Patent Application
20120257366
The subject matter herein relates generally to electrical interconnect devices for use between opposed arrays of contacts.
Interconnect devices are used to provide electrical connection between two or more opposing arrays of contacts for establishing at least one electrical circuit, where the respective arrays may be provided on a device, printed circuit board, Pin Grid Array (PGA), Land Grid Array (LGA), Ball Grid Array (BGA), and the like. In one interconnect technique, the electrical connection is provided by an interconnect device that is physically interposed between corresponding electrical contacts of the opposing arrays of contacts. However, the electrical connection may be unreliable due to height variations between electrical contacts of the opposing arrays, variations in thickness of a substrate supporting either of the opposing arrays or the conductive elements of the interconnect device, warping of a substrate of either of the opposing arrays, and the like.
At least some known interconnect devices use an array of elastomeric columns supported on a substrate. The elastomeric columns may be compressed to establish reliable contact between the opposing contacts. In some known interconnect devices, the elastomeric columns are conductive and provide the electrical connection. The interconnect devices are capable of accommodating size constraints, such as related to the reduced physical size of many electrical devices.
In known interconnect devices using conductive elastomeric columns, the elastomeric columns are held by an insulative carrier having coverlays provided on both sides of the insulative carrier to protect the elastomeric columns and provide mechanical stops for interfacing with the two electronic components connected by the interconnect device. The coverlays are extra layers of the interconnect device that add to the cost of the interconnect device. The interconnect devices are typically fixed within a frame and mounted to one of the electronic components. The frame and interconnect device both are removed from the electronic component to repair or replace the interconnect device. Additionally, because the interconnect device is fixed relative to the frame, the interconnect device may not properly seat or engage one or both of the electronic components. For example, one of the electronic components may be warped, causing some of the elastomeric columns to improperly connect to the electronic component.
A need remains for an electrical interconnect device that may adjust to the surface topography of the electronic components to which the electrical interconnect device is mounted.
In one embodiment, an electrical interconnect device is provided including a frame having frame walls that define a socket that extends along a socket axis between an open top and an open bottom of the frame. The socket is configured to receive an electronic package through the open top. The electrical interconnect device also includes a contact assembly having an insulative carrier that holds an array of conductive elastomeric columns with each of the elastomeric columns having opposite first and second ends. The elastomeric columns are internally conductive between the first and second ends. The elastomeric columns are configured to electrically interconnect the electronic package to a second electronic component. The insulative carrier is configured to float within the frame in a direction generally parallel to the socket axis.
In another embodiment, an electrical interconnect device is provided including a frame having frame walls that define a socket that extends along a socket axis between an open top and an open bottom of the frame. The frame has a foot that extends from a corresponding frame wall into the socket. The frame has a cap that extends from a corresponding frame wall into the socket. The socket is configured to receive an electronic package through the open top. The electrical interconnect device also includes a contact assembly having an insulative carrier that holds an array of conductive elastomeric columns with each of the elastomeric columns having opposite first and second ends. The elastomeric columns are internally conductive between the first and second ends. The elastomeric columns are configured to electrically interconnect the electronic package to a second electronic component. The insulative carrier is positioned between the foot and the cap. The insulative carrier is configured to float within the frame in a direction generally parallel to the socket axis. The foot defines a lower float limit for the insulative carrier. The cap defines an upper float limit for the insulative carrier.
In a further embodiment, an electrical interconnect device is provided including a frame having frame walls that define a socket that extends along a socket axis between an open top and an open bottom of the frame. The frame is configured to be mounted to an electronic component that has an array of component contacts. The socket is aligned with the array of component contacts. The socket is configured to receive, through the open top, an electronic package that has an array of package contacts. A contact assembly has an insulative carrier that holds an array of conductive elastomeric columns. The elastomeric columns are internally conductive. The elastomeric columns are configured to electrically interconnect the component contacts and corresponding package contacts. The contact assembly is movable with respect to the frame. The contact assembly is removable from the socket without removing the frame from the electronic component.
In the illustrated embodiment, the first electrical component 102 is an electronic package, such as a chip or processor. The second electrical component 104 is a printed circuit board. The interconnect device 106 constitutes a socket that is mounted to the printed circuit board and is configured to receive the chip. In alternative embodiments, other types of electrical components may be interconnected by the interconnect device 106. For example, both the first and second electrical components 102, 104 may be printed circuit boards.
The interconnect device 106 has a contact assembly 108 that is used to electrically connect the first and second electrical components 102, 104. For example, the contact assembly 108 is configured to engage the arrays of contacts of the first and second electrical components 102, 104. The contact assembly 108 has a first mating surface 110 and a second mating surface 112 (shown in
The interconnect device 106 includes a frame 114 having a plurality of frame walls 116 that define a socket 118. The frame 114 is configured to be mounted to the second electrical component 104, such as by using latches, fasteners and the like. The socket 118 receives the first electrical component 102 therein. The contact assembly 108 is held within the frame 114 such that the contact assembly 108 interconnects the first and second electrical components 102, 104. In an exemplary embodiment, the contact assembly 108 is removable from the frame 114 such that the contact assembly 108 may be removed and replaced while leaving the frame 114 attached to the second electrical component 104.
In an exemplary embodiment, the contact assembly 108 is configured to float within the frame 114 to properly align the second mating surface 112 with the second electrical component 104 and/or align the first mating surface 110 with the first electrical component 102. The floating of the contact assembly 108 within the frame 114 allows the contact assembly 108 to adjust to the surface topography of the second electrical component 104 and/or the first electrical component 102. For example, the mating surface of the second electrical component 104 may be non-planar, or may be non-parallel to the orientation of the frame 114 of the interconnect device 106, causing height variations between the first and second electrical components 102, 104. The second electrical component 104 may have variations in the thickness of the substrate of the circuit board such that the array of contacts on the surface of the second electrical component 104 is non-planar. The substrate of the second electrical component 104 may be warped due to exposure to high heat or may be non-planar due to manufacturing tolerances causing the array of contacts to be either non-planar or non-parallel a plane defined by the frame 114. Having the ability of the contact assembly 108 to float within the frame 114, and thus have a variable orientation with respect to the frame 114, allows the contact assembly 108 to be more accurately positioned between the first and second electrical components 102, 104.
The elastomeric columns 122 are arranged in an array having a predetermined pattern or layout that corresponds to the array of contacts of the first electrical component 102 and the second electrical component 104. The elastomeric columns 122 extend outward from both the first and second sides 124, 126. The elastomeric columns 122 extend between a first end 130 and a second end 132 opposite the first end 130. In an exemplary embodiment, the elastomeric columns 122 are frustoconically shaped, being wider about the mid-section and narrower at the first and second ends 130, 132. The elastomeric columns 122 are held at the mid-section by the insulative carrier 120. In an exemplary embodiment, the elastomeric columns 122 are conductive elastomeric columns, such as columns fabricated from a mixture of an elastic material and conductive flakes. The elastomeric columns 122 provide conductive paths between the first and second ends 130, 132. In an exemplary embodiment, the elastomeric columns 122 are metalized particle interconnects. The elastomeric columns 122 are at least partially compressible, such as when the first electrical component 102 is mounted to the contact assembly 108.
In an exemplary embodiment, the frame 114 has an open top 140 and an open bottom 142. The socket 118 extends along a socket axis 144 (e.g., in the Z direction) between the open top 140 and the open bottom 142. The socket axis 144 may be oriented generally perpendicular to a frame plane 145 defined by the bottom 142 (e.g., a plane extending in the X-Y direction). The socket axis 144 is generally parallel to interior surfaces 146 of the frame walls 116. In an exemplary embodiment, the first electrical component 102 (shown in
The frame 114 includes a pair of retention clips 150 used to retain the first electrical component 102 (shown in
The frame 114 includes a plurality of biasing springs 154 that extend from corresponding frame walls 116 into the socket 118. The biasing springs 154 have engagement surfaces 156 that engage the first electrical component 102. The biasing springs 154 are biased against the first electrical component 102 when the first electrical component 102 is received in the socket 118 to position the first electrical component 102 within the socket 118. In the illustrated embodiment, the biasing springs 154 are provided along two perpendicular frame walls 116. The biasing springs 154 tend to force the first electrical component 102 in the direction of arrow A and in the direction of arrow B generally away from the frame walls 116 having the biasing springs 154. The biasing springs 154 tend to force the first electrical component 102 to the corner generally opposite the intersection of the frame walls 116 having the biasing springs 154. The biasing springs 154 are cantilevered beams extending at least partially into the socket 118. The biasing springs 154 are deflected when the first electrical connector 102 is loaded into the socket 118, creating an internal bias within the biasing springs 154 that forces the first electrical component 102 away from the frame walls 116 having the biasing springs 154. Any number of biasing springs 154 may be provided. Any of the frame walls 116 may have biasing springs 154, including all of the frame walls 116.
The frame 114 includes one or more alignment posts 158 extending from the bottom 142. The alignment posts 158 are configured to be received within corresponding alignment openings (not shown) in the second electrical component 104 to position the frame 114 with respect to the second electrical component 104. Other types of alignment features may be used rather than the alignment posts 158 to orient the frame 114 with respect to the second electrical component 104. Optionally, the alignment posts 158 may be keyed to properly orient the frame 114 with respect to the second electrical component 104. For example, one of the alignment posts 158 may have a first shape, such as a rectangular shape, while the other alignment posts 158 may have a second shape, such as a triangular shape to avoid placing the alignment posts 158 in the wrong alignment opening in the second electrical component 104. Optionally, the alignment posts 158 may be secured in the alignment openings, such as by an interference fit.
The frame 114 includes a plurality of protrusions extending into the socket 118 from the frame walls 116 that support and/or block the contact assembly 108 within the socket 118. The protrusions define a floating envelope that limits the range of floating movement of the contact assembly 108 within the frame 114. The frame 114 thus controls the amount of floating of the contact assembly 108 within the socket 118. In the illustrated embodiment, the protrusions include feet 160 extending from the frame walls 116 into the socket 118 and caps 162 extending from the frame walls 116 into the socket 118. Each foot 160 defines a lower float limit for the contact assembly 108. Each cap 162 defines an upper float limit for the contact assembly 108. Any number of feet 160 and caps 162 may be provided. The feet 160 and the caps 162 may have any size or shape in order to support and/or block movement of the contact assembly 108 within the socket 118. Each foot 160 has an upward facing ledge 164. Each cap has a downward facing ledge 166. The upward facing ledge 164 defines the lower float limit for the contact assembly 108. The downward facing ledge 166 defines the upper float limit for the contact assembly 108. In the illustrated embodiment, the feet 160 and the caps 162 are offset with respect to one another with one or more caps 162 positioned between the feet 160. In the illustrated embodiment, the upward facing ledges 164 of the feet 160 have a greater surface area than the downward facing ledges 166 of the caps 162. In alternative embodiments, the feet and caps 160, 162 may be sized similar to one another. In an exemplary embodiment, the feet 160 are provided at the bottom 142. The caps 162 are provided at some vertical location (e.g., along the Z direction) above the bottom 142. The caps 162 are spaced vertically above the feet 160 such that a gap or space is created between the upward facing ledge 164 and downward facing ledge 166. The gap or space defines the floating envelope for the contact assembly 108.
The frame 114 includes a plurality of compression stops 170 extending from corresponding frame walls 116 into the socket 118. The compression stops 170 define mechanical stops for the loading of the first electrical component 102 into the socket 118. For example, upper surfaces 172 of the compression stops 170 limit loading of the first electrical component 102 into the socket 118. The first electrical component 102 is loaded into the socket 118 until the first electrical component 102 engages the upper surfaces 172 of the compression stops 170.
The frame 114 includes alignment features 174 extending from corresponding frame walls 116 into the socket 118. The alignment features 174 orient the contact assembly 108 within the socket 118. In the illustrated embodiment, the alignment features 174 constitute posts extending from the frame walls 116 into the socket 118. Side walls 176 of the alignment features 174 engage a cutout 178 of the insulative carrier 120 to position the contact assembly 108 within the socket 118. For example, the alignment features 174 may orient the contact assembly 108 in the X and/or Y direction.
The contact assembly 108 is loaded into the socket 118. Optionally, the contact assembly 108 may be loaded into the frame 114 through the open top 140 after the frame 114 is mounted to the second electrical component 104. Alternatively, prior to mounting the frame 114 to the second electrical component 104, the contact assembly 108 may be loaded into the socket 118 and the interconnect device 106 may be mounted to the second electrical component 104 as a unit.
The contact assembly 108 is received in the socket 118 such that second mating surface 112 extends along the mounting surface 190 of the second electrical component 104. The contact assembly 108 is able to float within the socket 118 to match the surface topography of the mounting surface 190. For example, the mounting surface 190 may be non-planar, with the component contacts 192 defining a component contact plane being non-parallel to the frame plane 145 defined by the bottom 142 of the frame 114. In some embodiments, due to manufacturing tolerances, improper assembly, damage to or degradation of the frame 114 or second electrical connector 104 over time or other factors, the bottom 142 of the frame 114 may be oriented on the mounting surface 190 in a skewed or non-parallel orientation. No matter what the reason, the contact assembly 108 is variably positionable within the socket 118 to accommodate offset or tolerances between the frame 114 and the second electrical component 104. The insulative carrier 120 is configured to float within the frame 114 in a direction generally parallel to the socket axis 144 (e.g., in the Z direction). Optionally, one side or the other of the insulative carrier 120 may float more or less than the other side, making the insulative carrier 120 slanted within the socket 118, such that one edge of the insulative carrier 120 is closer to the feet 160, while the opposite edge of the insulative carrier 120 is closer to the caps 162. The feet 160 define the lower float limit for the insulative carrier 120. The caps 162 define the upper float limit for the insulative carrier 120. Optionally, the insulative carrier 120 may be flexible. The flexibility of the insulative carrier 120 allows the insulative carrier 120 and the elastomeric columns 122 to conform to undulations in the plane defined by the component contacts 192 and the plane defined by the package contacts 196.
When mated, the first electrical component 102 is loaded into the socket 118. As the first electrical component 102 is loaded into the socket 118, a mating interface of the first electrical component 102 engages the contact assembly 108. The first electrical component 102 includes the array of package contacts 196 at the mating interface 194. The package contacts 196 engage corresponding elastomeric columns 122. When the first electrical component 102 is removed from the socket 118, the contact assembly 108 may be removed from the socket 118 without removing the frame 114 from the second electrical component 104. For example, the flexibility of the insulative carrier 120 may allow one or more sides to be removed from the frame 114, thus allowing the contact assembly 108 to be removed from the socket 118. The contact assembly 108 may be replaced by another contact assembly 108 such as to repair a damaged contact assembly 108 or to use a contact assembly 108 that has a different configuration of elastomeric columns 122.
The first electrical component 102 is loaded into the socket 118 until the bottom of the first electrical component 102 engages the compression stops 170. The compression stops 170 limit the amount of compression of the elastomeric columns 122. The compression stops 170 prevent damage to the elastomeric columns 122 from overloading the first electrical component 102. Because the compression stops 170 stop the loading of the first electrical component 102 into the socket 118, the contact assembly 108 may be used without a coverlay over the insulative carrier 120. As such, the contact assembly 108 may be manufactured at less cost than a contact assembly 108 that includes a coverlay. For example, the material cost of the contact assembly 108 may be reduced, as well as assembly cost of the contact assembly 108.
It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. 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. Dimensions, types of materials, orientations of the various components, and the number and positions of the various components described herein are intended to define parameters of certain embodiments, and are by no means limiting and are merely exemplary embodiments. Many other embodiments and modifications within the spirit and scope of the claims will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. Further, the limitations of the following claims are not written in means—plus-function format and are not intended to be interpreted based on 35 U.S.C. §112, sixth paragraph, unless and until such claim limitations expressly use the phrase “means for” followed by a statement of function void of further structure.
