Probe pin and socket

Abstract

To stabilize the contact state between a spring contact portion of a plunger and the inner periphery of a coil spring.SOLUTION: A plunger includes a first contact portion at one end thereof, the coil spring includes a coarsely wound portion at one end thereof that biases a flange portion of the plunger, the coil spring includes a tightly wound portion including a second contact portion at the other end thereof, the plunger includes a spring contact portion at the other end thereof, and the connecting portion that connects the flange portion of the plunger and the spring contact portion is thinner than the flange portion and the spring contact portion.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a probe pin that electrically connects a first electric component and a second electric component, and a socket equipped with the probe pin. [Background technology]

[0002] For example, a socket used for electrical testing of a first electrical component such as an IC package includes a socket body that can be mounted on a wiring board serving as a second electrical component, and the socket body has a housing portion for housing the first electrical component. The socket includes a plurality of probe pins provided on the socket body and a cover member that presses the plurality of probe pins toward the wiring board. As shown in Patent Document 1, the number of parts of the probe pins has been reduced to simplify the configuration.

[0003] The probe pin according to the prior art includes a plunger, which has a first contact portion at one end thereof that contacts a terminal of a first electrical component. The plunger has a flange portion that receives a biasing force. The probe pin according to the prior art includes a coil spring that is arranged coaxially with the plunger. The coil spring has a loosely wound portion at one end thereof that biases the flange portion. The coil spring has a tightly wound portion at the other end thereof, which includes an electrode contact portion that contacts an electrode of a wiring board. The plunger also has a spring contact portion at the other end thereof that can contact the inner periphery of the coil spring. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-089930 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, as first electrical components such as IC packages have become larger, the number of terminals on the first electrical components has also increased, and the number of probe pins in sockets has also increased. When the number of probe pins increases, for example, assuming the total pressing load remains the same, it is necessary to reduce the pressing load (pressing force) per probe pin being pressed.

[0006] On the other hand, if the pressure load per probe pin decreases, the posture of the probe pin becomes unstable, and the coil spring may buckle, causing parts of the plunger other than the spring contact part to come into contact with the inner periphery of the coil spring. As a result, the load that should be applied to the spring contact part is applied to parts other than the spring contact part, dispersing the load, reducing the contact load of the spring contact part of the plunger and causing the problem of unstable contact between the spring contact part of the plunger and the inner periphery of the tightly wound part of the coil spring.

[0007] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a probe pin and a socket that can stabilize the contact state between the spring contact portion of the plunger and the inner peripheral portion of the coil spring. [Means for solving the problem]

[0008] One aspect of the probe pin of the present invention is a plunger having a first contact portion at one end thereof that contacts the first electric component and a flange portion that receives a biasing force; a coil spring having a loosely wound portion at one end side that biases the flange portion, and a tightly wound portion at the other end side that includes a second contact portion that contacts a second electric component, The plunger has a spring contact portion at its other end that can contact the inner periphery of the coil spring, and the connecting portion that connects the flange portion of the plunger to the spring contact portion is thinner than the flange portion and the spring contact portion.

[0009] One aspect of the socket of the present invention is a socket body having an accommodating portion for accommodating a first electric component; and a probe pin provided on the socket body. [Effects of the Invention]

[0010] According to the present invention, it is possible to reduce the contact resistance of the probe pin and stabilize the contact state between the spring contact portion of the plunger and the inner peripheral portion of the coil spring. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic partial cross-sectional view showing a socket according to this embodiment. [Figure 2] FIG. 2 is a schematic external view showing the probe pin according to this embodiment. [Figure 3] FIG. 3 is a schematic cross-sectional view showing a probe pin according to this embodiment. [Figure 4] FIG. 4 is a schematic cross-sectional view showing the state before the socket according to this embodiment is disposed at a predetermined position on the wiring board. [Figure 5] FIG. 5 is a schematic cross-sectional view showing a state in which the socket according to this embodiment is disposed at a predetermined position on a wiring board. [Figure 6] FIG. 6 is a schematic cross-sectional view showing a coil spring deformed into a meandering shape due to buckling. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, this embodiment will be described with reference to the drawings. In the claims and specification of this application, "one end" refers to one end in the axial direction (longitudinal direction) of the probe pin, and in this embodiment, refers to the upper end. In the claims and specification of this application, "the other end" refers to the other end in the axial direction (longitudinal direction) of the probe pin, and in this embodiment, refers to the lower end. The axial direction of the plunger and the axial direction of the coil spring are the same as the axial direction of the probe pin. In the drawings, "UD" refers to the upward direction and "DD" refers to the downward direction, respectively.

[0013] The overall configuration of a socket 10 according to this embodiment will be described with reference to Fig. 1. Fig. 1 is a schematic partial cross-sectional view showing a socket 10 according to this embodiment.

[0014] 1, a socket 10 according to this embodiment is a device used for electrical testing of a first electric component P, such as an IC (Integrated Circuit) package. When electrical testing of the first electric component P is performed, the socket 10 is disposed at a predetermined position on a wiring board S, which serves as a second electric component, connected to a testing device (not shown).

[0015] The socket 10 includes a socket body 12, which can be disposed at a predetermined position on a wiring board S serving as a second electric component. The socket body 12 has an upper plate 14 made of an insulating material and a lower plate 16 also made of an insulating material and disposed below the upper plate 14. An accommodating portion 18 for accommodating a first electric component P is formed on the upper side of the upper plate 14.

[0016] A plurality of upper pin holes 14h are formed penetrating the upper plate 14, and one end (upper end) of each upper pin hole 14h is open toward the accommodation section 18. The number of upper pin holes 14h is the same as the number of terminals Pa (electrodes Sa of the wiring board S) of the first electric component P. An annular step portion 14u is formed at the middle of each upper pin hole 14h, and the inner diameter of the upper portion of step portion 14u in each upper pin hole 14h is smaller than the inner diameter of the lower portion of step portion 14u.

[0017] A plurality of lower pin holes 16h are formed through the lower plate 16, and each lower pin hole 16h is aligned with a corresponding upper pin hole 14h. The number of lower pin holes 16h is the same as the number of upper pin holes 14h. An annular step portion 16u is formed at the middle of each lower pin hole 16h, and the inner diameter of the upper portion of the step portion 16u in each lower pin hole 16h is larger than the inner diameter of the lower portion of the step portion 16u in each lower pin hole 16h. The inner diameter of the upper portion of the step portion 16u in each lower pin hole 16h is approximately the same as the inner diameter of the lower portion of the step portion 14u in each upper pin hole 14h.

[0018] The socket body 12 is provided with a plurality of probe pins 20 that electrically connect the first electric component P and a wiring board S serving as a second electric component. The number of probe pins 20 is the same as the number of upper pin holes 14h of the upper plate 14 (lower pin holes 16h of the lower plate 16). An upper portion of each probe pin 20 is accommodated in the upper pin hole 14h of the upper plate 14, and a lower portion of each probe pin 20 is accommodated in the lower pin hole 16h of the lower plate 16. In addition, a cover member (not shown) that presses the plurality of probe pins 20 toward the wiring board S is provided on the upper part of the socket body 12. As the number of probe pins 20 increases, the pressing load (pressing force) per probe pin 20 pressed toward the wiring board S by the cover member tends to decrease.

[0019] Next, a specific configuration of the probe pin 20 according to this embodiment will be described with reference to Fig. 1 to Fig. 5. Fig. 2 is a schematic external view showing the probe pin 20 according to this embodiment. Fig. 3 is a schematic cross-sectional view showing the probe pin 20 according to this embodiment. Fig. 4 is a schematic cross-sectional view showing the state before the socket 10 according to this embodiment is disposed at a predetermined position on the wiring board S. Fig. 5 is a schematic cross-sectional view showing the state after the socket 10 according to this embodiment is disposed at a predetermined position on the wiring board S.

[0020] 1 to 3, the probe pin 20 according to this embodiment includes a rod-shaped plunger 22, which is made of a metal such as a copper alloy or stainless steel. The plunger 22 is housed in a position from the upper part of the stepped portion 14u of the upper pin hole 14h of the upper plate 14 to the upper part of the stepped portion 16u of the lower pin hole 16h of the lower plate 16 so as to be movable in the vertical direction.

[0021] The plunger 22 has, at one end (upper end) thereof, a first contact portion 24 that comes into contact with the terminal (electrode) Pa of the first electric component P, and the first contact portion 24 is formed in a conical or truncated conical shape. The outer diameter (maximum outer diameter) of the first contact portion 24 is smaller than the inner diameter of the upper portion of the stepped portion 14u in the upper pin hole 14h of the upper plate 14.

[0022] Plunger 22 has a flange portion 26 that receives a biasing force, and the outer diameter of flange portion 26 is larger than the outer diameter of first contact portion 24. In addition, the outer diameter of flange portion 26 is larger than the inner diameter of the upper portion of stepped portion 14u in upper pin hole 14h of upper plate 14, but smaller than the inner diameter of the lower portion of stepped portion 14u.

[0023] The probe pin 20 includes a coil spring 28 that is coaxially disposed below the flange portion 26 of the plunger 22. The coil spring 28 is made of a metal wire such as piano wire or stainless steel wire. The coil spring 28 is housed in a position that allows it to move up and down from the lower portion of the stepped portion 14u of the upper pin hole 14h of the upper plate 14 to the lower portion of the stepped portion 16u of the lower pin hole 16h of the lower plate 16.

[0024] The coil spring 28 has, at one end (upper end) thereof, a coarsely wound portion 30 in which metal wire is wound at intervals. The coarsely wound portion 30 is compressible in the axial direction of the probe pin 20, and urges the flange portion 26 of the plunger 22 upward. The outer diameter of the coarsely wound portion 30 is smaller than the inner diameter of the lower portion of the stepped portion 14u in the upper pin hole 14h of the upper plate 14 (the inner diameter of the upper portion of the stepped portion 16u in the lower pin hole 16h of the lower plate 16).

[0025] The coil spring 28 has, at its other end (lower end), a tightly wound portion 32 formed by tightly wound metal wire. The lower end of the tightly wound portion 32 forms a second contact portion 34 that comes into contact with the electrode Sa of the wiring substrate S. In other words, the tightly wound portion 32 includes the second contact portion 34 that comes into contact with the electrode Sa of the wiring substrate S.

[0026] The plunger 22 has, at its other end (lower end), a spring contact portion 36 that can come into contact with the inner periphery of the dense winding portion 32. The spring contact portion 36 comes into contact with the inner periphery of the dense winding portion 32 when the second contact portion 34 comes into contact with an electrode Sa of a wiring board S serving as a second electric component and the first contact portion 24 comes into contact with a terminal Pa of a first electric component P.

[0027] The plunger 22 has a round-bar-shaped connecting portion 38 that connects the flange portion 26 and the first contact portion 24. In other words, the plunger 22 has the round-bar-shaped connecting portion 38 between the flange portion 26 and the first contact portion 24. The connecting portion 38 of the plunger 22 is thinner than the flange portion 26 and the spring contact portion 36, and the outer diameter d1 of the connecting portion 38 is constant along the axial direction (longitudinal direction) of the plunger 22. The outer diameter d1 of the connecting portion 38 of the plunger 22 is smaller than the outer diameter (maximum outer diameter) d2 of the spring contact portion 36.

[0028] The densely wound portion 32 of the coil spring 28 has a first densely wound portion 40 including a second contact portion 34, and a second densely wound portion 42 that is disposed between the loosely wound portion 30 and the first densely wound portion 40 and is capable of contacting the spring contact portion 36 of the plunger 22. The outer diameter of the first densely wound portion 40 is smaller than the inner diameter of a lower portion of the stepped portion 16u in the lower pin hole 16h of the lower plate 16. The outer diameter of the second densely wound portion 42 is smaller than the inner diameter of an upper portion of the stepped portion 16u in the lower pin hole 16h of the lower plate 16, but is larger than the inner diameter of the lower portion of the stepped portion 16u. The inner diameter of a portion of the second densely wound portion 42 is smaller than the inner diameter of the remaining portion of the second densely wound portion 42, and a portion of the second densely wound portion 42 is capable of contacting the spring contact portion 36 of the plunger 22. The inner diameter of the second densely wound portion 42 may be constant along the axial direction of the coil spring 28.

[0029] 4 and 5, before the first electric component P is accommodated in the accommodation portion 18 of the upper plate 14, the flange portion 26 of the plunger 22 is in contact with the step portion 14u of the upper pin hole 14h of the upper plate 14 by the biasing force of the loosely wound portion 30. As shown in FIG. 1, in a state in which the plurality of probe pins 20 are pressed toward the wiring board S by the cover member, the flange portion 26 of the plunger 22 is spaced downward from the step portion 14u of the upper pin hole 14h of the upper plate 14.

[0030] As shown in FIG. 4, the second contact portion 34 (first close winding portion 40) of the coil spring 28 protrudes downward from the lower surface of the lower plate 16 before the socket 10 (socket body 12) is disposed at a predetermined position on the wiring board S. As shown in FIG. 5, the second contact portion 34 of the coil spring 28 is recessed upward relative to the lower surface of the lower plate 16 after the socket 10 is disposed at a predetermined position on the wiring board S. Also, as shown in FIG. 4, the lower end of the second close winding portion 42 abuts against the stepped portion 16u of the lower pin hole 16h of the lower plate 16 before the socket 10 is disposed at a predetermined position on the wiring board S. As shown in FIG. 5, the lower end of the second close winding portion 42 is spaced upward from the stepped portion 16u of the lower pin hole 16h of the lower plate 16 after the socket 10 is disposed at a predetermined position on the wiring board S.

[0031] Next, the operation of using the socket 10 according to this embodiment will be described.

[0032] 5, socket 10 (socket body 12) is disposed at a predetermined position on wiring board S, which serves as a second electric component. Then, second contact portion 34 of each coil spring 28 contacts each electrode Sa of wiring board S and sinks upward relative to the lower surface of lower plate 16. The lower end of second close winding portion 42 of each coil spring 28 moves upward away from step portion 16u of lower pin hole 16h of lower plate 16.

[0033] 1, the first electric component P is accommodated in the accommodation portion 18 of the socket body 12, and the plurality of probe pins 20 are pressed toward the wiring board S (downward) by the cover member. Then, with the first contact portion 24 of each plunger 22 in contact with the respective terminal Pa of the first electric component P, each plunger 22 moves downward while compressing the coarsely wound portion 30 of each coil spring 28. The flange portion 26 of each plunger 22 moves downward away from the step portion 14u of the upper pin hole 14h of the upper plate 14.

[0034] This allows the biasing force of each coil spring 28 to maintain contact between the second contact portion 34 of each coil spring 28 and each electrode Sa of the wiring board S, and between the first contact portion 24 of each plunger 22 and each terminal Pa of the first electric component P. As a result, each terminal Pa of the first electric component P can be electrically connected to each electrode Sa of the wiring board S as the second electric component, and electrical inspection of the first electric component P can be performed using an inspection device.

[0035] According to the configuration of the probe pin 20 according to this embodiment, as described above, the connecting portion 38 of the plunger 22 is thinner than the flange portion 26 and the spring contact portion 36. Therefore, even if the pressing load per probe pin 20 is reduced and the posture of the probe pin 20 becomes unstable, the connecting portion 38 of the plunger 22 can be prevented from contacting the inner periphery of the coil spring 28 due to buckling of the coil spring 28, as shown in FIG. 6. In other words, the buckling of the coil spring 28 can be prevented from causing parts of the plunger 22 other than the spring contact portion 36 to come into contact with the inner periphery of the coil spring 28. FIG. 6 is a schematic cross-sectional view showing the coil spring 28 deformed into a serpentine shape due to buckling.

[0036] Therefore, according to this embodiment, it is possible to reduce the contact resistance of the probe pin 20 and to ensure a sufficient contact load of the spring contact portion 36 of the plunger 22, thereby stabilizing the contact state between the spring contact portion 36 and the inner periphery of the dense winding portion 32 (second dense winding portion 34). It was confirmed by CAE analysis that a sufficient contact load of the spring contact portion 36 of the plunger 22 could be ensured.

[0037] Furthermore, according to the configuration of the probe pin 20 of this embodiment, as described above, the outer diameter d1 of the connecting portion 38 of the plunger 22 is smaller than the outer diameter d2 of the spring contact portion 36. Therefore, according to this embodiment, even if the coil spring 28 is deformed due to buckling, it is possible to prevent portions of the plunger 22 other than the spring contact portion 36 from coming into contact with the inner peripheral portion of the coil spring 28.

[0038] Furthermore, according to the configuration of the probe pin 20 of this embodiment, as described above, the connecting portion 38 of the plunger 22 is constant along the axial direction of the plunger 22. Therefore, according to this embodiment, even if the coil spring 28 is deformed due to buckling, it is possible to sufficiently prevent portions of the plunger 22 other than the spring contact portion 36 from coming into contact with the inner peripheral portion of the coil spring 28.

[0039] Furthermore, according to the configuration of the probe pin 20 of this embodiment, as described above, the inner diameter of a portion of the second close winding portion 42 of the coil spring 28 is smaller than the inner diameter of other portions of the second close winding portion 42. Therefore, according to this embodiment, compared to when the inner diameter of the second close winding portion 42 is constant along the axial direction of the coil spring 28, the contact load of the spring contact portion 36 is increased, making the contact state between the spring contact portion 36 and the inner peripheral portion of the second close winding portion 34 more stable.

[0040] Although the present embodiment has been specifically described above, the present invention is not limited to the specific embodiment described above. Various modifications and changes to the specific examples described in the above embodiment are possible within the scope of the gist of the present invention as defined in the claims. [Industrial Applicability]

[0041] INDUSTRIAL APPLICABILITY The present invention is useful as a probe pin and socket that can stabilize the contact state between the spring contact portion of the plunger and the inner peripheral portion of the coil spring. [Explanation of symbols]

[0042] 10 sockets 12 Socket body 14 Upper Plate 14h Upper pinhole 16 Lower Plate 16h Lower pin hole 16u step section 18 Storage section 20 probe pins 22 Plunger 24 1st contact part 26 Flange 28 Coil spring 30 Coarse winding section 32 Closely wound section 34 Second contact part 36 Spring contact part 38 Connecting part 40 First tightly wound part 42 Second tightly wound part P 1st Electrical Part Pa terminal S Wiring board (secondary electrical component) Sa electrode

Claims

1. a plunger having a first contact portion at one end thereof that contacts the first electric component and a flange portion that receives a biasing force; a coil spring having a loosely wound portion at one end side that biases the flange portion and a tightly wound portion at the other end side that includes a second contact portion that contacts a second electric component, The plunger has a spring contact portion at the other end thereof that can come into contact with an inner circumferential portion of the coil spring, and a connecting portion that connects the flange portion of the plunger to the spring contact portion is thinner than the flange portion and the spring contact portion. Probe pin.

2. The outer diameter of the connecting portion is constant along the axial direction of the plunger. The probe pin according to claim 1 .

3. the dense winding portion includes a first dense winding portion including the second contact portion, and a second dense winding portion disposed between the coarse winding portion and the first dense winding portion and capable of contacting the spring contact portion, an inner diameter of a portion of the second tightly wound portion is smaller than an inner diameter of another portion of the second tightly wound portion; The probe pin according to claim 1 .

4. a socket body having an accommodating portion for accommodating a first electric component; and the probe pin according to any one of claims 1 to 3, which is provided on the socket body. socket.

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