JP5567523B2 - Connection pin - Google Patents

Description

  The present invention relates to a connection pin for electrically connecting between conductive members respectively provided on two substrates.

  Conventional connecting pins include a bottomed cylindrical barrel, a plunger slidably inserted into the barrel, and a direction in which the plunger protrudes from the barrel between the bottom of the barrel and the plunger. Some have a coil spring that biases them (see Patent Document 1). This connection pin has the bottom of the barrel as the electrode of the first substrate and the tip of the plunger as the electrode of the second substrate so that the coil spring is compressed between the bottom of the barrel and the proximal end of the plunger. The electrodes provided on both substrates are electrically connected to each other.

Japanese Patent Laid-Open No. 06-43183

  The connection pin is attached to each component such as a plunger that is in contact with one electrode, a barrel that is in contact with the other electrode, and a coil spring that biases the plunger and the barrel in a direction to move away from each other. It had the necessary functions. Therefore, each part is indispensable, and it has been difficult to reduce the number of parts.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a connection pin capable of reducing the number of parts and reducing the cost.

In order to solve the above problem, a connection pin according to the first invention of the present application includes a cylindrical barrel having conductivity and a coil spring having conductivity. The coil spring is provided between the connection portion accommodated and fixed in the barrel, the closely wound contact portion, the connection portion and the contact portion, and is accommodated in the barrel. And a loosely wound elastic deformation portion. The contact portion has a first end portion accommodated in the barrel with a gap, and a second end portion protruding from one end side of the barrel. The distal end portion of the second end portion has a shape that causes a force to tilt the contact portion to act on the contact portion when the distal end portion is pressed against a flat surface. When an external force is applied to the distal end portion of the second end portion, the elastic deformation portion is elastically deformed , the contact portion is inclined , and the first end portion is in contact with the inner surface of the barrel.

In such a first invention, the other end of the barrel or the connecting portion protruding from the barrel is brought into contact with the electrode of the first substrate, and the second end of the contact portion of the coil spring is brought into contact with the electrode of the second substrate. In this state, when an external force is applied from the electrode of the second substrate to the tip of the second end of the contact portion, the elastic deformation portion is elastically deformed, and the first end of the contact portion is applied to the inner surface of the barrel. Contact. At this time, the other end of the barrel that elastically contacts the electrode of the first substrate or the connecting portion protruding from the barrel, the location where the inner surface of the barrel and the first end of the contact portion contact, the contact portion and the contact portion A second end that elastically contacts the electrode of the second substrate is formed as the shortest electrical path connecting the first and second substrates, and the first and second substrates are electrically connected. As described above, since the essential constituent elements of the connection pin are the barrel and the coil spring, the number of parts can be reduced, and the cost of the connection pin can be reduced. Further, since the contact portion is closely wound, even if the contact portion that is a part of the coil spring is used for the electrical path, an increase in the resistance component of the contact portion can be suppressed. Further, since the shortest electrical path does not include a loosely wound elastic deformation portion, an increase in inductance due to the coil component of the elastic deformation portion can be suppressed when the first and second substrates are connected.
When the front end portion of the second end portion is pressed against a flat surface, the contact portion is inclined, so that the first end portion of the contact portion can be reliably brought into contact with the inner surface of the barrel. Therefore, the connection reliability of the connection pins can be improved.

  In the connection pin according to the second invention of the present application, the connection portion is closely wound with the same shape as the contact portion. According to the second aspect of the invention, since both ends of the coil spring are closely wound with the same shape, one dense winding can be used as a contact portion or a connecting portion, and the other dense winding can be used as a connecting portion or a contact portion. . For this reason, when inserting the coil spring into the barrel, it becomes possible to insert the coil spring without worrying about the direction of the coil spring, so that the workability of the assembly work of the connection pin is improved. Easy to assemble automatically. Therefore, also in this respect, the cost of this connection pin can be reduced.

In the connection pin according to the third invention of the present application, a tapered surface whose inner diameter is gradually reduced to the other end side of the barrel is provided on the end surface of the one end portion of the barrel. According to the third aspect of the invention, the tapered surface makes it easy to insert the coil spring into the barrel from one end side. In addition, when the external force is applied to the tip end portion of the second end portion of the contact portion of the coil spring by the tapered surface, and the first end portion of the contact portion contacts the inner surface of the one end portion of the barrel, the contact portion Can be prevented from being caught by the inner edge of the end face of the one end of the barrel, and as a result, the compression operation of the coil spring can be made smooth.

(A) is schematic sectional drawing of the connection pin which concerns on Example 1 of this invention, (b) is schematic partial sectional drawing of the probe card which concerns on Example 1 of this invention, Comprising: By the said connection pin, the said probe It is a figure which shows the state by which the wiring board of the card | curd and the main board | substrate were connected. (A) is schematic sectional drawing of the connection pin which concerns on Example 2 of this invention, (b) is schematic partial sectional drawing of the probe card which concerns on Example 2 of this invention, Comprising: By the said connection pin, the said probe It is a figure which shows the state with which the wiring board of the card | curd and the main board | substrate were connected. FIG. 3 is a schematic cross-sectional view showing a design change example of the connection pin of the first embodiment. (A) is schematic sectional drawing which shows the design change example of the 2nd end part of the contact part of the connection pin of Example 1 and 2, (b) is a design change of the protrusion part of the connection part of the connection pin of Example 2. FIG. It is a schematic sectional drawing which shows an example.

  Examples 1 and 2 of the present invention will be described in detail below.

  First, a connection pin according to Embodiment 1 of the present invention will be described with reference to FIG. A connection pin 100 shown in FIG. 1A includes a barrel 110 and a coil spring 120. Hereinafter, each part will be described in detail.

  The barrel 110 is a bottomed cylindrical metal tube having conductivity. An open end 111 (one end of the barrel 110) is provided on one end side of the barrel 110 in the length direction. The end surface of the open end 111 is provided with a tapered surface 111 a whose inner diameter gradually decreases toward the other end in the length direction of the barrel 110. A bottom 112 is provided on the other end side of the barrel 110. Further, a ring-shaped caulking portion 113 that protrudes inward is provided on one end side of the bottom portion 112 of the barrel 110.

  The coil spring 120 has a configuration in which a conductive wire having a circular cross section is wound in a cylindrical shape. The coil spring 120 includes a closely wound connection portion 121, a closely wound contact portion 122, and a loosely wound elastic deformation portion 123 provided between the connection portion 121 and the contact portion 122. Yes. The outer diameters of the connection part 121, the contact part 122, and the elastic deformation part 123 are the same, and are slightly smaller than the inner diameter of the barrel 110. The connecting part 121 is accommodated in the barrel 110 and fixed by a caulking part 113 of the barrel 110. The elastic deformation portion 123 is accommodated in the barrel 110 with a gap. The contact part 122 has a first end part 122 a accommodated in the barrel 110 with a gap, and a second end part 122 b protruding from the open end part 111 of the barrel 110. The tip end portion 122b1 of the second end portion 122b has a shape that causes a force to tilt the contact portion 122 to act on the contact portion 122 when the tip end portion 122b1 is pressed against a flat surface. Specifically, the tip end portion 122b1 of the wire portion constituting the second end portion 122b is eccentric from the axis of the coil spring 120 and can be in line contact with an electrode 210 (plane) of the main substrate 200 described later. When the distal end portion 122b1 of the second end portion 122b is in line contact with the electrode 210 (plane), the elastic deformation portion 123 is compressed and elastically deformed in the radial direction, and the contact portion 122 is inclined with the distal end portion 122b1 as a fulcrum, The first end 122 a contacts the inner peripheral surface of the barrel 110. In this way, the first end 122a of the contact portion 122 and the barrel 110 are electrically connected.

  Such a connection pin 100 is assembled as follows. First, a barrel 110 is prepared before the coil spring 120 and the caulking portion 113 formed by winding a conductive wire are formed. Thereafter, the connection part 121 of the coil spring 120, the elastic deformation part 123, and the first end part 122 a of the contact part 122 are inserted into the barrel 110 from the open end part 111. The end surface of the open end 111 is provided with a tapered surface 111a whose inner diameter gradually decreases on the other end side of the barrel 110, so that the coil spring 120 is guided into the barrel 110 by the tapered surface 111a during insertion. Thereafter, the coil spring 120 is positioned with the barrel 110 so that the length from the bottom 112 of the barrel 110 to the second end 122b of the contact portion 122 of the coil spring 120 is a predetermined length. The connecting portion 121 of the coil spring 120 is fixed to the barrel 110 by caulking the one end side portion of the bottom portion 112 inward. In addition, the convex part which crimped the part of the one end side of the bottom part 112 of the barrel 110 inside becomes the crimping part 113.

  As shown in FIG. 1B, the connection pin 100 assembled in this way connects between the main board 200 (the second board) and the wiring board 300 (the first board) of the probe card. Used for. Hereinafter, the probe card will be described. This probe card includes a plurality of connection pins 100, a main board 200, a wiring board 300, a guide plate 400, and a plurality of probes (not shown).

  The main substrate 200 is a well-known printed circuit board, and a plurality of electrodes 210 (one shown in the figure) are formed in a matrix on the surface. The wiring board 300 is disposed on the main board 200 in a state of being substantially parallel to the main board 200 and having a predetermined distance. The predetermined distance is set to be slightly smaller than the length dimension of the connection pin 100 (that is, the distance from the bottom 112 of the barrel 110 to the tip 122b1 of the second end 122b of the coil spring 120). The wiring substrate 300 is provided with a plurality of through-hole electrodes 310 (one in the figure). The through-hole electrode 310 is arranged so that the center is located on the vertical line of the center of the electrode 210. The probe is disposed on the non-opposing surface of the wiring board 300. The guide plate 400 is disposed between the main board 200 and the wiring board 300. The guide plate 400 is provided with a plurality of guide holes 410 penetrating the guide plate 400. The axial center of the guide hole 410 is located on the vertical line at the center of the electrode 210 and the through-hole electrode 310. The connection pin 100 is accommodated in the guide hole 410 and is interposed between the electrode 210 of the main board 200 and the through-hole electrode 310 of the wiring board 300 in a compressed state, and electrically connects the two.

Hereinafter, the procedure for assembling the probe card described above will be described, and the procedure for connecting the main board 200 and the wiring board 300 using the connection pins 100 will be described. First, a wiring board 300 provided with a plurality of probes and through-hole electrodes 310 and a guide plate 400 provided with a plurality of guide holes 410 are prepared. Thereafter, the wiring board 300 is attached to the guide plate 400 using a support means (not shown) so that the axis of the guide hole 410 is positioned on the vertical line at the center of the through-hole electrode 310. Thereafter, the connection pins 100 are respectively inserted into the guide holes 410 of the guide plate 400. Then, the bottom 112 of the barrel 110 of the connection pin 100 contacts the through-hole electrode 310 of the wiring board 300. Thereafter, the main substrate 200 having a plurality of electrodes 210 formed on the surface is prepared. Thereafter, the guide plate 400 and the wiring board 300 are attached to the main board 200 by fixing means (not shown) so that the axis of the guide hole 410 is located on the vertical line at the center of the electrode 210, and the main board 200 and the wiring board 300 are connected. The distance between them is set as the predetermined distance. At this time, the tip end portion 122b1 of the second end portion 122b of the contact portion 122 of the connection pin 100 is in line contact with the electrode 210 of the main substrate 200, and the tip end portion 122b1 of the second end portion 122b is the electrode of the main substrate 200. 210 is pressed (ie, an external force is applied). As a result, the elastic deformation portion 123 is compressed between the contact portion 122 and the connection portion 121 and elastically deforms in the radial direction, and the contact portion 122 is inclined with the tip end portion 122b1 as a fulcrum, and the first of the contact portion 122 The end 122a contacts the inner peripheral surface of the barrel 110. In this way, the connection pin 100 electrically connects the electrode 210 of the main board 200 and the through-hole electrode 310 of the wiring board 300. At this time, as the shortest electrical path of the connection pin 100 that conducts the electrode 210 of the main substrate 200 and the through-hole electrode 310 of the wiring substrate 300, a location where the second end 122b of the contact portion 122 elastically contacts the electrode 210, A path is formed where the contact portion 122, the first end portion 122a of the contact portion 122 contacts the inner peripheral surface of the barrel 110, and the barrel 110 and the bottom portion 112 of the barrel 110 elastically contact the through-hole electrode 310.

  As described above, since the connection pin 100 includes only the barrel 110 and the coil spring 120, the number of parts can be reduced, and the cost of the connection pin 100 can be reduced. Further, the tip 122b1 eccentric from the axis of the coil spring 120 of the contact portion 122 is in line contact with the electrode 210 (plane) of the main substrate 200, so that the contact portion 122 is inclined with the tip 122b1 as a fulcrum, and the contact 122. Since the first end portion 122a can be reliably brought into contact with the inner peripheral surface of the barrel 110, the connection reliability of the connection pin 100 can be improved. Moreover, since the contact part 122 is closely wound, even if the contact part 122 which is a part of the coil spring 120 is used for the electrical path, an increase in the resistance component of the contact part 122 can be suppressed. Further, since the shortest electrical path does not include the loosely wound elastic deformation portion 123, an increase in inductance due to the coil component of the elastic deformation portion 123 is suppressed when the main substrate 200 and the wiring substrate 300 are connected. can do.

In addition, the connection pin 100 is provided with a tapered surface 111 a whose inner diameter gradually decreases toward the other end of the barrel 110 on the end surface of the open end 111 of the barrel 110. The tapered surface 111a guides the coil spring 120 into the barrel 110 during insertion, so that the coil spring 120 can be easily inserted into the barrel 110. Further, when the tip end portion 122 b 1 of the contact portion 122 of the coil spring 120 is pressed by the electrode 210 of the main substrate 200, the first end portion 122 a of the contact portion 122 contacts the inner peripheral surface of the open end portion 111 of the barrel 110. The tapered surface 111a makes it difficult for the contact portion 122 to be caught on the inner edge of the end surface of the open end 111 of the barrel 110. As a result, the compression operation of the coil spring 120 can be made smooth.

  Further, as the means for fixing the connection part 121 of the coil spring 120 to the barrel 110, the caulking part 113 that caulks the barrel 110 inward and fixes the connection part 121 to the connection part 121 is used. The connecting portion 121 is easily positioned and fixed to the barrel 110 so that the length dimension from the contact portion 122 of the coil spring 120 to the tip end portion of the second end portion 122b becomes a predetermined length, and the operation is simple. . Further, since both ends of the coil spring 120 are densely wound in the connection pin 100, when the coil spring 120 is inserted into the barrel 110 by making both the densely wound coils the same shape, It is possible to insert without worrying about the direction, and the close winding on the bottom 112 side of the barrel 110 can be used as the connection portion 121 and the close winding on the open end 111 side can be used as the contact portion 122. In this case, the workability of the assembly work of the connection pin 100 can be improved, and the automatic assembly of the connection pin 100 can be facilitated.

  Next, connection pins according to Embodiment 2 of the present invention will be described with reference to FIG. The connection pin 100 ′ shown in FIG. 2A has the same configuration as the connection pin 100 of the first embodiment except that the shape of the barrel 110 ′ and the configuration of the connection portion 121 ′ of the coil spring 120 ′ are different. Yes. Therefore, only the difference will be described in detail, and the description of overlapping parts will be omitted. Note that the connection pins are distinguished from the connection pins 100 of the first embodiment by adding '.

  The barrel 110 'is a cylindrical metal tube having conductivity. That is, an open end 112 ′ is provided on the other end side of the barrel 110 ′ instead of the bottom 112. The caulking portion 113 ′ is located on one end side of the open end portion 112 ′. Similar to the open end 111, a tapered surface 111a 'is provided on the inner peripheral surface of the open end 111' of the barrel 110 '.

  The connection part 121 ′ of the coil spring 120 ′ is a tightly wound part longer than the connection part 121 ′, and has a protruding part 121 a ′ that protrudes to the outside from the open end part 112 ′ of the barrel 110 ′. As shown in FIG. 2B, the protruding portion 121 a ′ contacts the through-hole electrode 310 ′ of the wiring board 300 of the probe card instead of the bottom portion 112. The configuration of the probe card is the same as that of the probe card of Example 1 except that the connection pin 100 is a connection pin 100 '.

  Such a connection pin 100 'is assembled as follows. First, a barrel 110 ′ before a coil spring 120 ′ and a crimped portion 113 ′ formed by winding a conductive wire is prepared. Thereafter, the connecting portion 121 ′ of the coil spring 120 ′, the elastic deformation portion 123 ′, and the first end 122 a ′ of the contact portion 122 ′ are inserted into the barrel 110 ′ from the open end 111 ′ or the open end 112 ′. Thereafter, the coil spring 120 ′ is positioned at a predetermined position in the barrel 110 ′, and in this state, a portion on one end side of the open end portion 112 ′ of the barrel 110 ′ is crimped inward to connect the connection portion 121 ′ of the coil spring 120 ′. Is fixed to the barrel 110 '. Note that a convex portion formed by caulking the portion on one end side of the open end portion 112 ′ of the barrel 110 ′ into the caulking portion 113 ′.

  As described above, since the connection pin 100 ′ is composed only of the barrel 110 ′ and the coil spring 120 ′, the number of parts can be reduced and the cost of the connection pin 100 ′ can be reduced. Further, the tip 122b1 ′ decentered from the axis of the coil spring 120 ′ of the contact 122 ′ comes into line contact with the electrode 210 (plane) of the main substrate 200, so that the contact 122 ′ is inclined with the tip 122b1 ′ as a fulcrum. In addition, since the first end portion 122a ′ can be reliably brought into contact with the inner peripheral surface of the barrel 110 ′, the connection reliability of the connection pin 100 ′ can be improved. In addition, since the contact portion 122 ′ is closely wound, even if the contact portion 122 ′ that is a part of the coil spring 120 ′ is used for the electrical path, an increase in the resistance component of the contact portion 122 ′ can be suppressed. . Moreover, since the shortest electrical path does not include the loosely wound elastic deformation portion 123 ′, when the main substrate 200 and the wiring substrate 300 are connected, the inductance rises due to the coil component of the elastic deformation portion 123 ′. Can be suppressed.

Further, the connecting pin 100 ′ is provided with a tapered surface 111 a ′ whose inner diameter gradually decreases toward the other end of the barrel 110 on the end surface of the open end 111 ′ of the barrel 110 ′. Accordingly, when the coil spring 120 ′ is inserted into the barrel 110 ′ from the open end 111 ′, the coil spring 120 ′ is guided into the barrel 110 ′ by the tapered surface 111a ′. 'Easy to insert inside. Further, the tip 122b1 ′ of the contact portion 122 ′ of the coil spring 120 ′ is pressed against the electrode 210 of the main board 200, and the first end 122a ′ of the contact portion 122 ′ is within the open end 111 ′ of the barrel 110 ′. When contacting the peripheral surface, the tapered surface 111a ′ makes it difficult for the contact portion 122 ′ to be caught on the inner edge of the open end 111 ′ of the barrel 110 ′. As a result, the compression operation of the coil spring 120 ′ Can be smooth.

  Further, as the means for fixing the connecting portion 121 ′ of the coil spring 120 ′ to the barrel 110 ′, the crimping portion 113 ′ that crimps the barrel 110 ′ inward and is fixed to the connecting portion 121 ′ is used. Is easily positioned and fixed at a predetermined position of the barrel 110 ', and the operation is simple. In addition, since both ends of the coil spring 120 ′ are tightly wound in the connection pin 100 ′, when the coil spring 120 ′ is inserted into the barrel 110 ′ by making both the tightly wound windings the same shape, Insert the coil spring 120 ′ without worrying about the orientation, and use the close winding on the open end 112 ′ side of the barrel 110 ′ as the connection part 121 and the close winding on the open end 111 ′ side as the contact part 122 ′. Is possible. Further, since both sides of the barrel 110 ′ are open end portions 111 ′ and 112 ′, the coil spring 120 ′ can be inserted from either of the open end portions 111 ′ and 112 ′. In this case, it is possible to improve the workability of the assembly work of the connection pin 100 ′ and to facilitate the automatic assembly of the connection pin 100 ′.

  The probe of the probe card can be arbitrarily changed in design within the scope of the claims. Hereinafter, a detailed description will be given with reference to FIGS. 3 and 4.

The barrel mentioned above should just be a cylinder which has conductivity. For example, the contact pin 1 shown in FIG.
An open end 112 ″ is provided on the other end side of the barrel 110 ″ like a 00 ″ barrel 110 ″, and the open end 112 ″ is brought into contact with the through-hole electrode 310 of the wiring board 300. Is also possible. A tapered surface 111a ″ is provided on the inner peripheral surface of the open end 111 ″ of the barrel 110 ″ in FIG. However, the end surface of the open end portion on one end side of the barrel can be configured such that the above-described tapered surface is not provided.

  In the first and second embodiments, the coil spring is cylindrical. However, the coil spring may have any shape as long as it is a cylinder that can be inserted into the barrel. Moreover, in the said Example 1 and 2, although the contact part of the coil spring was cylindrical, it is not limited to this. For example, as shown in FIG. 4A, the tip of the second end portion 122b "'of the contact portion 122" "can have a conical cylinder shape whose diameter is temporarily reduced in the protruding direction. In this case, since the outer diameter of the distal end portion of the second end portion 122b ′ ″ is reduced, the connection reliability of the distal end portion of the second end portion 122b ′ ″ with respect to the electrode 210 of the main substrate 200 is improved. Can do. In addition, the outer shape of the electrode 210 of the main substrate 200 with which the tip end of the second end portion 122 b ″ ″ contacts can be reduced.

  In addition, although the tip of the second end of the contact portion described above is eccentric from the axis of the coil spring and can be in line contact with the electrode of the substrate, the tip of the second end of the contact portion When an external force is applied to the portion, the elastic deformation portion is elastically deformed, and the design can be arbitrarily changed as long as the first end of the contact portion comes into contact with the inner surface of the barrel. For example, the tip end portion of the second end portion is decentered from the axis of the coil spring and can have a shape capable of point contact with the electrode on the substrate. In this case, the tip portion of the second end portion makes point contact with the electrode of the substrate, the contact portion tilts with the point contact portion as a fulcrum, and the first end portion of the contact portion contacts the inner surface of the barrel.

  Moreover, in the said Example 1 and 2, although the connection part of the coil spring was taken as the cylindrical shape, what kind of shape may be sufficient as long as it can be accommodated and fixed in a barrel. That is, the connecting portion does not need to be closely wound. For example, as shown in FIG. 4B, the protruding portion 121 a ″ of the connecting portion 121 ″ ″ can be formed in a conical cylinder shape whose diameter is temporarily reduced in the protruding direction. In this case, since the outer diameter of the tip of the protrusion 121a ″ ″ is reduced, the connection reliability of the tip of the protrusion 121a ′ ″ with respect to the through-hole electrode 310 of the wiring board 300 can be improved. . In addition, the outer shape of the through-hole electrode 310 of the wiring board 300 with which the tip of the protruding portion 121 a ″ ″ contacts can be reduced. In the first and second embodiments, as a means for fixing the connecting portion to the barrel, a means for caulking a part of the barrel to the inside is used. However, the present invention is not limited to this. For example, the connecting portion can be fixed to the inner peripheral surface of the barrel by soldering or welding.

  Note that the materials, shapes, dimensions, arrangements, and the like that constitute each part of the connection pin described above are examples, and the design can be arbitrarily changed as long as the same function can be realized. In the first and second embodiments, the connection pins are used to connect the wiring board 300 and the main board 200. However, the connection pins are used to connect the electrodes of any two boards. Can do. Although the through-hole electrode 310 is formed on the wiring board 300, other electrodes can be formed instead of the through-hole electrode 310.

  The connection pins described above are adaptable to probes used to measure electrical characteristics of semiconductor devices.

100, 100 ', 100''... Connection pin 110, 110', 110 "... Barrel 111, 111 ', 111" ... Open end (one end of barrel)
111a, 111a ', 111a'', tapered surface 120, 120', 120 '' ... coil spring 121, 121 ', 121''... connection part 121a' ... projecting Part 122, 122 ', 122''... Contact part 122a, 122a', 122a '' First end 122b, 122b ', 122b''Second end
122b1, 122b1 ′, 122b1 ″, tip surface 200,... Main board (second board)
210 ... electrode 300 ... wiring board (first board)
310 ... through-hole electrode

Claims (3)

A cylindrical barrel having conductivity;
A coil spring having conductivity,
The coil spring is housed in and fixed to the barrel;
A closely wound contact portion;
A loosely wound elastically deforming portion provided between the connecting portion and the contact portion and housed in the barrel;
The contact portion has a first end portion accommodated in the barrel with a gap, and a second end portion protruding from one end side of the barrel,
The tip of the second end has a shape that causes a force to tilt the contact when the tip is pressed against a flat surface.
When an external force is applied to the distal end portion of the second end portion, the elastic deformation portion is elastically deformed , the contact portion is inclined , and the first end portion is in contact with the inner surface of the barrel. The connection pin according to claim 1,
A connection pin in which the connection portion is closely wound with the same shape as the contact portion. The connection pin according to claim 1,
A connecting pin provided with a tapered surface whose inner diameter is gradually reduced toward the other end of the barrel on an end face of one end of the barrel .

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