JP2002357622A - Contact probe and ic socket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make precise inspection at all times by suppressing damage of spherical bumps and production of solder chips even if an IC package is loaded in a displaced manner. SOLUTION: This contact probe is provided with a contact part press- contacting with the spherical bumps disposed in a grid shape in the bottom of the IC package. This contact probe is so formed that the contact part has multiple pointed projections projecting from the end part of the probe so that the spherical bump is seated inside the respective projections and the tips of the respective projections have blunt shaped by being chamfered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an IC such as BGA or CSP having a large number of spherical bumps on the bottom of a package.
The present invention relates to a contact probe used for an IC socket or the like for inspecting a package and an IC socket provided with the contact probe, and more particularly to an improvement in a shape of a contact portion of a spherical bump disposed at a tip portion of the contact probe.

[0002]

2. Description of the Related Art BGA (Ball Grid Array), CSP (C
For IC packages such as hip size package)
On the bottom of the package, a large number of hemispherical or spherical spherical bumps made of low melting point metal such as solder are projected in a matrix shape, and these spherical bumps are fused to the wiring pattern of the printed wiring board, The IC package is connected to the printed wiring board.

In an inspection IC socket used in an inspection apparatus for inspecting such an IC package, FIG.
As shown in FIG. 1, a large number of elastically expandable and contractable contact probes 10 are provided. The distal ends of the contact probes 10 face the spherical bumps 2 of the IC package 1, and the distal ends of the contact probes 10 face the wiring pattern of the printed wiring board. When the spherical bumps 2 of the IC package 1 are brought into pressure contact with the contact probes 10, the spherical bumps 2 of the IC package 1 and the wiring patterns of the printed wiring board are conducted through the contact probes 10.

Various shapes such as a tubular shape are adopted as the shape of the contact portion with the spherical bump 2 located on the tip side of the contact probe 10 mounted on such an IC socket. In many cases, a plurality of pointed projections projecting from the probe end face so-called a crown shape as shown in FIG. .

[0005]

However, in the contact probe having the crown-shaped contact portion, when the IC package 1 is loaded into the IC socket,
When the position of the IC package 1 is displaced, as shown in FIG. 6, the pointed projection at the tip of the contact probe 10 hits the spherical bump 2 of the IC package 1, damaging the spherical bump 2 and generating solder dust. Has the problem of adversely affecting

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and it is possible to always perform an accurate inspection without damage to spherical bumps and generation of solder dust even when an IC package is mounted with a displacement. Contact probe and I
An object is to provide a C socket.

[0007]

According to one aspect of the present invention,
In a contact probe having a contact portion that presses and contacts a spherical bump arranged in a lattice on the bottom surface of an IC package, the contact portion protrudes from an end of the probe such that the spherical bump is seated inside each protrusion. A plurality of pointed projections are provided, and the tip of each projection is chamfered.

According to the present invention, since the tips of the plurality of projections projecting from the probe end are chamfered to have a blunt shape, even if the IC package is misaligned and mounted, the spherical bumps are not removed. Damage and generation of solder dust are eliminated.

According to another aspect of the present invention, in an IC socket provided with a contact probe having a contact portion that presses into contact with spherical bumps arranged in a grid on the bottom surface of an IC package, the contact portion of the contact probe includes: The present invention is characterized in that the spherical bump has a plurality of pointed projections protruding from the probe end so as to be seated inside each projection, and the tip of each projection is chamfered.

In the present invention, since the tips of the plurality of projections protruding from the end of the probe are made blunt by chamfering or the like, the IC package is displaced and the IC package is displaced.
Damage to spherical bumps, even when loaded in sockets,
The generation of solder waste is eliminated.

[0011]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 shows an embodiment of an IC socket for IC inspection.

This IC socket is mounted on a printed wiring board, and has a socket body (insulating board) 20.
And an IC positioning table 25 provided to be vertically movable with respect to the socket body 20. The socket body 20 is formed with a concave portion 21 in which a IC positioning table 25 is arranged at a central portion.

The positioning base 25 is urged upward by a spring body (not shown) such as a coil spring interposed between the positioning base 25 and the socket main body 20 in a normal state (when the IC is not loaded). Are held by the socket body 20 in a state of being separated from the upper surface of the socket. The positioning table 25 has B
A concave IC mounting portion 26 for mounting an IC package 1 such as GA or CSP is formed. As shown in FIG. 2, a large number of through holes 27 into which the contact portions 32 on the tip side of the contact probe 30 are inserted are formed in the bottom surface of the IC mounting portion 26 in a matrix.

A large number of contact probes 30 are erected on the socket body 20 in a matrix.

Each contact probe 30 has a cylindrical sleeve 31 having openings at both ends, contact portions 32 and 33 inserted into the sleeve 31 so as to protrude from both sides of the sleeve 31, and contact portions 32 in the sleeve 31. , 33 and a spring body (not shown).

In these contact probes 30, the contact portion 32 on the distal end side can protrude from the upper surface of the socket body 20, as shown in FIG. It can be projected from the bottom.

When the IC socket is mounted on the printed wiring board, the contact portion 32 on the terminal side of the contact probe 30 protruding from the bottom surface of the socket body 20.
Is brought into pressure contact with a wiring pattern on a printed wiring board.

The IC package 1 is mounted on the positioning table 25.
2, the spherical bumps 2 of the IC package 1 and the contact portions 32 on the distal end sides of the contact probes 30 face one to one, as shown in FIG. Has become.

At the time of inspection, a pressing body (not shown) is used with the IC socket mounted on the printed wiring board and the IC package 1 positioned on the IC mounting portion 26 of the positioning table 25. The IC package 1 is pushed down together with the positioning table 25 against the urging force of the spring body of each contact probe 30. As a result, the bump 2 inserted into the through hole 27 of the positioning table 25 contacts the contact portion 32 on the tip end side of the contact probe 30 inserted into the through hole 27 and moves the contact portion 32 into the sleeve 31. Push in. Accordingly, the spherical bump 2 of the IC package 1 and the contact portion 32 on the tip end side of the contact probe 30 are brought into pressure contact with each other, whereby the contact portion 32, the spring body in the sleeve 31 and the contact portion 33 are separated from the spherical bump 2. An electrical conduction path to the printed wiring board is formed through the conductive path.

Here, as shown in FIGS. 2 and 3, the tip side contact portion 32 of the contact probe 30 has a crown shape in which a plurality of pointed projections 40 are projected from the probe end face. Each pointed projection 40 has an outer peripheral surface 40a having the same diameter as the contact portion 32, and two inner side surfaces 40b having the same shape as the side surface of the corner.

The contact part 3 on the tip side of the contact probe 30
2, the seating portion for seating the spherical bump 2 of the IC package 1 includes two inner surfaces 40 b of the pointed projection 40.
Are formed by four sides 40c formed by the intersection lines of. That is, the spherical bump 2 is seated on the four sides 40 c formed inside the pointed projection 40.

Here, the vertex of each pointed projection 40 is a flat chamfer 50 in this case.
Damage to the spherical bump 2 of the C package 1 is suppressed. Therefore, the IC package 1
As shown in FIG. 4, even when the bumps are loaded with displacement, damage to the spherical bumps 2 is reduced, and the generation of solder dust can be reduced.

The shape of the apex of the pointed projection 40 is not limited to the chamfer 50 in the above-mentioned plane, but the entire apex may be chamfered in a rounded R-plane. The point is that any shape can be adopted as long as the top portion is made dull and damage to the spherical bump 2 can be reduced.

Since the spherical bumps 2 are preferably supported at three or more points, it is desirable that there are three or more pointed projections 40.

In the above-described embodiment, the contact probe 30 has the contact portions 32 and 33 on both sides of the sleeve 31 movable with respect to the sleeve. It may be fixed.

[0027]

As described above, according to the present invention,
Since the tips of the multiple protrusions protruding from the probe end are chamfered and blunted, even if the IC package is misaligned and mounted, damage to the spherical bumps and generation of solder dust will occur. Can be suppressed, so that I
The adverse effect on the C inspection is also prevented.

[Brief description of the drawings]

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

FIG. 2 is a side view showing an embodiment of a main part of the contact probe according to the present invention.

FIG. 3 is a perspective view showing an embodiment of a main part of the contact probe according to the present invention.

FIG. 4 is a side view showing an abutting state of a contact probe according to the present invention with a spherical bump of an IC package mounted shifted.

FIG. 5 is a side view showing a conventional contact probe.

FIG. 6 is a side view showing the state of contact with a spherical bump of an IC package loaded shifted from a conventional contact probe.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 IC package 1 2 Spherical bump 10 Contact probe 20 Socket main body 21 Concave part 25 IC positioning stand 26 IC mounting part 27 Through hole 30 Contact probe 30 31 Sleeve 32 Tip side contact part 33 Terminal side contact part 40 Pointed projection 40a Outer perimeter Surface 40b Inner surface 40c Side 50 Chamfer

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Satoshi Kaneko 5-7-1 Shiba, Minato-ku, Tokyo NEC Corporation (72) Inventor Takuya Tsumoto 5-7-1 Shiba 5-minute, Minato-ku, Tokyo NEC Corporation F term (for reference) 2G003 AA07 AG01 AG12 2G011 AA15 AA21 AB01 AC13 AC14 AE22 AF02 5E024 CB05

Claims (2)

[Claims] 1. A contact probe having a contact portion that presses and contacts spherical bumps arranged in a grid on a bottom surface of an IC package, wherein the contact portion is configured such that the spherical bump is seated inside each protrusion. A contact probe comprising a plurality of pointed projections protruding from an end of a probe, and a tip of each of the projections is chamfered. 2. An IC socket provided with a contact probe having a contact portion that presses and contacts a spherical bump arranged in a grid on the bottom surface of an IC package, wherein the contact portion of the contact probe is formed by a protrusion. An IC socket comprising: a plurality of pointed projections protruding from an end of a probe so as to be seated inside the probe; and a tip of each of the projections is chamfered.