Land grid array connector assembly

[0002] 1. Field of the Invention

[0003] The present invention relates to an electrical connector assembly for electrically connecting an electronic package such as a central processing unit (CPU) with a circuit substrate such as a printed circuit board (PCB), and particularly to a land grid array connector assembly having a fastening device for securing the CPU therein.

[0004] 2. Description of Prior Art

[0005] FIG. 5 shows a conventional land grid array connector assembly 6 comprising a fastening device 60, and a socket 61 received in the fastening device 60. The fastening device 60 comprises a generally rectangular frame 63, and a lever 62 and a metal clip 64 respectively mounted to opposite sides of the frame 63. The frame 63 defines a pair of locating slots 66 at one side thereof, and a pair of guiding grooves 65 at an opposite side thereof. Each guiding groove 65 is bounded by a first wall 651 and an opposite second wall 652. The lever 62 has a pair of locating portions 623 pivotally received in the locating slots 66 of the frame 63, a driving portion 621 between the locating portions 623, and a handle portion 622 bent perpendicularly from one of the locating portions 623. The clip 64 has a pair of securing portions 641 movably received in the guiding grooves 65 of the frame 63, and a driving hook 644 formed at a free end thereof.

[0006] In use, the clip 64 is firstly oriented perpendicular to the frame 63, with the securing portions 641 disposed in the guiding grooves 65 close to the first walls 651. A central processing unit (CPU) 7 is attached on the socket 61, and a copper plate 8 which functions as a heat dissipation device is attached on the CPU 7. Then the clip 64 is rotated down to a horizontal position, with a pair of pressing arms and a pair of pressing pads of the clip 64 abutting the copper plate 8. The handle portion 622 of the lever 62 is rotated down, and the driving portion 621 of the lever 62 engages in the driving hook 644 of the clip 64. The driving portion 621 drives the driving hook 644 down until the clip 64 is in a final pressing position firmly pressing the copper plate 8 on the CPU 7. However, as can be seen from FIG. 6, during rotation of the clip 64, the securing portions 641 may simultaneously move along the guiding grooves 65 toward the second wall 652. When this happens, to the driving hook 644 moves beyond its correct position. As a result, when the handle portion 622 of the lever 62 is rotated, the driving portion 621 of the lever 62 cannot accurately engage in the driving hook 644 of the clip 64 to drive it. This leads to the clip 64 not reaching its correct final pressing position. Thus, the clip 64 fails to properly secure the copper plate 8 on the CPU 7.

[0007] In view of the above, a new land grid array connector assembly that overcomes the above-mentioned disadvantages is desired.

[0008] Accordingly, an object of the present invention is to provide an electrical connector assembly such as a land grid array (LGA) connector assembly for electrically connecting an electronic package such as a central processing unit (CPU) with a circuit substrate such as a printed circuit board (PCB), whereby the LGA connector assembly has a fastening device for securely and reliably locating the CPU in the LGA connector assembly.

[0009] Another object of the present invention is to provide a fastening device for an electrical connector such as a LGA socket to securely and reliably locate an electronic package such as a CPU in the LGA socket.

[0010] To achieve the above-mentioned object, a LGA connector assembly in accordance with a preferred embodiment of the present invention is for electrically connecting a CPU with a PCB. The LGA connector assembly comprises a socket and a fastening device surrounding the socket. The fastening device comprises an insulative frame having a first side and a second side opposite to the first side, a cam actuator pivotably mounted to the first side of the frame, and a metal clip pivotably mounted to the second side of the frame.

[0011] The clip comprises a plurality of pressing pads, and a post at a free end thereof. The cam actuator comprises a cam and a driver. The cam defines a spiral groove spanning between a circumferential surface of the cam and a center of the cam and facing the clip. The clip is rotated down from a vertical open position to a horizontal closed position, such that the post of the clip is received in the spiral groove of the cam. Movement of the post of the clip toward an end of the frame beyond the cam is limited by a wall of the cam at the spiral groove. Then, the driver is rotated to drive the cam to rotate about a central axis of the cam. The cam drives the post of the clip downwardly, and at the same time the clip moves slightly toward said end of the frame relative to the copper plate. However, excessive such movement in this direction is blocked by said wall of the cam. The handle portion of the driver continues to be rotated until it is locked in a final position. The clip is then at a final pressing position, in which the pressing pads of the clip firmly press down on the copper plate.

[0012] Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which:

[0013] FIG. 1 is a perspective view of a land grid array connector assembly in accordance with a preferred embodiment of the present invention, showing a metal clip of the connector assembly at a vertical open position;

[0014] FIG. 2 is similar to FIG. 1, but viewed from another aspect;

[0015] FIG. 3 is similar to FIG. 2, but showing the clip at a substantially horizontal closed position;

[0016] FIG. 4 is similar to FIG. 2, but showing the clip at the closed position;

[0017] FIG. 5 is a perspective view of a conventional land grid array connector assembly; and

[0018] FIG. 6 is a cross-sectional view taken along line VI—VI of FIG. 5.

[0019] Reference will now be made to the drawings to describe the present invention in detail.

[0020] Referring to FIGS. 1 and 2, a land grid array (LGA) connector assembly 1 in accordance with a preferred embodiment of the present invention is for electrically connecting a central processing unit (CPU) (not visible) with a printed circuit board (PCB) (not shown). The LGA connector assembly 1 comprises a socket (not visible) and a fastening device surrounding the socket. The socket has a plurality of LGA contacts provided therein. The fastening device comprises an insulative frame 2 having a first side and a second side opposite to the first side, a cam actuator 4 pivotably mounted to the first side of the frame 2, and a metal clip 3 pivotably mounted to the second side of the frame 2.

[0021] The frame 2 comprises a low-profile peripheral wall 21 on a top thereof. The peripheral wall 21 cooperates with a main body of the frame 2 to define a receiving recess 211 therebetween. The socket is arranged at a bottom of the receiving recess 211. The CPU is attached on the socket, and a copper plate 5 is attached on the CPU. Thus the CPU and the copper plate 5 are received in the receiving recess 211.

[0022] The first side of the frame 2 has an outer extending portion 22 adjacent a middle of a main portion thereof. A first hook-shaped lock 23 and a second hook-shaped lock 24 extend upwardly from respective opposite ends of the first side of the frame 2. A first supporting rack 221 is upwardly formed on the first side of the frame 2. A second supporting rack 222 is upwardly formed on the extending portion 22 of the frame 2, and is generally parallel to the first supporting rack 221. A receiving slot 223 is defined in the first side of the frame 2, between the first and second supporting racks 221, 222.

[0023] The clip 3 comprises a first end 31 pivotably mounted to the second side of the frame 2, an opposite second end 32 having an outer extending portion 321, and two spaced and parallel beams (not labeled) respectively interconnecting the first and second ends 31, 32. A plurality of symmetrically arranged pressing pads 33 extends perpendicularly from inner edges of the first and second ends 31, 32 and from the beams. A post 3211 is formed at a free end of the extending portion 321, and a gap 3212 is defined in the extending portion 321 between the post 3211 and the second end 32.

[0024] The cam actuator 4 comprises a cam 41 and a driver 42 for driving the cam 41. The cam 41 is partially received in the receiving slot 223 of the frame 2. A supporting pole sequentially passes through the first supporting rack 221, the cam 41 and the second supporting rack 222, thereby rotatably positioning the cam 41 on the frame 2. The supporting pole comprises a first supporting portion 411 at the first supporting rack 221, and a second supporting portion 412 respectively at the second supporting rack 222. The first supporting portion 411 is columnar, and the second supporting portion 412 has square cross-section. A spiral groove 413 is defined in the cam 41. The spiral groove 413 spans between a circumferential surface of the cam 41 and a center of the cam 41, and faces the clip 3. The driver 42 comprises a driving portion 421 fixed on the second supporting portion 412, a handle portion 423 for facilitating manual operation, and a connecting portion 422 interconnecting the driving portion 421 and the handle portion 423.

[0025] In use, the clip 3 is oriented perpendicular to the frame 2 in an open position. This enables the CPU and the copper plate 5 to be inserted into the receiving recess 211 of the frame 2 and then attached on the socket. The cam actuator 4 is oriented at an open position, in which the handle portion 423 of the driver 42 is locked by the first lock 23, and an outmost portion of the spiral groove 413 of the cam 41 is at a highest position (see FIGS. 1 and 2). Referring also to FIGS. 3 and 4, the clip 3 is rotated down to a substantially horizontal closed position until the pressing pads 33 abut the copper plate 5. At this position, the post 3211 of the clip 3 is received in the spiral groove 413 of the cam 41, and part of the first supporting rack 221 of the frame 2 is received through the gap 3212 of the clip 3. Thus the clip 3 is loosely engaged with the cam 41 of the cam actuator 4. Movement of the post 3211 of the clip 3 toward an end of the first side of the frame 2 is limited by a wall of the cam 41 at the spiral groove 413 (see FIG. 3). Then the driver 42 is rotated up and away from the first lock 23. The driver 42 drives the cam 41 to rotate about a central axis of the cam 41. The cam 41 drives the post 3211 of the clip 3 downwardly, and at the same time the clip 3 moves, slightly toward the end of the first side of the frame 2 relative to the copper plate 5. However, excessive such movement in this direction is blocked by the wall of the cam 41 at the spiral groove 413. The handle portion 423 of the driver 42 continues to be rotated until it is locked by the second lock 24. The clip 3 is then at a final pressing position, in which the pressing pads 33 of the clip 3 firmly press down on the copper plate 5.

[0026] While a preferred embodiment in accordance with the present invention has been shown and described, equivalent modifications and changes known to persons skilled in the art according to the spirit of the present invention are considered within the scope of the present invention as defined in the appended claims.