Socket having two cams

1. Field of the Invention

The present invention relates to a socket, especially to a Pin Grid Array (PGA) socket mounted to a printed circuit board and adapted for electrically connecting a semiconductor package.

2. Description of the Related Art

With the development of technology, socket connectors, which have pins or solder balls, are found widespread applications in computers and other electrical devices for transmitting signals and conducting current between a printed circuit board (PCB) and an IC package.

U.S. Pat. No. 6,500,019, issued to Honhai on Dec. 31, 2002 discloses a related socket, the socket comprises an insulative base, a dielectric cover, a metallic cam, a washer, a plurality of electrical contacts, and a metallic ring. The base comprises a plurality of passageways for contacts and a flange located at one side of the base and defining a hole. The cover comprises a plurality of passageways extending therethrough for insertion of pins of an IC package and a mounting portion corresponding to the flange of the base and defining a circular aperture. The metallic ring is secured in the aperture of the cover, the cam inserts into the metallic ring and extends beyond a bottom surface of the base, so that the cam is rotatably secured to the base and the cover by being riveted with the washer. The metallic cam comprises a head, an upper disk extending downwardly from the head, a lower disk and a riveting portion. A rotational axis of the lower disk is offset from a rotational axis of the upper disk. So, a rotation of the cam forces the cover to slide along the base and makes the pins (not shown) of the PGA chip engage/disengage with the contacts in the passageways.

However, the socket has a complex configure, that need more time to manufacture and assembly the socket, and that also means the product has a high cost.

Hence, an improved socket is required to overcome the disadvantages of the prior art.

An object of the invention is to provide a socket with simple configure.

To achieve the above-mentioned object, a socket, adapted for electrically connecting an IC package, comprises an insulative housing having a main body which defining a receiving space for the IC package and two flanges on two sides of the main body; and a pair of cams located on the flanges respectively, each cam defining a first position and a second position where the cam is close to a center of the receiving space relative to the first position, each cam can rotate between its first position and its second position.

Other features and advantages of the present invention will become more apparent to those skilled in the art upon examination of the following drawings and detailed description of preferred embodiments, in which:

FIG. 1 is an assembled, perspective view of a socket in accordance with a preferred embodiment of present invention;

FIG. 2 is another assembled, perspective view of the socket shown in FIG. 1 , taken from another side;

FIG. 3 is an exploded, perspective view of the socket shown in FIG. 1 ;

FIG. 4 is a section view of the socket along line 4 - 4 in FIG. 1 ;

FIG. 5 is top view of the socket;

FIG. 6 is a sketch view, showing a pin of an IC package inserting into the socket;

FIG. 7 is a front view of a cam of the socket;

FIG. 8 is a side view of the cam of the socket; and

FIG. 9 is a sketch view to show an operating process of the socket.

Reference will now be made in detail to the preferred embodiment of the present invention.

Referring to FIGS. 1-2 , a socket in accordance with a preferred embodiment of present invention is adapted for electrically connecting an IC package 5 to a printed circuit board (not shown), the socket comprises an insulative base 1 , a pair of metal cams 2 assembled to the base 1 , a pair of metal plates 3 for retaining the cams 2 on the base 1 and a plurality of contacts (not shown).

Referring to FIG. 3 , conjoining with FIG. 4 , the base 1 comprises a main body 10 in the shape of a square, and two flanges 12 symmetrically disposed on two opposed sides of the main body 10 . The main body 10 has a bottom wall 102 and a plurality of sidewalls 104 , which define a receiving space 100 for the IC package 5 , together with the bottom wall 102 . The bottom wall 102 defines a plurality of passageways 103 extending vertically there through.

The two flanges 12 have a same configure. Each of the two flange 12 is in an approximately arc shape and defines a recess 13 downwardly recessed from a center thereof and a circle hole 14 vertically passing through the recess 13 . The recess 13 has a bottom face which is coplanar with a top surface of the main body 10 , and communicates with the receiving space 100 . Each of the two flanges 12 further has a room 15 on a bottom surface 106 thereof to receive the metal plate 3 .

The two cams 2 include a first cam 21 and a second cam 22 , which have a same configure. Each of the first and the second cams 21 , 22 has an upper cylindrical post 25 , a lower cylindrical post 26 downwardly extending from the upper cylindrical post 25 , and a riveting end 27 on a bottom end of the lower cylindrical post 26 .

Each of the metal plates 3 has a tube portion 30 with an aperture 31 and a horizontal piece 32 outwardly extending from a circumference edge of the tube portion 31 and having a contour corresponding to a shape of the room 15 of the base 1 . The IC package 5 has a substrate plate 51 which can be directly forced by the cam 2 .

Conjoined with FIG. 1 , the metal plate 3 is mounted to the flange 12 of the base 1 from a bottom side, the horizontal piece 32 is received in the room 15 , and the tube portion 30 is received in and inserts into the circle hole 14 of the base 1 . The cam 2 is assembled to the flange 12 of the base 1 from a top side, the upper cylindrical post 25 is positioned in the recess 13 of the flange 12 and the lower cylindrical post 26 is received in the apertures 31 of the metal plate 3 , respectively. The riveting end 27 extends beyond the bottom surface 106 of the base 1 and is riveted with the metal plate 3 to retain the cam 2 on the base 1 .

Referring to FIG. 5 and FIG. 6 , FIG. 5 shows a working process of the socket, the IC package 5 is received in the receiving space 100 of the socket and reliably retained by the cams 2 . The IC package 5 has a plurality of pins 52 (only one is shown in FIG. 6 ) inserting into the passageway 103 of the socket to electrically connect with contact (now shown).

Referring to FIG. 7 and FIG. 8 , a center axis A of the upper cylindrical post 25 is offset from a center axis B of the lower cylindrical post 25 , while the center line B is a rotational axis, so the upper cylindrical 25 can occur a deflection rotation and enter the receiving space 100 to forces the IC package 5 to move. The upper cylindrical post 25 defines a cross groove (not labeled), so that a driver (not shown) can drive the cam 2 to rotate, furthermore the upper cylindrical post 25 has a stop block (not labeled) protruding from an out edge thereof, correspondingly, the flange 12 is formed with two spaced projections 16 around the recess 13 to prevent the stop block (not labeled) from over rotation and define a move range of the cam 2 .

Each of the cam 2 has a first position and a second position where the cam 2 is more close to a center of the space 100 relative to the first position, each cam 2 can rotate from its first position to its second position by being driven by the driver (not shown), the stop block (not labeled) engages with the projections 16 to limit a rotation the cam 2 only between its first position to its second position.

Referring to FIGS. 9A-9D , conjoined with FIG. 5 which showing the working process of the socket, firstly, the first cam 21 and the second cam 22 are both in the first positions (referring to FIG. 9A ), in this state, the socket is open, the IC package 5 can be easily put in the space 100 , then the first cam 21 is driven to rotate from its first position to its second position and forces the IC package 5 to move toward and abut against the opposed sidewall 104 (referring to FIG. 9B ), of course, the IC package 5 may also abut against the second cam 22 , anyway, the IC package 5 is retained by the cam 21 or by the cams 21 , 22 and the sidewall 104 in a steady close state, that also is a working state of the socket, and the IC package 5 electrically connects with the contacts (not shown).

When removing the IC package 5 from the socket, firstly, the first cam 21 back rotates to its first position (referring to FIG. 9C ), then the second cam 22 is driven to rotate from its first position to its second position to force the IC package 5 to return to an initial position (referring to FIG. 9D ), finally, the second cam 22 back rotates to its first position, which also is an original state of the socket shown in FIG. 9A , so the first and the second cams 21 , 22 both return to the first positions, then the IC package 5 is easily picked up from the receiving space 100 . Some indicates (not shown) may provided on a top surface of the flange 12 to lead operator to a correct operation.

The socket has a simple configure with a simple cam 2 and without a cover, the socket also can reliably retain the IC package 5 in the receiving space 100 of the socket with an easy operation. For the socket does not have a cover, correspondingly the pin 52 can be designed with a short length, obviously, that can reduce a cost of the IC package 5 .

While the present invention has been described with reference to preferred embodiments, the description of the invention is illustrative and is not to be construed as limiting the invention. Various of modifications to the present invention can be made to preferred embodiments by those skilled in the art without departing from the true spirit and scope of the invention as defined by the appended claims. For example, the side wall 104 may be equipped with a stepped structure to abut downwardly against the corresponding corners of the IC package 5 for retention. The second cam 22 may be equipped with a resilient device to urge the second cam 22 back to the first position once the rotation force is removed therefrom. Understandably, the first cam 21 may be equipped with the resilient device to urge the first cam 21 to back to the first position, if the retention of the IC package 5 is sufficient by the aforementioned steppe structures of the side wall.