PATENT DOCUMENT

Publication Number: US-10485103-B1
Application Number: US-201715439641-A
Country: US
Kind Code: B1

Title: Electrical components attached to fabric

Abstract:
An item may include fabric having insulating and conductive yarns or other strands of material. The conductive strands may form signal paths. Electrical components can be mounted to the fabric. Each electrical component may have an electrical device such as a semiconductor die that is mounted on an interposer substrate. The interposer may have contacts that are soldered to the conductive strands. A protective cover may encapsulate portions of the electrical component. To create a robust connection between the electrical component and the fabric, the conductive strands may be threaded through recesses in the electrical component. The recesses may be formed in the interposer or may be formed in a protective cover on the interposer. Conductive material in the recess may be used to electrically and/or mechanically connect the conductive strand to a bond pad in the recess. Thermoplastic material may be used to seal the solder joint.

Claims:
What is claimed is: 
     
       1. An item, comprising:
 fabric having a conductive strand; 
 an electrical component electrically connected to the conductive strand, wherein the electrical component has a recess interposed between first and second portions of the electrical component, wherein electrical current passes through the first and second portions, and wherein the conductive strand passes through the recess in the electrical component; and 
 a protective cover that encapsulates at least part of the electrical component. 
 
     
     
       2. The item defined in  claim 1  wherein the electrical component comprises:
 an interposer; and 
 an electrical device soldered to the interposer. 
 
     
     
       3. The item defined in  claim 2  wherein the protective cover at least partially covers the electrical device on the interposer. 
     
     
       4. The item defined in  claim 2  wherein the recess comprises a notch in the interposer. 
     
     
       5. The item defined in  claim 4  wherein the notch is lined with metal that forms a bond pad. 
     
     
       6. The item defined in  claim 4  further comprising an additional notch in the interposer, wherein the interposer has first and second opposing sides, and wherein the notch is located on the first side of the interposer and the additional notch is located on the second side of the interposer. 
     
     
       7. The item defined in  claim 5  further comprising conductive material that mechanically and electrically connects the conductive strand to the bond pad in the notch. 
     
     
       8. An item, comprising:
 fabric having a conductive strand; and 
 an electrical component electrically connected to the conductive strand, wherein the electrical component has a recess, wherein the conductive strand passes through the recess in the electrical component, and wherein the electrical component comprises:
 an interposer; and 
 an electrical device soldered to the interposer, wherein the interposer comprises a first layer having a first edge, a second layer having a second edge, and a third layer having a third edge, wherein the second layer is interposed between the first and third layers, and wherein the recess in the electrical component is formed from a recess in the interposer where the second edge is recessed relative to the first and third edges. 
 
 
     
     
       9. The item defined in  claim 8  wherein the first and third layers of the interposer each comprise a flexible printed circuit and the second layer of the interposer comprises a rigid printed circuit. 
     
     
       10. The item defined in  claim 8  wherein the recess in the interposer is lined with metal that forms a bond pad. 
     
     
       11. The item defined in  claim 10  further comprising conductive material in the recess that mechanically and electrically connects the conductive strand to the bond pad in the recess. 
     
     
       12. An item, comprising:
 fabric having a conductive strand; 
 a substrate having a notch that receives the conductive strand, wherein at least two sides of the notch are plated with metal; 
 an electrical device mounted to the substrate; and 
 conductive material in the notch that conveys electrical current between the conductive strand and the electrical device. 
 
     
     
       13. The item defined in  claim 12  wherein the conductive material comprises solder. 
     
     
       14. An item, comprising:
 fabric having first and second conductive strands; 
 a substrate having first and second opposing sides, a first recess in the first side, and a second recess in the second side, wherein the first conductive strand passes through the first recess and the second conductive strand passes through the second recess; and 
 an electrical device mounted to the substrate and electrically coupled to the first and second conductive strands, wherein the substrate has first and second portions, wherein the first and second conductive strands are interposed between the first and second portions, and wherein electrical current passes through the first and second portions. 
 
     
     
       15. The item defined in  claim 14  wherein the first conductive strand is soldered to a bond pad in the first recess and the second conductive strand is soldered to a bond pad in the second recess. 
     
     
       16. The item defined in  claim 14  wherein the substrate comprises a printed circuit. 
     
     
       17. The item defined in  claim 16  wherein the multi-layer printed circuit has first and second opposing surfaces, wherein the item further comprises an additional electrical device, wherein the electrical device is mounted to the first surface of the multi-layer printed circuit, and wherein the additional electrical device is mounted to the second surface of the multi-layer printed circuit. 
     
     
       18. The item defined in  claim 16  wherein the multi-layer printed circuit comprises a rigid printed circuit substrate interposed between two flexible printed circuit substrates, and wherein the first and second recesses are formed in locations where the rigid printed circuit substrate is recessed relative to the two flexible printed circuit substrates. 
     
     
       19. An item, comprising:
 fabric having first and second conductive strands; 
 a substrate having first and second opposing surfaces; 
 an electrical device mounted to the substrate; 
 first and second bond pads on the substrate, wherein the first and second bond pads are formed from elongated strips of metal, wherein the substrate has a width, and wherein the elongated strips of metal span the width of the substrate; and 
 conductive material that electrically connects the first and second conductive strands respectively to the first and second bond pads. 
 
     
     
       20. The item defined in  claim 19  wherein the conductive material comprises solder. 
     
     
       21. The item defined in  claim 19  wherein the first bond pad extends parallel to the first conductive strand and the second bond pad extends parallel to the second conductive strand.

Description:
This application claims the benefit of U.S. provisional patent application No. 62/298,050, filed on Feb. 22, 2016, which is hereby incorporated by reference herein in its entirety. 
    
    
     FIELD 
     This relates generally to items with fabric and, more particularly, to items with fabric and electrical components. 
     BACKGROUND 
     It may be desirable to form bags, furniture, clothing, and other items from materials such as fabric. Fabric items generally do not include electrical components. It may be desirable, however, to incorporate electrical components into fabric to provide a user of a fabric item with enhanced functionality. 
     It can be challenging to incorporate electrical components into fabric. Fabric is flexible, so it can be difficult to mount structures to fabric. Electrical components must be coupled to signal paths (e.g., signal paths that carry data signals, power, etc.), but unless care is taken, signal paths will be damaged or components may become dislodged as fabric is bent and stretched. 
     It would therefore be desirable to be able to provide improved techniques for incorporating electrical components into items with fabric. 
     SUMMARY 
     An item may include fabric such as woven fabric having insulating and conductive yarns or other strands of material. The conductive yarns may form signal paths (e.g., signal paths that carry data signals, control signals, power, etc.). Electrical components can be embedded within pockets in the fabric and may be electrically coupled to the signal paths. 
     Each electrical component may have an electrical device such as a semiconductor die that is mounted on an interposer. The electrical device may be a light-emitting diode, a sensor, an actuator, or other electrical device. The electrical device may have contacts that are soldered to contacts on the interposer. The interposer may have additional contacts that are soldered to the signal paths. Metal traces in the interposer may convey signals (e.g., data signals, control signals, power, etc.) between the contacts to which the electrical device is coupled and the contacts to which the conductive strands are coupled. 
     The interposer may be formed from a printed circuit such as a rigid printed circuit substrate layer or a flexible printed circuit substrate layer, or may be formed from both rigid and flexible printed circuit substrate layers. 
     To create a robust connection between the electrical component and the fabric, the conductive strands may be threaded through recesses, trenches, or openings in the component. The recesses, trenches, or openings may be formed in the electrical device itself, in the interposer to which the electrical device is mounted, or a protective cover that encapsulates portions of the electrical device and interposer. Conductive material in the recess may be used to electrically and mechanically connect the conductive strand to a bond pad in the recess. 
     In arrangements where strands are threaded through an interposer, a recess may be formed from a gap between upper and lower substrates in the interposer or from a notch that extends from an upper surface to a lower surface of the interposer. 
     In arrangements where strands are threaded through a protective cover, a trench may be formed from a gap between upper and lower protective covers or from a notch that extends from one edge of the protective cover to an opposing edge of the protective cover. The notch may have locally widened portions to help prevent the solder from shifting off of the bond pad in the trench. The trench may have straight or sloped sidewalls. 
     Thermoplastic material may be formed in the trenches. Heat may be applied to reflow solder in the trench and melt the thermoplastic material. Once cooled and hardened, the solder may form a secure electrical connection between the strand and the pad, while the thermoplastic may spread across the trench and provide a seal that protects the electrical connection from mechanical damage and environmental contaminants. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of an illustrative fabric item in accordance with an embodiment. 
         FIG. 2  is a side view of illustrative fabric in accordance with an embodiment. 
         FIG. 3  is a side view of layers of material that may be incorporated into a fabric item in accordance with an embodiment. 
         FIG. 4  is a cross-sectional side view of an illustrative electrical component in accordance with an embodiment. 
         FIG. 5  is a cross-sectional side view of an illustrative electrical component having an electrical device mounted on an interposer in accordance with an embodiment. 
         FIG. 6  is a cross-sectional side view of an illustrative electrical component having multiple electrical devices mounted on an interposer in accordance with an embodiment. 
         FIG. 7  is a perspective view of an illustrative electrical component mounted to conductive strands in accordance with an embodiment. 
         FIG. 8  is a perspective view of an illustrative electrical component having an interposer with recesses for receiving conductive strands in accordance with an embodiment. 
         FIG. 9  is a side view of an illustrative interposer with recesses that are lined with conductive material in accordance with an embodiment. 
         FIG. 10  is a side view of an illustrative interposer with recesses that are partially lined with conductive material in accordance with an embodiment. 
         FIG. 11  is a side view of an illustrative interposer with recesses that are partially lined with conductive material in accordance with an embodiment. 
         FIG. 12  is a side view of a panel of multiple interposers prior to being singulated into individual interposers in accordance with an embodiment. 
         FIG. 13  is a side view of the interposers of  FIG. 12  after being singulated into individual interposers in accordance with an embodiment. 
         FIG. 14  is a perspective view of an illustrative interposer having notches for receiving conductive strands on first and second opposing sides of the interposer in accordance with an embodiment. 
         FIG. 15  is a perspective view of an illustrative interposer having notches for receiving conductive strands on four sides of the interposer in accordance with an embodiment. 
         FIG. 16  is a perspective view of an illustrative interposer having multiple notches in each side of the interposer in accordance with an embodiment. 
         FIG. 17  is a perspective view an illustrative interposer having notches for receiving conductive strands that are cut to form two separate signal paths in accordance with an embodiment. 
         FIG. 18  is a perspective view of an illustrative interposer having notches at the corners of the interposer in accordance with an embodiment. 
         FIG. 19  is a top view of an illustrative interposer that is rotated relative to conductive strands in accordance with an embodiment. 
         FIG. 20  is a top view of an illustrative interposer that is rotated relative to conductive strands and that is trimmed to fit in a pocket in accordance with an embodiment. 
         FIG. 21  is a side view of an illustrative interposer having recesses in a lower surface that are partially enclosed to contain strands in the recesses in accordance with an embodiment. 
         FIG. 22  is a side view of an illustrative component having a protective cover with trenches through which fabric strands are threaded in accordance with an embodiment. 
         FIG. 23  is a bottom view of an illustrative component having a protective cover with trenches through which fabric strands are threaded in accordance with an embodiment. 
         FIG. 24  is a side view of an illustrative component having a protective cover with trenches through which fabric strands are threaded and openings for exposing electrical devices on an interposer in accordance with an embodiment. 
         FIG. 25  is a side view of an illustrative component having upper and lower protective covers that protrude beyond the edges of an interposer to form a trench through which fabric stands are threaded in accordance with an embodiment. 
         FIGS. 26, 27, and 28  show illustrative steps involved in attaching a component to fabric strands using trenches in a protective cover and a thermoplastic structure that guides the fabric strands into the trenches in accordance with an embodiment. 
         FIGS. 29, 30, 31, 32, and 33  show illustrative steps involved in attaching a component to fabric strands by threading the fabric strands through trenches in a protective cover and heating solder and thermoplastic material to draw the fabric strands down into the solder and under the thermoplastic material in accordance with an embodiment. 
         FIG. 34  is a side view of illustrative equipment including inductive heating equipment and a transducer which may be used to attach a component to fabric in accordance with an embodiment. 
         FIG. 35  is a side view of an illustrative component in which a thermoplastic structure presses fabric strands into trenches and is subsequently heated to seal the fabric strands in the trenches in accordance with an embodiment. 
         FIG. 36  is a side view of an illustrative component in which thermoplastic material has localized peaks around each trench to help prevent fabric strands from escaping the trenches during the attachment process in accordance with an embodiment. 
         FIG. 37  is a side view of an illustrative component in which trenches in a protective cover have straight sidewalls in accordance with an embodiment. 
         FIG. 38  is a side view of an illustrative component in which trenches in a protective cover have sloped sidewalls with a larger width at the top of the trench than at the bottom of the trench in accordance with an embodiment. 
         FIG. 39  is a side view of an illustrative component in which trenches in a protective cover have sloped sidewalls with a smaller width at the top of the trench than at the bottom of the trench in accordance with an embodiment. 
         FIG. 40  is a side view of an illustrative component in which solder hooks promote coupling between the fabric strands and the solder in accordance with an embodiment. 
         FIG. 41  is a bottom view of an illustrative component in which trenches in a protective cover have uniform width across the protective cover in accordance with an embodiment. 
         FIG. 42  is a bottom view of an illustrative component in which trenches in a protective cover have locally widened portions that are staggered relative to one another to accommodate larger pads in accordance with an embodiment. 
         FIG. 43  is a bottom view of an illustrative component in which trenches in a protective cover have locally widened portions at the outer edges of the protective cover to accommodate bends in fabric strands in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Items such as item  10  of  FIG. 1  may include fabric and may sometimes be referred to as a fabric item or fabric-based item. 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 item  10  is mounted in a kiosk, in an automobile, airplane, or other vehicle (e.g., an autonomous or non-autonomous 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 item that incorporates fabric. 
     Item  10  may include intertwined strands of material such as monofilaments and yarns that form fabric  12 . Fabric  12  may form all or part of a housing wall or other layer in an electronic device, may form internal structures in an electronic device, or may form other fabric-based structures. 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. 
     The strands of material in fabric  12  may be single-filament strands (sometimes referred to as fibers) or may be yarns or other strands that have been formed by intertwining multiple filaments of material together. Examples of fabric  12  formed from yarn are sometimes described herein as an example. This is, however, merely illustrative. Yarn-based fabric for item  10  may, if desired, be partly or completely formed from monofilaments. 
     The yarns in fabric  12  may be formed from polymer, metal, glass, graphite, ceramic, natural materials as cotton or bamboo, or other organic and/or inorganic materials and combinations of these materials. Conductive coatings such as metal coatings may be formed on non-conductive material. For example, plastic yarns and monofilaments in fabric  12  may be coated with metal to make them conductive. Reflective coatings such as metal coatings may be applied to make yarns and monofilaments reflective. Yarns may be formed from a bundle of bare metal wires or metal wire intertwined with insulating monofilaments (as examples). 
     Yarn may be intertwined to form fabric  12  using intertwining equipment such as weaving equipment, knitting equipment, or braiding equipment. Intertwined yarn may, for example, form woven fabric. Conductive yarn and insulating yarn may be woven, knit, braided, or otherwise intertwined to form contact pads that can be electrically coupled to conductive structures in item  10  such as the contact pads of an electrical component. 
     Conductive yarn and insulating yarn may also be woven, knit, or otherwise intertwined to form conductive paths. The conductive paths may be used in forming signal paths (e.g., signal buses, power lines for carrying power, etc.), may be used in forming part of a capacitive touch sensor electrode, a resistive touch sensor electrode, or other input-output device, or may be used in forming other patterned conductive structures. Conductive structures in fabric  12  may be used in carrying electrical current such as power, digital signals, analog signals, sensor signals, control signals, data, input signals, output signals, or other suitable electrical signals. 
     Item  10  may include additional mechanical structures  14  such as polymer binder to hold yarns in fabric  12  together, support structures such as frame members, housing structures (e.g., an electronic device housing), and other mechanical structures. 
     To enhance mechanical robustness and electrical conductivity at yarn-to-yarn connections, additional structures and materials (e.g., solder, crimped metal connections, welds, conductive adhesive such as anisotropic conductive film and other conductive adhesive, non-conductive adhesive, fasteners, etc.) may be used to help form yarn-to-yarn connections. These yarn-to-yarn connections may be formed where yarns cross each other perpendicularly or at other yarn intersections where connections are desired. Insulating material can be interposed between intersecting conductive yarns at locations in which it is not desired to form a yarn-to-yarn connection. The insulating material may be plastic or other dielectric, may include an insulating yarn or a conductive yarn with an insulating coating or insulated conductive monofilaments, etc. Solder connections may be formed between conductive yarns by melting solder so that the solder flows over conductive yarns. The solder may be melted using an inductive soldering head to heat the solder, using a reflow oven to heat the solder, using a laser or hot bar to heat the solder, or using other soldering equipment. During soldering, outer dielectric coating layers (e.g., outer polymer layers) may be melted away in the presence of molten solder, thereby allowing underlying metal yarns to be soldered together. 
     Circuitry  16  may be included in item  10 . Circuitry  16  may include electrical components that are coupled to fabric  12 , electrical components that are housed within an enclosure formed by fabric  12 , electrical components that are attached to fabric  12  using welds, solder joints, adhesive bonds (e.g., conductive adhesive bonds such as anisotropic conductive adhesive bonds or other conductive adhesive bonds), crimped connections, or other electrical and/or mechanical bonds. Circuitry  16  may include metal structures for carrying current, electrical components such as integrated circuits, light-emitting diodes, sensors, and other electrical devices. Control circuitry in circuitry  16  may be used to control the operation of item  10  and/or to support communications with item  18  and/or other devices. 
     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 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 item  10  may form a cover, case, bag, 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 fabric item that is attached to item  18  (e.g., item  10  and item  18  may together form a fabric-based item such as a wristwatch with a strap). In still other situations, item  10  may be an electronic device, fabric  12  may be used in forming the electronic device, and additional items  18  may include accessories or other devices that interact with item  10 . Signal paths formed from conductive yarns and monofilaments may be used to route signals in item  10  and/or item(s)  18 . 
     The fabric that makes up item  10  may be formed from yarns and/or monofilaments that are intertwined using any suitable intertwining equipment. With one suitable arrangement, which may sometimes be described herein as an example, fabric  12  may be woven fabric formed using a weaving machine. In this type of illustrative configuration, fabric may have a plain weave, a basket weave, a satin weave, a twill weave, or variations of these weaves, may be a three-dimensional woven fabric, or may be other suitable fabric. 
     A cross-sectional side view of illustrative woven fabric  12  is shown in  FIG. 2 . As shown in  FIG. 2 , fabric  12  may include yarns or other strands of material  80 . Strands  80  may include warp strands  20  and weft strands  22 . If desired, additional strands that are neither warp nor weft strands may be incorporated into fabric  12 . The example of  FIG. 2  is merely illustrative. In the illustrative configuration of  FIG. 2 , fabric  12  has a single layer of woven strands  80 . Multi-layer fabric constructions may be used for fabric  12  if desired. 
     Item  10  may include non-fabric materials (e.g., structures formed from plastic, metal, glass, ceramic, crystalline materials such as sapphire, etc.). These materials may be formed using molding operations, extrusion, machining, laser processing, and other fabrication techniques. In some configurations, some or all of item  10  may include one or more layers of material such as layers  24  of  FIG. 3 . Layers  24  may include layers of polymer, metal, glass, fabric, adhesive, crystalline materials, ceramic, substrates on which components have been mounted, patterned layers of material, layers of material containing patterned metal traces, thin-film devices such as transistors, and/or other layers. 
     A side view of an illustrative electrical component of the type that may be used in item  10  is shown in  FIG. 4 . Electrical components in item  10  such as illustrative electrical component  26  of  FIG. 4  may include discrete electrical components such as resistors, capacitors, and inductors, may include connectors, may include batteries, 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  26  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 pads  30  may be formed on body  28  of component  26 . Body  28  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  28  such as pads  30  may be protruding leads, may be planar contacts, may be formed in an array, may be formed on any suitable surfaces of body  28 , or may be any other suitable contacts for forming electrical connections to component  26 . For example, pads  30  may be metal solder pads. 
     As shown in the example of  FIG. 5 , body  28  may be mounted on a support structure such as interposer  36 . Interposer  36  may be a printed circuit, ceramic carrier, or other dielectric substrate. Interposer  36  may be larger than body  28  or may have other suitable sizes. Interposer  36  may have a planar shape with a thickness of 700 microns, more than 500 microns, less than 500 microns, or other suitable thickness. The thickness of body  28  may be 500 microns, more than 300 microns, less than 1000 microns, or other suitable thickness. The footprint (area viewed from above) of body  28  and interposer  36  may be 10 microns×10 microns, 100 microns×100 microns, more than 1 mm×1 mm, less than 10 mm×10 mm, may be rectangular, may be square, may have L-shapes, or may have other suitable shapes and sizes. 
     Interposer  36  may contain signal paths such as metal traces  38 . Metal traces  38  may have portions forming contacts such as pads  34  and  40 . Pads  34  and  40  may be formed on the upper surface of interposer  36 , on the lower surface of interposer  36 , or on the sides of interposer  36 . Conductive material such as conductive material  32  may be used in mounting body  28  to interposer  36 . Conductive material  32  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 pads  30  on body  28  to interposer pads  34 . Metal traces  38  in interposer  36  may couple pads  34  to other pads such as pads  40 . If desired, pads  40  may be larger and/or more widely spaced than pads  34 , thereby facilitating attachment of interposer  36  to conductive yarns and/or other conductive paths in item  10 . Solder, conductive adhesive, or other conductive connections may be used in coupling pads  40  to conductive yarn, conductive monofilament, printed circuit traces, or other conductive path materials in item  10 . 
       FIG. 6  shows an example in which component  26  includes a protective structure such as protective structure  130  on interposer  36 . Protective structure  130  may, for example, be a plastic structure that completely or partially encapsulates devices  28  and interposer  36  to provide mechanical robustness, protection from moisture and other environmental contaminants, heat sinking, and/or electrical insulation. Protective structure  130  may be formed from molded plastic (e.g., injection-molded plastic, transfer molded plastic, low-pressure molded plastic, two-part molded plastic, etc.) that has been molded over devices  28  and interposer  36  or that is pre-formed into the desired shape and subsequently attached to interposer  36 , may be a layer of polymer such as polyimide that has been cut or machined into the desired shape and subsequently attached to interposer  36 , or may be formed using other suitable methods. Illustrative materials that may be used to form protective structure  130  include epoxy, polyamide, polyurethane, silicone, other suitable materials, or a combination of any two or more of these materials. Protective structure  130  may be formed on one or both sides of interposer  36  (e.g., may completely or partially surround interposer  36 ). 
     Protective structure  130  may be entirely opaque, may be entirely transparent, or may have both opaque and transparent regions. Transparent portions of protective structure  130  may allow light emitted from one or more devices  28  to be transmitted through protective structure  130  and/or may allow external light to reach (and be detected by) one or more devices  28 . Protective cover  130  may, if desired, have different thicknesses. The example of  FIG. 6  in which protective cover  130  has uniform thickness across interposer  36  is merely illustrative. 
     If desired, interposer  36  may be sufficiently large to accommodate multiple electrical devices each with a respective body  28 . For example, multiple light-emitting diodes, sensors, and/or other electrical devices may be mounted to a common interposer such as interposer  36  of  FIG. 6 . The light-emitting diodes may be micro-light-emitting diodes (e.g., light-emitting diode semiconductor dies having footprints of about 10 microns×10 microns, more than 5 microns×5 microns, less than 100 microns×100 microns, or other suitable sizes). The light-emitting diodes may include light-emitting diodes of different colors (e.g., red, green, blue, white, etc.), infrared light, or ultraviolet light. Redundant light-emitting diodes or other redundant circuitry may be included on interposer  36 . In configurations of the type shown in  FIG. 6  in which multiple electrical devices (each with a respective body  28 ) are mounted on a common interposer, electrical component  26  may include any suitable combination of electrical devices (e.g., light-emitting diodes, sensors, integrated circuits, actuators, and/or other devices of the type described in connection with electrical component  26  of  FIG. 4 ). 
     The examples of  FIGS. 5 and 6  in which devices  28  are only located on one side of interposer  36  are merely illustrative. If desired, devices  28  may be mounted to both sides of interposer  36 . 
     Electrical components may be coupled to fabric structures, individual yarns or monofilaments, printed circuits (e.g., rigid printed circuits formed from fiberglass-filled epoxy or other rigid printed circuit board material or flexible printed circuits formed from polyimide substrate layers or other sheets of flexible polymer materials), metal or plastic parts with signal traces, or other structures in item  10 . 
     In some configurations, item  10  may include electrical connections between components  26  and conductive paths in fabric  12 . Fabric  12  may include strands  80  (e.g., conductive yarns and/or conductive monofilaments) for carrying electrical current (e.g., power, digital signals, analog signals, sensor signals, control signals, data, input signals, output signals, or other suitable electrical signals) to and/or from components  26 . The strands may be used to form fabric contact pads. Consider, as an example, fabric  12  of  FIG. 7 . As shown in  FIG. 7 , fabric  12  may contain strands  80 . Strands  80  may be warp strands, weft strands, or other suitable strands in fabric  12 . One or more of strands  80  may be conductive and may form a contact pad. Component  26  may have contact pads such as pad  40 . Solder or other conductive material  82  may be used to couple pads  40  to the pads formed by strands  80 . In the example of  FIG. 7 , pads  40  are formed on a lower surface of interposer  36  (e.g., a surface that is opposite the surface on which component  28  is mounted). Conductive material  82  may be used to electrically and mechanically couple component  26  to strands  80  of fabric  12 . 
     In the example of  FIG. 7 , pads  40  are formed from elongated strips of conductive material (e.g., metal) that extend from one edge of interposer  36  to an opposing edge of interposer  36 . This provides a large area with which to form a mechanical and electrical connection between interposer  36  and strands  80 . As shown in  FIG. 7 , each strand  80  extends parallel to one of pads  40 . The elongated shape of pads  40  allows conductive material  82  to attach a longer portion of strand  80  to pad  40 . The connection between pad  40  and strand  80  may, for example, span across the width of interposer  36 , thereby providing a robust connection between interposer  36  and strand  80 . 
     In some configurations, it may be desirable to provide a more robust mechanical connection between component  26  (e.g., component  26  of  FIGS. 4, 5, and 6 ) and fabric  12  to ensure that component  26  does not come loose when fabric  12  is bent or stretched. To increase the robustness of the connection between strands  80  and component  26 , component  26  may have one or more recesses for receiving strands  80 . For example, strands  80  may each be “threaded” through a portion of component  26  to help secure component  26  to fabric  12 . Strands  80  may be threaded through portions (e.g., recesses, openings, trenches, etc.) of device  28 , interposer  36 , protective structure  130 , and/or other portions of component  26 .  FIGS. 8-21  illustrate examples in which strands  80  are threaded through portions of interposer  36 .  FIGS. 22-43  illustrate examples in which strands  80  are threaded through portions of protective structure  130 . It should be understood, however, that the geometries of interposer  36  (e.g., the location, shape, and size of recesses in interposer  36 ) and other features of  FIGS. 8-21  may be applied to protective structure  130 , and that the geometries of protective structure  130  (e.g., the location, shape, and size of recesses in protective structure  130 ) and other features of  FIGS. 22-43  may be applied to interposer  36 . In general, component  26  may have any combination of features shown in  FIGS. 8-43 . 
     As shown in  FIG. 8 , interposer  36  may have multiple layers such as layers  42 . Interposer  36  may, for example, be a multi-layer printed circuit. Layers  42  may include flexible printed circuit layers, rigid printed circuit layers, or a combination of rigid and flexible printed circuit layers. Layers  42  of interposer  36  may include dielectric materials such as fiberglass-filled epoxy (e.g., as a rigid layer), polyimide (e.g., as a flexible layer), FR-2 (phenolic cotton paper), FR-3 (cotton paper and epoxy), FR-4 (woven glass and epoxy), FR-5 (woven glass and epoxy), FR-6 (matte glass and polyester), G-10 (woven glass and epoxy), CEM-1 (cotton paper and epoxy), CEM-2 (cotton paper and epoxy), CEM-3 (woven glass and epoxy), CEM-4 (woven glass and epoxy), CEM-5 (woven glass and polyester), paper impregnated with phenolic resin, polystyrene, polyimide, polytetrafluoroethylene (PTFE), plastic, other polymers, ceramics, or other suitable dielectrics. Layers  42  may include attachment layers such as layers of prepreg (e.g., pre-impregnated layers of fiber and resin). 
     Layers  42  may contain metal traces (sometimes referred to as interconnects). The metal traces may include patterned signal lines and vias for routing signals between components that are mounted on interposer  36 . The metal traces may include ground plane structures (e.g., blanket sections of metal traces that serve as ground). There may be any suitable number of metal layers in layers  42 . For example, layers  42  may contain two layers of metal, three layers of metal, four layers of metal, more than four layers of metal, or fewer than four layers of metal. Metal layers in layers  42  may be formed from copper, silver, tungsten, other suitable metals, or a combination of any two or more of these metals. 
     As shown in  FIG. 8 , interposer  36  includes first layer  42 - 1 , second layer  42 - 2  (sometimes referred to as a spacer layer), and third layer  42 - 3 . In one illustrative arrangement, first layer  42 - 1  and third layer  42 - 3  are flexible printed circuits and second layer  42 - 2  is a rigid printed circuit. This is, however, merely illustrative. If desired, layers  42 - 1  and  42 - 3  may be rigid printed circuits and layer  42 - 2  may be a flexible printed circuit, all three layers may be flexible printed circuits, all three layers may be rigid printed circuits, or layers  42  may include any other suitable combination of rigid and flexible layers. Arrangements where upper layer  42 - 1  and lower layer  42 - 3  are flexible printed circuits and layer  42 - 2  is a rigid printed circuit are sometimes described herein as an illustrative example. In still other arrangements, one or more of layers  42  may not contain any circuitry. For example, layer  42 - 2  and layer  42 - 3  may be structural support layers that do not include any circuitry, if desired. 
     The example of  FIG. 8  in which interposer  36  includes three printed circuit substrates  42 - 1 ,  42 - 2 , and  42 - 3  is merely illustrative. If desired, interposer may include four printed circuit substrates, five printed circuit substrate, six or more printed circuit substrates, or less than three printed circuit substrates. 
     If desired, components may be mounted to one or both of the opposing surfaces of interposer  36 . In the example of  FIG. 8 , one or more components such as component  28 - 1  is mounted to the upper surface of interposer  36  (e.g., the surface formed by upper layer  42 - 1 ) and one or more components such as component  28 - 2  is mounted to the opposing lower surface of interposer  36  (e.g., the surface formed by lower layer  42 - 3 ). 
     Interposer  36  may include recesses such as recesses  50 . In the example of  FIG. 8 , interposer  36  includes a first recess  50  on one side of interposer  36  and a second recess  50  on an opposing side of interposer  36 . Recesses  50  are formed where upper and lower layers  42 - 1  and  42 - 3  extend beyond the outer edge of middle layer  42 - 2 . In other words, recesses  50  are formed where middle layer  42 - 2  is recessed relative to upper and lower layers  42 - 1  and  42 - 3 , thereby forming a gap between upper layer  42 - 1  and lower layer  42 - 3 . The open space between upper and lower layers  42 - 1  and  42 - 3  at the edges of interposer  36  creates a cavity for receiving one of strands  80  of fabric  12 . As shown in  FIG. 8 , each strand  80  passes through a respective one of recesses  50 . 
     In the example of  FIG. 8 , recesses  50  (sometimes referred to as grooves or cavities) extend parallel to one another along the y-axis of  FIG. 8 . This allows recesses  50  to receive strands  80  that also extend along the y-axis of  FIG. 8 . This is, however, merely illustrative. If desired, recesses  50  may extend parallel to the x-axis of  FIG. 8  so that recesses  50  receive strands  80  that extend along the x-axis. Recesses  50  that extend parallel to the x-axis may be used in place of recesses  50  of  FIG. 8  or may be used in conjunction with recesses  50  of  FIG. 8 . Interposer  36  may have two recesses  50  for receiving two strands  80 , may have four recesses  50  for receiving four strands  80  (e.g., two warp strands and two weft strands), may have only one recess  50  for receiving one strand, may have six recesses  50  for receiving six strands, may have more than six recesses  50 , less than six recesses  50 , etc.). Arrangements where interposer  36  includes additional layers  42  may allow for additional recesses  50  in interposer  36 . For example, interposer  36  may have two additional layers  42  between layer  42 - 3  and component  28 - 2 . One of the additional layers may be recessed relative to the two adjacent layers, thereby forming additional recesses  50  for receiving strands  80 . 
     Strands  80  may be electrically and mechanically coupled to conductive pads in recesses  50  of interposer  36 .  FIGS. 9, 10, and 11  show illustrative examples of conductive pads that may be formed in recesses  50 . 
     In the example of  FIG. 9 , conductive pads  40  fully line the surfaces that form recesses  50 . A portion of lower surface  44  of layer  42 - 1 , a portion of upper surface  46  of layer  42 - 3  and edge surface  48  of layer  42 - 2  are covered with a conductive material to form pad  40 . Conductive material (e.g., conductive material  82  of  FIG. 7 ) may be used to electrically couple conductive portions of strands  80  to pads  40  of interposer  36 . 
     In the example of  FIG. 10 , conductive pads  40  partially line the surfaces that form recesses  50 . A portion of lower surface  44  of layer  42 - 1  and a portion of upper surface  46  of layer  42 - 3  are covered with a conductive material to form bond pads  40  in recesses  50 . 
     In the example of  FIG. 11 , only the peripheral edge surface of middle layer  42 - 2  is covered with conductive material to form bond pads  40  in recesses  50 . 
     Pads  40  may be formed by plating techniques or other suitable metal deposition techniques. In configurations where solder is used to electrically couple strands  80  to pads  40 , inductive soldering techniques or other soldering techniques (e.g., techniques involving application of heat to solder using a hot bar or reflow oven), may be used to melt solder and thereby cause molten solder to penetrate into recess  50 . Conductive strands  80  that are soldered to pads  40  in recesses  50  may be resistant to becoming dislodged due to the enhanced engagement between strands  80  and interposer  36 . 
     Signals may be conveyed between electrical devices  28  and conductive strands  80  using metal traces  38 . For example, layer  42 - 1  may include metal traces  38 - 1 , layer  42 - 2  may include metal traces  38 - 2 , and layer  42 - 3  may include metal traces  38 - 3  for conveying signals between the pads on interposer  36  coupled to device  28  (e.g., pads  34  of  FIG. 5 ) and the pads on interposer  36  coupled to strand  80  (e.g., pads  40  of  FIGS. 9, 10, and 11 ). 
       FIGS. 12 and 13  show an illustrative method for forming recesses of the type shown in  FIG. 8 . As shown in  FIG. 12 , interposers  36  may be formed from a panel such as panel  86  that includes multiple interposers  36 . At least some of layers  42  in panel  86  may be separated from one another using a solder bar such as solder bar  54 . In the example of  FIG. 12 , layers  42 - 1  and  42 - 3  are continuous across the multiple interposers  36  in panel  86 . Layer  42 - 2 , on the other hand, is broken up into portions that are separated from one another by solder bar  54 . Solder bar  54  may, for example, be a flux-core solder bar or other suitable solder material. Solder bar  54  may be electrically connected to conductive pads on each interposer  36  (e.g., conductive pads  40  of the type shown in  FIGS. 9, 10, and 11 ). 
     A laser, saw, or other cutting tool may be used to singulate interposers  36 . For example, a laser cutting tool such as laser  88  may be used to emit laser light in direction  90  to cut through panel  86  and thereby separate panel  86  into individual interposers  36 , as shown in  FIG. 13 . The laser light emitted by laser  88  during the singulation process may heat and melt solder bar  54  so that cavities  50  are formed between upper layer  42 - 1  and lower layer  42 - 3  of each interposer  36 . Strands  80  may be threaded through recesses  50  and solder  54  may be melted to lock strands in place in recesses  50  of interposers  36 . If desired, additional conductive material or other structures may be formed on the outside of the conductive strand so that the conductive strand is fully enclosed within recess  50 . If desired, other methods of forming recesses  50  may be used. The method of  FIGS. 12 and 13  is merely illustrative. 
       FIG. 14  illustrates another way of engaging interposer  36  with strands  80  of fabric  12 . Interposer  36  of  FIG. 14  may be a single layer interposer of the type shown in  FIG. 7 , may be a multi-layer interposer of the type shown in  FIG. 8 , or may have other suitable construction. As shown in  FIG. 14 , interposer  36  has notches such as notches  56  on opposing sides of interposer  36 . Notches  56  extend from upper surface  92  of interposer  36  to lower surface  94  of interposer  36  (e.g., parallel to the z-axis of  FIG. 14 ). 
     Notches  56  (sometimes referred to as recesses, openings, cavities, slots, holes, or castellations) may each be configured to receive an associated one of strands  80  of fabric  12 . As shown in  FIG. 14 , each strand  80  may have a first portion such as portion  96  that passes over top surface  92  of interposer  36 , a second portion such as portion  98  that passes over lower surface  94  of interposer  36 , and a third portion such as portion  100  that passes through notch  56  (e.g., from upper surface  92  to lower surface  94  or vice versa). In other words, strands  80  may be “threaded” through notches  56  to enhance the mechanical engagement between strands  80  and interposer  36 . 
     Notches  56  may be lined or partially lined with conductive material  40  that forms bond pads in notches  56 . Solder or other conductive material may be used to electrically and mechanically couple strands  80  to conductive pads  40  in notches  56  of interposer  36 . Pads  40  may be formed by plating techniques or other suitable metal deposition techniques. In configurations where solder is used to electrically couple strands  80  to pads  40 , inductive soldering techniques or other soldering techniques (e.g., techniques involving application of heat to solder using a hot bar or reflow oven), may be used to melt solder and thereby cause molten solder to penetrate into notch  56 . Conductive strands  80  that are soldered to pads  40  in notches  56  may be resistant to becoming dislodged due to the enhanced engagement between strands  80  and interposer  36 . 
     The example of  FIG. 14  in which notches  56  are formed on first and second opposing sides of interposer  36  is merely illustrative. If desired, notches  56  may be formed on one side, two sides, three sides, or all four sides of interposer  36 . In configurations where interposer  36  has multiple layers (e.g., layers  42  of  FIG. 8 ), each notch  56  may extend through all of the layers or may extend through less than all of the layers. 
       FIG. 15  shows an example in which notches  56  have been formed on all four sides of interposer  36 . As in the example of  FIG. 14 , each strand  80  may have a first portion such as portion  96  that passes over top surface  92  of interposer  36 , a second portion such as portion  98  that passes over lower surface  94  of interposer  36 , and a third portion such as portion  100  that passes through notch  56  (e.g., from upper surface  92  to lower surface  94  or vice versa). In other words, strands  80  may be “threaded” through notches  56  to enhance the mechanical engagement between strands  80  and interposer  36 . The arrangement of  FIG. 15  allows both warp strands and weft strands to be threaded through interposer  36 . For example, strands  80  extending parallel to the x-axis of  FIG. 15  may be weft strands and strands  80  extending parallel to the y-axis of  FIG. 15  may be warp strands, or vice versa. 
       FIG. 16  shows an example in which multiple notches  56  have been formed on each of the four sides of interposer  36 . In this example, each strand  80  extending parallel to the x-axis of  FIG. 16  has two portions  102  that pass over lower surface  94  of interposer  36 , two portions  106  that pass through notches  56 , and middle portion  104  that passes over upper surface  92  of interposer  36  (between notches  56 ). Each strand  80  extending parallel to the y-axis of  FIG. 16  has two portions  108  that pass over upper surface  92  of interposer  36 , two portions  112  that pass through notches  56 , and middle portion  110  that passes over lower surface  94  of interposer  36  (between notches  56 ). 
       FIG. 17  shows an example in which one or more of strands  80  have been cut to form first and second distinct signal paths from the same strand. Interposer  36  may have the same configuration as interposer  36  of  FIG. 16  or may have any other suitable configuration. Components on interposer  36  such as components  28  may have multiple terminals (e.g., two or more terminals, three or more terminals, four or more terminals, or other suitable number of terminals). It may be desirable to couple these terminals to a single strand while still using separate signal paths for each terminal. As shown in  FIG. 17 , portion  104  of strand  80  may be cut to form a gap  60  that separates strand  80  into first strand segment  80 A and second strand segment  80 B. Strand segment  80 A has a first end such as end  64 A coupled to conductive pad  40 A in notch  56 A and strand segment  80 B has a second end such as end  64 B coupled to conductive pad  40 B in notch  56 B. A component mounted to interposer  36  may have a first terminal coupled to pad  40 A and a second terminal coupled to pad  40 B. The first terminal of the component may be electrically coupled to strand segment  80 A, whereas the second terminal of the component may be electrically coupled to strand segment  80 B. 
     The example of  FIG. 17  in which both of the strands  80  extending parallel to the x-axis of  FIG. 17  are cut to form two separate signal paths is merely illustrative. If desired, only one of these two strands may be cut and the other may form a continuous path. If desired, one or more of strands  80  that extend parallel to the y-axis of  FIG. 17  may be cut to form two strand segments and separate signal paths. 
       FIG. 18  shows an example in which notches  56  are formed on opposing sides of each corner of interposer  36 . Strands  80  that extend parallel to the x-axis of  FIG. 18  may have a portion such as portion  114  that extends over lower surface  94  of interposer  36 . On either side of portion  114 , strand  80  has portions  116  that extend through notches  56  on opposing sides of interposer  36 . Strands  80  that extend parallel to the y-axis of  FIG. 18  may have a portion such as portion  118  that extends over upper surface  92  of interposer  36 . On either side of portion  118 , strand  80  has portions  120  that extend through notches  56  on opposing sides of interposer  36 . If desired, one or more of strands  80  may be cut (e.g., as in the example of  FIG. 17 ) to form separate signal paths from a single strand  80 . 
     If desired, strands  80  may be mechanically coupled to interposer  36  in additional locations (e.g., locations other than notches  56 ). For example, adhesive, solder, or other suitable attachment members may be used to attach strands  80  to upper surface  92  and/or lower surface  94  of interposer  36  (e.g., as in the example of  FIG. 7 ). Using notch connections in conjunction with upper/lower surface connections may help securely attach interposer  36  to fabric  12 . In this type of arrangement, some of the connections may be purely mechanical and need not be electrical. For example, upper/lower surface connections of the type shown in  FIG. 7  may be purely mechanical connections and notch connections of the type shown in  FIGS. 14-18  may be electrical and mechanical connections, or vice versa. 
     If desired, recesses of the type shown in  FIG. 8  and notches of the type shown in FIGS.  14 - 18  may be modified to fully surround conductive strand  70 . For example, rather than a recess or notch that exposes strand  80  on one side, recesses  50  and notches  56  may be holes in interposer  36  that are completely surrounded by portions of interposer  36 . In other words, rather than removing an outermost edge portion of interposer  36  to form notch  56 , a fully enclosed hole may be formed in interposer  36  slightly offset from the edge of interposer  36 . Holes of this type in interposer  36  may ensure that component  26  remains on fabric  12  even if a solder connection between interposer  36  and strand  80  fails. 
     In the examples of  FIGS. 7, 8, 14, 15, 16, 17, and 18 , interposer  36  is mounted to fabric  12  such that some strands  80  of fabric  12  extend parallel to the sides of interposer  36  and some strands  80  of fabric  12  extend perpendicular to the sides of interposer  36 . This is merely illustrative. If desired, interposer  36  may be mounted to fabric  12  such that the sides of interposer  36  are angled relative to strands  80  of fabric  12  (e.g., oriented at an angle between 0° and 90°). This type of arrangement is illustrated in  FIGS. 19 and 20 . 
     As shown in  FIG. 19 , interposer  36  may be mounted to strands  80  such that the sides of interposer  36  are angled relative to strands  80 . The angle θ between side  124  and strand  80  may, for example, be between 0° and 90°, 0° and 45°, 45° and 90°, 30° and 60°, about 45°, or other suitable angle. 
     Notches  56  may be located on opposing sides of one or more corners of interposer  36  such that each strand  80  extends through a notch  56  on one side of interposer  36  (e.g., side  122 ) and through a notch  56  on an adjacent side of interposer  36  (e.g., side  124 ). The example of  FIG. 19  in which strands  80  extend over the same side of interposer  36  is merely illustrative. If desired, one strand  80  may extend over the top of interposer  36  and another strand  80  may extend under the bottom of interposer  36 . Notches  56  may be formed on either side of one corner, on either side of two corners, on either side of three corners, or on either side of all four corners of interposer  36 . 
     In some arrangements, component  26  may be embedded in fabric  12  by inserting component  26  into a pocket formed in fabric  12 . For example, during the process of weaving or otherwise forming fabric  12 , a pocket may be formed in fabric  12  that helps fabric  12  receive electrical components  26  and that helps align the conductive pads of component  26  with the conductive structures in fabric  12 . Pockets in fabric  12  may be formed by omitting layers of fabric from internal portions of fabric layer  12 , thereby forming a pocket having a shape and size appropriate to receive component  26 . 
     It may be desirable to alter the shape of interposer  36  to fit the shape and size of the pocket in fabric  12 . As shown in  FIG. 20 , for example, fabric  12  may have a pocket such as rectangular pocket  68 . Pocket  68  may be formed during weaving operations (or other fabric assembly operations) and component  26  may be mounted in pocket  92  during weaving operations (or other fabric assembly operations). Pocket  68  may be formed by changing the architecture of the fabric using two or more layers of fabric. 
     In the example of  FIG. 20 , pocket  68  forms a rectangular recess in fabric  20  for receiving component  26 . In order to fit the shape of pocket  68 , the corners of interposer  36  may be trimmed (e.g., squared off) such that the edges of interposer  36  do not extend beyond the walls of pocket  68  in fabric  12 . The example of  FIG. 20  where all four corners have been trimmed and to fit within pocket  68  is merely illustrative. If desired, fewer than all four corners of interposer  36  may be trimmed to provide interposer  36  with a desired shape based on the corresponding shape of pocket  68  in fabric  12 . Arrangements where one or more sides of interposers  36  is trimmed to fit within pocket  68  may also be used. 
       FIG. 21  shows an example in which notches  56  have been formed in a lower surface of interposer  36 . Each strand  80  may pass through an associated one of notches  56 . In other words, strands  80  may be “threaded” through notches  56  to enhance the mechanical engagement between strands  80  and interposer  36 . If desired, a portion of interposer  36  such as portion  130  may extend behind strand  80  such that strand  80  is partially enclosed by interposer  36  within notch  56  (e.g., such that interposer  36  completely or partially surrounds the diameter of strand  80 ). Notches  56  may be lined or partially lined with conductive material  40  that forms bond pads in notches  56 . Solder or other conductive material may be used to electrically and/or mechanically couple strands  80  to conductive pads  40  in notches  56  of interposer  36 . 
       FIGS. 22-43  illustrate examples in which strands  80  are threaded through portions of protective structure  130  (e.g., in components of the type shown in  FIG. 6 ). In the example of  FIG. 22 , protective structure  130  is formed on opposing sides of interposer  36 . Protective structure  130  may include trenches such as trenches  134  (sometimes referred to as recesses, openings, notches, grooves, etc.). Trenches  134  may be formed by removing portions of protective structure  130  (e.g., using a laser, a mechanical saw, a mechanical mill, or other equipment) or may be formed by molding (e.g., injection molding) or otherwise forming protective structure  130  into a shape that includes trenches  134 . Trenches may have a width between 2 mm and 6 mm, between 1 mm and 5 mm, between 3 mm and 8 mm, greater than 3 mm, less than 3 mm, or other suitable width. If desired, trenches  134  may have different depths (e.g., to expose contact pads  40  that are located at different z-heights of interposer  36 ). 
     Trenches  134  may expose conductive pads  40  on interposer  36 . Strands  80  may each be threaded through an associated one of trenches  134  in protective structure  130 . Solder or other conductive material  142  may be used to electrically and mechanically couple strands  80  to conductive pads  40  in notches  134  of protective cover  130 . Because strands  80  are wedged between portions of protective cover  130 , strands  80  may be resistant to becoming dislodged from interposer  36 . In addition to holding strands  80  in place so that component  26  remains attached to fabric  12 , trenches  134  may also be used as a physical guide for aligning component  26  relative to fabric  12  during the attachment process. This may be beneficial when aligning and attaching component  26  to fabric  12  without line of sight. 
       FIG. 23  is a bottom view of component  26  (e.g., component  26  of  FIG. 22 ) showing how adhesive may, if desired, be used to enhance the mechanical robustness of the connection between component  26  and strands  80 . As shown in  FIG. 23 , adhesive  136  (e.g., a hot-melt adhesive, epoxy, a thermoplastic material such as ethylene-vinyl acetate, acrylic, polyethylene, other thermoplastic material, or other suitable adhesive) may attach portions of strands  80  in trenches  134  to interposer  36 . If desired, adhesive  136  may be used to attach non-conductive portions of strands  80  to interposer  36 , whereas conductive portions of strands  80  may be attached to pads  40  using solder  142  ( FIG. 22 ). This is, however, merely illustrative. If desired both solder and adhesive may be used to attach a given portion of strands  80  to interposer  36 . Solder may provide electrical coupling while a hot-melt adhesive or other material (e.g., an encapsulant) may form a seal around the electrical connection to protect the connection from mechanical damage as well as moisture and other environmental contaminants. If desired, a solder mask may be used in regions of trenches  134  without pads  40  to help prevent solder  142  from reaching those areas. 
       FIG. 24  shows an example in which devices  28 , protective cover  130 , and strands  80  are all formed on one side of interposer  36 . If desired, protective cover  130  may selectively expose one or more electrical devices  28  on interposer  36 . In the example of  FIG. 24 , top surface  138  of device  28  is exposed through an opening in protective cover  130 . This may allow an external electrical path (e.g., a flex circuit, a conductive strand, etc.) to couple to device  28  and/or may allow device  28  to send or receive information without requiring that information to pass through protective cover  130 . For example, if device  28  is a sensor that should be left exposed (e.g., to detect light, sound, moisture, temperature, etc.), then protective cover  130  may be shaped so that device  28  is exposed. 
       FIG. 25  shows an example in which strands  80  are threaded through trenches  134  that are formed along either side of interposer  36 . The upper and lower protective covers  130  protrude beyond the outer edges of interposer  36 , thereby forming trenches  134 . Protective cover  130  on one side of interposer  36  forms a first sidewall of each trench  134 , and protective cover  130  on an opposing side of interposer  36  forms a second sidewall of each trench. Solder or other conductive material  142  may be used to electrically and mechanically couple strands  80  to pads  40  in trenches  134 . 
     It may be desirable to further increase the mechanical robustness of the connection between strands  80  and component  26  by embedding strands  80  within a material in trenches  134 . For example, strands  80  may be embedded within solder, polymer, epoxy, other material, or a combination of materials that help to enclose strands  80  within trenches  134 . 
       FIGS. 26-28  show an illustrative process for enclosing strands  80  within trenches  134  using thermoplastic material and solder. 
     In the step shown in  FIG. 26 , solder  142  (e.g., solder paste, pre-apply solder, or preform solder) is formed in trenches  134  over pads  40 . Strands  80  are then inserted into trenches  134  over solder  142 . 
     In the step shown in  FIG. 27 , a thermoplastic structure such as thermoplastic structure  146  having protruding portions that match the shape of trenches  134  is press-fit onto protective cover  130  so that the protruding portions of thermoplastic structure  146  extend into trenches  134  of protective cover  130 . This causes thermoplastic structure  146  to press strands  80  against solder  142  and pads  40  in trenches  134 , thereby ensuring electrical contact between pads  40  and strands  80 . Thermoplastic structure  146  may be formed from a thermoplastic material such as ethylene-vinyl acetate, acrylic, polyethylene, or other suitable thermoplastic material. 
     In the step shown in  FIG. 28 , heat may be applied to melt thermoplastic structure  146  and reflow solder  142 , thereby forming a solder joint between strand  80  and pad  40  while also sealing the solder joint with thermoplastic material  146 . Heat may be applying using induction heating, hot air, resistive heating, or other heating techniques. In some scenarios, heating of solder  142  may cause strands  80  to penetrate down into the molten solder  142  such that solder  142  fully surrounds the diameter of strand  80 . Once cool, thermoplastic  146  and solder  142  may harden, leaving strands  80  securely embedded within solder  142  and thermoplastic  146 . Thermoplastic  146  may protect the solder joint from mechanical damage and environmental contaminants. 
       FIGS. 29-33  show another illustrative process for enclosing strands  80  in trenches  134  using solder and thermoplastic material. 
     In the step shown in  FIG. 29 , trenches  134  may be formed in protective cover  130  to expose contact pads  40  on interposer  36 . Solder  142  (e.g., solder paste, pre-apply solder, or preform solder) may be placed in trenches  134  over pads  40 . 
     In the step shown in  FIG. 30 , thermoplastic material  148  may be deposited in trenches  134  over solder  142 . Materials that may be used to form thermoplastic material  148  include ethylene-vinyl acetate, acrylic, polyethylene, or other suitable thermoplastic material. 
     In the step shown in  FIG. 31 , trenches  150  may be formed in thermoplastic material  148 . Trenches  150  may be formed using laser equipment, machining equipment, or other suitable equipment. This is, however, merely illustrative. If desired, thermoplastic material  148  may be deposited in trenches  134  around a structure that is then removed, thereby leaving openings  150  in thermoplastic material  148 . Trenches may also be formed in solder  142 , if desired. The example of  FIG. 31  is merely illustrative. 
     In the step shown in  FIG. 32 , strands  80  may be placed within trenches  150  (which in turn are located in trenches  134 ). 
     In the step shown in  FIG. 33 , heat may be applied to melt thermoplastic material  148  and reflow solder  142 . Heat may be applying using induction heating, hot air, resistive heating, or other heating techniques. When solder  142  becomes molten, strands  80  may sink down into solder  142 , as shown in  FIG. 33 . When thermoplastic  148  melts, it spreads across trench  134  (thereby closing opening  150  that was made in thermoplastic  148  in the step of  FIG. 31 ). After thermoplastic  148  and solder  142  have cooled, strands  80  will be firmly embedded in solder  142 , and hardened thermoplastic material  148  may form a seal over the electrical connection between strand  80  and pad  40 . 
     The order of steps described in connection with  FIGS. 29-33  are merely illustrative. For example, solder  142  may be reflowed to form a solder joint between strands  80  and pads  40  before thermoplastic material  148  is deposited in trenches  134  and melted to seal the solder joint. If desired, customized heating techniques may be used depending on which material is being targeted (e.g., a first heating method may be used to reflow solder and a second heating method may be used to subsequently melt thermoplastic material  148 ). 
       FIG. 34  shows how a transducer may be used during the attachment process (e.g., an attachment process of the type shown in  FIGS. 26-28  or of the type shown in  FIGS. 29-33 ) to help guide strands into trenches on component  26 . As shown in  FIG. 34 , component  26  may be placed between portions of fabric  12 . Without line-of-sight capability during the attachment process, it may be challenging to guide strands  80  of fabric  12  into trenches  134  and attach strands  80  to pads  40  on interposer  36 . To help guide strands  80  into trenches  134 , a transducer such as transducer  154  may be used to help press fabric  12  against component  26  during the attachment process. The force applied on fabric  12  from transducer  154  causes strands  80  to fall into trenches  134 . 
     If desired, transducer  154  may be used during the heating process (e.g., when solder  142  is being reflowed and/or when thermoplastic  148  is being melted in trenches  134 ). In the example of  FIG. 34 , induction coil  152  is used to inductively heat conductive structures in component  26 . For example, induction coil  152  may be used to inductively heat solder  142 , conductive portions of strand  80 , and/or other metal elements in component  26 . The heating of conductive elements in component  26  may in turn cause thermoplastic  148  to melt and spread across trenches  134  (e.g., as described in connection with  FIGS. 28 and 33 ). When transducer  152  is used during the heating process, strands  80  may be guided into trenches  134  and may sink down into molten solder  142 . After solder  142  and thermoplastic  148  have cooled and hardened, strands  80  may be mechanically and electrically coupled to pads  40  via solder  142 , with thermoplastic  148  providing a seal that protects the connection from mechanical damage and environmental contaminants. 
       FIG. 35  shows an example in which a layer of thermoplastic  148  is used to press down on strands  80  to help guide strands  80  into trenches  134  during the attachment process. With this type of arrangement, solder  142  may be placed on pads  40  in trenches  134 , and strands  80  of fabric  12  may be sandwiched between component  26  and thermoplastic structure  148 . Thermoplastic structure  148  may be brought into contact with protective cover  130 , forcing strands  80  into trenches  134 . Heat may then be applied to reflow solder  142  and melt thermoplastic  148  in trenches  134 , thereby creating a robust mechanical and electrical connection between strand  80  and pad  40  (e.g., a connection of the type shown in  FIGS. 28 and 33 ). 
     If desired, thermoplastic structure  148  and/or protective cover  130  may have a shape that helps contain solder  142  and strands  80  in trenches  134  during the attachment process. For example, thermoplastic structure  148  and/or protective cover  130  may form sloped sidewalls in trenches  134  or may have localized peaks surrounding trenches  134  to create deep recesses that are more difficult for solder  142  or strands  80  to escape during the attachment process. 
     As shown in  FIG. 36 , for example, thermoplastic  148  may have localized peaks  156  (e.g., raised portions) surrounding trench  134  to essentially increase the depth of trench  134  (e.g., so that the depth of trench  134  is greater than the thickness of protective cover  130 ). The increased depth of trenches  134  may help maintain solder  142  and strands  80  in trench  134  during the attachment process. When heat is applied to reflow solder  142  and melt plastic  148 , peaks  156  may melt into trenches  134 , resulting in a sealed electrical and mechanical connection between strands  80  and component  26  (e.g., a connection of the type shown in  FIGS. 28 and 33 ). 
       FIGS. 37-43  show illustrative examples of trench geometries and pad sizes that may be used in component  26  to help attach component  26  to strands  80  of fabric  12 . It should be understood that component  26  may have any suitable combination of features shown in  FIGS. 37-43  (e.g., the trench shape of  FIG. 39  may be used with the pad size of  FIG. 38 , etc.). The combinations of features shown are merely illustrative examples. 
     In the example of  FIG. 37 , protective cover  130  forms straight sidewalls of trench  134  (e.g., sidewalls that extend perpendicular to the upper surface of interposer  36 ), and the width of pad  40  is smaller than the width of trench  134 . 
     In the example of  FIG. 38 , protective cover  130  forms sloped sidewalls of trench  134 , where the width of trench  134  may be smaller at the bottom of trench  134  than at the top of trench  134 . The width of pad  40  may be greater than the width of the bottom of trench  134 . 
     In the example of  FIG. 39 , protective cover  130  forms sloped sidewalls of trench  134 , where the width of trench  134  may be greater at the bottom of trench  134  than at the top of trench  134 . The width of pad  40  may equal to the width of the bottom of trench  134 . The reduced width of trench  134  at the top of trench  134  may help contain solder  142  and strand  80  in trench  134 . 
     In the example of  FIG. 40 , solder  142  has a shape that helps “grab” strands  80  to keep strands  80  in trenches  134  during the attachment process. Solder  142  may, for example, have the shape of barbs, hooks, spurs, spikes, or other suitable shape. When heat is applied to reflow solder  142 , solder  142  may consolidate into a bead-like shape that surrounds strands  80 . 
       FIGS. 41-43  show bottom views of protective cover  130  having various trench shapes and pad arrangements. 
     In the example of  FIG. 41 , trenches  134  have a straight shape and uniform width across protective cover  130 . Each pad  40  may have an elongated shape in trenches  134 , creating a large area with which to attach strands  80  to pads  40 . 
     In the example of  FIG. 42 , trenches  134  have locally widened portions to accommodate larger pads  40 . The use of locally widened portions may help contain solder  142  on pad  40 . For example, the reduced width of trench  134  outside of the regions where pads  40  are located may help prevent solder from straying from pad  40 . If desired, a solder mask may be used in regions of trenches  134  without pads  40  to help prevent solder  142  from reaching those areas.  FIG. 42  also shows how pads  40  and locally widened portions of trenches  134  may be staggered relative to one another. By staggering pads  40 , the width of trenches  134  may be increased to accommodate larger pads  40 . This type of arrangement may also allow for a greater density of pads  40  on component  26  and a smaller strand-to-strand pitch. 
       FIG. 43  shows an example in which the width of trench  134  is wider at the outer edges of protective cover  130  than at the center of protective cover  130 . The locally widened portions of trench  134  at the edges of protective cover  130  may allow strand  80  to bend or change direction gradually as it exits trench  134  and prevent sharp corners of protective cover  130  from damaging strand  80 . 
     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: 20170222
Publication Date: 20191119
Grant Date: 20191119
Priority Date: 20160222
Inventors: SUNSHINE, Daniel D.
KINDLON, DAVID M.
NUSSBAUM, MICHAEL B.
ROSENBERG, ANDREW L.
STERIAN, ANDREW
SAUNDERS, BRETON M.
SCHULTZ, CHRISTOPHER A.
BOLT, DAVID A.
BEESLEY, MARK J.
MASH, PETER W.
KEATING, STEVEN
LIU, CHANG
HOANG, LAN
Assignee: APPLE INC
CPC Classifications: [{"code": "H01L2224/16225", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2203/107", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/2027", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/10287", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/09472", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/09181", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K3/34", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K1/117", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K1/189", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K1/038", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L23/5387", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L23/49805", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L23/13", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L23/5383", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L23/3121", "inventive": true, "first": true, "tree": "[]"}, {"code": "H05K1/189", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K2201/0129", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K1/0281", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L23/49838", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K2201/0969", "inventive": false, "first": false, "tree": "[]"}, {"code": "A41D1/002", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K2201/10984", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K1/038", "inventive": true, "first": true, "tree": "[]"}, {"code": "H05K2201/10378", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L23/49822", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L23/49833", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L23/3121", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K1/111", "inventive": true, "first": false, "tree": "[]"}, {"code": "D03D1/0088", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L23/4985", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K2201/1053", "inventive": false, "first": false, "tree": "[]"}, {"code": "A41D1/002", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L23/4985", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K1/038", "inventive": true, "first": true, "tree": "[]"}, {"code": "D03D1/0088", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K2201/0969", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K1/111", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L23/49822", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L23/49838", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K1/0281", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K2201/10378", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K1/189", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K2201/0129", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01L23/49833", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01L23/3121", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K2201/10984", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/1053", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y02P70/50", "inventive": false, "first": false, "tree": "[]"}, {"code": "D10B2401/18", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 68536217