JP2001021615A - Contact probe of socket for inspecting bga - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make stable measurement for inspection performable by allowing a terminal part to have a conical recessed part for receiving a solder ball at the tip and at the same time, to have a plurality of slits reaching an area near the bottom part of the conical recessed part from the tip. SOLUTION: The contact probe 1 is provided with a cylindrical body 1C, and terminal parts 1A and 1B are inserted into the cylindrical body 1C while they cannot be pulled out at both ends in a vertical direction. The terminal part 1A positioned at a side opposing the solder ball of an IC package out of the terminal parts 1A and 1B has the conical recessed part 1A1 at the tip, and a slit 1A2 reaching the bottom surface of the conical recessed part 1A1 from the tip is formed in all directions at the periphery. A coil spring 1D is loaded between the terminal parts 1A and 1B, thus giving a projection habit for the terminals 1A and 1B, thus compressing the terminal part 1A to the solder ball and enabling the terminal part 1A to bite the solder ball by the slit 1A2 formed at the terminal part 1A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact probe for a ball grid array (BGA) inspection socket, and more particularly, to a contact probe having a ball grid array.
The present invention relates to a terminal structure of a contact probe that forms a contact portion with a BGA in a socket used for product inspection of a C package.

[0002]

2. Description of the Related Art In the technology of mounting electronic parts such as semiconductors on electronic equipment, it is desired to respond to higher performance or higher density of electronic equipment. Alternatively, when realizing high density, miniaturization of the wiring is desired accordingly. Conventionally, printed circuit boards have been multi-layered as a method for meeting these demands. Electronic components such as ICs mounted on the multilayer printed circuit board also tend to have more pins due to higher densities.
As one of the C packages, a ball grid array (hereinafter, referred to as BGA) in which solder balls are arranged in a grid pattern instead of mounting external terminals on a printed circuit board as in the related art has been used in many cases. I have. This B
The GA is electrically connected to the conductor layer of the multilayer printed circuit board via a contact that is elastically urged and contacts the solder balls arranged in a grid on one side.

When performing a product inspection such as an energization inspection of an IC package using the BGA, a BG
A dedicated socket equipped with a contact probe in which terminals are arranged corresponding to the arrangement pitch of the solder balls in A is used. In this dedicated socket, an IC package having a BGA is loaded in the socket, and the solder ball is brought into contact with the terminal portion of the contact probe.

FIG. 4 is an explanatory view showing the structure of a socket used for the above product inspection. In the figure, a socket A is formed with a package mounting recess A1 corresponding to the outer dimensions of an IC package B to be inspected. The package mounting recess A1 has an arrangement pitch of the solder balls B1 of the IC package B. A matching opening is formed, and a contact probe C1 having a terminal portion C1 that can contact the solder ball B1 is arranged in the opening. In FIG. 4, reference symbol D indicates an inspection circuit board having a terminal portion with which the terminal portion C2 of the contact probe C contacts. In the inspection socket A having the above configuration, the solder balls B of the IC package B to be loaded are provided.
1 and the terminal portion C1 of the contact probe C are positioned, and the center position (L1) of each solder ball B1 and the center of each terminal portion C1, that is, the center position (S1) of the contact probe C are aligned. ing.

[0005]

FIG. 5 shows the structure of the contact probe in the above-described test socket. In FIG. 5, the contact probe C includes a cylindrical body C3, and terminal portions C1 and C2 are inserted into the cylindrical body C3 in a state where the terminal parts C1 and C2 are prevented from falling off in the vertical direction. Of the terminal portions, the terminal portion C1 located on the side facing the solder ball B1 of the IC package B has a conical concave portion C10 formed at the tip, and has a shape capable of receiving the solder ball B1 in the concave portion C10. I have. A coil spring C4 is mounted between the terminal portions C1 and C2 to give the terminal portions C1 and C2 a projecting behavior. Accordingly, the terminal portion C1 is pressed against the solder ball B1, and the terminal portion C2 is pressed against the terminal of the inspection circuit board, so that poor contact is less likely to occur.

However, in the above-described structure of the contact probe in the inspection socket, since the conical concave portion C10 of the terminal portion C1 has a cup shape, the solder residue generated when the terminal portion C1 comes into contact with the solder ball B1. And the like accumulate in the conical concave portion C10, and a problem arises in that the measured value of the conduction test cannot be accurately measured.
In order to avoid this, every time the measurement for inspection of one IC package B is completed, a maintenance work for cleaning the terminal portion C1 of the contact probe C of the socket A with a cleaning brush is required. In this maintenance work, the cleaning brush removes the solder gas and the like accumulated in the conical concave portion C10 of the terminal portion C1. Since it adheres to the bottom of the concave portion C10, the adhered solder residue cannot be easily removed, and there is a problem that the maintenance work becomes difficult.

The present invention has been proposed to solve the above-mentioned problem, and is directed to a ball grid array (BG).
In sockets used for product inspection of IC packages equipped with A), the structure of the contact probe that forms the contact part with the BGA is improved, maintenance is improved, and stable measurement for inspection is possible. The purpose is to.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a socket used for product inspection of an IC package having a ball grid array (BGA), and a contact portion with the BGA. In the contact probe, the terminal portion facing the solder ball of the BGA has a conical recess at the tip for receiving the solder ball, and has a plurality of slits reaching from the tip to near the bottom of the conical recess. It is characterized by the following.

According to the above arrangement, by providing the slit in the terminal portion, the cleaning brush for removing foreign matters such as solder residue accumulated in the conical concave portion of the terminal portion can sufficiently reach the bottom of the conical concave portion. In addition, solder scraps and the like can be easily swept out of the gap between the slits. Also,
By providing the above-mentioned slit, the solder residue and the like in the conical concave portion are naturally discharged to the outside of the terminal portion.
Therefore, the maintenance of the contact probe in the inspection socket can be facilitated, the number of maintenance operations can be reduced, and a plurality of IC packages can be continuously inspected and measured.

[0010] Further, in combination with the above-described improvement in maintainability, the opening of the conical concave portion for receiving the solder ball is elastically enlarged by the slit provided in the terminal portion.
The terminal portion elastically bites into the solder ball, and the contact between the solder ball and the terminal portion is improved to enable stable measurement.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory view showing the structure of a contact probe of an inspection socket according to one embodiment of the present invention. FIG. 1 (a) shows a partial cross-sectional view of the whole, and FIG. 1 (b) shows the structure of a terminal portion. It is a perspective view. In the figure, a contact probe 1 is provided with a cylindrical body 1C.
A and 1B are inserted. Of the terminal portions 1A and 1B,
The terminal portion 1A located on the side facing the solder ball of the IC package has a conical concave portion 1A1 formed at the tip, and slits 1A2 extending from the distal end to the bottom surface of the conical concave portion 1A1 are formed around the terminal portion 1A. Have been.

A coil spring 1D is mounted between the terminal portions 1A and 1B to give the terminal portions 1A and 1B a projecting behavior. As a result, the terminal portion 1A is pressed against the solder ball, and the terminal portion 1A bites into the solder ball by the slit 1A2 formed in the terminal portion 1A. Thereby, contact between the terminal portion 1A and the solder ball is ensured, and poor contact hardly occurs.

FIGS. 2 and 3 are explanatory diagrams of a BGA inspection socket employing the contact probe 1 according to the embodiment of the present invention. In FIG. 1, a BGA inspection socket 10 is shown.
Includes a socket body 10A integrated with the inspection circuit board 12, and a package holding member 10B.

The socket body 10A and the package holding member 10B are both formed of an electrically insulating resin material. The socket body 10A is arranged in accordance with the arrangement pitch of the solder balls 13A in the IC package 13 to be inspected. The above-mentioned contact probe 1 which forms the contact member is provided.

In the contact probe 1, a distance from an inner edge of an exposed portion 10D formed in a receiving portion 10C of a package holding member 10B to be described later to an arrangement position of the outermost contact probe 1 'is predetermined. The remaining contact probes 1 are arranged at an arrangement pitch corresponding to the arrangement pitch of the solder balls 13A with reference to the outermost contact probe 1 '.

The package holding member 10B is slidably supported by guide pins 15 implanted in the socket body 10A, and is maintained in a floating state by a spring 16 disposed between the bottom surface and the socket body 10A. It has become. The package holding member 10B has a receiving portion 10C formed of a concave portion for mounting the IC package 13.
An exposed portion 10D for exposing the solder ball 13A of the IC package 13 toward the contact probe 1 is formed in the receiving portion 10C.
In this embodiment, the exposed portion 10D is constituted by an opening.

As shown in the drawing, the exposed portion 10D has a size (P) that can contact the outermost solder ball 13A1 of the solder ball 13A of the IC package 13 for convenience. (FIG. 3).
Although not shown, since the solder balls 13A of the IC package 13 are provided in the same number in the vertical and horizontal pitches, the size (P) in FIG. 3 is the same even in the direction perpendicular to the paper surface. I have.

Since the configuration of the present embodiment is as described above,
When the product inspection of the IC package 13 is performed, the IC package 13 to be inspected is placed in the receiving portion 10B of the package holding member 10B with the solder ball 13A facing the contact probe 1 arranged in the inspection socket 10.
Place on C. Receiving part 10 of package holding member 10B
As shown in FIG. 2, the IC package 13 placed on C is in a state where the outermost solder ball 13A1 of the solder balls 13A is brought into contact with the inner edge of the opening forming the exposed portion 10D. You. When the outermost solder ball 13A1 of the solder balls 13A is brought into contact with the inner edge of the opening forming the exposed portion 10D, the solder ball 13A1
The center position of each solder ball 13A whose arrangement pitch is determined in advance with reference to the center position of the contact probe 1 arranged on the socket body 10A is matched.

In other words, the contact probe 1 in the inspection socket 10 is exposed because the position of the outermost contact probe 1 'is determined with reference to the inner edge of the opening forming the exposed portion 10D in the package holding member 10B. The position of opposition to the solder ball 13 with respect to the position in contact with the inner edge of the opening forming the portion 10D is the same as the exposed portion 1
The alignment can be performed by using the inner edge of the opening forming 0D as the positioning reference. Therefore, the IC package 13
Ball 13A located on the outermost side from the outer peripheral portion
Even if the distance to 1 is different due to a mechanical error, the positional relationship between the solder ball 13A and the contact probe 1 is aligned without shifting. The IC package 13 aligned with the position of the contact probe 1 is pushed into the socket body 10A side against the behavior of the panel 16 so that the solder ball 13A is pushed into the contact probe 1A.
The center positions (positions indicated by reference numerals L1 and S1 in FIG. 4) at this time are in contact with each other, and an electrical conduction state required for inspection is set.

At this time, since the contact probe 1 is provided with a projecting behavior by the coil spring 1D, the solder ball 13 positioned by the inner edge of the exposed portion 10D is provided.
When the terminal portion 1A is pressed against A, and the terminal portion 1B is pressed against the terminal portion of the test circuit board 12, the current path from the test circuit board 12 to the IC package 13 causes a contact failure on the way. It will be secured without.

Then, an IC is connected to the inspection socket 10 described above.
When the package 13 is loaded and the inspection is performed, the solder ball 13A of the IC package 13 comes into contact with the terminal 1A of the contact probe 1 to generate solder scum from the solder ball 13A, but the terminal 1A has a slit 1A2.
Is formed, the solder scum is discharged from the slit 1A2, and the IC package 13 can be inspected to some extent continuously in a state where proper energization is secured.
However, when a plurality of inspections of the IC package 13 are continued, the solder residue may
Since it accumulates in the conical concave portion 1A1 in A, a maintenance work is required to remove it. In this maintenance work, the solder residue is removed from the terminal portion 1A by a cleaning brush. The slit 1A2 is formed in the terminal portion 1A, so that the cleaning brush reaches the bottom of the conical concave portion 1A1 sufficiently. In addition, the solder residue can be easily discharged from the slit 1A2.

[0022]

The present invention relates to a ball grid array (BG).
In a contact probe provided in a socket used for product inspection of an IC package provided with A) and forming a contact portion with the BGA, the terminal portion facing the solder ball of the BGA has the solder ball at the tip. The cleaning brush has a plurality of slits extending from the tip to the vicinity of the bottom of the conical recess, thereby removing foreign matters such as solder residue accumulated in the conical recess of the terminal portion. Suffices to reach the bottom of the contact socket, and solder scraps and the like can be neatly swept out of the gap between the slits, so that maintenance of the contact probe in the inspection socket can be facilitated. In addition, by providing the above-mentioned slits, the solder residue and the like in the conical concave portion are naturally released outside the terminal portion, so that the number of maintenance can be reduced,
A plurality of IC packages can be inspected and measured continuously. Further, in combination with the improvement of the above-mentioned maintainability, the slit provided in the terminal portion allows the terminal portion to elastically bite into the solder ball, thereby improving the contact between the solder ball and the terminal portion and ensuring stable measurement. Enable.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a contact probe according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a test socket including a contact probe according to the embodiment of the present invention.

FIG. 3 is an explanatory diagram of a test socket including a contact probe according to the embodiment of the present invention.

FIG. 4 is an explanatory view of a conventional inspection socket.

FIG. 5 is an explanatory view of a conventional contact probe.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Contact probe 1A, 1B Terminal part 1A1 Conical recess 1A2 Slit 1C Tubular body 1D Coil spring

Claims (1)

[Claims] 1. A contact probe provided in a socket used for product inspection of an IC package having a ball grid array (BGA) and forming a contact portion with the BGA, a terminal facing the solder ball of the BGA. A contact probe for a BGA inspection socket, characterized in that the portion has a conical recess at the tip for receiving the solder ball and has a plurality of slits reaching from the tip to near the bottom of the conical recess.