Probe Unit

Abstract

To provide a probe unit capable of adjusting characteristic impedance of an entire contact probe.SOLUTION: A probe unit includes: a first contact probe that abuts on each of contact object electrodes in one end side in a longitudinal direction; a second contact probe connected to the external ground; and a probe holder for holding the second contact probe. In the probe holder, a first hollow section for inserting and holding the first contact probe, a second hollow section for inserting and holding the second contact probe, and a through hole provided around the first hollow section are formed, and the probe holder composes the through hole and has a conductive section for electrically connecting the through hole and the second contact probe.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a probe unit that houses a contact probe for performing signal input / output with respect to a predetermined circuit structure.

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 or a liquid crystal panel, a contact probe for making an electrical connection between the inspection target and a signal processing device that outputs an inspection signal, and a probe unit including a probe holder that houses a plurality of the contact probes are used.

[0003] Generally, when inputting and outputting high-frequency electrical signals, a signal loss called insertion loss occurs. In a probe unit, in order to operate with high precision and high speed, it is important to reduce this insertion loss in the frequency range used. For example, Patent Document 1 discloses a technique of providing an air layer around a contact probe to match characteristic impedance.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the technique disclosed in Patent Document 1, although the impedance of the central portion of the contact probe can be adjusted, the characteristic impedance of the tip portion and the base end portion cannot be adjusted.

[0006] The present invention has been made in view of the above, and an object thereof is to provide a probe unit capable of adjusting the characteristic impedance of the entire contact probe.

Means for Solving the Problem

[0007] In order to solve the above-described problems and achieve the object, the probe unit according to the present invention includes a plurality of first contact probes that respectively contact electrodes of a contact target on one end side in the longitudinal direction, a second contact probe connected to an external ground, and a probe holder that holds the first and second contact probes. The probe holder is formed with a first hollow portion that inserts and holds the first contact probe, a second hollow portion that inserts and holds the second contact probe, and a through hole provided around the first hollow portion. The probe holder is characterized by constituting the through hole and having a conductive portion that electrically connects the through hole and the second contact probe.

[0008] Further, in the probe unit according to the present invention, in the above invention, the conductive portion is provided on the through hole and a surface that forms an opening end of the through hole.

[0009] Further, in the probe unit according to the present invention, in the above invention, the through hole has a stepped hole shape with a partially different diameter.

[0010] Further, in the probe unit according to the present invention, in the above invention, the through hole has a stepped hole shape with different positions of the central axis.

[0011] Further, in the probe unit according to the present invention, in the above invention, the probe holder is made of one member.

[0012] Further, in the probe unit according to the present invention, in the above invention, the probe holder is formed by laminating a plurality of members in the penetrating direction of the first hollow portion.

[0013] In addition, the probe unit according to the present invention is characterized in that, in the above invention, the through holes are formed by through holes formed in each of the plurality of members, and in at least one member, the through holes have a stepped hole shape in which the diameters of the through holes are partially different.

[0014] Furthermore, in the probe unit according to the present invention, in the above invention, the through holes are formed by through holes formed in each of the plurality of members, and in at least one member, the through holes have stepped hole shapes in which the positions of the central axes of the through holes are different from each other.

[0015] Furthermore, the probe unit according to the present invention is characterized in that, in the above invention, the plurality of members each have a through hole that constitutes the through hole, and at least a portion of the through holes formed in members adjacent in the stacking direction of the members overlap with each other when viewed from the penetration direction of the through holes.

[0016] Furthermore, in the probe unit according to the present invention, the through-hole has an opening that has an elongated hole shape when viewed from the penetration direction. Effect of the Invention

[0017] According to the present invention, it is possible to advantageously adjust the characteristic impedance of the entire contact probe. [Brief description of the drawings]

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

[0019] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments. Furthermore, the drawings referred to in the following description merely show the shapes, sizes, and positional relationships in a schematic manner to enable the contents of the present invention to be understood, and therefore the present invention is not limited to only the shapes, sizes, and positional relationships exemplified in the drawings.

[0020] (Embodiment 1) FIG. 1 is a partial cross-sectional view showing the configuration of a main part of a probe unit according to Embodiment 1 of the present invention. The probe unit 1 shown in FIG. 1 is a device used when inspecting the electrical characteristics of a semiconductor integrated circuit as an object to be inspected, and is a device that electrically connects between a semiconductor integrated circuit (semiconductor integrated circuit 100 described later) and a circuit board (circuit board 200 described later) that outputs a test signal to the semiconductor integrated circuit.

[0021] The probe unit 1 contacts a semiconductor integrated circuit 100 and a circuit board 200, which are two different objects to be contacted at both ends in the longitudinal direction, and conducts a conductive signal contact probe 2A for conducting a test signal (hereinafter simply referred to as "signal probe 2A"), a ground contact probe 2B connected to an external ground electrode (hereinafter simply referred to as "ground probe 2B"), and a probe holder 3 that houses and holds the signal probe 2A and the ground probe 2B according to a predetermined pattern. Note that the probe unit 1 may be provided around the probe holder 3 and include a holder member that suppresses displacement of the semiconductor integrated circuit during inspection.

[0022] The signal probe 2A is formed of a conductive material, and includes a first plunger 21 that contacts an electrode to which a test signal of the semiconductor integrated circuit is input when inspecting the semiconductor integrated circuit, a second plunger 22 that contacts an electrode that outputs a test signal of a circuit board provided with a test circuit, and a spring member 23 that is provided between the first plunger 21 and the second plunger 22 and connects the first plunger 21 and the second plunger 22 so as to be telescopically connected. The first plunger 21, the second plunger 22, and the spring member 23 constituting the signal probe 2A have the same axis. In the signal probe 2A shown in FIG. 1, the longitudinal axes (central axes) of the first plunger 21, the second plunger 22, and the spring member 23 coincide with the axis N P and coincide.

[0023] When the signal probe 2A contacts the semiconductor integrated circuit, the spring member 23 expands and contracts to mitigate the impact on the connection electrode of the semiconductor integrated circuit, and applies a load to the semiconductor integrated circuit and the circuit board. In the following, in the signal probe 2A, the side that contacts the electrode of the semiconductor integrated circuit is defined as the tip side, and the side that is opposite to the semiconductor integrated circuit side in the axial direction is defined as the base end side. Also, when defining the tip side and the base end side with the plunger alone, in the plunger that contacts the semiconductor integrated circuit, the semiconductor integrated circuit side is defined as the tip side, and the side that is opposite to the semiconductor integrated circuit side in the axial direction is defined as the base end side. Also, in the plunger that contacts the circuit board, the circuit board side is defined as the tip side, and the side that is opposite to the circuit board side in the axial direction is defined as the base end side.

[0024] The first plunger 21 is movable in the axial direction by the expansion and contraction action of the spring member 23, and is biased in the direction approaching the semiconductor integrated circuit by the elastic force of the spring member 23 during inspection, and contacts the electrode of the semiconductor integrated circuit. Also, the second plunger 22 is movable in the axial direction by the expansion and contraction action of the spring member 23, and is biased in the direction approaching the circuit board by the elastic force of the spring member 23, and contacts the electrode of the circuit board.

[0025] One side of the spring member 23 is the closely wound portion 23a on the first plunger 21 side, while the other side is the coarsely wound portion 23b on the second plunger 22 side. The end of the closely wound portion 23a is connected to the first plunger 21. On the other hand, the end of the coarsely wound portion 23b is connected to the second plunger 22. Also, the first plunger 21, the second plunger 22, and the spring member 23 are joined by fitting and / or soldering by the winding force of the spring.

[0026] The ground probe 2B has the same configuration as the signal probe 2A. Specifically, the ground probe 2B is formed of a conductive material and includes a first plunger 21 that contacts the ground electrode of the semiconductor integrated circuit when inspecting the semiconductor integrated circuit, a second plunger 22 that contacts the ground electrode of the circuit board, and a spring member 23 provided between the first plunger 21 and the second plunger 22 to connect the first plunger 21 and the second plunger 22 so as to be telescopically connected. The first plunger 21, the second plunger 22, and the spring member 23 constituting the ground probe 2B have the same axis. In the ground probe 2B shown in FIG. 1, the longitudinal axes (central axes) of the first plunger 21, the second plunger 22, and the spring member 23 coincide with the axis N P and coincide.

[0027] The probe holder 3 is formed by laminating a first member 31, a second member 32, a third member 33, and a fourth member 34 made of an insulating material such as resin, machinable ceramic, or silicon. The probe holder 3 shown in FIG. 1 is laminated in the order of the third member 33, the first member 31, the second member 32, and the fourth member 34 from the upper side of the figure. The first member 31 to the fourth member 34 are fixed by a known method such as screwing or adhesion.

[0028] In the probe holder 3, a hollow portion 35 that forms a space for accommodating a plurality of signal probes 2A and a hollow portion 36 that forms a space for accommodating a plurality of ground probes 2B are formed. Further, a plurality of through holes 37 are formed around the signal probe 2A in the probe holder 3.

[0029] The surface of the first member 31 is plated. A conductive material is used for the plating. Therefore, a first conductive coating 31a and a second conductive coating 31b are formed on the surface of the first member 31. The first conductive coating 31a is formed on the surface excluding the hollow portion 35, including the portion where the through hole 37 is formed. The second conductive coating 31b is formed on the surface of the portion where the hollow portion 35 is formed. The first conductive coating 31a and the second conductive coating 31b are spaced apart from each other to ensure insulation. In the example shown in FIG. 1, the coatings are separated by removing a portion of the coating.

[0030] Like the first member 31, the second member 32 to the fourth member 34 are plated on their surfaces except for the portion that forms the inner circumferential surface of the hollow portion 35. A first conductive coating 32a and a second conductive coating 32b are formed on the surface of the second member 32. A first conductive coating 33a and a second conductive coating 33b are formed on the surface of the third member 33. A first conductive coating 34a and a second conductive coating 34b are formed on the surface of the fourth member 34. The first conductive coatings 32a to 34a are formed on the surface excluding the hollow portion 35, including the portion where the through hole 37 is formed. The second conductive coatings 32b to 34b are formed on the surface of the portion where the hollow portion 35 is formed. At least a portion of the first conductive coatings 31a to 34a constitutes a conductive portion. Therefore, in the probe holder 3 formed by laminating the first member 31 to the fourth member 34, conductive coatings are present at the boundaries between the members and on the outer surfaces.

[0031] The hollow portion 35 is formed by aligning the axes of the through holes formed in the first member 31 to the fourth member 34. Second conductive coatings 31b to 34b are formed on the inner circumferential surface of the hollow portion 35, forming a conductive inner circumferential surface. The hollow portion 35 extends in the stacking direction of the first member 31 to the fourth member 34.

[0032] The hollow portion 36 is formed by aligning the axes of the through holes formed in the first member 31 to the fourth member 34. The hollow portion 36 has first conductive coatings 31a to 34a formed on its inner circumferential surface, forming a conductive inner circumferential surface.

[0033] The positions where the hollow portions 35 and 36 are formed are determined according to the wiring pattern of the semiconductor integrated circuit. Both hollow portions 35 and 36 have a stepped hole shape with diameters that vary along the penetration direction. That is, each holder hole consists of a small-diameter portion that has an opening at the end face of the probe holder 3 and a large-diameter portion that is larger in diameter than the small-diameter portion. The probe holder 3 shown in FIG. 1 has stepped portions formed at the boundary between the first member 31 and the third member 33 and at the boundary between the second member 32 and the fourth member 34. The shape of each holder hole is determined according to the configuration of the signal probes 2A and ground probes 2B to be accommodated.

[0034] The first plunger 21 of the signal probe 2A has a flange abutting against the wall surface of the third member 33, thereby preventing the signal probe 2A from coming out of the probe holder 3. The second plunger 22 has a flange abutting against the wall surface of the fourth member 34, thereby preventing the signal probe 2A from coming out of the probe holder 3.

[0035] The first plunger 21 of the grounding probe 2B has a flange abutting against the wall surface of the third member 33, thereby preventing the grounding probe 2B from coming out of the probe holder 3. The second plunger 22 has a flange abutting against the wall surface of the fourth member 34, thereby preventing the grounding probe 2B from coming out of the probe holder 3.

[0036] The through holes 37 are formed by aligning the axes of the through holes formed in the first member 31 to the fourth member 34. That is, the through holes 37 are provided from the surface on the tip side to the surface on the base side of the signal probe 2A in the probe holder 3. The through holes 37 shown in FIG. 1 are arranged such that the central axis of each through hole is aligned with the axis N T Through-hole 37 has a circular opening in a direction perpendicular to the penetrating direction. First conductive films 31a to 34a are formed on the inner circumferential surface of through-hole 37, forming a conductive inner circumferential surface.

[0037] The through-hole 37 forms a cylindrical hollow space, and one or more through-holes 37 are formed around the signal probe 2A. In the first embodiment, an example will be described in which eight through-holes 37 are formed around one signal probe 2A. FIG. 2 is a diagram for explaining the arrangement of through-holes in a probe unit according to an embodiment of the present invention. For example, the arrangement position of the signal probe 2A (axis N) P 2, eight through holes 37 are provided at equal intervals around the axis N. In FIG. 2, the diameter of each through hole 37 is the same, and each through hole 37 and the axis N P The shortest distances between the through holes 37 and the signal probe 2A are the same as each other, i.e., the center of the circle (dashed line in FIG. 2) that passes through the centers of all the through holes 37 is the same as the center of the signal probe 2A (axis N P ) overlaps with the through holes 37. A group of through holes made up of all the through holes 37 has a coaxial structure with the signal probe 2A.

[0038] In this embodiment 1, the placement position, number, size of each through hole formed by the through holes 37, etc. are determined so that the characteristic impedance when the signal probe 2A and the ground probe 2B are viewed as one transmission path becomes a predetermined value (for example, 50 Ω).

[0039] 3 is a diagram showing a state of the probe unit 1 during testing of the semiconductor integrated circuit 100. During testing, the first plunger 21 of the signal probe 2A contacts the electrode 101 for the test signal of the semiconductor integrated circuit 100, and the second plunger 22 contacts the electrode 201 for the test signal of the circuit board 200. On the other hand, the first plunger 21 of the ground probe 2B contacts the electrode 102 for the ground of the semiconductor integrated circuit 100, and the second plunger 22 contacts the electrode 202 for the ground of the circuit board 200. During testing of the semiconductor integrated circuit 100, the spring member 23 is compressed by the contact load from the semiconductor integrated circuit 100.

[0040] During inspection, the test signal supplied from the circuit board 200 to the semiconductor integrated circuit 100 reaches the electrode 101 of the semiconductor integrated circuit 100 via, for example, the second plunger 22 of the signal probe 2A, the closely wound portion 23a (or the second conductive film), and the first plunger 21 from the electrode 201 of the circuit board 200. In this way, in the signal probe 2A, since the first plunger 21 and the second plunger 22 are electrically connected via the closely wound portion 23a, the conduction path of the electrical signal can be minimized. Therefore, it is possible to prevent the signal from flowing through the coarsely wound portion 23b during inspection, and to reduce the resistance and inductance. At this time, the path via the second plunger 22, the second conductive film, and the first plunger 21 can transmit the signal without passing through the spring member 23.

[0041] Also, the first plunger 21 of the ground probe 2B contacts the first conductive film 33a or 31a. On the other hand, the second plunger 22 of the ground probe 2B contacts the first conductive film 34a or 32a. Further, the spring member 23 of the ground probe 2B contacts the first conductive film 31a or 32a.

[0042] Generally, in an electronic circuit handling an AC signal, it is known that at the connection point between wirings with different impedances, the signal is reflected by an amount corresponding to the ratio between the different impedances, and the propagation of the signal is hindered. This is the same in the relationship between the semiconductor integrated circuit 100 to be used and the signal probe 2A. When the characteristic impedance of the semiconductor integrated circuit 100 and the characteristic impedance of the signal probe 2A have significantly different values, electrical signal loss occurs and the waveform of the electrical signal is distorted.

[0043] In addition, the ratio of signal reflection occurring at the connection point due to the difference in characteristic impedance increases with the high-speed operation, i.e., the high-frequency operation, of the semiconductor integrated circuit 100. Therefore, when manufacturing the probe unit 1 corresponding to the semiconductor integrated circuit 100 driven at high frequencies, it is important to accurately perform impedance adjustment so that the value of the characteristic impedance of the signal probe 2A matches that of the semiconductor integrated circuit 100.

[0044] However, it is not easy to change the shape of the signal probe 2A from the viewpoint of impedance matching. Since the outer diameter of the signal probe 2A is suppressed to 1 mm or less and it inherently has restrictions such as a complex shape composed of the first plunger 21, the second plunger 22, and the spring member 23, it is difficult to change it to a shape suitable for impedance matching from the viewpoints of design and manufacturing.

[0045] Therefore, in the present embodiment, instead of changing the structure of the signal probe 2A, a configuration is adopted in which the value of the characteristic impedance is adjusted by arranging through holes 37 around the first plunger 21, the second plunger 22, and the spring member 23. By adopting such a configuration, it becomes possible to use a conventional structure for the signal probe 2A. For example, the same probe as the conventional ground probe 2B can be used as the signal probe 2A.

[0046] In addition, in the present embodiment, since it is not necessary to change the signal probe 2A to a shape suitable for impedance matching, the degree of freedom in the probe shape to be used can be improved.

[0047] Furthermore, in the first embodiment, by providing a through hole 37 extending from the surface on the tip side to the surface on the base end side of the signal probe 2A in the probe holder 3 around the signal probe 2A, the characteristic impedance values of the tip portion and the base end portion of the signal probe 2A can be adjusted. Specifically, the value of the characteristic impedance can be adjusted by adjusting the number of disposed through holes, the diameter of the through hole of the through hole, and the arrangement of the through holes (distance from the signal probe 2A). Furthermore, by surrounding the signal probe 2A with a plurality of through holes 37, it is possible to make it less susceptible to the influence of external factors such as noise, and it is possible to reduce the energy loss due to energy outflow to the outside.

[0048] In the above-described first embodiment, the through hole 37 is arranged around the signal probe 2A and connected to the external ground via the ground probe 2B. According to the first embodiment, the characteristic impedance of the tip portion and the base end portion of the signal probe 2A can be adjusted by the through hole 37 indirectly connected to the external ground. According to the first embodiment, the overall characteristic impedance including the end portion of the signal probe 2A can be adjusted. Further, according to the first embodiment, by adjusting the position of the through hole, the ground position in the direction orthogonal to the axial direction with respect to the signal probe 2A can be adjusted.

[0049] Also, according to the above-described first embodiment, since the outer surface of the probe holder 3 is covered with a conductive film, it has excellent high-frequency characteristics as compared with the case where no plating treatment is performed.

[0050] Also, according to the above-described first embodiment, since the characteristic impedance can be adjusted by the through hole, the degree of freedom in arranging the ground probe 2B can be improved.

[0051] In the above-described first embodiment, the first conductive films 33a and 34a may be configured to be connected to the external ground.

[0052] In the above-described Embodiment 1, an example in which a plurality of through-holes are arranged symmetrically with respect to the axis N of the signal probe has been described, but an asymmetrical arrangement may also be used. P In the above-described Embodiment 1, an example in which a plurality of through-holes are evenly arranged with respect to one signal probe has been described, but the through-holes may be arranged unevenly. At this time, "uneven" may mean uneven at points where the circumferential distance of a circle centered on a point on the axis N of the signal probe is different, or uneven at points where the shortest distances (the distance d1 described above) from the axis N are different from each other, or both.

[0053] In the above-described Embodiment 1, an example in which a conductive film is formed on each member of the probe holder 3 has been described, but instead of the film, a conductive plate, sheet, film, etc. that are sufficiently thin compared to the thickness of the member may be used. P In the above-described Embodiment 1, an example in which a second conductive film 31b to 34b is formed on the surface of the hollow portion 35 to form a conductive through-hole has been described, but an insulating inner peripheral surface may be used without forming the second conductive film. P In the above-described Embodiment 1, an example in which a second conductive film 31b to 34b is formed on the surface of the hollow portion 35 to form a conductive through-hole has been described, but an insulating inner peripheral surface may be used without forming the second conductive film.

[0054] In the above-described Embodiment 1, an example in which a conductive film is formed on each member of the probe holder 3 has been described, but instead of the film, a conductive plate, sheet, film, etc. that are sufficiently thin compared to the thickness of the member may be used.

[0055] In the above-described Embodiment 1, an example in which a second conductive film 31b to 34b is formed on the surface of the hollow portion 35 to form a conductive through-hole has been described, but an insulating inner peripheral surface may be used without forming the second conductive film.

[0056] (Modification Example 1) FIG. 4 is a diagram for explaining the arrangement of through-holes of a probe unit according to Modification Example 1 of Embodiment 1 of the present invention. In the probe unit according to Modification Example 1, the sizes of some of the through-holes in the above-described probe holder 3 are different. Since the other configurations are the same as those of the probe unit 1, the description thereof is omitted.

[0057] In the probe holder according to Modification Example 1, six through-holes 37 and two through-holes 37A are formed around the signal probe 2A. In FIG. 4, three sets of through-holes 37 are arranged around the axis N Pand the through hole 37A is disposed on the axis N P 1 shows an example in which the two sensors are arranged opposite each other with a gap therebetween.

[0058] The through holes 37A are formed by aligning the axes of the through holes formed in the first member 31 to the fourth member 34. The through holes 37A form a cylindrical hollow space. The opening of the through holes 37A in a direction perpendicular to the penetration direction is circular. The through holes 37A have a conductive coating (for example, the above-mentioned first conductive coatings 31a to 34a) formed on their inner circumferential surfaces, making the inner circumferential surfaces conductive. The diameter of the through holes 37A is larger than the diameter of the through holes of the through holes 37.

[0059] The through holes 37 and 37A are arranged such that the center of each through hole is aligned with the axis N of the signal probe 2A. P The through hole 37A and the axis N are arranged at a position passing through a circle (dashed line in FIG. 4) with the axis N at the center. P The shortest distance d2 between the through hole 37 and the axis N P is shorter than the shortest distance d1 between them.

[0060] As in the present modified example 1, through holes 37 and 37A of different sizes are arranged around the signal probe 2A, and the signal probe 2A is connected to an external ground via the ground probe 2B. In the modified example 1, as in the first embodiment, the through holes 37 and 37A indirectly connected to the external ground allow the characteristic impedance of the tip and base ends of the signal probe 2A to be adjusted.

[0061] (Variation 2) 5 is a diagram illustrating the arrangement of through holes in a probe unit according to a second modification of the first embodiment of the present invention. The probe unit according to the second modification differs in the size and arrangement of some of the through holes in the probe holder 3 described above. The rest of the configuration is the same as that of the probe unit 1, so a description thereof will be omitted.

[0062] In the probe holder according to Modification 2, six through-holes 37 and two through-holes 37A are formed around the signal probe 2A. In FIG. 5, three sets of through-holes 37 are arranged opposite to each other via the axis N P and the through-holes 37A are arranged opposite to each other via the axis N P are shown as an example.

[0063] The through-holes 37 and 37A are arranged at positions where the shortest distance between the through-hole 37 and the axis N P and the shortest distance between the through-hole 37A and the axis N P are the same distance d1.

[0064] As in this Modification 2, through-holes 37 and 37A having different sizes from each other are arranged around the signal probe 2A, and are connected to the external ground via the ground probe 2B. Also in Modification 2, similar to Embodiment 1, the characteristic impedances of the tip and base ends of the signal probe 2A can be adjusted by the through-holes 37 and 37A indirectly connected to the external ground.

[0065] (Modification 3) FIG. 6 is a diagram for explaining the arrangement of the through-holes of the probe unit according to Modification 3 of Embodiment 1 of the present invention. In the probe unit according to Modification 3, the sizes and arrangements of some of the through-holes in the above-described probe holder 3 are different. Since the other configurations are the same as those of the probe unit 1, the description thereof is omitted.

[0066] In the probe holder according to Modification 3, eight through-holes 37B are formed around the signal probe 2A. In FIG. 6, an example in which four sets of through-holes 37B are arranged opposite to each other via the axis N P is shown.

[0067] The through-hole 37B has a long hole shape in the shape of the opening as viewed from the penetrating direction. The through-hole 37B has the center of gravity of each through-hole on the axis N of the signal probe 2A PThe through-hole 37B is also disposed at a position passing through a circle (dashed line in FIG. 6) having its center at . A conductive coating (for example, the above-described first conductive coatings 31a to 34a) is formed on the inner peripheral surface of the through-hole 37B, making the inner peripheral surface conductive.

[0068] As in the present modified example 3, a plurality of through holes 37B are arranged around the signal probe 2A, and the signal probe 2A is connected to an external ground via the ground probe 2B. In the modified example 3, as in the first embodiment, the through holes 37B indirectly connected to the external ground allow the characteristic impedance of the tip and base ends of the signal probe 2A to be adjusted.

[0069] In addition, in the third modification, the opening shape of the through hole 37B is an elongated hole, so that the area surrounding the signal probe 2A by the through hole 37B is larger than that of the through holes 37 and 37A. By using a shape other than a circle for the through hole, the degree of freedom in adjusting the characteristic impedance is increased, thereby improving the high-frequency characteristics of the probe unit. Furthermore, by increasing the surrounding area, energy loss due to energy leakage to the outside can be further reduced.

[0070] (Variation 4) 7 is a cross-sectional view illustrating the configuration of a main part of a through hole of a probe unit according to a fourth modification of the first embodiment of the present invention. The probe unit according to the fourth modification differs in the shape of the through hole in the above-described probe holder 3. The other configurations are the same as those of the probe unit 1, and therefore, description thereof will be omitted.

[0071] The through hole according to Modification 4 is formed by connecting the through holes formed in the first member 31 to the fourth member 34 to each other. A conductive film (for example, the first conductive films 31a to 34a described above) is formed on the inner peripheral surface of the through hole, and a conductive inner peripheral surface is formed. The through hole has a different diameter in part. Specifically, for example, the diameter Q1 of the through hole 37a formed in the third member 33 is different from the diameter Q2 of the through hole 37b formed in the first member 31. The central axis N1 of the through hole 37a and the central axis N2 of the through hole 37b are linearly continuous.

[0072] As in this Modification 4, by arranging a through hole having a stepped hole shape around the signal probe 2A and connecting it to an external ground via the ground probe 2B, the same effects as those of Embodiment 1 can be obtained, and characteristic impedance adjustment according to the shape of the signal probe 2A can be performed.

[0073] (Modification 5) FIG. 8 is a cross-sectional view for explaining the configuration of a main part of a through hole of a probe unit according to Modification 5 of Embodiment 1 of the present invention. The probe unit according to Modification 5 has a different shape of the through hole in the probe holder 3 described above. Since the other configurations are the same as those of the probe unit 1, the description thereof is omitted.

[0074] The through hole according to Modification 5 is formed by connecting the through holes formed in the first member 31 to the fourth member 34 to each other. A conductive film (for example, the first conductive films 31a to 34a described above) is formed on the inner peripheral surface of the through hole, and a conductive inner peripheral surface is formed. The through hole is partially different in the position of the axis. Specifically, for example, the central axis N1 of the through hole 37c formed in the third member 33 and the central axis N2 of the through hole 37d formed in the first member 31 are different in position. Also, the diameter Q3 of the through hole 37c and the diameter Q4 of the through hole 37d are the same diameter. Thus, the through hole according to Modification 5 is formed by through holes that are partially different in the position of the central axis. At this time, when the through hole is viewed from the stacking direction of the first member 31 to the fourth member 34, at least a part of the through holes formed in the members adjacent to each other in the stacking direction of the members overlap each other. The through hole is formed by at least partial communication of the through holes formed in each member with each other.

[0075] As in this Modification 5, by arranging a through hole having a stepped hole shape with the axes of some of the through holes displaced around the signal probe 2A and connecting it to the external ground via the ground probe 2B, the same effects as those in Embodiment 1 can be obtained, and the characteristic impedance can be adjusted according to the shape of the signal probe 2A.

[0076] (Modification 6) FIG. 9 is a cross-sectional view for explaining the configuration of the main part of the through hole of the probe unit according to Modification 6 of Embodiment 1 of the present invention. The probe unit according to Modification 6 has a different shape of the through hole in the probe holder 3 described above. Since the other configurations are the same as those of the probe unit 1, the description thereof is omitted.

[0077] The through holes according to the sixth modification are formed by interconnecting the through holes formed in the first to fourth members 31 to 34. The through holes have a conductive coating (for example, the above-described first conductive coatings 31a to 34a) formed on the inner circumferential surface, forming a conductive inner circumferential surface. The through holes have partially different diameters and axial positions. Specifically, for example, the diameter Q5 of the through hole 37e formed in the third member 33 is different from the diameter Q6 of the through hole 37f formed in the first member 31. Furthermore, the central axis N1 of the through hole 37e is different from the central axis N2 of the through hole 37f.

[0078] As in the present modification 6, by arranging through holes around the signal probe 2A, some of which have different diameters and have stepped hole shapes with offset axes, and connecting to an external ground via the ground probe 2B, it is possible to obtain the same effects as in the first embodiment and to adjust the characteristic impedance according to the shape of the signal probe 2A.

[0079] It is also possible to appropriately combine the through-hole configurations according to Modifications 1 to 6. For example, the signal probes arranged in the same probe holder may have at least some different shapes or arrangements.

[0080] (Embodiment 2) Next, a second embodiment will be described with reference to Fig. 10. Fig. 10 is a partial cross-sectional view showing the configuration of a main part of a probe unit according to the second embodiment of the present invention. The probe unit according to the second embodiment includes a probe holder 3A instead of the above-described probe holder 3. The other configurations are the same as those of the probe unit 1, so the description will be omitted.

[0081] The probe holder 3A is composed of a single member formed using an insulating material such as resin, machinable ceramic, or silicon. In the probe holder 3A, a hollow portion 35 that forms a space for accommodating a plurality of signal probes 2A and a hollow portion (the above-described hollow portion 36) that forms a space for accommodating a plurality of ground probes 2B are formed. The hollow portions 35 and 36 have a hole shape with a diameter that allows the contact probes to be inserted and removed and prevents them from coming off. Further, a plurality of through holes 38 are formed around the signal probe 2A in the probe holder 3A.

[0082] The surface of the probe holder 3A is subjected to a plating process. A conductive material is used for the plating process. For this reason, a first conductive film 3a and a second conductive film 3b are formed on the surface of the probe holder 3A. Note that the first conductive film 3a is formed on the surface other than the hollow portion 35, including the portion where the through hole 38 is formed. Further, the second conductive film 3b is formed on the surface of the portion where the hollow portion 35 is formed. The first conductive film 3a and the second conductive film 3b are spaced apart from each other to ensure insulation.

[0083] The through hole 38 is a through hole with a circular opening shape in a direction orthogonal to the penetration direction and having a different diameter in part. Specifically, the through hole 38 has a first hole portion 38a formed on one surface side (the side where the first plunger 21 extends in FIG. 10), a second hole portion 38b formed on the other surface side (the side where the second plunger 22 extends in FIG. 10), and a third hole portion 38c provided between the first hole portion 38a and the second hole portion 38b. The diameters of the openings of the first hole portion 38a and the second hole portion 38b are larger than the diameter of the opening of the third hole portion 38c. The first conductive film 3a is formed on the inner peripheral surface of the through hole 38, and a conductive inner peripheral surface is formed. Note that the central axes of the first hole portion 38a, the second hole portion 38b, and the third hole portion 38c are linearly continuous.

[0084] The through holes 38 form a cylindrical hollow space with stepped diameters that are partially different, and a plurality of them are formed around the signal probe 2A. For example, eight through holes 38 are formed around one signal probe 2A, similar to the first embodiment.

[0085] In the above-described second embodiment, the through holes 38 are arranged around the signal probe 2A and are connected to an external ground via the ground probe 2B. Thus, according to the second embodiment, the characteristic impedances of the tip and base ends of the signal probe 2A can be adjusted by the through holes 38 indirectly connected to the external ground. According to the second embodiment, the overall characteristic impedance including the ends of the signal probe 2A can be adjusted. Also, according to the second embodiment, by adjusting the position of the through holes, the ground position in the direction orthogonal to the axial direction with respect to the signal probe 2A can be adjusted.

[0086] Also, in the second embodiment, since the diameters of the through holes of the through holes 38 are partially different, characteristic impedance adjustment according to the shape of the signal probe 2A can be performed.

[0087] (Embodiment 3) Next, Embodiment 3 will be described with reference to FIG. 11. FIG. 11 is a partial cross-sectional view showing the configuration of the main part of the probe unit according to Embodiment 3 of the present invention. The probe unit according to Embodiment 3 includes a probe holder 4 instead of the above-described probe holder 3. Since the other configurations are the same as those of the probe unit 1, the description thereof will be omitted.

[0088] The probe holder 4 is formed by laminating a first member 41 and a second member 42 made of an insulating material such as resin, machinable ceramic, or silicon. The probe holder 4 shown in FIG. 11 is laminated in the order of the first member 41 and the second member 42 from the upper side of the figure. The first member 41 and the second member 42 are fixed by a known method such as screwing or adhesion.

[0089] The probe holder 4 is formed with a hollow portion 35 that forms a space for accommodating a plurality of signal probes 2A, and a hollow portion (not shown) that forms a space for accommodating a plurality of ground probes 2B. The probe holder 4 also has a plurality of through holes 43 formed around the signal probes 2A.

[0090] The surface of the first member 41 is plated. A conductive material is used for the plating. Therefore, a first conductive coating 41a and a second conductive coating 41b are formed on the surface of the first member 41. The first conductive coating 41a is formed on the surface excluding the hollow portion 35, including the portion where the through hole 43 is formed. The second conductive coating 41b is formed on the surface of the portion where the hollow portion 35 is formed. The first conductive coating 41a and the second conductive coating 41b are spaced apart from each other to ensure insulation.

[0091] Similar to the first member 41, the surface of the second member 42 is plated. A first conductive coating 42a and a second conductive coating 42b are formed on the surface of the second member 42. The first conductive coating 42a is formed on the surface excluding the hollow portion 35, including the portion where the through hole 43 is formed. The second conductive coating 42b is formed on the surface of the portion where the hollow portion 35 is formed. The first conductive coating 42a and the second conductive coating 42b are spaced apart from each other to ensure insulation. Therefore, in the probe holder 4 formed by laminating the first member 41 and the second member 42, a conductive coating is present at the boundaries between the members and on the outer surface.

[0092] Hollow portion 35 is formed by aligning the axes of through holes formed in first member 41 and second member 42. Second conductive coatings 41b, 42b are formed on the inner circumferential surface of hollow portion 35, forming a conductive inner circumferential surface.

[0093] The through-hole 43 is a through-hole having a stepped shape in which the shape of the opening in a direction orthogonal to the through direction is a circle and the positions of the central axes are partially different. Specifically, the through-hole 43 includes a first hole portion 43a formed on one surface side of the probe holder 4 (the side where the first plunger 21 extends in FIG. 11), a second hole portion 43b formed on the other surface side (the side where the second plunger 22 extends in FIG. 11), and a third hole portion 43c provided between the first hole portion 43a and the second hole portion 43b. The diameters of the openings of the first hole portion 43a, the second hole portion 43b, and the third hole portion 43c are the same as each other. Also, the central axes N T1 , N T2 of the first hole portion 43a and the second hole portion 43b and the central axis N T3 of the third hole portion 43c are different from each other within the range where adjacent hole portions communicate with each other. The through-hole 43 has first conductive films 41a and 42a formed on the inner peripheral surface, and a conductive inner peripheral surface is formed.

[0094] The through-hole 43 forms a stepped cylindrical hollow space and a plurality of through-holes 43 are formed around the signal probe 2A. For example, eight through-holes 43 are formed around one signal probe 2A in the same manner as in the first embodiment.

[0095] In the above-described third embodiment, the through-holes 43 are arranged around the signal probe 2A and are connected to an external ground via the ground probe 2B. Thus, according to the third embodiment, the characteristic impedances of the tip and the base end portions of the signal probe 2A can be adjusted by the through-holes 43 indirectly connected to the external ground. According to the third embodiment, the overall characteristic impedance including the end portion of the signal probe 2A can be adjusted. Also, according to the third embodiment, by adjusting the position of the through-hole, the ground position in a direction orthogonal to the axial direction with respect to the signal probe 2A can be adjusted.

[0096] Furthermore, in the third embodiment, the positions of the central axes of the through holes 43 are made to differ partially from each other, so that the characteristic impedance can be adjusted in accordance with the shape of the signal probe 2A.

[0097] The above-described first to third embodiments and their modifications can be combined as appropriate. Furthermore, the configuration of each contact probe can be individually selected from the arrangement or shape of the through holes of the first to third embodiments and modifications.

[0098] The contact probe configuration described here is merely an example, and various types of conventionally known probes can be applied. For example, the contact probe is not limited to the above-described one configured with a plunger and a coil spring, but may be a probe including a pipe member, a pogo pin, a solid conductive member, a conductive pipe, a wire probe that obtains a load by bending a wire into a bow shape, a connection terminal (connector) that connects electrical contacts, or an appropriate combination of these probes.

[0099] Furthermore, the probe holders according to the above-mentioned first to third embodiments and their modified examples have been described as being constructed by stacking four or two members, or by one member, but they may also be constructed by stacking three members or five or more members.

[0100] Furthermore, in the above-described first to third embodiments and their modifications, the conductive film may be formed in a pattern partially rather than entirely on the surface of the member of the probe holder 3, as long as it can electrically connect the through-hole and the grounding probe 2B. For example, the conductive film may be formed on the portion constituting the through-hole and on the outer surface of the member constituting the open end of the through-hole (for example, the third member 33 and the fourth member 34 shown in FIG. 1). In this case, the conductive film is electrically connected to the grounding probe 2B at least during testing.

[0101] As such, the present invention may include various embodiments not described here, and various design changes may be made within the scope of the technical idea specified by the claims. [Industrial Applicability]

[0102] As described above, the probe unit according to the present invention is suitable for adjusting the characteristic impedance of the entire contact probe. [Explanation of symbols]

[0103] 1 probe unit 2A Contact Probe (Signal Probe) 2B Contact Probe (Ground Probe) 3, 3A, 3B Probe Holder 3a, 31a to 34a, 41a, 42a First conductive film 3b, 31b~34b, 41b, 42b Second conductive film 21 First plunger 22 Second plunger 23 Spring member 23a Closely wound part 23b Coarse winding section 31, 41 First member 32, 42 Second member 33 Third member 34 Fourth member 35, 36 Hollow part 37, 37A, 37B, 38, 43 through holes 100 Semiconductor Integrated Circuit 101, 102, 201, 202 electrode 200 Circuit Boards

Claims

1. A first contact probe that contacts respective electrodes of a contact target on one end side in the longitudinal direction, A second contact probe connected to an external ground, A probe holder that holds the first and second contact probes, Comprising, In the probe holder, A first hollow portion that inserts and holds the first contact probe, A second hollow portion that inserts and holds the second contact probe, A through hole provided around the first hollow portion, Is formed, The probe holder constitutes the through hole and has a conductive portion that electrically connects the through hole and the second contact probe. A probe unit characterized by the above.

2. The conductive portion is provided on the through hole and a surface that forms an opening end of the through hole. The probe unit according to claim 1, characterized by the above.

3. The through hole has a stepped hole shape with a partially different diameter. The probe unit according to claim 1 or 2, characterized by the above.

4. The through hole has a stepped hole shape with different positions of the central axis. The probe unit according to any one of claims 1 to 3, characterized by the above.

5. The probe holder consists of one member. The probe unit according to any one of claims 1 to 4, characterized by the above.

6. The probe holder is formed by laminating a plurality of members in the penetrating direction of the first hollow portion. The probe unit according to any one of claims 1 to 4, characterized by the above.

7. The through hole is formed by through holes respectively formed in the plurality of members, In at least one member, the through hole has a stepped hole shape with a partially different diameter. The probe unit according to claim 6, characterized by the above.

8. The through hole is formed by through holes respectively formed in the plurality of members, In at least one member, the through hole has a stepped hole shape with different positions of the central axis. The probe unit according to claim 6 or 7, characterized by the above.

9. In the plurality of members, through holes that constitute the through hole are respectively formed, In the through hole, at least a part of the through holes formed in adjacent members in the lamination direction of the members overlap each other when viewed from the penetrating direction of the through hole. The probe unit according to claim 6, characterized in that...

10. The through hole has an elongated hole shape when viewed from the through direction, The probe unit according to any one of claims 1 to 9, characterized in that...

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