JPH11135217A - Ic socket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain stable connection by reducing an inductance between a solder ball of an integrated circuit and an electrode of a circuit board and by sufficiently absorbing a high coplanarity, to simplifying the structure to be suitable for mass production, and to reduce the outside dimensions. SOLUTION: On a flexible substrate 10 composed of a sheet of insulative plate material having flexibility, a plurality of movable pieces 11 corresponding to a plurality of solder balls 101 of an integrated circuit 100, with their three sides cut by slits 14 are formed in the cantilever constitution, and a contact plate 1 which forms electrode layers 12 electrically connected between the both sides of the movable pieces 11 is installed on each both sides of the movable pieces 11. Spacers 2 which hold the contact plates 1 with a prescribed interval for the surface of the circuit board 200 are installed. Each of the plural solder balls 101 is pressed against one of the electrode layers 12 of a plurality of the movable pieces 11 to curve the movable pieces 11, and a positioning frame 3, pressurizing springs 4, mounting screws 5, etc., are installed to press the electrode layer 12 of the other side of the movable piece 11 against the corresponding electrode 201.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an IC socket, and more particularly to a method for connecting an integrated circuit called a CSP type or a BGA type having a large number of ball-shaped electrodes arranged on a package mounting surface to a circuit such as a circuit board. Of IC sockets.

[0002]

2. Description of the Related Art A semiconductor integrated circuit (hereinafter simply referred to as an integrated circuit or an
CSP (Chip Size Package), which has a structure in which solder bumps are formed in a ball shape on the mounting side of the package,
What is called GA (Ball Grid Array) is increasing. 2. Description of the Related Art In a test apparatus for performing electrical tests and inspections of CSP type and BGA type ICs, and in an electronic device requiring replacement of these ICs, an IC socket for connecting these ICs to a circuit such as a circuit board is required. .

[0003] A typical conventional example of such an IC socket is shown below. In the first example of the conventional IC socket shown in FIG. 4, a contact 302 of both ends insertion type is held in a through hole of a socket body 301, and an upper pin 303 and a lower pin 304 are inserted from both ends of the contact 302. The upper pin 303 and the lower pin 304 are connected to the upper elastomer 30 provided on both sides of the socket body 301.
5 and a lower elastomer 306, and the lower pins 304 are connected to the electrodes 20 of the circuit board 200a.
1a, the upper pin 303 is pressed into contact with the solder ball 101a, which is a connection terminal of the integrated circuit 100a, to connect the integrated circuit 100a to the circuit of the circuit board 200a (for example, Japanese Patent Application Laid-Open No. 8-227770). reference).

In the IC socket 300a of the first example, since the upper pin 303 and the lower pin 304 can be formed thin, it is easy to narrow the pitch of the connection terminals, and from the characteristics of the upper elastomer 305 and the lower elastomer 306 Even if the size (height from the package surface) of the solder ball 101a of the integrated circuit 100a is slightly different (coplanarity), all of the solder ball 101a and the electrode 2
01a, a stable contact force can be obtained.

In a second example of the conventional IC socket shown in FIG. 5 (for example, see Japanese Patent Application Laid-Open No. 9-55273), a slit is formed at one end of a single elastic metal plate. The lever is opened in a V-shape, the solder ball 101b of the integrated circuit 100b is pressed against the V-shape, and the other end is bent to make contact with the electrode 201b of the circuit board 200b. The portion is held by the housing 307. This second
In the example of the IC socket 300b, the solder ball 101b is pressed against the V-shaped part at one end of the contact 308, the other end of the folded contact comes into contact with the electrode 201b, and the intermediate part is held by the housing. , The structure is simple and the solder ball 101b
-The distance between the electrodes 201b can be shortened to reduce the inductance component, and a stable contact force can be obtained even for coplanarity.

[0006] A third example shown in FIG. 6 shows a case in which the surface of a flexible substrate 310 such as a polyimide film is removed.
An electrode layer 311 is formed at a position corresponding to each of the plurality of solder balls 101c of the integrated circuit 100c. These electrode layers 311 are connected to the corresponding terminals 313 by the printed wiring 312. Elastomer 3 between the surface of the circuit board 200c
14 is provided. This third example I
In the C socket 300c, the deformation of the flexible substrate 310 and the elastomer 314 is used to form the solder ball 101.
co-planarity of c. Further, since only the flexible board 310 and the elastomer 314 are inserted between the solder ball 101c and the circuit board 200c, the thickness can be reduced.

FIGS. 4 to 6 showing these examples include:
Between the solder ball of the integrated circuit and the electrode of the IC socket,
In addition, the positioning means between the electrode of the IC socket and the electrode of the circuit board, the pressing means, and the like are omitted.

[0008]

In the above-described conventional IC socket, in the first example, the connection between the solder ball 101a of the integrated circuit 100a and the electrode 201a of the circuit board 200a is established by the upper pin 303 by the contact 302. And the lower pin 304 is connected in series in the axial direction, so that the distance between the solder ball 101a and the electrode 201a is increased and the inductance is increased.
There is a problem that the structure is complicated and not suitable for mass production, and the thickness is large. In the second example, the solder ball 101b of the integrated circuit 100b and the electrode 201b of the circuit board 200b are used.
Are connected by a contact 308 obtained by processing a single metal plate, so that the structure is simplified as compared with the first example, and the solder balls 101b.
Although the space between the electrodes 201b is short (thin), the contact 308 has a V-shaped portion for receiving the solder ball 101b, a portion held by the housing 307, and the electrode 2
01b is required to have a predetermined length, so that the solder ball 101b and the electrode 201b
There is a problem that the inductance between them is still large and the thickness is large.

In the third example, although the thickness between the solder ball 101c and the surface of the circuit board 200c is reduced,
Since the electrode layer 311 in contact with the solder ball 101c is formed on a continuous plane of the flexible substrate 310,
There is a limit to the deformation between the adjacent electrode layers 311, and when the coplanarity of the solder ball 101 c is large, the solder ball 101 c cannot sufficiently absorb the coplanarity, or a terminal connected to a circuit (electrode) of the circuit board 200 c. Since 313 is disposed outside the formation region of the electrode layer 311, the distance between the solder ball 101 c and the circuit of the circuit board 200 c becomes longer, the inductance between them increases, and the external dimensions also increase. There is a point.

SUMMARY OF THE INVENTION In view of the above-mentioned problems of the prior art, an object of the present invention is to reduce the distance between the solder balls of an integrated circuit and the electrodes of a circuit board to reduce the inductance, and at the same time, to increase the inductance. Provided is an IC connector that can sufficiently absorb coplanarity to obtain a stable connection, and can simplify the structure and is suitable for mass production, and can be reduced in thickness by reducing its thickness and external dimensions. It is in.

[0011]

SUMMARY OF THE INVENTION An IC socket according to the present invention comprises a plurality of solder ball type connection terminals formed on a surface of a package of an integrated circuit mounted on a plurality of electrodes formed on a surface of a circuit board. An IC socket for corresponding connection, characterized by having the following configuration to achieve the above object. (B) A plurality of movable pieces, each of which is made of a single plate material made of a flexible insulating material and corresponding to each of the plurality of connection terminals of the integrated circuit, is cut at three sides to form a cantilever structure. A contact plate comprising: a formed flexible substrate; and a plurality of electrode layers formed on both surfaces of each of the plurality of movable pieces and electrically connected between both surfaces. (B) The contact plate and the circuit board (C) a plurality of connection terminals of the integrated circuit corresponding to an electrode layer on one surface of the plurality of movable pieces of the contact plate; The integrated circuit, the contact plate, and the metal plate are pressed against the circuit board so that the plurality of movable pieces are bent to press the electrode layers on the other surface of the plurality of movable pieces in correspondence with the plurality of electrodes of the circuit board. Positioning and holding means for holding of over support

In addition, the positioning / holding means presses a package surface of the integrated circuit by positioning a positioning frame for aligning a plurality of connection terminals of the integrated circuit with a plurality of electrode layers of the contact plate. A plurality of connection terminals of the integrated circuit, a plurality of electrode layers of the contact plate, and a pressure spring for obtaining a pressing pressure between the plurality of electrodes of the circuit board;
The circuit board includes a lock mechanism for holding and fixing the contact plate, the spacer, the positioning frame, and the pressure spring. Furthermore, a conductive uneven electrode layer in which protrusions of a predetermined size are uniformly distributed is laminated on the entire surface of each of the plurality of electrode layers of the contact plate of the IC socket.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention comprises a single plate made of a flexible insulating material, and three sides are cut at positions corresponding to a plurality of connection terminals of an integrated circuit. A flexible substrate on which a plurality of movable pieces having a cantilever structure are formed, and a contact including a plurality of electrode layers formed on both surfaces of the plurality of movable pieces so as to be electrically connected between the respective surfaces. Plate, a spacer for holding the contact plate and the surface of the circuit board so as to be at a predetermined distance, and a plurality of connection terminals of the integrated circuit, one of a plurality of movable pieces of the contact plate. The circuit board is pressed in such a manner that the plurality of movable pieces are bent in correspondence with the electrode layers on the surface, and the electrode layers on the other surface of the plurality of movable pieces are pressed in correspondence with the plurality of electrodes of the circuit board. On Integrated circuits, and has a configuration having an aligning and holding means for performing contact plate and the spacer retention.

With such a configuration, the degree of curvature of the movable piece changes in accordance with the degree of coplanarity, so that a large coplanarity can be absorbed and a stable connection can be obtained. The distance between the terminal and the electrode on the circuit board can be reduced to the sum of the thickness of the movable piece, the thickness of the electrode layers on both sides thereof, and the dimension that can absorb coplanarity, so the inductance between them can be reduced. And the thickness of the IC socket can be reduced. Further, the structure of the contact plate for electrically connecting the connection terminals of the integrated circuit and the electrodes of the circuit board is simple and suitable for mass production. Since the outer region of the electrical connection structure only needs to have the dimensions necessary for positioning and holding the integrated circuit and the contact plate, the outer dimensions are reduced by reducing the thickness as described above. Can be

[0015]

Next, an embodiment of the present invention will be described with reference to the drawings. 1A and 1B are a sectional side view and a plan view of a contact plate portion showing a first embodiment of the present invention, and FIG. 2 is an exploded perspective view thereof. In this embodiment, a contact plate 1, a spacer 2, and a positioning frame 3 for positioning and holding means,
It is provided with a pressure spring 4, a mounting screw 5, an insulating sheet 6, and a back plate 7, and details of these configurations are as follows. The contact plate 1 is made of a single plate material made of a flexible insulating material, and has a plurality of (in this embodiment, nine in order to make the structure easy to understand) solder balls of connection terminals of the integrated circuit 100. 101, a flexible substrate 10 on which a plurality of movable pieces 11 each having a cantilever structure, each of which is cut by a slit 14 at three positions, are formed on both sides of each of the plurality of movable pieces 11; And a plurality of electrode layers 12 formed so as to be electrically connected to each other through through holes 13. The spacer 2 holds the outside of the region where the plurality of movable pieces of the contact plate 1 are formed, such that the distance between the contact plate 1 and the surface of the circuit board 200 is a predetermined distance.

The positioning and holding means comprises a plurality of solder balls 101 of the integrated circuit 100 by the positioning frame 3.
The package of the integrated circuit 100 is held so that the positions of the integrated circuit 100 and the plurality of electrode layers 12 of the contact plate 1 are matched, and the surface of the package of the integrated circuit 100 is pressed by the pressing spring 4 formed of an elastic plate material. Between the plurality of solder balls 101 of the integrated circuit 100 and the electrode layer 12 on one surface of the plurality of movable pieces 11 of the contact plate 1, and between the electrode layer 12 on the other surface of the plurality of movable pieces 11 and the circuit board 200 A plurality of electrodes 20
1 and a predetermined pressing force is applied to the mounting screw 5, the insulating sheet 6 and the tapped holes 7 on the back side of the circuit board 200.
1, the contact plate 1, the spacer 2, the positioning frame 3, the pressure spring 4, and the integrated circuit 10
0 is held on the circuit board 200,
The structure is such that the positions of the plurality of electrode layers 12 of the contact plate 1 are aligned with the plurality of zero electrodes 201.

In this embodiment, when the solder ball 101 of the integrated circuit 100 is pressed against the electrode layer 12 on one surface of the movable piece 11 of the contact plate 1 by the pressure spring 4, the movable piece 11 is pushed in and its tip ends. Electrode 2 of circuit board 200
It hits 01 and curves. At this time, the solder balls 10
1 contacts and connects with the electrode layer 12 on one surface of the movable piece 11, and the electrode layer 12 on the other surface of the movable piece 11 contacts and connects with the electrode 201 of the circuit board 200. The movable distance of the solder ball 101 from the start of bending of the movable piece 11 to the limit of bending (the state where it cannot be pushed further) is determined by the thickness of the spacer 2, and this thickness is set appropriately. Thus, even if there is a difference in the coplanarity, the connection can be sufficiently absorbed and a stable connection can be obtained.

Further, since the solder ball 101 and the electrode 201 are electrically connected by the electrode layers 12 formed on both surfaces of the movable piece 11 of the contact plate 1, the distance is extremely short, and the inductance is small. Can be greatly reduced, and the interval therebetween can be reduced, so that the thickness of the entire IC socket can be reduced. Moreover, the outer regions of the electrical connection structure such as the movable piece 11 and the electrode layer 12 are:
Since only the space necessary for positioning and holding the integrated circuit 100 and the contact plate 1 with respect to the circuit board 200 is sufficient, the external dimensions including the above-described thickness are reduced, and the size can be reduced.

Further, the contact plate 1 has a simple structure in which a slit 14 is formed in one flexible substrate 10 to form a movable piece 11 and the electrode layers 12 are formed on both surfaces of the movable piece 11. The manufacturing process is also simple, inexpensive and suitable for mass production. Although the movable piece 11 is square in this embodiment, the same effect can be obtained even if the movable piece 11 is made round. Although the electrode layers 12 on both surfaces of the movable piece 11 are connected by the through holes 13, the electrode layers 12 may be connected by a metallized layer on the side surface of the movable piece 11. Furthermore, although the movable piece 11 is formed by forming the slits 14 in three directions, it is also possible to simply make a cut.

FIG. 3 is an enlarged sectional side view of a movable piece and an electrode layer portion of a contact plate according to a second embodiment of the present invention. This embodiment has a structure in which projections and depressions having dimensions sufficiently smaller than the solder balls 101 of the integrated circuit 100 are uniformly distributed on the entire surface of the electrode layer 12 in the first embodiment. . The uneven electrode layer 15 can be easily formed on the movable piece 11 by composite plating or thermal spraying of a conductive material. By providing the uneven electrode layer 15,
Even if the surface of the solder ball 101 or the electrode 201 of the circuit board 200 is covered with an oxide film or a contaminant film, the protrusion of the uneven electrode layer 15 breaks through the oxide film or the contaminant film, so that conduction can be obtained. Therefore, even with a small contact pressure, the electrical connection between the solder ball 101 and the electrode 201 can be further stabilized.

[0021]

As described above, according to the present invention, a single flexible insulating plate is provided with a plurality of movable pieces corresponding to a plurality of solder ball type connection terminals of an integrated circuit in three directions. A contact plate formed by cutting to form a cantilevered structure and forming an electrode layer electrically connected between both surfaces of each of the plurality of movable pieces is provided at a predetermined distance from the surface of the circuit board by a spacer. And the plurality of connection terminals of the integrated circuit are pressed in correspondence with the electrode layers on one surface of the plurality of movable pieces of the contact plate to bend the plurality of movable pieces, and at the same time the other of the plurality of movable pieces. By pressing each electrode layer on the surface corresponding to the multiple electrodes on the circuit board, even if there is a difference in coplanarity, it can be sufficiently absorbed and a stable connection can be obtained. ,And The distance between the connection terminal of the integrated circuit and the electrode of the circuit board is shortened, so that the inductance therebetween can be greatly reduced, and at the same time, the thickness of the entire IC socket can be reduced. The external area of the electrical connection structure between the connection terminals and the plurality of electrodes of the circuit board need only be the space necessary for positioning and holding the integrated circuit, the contact plate, the spacer, etc. with respect to the circuit board. The thickness of the contact plate can be reduced, including the above thickness, so that the size can be reduced. Further, the contact plate has a simple structure and a simple manufacturing process, and is inexpensive and suitable for mass production.

Further, by providing a structure in which a concavo-convex electrode layer in which projections are uniformly distributed is provided on the entire surface of the electrode layer of each contact plate of the contact plate, the surface of the connection terminal of the integrated circuit or the electrode of the circuit board is provided. Even if is covered with an oxide film or a contaminant film, the protrusion of the uneven electrode layer breaks through the oxide film or the contaminant film, so that the electrical connection can be further stabilized even with a small contact pressure. There is.

[Brief description of the drawings]

FIG. 1 is a sectional side view and a plan view of a contact plate portion showing a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of the embodiment shown in FIG.

FIG. 3 is a sectional side view of a movable piece and an electrode layer portion of a contact plate according to a second embodiment of the present invention.

FIG. 4 is a partial cross-sectional side view of a first example of a conventional IC socket.

FIG. 5 is a partial cross-sectional side view of a second example of a conventional IC socket viewed from two directions.

FIG. 6 is a partial cross-sectional side view of a third example of a conventional IC socket.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Contact plate 2 Spacer 3 Positioning frame 4 Pressure spring 5 Mounting screw 6 Insulating sheet 7 Back plate 10 Flexible board 11 Movable piece 12 Electrode layer 13 Through hole 14 Slit 15 Uneven electrode layer 100, 100a-100c Integrated circuit 101, 101a- 101c Solder ball 200, 200a-200c Circuit board 201, 201a, 201b Electrode 300a-300c IC socket

Claims (3)

[Claims] An IC socket for connecting a plurality of solder ball type connection terminals formed on a surface of a package of an integrated circuit on a mounting side to a plurality of electrodes formed on a surface of a circuit board. IC having each configuration
socket. (B) A plurality of movable pieces, each of which is made of a single plate material made of a flexible insulating material and corresponding to each of the plurality of connection terminals of the integrated circuit, is cut at three sides to form a cantilever structure. A contact plate comprising: a formed flexible substrate; and a plurality of electrode layers formed on both surfaces of each of the plurality of movable pieces and electrically connected between both surfaces. (B) The contact plate and the circuit board (C) a plurality of connection terminals of the integrated circuit corresponding to an electrode layer on one surface of the plurality of movable pieces of the contact plate; The integrated circuit, the contact plate, and the metal plate are pressed against the circuit board so that the plurality of movable pieces are bent to press the electrode layers on the other surface of the plurality of movable pieces in correspondence with the plurality of electrodes of the circuit board. Positioning and holding means for holding of over support 2. A positioning frame for aligning a plurality of connection terminals of the integrated circuit with a plurality of electrode layers of the contact plate, and a positioning frame for pressing a package surface of the integrated circuit. A plurality of connection terminals of the integrated circuit, a plurality of electrode layers of the contact plate, and a pressure spring for obtaining a pressing pressure between the plurality of electrodes of the circuit board; and the contact plate on the circuit board, the spacer, the 2. The IC socket according to claim 1, comprising a positioning frame and a lock mechanism for holding and fixing the pressure spring. 3. An IC in which a conductive uneven electrode layer in which projections of a predetermined size are uniformly distributed over the entire surface of each of a plurality of electrode layers of the contact plate of the IC socket according to claim 1.
socket.