Inspection probe and probe unit

Abstract

To provide an inspection probe which can be applied to an object to be inspected for high-frequency use and an object to be inspected having a narrow pitch between electrodes, and also to provide a probe unit equipped with the inspection probe.SOLUTION: Disclosed is an inspection probe 1 which includes: a tubular barrel 10; a first plunger 12 provided in a first end part 10a of a barrel 10 while exposing a tip portion 12a; a second plunger 14 provided in a second end part 10b of the barrel 10 while exposing a tip portion 14a; and a rubber part 20 provided between the first plunger 12 and the second plunger 14 in the barrel 10. The first plunger 12 and the second plunger 14 are biased in a direction separating from each other by the rubber part 20.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an inspection probe and a probe unit. [Background technology]

[0002] 2. Description of the Related Art In testing semiconductor devices, electronic devices, and the like, a spring probe is widely used in which plungers are provided at both ends of a barrel, and each plunger is biased outward by a spring inside the barrel (eg, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-56764 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, since it is difficult to manufacture a minute spring, there is a limit to how small the spring probe can be made, and it is difficult to shorten the overall length of the spring probe to shorten the conductive path, or to reduce the barrel diameter to arrange the spring probes at a narrow pitch, making it difficult to apply the spring probe to high-frequency test objects or test objects with narrow electrode pitches.

[0005] An object of the present invention is to provide an inspection probe that can be applied to inspection objects for high frequency applications and inspection objects with narrow electrode pitches, and a probe unit including the inspection probe. [Means for solving the problem]

[0006] The present invention has the following configuration. [1] An inspection probe comprising: a tubular barrel; a plunger with an exposed tip portion disposed within at least one end of the barrel in the central axial direction; and a rubber portion disposed within the barrel, wherein the plunger is urged toward its tip by the rubber portion. [2] The inspection probe described in [1], comprising a first plunger provided with an exposed tip portion within a first end of the barrel, and a second plunger provided with an exposed tip portion within a second end of the barrel, wherein the rubber portion is provided between the first plunger and the second plunger within the barrel, and the rubber portion biases the first plunger and the second plunger in a direction away from each other. [3] The inspection probe according to [1] or [2], wherein the rubber portion contains conductive rubber in which a conductive material is blended with an elastomer. [4] The inspection probe described in [3], wherein the rubber portion comprises a conductive portion made of the conductive rubber and an insulating portion made of an elastomer, and the conductive portion and the insulating portion are arranged alternately in a radial direction perpendicular to the central axis of the barrel, and each extending in the direction of the central axis of the barrel, and are made of anisotropic conductive rubber. [5] The inspection probe described in [1] or [2], wherein the rubber portion is made of anisotropic conductive rubber having an insulating portion made of elastomer and a plurality of metal wires penetrating in the central axis direction of the barrel. [6] A probe unit comprising: a probe holder; and a plurality of the inspection probes according to any one of [1] to [5] held by the probe holder. Effect of the Invention

[0007] According to the present invention, it is possible to provide an inspection probe that can be applied to an object to be inspected for high frequency applications or an object to be inspected with a narrow electrode pitch, and a probe unit including the inspection probe. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a cross-sectional view showing an inspection probe according to an embodiment. [Diagram 2]FIG. 11 is a cross-sectional view showing an inspection probe according to another embodiment. [Diagram 3] FIG. 11 is a cross-sectional view showing an inspection probe according to another embodiment. [Figure 4] FIG. 11 is a cross-sectional view showing an inspection probe according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] An example of an embodiment of the present invention will be described below with reference to the drawings. Note that the dimensions of the drawings shown in the following description are merely examples, and the present invention is not necessarily limited thereto, and may be appropriately modified and implemented without departing from the spirit and scope of the present invention.

[0010] [Inspection probe] As shown in Fig. 1, the inspection probe 1 of this embodiment includes a barrel 10, a first plunger 12, a second plunger 14, and a rubber part 20. The barrel 10 is tubular, and the first plunger 12 is provided so that a tip portion 12a is exposed in a first end portion 10a of the barrel 10. The second plunger 14 is provided so that a tip portion 14a is exposed in a second end portion 10b of the barrel 10. The rubber part 20 is provided between the first plunger 12 and the second plunger 14 in the barrel 10.

[0011] The barrel 10 includes a cylindrical body 16, a first annular portion 17a that protrudes inwardly over the entire circumference from a first end 16a of the body 16, and a second annular portion 17b that protrudes inwardly over the entire circumference from a second end 16b of the body 16. At both ends of the barrel 10, openings 18a, 18b are formed on the inside of the first annular portion 17a and the inside of the second annular portion 17b, respectively.

[0012] The material of the barrel 10 is not particularly limited, and for example, known materials can be used without limitation. Specific examples include copper alloys such as brass, phosphor bronze, nickel silver, beryllium copper, and cupronickel. Among them, phosphor bronze is preferable because of its high strength and mechanical properties such as good bending and drawing workability. The material of the barrel 10 may be one type or two or more types.

[0013] A plating film may be formed on the inner surface of the barrel 10. If a plating film is formed on the inner surface of the barrel 10, the electrical continuity between the first plunger 12 and the second plunger 14 can be ensured through the plating film, so that the electrical continuity of the inspection probe 1 becomes more stable. The material of the plating film is not particularly limited, and examples thereof include gold, platinum, silver, palladium, rhodium, iridium, ruthenium, osmium, and nickel. Among these, gold is preferable because of its high electrical conductivity and high corrosion resistance. The plating film may be one layer or two or more layers.

[0014] The first plunger 12 has a cylindrical tip portion 12a and an expanded diameter portion 12b provided on the rear end side of the tip portion 12a and having a larger diameter than the tip portion 12a. The expanded diameter portion 12b of the first plunger 12 is accommodated in the first end portion 10a of the barrel 10, and the tip portion 12a protrudes from an opening 18a on the first end portion 10a side of the barrel 10. The first plunger 12 is biased toward the tip 12c side by the rubber portion 20, but the expanded diameter portion 12b is hooked on the first annular portion 17a of the barrel 10 to prevent it from falling off.

[0015] The first plunger 12 is electrically conductive. In the present invention, the term "electrically conductive" means that the surface electrical resistance value measured by a surface electrical resistance meter is 10 7Ω or less. The material of the first plunger 12 is not particularly limited, and any known material can be used without limitation. Specific examples include beryllium copper, palladium alloy, free-cutting carbon tool steel, and tungsten. Among them, palladium alloy is preferable because it has low resistance and does not require plating, and it can suppress transfer of solder. The material of the first plunger 12 may be one type or two or more types.

[0016] A plating film may be formed on the surface of the first plunger 12. The material of the plating film formed on the surface of the first plunger 12 is not particularly limited, and examples thereof include gold, platinum, silver, palladium, rhodium, iridium, ruthenium, osmium, and nickel. Among these, gold is preferable because of its high electrical conductivity and high corrosion resistance. The plating film on the surface of the first plunger 12 may be one layer or two or more layers.

[0017] The second plunger 14 has a cylindrical tip portion 14a and an expanded diameter portion 14b provided on the rear end side of the tip portion 14a and having a larger diameter than the tip portion 14a. The expanded diameter portion 14b of the second plunger 14 is accommodated in the second end portion 10b of the barrel 10, and the tip portion 14a protrudes from an opening 18b on the second end portion 10b side of the barrel 10. As with the first plunger 12, the second plunger 14 is biased toward the tip 14c side by the rubber portion 20, but the expanded diameter portion 14b is hooked on the second annular portion 17b of the barrel 10 to prevent it from falling off. In the inspection probe 1, the first plunger 12 and the second plunger 14 are biased by the rubber portion 20 in a direction away from each other.

[0018] The second plunger 14 is conductive. The material of the second plunger 14 may be the same as the material exemplified for the first plunger 12, and the preferred embodiment is also the same. The material of the second plunger 14 may be one type or two or more types. The materials of the first plunger 12 and the second plunger 14 may be the same or different, and are preferably the same. A plating film may be formed on the surface of the second plunger 14, similarly to the surface of the first plunger 12. The material and embodiment of the plating film formed on the surface of the second plunger 14 may be the same as those exemplified for the plating film formed on the surface of the first plunger 12, and the preferred embodiment is also the same.

[0019] The rubber part 20 in this example is made of conductive rubber in which a conductive material is mixed with elastomer, and has conductivity. As a result, in the inspection probe 1, the first plunger 12 and the second plunger 14 are electrically connected via the rubber part 20. In this way, the rubber part 20 in this example serves to electrically connect the first plunger 12 and the second plunger 14 while biasing the first plunger 12 and the second plunger 14 in a direction separating them from each other.

[0020] The shape of the rubber portion 20 is not particularly limited, and may be appropriately set within a range in which it can be accommodated within the barrel 10 and can bias the first plunger 12 and the second plunger 14, respectively. For example, cylindrical, spherical, or polygonal prism shapes such as a square prism can be cited as examples.

[0021] The thickness of the rubber part 20 in the central axis direction of the barrel 10 is preferably 0.005 mm to 5 mm, more preferably 0.05 mm to 3 mm, and even more preferably 0.1 mm to 2 mm. If the thickness of the rubber part 20 is equal to or greater than the lower limit of the above range, it becomes easy to bias the first plunger 12 and the second plunger 14 in a direction separating them from each other. If the thickness of the rubber part 20 is equal to or less than the upper limit of the above range, the conductive path becomes shorter and the high frequency characteristics are improved. The thickness of the rubber part 20 is calculated as the average value of the thicknesses measured at 10 points arbitrarily selected from a cross section of the rubber part 20 in the thickness direction.

[0022] The elastomer used in the rubber portion 20 is not particularly limited, and examples thereof include elastomeric thermosetting resins such as silicone resin and epoxy resin, and thermoplastic resins such as synthetic rubber, polyethylene resin, polyurethane resin, ABS resin, and soft polyvinyl chloride resin. Among these, silicone resin is preferable because of its high elasticity and excellent heat resistance. The elastomer used in the rubber portion 20 may be one type or two or more types.

[0023] The hardness of the elastomer used in the rubber portion 20, measured according to a durometer, is preferably 5 to 95, more preferably 10 to 80. If the hardness of the elastomer is equal to or greater than the lower limit of the range, the elastomer's biasing force on the plunger is easily secured, so that the contact between the plunger and the electrode becomes more stable. If the hardness of the elastomer is equal to or less than the upper limit of the range, the load applied from the plunger to the electrode is unlikely to be excessively high, so that even when an object having multiple electrodes is inspected, damage to the object is easily suppressed.

[0024] Conductive materials have a surface electrical resistance of 10 7 A material having a resistance of Ω or less. The conductive material to be mixed with the conductive rubber is not particularly limited, and examples thereof include carbon-based conductive materials such as graphite and carbon nanotubes, metal particles such as silver particles, gold particles, copper particles, and palladium particles, and polymer-based conductive materials such as polyacetylene and polythiophene. Among these, silver particles are preferred in terms of high electrical conductivity, high corrosion resistance, and material price. The conductive material to be mixed with the conductive rubber may be one type or two or more types.

[0025] The amount of the conductive material in the conductive rubber is preferably 10 parts by mass or more and 90 parts by mass or less, and more preferably 20 parts by mass or more and 80 parts by mass or less, relative to 100 parts by mass of the elastomer in the conductive rubber. If the amount of the conductive material is equal to or more than the lower limit of the above range, the conduction between the first plunger 12 and the second plunger 14 via the rubber part 20 becomes more stable. If the amount of the conductive material is equal to or less than the upper limit of the above range, the restoration property of the conductive rubber after compression is easily ensured, and therefore the first plunger 12 and the second plunger 14 can be easily sufficiently biased in the direction separating them from each other.

[0026] The total length of the inspection probe 1, i.e., the distance between the tip 12c of the first plunger 12 and the tip 14c of the second plunger 14 in the central axis direction of the barrel, is preferably 0.1 mm to 15 mm, more preferably 0.2 mm to 10 mm. If the total length of the inspection probe 1 is equal to or greater than the lower limit of the above range, a stroke that absorbs the variation in electrode height of the object to be inspected can be ensured, and the conduction becomes more stable. If the total length of the inspection probe 1 is equal to or less than the upper limit of the above range, the conduction path can be shortened, and the high-frequency characteristics are excellent, so that the inspection probe can be suitably used for inspecting semiconductor devices, electronic devices, and the like for high-frequency applications.

[0027] The barrel diameter of the inspection probe 1, i.e., the outer diameter of the barrel 10, is preferably 0.01 mm to 2 mm, more preferably 0.02 mm to 1 mm. If the barrel diameter is equal to or greater than the lower limit of the above range, the barrel has strength and can be used repeatedly. If the barrel diameter is equal to or less than the upper limit of the above range, the probe unit can be easily arranged with a narrow pitch for multiple inspection probes 1, and therefore can be suitably used for inspection of semiconductor devices, electronic devices, etc., with narrow inter-electrode pitches.

[0028] The method for manufacturing the inspection probe 1 is not particularly limited, and for example, a known method for manufacturing a spring probe can be used, except that the rubber portion 20 made of conductive rubber is used instead of a spring.

[0029] As described above, in the inspection probe 1, the rubber part 20 is provided in the barrel 10 instead of the spring of a spring probe. Compared to a spring, which has a limit to how much it can be reduced in size, the rubber part 20 can be easily reduced in size by punching, laser processing, molding with a fine mold, or the like, by providing the rubber part 20 in the barrel 10, so that the overall length and barrel diameter of the inspection probe 1 can be easily reduced. When the overall length of the inspection probe 1 is shortened, the conduction path is shortened and the high-frequency characteristics are improved. Furthermore, when the barrel diameter is reduced, the inspection probes 1 can be arranged at a narrow pitch. For these reasons, the inspection probe 1 can be suitably used for inspecting objects for high-frequency applications or objects with a narrow inter-electrode pitch.

[0030] In addition, since the rubber portion 20 can be easily made small, the load required to press the electrodes against the inspection probe 1 during testing can be reduced. Therefore, even if the electrode area of ​​the object to be tested is large and multiple inspection probes 1 are in contact with the electrodes, the load required during testing is reduced, making testing easier. Furthermore, by making the rubber portion 20 small, it is easy to prevent the electrical connection between the first plunger 12 and the second plunger 14 from becoming unstable due to thermal expansion.

[0031] In the case where the rubber portion 20 is made of conductive rubber as in this embodiment, the first plunger 12 and the second plunger 14 can be electrically connected by the rubber portion 20, so that conduction can be ensured even if a plating film is not formed on the inner surface of the barrel 10. In this case, the first plunger 12 and the second plunger 14 do not necessarily need to be in contact with the inner surface of the barrel 10, which increases the degree of freedom in design, and the cost of the inspection probe 1 can be reduced by the amount that the inner surface of the barrel 10 is not plated.

[0032] Furthermore, in the inspection probe 1, the rubber part 20 does not come into contact with the electrode during inspection, but the first plunger 12 or the second plunger 14 comes into contact with the electrode. Therefore, when inspections are repeated, the solder ball residue accumulates on the plunger, not on the rubber part 20, making it easy to remove the solder ball residue. Furthermore, if the inspection probe 1 is arranged for each electrode of the object to be inspected during inspection, it becomes easy to replace only the defective inspection probe 1 if the inspection probe 1 is defective.

[0033] The inspection probe of the present invention is not limited to the inspection probe 1 described above. For example, it may be the inspection probe 2 illustrated in Fig. 2. The same parts in Fig. 2 as those in Fig. 1 are given the same reference numerals and will not be described. The inspection probe 2 has the same configuration as the inspection probe 1, except that it includes a rubber part 20A instead of the rubber part 20.

[0034] The rubber part 20A includes a conductive part 22 made of conductive rubber and an insulating part 24 made of elastomer. The rubber part 20A is made of anisotropic conductive rubber, in which the conductive parts 22 and the insulating parts 24 are alternately provided in a radial direction perpendicular to the central axis of the barrel 10 in a cross section of the rubber part 20A cut along the central axis of the barrel 10, and each of the conductive parts 22 and the insulating parts 24 extends in the central axis direction of the barrel 10.

[0035] The conductive rubber constituting the conductive portion 22 may be the same as the conductive rubber constituting the rubber portion 20 of the inspection probe 1, for example, and the preferred embodiments are also the same. The elastomer constituting the insulating portion 24 is not particularly limited, and may be, for example, the same elastomer as exemplified in the rubber portion 20 of the inspection probe 1, and the preferred embodiments are also the same.

[0036] When a conductive material is blended into the entirety as in the rubber portion 20 of the inspection probe 1, the restoring property after compression tends to be lower than that of an elastomer alone, and the force biasing the first plunger 12 and the second plunger 14 in the direction of separating them from each other may decrease. In contrast, the insulating portion 24 does not contain a conductive material, so there is no decrease in the restoring force due to the conductive material. Therefore, by alternately providing the conductive portion 22 and the insulating portion 24 in the radial direction perpendicular to the central axis of the barrel 10 as in the rubber portion 20A, it is possible to achieve both excellent durability that can maintain a sufficient biasing force and electrical connection between the first plunger 12 and the second plunger 14 by the conductive portion 22.

[0037] The thickness of the rubber part 20A in the central axis direction of the barrel 10 is preferably 0.005 mm or more and 5 mm or less, more preferably 0.05 mm or more and 2.5 mm or less, and even more preferably 0.1 mm or more and 1 mm or less. If the thickness of the rubber part 20A is equal to or more than the lower limit of the above range, it becomes easy to bias the first plunger 12 and the second plunger 14 in the direction separating them from each other. If the thickness of the rubber part 20A is equal to or less than the upper limit of the above range, the conductive path is shortened and the high frequency characteristics are improved. The thickness of the rubber part 20A is calculated as the average value of the thicknesses measured at 10 points arbitrarily selected from the cross section of the rubber part 20 in the thickness direction.

[0038] The ratio of the total area of ​​the conductive parts 22 to the total area of ​​the rubber part 20A in a cross section of the rubber part 20A cut along the central axis of the barrel 10 is preferably 10% to 90%, more preferably 30% to 70%. If the ratio of the total area of ​​the conductive parts 22 is equal to or greater than the lower limit of the range, the electrical connection between the first plunger 12 and the second plunger 14 becomes more stable. If the ratio of the total area of ​​the conductive parts 22 is equal to or less than the upper limit of the range, a sufficient force is likely to be obtained that biases the first plunger 12 and the second plunger 14 in a direction separating them from each other.

[0039] The inspection probe of the present invention may be the inspection probe 3 illustrated in Fig. 3. The same parts in Fig. 3 as those in Fig. 1 are denoted by the same reference numerals and will not be described. The inspection probe 3 is similar to the inspection probe 1 except that it includes a rubber part 20B instead of the rubber part 20.

[0040] The rubber part 20B is made of anisotropic conductive rubber in which a plurality of metal wires 26 are provided penetrating an insulating part 24 made of elastomer from the first plunger 12 side to the second plunger 14 side in the central axis direction of the barrel 10. The length direction of each of the plurality of metal wires 26 in this example extends in the central axis direction of the barrel 10 and is provided parallel to one another. Note that the plurality of metal wires 26 may be inclined with respect to the central axis direction of the barrel 10.

[0041] The metal wire 26 is not particularly limited, and examples thereof include pure gold wire, gold alloy wire, silver wire, silver alloy wire, solder wire, copper alloy wire, CNT yarn, piano wire, and tungsten wire. As the metal wire 26, one type may be used alone, or two or more types may be used in combination.

[0042] A plating film may be formed on the outer periphery of the metal wire 26. The material of the plating film formed on the outer periphery of the metal wire 26 is not particularly limited, and examples of the material include gold, platinum, silver, palladium, rhodium, iridium, ruthenium, osmium, and nickel. The plating film formed on the outer periphery of the metal wire 26 may be a single layer or two or more layers.

[0043] Both ends of the metal wire 26 may protrude from the insulating portion 24. When both ends of the metal wire 26 protrude from the insulating portion 24, the average length of the protruding portions of both ends of the metal wire 26 can be, for example, 5 μm or more and 60 μm or less. The wire diameter of the metal wire 26 is not particularly limited, and can be, for example, 2 μm or more and 100 μm or less. The distance between the metal wires 26 is not particularly limited, and can be, for example, 1 μm or more and 100 μm or less.

[0044] The thickness of the rubber part 20B in the central axis direction of the barrel 10 is preferably 0.005 mm or more and 5 mm or less, more preferably 0.05 mm or more and 2.5 mm or less, and even more preferably 0.1 mm or more and 1 mm or less. If the thickness of the rubber part 20B is equal to or more than the lower limit of the above range, it becomes easy to bias the first plunger 12 and the second plunger 14 in the direction separating them from each other. If the thickness of the rubber part 20B is equal to or less than the upper limit of the above range, the conductive path is shortened and the high frequency characteristics are improved. The thickness of the rubber part 20B is calculated as the average value of the thicknesses measured at 10 points arbitrarily selected from the cross section of the rubber part 20 in the thickness direction.

[0045] In the rubber part 20B of the inspection probe 3, the insulating part 24 does not contain a conductive material, so there is no decrease in the restoring force. Therefore, compared to the rubber part 20 in which a conductive material is blended throughout, the rubber part 20B is more durable and is easier to maintain a sufficient biasing force, and the first plunger 12 and the second plunger 14 can be electrically connected by the metal wire 26.

[0046] In the inspection probe of the present invention, when a plating film is formed on the inner surface of the barrel to ensure electrical continuity between the first plunger and the second plunger, the rubber portion may be an insulator made of an elastomer.

[0047] The inspection probe of the present invention is not limited to the above-mentioned inspection probes 1 to 3, in which the plungers are provided at both ends in the central axis direction of the barrel and the plungers are movable in the central axis direction at both ends of the barrel. For example, the inspection probe may be an inspection probe in which a plunger is provided only at one end in the central axis direction of the barrel and the plunger is movable only at one end. As a specific example, as shown in FIG. 4, the inspection probe 4 may be an inspection probe 4 in which a plunger 12A is provided only at a first end 10a in the central axis direction of the barrel 10, and the plunger 12A is movable at the first end 10a but not at the second end 10b. Of the above statements regarding an inspection probe having plungers at both ends of a barrel in the direction of its central axis, everything except providing plungers at both ends also applies to an inspection probe having a plunger at only one end of the barrel in the direction of its central axis.

[0048] [Probe unit] The probe unit of the present invention is a probe unit including a probe holder and a plurality of the inspection probes of the present invention held by the probe holder. The probe unit of the present invention can be used for electrical inspection in the manufacture of a semiconductor device in which an IC chip, such as a BGA (Ball Grid Array), an LGA (Land Grid Array), a QFP (Quad Flat Package), or a CSP (Chip Size Package), is mounted in a package. The probe unit of the present invention can adopt a known embodiment other than the inclusion of the inspection probe of the present invention. For example, the probe unit may be a probe card for performing electrical inspection (on-wafer inspection) of each semiconductor IC in a semiconductor wafer in which a large number of semiconductor ICs are formed, in a wafer state, or a socket for performing electrical inspection of a packaged semiconductor (DUT) in which IC chips obtained by cutting a wafer into chips are packaged.

[0049] In the probe unit of the present invention, the multiple inspection probes can be held by the probe holder so as to be parallel to each other. For example, when an inspection probe having plungers at both ends such as the above-described inspection probes 1 to 3 is used in a probe card or a socket, the following embodiments can be exemplified. The probe card may have a configuration in which, for example, a circuit board of the testing device is placed on the first plunger side of a probe holder in which multiple testing probes are held with the first plunger facing up, and electrodes of the circuit board are pressed against the tip of the first plunger. In this case, the electrodes of each semiconductor IC in the semiconductor wafer to be tested are pressed against the tip of the second plunger from the underside of the probe card to perform the test. The socket may be configured such that, for example, a circuit board of the testing device is disposed on the second plunger side of a probe holder holding a plurality of testing probes with the first plunger facing up, electrodes of the circuit board are pressed against the tip of the second plunger, and a housing section for housing a packaged semiconductor (DUT) is provided on the first plunger side. In this case, the DUT to be tested is housed in the housing section of the socket, and the electrodes of the DUT are pressed against the tip of the first plunger to perform the test. When a test probe having a plunger provided at only one end of a barrel is used in a probe card or socket, each test probe is arranged so that the plunger faces the device to be tested.

[0050] The arrangement pattern of the test probes in the probe card or socket as viewed from the longitudinal direction of each test probe is not particularly limited, and examples include a two-dimensional array in which the test probes are arranged linearly and horizontally at a predetermined interval, a staggered pattern, etc.

[0051] The number of inspection probes held by the probe holder is not particularly limited and can be appropriately set depending on the application, and may be 1 or more, for example, 1 to 1000. In the probe unit, for example, two or more of the above-mentioned inspection probes 1 to 3 may be used in combination.

[0052] The above-described embodiments are presented as examples and are not intended to limit the scope of the invention. Various modifications can be made without departing from the gist of the invention. [Explanation of symbols]

[0053] 1 to 4... inspection probe, 10... barrel, 12... first plunger, 12A... plunger, 14... second plunger, 20, 20A, 20B... rubber part, 22... conductive part, 24... insulating part, 26... metal wire.

Claims

1. A tubular barrel; a plunger provided in at least one end of the barrel in the central axis direction with a tip portion exposed; A rubber portion provided in the barrel, The plunger is biased toward its tip by the rubber portion, The thickness of the rubber portion in the central axis direction of the barrel is 0.005 mm or more and 5 mm or less, the rubber portion comprises a conductive portion made of conductive rubber obtained by compounding a conductive material with an elastomer, and an insulating portion made of an elastomer, the conductive portion and the insulating portion being anisotropically conductive rubber that are alternately provided in a radial direction perpendicular to the central axis of the barrel and each extending in the central axis direction of the barrel, The inspection probe, wherein the conductive material is at least one selected from the group consisting of silver particles, a carbon-based conductive material, and a polymer-based conductive material.

2. 2. The inspection probe according to claim 1, comprising: a first plunger provided in a first end of the barrel with a tip portion exposed; and a second plunger provided in a second end of the barrel with a tip portion exposed, the rubber portion being provided between the first plunger and the second plunger in the barrel, and the rubber portion biasing the first plunger and the second plunger in a direction moving away from each other.

3. A probe unit comprising: a probe holder; and a plurality of the inspection probes according to claim 1 or 2 held by the probe holder.

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