Adapter apparatus with suspended conductive elastomer interconnect

An adapter apparatus for receiving a packaged device having a plurality of contact elements disposed on a surface thereof may include a conductive elastomer interconnect. The conductive elastomer interconnect may include a carrier having a plurality of openings defined therethrough from a first side to a second side thereof (e.g., the plurality of openings being arranged to align with the plurality of contact elements of the packaged device) and conductive elastomer suspended in each of the plurality of openings to contact a contact element of a plurality of contact elements of a packaged device when positioned adjacent the second side of the carrier. Further, the adapter apparatus may include one or more adapter wall members used with the conductive elastomer interconnect to define a socket cavity adapted to receive the packaged device.

BACKGROUND

The present disclosure relates generally to electrical adapters and methods related to such adapters. More particularly, the present disclosure pertains to adapters for packaged integrated circuit devices, e.g., ball grid array packages.

Certain types of integrated circuit packages are becoming increasingly popular due to their occupancy area efficiency. In other words, they occupy less area on a target board on which they are mounted while providing a high density of contact terminals. For example, one such high density package type is a ball grid array package (e.g., a micro ball grid array package). Generally, such packages contain an integrated circuit having its die bond pads electrically connected to respective conductive contact elements (e.g., spheres/balls) that are distributed on a surface of the package (e.g., the bottom surface of the package, for example, in an array).

A target printed circuit board upon which the package is to be mounted typically has formed on its surface a corresponding array of conductive pads which are aligned with the conductive contact elements of the packaged device for electrically mounting the package on the target board. The target board typically includes other conductive traces and elements which lead from the array of conductive pads used for mounting the package to other circuitry on the board for connecting various components mounted thereon. To mount such a package to a target board, for example, the package may be positioned with the contact elements thereof adjacent to the corresponding array of conductive pads on the target board and, for example, the resulting structure may be heated until solder melts and fuses the contact elements of the package to the conductive pads of the target board.

Such area efficient packaging, e.g., micro ball grid array packages, provides a high density of terminals at a very low cost. Also, this packaging provides for limited lead lengths (e.g., short leads). The limited lead lengths may reduce the risk of damage to such leads of the package, may provide for higher speed product, etc.

Generally, circuit boards and/or components mounted thereon are tested by designers as the circuit boards are being developed. For example, for a designer to test a circuit board and/or a package mounted thereon, the designer must first electrically connect the package to the target circuit board.

As described herein, this may include mounting the package on the target board and heating to fuse the contact elements of the package to the conductive pads of the target board. Therefore, the package may be prevented from being used again. It is desirable for various reasons to use package adapters for mounting the packages and reuse such packages after testing. For example, such device packages may be relatively expensive. Further, for example, once attached, the contacts may not be accessible for testing. In addition, it is often difficult to rework the circuit board with the packages soldered thereon.

Various adapters are available to electrically connect a package to a target printed circuit board without requiring that the contact elements on the package be fused to the target board. However, the high density of terminals for certain packages, e.g., micro ball grid array packages, leads to various interconnect problems for adapters being used with such packages. For example, alignment of the contact elements of the packaged device to the contact pads of the target board may be problematic when an electrical adapter is used. Further, providing effective contact with minimal adaptive structure may be difficult. Various adapters have been described for electrically connecting high density packaged devices to a target printed circuit board, such as, for example, U.S. Pat. No. 6,877,993 to Palaniappa et al., issued 12 Apr. 2005, entitled “Packaged Device Adapter Assembly with Alignment Structure and Methods Regarding Same,” and U.S. Pat. No. 6,394,820 to Palaniappa et al., issued 28 May 2002, entitled “Packaged Device Adapter Assembly and Mounting Apparatus,” describe adapter apparatus that use a conductive elastomer layer to provide electrical contact.

SUMMARY

The disclosure herein provides packaged device adapter assemblies useable for high density integrated circuit packages, e.g., micro ball grid array packages, etc.

One exemplary adapter apparatus disclosed herein for receiving a packaged device having a plurality of contact elements disposed on a surface thereof may include a conductive elastomer interconnect. The conductive elastomer interconnect may include a carrier having a plurality of openings defined therethrough from a first side to a second side thereof (e.g., the plurality of openings may be arranged to align with the plurality of contact elements of the packaged device) and conductive elastomer suspended in each of the plurality of openings to contact a contact element of a plurality of contact elements of a packaged device when positioned adjacent the second side of the carrier. Further, the adapter apparatus may include one or more adapter wall members along an adapter axis between a first end region of the adapter apparatus and a second end region of the adapter apparatus. The conductive elastomer interconnect may be positioned at the first end region of the adapter apparatus orthogonal to the adapter axis and the one or more adapter wall members and the conductive elastomer interconnect may define a socket cavity adapted to receive the packaged device with the plurality of contact elements thereof adjacent the conductive elastomer suspended in each of the plurality of openings.

Another exemplary adapter apparatus for use in an adapter configured to receive a packaged device having a plurality of contact elements disposed on a surface thereof may include a conductive elastomer interconnect that includes a carrier having a plurality of openings defined therethrough from a first side to a second side thereof (e.g., the plurality of openings are arranged to align with the plurality of contact elements of the packaged device) and conductive elastomer suspended in each of the plurality of openings to contact a contact element of a plurality of contact elements of a packaged device when positioned adjacent the second side of the carrier.

One or more embodiments of such adapter apparatus may include one or more of the following features: the first and second sides of the carrier may be free of conductive elastomer; the packaged device may include a ball grid array having a plurality of balls; each opening of the plurality of openings defined through the carrier may be a cylindrical opening having a diameter sized to receive a ball of the plurality of balls of the ball grid array; the conductive elastomer suspended in each of the plurality of openings may include a curable conductive elastomer material (e.g., a curable conductive elastomer material that includes a plurality of conductive particles); the conductive elastomer suspended in each of the plurality of openings may include a concave surface at the second side of the carrier for electrical contact with the contact elements of the packaged device; the conductive elastomer suspended in each of the plurality of openings may include a contact projection extending beyond the first side of the carrier for electrical contact with a contact pad of a plurality of contact pads of a target board when the target board is positioned adjacent the first side of the carrier; the one or more wall members may include alignment structure positioned at the first end region to align the packaged device within the socket cavity (e.g., the alignment structure may include at least an alignment plate positioned orthogonal to the adapter axis; the alignment plate may include a plurality of openings arranged to align with the plurality of contact elements of the packaged device and adapted to allow contact elements of the packaged device to be in electrical contact with the conductive elastomer suspended in each of the plurality of openings defined in the carrier layer, etc.); and an actuator apparatus including a floating member movable in the socket cavity and an actuator element (e.g., the actuator element may be operable to provide a force on the floating member resulting in a corresponding force being distributed to the packaged device when received in the socket cavity such that the plurality of contact elements are in electrical contact with the suspended conductive elastomer in each of the plurality of openings defined in the carrier, the suspended conductive elastomer in each of the plurality of openings defined in the carrier may be flexed towards the first side of the carrier when the force is applied, etc.).

One exemplary embodiment of a method of providing an adapter apparatus adapted to receive a packaged device having a plurality of contact elements disposed on a surface thereof (e.g., the adapter apparatus mountable to a target board to electrically connect the plurality of contact elements to a plurality of contact pads of the target board) may include providing a conductive elastomer interconnect such as described herein including, for example, a carrier and conductive elastomer suspended in each of a plurality of openings defined therethrough. The method may further include providing one or more adapter wall members along an adapter axis between a first end region and a second end region of the adapter apparatus and positioning the conductive elastomer interconnect at the first end region of the adapter apparatus orthogonal to the adapter axis to define a socket cavity of the adapter apparatus adapted to receive a packaged device such that the plurality of contact elements of the packaged device are adjacent the conductive elastomer suspended in each of the plurality of openings.

In one embodiment of the exemplary method, providing a conductive elastomer interconnect may include positioning the first side of the carrier adjacent a formation surface to close the plurality of openings defined through the carrier, providing conductive elastomer at least within the plurality of openings defined through the carrier, and curing the conductive elastomer within the plurality of openings to provide the suspended conductive elastomer in each of the plurality of openings. For example, the formation surface may be a planar surface or a nonplanar surface (e.g., a formation surface having at least one surface deformation defined therein corresponding to each of the plurality of openings defined through the carrier, wherein the at least one surface deformation forms a contact projection of the suspended conductive elastomer extending beyond the first side of the carrier for electrical contact with a contact pad of a plurality of contact pads of a target board when the target board is positioned adjacent the first side of the carrier).

In another embodiment of the exemplary method, the method may further include providing an actuator apparatus that includes a floating member movable in the socket cavity and an actuator element (e.g., the actuator element may be operable to provide a force on the floating member such that a corresponding force is distributed to a packaged device when received in the socket cavity) and providing electrical contact between the plurality of contact elements of the packaged device and the suspended conductive elastomer in each of the plurality of openings defined in the carrier via the force provided on the floating member (e.g., the suspended conductive elastomer in each of the plurality of openings defined in the carrier may be flexed towards the first side of the carrier when the force is applied).

The above summary of the present disclosure is not intended to describe each embodiment or every implementation thereof. Advantages, together with a more complete understanding of the disclosure, will become apparent and appreciated by referring to the following detailed description and claims taken in conjunction with the accompanying drawings.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Generally, packaged device adapter assemblies for use with packaged devices, e.g., high density devices, such as ball grid array packages, along with methods of using and forming such assemblies or portions thereof, shall be described herein. An illustrative packaged device adapter assembly10according to the present invention shall be described with reference to illustrativeFIGS. 1-3. Other features and or illustrations relating to packaged device adapter assemblies, including methods of forming such features, shall be described with reference toFIGS. 4-5.

In other words, exemplary adapter apparatus and methods for providing and using such adapters shall generally be described with reference toFIGS. 1-5. It will be apparent to one skilled in the art that elements from one embodiment may be used in combination with elements of the other embodiments, and that the possible adapter apparatus embodiments using features set forth herein is not limited to the specific embodiments described (e.g., various illustrative embodiments described may include some features or elements included in other illustrative embodiments and/or exclude other features). For example, as will be readily apparent from the description herein, various types of alignment structure, wall members used to form socket cavities, actuator structure, covers, etc., may be used in combination with each of the various embodiments of adapter assemblies described herein, and further other adapter assemblies may benefit from features described herein (e.g., adapter assemblies that may not be described herein). Further, it will be recognized that the embodiments described herein may include many elements that are not necessarily shown to scale. Further, it will be recognized that the size and shape of various elements herein may be modified without departing from the scope of the present disclosure, although one or more shapes and sizes may be advantageous over others.

FIGS. 1-3show a cross-section side view and various other views, including an exploded perspective view inFIG. 2B, of an illustrative and exemplary packaged device adapter assembly10for use with a packaged device80according to the present invention. Generally, the packaged device adapter assembly10is for mounting on a target board90. The packaged device adapter assembly10includes one or more wall members12(e.g., perimeter wall members, base socket member17, etc.) having a length along an adapter axis13. Generally, the length of the one or more wall members12extends between a first end region14of the packaged device adapter assembly10and a second end region16of the packaged device adapter assembly10. The one or more wall members12may include an inner surface region18facing towards the adapter axis13(e.g., used to form socket cavity15) and an opposing outer surface region20facing away from the adapter axis13.

The packaged device adapter assembly10further includes a conductive elastomer interconnect30. In at least one embodiment, the conductive elastomer interconnect30includes a carrier31including a plurality of openings33defined therethrough from a first side131to a second side133thereof. The plurality of openings33are arranged to align with a plurality of contact elements86of the packaged device80. In one or more embodiments, conductive elastomer35may be suspended in each of the plurality of openings33to contact a contact element of the plurality of contact elements86of the packaged device80when the packaged device80is positioned adjacent the second side133of the carrier31.

The one or more wall members12(e.g., various structure along the adapter axis13between the first end region14and second end region16of the adapter assembly10) and the conductive elastomer interconnect30(e.g., positioned at the first end region14of the adapter assembly10orthogonal to the adapter axis13) may define a socket cavity15sized or otherwise configured to receive the packaged device80. The socket cavity15is adapted to receive the packaged device80with each contact element of the plurality of contact elements86adjacent a corresponding conductive elastomer35suspended in an opening of the plurality of openings33.

In one or more embodiments, for example, as shown inFIGS. 2D-2E, the packaged device80may include an upper surface82and a lower surface84in addition to one or more side surfaces88extending therebetween at the perimeter of the packaged device80. A plurality of contact elements86(e.g., balls/spheres of a ball grid array) may be disposed at least at the lower surface84. For example, the contact elements86may be distributed in an array along x and y axes orthogonal to the adapter axis13or the contact elements (e.g., spheres or balls, etc.) may be distributed along the outer portions of the lower surface84proximate the perimeter thereof. However, any arrangement of contact elements86may be accommodated according to the present disclosure.

The packaged device80may be any packaged device having a plurality of contact elements86disposed on a surface thereof suitable for electrical connection with conductive elastomer35suspended within the plurality of openings33of the conductive elastomer interconnect30. In one or more embodiments, the packaged device may be a device having a high density of contact terminals, e.g., lands, solder spheres, bumps, contact pads, leads, etc., disposed on a surface thereof. For example, the high density packaged device may be a micro lead frame package, a micro lead chip carrier, a quad flat no lead package, a micro ball grid array package, or any other type of package such as a ball grid array package, a chip scale package, a flip chip package, a flat package, a quad flat package, a small outline package, a land grid array package, or any other package having contact elements disposed on a surface thereof suitable for electrical connection with conductive elastomer35suspended within the plurality of openings33of the conductive elastomer interconnect30.

In at least one embodiment, the packaged device80includes a ball grid array package device having contact elements86in the form of spheres or balls on the lower surface84. However, adapter assemblies and adapter concepts described herein may be used with any other packaged device having contact elements disposed on a surface thereof which would benefit from the use of the conductive elastomer interconnect30. Further, any number of different sizes and/or configurations of packaged devices may benefit from features described herein (e.g., packaged devices with only one planar surface having contact elements disposed thereon, packaged devices having upper and lower surfaces that are parallel to one another, packaged devices having upper and lower surfaces that are not parallel to one another, etc.).

Further, the packaged device adapter assembly10may include a cover member60positioned at the second end16of the one or more wall members12(e.g., adjacent the socket base member17along axis13) to close the socket cavity15. The cover member60may be movable, e.g., removable via fastening devices69as shown inFIGS. 1-2. However, the cover member may also be moveable about a hinge axis (not shown), or any other manner of removing or moving the cover to open the socket cavity for allowing a packaged device to be received therein. In other words, one or more cover member configurations may allow the packaged device80to be removed from the socket cavity15and another packaged device placed therein. The packaged device adapter assembly10is generally used to provide electrical contact between the contact elements86of the packaged device80and contact pads92of the target board90via the conductive elastomer interconnect30when the packaged device80is positioned in the socket cavity15.

The one or more wall members12may include any number of different structures (e.g., along the adapter axis13) between the first end region14and second end region16of the adapter assembly10. For example, the one or more wall members12may include a socket base member17extending from a first end located towards the first end region14of the adapter assembly10to a second end location towards the second end region16. For example, in one or more embodiments, such a socket base member17may define an opening therethrough along axis13(e.g., providing, at least in part, the inner surface region18of adapter assembly10) to form at least a part of the defined socket cavity15sized or otherwise configured to receive the packaged device80.

Further, for example, the one or more wall members12may include one or more types of alignment structure positioned at the first end region14(e.g., adjacent the first end of socket base member17) to align the packaged device80within the socket cavity15. For example, in one or more embodiments, the alignment structure may include an alignment plate48positioned orthogonal to the adapter axis13. For example, the alignment plate48may define an opening therethrough along axis13(e.g., providing, at least in part, the inner surface region18of adapter assembly10) to form at least a part of the defined socket cavity15sized or otherwise configured to receive the packaged device80. For example, the alignment plate48may include an inner surface49defining the opening along axis13(e.g., the opening being sized to align the packaged device80within the socket cavity15for effective electrical contact of the plurality of contact elements86of the packaged device80and the conductive elastomer35suspended in each of the plurality of openings33; each opening33of the conductive elastomer interconnect30corresponding to a particular contact element86). Such alignment structure may be of any configuration suitable to provide alignment within the socket cavity15. For example, alignment structure may include a single surface defining an opening to provide the alignment function or may be as described in U.S. Pat. No. 6,877,993 B2 to Palaniappa et al., issued 12 Apr. 2005, and entitled “Packaged Device Adapter Assembly Alignment Structures and Methods Regarding Same.”

One will recognize that the one or more wall members12may use any number of structures to provide an opening into which the packaged device80is received. Such structures may take any shape and/or form suitable to provide a socket cavity for receiving the packaged device80and the present disclosure is not limited to any particular configuration of such one or more wall members12(e.g., not limited to any number and/or shape described herein).

The packaged device adapter assembly10further includes actuator apparatus, such as, for example, a floating member40(e.g., a compression plate for providing a force on the packaged device80) as shown inFIGS. 1-2. The floating member40may be used in combination with other actuator apparatus, including, for example, an actuator element70, to provide a distributed force on the packaged device80when received in the socket cavity15such that the contact elements86disposed on the lower surface84of the packaged device80are in effective electrical contact with the conductive elastomer35suspended in the openings33of the conductive elastomer interconnect30. InFIG. 1, the floating member40is shown spaced apart from the packaged device80, as is the conductive elastomer interconnect30.

At least in one embodiment, the floating member40includes an upper surface41that is generally planar and orthogonal to the adapter axis13when the floating member40is positioned in the socket cavity15. Further, at least in one embodiment, the floating member40includes a lower surface42that is configured as a function of the upper surface82of the packaged device80. For example, as shown inFIG. 1, lower surface42of the floating member40is generally planar for direct contact with the planar upper surface82of a packaged device80. However, the lower surface of the floating member40may be configured in any manner and need not be planar. Further, the floating member may be formed of any number of different components. However, in at least one embodiment, at least a portion of the lower surface42of the floating member40is in direct contact with the upper surface82of the packaged device80. The floating member40as shown inFIGS. 1-2includes an edge surface44extending between the upper surface41and the lower surface42at the perimeter of the floating member40. The edge surface44lies adjacent, and may even be in contact with, the inner surface region18defined, for example, by the one or more wall members12, and is moveable relative thereto within the socket cavity15.

The actuator element70may be any actuator element operable to apply a force on the upper surface41of the floating member40. As a force is applied by the actuator element70to the upper surface41of the floating member40, the force is distributed generally equally along the upper surface82of the packaged device80. As such, an equivalent force is provided at each contact element86, e.g., ball or sphere, for effective contact between each contact element86and the suspended conductive elastomer35within a corresponding opening of the plurality of openings33defined in carrier31of the conductive elastomer interconnect30. Such a distributed force across the entire packaged device80reduces the potential application of excessive force on one part of the packaged device80versus another part thereof, e.g., the center versus the perimeter.

Generally, in one or more embodiments, the actuator element70is an element associated with the cover member60. For example, the actuator element may be a spring element, a leaf spring, or any other flexible element capable of applying a force to the floating member40via the association with the cover member60. Further, the cover member60itself may be used to apply a force to the floating member40such as by tightening the cover member directly down on the floating member40by fastening elements, e.g., screws.

At least in one embodiment as shown inFIG. 1, the actuator element70may be a threaded element that includes an upper region72with a threaded portion74extending therefrom. Further, in such an embodiment, the cover member60includes a threaded insert65positionable along the axis13of the adapter assembly10for mating with the threaded portion74of the actuator element70. The threaded portion74may terminate in a generally planer surface75.

With the packaged device80in the socket cavity15, the planer surface75is placed in direct contact with the upper surface41of the floating member40by turning the actuator element70. As such, the actuator element70is adjustable to provide an effective force to the upper surface41of floating member40such that the distributed force is applied for effective electrical coupling of the contact elements86to the suspended conductive elastomer35of conductive elastomer interconnect layer30. With use of the actuator element70and the floating member40, a suitable distributed force on the packaged device80can be achieved. The minimized load applied to the packaged device80and thus to the conductive elastomer35suspended in the openings33of the conductive elastomer interconnect30allows for operation of the adapter assembly10over many insertion cycles as the conductive elastomer interconnect30is not unnecessarily damaged by the force applied to the packaged device80to achieve contact between all of the contact elements86and suspended conductive elastomer35.

In one or more embodiments, the floating member40may be formed of a heat conductive material, e.g., aluminum, to provide heat sinking capability. Further, actuator element70and the one or more wall members12and cover60may be formed of such heat sinking material. In such a manner, the elements that form the socket cavity15which provide electrical coupling of the packaged device80to a target board90also function to dissipate heat away from the packaged device80when the packaged device80is operable. This is particularly beneficial for high density packaged devices in that such packaged devices tend to operate with greater heat output.

As can be seen fromFIG. 1, the floating member40may be sized and configured such that edge44thereof is in moveable contact with inner surface region18provided, at least in part, by the one or more wall members12which allows heat conduction therethrough and away from the packaged device80. Likewise, the contact between the actuator element70and the floating member40, such as provided by a screw formed of aluminum, may allow for heat conduction from the threaded portion74(which is in direct contact with the floating member40) to the exterior of the socket cavity15.

It will be recognized that various elements or portions of the adapter assembly10may be formed of multiple layers or components or as single piece elements. For example, it will be recognized that the one or more wall members12may include multiple pieces or it may be formed as a single piece element. Further, for example, the floating member40may be formed of one or more layers or components.

The adapter assemblies as described herein may be mounted relative to various target boards as illustrated generally inFIG. 1by target board90and may be mounted to the target board90in any number of different manners, many of which would be readily known by one skilled in the art. For example, such mounting may be performed as described in U.S. Pat. No. 6,394,820 issued 28 May 2002, entitled “Packaged Device Adapter Assembly and Mounting Apparatus,” which is incorporated herein by reference.

The target board90may be any substrate including contact pads or other conductive elements arranged thereon for electrical connection with the adapter assembly10. For example, the target board may be a printed circuit board including various other components mounted thereon or may be a surface mountable substrate (e.g., an interconnect board that may be used with printed circuit boards that do not have mounting holes therein or when it is undesirable to provide mounting holes in the target board90).

As shown inFIG. 1, the adapter assembly10may be mounted relative to target board90(e.g., a printed circuit board) in a manner using fastening devices (e.g., a threaded bolt66and washer/nut68). Target board90includes openings58defined therein for use in attachment of the adapter assembly10to the target board90using the fastening devices. The threaded bolts66extend through openings67,93defined in the one or more wall members12(e.g., such as socket base17, alignment plate48, etc.) and which further extend through openings58and beyond the lower surface71of the target board90. A mating device, e.g., washer/nut68, may then be coupled to the threaded bolts66which can be tightened to hold the assembly10in position relative to the target board90.

It will be recognized that the adapter assemblies as described herein may be mounted relative to various configurations of target boards, including but clearly not limited to those described herein (e.g., a surface mountable board, a printed circuit board, etc.). Further, such mounting of the adapter assemblies relative to such target boards may be accomplished in any manner, including but clearly not limited to those described herein (e.g., adhesive, fastening devices including bolts and nuts, threaded inserts, etc.).

The adapter assembly10, as shown inFIGS. 1-2, is formed in a substantially square configuration. However, one skilled in the art will recognize that the elements used in forming the packaged device adapter assembly10may include elements for forming an adapter assembly configured as a rectangle, a circle, or any other configuration sized to accommodate a packaged device received in a socket cavity therein. As such, one skilled in the art will recognize that the present disclosure is not limited to any particular shape of adapter assembly, but is limited only as described in the appended claims.

As described herein, the cover member60of the packaged device adapter assembly10may be configured in various manners. The cover member60is used to close the socket cavity15and may include various other elements associated therewith for facilitating other functionality. For example, as previously described herein, in one embodiment as shown inFIG. 1, cover member60may be integrated with threaded insert65for receiving the threaded portion74of the actuator element70(e.g., a compression screw) used in applying a direct force to floating member40(e.g., a compression plate). Further, cover member60as shown inFIG. 1may include openings61for receiving corresponding fastening elements69, e.g., screws or threaded bolts, to affix cover member60to the one or more wall members12(e.g., socket base member17). In such an embodiment, the one or more wall members12may include inserts57for receiving the fastening elements69therein. For example, as shown inFIG. 1, inserts57may be threaded inserts for retaining threaded screw portions of screws69to attach cover member60to the socket base member17.

However, in another embodiment, the cover member60may also be configured as a latchable hinge cover as shown and described in U.S. Pat. No. 6,394,820, e.g., a ZIF type or clam-type lid. Although several cover members are described herein, the present invention is not limited to only such configurations as various other configurations may provide suitable closure function for the adapter.

Further, with reference toFIGS. 1-2, and also with reference toFIGS. 3A-3D, the conductive elastomer interconnect30includes the carrier31through which a plurality of openings33are defined from the first side131to the second side133thereof. The carrier31, at least in one embodiment, includes parallel first and second sides131,133and has a thickness in the range of about 0.004 inches to about 0.010 inches. Further, for example, the thickness may be greater than about 0.002 inches or less than about 0.012 inches. By providing such a short contact between the target board contact pads92and the contact elements86of the packaged device80(e.g., the short contact being the thin layer of suspended conductive elastomer in the opening defined in the thin carrier layer), the adapter assembly10may be effective for high bandwidth applications.

Further, the carrier31may be formed of one or more layers and/or portions of any suitable material. For example, the carrier may be formed of one or more polymers, non-conductive high temperature material that can be exposed to reflow temperatures, etc. Further, for example, the carrier may be formed of Kapton polyimide, cirlex, FR4, etc.

The plurality of openings33defined through the carrier31are arranged such that each opening aligns with a corresponding contact element86(e.g., ball or sphere of a ball grid array) of the packaged device80. As such, for example, the plurality of openings33may be arranged and/or distributed in an array along x and y axes orthogonal to the adapter axis13to correspond to contact elements86distributed in such a manner or the plurality of openings33may be arranged and/or distributed along a region distal from the center of the carrier31to correspond to contact elements86distributed in such a manner at the perimeter of the package device80. However, any arrangement of contact elements86may be accommodated according to the present disclosure with use of an arrangement of the plurality of openings33which are aligned therewith.

Further, in one or more embodiments, each opening of the plurality of openings33defined through the carrier31is sized for contact with a corresponding contact element86. For example, where the packaged device80includes a ball grid array having a plurality of balls or spheres86at the lower surface84thereof, each of the plurality of openings33defined through the carrier31may be a cylindrical opening having a diameter sized to receive a ball/sphere of the packaged device80. For example, the diameter of such openings33may be in the range of about 0.006 inches to about 0.045 inches depending on the pitch of the openings (i.e., the distance between adjacent openings). In other words, at least in one embodiment, the conductive elastomer35is a flexible cylindrical suspended pad within the opening33.

Within each of the plurality of openings33, conductive elastomer35is suspended therein. For example, in one or more embodiments, the conductive elastomer35is suspended such that the first and second sides131,133are free of any conductive elastomer. In other words, the conductive elastomer35is attached (e.g., by thermal bonding, UV curing, atmospheric curing, etc.) to the inner walls36defining the openings33as shown, for example, inFIG. 3D. For example, such conductive elastomer35may be described as being suspended in an array of holes or openings provided in a matrix form.

The conductive elastomer35may be any suitable conductive elastomer material including, for example, any conductive polymer, any conductive flowable material having a plurality of conductive particles distributed therein, silver particle conductive epoxy, gold particle conductive epoxy, etc. In at least one embodiment, the conductive elastomer material may include a flexible epoxy having a plurality of conductive particles distributed therein (e.g., silver particles or balls, gold particles or balls, etc.; having a particle size in the range of about 3 microns to about 10 microns), electrically conductive RTV silicone, or any like conductive epoxy having a certain degree of flexibility (e.g., to provide certain degree of movement from its normal state when suspended in the opening).

Further, in one or more embodiments, the conductive elastomer35suspended in each of the plurality of openings33may include a curable conductive elastomer material. For example, the elastomer material may be flowable such that it can be provided within each of the plurality of openings33and then cured therein (e.g., such as by thermal, chemical, or other curing processes). Such curing may result in the suspended conductive elastomer35having a concave surface at the second side133of the carrier31(e.g., which may more effectively receive a sphere/ball of a ball grid array).

At least in one embodiment, conductive elastomer35suspended in each of the plurality of openings33is a flexible conductive material such that the suspended conductive elastomer35in each of the plurality of openings33is flexed towards the first side131of the carrier31when a force is applied to the packaged device80(e.g., such as with use of floating member40). In other words, at least in one embodiment, when the contact element86(e.g., a ball/sphere) is in contact with the suspended conductive elastomer35as shown inFIG. 2Eand the force is applied to the packaged device80, a compression force is also applied to the suspended conductive elastomer35resulting in the flexing of the suspended conductive elastomer35beyond the first side131of the carrier31and providing effective contact for the contact element86through the conductive elastomer35to the contact pad92of the target board90(e.g., moved from its normal state to a flexed state due to the compression force being applied, and then returning to its normal state when the compression force is removed). In such a case when compression is applied (e.g., in its flexed state), for example, the suspended conductive elastomer35may take the form of a concave shape at the second side133of the carrier31and a convex shape at the first side131of the carrier31. By providing a highly resilient elastomer, thousands of compression cycles can be accommodated.

Further, as shown inFIGS. 1-2, the adapter assembly10may further include additional guiding and/or alignment apparatus such as a ball guide50adjacent conductive elastomer interconnect30(e.g., along axis13) and upon which the packaged device80may be received within socket cavity15. In at least one embodiment, the ball guide50may include a plurality of openings51defined from the first side151thereof adjacent carrier31to a second side153adjacent a received package device80. The ball guide50, at least in one embodiment, may include parallel first and second sides and have a thickness in the range of about 0.002 inches to about 0.007 inches. Further, the ball guide50may be formed of one or more layers of any suitable material (e.g., non-conductive material). For example, the ball guide may be formed of one or more polymers or any other electrically non-conductive material or insulative material. Further, for example, the ball guide may be formed of Kapton polyimide, FR4, etc.

Providing such a ball guide50may prevent too large of a compression force being applied to the suspended conductive elastomer35in the openings33of the carrier31. For example, as shown inFIG. 2E, the thickness of the ball guide50may be such (e.g., depending on the size of the ball/sphere86) that, when the first side151of the ball guide50contacts the second side133of the carrier31and the second side153of the ball guide50contacts the lower surface84of the packaged device80, over compression on the suspended conductive elastomer35in the opening33is prevented.

The plurality of openings51defined through the ball guide50are arranged such that each opening aligns with a corresponding contact element86(e.g., ball or sphere of a ball grid array) of the packaged device80. As such, for example, the plurality of openings51may be arranged and/or distributed in an array along x and y axes orthogonal to the adapter axis13to correspond to contact elements86distributed in such a manner or the plurality of openings51may be arranged and/or distributed along a region distal from the center of the ball guide to correspond to contact elements86distributed in such a manner at the perimeter of the package device80. However, any arrangement of contact elements86may be accommodated according to the present disclosure with use of an arrangement of the plurality of openings51which are aligned therewith.

In at least one embodiment, the ball guide50may take form of the carrier31without the conductive elastomer suspended in the openings thereof. Further, for example, in one or more embodiments, each opening of the plurality of openings51defined through the ball guide50may be sized for allowing a corresponding contact element86to pass therethrough and contact the suspended conductive elastomer35in the opening33of the carrier31. For example, where the packaged device80includes a ball grid array having a plurality of balls or spheres86at the lower surface84thereof, each of the plurality of openings51defined through the ball guide50may be a cylindrical opening having a diameter sized to allow a ball/sphere of the packaged device80to pass therethrough. For example, the diameter of such openings51may be in the range of about 0.005 inches to about 0.045 inches.

As described herein, the conductive elastomer interconnect30for the adapter assembly10, at least in one embodiment, may be positioned at the first end region14of the adapter assembly10orthogonal to the adapter axis13to define the socket cavity15with the one or more wall numbers12. The conductive elastomer interconnect30may be formed in any suitable manner before being assembled to form the socket cavity15. In one embodiment, as shown inFIG. 4, the conductive elastomer interconnect30may be formed by positioning the first side131of carrier31adjacent a formation surface197of a fill plate138. For example, one or more alignment pins182may be used to position multiple carriers31on the formation surface197. At least in one embodiment, the formation surface197is a planar surface which closes the plurality of openings33defined through the carrier31. A flowable conductive elastomer is then provided within the plurality of openings33defined through the carrier31. The conductive elastomer within the plurality of openings33may then be cured (e.g., by thermal curing, UV curing, atmospheric curing, etc.) to provide the suspended conductive elastomer35in each of the plurality of openings33. In such a manner, for example, the conductive elastomer35fills the defined opening33with the conductive elastomer35having a surface that is flush with the first side131of the carrier31as shown inFIG. 3D.

At least in one embodiment, silver particles are dispersed in silicone paste to provide the conductive elastomer (e.g., a two part composition including a base material and a catalyst). When the material is to be provided into the openings33in the carrier31, the base material and catalyst are added together and mixed (e.g., with centrifugal movement) to make a consistent paste. The paste may then be provided onto the carrier31(e.g., screened onto the carrier31). For example, a flexible member (e.g., a rubber member or squeegee) may be used to force the paste into the openings33such that they are filled equally. The flexible member may be moved left to right and top to bottom several times to provide the fill in the openings33and to remove any excess paste. The carrier31may then be cured (e.g., thermally cured in an oven, for example, at 150 degrees C. for 30 minutes; or at room temperature, for example, for one day).

FIGS. 5A-5Bshow an alternate process of forming a conductive elastomer interconnect230including conductive elastomer235suspended in a plurality of openings240of a carrier231. For example, a first side232of carrier231is positioned adjacent a fill plate238. However, unlike the fill plate138shown inFIG. 4, fill plate238includes at least one surface deformation239defined in formation surface297(e.g., using a mask and etch process, or in any other manner, physical or chemical) corresponding to each of the plurality of openings240defined through the carrier231. When flowable elastomer material fills the opening240, the deformation239is also filled. When cured, the elastomer material in the at least one surface deformation239forms a contact projection250of conductive elastomer extending beyond the first side232of the carrier231. The contact projection250may provide more effective electrical contact between the conductive elastomer235and a contact pad of the plurality of contact pads92of the target board90when the target board90is positioned adjacent to the first side232of the carrier231. In other words, the formation surface297is a nonplanar formation surface configured to provide contact projections250.

One will recognize that various processing steps may be used in the formation of the conductive elastomer interconnects described herein. For example, overfilling holes may be permitted with subsequent planarization or other processes to remove undesirable material, varies masking and etching processes may be used to form openings and or deformations in surfaces, openings may be formed by mechanical drilling or laser drilling, etc.

All patents, patent documents, and references cited herein are incorporated in their entirety as if each were incorporated separately. This disclosure has been described with reference to illustrative embodiments and is not meant to be construed in a limiting sense. As described previously, one skilled in the art will recognize that various other illustrative adapter assembly embodiments may be provided which utilize various combinations of the elements described herein. Various modifications of the illustrative embodiments, as well as additional embodiments of the disclosure and combinations of various elements herein, will be apparent to persons skilled in the art upon reference to this description. It is therefore contemplated that the patented claims will cover any such modifications or embodiments that may fall within the scope of the present disclosure as defined by the accompanying claims.