PATENT DOCUMENT

Publication Number: US-9119285-B2
Application Number: US-201213527491-A
Country: US
Kind Code: B2

Title: Conductive gaskets with internal cavities

Abstract:
Electronic devices may be provided with conductive structures such as displays and conductive housing walls. Conductive gaskets may be used to form electrical paths between opposing conductive structures in an electronic device. During device assembly, a conductive gasket may be compressed between opposing conductive structures. The conductive gasket may be formed from a conductive gasket wall structure. The conductive gasket wall structure may surround and at least partly enclose an air-filled cavity. Conductive gasket wall structures may be formed from conductive fabric, dielectric sheets coated with metal, or other conductive wall materials. The interior of a conductive gasket may be hollow and completely devoid of supporting structures or may contain internal structures for biasing the conductive gasket wall outwards. Planar gaskets and gaskets with other cross sections may be provided.

Claims:
What is claimed is: 
     
       1. A conductive gasket configured to form an electrical path when compressed between opposing conductive structures in an electronic device, comprising:
 a conductive gasket wall surrounding at least one air-filled cavity; and 
 a compressible interior structure that is surrounded by the conductive gasket wall, wherein the compressible interior structure comprises a structure with protrusions, and wherein the at least one cavity is interposed between at least some of the protrusions. 
 
     
     
       2. The conductive gasket defined in  claim 1  wherein the conductive gasket has an elongated tubular shape extending along a longitudinal axis and wherein the conductive gasket wall extends around the longitudinal axis. 
     
     
       3. The conductive gasket defined in  claim 1  wherein the compressible interior structure comprises a fiber-based structure containing fibers. 
     
     
       4. The conductive gasket defined in  claim 1  wherein the structure has an undulating surface. 
     
     
       5. A conductive gasket configured to form an electrical path when compressed between opposing conductive structures in an electronic device, comprising:
 a conductive gasket wall surrounding at least one air-filled cavity, wherein the conductive gasket is a hollow gasket having a hollow air-filled interior, wherein the conductive gasket has an elongated tubular shape extending along a longitudinal axis, wherein the conductive gasket wall extends around the longitudinal axis, wherein the conductive gasket wall has an inner surface and an outer surface and wherein an edge portion of the inner surface is attached to an edge portion of the outer surface with adhesive. 
 
     
     
       6. A conductive gasket configured to form an electrical path when compressed between opposing conductive structures in an electronic device, comprising:
 a conductive gasket wall surrounding at least one air-filled cavity, wherein the conductive gasket is a hollow gasket having a hollow air-filled interior, wherein the conductive gasket has an elongated tubular shape extending along a longitudinal axis, wherein the conductive gasket wall extends around the longitudinal axis, and wherein the conductive gasket wall comprises conductive fiber. 
 
     
     
       7. The conductive gasket defined in  claim 6  wherein the conductive fiber comprises metal coated dielectric fibers. 
     
     
       8. A conductive gasket configured to form an electrical path when compressed between opposing conductive structures in an electronic device, comprising:
 a conductive gasket wall surrounding at least one air-filled cavity; and 
 a compressible interior structure that is surrounded by the conductive gasket wall, wherein the compressible interior structure comprises a sheet of material that lines the conductive gasket wall. 
 
     
     
       9. The conductive gasket defined in  claim 8  wherein the sheet of material comprises a sheet of foam that is attached to the conductive gasket wall with adhesive. 
     
     
       10. An elongated tubular gasket configured to form an electrical path when compressed between opposing conductive structures, wherein the elongated tubular gasket has a longitudinal axis, the elongated tubular gasket comprising:
 a conductive gasket wall that extends around the longitudinal axis and around at least one elongated cavity region to form the elongated tubular gasket that contains at least one air-filled cavity; and 
 a compressible interior structure that is surrounded by the conductive gasket wall, wherein the compressible interior structure is a fiber-based structure formed entirely from plastic fibers. 
 
     
     
       11. The elongated tubular gasket defined in  claim 10  wherein the conductive gasket wall comprises a layer of conductive fabric having conductive fibers. 
     
     
       12. The elongated tubular gasket defined in  claim 10  wherein the conductive gasket wall comprises a layer of dielectric coated with metal. 
     
     
       13. The elongated tubular gasket defined in  claim 10  wherein the conductive gasket wall comprises a conductive layer attached to a dielectric support layer with adhesive. 
     
     
       14. The elongated tubular gasket defined in  claim 10 , wherein elongated tubular gasket has an interior volume, and wherein the fiber-based structure takes up between 5% and 50% of the interior volume of the elongated tubular gasket. 
     
     
       15. An elongated tubular gasket configured to form an electrical path when compressed between opposing conductive structures, wherein the elongated tubular gasket has a longitudinal axis, the elongated tubular gasket comprising:
 a conductive fabric layer that extends at least partly around the longitudinal axis and around at least one elongated cavity region to form the elongated tubular gasket; and 
 a support structure formed in the elongated cavity region that is surrounded by the conductive fabric layer, wherein the support structure has a non-planar surface that forms a plurality of air-filled cavities in the elongated cavity region. 
 
     
     
       16. The elongated tubular gasket defined in  claim 15  wherein the conductive fabric layer has edges that are attached to each other to form an O-shaped cross section for the elongated tubular gasket. 
     
     
       17. The elongated tubular gasket defined in  claim 15  wherein the conductive fabric layer has edges that are attached to each other to form a P-shaped cross-section for the elongated tubular gasket. 
     
     
       18. The elongated tubular gasket defined in  claim 15  further comprising a planar conductive layer, wherein the conductive fabric layer has edges that are attached to the planar conductive with conductive adhesive. 
     
     
       19. The elongated tubular gasket defined in  claim 15  wherein the conductive fabric layer has a portion that is configured to form a C-shaped cross section for the elongated tubular gasket.

Description:
BACKGROUND 
     This relates generally to electronic devices and, more particularly, to conductive gaskets. 
     Conductive gaskets are used in electronic devices to short conductive structures together. For example, a conductive component such as a portion of a display or antenna may be electrically coupled to a conductive member by compressing a conductive gasket between the component and conductive member. This may short the conductive component to the conductive member, thereby grounding the conductive component and reducing interference in the electronic device. 
     Conductive gaskets are typically formed from foam that is wrapped in a conductive fabric. During assembly, the foam is compressed between the structures that are being shorted together. The foam attempts to return to its original uncompressed shape, thereby biasing the conductive fabric against the conductive structures. 
     It can be challenging to use foam gaskets. The biasing forces produced by compressed foam may tend to disassemble parts and may create undesired stresses. The electrical conductivity of foam gaskets may also depend on how much the foam gaskets are compressed. For example, if the foam gaskets are not sufficiently compressed, the foam gaskets may provide poor electrical grounding paths. To ensure adequate mechanical tolerances and to ensure sufficient conductivity of the foam gaskets, it may be necessary to use generously sized foam thicknesses. Overcoming the strong biasing forces that may result from the use of thick foam can be difficult and can force a designer to make undesired compromises when constructing an electronic device. 
     It would therefore be desirable to be able to provide improved conductive gaskets for use in electronic devices. 
     SUMMARY 
     Electronic devices may be provided with conductive structures such as displays and conductive housing walls. Conductive gaskets may be used to form electrical paths between opposing conductive structures in an electronic device. During device assembly, a conductive gasket may be compressed between opposing conductive structures. The compressed conductive gasket may press outwards against the conductive structures, thereby forming an electrical pathway between the conductive structures. 
     The conductive gasket may be formed from a conductive gasket wall structure. The conductive gasket wall structure may surround and at least partly enclose an air-filled cavity. By avoiding the use of internal support structure material in at least part of the interior of the gasket, outward biasing forces that are produced when the gasket is compressed may be minimized. 
     Conductive gaskets may be planar, may be tubular, or may have other shapes. For example, a conductive gasket may have an elongated tubular shape characterized by a longitudinal axis. Conductive gasket wall material may be wrapped around the longitudinal axis. The interior of the conductive gasket may be partly filled with internal support structures such as undulating foam, fiber-based material, a corrugated sheet of flexible material, hollow or solid rods or spheres, a sheet of foam or other flexible material that lines an inner surface of a conductive gasket wall structure, or other internal structures. If desired, the interior of a conductive gasket may be completely devoid of supporting structures and may form a hollow conductive gasket. 
     Conductive gasket wall structures may be formed from conductive fabric, metal coated on dielectric sheets, or other conductive wall structures. Conductive fabric may be formed from metal fibers, dielectric fibers coated with metal, combinations of conductive fibers and fibers that are not conductive, or other suitable fibers. 
     Conductive gaskets may be attached to opposing conductive structures using adhesives such as pressure-sensitive adhesives. Clamping tools may be used to apply pressure to the adhesives so that the conductive gaskets are attached to the opposing conductive structures. Support structures having protruding members may be used to help ensure that the conductive gaskets are not deformed when compressed by clamping tools. 
     Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an illustrative electronic device with conductive gasket structures in accordance with an embodiment of the present invention. 
         FIG. 2  is a cross-sectional side view of illustrative conductive gaskets within an illustrative electronic device in accordance with an embodiment of the present invention. 
         FIG. 3  is a top view of an illustrative electronic device with curved and straight elongated conductive gaskets in accordance with an embodiment of the present invention. 
         FIG. 4  is a perspective view of an illustrative tube-shaped conductive gasket compressed between two opposing conductive structures in accordance with an embodiment of the present invention. 
         FIG. 5  is a diagram of illustrative fibers in a conductive fabric gasket in accordance with an embodiment of the present invention. 
         FIG. 6  is a cross-sectional view of a fiber such as a solid fiber in a conductive fabric gasket in accordance with an embodiment of the present invention. 
         FIG. 7  is a cross-sectional view of a fiber coated with a conductive material such as metal in a conductive fabric gasket in accordance with an embodiment of the present invention. 
         FIG. 8  is a diagram of a conductive fabric having conductive fibers and other fibers in accordance with an embodiment of the present invention. 
         FIG. 9  is a cross-sectional view of a portion of a hollow gasket structure in which a gasket wall is formed from a single layer of material such as a layer of conductive foil or conductive fiber in accordance with an embodiment of the present invention. 
         FIG. 10  is a cross-sectional view of a portion of a hollow gasket structure in which a gasket wall is formed from a conductive outer layer of material such as a layer of conductive foil or conductive fiber and an inner support layer such as a layer of plastic or foam that lines the inner surface of the conductive outer layer in accordance with an embodiment of the present invention. 
         FIG. 11  is a cross-sectional view of a portion of a hollow gasket structure in which a gasket wall is formed from a conductive outer layer of material such as a metal coating on an inner layer such as a dielectric layer formed from plastic in accordance with an embodiment of the present invention. 
         FIG. 12  is a cross-sectional view of a portion of a conductive gasket having an internal support structure formed from a compressible material with an undulating surface such as foam having radially extending arms separated by air-filled cavity regions in accordance with an embodiment of the present invention. 
         FIG. 13  is a cross-sectional view of a portion of a conductive gasket having an internal biasing structure formed from fibers in accordance with an embodiment of the present invention. 
         FIG. 14  is a cross-sectional view of a portion of a conductive gasket having an internal biasing structure formed from a corrugated flexible member such as a corrugated sheet of plastic in accordance with an embodiment of the present invention. 
         FIG. 15  is a cross-sectional view of a portion of a conductive gasket having an internal biasing structure formed from compressible members such as rods or balls in accordance with an embodiment of the present invention. 
         FIG. 16  is a cross-sectional view of a conductive hollow gasket formed from a conductive sheet of material wrapped into an O-shaped tube in accordance with an embodiment of the present invention. 
         FIG. 17  is a cross-sectional view of a conductive hollow gasket formed from a conductive sheet of material wrapped into a P-shaped tube in accordance with an embodiment of the present invention. 
         FIG. 18  is a cross-sectional view of a conductive hollow gasket formed from a conductive sheet of material in a C-shaped tube in accordance with an embodiment of the present invention. 
         FIG. 19  is a cross-sectional view of a conductive hollow gasket formed from first and second attached sheets of conductive material in accordance with an embodiment of the present invention. 
         FIG. 20  is a cross-sectional view of a conductive hollow gasket formed from a conductive sheet of material wrapped into a P-shaped tube and filled with biasing structures such as fibers in accordance with an embodiment of the present invention. 
         FIG. 21  is a cross-sectional view of a conductive hollow gasket formed from a conductive sheet of material wrapped into a P-shaped tube and filled with biasing structures such as a compressible foam or plastic structure with radially extending arms that form an undulating surface in accordance with an embodiment of the present invention. 
         FIG. 22  is a cross-sectional view of a conductive hollow gasket formed from a conductive sheet of material wrapped into a P-shaped tube and lines with biasing structures such as a layer of foam or other resilient substrate material in accordance with an embodiment of the present invention. 
         FIG. 23  is a perspective view of a rod of material that may serve as a support structure for forming a hollow conductive tubular gasket in accordance with an embodiment of the present invention. 
         FIG. 24  is a perspective view of the rod of material of  FIG. 23  after being wrapped with a layer of conductive material to form a hollow conductive gasket in accordance with an embodiment of the present invention. 
         FIG. 25  is a perspective view of the hollow conductive gasket of  FIG. 24  following removal of the rod of supporting material in accordance with an embodiment of the present invention. 
         FIG. 26  is a cross-sectional view of a portion of an illustrative seam in a hollow conductive gasket in accordance with an embodiment of the present invention. 
         FIG. 27  is a cross-sectional view of a corrugated conductive gasket with a planar shape in accordance with an embodiment of the present invention. 
         FIG. 28  is a cross-sectional view of a planar conductive gasket structure formed from a sheet of material with a corrugated biasing structure in accordance with an embodiment of the present invention. 
         FIG. 29  is a cross-sectional view of a planar conductive gasket structure formed from a sheet of material with internal biasing structures such as spheres or rods in accordance with an embodiment of the present invention. 
         FIG. 30  is a cross-sectional view of an illustrative electronic device structure having conductive gasket structures of multiple types in accordance with an embodiment of the present invention. 
         FIG. 31  is a cross-sectional view of an illustrative planar conductive gasket structure having a corrugated shape with concave ridges in accordance with an embodiment of the present invention. 
         FIG. 32  is a cross-sectional view of an illustrative compressed corrugated gasket structure in accordance with an embodiment of the present invention. 
         FIGS. 33-35  are cross-sectional views of illustrative steps that may be performed to form a corrugated gasket structure with adhesive layers and protective layers in accordance with an embodiment of the present invention. 
         FIG. 36  is a cross-sectional view of an illustrative gasket structure that may be used to form a corrugated gasket structure in accordance with an embodiment of the present invention. 
         FIG. 37  is a cross-sectional view of an illustrative corrugated gasket structure having adhesive layers in accordance with an embodiment of the present invention. 
         FIG. 38  is a perspective view of an illustrative support structure that may be inserted into cavities of a corrugated gasket structure in accordance with an embodiment of the present invention. 
         FIG. 39  is a cross-sectional view of an illustrative corrugated gasket structure having cavities in which a support structure has been inserted in accordance with an embodiment of the present invention. 
         FIG. 40  is an illustrative diagram of a manufacturing system that may be used to form conductive gasket structures in accordance with an embodiment of the present invention. 
         FIG. 41  is a flow chart of illustrative steps that may be performed to attach a corrugated gasket structure to opposing conductive structures in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Electronic devices may be provided with antennas and other wireless communications circuitry. The wireless communications circuitry may be used to support wireless communications in wireless communications bands such as wireless local area network bands, cellular telephone bands, satellite navigation system bands, and other communications bands. Electronic device may also contain electronic components such as displays. When operating an electronic device, it is often desirable to short together conductive structures. For example, it may be desirable to ground a portion of a display or a portion of an antenna to a conductive housing structure. By shorting together the conductive structures, electromagnetic interference (EMI) within an electronic device may be reduced. Conductive structures may also be shorted together to reduce the likelihood of component damage during electrostatic discharge events and to ensure proper grounding for other device functions. 
     The conductive structures that are being shorted together in an electronic device are often separated by an air gap. A conductive gasket structure may be interposed between opposing conductive structures to form a shorting path. The conductive gasket structure may be configured to span the air gap between the opposing conductive structures when the conductive structures and gasket structures are assembled together into an electronic device. 
     A conductive gasket structure may be compressed between opposing conductive structures during device assembly. Excessive restoring force from the compressed gasket structure may be avoided by using hollow gasket arrangements and/or gasket configurations that include relatively weak internal biasing structures. Examples of weak internal biasing approaches include the use of hollow gaskets, the use of gaskets that are partially hollow, the use of gaskets that are only partly filled with foam, the use of gaskets filled with plastic wool, the use of corrugated internal biasing structures, and the use of other biasing structures that contain relatively large amounts of air so that the interior cavity regions within the gaskets are at least partly air filled. 
     An illustrative electronic device of the type that may be provided with one or more conductive gaskets is shown in  FIG. 1 . Electronic device  10  may be a computer such as a computer that is integrated into a display such as a computer monitor. Electronic device  10  may also be a laptop computer, a tablet computer, a somewhat smaller portable device such as a wrist-watch device, pendant device, headphone device, earpiece device, or other wearable or miniature device, a cellular telephone, a media player, or other electronic equipment. Illustrative configurations in which electronic device  10  is a computer formed from a computer monitor are sometimes described herein as an example. In general, electronic device  10  may be any suitable electronic equipment. 
     Conductive gaskets may be formed in device  10  in any suitable location such as locations  18 . Locations  18  may include, for example, edge locations that run parallel to the four edges of device  10  and corner locations at the upper or lower corners of device  10  (as examples). Device  10  may include conductive structures that are electrically shorted together using conductive gaskets. The conductive structures may include conductive housing structures, conductive structures such as metal traces on dielectric carriers, conductive structures that are parts of display modules (e.g., metal chassis structures), metal traces in flexible printed circuits and rigid printed circuits, metal foil supported by dielectric carrier structures, wires, cables, and other conductive materials. 
     Device  10  may include a display such as display  14 . Display  14  may be mounted in a housing such as electronic device housing  12 . Housing  12  may be supported using a stand such as stand  16  or other support structure. 
     Housing  12 , which may sometimes be referred to as a case, may be formed of plastic, glass, ceramics, fiber composites, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of these materials. In some situations, parts of housing  12  may be formed from dielectric or other low-conductivity material. In other situations, housing  12  or at least some of the structures that make up housing  12  may be formed from metal elements. 
     Display  14  may be a touch screen that incorporates capacitive touch electrodes or other touch sensor components or may be a display that is not touch sensitive. 
     A cross-sectional side view of device  10  is shown in  FIG. 2 . As shown in  FIG. 2 , display  14  may include a transparent display cover layer such as display cover layer  14 A. Display cover layer  14 A may be formed from a clear glass layer, a transparent layer of plastic, or other transparent material. Display  14  may include display structures  14 B. Display structures  14 B may include an array of display pixels for displaying images for a user. Display cover layer  14 A may be used to protect display structures  14 B and, if desired, touch sensor structures in display  14 . Display structures  14 B may include display pixels formed from light-emitting diodes (LEDs), organic LEDs (OLEDs), plasma cells, electrophoretic display structures, electrowetting display structures, liquid crystal display (LCD) components, or other suitable display pixel structures. 
     As shown in the example of  FIG. 2 , conductive gaskets such as conductive gaskets  20  may be used to electrically connect opposing conductive structures in device  10 . In the  FIG. 2  configuration, gaskets  20  are being used to electrically connect display structures  14 B to housing  12 . Display structures  14 B may include conductive structures such as a metal chassis member that surrounds and encloses the lower portion of display structures  14 B. Housing  12  may include metal walls. Gaskets  20  in regions  18  may be used in shorting the metal chassis member of display  14  or other conductive component structures to conductive housing  12  or may otherwise be used in shorting together conductive structures in device  10 . If desired, gaskets  20  may be used to short an antenna ground (e.g., an antenna cavity wall) in antennas such as antenna  22  to opposing conductive structures such as display structures  14 B and/or conductive housing  12 . 
     By forming conductive interfaces that fill gaps between opposing conductive structures such as display structures  14 B and housing  12  and by otherwise grounding conductive structures within device  10 , potential pathways for electromagnetic interference within device  10  may be reduced or eliminated. For example, by forming a conductive seal between display structures  14 B and housing  12 , potential pathways for electromagnetic interference between components  26  on printed circuit  24  and components such as antenna  22  may be blocked. Components  26  may include display driver circuitry, processors, memory, communications circuitry such as wireless transceiver circuitry, and application-specific integrated circuits. By blocking the air gap between components  14 B and housing  12 , a reduced number of interfering signals may pass between antenna  22  and components  26 , thereby improving wireless performance in device  10 . In general, conductive gaskets such as conductive gaskets  20  of  FIG. 2  may be used to short together any two or more conductive structures in device  10 . The illustrative configuration of  FIG. 2  is merely an example. 
       FIG. 3  is a top view showing how conductive gaskets  20  may have elongated shapes that are straight (e.g., straight gaskets  20 S) and curved (e.g., curved gaskets  20 C). In the illustrative configuration of  FIG. 3 , gaskets  20  have been placed so that they run parallel to the straight edges and curved corners of housing  12 . If desired, gaskets  20  may be placed within other locations in device  10 . The configuration of  FIG. 3  is merely illustrative. 
     Gaskets  20  may have a hollow tube shape or other configuration that is compressible, but that does not exert excessive restoring forces upon structures in device  10  following assembly. An illustrative arrangement in which a hollow tube-shaped conductive gasket has been compressed between two opposing conductive structures is shown in FIG.  4 . As shown in  FIG. 4 , conductive device structures such as structures  30  and  32  may be moved towards each other during device assembly operations. As structure  30  is moved downwards in direction  34  towards structure  32  and/or as structure  32  is moved upwards in direction  36  towards structure  30 , conductive gasket  20  may be compressed between structures  30  and  32 . 
     When compressed, gasket wall  38  may press outwards against conductive structures  30  and  32 , thereby forming an electrical pathway between structures  30  and  32 . For example, the upper portion of gasket wall  38  may press upwards in direction  40  against lower surface  48  of structure  30  in region  44  and the lower portion of gasket wall  38  may press downwards in direction  42  against upper surface  50  of structure  32 . Relatively large contact patches (i.e., the areas in regions  44  and  46 ) may be used in forming connections to structures  30  and  32 , thereby minimizing contact resistance. 
     Gaskets such as gasket  20  may have any suitable shape. In the example of  FIG. 4 , gasket  20  has an elongated hollow tube shape that extends along longitudinal axis  52 . If desired, conductive gaskets such as gasket  20  may be formed with other shapes (e.g., circular outlines, rectangular outlines, square outlines) and may have other cross-sectional shapes. Gaskets  20  may have shapes that accommodate internal biasing structures while leaving room for air-filled cavities within the interior of gasket  20 , may have shapes that are completely hollow at one location along their length but that are not completely hollow at another location along their length, etc. The elongated tubular shape of conductive gasket  20  of  FIG. 4  is merely illustrative. 
     Conductive material for gasket wall  38  may be formed from a sheet of metal, a metal coating on a sheet of dielectric, metal fibers, metal-coated fibers, or other suitable conductive material. As shown in  FIG. 5 , conductive gasket  20  (e.g., gasket wall  38 ) may be formed from fibers such as fibers  54  (e.g., gasket wall structure  38  may be formed from a layer of conductive fabric). Fibers  54  may include metal fibers, plastic fibers coated with metal, glass fibers, carbon fibers, organic fibers, inorganic fibers, fibers formed from other materials, and fibers formed from two or more of these materials. Fibers  54  may have circular cross-sectional shapes, oval cross-sectional shapes, rectangular cross-sectional shapes, square cross-sectional shapes, triangular cross-sectional shapes, and other cross-sectional shapes. 
     As shown in  FIG. 6 , fibers  54  in gasket wall  38  may be formed from a solid material such as material  56 . Material  56  may be, for example, a conductive material such as metal. As shown in  FIG. 7 , fibers  54  may include multiple materials such as inner material (core)  58  and outer material (coating)  60 . Core  58  may be, for example, a dielectric such as glass, plastic, or ceramic, or may be a conductive material such as metal (as examples). Outer layer  60  may be formed from a conductive material such as metal (as an example). Layer  60  may be formed on each of fibers  54  before fibers  54  are used in forming conductive fabric or other fiber-based material for gasket wall  38  or may be deposited as a coating on fibers  54  after fibers  54  have been used to form conductive fabric or other fiber-based material for gasket wall  38  (e.g., after fibers  54  have been woven into a fabric layer). 
     As shown in  FIG. 8 , gasket wall  38  (e.g., a fabric sheet for forming wall  38 ) may include multiple fibers such as fibers  54  and fibers  62 . Fibers  54  may include conductive fibers such as solid metal fibers and/or dielectric fibers coated with metal or other conductive fibers. Fibers  62  may be formed from plastic, glass, or other non-conductive material. For example, fibers  62  may be formed from solid dielectric material with a circular cross-sectional shape such as material  56  in  FIG. 6 . If desired, fabric gasket wall structures such as structures  38  of  FIG. 8  may be formed from three or more different types of fibers (e.g., conductive fibers and/or dielectric fibers). The example of  FIG. 8  in which structures  38  include two types of fiber is merely illustrative. 
       FIG. 9  is a cross-sectional view of a portion of conductive gasket structure  20  in which gasket wall  38  has been formed from a single layer of material. Gasket wall  38  may, for example, be formed from a woven conductive fabric with solid conductive fibers and/or fibers with two or more layers of material such as an inner core covered with an outer conductive layer of metal or may be formed from a sheet of flexible metal (e.g., metal foil). 
       FIG. 10  is a cross-sectional view of a portion of conductive gasket structure  20  in which gasket wall  38  has been formed from a conductive outer layer of material (layer  64 ) and one or more inner layers of material such as layer  66 . Outer layer  64  may be, for example, a conductive fabric such as a fabric formed from solid conductive fibers and/or fibers with two or more layers of material such as an inner core covered with an outer conductive layer of metal. If desired, some or all of outer layer  64  may be formed from a sheet of flexible metal (e.g., metal foil). 
     Outer layer  64  of conductive gasket structure  20  may be attached to one or more inner layers such as layer  66 . For example, outer layer  64  may be attached to inner layer  66  using adhesive layer  68 . Adhesive layer  68  may be formed from a pressure sensitive adhesive material, a conductive adhesive material, or other suitable adhesive materials. Inner layer  66  may line the interior surface of layer  64  and may provide layer  64  with additional strength and resiliency. Inner layer  66  may be formed from a flexible layer of metal, a flexible layer of fabric, a flexible layer of plastic, a flexible layer of foam, a flexible layer of one or more other materials, or a flexible layer formed from two or more such layers. If desired, additional layers may be stacked below layer  66  (e.g., layer  66  may be lined with one or more additional layers of fabric, one or more additional layers of plastic, one or more additional layers of foam, etc.). 
     As shown in the cross-sectional view of  FIG. 11 , wall  38  of conductive gasket structure  20  may have a conductive coating such as coating  70  that is formed on the outer surface of a flexible support layer such as layer  72 . Coating  70  may be, for example, a layer of metal or other conductive material. Layer  72  may be formed from fabric, a layer of plastic, a layer of metal, or a layer formed from one or more other dielectric and/or conductive materials. Coating  70  may be formed on the outer surface of sheet  72  using physical vapor deposition, using chemical vapor deposition, by spraying, by electrochemical deposition (e.g., by electroplating), or by using other suitable deposition techniques. 
       FIG. 12  is a cross-sectional view of a portion of conductive gasket  20  in a configuration in which gasket  20  has an outer wall structure such as wall  38  that is supported by an inner support structure with radially extending arms. As shown in  FIG. 12 , wall structure  38  may form an outer surface layer for gasket  20 . Wall structure  38  may be formed from a layer of conductive fabric (e.g., solid metal fibers woven into a fabric, dielectric fiber cores coated with metal, etc.) or a layer of other conductive material (e.g., metal foil, a coating of metal on a dielectric support layer, etc.). Wall structure  38  may be wrapped around support structure  74 . For example, wall structure  38  may be wrapped around longitudinal axis  52  of gasket  20  to form a tube-shaped conductive gasket structure. 
     Support structure  74  may be formed from foam or other compressible material. To help ensure that the amount of restoring force that is produced in outward directions  80  is less than would be produced when using a solid foam core for gasket  20 , support structure  74  may have a shape with an undulating surface that creates air-filled cavities such as cavities  78  within the interior of gasket  20 . As shown in  FIG. 12 , for example, support structure (biasing structure)  74  may have multiple radially extending portions such as extending portions (arms)  76 . Each extending portion  76  may extend radially outwards from axis  52  to wall structure  38  in direction  80 . When gasket  20  is compressed between opposing conductive structures, support structure  74  will compress accordingly. Portions  76  of compressed structure  74  will then bias wall structure  38  outwards in directions  80 , so that conductive wall structure  38  can short opposing conductive structures in device  10  together. The presence of one or more air filled cavities within the interior of gasket  20  such as air-filled cavities  78  may help prevent the biasing force produced by structure  74  from becoming excessive. 
       FIG. 13  is a cross-sectional view of a portion of conductive gasket  20  in a configuration in which internal support structure  74  has been formed from fibers  84  (e.g., plastic wool, steel wool, or other material formed from intertwined fibers of plastic, metal, glass, etc.). When wall structure  38  is compressed inwardly by compressing gasket  20  between opposing conductive structures, internal support structure  74  of  FIG. 13  will generate an outwardly directed restoring force. Material  74  may be relatively loosely packed to ensure that there are a sufficient number of internal cavities such as air-filled cavity regions  78  between fibers  84 . In configurations such as the configuration of  FIG. 12  and the configuration of  FIG. 13 , cavity regions  78  may, for example, occupy 5% or more, 10% or more, or 20% or more, 50% or more, or 75% or more of the interior volume of gasket  20  (as examples). 
     If desired, a corrugated structure such as corrugated internal structure  74  of  FIG. 14  may be used in supporting gasket wall structure  38 . Corrugated structure  74  may be formed from a sheet of material (e.g., a sheet of plastic, fabric, metal, etc.) and may be characterized by inwardly protruding folds such as fold  86  and outwardly protruding folds such as fold  88 . Air-filled voids such as cavities  78  may be formed between the folds of corrugated structure  74 . When compressed inwardly during installation of conductive gasket  20  between opposing conductive structures in device  10 , corrugated structures  74  may flex inwardly and may generate a corresponding outward restoring force that biases gasket wall structure  38  outwardly in directions  80 . 
     In the illustrative configuration for conductive gasket  20  of  FIG. 15 , gasket wall structure  38  is wrapped around longitudinal axis  52  and an internal structure (structure  74 ) that is formed from compressible structures  90 . Structures  90  may be formed from a compressible material such as foam, hollow structures (e.g., hollow beads or rods), or other structures that can generate a restoring force when compressed. Structures  90  may have the shapes of spheres, rods, cones, or other suitable shapes. The cross-sectional shapes of structures  90  may be circles, squares, rectangles, triangles, ovals, shapes with both straight and curved edges, or other suitable shapes. In situations in which structures  90  are elongated (e.g., when structures  90  have the shape of rods), structures  90  may each be characterized by a longitudinal axis that runs parallel to longitudinal axis  52  of gasket  20 . When gasket  20  and gasket wall  38  are compressed inwardly, structures  90  may exhibit an outward restoring force in directions  80 , biasing the outer surfaces of gasket  20  against adjacent conductive structures. Cavities such as cavities  78  may be formed between structures  90  to help reduce the outward force that is generated when gasket  20  is compressed. 
       FIG. 16  is a cross-sectional view of conductive gasket  20  in a configuration in which gasket wall  38  is wrapped around longitudinal axis  52  to form an O-shaped tube. As shown in  FIG. 16 , gasket wall structure  38  may have opposing edges (ends) such as edge  92  and edge  94 . Edges  92  and  94  may be wrapped on top of each other so that edge  92  overlaps edge  94 . Adhesive such as adhesive layer  96  and adhesive layer  98  may be used in securing gasket wall edges  92  and  94 . Adhesive  96  may be used to attach gasket wall portion  92  to gasket wall portion  94 . Adhesive  98  may be used to attach gasket wall portion  94  to conductive structure  32 . If desired, adhesives such as adhesives  96  and  98  may be formed from conductive adhesive to promote formation of a satisfactory electrical contact between gasket  20  and conductive structure  32 . Conductive structure  30  may form an electrical connection with upper portion  100  of gasket  20 , thereby allowing conductive gasket  20  to form an electrical path between opposing conductive structures  30  and  32 . 
     Conductive gaskets such as conductive gasket  20  of  FIG. 16  that are configured to form an O-shaped tubular gasket structure may be hollow, as illustrated by air-filled cavity  78  of  FIG. 16 . If desired, a support structure may be formed within the interior of gasket  20 . For example, the interior of O-shaped tubular conductive gasket  20  of  FIG. 16  may be filled with biasing and support structures such as an internal structure of the type shown in  FIG. 12  that has protruding portions  76 , an internal fiber-based structure of the type shown in  FIG. 13 , an internal structure of the type shown in  FIG. 14  that is formed from a corrugated sheet of material, an internal structure of the type shown in  FIG. 15  having compressible support members such as tubular or spherical structures  90 , an internal structure formed from an inner wrapped liner layer such as a foam layer, plastic layer, or inner fiber layer that is formed on the inner surface of an outer conductive layer (see, e.g.,  FIG. 10 ), an internal structure that is formed from other structures that provide support and outward biasing for gasket wall  38 , and internal structures that use two or more of these structures. 
     Internal support structures for O-shaped gasket  20  of  FIG. 16  may be varied in type and size along the length of longitudinal axis  52 . For example, one type of support structure may be used in one longitudinal position and another type of support structure (or no support structure) may be positioned at an adjacent longitudinal position. Support structures of different types (including solid foam support structures and/or structures of the types shown in  FIGS. 12 ,  13 ,  14 ,  15 ,  10 , other internal support structures, and cavities such as cavity  78  of  FIG. 16 ) may be alternated with each other along the length of longitudinal axis  52 , to ensure that gasket  20  provides a desired amount of outward restoring force when compressed between opposing conductive structures  30  and  32 . 
       FIG. 17  is a cross-sectional view of conductive gasket  20  in a configuration in which gasket wall  38  is wrapped around longitudinal axis  52  to form a P-shaped tube having main cavity portion  110  and compressed tail portion  102 . In main cavity portion  110 , gasket wall  38  may surround cavity  78  (i.e., the interior of gasket  20  may be completely hollow). In tail portion  102 , opposing edge portions  112  and  114  of cavity wall structure  38  may be pressed downwards against the upper surface of conductive structure  32  in direction  104  (e.g., using an assembly tool). Edges  112  and  114  may be wrapped on top of each other so that edge  112  overlaps edge  114  with the inner surface of edge  114  facing the inner surface of edge  112  (as opposed to the configuration of  FIG. 16  in which the outer surface of edge  92  faces the inner surface of edge  94 ). 
     Adhesive such as adhesive layer  106  and adhesive layer  108  may be used in securing gasket wall edges  112  and  114 . Adhesive  106  may be used to attach gasket wall portion  112  to gasket wall portion  114 . Adhesive  108  may be used to attach gasket wall portion  114  to conductive structure  32 . Adhesives such as adhesives  106  and  108  may be formed from conductive adhesive to promote formation of a satisfactory electrical contact between gasket  20  and conductive structure  32 . Conductive structure  30  may form an electrical connection with upper portion  116  of gasket  20 , thereby allowing conductive gasket  20  to form an electrical path between opposing conductive structures  30  and  32  through the conductive materials of gasket wall structure  38 . 
     Conductive gaskets such as conductive gasket  20  of  FIG. 17  that are configured to form a P-shaped tubular gasket structure may be hollow, as illustrated by air-filled cavity  78  of  FIG. 17 . Support structures may be formed within the interior of gasket  20  of  FIG. 17 , if desired. For example, the interior of P-shaped tubular conductive gasket  20  of  FIG. 17  may be filled with biasing and support structures such as an internal structure of the type shown in  FIG. 12  that has protruding portions  76 , an internal fiber-based structure of the type shown in  FIG. 13 , an internal structure of the type shown in  FIG. 14  that is formed from a corrugated sheet of material, an internal structure of the type shown in  FIG. 15  having compressible members such as tubular or spherical structures  90 , an internal structure formed from an inner wrapped layer of material such as a foam layer, plastic layer, or inner fiber layer that is formed as a liner on the inner surface of an outer conductive layer (see, e.g.,  FIG. 10 ), an internal structure that is formed from other structures that provide support and outward biasing for gasket wall  38 , or internal structures that use two or more of these structures. As with internal support structures for O-shaped gasket  20  of  FIG. 16 , internal support structures for P-shaped gasket  20  of  FIG. 17  may be varied in type and size along the length of longitudinal axis  52 . For example, one type of support structure may be used in one longitudinal position of P-shaped gasket  20  of  FIG. 17  and another type of support structure (or no support structure) may be positioned at an adjacent longitudinal position along axis  52  of P-shaped gasket  20 . Support structures of different types (including solid foam support structures and/or structures of the types shown in  FIGS. 12 ,  13 ,  14 ,  15 ,  10 , other internal support structures, and cavities such as cavity  78  of  FIG. 17 ) may be alternated with each other along the length of longitudinal axis  52  of gasket  20  of  FIG. 17 , to ensure that gasket  20  provides a desired amount of outward restoring force when compressed between opposing conductive structures  30  and  32 . 
       FIG. 18  is a cross-sectional view of conductive gasket  20  in a configuration in which gasket wall  38  is wrapped around longitudinal axis  52  sufficiently to form a C-shaped tube having main cavity portion  128  and compressed tail portions such as left tail portion  130  and right tail portion  132 . In main cavity portion  128 , gasket wall  38  may wrap around the upper portion of cavity  78 . The lower portion of cavity  78  may be bounded by a portion of conductive structure  32 . In tail portion  130 , edge portion  118  of gasket wall structure  38  may be pressed downwards against the upper surface of conductive structure  32 . In tail portion  132 , edge portion  122  of gasket wall structure  38  may be pressed downwards against the upper surface of conductive structure  32 . 
     Adhesive such as adhesive layer  120  and adhesive layer  124  may be used in securing gasket wall edges  118  and  122  to conductive structure  36 . Adhesive  120  may be used to attach gasket wall portion  118  to a left-hand portion of conductive structure  32 . Adhesive  124  may be used to attach gasket wall portion  122  to a right-hand portion of conductive structure  32 . Adhesives such as adhesives  120  and  124  may be formed from conductive adhesive to promote formation of a satisfactory electrical contact between gasket  20  and conductive structure  32 . Conductive structure  30  may form an electrical connection with upper portion  126  of gasket  20 , thereby allowing conductive gasket  20  to form an electrical path between opposing conductive structures  30  and  32  through the conductive materials of gasket wall structure  38 . 
     As with gaskets of other shapes, conductive gaskets such as conductive gasket  20  of  FIG. 18  that are configured to form a C-shaped tubular gasket structure may be hollow, as illustrated by air-filled cavity  78  of  FIG. 18 . If desired, support structures may be formed within the interior of gasket  20  of  FIG. 18 . For example, the interior of C-shaped tubular conductive gasket  20  of  FIG. 18  may be filled with biasing and support structures such as an internal structure of the type shown in  FIG. 12  that has protruding portions  76 , an internal fiber-based structure of the type shown in  FIG. 13 , an internal structure of the type shown in  FIG. 14  that is formed from a corrugated sheet of material, an internal structure of the type shown in  FIG. 15  having tubular or spherical structures or other compressible biasing members, an internal structure formed from an inner wrapped layer of material such as a foam layer, plastic layer, or inner fiber layer that is formed as a liner on the inner surface of an outer conductive layer (see, e.g.,  FIG. 10 ), an internal structure that is formed from other structures that provide support and outward biasing for gasket wall  38 , and internal structures that use two or more of these structures. As with the internal support structures for O-shaped gasket  20  of  FIG. 16  and P-shaped gasket  20  of  FIG. 17 , internal support structures for C-shaped gasket  20  of  FIG. 18  may be varied in type and size along the length of longitudinal axis  52 . For example, one type of support structure may be used in one longitudinal position of C-shaped gasket  20  of  FIG. 18  and another type of support structure (or no support structure) may be positioned at an adjacent longitudinal position along axis  52  of C-shaped gasket  20  of  FIG. 18 . Support structures of different types (including solid foam support structures and/or structures of the types shown in  FIGS. 12 ,  13 ,  14 ,  15 ,  10 , other internal support structures, and cavities such as cavity  78  of  FIGS. 17 and 18 ) may be alternated with each other along the length of longitudinal axis  52  of gasket  20  of  FIG. 18 , to ensure that gasket  20  provides a desired amount of outward restoring force when compressed between opposing conductive structures  30  and  32 . 
       FIG. 19  is a cross-sectional view of conductive gasket  20  in a configuration in which gasket wall  38  has two portions such as portion  38 A and portion  38 B. Planar portion  38 B forms a base for conductive gasket  20 . Portion  38 A is wrapped around the upper half of longitudinal axis  52  to form a C-shaped upper portion for gasket  20 . The C-shaped upper portion for gasket  20  that is formed from gasket sidewall portion  38 A and the planar lower wall portion for gasket  20  that is formed from gasket wall structure  38 B form a tubular gasket will walls that extend around longitudinal axis  52 . 
     Two-part conductive gasket  20  of  FIG. 19  may have a main cavity portion such as main cavity portion  136  and tail portions such as left tail portion  134  and right tail portion  138 . Lower gasket wall structure  38 B may be attached to conductive structure  32  using adhesive  148 . In main cavity portion  136 , gasket wall  38 A and gasket wall  38 B may surround cavity  78 . In tail portion  134 , edge portion  140  of gasket wall structure  38 A may be attached to edge portion  144  of gasket wall structure  38 B by adhesive  142  and edge portion  144  of gasket wall structure  38 B may be attached to conductive structure  32  by portion  146  of adhesive layer  148 . In tail portion  138 , edge portion  150  of gasket wall structure  38 A may be attached to edge portion  154  of gasket wall structure  38 B by adhesive  152  and edge portion  154  of gasket wall structure  38 B may be attached to conductive structure  32  by portion  156  of adhesive layer  148 . Adhesive such as adhesive layer  142 , adhesive layer  152 , and adhesive layer  148  may be formed from conductive adhesive to promote formation of a satisfactory electrical contact between gasket  20  and conductive structure  32 . Conductive structure  30  may form an electrical connection with upper portion  158  of gasket  20 , thereby allowing conductive gasket  20  to form an electrical path between opposing conductive structures  30  and  32  through the conductive materials of gasket wall structure  38 . 
     As with gaskets of other shapes, conductive gaskets such as two-part conductive gasket  20  of  FIG. 19  that are configured to form a tubular gasket structure with an upper C-shaped portion and a lower planar portion may be hollow, as illustrated by air-filled cavity  78  of  FIG. 19 . If desired, support structures may be formed within the interior of gasket  20  of  FIG. 19 . For example, the interior of tubular conductive gasket  20  of  FIG. 19  may be filled with biasing and support structures such as an internal structure of the type shown in  FIG. 12  that has protruding portions  76 , an internal fiber-based structure of the type shown in  FIG. 13 , an internal structure of the type shown in  FIG. 14  that is formed from a corrugated sheet of material, an internal structure of the type shown in  FIG. 15  having tubular or spherical structures or other compressible structures such as structures  90 , an internal structure formed from an inner wrapped layer of material such as a foam layer, plastic layer, or inner fiber layer that is formed on the inner surface of an outer conductive layer as a liner (see, e.g.,  FIG. 10 ), an internal structure that is formed from other structures that provide support and outward biasing for gasket wall  38 , and internal structures that use two or more of these structures. As with the internal support structures for O-shaped gasket  20  of  FIG. 16 , P-shaped gasket  20  of  FIG. 17 , and C-shaped gasket  20  of  FIG. 18 , internal support structures for two-part gasket  20  of  FIG. 19  may be varied in type and size along the length of longitudinal axis  52 . For example, one type of support structure may be used in one longitudinal position of gasket  20  of  FIG. 19  and another type of support structure (or no support structure) may be positioned at an adjacent longitudinal position along axis  52  of gasket  20  of  FIG. 19 . Support structures of different types (including solid foam support structures and/or structures of the types shown in  FIGS. 12 ,  13 ,  14 ,  15 ,  10 , other internal support structures, and cavities such as cavity  78  of  FIGS. 17 ,  18 , and  19 ) may be alternated with each other along the length of longitudinal axis  52  of gasket  20  of  FIG. 19 , to ensure that gasket  20  provides a desired amount of outward restoring force when compressed between opposing conductive structures  30  and  32 . 
       FIG. 20  is a cross-sectional view of an illustrative P-shaped gasket filled with an internal biasing structure such as fiber-based structure  74  of  FIG. 13 . As shown in  FIG. 20 , internal support structure  74  in P-shaped conductive gasket  20  may include fibers  84  such as plastic fibers, metal fibers, glass, fibers, other fibers, or combinations of these fibers. C-shaped gaskets, O-shaped gaskets, and gaskets formed from two or more gasket wall structures may be provided with internal support structures such as internal support structure  74  of  FIG. 20 , if desired. 
       FIG. 21  is a cross-sectional view of an illustrative P-shaped gasket filled with an internal biasing structure such as structure  74  of  FIG. 12 . As shown in  FIG. 21 , internal support structure  74  in P-shaped conductive gasket  20  may include cavity portions such as cavity portions  78  that are interposed between extending arm portions such as protruding portions  76  of support structure  74 . C-shaped gaskets, O-shaped gaskets, and gaskets formed from two or more gasket wall structures may be provided with internal support structures such as internal support structure  74  of  FIG. 21 , if desired. 
       FIG. 22  is a cross-sectional view of an illustrative P-shaped gasket having a gasket wall structure with multiple layers such as layers  64  and  66 . Adhesive layer  68  may be used to attach layers  64  and  66  to each other, if desired. Outer layer  64  may be a conductive layer (e.g., a conductive fabric layer, a metal foil layer, etc.). Inner layer  66  (e.g., a foam liner or other liner material) may serve as a support and biasing structure, as described in connection such as layer  66  of  FIG. 10 . As shown in  FIG. 22 , internal support structure  66  in P-shaped conductive gasket  20  may surround cavity  78 . C-shaped gaskets, O-shaped gaskets, and gaskets formed from two or more gasket wall structures may be provided with internal support structures such as internal support structure  66  of  FIG. 22 , if desired. 
       FIG. 23  is a perspective view of a rod of material that may serve as a support structure for forming a hollow conductive gasket. Rod  160  may be formed from foam, metal, plastic, glass, other materials, or combinations of these materials. 
       FIG. 24  is a perspective view of rod  160  of  FIG. 23  after being wrapped with gasket wall layer  38  to form a hollow conductive gasket structure. Following removal of rod  160  in direction  162 , gasket wall layer  38  may form conductive gasket  20  of  FIG. 25 .  FIG. 26  shows how opposing edges  162  and  164  of gasket wall structure  38  of gasket  20  of  FIG. 25  may be attached to each other using adhesive  166 . Adhesive  166  may be formed from a conductive adhesive material or other suitable adhesive. Edges  162  and  164  may be attached so that the inner surface of edge  164  faces the outer surface of edge  162  or edges  162  and  164  may be attached with their inner (or outer) edges facing one another. Extrusion tools and other equipment may also be used in forming gasket structures  20 , if desired. 
       FIG. 27  is a cross-sectional side view of a planar conductive gasket formed using a corrugated gasket wall structure. As shown in  FIG. 27 , gasket  20  may be formed from an undulating gasket structure such as gasket layer (wall)  38  that has portions  172  that protrude upwards in direction  176  and interleaved portions  174  that protrude downwards in direction  178 . Adhesive  170  such as conductive adhesive may be used in attaching gasket layer  38  to conductive structures  32 . When compressed between opposing conductive structures  30  and  32 , upper portions  172  of gasket  20  may make electrical contact with conductive structure  30 , thereby forming an electrical path between structures  30  and  32 . Conductive corrugated gasket  20  may have an elongated shape with a length L extending parallel to axis  52  (if desired) and may have a width W that is smaller than L (or that is larger than L). Thickness T may be smaller than width W and length L (as an example). In this type of configuration, conductive gasket  20  of  FIG. 27  may have a planar shape suitable for forming conductive paths between conductive structures  30  and  32  that have opposing planar surfaces. 
       FIG. 28  is a cross-sectional side view of an illustrative planar conductive gasket formed by providing conductive gasket structure  38  with a structure such as structure  74 P. Structure  74 P may be a compressible structure that serves to bias gasket structure  38  (e.g., a layer of gasket wall material) upwards in direction  182  when gasket  20  is compressed between opposing conductive structures  30  and  32 . Sheet  38  may be attached to conductive structure  32 . For example, adhesive  180  such as conductive adhesive may be used to attach edge portions  184  of gasket layer  38  to conductive structure  32 . Structures  74 P may be formed from foam, foam with protruding portions such as portions  76 P that are separated by cavity regions  78 , undulating plastic (corrugated plastic) or undulating structures formed from other materials, fiber-based materials, or other support structures (e.g., a liner structure attached to the underside of layer  38 ). 
     In the illustrative configuration for planar conductive gasket  20  that is shown in  FIG. 29 , support and outward (upwards) biasing have been provided by support structures  186 . Support structures  186  may be solid support structures (e.g., support structures in the shapes of spheres or rods) or may be hollow. For example, support structures  186  may be hollow and may have outer layers such as layer  190  that surround inner cavities such as cavity  188  (i.e., structures  186  may be hollow spheres or hollow rods). Support structures  186  may also be provided that have other shapes. The use of support structures  186  with spherical or cylindrical shapes in the example of  FIG. 29  is merely illustrative. 
     An electronic device may include conductive gaskets having structures of multiple different types.  FIG. 30  is a cross-sectional side view of an electronic device having conductive gaskets  20 A and  20 B that are formed with different types of structures. In the example of  FIG. 30 , Gasket  20 A may be formed with a hollow tube shape (e.g., similar to gasket  20  of  FIG. 4 ), whereas gasket  20 B may be formed having a corrugated structure (e.g., similar to gasket  20  of  FIG. 27 ). 
     Gasket  20 A may be used to electrically connect display structures  14 B to housing  12  (e.g., to help protect antenna  22  from electromagnetic interference). Gasket  20 B may be used to electrically connect antenna  22  and housing  12 . For example, gasket  20 B may serve as an electrical grounding path from antenna  22  to housing  12 . 
     Gasket  20 B may provide sufficient electrical conductivity between antenna  22  and housing  12  while accommodating manufacturing variations that affect the placement of antenna  22  relative to housing  12 . For example, due to manufacturing tolerances, the thickness of housing structure  12  and/or the dimensions of antenna  22  may vary. In this scenario, the distance between antenna  22  and housing  12  may increase (or decrease), thereby changing the amount by which gasket  20 B is compressed. Gasket  20 B may provide sufficient electrical conductivity even if compressed by different amounts, because the conductivity of the corrugated structure may be maintained. 
     Corrugated conductive gaskets such as gasket  20 B may be formed with any desired wave structure.  FIG. 31  is a cross-sectional diagram of an illustrative gasket  20  formed from a structure having concave ridges  202 . As shown in  FIG. 31 , each concave ridge  202  may have a top portion  204  that is wider than a bottom gap  206 . By forming ridges  202  having top portions  204  that are wider than bottom gaps  26 , contact surface area between gasket  20  and opposing conductive structures  30  and  32  may be increased, thereby improving the electrical connection between gasket  20  and the opposing conductive structures. 
     Conductive gasket  20  may be attached to opposing conductive structures  30  and  32  via conductive adhesives  170 . In the example of  FIG. 31 , conductive adhesives  170  may be used to couple top regions  204  to structure  30  and bottom regions  208  to structure  32 . Adhesives  170  may be applied to top regions  204  and bottom regions  208  using deposition techniques such as spraying or painting. (e.g., adhesives  170  may be applied to top regions  204  and bottom regions  208  of gasket  20  without being applied to other regions of gasket  20 ). 
     Adhesive  170  may be a pressure sensitive adhesive that adheres to gasket  20  and conductive structures  30  and  32  in response to a sufficient amount of applied pressure. In this scenario, gasket  20  may be compressed between opposing conductive structures  30  and  32  to apply pressure to pressure sensitive adhesive  170 .  FIG. 32  is a cross-sectional side view of corrugated conductive gasket  20  when compressed using opposing conductive structures  30  and  32 . 
     As shown in  FIG. 32 , portions of gasket  20  that overlap can potentially contact each other when gasket  20  is compressed. For example, portion  212  of gasket  20  may contact portion  214  and portion  216  may contact portion  218 . By applying adhesives  170  only to top regions  204  and bottom regions  208  (e.g., without applying adhesive  170  to portions  212 ,  214 ,  216 , or  218 ), gasket  20  may be able to recover its original undulating structure after compression (e.g., the structure of gasket  20  may return to the corrugated structure of  FIG. 31 ). 
     If desired, a conductive gasket may have top and bottom surfaces that are covered with adhesive layers.  FIG. 33  is a cross-sectional view of an illustrative conductive gasket  20  having a top surface covered by adhesive layer  222  and a bottom surface covered by an adhesive layer  224 . Adhesive layers  222  and  224  may be formed from a layer of conductive adhesive material. The conductive adhesive material may be pressure-sensitive adhesive material and/or heat-sensitive adhesive material (e.g., adhesive material that adheres in response to a sufficient amount of heat). Adhesive layers  222  and  224  may be covered by protective layers  226  and  228 . Layers  226  and  228  may serve to protect adhesive layers  222  and  224  from inadvertent adhesion to other surfaces. Layers  226  and  228  may be formed from materials such as plastics, paper, or other desired materials. 
     Gasket  20  may include a gasket structure  38  that is interposed between adhesive layers  222  and  224 . Gasket structure  38  may form a gasket layer. Gasket layer  38  may be formed from a conductive material. For example, gasket layer  38  may be formed from a conductive fabric (e.g., a fabric including metal fibers or other conductive fibers). This example is merely illustrative. If desired, gasket layer  38  may be formed from any desired conductive materials or structures such as those described in connection with  FIG. 4 . 
     Portions of protective layers  226  and  228  may be removed to expose regions of underlying adhesive materials.  FIG. 34  is a cross-sectional diagram of an illustrative gasket  22  with protective layers  226  and  228  that have been partially removed to expose regions  232  of adhesive layer  222  and regions  234  of adhesive layer  224 . 
     Portions of protective layers  226  and  228  over regions  232  and  234  may be removed using any desired removal technique. For example, protective layers  226  and  228  may be cut along dotted lines  236  (e.g., using cutting tools such as edged cutting tools, laser cutting tools, etc.). In this scenario, portions of protective layers  226  and  228  over regions  232  and  234  may be subsequently peeled away and removed from adhesive layers  222  and  224 . If desired, other removal techniques such as etching or grinding may be used to remove portions of protective layers  226  and  228  to expose regions  232  and  234  of adhesive material. 
     In a subsequent step, gasket  20  may be folded to form a corrugated structure as shown in  FIG. 35 . Exposed portions  232  of adhesive layer  222  may be used to form top regions (e.g., top regions  204  of  FIG. 31 ) that can be attached to a first conductive structure (e.g., conductive structure  30 ). Exposed portions  234  of adhesive layer  224  may be used to form bottom regions (e.g., bottom regions  208 ) that can be attached to a second conductive structure such as conductive structure  32 ). 
     Remaining portions of protective layers  226  and  228  may serve to help prevent deformation of gasket  20  when attached to conductive structures. For example, pressure may be applied to compress gasket  20  so that regions  232  and  234  of adhesive material are attached to the conductive structures. In this scenario, the remaining portions of protective layers  226  and  228  may cover regions of adhesive layers  222  and  224  that are not attached to the conductive structures, thereby helping to prevent undesired adhesion to surfaces other than the conductive structures (e.g., protective layers  226  and  228  may help prevent adhesion between overlapping portions of gasket layer  38 ). 
     If desired, a conductive gasket may have top and bottom surfaces that are covered with adhesive layers that are not protected by additional layers.  FIG. 36  is a cross-sectional diagram of an illustrative gasket  20  with adhesive layers  222  and  224  that cover respective top and bottom surfaces of gasket  20 . Gasket  20  may include a gasket layer  38  interposed between adhesive layers  222  and  224 . 
     Gasket  20  that is covered with conductive adhesive layers  222  and  224  may be folded to form a corrugated gasket structure as shown in  FIG. 37 . In scenarios in which gasket structure  38  is covered by adhesive layers  222  and  224  that are exposed (e.g., as shown in  FIG. 37 ), the adhesive layers may adhere to undesired surfaces when compressed (e.g., overlapping regions of gasket layer  38  may adhere when compressed together). Gasket structure  38  may be deformed and unable to return to its original corrugated shape when overlapping regions of gasket layer  38  have been attached via adhesive layers  222  and  224 . 
     Support structures may be used to help prevent deformation of gasket structure  38 .  FIG. 38  is a perspective view of an illustrative support structure  232  that may be used to help prevent structural deformation of gasket  20  during manufacturing processes such as when gasket  20  is compressed. As shown in  FIG. 38 , support structure  232  may include protruding members  234 . Protruding members  234  may be substantially cylindrical (e.g., rod-shaped) and may extend in parallel along a plane corresponding to a planar corrugated gasket  20 . Protruding members  234  may be inserted as shown by arrows  236  into cavities  238  of corrugated gasket  20 . 
     The example of  FIG. 38  in which protruding members  234  of support structure  232  are substantially cylindrical is merely illustrative. Protruding members  234  may have any desired shape for helping to prevent deformation of gasket  20  during manufacturing processes. For example, protruding members  234  may have cross-sectional shapes that correspond to the cross-sectional shapes of cavities in gasket  20  that may be compressed during manufacturing processes. 
     Protruding members  234  may be formed from materials that are resistant to adhesion (sometimes referred to herein as non-stick materials). For example, protruding members  234  may be formed from silicone, fluorocarbons such as polytetrafluoroethylene, or any other materials that are resistant to adhesion. If desired, protruding members  234  may be formed having interior cores that are coated with a non-stick material. The interior cores may be formed from any desired material (e.g., metals, plastics, etc.). 
       FIG. 39  is an illustrative cross-sectional diagram of gasket  20  with protruding members  234  of support structure  232  inserted into cavities of gasket  20  (e.g., cavities  238  of  FIG. 38 ). During manufacturing, gasket  20  may be compressed by opposing conductive structures  30  and  32  so that adhesive layers  222  and  224  adhere to structures  30  and  32 . Protruding members  234  may tend to resist compression and may help prevent deformation of gasket  20  (e.g., because overlapping regions of gasket  20  may not contact each other). 
     Manufacturing tools may be used to attach conductive gaskets to conductive structures.  FIG. 40  is an illustrative diagram of a manufacturing system  235  that may be used to attach conductive gaskets to conductive structures. As shown in  FIG. 40 , system  235  may include manufacturing tools  236  and device structures  240 . Devices structures  240  may include structures used in an electronic device such as device  10 . For example, structures  240  may include conductive structures such as antenna  22 , device housing  12 , display structures  14 B, conductive gaskets, etc. 
     Manufacturing tools  236  may include positioning tools  237 , heating tools  238 , and clamping tools  239 . Positioning tools  237  may be used to adjust the position of device structures  240  or portions of device structures  240 . For example, positioning tools  237  may include motors and actuators that can be used to adjust the position of antenna  22 , device housing  12 , conductive gaskets, or other portions of device structures  240 . Positioning tools  237  may include computer-controlled positioning tools or manual positioning tools. 
     Heating tools  238  may include oil-based heating tools, gas-based heating tools, electrical-based heating tools, or any other heating tools suitable for heating materials such as adhesive materials (e.g., adhesive materials used to form adhesive layers that cover conductive gaskets). 
     Clamping tools  239  may include clamps such as mechanical-based or hydraulic-based clamps. Clamping tools  239  may be used to hold device structures  240  in a fixed position during manufacturing (e.g., during assembly). Clamping tools  239  may also be used to apply pressure to portions of device structures  240 . For example, clamping tools  239  may be used to compress opposing conductive structures  30  of  FIG. 39  so that pressure is applied to adhesive layers  222  and  224 . 
     Manufacturing tools  236  may be used to attach a conductive gasket between first and second conductive structures.  FIG. 41  is a flow chart  241  of illustrative steps that may be to attach a corrugated gasket to first and second conductive structures. 
     In step  242 , a corrugated gasket may be formed having adhesive layers that cover the corrugated gasket. For example, corrugated gasket  20  of  FIG. 37  may be formed having adhesive layer  222  that covers a top surface of gasket  20  and adhesive layer  224  that covers a bottom surface of gasket  20 . 
     In step  244 , the corrugated gasket may be applied to a first conductive structure. For example, a top surface of the corrugated gasket that is covered by an adhesive layer may be applied to antenna  22  of  FIG. 2 . The corrugated gasket may be applied to the first conductive structure using positioning tools  237  (e.g., by positioning the corrugated gasket to contact the first conductive structure). 
     In step  246 , protruding members of a support structure may be inserted into cavities in the corrugated gasket. For example, protruding members  234  of support structure  232  may be inserted using positioning tools  237  into cavities  238  of gasket  20  as shown in  FIG. 38 . The protruding members may be formed from or covered by a non-stick material that is resistant to adhesion with the adhesive layers of the corrugated gasket. 
     In step  248 , pressure and/or heat may be applied to the adhesive layers of the corrugated gasket so that the corrugated gasket is attached to the first conductive structure and a second conductive structure. For example, positioning tools  237  may be used to position the corrugated gasket between antenna  22  and device housing  12  of  FIG. 2 . In this scenario, clamping tools  239  may be subsequently used to compress the corrugated gasket between antenna  22  and device housing  12  so that the adhesive layers (e.g., adhesive layers  222  and  224 ) covering the corrugated gasket attach to antenna  22  and device housing  12 . If desired, heating tools  238  may be used to apply heat in addition to or in place of pressure (e.g., when adhesive layers  222  and  224  are formed from a heat-sensitive adhesive material). 
     In step  250 , the support structure may be removed from the corrugated gasket. For example, positioning tools  237  may be used to remove the protruding members from cavities in the corrugated gasket. 
     The example of  FIG. 41  in which protruding members of a support structure are used to help prevent deformation of a corrugated gasket is merely illustrative. If desired, a corrugated gasket may be attached to first and second conductive structures without using the support structure. For example, steps  246  and  250  may be omitted when performing the operations of flow chart  241 . 
     The foregoing is merely illustrative of the principles of this invention and various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention.

Metadata:
Filing Date: 20120619
Publication Date: 20150825
Grant Date: 20150825
Priority Date: 20120619
Inventors: TARKINGTON DAVID P.
GOLDBERG MICHELLE R.
RUNDLE NICHOLAS A.
JEZIOREK PETER N.
HAYLOCK JONATHAN
GUTERMAN JERZY
Assignee: APPLE INC
CPC Classifications: [{"code": "H05K9/00", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/44", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/48", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K9/0015", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/526", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K9/0015", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/44", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K9/00", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/526", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01Q1/48", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K9/0015", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/48", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/44", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01Q1/526", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 49755382