Surface mounted socket assembly

Information

  • Patent Grant
  • 6755668
  • Patent Number
    6,755,668
  • Date Filed
    Wednesday, November 20, 2002
    22 years ago
  • Date Issued
    Tuesday, June 29, 2004
    20 years ago
Abstract
A socket assembly configured to be reflow soldered to a circuit board comprising a perimeter frame having a central open area surrounded by perimeter walls. The socket assembly may be configured to be surface mounted on a circuit board, wherein at least one of the perimeter walls includes a post extending downward therefrom. The socket assembly also comprises a base fit into the open area of the perimeter frame. The base is separate and distinct from the socket frame. The base has a post hole therein positioned to mate with the post. Additionally, the socket assembly comprises contacts held by the base, and solder balls provided on a bottom of the base. The solder balls engage the contacts and, prior to, and after, soldering, extend beyond a bottom of the socket frame.
Description




BACKGROUND OF THE INVENTION




The present invention generally relates to a separable interface connector, and more particularly relates to a separable interface connector that joins a printed circuit board through reflow soldering to an electrical component, such as a motherboard.




Various electronic systems, such as computers, comprise a wide array of components mounted on printed circuit boards, such as daughterboards and motherboards, which are interconnected to transfer signals and power throughout the system. The transfer of signals and power between the circuit boards requires electrical interconnection between the circuit boards.




Certain interconnections include a socket assembly and a plug assembly, or integrated circuit (IC) chip. Some socket assemblies include spring contacts, which are configured to mate with conductive pads on the plug assembly. As the socket assembly and plug assembly mate, the spring contacts exert a normal force on the contact pads, thus ensuring proper electrical contact between the spring contacts and the conductive pads.




In order to establish adequate contact, the spring contacts wipe across the conductive pads, cleaning both surfaces, as the plug assembly is mated into the socket assembly. Typically, during mating, the spring contacts are deflected. During deflection, the spring contacts exert a resistive force on the plug assembly. The resistive force typically has normal and tangential components. The normal force is usually referred to as the contact force and the tangential force is usually caused by the frictional behavior of the wiping motion.




Typical socket assemblies, whether pin grid array (PGA), land grid array (LGA), or ball grid array (BGA) assemblies, are soldered to an electrical component, such as a motherboard. Typically, solder balls are attached to the bottom of the socket assembly. The socket assembly is positioned on a motherboard, and both components are passed through an oven, or other heating device, to begin the solder reflow process. During the solder reflow process, the solder balls melt and form a cohesive layer between the socket assembly and the motherboard. The solder layer cools after the heating and forms an electrically conductive bond between the socket assembly and the motherboard.




Some socket assemblies are soldered to motherboards such that the solder layer is the only intervening material that supports and extends between the socket assembly and the motherboard. That is, the socket assembly does not contact the motherboard at any other point during or after the solder reflow process. When the plug assembly is mated into the socket assembly, however, the mating or clamping force exerted into the socket assembly is fully translated to, and absorbed by, the solder layer. The solder layer may be further collapsed, disrupted or otherwise compressed due to the forces absorbed. Consequently, the electrical connection between the socket assembly and the motherboard may be adversely affected.




In order to counter the effects of mating or clamping forces being exerted into the solder layer, some socket assemblies include standoffs that support and stabilize the socket assembly onto the motherboard. Typically, the standoffs extend a distance that is less than that of the solder balls, but more than that of the natural reflow height of the solder balls. That is, before the solder reflow process, the standoffs do not touch the motherboard. When the socket assembly is soldered to the motherboard, the height of the socket assembly from the motherboard is dictated by the standoffs. U.S. Pat. No. 6,155,848, issued to Lin (“the '848 patent”), describes an auxiliary device for a ZIF electrical connector that uses standoffs. The '848 patent discloses that the height of the stand-off portion is less than the height of the solder balls before soldering, and equal to the height of the solder balls after soldering. Thus, after the solder reflow process, the resulting solder layer is dictated by the height of the standoffs. U.S. Pat. No. 6,220,884, issued to Lin (“the '884 patent”) discloses a BGA socket that comprises an insulative cover supported by standoffs on a base. The standoffs of the cover extend beyond a bottom surface of the base. After the solder reflow process, the resulting solder layer is dictated by the height of the standoffs.




Additionally, in both the '848 and '884 patents, the components (such as IC chips) that mate with each socket include pins. That is, the IC chips include pins that are mated into the socket. The existence of pins on the IC chips mandates that the height of the sockets is adequate to receive and retain the pins.




However, conventional socket assemblies, including those of the '848 and '884 patents, do not allow the solder balls to reflow to the height they naturally would if there were no components that interfered. That is, the solder balls do not melt to a natural reflow height. Rather, the height of the resulting solder layer is dictated by the height of the standoffs. Because the solder layer is not necessarily at its natural height, electrical transmission through the solder layer may be adversely affected. For example, the solder layer may be too dense or too sparse due to the fact that the standoffs dictate the height of the solder layer.




Thus, a need exists for a socket assembly that may be reflow soldered to an electrical component more efficiently, and in a manner that ensures a better conductive path through the resulting solder layer.




BRIEF SUMMARY OF THE INVENTION




Certain embodiments of the present invention provide a socket assembly configured to be reflow soldered to a circuit board. The socket assembly comprises a socket frame, or perimeter frame, having a central open area surrounded by perimeter walls. The socket assembly may be configured to be surface mounted on a circuit board, wherein at least one of the perimeter walls includes a post extending downward therefrom. The socket assembly also comprises a socket board, or base, fit into the open area of the socket frame. The socket board is separate and distinct from the socket frame. Optionally, the socket frame may be integrally formed with the socket board as a single unit during manufacture. During assembly, the socket frame may then separate, or break away, from the socket board by way of a separation zone, such as a perforated area between the socket frame and the socket board.




The socket board has a post hole therein positioned to mate with the post. Additionally, the socket assembly comprises contacts held by the socket board, and solder balls provided on a bottom surface of the socket board. The solder balls engage the contacts and, prior to, and after, soldering, extend beyond a bottom of the socket frame.




The post is held partially seated in the post hole when the socket board and frame are positioned in a pre-soldered state. The post becomes fully seated in the post hole when the socket board and frame move during a plug assembly mating state, that is, when a plug assembly is mated into the socket assembly. The assembly process is controlled in that, after the reflow process, the post is able to move through the post hole in a mating direction defined by the direction of the plug assembly moving into the socket assembly.











BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS





FIG. 1

is an isometric view of a socket assembly formed in accordance with an embodiment of the present invention.





FIG. 2

is a top view of a socket frame of a socket assembly according to an embodiment of the present invention.





FIG. 3

is a bottom view of a socket frame according to an embodiment of the present invention.





FIG. 4

is a cross-sectional view of a socket frame through line


4





4


of

FIG. 2

according to an embodiment of the present invention.





FIG. 5

is a bottom view of a post according to an embodiment of the present invention.





FIG. 6

is a top view of a socket assembly according to an embodiment of the present invention.





FIG. 7

is a bottom view of a socket assembly according to an embodiment of the present invention.





FIG. 8

is a partial cross-sectional view of a socket assembly taken through line


8





8


shown in

FIG. 6

according to an embodiment of the present invention.





FIG. 9

is a side view of a socket assembly according to an embodiment of the present invention.





FIG. 10

is a cross-sectional view of a socket assembly through line


10





10


of

FIG. 6

according to an embodiment of the present invention.





FIG. 11

is a side view of a socket assembly mounted on a motherboard before the reflow solder process, according to an embodiment of the present invention.





FIG. 12

is a side view of a plug assembly mated into a socket assembly according to an embodiment of the present invention.





FIG. 13

is a partial cross-sectional view of a socket assembly in a pre-soldered position according to an embodiment of the present invention.





FIG. 14

is a partial cross sectional view of a socket assembly in a fully seated position according to an embodiment of the present invention.





FIG. 15

is an isometric view of a socket board according to an alternative embodiment of the present invention.











The foregoing summary, as well as the following detailed description of certain 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, certain embodiments. It should be understood, however, that the present invention is not limited to the arrangements and instrumentalities shown in the attached drawings.




DETAILED DESCRIPTION OF THE INVENTION





FIG. 1

is an isometric view of a socket assembly


10


formed in accordance with an embodiment of the present invention. The socket assembly


10


is a two-piece, assembly that includes a socket board


12


and a socket frame


14


. The socket board


12


includes a plurality of spring contacts


16


mounted thereon. For the sake of simplicity, only one row of spring contacts


16


is shown in FIG.


1


. The socket assembly


10


may be a Ball Grid Array (BGA) assembly.




The socket board


12


and socket frame


14


are separate and distinct components. The socket board


12


connects to the perimeter frame by the mating, engagement or otherwise interaction of posts


26


(discussed below) of the socket frame


14


with post cavities


34


(discussed below) of the socket board


12


. The socket board


12


forms the base of the socket assembly


10


.





FIG. 2

is a top view of the socket frame


14


of the socket assembly


10


. The socket frame


14


includes perimeter walls


18


having corners


20


, midsections


22


and an opening


24


defined between the perimeter walls


18


.





FIG. 3

is a bottom view of the socket frame. The socket frame


14


also includes posts


26


, which extend downwardly from the bottom surface of the perimeter walls


18


. While five posts


26


are shown, more or less posts


26


may be formed on the perimeter walls


18


.





FIG. 4

is a cross-sectional view of the socket frame


14


through line


4





4


of FIG.


2


. The socket frame


14


also includes recesses


28


formed in the perimeter walls


18


between the corners


20


and the midsections


22


. The recesses


28


are formed so that the socket frame


14


may fit together with the socket board


12


. As shown in

FIG. 4

, the posts


26


extend downwardly from the bottom surface of the perimeter walls


18


. The posts


26


do not extend beyond the plane defined by the bottom surfaces of the corners


20


and midsections


22


. Alternatively, the posts


26


may extend beyond the plane defined by the bottom surfaces of the corners


20


and midsections


22


.





FIG. 5

is a bottom view of a post


26


. The post


26


is hexagonal, but may be any shape that provides an adequate interference fit with a post hole or cavity formed in the socket board


12


. For example, the posts


26


may be formed as octagons, squares, triangles, circles, etc.





FIG. 6

is a top view of the socket assembly


10


.

FIG. 6

shows the socket frame


14


and the socket board


12


fitted together. The perimeter walls


18


of the socket frame


14


overlap outer edge


30


(as shown, for example, in

FIG. 8

) of the socket board


12


when the socket board


12


and the socket frame


14


are fit together. As shown in

FIG. 6

, a plurality of spring contacts


16


are mounted on the socket board


12


, which acts as the base of the socket assembly


10


. More or less spring contacts


16


than those shown may be positioned on the socket board


12


.





FIG. 10

is a cross-sectional view of the socket assembly


10


taken through line


10





10


of FIG.


6


. Each spring contact


16


includes a wiping tip


38


formed integrally with a deflectable extension portion


40


. The deflectable extension portion


40


is formed integrally with a curved transition portion


42


, which is in turn formed integrally with a retained portion


44


. The retained portion


44


is securely held by a contact cavity formed in the socket board


12


of the socket assembly


10


. A terminal end of the retained portion


44


contacts a solder ball


27


. As shown in

FIG. 10

, the socket board


12


is not formed integrally with the socket frame


14


. That is, the socket board


12


and the socket frame


14


abut against or arc spaced apart from one another at interface


29


.





FIG. 7

is a bottom view of the socket assembly


10


to better illustrate that the socket board


12


is generally formed as a square with chamfered corners


31


. Notches


32


are also cut in the sides of the socket board


12


. The corners


20


and the midsections


22


extending downward from the socket frame


14


are received by corresponding chamfered corners


31


and notches


32


, respectively, in the socket board


12


. That is, the socket board


12


and the socket frame


14


fit together through the interaction of corresponding corners and midsections


20


and


22


with chamfered corners and notches


31


and


32


, respectively. The socket board


12


also includes post cavities


34


arranged about the perimeter and an array of solder balls


27


, which may correspond to the number of spring contacts


16


.





FIG. 8

is a partial cross-sectional view of the socket assembly


10


through line


8





8


shown in FIG.


6


. The post cavities


34


are positioned on the outer edges of the socket board


12


and correspond to positions of the posts


26


located on the socket frame


14


. Upon initial mating of the post


26


and the post cavities


34


, a clearance area


36


is formed between the socket board


12


and the socket frame


14


. When a plug assembly (discussed below) is inserted into the socket assembly


10


, the clearance area


36


is either decreased or eliminated. That is, when the plug assembly is mated into the socket assembly


10


, the socket frame


14


is pressed toward the socket board


12


along with the plug assembly in the direction of line A until becoming fully seated. The posts


26


and post receptacles


34


are configured so that an interference fit exists between the two when mated. Further, the interference fit is such that additional force in the direction of line A moves the socket frame


14


into the socket board


12


. In other words, as shown, for example in

FIGS. 8 and 13

, the posts


26


of socket frame


14


are mated into the post cavities


34


of the socket board


12


to a pre-plug position (in which the socket assembly


10


does not touch a motherboard or other circuit board to which it is soldered). Also, after the socket assembly


10


is soldered to the board, but before the plug assembly is fully mated with the socket assembly


10


, the posts


26


may remain in the same position with respect to the post cavities


34


. After the plug assembly is fully mated into the socket assembly


10


, as shown for example in

FIG. 14

, the socket frame


14


is in its fully seated position with respect to the socket board


12


(in which the socket assembly


10


may abut the motherboard or other circuit board to which it is soldered).





FIG. 9

is a side view of the socket assembly


10


before reflow soldering. As shown in

FIG. 9

, the solder balls


27


extend below the bottom surfaces of the corners


20


and the midsections


22


of the socket frame


14


. Because the solder balls


27


extend below the bottom surfaces of the corners


20


and the midsections


22


, the solder balls


27


are the only components of the socket assembly


10


that directly abut a motherboard


46


(as discussed below) when the socket assembly


10


is initially positioned on the motherboard


46


.





FIG. 11

is a side view of the socket assembly


10


mounted on a motherboard


46


before the solder reflow process. Before the solder reflow process (i.e., heating of the solder balls


27


), the only portion of the socket assembly


10


that touches the motherboard


46


is the solder balls


27


. The socket frame


14


does not touch, and is spaced a distance from, the motherboard


46


. As shown in more detail in

FIG. 13

, the clearance area


36


is formed between the socket board


12


and the socket frame


14


. Also, a clearance area


37


exists between the corners


20


(and midsections


22


, although not shown with respect to

FIG. 13

) and the motherboard


46


.




As solder balls are heated, such as solder balls


27


, they melt to a natural height or level if there is no interfering or intervening components between the solder balls and the component to which they are being reflow soldered, such as the motherboard


46


. The natural height or level of solder reflow, that is, the natural height or level to which the solder balls melt, is determined by the physical properties of the solder balls. During the solder reflow process, the solder balls


27


are allowed to reflow naturally without any interfering structure, such as the corners


20


and midsections


22


, touching the motherboard


46


. Hence, the corners


20


and midsections


22


do not dictate the distance of the socket board


12


from the motherboard


46


. The distance between the socket board


12


and the motherboard after the reflow process is dictated by the natural height (H


N


) of the molten solder balls


27


.





FIG. 12

is a side view of a plug assembly


47


mated into the socket assembly


10


after the solder reflow process is complete and the reflown solder balls


27


form solder connections


48


between the socket assembly


10


and the motherboard


46


. The height of the solder connections


48


is the natural height of the reflown solder balls (H


N


). The plug assembly


47


, or integrated circuit (IC) chip, mates with the socket assembly


10


in the direction of line A. The plug assembly


47


includes contacts, such as conductive pads (not shown), which mate with the spring contacts


16


positioned on the socket board


12


. The spring contacts


16


are deflected by the plug assembly


47


and wipe across the contacts of the plug assembly


47


. As the plug assembly


47


is mated into the socket assembly


10


, the mating force in the direction of line A causes the posts


26


to move further into the post cavities


34


(in the direction of line A), as discussed above with respect to FIG.


8


. That is, the mating or clamping force of the plug assembly


47


into the socket assembly


10


causes the socket frame


14


to slide or otherwise move toward the socket board


12


by way of the posts


26


sliding through the post cavities


34


. The socket frame


14


is a moving frame in that it moves with respect to the socket board


12


.




Upon full mating of the plug assembly


47


into the socket assembly


10


, the socket frame


14


may touch the motherboard


46


, as shown with respect to FIG.


14


. That is, as the plug assembly


47


is mated into the socket assembly


10


, the movement of the plug assembly


47


in the direction of line A causes the socket frame


14


to move (by way of the interaction of the posts


26


through the post cavities


34


) toward the motherboard


46


. Preferably, the socket frame


14


touches or abuts the motherboard


46


at the end of the mating process. In doing so, the excess clamping or mating force when joining the plug assembly


47


and the socket assembly


10


is translated into the socket frame


14


. Because the socket frame


14


touches the motherboard


46


, the excess mating or clamping force is translated directly to the motherboard


46


, but not through the solder connections


48


. Further, an accurate connection between the plug assembly


47


and the socket assembly


10


may be ensured if the socket frame


14


contacts the motherboard during the plug assembly/socket assembly mating process. That is, the corners


20


and midsections


22


may ensure that the mating surface of the plug assembly


47


is approximately parallel to the spring tips


38


of the socket assembly


10


(due to the bottom surfaces of the standoffs


20


and


22


being in parallel contact with the top surface of the motherboard


46


). In any event, the natural reflow height of the solder balls


27


is not disturbed during the reflow process or the plug assembly


47


/socket assembly


10


mating process.





FIG. 14

is a partial cross sectional view of a socket assembly


10


in a fully seated position. For the sake of clarity, the plug assembly


47


is not shown. However, the spring contact


16


is shown in a fully deflected position. In this view, the plug assembly


47


, while not shown, is in a fully mated position with respect to the socket assembly


10


. Further, the socket frame


14


is fully seated with respect to the socket board


12


and the motherboard


46


. It is to be noted that while the corners


20


(and midsections


22


, although not shown with respect to

FIG. 14

) abut the motherboard


46


, the corners


20


and midsections


22


do not abut the motherboard


46


during the reflow solder process. Only when the plug assembly


47


is fully seated into the socket assembly


10


does the socket frame


14


contact the motherboard


46


. That is, the mating force of the plug assembly


47


into the socket assembly


10


causes the posts


26


to slide through the post cavities


34


, and therefore the corners


20


and midsections


22


of the socket assembly


10


contact the motherboard


46


. Also, the clearance area


36


shown with respect to

FIGS. 8 and 13

is eliminated or decreased when the socket assembly


10


is fully seated. Preferably, the socket frame


14


abuts the motherboard


46


before the plug assembly


47


is fully clamped into the socket assembly


10


, so that the motherboard


46


will absorb most, if not all, of the excess mating force.




As mentioned above, more or less posts


26


and post cavities


34


may be used with the socket assembly


10


. Additionally, the shape of the socket frame


14


and socket board


12


may be different shapes, as long as both fit together. Additionally, the posts


26


may be any shape that interferingly fits into the post cavities


34


. Further, the post cavities


34


may be any shape that interferingly engages the posts


34


. Also, the posts may be positioned on, and extending upward from, the socket board


12


, while the cavities, or holes, are formed within the perimeter walls of the socket frame


14


.





FIG. 15

is an isometric view of a socket board


60


according to an alternative embodiment of the present invention. The socket board


60


includes a base


62


having spring contacts


16


mounted thereon and a post


64


upwardly extending from the base


62


. The post


64


is configured to be slidably received by a corresponding hole in the plug assembly. Thus, instead of having a perimeter frame having posts, the socket board


60


includes the post


64


, over which the plug assembly may slide down into a fully seated position. Alternatively, the socket board


60


may include multiple posts


64


upwardly extending from various locations on the base


62


. For example, the posts


64


may be located in the corners.




Thus, embodiments of the present invention provide a socket assembly that may be reflow soldered to a motherboard more efficiently. Because the resulting solder layer is reflown to its natural height, a more reliable electrical conductive path results. Also, when a plug assembly (such as an IC chip) is mated into the socket assembly, the excess clamping or mating force is translated into the motherboard. Thus, the solder layer is not excessively stressed during the mating process.




While the invention has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.



Claims
  • 1. A socket assembly configured to be reflow soldered to a circuit board, comprising:a socket frame having a central open area surrounded by perimeter walls, wherein at least one of said perimeter walls includes a post extending downward therefrom; a socket board fit into said open area of said socket frame, said socket board having a post hole therein positioned to mate with said post; contacts held by said socket board; and solder balls provided on a bottom of said socket board, said solder balls engaging said contacts and, prior to soldering, extending beyond a bottom surface of said socket frame; wherein said post is held partially seated in said post hole when said socket board and frame are positioned in a pre-soldered state, said post becoming fully seated in said post hole when said socket board and frame move together when a plug assembly is mated into said socket assembly.
  • 2. The socket assembly of claim 1, wherein a solder layer, formed from said solder balls, extends beyond said bottom surface of said socket frame after reflow soldering.
  • 3. The socket assembly of claim 1, wherein said socket frame is one of separate and distinct from said socket board and integrally formed with said socket board and configured to separate from said socket board upon assembly.
  • 4. The socket assembly of claim 1, wherein prior to reflow soldering, said socket frame is above said socket board so as to form a gap between mating surfaces of said socket board and frame.
  • 5. The socket assembly of claim 1, wherein said socket board is fully seated with and rests on said socket frame after reflow soldering and when said socket assembly is mated to a plug assembly.
  • 6. The socket assembly of claim 1, wherein said socket frame and board are configured to contact a motherboard only through a solder layer formed by said solder balls before and after a solder reflow process.
  • 7. The socket assembly of claim 1, wherein a clearance area is formed between said socket frame and said socket board when said socket frame is initially connected to said socket board, said clearance area decreasing when a plug assembly is mated with said socket assembly.
  • 8. The socket assembly of claim 1, wherein said contacts comprise spring contacts extending from a top surface of said socket board, said spring contacts comprising wiping tips formed integrally with deflectable extension portions, said deflectable extension portions being integrally formed with curved transition portions.
  • 9. A socket assembly comprising:a base holding a plurality of spring contacts extending outwardly from a plug mating side of said base; a plurality of solder balls extending outwardly from a board mating side of said base; a perimeter frame that is separate and distinct from said base, said perimeter frame being moveable relative to said base along a plug mating direction when said base is connected to said perimeter frame; and a clearance area formed between said perimeter frame and said base when said perimeter frame is initially connected to said base, wherein said clearance area is decreased when a plug assembly is mated with said socket assembly after a solder reflow process.
  • 10. The socket assembly of claim 9, wherein said perimeter frame comprises a plurality of posts that mate with a corresponding number of holes formed in said base, said posts moving within said holes between partially and fully seated positions as a plug connector is joined with said base and said perimeter frame.
  • 11. The socket assembly of claim 9, wherein said solder balls extend beyond a bottom surface of said perimeter frame when said perimeter frame is connected to said base.
  • 12. The socket assembly of claim 9, wherein said socket assembly is configured to be positioned on a circuit board prior to a solder reflow process, said socket assembly contacting the circuit board only through said solder balls prior to and after the solder reflow process.
  • 13. The socket assembly of claim 9, wherein said perimeter frame is configured to move toward said base when a plug assembly is mated into said socket assembly.
  • 14. The socket assembly of claim 9, wherein each of said plurality of spring contacts comprises a wiping tip formed integrally with a deflectable extension portion, said deflectable extension portion being integrally formed with a curved transition portion.
  • 15. A socket assembly configured to be reflow soldered to a circuit board, comprising:a base having a plurality of spring contacts extending outwardly from a plug mating side of said base; a plurality of solder balls extending outwardly from a circuit board mating side of said base, said base being configured to contact a circuit board only through said solder balls prior to and after a solder reflow process; and a perimeter frame that is separate and distinct from said base and postionable to engage a plug assembly, said perimeter frame being moveable relative to said base along a plug mating direction when said base is connected to said perimeter frame, said perimeter frame comprising a plurality of posts that mate with a corresponding number of holes formed in said base, said posts positionable relative to said holes in a first position after soldering said base to said circuit board and a second position after said socket assembly is mated to said plug assembly.
  • 16. The socket assembly of claim 15, wherein said posts are held partially seated in said holes when said base and perimeter frame are positioned in a pre-soldered state, said posts becoming fully seated in said holes when said base and perimeter frame move to a fully mated state when a plug assembly is mated into said socket assembly.
  • 17. The socket assembly of claim 15, wherein said solder balls, prior to reflow soldering, support said base, and wherein said perimeter frame is above said base to form a gap between mating surfaces of said base and perimeter frame.
  • 18. The socket assembly of claim 15, wherein after reflow soldering and plug assembly mating, said perimeter frame is fully seated with and rests on the circuit board.
  • 19. A socket assembly comprising:a base holding a plurality of spring contacts extending outwardly from a plug mating side of said base; a plurality of solder balls extending outwardly from a board mating side of said base; and a perimeter frame that is separate and distinct from said base, said perimeter frame comprising at least one post being slidably positionable relative to said base after a solder reflow process, thereby permitting movement of said post when a plug assembly is mated to said socket assembly such that a natural reflow height of said solder balls is not disturbed.
  • 20. A socket assembly configured to be reflow soldered to a circuit board comprising:a base holding a plurality of spring contacts extending outwardly from a plug mating side of said base; a plurality of solder balls extending outwardly from a board mating side of said base; and a perimeter frame that is separate and distinct from said base, said perimeter frame comprising at least one post being slidably received in a hole formed in said base, said post being positionable relative to said base within said hole after said solder balls are reflowed, whereby when a plug assembly is mated to said socket assembly, excess clamping forces are transmitted from said frame to said circuit board without affecting the reflowed solder balls.
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5829988 McMillan et al. Nov 1998 A
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