JP2020165803A - Contact probe and inspection socket having the same - Google Patents

Abstract

To provide a contact probe which has a simple shape and can be manufactured at a low cost.SOLUTION: The present invention includes: a barrel 15; an upper plunger 16; a lower plunger 17; and a coil spring 18. The upper plunger 16 is a moving terminal, which moves in a direction of a center axis line L1 to the barrel 15, and the lower plunger 17 is a fixed terminal fixed to the barrel 15. The lower plunger 17 has a contact shaft part extending in the direction of the center axis line L1 and has a large-diameter part with a larger diameter than the contact shaft part. The barrel 15 has a swage part for fixing both sides of the large-diameter part in the direction of the center axis line L1.SELECTED DRAWING: Figure 2

Description

The present invention relates to a contact probe used for inspecting an electronic device such as an IC package and an inspection socket provided with the contact probe.

Electronic devices such as IC packages mounted on electronic devices and the like are generally tested using an inspection socket to remove potential defects before they are mounted on a wiring board. The inspection socket includes a contact probe that electrically connects an electrode portion such as a solder ball or a solder bump of an electronic device and a printed wiring board (board) as a test board or a mounting board (the following patent). References 1 and 2).

Japanese Unexamined Patent Publication No. 2012-207994 Japanese Unexamined Patent Publication No. 2013-19528

The contact probes described in the above patent documents have a hollow barrel having a chevron-shaped pointed portion formed at the tip, a coil spring provided in the barrel, and a coil spring provided at the lower end of the barrel to provide urging force of the coil spring. It has a lower contactor that moves forward and backward while receiving it.

The lower contactor must be locked to the lower end of the barrel and move forward and backward while receiving the urging force of the coil spring, so that the lower contactor has to have a complicated shape. Therefore, there is a problem that it is costly to manufacture the lower contactor.

Since the lower contactor is to be advanced and retracted, it is necessary to lengthen the shaft portion protruding downward by the amount of advancement and retreat, resulting in an elongated shape. As a result, the strength of the tip of the lower contactor is reduced, and there is a risk of damage when connecting to or removing the substrate.

Further, since it is necessary to form the barrel in a hollow shape and then to form a sharp portion at the tip, there is a problem that the processing becomes complicated.

Further, although the solder ball of the electronic device is received by the sharp portion at the tip of the barrel, the strength is low due to the hollow structure, and there is a risk of bending when it comes into contact with the solder ball. If the sharp portion at the tip of the barrel bends, the solder debris may enter the barrel by scratching the solder ball, causing sliding failure when the lower contactor moves forward and backward. Further, by scraping the solder, the solder may be transferred to a sharp portion, and the transferred solder may be damaged to cause a measurement error.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a contact probe having a simple shape and being able to be manufactured at low cost, and an inspection socket provided with the contact probe.

The contact probe according to one aspect of the present invention is arranged so that a barrel having a tubular shape with both ends open and extending in the axial direction and a base end side being accommodated at one end of the barrel, and the tip thereof is an inspection device. An inspection device-side terminal that is in electrical contact, a substrate-side terminal that is arranged so that the base end side is accommodated in the other end of the barrel and the tip of which is in electrical contact with the substrate, and the inspection device side in the barrel. A spring is provided in contact with the base end of the terminal and the base end of the substrate side terminal, and one of the inspection device side terminal or the board side terminal is relative to the barrel. It is an advance / retreat terminal that advances and retreats in the axial direction, the other of the inspection device side terminal or the substrate side terminal is a fixed terminal fixed to the barrel, and the fixed terminal extends in the axial direction. The barrel has a shaft portion and a large-diameter portion having a diameter larger than that of the shaft portion, and the barrel is provided with a caulking portion formed so as to fix both sides of the large-diameter portion in the axial direction. ing.

It was composed of four parts: a barrel, an inspection device side terminal, a board side terminal, and a spring. Then, a large diameter portion is provided on the fixed terminal, and a caulking portion is provided on the barrel so as to fix both sides of the large diameter portion in the axial direction. As a result, a large diameter portion is provided and the terminal can be easily fixed to the barrel. In this way, the terminal can be fixed to the barrel simply by providing a large diameter portion on the terminal, so the difficulty of processing the terminal can be reduced and the manufacturing cost can be reduced. It can be reduced.

Further, in the contact probe according to one aspect of the present invention, the substrate side terminal is the fixed terminal.

Since the terminal on the board side makes electrical contact with the board, there is a risk of being caught in the pattern formed on the board when it is mounted on the board. If the terminals get caught in the pattern on the board, the terminals may break or be damaged. When the board-side terminal is used as an advancing / retreating terminal, the shaft portion becomes long in order to secure the advancing / retreating amount, which may result in an elongated shape and reduced strength. On the other hand, if the board-side terminal is a fixed terminal, it can be shortened by the amount of advance / retreat. As a result, the strength of the board-side terminals can be increased, and the risk of damage to the board-side terminals when mounted on or removed from the board can be reduced.
Moreover, since the terminal on the board side can be shortened by using a fixed terminal, the contact length of the contact probe (distance between the contacts of both terminals) is shorter when the spring length is the same than when the terminal on the board side is used as the advancing / retreating terminal. Therefore, it is advantageous for high frequency measurement.

Further, in the contact probe according to one aspect of the present invention, the shaft portion on the tip end side of the fixed terminal is thicker than the shaft portion on the tip end side of the advancing / retreating terminal.

By making the shaft portion on the tip side of the fixed terminal thicker than the shaft portion on the tip side of the advancing / retreating terminal, the strength of the shaft portion of the tip side terminal can be improved.

Further, in the contact probe according to one aspect of the present invention, the fixed terminal is formed by cold heading.

Since the fixed terminals are formed by cold heading (header processing), they can be manufactured at a lower cost than cutting processing. In particular, the fixed terminal need only have a structure having a large diameter portion and does not require a complicated shape, and is therefore suitable for header processing.

Further, in the contact probe according to one aspect of the present invention, the inspection device side terminal is solid.

Since the terminal on the inspection device side is solid, dust and solder debris on the inspection device side do not enter the inside of the contact probe as compared with the hollow terminal. As a result, it is possible to suppress sliding defects of the terminals that move forward and backward.

Further, in the contact probe according to one aspect of the present invention, a chevron-shaped sharp portion is formed at the tip of the terminal on the inspection device side.

Since a mountain-shaped sharp portion is provided at the tip of the terminal on the inspection device side, good contact with the solder ball of the inspection device can be obtained. Further, since the inspection device side terminal is solid, the strength of the sharp portion can be increased as compared with the hollow inspection device side terminal. As a result, it is possible to prevent the sharp portion from bending and scraping the solder when it comes into contact with the solder ball, and the solder from being transferred to the tip of the terminal on the inspection device side. Therefore, it is possible to suppress the possibility that the solder transferred to the tip of the terminal on the inspection device side is oxidized to cause a measurement error.

Further, the inspection socket according to one aspect of the present invention includes the contact probe according to any one of the above, and an accommodating hole for accommodating the contact probe.

The contact probe is housed in a housing hole formed in the inspection socket. The inspection device is inspected by obtaining continuity between the inspection device and the substrate by the inspection socket.

Since it is a fixed terminal with a simple shape, it can be manufactured at low cost.

It is a vertical sectional view which showed the state which the socket provided with the contact probe which concerns on one Embodiment of this invention is fixed with respect to a substrate. FIG. 3 is a vertical cross-sectional view showing a state in which the socket shown in FIG. 1A is separated from the substrate. It is the front view which showed the right half part which showed the contact probe in the cross section. It is a front view which showed the upper plunger. It is the perspective view which showed the tip of the upper plunger enlarged. It is a front view which showed the lower plunger. It is the schematic front view which showed the cutting method of the lower plunger. It is a front view which showed the coil spring. It is a front view of the contact probe in which the plunger is viewed in a vertical section. It is a schematic front view which showed the roller processing of the end part of a plunger. It is the schematic front view which showed the die processing of the end part of a plunger. It is a schematic front view which showed the state before the point caulking process. It is a schematic front view which showed the state during the point caulking process. It is a schematic plan view which showed the state before the point caulking process. It is a vertical cross-sectional view which showed one of the accommodation holes enlarged. It is a vertical cross-sectional view which showed the state which installed the contact probe in the accommodation hole part of FIG. 11A. It is a vertical cross-sectional view which showed the state which installed the contact probe in the accommodation hole part of FIG. 11A. It is a vertical sectional view which showed the state which the socket shown in FIG. 11C was installed on the substrate. It is a vertical sectional view which showed the state which the IC package was installed with respect to the socket shown in FIG. 11D. It is a front view which showed the comparison between the contact probe of this embodiment and the contact probe which concerns on a reference example. It is a front view which showed the contact probe which concerns on the modification. It is a vertical cross-sectional view which showed the lower part of FIG. 13 enlarged. It is a front view which showed the lower plunger of FIG. It is a front view which showed the contact probe which concerns on another modification.

Hereinafter, an embodiment of an inspection socket including the contact probe of the present invention will be described with reference to the drawings.
FIG. 1A shows an inspection socket 1 (hereinafter, simply referred to as “socket 1”). The socket 1 is arranged on, for example, a printed wiring board as a test board (hereinafter, simply referred to as "board 3"). The socket 1 and the substrate 3 are fixed to each other by the substrate fixing bolt 4a and the substrate fixing nut 4b.

FIG. 1B shows a state in which the socket 1 and the substrate 3 are separated from each other. A washer 4c is inserted between the substrate 3 and the substrate fixing nut 4b. Positioning of the socket 1 and the substrate 3 is performed by inserting the substrate positioning pin 5 provided in the socket 1 into the substrate positioning hole 6 of the substrate 3.

The socket 1 includes an upper socket body 1a and a probe array board 1b that is attached to the socket body 1a from below. The socket body 1a and the probe array substrate 1b are made of insulating members. The socket body 1a and the probe array substrate 1b are positioned by the socket positioning pin 10 and then fixed to each other by the socket fixing bolt 11.

A device accommodating portion 8 for accommodating an IC package (inspection device) 7 is formed on the upper surface of the socket body 1a. The device accommodating portion 8 is a recess formed downward from the upper surface of the socket body 1a.

In the following embodiments, the upper or upper side means the device accommodating portion 8 side, and the lower or lower side means the substrate 3 side.

A plurality of contact probes 12 are provided below the device accommodating portion 8 in a parallel state so as to extend in the vertical direction. The contact probe 12 conducts the substrate 3 and the IC package 7. As shown in FIG. 1A, a plurality of solder balls 7a are provided as electrodes on the lower surface of the IC package 7, and conduction is performed by contacting the upper ends of the contact probes 12 with each solder ball 7a. ..

FIG. 2 shows the contact probe 12. As shown in the figure, the right side of the central axis L1 is shown as a cross section.
The contact probe 12 includes a barrel 15 having a central axis L1 and a substantially cylindrical shape, an upper plunger (inspection device side terminal) 16 arranged at the upper end of the barrel 15, and a lower plunger (inspection device side terminal) 16 arranged at the lower end of the barrel 15. A substrate side terminal) 17 and a coil spring (spring) 18 inserted into the barrel 15 are provided. The contact probe 12 has a four-part configuration consisting of a barrel 15, an upper plunger 16, a lower plunger 17, and a coil spring 18.

The upper plunger 16 is made of metal, and for example, a base material such as beryllium copper, phosphor bronze, or SK material is plated with nickel gold, or an unplated palladium alloy is used.

As shown in FIG. 3A, the upper plunger 16 has a round bar shape having a central axis L1 common to the barrel 15. The upper plunger 16 has a contact shaft portion (shaft portion) 16a located at the upper tip, a first large diameter portion 16b connected to the lower end of the contact shaft portion 16a and having a diameter larger than that of the contact shaft portion 16a, and a first large diameter portion 16b. The second large diameter portion 16c connected to the lower end of the first large diameter portion 16b and having a larger diameter than the first large diameter portion 16b, and the second large diameter portion 16c connected to the lower end of the second large diameter portion 16c and having a smaller diameter than the contact shaft portion 16a. It is provided with a guide shaft portion (base end portion) 16d.
A first tapered portion 16e forming a conical surface is provided between the contact shaft portion 16a and the first large diameter portion 16b, and a conical surface is provided between the first large diameter portion 16b and the second large diameter portion 16c. A second tapered portion 16f is provided to form the above.

A coil spring 18 (see FIG. 2) is inserted into the guide shaft portion 16d, and the upper end of the coil spring 18 is arranged so as to abut on the lower surface of the second large diameter portion 16c.
The upper plunger 16 can be manufactured by carving out a round bar. Therefore, the upper plunger 16 is considered solid.

As shown in FIG. 3B, a plurality of chevron-shaped sharp portions 16a1 having a so-called crown cut are formed at the tip of the contact shaft portion 16a. The solder balls 7a of the IC package 7 come into contact with each other so as to be sandwiched between the slopes of the sharp portions 16a1.

As shown in FIG. 4, the lower plunger 17 has a round bar shape having a central axis L1 common to the barrel 15. The lower plunger 17 is connected to a contact shaft portion (shaft portion) 17a located at the lower tip, a large diameter portion 17b having a diameter larger than that of the contact shaft portion 16a, and a contact shaft portion connected to the lower end of the large diameter portion 17b. It is provided with a guide shaft portion (base end portion) 17d having a diameter smaller than that of 17a.
A first tapered portion 17e forming a conical surface is provided between the contact shaft portion 17a and the large diameter portion 17b, and a second tapered portion 17f forming a conical surface is provided on the guide shaft portion 17d side of the large diameter portion 17b. Is provided.

At the tip of the contact shaft portion 17a, a tip detail 17a1 having a conical shape that gradually reduces the diameter toward the tip (that is, downward) is formed. The tip of the tip 17a1 comes into contact with the substrate 3. The diameter d2 of the contact shaft portion 17a of the lower plunger 17 is made larger than the diameter d1 of the contact shaft portion 16a of the upper plunger 16 (see FIG. 3A).

A coil spring 18 (see FIG. 2) is inserted into the guide shaft portion 17d, and the lower end of the coil spring 18 is arranged so as to abut on the upper surface of the large diameter portion 17b.

FIG. 5 shows a method of manufacturing the lower plunger 17. As shown in the figure, the lower plunger 17 can be manufactured by rotating the round bar B1 around the rotation axis L2 and cutting with the cutting blade N1.

FIG. 6 shows the coil spring 18. The coil spring 18 has a central axis L1 common to the barrel 15. For the coil spring 18, for example, a piano wire or a stainless wire is used. The natural length A1 of the coil spring 18 is set to a length that is compressed when it is housed in the barrel 15 as shown in FIG.

As shown in FIG. 7, the barrel 15 is formed by plastic working a hollow cylinder. The upper end 15a of the barrel 15 is formed so that the end portion is reduced in diameter over the entire circumference. The upper end 15a can be formed by the roll processing shown in FIG. 8 or the mold processing shown in FIG. That is, as shown in FIG. 8, the barrel 15 is fixed to the turntable J1 that rotates around the rotation axis L3, and the roller R1 is pressed against the upper end 15a of the barrel 15 over the entire circumference. Further, as shown in FIG. 9, the upper end 15a of the barrel 15 is inserted into the recess D2 of the mold D1 in the direction of the arrow in the drawing, and processing is performed by applying a predetermined pressing force.

The inner diameter of the tip of the upper end 15a is set to be smaller than the outer diameter of the second large diameter portion 16c of the upper plunger 16. As a result, the upper plunger 16 is prevented from being separated from the upper end 15a of the barrel 15.

The lower end 15b of the barrel 15 is formed so that the end portion is reduced in diameter over the entire circumference. The lower end 15b can be processed by rolling (see FIG. 8) or molding (see FIG. 9) in the same manner as the upper end 15a.

The inner diameter of the tip of the lower end 15b is set to be smaller than the outer diameter of the large diameter portion 17b of the lower plunger 17. As a result, the lower plunger 17 is prevented from being separated from the lower end 15b of the barrel 15.

A point caulking portion 15c is formed at a position separated from the lower end 15b of the barrel 15 by the axial dimension (thickness) of the large diameter portion 17b of the lower plunger 17. As shown in FIG. 10A, the point caulking portion 15c is performed after the lower end 15b of the barrel 15 is diameter-reduced as shown in FIGS. 8 and 9 and the lower plunger 17 is inserted. As shown in FIG. 10B, the point caulking portion 15c is formed by pressing the tip of the caulking rod J2 from the outside of the side surface of the barrel 15. As shown in FIG. 10C, by using the caulking rods J2 at intervals of 90 °, point caulking portions 15c are formed at four symmetrical positions on the outer circumference of the barrel 15. The number of point caulking portions 15c is not limited to four, and may be two or more.
In this way, the point caulking portion 15c is formed so that the inner diameter is partially reduced slightly above the large diameter portion 17b of the lower plunger 17. That is, a caulking portion is formed by the point caulking portion 15c and the reduced diameter lower end 15b, and the large diameter portion 17b is fixed to the barrel 15.

Next, as shown in FIG. 1A, a step of accommodating the contact probe 12 in the socket 1 is shown.
FIG. 11A shows one of the accommodation holes 20 accommodating the contact probe 12 in an enlarged manner. The accommodating hole 20 has a circular cross section, and includes a main body side accommodating hole 21 formed on the socket body 1a side and a substrate side accommodating hole 22 formed on the probe array substrate 1b side. There is. A predetermined distance d is formed between the surfaces of the socket body 1a and the probe array substrate 1b facing each other.

The main body side accommodating hole 21 has a main body hole 21a and a tip hole 21b connected above the main body hole 21a. The lower part of the main body hole 21a is open, and the upper part of the tip hole 21b is open. A conical connection taper portion 21c is provided between the main body hole portion 21a and the tip hole portion 21b.

The inner diameter of the main body hole 21a is slightly larger than the outer diameter of the barrel 15. The inner diameter of the tip hole portion 21b is slightly larger than the outer diameter d1 (see FIG. 3A) of the contact shaft portion 16a of the upper plunger 16 and smaller than the first large diameter portion 16b of the upper plunger 16. ing. As a result, the first tapered portion 16e of the upper plunger 16 engages with the connecting tapered portion 21c and is prevented from coming out from above the main body side accommodating hole portion 21.

The substrate-side accommodating hole 22 has a main body hole 22a and a tip hole 22b connected below the main body hole 22a. The upper part of the main body hole 22a is open, and the lower part of the tip hole 22b is open. A conical connection tapered portion 22c is provided between the main body hole portion 22a and the tip hole portion 22b.

The inner diameter of the main body hole 22a is slightly larger than the outer diameter of the barrel 15, and is preferably the same as the main body hole 21a of the main body side accommodating hole 21. The inner diameter of the tip hole portion 22b is slightly larger than the outer diameter d2 (see FIG. 4) of the contact shaft portion 17a of the lower plunger 17, and is smaller than the large diameter portion 17b of the lower plunger 17. .. As a result, the first tapered portion 17e of the lower plunger 17 engages with the connecting tapered portion 22c and is prevented from coming out from below the substrate side accommodating hole portion 22.

FIG. 11B shows a step of installing the contact probe 12 in the accommodating hole 20 shown in FIG. 11A. FIG. 11B shows a state before fixing the probe array substrate 1b to the socket body 1a. As shown in the figure, when installing the contact probe 12 in the accommodating hole 20, first, the upper plunger 16 side of the contact probe 12 is inserted from below the accommodating hole 21 on the main body side. After that, the probe array substrate 1b is brought closer to the socket body 1a so that the lower plunger 17 is accommodated in the substrate side accommodating hole 22 from below.

Then, as shown in FIG. 11C, the probe array substrate 1b is fixed to the socket body 1a. In this state, the tip of the contact shaft portion 17a of the lower plunger 17 protrudes by a predetermined amount. The protrusion amount p1 can be determined according to the specifications applied at the time of manufacturing the lower plunger 17. In particular, since the lower plunger 17 does not advance or retreat like the upper plunger 16, the protrusion amount p1 can be determined with the minimum necessary dimensions.

Next, as shown in FIG. 11D, the substrate 3 is fixed to the socket 1. When fixing, as shown in FIG. 1A, the substrate fixing bolt 4a and the substrate fixing nut 4b are used to fix the socket body 1a, the probe array substrate 1b, and the substrate 3 so as to be integrated. At this time, the lower plunger 17 is pushed upward by the substrate 3. As a result, the first tapered portion 16e of the upper plunger 16 comes into contact with the lower end of the tip hole portion 21b of the main body side accommodating hole portion 21, the upper plunger 16 is pushed down with respect to the barrel 15, and the coil spring 18 contracts. In this way, the lower plunger 17 is pushed up by the substrate 3 to give a preload, and the lower plunger 17 and the substrate 3 are surely brought into contact with each other. Further, since the lower plunger 17 is fixed to the barrel 15 and is not configured to advance and retreat in the barrel 15, the lower plunger 17 prevents the lower plunger 17 from hitting the substrate 3 when it is attached to or detached from the substrate 3. Therefore, the impact on the substrate 3 can be softened.

Then, as shown in FIG. 11E, when the IC package 7 is inserted into the device accommodating portion 8 of the socket body 1a during inspection (see FIG. 1A), the lower side of the solder ball 7a of the IC package 7 is the contact shaft portion of the upper plunger 16. The contact is made so as to be sandwiched between the sharp portions 16a1 formed at the tip of 16a. At this time, the upper plunger 16 is pushed down to contract the coil spring 18 and apply a pressing force to the solder balls 7a. As a result, the upper plunger 16 and the solder ball 7a are surely brought into contact with each other.

FIG. 12 shows a comparison between the contact probe 12 of this embodiment and a reference example. The contact probe 12 of the present embodiment is shown on the right side, the contact probe 32 according to Reference Example 1 is shown on the left side, and the contact probe 42 according to Reference Example 2 is shown in the center. Each contact probe 12 is compared as the same coil spring 18 length b1.

The contact probe 32 according to Reference Example 1 has a four-part configuration as in the present embodiment, except that the lower plunger 37 moves up and down and the upper plunger 36 is fixed to the barrel 35. .. Since the lower plunger 37 advances and retreats in the contact probe 32 of Reference Example 1 as compared with the contact probe 12 of the present embodiment, the contact probe 32 is longer by the dimension p2 corresponding to the amount of advance and retreat. Further, in the contact probe 32 of Reference Example 1, when fixing the upper plunger 36 to the barrel 35, the upper end of the barrel 35 is abutted against the large diameter portion 36b of the upper plunger 36, and then the barrel 35 is crimped. Since it has a fixed structure, it is lengthened upward by the dimension p2. As described above, the contact probe 32 of Reference Example 1 has a longer contact length (the length from the lower end of the lower barrel to the upper end of the upper barrel) than the contact probe 12 of the present embodiment.

The contact probe 42 according to Reference Example 2 is different in that it has a three-part configuration using a barrel 45 in which a lower plunger is integrated. The contact probe 42 of Reference Example 2 has the same contact length as the contact probe 12 of the present embodiment. However, since the barrel 45 integrated with the lower plunger is used, the cost for manufacturing the barrel 45 increases. That is, when manufacturing the barrel 45 of Reference Example 2, it is necessary not only to boring a round bar to form a barrel shape, but also to cut an outer diameter in order to obtain a lower plunger shape. On the other hand, in the contact probe 12 of the present embodiment, the barrel 15 can be obtained by pressing the pipe, and the lower plunger 17 can be obtained only by cutting the outer diameter of the round bar (FIG. 5). (See), so it does not require a large production cost.

As described above, according to the present embodiment, the following effects are exhibited.
The barrel 15, the upper plunger 16, the lower plunger 17, and the coil spring 18 are composed of four parts. Then, a large diameter portion 17b is provided on the lower plunger 17, and a point caulking portion 15c and a reduced diameter lower end 15b are used to crimp the barrel 15 so as to fix both sides of the large diameter portion 17b in the central axis L1 direction. Was decided to be provided. As a result, the large diameter portion 17b is provided, and the lower plunger 17 can be easily fixed to the barrel 15. In this way, the lower plunger 17 can be fixed to the barrel 15 simply by providing the lower plunger 17 with a large diameter portion 17b, which makes it difficult to process the lower plunger 17. It can be lowered and the manufacturing cost can be reduced.

Since the lower plunger 17 makes electrical contact with the substrate 3, there is a possibility that the lower plunger 17 may get caught in the pattern formed on the substrate 3 when it is mounted on the substrate 3. If the terminal is caught in the pattern of the substrate 3, the tip of the lower plunger 17 may be broken or damaged. When the lower plunger 17 is used as an advancing / retreating terminal (see, for example, the contact probe 32 of Reference Example 1 in FIG. 12), the shaft portion becomes long in order to secure the advancing / retreating amount, which may result in an elongated shape and a decrease in strength. On the other hand, since the lower plunger 17 is a fixed terminal fixed to the barrel 15, it can be shortened by the amount of advance / retreat. As a result, the strength of the contact shaft portion 17a of the lower plunger 17 can be increased, and the risk of damage to the lower plunger 17 when the lower plunger 17 is attached to or removed from the substrate 3 can be reduced.
Further, since the contact shaft portion 17a can be shortened by using the lower plunger 17 as a fixed terminal, when the spring lengths are the same, the lower plunger 37 (see the contact probe 32 of Reference Example 1 in FIG. 12) is used as the advancing / retreating terminal. The contact length of the contact probe 12 is shorter than that of the contact probe 12, which is advantageous for high frequency measurement.

By making the outer diameter d2 (see FIG. 4) of the contact shaft portion 17a of the lower plunger 17 larger than the outer diameter d1 (see FIG. 3A) of the contact shaft portion 16a of the upper plunger 16, the contact shaft portion of the lower plunger 17 The strength of 17a can be improved.

Since the upper plunger 16 is solid, dust and solder debris on the inspection device side do not enter the inside of the contact probe 12 as compared with the hollow upper plunger as in Patent Documents 1 and 2. As a result, it is possible to suppress sliding defects of the upper plunger 16.

Since the mountain-shaped sharp portion 16a1 is provided at the tip of the contact shaft portion 16a of the upper plunger 16, good contact with the solder ball 7a of the IC package 7 can be obtained. Further, since the upper plunger 16 is solid, the strength of the sharp portion 16a1 can be increased as compared with the hollow upper plunger as in Patent Documents 1 and 2. As a result, it is possible to prevent the sharp portion 16a1 from bending and scraping the solder when it comes into contact with the solder ball 7a, and suppressing the transfer of the solder to the tip of the upper plunger 16. Therefore, it is possible to suppress the possibility that the solder transferred to the tip of the upper plunger 16 is oxidized to cause a measurement error.

[Modification example]
This embodiment can be modified as shown in FIGS. 13 to 15. Specifically, the shape of the lower plunger 17'is different from the above-described embodiment. Since other configurations are the same as those in the above-described embodiment, the description thereof will be omitted.

As shown in FIG. 15, the lower plunger 17'has a round bar-shaped contact shaft portion 17a', a large diameter portion 17b' having a larger diameter than the contact shaft portion 17a', and a smaller diameter than the large diameter portion 17b'. It has a round bar-shaped guide shaft portion 17d'. The outer diameters of the contact shaft portion 17a'and the guide shaft portion 17d' may be the same. It is preferable that the tip corners of the contact shaft portion 17a'and the guide shaft portion 17d' and the corner portion of the large diameter portion 17b'have a chamfered shape.

The lower plunger 17'having such a shape can be easily formed from a round bar by cold heading (header processing). As a result, it can be manufactured at a lower cost than cutting. In particular, as the function of the lower plunger 17', it is sufficient to have a structure having a large diameter portion 17b' corresponding to the crimped portion, so that a complicated shape is not required and it is suitable for header processing.

In the above-described embodiment and modification, the lower plungers 17 and 17'are fixed to the barrel 15 and the upper plunger 16 moves forward and backward with respect to the barrel 15. However, the lower plunger 16 is turned upside down. The plungers 17 and 17'may be the upper plunger, and the upper plunger 16 may be the lower plunger. Specifically, as shown in FIG. 16, the upper plunger 16 "is fixed to the barrel 15 and the lower plunger 17" is moved forward and backward with respect to the barrel 15. In the upper plunger 16 ", the large diameter portion 16c" is fixed to the barrel 15 by the reduced diameter upper end 15a and the point caulking portion 15c. Point caulking can be performed using the steps described with reference to FIGS. 10A-10C. According to this, it is not possible to obtain the advantage of fixing the lower plunger to the barrel 15, but it is easy to manufacture the upper plunger 16 "by simplifying the shape of the plunger like the lower plungers 17 and 17'. As a result, the production cost can be reduced.

1 socket (inspection socket)
1a Socket body 1b Probe array board 3 Board 4a Board fixing bolt 4b Board fixing nut 4c Washer 5 Board positioning pin 6 Board positioning hole 7 IC package (inspection device)
7a Solder ball 8 Device housing 10 Socket positioning pin 11 Socket fixing bolt 12 Contact probe 15 Barrel 16, 16 ”Upper plunger (inspection device side terminal)
16a Contact shaft (shaft)
16a1 Sharp part 16b 1st large diameter part 16c 2nd large diameter part 16d Guide shaft part (base end part)
16e 1st taper part 16f 2nd taper part 17, 17', 17 "Lower plunger (board side terminal)
17a, 17a'contact shaft (shaft)
17a1 Detail 17b, 17b'Large diameter part 17d, 17d' Guide shaft part (base end part)
17e 1st taper part 17f 2nd taper part 18 Coil spring (spring)
20 Accommodating hole 21 Main body side accommodating hole 21a Main body hole 21b Tip hole 21c Connection taper 22 Substrate side accommodating hole 22a Main body hole 22b Tip hole 22c Connection taper 32 (reference example 1) Contact probe 42 Contact probe L1 center axis (axis) (of Reference Example 2)

Claims (7)

A barrel that has a tubular shape with both ends open and extends in the axial direction,
An inspection device-side terminal that is arranged so that the base end side is accommodated at one end of the barrel and whose tip is in electrical contact with the inspection device.
A substrate-side terminal that is arranged so that the base end side is accommodated at the other end of the barrel and whose tip is in electrical contact with the substrate.
A spring arranged in the barrel in contact with the base end of the inspection device side terminal and the base end of the substrate side terminal.
With
One of the inspection device side terminal or the substrate side terminal is an advancing / retreating terminal that advances / retreats in the axial direction with respect to the barrel.
The other of the inspection device side terminal or the board side terminal is a fixed terminal fixed to the barrel.
The fixed terminal has a shaft portion extending in the axial direction and a large diameter portion having a diameter larger than that of the shaft portion.
A contact probe provided with a caulking portion formed so as to fix both sides of the large diameter portion in the axial direction on the barrel. The contact probe according to claim 1, wherein the substrate-side terminal is the fixed terminal. The contact probe according to claim 1 or 2, wherein the shaft portion on the tip end side of the fixed terminal is thicker than the shaft portion on the tip end side of the advancing / retreating terminal. The contact probe according to any one of claims 1 to 3, wherein the fixed terminal is formed by cold heading. The contact probe according to any one of claims 1 to 4, wherein the inspection device side terminal is solid. The contact probe according to claim 5, wherein a chevron-shaped sharp portion is formed at the tip of the terminal on the inspection device side. The contact probe according to any one of claims 1 to 6 and
An accommodating hole for accommodating the contact probe and
Inspection socket equipped with.

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