JPH06289051A - Metal wire material and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide a metal wire material and a method for manufacturing the same in which new mechanical function different from a function of the material itself can be imparted, or another functions such as wear resistance, conductivity, etc., can be, for example, imparted in a state that the strength, toughness, etc., of the material is obtained. CONSTITUTION:After an end face part of a metal wire material 4 as a base material is integrally melted to a function imparting metal element such as an Ni film 5, an Au film 6, etc., by emitting a laser beam, they are quenched, thereby forming a functional part having a quenched solidified structure alloyed thereby at an end of the material 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used, for example, when inspecting the electrical conductivity of a dot pin used in the head of a print printer, a semiconductor integrated circuit (IC), a liquid crystal display (LCD) or the like. Regarding a metal wire rod constituting a probe pin and the like and a method for manufacturing the metal wire rod, in detail, while maintaining the function of the base metal itself, imparting another function such as abrasion resistance or conductivity to the metal wire rod. The present invention relates to a structure and a manufacturing method capable of achieving higher performance. The present invention is suitable for the probe pin used in the probe unit, and will be described below as an example.

[0002]

2. Description of the Related Art Generally, when manufacturing a liquid crystal display used in a screen device such as a personal computer or a television, or a semiconductor integrated circuit used in a computer or a communication device,
Various continuity tests are performed in this manufacturing process. For example, in the case of conducting a continuity inspection of a conductor line of a liquid crystal substrate or a circuit wiring of an IC substrate, conventionally, a probe unit as shown in FIGS. 18 and 19 has been adopted (JP-A-1-32115).
No. 8). This probe unit 51 has a wire diameter of 15
Attach the probe pin 52 of 0 μm or less to the U-shaped mounting portion 52a.
The mounting portion 52a is mounted on the insulating base 53 at a predetermined pitch, and the contact portion 52a is inclined with respect to the inspected substrate 50. In addition, 54 is a lead wire connected to a measuring instrument. This is to lower the probe unit 51 in the vertical direction to bring the contact 52c at the tip of the probe pin 52 into contact with each conductor of the inspected substrate 50, thereby checking the electrical continuity. According to the probe unit 51, since the variation in the load at the time of contact can be absorbed by the self-elasticity of the probe pins 52, the probe units 52 come into contact with the substrate 50 to be inspected at substantially the same time, and stable inspection performance can be obtained.

[0003]

However, the metal wire rod used in the above-mentioned conventional probe pin has a structure in which a conductive metal film is merely coated on the metal wire rod, so that the metal wire rod is easily worn by repeated conduction tests and has a long life. There is a problem that is short. Here, in order to avoid the problem of wear, it is conceivable to adopt a metal material with high hardness, but if this hard metal material is adopted, there are cases where problems such as toughness occur and the function required as a probe pin cannot be obtained. is there.

Further, in the case of manufacturing the above-mentioned conventional probe pin, after bending the metal fine wire for probe pin into the above-mentioned predetermined shape, the tip end thereof is cut in a direction orthogonal to the axis by a cutter or the like to form the contact 52c. I am trying to form. Therefore, there is a problem that the contact resistance when the contactor 42c having the fracture surface is brought into contact with the surface to be inspected is large, and the contact state at the time of contact becomes unstable, and it may be difficult to obtain the contact position accuracy. .

The present invention has been made in view of the above-mentioned conventional circumstances, and it is possible to improve the performance by adding another function such as abrasion resistance or conductivity to the base material itself while securing the function of the base material itself. An object of the present invention is to provide a metal wire rod which can improve performance, can stabilize the contact state by reducing the contact resistance, and can improve the contact position accuracy, and a manufacturing method thereof.

[0006]

In order to solve the problems, the invention of claim 1 provides a functional part which is formed by alloying an end surface portion of a metal bus bar as a base material and a function-imparting metal element and has a rapidly solidified structure. It is a metal wire rod characterized in that it is formed on the end face portion of.

Further, the invention of claim 2 specifies the above-mentioned function-imparting metal element, and as the metal element,
Conductive metal materials such as Au, Ag, Cu, Pt, Cr, S
Hard metal materials such as i, W, Ti and Mo, or corrosion resistant metal materials such as Ni can be adopted, and these may be appropriately mixed. These metal materials may be formed into a chip shape, a metal powder shape, a metal paste shape or the like, and these may be attached to the end faces of the metal wire, or the surface of the metal wire may be coated and formed by means such as electroplating. Good.

A second aspect of the present invention is a method for manufacturing the metal wire rod, wherein the end surface portion of the metal wire rod is irradiated with laser light in a state where a metal element imparting a function is interposed. And the metal element are melted together and then rapidly cooled, thereby forming a functional portion having a rapidly solidified structure alloyed.

Here, when the end face of the metal busbar is irradiated with the laser beam, the laser beam may be irradiated either in the axial direction of the metal busbar or in the direction perpendicular to the axis. The focal position of the laser light is preferably close to the metal bus bar, for example, about 5 mm. As a result, the end surface portion becomes spherical due to the surface tension of the end surface portion at the time of melting, and by rapidly cooling in this state, a functional portion having a rapidly solidified structure can be obtained.

Further, for the metal bus bar, in addition to conventional materials such as tungsten wire and beryllium copper alloy wire, for example, stainless wire, piano wire, tungsten wire, amorphous wire or low carbon dual phase steel wire is adopted. Is preferred. Above all, when the low carbon dual phase steel wire is adopted, the strength, durability and toughness can be improved and the function can be further improved as compared with the stainless wire, the piano wire and the like. This low carbon dual phase steel wire has Fe as a main component, and C,
This wire is manufactured by subjecting a wire rod containing Si and Mn to strong working by cold drawing, and has a tensile strength of 300 to 600 Kgf / mm ² with a wire diameter of 150 μm or less. Akira
62-20824).

[0011]

According to the metal wire and the method for producing the same according to the present invention, the end face portion of the metal bus bar and the function-imparting metal element are integrally melted and solidified, and the end face portion has a rapidly solidified structure alloyed with the functional portion. Since this is formed, a new function different from the function of the metal bus bar itself can be provided, and high performance can be achieved. For example, by adopting a conductive metal material such as Au or Ag or a hard metal material such as Cr or Si as the function-imparting metal element, excellent wear resistance while ensuring strength, rigidity, toughness, etc. of the metal busbar. , And electrical conductivity can be obtained. By adopting such a metal wire rod for a probe pin, for example, it is possible to secure a self-elasticity function of ensuring contact with the surface to be inspected by its own elasticity when contacting the surface to be inspected, and wear even if repeated continuity inspection is performed. Can be reduced and the life can be greatly extended.

Further, since the function-provided metal-arranged portion on the end face of the metal busbar is irradiated with laser light to melt the portion, and then the portion is rapidly cooled to form the functional portion, the functional portion is formed by the surface tension during the melting. Tends to be spherical. Therefore, for example, when the probe pin is adopted, the contact resistance when contacting the surface to be inspected can be reduced, the contact state at the time of contact can be stabilized, and the contact position accuracy can be improved.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 8 are views for explaining a metal wire rod and a method for manufacturing the same according to the present invention. In the present embodiment, a case where the present invention is applied to a probe pin that constitutes a probe unit used for a continuity test of a semiconductor integrated circuit will be described as an example.

In the figure, 1 is a probe unit of the present embodiment, which has 70 to 300 probe pins 2 to 300.
They are arranged with a pitch of not more than μm and a pitch error of ± 20 μm or less, and these are fixed on the thermoplastic resin base 3. In the probe pin 2, a Ni film 5 is coated on the surface of a low carbon dual phase steel wire 4 having a wire diameter of 20 to 150 μm by electroplating or the like, and Au, Ag, Pt is formed on the surface of the Ni film 5.
A conductive noble metal film 6 made of, for example, is also formed by coating by plating.

The low carbon dual-phase steel wire 4 is manufactured by subjecting a metal wire rod to strong working by cold drawing as described above, and the working cells generated thereby are arranged in one direction in the form of fibers. It has a fine fibrous microstructure and has a tensile strength of 30.
It is 0 to 600 Kgf / mm ² .

The Ni film 5 has a working strain due to the plastic working during cold drawing of the metal wire, which improves self-lubricating property and corrosion resistance, and at the same time as the noble metal film 6. The adhesiveness and adhesiveness of are improved. The noble metal film 6 has a working strain due to plastic working when the metal wire coated with the Ni film 5 is further drawn by cold drawing to a thickness of about several μm. As a result, the pinholes or particles generated during the plating coating are crushed during the above wire drawing, resulting in a smooth surface with no defects.

Each of the probe pins 2 is composed of a main body 2a located on the resin base 3 and a protrusion 2b protruding outward from the base 3. Approximately ½ of the diametrical direction of the main body 2 a is embedded in the resin base 3, and the remaining part is exposed on the lower surface of the base 3.

The body 2a of each probe pin 2 of the probe unit 1 has a TAB (Tape Aut) not shown.
omated Bondig) is attached and the TAB is connected to a measuring instrument. The TAB is formed by patterning a wiring to which each probe pin 2 is connected to a flexible film by an etching method or the like. Each wiring of the TAB and each probe pin 2 are collectively and simultaneously subjected to thermocompression bonding. It is connected. In addition to TAB, an FPC (flexible printed circuit board) can be used as a means for connecting the probe unit 1 and the measuring device.

The protruding portion 2b of the probe pin 2 is bent and formed in an arc shape which is curved from the shoulder portion 2c thereof toward the surface A to be inspected, and as a result, the protruding portion 2b is elastic by the descending amount of the probe unit 1. It has a so-called self-elasticity that deforms. Further, a taper-shaped, ie, a needle-shaped pointed portion 2d is formed at the tip of the protruding portion 2b.

A spherical functional portion 2e is formed at the tip of the pointed portion 2d of the protruding portion 2b, and the functional portion 2e contacts the surface A to be inspected. The functional portion 2e draws the tip portion of the protruding portion 2b in a tensioned state while heating with a laser beam to draw a wire, whereby the tapered pointed portion 2 is formed.
It is formed by forming d, melting the tip surface of the d, and then rapidly cooling. As a result, the functional portion 2e has a rapidly solidified structure in which the steel wire 4 as the base material and the Ni film 5 and the noble metal film 6 as the function-imparting metal element coated on the steel wire 4 are alloyed.

Next, a method of manufacturing the probe unit 1 will be described. The manufacturing method of the present embodiment includes a first step of manufacturing a low-carbon two-phase structure steel wire 4 from a metal wire rod and a first step of arranging and fixing the low-carbon two-phase structure steel wire 4 on the resin base 3 at a predetermined pitch. Third step of bending and forming the protruding portion 2b of the low carbon dual phase steel wire 4 into a shape having self-elasticity
The process includes a step and a fourth step of manufacturing the probe pin 2 by forming the pointed portion 2d and the functional portion 2e on the protrusion 2b. Hereinafter, each of the above steps will be described in detail.

First Step First, a Fe-C-Si-Mn-based alloy wire as a base material is coated with a Ni film 5 by electroplating, and the Ni film 5 is subjected to strong working by cold drawing to form a plastic film on the Ni film 5. A processing strain is applied by processing, and a metal wire rod having a predetermined wire diameter is formed. Next, the surface of this metal wire is coated with a noble metal film 6 made of Au, and this is similarly strongly worked by cold drawing to give a working strain due to plastic working to the noble metal film 6. This wire drawing process is repeated until a predetermined wire diameter is obtained, whereby a low carbon dual phase steel wire 4 having a wire diameter of 20 to 150 μm or less is obtained.

Next, while pulling the low carbon dual phase steel wire 4 in a tensioned state, the steel wire 4 is heat treated by being held in a heating furnace heated to, for example, 430 ° C. for 30 seconds. After that, the steel wire 4 is wound around the bobbin 14. As a result, the low-carbon dual-phase steel wire 4 linearly drawn straight is manufactured.
The temperature and holding time in this heat treatment are not particularly limited, and the temperature and time suitable for removing the working strain without reducing the strength are set.

Second Step First, the wiring device 8 shown in FIG. 5 is prepared. This wiring device 8
Is a rectangular fixed base 9 and a pair of clamps 10a, 10a arranged so as to be movable in the a direction with respect to the fixed base 9.
And a heating control device 12 movably arranged in the a direction and the b direction orthogonal thereto, and the control device 12 is provided with a + electrode 12a and a − electrode 12b.

Further, a rectangular plate-shaped mother base 13 used for the above wiring work is prepared. The mother base 13 is made of a thermoplastic resin such as polycarbonate, and other materials such as polyether and ether ketone can be used. Then, a rectangular opening window portion 13a is formed on one edge of the mother base 13, and one side portion of the window portion 13a of the mother base 13 serves as a holding base 13b during bending processing described later, and the other side. The part becomes the above-mentioned resin base 3. The resin base 3 and the holding base 13b may be formed as separate parts, and the bases 3 and 13b may be fixed with a space therebetween, and the space may be used as the window 13a.

Then, the mother base 13 is placed on the fixed base 9 of the wiring device 8 and the mother base 13 is fixed with screws. Next, the bobbin 14 on which the low carbon dual phase steel wire 4 is wound is set on the wiring device 8, and the steel wire 4 is inserted and bridged between the clamp devices 10a and 10a, and the clamp The device 10a applies tension to the steel wire 4 to support it in a tensioned state.

Next, the two clamping devices 10a are moved in the direction a, and the low carbon dual phase steel wire 4 is set at a predetermined position passing over the window 13a of each mother base 13. In this state, both electrodes 12a, 12b of the heating control device 12 are energized to heat and press the steel wire 4 to, for example, 180 to 220 ° C., and the control device 12 is moved along the steel wire 4 in the b direction. Then, the portion of the mother base 13 in contact with the steel wire 4 is melted, and the steel wire 4 is embedded in the mother base 13 in a state of traversing the window portion 13a, whereby the low carbon two-phase structure steel wire 4 is formed. ½ or more, for example 70%, in the diameter direction is embedded in the mother base 13, and the remaining part is exposed on the upper surface of the mother base 13. In this case, for example, a V-shaped groove may be previously formed in a portion of the mother base 13 in which the steel wire 4 is embedded, and the steel wire 4 may be arranged in this groove. In forming the groove, the width and depth of the groove are appropriately set so as to sandwich the lower surface of the steel wire 4.

When the first wiring is completed, the clamping devices 10a, 10a are moved by a predetermined pitch to perform the second wiring work. Such wiring work is sequentially repeated to embed 70 to 300 steel wires 4, and then the steel wires 4 at both edges of the mother base 13 are cut and separated (see FIG. 6 (a)).
Here, a large number of the low carbon dual phase steel wires 4 may be arranged in advance at a predetermined pitch, and the steel wires 4 may be embedded at the same time. The fixing to the mother base 13 may be performed with an adhesive.

Third Step The above-mentioned wiring base matrix 13 is set in the pin molding die device 15, and the device 15 is used for holding bases 13b at both ends of the mother base 13 in the steel wire 4 direction and a resin base. The table 3 side is clamped. In this state, both edges of the window portion 13a of the mother base 13 are cut to separate the mother base 13 into both bases 3 and 13b (FIG. 6).
(See (b)).

Next, as shown in FIG. 7, the resin base 3 is clamped and fixed, and a tension is applied to the holding base 13b so that both bases 3,
The low carbon dual phase steel wire 4 between 13b is pulled to a tension state. In this state, the first mold 15a of the mold device 15 is brought into contact with the steel wire 4 (see FIG. 7 (a)), and the steel wire 4 is laid down along the mold 15a so that the mold 15a The second mold 15b is pressed to form a curved portion on the steel wire 4 corresponding to the protruding portion 2b of the probe pin 2 (see FIG. 7 (b)).

Fourth Step While the protruding portion 2b is pressed and sandwiched by the first and second molds 15a and 15b, tension is applied to the holding base 13b to pull the tip portion of the protruding portion 2b in a tensioned state. Then, the laser light 20 is applied to the tip of the protrusion 2b by the laser heating device 20.
It is irradiated with a to heat the portion (see FIG. 7 (c)).

In this case, as shown in FIG.
The focus position of 0a is set to a position apart from the steel wire 4, and the entire tip is heated (see FIG. 8 (a)). By shifting the focus position of the laser light 20a, a temperature gradient is generated in the axial direction of the tip portion, whereby the temperature of the central portion of the laser light 20a is the highest and the temperature becomes lower as it spreads in the axial direction.

By applying tension to the tip portion of the steel wire 4 in this state, the elongation of the high temperature portion at the center of the tip portion is the largest and the extension becomes smaller as it widens, so that it deforms into a taper shape (Fig. 8 ( b)). Next, tension is further applied, and the focal position of the laser beam 20a is narrowed down and brought closer to the steel wire 4, thereby further tapering, thereby forming the pointed portion 2d (see FIG. 8 (c)).

Subsequently, the focal position of the laser beam 20a is further narrowed down and the laser beam 20a is irradiated in the vicinity of the thinnest tip of the pointed portion 2d to melt the portion. Simultaneously with this fusing, the tip surface of the pointed portion 2d is melted and then cooled in a short time. Then, the end surface becomes spherical due to the surface tension at the time of melting, and in this state, it is rapidly cooled and solidified to form the spherical functional portion 2e (see FIG. 8D). As a result, the probe unit 1 of this embodiment is manufactured. After that,
Main body 2 of each probe pin 2 of this probe unit 1
The above-mentioned TAB is attached to a.

Next, the function and effect of this embodiment will be described. The probe unit 1 of the present embodiment is shown in FIGS.
As shown in FIG. 3, the conductivity inspection of the electrodes formed by patterning on the circuit board 17 of the semiconductor integrated circuit is performed. The probe unit 1 is arranged above the circuit board 17, and the probe unit 1 is vertically lowered to make the functional portion 2e of each probe pin 2 visible.
Is brought into contact with each electrode that is the surface A to be inspected of the circuit board 17. This checks the electrical continuity.

In this case, since the spherical functional portion 2e is formed at the tip of the probe pin 2 as shown in FIGS. 1 and 2, the contact resistance when the probe pin 2 is brought into contact with the surface A to be inspected can be reduced, Moreover, since the spherical surfaces make contact, the contact state at the time of contact can be stabilized, the contact position accuracy can be improved, and the approach to the contact point can be performed accurately.

In the present embodiment, the functional portion 2e is a rapidly solidified structure composed of an alloy of a low carbon two-phase structure steel wire 4 as a base material and a Ni film 5 and an Au precious metal film 6 as a function-imparting metal element. Therefore, it has a hardness higher than that of the base steel wire 4, and also has an excellent function in conductivity. Therefore, even if the continuity test is repeatedly performed, the wear of the functional portion 2e can be reduced, and thus the probe unit 1
The life of itself can be improved. Further, since the functional portion 2e is formed by laser heating, it can be manufactured easily and continuously, and productivity can be improved.

Here, conventionally, there is a method of separately welding and adhering a metal material to the end surface of the metal wire, but this has a structure in which only the mating surfaces of the two are joined and the structure can be easily removed. On the other hand, in the functional portion 2e of this embodiment, the end portion of the steel wire 4 as the base material and the Ni and Au coated on the end portion are integrally melted. It does not peel off or come off.

FIG. 9 is a characteristic diagram showing a change in hardness in the axial direction of the tip portion of the probe pin 2 of this embodiment. As is clear from the figure, the low carbon dual phase steel wire 4 of the base material
Has a constant hardness, and the tapered pointed portion 2d has a slightly higher hardness due to narrowing. On the other hand, since the functional part 2e has an alloyed rapidly solidified structure, the hardness is rapidly increased, and it can be seen that another function is added.

Further, according to the present embodiment, the protruding portion 2b of each probe pin 2 is curved from the shoulder portion 2c thereof toward the surface A to be inspected, and the tip portion is tapered in a tapered shape. Therefore, at the same time when the functional portion 2e comes into contact with the surface A to be inspected, the protrusion 2b is elastically deformed, whereby a high contact surface pressure can be obtained while keeping the load applied to the surface A to be inspected constant.
As a result, extremely good electrical conductivity can be obtained, and the reliability of the inspection performance can be improved. That is, in the case of a semiconductor integrated circuit, since the substrate area is small and the contact area of the electrodes is also very small, it is necessary to obtain conductivity at the same time when the probe pin 2 is abutted. The probe pin 2 of this embodiment can sufficiently cope with this.

10 and 11 are views for explaining a metal wire rod according to a modification of the above embodiment. In this embodiment, a case where the present invention is applied to a probe pin of a probe unit used for a continuity inspection of a liquid crystal display will be described as an example.

The probe unit 45 includes a resin base 4
0, the main body 41a of the probe pin 41 is fixedly attached at a predetermined pitch, and the basic structure is substantially the same as that of the above embodiment. The protruding portion 41b of the probe pin 41 is bent and formed so as to be inclined forward with respect to the surface A to be inspected, and the inclination angle is set to about 30 degrees.

Then, the protruding portion 41 of the probe pin 41 is provided.
The spherical functional portion 41 is provided at the tip end that abuts the surface A to be inspected b.
c is formed. The functional portion 41c is formed by irradiating a laser beam on the front end surface of the functional portion 41c to melt it, and then rapidly cooling it. As a result, the functional portion 41c is formed of the steel wire of the base metal and the same as in the above embodiment. Ni film coated on
It has a rapidly solidified structure alloyed with the Au film.

Next, a method of manufacturing the probe pin 41 will be described. Since the method of this embodiment is similar to the first to third steps described above, only the fourth step will be described. In FIG. 7B of the method of the above embodiment, the mold device 15
After bending the protruding portion 41b (corresponding to 2b in the figure) to a predetermined shape with, the holding base 13b side portion C of the steel wire 4 is cut with the cutting blade 42 in this state (see FIG. 11 (a)). .
Next, the laser heating device 20 irradiates the cut surface of the steel wire 4 with a laser beam 20a having a size equal to the wire diameter of the steel wire 4 in the direction orthogonal to the axis thereof. Then, the end face is locally melted into a spherical shape, and the functional part 41c having a rapidly solidified structure is formed by rapid cooling (FIG. 11).
(See (b)). Here, the irradiation direction of the laser beam 20a may be from either the direction orthogonal to the axis of the steel wire 4 or the axial direction. The focal point of the laser light 20a is 5 m from the steel wire 4
It is better to set them at positions separated by about m.

The probe unit 45 of this embodiment is used for the continuity inspection of the liquid crystal substrate 43 of the liquid crystal display, and the probe unit 45 is vertically lowered so that the functional portion 41c of each probe pin 41 becomes a liquid crystal substrate 43. Conductivity is checked by contacting each conductor wire which is the surface B to be inspected. In this case, the functional portion 41c of the probe pin 41 comes into contact with the surface B to be inspected and simultaneously slides forward. That is, in the case of a liquid crystal display, since the substrate area and the conductor length are larger than those of a semiconductor integrated circuit, it is better to slide by soft touch rather than point contact. On the other hand, since the probe pin 41 of this embodiment has a spherical functional portion 41c having a rapidly solidified structure at its tip, the contact resistance can be reduced as compared with the case of sliding a conventional corner edge. Therefore, excellent performances such as stabilizing the contact state at the time of contact and reducing deterioration due to wear can be obtained.

12 and 14 are views showing a fibrous metallographic structure of the functional portion 41c of the probe pin 41 of this embodiment and the tip surface of the conventional probe pin observed by SEM, respectively, and FIGS. FIG. 3 is a diagram showing a metal element obtained by analyzing each of the above-mentioned tip portions by EPMA.

In FIG. 14 and FIG. 15, in the case of the conventional probe pin, the tip surface of this is a fracture surface due to cutting, and only the metal element Au is detected. On the other hand, in the case of this embodiment shown in FIGS. 12 and 13, the tip has a spherical shape, and the functional portion is made of Si, Au, F.
The metal elements of e and Ni are detected. As described above, it is understood that the functional portion of this embodiment has a rapidly solidified structure in which the above metal elements are alloyed.

In the above embodiments, the case where the functional portion is formed by irradiating the tip end surface of the low carbon dual phase steel wire covered with the Ni film and the Au film with the laser beam has been described.
The present invention is not limited to this, and the following method can be adopted, for example.

In FIG. 16, another metal tip 47 is interposed on the end face 46a of the metal ultrafine wire 46, and the laser beam 20a is applied thereto.
Is irradiated to simultaneously melt and solidify the metal tip 47 and the end surface 46a, thereby forming a functional portion 46b in which the both are integrally alloyed. Further, for example, Au, Ag, Cu, P having excellent electrical conductivity can be added to the metal chip.
A new function can be imparted to the base material by using t or the like, using Cr, Si or the like having high hardness, or using Ni or the like having excellent corrosion resistance. Furthermore, in addition to the above metal chips, metal powder, metal paste,
A metal wire or the like may be used.

Further, in FIG. 17, a large number of metal fine wires 48 are arranged on the base 40 at a predetermined pitch, and conductive metal wires 49 are formed at the tips 48b of the projections 48a of each of the fine wires 48 in a direction perpendicular to the tips 48b. And the metal wire 49 and each tip 48
This is an example in which a laser beam 20a is sequentially irradiated to the intersections of b to form continuous spherical functional portions 48c on a straight line.

Further, in the above-mentioned embodiment, the case where the present invention is applied to the probe pin for continuity inspection has been described as an example, but the use of the metal wire of the present invention is not limited to this. For example, it can be applied to a dot pin used in a print head of a print printer, and in this case also, abrasion resistance can be improved by forming a functional portion on the tip surface of the dot pin.

[0052]

As described above, according to the metal wire rod and the method for manufacturing the same according to the present invention, the function-imparting metal element is integrally melted and solidified at the end face portion of the metal wire rod, alloyed at the end face portion, and rapidly cooled. Since the functional part having a solidified structure is formed, it is possible to add another new function to the function of the metal wire itself, for example, in the state where the strength and toughness of the metal wire are secured, Another function such as wear resistance or conductivity can be added, and there is an effect that high performance can be achieved.

[Brief description of drawings]

FIG. 1 is a side view illustrating a metal wire rod and a method for manufacturing the same according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a tip portion of a probe pin of the above embodiment.

FIG. 3 is a perspective view showing an inspection method using the probe unit of the above embodiment.

FIG. 4 is a cross-sectional view of the probe pin of the above embodiment.

FIG. 5 is a schematic configuration diagram showing a wiring device used in the manufacturing method of the above embodiment.

FIG. 6 is a process drawing for explaining the manufacturing method in the embodiment.

FIG. 7 is a process drawing for explaining the manufacturing method in the embodiment.

FIG. 8 is a process diagram for explaining a method of molding the functional portion of the pin of the embodiment.

FIG. 9 is a characteristic diagram showing hardness of the tip portion of the probe pin of the above-described embodiment.

FIG. 10 is a side view for explaining a metal wire rod and a method for manufacturing the same according to a modified example of the above embodiment.

FIG. 11 is a process drawing for explaining a method of molding a functional unit according to the above modification.

FIG. 12 is a view showing a fibrous metal structure of a functional portion of the example pin.

FIG. 13 is a diagram showing a metal element in a functional portion of the example pin.

FIG. 14 is a view showing a fibrous metal structure at the tip of a conventional probe pin.

FIG. 15 is a diagram showing a metal element of the conventional tip portion.

FIG. 16 is a diagram for explaining a modified example of the functional unit of the above embodiment.

FIG. 17 is a diagram for explaining another modification of the functional unit of the above embodiment.

FIG. 18 is a perspective view showing a conventional probe unit.

FIG. 19 is a side view showing a conventional probe unit.

[Explanation of symbols]

 2e, 41c, 46b, 48c Functional part 4 Low carbon dual phase steel wire (metal wire) 5 Ni film (functionalizing metal element) 6 Au film (functionalizing metal element)

Claims (3)

[Claims] 1. A metal, which is formed by alloying an end surface portion of a metal bus bar as a base material and a function-imparting metal element, and has a functional portion having a rapidly solidified structure on the end surface portion of the metal bus bar. wire. 2. The metal wire according to claim 1, wherein the function-imparting metal element is any one of a conductive metal material, a hard metal material, and a corrosion-resistant metal material. 3. A function-imparting metal element is arranged on an end face portion of a metal bus bar as a base material, and the arranged portion is irradiated with laser light to melt the end face portion and the metal element, followed by rapid cooling, Thus, a method of manufacturing a metal wire rod, wherein a functional portion formed by alloying the metal busbar with a metal element and having a rapidly solidified structure is formed at an end face portion of the metal busbar.