Contact probe

Abstract

To provide a contact probe capable of maintaining stable contact resistance during repeated use.SOLUTION: The contact probe according to the present invention is a contact probe that transmits signals by contacting different electrodes at both ends in a longitudinal direction, and comprises a conductive member extending in the longitudinal direction and a pipe member provided at least one end of the conductive member and made of a platinum group element or an alloy containing a platinum group element as a main component, where the pipe member has a flat shape at one end.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a contact probe.

Background Art

[0002] Conventionally, when performing a conduction state inspection or an operation characteristic inspection of an inspection target such as a semiconductor integrated circuit (package) or a liquid crystal panel, in order to establish an electrical connection between the inspection target and a signal processing device that outputs an inspection signal, a probe unit that houses a plurality of contact probes, which are connection terminals, is used. As a probe unit, a probe unit having a contact probe that electrically connects between a semiconductor integrated circuit and a circuit board by contacting electrodes of an electric circuit of a printed wiring board and electrodes of a circuit board that outputs an inspection signal at both ends is disclosed (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, the contact probe described above is repeatedly used for inspections. For this reason, there has been a risk that the contact resistance changes due to wear and tear of the end portion of the contact probe or by scraping the plating or base material of the electrode on the substrate side. The contact probe disclosed in Patent Document 1 is provided with a detachable chip at the end portion, and by replacing this chip, changes in electrical characteristics due to wear are suppressed. However, in view of the difficulty of specifying the timing of chip replacement and the labor involved in the replacement, it is required to improve the durability of the contact portion itself.

[0005] The present invention has been made in view of the above, and an object thereof is to provide a contact probe and a signal transmission method that can maintain a stable contact resistance in repeated use.

Means for Solving the Problems

[0006] In order to solve the above-described problems and achieve the object, a contact probe according to the present invention is a contact probe that transmits a signal by contacting different electrodes at both ends in the longitudinal direction, and includes a conductive member extending in the longitudinal direction, and a pipe member provided at at least one end of the conductive member and made of a platinum group element or an alloy mainly composed of the platinum group element.

[0007] Further, the contact probe according to the present invention is the above invention, wherein the conductive member has a first plunger located on one end side in the longitudinal direction, a second plunger located on the other end side in the longitudinal direction, and a coil spring connected to the first plunger at one end and connected to the second plunger at the other end.

[0008] Further, the contact probe according to the present invention is the above invention, wherein the pipe member is made of a single platinum group element.

[0009] Further, the contact probe according to the present invention is the above invention, wherein the conductive member has a protruding portion that protrudes in a direction perpendicular to the longitudinal direction and presses against the pipe member.

[0010] Further, the contact probe according to the present invention is the above invention, wherein the conductive member is provided at an end portion to which the pipe member is attached, and has a flat surface portion perpendicular to a direction perpendicular to the longitudinal direction.

[0011] Further, in the contact probe according to the present invention, in the above invention, the conductive member has a tip portion press-fitted into the pipe member, and the pipe member covers the entire tip portion.

[0012] Further, in the contact probe according to the present invention, in the above invention, the conductive member has a tip portion press-fitted into the pipe member, and the pipe member covers a part of the tip portion.

[0013] Further, in the contact probe according to the present invention, in the above invention, the conductive member has a tip portion press-fitted into the pipe member, and a convex portion that locks to the tip portion is formed on the inner peripheral surface of the pipe member.

[0014] Further, in the contact probe according to the present invention, in the above invention, a concave portion that locks to the convex portion is formed at the tip portion.

[0015] Further, in the contact probe according to the present invention, in the above invention, the pipe member has a cylindrical shape in which a plane passing through an opening on one end side and a plane passing through an opening on the other end side are parallel to each other.

[0016] Further, in the contact probe according to the present invention, in the above invention, the pipe member has a cylindrical shape in which a plane passing through an opening at one end is inclined with respect to the central axis.

[0017] Further, in the contact probe according to the present invention, in the above invention, one end of the pipe member has a flat shape.

[0018] Further, in the contact probe according to the present invention, in the above invention, in the portion having the flat shape, the inner peripheral surfaces of the pipe member are in contact with each other.

[0019] In addition, in the contact probe according to the present invention, in the above invention, one end of the pipe member forms a chamfered curved surface, which is characterized in that.

[0020] In addition, in the contact probe according to the present invention, in the above invention, the pipe member is provided at an end on the side opposite to the side connected to the conductive member, and has a reduced-diameter portion that tapers toward the tip, which is characterized in that.

Effect of the Invention

[0021] According to the present invention, there is an effect that a stable contact resistance can be maintained in repeated use.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Embodiments for Carrying Out the Invention

[0023] Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited by the following embodiments. Also, each drawing referred to in the following description only schematically shows the shape, size, and positional relationship to the extent that the content of the present invention can be understood. Therefore, the present invention is not limited only to the shape, size, and positional relationship illustrated in each drawing.

[0024] FIG. 1 is a perspective view showing the configuration of a probe unit according to an embodiment of the present invention. The probe unit 1 shown in FIG. 1 is a device used when performing an electrical characteristic inspection of a semiconductor integrated circuit 100 as an object to be inspected, and is a device that electrically connects between the semiconductor integrated circuit 100 and a circuit board 200 that outputs an inspection signal to the semiconductor integrated circuit 100.

[0025] The probe unit 1 includes a conductive contact probe 2 (hereinafter simply referred to as "probe 2") that contacts two different objects to be contacted at both ends in the longitudinal direction, namely, the semiconductor integrated circuit 100 and the circuit board 200, a probe holder 3 that houses and holds a plurality of probes 2 according to a predetermined pattern, and a holder member 4 provided around the probe holder 3 to suppress the occurrence of misalignment of the semiconductor integrated circuit 100 that contacts a plurality of probes 2 during inspection.

[0026] FIG. 2 is a partial cross-sectional view showing a detailed configuration of the probe 2 housed in the probe holder 3. The probe 2 shown in FIG. 2 is formed of a conductive material, and includes a first plunger 21 located on the semiconductor integrated circuit 100 side when inspecting the semiconductor integrated circuit 100, a second plunger 22 that contacts an electrode of a circuit board 200 provided with an inspection circuit, a coil spring 23 provided between the first plunger 21 and the second plunger 22 to connect the first plunger 21 and the second plunger 22 in a telescopic manner, and a pipe member 24 provided on the first plunger 21 to contact an electrode of the semiconductor integrated circuit 100. The first plunger 21, the second plunger 22, the coil spring 23, and the pipe member 24 constituting the probe 2 have the same axis. That is, the central axes of the first plunger 21, the second plunger 22, the coil spring 23, and the pipe member 24 are located on the same straight line. When the semiconductor integrated circuit 100 is contacted, the probe 2 reduces the impact on the electrode of the semiconductor integrated circuit 100 by the telescopic movement of the coil spring 23 in the axial direction and applies a load to the semiconductor integrated circuit 100 and the circuit board 200. In this specification, "identical (equivalent)" includes manufacturing errors.

[0027] The first plunger 21 has a tip portion 21a to which the pipe member 24 is attached, a flange portion 21b having a diameter larger than that of the tip portion 21a, a boss portion 21c that extends to the side opposite to the tip portion 21a via the flange portion 21b and into which one end of the coil spring 23 is press-fitted and has a diameter smaller than that of the flange portion 21b, and a base end portion 21d that extends to the side opposite to the flange portion 21b via the boss portion 21c and has a diameter smaller than that of the boss portion 21c. The first plunger 21 is movable in the axial direction by the expansion and contraction action of the coil spring 23 and is biased in the direction of the semiconductor integrated circuit 100 by the elastic force of the coil spring 23.

[0028] The second plunger 22 has a tapered tip shape, a tip portion 22a that contacts the electrode of the circuit board 200, a flange portion 22b having a diameter larger than that of the tip portion 22a, a boss portion 22c that extends to the side opposite to the tip portion 22a via the flange portion 22b and into which the other end of the coil spring 23 is press-fitted and has a diameter smaller than that of the flange portion 22b, and a base end portion 22d that extends to the side opposite to the flange portion 22b via the boss portion 22c and has a diameter smaller than that of the boss portion 22c. The second plunger 22 is movable in the axial direction by the expansion and contraction action of the coil spring 23 and is biased in the direction of the circuit board 200 by the elastic force of the coil spring 23 and contacts the electrode of the circuit board 200.

[0029] One end of the coil spring 23 is attached to the boss portion 21c of the first plunger 21, and it has a closely wound portion 23a formed by closely winding a wire material, and a coarsely wound portion 23b that extends from the other end of the closely wound portion 23a and is wound at a predetermined interval and attached to the boss portion 22c. The coarsely wound portion 23b is preferably wound at an interval such that the adjacent wire materials do not contact each other in the axial direction of the winding when the probe 2 is maximally contracted. The coil spring 23 is formed by winding, for example, a single conductive wire material.

[0030] The end of the closely wound portion 23a is joined to the boss portion 21c of the first plunger 21, for example, by the winding force of the spring and / or soldering, and is in contact with the flange portion 21b. On the other hand, the end of the coarsely wound portion 23b is in contact with the flange portion 22b. The second plunger 22 and the coil spring 23 may also be joined by the winding force of the spring and / or soldering. The probe 2 expands and contracts in the axial direction due to the expansion and contraction of the coarsely wound portion 23b.

[0031] The pipe member 24 has a cylindrical shape in which a plane passing through the opening on one end side and a plane passing through the opening on the other end side are parallel to each other. The outer diameter of the pipe member 24 is smaller than the diameter of the flange portion 21b. The pipe member 24 is press-fitted and attached to the tip portion 21a of the first plunger 21, for example. In addition, the pipe member 24 may be attached to the tip portion 21a by known joining such as soldering, brazing, or welding.

[0032] The pipe member 24 is formed using a conductive material composed of a platinum group element. Examples of the material constituting the pipe member 24 include platinum group metals and alloys mainly composed of platinum group metals. Here, the main component refers to the component with the highest content rate among the elements constituting the alloy. The alloy is preferably an alloy composed of a plurality of different platinum group elements. Note that the platinum group elements in this specification refer to the elements of Group 8, Group 9, and Group 10 in the 5th and 6th periods of the periodic table, that is, ruthenium, rhodium, palladium, osmium, iridium, and platinum. The pipe member 24 is preferably formed of a single platinum group element.

[0033] On the other hand, the first plunger 21, the second plunger 22, and the coil spring 23 are formed using a conductive material. Examples of the conductive material include beryllium copper. The conductive material forming the first plunger 21, the second plunger 22, and the coil spring 23 has lower hardness and oxidation resistance than the conductive material (platinum group element) forming the pipe member 24.

[0034] The probe holder 3 is formed using an insulating material such as resin, machinable ceramic, or silicon, and is formed by laminating a first member 31 located on the upper surface side in FIG. 2 and a second member 32 located on the lower surface side. A plurality of holder holes 33 and 34 for accommodating the plurality of probes 2 are formed in the first member 31 and the second member 32 in the same number respectively, and the holder holes 33 and 34 for accommodating the probes 2 are formed such that their axes coincide with each other. The formation positions of the holder holes 33 and 34 are determined according to the wiring pattern of the semiconductor integrated circuit 100.

[0035] Both the holder holes 33 and 34 have a stepped hole shape with different diameters along the penetration direction. That is, the holder hole 33 includes a small-diameter portion 33a having an opening on the upper end surface of the probe holder 3 and a large-diameter portion 33b having a larger diameter than the small-diameter portion 33a. On the other hand, the holder hole 34 includes a small-diameter portion 34a having an opening on the lower end surface of the probe holder 3 and a large-diameter portion 34b having a larger diameter than the small-diameter portion 34a. The shapes of these holder holes 33 and 34 are determined according to the configuration of the probe 2 to be accommodated. The flange portion 21b of the first plunger 21 has a function of preventing the probe 2 from being pulled out of the probe holder 3 by contacting the boundary wall surface between the small-diameter portion 33a and the large-diameter portion 33b of the holder hole 33. Also, the flange portion 22b of the second plunger 22 has a function of preventing the probe 2 from being pulled out of the probe holder 3 by contacting the boundary wall surface between the small-diameter portion 34a and the large-diameter portion 34b of the holder hole 34.

[0036] FIG. 3 is a diagram showing the state during the inspection of the semiconductor integrated circuit 100 using the probe holder 3. During the inspection of the semiconductor integrated circuit 100, the coil spring 23 is compressed along the longitudinal direction due to the contact load from the semiconductor integrated circuit 100. When the coil spring 23 is compressed, the pitch of the coarse-wound portion 23b becomes smaller. At this time, since the closely-wound portion 23a contacts the base end portion 22d, the axis of the second plunger 22 does not deviate significantly from the axis of the first plunger 21.

[0037] During inspection, the inspection signal supplied from the circuit board 200 to the semiconductor integrated circuit 100 reaches the electrode 101 of the semiconductor integrated circuit 100 via the second plunger 22 of the probe 2, the coil spring 23, the first plunger 21, and the pipe member 24 from the electrode 201 of the circuit board 200.

[0038] In the embodiment described above, the pipe member 24 made of a platinum group element is attached to the first plunger 21, and electrical conduction is achieved by bringing the pipe member 24 into contact with the electrode 101 of the semiconductor integrated circuit 100. According to this embodiment, a stable contact resistance can be maintained in repeated use.

[0039] (Modification 1) FIG. 4 is a partial cross-sectional view showing the configuration of the first plunger and the pipe member in the probe unit according to Modification 1 of the embodiment of the present invention. Modification 1 has the same configuration as the above-described embodiment except for the configuration of the tip of the first plunger and the pipe member. The same components as those in the above-described embodiment are denoted by the same reference numerals.

[0040] The probe according to Modification 1 is formed of a conductive material and includes a first plunger 21A located on the side of the semiconductor integrated circuit 100 when inspecting the semiconductor integrated circuit 100, a second plunger 22 that contacts the electrode of the circuit board 200, a coil spring 23 provided between the first plunger 21A and the second plunger 22 to connect the first plunger 21A and the second plunger 22 so as to be telescopically connected, and a pipe member 24A provided on the first plunger 21A to contact the electrode of the semiconductor integrated circuit 100.

[0041] A recess 21e is formed at the tip portion 21a so as to go around the outer surface with the longitudinal direction of the first plunger 21A as the central axis.

[0042] The pipe member 24A contacts the electrode of the semiconductor integrated circuit 100. The pipe member 24A has an outer diameter smaller than the diameter of the flange portion 21b. The pipe member 24A is formed using the above-described platinum group element.

[0043] FIG. 5 is a perspective view showing the configuration of the pipe member in Modification 1 of the embodiment of the present invention. In the pipe member 24A, a convex portion 24a is formed that circulates around the inner peripheral surface around the central axis of the pipe member 24A. The pipe member 24A is fixed with the convex portion 24a locked to the concave portion 21e of the tip portion 21a.

[0044] FIGS. 6 and 7 are diagrams for explaining a method of attaching the first plunger and the pipe member in Modification 1 of the embodiment of the present invention. First, the base material 241 of the pipe member 24A is placed on the tip portion 21a (see FIG. 6). Here, the base material 241 is a cylindrical member in which the convex portion 24a is not formed. Further, a concave portion 21e is formed in advance at the tip portion 21a.

[0045] After covering the tip portion 21a with the base material 241, the convex portion 24a is formed in accordance with the formation position of the concave portion 21e. As a result, the pipe member 24A is locked to the first plunger 21A (see FIG. 7). Note that the inner diameter of the base material 241 is, for example, equal to or greater than the outer diameter of the tip portion.

[0046] In Modification 1 described above, while obtaining the effects of the above-described embodiment, by forming the concave portion 21e and the convex portion 24a in the tip portion 21a and the pipe member 24A, respectively, the fixing state of the pipe member 24A to the tip portion 21a can be further stabilized.

[0047] In Modification 1, the locking state between the first plunger 21A and the pipe member 24A may be a state where it does not rotate around the central axis, or may be a state where it is rotatable around the central axis. Further, after press-fitting the tip portion of the first plunger 21A into the pipe member 24A, the convex portion 24a may be formed.

[0048] In Modification 1, the configuration in which the convex portion 24a is continuously provided around the central axis of the pipe member 24A has been described, but a configuration in which a plurality of convex portions are provided on a part of the inner peripheral surface of the pipe member 24A may also be used.

[0049] Further, the concave portion 21e according to the first modification may be provided at the proximal end on the flange portion 21b side at the distal end portion 21a, and the end portion on the side located on the flange portion 21b side of the pipe member 24A may be bent inward to lock and fix the pipe member 24A and the concave portion 21e of the distal end portion 21a.

[0050] (Second Modification) FIG. 8 is a partial cross-sectional view showing the configuration of the first plunger and the pipe member in the probe unit according to the second modification of the embodiment of the present invention. The second modification is the same as the configuration of the above-described embodiment except that the configuration of the first plunger and the attachment mode of the pipe member to the first plunger are changed. The same components as those in the above-described embodiment are denoted by the same reference numerals.

[0051] The probe according to the second modification is formed using a conductive material, and includes a first plunger 21B located on the semiconductor integrated circuit 100 side when inspecting the semiconductor integrated circuit 100, a second plunger 22 that contacts the electrode of the circuit board 200, a coil spring 23 provided between the first plunger 21B and the second plunger 22 to connect the first plunger 21B and the second plunger 22 so as to be telescopically connected, and a pipe member 24 provided on the first plunger 21B and contacting the electrode of the semiconductor integrated circuit 100.

[0052] The first plunger 21B has a distal end portion 21f to which the pipe member 24 is attached, a flange portion 21b having a diameter larger than that of the distal end portion 21f, a boss portion 21c, and a proximal end portion 21d.

[0053] On the distal end portion 21f, a convex portion 21g extending in a columnar shape having a diameter equivalent to the inner diameter of the pipe member 24 is formed on the side opposite to the side connected to the flange portion 21b (the distal end). The convex portion 21g is press-fitted into the pipe member 24. Thereby, the pipe member 24 is erected on the distal end portion 21f.

[0054] According to Modification Example 2 described above, even when the first plunger is press-fitted into a part of the pipe member to fix the pipe member to the first plunger, the effects of the above-described embodiment can be obtained.

[0055] Also, according to Modification Example 2, by adopting a configuration in which the pipe member 24 is attached to the convex portion 21g formed at the tip portion 21f, the length of the pipe member in the central axis direction (longitudinal direction) can be made shorter than that of the above-described embodiment.

[0056] Further, according to Modification Example 2, at the tip portion 21f, by making the diameter of the outer periphery of the portion other than the convex portion 21g larger than the diameter of the outer periphery of the pipe member 24, when the contact probe slides (expands and contracts) in the probe holder 3, it is possible to suppress the pipe member from contacting the probe holder 3. As a result, it is possible to prevent the pipe member from detaching due to friction between the pipe member and the probe holder.

[0057] (Modification Example 3) FIG. 9 is a perspective view showing the configuration of the tip portion of the first plunger in Modification Example 3 of the embodiment of the present invention. Modification Example 3 has the same configuration as the above-described embodiment except for changing the configuration of the tip of the first plunger. The same components as those in the above-described embodiment are denoted by the same reference numerals.

[0058] The tip portion 21h of the first plunger according to Modification Example 3 has a protruding portion 21i that protrudes by orbiting the outer surface around the longitudinal direction of the first plunger as the central axis. The diameter of the portion of the tip portion 21h other than the protruding portion 21i is smaller than the inner diameter of the pipe member 24. On the other hand, the maximum of the diameters formed by the outer periphery of the protruding portion 21i is equal to or larger than the inner diameter of the pipe member 24. The pipe member 24 is press-fitted and attached with the tip portion 21h. At this time, the protruding portion 21i is in pressure contact with the inner wall of the pipe member 24.

[0059] In the above-described Modification 3, while obtaining the effects of the above-described embodiment, the protruding portion 21i formed at the tip portion 21h can further stabilize the fixed state of the pipe member 24 with respect to the tip portion 21h by press-fitting into the pipe member 24.

[0060] In the above-described Modification 3, the configuration in which one protruding portion 21i is provided in the longitudinal direction of the first plunger has been described. However, a configuration in which a plurality of protruding portions 21i are provided in the longitudinal direction may also be used.

[0061] (Modification 4) FIG. 10 is a perspective view showing the configuration of the tip portion of the first plunger in Modification 4 of the embodiment of the present invention. Modification 4 has the same configuration as the above-described embodiment except for changing the configuration of the tip of the first plunger. The same components as those in the above-described embodiment are denoted by the same reference numerals.

[0062] The tip portion 21j of the first plunger according to Modification 4 has a tapered reduced-diameter portion 21k provided at the tip on the side opposite to the flange portion 21b. When the pipe member 24 inserts the tip portion 21j by means of the reduced-diameter portion 21k, the tip portion 21j is guided with respect to the pipe member 24.

[0063] In the above-described Modification 4, while obtaining the effects of the above-described embodiment, the reduced-diameter portion 21k formed at the tip portion 21j can facilitate the insertion into the pipe member 24.

[0064] Note that Modifications 3 and 4 described above may be combined to form a tip portion having one or more protruding portions and a reduced diameter at the tip.

[0065] (Modification 5) FIG. 11 is a perspective view showing the configuration of the tip portion of the first plunger in Modification 5 of the embodiment of the present invention. Modification 5 has the same configuration as the above-described embodiment except for changing the configuration of the tip of the first plunger. The same components as those in the above-described embodiment are denoted by the same reference numerals.

[0066] The tip 21l of the first plunger according to Modification 5 has a flat portion 21m formed by cutting out a part of the cylindrical side surface. The flat portion 21m forms a plane perpendicular to the direction orthogonal to the longitudinal direction of the probe. Note that a flat portion having a surface parallel to the surface of the flat portion 21m may be provided on the side opposite to the flat portion 21m.

[0067] Modification 5 described above can obtain the effects of the above-described embodiment, and the tip 21l can be easily inserted into the pipe member 24, and the diameter control between the tip 21l and the pipe member 24 can be simplified.

[0068] In addition to Modification 5 described above, the tip may be configured to form a slit cut along the longitudinal direction of the first plunger. Further, a slit extending in the central axis direction of the pipe member may be formed in a part of the pipe member. By forming a slit in either the tip or the pipe member, the same effects as those of Modification 5 can be obtained.

[0069] (Modification 6) FIG. 12 is a perspective view showing the configuration of a pipe member in Modification 6 of the embodiment of the present invention. Modification 6 has the same configuration as that of the above-described embodiment except that the configuration of the pipe member is changed. The same components as those in the above-described embodiment are denoted by the same reference numerals.

[0070] The pipe member 24B according to Modification 6 has a reduced-diameter portion 24b in which the end portion on the side opposite to the side into which the tip 21a is inserted is reduced in diameter toward the tip.

[0071] Modification 6 described above can obtain the effects of the above-described embodiment, and the reduced-diameter portion 24b formed in the pipe member 24B can ensure contact even when the electrode is small.

[0072] Further, in addition to the reduced-diameter portion 24b according to Modification 6 described above, the pipe member may be configured to have a diameter-expanded portion that expands in diameter toward the tip, or may be configured to have a crown shape having a plurality of claw portions.

[0073] (Modification Example 7) FIG. 13 is a cross-sectional view showing the configuration of the tip of the pipe member in Modification Example 7 of the embodiment of the present invention. Modification Example 7 has the same configuration as the above-described embodiment except that the configuration of the pipe member is changed. The same components as those in the above-described embodiment are denoted by the same reference numerals.

[0074] The pipe member 24C according to Modification Example 7 has an end portion 24c that is chamfered to form a curved surface at the end opposite to the side where the tip portion 21a is inserted. The end portion 24c is chamfered at both the end face on the outer surface side and the end portion on the inner peripheral surface side.

[0075] Modification Example 7 described above can obtain the effects of the above-described embodiment, and the end portion 24c formed on the pipe member 24C can suppress damage to the electrode of the contact target.

[0076] (Modification Example 8) FIG. 14 is a perspective view showing the configuration of the pipe member in Modification Example 8 of the embodiment of the present invention. Modification Example 8 has the same configuration as the above-described embodiment except that the configuration of the pipe member is changed. The same components as those in the above-described embodiment are denoted by the same reference numerals.

[0077] The pipe member 24D according to Modification Example 8 has a flat portion 24d formed by pressing at the end opposite to the side where the tip portion 21a is inserted. The end face (upper surface) of the flat portion 24d forms a plane having arc-shaped or linear opposing outer edges. At least a part of the inner peripheral surfaces in the flat portion 24d are in contact with each other.

[0078] According to Modification Example 8 described above, even when the pipe member 24D has the flat portion 24d, the effects of the above-described embodiment can be obtained. Further, according to Modification Example 8, since the tip of the pipe member 24D has a flat shape, it can surely make contact even when the electrode is small.

[0079] Further, according to Modification 8, since the direction orthogonal to the pressing direction becomes longer at the tip by the crushing process, by adjusting the longitudinal direction at the tip, the contactable range with the electrode can be made wider than that of the pipe member not subjected to the crushing process.

[0080] (Modification 9) FIG. 15 is a perspective view showing the configuration of the pipe member in Modification 9 of the embodiment of the present invention. Modification 9 has the same configuration as the above-described embodiment except for changing the configuration of the pipe member. The same configurations as those in the above-described embodiment are denoted by the same reference numerals.

[0081] The pipe member 24E according to Modification 9 has a hollow flat portion 24e formed by a crushing process at the end opposite to the side where the tip portion 21a is inserted. The end face (upper face) of the hollow flat portion 24e has opposing outer edges that are arcuate or linear, and forms an annular shape with an elliptical opening.

[0082] According to Modification 9 described above, even when the pipe member 24E has the hollow flat portion 24e, the effects of the above-described embodiment can be obtained. Further, according to Modification 9, since the tip of the pipe member 24E has a flat shape, it can surely come into contact even when the electrode is small.

[0083] (Modification 10) FIG. 16 is a perspective view showing the configuration of the pipe member in Modification 10 of the embodiment of the present invention. Modification 10 has the same configuration as the above-described embodiment except for changing the configuration of the pipe member. The same configurations as those in the above-described embodiment are denoted by the same reference numerals.

[0084] The pipe member 24F according to Modification 10 has an inclined end portion 24f that is inclined with respect to the central axis at the end opposite to the side where the tip portion 21a is inserted.

[0085] FIG. 17 is a diagram showing a usage example of a pipe member according to Modification Example 10 of the embodiment of the present invention, and is a cross-sectional view showing the configuration of the main part of the probe unit. Four-terminal measurement is performed using the probe 2A to which the pipe member 25F (see FIG. 16) of this Modification Example 10 is attached. The configuration is the same as that of the above-described embodiment except that the pipe member 25F is replaced. The same components as those in the above-described embodiment are denoted by the same reference numerals.

[0086] In FIG. 17, a pair of probes 2A are in contact with one electrode of the semiconductor integrated circuit 100 and are also in contact with different electrodes of the circuit board 200. In four-terminal measurement, two probes 2A form a pair. That is, in the two probes 2A forming a pair, each pipe member 24F is in contact with the same electrode 101 (see FIG. 3), and each second plunger 22 is in contact with different electrodes 201.

[0087] According to Modification Example 10 described above, even if the end portion of the pipe member 24F is inclined, the effects of the above-described embodiment can be obtained. Further, by using the pipe member 24F according to this Modification Example 10, the effects of the above-described embodiment can also be obtained in the probe 2A used for four-terminal measurement.

[0088] Further, according to Modification Example 10, by bringing only the tip (top portion) of the pipe member into contact with the electrode, the contact area with respect to the electrode becomes smaller, the contact pressure with respect to the electrode becomes higher, and conduction can be further stabilized.

[0089] (Modification Example 11) FIG. 18 is a perspective view showing the configuration of the pipe member in Modification Example 11 of the embodiment of the present invention. Modification Example 11 has the same configuration as that of the above-described embodiment except that the configuration of the pipe member is changed. The same components as those in the above-described embodiment are denoted by the same reference numerals.

[0090] The pipe member 24G according to Modification Example 11 has an inclined flat portion 24g formed by swaging, at an end opposite to the side where the tip portion 21a is inserted, and the end is inclined with respect to the central axis. The end face (upper face) of the inclined flat portion 24g has opposing outer edges that are arcuate or linear, and forms a plane inclined with respect to the central axis of the pipe member 24G.

[0091] According to Modification Example 11 described above, even when the pipe member 24G has the inclined flat portion 24g, the effects of the above-described embodiment can be obtained. Further, by applying the pipe member 24G according to this Modification Example 11 to a probe for four-terminal measurement, the distance between the tips of the probes can be made smaller than when using the pipe member 24F according to Modification Example 10 described above.

[0092] Also, according to Modification Example 11, similar to Modification Example 10, by bringing only the tip (top portion) of the pipe member into contact with the electrode, the contact area with respect to the electrode becomes smaller, the contact pressure with respect to the electrode becomes higher, and conduction can be made more stable.

[0093] In the pipe member 24G according to Modification Example 11, similar to Modification Example 9, swaging may be performed on the end opposite to the side where the tip portion 21a is inserted to form a hollow flat portion.

[0094] In the above-described embodiment, an example in which the first plunger 21 and the second plunger 22 constitute a contact portion by the tip portion and the flange portion has been described, but the tip portion and the flange portion may be integrated to constitute a contact portion having no stepped portion.

[0095] The configuration of the tip portion of the first plunger and the configuration of the pipe member described in the above-described embodiment and modification examples may be applied to the second plunger side.

[0096] Also, the configuration of the contact probe described here is merely an example, and it is possible to apply various types of probes known in the art. For example, it is not limited to the configuration composed of a plunger and a coil spring as described above, and it may be a pogo pin, a wire probe that bends a wire in an arc shape to obtain a load, or a configuration in which a pipe member is attached to the tip of a conductive member such as a connection terminal (connector) that connects electrical contacts, or these probes may be appropriately combined.

[0097] In the above-described embodiments and modifications, an example in which the electrodes of the semiconductor integrated circuit are hemispherical (see FIG. 3) has been described. However, the present invention is not limited to this, and for example, the electrodes may be plate-shaped. That is, the electrodes of the semiconductor integrated circuit to be inspected by the probe unit may be spherical (hemispherical) like a BGA (Ball grid array), or may be plate-shaped like a QFP (Quad Flat Package).

[0098] As described above, the present invention can include various embodiments not described herein, and various design changes and the like can be made without departing from the technical idea specified by the claims.

[0099] As described above, the contact probe according to the present invention is suitable for maintaining a stable contact resistance in repeated use.

Explanation of Reference Numerals

[0100] 1 Probe unit 2, 2A Contact probe (probe) 3 Probe holder 21, 21A, 21B First plunger 21a, 21f, 21h, 21j, 21l, 22a Tip portion 21b, 22b Flange portion 21c, 22c Boss portion 21d, 22d Base end portion 21e Recess 21g, 24a Protrusion 21i protrusion 21k, 24b reduced diameter portion 22 second plunger 23 coil spring 23a closely wound portion 23b coarsely wound portion 24, 24A, 24B, 24C, 24D, 24E, 24F, 24G pipe member 24d flat portion 24e hollow flat portion 24f inclined end portion 24g inclined flat portion 31 first member 32 second member 33, 34 holder holes 33a, 34a small diameter portions 33b, 34b large diameter portions 100 semiconductor integrated circuit 101, 201 electrodes 200 circuit board

Claims

1. A contact probe that transmits signals by contacting different electrodes at both ends in the longitudinal direction, a conductive member extending in the longitudinal direction, a pipe member provided at at least one end of the conductive member and made of a platinum group element or an alloy mainly composed of the platinum group element, comprising: one end of the pipe member located on the side opposite to the side attached to the conductive member has a flat shape formed by pressing from two opposite directions, characterized in that it is a contact probe.

2. The pipe member has a cylindrical shape in which a plane passing through the opening on one end side and a plane passing through the opening on the other end side are parallel to each other, characterized in that it is the contact probe according to Claim 1.

3. The pipe member has a cylindrical shape in which a plane passing through the opening at one end is inclined with respect to the central axis, characterized in that it is the contact probe according to Claim 1.

4. In the portion of the pipe member having the flat shape, the inner peripheral surfaces are in contact with each other, characterized in that it is the contact probe according to Claim 1.

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