JPH07287048A - Ic socket and its electrical contact - Google Patents

Abstract

PURPOSE:To connect a BGA(Ball Grid Array) type package IC and its reliable IC socket with an improved electrical contact. CONSTITUTION:An IC socket is provided with a contact means 19 consisting of a metal electrical contact 10 and an elastic rubber 20. When a bump 30 is pressed against the electrical contact 10, the bump 30 receives the elastic force of a metal plate and the elastic rubber 20 and generates wiping operation in reference to a contact part 17 of the electrical contact 10 and at the same time is electrically and mutually connected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an IC socket, especially a BG.
The present invention relates to an IC socket accommodating an IC of a ball (ball grid array) type package, and particularly to an IC socket suitable for a burn-in socket for performing a burn-in test.

[0002]

2. Description of the Related Art Conventionally, various types of IC sockets have been proposed, for example, Japanese Utility Model Laid-Open No. 63-41886.
JP 63-41887 JP, JP 4-218284 JP, JP JP
5-90378, etc. IC to house these
Can be classified according to the type of package. At present, the main packaging method is QFP (quad flat package) or TQFP (thin quad flat package). According to these packages,
A plurality of leads for electrical connection are formed in a shape that extends from the side surface of the IC and extends downward, and is electrically connected to a pad on the substrate at a substantially lower surface of the lead. Therefore, in these packages, the leads extend laterally, so that the mounting area is not always effectively utilized.

In consideration of this point, as a package for increasing the mounting density, there is a package method called BGA (ball grid array) which has been used for some applications from the past (Actual Publication No. 5-90378). See the bulletin). According to this package, solder bumps (hemispherical protrusions) are formed on the bottom surface of the IC, and these bumps are brought into electrical contact with mating terminals, pads and the like. Since the bottom surface of the IC is used for mounting, the mounting area can be effectively used.

[0004]

However, at present, there are few IC sockets corresponding to the BGA package, and an IC socket having a simple structure corresponding to the BGA package and having higher reliability has been desired. In particular, burn-in sockets are tested under high-temperature, low-temperature, or high-low temperature cycles, so even IC sockets compatible with BGA packages have high contact reliability under such severe conditions. Was desired.

[0005]

The present invention has a plate-shaped elastic rubber and metal electrical contacts arranged approximately two-dimensionally along the plate surface of the elastic rubber. A connector is provided with an contact portion for contacting a conductive bump on one side of the plate surface, and the elastic rubber supports the elastic deformation of the metal of the electric contact at the time of contact, thereby providing an IC socket. .

Further, according to the present invention, a contact portion elastically contacting a contact (conductive bump) of a BGA package type IC, a connection portion connected to a conductor of a circuit board, and between the connection portion and the contact portion. An electric contact for an IC socket, the fixing part being formed and supported and fixed in the opening of the insulating elastic plate, the contact part being configured to cooperate with the surface of the insulating elastic plate. It is a thing.

In the IC socket of the present invention, a large number of metallic electrical contacts that come into contact with the bumps of the BGA type package IC are arranged at a suitable pitch along the substantially plate-like elastic rubber surface.
It is arranged dimensionally.

Each electrical contact has a contact near one free end. The contact portion is located on the flexible elastic portion of each electrical contact. When electric sound is placed in the elastic rubber, the contact portion extends obliquely from the top surface of the elastic rubber. Further, the vicinity of the free end is bent and formed so as to be substantially in contact with the elastic rubber top surface.

When the BGA type package IC is mounted, each bump is placed facing each electrical contact and abutted against each other. Thereafter, the IC is pressed against each contact, so that the contact portion receives a pressing force through the bump from a direction substantially perpendicular to the elastic rubber plate surface. This causes the electrical contacts and the elastic rubber to flex, creating a wiping effect between the contact and the bump. Electrical contact is maintained by the elasticity of the electrical contacts and elastic rubber.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of an IC socket of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an electrical contact 10 used in an IC socket according to the first embodiment of the present invention. The electrical contact 10 comprises a head 11 and a leg (connection part) 12. head
11 has a contact portion 17 composed of a pair of arms 13 at one end. The pair of arms 13 are arranged in a substantially coplanar relationship.
Grooves 15 are formed between 13. The arm 13 has a spring portion 16 near the tip. The head portion 11 further includes a plate portion 14 that connects the pair of arms 13 and the leg portion 12 to each other.

According to FIG. 1, the leg 12 is formed in a substantially elongated plate shape having a slot 18. This allows the legs 12 to be elastically sandwiched within the through holes in the printed circuit board and then soldered. FIG. 2 shows an electric contact disposed in an elastic rubber (all organic materials having elasticity are collectively referred to as elastic rubber. Si rubber, viton, which will be described later, and a polymer material such as an elastomer are included.) 20. 10 is shown. This constitutes the contact material 19 with the bumps 30 of the BGA type package IC. The plate portion (fixed portion) 14 is located inside the elastic rubber 20, and inside the elastic rubber 20 is a top surface 21 and a bottom surface.
It extends in a direction substantially perpendicular to 22. As shown in Fig. 1, the plate part
The leg 14 is formed wider than the leg 12. The pair of arms 13 projects from the top surface 21 and extends upward. The spring portion 16 of the arm 13 contacts the top surface 21 of the elastic rubber 20 near the free end.

As shown in FIG. 2, the bump 30 of the BGA package IC is pressed against the arm and elastically contacts. Upon contact, the bump 30 is located in the groove 15 formed between the pair of arms 13. Since the groove 15 is formed sufficiently narrower than the size of the bump 30, the bump 30 and the pair of arms 13 make elastic contact with each other at two points. Further, since the arm 13 is formed to extend obliquely at a desired angle with respect to the pressing direction of the bump 30, the elasticity of the spring portion 16 and the elastic rubber 20 causes a wiping effect with the bump 30 during the pressing process. Cause

At the time of contact between the bump 30 and the arm 13, the elastic force caused by both the electric contact 10 made of metal and the elastic rubber 20 acts as a contact force. Therefore, the contact pressure is a relatively high value of approximately 100 g or more.

The electrical contact 10 is formed by stamping and bending a metal plate. The material is made of metal such as beryllium copper and phosphor bronze for springs. Also the contact part of the electrical contact 10
The 14 is plated with gold or solder.

Further, as the elastic rubber 20, Si rubber, viton or the like is used. Since these materials have excellent heat resistance, they are suitable for application to burn-in sockets and the like.

The contact means 19, ie, the assembly of the electrical contacts 10 and the elastic rubber 20, is prepared by pouring the flowable Si rubber material into the mold after the electrical contacts 10 are arranged at an appropriate pitch, or is cured. Contact receiving slots (openings) are formed at a pitch compatible with the plate-like Si rubber, and the electric contacts 10 are arranged in the contact receiving slots.

FIG. 3 shows a schematic view of the IC socket 40 of the present invention. The IC socket has a housing part 41 arranged facing the printed circuit board 45, the above-mentioned contact means 19, and a cover 42. The contact means 19 is fixedly arranged in the frame-shaped housing part 41. BGA type package IC50 is contact means
The cover 42 is arranged on the BGA package IC 50 and is pressed by the cover 42. Although not shown, the housing part 41 and / or the cover 42 are provided with fixing means for engaging and fixing with each other.

FIG. 4 is a schematic view showing a cross section of the contact of the IC socket using the contact means 19 with the bump 30 of the BGA type package IC 50. As described above, the bump 30 is pressed by the cover 42 to make electrical contact with the contact portion 17 of the electrical contact 10. Further, the leg portion 12 of the electric contact 10 penetrates a through hole (not shown) of the printed circuit board and is soldered and connected to the outside by a pattern formed on the printed circuit board.

FIG. 5 shows an electrical contact 110 used in the IC socket of the second embodiment of the present invention. The electric contact 110 has a head portion 111 and a leg portion (connecting portion) 112 which are integrally formed, like the electric contact 10. Head 11
1 is a flat plate part 114 and a plate part (fixed part) 114
Contact part 117 formed by bending a curved surface on the free end side of
Have. Further, a supporting portion 115 having a supporting surface 116 is bent and formed on the leg side of the head portion 111. Support surface 115 is a slot
The leg portion 112 having 118 extends in a direction substantially perpendicular to the length direction.

In FIG. 6, the electrical contact 110 has an elastic rubber 12
The plate portion 114 of the head portion 111, in which the contact means 119 arranged at 0 is shown, is disposed in the elastic rubber 120 so as to extend obliquely at a predetermined angle, and the support portion 115 is arranged at the bottom surface 122 of the elastic rubber 120.
And the support surface 116 abuts the bottom surface 122.
Further, the contact portion 117 of the head portion 111 projects from the top surface 121 of the elastic rubber 120, and the end portion thereof is positioned substantially in contact with the top surface 121. The materials for the electric contact 110 and the elastic rubber 120 are similar to those of the first embodiment.

The operation of each member is similar to that of the first embodiment. Since the contact portion 117 of the electric contact 110 is formed in a curved shape, when the pressing force of the bump 30 is applied, a metal plate and elastic rubber are used.
It is wiped by the elasticity of 120 and then electrically contacted with a high contact pressure.

FIG. 7 shows the contact means 319 used in the IC socket of the third embodiment of the present invention. Means of contact 319
Consists of electrical contacts 310 and elastic rubber 320. The electrical contact 310 comprises a contact 317 consisting of a pair of opposed arms 313 forming a slot 315 between the pair of arms 313. The arm 313 extends from the fixed portion 314. The electrical contact 310 is housed in a cavity 350 of elastic rubber 320. The arm 313 contacts the inner surface 351 of the cavity 350 in the elastic rubber 320, and is formed slightly inward in the vicinity of the contact side with the bump 30, and the groove 316 on the contact side of the arm 313 is located outside the inner side. The inward elastic rubber top surface 321 is formed beyond the outer edge of the cavity 350. The legs 312 (connections) at the opposite ends are fixed in the through holes of the printed circuit board 345, and when the bumps 30 are pressed against the ends 316 of the arms 313 of the electrical contacts 310, the arms 313 have elasticity. Bends outwards. When further pressed, the arm 313 deforms the inner surface 351 of the cavity 350 outward. Therefore, the arm 313 and the elastic rubber are provided between the bump 30 and the end 316.
The elastic force caused by both 320 acts as a contact force.

In the process of pressing the bump 30 as described above, a wiping action occurs between the end portion 316 and the bump 30.

Although the embodiments have been described above, the above embodiments do not limit the present invention, and various modifications can be made by those skilled in the art.

For example, in the first embodiment, the plate portion 14 may be formed to extend obliquely. Also contact means 19,
At 119, the elastic rubber 20, 120 may include slots or openings between adjacent contacts. That is, elastic rubber 20, 120
Can be formed in a generally greed shape. Further, the above-mentioned slots and openings do not need to connect the top surfaces 21, 121 and the bottom surfaces 22, 122 to each other, and may be formed in the middle of the plate thickness direction.

Further, the shape of the legs can be attached to the printed circuit board by various fixing methods such as press fitting and soldering.

[0028]

The IC socket of the present invention comprises a metal electric contact having a spring property and an elastic rubber for providing further spring property. Therefore, electrical contact can be realized by a high contact pressure even though the size is small. Further, since the wiping effect is produced when the solder bump is pressed against the electrical contact, the reliability of the electrical contact is high.

Further, since the IC socket of the present invention has a simple structure, it is highly economical in manufacturing. Further, the electric contact of the present invention is securely fixed to the elastic rubber plate, and can cooperate with the elastic rubber plate to come into contact with the mating solder bump with high contact pressure.

[Brief description of drawings]

FIG. 1 is a perspective view showing an electric contact used in an IC socket according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a contact means used in the IC socket of the first embodiment of the present invention.

FIG. 3 is a perspective view showing the assembly of the IC socket of the first embodiment of the present invention.

4 is a schematic cross-sectional view showing the configuration of the IC socket of FIG.

FIG. 5 is a perspective view showing an electric contact used in the IC socket of the second embodiment of the present invention.

FIG. 6 is a cross-sectional view showing a contact means used in the IC socket of the second embodiment of the present invention.

FIG. 7 is a sectional view showing a contact means used in the IC socket of the third embodiment of the present invention.

[Explanation of symbols]

 10, 110, 310 Electrical contact 30 Conductive bump (contact) 12, 112, 312 Leg (connecting part) 17, 117, 317 Contact part 18, 119, 319 Contact means 20, 120, 320 Elastic rubber (elastic plate)

Claims (2)

[Claims] 1. A plate-shaped elastic rubber, and a metal electrical contact arranged substantially two-dimensionally along the plate surface of the elastic rubber, wherein the electrical contact is provided on one side of the plate surface. An IC socket, comprising: a contact portion that comes into contact with a conductive bump, wherein the elastic rubber supports metal elastic bending of the electrical contact at the time of contact. 2. A contact portion elastically contacting a contact of a BGA package type IC, a connecting portion connected to a conductor of a circuit board, and an opening of an insulating elastic plate formed between the connecting portion and the contact portion. An electric contact for an IC socket, comprising: a fixing portion that is supported and fixed inside, and the contact portion is configured to cooperate with the insulating elastic plate surface.