JP4275931B2 - Processing method of ultra fine wire - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a processing method of an ultrafine diameter wire in which one end of an ultrafine diameter wire such as a probe probe of an electrical resistance test apparatus or a medical catheter is micromachined to ultraprecision (μm order).
[0002]
[Prior art]
The conventional method for processing ultra-fine diameter wires is to chamfer one end of the wire by grinding. After the primary processing, there is a secondary processing for barrel polishing. (For example, refer to Patent Document 1).
[0003]
In addition, the present applicant has not found any prior art documents closely related to the present invention by the time of filing other than the prior art documents specified by the prior art document information described in the present specification.
[0004]
[Patent Document 1]
JP-A-8-104015 (paragraph 0009, FIG. 1)
[0005]
[Problems to be solved by the invention]
In the conventional ultrafine diameter wire processing method described above, in order to prevent the wire from being bent when chamfering by grinding, the wire is supported after the end portion of the wire is rotatably supported by the support portion. Grinding is performed while rotating and observing with a magnifying glass by pressing a grinding stone against one end exposed and protruding from the support. In this method, it is possible to process a wire having a diameter of about 1 mm. However, if an ultrafine wire having a diameter of about 100 μm or less is processed, the rigidity of the wire is reduced, so that the support portion is It needs to be close to the part to be processed. However, when the support part is brought close to the part to be processed, the grinding wheel is brought into contact with the grinding part. Therefore, there is a limit to bringing the support part close to the part to be processed. For this reason, the one end part of the wire was bent by the pressing of the grinding wheel during processing, and not only the processing accuracy was lowered, but also the one end part of the wire was bent. In addition, since both are performed by mechanical processing, such as grinding with a grinding wheel as the primary processing and barrel polishing as the secondary processing, the finishing accuracy at one end varies and the accuracy is poor. It was stable. In particular, when a wire formed of a hard material is processed, there is a problem that the material is hard and therefore breakage is likely to occur, and the processing time is increased to prevent damage.
[0006]
The present invention has been made in view of the above-described conventional problems, and a first object is to improve machining accuracy. The second object is to prevent the wire from being bent and to improve the yield. The third purpose is to shorten the machining time.
[0007]
[Means for Solving the Problems]
In order to achieve this object, the invention according to claim 1 is characterized in that one end of a tungsten carbide wire is first processed into a curved surface by electrolytic polishing, and then one end of the wire is rotated while the wire is rotated around an axis. An elastically deformable polishing body having rigidity smaller than the rigidity of the wire is pressed against the wire, and one end of the wire is secondarily processed into a substantially conical shape.
Therefore, the work time of primary processing is shortened. Moreover, the polishing body pressed against the wire is elastically deformed.
[0008]
The invention according to claim 2 is the invention according to claim 1, wherein the abrasive of the abrasive body is diamond particles, and after the wire is polished with the abrasive body, the diamond particles attached to the wire are removed. Perform post-processing.
Therefore, the processed part of the wire is washed.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a model diagram for explaining primary processing in a processing method of an ultrafine wire according to the present invention, and FIG. 1 (a) shows a state in which a wire before processing is attached to a fixing jig. FIG. 4B shows the electropolishing apparatus, and FIG. 3C shows the wire after processing. 2A and 2B are model views of a polishing apparatus used for secondary processing. FIG. 2A is a plan view, FIG. 2B is a front view, and FIG. 3 is an enlarged view of a wire guide. (A) is a front view, (b) is a side view, and (c) is a diagram for explaining the eccentricity of one end of the processed wire. FIG. 4 is a photograph of one end of the wire 1 processed by the secondary processing, taken with a microscope with a magnification of 1500 times.
[0010]
First, the primary processing electropolishing will be described with reference to FIG.
In FIG. 1 (a), reference numeral 1 denotes a tungsten carbide wire, which is a workpiece formed in an extremely thin cylindrical shape having an outer diameter of 50 μm, and one end 1a of the wire 1 is curved by processing described later. To form. Reference numeral 2 denotes a fixing jig formed in a cylindrical shape by a relatively small aluminum tube, and the inner diameter of the through hole 2a provided in the center is formed to be 60 μm which is slightly larger than the outer diameter of the wire 1. Yes. Therefore, as shown in FIG. 5A, when the wire 1 is inserted into the through hole 2a of the jig 2, the wire 1 is attached to the through hole 2a without any gap and can be attached and detached. One end 1a of the wire 1 engaged with the through hole 2a is exposed from the through hole 2a.
[0011]
One end 1a of the wire 1 thus attached to the jig 2 is immersed in the electrolytic solution 6 in the electrolytic bath 5 and the electrode plate 7 immersed in the jig 2 and the electrolytic solution 6 as shown in FIG. Are applied by a low-frequency AC power supply 8. As a result of the experiment, 30% caustic soda was used as the electrolytic solution, and 50 Hz, 100 V, and 1 A were applied as low-frequency alternating current for 2 to 3 minutes. As shown in FIG. A curved surface with a curvature of about 25 μm could be processed. By removing the wire 1 from the through hole 2a of the jig 2, the primary processing is completed. In this way, by using electropolishing for primary processing, processing time can be reduced compared to machining, and the processing time for wires made of particularly hard materials can be greatly reduced. become.
[0012]
Next, a polishing apparatus used for secondary processing will be described with reference to FIGS. 2 and 3.
As shown in FIG. 2, the polishing apparatus shown as a whole by 9 is provided with a work table 10 for polishing the tip 1 a of the wire 1, and this work table 10 is shown in the figure by guide means (not shown). It is supported so as to be movable in the X and Y directions. The work table 10 can be adjusted in position in the Y direction by gripping a knob 11 protruding from one side, and can be adjusted by gripping a knob 12 protruding from the other side. The position in the direction can be adjusted.
[0013]
A pole 14 that is rotatably supported is erected at the center portion of the work table 10, and a polishing body 15 protrudes perpendicularly to the axial direction of the pole 14 on a part of the outer peripheral surface of the pole 14. Is attached. In addition, a lever 16 is attached at a position opposite to the circumferential direction from the position where the polishing body 15 is attached on the outer peripheral surface of the pole 14 so as to protrude perpendicular to the axial direction. Therefore, by holding the lever 16 and rotating the pole 14 clockwise or counterclockwise as shown in FIG. 5A, the polishing body 15 is applied to the one end 1a of the wire 1 by a predetermined pressing force. Can be pressed.
[0014]
The polishing body 15 is formed into a flat rectangular parallelepiped shape by an engineering plastic that can be elastically deformed. A large number of diamond fine particles as an abrasive are exposed from the surface of the polishing body 15 on the polishing surface 15a of the polishing body 15. It is press-fitted to do. The rigidity of the polishing body 15 is formed to be smaller than the rigidity of the wire 1 to be processed. Reference numeral 17 denotes a camera for observing the processing state of the one end 1 a of the wire 1.
[0015]
Reference numeral 18 denotes a wire guide that rotatably supports the rotating wire 1 so as not to be eccentric. As shown in FIG. 3, the wire guide 18 includes a pedestal 20 and a lid 21 that are formed in a rectangular parallelepiped shape. Screw holes 20a and 20a are screwed into both ends of the pedestal 20, and a groove 20b having a trapezoidal cross section is provided in the center of the upper surface. The depth T of the groove 20b is slightly smaller than the diameter of the wire 1 as shown in FIG. 5B, and when the wire 1 is engaged in the groove 20b, the bottom and both sides of the groove 20b are formed. And the peripheral surface of the wire 1 is formed in contact with three points. Insertion holes 21 a and 21 a through which the through screws 22 are inserted are provided at both ends of the lid body 21.
[0016]
In the wire guide 18 having such a configuration, the pedestal 20 is fixed to the work table 10, the wire 1 is engaged in the groove 20 b of the pedestal 20, and the lid 21 is placed on the upper surface of the pedestal 20. A guide hole 19 is formed by the groove 20 b of the pedestal 20 and the lower surface of the lid 21 by inserting the through screw 22 into the insertion hole 21 a of the lid 21 and screwing it into the screw hole 20 a of the pedestal 20.
[0017]
The guide hole 19 adjusts the screwing amount of the through screw 22 into the screw hole 20a by contacting the groove 20b with the circumferential surface of the wire 1 at three points, and the upper surface of the base 20 and the lower surface of the lid 21 By adjusting the interval δ, the wire 1 is supported in the guide hole 19 so as to be freely rotatable without a gap. Therefore, when the wire 1 is rotated by a motor (not shown), the eccentric rotation of the wire 1 is restricted. The guide hole 19 is positioned so as to be coaxial with the rotation center of the motor, and is positioned in the vicinity of the polishing body 15.
[0018]
With this configuration, the other end of the wire 1 processed by the primary processing described above is engaged with the through hole 2a of the fixing jig 2, and rotates integrally with the motor shaft of the motor. The jig 2 is tightened by a chuck member (both not shown). At this time, since the jig 2 is formed of an aluminum tube having a relatively small rigidity, the jig 2 is plastically deformed by tightening the chuck member, and the gap between the through hole 2a and the wire 1 is removed and penetrated. The wire 1 is fixed to the hole 2a. Therefore, the rotation of the motor is integrally transmitted to the wire 1 and the wire 1 rotates around the axis.
[0019]
When one end side of the wire 1 is rotatably supported by the guide hole 19 of the wire guide 18, the wire guide 18 positions the wire 1 and the rotation shaft of the motor on the same axis. Therefore, the wire 1 rotated by the rotation of the motor does not rotate eccentrically.
[0020]
In this state, the position of the polishing body 15 is determined by grasping the knobs 11 and 12 and moving the work table 10 in the Y direction or the X direction while confirming the position of the one end 1a of the wire 1 with the camera 17. Adjust. The motor 1 is driven to rotate the wire 1 around the axis, and the lever 16 is operated to rotate the pole 14 counterclockwise as shown in FIG. 15 a is pressed against one end 1 a of the wire 1. At this time, since the rigidity of the polishing body 15 is formed to be smaller than the rigidity of the wire 1 and the polishing body 15 is formed of a member that can be elastically deformed, the wire 1 is not subjected to excessive pressing force. . For this reason, since the wire 1 is not bent and the one end side of the wire 1 is not eccentrically rotated, the processing accuracy can be improved.
[0021]
FIG. 4 is an image of one end 1a of the wire 1 processed by the secondary processing, taken with a microscope with a magnification of 1500 times, and it is actually measured that the radius of the one end 1a is processed to 10.343 μm. It was done. As a result of experiments by the present applicant, it was confirmed that the radius could be processed to about 5 μm. Also, from the photographed FIG. 4, it was actually measured that the eccentric amount γ of the processed end 1a of the wire 1 having a diameter of 50 μm was within 1 μm. That is, in FIG. 3C, when the distance from the center line C to both ends of the wire 1 is d1 and d2, respectively.
γ = | d1-d2 | ≦ 1 μm
It became. Thus, the present invention is suitable for micro-processing one end of a wire, and particularly suitable for ultra-precision processing one end of a wire having a diameter of 100 μm or less on the order of μm.
[0022]
When diamond fine particles adhere to the processed surface of the one end 1a of the wire 1 by this secondary processing, a post-treatment polishing body is attached to the pole 14 in order to remove the diamond fine particles instead of the polishing body 15. The processed surface at one end of the wire 1 may be cleaned with this post-treatment polishing body. As a polishing body for this post-treatment, a polishing body covered with a polishing cloth may be used, or a polishing material with low hardness may be used, and various selections may be made depending on the adhesion state of the adhered diamond. Is possible. Thus, by polishing with diamond fine particles having a relatively high hardness, the processing time can be shortened, and the quality of the processed surface of the one end 1a of the wire 1 can be improved by the post-processing polishing body.
[0023]
【Example】
When the wire 1 was applied to probe processing of a four-probe probe for measuring electrical resistance in a minute region, a four-probe probe having a fine pitch with a probe diameter of 50 μm and a pitch between the probes of 100 μm was produced. . The thickness of the polishing body 15 was set to 30 to 40 μm. In the electropolishing, the electrode plate 7 differs depending on the material of the workpiece, but in the present invention, the electrode 1 is made of nickel because the wire 1 is formed of tungsten carbide.
[0024]
In this embodiment, an example in which the probe probe is processed by the ultrafine diameter wire processing of the present invention has been shown. However, a medical stainless steel catheter or a wire for a dot printer can also be processed, Applicable to processing of intended use.
[0025]
【The invention's effect】
As described above, according to the invention according to claim 1, not only the machining accuracy can be improved, but also the yield of the wire can be prevented by preventing the wire from being bent, and the machining time can be shortened. Can do.
[0026]
Moreover, according to the invention which concerns on Claim 2, while processing time can be shortened, the quality of the process surface of the end of a wire can be improved.
[Brief description of the drawings]
FIG. 1 is a model diagram for explaining primary processing in a processing method of an ultrafine wire according to the present invention, in which FIG. 1 (a) is attached to a fixing jig before processing; Sectional drawing of a state, the figure (b) shows an electropolishing apparatus, and the figure (c) shows the wire after a process.
FIGS. 2A and 2B are model views of a polishing apparatus used for secondary processing in the method for processing an ultrafine wire according to the present invention, in which FIG. 2A is a plan view and FIG. 2B is a front view.
FIG. 3 is an enlarged view of a wire guide in a polishing apparatus used in a method for processing an ultrafine diameter wire according to the present invention. FIG. 3 (a) is a front view, FIG. 3 (b) is a side view, and FIG. FIG. 3C is a diagram for explaining the amount of eccentricity at one end of the processed wire.
FIG. 4 is a photograph of one end of a wire 1 processed by secondary processing in a method for processing an ultrafine wire according to the present invention, taken with a microscope photographer with a magnification of 1500 times.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Wire, 1a ... One end, 2 ... Fixing jig, 6 ... Electrolyte, 7 ... Electrode plate, 8 ... Low frequency alternating current power supply, 9 ... Polishing apparatus, 10 ... Work table, 15 ... Polishing body, 15a ... Polishing surface, 18 ... wire guide, 19 ... guide hole.

Claims (2)

One end of a tungsten carbide wire is first processed into a curved surface by electrolytic polishing, and then the elastically deformable polishing body having a rigidity smaller than the rigidity of the wire at one end of the wire while rotating the wire around the axis. And processing one end of the wire into a substantially conical shape by pressing the wire.   2. The ultrafine diameter wire processing method according to claim 1, wherein after the polishing material of the abrasive body is diamond particles and the wire is polished by the abrasive body, the post-processing process is performed to remove the diamond particles attached to the wire. A method of processing an ultrafine diameter wire characterized by being performed.

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