Contact pin and contact pin unit

Abstract

To provide a contact pin, a contact pin subassembly, and a contact pin unit capable of obtaining a stable contact state while facilitating replacement.SOLUTION: A contact probe 17 as a contact pin is provided by projection of a plunger 21 at one end of a barrel 35, and is biased by a coil spring 37 housed in the barrel 35. A press-fit portion 34b is provided at the other end of the barrel 35 by crimping and fixing a shaft portion 34a of a press-fit pin 34 inserted into a cylindrical shaft fixing portion 35b provided in the barrel 35. During replacement of the contact probe 17, by inserting and removing the press-fit portion 34b into and from a through-hole provided in a relay substrate, electrical isolation and connection with the relay substrate are performed, and a unit holding the contact probe 17 in a holder and the relay substrate are assembled.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a contact pin, a contact pin subassembly, and a contact pin unit. [Background technology]

[0002] As a contact pin, a contact probe is known that electrically connects a test object such as a circuit board on which a circuit element is mounted, a semiconductor integrated circuit, or various electronic devices to a tester or the like. A contact probe has a plunger that contacts an electrode such as a pad or a solder bump, a coil spring that biases the plunger so as to press it against the electrode, and a barrel that houses the base end of the plunger and the coil spring in a hollow interior. Contact probes can be broadly divided into single-ended contact probes in which a plunger is provided only at one end of the barrel (see, for example, Patent Document 1) and double-ended contact probes in which a plunger is provided at each end of the barrel (see, for example, Patent Document 2).

[0003] A single-ended contact probe has a lead wire soldered to the other end, i.e., the end opposite the plunger, and is electrically connected to a tester via the lead wire. Some single-ended contact probes have the end opposite the plunger soldered to a through hole in a circuit board, and are electrically connected to a tester via the circuit board. A double-ended contact probe has a plunger at one end pressed against an electrode to be tested, and a plunger at the other end pressed against an electrode on a relay board, and is electrically connected to a tester via a connection board (relay board).

[0004] Since the contact probe repeatedly transitions between a state in which the plunger is in contact with the electrode to be tested and a state in which it is released, the plunger may deteriorate due to, for example, sparks generated between the plunger and the electrode. When the plunger deteriorates in this way, the contact resistance increases and the test cannot be performed correctly, so the contact probe is replaced.

[0005] A pin-shaped press-fit pin is known, in which a press-fit portion is provided at one end of a shaft portion to be press-fitted into a through-hole provided in a substrate (see, for example, Patent Document 3). The through-hole provided in the substrate has an inner peripheral surface that is, for example, copper-plated, and by pressing the press-fit portion into the through-hole, the press-fit pin is fixed to the substrate and the press-fit pin is electrically connected to the wiring on the substrate. The shaft portion of the press-fit pin is used as a terminal of a connector, etc. By using such a press-fit pin, a connector can be attached to a substrate without soldering. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2012-32162 A [Patent Document 2] Patent Publication No. 2021-42974 [Patent Document 3] JP 2004-335409 A Summary of the Invention [Problem to be solved by the invention]

[0007] Incidentally, when replacing a contact probe, in the case of a single-ended contact probe, for example, it is necessary to remove the deteriorated contact probe, solder the lead wires to the new contact probe and the board on the inspection device side, and solder the other end of the new contact probe to the through hole, making the replacement work complicated. In contrast, the replacement work of a double-ended contact probe is relatively easy. However, since a double-ended contact probe is structured to electrically connect by contacting the plunger with the electrode of the connection board, there is a tendency for the contact resistance to be high because the contact area between the plunger and the electrode of the connection board cannot be sufficiently secured, and there is also a problem that the contact state between the plunger and the electrode of the connection board changes due to distortion or bending of the connection board, making the contact resistance unstable. Similar problems also exist with contact pins other than contact probes, for example, contact pins used for electrically connecting with electrical components when the electrical components, such as modules and IC packages, which are unitized by assembling electronic components, are assembled into a device.

[0008] The present invention has been made in consideration of the above circumstances, and has an object to provide a contact pin, a contact pin subassembly, and a contact pin unit that can provide a stable contact state while being easily replaced. [Means for solving the problem]

[0009] The contact pin of the present invention comprises a cylindrical barrel, a contact portion provided at one end of the barrel, the tip of which contacts an electrode, and a press-fit portion provided at the other end of the barrel to be pressed into a through hole provided in a connection board.

[0010] The contact pin subassembly of the present invention comprises a cylindrical barrel, a contact portion provided at one end of the barrel, the tip of which contacts an electrode, and a shaft mounting portion provided at the other end of the barrel into which the shaft portion of a press-fit pin having a press-fit portion formed therein is inserted and mounted.

[0011] The contact pin unit of the present invention comprises a cylindrical barrel, a plunger held in the barrel so as to be freely movable in its axial direction, with its base end contained within the barrel and its tip which contacts an electrode protruding from one end of the barrel, a biasing member which biases the plunger in a direction causing it to protrude from the one end of the barrel, a contact pin provided at the other end of the barrel and having a press-fit portion which is pressed into a through hole provided in a connection board, and a holder which holds the contact pin and to which the contact pin can be attached and detached. Effect of the Invention

[0012] According to the present invention, a press-fit portion is provided at the other end of the barrel opposite the contact portion of the contact pin, so that electrical isolation and connection can be achieved by inserting and removing the press-fit portion into the through hole, and a stable contact state can be obtained between the through hole and the press-fit portion even if the connection board is bent or distorted. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is an explanatory diagram showing a configuration of an inspection device according to an embodiment. [Diagram 2] FIG. 2 is an exploded perspective view showing a configuration of a contact pin unit. [Diagram 3] 4 is a cross-sectional view showing the configuration of a contact probe and the configuration of a through hole. FIG. [Figure 4] 11 is an explanatory diagram showing the assembly of the relay board and the contact pins. FIG. [Diagram 5] 11 is an explanatory diagram showing a state in which a plunger of a contact probe is pressed against an electrode of a circuit board. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] In FIG. 1, the inspection device 10 of this example inspects a circuit board 11 on which a semiconductor element or the like is mounted as an inspection object. The inspection device 10 is composed of a contact pin unit (hereinafter, simply referred to as a unit) 12, a relay board 14, an inspection device 15, and the like. In the following, as shown in FIG. 1, the side on which the circuit board 11 is arranged with respect to the unit 12 is defined as the lower side as the upper and lower directions, but the upper and lower directions do not limit the posture or orientation of the unit 12 in use. Therefore, for example, the circuit board 11 may be arranged above, to the side, diagonally above, or diagonally below the unit 12 and inspected. In this example, the inspection object is the circuit board 11, but the inspection object is not limited to this and may be a semiconductor integrated circuit, various electronic devices, a liquid crystal panel, or the like. A measuring device may be connected instead of the inspection device 15 to configure a measuring device, or the like.

[0015] The unit 12 includes a plurality of contact probes 17 (four in this example) as contact pins, and a holder 18 that holds the contact probes 17. A plurality of holding holes 19 are formed in the holder 18, and the contact probes 17 are held in the holding holes 19. The holder 18 is capable of attaching and detaching the contact probes 17, so that the contact probes 17 can be replaced. The unit 12 is moved by an elevation mechanism (not shown) between a pressure contact position where a plunger 21 as a contact portion of the contact probe 17 is pressed against an electrode (pad) 11a on the circuit board 11, and a retracted position where the plunger 21 is moved upward from the pressure contact position and separated from the electrode 11a. The number of contact probes 17 held by the holder 18 is not limited to four, and may be one or more.

[0016] The contact probe 17 is electrically connected to the inspection device 15 via the relay board 14 as a connection board. The relay board 14 has a through hole 22 formed therein. The through hole 22 is provided so as to penetrate the relay board 14 in the thickness direction, and the inner peripheral surface of the through hole 22 is plated with, for example, a copper-plated portion 22a (see FIG. 4). The copper-plated portion 22a is connected to a printed wiring (not shown) provided on the relay board 14, and is connected to the inspection device 15 via the printed wiring. The contact probe 17 is electrically connected to the through hole 22 (copper-plated portion 22a). During inspection, the contact probe 17 is electrically connected to the electrode 11a, i.e., the circuit on the circuit board 11, by pressing the plunger 21 against the electrode 11a. The inspection device 15 applies an inspection signal to the circuit on the circuit board 11 via the relay board 14, the contact probe 17, and the electrode 11a, and obtains an output signal from the circuit in response to the inspection signal, thereby inspecting the circuit.

[0017] 2, the holder 18 is composed of a first holder member 23, a second holder member 24 that is layered on the first holder member 23, and a fixing portion 25 that fixes the first holder member 23 and the second holder member 24. The first holder member 23 and the second holder member 24 are formed of an insulating material, for example a plastic material, and hold each contact probe 17 while electrically insulating it.

[0018] The first holder member 23 is a block-shaped member that is long in the direction in which the contact probes 17 are arranged. The first holder member 23 has a central portion 26 that bulges downward in the center of its longitudinal direction. The upper surface 23a of the first holder member 23 and the lower surface 26a of the central portion 26 are both flat surfaces. The second holder member 24 has a block shape similar to the first holder member 23, but the central portion 27 in the center of the longitudinal direction bulges upward, and the lower surface 24a of the second holder member 24 and the upper surface 27a of the central portion 27 are flat surfaces. The upper surface 23a of the first holder member 23 and the lower surface 24a of the second holder member 24 have the same shape and size. When holding the contact probes 17, the first holder member 23 and the second holder member 24 are fixed in a state in which the longitudinal directions are aligned and the upper surface 23a and the lower surface 24a are in close contact with each other. Note that first holder member 23 and second holder member 24 may be fixed together to hold contact probe 17 with a gap provided between them.

[0019] The first holder member 23 has a plurality of first through holes 31 in its central portion 26, and the second holder member 24 has a plurality of second through holes 32 in its central portion 27. The first through holes 31 penetrate the central portion 26 in its thickness direction, and the second through holes 32 penetrate the central portion 27 in its thickness direction. One end side (plunger 21 side) of the contact probe 17 is inserted into the first through hole 31, and the other end side (opposite to the plunger 21) of the contact probe 17 is inserted into the second through hole 32. The first through holes 31 and the second through holes 32 that correspond to each other are connected to form the holding hole 19.

[0020] In this example, the fixing part 25 is composed of two sets of bolts 25a and nuts 25b. At both ends of the longitudinal direction of the first holder member 23 and the second holder member 24, through-holes 23b, 24b are formed, respectively, penetrating in the thickness direction. The fixing part 25 fixes the first holder member 23 and the second holder member 24 by passing each bolt 25a through the through-holes 23b, 24b and screwing the nut 25b, respectively. In addition, the first holder member 23 and the second holder member 24 can be separated by removing the nut 25b from the bolt 25a. By separating the first holder member 23 and the second holder member 24, the contact probe 17 can be inserted into the holding hole 19 and the contact probe 17 can be removed from the holding hole 19.

[0021] The configuration of the fixing portion 25 that fixes the first holder member 23 and the second holder member 24 together is not limited to the above, as long as it can fix the first holder member 23 and the second holder member 24 separably. For example, as the fixing portion, a protrusion may be provided on one side surface of the first holder member 23 and the second holder member 24, and an engagement claw may be provided on the other side. In this case, when the first holder member 23 and the second holder member 24 are stacked, the engagement claw engages with the protrusion to fix them, and the engagement between the engagement claw and the protrusion can be released to separate them.

[0022] In Fig. 3, the contact probe 17 is configured by assembling a press-fit pin 34 to a subassembly 33 as a contact pin subassembly. The subassembly 33 has the above-mentioned plunger 21, barrel 35, and coil spring 37 as an elastic member. The plunger 21, press-fit pin 34, barrel 35, and coil spring 37 are formed of a conductive material or have surfaces plated with a conductive material, and the plunger 21 and press-fit pin 34 are electrically connected through the barrel 35 and coil spring 37. For example, the plunger 21, barrel 35, and press-fit pin 34 are made of a copper alloy such as brass, phosphor bronze, or beryllium copper, and the coil spring 37 is made of piano wire or stainless steel, and the surfaces of each are plated with Au (gold), Ni (nickel), Rh (rhodium), Pd (palladium), or the like.

[0023] The barrel 35 is hollow and cylindrical, and has a hole 39 penetrating the barrel 35 in the axial direction X. The barrel 35 has a tubular portion 35a at one end (lower side in FIG. 3) and a shaft fixing portion 35b as a shaft mounting portion at the other end. The barrel 35 has a large diameter portion 35c as a first protruding portion between the tubular portion 35a and the shaft fixing portion 35b, and a boss 35d as a second protruding portion between the large diameter portion 35c and the shaft fixing portion 35b. The large diameter portion 35c has an outer diameter larger than that of the tubular portion 35a and protrudes in the radial direction of the barrel 35. The boss 35d has an outer diameter smaller than that of the large diameter portion 35c and larger than that of the shaft fixing portion 35b. That is, the cross-sectional size of the boss 35d perpendicular to the axial direction is smaller than that of the large diameter portion 35c.

[0024] The plunger 21 is rod-shaped with the outside diameter of the base end 21b being larger than that of the tip end 21a. In this example, the plunger 21 has a hemispherical tip, but can be needle-shaped, crown-shaped, conical, or other shapes depending on the shape of the electrode 11a. The base end 21b of the plunger 21 is disposed in the cylindrical portion 35a, i.e., in the hole 39, and the tip end 21a protrudes from the tip of the cylindrical portion 35a. The tip of the cylindrical portion 35a is bent inwardly so that the inner diameter of the opening through which the tip end 21a is inserted is the same as or slightly larger than the outer diameter of the tip end 21a and is smaller than the base end 21b. As a result, the base end 21b is engaged with the tip of the cylindrical portion 35a, and the plunger 21 is held by the barrel 35 while being movable in the axial direction X and prevented from falling out of the barrel 35. In this example, the base end 21b is inserted into the hole 39 from the tip of the tubular portion 35a, and then the tip of the tubular portion 35a is bent as described above. However, the tip of the tubular portion 35a may be pre-machined into a shape such as that described above, and the plunger 21 may be inserted into the hole 39 from the other end side of the barrel 35 (in this example, the shaft fixing portion 35b side).

[0025] The hole 39 has an inner diameter smaller on the other end side than on the one end side of the barrel 35, and a step surface 39a is provided near the center in the axial direction X. The coil spring 37 has an outer diameter larger than the inner diameter on the other end side of the hole 39. The coil spring 37 is disposed between the step surface 39a and the base end 21b of the plunger 21 in the barrel 35 (in the hole 39), and one end of the coil spring 37 abuts against the base end 21b of the plunger 21, and the other end is engaged with the step surface 39a. As a result, the coil spring 37 biases the plunger 21 in a direction from the other end to one end of the barrel, that is, in a direction to protrude from the tip of the cylindrical portion 35a. In a non-contact state in which the tip end 21a is not in contact with the electrode 11a, the plunger 21 is in a state in which the base end 21b is engaged with the tip of the cylindrical portion 35a by the bias of the coil spring 37.

[0026] The above-mentioned configuration for biasing and holding the plunger 21 against the barrel 35 is an example, and is not limited thereto. For example, a bushing may be fitted into the opening at the tip of the tubular portion 35a to reduce the opening diameter and prevent the plunger 21 from falling off. In this example, the coil spring 37 is disposed in the barrel 35 as a biasing member, but for example, the coil spring 37 may be disposed between the flange provided at the tip portion 21a of the plunger 21 and the barrel 35. A leaf spring or the like may be used as the biasing member instead of the coil spring 37. The barrel 35 in this example is cylindrical, but the cylindrical shape is not limited thereto, and may be, for example, a rectangular tube shape such as a triangular or hexagonal cross section.

[0027] The shaft portion 34a of the press-fit pin 34 is crimped and fixed to the shaft fixing portion 35b. The shaft fixing portion 35b is formed in a cylindrical shape, and is crimped in a state in which the shaft portion 34a of the press-fit pin 34 is inserted into the hollow interior (hole 39 in the shaft fixing portion 35b in this example) from the opening on the other end side. As a result, the press-fit pin 34 is fixed to the barrel 35, the press-fit portion 34b is provided at the other end of the barrel 35, and the barrel 35 and the press-fit pin 34 are electrically connected. In this example, the hole 39 penetrates from the cylindrical portion 35a to the shaft fixing portion 35b, but a hole in the shaft fixing portion 35b into which the shaft portion 34a of the press-fit pin 34 is inserted may be provided separately from the hole in which the base end portion 21b of the plunger 21 and the coil spring 37 are disposed.

[0028] The press-fit pin 34 has a shaft portion 34a, a press-fit portion 34b, and a tip portion 34c. The press-fit pin 34 is produced, for example, by pressing a wire material into a predetermined shape and then plating it. In this example, the shaft portion 34a is a rod-like (prism-like) that extends linearly, and the press-fit portion 34b is formed at one end of the shaft portion 34a. The tip portion 34c is formed in a short rod shape at the end of the press-fit portion 34b opposite to the shaft portion 34a.

[0029] The press-fit pin 34 in this example is of a needle-eye shape, with a hole 41 formed in the center of the press-fit portion 34b in the width direction perpendicular to the extension direction of the shaft portion 34a, and arms 42 on both sides of the hole 41 projecting in the width direction. As a result, when the press-fit portion 34b is press-fitted into a through-hole 22 whose inner diameter is smaller than the width of the press-fit portion 34b, the arm 42 elastically deforms so as to narrow the width of the hole 41, and the elastic force causes the surface of the arm 42 to adhere closely to the inner wall surface of the through-hole 22, maintaining a stable surface contact state. Furthermore, the contact between the press-fit portion 34b and the through-hole 22 results in the relay board 14 being assembled to the unit 12.

[0030] As described above, the shape of the press-fit portion 34b in this example is a needle eye shape, but the shape is not limited to this and can be various shapes such as an N shape, an H shape, etc. The method of fixing the barrel 35 and the press-fit pin 34 is not limited to crimping and can be, for example, soldering or welding, or the press-fit pin 34 can be fixed to the barrel 35 by press-fitting the shaft portion 34a into the shaft fixing portion 35b.

[0031] Furthermore, in this example, the press-fit pin 34 is fixed to the barrel 35 to provide the press-fit portion 34b at the other end of the barrel 35, but the method of providing the press-fit portion 34b is not limited to this. For example, the press-fit portion 34b, which does not include the shaft portion 34a, may be fixed to the other end of the barrel 35 by soldering, welding, or the like to electrically connect the press-fit portion 34b and the barrel 35.

[0032] As described above, the first holder member 23 is provided with the first through hole 31, and the second holder member 24 is provided with the second through hole 32. The first through hole 31 is formed by connecting the small diameter hole portion 31a as the first small hole portion in which the cylindrical portion 35a, which is one end of the barrel 35, is disposed, and the large diameter hole portion 31b as the first large hole portion in which the large diameter portion 35c is disposed. In this example, the inner diameter of the small diameter hole portion 31a is set to be the same as the outer diameter of the cylindrical portion 35a, and the cylindrical portion 35a is fitted into the small diameter hole portion 31a, that is, the cylindrical portion 35a is fitted in a state in which the outer peripheral surface of the cylindrical portion 35a contacts the inner peripheral surface of the small diameter hole portion 31a. This prevents the plunger 21 from being displaced in a direction perpendicular to the axial direction X.

[0033] The depth (length in the axial direction X) of the small diameter hole 31a is smaller than the height (length in the axial direction X) of the cylindrical portion 35a, and the tip portion 21a of the plunger 21 and a part of the tip side of the cylindrical portion 35a protrude downward from the small diameter hole 31a and are exposed. Note that only the tip portion 21a of the plunger 21 may protrude from the small diameter hole 31a.

[0034] The inner diameter of the large diameter hole portion 31b is the same as the outer diameter of the large diameter portion 35c and is larger than the inner diameter of the small diameter hole portion 31a. That is, the cross-sectional size of the large diameter hole portion 31b perpendicular to the axial direction is larger than that of the small diameter hole portion 31a. As a result, a step surface 31c is formed at the boundary between the small diameter hole portion 31a and the large diameter hole portion 31b. In addition, the depth of the large diameter hole portion 31b is the same as the height of the large diameter portion 35c. As a result, the large diameter portion 35c fits into the large diameter hole portion 31b so that the entirety of the large diameter portion 35c is accommodated in the large diameter hole portion 31b. The end face of the lower side (one end side of the barrel 35) of the large diameter portion 35c thus fitted into the large diameter hole portion 31b contacts the step surface 31c. As a result, the movement of the barrel 35 downward in the first through hole 31 is restricted to prevent the barrel 35 from falling off. An end face on the upper side (the other end side of the barrel 35) of the large diameter portion 35c is flush with the upper surface 23a of the first holder member 23 and contacts the lower surface 24a of the second holder member 24, thereby restricting the upward movement of the barrel 35. As a result, the contact probe 17 is held in the holding hole 19 while its movement in the axial direction X is restricted.

[0035] The second through hole 32 is formed as a hole with a constant inner diameter, and the inner diameter is determined to be large enough to allow the shaft fixing portion 35b to which the shaft portion 34a is fixed and the press-fit portion 34b to pass through. In this example, the inner diameter of the second through hole 32 is slightly larger than the width of the press-fit portion 34b when not pressed into the through hole 22. The boss 35d of the barrel 35 has an outer diameter equal to the inner diameter of the second through hole 32 and fits into the second through hole 32. This prevents the press-fit pin 34 from being displaced from the axis of the second through hole 32.

[0036] The depth of the second through hole 32 is determined so that the press-fit portion 34b protrudes upward from the second through hole 32 and is exposed. That is, the length from the upper end face of the large diameter portion 35c to the base of the press-fit portion 34b (the boundary with the shaft portion 34a) is greater than the depth of the second through hole 32. A part of the shaft fixing portion 35b may protrude from the second through hole 32.

[0037] The configuration for restricting the movement of contact probe 17 in axial direction X and the configuration for suppressing displacement of press-fit pin 34 are not limited to the above. For example, the outer diameter of large diameter portion 35c and boss 35d may be the same. The configuration of holder 18 for holding contact probe 17, such as first holder member 23, second holder member 24, and the shapes of through holes formed therein, may be selected according to the shape of contact probe 17, etc.

[0038] When subjecting unit 12 to inspection, prior to the inspection, as shown in FIG. 4(A), each press-fit portion 34b protruding and exposed from holder 18 is aligned with each through-hole 22 formed in relay board 14, and as shown in FIG. 4(B), each press-fit portion 34b is pressed into the corresponding through-hole 22, thereby attaching unit 12 to relay board 14.

[0039] When press-fitting, the press-fit portion 34b is inserted into the through-hole 22 from the tip portion 34c of the press-fit pin 34, using the tip portion 34c as a guide, as in the case of a conventional press-fit pin. As a result, each arm 42 abuts against the periphery of the opening of the through-hole 22 and elastically deforms to reduce the width of the press-fit portion 34b, so that the press-fit portion 34b is pressed into the through-hole 22. When the press-fit portion 34b is pressed in this manner, the elastic force of the arm 42 maintains a state in which the surface of the arm 42 is in surface contact with the copper plating portion 22a. As a result, the contact probe 17 is electrically connected to the inspection device 15 via the relay board 14, and the unit 12 is assembled to the relay board 14.

[0040] The press-fit portion 34b is in close surface contact with the copper-plated portion 22a of the through-hole 22, and this contact state is stable. Therefore, the contact resistance between the press-fit portion 34b and the copper-plated portion 22a of the through-hole 22 is low, and good contact is achieved. Furthermore, even if the relay board 14 is distorted or bent, the above-mentioned stable contact state is maintained.

[0041] During testing, with the circuit board 11 to be tested disposed below the unit 12, the unit 12 moves down from the retracted position to the pressure contact position together with the relay board 14. As a result, as shown in Fig. 5, the plungers 21 of the contact probes 17 come into contact with the electrodes 11a on the circuit board 11, and move in a direction that reduces the protruding length of the tip 21a from the barrel 35 against the bias of the coil spring 37. In this way, the bias of the coil spring 37 presses the tip 21a of the plunger 21 against the electrode 11a.

[0042] As described above, the tip 21a of the plunger 21 is pressed against the electrode 11a, so that the contact probe 17 is electrically connected to the electrode 11a. Since the contact probe 17 is connected to the through hole 22 via the press-fit portion 34b, each electrode 11a is electrically connected to the inspection device 15. In this manner, with the inspection device 15 and the circuit board 11 connected by the contact probe 17, signals are exchanged between them to inspect the circuit board 11.

[0043] After the inspection is completed, the unit 12 is raised from the pressure contact position to the retracted position together with the relay board 14. At this time, as the unit 12 rises, the plunger 21 moves in a direction in which its protruding length increases due to the bias of the coil spring 37, and the base end 21b is engaged with the tip of the cylindrical part 35a. Thereafter, as the unit 12 rises, the plunger 21 separates from the electrode 11a and rises. After the movement to the retracted position, a new circuit board 11 is set and inspection is performed in the same manner.

[0044] Inspection of the circuit board 11 is repeated as described above. When the contact probe 17 is to be replaced due to deterioration of the plunger 21 or the like, the press-fit portion 34b is first removed from each through hole 22 to separate the unit 12 from the relay board 14. After this, the two sets of bolts 25a and nuts 25b are loosened and removed, and the first holder member 23 and the second holder member 24 are moved away from each other in the axial direction X. Then, the contact probe 17 to be replaced is removed from the first through hole 31 of the first holder member 23 or the second through hole 32 of the second holder member 24, and a new contact probe 17 is inserted. After this, the first holder member 23 and the second holder member 24 are assembled in the reverse order and fixed with the two sets of bolts 25a and nuts 25b.

[0045] After replacing the contact probes 17 with new ones as described above, the press-fit portions 34b of the contact probes 17 are pressed into the through-holes 22, respectively, and the relay board 14 is assembled to the unit 12. In this manner, when replacing the contact probes 17, electrical separation and connection can be completed simply by inserting and removing the press-fit portions 34b into and from the through-holes 22, making the replacement work easy.

[0046] In addition, since the elastic force of the press-fit portion 34b weakens as the press-fit portion 34b is repeatedly inserted and removed from the through-hole 22, it is preferable to replace the contact probe 17, for example, when the press-fit portion 34b has been inserted and removed from the through-hole 22 a predetermined number of times, with a new one regardless of the presence or absence of deterioration. In addition, all the contact probes 17 may be replaced every time the unit 12 is removed from the relay board 14.

[0047] In the above example, the holder 18 holds the contact probes 17 arranged in a line, but they may be arranged two-dimensionally. Also, the holder 18 may hold a plurality of contact probes 17 in which the press-fit portion 34b is press-fitted into the through-holes 22 provided in a plurality of relay boards 14 having different heights (intervals from the holder 18). In this case, for example, the height of the tip of each plunger 21 can be made uniform by using contact probes 17 having different lengths in the axial direction X, or the tips of the plungers 21 can be arranged at different heights by using contact probes 17 having the same length. Also, the tips of the plungers 21 can be arranged at different heights by pressing the press-fit portions 34b of a plurality of contact probes 17 having different lengths into the through-holes 22 of one relay board 14. The configuration in which the tips of the plungers 21 are arranged at different heights can be used when the plungers 21 are simultaneously abutted against a plurality of electrodes 11a arranged at different heights.

[0048] The above-mentioned contact probe configuration is an example, and is not limited to the above. For example, a configuration may be used in which a probe pin as a contact portion is fixed to one end of the barrel, and a press-fit portion is held at the other end of the barrel so as to be movable in the axial direction of the barrel. In such a configuration, for example, the shaft portion of the press-fit pin is inserted into the shaft mounting portion on the other end side of the barrel, and held so as to be movable in the axial direction X, and a coil spring is passed through the shaft portion so as to be disposed between the flange provided on the shaft portion and the barrel. In this way, the coil spring biases the probe pin together with the barrel in a direction from the other end to one end of the barrel. Note that a plunger may be held at one end of the barrel and a press-fit portion may be held at the other end of the barrel so as to be movable in the axial direction of the barrel, and they may be biased in the axial direction, i.e., in a direction away from each other.

[0049] In the above example, an inspection device using contact pins as contact probes has been described as an example, however, the contact pins, contact pin subassemblies, and contact pin units of the present invention can also be used for electrical connections for assembling and using electrical components such as circuit boards, various electronic devices, modules unitized by assembling electronic components, and IC packages in devices. [Explanation of symbols]

[0050] 10 Inspection equipment 12 Contact pin unit 14 Relay board 17 Contact Probe 18 Holder 21 Plunger 22 through hole 23 First holder member 24 Second holder member 25 Fixed part 31 First through hole 31a Small diameter hole 31b Large diameter hole 31c Step surface 32 Second through hole 33 Subassembly 34 Press-fit pin 34a Shaft 34b Pressfit part 35 barrels 35b Shaft fixing part 35c Large diameter section 35d Boss 37 Coil spring

Claims

1. A cylindrical barrel, a contact portion provided at one end of the barrel, the tip of which contacts an electrode; a press-fit portion provided at the other end of the barrel and press-fitted into a through-hole provided in a connection board; A contact pin comprising:

2. the barrel holds at least one of the contact portion and the press-fit portion so as to be movable in an axial direction of the barrel, 2. The contact pin according to claim 1, further comprising a biasing member for biasing the contact portion in a direction from the other end of the barrel toward the one end of the barrel.

3. the contact portion is a plunger that is held by the barrel so as to be freely movable in an axial direction thereof, the base end of the plunger being accommodated in the barrel and the tip end of the plunger protruding from one end of the barrel, The biasing member biases the plunger in a direction to protrude from one end of the barrel.

3. The contact pin according to claim 2.

4. The barrel has a cylindrical shaft fixing portion at the other end, 4. The contact pin according to claim 3, comprising a press-fit pin having a rod-shaped shaft portion and the press-fit portion formed on one end of the shaft portion, the shaft portion being inserted and fixed into the shaft fixing portion.

5. The contact pin according to claim 4 , wherein the shaft portion is fixed to the shaft fixing portion by crimping.

6. A cylindrical barrel, a contact portion provided at one end of the barrel, the tip of which contacts an electrode; a shaft mounting portion provided at the other end of the barrel, into which a shaft portion of a press-fit pin having a press-fit portion is inserted and mounted; A contact pin subassembly comprising:

7. The shaft portion is fixed to the shaft mounting portion, the contact portion is a plunger that is held by the barrel so as to be freely movable in an axial direction thereof, the base end of the plunger being accommodated in the barrel and the tip end of the plunger protruding from one end of the barrel, 7. The contact pin subassembly according to claim 6, further comprising a biasing member for biasing the plunger in a direction in which the plunger projects from the one end of the barrel.

8. a contact pin having a cylindrical barrel, a plunger held by the barrel so as to be freely movable in an axial direction thereof, a base end of which is accommodated within the barrel, and a tip end of which contacts an electrode and protrudes from one end of the barrel, a biasing member for biasing the plunger in a direction such that the plunger protrudes from the one end of the barrel, and a press-fit portion provided at the other end of the barrel and press-fitted into a through hole provided in a connection board; a holder for holding the contact pin, to which the contact pin can be detached; A contact pin unit comprising:

9. The barrel has a first protruding portion protruding in a radial direction between one end and the other end, The holder includes: a first holder member including a first small hole portion in which one end of the barrel is disposed and a first large hole portion having a cross-sectional size perpendicular to the axial direction larger than that of the first small hole portion and accommodating the first protrusion portion, the first holder member including a first through hole through which the plunger protrudes; a second holder member having a wall surface that abuts against an end surface of the other end of the first protruding portion, the second holder member being detachable from the first holder member, the second through hole being formed in the second through hole and the press-fit portion protruding from the inside of the hole, and the second holder member being detachable from the first holder member; The contact pin unit according to claim 8, further comprising:

10. The contact pin unit according to claim 9, characterized in that a second protrusion having a smaller cross-sectional size perpendicular to the axial direction than the first protrusion is formed between the other end of the barrel and the first protrusion, and which fits into the second through hole.

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