A device for making electrical connections to flexible circuits.

Abstract

An apparatus for making electrical connections to an electrical circuit on a stretchable flexible substrate includes a foldable and connected support area and a connection area. These areas further include connection pads that define areas for attaching conductive traces. By folding these areas, electrical contacts are formed between the connection pads and the circuit on the stretchable flexible substrate placed between the areas.

Description

Technical Field

[0001] The present disclosure generally relates to the fields of printed circuits, substrates, and stretchable electronic components.

Background Art

[0002] There are various types of printed circuits for electronic systems that can provide effective performance under normal and extreme operating conditions. However, it is difficult to use currently available electrical circuits to reliably make electrical connections to electronic elements provided on stretchable or flexible substrate materials.

Brief Description of the Drawings

[0003] [Figure 1] A perspective view of a first embodiment of an apparatus for making an electrical connection to a circuit disposed on a flexible stretchable substrate. [Figure 2] A perspective view of a second embodiment of an apparatus for making an electrical connection to a circuit disposed on a flexible stretchable substrate. [Figure 3] A perspective view showing an electrical connection to the embodiments of the apparatus of FIGS. 1 and 2. [Figure 4] A view of an embodiment of a bendable member, showing a continuous bend for forming a ferrule. [Figure 5] A perspective view of the apparatus of FIG. 1 in an initial deployed state. [Figure 6A] A perspective view of the apparatus of FIG. 1 showing an intermediate state with an external conductive element attached. [Figure 6B] A perspective view seen from the reverse of the intermediate state with an external conductive element attached. [Figure 7] A perspective view of the apparatus of FIG. 1 in a final stage closed state. [Figure 8] A top view of the apparatus of FIG. 1 in a fully assembled state. [Figure 9A] A perspective view of another embodiment of an apparatus for making an electrical connection to a circuit disposed on a flexible stretchable circuit. [Figure 9B] Figure 9A is an exploded view of the apparatus. [Figure 10] Figure 9A is an exploded view showing the compatibility between the circuit elements of the device and its embodiment. [Figure 11] This graph shows the measured electrical resistance of a stretchable circuit as it undergoes multiple stretching cycles. [Figure 12] This graph shows the measured electrical resistance of a stretchable circuit as it undergoes multiple stretching cycles. [Figure 13] This graph shows the measured electrical resistance of a stretchable circuit as it undergoes multiple stretching cycles. [Figure 14] This graph shows the measured electrical resistance of the stretchable circuit as the number of cleaning cycles increases. [Figure 15] This graph shows the output power of the expandable circuit according to the number of cleaning cycles. [Figure 16] These are infrared images of the stretchable circuit before cleaning and after the 15th cleaning. [Modes for carrying out the invention]

[0004] Before referring to the figures, please understand that this disclosure is not limited to the details revealed in the description or shown in the figures. Furthermore, please understand that the technical terms used herein are for illustrative purposes only and should not be considered limiting.

[0005] In this specification, references to the position of elements (e.g., “top,” “bottom”) are used solely to describe the orientation of various elements in the drawings. It should be noted that the orientation of various elements may differ in other exemplary embodiments, and such variations are intended to be covered by this disclosure.

[0006] Referring here to Figure 1, an embodiment of the apparatus 100 for making electrical connections to circuits arranged on a flexible stretchable substrate is shown, including a support region 102 and a connection region 106. The connection region includes a connection pad 110, an adhesive window 112, a slot 108, a first opening 114, a second opening 118, a channel 116, and a gas-permeable material 120. The support region 102 includes the adhesive window 112 and an extension edge 104.

[0007] Referring further to Figure 1, more specifically, the support region 102 and the connecting region 106 may be circular in shape. The support region 102 may have a larger diameter than the connecting region 106, thereby allowing the extended edge 104 of the support region 102 to extend beyond the outer circumference of the connecting region 106. In some embodiments, the support region 102 has a thickness of 0.002 inches. In some embodiments, the support region 102 may have a thickness of 0.001 inches, 0.004 inches, or 0.005 inches. In some embodiments, the support region 102 and the connecting region 106 may be made from materials such as thermoplastic polyurethane (TPU), thermoplastic polyamide, thermoplastic copolyester, or polyethylene terephthalate (PET). In certain embodiments, the support region 102 made of PET provides enhanced thermal stability and a coating to maximize the peelability of circuits printed on a flexible stretchable substrate. In certain embodiments, the connecting region 106 made of TPU may provide good elasticity to the flexible stretchable substrate. Although shown as circular in Figure 1, the support area 102 and the connection area 106 can be of different shapes, such as circles, rectangles, triangles, rectangles with rounded corners, triangles with rounded corners, or irregular shapes. Furthermore, in other embodiments, the support area 102 and the connection area 106 may have different shapes from each other. In these embodiments, the support area 102 has a larger total surface area than the connection area 106 so as to define the extension edge 104. In some embodiments, the support area 102 and the connection area 106 may be made to be of a size and shape such that the extension edge 104 is defined only on a specific edge of the support area 102. In some embodiments, for aesthetic purposes, a woven material or cloth may be used to cover part or all of the support area 102, the connection area 110, and / or the outer part of the flexible stretchable substrate.

[0008] Furthermore, as shown in Figure 1, the extension edge 104 of the support region 102 may be lined with adhesive. The adhesive on the extension edge 104 may be shaped to conform to the edge profile of the support region 102 and the edge profile of the connecting region 106. In some embodiments, the adhesive may partially cover the extension edge 104. In some embodiments, the adhesive may be discontinuously arranged on the extension edge 104. In some embodiments, the adhesive may be arranged on the extension edge 104 in a patterned manner, such as multiple equally spaced circular adhesive materials, equally spaced rectangular adhesive materials, or irregularly spaced adhesive materials. In yet other embodiments, the adhesive may be applied over the entire support region 102. In some embodiments, the adhesive on the extension edge 104 may be a layer with a thickness of 0.002 inches. In other specific embodiments, the adhesive on the extension edge 104 may be a layer with a thickness of 0.001 inches, 0.004 inches, or 0.005 inches.

[0009] The connection area 106 can define multiple adhesive windows 112 of various covering areas. As shown in Figure 1, the adhesive windows 112 on the connection area 106 can be positioned radially around the connection pad 110. Furthermore, circular adhesive windows 112 can be defined between the connection pads 110. In some embodiments, the adhesive windows 112 can have different shapes, such as circles, rectangles, rectangles with rounded corners, triangles, triangles with rounded corners, or irregular shapes. In some embodiments, there may be a single adhesive window 112 surrounding the outer perimeter of the connection pad 110. In some embodiments, there may be an adhesive window covering a portion of the area between the connection pads 110.

[0010] In other embodiments, the support region 102 may also define multiple adhesive windows 112 in various covering areas. The adhesive windows 112 defined by the support region 102 may be substantially aligned with those defined by the connecting region 106. In some embodiments, the adhesive windows may have different shapes, such as circles, rectangles, rectangles with rounded corners, triangles, triangles with rounded corners, or irregular shapes.

[0011] In some embodiments, the adhesive may be a phase-change adhesive, such as a hot-melt adhesive, that can adhere to the support region 102, the connection region 106, and the stretchable flexible substrate (not shown). In some embodiments, the adhesive may be an adhesive that flows onto the support region 102 and the connection region 106 when heated. The adhesive then cools and solidifies, forming a bonded stack of elements including the support region 102, the connection region 106, and the stretchable flexible substrate placed between them. Subsequently, this bonding enables bonding or close contact between the support region 102, the connection region 106, the connection pad 110, the stretchable flexible substrate, and the terminals of the stretchable flexible substrate (not shown). As a result of this bonding or close contact, the connection pad 110 and the terminals of electronic elements on the stretchable flexible substrate can move relative to each other with minimal restriction. This close contact can maintain electrical communication between the connection pad 110, conductive traces such as wires, and electronic elements on the stretchable flexible substrate. Furthermore, in some embodiments, the adhesive may withstand multiple cleaning cycles and mechanical operations (e.g., stretching) of the stretchable flexible substrate. In some embodiments, the adhesive can bond well to a variety of materials such as polyester, polycotton, Lycra, polycarbonate, polyvinyl chloride, polyurethane, acrylonitrile butadiene styrene, wood, leather, fiberglass, aluminum, copper, and steel. In some embodiments, the adhesive placed on the bonding window 112 may have a thickness of 0.001 inches, 0.002 inches, 0.004 inches, or 0.005 inches.

[0012] In some embodiments, the connection pad 110 may be made of a conductive material such as copper, gold, silver, or platinum. In some embodiments, the connection pad 110 may be manufactured using one of several inks manufactured by Applied Cavitation, Inc. (Goleta, California). Two connection pads 110 are shown in Figure 1, but any number of connection pads 110 may be used to connect to the flexible stretchable substrate. In some embodiments, the connection pad 110 may have a thickness of 34 mils (34 / 1000 inches). In some embodiments, the connection pad 110 may have a thickness of 25 mils, 45 mils, or 50 mils. In some embodiments, the connection pad 110 may have a thickness approximately the same as the diameter of a human hair. In some embodiments, the connection pad 110 making electrical contact with the terminals of the stretchable flexible substrate (not shown) may have a surface area sufficient to conduct a current of 1 ampere or more. In some embodiments, the connecting pad 110, which is in electrical contact with the terminals of a stretchable flexible substrate (not shown), may have a surface area sufficient to conduct currents of 2.5 amperes, 4.0 amperes, or 5.0 amperes. In some embodiments, the connecting pad 110 may be irregularly molded. In some embodiments, the connecting pad 110 may be positioned on a support region 102 and a connecting region 106, so that the connecting pad 110 is on the opposite side of the stretchable flexible substrate positioned between those regions. In some embodiments, strain relief may be incorporated in the area where the terminals of the flexible stretchable substrate, the connecting pad 110, and / or adhesive material are bonded to the flexible stretchable substrate. In some embodiments, the connecting pad 110 may be separated by a dielectric material.

[0013] In some embodiments, the dielectric material can be formed from any material having a relatively large dielectric constant. In certain embodiments, the dielectric material can include materials such as parylene, fluoropolymers, atomic layer deposition, molecular vapor deposition, etc. In some embodiments, the dielectric material can be a polyimide material, such as a Kapton film, such as a film supplied by DuPont (Wilmington, USA). In some embodiments, the thickness of the dielectric layer can be 25 mils. In certain embodiments, the dielectric material can be 18 mils, 27 mils, or 30 mils.

[0014] Referring further to FIG. 1, the connection pad 110 can define a plurality of slots 108 for receiving ferrules. In some embodiments, the slots 108 can be a combination of different shapes, such as circles, rectangles, triangles, or irregular shapes. In some embodiments, the size of the slots 108 can match the cross-sectional end of the bendable member 402a that forms the ferrule 306. In some embodiments, the spacing between a pair of slots 108 can depend on the diameter of the wire 302 installed between the slots 108. In some embodiments, the slots 108 can be oriented perpendicular to each other. In yet other embodiments, the slots can be arranged at various angles to each other. In some embodiments, the slots can be positioned anywhere within the area covered by the connection pad 110.

[0015] Referring further to FIG. 1, the first opening 114 in fluid communication with the channel 116 can be a circular through-hole for equalizing the atmospheric pressure outside a flexible and stretchable substrate (not shown) and the pressure within the area of the electrical contact between the terminals of an electronic device (not shown) having the flexible and stretchable substrate and the connection pad 110. In some embodiments, the first opening can be rectangular. In some embodiments, the first opening can be circular, triangular, rectangular with rounded corners, or irregular in shape.

[0016] In some embodiments, channel 116 can be a depression formed on connection region 106. In some embodiments, the channel can be formed by the peripheral sides of parallel adhesive strips. In some embodiments, the channel can follow a zigzag path or a wavy path implemented to reduce access of water or moisture to an area where connection pad 110 makes electrical contact with a terminal (not shown) of the flexible stretchable substrate.

[0017] Referring further to FIG. 1, second opening 118 is in fluid communication with channel 116, as shown in FIG. 1. In some embodiments, second opening 118 can be a circle as shown in FIG. 1. In some embodiments, second opening 118 can be another shape such as a triangle, rectangle, rectangle with rounded corners, or irregular shape.

[0018] In some embodiments, second opening 118 can be covered by a permeable material 120 as shown in FIG. 1, thereby reducing access of water or moisture and allowing air and other gases to permeate through permeable material 120. Permeable material 120 can be attached to connection area 106 by an adhesive material. In some embodiments, the area between connection pads 110 can be at least partially covered by a permeable material. In other embodiments, the area between connection pads 110 can be completely covered by a permeable material. In some embodiments, the permeable material can be 50% Gore-Tex manufactured by WL Associates, Inc. (Newark, USA). In some embodiments, the permeable material can be a water-resistant treated polyethylene-based material, a water-resistant treated stretched polytetrafluoroethylene-based material, nylon, or polyester. FIG. 1 shows an embodiment where connection pads 110 are separated by first opening 114, second opening 118, and channel 116, and other positions of first opening 114, second opening 118, and channel 116 are also possible.

[0019] Referring here to Figure 2, another embodiment of the apparatus 100 for making electrical connections to circuits arranged on a flexible stretchable substrate is shown, and the other embodiment of the apparatus 100 is described, in addition to other defined features, including a protruding edge 202 on the support area 102, a connection area 106, a connection pad 110, an adhesive window 112, a slot 108, a first opening 114, a second opening 118, a channel 116, and a gas permeable material 120. The support area 102 includes the adhesive window 112 and the extension edge 104. The adhesive window 112 and the extension edge 104 provide defined areas for applying adhesive on the support area 102 and the connection area 106.

[0020] Referring further to Figure 2, in more detail, the protruding edge 202 can provide stability and additional support to the wire 302. Although shown as a rectangle in Figure 2, the protruding edge 202 can have different shapes, including a semicircle, a triangle, a triangle with rounded corners, or an irregular shape. In some embodiments, the protruding edge 202 may be made to be sized and shaped so as to extend only over a specific edge of the support area 102. In some embodiments, the protruding edge 202 may function as a grippable edge.

[0021] Referring here to Figure 3, a brief overview illustrates the electrical connection between the connecting pad 110 and a conductive trace such as a wire 302. As shown in Figure 3, the wire 302 is wrapped in cloth 304 and attached to the connecting area 106.

[0022] Referring further to Figure 3, in more detail, in an embodiment of the apparatus 100, the wire 302 can be securely attached using a ferrule 306 that passes through a slot 108 on the connection area 106. The ferrule 306 wraps around the wire 302, creating an electrical contact between the wire 302 and the connection pad 110. In some embodiments, a woven material or cloth can be used to cover the support area 102, the connection area 110, and / or the wire 302. In some embodiments, the end of the wire 302 may be tin-plated. In some embodiments, the wire 302 may be made of copper, aluminum, gold, silver, or any conductive metal. In some embodiments, the wire 302 may be covered with a wire insulator or protective coating such as a nylon jacket, a polyvinyl chloride jacket, heat shrink tubing, or wire sheathing. In some embodiments, the wire 302 may be a single-wire cable. In some embodiments, the wire 302 may be 18 gauge, 20 gauge, or 22 gauge.

[0023] In certain embodiments, the ferrule 306 may be made of copper, aluminum, or any other type of conductive material. In some embodiments, the ferrule 306 may be a wire ferrule having a circular or rectangular cross-sectional area. By changing the length of the ferrule 306, wires of different diameters can be attached to the connection area 306. In some embodiments, a thicker ferrule may be used to provide greater stability to the wire 302. In some embodiments, multiple ferrules of different lengths, thicknesses, and / or materials may be used in combination.

[0024] Referring here to Figure 4, a brief overview is given of one embodiment of the bendable member 402a, which forms a ferrule 306, along with its continuous bends 402b-c. In some embodiments, one end of the bendable member 402a is guided through a slot 108 and bent toward the center of the bendable member 402a to form an intermediate state 402b of the ferrule 306. Subsequently, the wire 302 is placed between the slots 108, and the other end of the bendable member 402b is guided through a slot 108 and bent toward the center of the bendable member 402b to form an intermediate state 402c of the ferrule 306. After positioning the wire 302, the bent end of 402c is further compressed to securely attach the wire 302 to the connection region 106. In other embodiments, the intermediate state 402c may be formed before the wire 302 is installed, so that the end of the intermediate state 402c partially penetrates the slot 108, allowing the wire 302 to be inserted directly beneath the partially inserted intermediate state 402c of the ferrule 306. In these embodiments, the wire 302 is securely attached to the connection area 106 after the final compression of the bent end of 402c. In yet another embodiment, the intermediate state 402c of the ferrule 306 may be formed by bending both ends of the bendable member 402a in parallel. In some embodiments, the bending of the bendable member 402a, the insertion of the wire 302, and the insertion of the end of the bendable member through the slot 108 may occur simultaneously. In some embodiments, the process of bending the bendable member 402a may be performed manually by hand or with a tool, or it may be automated by machine.

[0025] Referring here to Figure 5, an isometric view of the deployed configuration 500 of an embodiment of the apparatus 100 is shown, which includes features defined and described with respect to the embodiment of the apparatus 100, such as the support area 102, the connection area 106, the connection pad 110, the adhesive window 112, the extension edge 104, the slot 108, the first opening 114, the second opening 118, the channel 116, and the gas permeable material 120. As shown in Figure 5, the support area 102 and the connection area 106 are foldably connected. The foldable connection between the support area 102 and the connection area 106 can provide a rim for aligning the terminals of a flexible stretchable substrate (not shown) when the substrate is positioned between the support area 102 and the connection area 106.

[0026] Referring further to Figure 5, more specifically, the support region 102 may define multiple adhesive windows 112 of various covering areas, as shown by the dashed lines in Figure 5. The adhesive windows 112 defined by the support region 102 may be substantially aligned with those defined by the connecting region 106. As shown in Figure 5, the adhesive windows 112 on the support region 102 may be positioned radially from the center of the support region 102. Furthermore, a circular adhesive window 112 may be positioned at the center of the support region 102. In some embodiments, the adhesive windows 112 may have different shapes, such as circles, rectangles, rectangles with rounded corners, triangles, triangles with rounded corners, or irregular shapes. In some embodiments, there may be a single adhesive window 112 that partially or completely covers an area of ​​the support region 102.

[0027] Referring here to Figures 6A and 6B, various diagrams of the deployed configuration 600 and 650 of the device 100, including the wire 302 attached to the connection area 106 by the ferrule 306, are shown. View 600 shows the exterior of the connection area 106, including the ferrule 306 wrapped around the wire 302 and the ferrule 306 passing through the slot 108. For clarity, view 650 shows the interior of the device 100 and further shows the electrical contact made between the bent end of the ferrule 306 and the connection pad 110.

[0028] Referring here to Figure 7, a diagram of a closed configuration 700 of an embodiment of the apparatus 100 is shown, which includes a wire 302, a ferrule 306, and exemplary arrows (indicating locations where heat can be applied to the bottom and top of the closed configuration to bond with a stretchable flexible substrate (not shown) placed between the connection area 106 and the support area 102). By applying heat, the solid layer of adhesive material placed on the connection area 106 and the support area 102 can be melted. By melting the solid layer of adhesive material, the adhesive can flow from the connection area 106 and the support area 102 onto the substrate placed between the connection area 106 and the support area 102. Mechanical pressing of the connection area 106, the support area 102, and the substrate position between these areas can facilitate both the spreading of the adhesive and greater contact or bonding of the connection area 106, the connection pad 110, the attached ferrule 306, and the support area 10 to the flexible stretchable substrate. In practice, this allows for durable electrical communication with conductive traces such as wires 302 once the connecting pad 110 makes electrical contact with the terminals of the flexible stretchable substrate.

[0029] Referring here to Figure 8, a wire assembly configuration 800 of an embodiment of the device 100 for making electrical connections to circuits arranged on a flexible stretchable substrate is shown with a plurality of protruding edges 202, 802, where the protruding edges 202 are rectangular and the protruding edges 802 are semicircular.

[0030] Referring further to Figure 8, in more detail, the protruding edge 202 can provide stability and additional support for the wire 302. In some embodiments, the protruding edge 802 can function as a grippable edge. Although shown as a specific shape in Figure 8, the protruding edges 202, 802 can have different shapes, including semicircles, triangles, triangles with rounded corners, or irregular shapes. In some embodiments, the protruding edges 202, 802 can be made to be sized and shaped so as to extend only over a specific edge of the support area 102.

[0031] Referring here to Figure 9A, a brief overview shows another embodiment of the apparatus 900 for making electrical connections to circuits arranged on a flexible stretchable substrate. Referring to Figure 9A, another embodiment of the apparatus 900 includes a dielectric material 902, a plug housing 906, a plug body 908, an adhesive layer 910, a plug cap 912, a connection pad 110, and a connection pad terminal 914. While embodiments of the apparatus 900 are generally rectangular in shape, the apparatus may have other shapes, including circular, polygonal, or irregular shapes.

[0032] For clarity, Figure 9B shows an exploded assembly view of an embodiment of the device 900, which includes a dielectric 902, a connecting pad 110, a plug housing 906, a plug body 908, an adhesive layer 910, a plug cap 912, and a connecting pad terminal 914.

[0033] Referring further to Figures 9A and 9B, more specifically, the connecting pads 110 can be separated by the dielectric material 902. In certain embodiments, the dielectric material can be formed from any material having a relatively large dielectric constant. In certain embodiments, the dielectric material may include materials such as parylene, fluoropolymers, atomic layer deposition, and molecular deposition. In some embodiments, the dielectric material may be a polyimide material, such as a Kapton film supplied by DuPont (Wilmington, USA). In some embodiments, the thickness of the dielectric layer may be 25 mils. In certain embodiments, the dielectric material may be 18 mils, 27 mils, or 30 mils.

[0034] Referring further to Figures 9A and 9B, more specifically, the connection pad 110 may have a rectangular shape. In some embodiments, the connection pad 110 may be circular, polygonal, or irregularly shaped. In some embodiments, the connection pad 110 may be made of a conductive material such as copper, gold, silver, or platinum. In some embodiments, the connection pad 110 may be manufactured using one of several inks manufactured by Applied Cavitation, Inc. (Goleta, California). In some embodiments, the connection pad 110 may have a thickness of 34 mils (34 / 1000 inches). In some embodiments, the connection pad 110 may have a thickness of 25 mils, 45 mils, or 50 mils. In some embodiments, the connection pad 110 may have a thickness approximately the same as the diameter of a human hair. In some embodiments, the connection pad 110, which is in electrical contact with a terminal of a stretchable flexible substrate (not shown), may have a surface area sufficient to conduct a current of 1 ampere or more. In some embodiments, the connection pads 110 that are in electrical contact with terminals of a stretchable flexible substrate (not shown) may have a surface area sufficient to conduct currents of 2.5 amperes, 4.0 amperes, or 5.0 amperes. Two connection pads 110 are shown in Figure 9A, but any number of connection pads 110 may be used to connect to the flexible stretchable substrate. In some embodiments, multiple plug housings 906 and plug bodies 908 may be connected and may be in electrical contact with any number of connection pads 110. In some embodiments, the connection pads 110 are coupled to one or more plug pads 916 and plug bodies 908 for bonding such as soldering or pressure fitting. In some embodiments, the connection pads 110 are located on one side of the stretchable flexible substrate and may be in electrical contact with terminals provided by electronic elements on the stretchable flexible substrate. In some embodiments, the connection pads 110 are located on the opposite side of the stretchable flexible substrate and may be in electrical contact with terminals provided by electronic elements on the stretchable flexible substrate.

[0035] Referring further to Figures 9A and 9B, the connection pad 110 can be continuously connected to the connection pad terminal 914. In some embodiments, the connection pad terminal 914 can pass through the plug cap 912 and be coupled to the plug pad 916. In some embodiments, the length of the connection pad terminal 914 may be 0.1 inches, 0.25 inches, or 1 inch.

[0036] Referring further to Figures 9A and 9B, in some embodiments, the adhesive layer 910 may be a rectangular frame aligned with the outermost edge of the connecting pad 110 and the dielectric material 902. In some embodiments, the adhesive layer 910 may be of other shapes, such as a circular frame, a polygonal frame, or an irregularly shaped frame. In some embodiments, there may be multiple adhesive layers 910 arranged on the dielectric material. In some embodiments, the adhesive layer 910 may partially cover the area where the dielectric material 902 is placed. In some embodiments, the adhesive layer 910 may completely cover the area where the dielectric material 902 is placed.

[0037] In some embodiments, the adhesive may be a phase-change adhesive, such as a hot-melt adhesive, that can bond to the dielectric material 902 and a stretchable flexible substrate (not shown). In some embodiments, the adhesive may be an adhesive that flows onto the dielectric material 902 when heated. The adhesive then cools and solidifies, forming a bonded stack of elements including the dielectric material 902, the connection pad 110, and the terminals of the electronic element on the flexible stretchable substrate. Subsequently, this bonding enables bonding or close contact between the dielectric material 902, the connection pad 110, and the terminals of the electronic element on the flexible stretchable substrate. As a result of this bonding or close contact, the connection pad 110 and the terminals of the electronic element on the flexible stretchable substrate can move relative to each other with minimal restriction. In some embodiments, this close contact can permanently maintain electrical communication between the connection pad 110, an external power supply, and the electronic element on the flexible stretchable substrate. In some embodiments, if the shape of the stretchable flexible substrate deforms (e.g., stretches), the electrical coupling between the connection pad 110 and the terminals of the flexible stretchable substrate may be affected. In some of these embodiments, the connecting pad 110 may move relative to the terminals of the stretchable flexible substrate, and the electronic coupling may be suspended while the shape of the substrate is substantially deformed. Subsequently, the conductive pad 110 may be configured to reactivate the electrical coupling when the flexible substrate returns to a specified operating state.

[0038] Furthermore, in some embodiments, the adhesive may withstand multiple cleaning cycles and mechanical operations (e.g., stretching) of the stretchable flexible substrate. In some embodiments, the adhesive can bond well to a variety of materials such as polyester, polycotton, Lycra, polycarbonate, polyvinyl chloride, polyurethane, acrylonitrile butadiene styrene, wood, leather, fiberglass, aluminum, copper, and steel. In some embodiments, the adhesive layer 910 may have a thickness of 0.001 inches, 0.002 inches, 0.004 inches, or 0.005 inches.

[0039] Referring further to Figures 9A and 9B, the plug body 908 can be at least partially enclosed within the plug housing 906 and covered on one side by the plug cap 912. Although a pressure fit between the plug body 908, plug housing 906, and plug cap 912 is shown in the figures, the plug assembly can be secured to the connection pad 110 using any other fastening mechanism. In some embodiments, alternative fastening mechanisms such as a tabbed locking mechanism can be used to connect the components of the plug assembly. The plug cap 912 may allow the connection pad terminal 914 to pass through the plug cap 912 and connect to the plug pad 916. In some embodiments, the plug body may have a plug cover (not shown) that covers the opposite side of the plug body 908. The plug cover can enclose the exposed ends of the plug body 908 and / or the plug housing 906 to create a waterproof plug assembly including the plug body 908, plug cap 912, plug housing 906, and plug cover. In some embodiments, the flexible stretchable substrate and the section of the connecting pad terminal 914 may be enclosed within a waterproof casing, such as a waterproof casing formed by a plug assembly and / or an adhesive layer 910 as shown in Figures 9A-9B. In some embodiments, such a waterproof casing may include the connecting pad terminal 914 and the connecting pad 110. In some embodiments, the connecting pad terminal 914 may not be present in the device 900. In those embodiments, the waterproof casing may include only the connecting pad 110.

[0040] In some embodiments, the waterproof plug assembly may include a standard electrical connector, such as a standard plug, and a waterproof closure outside the connecting pad 110 and / or flexible stretchable electronic elements. In some embodiments, a standard electrical connection can provide a way to disconnect the connection to the electronic elements outside the waterproof plug assembly. During use, the control circuit and battery can be plugged into the plug connector. When not in use, the plug can be disconnected from the control circuit and battery, and a plug cover can be used to cover the exposed end of the plug body 908 from which the standard electrical connector is accessed. The plug housing 906, plug cap 912, and plug cover may be formed from any suitable material that supports the plug body and facilitates connection to the connecting pad terminal 914. In some embodiments, the plug housing 906, plug cap 912, and plug cover may be made of plastic such as polyethylene terephthalate, high-density polyethylene, polyvinyl chloride, low-density polyethylene, or polypropylene. In yet other embodiments, the plug housing 906, plug cap 912, and plug cover may be made of rubber.

[0041] In some embodiments, the plug body 908 may receive a corresponding plug receptacle, which enables electronic coupling between an external power source and the connection pad 110, and further conducts current to electronic elements arranged on a stretchable flexible substrate. In some embodiments, the plug body 908 may receive a USB-A, USB-C, or rectangular header plug. In some embodiments, the plug body 908 may receive a barrel plug with a center pin and cantilever spring, an EIAJ connector, or an RCA-type barrel plug.

[0042] Referring here to Figure 10, the exploded view shows the resistive heating element 1002 aligned with one embodiment of the apparatus 900, which includes a dielectric 902, a connecting pad 110, a plug housing 906, a plug body 908, an adhesive layer 910, a plug cap 912 (not shown), a connecting pad terminal 914, a first opening 114, a second opening 118, and a channel 116. As shown in Figure 10, the adhesive layer 910 defines the zigzag path of the channel 116.

[0043] In some embodiments, the connection pad 110 may be in close contact with each terminal to which a resistive heating element has been added, as shown in Figure 10. In some embodiments, the electrical coupling between the connection pad 110 and the terminals of the stretchable flexible substrate may be affected when the shape of the stretchable flexible substrate is deformed (e.g., stretched). In some of those embodiments, the connection pad 110 may move relative to the terminals of the stretchable flexible substrate, and the electronic coupling may be suspended while the shape of the substrate is substantially deformed. Subsequently, the connection pad 110 may be configured to reactivate the electrical coupling when the flexible substrate returns to a specified operating state.

[0044] Referring further to Figure 10, more specifically, the peripheral side of the adhesive layer 910 may define a first opening 114, a second opening 118, and a channel 116. In some embodiments, the channel path may be a zigzag path, a wavy path, a straight path, or any path that significantly reduces access of water or moisture to the area where the connecting pad 110 makes electrical contact with the terminals of electronic elements on the flexible stretchable substrate. In some embodiments, the first opening is one or more layers such as a polyimide layer (e.g., a Kapton film) supplied by DuPont (Wilmington, USA), or a through-hole through which other layers of the system can pass until the first opening reaches the flexible stretchable substrate. The first opening can equalize the atmospheric pressure outside the substrate with the pressure in the area of ​​electrical contact between the terminals of the stretchable flexible substrate and the connecting pad 110.

[0045] In some embodiments, the second opening 118 may be covered with a gas-permeable material to reduce access to water or moisture while allowing air and other gases to pass through the gas-permeable material. The gas-permeable material may be attached to an adhesive material. In some embodiments, the covering area of ​​the gas-permeable material may extend beyond the second opening 118. In some embodiments, the gas-permeable material may be 50% Gore-Tex manufactured by WL Associates, Inc. (Newark, USA). In some embodiments, the gas-permeable material may be a water-resistant treated polyethylene-based material, a water-resistant treated stretched polytetrafluoroethylene-based material, nylon, or polyester. Figure 10 shows a specific orientation and position of the first opening 114, the second opening 118, and the channel 116, but other positions of the first opening 114, the second opening 118, and the channel 116 are also possible.

[0046] In some embodiments, strain relief may be incorporated in the area where the terminals of the flexible stretchable substrate, the connecting pad 110, and / or the adhesive material are bonded to the flexible stretchable substrate. In some embodiments, a cloth or woven material may be used to cover some or all of the connecting pad 110, the adhesive material, and / or other elements of the embodiment of the device.

[0047] Referring here to Figure 11, a brief overview is shown of the electrical resistance measured as the number of stretch cycles of a smart textile having an electrical connection to the embodiment of the apparatus in Figure 10. In this case, the smart textile stretches to 20% elongation (displacement of 15.2 mm) at an elongation rate of 20% / s (15.2 mm / s). The smart textile shown in the measurements shown in Figure 11 was manufactured by forming a thermoplastic polyurethane (TPU) base film layer on the fabric. Subsequently, a stretchable heater ink with fixed resistance was placed on the TPU layer, and a stretchable printed silver conductor was placed on the heater ink. Finally, the heating element was covered with a stretchable insulating ink.

[0048] The base TPU layer is printed on a fabric substrate and can be customized to meet the performance requirements of smart textiles. In some embodiments, polyester-extruded TPU provides resistance to chemicals and oils, while materials extruded with polyether TPU provide flexibility and tear resistance. Polycaprolactone-extruded TPU is hydrolysis-resistant and useful for applications exposed to water for extended periods. In some embodiments, the TPU film may contain metal to provide metallic color to the fabric. In yet another embodiment, the TPU film may contain additives to enhance antistatic properties.

[0049] In some embodiments, the resistive element is printed on a TPU film 84. In some embodiments, the resistive element is printed using SE5025, a stretchable resistive ink manufactured by Applied Cavitation Inc. (Goleta, California). SE5025 is designed for heating applications integrated on elastomer substrates. When cured, the ink has a set resistance value and provides excellent flexibility and stretchability. SE5025 has excellent adhesion to TPU and other elastomer substrates.

[0050] In some embodiments, the silver conductor is printed on a TPU film 84. In some embodiments, the silver conductor and busbar system are printed on a resistive element. In some embodiments, the resistive element is printed using SE1109, a stretchable silver conductive ink manufactured by Applied Cavitation Inc. (Goleta, California). SE1109 is a silver-filled conductor for printed interconnects of devices on an elastomer substrate. After drying, the ink has excellent conductivity and provides excellent stretchability and flexibility. SE1109 has excellent adhesion to thermoplastic polyurethane (TPU). SE1109 can be used in stretchable electronic elements and e-textile applications to power components and / or devices and to transmit signals from embedded devices and / or sensors.

[0051] Stretchable carbon conductive elements can be placed on silver conductive elements. In some embodiments, the carbon elements are printed on silver conductive elements. In some embodiments, the carbon elements are printed using SE1502, a stretchable carbon conductor manufactured by Applied Cavitation Inc. (Goleta, California). SE1502 is a carbon-filled conductor for printed circuits and / or devices on elastomer substrates. SE1502 can be dried at low temperatures to accommodate sensitive substrates and devices. After curing, the ink has sufficient conductivity and provides excellent stretchability and flexibility. When SE1502 is applied on a silver trace, it limits the migration of silver.

[0052] In some embodiments, the insulating layer is printed on a carbon conductive element, at least partially. In some embodiments, the insulating layer is printed using SE3104, a stretchable printable insulator manufactured by Applied Cavitation Inc. (Goleta, California). SE3104 is a screen-printable thermosetting ink that is stretchable upon curing. SE3104 can be used as an insulator and / or crossover dielectric. Upon curing, the ink exhibits exceptional durability and excellent flexibility, as well as high insulation resistance.

[0053] An insulating layer is placed on top of the silver conductor and busbar system. In some embodiments, the insulating layer is printed on a silver trace 90a. In some embodiments, the insulating layer is printed using SE3104, a stretchable printable insulator manufactured by Applied Cavitation Inc. (Goleta, California). SE3104 is a screen-printable thermosetting ink that is stretchable upon curing. SE3104 can be used as an insulator and / or crossover dielectric. Upon curing, the ink exhibits exceptional durability and excellent flexibility, as well as high insulation resistance.

[0054] The smart textiles manufactured as described were tested to demonstrate their performance using a custom stretch tester capable of controlling elongation, elongation rate, and number of stretch cycles. High-performance fiber samples were printed on 200.0016 stainless steel mesh with dimensions of 76.2 mm × 2.00 mm (L × W). Three cases or conditions were tested and defined as follows: Case 1 is SE1109 printed on 4 mil TPU. Case 2 is SE1109 on 4 mil TPU with three layers of SE3104 insulation. Case 3 is SE1109 on 4 mil TPU including three layers of SE3104 insulation, bonded to the fabric with 3 mil hot melt adhesive. The resistance per cycle in ohms when stretched and the resistance per cycle in ohms when not stretched were measured for each case tested, as shown in Figure 11.

[0055] The stretch tests were performed for two additional stretch states shown in Figures 12 and 13. Referring here to Figure 12, the electrical resistance measured according to the number of stretch cycles of the smart textile with an electrical connection to the embodiment of the apparatus in Figure 10 is shown for Case 1. In this case, the smart textile stretches to 50% (displacement of 38.1 mm) at a stretching rate of 20% / s (15.2 mm / s). Referring here to Figure 13, a brief overview shows the electrical resistance measured according to the number of stretch cycles of the smart textile with an electrical connection to the embodiment of the apparatus in Figure 10. In this case, the smart textile stretches to 100% (displacement of 76.2 mm) at a stretching rate of 20% / s (15.2 mm / s).

[0056] Overall, Figures 11–13 show the increase in electrical resistance measured during stretching of the smart textile and the minimum resistance measured while the smart textile is not stretched.

[0057] The effect of the washing cycle on the measured electrical output and output power of the smart textiles was also measured. In the tests shown in Figures 14 to 16, the front-loading washing machine was used with the following settings and conditions: delicate cycle with laundry bag, medium to low water temperature, unscented liquid laundry detergent, washing with delicate cotton products, and hanging to dry.

[0058] Referring here to Figure 14, a brief overview shows the electrical resistance measured over a number of washing cycles of a smart textile having an electrical connection to the embodiment of the apparatus in Figure 10. The electrical resistance measured after multiple washing cycles shows a sustained electrical resistance after 15 washes, indicating that the connection between the connection pad 110, the connection pad terminal 914, and the smart textile terminal was robust and maintained consistent electrical contact after washing.

[0059] Referring here to Figure 15, a brief overview shows the output power of the heating element as it progresses through the number of washing cycles of the smart textile having an electrical connection to the embodiment of the apparatus in Figure 10. The output power measured after multiple washing cycles shows the output power after 15 washes, which indicates that the connection between the connection pad 110, the connection pad terminal 914, and the smart textile terminal was robust and maintained consistent electrical contact after each wash. As shown in Figure 16, corresponding infrared images of the heating element before washing and after the 15th wash are shown. The infrared images show gray shading to indicate the temperature of the heating element, with lighter gray areas indicating higher temperatures and darker or black areas corresponding to lower temperatures. As can be seen in Figure 16, the heating element is able to reach the temperature observed before washing, even after 15 washing cycles.

[0060] This disclosure discloses embodiments of apparatus for making electrical connections to circuits arranged on a flexible stretchable substrate. The described embodiments for making electrical connections to hot press circuits, printed circuits, are intended to make electrical connections that can withstand the intense mechanical, electrical, thermal, and environmental stresses that stretchable flexible substrates such as e-textiles or smart textiles are subjected to throughout their entire lifecycle. The term “printed circuit” is intended to include circuits formed by all forms of printing and coating, including pre-measured coatings such as patch die coating, slot coating or extrusion coating, slide coating or cascade coating, curtain coating; roll coatings such as knife-over roll coating, forward and reverse roll coating; gravure coating; dip coating; spray coating; meniscus coating; spin coating; brush coating; air knife coating; screen printing processes; electrostatic printing processes; thermal printing processes; inkjet printing processes; direct writing printing processes; jet deposition processes; and other similar techniques.

[0061] Interfaces where terminals of a flexible, stretchable substrate connect to a control circuit or voltage source can be areas of mechanical and electrical interference. The described embodiments of devices for making electrical connections to hot-press circuits and printed circuits can serve a variety of purposes, including shielding terminal connections, mechanically securing connections, housing terminal connectors, and enabling external control of circuits or voltage sources. For example, embodiments of this disclosure may be used with materials such as crystalline films that are prone to damage using typical connectors that utilize a clamping mechanism.

[0062] For example, embodiments of the present disclosure may be implemented by a smart textile that includes an additively manufactured resistive heating element to power a circuit provided by the smart textile. In yet another example, embodiments of the present disclosure may be implemented with a stretchable flexible substrate that includes a light-emitting circuit and a sound-producing circuit.

[0063] Embodiments of the present disclosure may be implemented with a stretchable flexible substrate and integrated with a variety of materials, including neoprene, leather, rubber, silicone, synthetic materials, polyester, or nylon. Furthermore, embodiments of the present disclosure may be implemented with a stretchable flexible substrate that can be integrated into fabrics, jackets, activewear, underwear, base layers, gloves, socks, chairs for outdoor activities, wetsuits, work gear, and athletic gear. For example, embodiments of the present disclosure may also be integrated into therapeutic or medical products, including breathers, wraps, pads, bedding, and textiles for pain management. Embodiments of the device may power a stretchable flexible substrate that provides electromuscular stimulation. Other applications may include military applications, including embodiments of the device with circuits located on a flexible stretchable substrate in jackets, gloves, seats, and other gear. Additional applications may include automotive applications, including embodiments of the device with circuits located on a flexible stretchable substrate integrated into car seats, steering wheels, interior panels, and other areas of the vehicle for defrosting or heating. In other applications, embodiments of the device may power stretchable flexible substrates integrated into materials intended for entertainment, fashion, or technology purposes. Furthermore, as an example, embodiments of the device may power stretchable flexible substrates having light-emitting and / or sound-emitting circuits integrated into work gear used by police or medical personnel, or activewear worn by runners for the purpose of increasing personal visibility in dimly lit environments or crowded areas. Any combination of the above also falls within the scope of embodiments of the device for making electrical connections to circuits arranged on a flexible stretchable substrate.

Claims

1. A device for making electrical connections to circuits arranged on a flexible stretchable substrate, Support area and The apparatus comprises a connection area foldably connected to the support area, wherein the connection area includes a plurality of connection pads, each of the plurality of connection pads defining a slot for electrical communication with a conductive trace, and when folded, the connection pads electrically contact a circuit disposed on a flexible stretchable substrate.

2. The apparatus according to claim 1, wherein the connecting pad defines a slot for receiving a ferrule.

3. The apparatus according to claim 1, wherein the conductive trace includes a wire.

4. The apparatus according to claim 3, wherein the wire is in contact with the ferrule and is attached to the slot.

5. The apparatus according to claim 1, further comprising a plurality of adhesive windows.

6. The apparatus according to claim 5, wherein the adhesive is placed in the adhesive window.

7. The apparatus according to claim 1, wherein the connection area has a smaller surface area than the support area.

8. The apparatus according to claim 1, wherein the connection region and the support region have the same edge cross-section.

9. The apparatus according to claim 1, wherein the connection region and the support region define an extended edge only on a specific edge of the support region.

10. The apparatus according to claim 1, further comprising a first opening for equalizing the pressure between the electrical contacts of the connecting pad and the flexible stretchable substrate with atmospheric pressure.

11. The apparatus according to claim 10, further comprising an adhesive layer defining a channel that communicates with the first opening.

12. The apparatus according to claim 11, wherein the channel has a zigzag path.

13. The apparatus according to claim 11, further comprising a second opening that is in fluid communication with the channel.

14. The apparatus according to claim 1, wherein the gas-permeable material is placed on the area between the connecting pads.

15. A cloth comprising the apparatus described in claim 1.

16. Clothing comprising the device described in claim 1.

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