter can be manufactured by one plasma etching. Therefore, the number of processing steps can be significantly reduced and the processing time can be shortened. Moreover, since the metal wire material is isotropically plasma-etched, the processing accuracy can be improved. further,
By adjusting the etching amount, it is possible to make the line thinner.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a thin metal wire manufacturing apparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a structure of an electrode portion of the thin metal wire manufacturing apparatus of the present invention.

FIG. 3 is a diagram showing another example of the structure of the electrode portion of the thin metal wire manufacturing apparatus of the present invention.

FIG. 4 is a diagram schematically showing a thin metal wire manufacturing apparatus according to a second embodiment of the present invention.

FIG. 5 is a control block diagram of the thin metal wire manufacturing apparatus shown in FIG.

[Explanation of symbols]

1a ... Metal wire material 1b ... Metal thin wire 2 ... Metal wire feeding mechanism 3 ... Electrode part 4 ... Metal wire winding mechanism 5 ... Reaction vessel 6 ... Motor 7a, 7b ... Roller 8 ... Electrode 9 ... High frequency power supply 10 ... Ground 11 ... Motor 12 ... Winding roller 13 ... Torque measuring machine 20 ... Wire diameter measuring mechanism 30 ... Control unit 40 ... Input device

Claims (8)

[Claims] 1. An apparatus for producing a fine metal wire having a minute diameter by reacting a rod-shaped metal member with a plasma-generated reaction gas, wherein a plasma-generated reaction gas for plasma-processing the rod-shaped metal member is used. Plasma generating means for generating, a moving mechanism for moving the rod-shaped metal member in a longitudinal direction thereof, a plasma generating means, and a reaction container accommodating at least the plasma generating means of the moving mechanism, A metal thin wire manufacturing device. 2. The moving mechanism comprises a feeding means for feeding the rod-shaped metal member to the plasma generating means, a winding means for winding a metal thin wire produced by plasma processing by the plasma generating means, and the rod-shaped member. Wire diameter measuring means for measuring the diameter dimension of the metal member, and according to the measured value measured by the wire diameter measuring means and the target diameter dimension of the metal thin wire to be manufactured, the feeding speed of the feeding means and the winding means. 2. The thin metal wire manufacturing apparatus according to claim 1, further comprising a control unit that controls a winding speed of the wire. 3. The plasma generating means reacts with any one of atoms and molecules constituting the rod-shaped metal member to generate a reactive gas that is turned into plasma to generate a volatile compound. It has a discharge electrode for applying a high frequency electric field to the gas and a high frequency power source for generating a high frequency electric field, and one of the discharge electrode and the rod-shaped metal member is connected to the high frequency power source, and the other is grounded. The thin metal wire manufacturing apparatus according to claim 1 or 2, which is characterized. 4. The discharge electrode has one of a ring shape and a cylindrical shape, and the rod-shaped metal member is configured to pass near the axis of the hollow space of the discharge electrode. The thin metal wire manufacturing apparatus according to claim 3, which is characterized in that. 5. A plasma generating unit that reacts with one of atoms and molecules forming a rod-shaped metal member to generate a reactive gas that is turned into a plasma to generate a volatile compound, and the rod-shaped metal member. In a metal thin wire manufacturing apparatus having a moving mechanism for moving in the longitudinal direction, the plasma generating means, and a reaction container accommodating at least the plasma generating means of the moving mechanism, the rod-shaped metal member is moved by the moving mechanism. A method for producing a fine metal wire, wherein the fine metal wire having a minute diameter is made to move by moving the rod-shaped metal member and the reaction gas converted into plasma by the plasma generating means at a predetermined speed. 6. The moving mechanism comprises a feeding means for feeding the rod-shaped metal member to the plasma generating means, a winding means for winding a metal thin wire produced by plasma processing by the plasma generating means, and the rod-shaped member. Wire diameter measuring means for measuring the diameter dimension of the metal member, according to the measured value measured by the wire diameter measuring means and the target diameter dimension of the thin metal wire to be manufactured, the feeding speed of the feeding means and the winding means Control means for controlling the winding speed, and, by the control means, controlling the feeding speed of the feeding means and the winding speed of the winding means according to the target dimension, the rod-shaped metal member at a predetermined speed The fine metal wire manufacturing method according to claim 5, wherein the fine metal wire is moved by. 7. The plasma generating means has a discharge electrode for applying a high frequency electric field to the reaction gas in order to turn the reaction gas into a plasma, and a high frequency power source for generating a high frequency electric field. One of the metal members is connected to the high-frequency power source and the other is grounded to generate a discharge between the rod-shaped metal member and the discharge electrode, whereby the reaction gas is turned into plasma, and this is turned into plasma. The method for producing a metal thin wire according to claim 5 or 6, wherein a reaction gas is reacted with the rod-shaped metal member to form a thin wire. 8. The discharge electrode has one of a ring shape and a cylindrical shape, and the rod-shaped metal member is passed near the axis of the hollow space of the discharge electrode so that the rod-shaped metal member has the same shape. The thin metal wire manufacturing apparatus according to claim 7, wherein the thin metal wire manufacturing apparatus is configured to be reacted in an anisotropic manner.