PATENT DOCUMENT

Publication Number: US-10472742-B1
Application Number: US-201715424607-A
Country: US
Kind Code: B1

Title: Fabric-based items with fusible insulating strands

Abstract:
An item may include fabric or other materials formed from intertwined strands of material. The item may include circuitry that produces signals. The strands of material may include non-conductive strands and conductive strands. The conductive strands may carry the signals produced by the circuitry. Conductive strands may be insulated by insulating strands that have been wrapped around the conductive strands. Insulating strands may include strands of fusible material that softens when heated to the appropriate temperature. Fusible insulating strands may be interspersed with insulating strands of a different material. The fusible insulating strands may be heated such that the fusible material melts and fills gaps between the other insulating strands, thereby forming a watertight covering over the conductive strand. The fusible insulating strands may be used to insulate electrical connections between conductive strands and/or between electronic components and conductive strands.

Claims:
What is claimed is: 
     
       1. A fabric-based item, comprising:
 conductive yarns that are intertwined with nonconductive yarns to form fabric, wherein at least one of the conductive yarns comprises:
 a conductive strand that forms a conductive core of the at least one conductive yarn; 
 a first insulating strand wrapped around the conductive strand, wherein the first insulating strand comprises polymer; and 
 a second insulating strand wrapped around the conductive strand, wherein the second insulating strand comprises fusible material having a lower melting temperature than that of the first insulating strand and wherein the first and second insulating strands form an insulator that covers the conductive core. 
 
 
     
     
       2. The fabric-based item defined in  claim 1  wherein the second insulating strand comprises thermoplastic polymer material. 
     
     
       3. The fabric-based item defined in  claim 1  wherein the second insulating strand is mechanically bonded to the first insulating strand and wherein the insulator formed by the first and second insulating strands comprises a watertight insulator around a first portion of the conductive strand. 
     
     
       4. The fabric-based item defined in  claim 3  wherein the watertight insulator has a gap that exposes a second portion of the conductive strand. 
     
     
       5. The fabric-based item defined in  claim 4  further comprising:
 an integrated circuit mounted to the second portion of the conductive strand that is exposed by the gap in the watertight insulator. 
 
     
     
       6. The fabric-based item defined in  claim 5  further comprising conductive material that electrically connects the integrated circuit to the conductive strand. 
     
     
       7. The fabric-based item defined in  claim 6  wherein the second insulating strand covers at least some of the conductive material. 
     
     
       8. The fabric-based item defined in  claim 1  wherein the conductive strand comprises a conductive coating on a non-conductive core. 
     
     
       9. The fabric-based item defined in  claim 8  wherein the non-conductive core comprises polymer. 
     
     
       10. The fabric-based item defined in  claim 9  wherein the polymer comprises a material selected from the group consisting of: polyamide, aromatic polyamide, polyimide, polyester, polyolefin, acrylic, aromatic polyesters, polyethylene, cellulosic polymer, and polyurethane. 
     
     
       11. The fabric-based item defined in  claim 8  wherein the conductive coating comprises a material selected from the group consisting of: gold, silver, copper, aluminum, nickel, palladium, molybdenum, platinum, titanium, and tungsten. 
     
     
       12. An item, comprising:
 strands of material that are intertwined to form fabric, wherein at least one of the strands of material comprises a conductive core and first and second polymer strands that are wrapped around the conductive core; and 
 an integrated circuit that is mounted and electrically connected to the conductive core using a conductive material, wherein the first polymer strand comprises fusible material that insulates the conductive core around the integrated circuit, wherein the conductive material has edge portions, and wherein the fusible material covers the edge portions to insulate the conductive material. 
 
     
     
       13. The item defined in  claim 12  wherein the conductive material comprises solder having a first melting temperature, wherein the fusible material of the first polymer strand has a second melting temperature, and wherein the second melting temperature is lower than the first melting temperature. 
     
     
       14. The item defined in  claim 12  wherein the fusible material comprises thermoplastic polymer material that has been melted to form a watertight covering over the conductive core. 
     
     
       15. The item defined in  claim 12  wherein the second polymer strand is interspersed with and mechanically bonded to the first polymer strand, and wherein the first polymer strand fills gaps between portions of the second polymer strand. 
     
     
       16. An item, comprising:
 a conductive strand; 
 a first insulating material wrapped around the conductive strand, wherein the first insulating material has a first melting temperature; 
 a second insulating material wrapped around the conductive strand, wherein the second insulating material has a second melting temperature that is lower than the first melting temperature, wherein the first and second insulating materials form a watertight cover around a first portion of the conductive strand; and 
 an electronic component electrically connected to a second portion of the conductive strand using solder, wherein the solder is located inside an opening in the second insulating material, wherein the electronic component is interposed between two strand segments of the first insulating material, wherein the electronic component has a periphery, wherein the second insulating material extends around the entire periphery and contacts the electronic component to provide electrical insulation around the electronic component, and wherein the electronic component is selected from the group consisting of: a sensor and a light-emitting diode. 
 
     
     
       17. The item defined in  claim 16  wherein the first insulating material comprises nylon and the second insulating material comprises polyamide. 
     
     
       18. The item defined in  claim 16  wherein the first insulating material has additional strand segments that are separated by gaps and wherein the second insulating material fills the gaps. 
     
     
       19. The item defined in  claim 16  wherein the conductive strand comprises a polymer core and a metal coating that surrounds the polymer core.

Description:
This application claims the benefit of provisional patent application No. 62/296,293, filed Feb. 17, 2016, which is hereby incorporated by reference herein in its entirety. 
    
    
     FIELD 
     This relates generally to fabric-based items and, more particularly, to fabric-based items with electrical components. 
     BACKGROUND 
     It may be desirable to form items such a bags, clothing, and other items from intertwined strands of material. For example, woven or knitted fabric or braided strands may be used in forming portions of an item. 
     In some situations, it may be desirable for some or all of a strand of material in an item to be conductive. Conductive strands may be used, for example, to carry signals between circuitry in different portions of an item. Strands such as conductive strands may serve mechanical functions (e.g., by forming a part of a fabric) and/or electrical functions (e.g., by conveying signals). 
     Challenges may arise when forming items such as fabric-based items with conductive strands. It is often desirable for conductive strands to exhibit good mechanical properties, such as high strength and flexibility. Because conductive strands may need to carry electrical signals, the resistance of a conductive strand should generally not be too high. Conductive strands should also be compatible with the non-conductive strands in a fabric and should not form undesired short circuits with surrounding structures. If care is not taken, conductive strands in a fabric-based item may be overly fragile, may exhibit poor signal carrying capabilities, may be insufficiently isolated from surrounding structures, or may adversely affect the appearance and feel of the item. 
     SUMMARY 
     An item may include fabric or other materials formed from intertwined strands of material. The item may include circuitry that produces signals. The strands of material may include non-conductive strands and conductive strands. Strands may be intertwined using weaving equipment, knitting equipment, braiding equipment, or other equipment for intertwining strands of material. If desired, the non-conductive strands and conductive strands may be close in size (e.g., to minimize or eliminate perceptible differences in the appearance and feel of the non-conductive and conductive strands). 
     The conductive strands may carry the signals produced by the circuitry. Each conductive strand may have a conductive core that carries electrical signals. The conductive core may be a solid conductive core or may be formed from a non-conductive inner core that has been covered with a conductive coating. In arrangements where the conductive core is formed from a non-conductive inner core that has been covered with a conductive material, the non-conductive inner core may be formed from polymers such as para-aramids and aromatic polyesters (as examples). The conductive coating may be formed from a metal such as silver or other metals. 
     To mechanically and electrically insulate and isolate conductive strands, insulating material may surround the conductive core of the conductive strands. Examples of materials that may be used for forming the insulator include polyvinyl formal, polyester-polyimide, polyamide-polyimide, polyamide, polyimide, polyester, polytetrafluoroethylene, polyurethane, and other polymers. In some arrangements, the insulating material may be a relatively thin insulator coating such as an insulator coating with a thickness of less than 5 microns or other suitable thickness. In some arrangements, the insulating material may be formed from non-conductive strands that have been wrapped around the conductive core to electrically insulate the conductive core and protect the conductive core from moisture and other contaminants. Fabric-based items that include a combination of insulating coatings and insulating strands may also be used. 
     Inner polymer strand cores may be formed by extrusion, spinning, or other techniques. Metal coatings for the inner strand cores may be formed by electrochemical deposition or other metal deposition techniques. 
     Insulating strands may include strands of fusible material that softens when heated to the appropriate temperature. Fusible insulating strands may be interspersed with insulating strands of a different material. The fusible insulating strands may be heated such that the fusible material melts and fills gaps between the other insulating strands, thereby forming a watertight covering over the conductive strand. The fusible insulating strands may be used to insulate electrical connections between conductive strands and/or between electronic components and conductive strands. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of an illustrative item that may include strands of material in accordance with an embodiment. 
         FIG. 2  is a diagram of a portion of a fabric with conductive strands in accordance with an embodiment. 
         FIG. 3  is a cross-sectional side view of an illustrative conductive strand formed from solid conductive core in accordance with an embodiment. 
         FIG. 4  is a cross-sectional side view of an illustrative conductive strand formed from a non-conductive inner core surrounded by a conductive coating in accordance with an embodiment. 
         FIG. 5  is a cross-sectional side view of an illustrative conductive strand formed from a bundle of non-conductive inner cores that are each surrounded by a conductive coating in accordance with an embodiment. 
         FIG. 6  is a cross-sectional side view of an illustrative conductive strand formed from a bundle of non-conductive inner cores that have all been surrounded by a conductive coating in accordance with an embodiment. 
         FIG. 7  is a diagram of illustrative equipment of the type that may be used in forming insulated conductive strands and strand-based items that include insulated conductive strands in accordance with an embodiment. 
         FIG. 8  is a cross-sectional side view of an illustrative insulated conductive strand having a conductive core wrapped in a non-conductive strand in accordance with an embodiment. 
         FIG. 9  is a side view of an illustrative conductive strand that is wrapped with a non-conductive strand in a Z-wrap configuration in accordance with an embodiment. 
         FIG. 10  is a side view of an illustrative conductive strand that is wrapped with a non-conductive strand in an S-wrap configuration in accordance with an embodiment. 
         FIG. 11  is a side view of an illustrative conductive strand that is wrapped with non-conductive strands of different materials in accordance with an embodiment. 
         FIG. 12  is a cross-sectional side view of an illustrative conductive strand that is wrapped in fusible insulating strands in accordance with an embodiment. 
         FIG. 13  is a cross-sectional side view of the conductive strand of  FIG. 12  in which the fusible insulating strands have been fused to cover the conductive strand in accordance with an embodiment. 
         FIG. 14  is a cross-sectional side view of an illustrative conductive strand that is wrapped in fusible insulating strands in accordance with an embodiment. 
         FIG. 15  is a cross-sectional side view of the conductive strand of  FIG. 14  in which an electronic component has been mounted to an exposed portion of the conductive strand in accordance with an embodiment. 
         FIG. 16  is a cross-sectional side view of the conductive strand of  FIG. 15  in which the fusible insulating strand has been fused around the conductive strand and electronic component in accordance with an embodiment. 
         FIG. 17  is a flow chart of illustrative steps involved in mounting an electronic component to a conductive strand that is wrapped in fusible insulating strands in accordance with an embodiment. 
         FIG. 18  is a flow chart of illustrative steps involved in mounting an electronic component to a conductive strand that is partially covered with fused insulating strands in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Strands of material may be incorporated into strand-based items such as strand-based item  10  of  FIG. 1 . Item  10  may be an electronic device or an accessory for an electronic device such as a laptop computer, a computer monitor containing an embedded computer, a tablet computer, a cellular telephone, a media player, or other handheld or portable electronic device, a smaller device such as a wrist-watch device, a pendant device, a headphone or earpiece device, a device embedded in eyeglasses or other equipment worn on a user&#39;s head, or other wearable or miniature device, a television, a computer display that does not contain an embedded computer, a gaming device, a navigation device, an embedded system such as a system in which fabric-based item  10  is mounted in a kiosk, in an automobile, airplane, or other vehicle, other electronic equipment, or equipment that implements the functionality of two or more of these devices. If desired, item  10  may be a removable external case for electronic equipment, may be a strap, may be a wrist band or head band, may be a removable cover for a device, may be a case or bag that has straps or that has other structures to receive and carry electronic equipment and other items, may be a necklace or arm band, may be a wallet, sleeve, pocket, or other structure into which electronic equipment or other items may be inserted, may be part of a chair, sofa, or other seating (e.g., cushions or other seating structures), may be part of an item of clothing or other wearable item (e.g., a hat, belt, wrist band, headband, etc.), or may be any other suitable strand-based item. 
     Strands in strand-based item  10  may form all or part of a housing wall for an electronic device, may form internal structures in an electronic device, or may form other strand-based structures. Strand-based item  10  may be soft (e.g., item  10  may have a fabric surface that yields to a light touch), may have a rigid feel (e.g., the surface of item  10  may be formed from a stiff fabric), may be coarse, may be smooth, may have ribs or other patterned textures, and/or may be formed as part of a device that has portions formed from non-fabric structures of plastic, metal, glass, crystalline materials, ceramics, or other materials. 
     Item  10  may include intertwined strands  12 . The strands may be intertwined using strand intertwining equipment such as weaving equipment, knitting equipment, braiding equipment, or equipment that intertwines strands by entangling the strands with each other in other ways (e.g., to form felt). Intertwined strands  12  may, for example, form woven or knitted fabric or other fabric (i.e., item  10  may be a fabric-based item), a braided cord, etc. 
     Strands  12  may be single-filament strands or may be threads, yarns, or other strands that have been formed by intertwining multiple filaments of material together. Strands  12  may be formed from polymer, metal, glass, graphite, ceramic, natural fibers such as cotton, bamboo, wool, or other organic and/or inorganic materials and combinations of these materials. Strands  12  may be insulating or conductive. 
     Conductive coatings such as metal coatings may be formed on non-conductive strands (e.g., plastic cores) to make them conductive and strands such as these may be coated with insulation or left bare. Reflective coatings such as metal coatings may be applied to strands  12  to make them reflective. Strands  12  may also be formed from single-filament metal wire, multifilament wire, or combinations of different materials. 
     Strands  12  may be conductive along their entire length or may have conductive segments (e.g., metal portions that are exposed by locally removing insulation or that are formed by adding a conductive layer to a portion of a non-conductive strand.). Threads and other multifilament yarns that have been formed from intertwined filaments may contain mixtures of conductive fibers and insulating fibers (e.g., metal strands or metal coated strands with or without exterior insulating layers may be used in combination with solid plastic fibers or natural fibers that are insulating). 
     Item  10  may include additional mechanical structures  14  such as polymer binder to hold strands  12  together, support structures such as frame members, housing structures (e.g., an electronic device housing), and other mechanical structures. 
     Circuitry  16  may be included in item  10 . Circuitry  16  may include components that are coupled to strands  12 , components that are housed within an enclosure formed by strands  12 , components that are attached to strands  12  using welds, solder joints, adhesive bonds (e.g., conductive adhesive bonds), crimped connections, or other electrical and/or mechanical bonds. Circuitry  16  may include metal structures for carrying current, integrated circuits, discrete electrical components such as resistors, capacitors, and inductors, switches, connectors, light-emitting components such as light-emitting diodes, audio components such as microphones and speakers, vibrators, solenoids, piezoelectric devices, and other electromechanical devices, connectors, microelectromechanical systems (MEMs) devices, pressure sensors, light detectors, proximity sensors, force sensors, moisture sensors, temperature sensors, accelerometers, gyroscopes, compasses, magnetic sensors, touch sensors, and other sensors, components that form displays, touch sensors arrays (e.g., arrays of capacitive touch sensor electrodes to form a touch sensor that detects touch events in two dimensions), and other input-output devices. Circuitry  16  may also include control circuitry such as non-volatile and volatile memory, microprocessors, application-specific integrated circuits, system-on-chip devices, baseband processors, wired and wireless communications circuitry, and other integrated circuits. 
     Item  10  may interact with electronic equipment or other additional items  18 . Items  18  may be attached to item  10  or item  10  and item  18  may be separate items that are configured to operate with each other (e.g., when one item is a case and the other is a device that fits within the case, etc.). Circuitry  16  may include antennas and other structures for supporting wireless communications with item  18 . Item  18  may also interact with strand-based item  10  using a wired communications link or other connection that allows information to be exchanged. 
     In some situations, item  18  may be an electronic device such as a cellular telephone, computer, or other portable electronic device and strand-based item  10  may form a case or other structure that receives the electronic device in a pocket, an interior cavity, or other portion of item  10 . In other situations, item  18  may be a wrist-watch device or other electronic device and item  10  may be a strap or other strand-based item that is attached to item  18 . In still other situations, item  10  may be an electronic device, strands  12  may be used in forming the electronic device, and additional items  18  may include accessories or other devices that interact with item  10 . 
     If desired, magnets and other structures in items  10  and/or  18  may allow items  10  and  18  to interact wirelessly. One item may, for example, include a magnet that produces a magnetic field and the other item may include a magnetic switch or magnetic sensor that responds in the presence of the magnetic field. Items  10  and  18  may also interact with themselves or each other using pressure-sensitive switches, pressure sensors, force sensors, proximity sensors, light-based sensors, interlocking electrical connectors, etc. 
     The strands that make up item  10  may be intertwined using any suitable strand intertwining equipment. For example, strands  12  may be woven together to form a fabric. The fabric may have a plain weave, a satin weave, a twill weave, or variations of these weaves, may be a three-dimensional woven fabric, or may be other suitable woven fabric. If desired, the strands that make up item  10  may be intertwined using knitting equipment, braiding equipment, or other strand intertwining equipment. Item  10  may also incorporate more than one type of fabric or intertwined strand-based material (e.g., item  10  may include both woven and knitted portions). 
     The strands that make up item  10  may be intertwined to form a fabric such as illustrative fabric  20  of  FIG. 2 . Fabric  20  may include strands  12 . Strands  12  may be formed from conductive and/or insulating materials. As an example, fabric may be formed from insulating strands  82  interspersed with conductive strands  22 . In the illustrative configuration of  FIG. 2 , a first conductive strand  22  extends vertically and electrically connects node A with junction  24  and a second conductive strand  22  extends horizontally (i.e., perpendicular to the first conductive strand) and electrically connects node B with junction  24 . At the intersection of the first and second conductive strands at junction  24 , the first and second strands may be electrically connected using mechanical contact, solder, welds, conductive adhesive, a crimped metal connection or other metal connector, or other electrical connection structure. Using this type of technique, desired signal paths such as illustrative signal path  26  between nodes A and B may be formed within fabric  20  (e.g., to form signal busses, to form electrodes or other parts of sensors, to form other conductive structures, etc.). 
     In addition to forming electrical connections between conductive strands  22 , electrical connections may be formed between electronic components and conductive strands  22 . For example, an electronic component may be electrically and mechanically connected to one or more strands  22  using mechanical contact, solder, welds, conductive adhesive, a crimped metal connection or other metal connector, or other electrical connection structures. 
     Conductive strands such as conductive strands  22  in illustrative fabric  20  for item  10  may be formed from one or more layered materials. For example, conductive strand  22  may have an inner core (e.g., an elongated member such as a monofilament), one or more coatings (e.g., insulating or conductive coatings) on the inner core, and/or one or more outer layers formed from additional strands that have been wrapped (e.g., twisted or braided) around the core. 
     The different portions of the conductive strand may be formed from different materials or, if desired, two or more of the portions of the conductive strand may be formed from the same material. As an example, a conductive strand may have a core and an outer coating that are formed from a common dielectric and that are separated by an intermediate layer formed from a conductive material. Configurations may also be used in which a conductive strand has a core formed from a first dielectric and an outer layer formed from a second dielectric and in which the first and second dielectrics are separated from each other by an intervening conductive layer such as a metal layer. 
     In some configurations, conductive strand  22  may contain polymer. For example, conductive strand  22  may contain a polymer core to provide strand  22  with strength and flexibility. Polymer may also be used in forming insulating outer coating layers. Examples of polymers that may be used in forming a core and/or an outer insulating coating for conductive strand  22  include polyamide (nylon—e.g., nylon6, nylon6,6, nylon 11), aromatic polyamide (i.e., para-aramids such as Kevlar® or other aramids), polyimide, polyester, polyolefin, acrylic, aromatic polyesters such as Vectran®, polyethylene, extruded cellulosic polymers such as rayon and Tencel®, polyvinyl formal, polyester-polyimide, polyamide-polyimide, polytetrafluoroethylene, and polyurethane. Other polymers or mixtures of these polymers may be used, if desired. Inorganic materials may also be used in forming dielectric strand cores and insulating layers. Illustrative configurations in which these strand structures are formed from polymers are sometimes described herein as an example. 
     The polymer materials of strand  22  may be formed from conductive organic material, from insulating polymeric materials (e.g., materials to form a dielectric core and/or outer coating), from polymer that includes conductive filler such as particles of metal, particles of carbon nanotube material, graphene particles, fibrous carbon material, or other conductive particles. Conductive filler may be incorporated into the polymer in a concentration that renders a portion of strand  22  conductive or may be incorporated into the polymer in a lower concentration (e.g., to promote adhesion or otherwise enhance compatibility with other portions of strand  22  without necessarily increasing the conductivity of the polymer to a level that allows the material to serve as a conductive signal path in fabric  20 ). 
     In some situations, monofilaments may be formed of metal or polymer (i.e., polymer with conductive filler or without conductive filler). These monofilaments may be intertwined to form strands  22  or portions of strands  22 . In general, strands  22  may have one or more materials, two or more materials, three or more materials, four or more materials, or five or more materials. The structures of strands  22  may incorporate conductive materials such as metal, insulating materials such as polymer, conductive organic materials such as conductive polymer, polymer filled with metal particles and other conductive filler, other materials, and/or combinations of these materials. 
     Illustrative examples of conductive strands that may be used in fabric-based item  10  are shown in  FIGS. 3, 4, 5, and 6 . 
     In the example of  FIG. 3 , conductive strand  22  is formed from a solid core of conductive material  36 . Conductive material  36  may be formed from metal or other conductive material. Examples of metals that may be used in forming conductive material  36  include gold, silver, copper, aluminum, nickel, palladium, molybdenum, platinum, titanium, and tungsten. Other metals may also be used for material  36  of strand  22 . 
     In the example of  FIG. 4 , conductive strand  22  is formed from an inner core of non-conductive material  38  and an outer coating of conductive material  36 . Conductive material  38  may be a conductive inner core having a circular cross-sectional shape or other suitable cross-sectional shape. Non-conductive inner core  38  may be formed from para-aramid fiber (e.g., Kevlar®), spun aromatic polyester fiber (e.g., Vectran®), or other polymer fiber. Core  38  is preferably thermally stable (e.g., core  38  is preferably able to withstand exposure to elevated temperatures without incurring damage). The elevated temperatures may be, for example, temperatures of 200-300° C., more than 150° C., more than 250° C., more than 350° C., less than 250° C., 210-220° C., or other suitable temperatures. Core  38  also preferably has a high elastic modulus (Young&#39;s modulus), such as a modulus of 50-250 GPa, 50-150 GPa, 100-200 GPa, more than 50 GPa, less than 250 GPa, etc. If desired, core  38  may have other advantageous physical attributes such as being insensitive to degradation due to exposure to light, having a good abrasion resistance, being highly flexible, exhibiting a high strength-to-weight ratio, forming a good electrical insulator, etc. 
     To form fabrics and other intertwined strands with desired properties, it may be desirable for the diameter of core  38  to be relatively small. As an example, diameter D of core  38  may be 50-70 microns, 25-100 microns, less than 100 microns, less than 150 microns, more than 10 microns, 10-200 microns, 10-500 microns, 150-250 microns, more than 50 microns, less than 400 microns, or other suitable diameter. The linear mass density of core  38  may be 220 denier, 130 denier, 55 denier, 28 denier, less than 100 denier, less than 75 denier, 75-20 denier, 75-25 denier, less than 60 denier, 60-25 denier, more than 10 denier, more than 20 denier, or other suitable linear mass density. 
     The thickness TI of conductive coating  36  may be 25 microns, more than 1 micron, more than 5 microns, less than 25 microns, less than 10 microns, less than 100 microns, 10-50 microns, 20-70 microns, more than 15 microns, more than 20 microns, less than 35 microns, less than 50 microns, less than 5 microns, or other suitable thickness. Coating  36  may be a metal (e.g., an elemental metal such as silver and/or a metal alloy) that has been deposited by electrochemical deposition, physical vapor deposition, etc. or may be any other suitable conductive layer. 
     In some arrangements, conductive strands  22  may be formed from multiple conductive strands that are bundled together. Each strand in the bundle may have a circular cross-section of the type shown in  FIGS. 3 and 4  or may have other suitable cross-section. In the example of  FIG. 5 , conductive strand  22  is formed from a bundle of non-conductive cores  38  that have each been coated with conductive material  36 . In the example of  FIG. 6 , conductive strand  22  is formed from a bundle of non-conductive cores  38 . The entire bundle of non-conductive strands  38  may be coated in conductive material  36  to form conductive strand  22 . 
     The examples of  FIGS. 3, 4, 5, and 6  are merely illustrative, however. In general, conductive strands  22  may be formed using other combinations of conductive material  36  and nonconductive material  38  or may include only conductive material  36 . 
       FIG. 7  is a diagram showing different types of equipment  80  that may be used in processing strands  12  (e.g., non-conductive strands  82  and conductive strands  22 ) and/or that may be used in processing strand-based item  10 . As shown in  FIG. 7 , equipment  80  may include strand core formation equipment  68 . Equipment  68  may include, for example, equipment for extruding and/or otherwise forming polymer cores for strands  12 . Conductive coating application tool  62  may be used to apply one or more conductive coatings. For example, tool  62  may be used to apply a metal coating such as coating  36  ( FIGS. 4, 5, and 6 ) to a polymer strand core such as core  38  ( FIGS. 4, 5, and 6 ) to form a conductive strand  22 . Strand wrapping equipment  66  may be used to wrap strands  12  in additional strands. Equipment  66  may include braiding equipment, twisting equipment, cabling equipment, or other suitable equipment for wrapping strands around strands. As an example, equipment  66  may wrap conductive strands in insulating strands (e.g., fusible insulating strands) to thereby form an insulated conductive strand. Arrangements in which equipment  66  wraps strands in conductive strands may also be used. 
     Equipment  64  may be used in processing strands  12 . Equipment  64  may include a heat source (e.g., a flame, a heated metal structure or other heated structure, a lamp that produces heat, an oven, etc.). Equipment  64  may also include a laser, light-emitting diode, or other light source (e.g., an infrared laser or infrared light-emitting diode, a visible laser or visible light-emitting diode, and/or an ultraviolet laser or light-emitting diode). By applying heat or light or other energy to strands  12  or by using equipment  64  to mechanically or chemically remove material from strands  12 , fusible strands (e.g., applied using equipment  66 ) may be fused, coatings can be selectively removed, liquid polymers and other coating materials may be cured, the texture of strand  12  may be altered, or other strand modifications can be made. 
     Equipment  64  may be used in attaching electrical components such as electrical components in circuitry  16  of  FIG. 1  to strands such as conductive strands  22 . For example, equipment  64  may be used to attach electrical components to strands  22  using solder joints, crimped metal connections, welds, conductive adhesive, or other conductive attachment structures. The electrical components that are attached to strands in this way may include light-emitting components, integrated circuits, light-emitting diodes, light-emitting diodes that are packaged with transistor-based circuitry such as communications circuitry and/or light-emitting diode driver circuitry that allows each component to operate as a pixel in a display, discrete components such as resistors, capacitors, and inductors, audio components such as microphones and/or speakers, sensors such as touch sensors (with or without co-located touch sensor processing circuitry), accelerometers, temperature sensors, force sensors, microelectromechanical systems (MEMS) devices, transducers, solenoids, electromagnets, pressure sensors, light-sensors, proximity sensors, buttons, switches, two-terminal devices, three-terminal devices, devices with four or more contacts, etc. Electrical connections for attaching electrical components to strands  12  using equipment  64  may be formed using solder, conductive adhesive, welds, molded package parts, mechanical fasteners, wrapped strand connections, press-fit connections, crimped connections (e.g., bend metal prong connections), and other mechanical connections, portions of liquid coatings (e.g., metallic paint, conductive adhesive, etc.) that are selectively applied to strands  12  using equipment  64 , or using any other suitable arrangement for forming an electrical short between conductive structures. 
     Strand intertwining equipment  70  (e.g., weaving equipment, knitting equipment, braiding equipment, or other strand intertwining equipment) may be used in intertwining strands  12  to form fabric and other structures for strand-based item  10 . Equipment  64  may be used to process strands  12  before, during, or after processing of strands  12  with equipment  70  to form item  10 . 
     To enhance the robustness of conductive strands  22 , portions or all of conductive strands  22  may be covered in insulating material. As shown in  FIG. 8 , conductive strand  22  (e.g., a conductive strand having the configuration of  FIG. 3, 4, 5 , or  6 ) may be covered in insulator  34  to form insulated conductive strand  28 . In some arrangements, insulator  34  may be an insulating coating formed from one or more dielectric sublayers (e.g., one layer, two layers, three layers, four layers, or more than four layers). To ensure that strand  22  can withstand elevated temperatures, coating  34  may be able to withstand elevated temperatures (e.g., temperatures of 200-300° C., more than 150° C., more than 250° C., more than 350° C., less than 250° C., 210-220° C., or other suitable temperatures). Examples of insulating coating materials that may be used for insulator  34  include polyvinyl formal, polyester-polyimide, polyamide-polyimide, polyamide, polyimide, polyester, polytetrafluoroethylene, and polyurethane (e.g., thermoplastic polyurethane). Other polymers or mixtures of these polymers may be used, if desired. In configurations in which coating layer  34  is formed from multiple sublayers, each sublayer may be formed from the same material or some or all of the sublayers may be formed from different materials. 
     In some arrangements, insulator  34  may be formed from one or more strands of insulating yarn that has been wrapped (e.g., twisted, braided, cabled, etc.) around conductive strand  22 . Examples of materials that may be used to form insulating yarn  34  include polyvinyl formal, polyester-polyimide, polyamide-polyimide, polyamide, polyimide, polyester, polytetrafluoroethylene, polyurethane, and other polymers. If desired, one or more of the yarns that form insulator  34  may be fusible yarn that becomes soft and pliable above a certain temperature and solidifies upon cooling. 
     Insulating yarns may be wrapped around conductive strand  22  in any suitable fashion. In the example of  FIG. 9 , insulating yarn  34  has been wrapped around conductive strand  22  in a Z-twist configuration. In the example of  FIG. 10 , insulating yarn  34  has been wrapped around conductive strand  22  in an S-twist configuration. If desired, one or more insulating yarns  34  may be wrapped around conductive strand  22  in a Z-twist and one or more insulating yarns  34  may be wrapped around conductive strand  22  in an S-twist. Other wrapping arrangements such as braiding or cabling may also be used to cover conductive strand  22  in insulating yarn  34 . 
       FIG. 11  shows an example in which insulating yarns of different materials are wrapped around conductive strand  22 . Insulating yarns  34  may include insulating yarn  30  and insulating yarn  32 . Insulating yarn  32  may be a fusible insulating yarn that becomes soft and pliable above a certain temperature and solidifies upon cooling. Fusible yarn  32  may be formed from a thermosetting polymer material (e.g., thermosetting polyester, polyurethane, polyimide, or other thermosetting resin), thermoplastic material (e.g., thermoplastic polyester, nylon or other suitable polyamide, thermoplastic polyurethane, etc.), or other fusible material that becomes soft when heated to an appropriate temperature (e.g., between 60° C. and 140° C., between 60° C. and 160° C., 80° C. and 100° C., less than 180° C., etc.). 
     Insulating yarn  30  may be formed from a different material than fusible yarn  32 . For example, insulating yarn  30  and fusible yarn  32  may be formed from thermoplastic materials with different melting temperatures. Fusible yarn  32  may have a lower melting temperature than that of insulating yarn  30  so that the application of heat causes fusible yarn  32  to melt and become soft (e.g., while yarn  30  remains solid). In one illustrative example, insulating yarn  30  is formed from nylon and fusible yarn  32  is formed from polyamide, polyester, or other thermoplastic material. When heated to its melting/softening temperature, fusible yarn  32  may soften and spread between insulating yarns  30 . Any gaps between insulating yarns  30  may be filled by fusible yarn  32  as it melts. As fusible yarn  32  cools, it solidifies and forms mechanical bonds with yarn  30  to thereby form a watertight covering over conductive strand  22 . 
       FIG. 12  is a cross-sectional side view of insulated conductive strand  28  of  FIG. 11  prior to fusing fusible yarn  32 . As shown in  FIG. 12 , conductive strand  22  may be wrapped in insulating strands  34 . Insulating strands  34  include insulating strands  30  and fusible insulating strands  32 . After wrapping conductive strand  22  in insulating strands  30  and  32 , heat may be applied using steam, hot air, infra-red rays, a heated element, one or more heated structures, or other heat source to raise the temperature of fusible yarn  32  to its melting temperature (or softening temperature). 
     When fusible yarn  32  is heated to its melting/softening temperature, it spreads between insulating strands  30 . Once cooled, fusible yarn  32  solidifies and forms mechanical bonds with insulating strands  30 . As shown in  FIG. 13 , fusible material  32  fills any gaps between insulating strands  30 . The solidified fusible yarn  32  and insulating yarn  30  form a solid, watertight cover over conductive strand  22 , providing both electrical insulation and environmental protection for strand  22 . 
     The example of  FIG. 13  in which insulator  34  includes insulating strands of different materials is merely illustrative. If desired, insulator  34  may be formed exclusively from fusible yarn  32 , may include other fusible materials, may include fusible yarn and one or more non-fusible materials, etc. Arrangements in which insulator  34  is formed from fused strands  32  that are fused between one or more non-fused strands  30  are sometimes described herein as an example. Insulator  34  may be used only on certain portions of a conductive strand  22  or may be used to entirely cover a conductive strand in fabric-based item  10 . Insulator  34  may be used to prevent adjacent conductive strands  22  from being shorted together and/or may be used to insulate an electrical connection between an electronic component and conductive strand  22 . 
       FIGS. 14, 15, and 16  show illustrative steps involved in mounting an electronic component to a conductive strand and insulating the electrical connection using fusible strands. As shown in  FIG. 14 , conductive strand  22  may be wrapped in insulating strands  34 . Insulating strands  34  include insulating strands  30  and fusible insulating strands  32 . Insulating strands  34  may be wrapped around conductive strand  22  using strand wrapping equipment  66  of  FIG. 7  (e.g., braiding equipment, twisting equipment, cabling equipment, or other suitable equipment for wrapping insulating strands  34  around conductive strand  22 ). Insulating strands  30  and  32  may be wrapped around conductive strand  22  at the same time or may be wrapped around conductive strand  22  in sequential steps. 
     After wrapping conductive strand  22  in insulating strands  30  and  32 , an electronic component such as electronic component  60  may be mounted to conductive strand  22 . 
     Electrical components in item  10  such as illustrative electrical component  60  of  FIG. 15  may include discrete electrical components such as resistors, capacitors, and inductors, may include connectors, may include input-output devices such as switches, buttons, light-emitting components such as light-emitting diodes, audio components such as microphones and speakers, vibrators (e.g., piezoelectric actuators that can vibrate), solenoids, electromechanical actuators, motors, and other electromechanical devices, microelectromechanical systems (MEMs) devices, pressure sensors, light detectors, proximity sensors (light-based proximity sensors, capacitive proximity sensors, etc.), force sensors (e.g., piezoelectric force sensors), strain gauges, moisture sensors, temperature sensors, accelerometers, gyroscopes, compasses, magnetic sensors (e.g., Hall effect sensors and magnetoresistance sensors such as giant magnetoresistance sensors), touch sensors, and other sensors, components that form displays, touch sensors arrays (e.g., arrays of capacitive touch sensor electrodes to form a touch sensor that detects touch events in two dimensions), and other input-output devices, electrical components that form control circuitry such as non-volatile and volatile memory, microprocessors, application-specific integrated circuits, system-on-chip devices, baseband processors, wired and wireless communications circuitry, and other integrated circuits. Electrical components such as component  60  may be bare semiconductor dies (e.g., laser dies, light-emitting diode dies, integrated circuits, etc.) or packaged components (e.g. semiconductor dies or other devices packaged within plastic packages, ceramic packages, or other packaging structures). 
     One or more electrical terminals such as contact pad  42  may be formed on body  40  of component  60 . Body  40  may be a semiconductor die (e.g., a laser die, light-emitting diode die, integrated circuit, etc.) or may be a package for a component (e.g., a plastic package or other dielectric package that contains one or more semiconductor dies or other electrical devices). Contacts for body  40  such as pad  42  may be protruding leads, may be planar contacts, may be formed in an array, may be formed on any suitable surfaces of body  40 , or may be any other suitable contacts for forming electrical connections to component  60 . For example, pad  42  may be a metal solder pad. 
     Electronic component  60  may be mounted directly to conductive strand  22  or electronic component  60  may be mounted to a support structure (sometimes referred to as an interposer) that is mounted to conductive strand  22 . For example, electronic component  60  may be mounted to a printed circuit, ceramic carrier, or other dielectric substrate having contacts that electrically connect electronic component  60  to conductive strand  22 . 
     Conductive material such as conductive material  44  may be used in mounting body  40  to conductive strand  22 . Conductive material  44  may be solder (e.g., low temperature or high temperature solder), may be conductive adhesive (isotropic conductive adhesive or anisotropic conductive film), may be formed during welding, or may be other conductive material for coupling electrical device pads (body pads) such as pad  42  on body  40  to conductive strand  22 . 
     In some arrangements, insulating strands  34  may be moved to the side to accommodate electronic component  60 . In other words, some or most of conductive strand  22  may be covered in insulating strands  34  but insulating strands  34  may be moved to expose a portion of conductive strand  22 . Electronic component  60  may be mounted to the exposed portion of conductive strand  22 . In other arrangements, insulating strands  34  need not be moved. For example, solder  44  may be placed on insulating strands  34  but may wick between insulating strands  34  to make contact with conductive strand  22  when solder  44  is heated to its melting temperature. 
     After mounting electronic component  60  to the exposed portion of conductive strand  22 , heat may be applied to raise the temperature of strands  32  to their melting/softening temperature. Once strands  32  reach the appropriate temperature, the fusible material of strands  32  becomes soft and spreads between insulating strands  30 . As shown in  FIG. 16 , melted fusible material  32  fills any gaps between insulating strands  30  and covers exposed portions of conductive material  44 . Fusible material  32  is then allowed to cool so that material  32  solidifies and forms bonds with insulating strands  30 . Insulating fusible material  32  an insulating strands  30  together form a watertight cover over conductive strand  22  that provides both electrical insulation and environmental protection of conductive strand  22  and the electrical connection between component  60  and conductive strand  22 . 
     The example of  FIG. 16  in which fusible strands  32  insulate an electronic component is merely illustrative. If desired, fusible strand  32  may be used to insulate other electrical connections (e.g., electrical connections between two conductive strands  22 ) and/or may be used to form a watertight covering over portions of fabric-based item  10  to protect portions of fabric-based item  10  from moisture and other contaminants. 
       FIG. 17  is a flow chart of illustrative steps involved in mounting an electrical component to a conductive strand and insulating the electrical connection with fusible yarn. 
     At step  100 , strand wrapping equipment  66  ( FIG. 7 ) may be used to wrap a conductive strand such as conductive strand  22  of  FIG. 3, 4, 5 , or  6  in one or more insulating strands. The strand wrapping equipment may twist, braid, cable, or otherwise wrap insulating strands such as fusible strands  32  and insulating strands  30  of  FIG. 11  around conductive strand  22 . 
     At step  102 , an electronic component such as electronic component  60  of  FIG. 15  may be mounted and electrically connected to conductive strand  22 . This may include, for example, forming an electrical and mechanical connection between the conductive contacts of the electronic component and the conductive outer surface of conductive strand  22 . Solder, conductive adhesive, or other suitable conductive material may be used to electrically and mechanically connect the electronic component to strand  22 . In arrangements where solder is used, the solder may wick in between insulating strands  30  and fusible insulating strands  32  to reach conductive strand  22 . 
     At step  104 , heat may be applied to raise the temperature of strands  32  to their melting/softening temperature. Once strands  32  reach the appropriate temperature, the fusible material of strands  32  becomes soft and spreads between insulating strands  30  (e.g., as shown in  FIGS. 13 and 16 ). Fusible material  32  is then allowed to cool so that material  32  solidifies and forms bonds with insulating strands  30 . Fusible insulating strands  32  an insulating strands  30  together form a watertight cover over conductive strand  22  that provides both electrical insulation and environmental protection of conductive strand  22  and the electrical connection between component  60  and conductive strand  22 . 
     The example of  FIG. 17  in which fusible yarn  32  is fused following attachment of component  60  is merely illustrative. If desired, electrical connections to conductive strand  22  may be formed after yarn  32  is fused.  FIG. 18  is a flow chart of illustrative steps involved in mounting an electronic component to a conductive strand after fusible yarn around the conductive strand has been fused. 
     At step  200 , strand wrapping equipment  66  ( FIG. 7 ) may be used to wrap a conductive strand such as conductive strand  22  of  FIG. 3, 4, 5 , or  6  in one or more insulating strands. The strand wrapping equipment may twist, braid, cable, or otherwise wrap insulating strands such as fusible strands  32  and insulating strands  30  of  FIG. 11  around conductive strand  22 . 
     At step  202 , heat may be applied to raise the temperature of strands  32  to their melting/softening temperature. Once strands  32  reach the appropriate temperature, the fusible material of strands  32  becomes soft and spreads between insulating strands  30  (e.g., as shown in  FIGS. 13 and 16 ). Fusible material  32  is then allowed to cool so that material  32  solidifies and forms bonds with insulating strands  30 . 
     At step  204 , portions of insulator  34  formed from strands  30  and fused strands  32  may be removed to expose a conductive surface of conductive strand  22 . Equipment that may be used to selectively remove portions of insulator  34  include laser ablation equipment, chemical removal equipment, selective abrasion equipment, cutting equipment, machining equipment, or other suitable equipment. 
     At step  206 , an electronic component such as electronic component  60  of  FIG. 15  may be mounted and electrically connected to the exposed portion of conductive strand  22 . This may include, for example, forming an electrical and mechanical connection between the conductive contacts of the electronic component and the conductive outer surface of conductive strand  22 . Solder, conductive adhesive, or other suitable conductive material may be used to electrically and mechanically connect the electronic component to strand  22 . 
     At optional step  208 , strand wrapping equipment may be used to wrap additional insulating strands (e.g., additional fusible or non-fusible strands) around conductive strand  22 . The additional insulating strands may be wrapped around the entire length of strand  22  or may be wrapped around the portion of strand  22  where electronic component  60  is mounted. The additional insulating strands may then be fused by applying heat so that the fusible material melts and spreads around strand  22  and covers the electrical connection between component  60  and strand  22 . 
     The foregoing is merely illustrative and various modifications can be made by those skilled in the art without departing from the scope and spirit of the described embodiments. The foregoing embodiments may be implemented individually or in any combination.

Metadata:
Filing Date: 20170203
Publication Date: 20191112
Grant Date: 20191112
Priority Date: 20160217
Inventors: May, Maurice P.
MALLADI, KIRAN K.
PODHAJNY, DANIEL A.
SUNSHINE, Daniel D.
Assignee: APPLE INC
CPC Classifications: [{"code": "H05K2201/0281", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K1/038", "inventive": true, "first": false, "tree": "[]"}, {"code": "D02G3/441", "inventive": true, "first": true, "tree": "[]"}, {"code": "D02G3/402", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/0129", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K3/34", "inventive": true, "first": false, "tree": "[]"}, {"code": "D10B2501/00", "inventive": false, "first": false, "tree": "[]"}, {"code": "D10B2401/16", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/10378", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K1/111", "inventive": true, "first": false, "tree": "[]"}, {"code": "D02G3/38", "inventive": true, "first": true, "tree": "[]"}, {"code": "H05K1/189", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K1/038", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K2201/10984", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/10378", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K1/038", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K2201/0129", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K1/189", "inventive": true, "first": false, "tree": "[]"}, {"code": "D02G3/38", "inventive": true, "first": true, "tree": "[]"}, {"code": "D10B2501/00", "inventive": false, "first": false, "tree": "[]"}, {"code": "D10B2401/16", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K3/34", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K2201/10984", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K1/111", "inventive": true, "first": false, "tree": "[]"}, {"code": "D03D15/292", "inventive": true, "first": false, "tree": "[]"}, {"code": "D03D15/47", "inventive": true, "first": false, "tree": "[]"}, {"code": "D03D15/292", "inventive": true, "first": false, "tree": "[]"}, {"code": "D03D15/47", "inventive": true, "first": false, "tree": "[]"}, {"code": "D03D15/258", "inventive": true, "first": false, "tree": "[]"}, {"code": "D03D1/0088", "inventive": true, "first": false, "tree": "[]"}, {"code": "D10B2401/041", "inventive": false, "first": false, "tree": "[]"}, {"code": "D10B2401/16", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 68466372