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  Electrical contactUSPTO Application #: 20060189176Title: Electrical contact Abstract: An electrical contact formed from a plurality of interlaced and annealed wires by weaving or braiding the wires together to form a mesh, annealing the mesh, and cutting the annealed mesh so as to form a plurality of individual electrical contacts. A method for forming a precursor material for use in manufacturing an electrical contact is also provided that includes manipulating a plurality of wires so as to interlace the wires into a unitary structure. The unitary structure is then annealed. An electrical contact may then be formed from the precursor material by elastically rolling a portion of the unitary structure so as to form a tube, annealing the tube, and then cutting the unitary structure so as to release the tube thereby to form an electrical contact. An electrical contact may also be formed by folding a portion of the unitary structure so as to form one or more pleats, annealing the pleated unitary structure, and then cutting the pleated unitary structure so as to release one or more electrical contacts. The precursor material may also be formed by photo-etching a sheet of conductive material so as to form a mesh, and then annealing the mesh. A connector system may be formed including a housing defining a plurality of openings that are each filled with an electrical contact comprising a plurality of interlaced and annealed wires that have been previously either rolled or pleated. (end of abstract)
Agent: Duane Morris LLPIPDepartment - Philadelphia, PA, US Inventor: Che-Yu Li USPTO Applicaton #: 20060189176 - Class: 439066000 (USPTO) Related Patent Categories: Electrical Connectors, Preformed Panel Circuit Arrangement, E.g., Pcb, Icm, Dip, Chip, Wafer, Etc., With Provision To Conduct Electricity From Panel Circuit To Another Panel Circuit, Conductor Is Compressible And To Be Sandwiched Between Panel Circuits The Patent Description & Claims data below is from USPTO Patent Application 20060189176. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a Divisional application of copending U.S. application Ser. No. 10/736,280, filed Dec. 15, 2003, and entitled Electrical Contact, which application claims the benefit of U.S. Provisional Patent Application No. 60/457,076, filed Mar. 24, 2003, U.S. Provisional Patent Application No. 60/457,258, filed Mar. 25, 2003, and U.S. Provisional Patent Application No. 60/462,143, filed Apr. 8, 2003. FIELD OF THE INVENTION [0002] The present invention generally relates to [the] electrical interconnection devices, and more particularly to electrical contacts that are at the interface between a first electronic device and a substrate or between an electrical connector and the same. BACKGROUND OF THE INVENTION [0003] High density integrated circuit (IC) packages that house LSI/VLSI type semiconductor devices are well known. Input/output pins for such IC packages are often arranged in such a dense pattern (sometimes more than two hundred closely spaced contacts) that direct soldering of the IC package to a substrate, such as a printed wiring or circuit board (PCB) creates several significant problems related to inspection and correction of any resulting soldering faults. Land grid array (LGA) connectors are known for interconnecting IC packages to PCB's. LGA's typically do not require soldering procedures during engagement with the PCB. Referring to FIG. 1, prior art LGA assemblies are used to interconnect an IC package A having a plurality of flat contact pads or solder bumps B formed on a bottom surface, to contact pads C arranged in a regular pattern on a surface of PCB D. [0004] Prior art LGA assemblies are known which include an insulative housing E and a plurality of resilient conductive contacts F received in passageways formed in housing E. Resilient conductive contacts F typically have exposed portions at the upper and lower surfaces of insulative housing E for engaging flat contact pads B,C. When IC package A is accurately positioned in overlying aligned engagement with PCB D, such that conductive pads B engage conductive pads C, a normal force is applied to the exposed portions of each resilient conductive contact F to electrically and mechanically engage the respective contact pads B,C. [0005] The resilient conductive contacts associated with prior art LGA's have had a variety of shapes. A commonly used form of resilient conductive contact includes two free ends connected by a curved, resilient portion which provides for the storage of elastic energy during engagement with the IC package and PCB. Prior art resilient conductive contacts may be a single metal structure in the form of a spring to provide the required elastic response during service while also serving as a conductive element for electrical connection. Alternatively, contact buttons have been developed in which a connector is wound around, embedded, or otherwise engaged with a dielectric core, which often provides for elastic energy storage during operation with the conductor merely providing an electrical conduction pathway. Typically, a combination of barrier metal and noble metal platings are applied to the surface of the spring for corrosion prevention and for electrical contact enhancement. It is often the case that these platings are not of sufficient thickness for electrical conduction along only the surface of the spring. Examples of such prior art resilient conductive contacts may be found in U.S. Pat. Nos.: 2,153,177; 3,317,885; 3,513,434; 3,795,884; 4,029,375; 4,810,213; 4,820,376; 4,838,815; 4,922,376; 5,030,109; 5,061,191; 5,101,553; 5,127,837; 5,215,472; 5,228,861; 5,232,372; 5,308,252; 5,350,308; 5,385,477; 5,403,194; 5,427,535; 5,441,690; 5,473,510; 5,495,397; 5,599,193; 5,653,598; 5,791,914; 5,800,184; 5,806,181; 5,810,607; 5,817,986; 5,823,792; 5,833,471; 5,949,029; 6,074,219; and 6,264,476. The foregoing patents are hereby incorporated herein by reference. [0006] One problem in the art exists in that a good material for the construction of a spring, such as a high strength steel, is not a very good electrical conductor. On the other hand, a good electrical conductor, such as a copper alloy or precious metal, often does not provide adequate spring properties. There is a need for a more resilient conductive contact which incorporates the seemingly opposing requirements of good spring properties, temperature resistance, and high conductivity, but without the need for any integral supporting structure. Therefore, an improved electrical contact for use in an LGA socket or electrical connector is needed which can overcome the drawbacks of conventional electrical contacts. [0007] Thus, it is desirable that a good electrical contact element possesses the following attributes: (a) usable for both a production socket, as well as, test and burn-in sockets, where the latter use requires high durability; (b) a large elastic compliance range and low contact forces; (c) capable of transmitting high frequency signals and high currents; (d) capable of withstanding high operating temperatures; and (e) exhibiting high durability, i.e. >500K repeated deflections [0008] The prior art has been devoid of at least one of the foregoing attributes necessary for a universally applicable electrical contact. SUMMARY OF THE INVENTION [0009] The present invention provides an electrical contact formed from a precursor material, such as an etched or stamped metal sheet, or a plurality of interlaced metal wires. The precursor materials may be formed into a tube or other appropriate shape, and annealed to set their structural form. The annealed structure may then be cut into short segments to form a plurality of individual electrical contacts. The precursor materials are often formed by photo-etching a sheet of conductive material into a mesh with openings of predetermined size and shape. The mesh may also be made by stamping with a conventional metal working die. Alternatively, the precursor material may be made by manipulating a plurality of wires so as to interlace the wires into a unitary structure in the form of a mesh. The desired form factor of the electrical contact can be made by first rolling a portion of the precursor material into a tube and followed by annealing under a constraint to set the form factor permanently. The tubular structure is then cut into short segments to form individual electrical contacts. The preferred structural forms include folded structures of one or more pleats formed from the precursor material. Such a structure can be made by pressing a unitary mesh structure in a die adapted to form pleated or folded structure in the mesh, followed by annealing the pleated or folded mesh while resident in the die to set permanently the structural form. It is then cut to form individual electrical contacts. [0010] In one embodiment, the present invention provides an electrical contact formed from a plurality of interlaced and annealed wires. The electrical contact is often formed by weaving or braiding a plurality of wires together to form a mesh, annealing the mesh, and cutting the annealed mesh so as to form a plurality of individual electrical contacts that each have an extended elastic range as a result of the annealing process. [0011] A method for forming a precursor material for use in manufacturing an electrical contact is also provided that includes manipulating a plurality of wires so as to interlace the wires into a unitary structure. The unitary structure is then annealed. An electrical contact may then be formed from the precursor material by rolling a portion of the unitary structure so as to form a tube, annealing the rolled unitary structure, and then cutting the unitary structure so as to release the tube thereby to form an electrical contact. An electrical contact may also be formed by folding a portion of the unitary structure so as to form one or more pleats, annealing the folded unitary structure, and then cutting the pleated unitary structure so as to release one or more electrical contacts. The precursor material may also be formed by photo-etching a sheet of conductive material so as to form a mesh, and then annealing the mesh. [0012] A connector system may be formed in accordance with the invention including a housing defining a plurality of openings that are each filled with an electrical contact of the present invention. In one embodiment, a connector system may be formed including a housing defining a plurality of openings that are each filled with an electrical contact comprising a plurality of interlaced and annealed wires. The connector system may also include electrical contacts comprising a plurality of interlaced and annealed wires arranged in a unitary mesh having at least one pleat. BRIEF DESCRIPTION OF THE DRAWINGS [0013] These and other features and advantages of the present invention will be more fully disclosed in, or rendered obvious by, the following detailed description of the preferred embodiments of the invention, which are to be considered together with the accompanying drawings wherein like numbers refer to like parts and further wherein: [0014] FIG. 1 is a perspective exploded view of a prior art land grid array assembly; [0015] FIG. 2 is a perspective view of a woven electrical contact formed in accordance with one embodiment of the present invention; [0016] FIG. 3 is a perspective view, partially in phantom, illustrating the winding of individual wires about a central core during the manufacture of an electrical contact in accordance with the present invention; [0017] FIG. 4 is a perspective view of a land grid array assembly, similar to that shown in FIG. 1, but incorporating electrical contacts formed in accordance with the present invention; [0018] FIG. 5 is a cross-sectional view of the land grid array assembly shown in FIG. 4; [0019] FIG. 6 is a side cross-sectional view, partially broken-way, of the land grid array assembly shown in FIG. 4; Continue reading... Full patent description for Electrical contact Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Electrical contact patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Electrical contact or other areas of interest. ### Previous Patent Application: Edge connector including internal layer contact, printed circuit board and electronic module incorporating same Next Patent Application: Low profile surface mount connector Industry Class: Electrical connectors ### FreshPatents.com Support Thank you for viewing the Electrical contact patent info. 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