BACKGROUND

[0001] Many integrated circuits (IC) are mounted to a printed circuit (PC) board using a socket. One type of socket is a land grid arrays (LGA) socket . Older style sockets have holes in the socket that, mate with pins attached to the underside of an IC. LGA sockets have protruding pins or spring contacts which touch contact pads on the underside of an IC, LGA sockets typically do not require any insertion force when installing the IC into the socket. The IC is held into the socket against the spring contacts by a Sid. The lid is clamped in place once the IC has been loaded into the socket.

[8002] Aligning and inserting or removing the IC from the socket can be difficult.

Many ICs have special tools designed to assist the insertion of the IC into the socket Even using the special tool the spring contacts may be damaged when the IC is being inserted or removed from the socket. When the spring contacts in the socket become damaged, the socket must be replaced.

BRIEF DESCRIPTION OF THE DRAWINGS

[0003] FIG. LA is an isometric top view of a .detachable lid assembly 100 in an. example embodiment of the invention,

[0004] FIG, IB is an Isometric top view of a socket bottom 150 in an example embodiment of the invention.

[0005] FIG. 1€ is an isometric top cutaway view of socket assembly .180 in an example embodiment of the invention.

[0006] FIG. I D is an isometric top view of a section of a detachable lid assembly in an example embodiment of the invention. [0007] FIG. 2 A Is an isometric, top view of a socket assembly 290 in an example embodiment of die invention,

|000S| FIG. 2B is a close-up isometric view of the spring loading part of socket assembly 290.

[0009] FIG. 2C is an isometric top view of detachable lid assembly 200 in an example embodiment of the invention.

[0010] FIG. 2D is an isometric bottom view of detachable lid assembly 200 in an example embodiment of me invention.

[0011] FIG. 3(A-C) is a pictorial representation for the assembly steps of a socket assembly in an example embodiment of the invention.

[8012] FIG. 4 A is an isometric top view of a socket assembly 490 in an example, embodiment of the invention.

[0013] FIG. 4B. is an isometric top view of independent detachable IC holder 480, in an example embodiment of the invention,

[0014] FIG. 4C is an isometric bottom view of independent detachable IC holder

480, in. an example embodiment of the invention.

DETAILED DESCRIPTION

[0015] FIGS. 1. - 4 and the following description depict specific examples to teach those ski lled in the art how to make and use the best mode of the invention. For the purpose of teaching inventive principles, some conventional aspects have been simplified or omitted. Tbose skilled, in the an will appreciate variations from these examples that fall within the scope of the invention. Those skilled in the art will appreciate that the features described below can be combined in various ways to form multiple variations of the invention. As a result, the invention is not limited to the specific examples described below, but only by the claims and their equivalents. [0016] In one example embodiment of the invention, an LGA socket will have a spring loaded lid. The spring loaded lid may have a bracket attached to the lid. The IC will be mounted into the lid/bracket. The spring will force the iid away from the contacts in the socket until a locking lever is moved into a closed position. Because the spring loaded lid is force away from the socket contacts, damage to the contacts in die socket may be reduced.

[0017] Figure 1 A is an isometric top view of a detachable lid assembly 100 in an example embodiment of the invention. Detachable lid assembly .100 comprises lid 102, bracket 104 and integrated circuit (IC) 106, Lid 1.02 is typically fabricated from a stiff material, for example metal Bracket .104 is fabricated from a flexible material, for example Thermal Plastic Polyurethane (TPU). IC 106 may be any type of semiconductor device, for example a CPU, an application specific integrated circuit (ASIC), a memory device, or the like. Ltd 102 has at least one tongue 108 that extends from one side of Ik! 102. Lid 102 has binge pin 1 10 attached to iid 102 on the opposite side from tongue 106.

[0018] Figure 1 B is an isometric top view of a socket bottom 150 in an example embodiment of the invention. Socket bottom 150 comprises frame 152,. two locking levers (154a and 154b), socket contacts 156 and spring 164. Socket bottom 150 is attached to PC board 168 with screws 158. In some example embodiments of the invention, a stiffener plate (not shown) may he used on the bottom side of PC board 168 capturing PC board 168 between the stiffener plate and the frame 152. The PC board 168 may be the mother board for a personal computer, the processor board of a blade, the memory board of a memory system, or the like ,

[0019] A U-shaped tab 162 is formed at one end of frame 152. The inside ofU- shaped tab 162 forms a .pivot channel that mates with hinge pin 1 10 on lid 102. A pivot channel is a structure that allows the hinge pin to move vertically with respect to the frame, but restricts horizontal motion of the hinge pin. In addition the pivot channel allows the hinge pin to rotate inside the pivot channel about the long axis of the hinge pin. During assembly, the detachable iid assembly is positioned at. an angle with respect to socket base 150 with, the hinge pin closest to the socket base. The hinge pin. 110 is then snapped into the U-shaped tab on the frame 152. When detachable lid 102 is snapped into socket base ISO, hinge pin 110 fits into the pivot channel (inside the curved section of U-shaped tab 162). Spring 164, forces hinge pin 1 10 against the top of the pivot chancel. The width X' of U-shaped tab 162 fits inside the gap X of hinge, pin 1 10. In one example embodiment of the invention, the position of hinge pin I I 0 with respect to the pivot channel is used to align IC 106 to the socket contacts 156. In other embodiments, the IC may be aligned to the socket contacts 156 by one or more edges surrounding socket contacts 156. Once the detachable lid 102 has been snapped into the frame, the lid 10.2 can be rotated, inside the pivot channel, onto the socket bottom 150. In the open position detachable ltd 102 will make an angle of between 45 and 115 degrees with respect to the socket contacts. The two locking Severs can then be rotated from the open position into the closed position. As the locking levers are rotated into the closed position, locking bars 160a and 160b mate with the lid 102 and force the IC mounted in the lid 102 against the socket contacts 156.

[0020] Figure IC is an isometric- ^' top cutaway -view of socket assembly 180 in an example embodiment of the invention. Socket assembly 180 comprises detachable lid 102, IC 106, frame 152, spring 164, screws 158, locking lever 154b and locking bars 160a and 160b. Figure le shows detachable lid 102 in the closed position with both locking levers in the closed position. Locking bar 160b is shown forcing tongue- 108 downward, and locking bar 160a is shown forcing hinge pin 1 10 downward. Before locking lever 154a (see figure lb) is rotated into the dosed position, locking bar 160a does not force hinge pin 110 downwards. Therefore- when locking lever 160a is in the open position, spring 1.64 keeps hinge pin 1 10 pressed against the top of the pivot channel When locking lever 154a (see figure lb) is rotated into the closed position, locking bar 160a forces hinge pin 110 downwards by distance d, forcing the underside of IC 106 against the socket contacts 156. in one example embodiment of the invention distance d is between .5 ··· 3.5 mm. Distance d may be 2.4 mm.

[0021] Because spring 164 keeps hinge pin 110 up against the top of the pivot channel until locking lever is rotated into the closed position, the bottom surface of IC

106 may not make contact with socket contacts 156 until IC 106 is properly aligned with the socket contacts 156. In one embodiment of the invention, the bottom surface of the IC may not touch the socket contacts when the hinge pin is at the top of the pivot channel and the lid is in the closed position. In other embodiment, the bottom surf ace of the IC may be resting on, or slightly compressing, the socket contacts when the hinge pin is at the top of the pivot channel and the lid is in the closed position. In one example embodiment of the invention, the force acting against hinge pin 1.10 by spring 164 is between 1 lb and 3 lbs when the hinge pin is at the top of the pivot channel, and between 6 lbs and 10 lbs when the hinge pin is at the bottom of the pivot channel The spring force may be 2 lbs when the hinge pin is at the top of the pivot channel, and 7 lbs when the hinge pin is at the bottom of the pivot channel. In some example embodiments the spring force is supplies by two springs. In one example embodiment, the lid 200 may not be detachable, but may be permanently attached to the socket frame.

[0922] In another example embodiment of the invention, hinge pin 1 10. may not be cylindrical in shape. Figure ID is an isometric top view of a section of a detachable lid assembly in another example embodiment of the invention. Hinge pin 1 10 in figure ID is not a separated cylindrical part, held by tabs of the lid 102. Hinge pin 1 10 in figure ID is formed as part of the sheet metal of lid 102 and comprises a flat section of length X. When detachable lid 102 is snapped, into socket base 150, the fiat hinge pin 1.10 fits into the pivot channel (inside the curved section of U-shaped tab 162). Spring 164, forces hinge pin 1 .1.0.against the top of the pivot channel. The width X' of U-shaped tab 162 fits inside the gap X of hinge pin 1 10. The fiat hinge pin is able to move vertically with respect to ^' the frame, but is restricted, in horizontal motion. In addition the pivot channel allows the flat hinge pin to rotate inside the pivot channel about the long axis of the hinge pin.

[0023] In another example embodiment of the invention, the lid may be divided into two parts: a detachable part, and a spring loaded part. Figure 2A is an isometric top view of a socket assembly 290 in an example embodiment of the invention. Socket assembly 290 comprises: frame 252, screws 25 S, socket contacts 256, two locking levers 254a and 254b, detachable lid 200, spring loaded lid 270 and IC 206. Figure 2a shows detachable lid 200 detached from spring loaded lid 270 with IC 206 ready to be installed into detachable lid 200. Spring loaded lid 270 is shown in the open position making an angle of approximately 95 degrees with respect to socket contacts 256.

[0024] Figure 3(A-C) is a pictorial representation for the steps used to assemble a socket assembly in an example embodiment of the invention. At step one (figure 3a) the IC is loaded into the detachable lid. At step 2 (figure 3b) the detachable lid is inserted into the spring loaded lid while the spring loaded iid is in its open position. Spring loaded lid makes a large angle (45 ··· 115 degrees) with respect to socket contacts 256 when in the open position. At step 3 (figure 3c) the two part lid (the detachable lid and the spring loaded Hd) is rotated down onto the socket bottom (as shown by arrow 1 ). At step 4 (figure 3c) the lower locking lever is rotated into its closed position (shown by arrow 2), thereby capturing tongue 208 and forcing one end of the IC mounted in the two part lid down against the socket contacts. At step 5 (figure 3c) the upper locking level is rotated into its closed position (as shown by arrow 3), compressing springs 264 and pushing hinge pin 210 down in the pivot channel, thereby forcing the other end of IC mounted in the two ^' part lid down, against the. socket contacts..

[0025] The two locking levers are installed into frame- 252 with one locking J ever mounted at each end of frame 252 (see figure 2a). Each locking lever (254a and 254b) has a locking ^' bar 260a and 260b. Locking bar 260a is shown in front of spring loaded lid 270 (for clarity), in actual operation, locking bar 260a is located behind spring loaded lid 270 (as shown in figure 2b). Both locking levers (254a and 254b) can. be rotated between an open position and a closed position. Both locking levers are shown -in the open position in figure 2a. When locking lever 254b is rotated into its closed position, locking bar 260b captures tongue 208, forcing detachable lid downward. When locking - lever 254a. is rotated into Its closed position, locking bar 260a forces spring loaded lid downward.

[0026] Figure 2B is a close-up isometric view of the spring loading part of socket assembly 290. A hinge pin 210 is attached to one end of spring loaded lid 270. Hinge pin 210 is captured inside slots formed in two parallel tabs 262 bent vertically from, frame 253. The two slots form, a pivot channel A pivot channel is a structure that allows the hinge pin to move vertically with respect to the frame, but restricts horizontal motion of the hinge pin. In addition the pivot channel allows the hinge pin to rotate inside the pivot channel about -the cylindrical axis of the hinge pin. At least one spring 264 is attached to hinge pin 210 and pushes against the bottom of socket assembly 290, forcing hinge pin 210 up into the top of the pivot channel. Hinge pin 210 can move distance d downwards inside the pivot channel, by compressing spring 264. Hinge pin 210 is free to rotate around its cylindrical axis inside pivot channel. Locking lever 254s is shown in the open position with locking bar 260a behind spring loaded lid.

[0027] Figure 2C i s an isometric top view of detachable lid assembly 200 in an example embodiment of the invention- Figure 2D is an isometric bottom view of detachable lid assembly 200 in an. example embodiment of the invention. Detachable lid assembly 200 comprises lid 202, IC holder 280, and 2 stiffeners 284. Lid 202 is fabricated from a stiff material, for example metal Lid 202 has tongue 208 formed at one end. IC. holder 280 is attached to lid 202. Stiffeners 284 are attached to IC holder with IC holder in-between the lid and the stiffeners (see figure 2d). IC ho lder is formed to retain an IC inserted into IC holder. In one embodiment, IC holder 280 may be ^' fabricated from a flexible material and uses an interference fit to retain the IC. In. another embodiment, the IC may snap into IC holder 280 and be retained by the snap features in IC holder 280.

[0028] Detachable lid is configured to be inserted into the. spring loaded lid 270.

Stiffeners 284 mate with channels formed in the spring loaded lid, allowing the detachable. iid to be slid into the spring loaded lid. IC holder may have 2 "click ^' " detents 282 formed in the top surface of IC holder 280, one on each side. The "click" detents 282 snap into corresponding features in the spring loaded lid 270 to let a user know when the detachable lid. has been fully inserted into the spring loaded lid 270. By depressing the "click" features, detachable lid can be removed from the spring loaded lid.

[0029] In another example embodiment of the invention, the spring loaded lid may have an independent detachable IC holder that slides into the lid when the lid is in the open position. Figure 4 A is an isometric top view of a socket assembly 490 in an example embodiment of the invention. Socket assembly 490 comprises: frame 452, screws 458, socket contacts 456, two locking levers 454a and 454b, independent detachable IC holder 480, spring loaded lid 402 and IC 406. Figure 4A. shows independent detachable IC holder 480 detached from spring loaded lid. 402. and ready to be installed into spring loaded lid 402 (as shown by arrows). IC is shown loaded into the independent detachable IC holder 480. Spring loaded lid 402 is shown in the open position making an angle (between 45 and 1. 15 degrees) with respect to socket contacts 456. In one example embodiment, when independent detachable IC holder 480 is slid into spring loaded iid 402, the edges of independent detachable IC holder 480 tit into channels in spring loaded lid. Independent detachable IC holder 480 may have features that snap into place and lock independent detachable IC holder 480 into spring loaded lid 402 when independent detachable IC holder 480 is fully installed.

[0030] Figure 4B is an isometric top view of independent detachable IC holder

480, in an example embodiment of the invention. Figure 4C is an isometric bottom view of independent detachable IC holder 48.0, in an example embodiment of the invention. In figure 4B two slide in detents 490 can be seen formed into the two sides of the

Independent detachable IC holder 480. The two slide In detents interact with two pins 496 (one pin. can be seen in figure 4 A) formed in the two channels on spring loaded lid 402, The two slide in detents "snap'- into place when the independent detachable IC holder 480 is .fully inserted into spring loaded lid 402, Two friction stop features 492 are formed on the bottom side ( see figure 4C) of independent detachable IC holder 480. The friction stop features interact with the two channels formed in spring loaded lid to hold the independent detachable IC holder 480 into the spring loaded lid.

[0031] In one example, embodiment, IC 406 will be loaded into independent detachable IC holder before the IG is provided to a user. In another example- embodiment, IC 406 will be loaded into independent detachable IC holder when IC is loaded into socket assembly 490. Independent detachable IC holder is .formed to retain an IC inserted into the independent detachable IC holder. In one embodiment, independent detachable IC holder 280 may be fabricated .from a flexible material and. uses an interference fit to retain the IC, In another embodiment, the IC may snap into independent detachable IC holder 280 and be retained by snap features in IC holder 280. In another example embodiment of the invention, IC may be held in place using glue or epoxy.

[0032] In some example embodiment of the invention, the spring loaded lid will be friction loaded such that the lid will be held in place at any angle between the open position and the closed position. In one example embodiment of the invention, the friction loading will be supplied by the interaction of the hinge pin against the pivot channel and the spring. The spring and the pivot channel remain stationary as the hinge pin rotates when the lid is rotated between the open position and the closed position. The spring pushes against the hinge pin creating friction between the hinge pin and the spring. The hinge pin is also forced against the top side of the pivot, channel creating friction between the hinge pin and the pivot channel. The tolerance between the hinge pin and the spring and pivot channel, as well as the spring force of the spring, can be adjusted to hold the lid in place. at any position between the open and closed position.

[0033] hi another example embodiment of the invention, the -friction loading may be supplemented by the interaction of the tabs 262 and the ends of the hinge pin 210. Tabs 262 may be bent slightly inward such thai the distance between the tabs is smaller at the top of the pivot channel than at the bottom of the pivot channel. As hinge pin moves towards the top of the pivot channel the tabs 262 will act like springs holding the edges of lid 270 between them. The tolerance between the edges of lid 270 and the angle of the tabs 262. can be adjusted to help hold the lid in place at any position between the open and closed position.