JP2014102103A - Probe pin, probe pin unit, and IC socket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve durability of a probe pin while ensuring a smooth and reliable operation of the probe pin, by allowing determination of the buckling direction and buckling angle of a compression coil spring to a plunger and bringing the plunger and a barrel into contact with each other and bringing the compression coil spring and the barrel into contact with each other with a contact pressure smaller than that in a prior art.SOLUTION: On the assumption that a virtual plane orthogonal to a center axis 23 of a compression coil spring 4 is seen in plan view, the compression coil spring 4 has a front end of a coil 22 butted against a side surface 17a of a projection 17 of a plunger 3 and an end surface 16 facing the plunger 4 and is positioned in a first quadrant when the plunger 3 is put on an end part of the coil 22. In a second quadrant, an outer surface of the coil 22 is brought into contact with a front end surface 17b of the projection 17, and within a range of a third quadrant and a fourth quadrant, a buckling direction and a buckling angle are determined by providing a space so as not to bring the outer surface of the coil 22 into contact with the end surface 16 .

Description

The present invention relates to a probe pin used for electrical testing of an IC package, a probe pin unit containing the probe pin, and an IC including the probe pin unit
It relates to sockets.

Conventionally, an IC socket used to conduct an electrical test of an IC package is to press a terminal of the IC package against one end side of a plurality of probe pins accommodated in the socket body,
The IC package and an external electrical test circuit are electrically connected via probe pins.

FIG. 15 shows a probe pin 101 used for such an IC socket 100. The probe pin 101 shown in FIG. 15 is formed of a bottomed cylindrical body (barrel) 102 formed of a conductive metal member and a conductive metal member accommodated in the bottomed cylindrical body 102. A compression coil spring 103 and a plunger 104 that is slidably accommodated in the bottomed cylindrical body 102 and is constantly urged toward the outside of the bottomed cylindrical body 102 by the compression coil spring 103. And.

In the probe pin 101 shown in FIG. 15, the plunger 104 has a small-diameter portion 108 formed integrally with one end side of the large-diameter portion 105, and the small-diameter portion 108 is outward from the opening 106 of the bottomed cylindrical body 102. It is designed to protrude. Further, the plunger 104 has a large diameter portion 105.
An inclined surface 111 in which the surface on the other end side obliquely intersects the central axis 110 of the probe pin 101.
Since the inclined surface 111 is constantly pressed by the spring force of the compression coil spring 103, the outer peripheral surface of the large-diameter portion 105 is pressed against the inner surface of the bottomed cylindrical body 102 and one end of the large-diameter portion 105. Edge (stopper) of opening 106 whose side is reduced in diameter of bottomed cylindrical body 102
107 is pressed. A structure having the same structure as the probe pin 101 is disclosed in Patent Document 1.

As shown in FIG. 15, the probe pin 101 is accommodated in, for example, a socket main body 112, the projection 113 of the bottomed cylindrical body 102 contacts the energization electrode 115 of the substrate 114, and the small diameter portion 108 of the plunger 104 When the terminal 117 of the IC package 116 is pressed against the tip, the plunger 104 presses and compresses the compression coil spring 103 and is pushed into the bottomed cylindrical body 102. At this time, the compression coil spring 103 is pressed and buckled by the plunger 104, and the tip end of the compression coil spring 103 presses the inclined surface 111 of the plunger 104, and the outer peripheral surface of the large-diameter portion 105 of the plunger 104 is covered with the bottomed cylindrical body 102. It is designed to be pressed against the inner surface. As a result, the terminal 117 of the IC package 116 and the energization electrode 115 (external electrical test circuit) of the substrate 114 are electrically connected via the plunger 104 and the bottomed cylindrical body 102.

Japanese Patent No. 3195295

However, in the conventional probe pin 101 shown in FIG. 15, when the plunger 104 is pushed into the bottomed cylindrical body 102, the plunger 104 slips at the contact portion with the compression coil spring 103, and the plunger 104 In order to move the plunger 104 until it comes into contact with the inner surface of the bottomed cylindrical body 102 and the plunger 104 is pressed against the inner surface of the bottomed cylindrical body 102 by the spring force of the compression coil spring 103, the inclination angle α of the inclined surface 111 is set. It is set to 10 ° to 30 °. In this conventional probe pin 101, the compression coil spring 103 is provided with a coil 11.
Only one side of the end portion 8 is pushed by the plunger 104 and is buckled in the bottomed cylindrical body 102. As a result, the conventional probe pin 101 shown in FIG. 15 has a large frictional force at the contact portion between the plunger 104 and the bottomed cylindrical body 102 and at the contact portion between the compression coil spring 103 and the bottomed cylindrical body 102. Too much, the friction caused by the friction of these contact parts,
This causes a problem that durability is lowered. In addition, when the buckling angle of the compression coil spring 103 becomes too large, the conventional probe pin 101 cannot slide in the contact portion between the buckled compression coil spring 103 and the bottomed cylindrical body 102 (stack). This causes a problem that the plunger 104 cannot be smoothly operated.

In order to solve such a problem, the buckling angle of the compression coil spring 103 is reduced, the contact pressure between the plunger 104 and the bottomed cylindrical body 102, and the compression coil spring 103 and the bottomed cylindrical body 102.
It is necessary to ensure that the plunger 104 and the bottomed cylindrical body 102 are in contact with each other in a state where the contact pressure with the bottom is kept as small as possible.

However, since the conventional probe pin 101 shown in FIG. 15 has no means (positioning means) for determining the contact position between the end portion of the compression coil spring 103 and the inclined surface 111 of the plunger 104, the end portion of the compression coil spring 103 is used. And the contact position between the inclined surface 111 of the plunger 104 vary from product to product. As a result, it is assumed that the conventional probe pin 101 shown in FIG. 15 is a plan view of a virtual plane orthogonal to the central axis 110 of the compression coil spring 103. For example, FIG.
As shown in FIG. 17, the tip 118a of the coil 118 of the compression coil spring 103 is in the first quadrant, and the tip 118a of the coil 118 of the compression coil spring 103 is third as shown in FIG.
Compared with the case in the quadrant (when the tip 118a of the coil 118 of the compression coil spring 103 is 180 ° different from the tip 118a of the coil 118 of the compression coil spring 103 in FIG. 16),
The initial contact position 120 of the plunger 104 and the compression coil spring 103 is different, and the amount (δ) of the compression coil spring 103 being compressed in the bottomed cylindrical body 102 is different (FIG. 18).
reference). 16 to 18 show a state in which the plunger 104 is simply placed on the end of the compression coil spring 103 (only the weight of the plunger 104 is acting), and the compression coil spring 103 is not compressed. Indicates the state. In FIG. 18, the compression coil spring 103 indicated by the solid line corresponds to the compression coil spring 103 of FIG. 16, and the compression coil spring 103 indicated by the phantom line corresponds to the compression coil spring 103 of FIG.

Further, in the conventional probe pin 101 shown in FIG. 15, the contact state between the compression coil spring 103 and the plunger 104 is set to the pushing amount of the plunger 104 (the amount by which the compression coil spring 103 is compressed) as shown in FIG. Will change accordingly.

That is, as shown in FIGS. 19 (a-1 and a-2), the conventional probe pin 101 has a plunger 104 and a compression coil spring in a state where the plunger 104 rides on the end of the compression coil spring 103 only by its own weight. 103 is in contact at one location S10. Next, FIG.
1, b-2), the plunger 104 and the compression coil spring 103 are in two locations S10, S in a state where the plunger 104 is pushed in a little to compress and compress the compression coil spring 103.
11 is in contact. Next, as shown in FIG. 19 (c-1, c-2), the plunger 104
Is further pushed (the plunger 104 is pushed further from the state shown in FIG. 19B-1), and the compression coil spring 103 is pushed and contracted.
3 is in contact at two locations S10 and S11, but the second contact location S11 in FIG. 19 (b-2) is moving so as to approach the first contact location S10 side. As a result, FIG.
1, c-2) the buckling direction of the compression coil spring 103 is different from the buckling direction of the compression coil spring 103 of FIG. 19 (b-1, b-2). In addition, when the buckling direction of the compression coil spring 103 with respect to the plunger 104 is different, the contact state between the inclined surface 111 of the plunger 104 and the compression coil spring 103 is different, and the buckling angle is different.

Moreover, as the compression coil spring 103, for example, a closed end (non-ground) one is a ground angle at the end of the coil 118 (an angle formed between the outer surface of the coil 118 and the virtual horizontal plane H).
β is about 5 ° (see FIGS. 16 and 17). Therefore, the conventional probe pin 101 shown in FIG. 15 has a contact position 1 between the inclined surface 111 of the plunger 104 and the compression coil spring 103.
16 and FIG. 17 are compared, the angle θ formed between the end of the coil 118 of the compression coil spring 103 and the inclined surface 111 of the plunger 104 in the case of FIG.
Is α + β, and the angle θ between the end of the coil 118 of the compression coil spring 103 and the inclined surface 111 of the plunger 104 in the case of FIG. 17 is α−β, and the case of FIG.
The angle θ is larger than in the case of 7. As a result, the conventional probe pin 101 is, for example,
Contact position 1 between the inclined surface 111 of the plunger 104 and the compression coil spring 103 in FIG.
Even if the inclination angle α and angle θ of the inclined surface 111 of the plunger 104 are designed with reference to 20, the contact position 120 between the inclined surface 111 of the plunger 104 and the compression coil spring 103 in FIG. If changed, the angle θ formed between the end of the coil 118 of the compression coil spring 103 and the inclined surface 111 of the plunger 104 becomes too small, and the plunger 104
There is a possibility that contact between the outer surface of the tube and the inner surface of the bottomed cylindrical body 102 may be poor. On the other hand, in the conventional probe pin 101, for example, the inclination angle α and angle θ of the inclined surface 111 of the plunger 104 are designed based on the contact position 120 between the inclined surface 111 of the plunger 104 and the compression coil spring 103 in FIG. If the position changes to the contact position 120 between the inclined surface 111 of the plunger 104 and the compression coil spring 103 in FIG.
The angle θ formed by the end of the coil 118 and the inclined surface 111 of the plunger 104 becomes too large (the buckling angle of the compression coil spring 103 becomes too large), and the plunger 104 and the bottomed cylindrical body 102 are The frictional force of the contact portion and the contact portion between the compression coil spring 103 and the bottomed cylindrical body 102 is excessively increased, and abrasion occurs due to friction between these contact portions, and the durability is reduced or the compression coil spring 103 is provided. There arises a problem of stacking at the contact portion with the inner surface of the bottom cylindrical body 102. Since the buckling of the compression coil spring 103 is determined by the angle θ formed between the end of the coil 118 of the compression coil spring 103 and the inclined surface 111 of the plunger 104, the angle θ is referred to as a buckling angle.

Thus, it is difficult for the conventional probe pin 101 shown in FIG. 15 to design the buckling angle θ of the compression coil spring 103 to a desired angle, and the plunger 104 and the bottomed cylindrical body 10 are difficult to design.
It is difficult to design the contact pressure at the contact portion with 2 and the contact pressure at the contact portion between the compression coil spring 103 and the bottomed cylindrical body 102 within a desired numerical range.

Therefore, the present invention makes it possible to determine the buckling direction and the buckling angle of the compression coil spring with respect to the plunger, bring the plunger and the barrel and the compression coil spring and the barrel into contact with a contact pressure smaller than that of the conventional example, and The object is to improve the durability of the probe pin while ensuring the smooth and reliable operation of the pin.

1 to 3, 4, 6, 7 and 9, the present invention includes (1) a cylindrical barrel 2 having conductivity, and (2) a large diameter on the end side inside the barrel 2. Part 11 is slidably accommodated,
A conductive plunger 3 having a small-diameter portion 12 projecting outward from the end side of the barrel 2; and (3) accommodated in the barrel 2, and the plunger 3 is removed from the barrel 2. A compression coil spring 4 urged in the pushing direction; and (4) located at an end of the barrel 2 and abutted against an end of the large-diameter portion 11 of the plunger 3 urged by the compression coil spring 4. And a stopper 6 that prevents the plunger 3 from being pushed out of the barrel 2 by the spring force of the compression coil spring 4.

In the present invention, an inner end portion of the plunger 3 located inside the barrel 2 protrudes toward the inside of the barrel 2 from the end surface 16 facing the compression coil spring 4 and the end surface 16. And a protrusion 17.

The compression coil spring 4 is
When assuming that a virtual plane orthogonal to the central axis 23 of the compression coil spring 4 is viewed in plan view,
In the process in which the plunger 3 is housed in the barrel 2 in a state where the compression coil spring 4 is compressed, the first quadrant of the first to fourth quadrants centered on the central axis 23 In either one of the second quadrants, the tip 22a of the coil 22 is connected to the side surface 17 of the protrusion 17.
a and abutting against the end face 16, and in either one of the first quadrant and the second quadrant, the outer surface of the coil 22 abuts on the tip face 17b of the protrusion 17, and the first quadrant to There is a state in which the outer surface of the coil 22 does not contact the end face 16 within the range of the third quadrant to the fourth quadrant of the fourth quadrant,
At least when the plunger 3 is housed in the barrel 2 in a state where the compression coil spring 4 is compressed, the first of the first to fourth quadrants centered on the central axis 23. In either the quadrant or the second quadrant, the tip 22a of the coil 22 is connected to the projection 1
7, the outer surface of the coil 22 abuts against the tip end surface 17 b of the projection 17 in either one of the first quadrant and the second quadrant, and Within the range of the third quadrant to the fourth quadrant of the first quadrant to the fourth quadrant, the coil 2
When the outer surface of 2 abuts against the end face 16,
A buckling direction and a buckling angle inside the barrel 2 are determined, and the plunger 3 is pressed against the inner wall surface 2a of the barrel 2 to come into contact with the barrel in a buckled state.

The present invention makes it possible to determine a buckling direction and a buckling angle of a compression coil spring with respect to a plunger, bring a plunger and a barrel and a compression coil spring and a barrel into contact with a contact pressure smaller than that of the conventional example, and The durability of the probe pin can be improved while ensuring a smooth and reliable operation.

FIG. 1A shows a probe pin according to an embodiment of the present invention, FIG. 1A is a front view of the probe pin, and FIG. 1B is a top view of the probe pin in FIG. FIG. 1C is a diagram (a top view of the probe pin) as viewed toward the direction), and FIG. 1C illustrates the state viewed from the lower side of the probe pin in FIG. 1A toward the upper side (+ Z direction). It is a figure (bottom view of a probe pin) shown. It is a figure of the probe pin of the state which fractured | ruptured the barrel along the A1-A1 line | wire of Fig.1 (a), and is a figure which shows the internal structure of a probe pin. It is a figure which shows the edge part shape of a plunger, Fig.3 (a) is an end part side front view of a plunger, FIG.3 (b) is an end part side bottom view (end view) of a plunger. It is a figure which shows the state which put the 1st plunger on the one end part of a compression coil spring, FIG. 4 (a) is a front view which shows the relationship between a 1st plunger and the one end part of a compression coil spring, FIG. ) Is a plan view showing the relationship between the first plunger and one end of the compression coil spring (however, the plan view showing the first plunger in phantom lines). It is a figure which shows the state which put the other end part of the compression coil spring on the 2nd plunger, and Fig.5 (a) is a front view which shows the relationship between a 2nd plunger and the other end part of a compression coil spring, FIG. (B) is a top view which shows the relationship between a 2nd plunger and the other end part of a compression coil spring. It is a figure which shows an example of the assembly procedure of the probe pin. Fig.7 (a) is a front view which shows the relationship between the 1st plunger in the probe pin of FIG. 2, and the one end part of a compression coil spring. FIG. 7B is a plan view showing the relationship between the first plunger and one end portion of the compression coil spring in the probe pin of FIG. 2 (however, the plan view showing the first plunger in phantom). Fig.8 (a) is a front view which shows the relationship between the 2nd plunger in the probe pin of FIG. 2, and the other end part of a compression coil spring. FIG. 8B is a plan view showing the relationship between the second plunger and the other end of the compression coil spring in the probe pin of FIG. FIG. 9A is a view showing a state in which a minute gap is generated between the distal end surface of the protrusion of the first plunger and the outer surface of the coil of the compression coil spring. FIG. 9B is a diagram illustrating a state in which a minute gap is generated between the end surface of the first plunger and the tip of the coil of the compression coil spring. It is a figure which shows the 1st modification of the end surface side shape in a 1st plunger and a 2nd plunger, FIG. 10 (a) is a front view of the end surface side shape in a 1st plunger and a 2nd plunger, FIG. ) Is a bottom view of the end face side shape of the first plunger and the second plunger, and FIG. 10C is a view showing a modification of the end face side shape shown in FIG. It is a figure which shows the 2nd modification of the end surface side shape in a 1st plunger and a 2nd plunger, Fig.11 (a) is a front view of the end surface side shape in a 1st plunger and a 2nd plunger, FIG.11 (b) ) Is a bottom view of the end face side shape of the first plunger and the second plunger, and FIG. 11C is a view showing a modification of the end face side shape shown in FIG. It is a figure which shows the 3rd modification of the end surface side shape in a 1st plunger and a 2nd plunger, FIG. 12 (a) is a front view of the end surface side shape in a 1st plunger and a 2nd plunger, FIG. ) Is a bottom view (or a plan view) of the end face side shape of the first plunger and the second plunger. It is a figure which shows the 4th modification of the end surface side shape in a 1st plunger and a 2nd plunger, Fig.13 (a) is a front view of the end surface side shape in a 1st plunger and a 2nd plunger, FIG.13 (b) ) Is a bottom view (or a plan view) of the end face side shape of the first plunger and the second plunger. FIG. 2 is a diagram (a schematic cross-sectional view of the main part of an IC socket schematically showing) a probe pin unit containing a plurality of probe pins according to an embodiment of the present invention and an IC socket provided with the probe pin unit. It is a figure which shows the conventional probe pin (structure figure which fractures | ruptures and shows a bottomed cylindrical body). It is a figure which shows the 1st state of the plunger and compression coil spring in the conventional probe pin, FIG.16 (a) is a front view which shows the 1st state of a plunger and compression coil spring, FIG.16 (b) ) Is a plan view showing a first state of the plunger and the compression coil spring (however, the plan view showing the plunger in phantom lines). It is a figure which shows the 2nd state of the plunger and compression coil spring in the conventional probe pin, FIG.17 (a) is a front view which shows the 2nd state of a plunger and compression coil spring, FIG.17 (b) ) Is a plan view showing a second state of the plunger and the compression coil spring (however, the plan view showing the plunger in phantom lines). FIG. 16A shows a first state of the plunger and the compression coil spring (shown by a solid line) in FIG. 16A, and shows a second state of the plunger and the compression coil spring in FIG. It is a figure which overlaps and shows the tip position of the coil of a compression coil spring so that it may correspond. It is a figure which shows the contact state of the plunger and compression coil spring in the conventional probe pin. FIG. 19A-1 is a front view showing a state where the plunger is in contact with the compression coil spring only by its own weight. FIG. 19 (a-2) is a diagram illustrating a state in which the compression coil spring of FIG. 19 (a-1) is viewed in plan, and is a diagram illustrating a contact point with the plunger. FIG. 19B-1 is a front view showing a state where the plunger is pushed in and the compression coil spring is pushed and contracted. FIG.19 (b-2) is a figure which shows the state which planarly viewed the compression coil spring of FIG.19 (b-1), and is a figure which shows a contact point with a plunger. FIG. 19 (c-1) is a front view showing a state where the plunger is further pushed in and the compression coil spring is further compressed. Fig. 19 (c-2) is a diagram illustrating a state in plan view of the compression coil spring of Fig. 19 (c-1), and is a diagram illustrating a contact point with the plunger.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Probe pin structure)
1 and 2 show a probe pin 1 according to the present embodiment. In FIG. 1, FIG. 1 (a) is a front view of the probe pin 1, and FIG. 1 (b) is viewed from the upper side to the lower side (−Z direction) of the probe pin 1 in FIG. 1 (a). It is a figure (top view of probe pin 1) which shows a state, and a figure (probe pin) in which Drawing 1 (c) looked from the lower part of probe pin 1 of Drawing 1 (a) toward the upper part (+ Z direction) 1 is a bottom view of FIG. Further, FIG. 2 is shown in FIG.
It is a figure of the probe pin 1 of the state which fractured | ruptured the barrel 2 along the A1-A1 line | wire, and is a figure which shows the internal structure of the probe pin 1. FIG.

As shown in these drawings, the probe pin 1 houses the first plunger 3, the compression coil spring 4 and the second plunger 5 inside the barrel 2, and has a first stopper 6 on one end side of the barrel 2. The second stopper 7 is provided on the other end side of the barrel 2.

As shown in FIGS. 1 and 2, the barrel 2 is formed in a cylindrical shape from a conductive metal material.
The barrel 2 is integrally formed with the first stopper 6 by being reduced in diameter and tapered so that the diameter of the barrel 2 gradually decreases toward the end (upper end). Also,
The barrel 2 is deformed into a taper shape so that the diameter of the barrel 2 gradually decreases toward the end (lower end) toward the end (lower end), so that the second stopper 7 is integrally formed. As a result, the barrel 2 has an inner diameter of the opening 8 on one end side and an inner diameter of the opening 10 on the other end side smaller than the inner diameter of the other part. The barrel 2 is formed of a pipe-like conductive metal material so that the portions excluding the first stopper 6 and the second stopper 7 have the same inner diameter.

As shown in FIGS. 1 and 2, the first plunger 3 is formed of a round bar-like conductive metal material and has a large diameter portion 11 and a small diameter portion 12. The first plunger 3 is configured such that the large diameter portion 11 is slidably accommodated inside the barrel 2, and the small diameter portion 12 projects outward from the opening 8 on one end side of the barrel 2. Yes. Further, the small-diameter portion 12 of the first plunger 3
The tip of each is formed in a crown shape with a plurality of protrusions so as to be surely brought into contact with the terminal 14 of the IC package 13 (see FIG. 14). The large diameter portion 11 and the small diameter portion 12 of the first plunger 3 are smoothly connected by a tapered connection portion 15. The first plunger 3 has a protrusion 17 integrally formed on the end face 16 of the large-diameter portion 11 (end face 16 on the side facing the compression coil spring 4) (see FIG. 3).

As shown in FIGS. 2 and 3, the protrusion 17 extends from the end surface 16 to the central axis 18 of the first plunger 3.
Projecting along the central axis 20 of the barrel 2 and the end face 16 is viewed in plan (
3. When viewed from the bottom of FIG. 3 toward the + Z-axis direction), the chord 21 parallel to the center line C1 along the X-axis direction and the large-diameter portion of the first plunger 3 along the + Y-axis direction 11 is separated from the end face 16 by a chord 21 (an end edge of the protrusion 17) located so as to divide the radius of 11 into two. Further, when the compression coil spring 4 has a closed end (no grinding), the protrusion 17 has a tip (upper end) 22a of the coil 22 of the compression coil spring 4 that abuts against the side surface 17a of the protrusion 17 and the coil 22 of the compression coil spring 4. The first plunger 3 is arranged so that the tip 22a abuts against the end face 16.
Is placed on the end of the compression coil spring 4 and the center axis 18 of the first plunger 3 and the center axis 23 of the compression coil spring 4 are aligned so as to be concentric, the tip surface 17b of the projection 17 is It is formed in the protrusion height which contact | abuts the outer surface of the coil 22 of the compression coil spring 4 (refer FIG. 4).
. As shown in FIG. 4, the contact state between the first plunger 3 and the compression coil spring 4 at this time is the center axis 2 assuming that a virtual plane orthogonal to the center axis 23 of the compression coil spring 22 is viewed in plan view.
In the first quadrant centered on 3, the tip 22 a of the coil 22 of the compression coil spring 4 abuts the side surface 17 a and the end surface 16 of the projection 17 of the first plunger 3, and in the second quadrant centered on the central axis 23, The outer surface of the coil 22 of the compression coil spring 4 abuts on the distal end surface 17b of the protrusion 17 of the first plunger 3, and the first plunger 3 and the compression coil spring in the third and fourth quadrants centered on the central axis 23. 4 is not in contact. That is, in the third and fourth quadrants centered on the central axis 23, a gap corresponding to an angle θ is generated between the end face 16 of the first plunger 3 and the outer surface of the coil 22 of the compression coil spring 4. It has become. Thereby, the buckling direction of the compression coil spring 4 with respect to the plunger 3 is uniquely determined. Further, the buckling angle of the compression coil spring 4 is determined according to the gap of the angle θ between the end face 16 of the first plunger 3 and the outer surface of the coil 22 of the compression coil spring 4 ( FIG. 4 (a)
reference). The buckling direction is the direction of a line segment Fa connecting the middle of the imaginary straight line connecting the contact points S <b> 1 and S <b> 2 between the compression coil spring 4 and the plunger 3 and the central axis 23 of the compression coil spring 4. In the present embodiment, the contact position between the tip 22a of the coil 22 of the compression coil spring 4 and the side surface 17a of the protrusion 17 of the first plunger 3 is defined as the first quadrant for convenience of explanation.

As shown in FIG. 2, the second plunger 5 is made of a round bar-like conductive metal material and has a large diameter portion 24 and a small diameter portion 25. The second plunger 5 is configured such that the large diameter portion 24 is slidably accommodated inside the barrel 2, and the small diameter portion 25 projects outward from the opening 10 on the other end side of the barrel 2. ing. Further, the distal end side of the small diameter portion 25 of the second plunger 5 is formed in a substantially conical shape so as to be surely brought into contact with the energizing electrode 27 of the substrate 26 (see FIG. 14). The large diameter portion 24 and the small diameter portion 25 of the second plunger 5 are smoothly connected by a tapered connection portion 28. Further, in the second plunger 5, a protrusion 31 is integrally formed on the end surface 30 (the end surface 30 on the side facing the compression coil spring 4) of the large diameter portion 24.

As shown in FIGS. 2 and 3, the protrusion 31 extends from the end surface 30 to the central axis 32 of the second plunger 5.
Projecting along the central axis 20 of the barrel 2 and when the end face 30 is viewed in plan (
2 when viewed from the top in the −Z-axis direction), the large diameter of the second plunger 5 which is the chord 33 parallel to the center line C1 along the X-axis direction and along the + Y-axis direction. The end face 30 is defined by a chord 33 (an end edge of the protrusion 31) located so as to divide the radius of the portion 24 into two. Further, when the compression coil spring 4 has a closed end (no grinding), the protrusion 31 has the tip (lower end) 22b of the coil 22 of the compression coil spring 4 abutted against the side surface 31a of the protrusion 31 and the coil 22 of the compression coil spring 4 The end of the compression coil spring 4 is placed on the second plunger 5 such that the outer surface on the front end side contacts the end surface 30, and the center axis 32 of the second plunger 5 and the center axis 23 of the compression coil spring 4 are connected. When aligned so as to be concentric, the tip end surface 31 b of the projection 31 is formed at a protruding height that abuts against the outer surface of the coil 22 of the compression coil spring 4. As shown in FIG. 5, the contact state between the second plunger 5 and the compression coil spring 4 at this time is assumed to be a plan view of a virtual plane orthogonal to the center axis 23 of the compression coil spring 4. In the second quadrant centered, the tip 22b of the coil 22 of the compression coil spring 4 abuts the side surface 31a and the end surface 30 of the projection 31 of the second plunger 5, and in the first quadrant centered on the central axis 23,
The outer surface of the coil 22 of the compression coil spring 4 abuts on the tip surface 31b of the protrusion 31 of the second plunger 5, and the second plunger 5 and the compression coil spring in the third and fourth quadrants centered on the central axis 23. 4 is not in contact. In other words, in the third and fourth quadrants centered on the central axis 23, a gap is generated between the end surface 30 of the second plunger 5 and the outer surface of the coil 22 of the compression coil spring 4. Thereby, the buckling direction of the compression coil spring 4 with respect to the second plunger 5 is uniquely determined. The buckling angle of the compression coil spring 4 is determined according to the gap of the angle θ between the end face 30 of the second plunger 5 and the outer surface of the coil 22 of the compression coil spring 4 ( (See FIG. 5 (a)). The buckling direction is a direction of a line segment Fb connecting the middle of the imaginary straight line connecting the contact points S3 and S4 between the compression coil spring 4 and the second plunger 5 and the central axis 23 of the compression coil spring 4. . Second
The shapes of the end face 30 and the protrusion 31 of the plunger 5 are the same as the end face 16 and the protrusion 1 of the first plunger 3.
The shape is the same as that of FIG. The first plunger 3, the second plunger 5, the compression coil spring 4 and the barrel 2 are formed so that the buckling angle on the one end side of the compression coil spring 4 and the buckling angle on the other end side are the same. ing.

The compression coil spring 4 is formed of a conductive metal material in a right-handed manner, and a closed end (non-ground) type is used.

The compression coil spring 4 may be an open end (no grinding). However, in this case (when the compression coil spring 4 is open-ended (unground)), the first plunger 3
The height of the protrusion 17 (height along the central axis 18 from the end face 16), the shape of the end face 16, and the second
The height of the protrusion 31 of the plunger 5 (height along the central axis 32 from the end face 30) and the shape of the end face 30 need to be determined in accordance with the end shape of the compression coil spring 4.

The compression coil spring 4 may be a left-handed one. However, in this case (when the compression coil spring 4 is left-handed), the contact position between the tip 22a side of the coil 22 of the compression coil spring 4 and the first plunger 3 is in the second quadrant centered on the central axis 18 (23). It is. The first
The contact position between the distal end surface 17b of the protrusion 17 of the plunger 3 and the outer surface of the coil 22 of the compression coil spring 4 is in the first quadrant centered on the central axis 18 (23). Further, the contact position between the distal end 22b side of the coil 22 of the compression coil spring 4 and the second plunger 5 is in the first quadrant with the central axis 32 (23) as the center. The contact position between the tip surface 31b of the projection 31 of the second plunger 5 and the outer surface of the coil 22 of the compression coil spring 4 is in the second quadrant with the center axis 32 (23) as the center.

(Assembly procedure of probe pin)
With reference to FIG. 6, an example of the assembly procedure of the probe pin 1 is shown. First, as shown in FIG. 6A, a small diameter portion 25 of the second plunger 5 is disposed inside the barrel 2 where the second stopper 7 is formed.
Is accommodated so as to protrude from the opening 10 on the other end side of the barrel 2 to the outside of the barrel 2. At this time, the second plunger 5 is stopped with the large-diameter portion 25 in contact with the second stopper 7 of the barrel 2.

Next, as shown in FIG. 6B, the compression coil spring 4 is accommodated inside the barrel 2. In the compression coil spring 4, the tip 22 b of the coil 22 on the other end side is placed on the end surface 30 of the large diameter portion 24 of the second plunger 5 and is abutted against the side surface 31 a of the protrusion 31 of the second plunger 5. Thereby, the compression coil spring 4 is positioned with respect to the second plunger 5 (see FIG. 5). In the compression coil spring 4, the outer surface of the coil 22 is the tip surface 31 of the protrusion 31.
b (see FIG. 5).

Next, as shown in FIG. 6 (c), the first plunger 3 is placed in the large diameter portion 11 inside the barrel 2.
Is inserted first (down). At this time, the first plunger 3 has an end face 1 of the large diameter portion 11.
6 is placed on one end side of the compression coil spring 4, and the side surface 17 a of the protrusion 17 of the large diameter portion 11 is abutted against the tip 22 a of the coil 22 of the compression coil spring 4. Thus, the first plunger 3 is positioned with respect to the compression coil spring 4 (see FIG. 4). The compression coil spring 4
The outer surface of the coil 22 is in contact with the tip end surface 17b of the protrusion 17 (see FIG. 4).

Next, as shown in FIGS. 6D to 6E, the first plunger 3 is pushed into the barrel 2 by a predetermined amount while pushing and compressing the compression coil spring 22, and one end of the barrel 2 is deformed to a reduced diameter. As a result, the first stopper 6 is formed. Thereafter, when the force for pushing the first plunger 3 into the barrel 2 is released, the large-diameter portion 11 of the first plunger 3 is pressed against the first stopper 6 by the spring force of the compression coil spring 4. Thereby, the assembly work of the probe pin 1 is completed (
(See FIG. 2).

Then, as shown in FIG. 7, at the stage where the assembly work of the probe pin 1 is completed, the first
Assuming that the contact state between the plunger 3 and the compression coil spring 4 is a plan view of a virtual plane orthogonal to the center axis 23 of the compression coil spring 4, the compression coil spring 4 is in the first quadrant centered on the center axis 23. The tip 22a of the coil 22 on one end side of the
7, the outer surface of the coil 22 of the compression coil spring 4 is in contact with the distal end surface 17 b of the protrusion 17 of the first plunger 3, and the center surface 23 is in contact with the side surface 17 a and the end surface 16. The outer surface of the coil 22 of the compression coil spring 4 is within the range of the first plunger 3 within a range extending over the first quadrant, the fourth quadrant, and the third quadrant centered on the shaft 23 (the range indicated by the arcuate dotted line 34a in FIG. The end surface 16 abuts linearly. As a result, the buckling angle of the compression coil spring 4 is limited to a predetermined angle (θ) by the first plunger 3. The buckled compression coil spring 4 abuts on the inner wall surface 2a of the barrel 2 at a position away from the one end side toward the other end side, and the one end side makes the first plunger 3 the inner wall surface 2a of the barrel 2. The first plunger 3 and the barrel 2 are securely brought into contact with each other (see FIG. 2).

Further, as shown in FIG. 8, when the assembly work of the probe pin 1 is completed, the contact state between the second plunger 5 and the compression coil spring 4 is a flat plane perpendicular to the central axis 23 of the compression coil spring 4. In the second quadrant centered on the central axis 23, it is assumed that the tip 22b of the coil 22 on the other end side of the compression coil spring 4 is the protrusion 31 of the second plunger 5,
The outer surface of the coil 22 of the compression coil spring 4 is in contact with the distal end surface 31b of the projection 31 of the second plunger 5 in the first quadrant centered on the central axis 23.
The outer surface of the coil 22 of the compression coil spring 4 faces the end face 30 of the second plunger 5 within a range extending from the second quadrant to the fourth quadrant centered on the central axis 23 (a range indicated by an arc-shaped dotted line 34 b in FIG. 8). It is in linear contact. As a result, the buckling angle of the compression coil spring 4 is limited to a predetermined angle (θ) by the second plunger 5. Then, the buckled compression coil spring 4 abuts on the inner wall surface 2a of the barrel 2 at a position away from the other end portion toward the one end side, and the other end portion side connects the second plunger 5 to the inner wall surface of the barrel 2. The second plunger 5 and the barrel 2 are securely brought into contact with each other (see FIG. 2).

In FIG. 4A, due to manufacturing errors of the first plunger 3 and the compression coil spring 4, as shown in FIG. 9A, the tip surface 17b of the projection 17 of the first plunger 3 and the compression coil spring 4 A small gap δ1 is formed between the outer surface of the coil 22 and a small space between the end surface 16 of the first plunger 3 and the tip 22a of the coil 22 of the compression coil spring 4 as shown in FIG. The gap δ2 may occur. However, in the assembly process of the probe pin 1 shown in FIGS. 6C to 6D, the compression coil spring 4 is compressed by the first plunger 3, so that the minute gap δ1 shown in FIG. The minute gap δ2 shown in FIG. 9B disappears, and the state shown in FIG. Further, in FIG. 5A, due to manufacturing errors of the second plunger 5 and the compression coil spring 4, a gap between the tip end surface 31 b of the protrusion 31 of the second plunger 5 and the outer surface of the coil 22 of the compression coil spring 4. Even if a minute gap occurs or a minute gap occurs between the end surface 30 of the second plunger 5 and the tip 22b of the coil 22 of the compression coil spring 4, the probe pin 1 shown in FIGS. Since the compression coil spring 4 is compressed and contracted by the first plunger 3 in the assembly process of FIG. 5, the minute gap is eliminated as in the relationship between the first plunger 3 and the compression coil spring 4, and FIG. It will be in the state shown.

(Function and effect of probe pin)
As described above, the probe pin 1 according to the present embodiment can position the contact point between the tip 22a of the coil 22 and the first plunger 3 on one end side of the compression coil spring 4, and the seat of the compression coil spring 4 with respect to the first plunger 3 can be positioned. Since the bending direction can be determined, the buckling angle on one end side of the compression coil spring 4 can be set to a predetermined angle (θ). Therefore, the probe pin 1 according to the present embodiment is the first even if the contact pressure between the first plunger 3 and the barrel 2 and the contact pressure between the compression coil spring 4 and the barrel 2 are reduced as compared with the conventional example. The plunger 3 and the barrel 2 can be reliably brought into contact with each other.

Further, the probe pin 1 according to the present embodiment can position the contact point between the tip 22b of the coil 22 and the second plunger 5 on the other end side of the compression coil spring 4, and the second of the compression coil spring 4 can be positioned.
Since the buckling direction with respect to the plunger 5 can be determined, the buckling angle on the other end side of the compression coil spring 4 can be set to a predetermined angle (θ). Therefore, the probe pin 1 according to the present embodiment has the second advantage that even if the contact pressure between the second plunger 5 and the barrel 2 and the contact pressure between the compression coil spring 4 and the barrel 2 are reduced as compared with the conventional example. The plunger 5 and the barrel 2 can be reliably brought into contact with each other.

As a result, the probe pin 1 according to this embodiment includes the first plunger 3 and the second plunger 5.
Since the wear at the contact portion between the compression coil spring 4 and the barrel 2 can be reduced, smooth operation can be ensured for a long period of time, and the durability can be improved. Become.

Further, the probe pin 1 according to the present embodiment can reduce variations in spring force that the compression coil spring 4 biases the first plunger 3 and the second plunger 5 as compared with the conventional example. The contact pressure between the terminal 14 of the package 13 and the first plunger 3 can be made constant, and the contact pressure between the energization electrode 27 of the substrate 26 and the second plunger 5 can be made constant. The test can be performed with high accuracy and stability.

(Modifications of the first plunger and the second plunger)
10 to 13 show modified examples of the shapes of the end surfaces 16 and 30 of the first plunger 3 and the second plunger 5.

That is, as shown in FIGS. 10A to 10B and FIGS. 11A to 11B, the first plunger 3 and the second plunger 5 are adjacent to the protrusions 17 and 31 of the end surfaces 16 and 30, respectively. The recesses 35 are recessed in parallel with the strings 21 and 33 of the protrusions 17 and 31 to form the recesses 35, and the end surfaces 16 and 30 and the compression coil springs 4 The contact area is narrowed. In the probe pin 1 using the first plunger 3 and the second plunger 5 according to this modification, the contact range between the compression coil spring 4 and the end faces 16 and 30 is a part of the fourth quadrant and the third quadrant. (See FIGS. 7 and 8). Note that FIG. 10C and FIG.
As shown in FIG. 1 (c), the first plunger 3 and the second plunger 5 are formed by cutting off the tip surfaces 17b and 31b of the protrusions 17 and 31 along the strings 21 and 33, so that the tip surfaces 17b and 31b are substantially drawn. The end surfaces 16 and 30 are cut out along the chords 29 and 39, and the end surfaces 16 and 30 are formed.
May be a substantially linear minute end face.

Further, as shown in FIGS. 12 and 13, the first plunger 3 and the second plunger 5 are composed of the tips 22 a and 22 b of the coil 22 of the buckled compression coil spring 4 and the side surfaces 17 of the protrusions 17 and 31.
The outer surface of the coil 22 of the compression coil spring 4 buckled from the contact position with a and 31a and the protrusion 17
31 of the compression coil spring 4 buckled in the whole area (part of the first quadrant, part of the second quadrant, whole area of the third and fourth quadrants) up to the contact position with the tip surfaces 17b, 31b of The outer surface 22 is supported by the end faces 16 and 30 (see FIGS. 7 and 8). In addition, FIG. 12 has shown the case where the large diameter parts 11 and 24 of the 1st plunger 3 and the 2nd plunger 4 are solid round bar shapes. FIG. 13 shows the large diameter portion 11 of the first plunger 3 and the second plunger 5.
24 have a hollow round bar shape or a circular hole (dent) 36 at the center.

(Probe pin unit and IC socket equipped with the same)
FIG. 14 shows a probe pin unit 40 provided with the probe pin 1 according to this embodiment and an IC socket 41 into which the probe pin unit 40 is incorporated.

As shown in FIG. 14, the probe pin unit 40 has a plurality of probe pin accommodation holes 43 formed at a predetermined pitch in a probe pin accommodation body 42 made of an insulating resin material. 1 can be accommodated in each probe pin accommodation hole 43. As for the probe pin 1 accommodated in the probe pin accommodation hole 43 of the probe pin accommodation body 42, one end (the upper end of FIG. 14) of the barrel 2 is pressed against the retaining projection 44 of the probe pin accommodation body 42. The probe pin 1 accommodated in the probe pin accommodation hole 43 of the probe pin accommodation body 42 has the small diameter portion 12 of the first plunger 3 from the one end side opening 45 of the probe pin accommodation hole 43 of the probe pin accommodation body 42. It protrudes outward.

As shown in FIG. 14, the IC socket 41 has a probe pin unit 40 accommodated in a probe pin unit accommodation portion 48 of the socket body 47. In the probe pin 1 of the probe pin unit 40 accommodated in the IC socket 41, the tip of the small diameter portion 25 of the second plunger 5 is pressed by the energizing electrode 27 on the substrate 26, and the small diameter portion of the first plunger 3 is pressed. The terminal 14 of the IC package 13 is pressed against the tip of 12 by the IC package pressing means 50. At this time, the probe pin 1 shown in FIGS.
The first plunger 3 is pushed by the IC package 13 and pushed into the barrel 2, and the compression coil spring 4 is pushed and compressed in the barrel 2. The first plunger 3 and the second plunger 5 are pressed against the inner wall surface 2 a of the barrel 2 by the spring force of the compression coil spring 4 buckled in the barrel 2. In such a state, in the IC socket 41, the terminal 14 of the IC package 13 and the energizing electrode 27 of the substrate 26 are electrically connected via the first plunger 3, the barrel 2 and the second plunger 5 of the probe pin 1. Thus, the electrical test of the IC package 13 can be reliably performed over a long period of time.

(Other variations)
As shown in FIG. 6, the barrel 2 is formed with the second stopper 7 in advance, and then the first stopper 6 is formed later. However, the present invention is not limited to this. Alternatively, the second stopper 7 may be formed later. In this case, however, barrel 2
The first plunger 3, the compression coil spring 4, and the second plunger 5 are accommodated in this order. Moreover, you may form the 1st, 2nd stoppers 6 and 7 simultaneously.

In the present invention, the second plunger 5 is fixed to the barrel 2 and the first plunger 3 is slidable with respect to the barrel 2 (see, for example, the probe pin 101 shown in FIG. 15). Is also applicable. In this case, the support structure of the compression coil spring 4 in the first plunger 3 is the structure shown in FIGS. 4 and 7. On the other hand, the support structure of the compression coil spring 4 in the second plunger 5 is not limited to the structure shown in FIGS.
For example, the support surface of the compression coil spring 4 in the second plunger 5 may be a flat surface or a conical surface.

DESCRIPTION OF SYMBOLS 1 ... Probe pin, 2 ... Barrel, 2a ... Inner wall surface, 3 ... 1st plunger (plunger), 4 ... Compression coil spring, 5 ... 2nd plunger, 6 ... 1st stopper (stopper) 7, second stopper, 11, 24 ... large diameter part, 12, 25 ... small diameter part, 13 ... IC
Package, 14 ... terminal, 16, 30 ... end face, 17, 31 ... projection, 17a, 31a
…… Side, 17b, 31b …… Tip, 22 …… Coil, 22a, 22b …… Tip, 23
…… Center axis, 26 …… Substrate, 27 …… Electroconductive electrode, 40 …… Probe pin unit, 41
... IC socket, 42 ... probe pin housing, 43 ... probe pin housing hole, 47 ...
... Socket body, 50 ... IC package pressing means

Claims (4)

A barrel having a cylindrical conductivity;
A plunger having conductivity, wherein a large diameter portion is slidably accommodated on an end portion inside the barrel, and a small diameter portion protrudes outward from the end portion side of the barrel;
A compression coil spring housed in the barrel and biasing the plunger in a direction of pushing out the barrel;
The plunger is pushed out of the barrel by the spring force of the compression coil spring, located at the end of the barrel, abutting against the end of the large diameter portion of the plunger biased by the compression coil spring. A stopper to prevent
A probe pin comprising:
The inner end portion of the plunger located inside the barrel has an end surface facing the compression coil spring, and a protrusion protruding toward the inside of the barrel from the end surface,
The compression coil spring is
When assuming that the virtual plane orthogonal to the central axis of the compression coil spring is viewed in plan,
In the process in which the plunger is housed in the barrel with the compression coil spring compressed, the first quadrant and the second quadrant of the first to fourth quadrants centered on the central axis.
In one of the quadrants, the tip of the coil is positioned against the side surface and the end surface of the projection, and in either one of the first quadrant or the second quadrant, the outer surface of the coil is the tip of the projection. In contact with the surface, within the range of the third quadrant to the fourth quadrant of the first quadrant to the fourth quadrant,
There is a state where the outer surface of the coil does not contact the end surface,
At least the first and second quadrants of the first to fourth quadrants centered on the central axis in the stage where the plunger is housed in the barrel with the compression coil spring compressed. Either of the first and second quadrants is positioned so that the tip of the coil hits the side surface and the end surface of the projection, and the outer surface of the coil is the tip surface of the projection. And the outer surface of the coil is in contact with the end face within the range of the third quadrant to the fourth quadrant of the first quadrant to the fourth quadrant,
The buckling direction and the buckling angle inside the barrel are determined, the plunger is pressed against the inner wall surface of the barrel, and comes into contact with the barrel in a buckled state.
A probe pin characterized by that. A barrel having a cylindrical conductivity;
A first plunger having conductivity, wherein a large-diameter portion is slidably accommodated at one end inside the barrel, and a small-diameter portion protrudes outward from one end of the barrel;
A second plunger having conductivity, wherein a large-diameter portion is slidably accommodated on the other end side of the barrel, and a small-diameter portion protrudes outward from the other end side of the barrel;
Housed within the barrel and between the first plunger and the second plunger;
A compression coil spring that biases the first plunger and the second plunger in a direction to push out the barrel;
The first plunger is located at one end of the barrel and abuts on the end of the large diameter portion of the first plunger biased by the compression coil spring, and the first plunger is pressed by the spring force of the compression coil spring. A first stopper for preventing the first stopper from being pushed out,
The second plunger is located at the other end of the barrel and abuts against an end of the large diameter portion of the second plunger biased by the compression coil spring, and the second plunger is moved by the spring force of the compression coil spring. A second stopper to prevent extrusion from the barrel;
A probe pin comprising:
Of the first plunger and the second plunger, an inner end portion located inside the barrel includes an end face facing the compression coil spring, and a protrusion protruding toward the inside of the barrel from the end face. Have
The compression coil spring is
When assuming that the virtual plane orthogonal to the central axis of the compression coil spring is viewed in plan,
In the process in which the first plunger and the second plunger are accommodated in the barrel in a state where the compression coil spring is compressed, the first quadrant to the fourth quadrant centering on the central axis.
One of the first quadrant and the second quadrant of the quadrant, the tip of the coil is positioned against the side surface and the end surface of the projection, and in either one of the first quadrant and the second quadrant, The outer surface of the coil abuts on the tip surface of the protrusion, and the outer surface of the coil does not abut on the end surface within the third to fourth quadrants of the first to fourth quadrants. There is a state
At least when the first plunger and the second plunger are accommodated in the barrel in a state where the compression coil spring is compressed, the first plunger centered on the central axis
One of the first quadrant and the second quadrant of the quadrant to the fourth quadrant, the tip of the coil is positioned against the side surface and the end surface of the projection, and either the first quadrant or the second quadrant On the other hand, the outer surface of the coil abuts against the tip surface of the protrusion, and the first quadrant to the fourth quadrant.
Within the range of the third quadrant to the fourth quadrant of the quadrant, the outer surface of the coil abuts on the end face,
A buckling direction and a buckling angle inside the barrel are determined, the first plunger and the second plunger are pressed against the inner wall surface of the barrel, and are in contact with the barrel in a buckled state.
A probe pin characterized by that. A probe pin housing formed of an insulating material;
The probe pin accommodating body is accommodated in a plurality of probe pin accommodating holes formed in the probe pin accommodating body.
Or the probe pin according to 2,
A probe pin unit comprising: A socket body installed on the board;
The probe pin unit according to claim 3 accommodated in the socket body,
A terminal of the IC package is pressed against one end portion of the probe pin housed in the probe pin housing hole of the probe pin unit, and the terminal of the IC package and the current-carrying electrode of the substrate are interposed through the probe pin. IC package pressing means for enabling electrical connection;
An IC socket characterized by comprising:

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