JP3256174B2 - Ball grid array socket - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ball grid array socket, and more particularly, to a socket used for product inspection of an IC package provided with a ball grid array.

[0002]

2. Description of the Related Art As is well known, in the technology of mounting electronic parts such as semiconductors on electronic equipment, it is desired to cope with higher functionality or higher density of electronic equipment. On the other hand, in order to realize higher functionality or higher density of the electronic devices described above, it has been desired to reduce the size of the wiring accordingly. Is being done.

[0003] Electronic components such as ICs mounted on a multilayer printed circuit board also tend to have more pins due to higher densities. For this reason, one of the IC packages is a conventional external terminal. Is mounted on a printed circuit board, and a ball grid array (hereinafter, referred to as BGA) in which solder balls are arranged in a lattice shape may be used. The BGA is configured to be electrically connected to a conductor layer of a multilayer printed circuit board via a connector that is elastically urged and contacts a solder ball arranged on one side in a lattice.

When performing a product inspection such as an energization inspection of an IC package using the BGA, the BG
In some cases, a dedicated socket equipped with a probe in which contact pins are arranged corresponding to the arrangement pitch of the solder balls included in A is used.
The C package is loaded, and the solder balls are brought into contact with the contact pins of the probe. FIG. 4 is a schematic diagram showing a configuration of a socket used for the above product inspection. In FIG. 4, a socket A for inspection has a package loading recess A1 corresponding to the external dimensions of an IC package B to be inspected. ing. An opening corresponding to the arrangement pitch of the solder balls B1 of the IC package B is formed in the package mounting recess A1, and a probe C having a contact pin C1 that can contact the solder ball B1 is arranged in the opening. ing. Note that, in FIG. 4, reference symbol D indicates an inspection circuit board having a terminal portion that contacts the contact pin C2 of the probe C. The inspection socket A having the above configuration is provided with the package loading recess A.
The positioning of the solder ball B1 and the contact pin C1 of the probe C is performed with reference to the outer peripheral portion of the IC package B loaded in the device 1. That is, the outer peripheral portion of the IC package B is brought into contact with the inner wall surface of the socket mounting concave portion A1, so that the center position (L1) of each solder ball B1 and the center of each contact pin C1, that is, the center position (S1) of the probe C. And match.

[0005]

The following problems arise when the above-described socket for inspection is used. That is, I
In the C package, the distance between the outer peripheral portion and the solder ball may be different due to an error in the outer dimensions. In this case, as shown in FIG. 5, even if the outer peripheral portion of the IC package B is brought into contact with the inner wall surface of the concave portion A1 for loading the package, the center position (L1) of the solder ball B1 and the center position (S1) of the probe C are obtained. Are not matched, a shift may occur as shown by reference numeral G. For example, plastic
In the case of BGA or the like, the outer dimensions are ± 0.1 to 0.
There is an error of about 2 mm, especially 0.5 or 0.4
In an IC package having an arrangement pitch of solder balls such as a mm pitch, the corresponding center position between the solder ball B1 and the probe C may be shifted due to the existence of the error. If the center position is shifted in this way, for example, when the tip shape of the contact pin C1 shown in FIGS. 4 and 5 is cut off at an acute angle, the solder ball B1 When a surface other than the center portion hits, the solder ball B1 is damaged by the peripheral edge of the tip, or a small contact state is obtained, resulting in a contact failure and an unstable electrical conduction state. . The tip shape of the contact pin C1 is set so as to guide when the solder ball B1 enters the tip and align the center positions of the two.

SUMMARY OF THE INVENTION In view of the above-mentioned problems in the conventional ball grid array socket, the object of the present invention is to optimize the contact relationship between the solder balls included in the ball grid array and the conductive members that come into contact with the solder balls, thereby preventing the solder balls from being damaged. An object of the present invention is to provide a ball grid array socket having a configuration capable of preventing the occurrence of an electric contact and maintaining a good electrical contact state.

[0007]

In order to achieve this object, the present invention is directed to an I-type semiconductor device having a ball grid array having solder balls arranged in a grid pattern on the surface.
A package holding member for holding the C package ;
The solder balls of the IC package to a socket provided with a counter capable of abutting against the contact member, the IC package holder
The material consists of a recess for mounting the IC package.
Receiving unit comprising a that the exposed portion of the solder ball is formed at the receiving portion, the exposed portion is formed within at possible contact with the solder balls located outermost size of the solder ball, The outermost solder ball is brought into contact with the inner edge of the exposed portion to position the solder ball and the contact member facing the solder ball.

[0008] According to a second aspect of the invention, the ball grid socket array according to claim 1, wherein said exposed portion, said package being floatingly supported with respect to the socket body in which the contact member is disposed The opening is formed in the holding member, and the inner wall surface of the opening can be brought into contact with the outermost solder ball of the solder balls.

According to a third aspect of the present invention, in the ball grid array socket according to the first aspect, the contact member is constituted by a probe having terminals arranged in a cylinder, and the terminals are disposed at both axial ends of the cylinder. , Each having a protruding property by an elastic body disposed in the cylindrical body, and one of the elastic bodies being in contact with the solder ball.

[0010]

According to the first aspect of the present invention, since the exposed portion formed in the receiving portion is formed to have a size capable of contacting the outermost solder ball in the IC package.
Only by bringing the outermost solder ball into contact with the inner edge of the exposed portion, positioning with the contact member facing the solder ball can be performed. Accordingly, even if an error occurs in the positional relationship between the outer shape of the IC package and the outermost solder ball, only the positional relationship between the outermost solder ball, which is a reference for the arrangement pitch, and the inner edge of the exposed portion is defined. Thus, the positional relationship facing the contact member provided on the socket having the exposed portion can be accurately determined.

According to the second aspect of the present invention, an opening is provided in the exposed portion, and the inner wall surface of the opening has a relationship capable of abutting on the outermost solder ball, so that the contact with the solder ball can be achieved with a simple structure. The positional relationship with the member can be defined.

According to the third aspect of the present invention, a probe having terminals at both ends in the axial direction of the cylindrical body is used as the contact member, and these terminals can be protruded by the elastic body disposed inside the cylindrical body. Therefore, good contact can be easily made to the solder ball positioned by the contact between the outermost solder ball and the inner edge of the exposed portion.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 is a schematic view of a ball grid array socket according to an embodiment of the present invention. In FIG. 1, a ball grid array (hereinafter referred to as BGA for convenience) socket 1 is integrated with an inspection circuit board 2. 1A and a package holding member 1B.
The socket body 1A and the package holding member 1B are both formed of an electrically insulating resin material, and the socket body 1A is provided with a contact arranged in accordance with the arrangement pitch of the solder balls 3A of the IC package 3 to be inspected. A probe 4 as a member is provided.

The probe 4 has the structure shown in FIG. In FIG. 2, the probe 4 includes a cylindrical body 4A, and terminals 4A1 and 4A2 are inserted into the cylindrical body 4A in such a manner that the terminals 4A1 and 4A2 are prevented from coming off at both ends in the axial direction. Of the terminals, the terminal 4A1 located on the side of the IC package 3 that faces the solder ball 3A has a sharp end that is cut off at an acute angle, and has a shape capable of receiving the solder ball 3A. A coil spring 4B is provided between the terminals 4A1 and 4A2.
Are loaded, and the terminals 4A1 and 4A2 are given a protruding behavior. Thus, the terminal 4A1 is pressed against the solder ball 3A, and the terminal portion 4A2 is pressed against the terminal of the inspection circuit board 2, so that poor contact is less likely to occur.

The probe 4 is a distance from an inner edge of an exposed portion 1D formed in a receiving portion 1C of a package holding member 1B to be described later to an arrangement position of an outermost probe (indicated by reference numeral 4 'for convenience). Are determined in advance, and the solder balls 3 are determined based on the outermost probe 4 '.
The remaining probes 4 are arranged at an arrangement pitch corresponding to the arrangement pitch of
Is arranged.

The package holding member 1B is slidably supported by guide pins 5 implanted in the socket body 1A, and is maintained in a floating state by a spring 6 disposed between the bottom surface and the socket body 1A side. It has become. The package holding member 1B has a receiving portion 1C formed of a concave portion for mounting the IC package 3, and the solder ball 3A of the IC package 3 is exposed to the probe 4 in the receiving portion 1C. Exposure 1D for
Are formed. In this embodiment, the exposed portion 1D is constituted by an opening. As shown in FIG. 3, the exposed portion 1D is formed to have a size (P) capable of contacting the outermost solder ball (indicated by reference numeral 3A1) among the solder balls 3A of the IC package 3. ing.
Although not shown, the solder balls 3 of the IC package 3 are not shown.
Since A has the same number of vertical and horizontal arrangement pitches and is provided in the same number, the size (P) in FIG. 3 is the same even in a direction perpendicular to the paper surface.

Since the present embodiment has the above configuration,
When performing the product inspection of the IC package 3, the IC package 3 to be inspected is placed on the receiving portion 1C of the package holding member 1B with the solder ball 3A facing the probe 4 arranged in the socket 1. . IC package 3 placed on receiving portion 1C of package holding member 1B
As shown in FIG. 3, the outermost solder ball 3A1 of the solder balls 3A is brought into contact with the inner edge of the opening constituting the exposed portion 1D. The outermost solder ball 3A1 of the solder balls 3A is exposed 1D.
When the solder ball 3 is brought into contact with the inner edge of the opening
The center position of each solder ball 3A whose arrangement pitch is determined in advance based on A1 and the center position of the probe 4 arranged on the socket body 1A are matched. That is,
Since the position of the probe 4 'located on the outermost side is determined with reference to the inner edge of the opening constituting the exposed portion 1D of the package holding member 1B, the probe 4 in the socket 1 is in contact with the inner edge of the opening forming the exposed portion 1D. The positional relationship facing the solder ball 3 with respect to the determined position can be matched by using the inner edge of the opening forming the same exposed portion 1D as the positioning reference. Therefore, even if the distance from the outer peripheral portion of the IC package 3 to the outermost solder ball 3A1 is different due to a mechanical error, the solder ball 3
The positional relationship between the probe and the probe 4 is aligned without shifting.

The IC package 3 which is necessarily aligned with the position of the probe 4 by bringing the outermost solder ball 3A1 into contact with the inner edge of the opening forming the exposed portion 1D is provided with a spring 6
The solder ball 3A can be brought into contact with the probe 4 by being pushed into the socket main body 1A side against the habit of the above, and the center position at this time (reference numerals L1, S in FIG. 4)
(Positions indicated by 1) are in contact with each other, and an electrical conduction state required for the inspection is set. Since the probe 4 is provided with a protrusion behavior by the coil spring 4B,
Solder ball 3 positioned by inner edge of exposed portion 1D
A is pressed against the terminal portion 4A1 and the terminal portion 4A
2 is pressed into contact with the terminal portion of the circuit board 2 for inspection, so that a current path from the circuit board 2 for inspection to the IC package 3 is secured without causing a contact failure in the middle.

[0019]

As is apparent from the above embodiment, according to the first aspect of the present invention, the exposed portion formed in the receiving portion can be brought into contact with the outermost solder ball in the IC package. Since the solder ball is formed in such a size, the outermost solder ball can be positioned with respect to the contact member facing the solder ball only by bringing the solder ball into contact with the inner edge of the exposed portion. Accordingly, even if an error occurs in the positional relationship between the outer shape of the IC package and the outermost solder ball, only the positional relationship between the outermost solder ball, which is a reference for the arrangement pitch, and the inner edge of the exposed portion is defined. The position of the opposing contact with the contact member provided on the socket having the exposed portion can be accurately determined, so that damage to the solder ball by the probe can be prevented and the electrical contact relation is not hindered. Becomes possible.

According to the second aspect of the present invention, the opening is provided in the exposed portion, and the inner wall surface of the opening is in a relationship capable of contacting the outermost solder ball, so that the solder ball has a simple structure. And the positional relationship between the contact member and the contact member. This makes it possible to define the positional relationship between the solder ball and the probe irrespective of the external error of the IC package without providing a special positioning mechanism.

According to the third aspect of the present invention, a probe having terminals at both ends in the axial direction of the cylindrical body is used as the contact member, and the terminals are projected by an elastic body disposed inside the cylindrical body. Therefore, good contact can be easily made with the solder ball positioned by the contact between the outermost solder ball and the inner edge of the exposed portion. This makes it possible to almost certainly prevent poor contact by improving the contact state in addition to the alignment of the positional relationship.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a configuration of a ball grid array socket according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view for explaining a structure of a probe used in the ball grid array shown in FIG.

FIG. 3 is a schematic diagram for explaining the operation of the ball grid array socket shown in FIG. 1;

FIG. 4 is a schematic diagram for explaining an example of a conventional structure of a ball grid array.

FIG. 5 is a schematic diagram for explaining a problem in the ball grid array shown in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Socket for ball grid array 1A Socket main body 1B Package holding member 1C Receiving part constituted by concave part 1D Exposure part constituted by opening 3 IC package 3A Solder ball 3A1 Solder ball located at the outermost side 4 Probe serving as a contact member 4A Cylindrical body 4A1 Terminal part facing the solder ball 4A2 Terminal part facing the terminal part of the inspection circuit board 4B Coil spring as an elastic body 6 Spring that allows the exposed part to be raised and lowered

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01R 33/76 H01R 13/24

Claims (3)

(57) [Claims] A package holding member for holding an IC package having a ball grid array having solder balls arranged in a grid pattern on a surface of the IC package;
A socket having the solder balls di opposing contactable contact member, the IC package holding member, the I
A receiving portion formed of a concave portion for mounting the C package; an exposed portion of the solder ball is formed in the receiving portion; and the exposed portion is in contact with an outermost solder ball among the solder balls. A ball grid array formed in a size that can be contacted, and positioning the solder ball and a contact member facing the solder ball by bringing the outermost solder ball into contact with the inner edge of the exposed portion. Socket. 2. A ball grid socket array according to claim 1, wherein the exposed portion is formed in said package holding member is floatingly supported with respect to the socket body in which the contact member is disposed A ball grid array socket comprising an opening, wherein an inner wall surface of the opening can be in contact with an outermost solder ball of the solder balls. 3. The ball grid array socket according to claim 1, wherein the contact member comprises a probe having terminals arranged in a cylinder, and the terminals are arranged at both ends in the axial direction of the cylinder, respectively. A ball grid array socket characterized in that it has a protruding behavior due to an elastic body disposed in a cylindrical body, one of which is in contact with the solder ball.