JP2003217774A - Contact pin and ic socket - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a contact pin capable of suppressing the deformation of a spherical terminal and an IC socket provided with this contact pin. <P>SOLUTION: This contact pin 15 has contact parts 15e and 15f brought into contact with and electrically connected to solder ball 12b that is the spherical terminal provided on the lower face of an IC package. The contact faces 15g and 15h to make contact with the solder ball 12b of the contact parts 15e and 15f are formed in a curved shape according to the curvature radius of the solder ball 12b, whereby the contact faces 15g and 15h can make face contact with the solder ball 12b. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact pin which is in contact with a spherical terminal of an IC package and electrically connected thereto, and an IC socket provided with the contact pin.
In particular, the present invention relates to a contact pin and an IC socket that suppress the deformation of the spherical terminal.

[0002]

2. Description of the Related Art Conventionally, there is an IC socket that accommodates an IC package and performs a burn-in test or the like.

The IC package has a so-called BGA.
There is a so-called (Ball Grid Array) type, in which a large number of solder balls as spherical terminals are projected on the lower surface of the package body, and these solder balls are arranged in a matrix in columns and rows. .

On the other hand, in the IC socket, a contact pin that is in contact with a solder ball of the IC package is provided in a socket body that accommodates the IC package, and the contact pin is elastically deformed to solder the IC package. A moving member for moving the moving member in and out of contact with the ball is provided movably, and an operating member for moving the moving member is provided movably in the vertical direction.

The contact pins are provided with a pair of elastic pieces, and by elastically deforming these elastic pieces by a moving member, both contact portions provided on the upper ends of both elastic pieces are opened and closed. The solder balls are sandwiched and separated.

[0006]

However, in such a conventional one, the contact portion of the contact pin and the solder ball are in point contact with each other at one point or multiple points. When the stress is concentrated on the point contact portion and the temperature of the solder ball rises and is softened by a burn-in test or the like, there is a possibility that the solder ball may be deformed by the stress due to the contact of the contact pin.

Therefore, it is an object of the present invention to provide a contact pin for suppressing the deformation of the spherical terminal and an IC socket provided with this contact pin.

[0008]

In order to achieve the above object, the invention according to claim 1 has a contact portion which is in contact with a spherical terminal provided on the lower surface of the IC package to be electrically connected. In the contact pin, of the contact portion,
The contact pin, which is in contact with the spherical terminal, is formed into a curved shape along the curvature of the spherical terminal so that the contact surface comes into surface contact with the spherical terminal. .

According to a second aspect of the present invention, in addition to the structure of the first aspect, the contact portion is a side surface portion of the spherical terminal, and the contact portion is contacted above the center of the spherical shape. To do.

According to a third aspect of the present invention, in addition to the structure of the first aspect, the contact portion is in contact with the lower surface portion of the spherical terminal and is a non-contact with the lowermost portion of the spherical terminal. It is characterized in that a part is formed.

The invention according to claim 4 is the invention according to claims 1 to 3.
The contact pin according to any one of the above is an IC socket arranged in a socket body that accommodates the IC package.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.

[First Embodiment of the Invention] FIGS. 1 to 9 show a first embodiment of the present invention.

First, the configuration will be described. In the figure, reference numeral 11 is I.
This IC socket 11 is a C socket and is used to perform a performance test of the IC package 12.
This is to electrically connect the solder ball 12b as the “spherical terminal” 2 and the printed wiring board (not shown) of the measuring device (tester).

As shown in FIG. 9, this IC package 12 is of a so-called BGA (Ball Grid Array) type, in which a large number of solder balls 12b are projected on the lower surface of a rectangular package body 12a so as to be arranged in rows and columns. And are arranged in a matrix.

On the other hand, as shown in FIG. 2, the IC socket 11 has a socket body 13 made of synthetic resin, which is mounted on a printed wiring board (not shown). A contact pin 15 which is separated from and brought into contact with the solder ball 12b is arranged, and a moving member 17 which displaces the contact pin 15 is arranged.
A top plate 19 is fixed to the socket body 13 and arranged above the moving member 17. The top plate 19 is provided with a guide portion 20 for guiding the IC package 12 and arranging the IC package 12 at a predetermined position when the IC package 12 is accommodated, and an operation member 21 for moving the moving member 17 in the lateral direction. It is arranged so as to be vertically movable with respect to the socket body 13.

The contact pin 15 is made of a plate material having a spring property and excellent in conductivity and formed into a shape as shown in FIG. 2, FIG. 4, FIG. 6 to FIG.

More specifically, the contact pin 15 has, on the upper side, a pair of movable elastic pieces 15a and fixed elastic pieces 15b.
Is formed, and one solder tail portion 15c is formed on the lower side. The pair of elastic pieces 15a, 15b
Although not described in detail, the base portions 15d on the lower end side are formed so as to face each other by being bent in a substantially U shape. Further, the solder balls 1 of the IC package 12 are attached to the upper ends (tips) of the elastic pieces 15a and 15b.
Contact portions 15e and 15f are formed on and away from the side surface portion of 2b, and the solder balls 12b are sandwiched between these contact portions 15e and 15f to be electrically connected.

The contact surfaces 15g and 15h of these contact portions 15e and 15f, which come into contact with the solder balls 12b, are formed in a curved shape along the curvature of the side surfaces of the solder balls 12b. So that the contact surface 15g,
15h is in surface contact with the side surface of the solder ball 12b.

The base portion 15d of the contact pin 15 is press-fitted into the press-fitting hole 13a formed in the socket body 13 as shown in FIG.
The retaining portion (not shown) formed in FIG. 2 cuts into the socket body 13 to prevent the contact pin 15 from coming off upward. And the socket body 1
The solder tail portion 15c that protrudes downward from 3 is shown in FIG.
As shown in FIG. 3, the locator board 26 is projected further downward, inserted into each through hole of a printed wiring board (not shown), and soldered to be connected.

As shown in FIG. 1, such contact pins 15 are arranged in a grid pattern in rows and columns at the same pitch as the solder balls 12b of the IC package 12.

The moving member 17 is slidably arranged in the left-right direction (horizontal direction) in FIGS. 3 to 5, and by sliding the moving member 17, the contact pin arranged in the socket body 13 is slidable. 15 movable elastic pieces 1
5a is elastically deformed and displaced as shown in FIG.

The moving member 17 is adapted to slide through the X-shaped link 22 shown in FIGS. 2 and 3 by moving the operating member 21 up and down. 1, as shown in FIGS. 4 and 5, a pressing portion 17 for pressing and elastically deforming the movable elastic piece 15a.
a is formed.

The X-shaped link 22 is a rectangular moving member 1
7 are arranged corresponding to both side surface portions along the sliding direction.

Specifically, as shown in FIGS. 2 and 3, the X-shaped link 22 has a first link member 2 of the same length.
3 and a second link member 25, which are rotatably connected by a central connecting pin 27.

The lower end 23a of the first link member 23 is rotatably connected to the socket body 13 by the lower end connecting pin 29, while the lower end 25a of the second link member 25 is movable. A lower end connecting pin 30 is rotatably connected to one end of the side surface along the slide direction. In addition, these first and second link members 23, 25
The upper end portions 23b and 25b are rotatably connected to the operation member 21 by upper end connecting pins 33 and 34, respectively. In addition, the upper end portion 23b of the first link member 23 has a long hole 23c.
The first link member 23 is connected to the operating member 21 by the upper end connecting pin 33 via the elongated hole 23c.

As a result, when the operating member 21 is lowered, the X-shaped link 22 is displaced as shown by the chain double-dashed line in FIG. 3, so that the moving member 17 is moved through the X-shaped link 22 in FIG. The movable side elastic piece 15a of the contact pin 15 is pressed and elastically deformed by the pressing portion 17a of the moving member 17, which is slid to the right as shown by the chain double-dashed line, and the contact portion 15e is displaced in the opening direction. .

As shown in FIGS. 1, 2, 4 and 5, the top plate 19 has a mounting surface portion 19a on which the IC package 12 is mounted, and
Also, as shown in FIG. 5, a positioning rib 1 inserted between the pair of contact portions 15e and 15f of each contact pin 15.
9c is formed, and both elastic pieces 15 of the contact pin 15 are formed.
a state in which no external force acts on a and 15b (both contact portions 15
e, 15f closed), the positioning rib 19
c is in a state of being sandwiched by both elastic pieces 15a and 15b.

Further, as shown in FIG. 1, the operating member 21 has a quadrangular frame shape and has an opening 21b having a size into which the IC package 12 can be inserted, and the IC package 12 can be inserted through the opening 21b. It is adapted to be inserted and mounted at a predetermined position on the mounting surface portion 19a of the top plate 19. The operating member 21 is arranged so as to be movable up and down with respect to the socket body 13, is biased upward by a spring (not shown), and has a locking claw (not shown) at the highest position. The operation member 21 is prevented from coming off by being locked to the locked portion of the.

Further, the operating member 21 is formed with an operating portion 21a for rotating the latch 36 shown in FIG.

Although not described in detail, the latch 36 is rotatably attached to the socket body 13 about a shaft 37 and is urged in a closing direction by a spring 38 as shown in FIG. The pressing portion 36 provided on the
It is configured to press the peripheral portion of the package body 12a of the IC package 12 by a.

Further, the operating member 21 is attached to the latch 36.
The pressed portion 36b with which the operating portion 21a of the
When the operation member 21 is lowered, the operating portion 21a presses the pressed portion 36b, whereby the latch 36 is rotated in the opening direction (counterclockwise in FIG. 2), and the holding portion 36a is moved. It is configured to be retracted from the installation position.

Next, a method of using the IC socket 11 will be described.

To set the IC package 12 in the IC socket 11, first, the operating member 21 is pushed down. Then, with this operation member 21, the X-shaped link 2
The upper ends 23b, 25b of the two link members 23, 25 of No. 2 are pressed downward, and the moving member 17 is slid rightward in the figure through the X-shaped link 22 as shown by the chain double-dashed line in FIG. .

By the sliding of the moving member 17, the movable side elastic piece 15 of the contact pin 15 is pressed by the pressing portion 17a.
When a is elastically deformed, both the contact portions 15e and 15f are opened from the state shown in FIG. 4 to the state shown in FIG.

At the same time, the operating portion 21 of the operating member 21.
By a, the pressed portion 36b of the latch 36 is pushed and rotated in the opening direction against the biasing force of the spring 38, and the holding portion 36a is displaced to the retracted position.

In this state, the IC package 12 is released from the automatic machine and guided by the guide portion 20 to the predetermined position, so that the IC package 12 is placed at the predetermined position.

As a result, each solder ball 12b of the IC package 12 is inserted between the pair of opened contact portions 15e, 15f of each contact pin 15 in a non-contact state.

After that, when the downward pressing force of the operating member 21 is released, the operating member 21 is lifted by the urging force of a spring or the like, so that the moving member 17 also moves to the original position side and the latch 36. Is rotated in the closing direction by the urging force of the spring 38.

When the moving member 17 is moved to the original position side, the pressing force applied to the movable side elastic piece 15a of the contact pin 15 by the pressing portion 17a is released, and from the state shown in FIG. , 15f move in a direction of closing (narrowing) each other, and as shown in FIG.
The solder ball 12b is sandwiched between the e and 15f. In this state, the contact surfaces 15g, 15h of the contact pin contact portions 15e, 15f are formed in a curved shape along the curvature of the solder ball 12b, so that the contact surfaces 15g, 1
5h is in surface contact with the solder ball 12b.

When a burn-in test is conducted in this state,
When the temperature in the burn-in bath in which the IC socket 11 is housed rises, for example, rises to about 125 ° C., the solder balls 12b are softened and easily deformed. However, as described above, the contact surfaces 15g and 15h are solder balls 1
Since it is in surface contact with 2b, it is possible to suppress a localized concentrated load from acting on the solder balls 12b, and it is possible to suppress deformation of the solder balls 12b.

On the other hand, in order to remove the IC package 12 from the mounted state, the operating member 21 is similarly lowered to bring the pair of contact portions 15e, 15 of the contact pin 15 into contact with each other.
Since f is separated from the solder ball 12b, the IC package 12 can be easily removed with a weaker force than when the solder ball 12b is pulled out from the state of being sandwiched by the pair of contact portions 15e and 15f.

[Second Embodiment of the Invention] FIGS. 10 and 11
2 shows Embodiment 2 of the present invention.

In the second embodiment, the contact surfaces 15g and 15h of the contact pin contact portions 15e and 15f are the side surfaces of the solder ball 12b, which are above the center O1 of the sphere, that is, above the horizontal line passing through the center O1. The contact surfaces 15g and 15h are formed in a curved shape along the curvature of the solder ball 12b, so that the contact surfaces 15g and 15h are contacted with the solder ball 1
It comes into surface contact with 2b.

In such a case, as shown in FIG. 11, the solder ball 12 is made up of a pair of elastic pieces 15a and 15b.
Since the upper side of the center O1 of b is gripped, the force of pulling the IC package 12 downward acts, so that the force of pressing the IC package 12 by the latch 36 can be reduced.

Since the other structure and operation are the same as those of the first embodiment, the same reference numerals are used and the description thereof is omitted.

[Third Embodiment of the Invention] FIGS. 12 and 13
3 shows Embodiment 3 of the present invention.

In the third embodiment, the contact pin 41 is used.
The contact surface 41b of the contact portion 41a formed at the upper end of the is formed in a spherical shape along the curvature of the solder ball 12b, and is configured to be in surface contact with the lower surface of the solder ball 12b.

The contact portion 41a is provided with a concave escape portion 41c which is not in contact with the lowermost portion 12c of the solder ball 12b.

In such a case, since the contact pin contact portion 41a does not contact the lowermost portion 12c of the solder ball 12b, this portion is not deformed.
The quality of the package 12 can be ensured.

Although the contact pin 15 is provided with the pair of elastic pieces 15a and 15b in the first and second embodiments, the invention is not limited to this, and the elastic piece may be provided only on one side. .

[0052]

As described above, according to the inventions described in the claims, the contact surface of the contact portion of the contact pin, which comes into contact with the spherical terminal, is formed in a curved shape along the curvature of the spherical terminal. As a result, the contact surface is brought into surface contact with the spherical terminal, so even if the spherical terminal is softened and easily deformed by a burn-in test or the like, localized concentrated load acts on the spherical terminal locally. Therefore, it is possible to suppress the deformation of the spherical terminal.

According to the second aspect of the present invention, in addition to the above effects, the contact portion is made to contact the side surface of the spherical terminal above the center of the spherical shape. By acting, the force of pressing the IC package by the latch or the like can be reduced.

According to the invention described in claim 3, in addition to the above effect, the contact portion is formed in contact with the lower surface portion of the spherical terminal to form an escape portion which is not in contact with the lowermost portion of the spherical terminal. As a result, the contact pin contact portion does not contact the bottom dead center portion of the solder ball, and this portion is not deformed, so that the quality of the IC package can be secured.

[Brief description of drawings]

FIG. 1 is a plan view of an IC socket according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG. 1 according to the first embodiment.

FIG. 3 is a schematic view showing an X-shaped link, a moving member and the like according to the first embodiment.

FIG. 4 is an enlarged sectional view of an essential part showing a state in which the contact pin according to the first embodiment is closed.

FIG. 5 is an enlarged sectional view of an essential part showing a state where the contact pin according to the first embodiment is opened.

FIG. 6 is a perspective view showing a contact portion of an elastic piece of the contact pin according to the first embodiment.

FIG. 7 is a cross-sectional view taken along the horizontal direction showing a state before the solder balls of the IC package according to the first embodiment are clamped by the pair of contact portions.

FIG. 8 is a sectional view taken along the vertical direction showing a state in which the solder balls of the IC package according to the first embodiment are sandwiched by a pair of contact portions.

9A and 9B are views showing the IC package according to the first embodiment, where FIG. 9A is a bottom view of the IC package, and FIG.
FIG.

FIG. 10 is a perspective view corresponding to FIG. 6 according to the second embodiment of the present invention.

FIG. 11 is a sectional view corresponding to FIG. 8 according to the second embodiment.

FIG. 12 is a perspective view of a contact pin contact portion side according to Embodiment 3 of the present invention.

FIG. 13 is a cross-sectional view showing a state where a contact pin contact portion is brought into contact with a solder ball of the IC package according to the third embodiment.

[Explanation of symbols]

11 IC socket 12 IC package 12a package body 12b Solder ball (spherical terminal) 12c bottom 13 Socket body 15 contact pins 15a Movable elastic piece 15b Fixed side elastic piece 15e, 15f Contact part 15g, 15h contact surface 41 Contact pin 41a Contact part 41b contact surface 41c escape section O1 solder ball center

Claims (4)

[Claims] 1. A contact pin having a contact portion for electrically connecting to a spherical terminal provided on the lower surface of an IC package, wherein a contact surface of the contact portion that contacts the spherical terminal is the spherical shape. A contact pin, characterized in that the contact pin is formed in a curved shape along the curvature of the terminal so that the contact surface is in surface contact with the spherical terminal. 2. The contact pin according to claim 1, wherein the contact portion is a side surface portion of the spherical terminal and is in contact with the spherical terminal above a center of the spherical shape. 3. The contact pin according to claim 1, wherein the contact portion is in contact with a lower surface portion of the spherical terminal to form an escape portion that is not in contact with the lowermost portion of the spherical terminal. . 4. An IC socket, wherein the contact pin according to any one of claims 1 to 3 is arranged in a socket body that accommodates the IC package.