JPH09167667A - Contact pin for ic socket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate stress concentration, eliminate the development of buckling deformation and breaking, increase a wiping quantity in contact part, obtain reliable contact pressure with a solder ball, and reduce an inductance of a socket. SOLUTION: In a conductive contact pin where elastic parts are arranged by two or more pieces, the operational direction of an additional elastic part 3 is contained in a surface moved in parallel in the vertical direction to a surface containing the operational direction of a single elastic part 2. When the contact pins are adjacently installed by two or more pieces in an IC socket, the whole constituted elastic parts are constituted so as not to interfere with operation of the adjacent elastic parts by being elastically displaced in the same direction to the respectively adjacent elastic parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact pin for an IC package, which can obtain a reliable electrical connection with a solder ball in a BGA or LGA type IC package.

[0002]

2. Description of the Related Art A contact pin is a part for contacting with a lead or bump extending from an IC package body by being aligned and mounted in an IC socket to maintain an appropriate contact pressure and to conduct electricity to various devices. BGA (Ball Grid Array)
As shown in FIGS. 17A and 17B, is an IC package in which solder balls 19 are arranged in a grid on a package body 18 formed by molding a glass epoxy substrate. As the package body 18, packages made of various materials and shapes such as a type in which an IC chip is sealed with a metal cap on a ceramic substrate have been developed. Further, there is also a package such as an LGA (Land Grid Array) which is composed only of the package body 18 before mounting the solder balls 19 and the pads of the substrate. This BGA package is a QFP (Quad Flat).
It is said that it is becoming an advantage as a market trend of IC packages because it has a better product yield without lead deformation than that of Package) and is easy to develop MCM (Multi Chip Module). ing.
Although it is necessary to supply BGA package sockets as a medium for evaluating the performance of BGA package products and screening for initial defects, there are still many problems with the characteristics of BGA sockets, and improvements are desired. .

The BGA contact pin is basically a component having the same purpose as described above, but since the solder balls arranged in a grid and the contact pins are brought into contact with each other, the contact pins have a structure suitable for the application. ing. The structure of a conventional general BGA contact pin is shown in FIG. The contact pin 13 is punched out from a conductive material having a certain plate thickness into the shape shown in the drawing, and the contact portion 11 comes into contact with the solder ball.
And an arcuate elastic portion 12 and a contact pin foot portion 14. The solder balls 19 of the BGA package are
Since the contact pins 13 are arranged in a grid pattern, the contact pins 13 follow and are aligned and mounted in a grid pattern in the sockets 16 formed of an insulating material. For this reason, the contact pins 13 are also in a dense state, and in order to maintain the insulation state between the adjacent contact pins, the elastic portions 1 are separated by a certain distance.
2 must be formed. In this case, the elastic portions 12 of all the configured pins have the elastic portions 12 adjacent to each other.
With respect to the same, the elastic displacement is performed in the same direction so that there is no relative interference with the operation of the adjacent elastic portion. For this reason, it is possible to extend the arc spring shape in the lateral direction for the time being, but since there is blurring in the rotation direction when the contact pin 13 is viewed from the top surface, the arc spring is extended in the lateral direction and adjacent to each other. There is a limit in maintaining the insulation state of the contact pin 13, and the elastic portion 12 is extended in the height direction as a means for ensuring displacement of the elastic portion.

On the other hand, the BGA package has variations in solder ball height (reference numeral H in FIG. 18) due to deformation during formation of solder balls and warpage of the package. In order to obtain good electrical contact with all solder balls, the elastic stroke in the height direction of the contact pin is configured to be large,
A slightly larger load is applied so that the proper contact pressure is applied to the solder ball with the smallest height.

[0005]

The above-mentioned conventional BGA
The shape of the contact pin has various drawbacks.
As shown in FIG. 18, the wiping amount, which is the amount by which the contact pin 13 is displaced in the arrow direction or another direction and slides on the surface of the solder ball 19, is small. As a result, the self-cleaning effect of scraping off the oxide film formed on the contact portion 11 with the solder ball 19 is reduced, or the oxide film is formed on the solder ball 19 itself, which may cause deterioration of the electrical characteristics. There is a drawback. Further, in order to reduce the inductance of the body socket, the loop length from the contact position 11 of the contact pin 13 with the solder ball 19 to the mounting position of the contact pin foot portion 14 must be shortened. The dimension of the elastic portion 12 is elongated to obtain an appropriate spring elasticity. For this reason, the self-inductance of the contact pin 13 becomes large, and there is a drawback that the electrical performance of the socket is degraded. Further, since the contact pin 13 is small and thin, when it is repeatedly used, there is a drawback that stress is concentrated and buckling deformation or bending occurs. Further, as a measure against the variation of the height of the solder ball, the contact pin 13 is configured to have a large elastic stroke amount in the height direction and a large load is applied, but the solder ball is deformed in the height direction by the load of the socket pressing. Has the drawback of becoming large.

The present invention has been made in order to eliminate the above-mentioned drawbacks. It does not cause buckling deformation or bending, has a large wiping amount, can reduce the inductance of the socket, and can deform the solder ball. It is an object of the present invention to provide a contact pin for an IC socket, which can surely make a contact pressure with a solder ball and can be stably electrically connected.

[0007]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventor has found that the above object can be achieved by providing two or more elastic portions. The invention has been completed.

That is, the present invention is a conductive contact pin provided with two or more elastic portions, which is a surface parallel to the surface including the operation direction of one formed elastic portion in the vertical direction. Is a contact pin for an IC socket, wherein when two or more contact pins are mounted adjacent to the IC socket, all the configured elastic parts are 2. The IC socket contact pin according to claim 1, wherein the contact pins are elastically displaced in the same direction with respect to the adjacent elastic portions so as not to relatively interfere with the operation of the adjacent elastic portions.

[0009]

In the IC socket contact pin according to the present invention, the load applied to the contact pin is shared by the two or more elastic portions, so that stress concentration, buckling deformation, and bending are less likely to occur. Moreover, since the loop lengths of the contact pins can be configured in parallel, it is expected that the socket has low inductance. The two or more elastic portions are displaced in opposite directions at the contact portion with the solder ball, and the contact portion slides in the twisting direction with respect to the center of the solder ball, and a large wiping effect can be expected. Furthermore, since the spring operation direction also operates in the vertical direction, the displacement amount can be increased with a small load due to the complex and flexible operation of the spring. Further, since the solder balls can be sandwiched from the lateral direction, the contact pressure of the solder balls can be obtained not only by the load in the height direction but also by the lateral load. From these, the deformation of the solder ball is reduced, and even if the dimension of the solder ball varies in the height direction, a reliable contact pressure with the solder ball can be obtained.

[0010]

Embodiments of the present invention will be described with reference to the drawings.

1 and 2 show the shape and configuration of a contact pin according to a first embodiment of the present invention. More specifically, FIG. 1 (a) is an exploded perspective view of the contact pin before bending, and FIG. A perspective view is shown in FIG. 1 (b), and a plan view after the bending process as seen from the direction A in FIG. 1 (b) is shown in FIG.

In FIG. 1 (a), a contact portion 1 for contacting a solder ball of a contact pin and elastic portions 2, 3 in both directions are provided in the center of a conductive material having a constant plate thickness, and a contact is provided on the extension thereof. The pin foot portion 4 is provided, and the one foot portion 4 is provided with the press-fitting margin portion 5 for the socket substrate, and punching is performed. Next, the elastic portions 2 and 3 are three-dimensionally crossed to each other, as shown in FIG.
As shown in (b), the foot portion 4 is bent into an arc shape to complete the shape. At this time, the leg portions 4 respectively bent from the elastic portions 2 and 3 are in contact with each other, and the arc-shaped elastic portions 2 and 3 are formed symmetrically with respect to the center line as shown in FIG. Has been done.

3 and 4 show the shape and configuration of the contact pin according to the second embodiment of the present invention. More specifically, FIG. 3 (a) is an exploded perspective view of the contact pin before bending, and FIG. A perspective view is shown in FIG. 3 (b), and a plan view seen from the direction A in FIG. 3 (b) after bending is shown in FIG.

In FIG. 3 (a), a contact material 1 for contacting a solder ball of a contact pin and arcuate elastic parts 2, 3 in both directions are provided in the center of a conductive material having a constant plate thickness, and the extension thereof is further provided. The contact pin foot portion 4 is provided on the top and punching is performed. Next, the arc-shaped elastic portions 2 and 3 are processed so as to be bilaterally symmetrical as shown in FIG. 3B, and the foot portion 4 is bent to complete the shape. In this case, similarly to FIG. 1, the leg portions 4 respectively bent from the arc-shaped elastic portions 2 and 3 are in contact with each other, and the arc-shaped elastic portions 2 and 3 are connected to each other.
As shown in, it is formed symmetrically with respect to the center line.
The difference between FIG. 1 and FIG. 3 is that the shape of the arc-shaped elastic portions 2 and 3 in FIG. 3 can be freely designed by changing the connection portion between the contact portion 1 with the solder ball and the elastic portions 2 and 3. It is in the point that I made it. This bending method has an advantage that the width of the elastic portions 2 and 3 where stress is likely to be concentrated is increased to prevent buckling deformation or breakage of the contact pin.

FIG. 5 shows a sketch of the contact pin of the first embodiment mounted on the socket substrate. The press-fitting margin portions 5 formed at both ends of the foot portion 4 of the contact pin,
The socket substrate 6 is press-fitted into the square holes 7 arranged and arranged in a grid pattern to be mounted. When the BGA package is mounted, the square hole 7 is located at the center of the solder ball and the contact portion 1 of the contact pin.
The centers of are aligned so that they match.

Next, the operation of the contact pin will be described with reference to FIG. 6, in which the package body of the BGA package is omitted and only the solder balls 9 are shown.
For the C socket, the socket substrate is omitted. The BGA package is mounted on the socket, and the solder balls 9 come into contact with the contact portions 1 of the contact pins. By the pressing mechanism of the socket, the BGA package is pressed downward, and the contact portion 1 between the solder ball 9 and the contact pin also descends (large arrow). Then, the arc-shaped elastic portions 2 and 3 are displaced. The elastic portion 2 is displaced in the dotted arrow direction A, and the elastic portion 3 is displaced in the solid arrow direction B. In this case, all the configured elastic portions are not elastically displaced in the same direction with respect to the adjacent elastic portions, and do not relatively interfere with the operation of the adjacent elastic portions. Further, the contact portion 1 of the contact pin follows the displacement of the elastic portions 2 and 3 and is displaced in the twisting direction, so that the wiping effect is exerted on the solder ball 9.
When the socket is pressed at the desired height of contact pressure, BGA
The package is held.

Another embodiment of the shape and configuration of the contact pin according to the present invention will be described below.

In the third embodiment shown in FIGS. 7A and 7B, the arc-shaped spring is formed as it is without intersecting the elastic portions 2 and 3 of the contact pin in FIG. Therefore, there is an advantage that the height of the contact pin can be reduced.

The fourth embodiment shown in FIG. 8 is one in which the elastic portions 2 and 3 of the contact pin in FIG. Elastic part 2 of the contact pin when there is a margin in the direction,
3 can be secured largely.

The fifth embodiment shown in FIG. 9 is one in which the elastic portions 2, 3 of the contact pin shown in FIG. The elastic portions 2 and 3 of the contact pin can be secured large when there is a margin in the vertical direction.

FIG. 10 shows a sixth embodiment. FIG.
(A) As shown in the developed view, the conductive material is punched out to form the contact portion 1, the elastic portions 2, 3, and the foot portion 4. As shown in the front view of FIG. 10 (b), the plan view of FIG. 10 (c) and the side view of FIG. 10 (d), the elastic portions 2 and 3 are formed by alternately bending the contact portions 1 into an arc shape. . The contact portion 1 is the elastic portion 2,
There is a feature that the wiping operation is performed in cooperation with the item 3.

FIG. 11 shows a seventh embodiment. FIG.
(A) As shown in the developed view, the conductive material is punched out to form the contact portion 1, the elastic portions 2, 3, and the foot portion 4. FIG.
As shown in (b) front view, (c) plan view, and (d) side view of the same figure, the contact parts 1, elastic parts 2, 3 are twisted one or more times and the coil springs are laid sideways. It is formed by bending into a shape. The elastic portions 2 and 3 can be formed by extending in the vertical direction from the state of FIG. 11A, and the contact portion 1 cooperates with the elastic portions 2 and 3 to perform a wiping operation.

FIG. 12 shows a seventh embodiment. FIG.
As shown in the development view of (a), punching out the conductive material,
The contact part 1, the elastic parts 2, 3, and the foot part 4 are formed. FIG.
As shown in (b) front view, (c) plan view and (d) side view of the same figure, the elastic portions 2 and 3 are split and alternately bent to form an arc shape. This contact pin can be constructed by reducing the number of bending steps.

FIGS. 13 and 14 show an eighth embodiment similar to the contact pin shown in FIG. FIG.
(A) As shown in the exploded perspective view, a conductive material is punched out to form a U-shaped contact portion 1 facing one end, elastic portions 2 and 3 at the center, and a foot portion 4 at the other end. Next, the contact portion 1 is bent, and the elastic portions 2 and 3 are bent into an arc shape as shown in the perspective view of FIG. 13B to complete the shape. The arc-shaped elastic portions 2 and 3 are formed symmetrically with respect to the center line as shown in the front view of FIG. This contact pin is different from the contact pin of FIG. 1 in that the elastic portions 2 and 3 can be operated independently without being affected by the elastic portions forming a pair. As compared with the elastic portion shown in FIG. 1, since the spring is flexibly operated in the spring operating direction and the vertical direction, the elastic stroke amount in the height direction of the contact pin can be increased with a small load. Further, even when the spring is displaced in the vertical direction, since it is elastically displaced in the same direction with respect to the adjacent elastic portions, there is no relative interference with the operation of the adjacent elastic portions. However, since the U-shaped portions on both sides of the contact portion 1 are displaced toward the adjacent contact pins in the opposite directions, the portions are surrounded by a lattice-shaped insulating portion or have a minimum area. This part is configured so as not to interfere with the adjacent U-shaped part. Further, the contact portion 1 is provided with an inclination so that the solder ball is hard to be deformed and the wiping is easy.

15 and 16 show a ninth embodiment similar to the contact pin shown in FIG. FIG.
(A) As shown in the exploded perspective view, a conductive material is punched out, contact portions 1 are formed at both ends, a foot portion 4 is formed at the center, and elastic portions 2 and 3 are formed therebetween. Next, the foot portion 4 is bent to produce the shape shown in FIG.
(B) Complete the shape shown in the perspective view. The arcuate elastic portions 2 and 3 are formed symmetrically with respect to the center line as shown in the front view of FIG. This contact pin is shown in Figure 3.
The contact pin is different from the contact pin described above in that the elastic parts 2 and 3 can operate independently without being affected by the elastic parts forming a pair. As compared with the elastic portion shown in FIG. 3, since the spring is flexibly operated in the spring operation direction and the vertical direction, the elastic stroke amount of the contact pin in the height direction can be increased with a small load. Further, even when the spring is displaced in the vertical direction, since it is elastically displaced in the same direction with respect to the adjacent elastic portions, there is no relative interference with the operation of the adjacent elastic portions. However, since the L-shaped side surface portions on both sides of the contact portion 1 are displaced toward opposite contact pins in the opposite directions to approach each other, this portion is surrounded by a lattice-shaped insulating portion or has a minimum area. This part is configured so that it does not interfere with the adjacent L-shaped side surface part. Further, the contact portion 1 is provided with an inclination so that the solder ball is hard to be deformed and the wiping is easy.

[0026]

As is apparent from the above description and the drawings, the contact pin for IC socket of the present invention has no stress concentration, buckling deformation or breakage, a large wiping amount, and reliable contact with a solder ball. It is possible to obtain high contact pressure, and it can be expected that the socket will have low inductance.

[Brief description of the drawings]

FIG. 1A is an exploded perspective view and FIG. 1B is a perspective view illustrating an IC socket contact pin according to a first embodiment.

2 is a front view of the IC socket contact pin according to the first embodiment of FIG. 1 as seen from the direction A in FIG. 1 (b).

FIG. 3A is a developed perspective view and FIG. 3B is a perspective view illustrating an IC socket contact pin according to a second embodiment.

4 is a front view of the IC socket contact pin according to the second embodiment of FIG. 3 as seen from the direction A in FIG. 3 (b).

FIG. 5 is a perspective view for mounting the IC socket contact pin according to the first embodiment on a socket substrate.

FIG. 6 is a perspective view for explaining the operation of the IC socket contact pin according to the first embodiment.

7 (a) is a developed plan view and FIG. 7 (b) is a front view for explaining an IC socket contact pin according to a third embodiment.

FIG. 8 is a front view illustrating an IC socket contact pin according to a fourth embodiment.

FIG. 9 is a front view illustrating an IC socket contact pin according to a fifth embodiment.

10 (a) is a developed plan view, FIG. 10 (b) is a front view, FIG. 10 (c) is a plan view, and FIG. 10 (d) is a side view showing an IC socket contact pin according to a sixth embodiment. It is a figure explaining.

11A is a developed plan view, FIG. 11B is a front view, FIG. 11C is a plan view, and FIG. 11D is a side view showing a contact pin for an IC socket according to a seventh embodiment. It is a figure explaining.

12A is a developed plan view, FIG. 12B is a front view, FIG. 12C is a plan view, and FIG. 12D is a side view showing an IC socket contact pin according to an eighth embodiment. It is a figure explaining.

13A is a developed perspective view and FIG. 13B is a perspective view illustrating an IC socket contact pin according to a ninth embodiment.

14 is a front view of the IC socket contact pin according to the ninth embodiment of FIG. 13 as seen from the direction A in FIG. 13 (b).

15A is a developed perspective view and FIG. 15B is a perspective view illustrating an IC socket contact pin according to a tenth embodiment.

16 is a front view of the IC socket contact pin according to the tenth embodiment of FIG. 15 as seen from the direction A in FIG. 15 (b).

FIG. 17 (a) is a front view and FIG. 17 (b) is a plan view for explaining a BGA package to which the present invention relates.

FIG. 18 is a cross-sectional view illustrating the structure and function of a conventional BGA package and its contact pin.

[Explanation of symbols]

 1,11 Contact part of contact pin 2,12 Elastic part 3 Elastic part (pair with 2) 13 Contact pin 4,14 Contact pin foot part 5 Press-fitting part 6,16 Socket board 7 Square hole 8,18, BGA package body 9,19 Solder balls

Claims (2)

[Claims] 1. A conductive contact pin provided with two or more elastic portions, wherein additional elasticity is added to a plane parallel to a plane including a moving direction of one formed elastic portion in a vertical direction. A contact pin for an IC socket, characterized in that the operation direction of the part is included. 2. When mounting two or more contact pins adjacent to an IC socket, all the configured elastic portions are elastically displaced in the same direction with respect to the adjacent elastic portions, respectively, and the adjacent elastic portions are attached. The contact pin for an IC socket according to claim 1, wherein the contact pin is configured so as not to relatively interfere with the operation of the section.