JPH06289056A - Probe unit - Google Patents

Abstract

PURPOSE:To provide a prove unit in which a contact resistance when a probe pin is brought into contact with a surface to be inspected is reduced to stabilize a contact state, a contact position accuracy can be improved and further surface pressure at the time of contact is increased to obtain an excellent electrical connection. CONSTITUTION:A probe pin 2 made of an extrafine metal wire having a diameter of 150mum and coated with a conductive metal film is so fixed as to partly protrude from an insulation base 3 at a predetermined pitch on the base 3, thereby forming a probe unit 1. In this case, a protruding part 2b of the pin 2 is bent in a shape having self-elasticity, a tapered pointed part 2d is formed at an end of the part 2b, and a spherical part 2e having a quenched solidified structure formed by melting and solidifying an end face of the wire is formed at an end of the part 2b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a probe unit used for inspecting electrical conductivity of a semiconductor integrated circuit (IC), a liquid crystal display (LCD), etc.
Specifically, the contact resistance when the probe pin is brought into contact with the surface to be inspected can be reduced to stabilize the contact state, the contact position accuracy can be improved, and the surface pressure at the time of contact can be increased to improve the contact state. The present invention relates to a probe pin structure capable of obtaining electric conduction.

[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, a probe unit as shown in FIGS. 16 and 17 has been conventionally used for conducting a continuity inspection of a conductor line of a liquid crystal substrate or a circuit wiring of an IC substrate (Japanese Patent Laid-Open No. 1-32115).
No. 8). In this probe unit 51, a probe pin 52 is composed of a U-shaped mounting portion 52a and a contact portion 52b. The mounting portion 52a is mounted on an insulating base 53 at a predetermined pitch, and the contact portion 52a is The structure is inclined with respect to the inspected substrate 50. In addition,
Reference numeral 54 is a lead wire connected to the measuring device. 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, in the above-mentioned conventional probe unit, since the end surface of the contact of the probe pin is cut in a direction orthogonal to the axis by a cutter or the like, when contacting the surface to be inspected. There is a problem that the contact resistance is large, and there is a problem that the contact state at the time of contact becomes unstable and the contact position accuracy cannot be improved.

Further, in the probe unit, it is necessary to absorb variations in the load on the surface to be inspected and to obtain conductivity at the same time when the probe unit is used, depending on its application. For that purpose, it is necessary to increase only the contact pressure of the probe pin without increasing the pressing load of the probe unit, and improvement in this respect is required.

The present invention has been made in view of the above-mentioned conventional circumstances, and it is possible to reduce the contact resistance when brought into contact with the surface to be inspected to stabilize the contact state and improve the contact position accuracy. Aims to provide a probe unit in which the surface pressure at the time of contact can be increased to obtain good electrical contact.

[0006]

In order to solve the problems, the invention of claim 1 provides probe pins made of a metal ultrafine wire having a wire diameter of 150 μm or less coated with a conductive metal film at a predetermined pitch on an insulating base. Further, in a probe unit in which a part of the probe pin is protruded and fixed from the base, the protrusion of the probe pin is bent and formed into a shape having self-elasticity, and abutted on a surface to be inspected of the protrusion. The feature is that a spherical portion is formed at the tip.

The invention according to claim 2 is characterized in that a tapered pointed portion is formed at the tip portion of the projecting portion, and a spherical surface portion that abuts on the surface to be inspected with high surface pressure is formed at the pointed portion. There is. Further, the invention of claim 3 is characterized in that the spherical portion is a rapidly solidified structure formed by melting and solidifying the tip of the metal ultrafine wire, and the invention of claim 4 is characterized in that the metal ultrafine wire has tensile strength. It is characterized by being a low-carbon dual-phase steel wire of 300 Kgf / mm ² or more.

Here, in order to form the spherical portion, for example, a chemical polishing method of dipping in an acid solution, an electrolytic polishing method, a heating by a burner, an infrared heating, a laser heating, an induction heating method or the like can be adopted. In particular, when the above laser heating method is used, it is easy to manufacture and the performance as a probe pin can be further improved. This laser heating method is a method in which the end surface of the cut metal ultrafine wire is irradiated with laser light to locally melt the end surface portion, and then cooled in a short time. That is, the end surface becomes spherical due to the surface tension at the time of melting, and the spherical portion is formed by rapid cooling in this state. In this case, the formed spherical surface portion has a rapidly solidified structure in which the metal ultrafine wire of the base material and the conductive metal or the like coated on the metal are alloyed. The spherical portion having such a rapidly solidified structure has excellent electrical conductivity and wear resistance as compared with the base material.

Further, the tapered pointed portion can be formed by drawing the wire by applying a tensile force while heating the tip portion of the protruding portion. In this case, when the laser heating method is used, the tip portion is irradiated with the laser beam to form a tapered point while drawing,
The spherical portion can be formed at the same time when this is fused.

Further, in addition to conventional materials such as tungsten wire and beryllium copper alloy wire, stainless wire, piano wire, amorphous wire, or low carbon dual phase steel wire can be adopted for the metal ultrafine wire. By using metal, it is possible to secure the rigidity and strength when it is made extremely thin. In particular, when the low carbon dual phase steel wire is adopted, the strength, rigidity, durability,
In addition, the toughness can be improved, and the diameter can be reduced and the pitch can be narrowed. This low carbon dual phase steel wire is produced by subjecting a wire material containing Fe as a main component to which C, Si, and Mn are added to a strong work by cold drawing, and thereby a wire diameter. The tensile strength is 300 to 600 Kgf / mm ² at 150 μm or less (see JP-A-62-20824).

[0011]

According to the probe unit of the first aspect of the present invention, the protruding portion of the probe pin is formed by bending into a shape having self-elasticity, and the spherical portion is formed at the tip end of the protruding portion that abuts the surface to be inspected. , The contact resistance at the time of contacting the surface to be inspected can be reduced, and the contact state at the time of contact can be stabilized accordingly.
In addition, the contact position accuracy can be improved.

According to the second aspect of the present invention, since the tapered pointed portion is formed at the tip portion of the protruding portion and the spherical portion is formed at the tip end of the pointed portion, the contact with the surface to be inspected is made at the same time. The pressure is significantly increased, and good electrical conductivity can be instantaneously obtained without increasing the pressing load of the probe unit.

Further, according to the invention of claim 3, since the spherical surface portion having the rapidly solidified structure is formed by melting and solidifying the end surface of the metal ultrafine wire, the spherical surface portion formed by this is formed as described above. It has a metallographic structure in which a metal ultrafine wire and a conductive metal are alloyed, and it is possible to obtain excellent wear resistance and electrical conductivity with high hardness, and as a result, the life as a probe unit. Can be extended.

Further, in the invention of claim 4, since the low carbon dual phase steel wire is adopted as the ultrafine metal wire, the tensile strength of 300 to 600 Kgf / mm ² can be obtained with the wire diameter of 150 μm or less. Therefore, when this is adopted, the strength, rigidity, and toughness can be improved while reducing the diameter and the pitch, and the function as a probe pin can be further improved.

[0015]

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

In the figure, reference numeral 1 is a probe unit of this 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 a unidirectional fiber form. It has a fine fibrous microstructure and has a tensile strength of 30.
It is 0 to 600 Kgf / mm ² . Also, the above low carbon dual phase steel wire 4
Has been subjected to stretcher annealing treatment,
This is the steel wire 4 heat-treated at a predetermined temperature while applying tension. By this heat treatment, the probe pin 2 which is linearly stretched is formed.

The Ni film 5 has a working strain due to plastic working during cold drawing of the metal wire, which improves self-lubricating property and corrosion resistance. 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 plating are crushed during the wire drawing, resulting in a smooth surface with no defects.

Each of the probe pins 2 is composed of a body portion 2a located on the resin base 3 and a protruding portion 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. This is because the low carbon dual phase steel wire 4 is placed on the resin base 3 by applying tension in a tensioned state, and the main body 2a is heated in this state to contact the main body 2a. 3 was melted and buried.

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 portion 2e is formed at the tip of the pointed portion 2d of the projecting portion 2b, and the spherical portion 2e contacts the surface A to be inspected. This spherical surface portion 2e is the same as the protruding portion 2
It is formed by drawing the tip portion of b with a laser beam while pulling it in a tensioned state and drawing it to form a tapered pointed portion 2d, melting the tip surface of this, and then rapidly cooling it. It is a thing. As a result, the spherical surface 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 covering 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 method includes a step and a fourth step of forming the pointed portion 2d and the spherical surface 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 for 30 seconds in a heating furnace heated to, for example, 430.degree. 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.

A rectangular plate-shaped mother base 13 used for the above-mentioned 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 arranged 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, both of the clamp devices 10a are moved in the direction a to set the low carbon dual phase steel wire 4 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 wiring-laid mother base 13 is set in the pin forming die device 15, and the device 15 holds the holding bases 13b at both ends of the mother base 13 in the steel wire 4 direction and the 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 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 heating device 20 is used to move the tip portion of the protrusion 2b to the laser beam 20.
It is irradiated with a and heated (see FIG. 7 (c)).

In this case, as shown in FIG.
The focal position of 0a is set to a position apart from the steel wire 4, and the entire tip portion is heated (see FIG. 8 (a)). By shifting the focal position of the laser light 20a, a temperature gradient is formed 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 expands, 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)).

Then, the focal position of the laser beam 20a is further narrowed down and the laser beam 20a is irradiated near the thinnest tip of the pointed portion 2d, and the portion is fused. 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.
e is formed (see FIG. 8 (d)). As a result, the probe unit 1 of this embodiment is manufactured. After that, the above-mentioned TAB is attached to the main body portion 2a of each probe pin 2 of the probe unit 1.

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 a spherical surface portion 2e of each probe pin 2.
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, as shown in FIGS. 1 and 2, since the spherical portion 2e is formed at the tip of the probe pin 2, the contact resistance when the probe pin 2 is brought into contact with the surface A to be inspected can be reduced and the spherical surface Since the contact is made, the contact state at the time of contact can be stabilized and the contact position accuracy can be improved.

Further, in this embodiment, since the spherical surface portion 2e has a rapidly solidified structure made of an alloy of the low carbon dual phase steel wire 4 and the Ni film 5 and the Au precious metal film 6, the base steel wire is used. Four
It has a higher hardness than that of, and also has an excellent function in conductivity. Therefore, even if the continuity test is repeated, the wear of the spherical surface portion 2e can be reduced, and the life of the probe unit 1 itself can be improved. Further, the spherical surface portion 2
Since e is formed by laser heating, it can be manufactured easily and continuously, and productivity can be improved.

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 spherical surface portion 2e has an alloyed rapidly solidified structure, the hardness is rapidly increased, and it can be seen that different functions are imparted.

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 spherical surface portion 2e contacts the surface A to be inspected, the projecting portion 2b elastically deforms, whereby a high contact surface pressure is instantaneously obtained while the load applied to the surface A to be inspected is kept 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 probe unit according to a modification of the above embodiment. This embodiment is applied to a probe unit used for a continuity inspection of a liquid crystal display.

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
A spherical surface portion 41c is formed at the tip end of the surface b which contacts the surface A to be inspected. This spherical surface portion 41c is formed by irradiating the tip surface of the spherical surface with a laser beam to melt it, and then rapidly cooling it. As a result, the spherical surface portion 41c is formed of the steel wire of the base material and the same as in the above embodiment. It has a rapidly solidified structure in which the Ni film and the Au film coated on the alloy are alloyed.

The spherical portion 41c is manufactured by the following method. In FIG. 7 (b) of the above-described embodiment method, the protrusion 41b (corresponding to 2b in the figure) in the mold device 15 is used.
After being bent into a predetermined shape, the holding wire 13b side portion C of the steel wire 4 is cut by 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 to form a spherical surface, and the spherical surface 41c is manufactured by rapidly cooling the end surface (FIG. 11).
(See (b)). Here, the irradiation direction of the laser beam 20a may be a direction orthogonal to the axis of the steel wire 4 or may be from the axial direction. The focal position of the laser light 20a is 5 mm from the steel wire 4
Set them at positions that are about a distance apart.

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 spherical surface portion 41c of each probe pin 41 is attached to the liquid crystal substrate 43. Conductivity is checked by contacting each conductor wire which is the surface B to be inspected. In this case, the spherical 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, in the probe pin 41 of this embodiment, the tip end of the probe pin 41 is the spherical surface portion 41c having the rapidly solidified structure, so that the contact resistance can be reduced as compared with the case of sliding the conventional corner edge. Excellent performance is obtained such that the contact state at the time of contact can be stabilized and deterioration due to wear can be reduced.

FIGS. 12 and 14 are views showing a fibrous metal structure obtained by observing the spherical surface portion 41c of the probe pin 41 of the present embodiment and the tip end surface of the conventional probe pin 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 FIGS. 14 and 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 is spherical and the spherical portion is made of Si, Au, F.
The metal elements of e and Ni are detected. Thus, it can be seen that the spherical portion of this example has a rapidly solidified structure in which the above metal elements are alloyed.

[0049]

As described above, according to the probe unit of the present invention, since the spherical portion is formed at the tip of the probe pin that contacts the surface to be inspected, the contact resistance when contacting the surface to be inspected is small. Yes, you can stabilize the contact state,
This has the effect of improving the contact position accuracy. Further, in claim 3, since the spherical surface portion has a rapidly solidified structure formed by melting and solidifying, there is an effect that high hardness and excellent wear resistance can be obtained. Further, in claim 2, the tip of the probe pin is obtained. Since the tapered point is formed on the spherical surface, there is an effect that a high contact pressure can be instantaneously obtained at the same time when the surface to be inspected is contacted. Further, in the invention of claim 4, since the low carbon dual-phase steel wire is adopted as the ultrafine metal wire, the tensile strength of 300 to 600 Kgf / mm ² can be obtained at the wire diameter of 150 μm or less, and the diameter reduction and pitch It has the effect of improving strength, rigidity, and toughness while achieving narrowing.

[Brief description of drawings]

FIG. 1 is a side view illustrating a probe unit according to an exemplary 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 method of manufacturing the unit of the embodiment.

FIG. 6 is a process drawing for explaining the manufacturing method of the example unit.

FIG. 7 is a process drawing for explaining the manufacturing method of the example unit.

FIG. 8 is a process chart for explaining a method of forming the pointed portion and the spherical portion of the unit of the above 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 probe unit according to another embodiment of the above embodiment.

FIG. 11 is a process drawing for explaining a method of forming a spherical surface portion according to another embodiment.

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

FIG. 13 is a diagram showing a metal element in a spherical surface 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 perspective view showing a conventional probe unit.

FIG. 17 is a side view showing a conventional probe unit.

[Explanation of symbols]

 1,45 Probe unit 2,41 Probe pin 2b, 41b Protruding part 2d Sharp part 2e, 41c Spherical part 3,40 Insulating base 4 Low carbon two-phase structure steel wire (fine metal wire) 6 Conductive metal film A, B Inspection surface

Claims (4)

[Claims] 1. A wire diameter 150 coated with a conductive metal film.
A probe unit in which a probe pin made of a metal ultrafine wire of μm or less is fixed on an insulating base at a predetermined pitch, and a part of the probe pin is protruded from the base to be fixed, A probe unit characterized in that the protrusion is formed by bending into a shape having self-elasticity, and a spherical portion is formed at the tip of the protrusion contacting the surface to be inspected. 2. A wire diameter 150 coated with a conductive metal film.
A probe unit in which a probe pin made of a metal ultrafine wire of μm or less is fixed on an insulating base at a predetermined pitch, and a part of the probe pin is protruded from the base to be fixed, The protrusion is formed by bending into a shape having self-elasticity, the tip of the protrusion is formed with a tapered pointed portion, and the pointed portion is formed with a spherical portion that comes into contact with the surface to be inspected with high surface pressure. Characteristic probe unit. 3. The probe unit according to claim 1 or 2, wherein the spherical surface portion has a rapidly solidified structure formed by melting and solidifying the tip of the metal ultrafine wire. 4. The probe unit according to claim 1, wherein the fine metal wire is a low carbon dual phase steel wire having a tensile strength of 300 Kgf / mm ² or more.