Probe
Patent Information
- Application Number
- JP2022085828
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2022-05-26
- Publication Date
- 2025-05-23
AI Technical Summary
Conventional probes with concentrically tapered spring ends face instability in generating lateral pressure, leading to unstable resistance values, while complex spring structures complicate manufacturing.
A probe design featuring a conductive spring with a loosely wound portion and offset end turn portions that generate stable lateral pressure, ensuring consistent resistance values and simplified assembly.
The design achieves stable low resistance values and easy assembly by generating reliable lateral pressure through offset end turn portions, enhancing manufacturing efficiency and performance.
Smart Images
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Abstract
Description
[Technical Field]
[0001] The present invention relates to a probe. [Background technology]
[0002] 1 and 2 show a conventional probe 5. This probe 5 has a conductive first plunger 60 fixed to one end of a conductive hollow barrel (tube) 50, and a conductive second plunger 70 slidably provided so as to protrude from the other end of the barrel 50. The probe 5 is configured such that a conductive spring 80 inside the barrel 50 biases the tip of the second plunger 70 in a direction that causes it to protrude from the barrel 50.
[0003] In this case, the spring 80 has tapered ends with a smaller diameter, and the ends of the spring 80 engage with the outer peripheries of the protrusions 61, 71 formed on the base-end surfaces of the first and second plungers 60, 70. However, if the ends of the spring 80 are tapered and concentric with the middle portion, the spring 80 will compress linearly to a nearly tightly wound state as shown in Figure 2 when compressed. This makes it difficult to generate lateral pressure, i.e., lateral pressure in a direction that presses the inlet tube portion 72 of the second plunger 70 against the inner wall of the barrel 50. This results in an unstable resistance value of the probe 5, in other words, the resistance value between the first plunger 60 and the second plunger 70.
[0004] Furthermore, Patent Document 1 below discloses a probe pin in which the portion of the pin that contacts the spring (hereinafter referred to as the pin bottom) is machined into a cone shape, and a spring is installed in the space formed by the pin and the tube hole. In this case, the spring has a central portion with a roughly uniform diameter and an adjacent tapered portion with a gradually decreasing diameter and whose central axis is offset diagonally from the central axis of the central portion, resulting in an overall curved shape. During use, when both ends of the spring are compressed by the conical portion of the pin bottom and the bottom of the tube hole, the pin is subjected to a load by the tapered portion of the spring in a direction oblique to the axial direction of the tube. As a result, the pin is in an inclined state, and the pin is pressed against the inner wall of the tube, generating lateral pressure according to the amount of axial compression of the spring. However, the spring structure is complex and may be time-consuming to manufacture. [Prior art documents] [Patent documents]
[0005] [Patent Document 1] Patent No. 5197754 Summary of the Invention [Problem to be solved by the invention]
[0006] As described above, the probe with the general spring structure shown in Figures 1 and 2 cannot generate a stable lateral pressure, and the resistance value of the probe is unstable. Also, the probe pin of Patent Document 1 is difficult to apply to cases where the spring structure is complex.
[0007] The present invention has been made in recognition of these circumstances, and one object of the present invention is to provide a probe that reliably generates internal lateral pressure in the plunger with a relatively simple spring structure, thereby stabilizing the resistance value. Other objects of the present invention will become apparent from the description of this specification. [Means for solving the problem]
[0008] One aspect of the present invention is a probe comprising: a conductive hollow barrel; a conductive first plunger provided at one end of the barrel; a conductive second plunger slidable within the barrel and protruding from the other end of the barrel; a spring provided in the barrel and biasing the first plunger and the second plunger in directions away from each other; the spring has an openly wound portion, a first end winding portion located on one end side of the openly wound portion and in contact with the first plunger, and a second end winding portion located on the other end side of the openly wound portion and in contact with the second plunger, The central axis of the first end winding portion is offset in a first direction from the central axis of the open winding portion, and the central axis of the second end winding portion is offset in a second direction opposite to the first direction from the central axis of the open winding portion.
[0009] According to the above aspect of the present invention, it is possible to reliably generate internal lateral pressure in the plunger with a relatively simple spring structure, thereby stabilizing the resistance value. [Brief explanation of the drawings]
[0010] [Figure 1] FIG. 1 is a longitudinal sectional view of a conventional probe. [Figure 2] FIG. 1 is a longitudinal cross-sectional view of a conventional probe in a compressed state. [Figure 3] 1 is a longitudinal sectional view showing a first embodiment of a probe according to the present invention. [Figure 4] FIG. 1 is a longitudinal cross-sectional view of the first embodiment in a compressed state. [Figure 5] FIG. 5 is an enlarged cross-sectional view of a main part of FIG. 4. [Figure 6] FIG. 2 is a front view of a spring used in the first embodiment. [Figure 7] FIG. [Figure 8] FIG. [Figure 9] FIG. 2 is an explanatory diagram showing an example of use of the probe shown in the first embodiment. [Figure 10] FIG. 10 is a longitudinal sectional view showing a second embodiment of a probe according to the present invention. DETAILED DESCRIPTION OF THE INVENTION
[0011] Preferred embodiments of the present invention will be described in detail below with reference to the drawings. The same or equivalent components, parts, processes, etc. shown in each drawing are designated by the same reference numerals, and redundant explanations will be omitted where appropriate. Furthermore, the embodiments are illustrative and do not limit the invention, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.
[0012] A first embodiment of the probe according to the present invention will be described with reference to FIGS. 3 to 8. FIG. 3 is a longitudinal cross-sectional view of the first embodiment of the probe according to the present invention, FIG. 4 is a longitudinal cross-sectional view of the same in a compressed state, and FIG. 5 is an enlarged cross-sectional view of a main portion of FIG. 4. As shown in these figures, the probe 1 includes a conductive hollow barrel (tube) 10 having a conductive first plunger 20 fixed to one end thereof, and a conductive second plunger 30 slidably provided so as to protrude from the other end of the barrel 10. A spring 40 biases the first plunger 20 and the second plunger 30 in directions away from each other. The probe 1 is configured such that the conductive spring 40 inside the barrel 10 biases the tip of the second plunger 30 in a direction that causes it to protrude from the barrel 10. However, the configuration of the spring 40 is significantly different from that of the conventional example shown in FIGS. 1 and 2.
[0013] Fig. 6 is a front view of spring 40 when no external force is applied, Fig. 7 is a left side view, and Fig. 8 is a right side view. As shown in these figures, spring 40 is a conductive coil spring made of elastic metal wire wound around it, and has an open winding portion 41 wound to a constant outer diameter, a first end winding portion 42 located at one end of open winding portion 41 and abutting against first plunger 20, and a second end winding portion 43 located at the other end of open winding portion 41 and abutting against second plunger 30. Open winding portion 41 is an active winding portion that functions as a compression spring. First end winding portion 42 and second end winding portion 43 have a smaller diameter than open winding portion 41 and are, for example, densely wound. 7 and 8, the central axis a of the first end winding portion 42 is offset in a first direction from the central axis c of the open winding portion 41, and the outer peripheral ends of the open winding portion 41 and the first end winding portion 42 are aligned on the outside in the first direction offset from the central axis c of the open winding portion 41. The central axis b of the second end winding portion 43 is offset in a second direction opposite to the first direction from the central axis c of the open winding portion 41, and the outer peripheral ends of the open winding portion 41 and the second end winding portion 43 are aligned on the outside in the second direction offset from the central axis c of the open winding portion 41.
[0014] In the probe 1, the barrel 10 has a cylindrical hollow portion, and the first plunger 20 provided at one end of the barrel 10 has a flange portion 21, an inlet tube portion 22 on the base end side that fits into one end of the barrel 10, and a tip portion 25 that protrudes outside the barrel 10. The tip portion 25 has a plurality of pointed protrusions 26. The inlet tube portion 22 has a smaller diameter than the flange portion 21, and a recessed groove 23 is formed around the outer periphery of the inlet tube portion 22 at an intermediate position. The barrel 10 is then machined (e.g., punched) to form a protrusion 11 on the inner periphery of the barrel 10 that engages with the recessed groove 23, thereby fixing the first plunger 20 to the barrel 10. Note that there is no protrusion on the base end face of the first plunger 20 that engages with the spring 40.
[0015] The second plunger 30, which is provided at the other end of the hollow barrel 10, has an inlet tube 31 on the base end side and a tip portion 35 with a smaller diameter than the inlet tube 31. The inlet tube 31 has a sliding portion 31a that can slide freely along the inner wall of the cylindrical hollow portion of the barrel 10, and a tapered chamfered portion 31b formed on its base end side. The inlet tube 31 is held in place from coming off the barrel 10 by a crimped portion 12 at the end of the barrel 10. The second plunger 30 has a protrusion 32 formed on its base end face. The protrusion 32 is, for example, cylindrical and concentric with the central axis 30a of the second plunger 30, and is tapered toward the tip side to facilitate fitting of the second end coil portion 43 of the spring 40.
[0016] The first coil end portion 42 abuts against the flat base-side end surface of the first plunger 20. The second coil end portion 43 abuts against the base-side end surface of the second plunger 30, biasing the tip portion 35 of the second plunger 30 in a direction that protrudes from the barrel 10, and engages with one side of the base of the protrusion 32 of the second plunger 30 (the lower side of the base in FIG. 5 ), generating a force that tilts the second plunger 30. That is, in the enlarged cross-sectional view of the compressed state of the spring in FIG. 2C , the loosely wound portion 41 of the spring 40 contracts into a generally diamond shape, so that it contracts at an angle relative to the central axis 10a of the barrel 10. Therefore, when viewed from the spring 40 side, the second coil end portion 43 presses the second plunger 30 with a force Fa that is tilted relative to the central axis 10a of the barrel 10. The force Fa can be broken down into a lateral pressure component Fa1 and a component Fa2 that is parallel to the central axis 10a of the barrel 10 and does not contribute to the lateral pressure, and it can be seen that the lateral pressure component Fa1 is generated. Furthermore, when viewed from the side of the second plunger 30 that compresses the spring 40, the second plunger 30 presses the spring 40 with a force Fb that is inclined with respect to the central axis 10a of the barrel 10. The force Fb can be broken down into a lateral pressure component Fb1 and a component Fb2 that is parallel to the central axis 10a of the barrel 10 and does not contribute to the lateral pressure, and it can be seen that the lateral pressure component Fb1 is generated. This lateral pressure component ensures that the base end portion of the sliding portion 31a of the inlet tube portion 31 comes into contact with the inner wall of the barrel 10.
[0017] In the configuration of the first embodiment described above, even in the no-load state of FIG. 3 , the first end winding portion 42 of the spring 40 is offset in a first direction relative to the openly wound portion 41, and the second end winding portion 43 is offset in a second direction relative to the openly wound portion 41, causing the openly wound portion 41 to tilt relative to the central axis 10a of the barrel 10 and generating lateral pressure. As a result, a force is applied to the central axis 30a of the second plunger 30 in a direction that tilts it relative to the central axis 10a of the barrel 10, and the base end portion of the sliding portion 31a of the second plunger 30 contacts the inner wall of the barrel 10. Therefore, the resistance value of the probe 1, i.e., the resistance value between the first plunger 20 and the second plunger 30, is kept sufficiently low. 4 and 5, when the tip 25 of the second plunger 30 is pressed in by a load, the loosely wound portion 41 of the spring 40 contracts into a generally diamond shape, tilting it relative to the central axis 10a of the barrel 10, and a force in the offset direction is applied to the protrusion 32 of the second plunger 30 via the second end coil portion 43, generating lateral pressure. In this case as well, the resistance between the first plunger 20 and the second plunger 30 is kept sufficiently low.
[0018] 9 is an explanatory diagram showing an example of use of the probe 1 shown in embodiment 1. In this case, the probe 1 is incorporated into a socket 90 having an insulating support 100. The insulating support 100 has a structure in which a first insulating support 101 having a through hole 101a is stacked on a second insulating support 102 having a through hole 102a, and the probe 1 is held in the through holes 101a and 102a so as not to fall out.
[0019] When the socket 90 is used to test the test object 110 such as a semiconductor, the protrusion 26 of the first plunger 20 is pressed against the bump 111 of the test object 110 and comes into contact with it, and the tip 35 of the second plunger 30 abuts against the electrode 121 of the test board 120. This establishes an electrical connection between the bump 111 of the test object 110 and the test board 120 via the probe 1.
[0020] According to this embodiment, the following effects can be achieved.
[0021] (1) The spring 40 in the barrel 10 has a first end winding portion 42 and a second end winding portion 43, each of which has a smaller diameter than the open winding portion 41, on one end side and the other end side of the open winding portion 41. The central axis a of the first end winding portion 42 is offset from the central axis c of the open winding portion 41 in a first direction, and the central axis b of the second end winding portion 43 is offset from the central axis c in a second direction opposite to the first direction. Therefore, the open winding portion 41 is compressed with its central axis c tilted relative to the central axis 10a of the barrel 10. As a result, an internal lateral pressure is generated that pushes the second plunger 30, which is slidably mounted in the barrel 10, toward the inner wall of the barrel. This maintains the resistance of the probe 1, i.e., the resistance between the first plunger 20 and the second plunger 30, at a stable, low value. Conventional probes have difficulty in generating spring deflection, resulting in unstable resistance. However, the structure of this embodiment reliably generates lateral pressure, achieving a stable, low resistance.
[0022] (2) The second plunger 30 has a base end surface against which the second end winding portion 43 of the spring 40 abuts, and also has a protrusion 32 protruding from the base end surface. The second end winding portion 43 engages with this protrusion 32 to apply force in the offset direction of the second end winding portion 43, thereby more reliably generating lateral pressure. Note that the first plunger 20 is fixed to the barrel 10, and its base end surface may be a flat surface without a protrusion. Even if the surface is flat, the spring 40 is stable in a state tilted relative to the central axis 10a of the barrel 10, as shown in Figures 3, 4, and 5.
[0023] (3) The protrusion 32 has a tapered diameter that decreases toward the tip, so that the second end turn portion 43 of the spring 40 fits easily, resulting in good assembly workability.
[0024] (4) The first end winding portion 42 and the second end winding portion 43 of the spring 40 maintain the same positional relationship with the open winding portion 41 even when rotated 180° around an axis perpendicular to the central axis of the spring 40 (which can be considered the central axis c of the open winding portion 41). This means that the same performance is obtained even when the spring is turned upside down, making assembly easy. There is no need to consider the insertion direction of the spring 40 into the barrel 10 during assembly.
[0025] (5) The outer peripheral end of the open coil portion 41 of the spring 40 and the outer peripheral end of the first end coil portion 42 are aligned on the outside in the direction in which the central axis of the first end coil portion 42 is offset from the central axis of the open coil portion 41. That is, in FIG. 3 and other figures, the bottom of the first end coil portion 42 is aligned with the bottom left of the open coil portion 41. Also, the outer peripheral end of the open coil portion 41 of the spring 40 and the outer peripheral end of the second end coil portion 43 are aligned on the outside in the direction in which the central axis of the second end coil portion 43 is offset from the central axis of the open coil portion 41. That is, in FIG. 3 and other figures, the top of the second end coil portion 43 is aligned with the top right of the open coil portion 41. From the above, the central axes of the first end coil portion 42 and the second end coil portion 43 can be offset by a large amount from the central axis of the open coil portion 41, and the probe 1 can be easily manufactured.
[0026] 10 shows a second embodiment of a probe according to the present invention. In this case, a first plunger 20A of a probe 2 is not fixed to a barrel 10, but has a structure similar to that of a second plunger 30 and is slidable relative to the barrel 10. The other configurations are the same as those of the first embodiment described above.
[0027] In the configuration of the second embodiment, both the first plunger 20A and the second plunger 30 are movable, so that it is possible to increase the stroke of extension and contraction. Other effects are similar to those of the first embodiment.
[0028] While the present invention has been described above using the embodiments as examples, it will be understood by those skilled in the art that various modifications can be made to the components and processes of the embodiments within the scope of the claims. Modifications will be discussed below.
[0029] In the first embodiment, the barrel and the first plunger are separate components, but the first plunger may be formed as a single component integrally with the barrel in a barrel-plunger structure. Also, the configuration may not have an independent barrel.
[0030] In embodiment 1, the first plunger is illustrated as having multiple pointed protrusions at its tip, but it may have only one protrusion, and its shape and arrangement can be changed as appropriate to correspond to the bumps or electrodes of the object to be inspected.
[0031] In the first and second embodiments, the spring 40 is illustrated as being clockwise wound when viewed from the first plunger 20 (20A), but it may also be counterclockwise wound.
[0032] According to the present specification, there are provided probes having the following aspects. (Aspect 1) Aspect 1 includes a conductive hollow barrel; a conductive first plunger provided at one end of the barrel; a conductive second plunger slidable within the barrel and protruding from the other end of the barrel; a spring provided in the barrel and biasing the first plunger and the second plunger in directions away from each other; the spring has an openly wound portion, a first end winding portion located on one end side of the openly wound portion and in contact with the first plunger, and a second end winding portion located on the other end side of the openly wound portion and in contact with the second plunger, The probe has a central axis of the first end winding portion offset in a first direction from a central axis of the open winding portion, and a central axis of the second end winding portion offset in a second direction opposite to the first direction from the central axis of the open winding portion.
[0033] According to the above-described first aspect, an internal lateral pressure is generated that pushes the second plunger toward the inner wall of the barrel, thereby making it possible to maintain the resistance value of the probe, i.e., the resistance value between the first plunger and the second plunger, at a stably low value.
[0034] (Aspect 2) In a second aspect, the second plunger has a protrusion that engages with the second end coil portion.
[0035] According to the above-described second aspect, the second end coil portion engages with the convex portion on the second plunger side to apply a force in the offset direction of the second end coil portion, thereby more reliably generating lateral pressure.
[0036] (Aspect 3) In a third aspect, the first plunger has a protrusion that engages with the first end winding portion, and the second plunger has a protrusion that engages with the second end winding portion.
[0037] According to the above-mentioned third aspect, even when the first and second plungers are slidable within the barrel, the first coil end portion engages with the convex portion on the first plunger side to apply a force in the offset direction of the first coil end portion, and the second coil end portion engages with the convex portion on the second plunger side to apply a force in the offset direction of the second coil end portion, so that side pressure can be reliably generated on both sides of the first and second plungers.
[0038] (Aspect 4) In a fourth aspect, the outer peripheral end of the open winding portion and the outer peripheral ends of the first end winding portion and the second end winding portion are aligned on the outside in a direction in which the central axes of the first end winding portion and the second end winding portion are offset from the central axis of the open winding portion.
[0039] According to the above-mentioned fourth aspect, the offset amount of the first and second end winding portions with respect to the open winding portion can be increased, and manufacturing is also easy.
[0040] (Aspect 5) In a fifth aspect, the first end winding portion and the second end winding portion have the same positional relationship with respect to the open winding portion when rotated 180° around an axis perpendicular to the central axis of the spring as a rotation fulcrum.
[0041] According to the above-mentioned fifth aspect, the spring has the same performance even when it is upside down, which makes it easy to assemble. There is no need to consider the direction in which the spring is inserted into the barrel during assembly. [Explanation of symbols]
[0042] 1,2 Probe 10 barrels 10a Barrel center axis 20,20A First plunger 30 Second plunger 30a Central axis of second plunger 40 Spring 41 Sparse winding section 42 First end coil 43 Second end coil a Central axis of the first end winding b Central axis of the second end winding c Central axis of the sparsely wound part
Claims
1. A conductive hollow barrel; a conductive first plunger provided at one end of the barrel; a conductive second plunger slidably disposed within the barrel and projecting from the other end of the barrel; a spring provided in the barrel and biasing the first plunger and the second plunger in directions away from each other; the second plunger has a base end surface provided on a base end side in contact with the spring, and a protrusion formed on the base end surface, the spring has an openly wound portion, a first end winding portion located on one end side of the openly wound portion and in contact with the first plunger, and a second end winding portion located on the other end side of the openly wound portion and in contact with the second plunger, a central axis of the first end winding portion is offset in a first direction with respect to a central axis of the open winding portion, and a central axis of the second end winding portion is offset in a second direction opposite to the first direction with respect to the central axis of the open winding portion, The second coil end portion is engaged with one side of a base portion of the protrusion of the second plunger. probe.
2. The probe of claim 1 , wherein the first plunger has a protrusion that engages with the first end turn.
3. 3. The probe according to claim 1, wherein an outer circumferential end of the open winding portion and an outer circumferential end of the first end winding portion and the second end winding portion are aligned on the outside in a direction in which central axes of the first end winding portion and the second end winding portion are offset from a central axis of the open winding portion.
4. 3. The probe according to claim 1, wherein the first end winding portion and the second end winding portion have the same positional relationship with respect to the open winding portion when rotated 180 degrees about an axis perpendicular to a central axis of the spring.
5. A conductive barrel having a hollow portion; a conductive first plunger provided at one end of the barrel; a conductive second plunger slidably disposed within the barrel and projecting from the other end of the barrel; a spring provided in the barrel and biasing the first plunger and the second plunger in directions away from each other; the spring has an openly wound portion, a first end winding portion located on one end side of the openly wound portion and in contact with the first plunger, and a second end winding portion located on the other end side of the openly wound portion and in contact with the second plunger, a central axis of the first end winding portion is offset from a central axis of the open winding portion in a first direction, and a central axis of the second end winding portion is offset from the central axis of the open winding portion in a second direction opposite to the first direction, The first plunger has a groove in an inlet portion that inlets into the hollow portion and engages with a protrusion provided on an inner periphery of the hollow portion. probe.