JP2001305182A - Ic socket and contact for the ic socket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an IC socket for ball grid array having good high frequency characteristics and high contact stability and a contact for the IC socket. SOLUTION: A movable contact is formed with a conductive plate having a width of 1/3 or more of ball diameter of the ball grid array to contact. A terminal is formed in succession with the conductive plate having the same width as the movable contact. With the movable contact and the terminal, the contact for IC socket having small inductance component and the IC socket are constituted.

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to, for example, BGA (Ball Grid Arr).
a)) and a contact for an IC socket to be brought into contact with a hemispherical pin (hereinafter, referred to as a ball) called this ball.
The present invention relates to an IC socket using a C socket contact.

[0001]

When testing an IC equipped with a BGA type ball, an IC contacting the ball is required.
C socket is required. Various IC sockets that conform to the BGA have been proposed, but the shape is extremely small (the ball to be contacted is a hemisphere of 0.5 mmφ, and the pitch of the arrangement is about 1.00 mm to 1.27 mm).
Therefore, a product that satisfies the durability against the number of times of attachment and detachment and the electrical characteristics (generation of an inductance component) has not yet been developed.

In particular, a BGA type IC operates at a high speed.
Since C is common, the frequency of the signal is also high. For this reason, if an inductance component exists in the socket portion, the waveform will be deteriorated, and the test accuracy will be adversely affected. An object of the present invention is to propose a BGA type IC socket having high durability and a small inductance component, and a contact used for the IC socket.

[0003]

According to a first aspect of the present invention, a movable contact piece is formed by a conductive plate having a width of about 1/3 or more of the diameter of a ball grid array to be contacted. The present invention proposes a contact for an IC socket in which a terminal is formed by a conductive plate having an equivalent width. According to a second aspect of the present invention, a plurality of cuts are formed parallel to both short sides and long sides of the rectangular elastic conductive plate, and a plurality of tongues formed by the plurality of cuts are formed. Any one of
An IC in which one or two sheets are cut and raised in one direction and a movable contact piece is formed by the tongue pieces, and a terminal is formed by the tongue pieces cut and raised in the other remaining tongue pieces in the opposite direction. Suggest a socket contact.

According to a third aspect of the present invention, a plurality of tongues are formed in a radial direction from a polygonal conductive plate, and all of the plurality of tongues are cut and raised in the same direction to form a movable contact piece.
A contact for an IC socket is proposed in which a conductor is projected from a surface of a polygonal conductive plate in a direction opposite to a direction in which a movable contact piece projects, and a terminal is formed by the conductor. According to a fourth aspect of the present invention, there is provided a bottom plate made of an insulating material, and an insulating partition protruding from one plate surface of the bottom plate in a substantially vertical direction. I is characterized by storing any one of the IC socket contacts described in 1 to 3 above.
Suggest C socket.

[0005]

According to the contact for an IC socket of the present invention, the width of the conductive plate from the movable contact piece to the terminal is at least about 1/3 of the diameter of the ball to be contacted. The inductance component can be made sufficiently small. Therefore, an IC socket having excellent high-frequency characteristics could be formed. According to the IC socket contact of the present invention, a plurality of movable contact pieces are formed by cutting and raising from a conductive plate having elasticity, and the movable contact piece is configured to be in contact with a hemispherical ball. The piece is easily elastically deformed, and has an advantage that durability can be improved. Further, since the contact is good with the pins of the IC, it is possible to provide an IC socket contact with good contact.

[0006]

FIG. 1 shows an embodiment of an IC socket according to the present invention. In the figure, 10 is the IC under test, 20 is I
Shows the C socket. As shown in FIG. 2, a large number of hemispherical balls B protrude from the bottom surface of the IC under test 10, as shown in FIG.
The IC socket 20 has a concave portion 21 that engages with a ball B provided on the IC under test 10.
The C socket contact 30 is mounted, and the IC socket contact 30 and the ball B are brought into electrical contact, and all the balls B of the IC under test 10 are brought into electrical contact with a test head (not particularly shown).

FIG. 3 shows an IC proposed in claim 2 of the present invention.
1 shows an embodiment of a socket contact. FIG. 4 shows a process of manufacturing the IC socket contact shown in FIG. In the embodiment shown in FIG. 4, a plurality of cuts 32 are formed from both short sides of a rectangular conductive plate 31 having elasticity (spring properties) like a beryllium copper toward a center almost in parallel with a long side. Then, a plurality of tongue pieces are formed by forming the cuts 32. A part of the plurality of tongue pieces is cut and raised from the plate surface of the conductive plate 31, and the cut and raised tongue pieces move the movable contact pieces 33A and 33A.
B, 33C and 33D are formed. In this example, two cuts 32 are formed, and three tongues are formed by these two cuts 32. Tongues located on both sides of the three tongues, for example, are cut upward. The movable contact piece 33A
~ 33D, and the central tongue piece is cut downward to raise the terminal 3
4A and 34B are shown. Movable contact 33A,
33B, 33C, and 33D, by bending each of the corners on the tip side, the bent portion is placed on the ball B
It is used as a contact part CON for contacting the contact. still,
The contacts 30 are, for example, plated with gold while being bent to the state shown in FIG.

FIG. 5 shows one recess 21 of the IC socket 20.
FIG. The concave portion 21 formed in the IC socket 20 is formed by a bottom plate 22 made of an insulating material and an insulating partition 23 protruding from the upper surface of the bottom plate 22. The insulating partition 23 is integrally formed of the same material as the bottom plate 22. In the example shown in FIG. 1, the partition 23 is formed in a lattice shape. As the shape of the partition walls 23, there may be a case where the partitions are arranged in a staggered manner by shifting the position by a half pitch for each row in addition to the lattice shape. In any case, the IC under test 1
0 is determined by the arrangement of the ball B.

A hole 24 is formed in the bottom plate 22 for inserting the terminals 34A and 34B, and the terminals 34A and 34B are led out to the back side of the bottom plate 22 through the hole 24. Terminals 34A and 34B are provided with, for example, cut-outs 35 for retaining.
Is formed, and the IC socket contact 30 is held in the concave portion 21 by the cut-and-raised portion 35 for retaining. Here, the width W of each of the movable contact pieces 33A to 33D and the terminals 34A and 34B.
(See FIG. 4) is about 1/3 of the diameter D of the ball B. By setting the width to at least 1/3 of the diameter D of the ball B, sufficient conductivity can be obtained.
Generation of an inductance component between the terminal 33D and the ends of the terminals 34A and 34B can be minimized. Incidentally, in the case of the IC socket contact 30 having the structure shown in FIG. 3, each of the movable contact pieces 33A from the ends of the terminals 34A and 34B.
The inductance component between each tip of .about.33D is 0.3.
It was about 4 μH.

In the above description, a case was described in which a total of four movable contact pieces were formed. However, as shown in FIG. 7, three movable contact pieces and three terminals may be formed. As shown in FIG. 8, the number of cuts is three, four tongues are formed on one side, and these four tongues are appropriately selected to make movable contact pieces 33A to 33D.
And the terminals 34A to 34D. Further, as shown in FIG.
6 can be formed, and the protrusions 36 can prevent the IC socket contact 30 from coming off inside the insulating partition wall 23. Further, as shown in FIG. 10, a wire having spring properties is bent into a U-shape, and the U-shaped bodies are welded to each other to form movable contact pieces 33A, 33B, 33C, 33D.
And the terminals 34A and 34B.

FIGS. 11 to 14 show still another embodiment of the present invention. This embodiment shows an embodiment of a contact for an IC socket proposed in claim 3 of the present invention. According to a third aspect of the present invention, a plurality of tongues are formed in the radial direction from the conductive plate 31 having a polygonal shape (a circle in the example of FIG. 11), and the plurality of tongues are bent in the same direction to move the movable contact pieces 33A, 33.
B and 33C are formed, and a small hole is formed in the center of the conductive plate 31 (see FIG. 12). A conductive pin is passed through the small hole, and an IC socket contact having a structure in which the conductive pin is used as a terminal 37 is shown. .

The conductive pin constituting the terminal 37 has a head 37A at one end, and the conductive plate 31 is held down by the head 37A. Terminal 37 is the IC socket 20 shown in FIG.
And protrudes to the back side of the bottom plate 22. A printed wiring board PB is arranged on the back side of the bottom plate 22 and is soldered to the printed wiring board PB to hold the movable contact pieces 33A, 33B and 33C inside the recess 21 forming the IC socket 20.

The movable contact pieces 33A, 33B and 33C are shown in FIG.
Are arranged at approximately 120 ° angular intervals, and make three-point contact with the outer peripheral surface of the ball B as shown in FIG. IC socket 2 shown in FIG.
Reference numeral 0 denotes a circular concave portion 21 formed on the upper surface side facing the position of each ball B of the IC under test 10, into which the IC socket contact 30 is inserted as shown in FIGS. Thus, an IC socket is configured.

FIGS. 15 and 16 show another embodiment of the IC socket contact shown in FIGS. In the embodiment shown in FIGS. 15 and 16, the plate-shaped conductive spring material is supported on the bottom plate 22 so that the plate surfaces are spaced at substantially 120 ° intervals. Further, a notch 38 is formed in the conductive spring material, and the movable contact 33A, 33B, 33C is formed by forming the notch 38 so that the tip can be elastically deformed. Further, in this embodiment, a case is shown in which only the conductive plate on which the movable contact piece 33A is formed is largely protruded to the back side of the bottom plate 22, and the protruded portion is used as the terminal.
In this case, the width of the conductive plate constituting the movable contact pieces 33A to 33C and the terminals 34 is close to about 1/2 of the diameter of the ball B as is clear from FIG.

FIGS. 17 and 18 show still another embodiment of the present invention. In this embodiment, an IC socket contact having a structure in which a conductive pattern 24 is formed on a bottom plate 22 and movable contact pieces 33A, 33B, and 33C formed of a conductive spring material are fixed to the conductive pattern 24 by soldering.
Also in this case, for example, the movable contact 33A is electrically led out to the back side of the bottom plate 22 by a through hole or the like, and the movable contact 33A
Only the case where only the contact is operated as an electric contact is shown.

[0016]

As described above, according to the present invention, the width of each of the movable contact pieces 33A, 33B and 33C is set to about one third or more of the diameter of the ball to be contacted, so that good conductivity is maintained. And the inductance component generated in the movable contact pieces 33A, 33B, 33C is made as small as possible (0.4
μH). As a result, an IC socket having good high-frequency characteristics can be provided.

Further, a ball B is formed by setting three movable contact pieces as one set.
, The ball B receives reaction forces from three directions, and can maintain the contact state in a stable state. Therefore, since the contact state is stable, I
The advantage that a C socket can be obtained is obtained.

[Brief description of the drawings]

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

FIG. 2 is a side view for explaining a structure of a terminal of an IC under test which comes into contact with an IC socket according to the present invention.

FIG. 3 is an exemplary perspective view showing an embodiment of an IC socket contact used in the IC socket shown in FIG. 1;

FIG. 4 is a plan view for explaining a manufacturing process of the IC socket contact shown in FIG. 3;

FIG. 5 is a cross-sectional view showing an enlarged part of the IC socket shown in FIG. 1;

FIG. 6 is a plan view of FIG. 5 as viewed from above.

FIG. 7 is a perspective view showing a modified example of the IC socket contact shown in FIG. 3;

FIG. 8 is a perspective view showing still another modified embodiment of the IC socket contact shown in FIG. 3;

FIG. 9 is a plan view showing still another modified example of the IC socket contact shown in FIG. 3;

FIG. 10 is a perspective view showing still another modified example of the IC socket contact shown in FIG. 3;

FIG. 11 is a plan view showing an embodiment of an IC socket contact proposed in claim 2 of the present invention.

12 is a cross-sectional view for explaining a mounting body of the IC socket contact shown in FIG. 11;

FIG. 13 is a plan view for explaining a contact state with a contact ball for an IC socket shown in FIG. 11;

FIG. 14 is a perspective view for explaining an IC socket on which the contacts for the IC socket shown in FIGS. 11 to 13 are mounted.

FIG. 15 is a plan view showing another embodiment of the IC socket contact shown in FIGS. 11 to 13;

16 is a cross-sectional view for explaining a contact body between the IC socket contact and the ball shown in FIG.

FIG. 17 is a plan view showing another embodiment of the IC socket contact shown in FIGS. 11 to 13;

FIG. 18 is a sectional view for explaining the structure of FIG. 17;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 IC under test B ball 20 IC socket 21 Depression 22 Bottom plate 23 Partition wall 30 Contact for IC socket 31 Conductive plate 32 Cut 33A-33D Movable contact piece 34A-34C Terminal

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2G003 AA07 AG01 AG12 AH05 AH07 2G011 AA01 AA16 AC06 AC14 AC32 AE22 AF02 5E024 CA18 CB02

Claims (4)

[Claims] 1. A movable contact piece is formed by a conductive plate having a width of at least about 1/3 of a diameter of a ball of a ball grid array to be contacted, and the movable contact piece is followed by a conductive plate having an equivalent width. A contact for an IC socket, wherein a terminal is formed. 2. The rectangular conductive plate has two cuts formed in parallel from both short sides to long sides thereof, and each of the three tongues formed by the two cuts is formed. Is cut and raised in one direction, and a movable contact piece is formed by this tongue piece, and a terminal is formed by a tongue piece formed by cutting and raising the other remaining tongue pieces in the opposite direction. An IC socket contact having a structure. 3. A plurality of tongues are formed in the radial direction from the polygonal conductive plate, and all of the plurality of tongues are cut and raised in the same direction to form a movable contact piece. A contact for an IC socket, wherein a conductor is protruded from the plate surface in a direction opposite to the direction in which the movable contact piece protrudes, and a terminal is formed by the conductor. 4. A bottom plate made of an insulating material, and an insulating partition protruding substantially vertically from one surface of the bottom plate, wherein a concave portion surrounded by the insulating partition is provided. An IC socket characterized by storing any one of the IC socket contacts described in any one of (1) to (3).