Surface mount technology land grid array socket

Information

  • Patent Grant
  • 6796805
  • Patent Number
    6,796,805
  • Date Filed
    Monday, August 5, 2002
    22 years ago
  • Date Issued
    Tuesday, September 28, 2004
    20 years ago
Abstract
An electrical socket is provided for receiving processors requiring only vertical mounting actuation. The socket includes a housing having an array of contacts, and a frame having a bottom surface and a contacting surface. The contacts have a loaded position and an unloaded position. The loaded position corresponds to the placement of a desired vertical load. The housing is slidably mounted to the frame. The contacting surface is located such that a processor abuts the contacting surface when the contacts are in the loaded position due to the placement of a processor and the bottom surface of the frame abuts a flat surface, such as a circuit board to which the socket is mounted.
Description




BACKGROUND OF THE INVENTION




Certain embodiments of the present invention generally relate to a socket configured to accept a processor while transferring excess mating force away from more fragile components such as solder balls and maintaining a desired biasing force on contacts of the processor.




Pin grid array (PGA) sockets are used to accept electronic packages on printed circuit boards. PGA sockets facilitate electrical communication between a large number of pins on processors and electrical components to which the PGA sockets are mounted (such as circuit boards). PGA sockets may utilize a cover that is slidably movable on a base between open and closed positions. The sliding movement may be actuated, for example, by a lever. The cover has a hole array configured to match a pin array on an electronic package. Similarly, the base has an array of pin receiving chambers configured to accept the pin array of the electronic package. The electronic package is mated to the socket by first placing the electronic package such that its pins penetrate the holes of the cover. With the cover in the open position, the pins penetrate through the holes of the cover into the pin receiving chambers of the base, but are not electrically connected to the pin receiving chambers of the base. When the cover is slid to the closed position, the pins become electrically connected to the base via the pin receiving chambers. This PGA base and cover arrangement, however, requires use of a mechanism, such as a lever assembly, thereby introducing excess parts and manufacturing cost. The PGA base and cover arrangement also requires additional space as the contacts must be able to move within the pin receiving chambers. These drawbacks are especially troublesome in applications where space is at a premium, such as on motherboards for desktop and laptop computers.




Consequently, land grid array (LGA) sockets have been developed which require only vertical compression to allow a processor and circuit board to electrically communicate. The LGA sockets do not require the lever mechanism, and can be used in applications with more stringent space requirements. LGA sockets, however, require a vertical compression force to be continuously applied to the processor to maintain proper communication between the processor and the circuit board. The applied vertical compressive force may become excessive and damage the socket components if not closely controlled. Hence, LGA sockets can not use low cost mounting techniques such as the use of solder balls, and in addition require expensive materials such as gold plated pads on the motherboards to be used.




A need exists for an improved LGA socket to overcome the above-noted and other disadvantages of conventional PGA and LGA sockets.




BRIEF SUMMARY OF THE INVENTION




At least one embodiment is provided that includes a socket for receiving processors that use vertical mounting actuation to securely engage processor contacts. The socket includes an opening for receiving a processor, a bottom surface, and an array of contacts having a first position and a second position. The opening extends from an upper surface of the socket and terminates at a shelf. A first contact position is defined corresponding to an absence of load on the contacts, and a second contact position is defined corresponding to the placement of a desired vertical load on the contacts. The shelf is substantially parallel to the bottom surface and spaced from the bottom surface a distance corresponding to a distance between the first and second positions of the contacts.




The socket may also include an array of holes that receive the contacts. Each contact may include a solder ball at one end for mounting the contacts to a secondary structure, such as the mother board. Each contact may include a resiliently flexible contact arm at one end and the solder ball at the opposite end. The vertical distance from the base of the solder ball to the top of the contact arm defines the first and second positions of the contacts.




A cover that is removably mounted to the socket for handling the socket and protecting the contact arms during shipping may also be provided.




At least one embodiment provides a vertical mounting actuation socket for receiving processors. The socket includes a housing having an array of contacts, and a frame having a bottom surface and a contacting surface. The contacts have a loaded position and an unloaded position. When in the loaded position, the contacts are placed under a desired vertical load. The housing is slidably mounted to the frame. The contacting surface of the frame is located such that when a processor is loaded onto the contacting surface, the contacts are in the loaded position and the bottom surface of the frame abuts a flat surface.




The housing may be interferably slidably mounted to the frame. In this regard, a force is applied to overcome a physical interference between the frame and housing to move the housing relative to the frame. Further, the frame may include an opening to receive the housing. One of the frame and housing includes a key, and the other of the frame and housing includes a keyway corresponding to the key for slidably mounting the housing to the frame.




The frame may include a first opening extending from the bottom surface and a second opening extending from a top surface of the frame. The first opening receives the housing, and the second opening receives a processor. The first and second openings are joined by a shelf that is substantially parallel to the bottom surface and spaced from the bottom surface a distance corresponding to the loaded position of the contacts.




At least one embodiment provides an electrical system including a circuit board, a processor having a first contacting surface, and a socket mounted to the circuit board. The socket receives the processor and facilitates electrical communication between the circuit board and the processor. The socket includes a housing having an array of contacts and frame having a bottom surface and a second contacting surface. The housing is slidably mounted to the frame. The contacts have an unloaded position and a loaded position, the loaded position corresponding to the placement of a desired vertical load on the contacts. The second contacting surface of the frame is located such that the first contacting surface of the processor abuts the second contacting surface when the processor abuts and biases the contacts to the loaded position and the bottom surface of the frame abuts the circuit board.




Certain embodiments of the present invention thus provide a socket capable of transferring excess force from vulnerable components. Certain embodiments of the present invention also provide a socket that allows for closer spacing of contacts in an array.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

illustrates a perspective view of an electrical socket system formed in accordance with an embodiment of the present invention.





FIG. 2

illustrates a perspective view of a frame formed in accordance with an embodiment of the present invention.





FIG. 3

illustrates a top plan view of a frame formed in accordance with an embodiment of the present invention.





FIG. 4

illustrates a sectional view of the frame taken along line


4





4


of FIG.


3


.





FIG. 5

illustrates an enlarged view of a keyway from the frame of FIG.


3


.





FIG. 6

illustrates an enlarged view of a key from the frame of FIG.


3


.





FIG. 7

illustrates a perspective view of a biasing spring arm formed in accordance with an embodiment of the present invention.





FIG. 8

illustrates a top plan view of a housing formed in accordance with an embodiment of the present invention.





FIG. 9

illustrates a sectional view of the housing of

FIG. 8

showing contacts inside of holes.





FIG. 10

illustrates an enlarged view of a key from the housing of FIG.


8


.





FIG. 11

illustrates an enlarged view of a keyway from the housing of FIG.


8


.





FIG. 12

illustrates a sectional view of a housing and frame formed in accordance with an embodiment of the present invention.





FIG. 13

illustrates a sectional view of a housing and frame formed in accordance with an embodiment of the present invention.





FIG. 14

illustrates a perspective view of a cover mounted to a frame formed in accordance with an embodiment of the present invention.





FIG. 15

illustrates an elevation view of a cover formed in accordance with an embodiment of the present invention.











The foregoing summary, as well as the following detailed description of the preferred embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings, embodiments which are presently preferred. It should be understood, however, that the present invention is not limited to the precise arrangements and instrumentality shown in the attached drawings.




DETAILED DESCRIPTION OF THE INVENTION





FIG. 1

illustrates an electrical system


10


including a surface mount land grid array socket


11


formed in accordance with an embodiment of the present invention. The electrical system


10


also includes a circuit board


12


to which the socket


11


is mounted. The circuit board


12


may be, for example, a mother board of a computer. Further, the electrical system


10


includes a processor


18


mounted to the socket


11


. The socket


11


includes a frame


14


, a housing


16


(see FIG.


2


), and bias spring arms


20


. The bias spring arms


20


locate and position the processor


18


with respect to the socket


11


. The socket


11


facilitates electrical communication between the processor


18


and the circuit board


12


.





FIGS. 2-6

illustrate various aspects of the frame


14


, which may be molded of Stanyl 46HF5040 supplied by DSM.

FIG. 2

illustrates a perspective view of the frame


14


, with the housing


16


and bias spring arms


20


. The frame


14


includes a bottom surface


30


that abuts the circuit board


12


when the socket


11


is mounted to the circuit board


12


and a clamping load is applied. As shown in

FIG. 2

, the frame


14


includes a housing opening


32


that accepts the housing


16


.





FIG. 3

illustrates a plan view of the frame


14


, and

FIG. 4

illustrates a sectional view of the frame


14


taken along section line


4





4


in FIG.


3


. As shown in

FIG. 3

, the housing opening


32


extends upward from the bottom surface


30


to a shelf


44


, and is defined by the four housing opening sides


33


. Each housing opening side


33


forms a substantially right angle with its adjacent housing opening sides


33


, and the housing opening


32


is sized to accept the housing


16


. The frame


14


includes an orientation point


34


located proximal to the juncture of two housing opening sides


33


. The orientation point


34


provides a visible cue for orienting the processor


18


.




The frame


14


includes a processor opening


36


defined by four processor opening sides


38


extending upward from the shelf


44


. The processor opening


36


is generally rectangular, and is sized to accept the processor


18


with a slight clearance. Further, the frame


14


includes a leading edge


40


extending from at least one of the processor opening sides


38


to facilitate easier placement of the processor


18


with the processor opening


36


.




As mentioned above, the frame


14


includes a shelf


44


that extends about the perimeter of the frame


14


. The shelf


44


is substantially parallel to the bottom surface


30


, and is located a shelf height


46


from the bottom surface


30


. The shelf


44


joins the housing opening


32


and the processor opening


36


, forming an upper boundary for the housing opening


32


and a lower boundary for the processor opening


36


. When the electrical system


10


is fully assembled, the processor


18


rests on and abuts against the shelf


44


.




The frame


14


also includes bias arm mounting areas


42


. The bias spring arms


20


are mounted to the frame


14


at the bias arm mounting areas


42


, for example, through a fastener such as a capscrew. The frame


14


also includes frame keyways


48


and frame keys


58


for slidably engaging the housing


16


. The frame keyways


48


and frame keys


58


are distributed about the perimeter of the processor opening


36


. The frame key


58


extends from a housing opening side


33


. The frame keyway


48


extends horizontally outward from a housing opening side


33


and vertically through the housing opening


32


.




As illustrated in

FIG. 5

, the frame keyway


48


extends back from a throat


56


along sides


50


formed at an obtuse angle to the housing opening side


33


. The sides


50


are joined by the back


52


of the frame keyway


48


. The back


52


is substantially parallel to the housing opening side


33


from which the keyway


48


extends. Protruding from the back


52


is a crush rib


54


. The crush rib


54


provides an interference when a housing key


100


engages the frame keyway


48


.




As illustrated in

FIG. 6

, the frame key


58


includes a neck


60


that extends to the sides


62


. The sides


62


are substantially perpendicular to the housing opening side


33


and are joined by the front


64


, which is substantially perpendicular to the sides


62


.




Referring back to

FIGS. 1 and 2

, the frame


14


includes cover notches


66


. The cover notches


66


extend into the frame


14


and cooperate with a pick and place cover


22


(see

FIGS. 14 and 15

) to maintain the pick and place cover


22


in place on the frame


14


during shipping of the socket


11


as well as when placing the socket


11


on the circuit board


12


.





FIG. 7

illustrates a perspective view of a bias spring arm


20


. The bias spring arm


20


may be made of a plastic, such as Stanyl 46HF5040 supplied by DSM. The bias spring arms


20


are mounted to the frame


14


, and are used to assist in the proper positioning of the processor


18


in the socket


11


. The bias spring arms


20


help bias a corner of the processor


18


toward the orientation point


34


(see FIGS.


1


and


3


). The bias spring arm


20


includes a mounting area


70


that corresponds to and cooperates with the bias arm mounting area


42


on the frame


14


to secure the bias spring arm


20


to the frame


14


. The bias spring arm


20


also includes a flex arm


72


extending from near the mounting area


70


toward a contact face


76


. The contact face


76


abuts against the side of the processor


14


and urges the processor


14


into proper orientation due to the resilient biasing of the flex arm


72


. A leading edge


74


extends from the contact face


76


to facilitate easy placement of the processor


18


.





FIG. 8

illustrates a plan view of the housing


16


, which may be made of a plastic, such as Titan LG441 supplied by Eastman Chemical. The perimeter of the housing


16


is defined by sides


80


. Each side


80


is substantially perpendicular to its adjacent sides


80


. The sides


80


join a top surface


82


and a bottom surface


84


(FIG.


9


). The top surface


82


and bottom surface


84


are substantially parallel to each other and perpendicular to the sides


80


.




The housing


16


includes holes


86


arranged in a hole array


88


. The hole array


88


of the illustrated embodiment includes 735 holes


86


, not all of which are shown for clarity. The holes


86


extend through the housing


16


and are sized to accept contacts


90


(see

FIG. 9

) before becoming fixed in the holes


86


. The hole array


88


corresponds to contact arrays on the processor


18


and the circuit board


12


, and the contacts


90


provide paths for electrical communication between the processor


18


and the circuit board


12


.





FIG. 9

illustrates the contacts


90


when positioned in the holes


86


. Each hole


86


accepts a contact


90


that includes a contact arm


92


and a solder ball


94


located at opposite ends of a contact base


91


. The holes


86


are sized to properly align, secure, and position the contacts


90


in the desired location. The contact arm


92


extends from the top surface


82


of the housing


16


. The contact


90


has an unloaded contact height


96


measured from the end of the solder ball


94


to the tip of the contact arm


92


when unloaded. When the processor


18


is properly positioned in the socket


11


and a desired clamping load is applied, the contacts


90


will have a loaded contact height (not shown) that is less than the unloaded contact height


96


. At the loaded contact height, the resilient biasing of the contact arms


92


result in a contact force between the contacts


90


and the processor


18


. The contacts


90


are selected to provide geometry to meet the impedance, inductance, and capacitance requirements of a specified application. As shown in

FIG. 9

, each contact


90


also includes a solder ball


94


that extends beneath the bottom surface


84


. The solder balls


94


are used for mounting the housing


16


to the circuit board


12


and to allow electrical communication between the contacts


90


and the circuit board


12


. The solder balls


94


, for example, may be selected to accommodate either SnPb or Pb free processing. After solder reflow, the solder balls


94


are more oval in shape than shown in FIG.


9


.




With reference again to

FIG. 8

, the housing


16


also includes housing keys


100


and housing keyways


108


for slidably engaging the frame


14


.

FIG. 10

illustrates a housing key


100


. The housing key


100


slidably engages the frame keyway


48


. The housing key


100


extends from a side


80


of housing


16


. The housing key


100


includes a neck


102


that meets sides


104


that extend away from the neck


102


at an obtuse angle. The sides


104


are joined by the front


106


, which is substantially parallel to the side


80


from which the housing key


100


extends. The neck


102


and sides


104


are sized to provide a small clearance from the throat


56


and sides


50


of the frame keyway


48


. There is an interference however between the crush rib


54


and the front


106


. This interference results in a force being required to overcome the interference to slide the housing


16


within the frame


14


. The housing key


100


and frame keyway


48


are sized with respect to each other in light of the materials used for the frame


14


and housing


16


to provide an appropriate required force.





FIG. 11

illustrates a housing keyway


108


that slidably engages frame key


58


. The housing keyway


108


extends from a side


80


and from the top surface


82


to the bottom surface


84


of the housing


16


. The housing keyway


108


includes a throat


114


that leads to sides


110


. The sides


110


of the housing keyway


108


are substantially perpendicular to the side


80


of the housing


16


from which the housing keyway


108


extends. A back


112


that is substantially perpendicular to the sides


110


join the sides


110


. The housing keyway includes a crush rib


116


that extends from the back


112


. The throat


114


and the sides


110


are sized to provide a small clearance from the neck


60


and sides


62


of the frame key


58


. However, the crush rib


116


provides an interference with the front


64


of the frame key


58


, thereby requiring a force to slide the housing


16


within the frame


14


. As above, the frame key


58


and housing keyway


108


are sized with respect to each other to provide an appropriate required force.




Returning to

FIG. 1

, the processor


18


includes a top portion


120


and a bottom portion


122


(see FIG.


13


). Sides


124


bound the bottom portion


122


, and the bottom portion includes a bottom surface


126


. The bottom portion


122


is accepted by the processor opening


36


of the frame


14


.




The assembly of the electrical system will now be described with particular reference to

FIGS. 12-13

.

FIG. 12

illustrates a sectional view of the socket


11


before the housing


16


is soldered to the circuit board


12


. As shown, the housing


16


is lowered into the housing opening


32


of the frame


14


such that the above described keys and keyways (the housing key


100


and frame keyway


48


, and frame key


58


and housing keyway


108


) slidably engage each other and the solder balls


94


extend beneath the bottom surface


30


of the frame


14


by a predefined clearance to facilitate soldering the solder balls


94


to the circuit board


12


. The contact arms


92


extend upward by the unloaded contact height


96


. After the socket


11


, with the frame


14


and housing


16


positioned as above described, is oriented and placed on the circuit board


12


, the housing


16


may be soldered to the circuit board


12


. The solder balls


94


will no longer have the round shape illustrated after solder reflow.




Next, the processor


18


may be placed as illustrated in FIG.


13


. The processor


18


encounters the leading edge


74


of the biasing spring arm


20


and/or the leading edge


40


of the processor opening


36


of the frame


14


. As the processor


18


is lowered, the biasing spring arms


20


will help properly orient the processor


18


with respect to the hole array


88


of the housing


16


. Once the processor


18


is placed within the processor opening


36


, a clamping mechanism (not shown) may be used to force the processor


18


down into the proper position and provide the desired biasing force on the contact arms


92


. The clamping mechanism may also include a heat sink. As the processor


18


is lowered, the contact arms


92


are flexed in the direction of arrow A in FIG.


9


. Also, the bottom surface


126


of the processor


18


will encounter the shelf


44


of the frame


14


.

FIG. 13

illustrates the condition where the processor


18


first encounters the shelf


44


as the processor


18


is urged downward. A further applied clamping force will bias the contact arms


92


and simultaneously urge the frame


14


downward until the bottom surface


30


of the frame


14


abuts against the circuit board


12


. Any clamping force applied to the processor


18


after the frame


14


is against the circuit board


12


will not result in any further biasing of the contact arms


92


beyond the desired position, or loaded position. Rather, the force will be transferred to the frame


14


and circuit board


12


. Thus, the force seen by the solder balls


94


is controlled and limited to a predetermined level. Thus, the contact arms


92


are not biased beyond the desired position.




The shelf height


46


is sized to allow the contact arms


92


to be biased to the desired loaded position and no more. This is accomplished by setting the shelf height


46


equal to the vertical distance from the bottom of the solder balls


94


(after reflow) to the tip of the contact arms


92


when the contact arms


92


are loaded by a desired amount. By way of example, the illustrated embodiment is intended for use with a clamping system that provides 100 pounds of clamping force. By way of example, the keys and keyways of the housing


16


and frame


14


are sized such that approximately 35 pounds of force are used to slide the housing


16


and frame


14


with respect to each other. By way of example, the force used to bias all of the contact arms


92


of the illustrated embodiment may be 65 pounds. Thus, the 100 pounds is sufficient to move the frame


14


toward the circuit board


12


and properly bias the contact arms


92


. Any excess force applied will not damage the solder balls


94


or improperly position the contact arms


92


once the frame


14


abuts the circuit board


12


, thereby protecting those components from damage and providing proper electrical communication. The ability of the frame


14


and housing


16


to move relative to one another helps account for potential variability in the height of the solder balls


94


after reflow while maintaining the force on the contacts


90


near the desired level at the loaded position.




The electrical system


10


may also include a pick and place cover


22


for shipping as well as positioning the socket


11


.

FIGS. 14 and 15

illustrate the pick and place cover


22


.

FIG. 14

illustrates a perspective view of the frame


14


with the pick and place cover


22


in place, and

FIG. 15

illustrates a sectional elevation view of the pick and place cover


22


taken along the center of the pick and place cover


22


.




The pick and place cover


22


, which may be molded from a plastic such as Questra EA535, 30% glass filled syndiotactic polystyrene available from Dow Chemical, includes a top surface


130


and cover arms


132


extending from the top surface


130


. The cover arms


132


terminate in retention portions


134


that cooperate with the cover notches


66


of the frame


14


to hold the pick and place cover


22


in place on the frame


14


. When the pick and place cover


22


is placed on the frame


14


, the cover arms


132


bias outward from the sides of the frame


14


until the retention portions


134


are aligned with the cover notches


66


, at which point the cover arms


132


return to their unbiased position, thereby snappably securing the pick and place cover


22


in place.




For shipping, the housing


16


is slid into the frame


14


. The above described interferences for the keys and keyways of the housing


16


and frame


14


keep the housing


16


from sliding out of the frame


14


. The pick and place cover


22


is then snapped into place on the frame


14


. The pick and place cover


22


provides a convenient surface to grasp either manually or in an automated process, such as with a vacuum at the end of a robotic arm, and also provides protection to the contacts


90


during shipping. To place the socket


11


on a circuit board


12


, the socket


22


may be handled by grasping the pick and place cover


22


and positioning appropriately. Once the socket


11


is in place, the pick and place cover


22


may be easily snapped off.




While particular elements, embodiments and applications of the present invention have been shown and described, it will be understood, of course, that the invention is not limited thereto since modifications may be made by those skilled in the art, particularly in light of the foregoing teachings. For example, a different surface other than the bottom surface of the processor may be used to contact the frame, thereby changing the location of the shelf, or using a different contacting surface on the frame to be contacted by the processor. It is therefore contemplated by the appended claims to cover such modifications as incorporate those features which come within the spirit and scope of the invention.



Claims
  • 1. An electrical socket, comprising:a frame having a bottom surface configured to abut against a circuit board and having a processor opening opposite said bottom surface and a housing opening adjacent said bottom surface, said processor opening being configured to accept a processor, said frame including sides surrounding said processor opening and surrounding said housing opening, at least one of said sides including a ledge extending parallel to said bottom surface and defining said housing opening, said housing opening smaller than said processor opening and said ledge being spaced a maximum load distance from said bottom surface; and a housing having an array of contacts mounted therein, said housing slidaby received within said frame wherein said contacts extend into said processor opening and beyond said bottom surface, said array of contacts being flexed between loaded and unloaded positions, said maximum load distance defining an amount that said array of contacts are biased when flexed to said loaded position, said slidably mounted housing permitting relative movement of said housing with respect to said frame when said contacts are soldered to a circuit board.
  • 2. The electrical socket of claim 1 further including an array of holes that receive said array of contacts.
  • 3. The electrical socket of claim 1 wherein said contacts include a solder ball at one end of said contacts for mounting said contacts.
  • 4. The electrical socket of claim 1 wherein said contacts include a resiliently flexible contact arm and a solder ball at opposite ends of said contacts, and said first and second positions are defined by the vertical distance from the base of said solder ball to the top of said contact arm.
  • 5. The electrical socket of claim 1 further including biasing arms mounted to said electrical socket, said biasing arms being resiliently biased and providing an orienting force when a processor is placed in said electrical socket.
  • 6. The electrical socket of claim 1 further including a cover removably mounted to said electrical socket for handling said electrical socket.
  • 7. An electrical socket, comprising:a housing having an array of contacts, said contacts being flexed between an unloaded position and a loaded position; and a frame having a bottom surface and a contacting surface, said housing being slidably mounted to said frame, said contacting surface being spaced a maximum load distance from said bottom surface, said maximum load distance defining an amount that said array of contacts are biased when flexed to said loaded position, said contacting surface located such that a processor abuts said contacting surface when said contacts are in said loaded position, said bottom surface of said frame being configured to abut a circuit board; wherein said slidably mounted housing is movable relative to said frame to approximately maintain a desired force on said contacts in said loaded position despite variability in solder height when connecting said contacts to said circuit board.
  • 8. The electrical socket of claim 7, wherein said housing is interferably slidably mounted to said frame, whereby a force must be applied to overcome a physical interference between said frame and housing to move said housing relative to said frame.
  • 9. The electrical socket of claim 7, wherein said frame includes an opening to receive said housing, one of said frame and housing having a key, and the other of said frame and housing having a keyway corresponding to said key for slidably mounting said housing to said frame.
  • 10. The electrical socket of claim 7, wherein said frame includes a first opening extending from said bottom surface to receive said housing, and a second opening extending from a top surface of said frame to receive a processor, said first and second openings being joined by a shelf that is substantially parallel to said bottom surface and spaced from said bottom surface a distance corresponding to said loaded position of said contacts.
  • 11. The electrical socket of claim 7 further including an array of holes that receive said contacts.
  • 12. The electrical socket of claim 7 wherein said contacts include a solder ball at one end of said contacts for mounting said contacts.
  • 13. The electrical socket of claim 7 wherein said contacts include a resiliently flexible contact arm and a solder ball at opposite ends of said contacts, and said loaded and unloaded positions are defined by the vertical distance from the base of said solder ball to the top of said contact arm.
  • 14. The electrical socket of claim 7 further including biasing arms mounted to said electrical socket, said biasing arms being resiliently biased and providing an orienting force when a processor is placed in said electrical socket.
  • 15. The electrical socket of claim 7 further including a cover removably mountable to said socket for handling said electrical socket.
  • 16. An electrical system comprising:a circuit board; a processor having a first contacting surface; and an electrical socket mounted to said circuit board, said socket receiving said processor and facilitating electrical communication between said circuit board and said processor, said electrical socket including a housing having an array of contacts, solder balls for connecting said contacts to said circuit board and a frame having a bottom surface and a second contacting surface, said contacts being flexed between an unloaded position and a loaded position, said housing being slidably mounted to said frame and movable relative to said frame during reflow of said solder balls to account for variability in a height of said solder balls after reflow; wherein said second contacting surface being spaced a maximum load distance from said bottom surface, said maximum load distance defining an amount that said contacts are biased when flexed to said loaded position, said second contacting surface of said frame located such that said first contacting surface of said processor abuts said second contacting surface when said processor abuts and biases said contacts to said loaded position and said bottom surface of said frame abuts said circuit board.
  • 17. The electrical system of claim 16 wherein said housing is interferably slidably mounted to said frame, whereby a force must be applied to overcome a physical interference between said frame and housing to move said housing relative to said frame.
  • 18. The electrical system of claim 16 wherein said frame includes a first opening extending from said bottom surface to receive said housing, and a second opening extending from a top surface of said frame to receive said processor, said first and second openings being joined by a shelf that is substantially parallel to said bottom surface and spaced from said bottom surface a distance corresponding to said loaded position of said contacts, said second contacting surface including said shelf.
  • 19. The electrical system of claim 16 wherein each of said contacts include a resiliently flexible contact arm at a first end and a solder ball at a second end opposite said first end, and said loaded and unloaded positions are defined by the vertical distance from the base of said solder ball to the top of said contact arm.
  • 20. The electrical system of claim 16 further including a cover removably mountable to said electrical socket for handling said electrical socket.
US Referenced Citations (5)
Number Name Date Kind
5772451 Dozier et al. Jun 1998 A
5820389 Hashiguchi Oct 1998 A
6155848 Lin Dec 2000 A
6196849 Goodwin Mar 2001 B1
6443750 Lemke et al. Sep 2002 B1