JP2014127407A - Electric contact and socket for electric component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an accurate test result without damaging an electrode pad of a wiring board in an electric contact configured to electrically come into contact with the wiring board by bringing the tip of a contact portion into contact with a substantially plane-shaped electrode pad, and a socket for an electric component.SOLUTION: An electric contact 14 has a contact part 21 in contact with a substantially plane-shaped electrode pad 1a of a wiring board 1. The contact part has the tip 27 which is formed in a substantially plane shape. The electric contact 14 electrically comes into contact with the wiring board by bringing the tip into face contact with the electrode pad.

Description

  The present invention relates to an electrical contact that is electrically connected to an electrical component such as a semiconductor device (hereinafter referred to as an “IC package”), and an electrical component socket in which the electrical contact is disposed.

  Conventionally, as this type of electrical contact, a probe pin provided in an IC socket as an electrical component socket is known. The IC socket is arranged on the wiring board and accommodates the IC package to be inspected. The terminals of the IC package and the electrodes of the wiring board are connected via the probe pins. It is electrically connected to perform tests such as a continuity test.

  Among such probe pins, those connected to a substantially planar electrode pad as an electrode of a wiring board have a substantially conical shape so that a portion in contact with the electrode pad ensures contact with the electrode pad. Such a tip is formed in a sharp shape, and the tip of the tip is in contact with the electrode pad of the wiring board (see, for example, Patent Document 1).

JP 2012-122905 A

  However, with such a probe pin, the electrode pad of the wiring board may be damaged at the sharply shaped contact portion of the probe pin, and as a result, an inaccurate test result cannot be obtained. It was.

  Therefore, the present invention provides an electrical contact (probe pin) and electrical component socket (IC socket) configured to be in electrical contact with the wiring board by contacting the tip of the contact portion with the substantially planar electrode pad. An object of the present invention is to provide an electrical contact and an electrical component socket that can obtain accurate test results without damaging the electrode pads of the wiring board.

  In order to achieve such an object, the invention described in claim 1 has a contact portion that comes into contact with the substantially planar electrode pad of the wiring board, and the tip of the contact portion is formed in a substantially planar shape. The tip is in surface contact with the electrode pad to provide an electrical contact that makes electrical contact with the wiring board.

  The invention according to claim 2 is the configuration according to claim 1, wherein the contact portion includes a substantially columnar main body portion, a substantially crown-shaped tip portion protruding from the main body portion toward the wiring board, Each tip of the plurality of protrusions of the tip is formed in a substantially planar shape, and each tip is in surface contact with the electrode pad, thereby making electrical contact with the wiring board. It is characterized by.

  According to a third aspect of the invention, in addition to the configuration of the first aspect, the contact portion has a substantially columnar shape, and the entire tip of the contact portion is formed in a substantially flat shape, and the tip is the electrode. By making surface contact with the pad, it is in electrical contact with the wiring board.

  According to a fourth aspect of the present invention, in addition to the configuration according to the first aspect, the contact portion includes a substantially columnar main body portion and a tip portion that protrudes from the main body portion toward the wiring board. The tip of the tip is formed in a substantially flat shape, and the tip is in surface contact with the electrode pad, thereby making electrical contact with the wiring board.

  According to a fifth aspect of the present invention, there is provided a socket main body having a receiving portion that is disposed on a wiring board and in which an electric component is stored, a terminal disposed on the socket main body and provided on the electric component, and the wiring board An electrical component socket having the electrical contact according to any one of claims 1 to 4, which contacts both of the electrode pads provided on the electrical component.

  According to the first aspect of the present invention, the tip of the contact portion of the electric contactor is formed in a substantially flat shape, and the tip is in surface contact with the electrode pad of the wiring board, so that it is electrically connected to the wiring board. Since the contact is made, the contact portion of the electric contact can be brought into contact with the electrode pad of the wiring board without damaging the electrode pad. As a result, an accurate test result can be obtained even after the test is repeated, whereby a highly durable electric contact that can be used for a longer period of time than before can be obtained.

  According to the invention described in claim 2, it has a substantially crown-shaped tip portion protruding from the main body portion toward the wiring board, and each tip of the plurality of protrusions of the tip portion is formed in a substantially planar shape, The contact portion of the electrical contact is connected to the wiring board without damaging the electrode pad with respect to the electrical contact that makes contact with the electrode pad at a plurality of points by making each tip contact the electrode pad of the wiring board It is possible to make an electrical contact with good durability that can obtain accurate test results for a long period of time.

  According to the third aspect of the present invention, the entire tip of the contact portion having a substantially columnar shape is formed in a substantially flat shape, and the tip is in surface contact with the electrode pad of the wiring board, so that the electrode pad 1 For electrical contacts that make contact at a point, the contact part of the electrical contact can be brought into contact with the electrode pad of the wiring board without damaging the electrode pad. A good electrical contact can be obtained.

  According to the fourth aspect of the present invention, the front end portion protrudes from the main body portion toward the wiring board side, the front end portion of the front end portion is formed in a substantially flat shape, and the front end portion is formed on the wiring board. Wiring the contact portion of the electrical contact without damaging the electrode pad with respect to the electrical contact that contacts the electrode pad at a single point in a configuration different from that of claim 3 by making surface contact with the electrode pad It can be brought into contact with the electrode pads of the substrate, and a highly durable electrical contact that can obtain accurate test results for a long period of time can be obtained.

  According to the fifth aspect of the present invention, since the electric contact according to any one of the first to fourth aspects is provided, the contact of the electric contact can be achieved without damaging the electrode pads of the wiring board. Can be brought into contact with the electrode pads of the wiring board, and as a result, accurate test results can be obtained even after repeated tests. It can be.

It is an expanded sectional view near the probe pin in the IC socket according to Embodiment 1 of the present invention. FIG. 2 is an enlarged cross-sectional view illustrating a state in which the IC package of FIG. 1 is disposed on a wiring board and an IC package is accommodated. It is an expanded sectional view near the probe pin in the IC socket according to Embodiment 2 of the present invention. FIG. 4 is an enlarged cross-sectional view illustrating a state where the IC socket of FIG. 3 is arranged on a wiring board and an IC package is accommodated. It is an expanded sectional view of the probe pin vicinity in the IC socket which concerns on Embodiment 3 of this invention. FIG. 6 is an enlarged cross-sectional view showing a state in which the IC package of FIG. 5 is arranged on a wiring board and an IC package is accommodated. It is a perspective view of the front-end | tip part of the 1st plunger of embodiment of this invention and a prior art example, (1) is a figure of Embodiment 1 of this invention, (2) is a figure of Embodiment 2 of this invention, (3) is a diagram of Embodiment 3 of the present invention, and (4) is a diagram of a conventional example. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view and an enlarged side view of a distal end portion of a first plunger of an embodiment of the present invention and a conventional example, (1) is a diagram of Embodiment 1 of the present invention, and (2) is an embodiment of the present invention. FIG. 2 is a diagram of Embodiment 3 of the present invention, and FIG. 4 is a diagram of a conventional example. It is a plane photograph of the tip of the first plunger and a plane photograph of the electrode pad of the wiring board showing the results of the comparative experiment between the embodiment of the present invention and the conventional example, and (1) is a photograph of the first embodiment of the present invention. , (2) are photographs of Embodiment 2 of the present invention, (3) are photographs of Embodiment 3 of the present invention, and (4) are photographs of a conventional example. It is a graph which shows the result of the comparative experiment of embodiment of this invention and a prior art example, (1) is a graph of Embodiment 1 of this invention, (2) is a graph of Embodiment 2 of this invention, (3 ) Is a graph of Embodiment 3 of the present invention, and (4) is a graph of a conventional example.

Embodiments of the present invention will be described below.
Embodiment 1 of the Invention
1, 2, 7 (1), and 8 (1) show Embodiment 1 of the present invention.

  As shown in FIG. 2, the IC socket 10 as the “electrical component socket” of the first embodiment is arranged on the wiring board 1, and the IC package 2 as the “electrical component” is accommodated in the upper part. A substantially planar electrode pad 1a of the wiring board 1 and a solder ball 2a as a “terminal” of the IC package 2 are electrically connected. For example, a burn-in test and a reliability test for the IC package 2 are performed. It is used for a test device for the continuity test.

  In the IC package 2 of the first embodiment, a plurality of spherical solder balls 2a are provided on the lower surface of a substantially rectangular package body 2b.

  As shown in FIGS. 1 and 2, the IC socket 10 is arranged in a matrix in a socket body 13 having an upper plate 11 and a lower plate 12, and the socket body 13 is arranged in the vertical direction. And a plurality of probe pins 14 as “electrical contacts” disposed therethrough. The socket body 13 is positioned on the wiring board 1 by positioning pins (not shown) in a state where the upper plate 11 and the lower plate 12 are fixed by fixing screws (not shown). On the upper plate 11, a floating plate 15 is provided as an “accommodating portion” that accommodates the IC package 2 and can move up and down.

  In the first embodiment, the arrangement pitch of the solder balls 2a of the IC package 2 is the same as the arrangement pitch of the electrode pads 1a of the wiring board 1 electrically connected to the solder balls 2a. These arrangement pitches are the same as these arrangement pitches.

  As shown in FIGS. 1 and 2, each probe pin 14 has an electrode pad 1a of the wiring board 1 at the tip thereof along the longitudinal axis L (in the first embodiment, the central axis of the probe pin 14). A first plunger 20 having a first contact portion 21 as a “contact portion” that is in electrical contact, and a second plunger 30 having a second contact portion 31 in electrical contact with the solder ball 2a of the IC package 2 at the tip. And a cylindrical member 40 that is continuous between the first plunger 20 and the second plunger 30, and the first plunger 20 and the second plunger 30 are placed on the axis L inside the cylindrical member 40. A coil spring 50 is accommodated which is urged in a direction away from each other.

  The first plunger 20 is made of a material such as beryllium copper, and includes a first contact portion 21 that comes into contact with the electrode pad 1 a of the wiring substrate 1 and a first insertion portion 22 that is thicker than the first contact portion 21.

  Among these, the 1st insertion part 22 is formed in the substantially column shape (this Embodiment 1 is substantially cylindrical shape), and is accommodated in the state which contacted slidably in the cylindrical member 40, and is a cylindrical member. The movement of the first plunger 20 in the protruding direction (downward direction) is restricted by the first locking portion 41 formed at the lower end portion of 40. A first receiving portion 23 that locks the coil spring 50 is integrally formed in a conical shape with the axis L as the center at the upper end of the first insertion portion 22.

  Further, as shown in FIGS. 7A and 8A, the first contact portion 21 is formed in a substantially columnar shape (substantially cylindrical shape in the first embodiment) thinner than the first insertion portion 22. As shown in FIG. 1, it has a first body part 24 as a “body part” and a first tip part 25 as a “tip part” protruding from the first body part 24 toward the wiring board 1 side. The lower plate 12 is slidably inserted into the through hole 12a, and a part of the lower plate 12 projects downward.

  This 1st front-end | tip part 25 is formed in the taper shape and the substantially crown shape. 7 (1) and 8 (1), the tips 27 of the plurality of protrusions 26 of the first tip portion 25 formed in the substantially crown shape are formed in a substantially planar shape. As shown in FIG. 2, each tip 27 is in electrical contact with the wiring board 1 by being in surface contact with the substantially planar electrode pad 1 a of the wiring board 1.

  In the first embodiment, four substantially crown-shaped projections 26 of the first tip portion 25 are provided at equal intervals, and the tips 27 of these projections 26 are on the same plane orthogonal to the axis L. It is formed to have an upper plane.

In the first embodiment, the areas of the substantially planar portions of the tips 27 of the four protrusions 26 of the first tip 25 are each 250 μm ² , and the areas of the tips 27 of the first tip 25 are The total area of the substantially planar portions is 1000 μm ² . In addition, it is preferable that the area of the substantially planar portion of each tip 27 of the protrusion 26 of the first tip portion 25 is 175 μm ² or more. The total area of the substantially planar portion of the tip 27 of the first tip 25 is preferably 700 μm ² or more.

  The second plunger 30 includes a second contact portion 31 that contacts the solder ball 2 a of the IC package 2 and a second insertion portion 32 that is thicker than the second contact portion 31.

  Among these, the 2nd insertion part 32 is formed in the substantially column shape (this Embodiment 1 is substantially cylindrical shape), and is accommodated in the state which contacted slidably in the cylindrical member 40, and is a cylindrical member. The movement of the second plunger 30 in the protruding direction (upward direction) is restricted by the second locking portion 42 formed at the upper end portion of 40. A second receiving portion 33 that locks the coil spring 50 is integrally formed in a conical shape with the axis L as the center at the lower end portion of the second insertion portion 32.

  The second contact portion 31 includes a second main body portion 34 formed in a substantially columnar shape (substantially cylindrical shape in the first embodiment) thinner than the second insertion portion 32, and the IC package 2 from the second main body portion 34. And a second tip 35 having a predetermined shape (substantially crown shape in the first embodiment) projecting to the side and projecting upward from the upper plate 11 as shown in FIG. The ball 2a is slidably inserted into the through hole 15a of the floating plate 15 that can accommodate the ball 2a.

  Next, the operation of the IC socket 10 including the probe pin 14 having the first plunger 20 will be described.

  In this IC socket 10, a plurality of probe pins 14 are respectively mounted between the upper plate 11 and the lower plate 12 of the socket main body 13, and as shown in FIG. The first contact portion 21 protrudes below the lower plate 12, and the second contact portion 31 of the second plunger 30 faces the through hole 15 a of the floating plate 15 and is disposed on the wiring substrate 1. The

  That is, as shown in FIGS. 2, 7 (1), and 8 (1), each tip 27 of the plurality of protrusions 26 of the first tip portion 25 of the first contact portion 21 of the first plunger 20 is connected to the wiring board. The IC socket 10 is disposed on the wiring board 1 by positioning so as to be in surface contact with each of the electrode pads 1a. At this time, the coil spring 50 is compressed in the cylindrical member 40 by the first receiving portion 23 of the first insertion portion 22 of the first plunger 20.

  From this state, by accommodating the IC package 2 on the floating plate 15, the solder balls 2a are inserted into the through holes 15a. Thereafter, when the floating plate 15 is lowered by pressing the IC package 2 downward, the second tip portion 35 of the second contact portion 31 of the second plunger 30 contacts the solder ball 2 a of the IC package 2. When the floating plate 15 is further lowered until it comes into contact with the upper plate 11, the coil spring 50 is moved into the second receiving portion 33 of the second insertion portion 32 of the second plunger 30 as shown in FIG. 2. Compressed by

  In the first embodiment, the pressing force for pressing the IC package 2 downward is set to 0.246 N with respect to one probe pin 14 (that is, the first plunger 20). Further, it is preferable that the pressing force for pressing the IC package 2 downward is set to 0.147N or more and 0.294N with respect to one probe pin 14 (that is, the first plunger 20).

  Then, by compressing the coil spring 50 by the first plunger 20 and the second plunger 30 in this way, the first contact portion 21 of the first plunger 20 and the second contact portion 31 of the second plunger 30 are compressed by the coil spring 50. Are urged in a direction away from each other, and a continuity test such as a burn-in test of the IC package 2 is performed with the electrode pads 1a of the wiring board 1 and the solder balls 2a of the IC package 2 being brought into contact with each other with a predetermined contact pressure. To do.

  As described above, the probe pin 14 according to the first embodiment has the substantially crown-shaped first tip portion 25 protruding from the first body portion 24 of the first contact portion 21 of the first plunger 20 toward the wiring board 1 side. The tips 27 of the plurality of projections 26 of the first tip portion 25 are formed in a substantially flat shape, and the tips 27 come into surface contact with the electrode pads 1a of the wiring board 1 so that the electrode pads 1a and Since the contact is made at a plurality of points, the first contact portion 21 of the first plunger 20 of the probe pin 14 can be brought into contact with the electrode pad 1a of the wiring board 1 without damaging the electrode pad 1a. As a result, even after the continuity test is repeated, an accurate test result can be obtained, whereby the probe pin 14 having good durability that can be used for a longer period of time than before can be obtained.

  Also, according to the IC socket 10 of the first embodiment, since the probe pin 14 is provided, the first plunger 20 of the probe pin 14 is not damaged without damaging the electrode pad 1a of the wiring board 1. The first contact portion 21 can be brought into contact with the electrode pad 1a of the wiring board 1. As a result, an accurate test result can be obtained even after repeating the continuity test, and it can be used for a longer period of time than before. A good IC socket 10 can be obtained.

In the first embodiment, the four protrusions 26 are provided at equal intervals. However, the present invention is not limited to this, and can be stably brought into contact with the electrode pad 1a of the wiring board 1. The protrusions 26 may not be provided at equal intervals, and the number thereof is not four, but may be two, three, five or more.
[Embodiment 2 of the Invention]
3, 4, 7 (2), and 8 (2) show a second embodiment of the present invention. The second embodiment of the present invention is the same as the first embodiment except for the items described below, and therefore, the same reference numerals are used for the description other than the items different from the first embodiment. Omitted.

  In the second embodiment, the first plunger 20 of the probe pin 14 in the first embodiment is changed to a first plunger 120 having a different tip shape. Hereinafter, the 1st plunger 120 in this Embodiment 2 is demonstrated.

  As shown in FIGS. 3 and 4, the first plunger 120 of the second embodiment includes a first contact portion 121 as a “contact portion” that contacts the electrode pad 1 a of the wiring substrate 1, and a first contact portion 121. And a thicker first insertion portion 122.

  Among these, the 1st insertion part 122 is formed in the substantially column shape (this Embodiment 2 is substantially cylindrical shape), and is accommodated in the state contacted slidably in the cylindrical member 40, and is a cylindrical member. The movement of the first plunger 120 in the protruding direction (downward) is restricted by the first locking portion 41 formed at the lower end portion of 40. A first receiving portion 123 that locks the coil spring 50 is provided at the upper end of the first insertion portion 122 with a longitudinal axis L (the central axis of the probe pin 14 in the second embodiment). It is integrally formed in a conical shape with a center.

  Further, as shown in FIGS. 7 (2) and 8 (2), the first contact portion 121 has a substantially columnar shape (substantially cylindrical shape in the second embodiment), and the entire tip 127 is substantially the same. It is formed in a planar shape.

  More specifically, the first contact portion 121 has a first main body portion 124 as a “main body portion” formed in a substantially columnar shape (substantially cylindrical shape in the second embodiment) thinner than the first insertion portion 122. The entire front end 127 of the first main body portion 124 on the wiring board 1 side is a first front end portion 125 as a “front end portion” having substantially the same diameter as the first main body portion 124, as shown in FIG. The lower plate 12 is slidably inserted into the through hole 12 a, and a part of the lower plate 12 projects downward.

  The first tip portion 125 has the entire tip 127 formed in a substantially flat shape, and as shown in FIGS. 4, 7 (2), and 8 (2), the entire tip 127 of the first tip 125 is formed. Is brought into electrical contact with the wiring board 1 by being in surface contact with the substantially planar electrode pad 1 a of the wiring board 1. In the second embodiment, the tip 127 of the first tip 125 is formed so that the whole has a plane orthogonal to the axis L.

Further, in the second embodiment, the area of the tip 127 formed in a substantially planar first end 125 has a 20106Myuemu ^2. The area of the substantially planar tip 127 of the first tip 125 is preferably 700 μm ² or more.

  Then, the IC socket 10 having the probe pin 14 having the first plunger 120 has a first contact portion of the first plunger 120 as shown in FIGS. 4, 7 (2), and 8 (2). The entire tip 127 of the first tip portion 121 of 121 is positioned so as to be in surface contact with the electrode pad 1 a of the wiring board 1, and the IC socket 10 is disposed on the wiring board 1. Since the rest is performed in the same manner as in the first embodiment, the description thereof is omitted.

  As described above, the probe pin 14 according to the second embodiment has the entire tip 127 of the first tip 125 on the tip of the first main body 124 of the first contact portion 121 having a substantially columnar shape in the first plunger 120. Since the entire tip 127 of the first tip 125 is in surface contact with the electrode pad 1a of the wiring board 1, it is in contact with the electrode pad 1a at a single point. The first contact portion 121 of the first plunger 120 of the probe pin 14 can be brought into contact with the electrode pad 1a of the wiring board 1 without damaging the electrode pad 1a. As a result, even after the continuity test is repeated, an accurate test result can be obtained, whereby the probe pin 14 having good durability that can be used for a longer period of time than before can be obtained.

Further, according to the IC socket 10 of the second embodiment, since the probe pin 14 is provided, the first plunger 120 of the probe pin 14 is not damaged without damaging the electrode pad 1a of the wiring board 1. The first contact portion 121 can be brought into contact with the electrode pad 1a of the wiring board 1. As a result, an accurate test result can be obtained even after repeating the continuity test, and it can be used for a longer period of time than before. A good IC socket 10 can be obtained.
Embodiment 3 of the Invention
FIGS. 5, 6, 7 (3), and 8 (3) show a third embodiment of the present invention. The third embodiment of the present invention is the same as the first embodiment except for the matters described below, and therefore, the same reference numerals are used for the description other than the matters different from the first embodiment. Omitted.

  In the third embodiment, the first plunger 20 of the probe pin 14 in the first embodiment is changed to a first plunger 220 having a different tip shape. Hereinafter, the 1st plunger 220 in this Embodiment 3 is demonstrated.

  As shown in FIGS. 5 and 6, the first plunger 220 of the third embodiment includes a first contact portion 221 as a “contact portion” that contacts the electrode pad 1 a of the wiring substrate 1, and a first contact portion 221. And a thicker first insertion portion 222.

  Among these, the 1st insertion part 222 is formed in the substantially column shape (this Embodiment 3 is substantially cylindrical shape), and is accommodated in the state which contacted slidably in the cylindrical member 40, and is a cylindrical member. The movement of the first plunger 220 in the protruding direction (downward) is restricted by the first locking portion 41 formed at the lower end portion of 40. A first receiving portion 223 that locks the coil spring 50 is provided at the upper end portion of the first insertion portion 222 with a longitudinal axis L (the central axis of the probe pin 14 in the third embodiment). It is integrally formed in a conical shape with a center.

  Further, as shown in FIGS. 7 (3) and 8 (3), the first contact portion 221 is formed in a substantially columnar shape (substantially cylindrical shape in the third embodiment) thinner than the first insertion portion 222. 5 includes a first main body 224 as a “main body” and a first front end 225 as a “tip” that protrudes from the first main body 224 toward the wiring board 1. As shown, the lower plate 12 is slidably inserted into the through hole 12 a, and a part of the lower plate 12 protrudes below the lower plate 12.

  The first tip portion 225 is formed in a taper shape and one shape on the central axis L in the longitudinal direction of the probe pin 14 protrudes. And the front-end | tip 227 of the said 1st front-end | tip part 225 is formed in substantially planar shape, and the said front-end | tip 227 is substantially planar of the wiring board 1, as shown in FIG.6, FIG.7 (3) and FIG.8 (3). By making surface contact with the electrode pad 1a having a shape, it is in electrical contact with the wiring substrate 1. In the third embodiment, the tip 227 of the first tip 225 is formed to have a plane orthogonal to the axis L.

In the third embodiment, the area of the substantially planar portion of the tip 227 of the first tip 225 is 2827 μm ² . The area of the substantially planar portion of the tip 227 of the first tip 225 is preferably 700 μm ² or more.

  Then, the IC socket 10 having the probe pin 14 having the first plunger 220 has a first contact portion of the first plunger 220 as shown in FIGS. 6, 7 (3), and 8 (3). The IC socket 10 is placed on the wiring board 1 by positioning so that one tip 227 of the first tip 225 of the 221 is in surface contact with the electrode pad 1 a of the wiring board 1. Since the rest is performed in the same manner as in the first embodiment, the description thereof is omitted.

  As described above, the probe pin 14 according to the third embodiment has the first tip portion 225 that protrudes from the first body portion 224 of the first contact portion 221 of the first plunger 220 toward the wiring board 1. The tip 227 of the first tip 225 is formed in a substantially flat shape, and the tip 227 comes into surface contact with the electrode pad 1a of the wiring board 1 so that it comes into contact with the electrode pad 1a at one point. Therefore, the first contact portion 221 of the first plunger 220 of the probe pin 14 can be brought into contact with the electrode pad 1a of the wiring board 1 without damaging the electrode pad 1a. As a result, even after the continuity test is repeated, an accurate test result can be obtained, whereby the probe pin 14 having good durability that can be used for a longer period of time than before can be obtained.

  Further, according to the IC socket 10 of the third embodiment, since the probe pin 14 is provided, the first plunger 220 of the probe pin 14 is not damaged without damaging the electrode pad 1a of the wiring board 1. The first contact portion 221 can be brought into contact with the electrode pad 1a of the wiring board 1. As a result, an accurate test result can be obtained even after repeating the continuity test, and it can be used for a longer period of time than before. A good IC socket 10 can be obtained.

  Next, an evaluation test that supports the effect of the present invention will be described with reference to FIGS.

  Here, first, as an example of the first contact portion 21 of Embodiment 1 of the present invention, the probe pin 14 provided with the first plunger 20 having the contact portion of the size and shape shown in FIG. An IC socket 10 was prepared. Further, as an example of the first contact portion 121 according to the second embodiment of the present invention, the IC socket 10 to which the probe pin 14 provided with the first plunger 120 having the contact portion having the size and shape shown in FIG. Prepared. Further, as an example of the first contact portion 221 according to the third embodiment of the present invention, the IC socket 10 to which the probe pin 14 provided with the first plunger 220 having the contact portion of the size and shape shown in FIG. Prepared.

  Further, as a conventional IC socket to be compared with these, an IC socket 10 equipped with a probe pin 14 provided with a first plunger 520 as shown in FIG. 7 (4) was used. The first plunger 520 includes a first contact portion 521 that contacts the electrode pad 1a of the wiring board 1 and a first insertion portion 522 that is thicker than the first contact portion 521. The first contact portion 521 is substantially columnar ( Here, the first main body portion 524 formed in a substantially cylindrical shape), one central portion protrudes from the first main body portion 524 to the wiring board 1 side, and the tip 527 is not formed in a substantially flat shape. The first tip portion 525 has a round shape. Other configurations are the same as those in the first to third embodiments of the present invention. As an example of the conventional first contact portion 521, an IC socket 10 equipped with a probe pin 14 provided with a first plunger 520 having a first contact portion 521 having the size and shape shown in FIG. 8 (4) is prepared. did.

  The same test was repeated a total of 1 million times for each of these four IC sockets 10, and the intermediate results and final results were recorded.

(1) Test Contents <1> First, the above-described four IC sockets 10 are arranged on the wiring board 1 by positioning the first contact portions 21, 121, 221, and 521 and the electrode pads 1a.
<2> Then, the IC package 2 is accommodated in the IC socket 10 and pressed with a predetermined force.
<3> In this state, the contact resistance (mΩ) between the first plunger 20, 120, 220, 520 of each IC socket 10 and the electrode pad 1a of the wiring board 1 is measured.
<4> Thereafter, the pressing force is released and the IC package 2 is once taken out.
<5> Repeat <2> to <4> among the above one million times.
<6> Then, the IC socket 10 is removed from the wiring board 1 and the state of the electrode pad 1a is visually confirmed.

(2) Specifications The first plungers 20, 120, 220, and 520 of the probe pins 14 used in this test and the electrode pads 1a of the wiring board 1 have the following specifications.
Specification material of the plunger of the probe pin in Embodiment 1 of the present invention Material: Area of each tip of beryllium copper substantially flat: 250 μm ²
Total area of the substantially planar tip: 1000 μm ²
Specification material of the plunger of the probe pin in Embodiment 2 of the present invention Material: Area of beryllium copper substantially planar tip: 20106 μm ²
Specification material of the plunger of the probe pin in the third embodiment of the present invention Material: Area of beryllium copper substantially planar tip: 2827 μm ²
・ Specification material of plunger of probe pin in conventional example: Area of tip of substantially flat beryllium copper: No substantially planar portion ・ Specification material of electrode pad of wiring board: Copper (3) Test method ・ First plunger of IC socket Measuring method of contact resistance (mΩ) between electrode pad and wiring board electrode pad: measured with prober and resistance meter.
-Visualizing method of electrode pads on wiring board: Laser microscope (example) With Keyence laser microscope VK-9500, it was visually confirmed whether or not there was a concave portion, and when there was a concave portion, its diameter and depth were measured.
Test condition for one time Force to press one probe pin (one first plunger): 0.246N
Pressing time: 0.5 seconds Ambient temperature: 25 ° C
(4) Results After performing the above test, the electrode pads 1a of the wiring board 1 in which the first contact portions 21, 121, 221, and 521 of the first plungers 20, 120, 220, and 520 of the probe pins 14 were in contact with each other. The state of was visually confirmed. As a result, the electrode pad 1a in contact with the first contact portion 21 of the first embodiment of the present invention and the electrode pad 1a in contact with the first contact portion 121 of the second embodiment of the present invention are shown in FIG. 9 As shown in (1) and (2), no change was observed. However, the electrode pad 1a in contact with the first contact portion 221 of Embodiment 3 of the present invention and the electrode pad 1a in contact with the first contact portion 521 of the conventional example are shown in FIGS. As indicated by the dotted circle in 4), a recess with a diameter of about 0.016 mm and a depth of about 0.3 to 0.8 μm due to the tips of the first contact portions 221 and 521 remained.

  Moreover, when the graph of FIG. 10 which showed transition of the contact resistance (m (ohm)) between the 1st plunger 20,120,220,520 of each probe pin 14 and the electrode pad 1a of the wiring board 1 is seen, this invention is shown. The contact resistance between the first plunger 20 and the electrode pad 1a in the first embodiment and the contact resistance between the first plunger 120 and the electrode pad 1a in the second embodiment of the present invention are shown in FIGS. ), Even when the number of tests reached 1,000,000, it was 300 mΩ or less, and the numerical value sufficiently withstanding practical use was maintained. Further, as shown in FIG. 10 (3), the contact resistance between the first plunger 220 and the electrode pad 1a of Embodiment 3 of the present invention exceeds 300 mΩ when the number of tests reaches 1 million times, Although it was a numerical value that could not be practically used, the numerical value that can withstand practical use of 300 mΩ or less was maintained up to about 400,000 tests. On the other hand, the contact resistance between the first plunger 520 of the conventional example and the electrode pad 1a has already exceeded 300 mΩ after about 150,000 tests as shown in FIG. There was no figure.

  For these reasons, the probe pin 14 provided with the first plungers 20, 120, 220 having the first contact portions 21, 121, 221 of the first to third embodiments of the present invention and the IC socket on which the probe pin 14 is mounted. No. 10 was able to obtain accurate test results up to about 400,000 tests, and was able to withstand practical use up to 400,000 tests.

  In particular, for the probe pin 14 including the first plungers 20 and 120 having the first contact portions 21 and 121 of Embodiments 1 and 2 of the present invention and the IC socket 10 to which the probe pin 14 is mounted, the number of tests is 100. Even if it reaches 10,000 times, accurate test results can be obtained, and even if the number of tests reaches 1,000,000 times, the electrode pad 1a of the wiring board 1 is not damaged. The result of being able to endure was obtained.

  On the other hand, the probe pin 14 having the first plunger 520 having the first contact portion 521 of the conventional example and the IC socket 10 to which the probe pin 14 is attached obtain an accurate test result after about 150,000 tests. As a result, the electrode pad 1a of the wiring board 1 was obviously damaged at the time when the number of tests was 1 million times, and the result that the test could not be put to practical use after about 150,000 times was obtained. It was.

  Therefore, the probe pin 14 in which the tip of the contact portion with the electrode pad 1a of the wiring board 1 as in the first to third embodiments of the present invention is formed in a substantially flat shape and the IC socket 10 to which the probe pin 14 is attached are as follows. The electrode pad 1a is not damaged by the probe pin 14 and the IC socket 10 to which the probe pin 14 is mounted, in which the tip of the contact portion with the electrode pad 1a of the wiring board 1 is not formed in a substantially flat shape as in the prior art. In addition, it was concluded that accurate test results could be obtained for a long period of time and durability was good.

Further, as in the first to third embodiments of the present invention, the contact portion of the wiring board 1 with the electrode pad 1a is made of a material of beryllium copper, and the substantially planar portion formed at the tip of the contact portion. When pressing one probe pin 14 with a force of 0.147 N or more and 0.294 N or less against the probe pin 14 having an area of 700 μm ² or more and the IC socket 10 to which the probe pin 14 is mounted. In particular, the durability can be improved while ensuring the contact pressure of the probe pin 14 to the electrode pad 1a.

  The “electric contactor” of the present invention is not limited to the probe pin having the structure as in the first to third embodiments, but can be applied to other structures. In the first to third embodiments, the “electrical socket” of the present invention is applied to an IC socket. However, the present invention is not limited to this and can be applied to other sockets.

1 Wiring board
1a Electrode pad
2 IC package (electrical parts)
2a Solder ball (terminal)
10 IC socket (socket for electrical parts)
13 Socket body
14 Probe pin (electric contact)
20,120,220 1st plunger
21,121,221 First contact part (contact part)
24,124,224 1st body part (body part)
25,125,225 First tip (tip)
26 Protrusions
27,127,227 tip
30 Second plunger
31 Second contact area
40 Tubular member
50 coil spring

Claims (5)

Having a contact portion that contacts the substantially planar electrode pad of the wiring board;
The tip of the contact portion is formed in a substantially flat shape,
An electrical contact, wherein the tip is in surface contact with the electrode pad to make electrical contact with the wiring board. The contact portion has a substantially columnar main body portion, and a substantially crown-shaped tip portion protruding from the main body portion toward the wiring board,
Each tip of the plurality of protrusions of the tip is formed in a substantially planar shape,
The electrical contact according to claim 1, wherein each of the tips is in electrical contact with the wiring board by being in surface contact with the electrode pad. The contact portion has a substantially columnar shape,
The entire tip of the contact portion is formed in a substantially planar shape,
The electrical contact according to claim 1, wherein the tip is in surface contact with the electrode pad to make electrical contact with the wiring board. The contact portion has a substantially columnar main body portion, and a tip portion that protrudes from the main body portion to the wiring board side, and
The tip of the tip is formed in a substantially flat shape,
The electrical contact according to claim 1, wherein the tip is in surface contact with the electrode pad to make electrical contact with the wiring board. A socket body that is disposed on the wiring board and has a housing portion that houses electrical components;
The electrical contact according to any one of claims 1 to 4, wherein the electrical contact is disposed on the socket body and contacts both a terminal provided on the electrical component and an electrode pad provided on the wiring board.
A socket for electrical parts, comprising: