Patent Grant
7568917
The subject matter described and illustrated herein relates generally to electrical contacts, and more particularly, to the electrical contacts of an interposer.
Interconnect devices are sometimes used to provide electrical connection between different electrical components, such as, but not limited to, integrated circuits and printed circuit boards, for example when removal, replacement, and/or testing of the electrical components is desired. Many of these electrical components have electrical contacts arranged in a “land grid array” (LGA) which is a two-dimensional array of contact pads. One type of interconnect device, known as an “interposer”, has an array of electrical contacts which is placed between the two opposing arrays of the electrical components to provide an electrical connection between the electrical contacts of the opposing arrays.
Establishing reliable contact between the electrical contacts of the opposing electrical component arrays and the electrical contacts of the interposer may sometimes be difficult due to, for example, misalignment between electrical contacts of the opposing electrical component arrays and/or the electrical contacts of the interposer. Moreover, it may be difficult to provide the electrical contacts of the interposer with a shape that facilitates mechanical stability between the interposer and the electrical components. Some known interposers use elastomeric elements that are compressed by the electrical contacts of the opposing electrical component arrays such that the elastomeric elements apply a mechanical force to the electrical contacts to facilitate establishing and maintaining reliable electrical contact between the opposing electrical component arrays. Compression of the elastomeric elements may allow for some degree of misalignment of the electrical contacts of the interposer and/or the opposing electrical component arrays. However, at least some known interposers that use elastomeric elements may still suffer from misalignment and/or a less than desired mechanical stability between electrical contacts of the opposing electrical component arrays and/or the electrical contacts of the interposer. Moreover, some known interposers require that a substrate of the interposer be dielectric to electrically insulate the electrical contacts of the interposer from each other.
What is needed therefore is an interposer having less misalignment and/or greater mechanical stability than at least some known interposers. Moreover, what is needed is an interposer that does not require a dielectric substrate.
In one embodiment, a laminated electrical contact strip is provided. The laminated electrical contact strip includes a plurality of electrical contacts. Each electrical contact includes a pair of opposite first and second surfaces extending between a pair of opposite end portions. First and second dielectric layers are laminated over the plurality of electrical contacts such that the first and second dielectric layers hold the plurality of electrical contacts therebetween. The first dielectric layer is bonded to and covers a portion of the first surface of each of the electrical contacts. The second dielectric layer is bonded to and covers a portion of the second surface of each of the electrical contacts.
In another embodiment, an electrical contact strip assembly is provided. The electrical contact strip assembly includes a base having opposite first and second base surfaces, a plurality of first elastomeric elements extending outwardly from the first base surface, and a plurality of second elastomeric elements extending outwardly from the second base surface. A laminated electrical contact strip is held by the base. The laminated electrical contact strip includes a plurality of electrical contacts. Each electrical contact includes a pair of opposite first and second surfaces extending between a pair of opposite first and second end portions. First and second dielectric layers are laminated over the plurality of electrical contacts such that the first and second dielectric layers hold the plurality of electrical contacts therebetween. The first dielectric layer is bonded to and covers a portion of the first surface of each of the electrical contacts. The second dielectric layer is bonded to and covers a portion of the second surface of each of the electrical contacts.
In another embodiment, an interposer is provided for electrically connecting a pair of electrical components. The interposer includes a substrate and an electrical contact strip assembly held by the substrate. The electrical contact strip assembly includes a base having opposite first and second base surfaces, a plurality of first elastomeric elements extending outwardly from the first base surface, and a plurality of second elastomeric elements extending outwardly from the second base surface. A laminated electrical contact strip is held by the base. The laminated electrical contact strip includes a plurality of electrical contacts. Each electrical contact includes a pair of opposite first and second surfaces extending between a pair of opposite first and second end portions. First and second dielectric layers is laminated over the plurality of electrical contacts such that the first and second dielectric layers hold the plurality of electrical contacts therebetween. The first dielectric layer is bonded to and covers a portion of the first surface of each of the electrical contacts. The second dielectric layer is bonded to and covers a portion of the second surface of each of the electrical contacts.
The electrical components 12 and 14 may each be any suitable type of electrical component, such as, but not limited to, printed circuit boards, integrated circuits, electrical modules, and/or other electrical devices. The arrays 16 and 18 may each be any suitable type of array of electrical contacts that enables operative electrical connection between the electrical components 12 and 14, such as, but not limited to, Pin Grid Arrays (PGAs), Land Grid Arrays (LGAs), and/or Ball Grid Arrays (BGAs). Moreover, the arrays 16 and 18 may have any suitable configuration, arrangement, and/or pattern of electrical contacts that enables operative electrical connection between the electrical components 12 and 14.
The interposer 10 includes a substrate 28 having opposite surfaces 30 and 32 and a plurality of electrical contact strip assemblies 34 held by the substrate 28. Each electrical contact strip assembly 34 includes a plurality of the electrical contacts 26 held in a row. The electrical contacts 26 are spaced apart from each other within the corresponding row such that the electrical contacts 26 are electrically isolated from adjacent electrical contacts 26 within the corresponding row. In the exemplary embodiment, the electrical contact strip assemblies 34 are held by the substrate 28 in a side-by-side arrangement such that the electrical contact strip assemblies 34 form a plurality of rows of the electrical contacts 26. Although twenty electrical contact strip assemblies 34 are shown in
The substrate 28 may be fabricated from any suitable material(s) that enables the substrate 28 to function as described herein, such as, but not limited to, Kapton®, polyethylene terephthalate (PET), polyimide, polyester, epoxy, other materials having a low and uniform dielectric constant, and/or electrically conductive materials, such as, but not limited to, metallic materials, such as, but not limited to, stainless steel. In some embodiments, the substrate 28 is fabricated entirely from one or more materials having a low and uniform dielectric constant. Alternatively, the substrate 28 is fabricated from one or more electrically conductive materials, such as, but not limited to, stainless steel. As will be described below, in some embodiments the substrate 28 need not be dielectric to electrically insulate, or isolate, the electrical contacts 26 from each other.
A plurality of elastomeric elements 52 extend outwardly from the surface 40, and a plurality of elastomeric elements 54 extend outwardly from the surface 42. The elastomeric elements 52 and 54 may each be referred to herein as a “first elastomeric element” and/or a “second elastomeric element”. Each of the elastomeric elements 52 extends opposite a corresponding one of the elastomeric elements 54. The elastomeric elements 52 and 54 are compressible such that they apply a mechanical force, via the electrical contacts 26, to the electrical contacts 20 and 22 (
The elastomeric elements 52 and 54 may be fabricated from any suitable material(s) that enable the elastomeric elements 52 and 54 to function as described herein, such as, but not limited to, silicone rubber, flourosilicone rubber, polyepoxide, polyimide, polybutadiene, neoprene, ethylene propylene diene monomer (EPDM), a thermoplastic elastomer, and/or polystyrene. The elastomeric elements 52 and 54 may have any suitable shape that enables the elastomeric elements 52 and 54 to function as described herein, such as, but not limited to, a cone, a truncated cone (a frustoconical shape), a pyramid, a truncated pyramid, a prism, and/or a hemisphere. In the exemplary embodiment, the elastomeric elements 52 and 54 include a frustoconical shape. Some or all the elastomeric elements 52 may optionally be connected together by a corresponding elastomeric member 56. Similarly, some or all of the elastomeric elements 54 may optionally be connected together by a corresponding elastomeric member 56. The elastomeric members 56 may facilitate preventing the elastomeric elements 52 and 54 from laterally deflecting when the electrical components 12 and 14 are connected together by the interposer 10.
The base 36 includes a pair of opposite side portions 58 and 60 that extend between the surfaces 40 and 42. The side portion 58 includes one or more extensions 62 that extend outwardly therefrom. As will be described below, the extensions 62 are each received within a corresponding opening 64 (
The base 36 may be fabricated from any suitable material(s) that enables the base 36 to function as described herein, such as, but not limited to, Kapton®, polyethylene terephthalate (PET), polyimide, polyester, epoxy, other materials having a low and uniform dielectric constant, and/or electrically conductive materials, such as, but not limited to, metallic materials, such as, but not limited to, stainless steel. In some embodiments, the base 36 is fabricated entirely from one or more materials having a low and uniform dielectric constant. Alternatively, the base 36 is fabricated from one or more electrically conductive materials, such as, but not limited to, stainless steel. As will be described below, in some embodiments the base 36 need not be dielectric to electrically insulate, or isolate, the electrical contacts 26 from each other.
The dielectric layers 66 and 68 are laminated over the electrical contacts 26 such that the dielectric layers 66 and 68 hold the electrical contacts 26 therebetween. Specifically, the dielectric layer 66 is bonded to, and covers, a portion of the surface 70 of each of the electrical contacts 26, and the dielectric layer 68 is bonded to, and covers, a portion of the surface 72 of each of the electrical contacts 26. The dielectric layers 66 and 68 may be laminated over the electrical contacts 26 using any suitable method, process, structure, means, and/or the like. In some embodiments, lamination may include providing an adhesive between the dielectric layer 66 and 68 and the respective contact surface 70 and 72 to facilitate bonding the dielectric layers 66 and 68 to the electrical contacts 26.
As described above, the electrical contacts 26 are held by the dielectric layers 66 and 68 in a row such that the electrical contacts 26 are spaced apart from each other along the length of the row. Between some or all of the adjacent pairs of electrical contacts 26, the dielectric layers 66 and 68 may include the opening 64. As described in more detail below, the openings 64 each receive a corresponding extension 62 (
The electrical contacts 26 may be fabricated from any suitable material(s) that enable the electrical contacts 26 to function as described herein, such as, but not limited to, copper, aluminum, silver, nickel, palladium, platinum, rhodium, rhenium, tin, and/or gold. Non-noble metals covered with a conductive layer may be used as a base material(s) to provide strength and/or rigidity. Such non-noble metals may be covered with a barrier metal that is covered with a surface structure of a noble metal to ensure chemical inertness and provide suitable asperity distribution to facilitate good metal-to-metal contact.
The dielectric layers 66 and 68 may be fabricated from any suitable material(s) that enables the dielectric layers 66 and 68 to function as described herein, such as, but not limited to, Kapton®, polyethylene terephthalate (PET), polyimide, polyester, epoxy, other materials having a low and/or uniform dielectric constant, and/or the like.
When the base 36 and the laminated electrical contact strip 38 are assembled as shown in
The embodiments described and illustrated herein may provide an interposer having less misalignment and/or greater mechanical stability than at least some known interposers. Moreover, the embodiments described and illustrated herein may provide an interposer that does not require a dielectric substrate.
Exemplary embodiments are described and/or illustrated herein in detail. The embodiments are not limited to the specific embodiments described herein, but rather, components and/or steps of each embodiment may be utilized independently and separately from other components and/or steps described herein. Each component, and/or each step of one embodiment, can also be used in combination with other components and/or steps of other embodiments. When introducing elements/components/etc. described and/or illustrated herein, the articles “a”, “an”, “the”, “said”, and “at least one” are intended to mean that there are one or more of the element(s)/component(s)/etc. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional element(s)/component(s)/etc. other than the listed element(s)/component(s)/etc. Moreover, the terms “first,” “second,” and “third,” etc. in the claims 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.
While the subject matter described and illustrated herein has been described in terms of various specific embodiments, those skilled in the art will recognize that the subject matter described and illustrated herein can be practiced with modification within the spirit and scope of the claims.
This application claims the benefit of U.S. Provisional Application No. 61/020,329 filed Jan. 10, 2008, the subject matter of which is herein incorporated by reference in its entirety.
| Number | Name | Date | Kind |
|---|---|---|---|
| 3954317 | Gilissen et al. | May 1976 | A |
| 5061192 | Chapin et al. | Oct 1991 | A |
| 5297967 | Baumberger et al. | Mar 1994 | A |
| 5462440 | Rothenberger | Oct 1995 | A |
| 5759048 | Korsunsky et al. | Jun 1998 | A |
| 6045367 | Maldonado | Apr 2000 | A |
| 6146151 | Li | Nov 2000 | A |
| 6375474 | Harper et al. | Apr 2002 | B1 |
| 6474997 | Ochiai | Nov 2002 | B1 |
| 6719569 | Ochiai | Apr 2004 | B2 |
| 6926536 | Ochiai | Aug 2005 | B2 |
| 6994565 | Harper, Jr. | Feb 2006 | B2 |
| 7025601 | Dittmann | Apr 2006 | B2 |
| 7059865 | Kister et al. | Jun 2006 | B2 |
| 7070420 | Wakefield et al. | Jul 2006 | B1 |
| 7448877 | Pennypacker et al. | Nov 2008 | B1 |
| 20050208786 | Dittmann | Sep 2005 | A1 |
| 20080227307 | Alden et al. | Sep 2008 | A1 |
| Number | Date | Country | |
|---|---|---|---|
| 61020329 | Jan 2008 | US |
