Continuous Interconnection between Heterogeneous Materials

Abstract

A structure can include a first material, a second material connected to the first material at a joint between the first material and the second material, and one or more dielectrics extending across the joint to form a continuous interconnect between the first material and the second material, wherein the first material and the second material are heterogeneous. The structure can further include a transition portion at the joint between the first material and the second material. The one or more dielectrics can include a conductive functional material. The structure can also include a third material connected to the second material at a second joint between the second material and the third material, the dielectric can extend across the second joint to form a continuous interconnect between the first material, the second material, and the third material, and the second material and the third material can be heterogeneous.

Description

[0001] Cross - reference to Related Applications

[0002] This application claims priority to U.S. Provisional Patent Application Serial No. 62 / 853,481, filed on May 28, 2019, which is incorporated herein by reference.

[0003] Background

[0004] The inventive principles disclosed in this patent generally relate to the interconnection between two heterogeneous materials, and more specifically to a structure having one or more dielectrics extending between the two heterogeneous materials to form a continuous interconnect between the materials, and / or a method of forming such a structure.

[0005] Overview

[0006] A structure can include a first material, a second material connected to the first material at a joint between the first material and the second material, and one or more dielectrics extending across the joint to form a continuous interconnect between the first material and the second material, wherein the first and second materials are heterogeneous. The structure can further include a transition portion at the joint between the first and second materials. The transition portion can include an overlap portion. One or more dielectrics can include a functional material. The functional material can be conductive. The functional material can include a conductive gel. The first material can be significantly more rigid than the second material. The first material can be significantly more elastic than the second material. The structure can also include a first sealant disposed on the first material to substantially enclose a portion of the dielectric. The structure can also include a second sealant disposed on the second material to substantially enclose a portion of the dielectric. The first material can include a through - hole through which at least a portion of the dielectric passes. The structure can include an overlap portion at the joint between the first material and the second material, and the through - hole passes through the overlap portion. The structure can also include an electrical component attached to the first material and electrically coupled to the dielectric.

[0007] The joint between the first material and the second material can include a first joint, and the structure can further include a third material connected to the second material at a second joint between the second material and the third material, the dielectric can extend across the second joint to form a continuous interconnect between the first material, the second material, and the third material, and the second and third materials can be heterogeneous. The dielectric can be conductive, and the structure can further include a first electrical component attached to the first material and electrically connected to the dielectric, and a second electrical component attached to the third material and electrically connected to the dielectric.

[0008] A sensor structure may include a first substrate comprising a first material, a conductive contact layer comprising a second material disposed on the first substrate, a second substrate comprising a third material disposed on the first substrate, and a conductive gel disposed in a patterned manner on the second substrate and forming a continuous electrical interconnect with the conductive contact layer, wherein at least two of the first material, the second material, and the third material are heterogeneous. The sensor structure may further include an electrical component disposed on the second substrate and electrically connected to the continuous electrical interconnect. The first substrate may include a through hole through which the continuous electrical interconnect is connected to the conductive contact layer.

[0009] A method may include connecting a first material to a second material at a joint and forming a continuous interconnect between the first material and the second material across the joint, wherein the first material and the second material may be heterogeneous. The method may further include encapsulating the continuous interconnect. Brief Description of the Drawings

[0011] The drawings are not necessarily to scale, and for purposes of illustration, in all the drawings, elements of similar structure or function are generally denoted by like reference numerals. The drawings are only intended to facilitate the description of the various embodiments described herein. The drawings do not depict every aspect of the teachings disclosed herein and do not limit the scope of the claims. To prevent the drawings from becoming cluttered, not all components, connections, etc. may be shown, and not all components may have reference numerals. However, the pattern of the component configuration can be readily seen from the drawings.

[0012] Figure 1 An embodiment of a structure in accordance with some inventive principles disclosed in this patent is shown.

[0013] Figure 2 Another embodiment of a structure in accordance with some inventive principles disclosed in this patent is shown.

[0014] Figure 3 is an exploded perspective view showing an example embodiment of an interconnect design in accordance with some inventive principles disclosed in this disclosure.

[0015] Figure 4 is a cross-sectional view of another example embodiment of a heterogeneous structure in accordance with some inventive principles disclosed in this disclosure.

[0016] Figure 5 Another example embodiment of a heterogeneous structure using a conductive gel as a trace in accordance with some inventive principles disclosed in this disclosure is shown.

[0017] Figure 6 Another embodiment of a structure having a continuous interconnect in accordance with some inventive principles disclosed in this disclosure is shown.

[0018] Figure 7 andFigure 8 Side and top views of an embodiment of a structure having continuous interconnects between different materials, in accordance with some inventive principles of the present disclosure.

[0019] Figure 9 is Figure 7 and Figure 8 Another side view of the structure of

[0020] Figure 10 A cross-sectional view of another embodiment of a structure having continuous interconnects between different materials, in accordance with some inventive principles of the present disclosure.

[0021] Figure 11 A cross-sectional view of another exemplary embodiment of a heterostructure, in accordance with some inventive principles of the present disclosure.

[0022] DETAILED DESCRIPTION

[0023] Figure 1 Illustrates an embodiment of a structure in accordance with some inventive principles of the present patent disclosure. Figure 1 The system of may include at least two heterogeneous materials: Material A (10) and Material B (12). Materials A and B may differ in that they have at least one different mechanical property, constraint, processing parameter, etc. One or more media may extend between Materials A and B to form a continuous interconnect between the materials. Figure 2 Illustrates another embodiment similar to the embodiment of Figure 1 but Figure 2 the embodiment of may include a transition section A / B (16) between Materials A and B.

[0024] Examples of suitable media include viscous, elastic, viscoelastic, and / or any other material that can deform in response to deformation of one or more of Materials A and B and then return to its previous form when one or more of Materials A and B return to their previous form. One or more media may return to their previous form by their own action (e.g., if the medium is an elastic material) or by the action of one or more of Materials A and B returning to their previous form (e.g., if the medium is a fluid).

[0025] In some embodiments, the medium may include one or more functional materials, which may have at least one function that is not primarily structural, such as: electrical conductivity, light, sound, etc.; sensing one or more stimuli, such as stress, strain, pressure, temperature, elongation, etc.; mass transfer (such as the mass transfer of the material itself); heat transfer; mechanical connection, such as transmitting force, motion, pressure, vibration, etc.; and / or any other type of function. In some embodiments, the functional material may have at least one fluid property or component, such as a fluid component as a fluid phase material or a gel material, etc.

[0026] In some embodiments, the functional material can be implemented with a viscoelastic material having both a fluid component and a solid component. Such a material can perform, for example, electroactive functions (such as electrical conductivity), or it can be used as a mechanical interconnect, an actuation interconnect, a fuel line, or a fluid reservoir or any other function. The viscoelastic interconnect material can be arranged in any suitable geometry to accommodate any desired function.

[0027] In rheology, G* can refer to the complex shear modulus that may contain two components: G’ and G”, which can be referred to as the storage modulus and the loss modulus, respectively. The storage modulus can essentially characterize the elastic component of the material, while the loss modulus can characterize the viscous or liquid component of the material. In some embodiments, by selecting a functional material with a higher G’ than one or both of materials A or B, the functional material can withstand a certain degree of compression during the formation and / or use of the structure. In some embodiments, and depending on the implementation details, the storage modulus of the functional material can be considered “higher” than the storage modulus of one or both of materials A or B if the amount by which it is higher enables the functional material to withstand compression or other distortive stimuli during formation and / or use while still maintaining its function after the structure is formed and / or used.

[0028] Examples of the different mechanical properties of materials A and B include modulus (such as Young's, shear, bulk, etc.), hardness (Shore, Mohs, Brinell, Rockwell, etc.), strength (such as tensile, compressive, etc.), density, etc.

[0029] Examples of the different processing parameters of materials A and B include temperature, pressure, time, reagents (such as reactants, solvents, catalysts, activators, etc.), exposure to UV, IR, RF, sonication, etc.

[0030] Examples of the different constraints of materials A and B include: deformation limits (e.g., because of rigid components mounted on it, placed on an object such as a human body or a sensitive mechanical instrument), exposure limits (e.g., limited to temperature, radiation, UV, IR, RF, ultrasound, chemicals, etc.), etc.

[0031] One or more media forming the interconnection can be formed on one or more surfaces of Material A and / or B or the transition A / B, in a channel through either Material A and / or B or the transition A / B, or in any other arrangement creating an operative interconnect between Materials A and B.

[0032] The transition A / B (if any) can include an overlap, interleave, material gradient, and / or the like between Materials A and B, and / or one or more intermediate, transition, buffer, etc. materials between Materials A and B.

[0033] Deformation of one or more of Materials A and B and corresponding deformation of the interconnection 14 can respond to any one or all of tensile, compressive, stretching, flexing, twisting, swelling, etc. forces on one or more of Materials A and B.

[0034] Examples of the type of interconnection formed by one or more media can include mechanical, electrical, electro - magnetic, electronic, electromechanical, electromagnetic, and / or other electro - active interconnections, optical, photon, audio, mass transfer, etc.

[0035] Examples of materials suitable for use as Materials A and B in any combination can include any type of natural and / or synthetic polymer, which includes rubber and plastic materials, such as silicone - based materials including polydimethylsiloxane (PDMS), polyurethane rubbers including thermoplastic polyurethane (TPU), ethylene propylene diene monomer (EPDM), neoprene, and epoxy resins, pure metals and alloy metals, woven or non - woven fabrics, wood, leather, paper, fiberglass, and carbon, and other composite materials, etc., or any combination of the above materials.

[0036] Examples of materials suitable for use as one or more media for forming interconnections include, but are not limited to, deformable conductors, which include conductive gels such as gallium indium alloys, some examples of which are disclosed in U.S. Patent Application Publication No. 2018 / 0247727, published August 30, 2018, which is incorporated by reference. Other suitable electroactive materials can include: any conductive metal including gold, nickel, silver, platinum, copper, etc.; semiconductors based on silicon, gallium, germanium, antimony, arsenic, boron, carbon, selenium, sulfur, tellurium, etc.; semiconductor compounds including gallium arsenide, indium antimonide, and many metal oxides; organic semiconductors; and conductive non-metallic substances such as graphite. Other examples of conductive gels include graphite-based gels or other forms of carbon and ionic gels. Examples of suitable non-electroactive compositions include many other types of gels, such as silicone gels and chafing fuels such as Sterno. Other examples include liquids such as water, oil, ink, alcohol, etc. (any of which can be electroactive or non-electroactive), and any elastic material that can be electroactive or non-electroactive.

[0037] Some additional inventive principles disclosed in this patent relate to the use of structures such as Figure 1 and Figure 2 shown in, for use as interconnections between heterogeneous materials that carry various specialized components, for example, in deformable electronic assemblies such as flexible hybrid electronic (FHE) assemblies. In some non-limiting example embodiments, the interconnection can span a heterogeneous joint between a deformable circuit board such as a printed circuit board (PCB) like a flexible printed circuit board (FlexPCB) and / or a stretchable printed circuit board (StretchPCB) and other deformable structures (e.g., TPU or silicone structures). Techniques that can be used to form these structures can include molding, adhesive bonding, thermoforming, tape bonding, ultrasonic bonding, and / or others. In some embodiments, these techniques can be combined with FHE techniques and one or more interconnections disclosed in this patent disclosure to create one or more integrated textile / electronic assemblies having applications, for example, in industrial electronic devices, consumer electronic devices, and / or wearable electronic devices.

[0038] Hybrid-mode interconnections, especially those between hard and soft materials or between rigid components and materials that conform to non-linear shapes, can pose challenges in deformable electronic devices such as FHE. FHE and other deformable electronic devices can be applied to the Internet of Things (IoT) and wearable applications, where electronic devices can exist in close association with mechanical elements that are traditionally considered different from traditional electronic components. Materials such as fabrics, rubber membranes, thermoformed plastics, and the like can directly integrate electronic components to support intelligent or active control functions.

[0039] Interconnections between different materials can be handled with specialized solders, conductive adhesives, or mechanical connectors. However, some of these may involve compatibility with individual traces built on two different substrates, each of which may have its own mechanical constraints. This can involve engineering both the interconnection of different materials and the mechanical structure, and can impose substantial constraints and overhead on the design of FHEs or other deformable electronic devices.

[0040] The inventive principles disclosed in this patent can enable bypassing potential interconnection issues, such as multimodal metallization, by using continuous interconnections created by conductive gels and / or other conductive functional materials passing through vias or other channels, which are cut or formed in a hybrid material substrate, printed directly on the substrate, or otherwise arranged with the substrate in any other suitable manner. In some embodiments, continuous circuits including vias and other structures having single and / or hybrid material multi-layer circuit configurations can be fabricated with interconnections formed by conductive gels and / or other conductive functional materials. In some embodiments, components can be directly coupled to traditional electronic components, including surface mount components, flexible circuits, and conductive fabrics, through vias in an adhesive substrate, which vias can be filled with conductive gels and / or other conductive functional materials. Both of these structures can create low-impedance ohmic contacts that, for example, withstand strain cycling and / or bending tests and / or have the ability to endure dynamic loads applied to the structure during both final assembly and during use in applications such as wearable electronic devices, strain monitoring electronic devices, etc., where dynamic movement may be anticipated.

[0041] In some embodiments, the inventive principles disclosed in this patent can be applied to many substrate materials and manufacturing methods that can permit both hosting rigid surface mount components on FlexPCB or StretchPCB substrates and creating mechanically robust interconnections attached to the PCB components, which interconnections should be able to withstand significantly greater strain, all of which is spanned by continuous wires formed of conductive gels.

[0042] In some example embodiments, an FHE or other deformable electronic device can include both a first substrate portion hosting surface mount components and a second substrate portion serving as a textile integrated conductor and / or strain gauge having a relatively high elongation rate, which conductor and / or strain gauge is made of, for example, a conductive gel. The higher elongation rate portion of the circuit can provide a variable resistance and / or conductive path to a lower elongation rate flexible circuit that can host one or more passive and / or active surface mount technology (SMT) components capable of creating a visual output of, for example, the stretching experienced by the higher elongation rate portion.

[0043] According to some inventive principles disclosed in this patent, some examples of materials that can be used in FHE devices or other deformable devices include, but are not limited to, the following: any TPU, including, for example, low Shore A TPU and / or other TPU with high Shore A; thermosetting and / or epoxy-based films; silicone, such as any type of cured silicone, which can be applied, for example, to high-stretch knitted fabrics; copper or metal-clad polyamide or other substrates that can be used in FlexPCB, StretchPCB, and / or the like; and any active and / or passive through-hole and / or surface-mounted components. In some example embodiments, copper-clad polyamide and SMC components can be used to form a stable electrical connection with a through-hole filled with conductive gel and can be applied as components in, for example, hybrid assemblies.

[0044] Figure 3 is an exploded perspective view showing an example embodiment of an interconnect design suitable for an FHE device or other device according to some inventive principles disclosed in this patent. Two pads 101 and 102 having diameters D1 and D2, respectively, can be printed on separate layers of different substrates A (103) and B (104), for example, with holes through the pads to achieve electrical continuity. Pad 101 can be in communication with a trace 107 on substrate A, while pad 102 can be in communication with a trace 108 on substrate B.

[0045] The pad size and via size can be selected to facilitate the manufacturability design of the circuit board. In some example embodiments of heterogeneous interconnects on flexible and / or stretchable substrates, the sizes of these features can be selected according to the expected deformation of the substrate and / or to facilitate the assembly and testing of the heterogeneous interconnect. In some embodiments, these through-hole pads can extend directly to a surface-mounted component that can be adhered to a pad on a surface or circuit (e.g., a polyamide circuit).

[0046] Figure 3 An example of shows a transition substrate A / B (105) that has a through-hole 106 with a diameter of D3 between the overlapping portions of substrates A and B, but the transition substrate can be omitted in some embodiments. The materials for substrates A and B and the transition substrate A / B (if used) can be selected from any of the materials determined above or any other suitable materials. The pads, traces, and filling materials for the through-holes can be implemented with conductive gel or any other suitable conductive material.

[0047] Figure 4FIG. 0 is a cross-sectional view of another exemplary embodiment of a heterostructure that uses a conductive gel and / or other interconnect medium 114 as a trace according to the present disclosure (in some embodiments, the heterostructure may be implemented as a stack). Substrate A (110) may overlap and be directly attached to substrate B (112). In other embodiments, an intervening substrate may be used. In this embodiment, vias 116 may be formed through substrate A such that, for example, traces 122 and / or pads 124 on substrate A may align with the tops of pads 120 and / or traces 118 on substrate B, and thus the conductive gel in the vias 116 of substrate A may directly contact the pads 120 at the top of substrate B.

[0048] Figure 4 The structure shown may include one or more sealants to confine and / or protect the traces, pads, and / or vias of the conductive gel and / or other interconnect medium 114. For example, at least a portion of substrate A may be coated with sealant A (126), and at least a portion of substrate B may be coated with sealant B (128). Any suitable material may be used for the sealant, such as silicone-based materials such as PDMS, TPU, polyurethane, epoxy resin, polyester, polyamide, varnish, and any other material that can provide a protective coating and / or help hold the components together. Substrates 110 and 112 may be joined together using any suitable technique, including adhesive bonding, thermoforming, tape bonding, ultrasonic bonding, etc.

[0049] Similar to Figure 4 Example applications that may be useful in the structure shown include the following applications: where substrate A may be implemented with a material that can be used to carry one or more electronic components, and substrate B may be implemented with a material that can be used to provide connections to remote sensors, displays, electronic modules, etc. For example, substrate A may be made of a relatively rigid material, while substrate B may be made of a relatively flexible and / or stretchable material.

[0050] In some embodiments, traces 122 may be formed on the bottom of substrate A (110), eliminating the vias 116. In such embodiments, sealant A (126) may be applied to the bottom surface of substrate A (110). In some embodiments, sealant A (126) and sealant B (128) may be combined as a single component.

[0051] In some embodiments, Figure 4 Some or all of the structures shown (and any other structures described in the present disclosure) may be manufactured at least in part using any of the materials and / or manufacturing techniques described in U.S. Patent Application Publication No. 2020 / 0066628, published Feb. 27, 2020, which is incorporated by reference and may be used in combination with any of the methods and / or articles described herein.

[0052] Figure 5 Another exemplary embodiment of a heterostructure using a conductive gel as a trace is shown in accordance with some inventive principles disclosed in this patent. In Figure 5 the illustrated embodiment, a thermoset plastic laminate tape 130 (Material A) can overlap a TPU tape 132 (Material B) at an overlap region 134 (A / B). A heterogenous interconnect medium made of, for example, a eutectic gallium alloy can have a first portion 136 on Material A, a second portion 138 on Material B, and a transition portion 140 in the overlap region 134. All three portions of the trace can be encapsulated, for example, with one or more sealants such as silicone, TPU, polyurethane, epoxy resin, etc.

[0053] The thermoset plastic (Material A) and the TPU (Material B) can have significantly different mechanical properties across which a continuous conductive trace extends, thus forming a heterogenous interconnect that transitions between the two heterogenous materials. For example, in some embodiments, the thermoset plastic laminate (Material A) can be significantly more rigid than the TPU (Material B).

[0054] An electromechanical connector such as a weldable connector 142 can overlap the second portion 138 of the trace in an overlap region 144 to form another heterogenous electrical connection between the continuous trace and any other electrical device. Alternatively, in some embodiments, a polyamide layer can be adhered to the conductive fabric as a terminal layer to provide an interconnect between the conductive gel encapsulated in TPU or silicone and the weldable connector mechanically connected to the conductive fabric.

[0055] Figure 6 Another embodiment of a structure with continuous interconnects in accordance with this disclosure is shown. In Figure 6 the illustrated embodiment, an outer ring 150 of conductive gel and an inner ring 152 of conductive gel can be patterned on a first substrate 154 (Material A) formed of a relatively rigid material such as a thermoset plastic. The first substrate 154 can transition to a second substrate 156 (Material B) formed of a relatively flexible and / or stretchable material such as silicone. The first substrate 154 and the second substrate 156 can transition by lapping, butting, or any other means. A first linear trace 158 that can be electrically connected to the outer ring 150 can be patterned on the first substrate 154 and the second substrate 156 to span the transition between Material A and Material B. A second linear trace 160 that can be electrically connected to the inner ring 152 can be patterned on the first substrate 154 and the second substrate 156 to span the transition between Material A and Material B.

[0056] One or more two-terminal electronic components, such as light-emitting diodes (LEDs) 162, can be mounted on the first substrate 154, where each of the inner and outer rings is in direct contact with a terminal. The first substrate 154 can be encapsulated, for example, with a transparent sealant such as silicone, to enable the LEDs to be visible through the sealant. The second substrate can be encapsulated with, for example, another layer of silicone, and the linear traces 158 and 160 are incorporated therebetween. The portions of the linear traces 158 and 160 shown by the dashed lines can be covered by the sealant on the second substrate 156, which may be opaque in some embodiments.

[0057] In some embodiments, a fabric mesh can be applied to the first substrate 154, for example, by including it within the sealant or by combining it with another sealant to provide selective strain limitation for the first substrate 154 and the patterns of conductive gel and LEDs formed thereon.

[0058] Thus, Figure 6 The illustrated embodiments can provide an electronic assembly where a relatively rigid but still flexible and / or stretchable first substrate 154 (Material A) can provide a substrate for the electronic components, while in some implementations, electrical connections to the substrate are provided by a relatively more flexible and / or stretchable second substrate 156 (Material B) without using any solid wires.

[0059] Conductive gels made of gallium alloys (such as those described in U.S. Patent Application Publication No. 2018 / 0247727) can be particularly beneficial for the use of interconnects between heterogeneous materials because they can be patterned on various substrates including TPU, silicone, epoxy, EPDM, and various thermoset elastomers. In some embodiments, the patterning method can be inherently graphical and can form a mechanical bond between the substrate and the conductive gel. In some embodiments, there may be no curing stage or chemical reaction that helps to wet the functional pattern onto many substrates. An example is a composition of a gallium-indium-tin eutectic alloy into which cross-linked gallium oxide nanostructures have been introduced to change the viscosity and wetting parameters, which allows the material to be controllably patterned onto various substrates. The eutectic gallium alloy gel may also not have a structure that decomposes during strain cycling because the material can conduct electricity in an amorphous fluid state, making it robust when the strain cycle reaches the upper limit of its substrate. Thus, they can provide an effective solution for interconnects between heterogeneous materials in FHE and many other applications, especially in the critical hard-to-soft transitions. The eutectic gallium alloy gel can also have excellent electrical properties, which provide low-resistance DC connections and transmission line parameters (primarily S11) up to 5 GHz and above.

[0060] Figure 7 and Figure 8Side and top views of embodiments of structures with continuous interconnects between different materials in accordance with some inventive principles disclosed in this patent.

[0061] Figure 7 and Figure 8 Embodiments of may include first, second, and third different substrates 18, 20, and 22. In this example, the first substrate 18 may be rigid TPU, the second substrate 20 may be more flexible but still rigid TPU, and the third substrate 22 may be soft TPU, but the principles of the present invention are not limited to these details and any combination of materials with various properties may be used. The first and second substrates may be joined together at joint 19 using any suitable joining technique, and the second and third substrates may be joined together at joint 21 using any suitable joining technique. Figure 7 and Figure 8 The components in and are not necessarily to scale. For example, the substrates may be made of very thin sheets of material, in which case, Figure 7 and Figure 8 the vertical scale is exaggerated.

[0062] Traces of a conductive medium, such as a conductive gel, may be formed in a U-shaped pattern 28 on the upper surface of the substrates and span the joints between the substrates. Due to the rigid nature of the first substrate 18, the ends of the U-shaped pattern 28 may terminate at contact pads 24 and 26, which may be conventional electrical contact pads. Although Figure 7 and Figure 8 are not shown, a sealant may be formed on the U-shaped pattern 28 and the top surfaces of the substrates 18, 20, and 22.

[0063] The resulting structure may bend in response to various forces, with the different substrates providing different radii of curvature, as shown by R1 and R2 in Figure 9 , Figure 9 is Figure 7 and Figure 8 another side view of the structure of, Figure 9 showing the structure deforming. In some embodiments, such a structure may serve as strain relief.

[0064] Figure 7 and Figure 8The structure can also include transitions between other materials, such as TPU to epoxy, silicone to epoxy, silicone to fabric, or TPU, etc. In some embodiments, and depending on implementation details, having a continuous interconnect between TPU and silicone can be particularly beneficial because it is often difficult to make electrical connections to silicone, but relatively easy to make electrical connections to TPU. Thus, the electrical connection can be placed on a TPU substrate, which can then transition to silicone, which can provide a more sensitive substrate for sensors made of deformable conductors such as conductive gels.

[0065] In some embodiments, after printing the circuit by stencil printing, flexographic printing, or some other deposition process, a sealant layer with vias filled with a deformable conductor can be added, or the exposed circuit can simply remain exposed. Next, an integrated circuit (IC) or other electronic device can be placed on the circuit. The metal layer on the IC can form a low-impedance ohmic contact with the conductive gel. In some embodiments, the substrate itself can be an adhesive, which can hold the IC (or packaged surface mount component (SMC)) in place. Alternatively, the adhesive can be placed on the landing area or on the IC (or SMC). Finally, a encapsulation layer can be placed on the assembly to fix the conductive gel and the IC in place.

[0066] In some embodiments according to the inventive principles disclosed in this patent, having a very soft / conforming conductor can be beneficial for any of soft interconnect attachment, direct die attachment, direct IC attachment, and / or soft interconnect chip-on-board (COB) processes. In some embodiments, this can be achieved by using a conductive gel (e.g., a gallium-indium-tin alloy doped with oxides and micron-sized particles to control viscosity). In some embodiments, this technique can be used with other conformal conductors that can form a low-impedance contact with the metal layer.

[0067] In some other embodiments according to some inventive principles disclosed in this patent, a gasket made of a material such as EPDM (ethylene propylene diene monomer) can have a deformable conductor pattern arranged to sense the gasket properties. Since it may be relatively difficult to connect electrical contacts to EPDM, the deformable conductor can be coupled through a continuous interconnect between the EPDM gasket and another material such as TPU, which can be a good substrate for electrical contacts. Thus, the sensing circuit can be connected to the contacts on the TPU substrate while still providing a good electrical connection to the deformable conductor pattern in or on the EPDM gasket.

[0068] Figure 10 is a cross-sectional view of another embodiment of a structure having a continuous interconnect between different materials according to some inventive principles disclosed in this patent.Figure 10 Embodiments may include a pattern of conductive material 30 formed on a first substrate 32. The first substrate 32 may be attached to a second substrate 34, which may have traces 36 of a deformable conductor such as a conductive gel. A sealant 38 may cover the second substrate 34 and the traces 36. Through-holes 41 and 43 passing through the first substrate 32 and the second substrate 34, respectively, may enable the deformable conductor to form a continuous interconnect 40 between the pattern of conductive material 30 and the traces 36 on the second substrate 34. Figure 10 Any or all of the layers shown may have one or more different properties, and using functional materials such as a conductive gel for the continuous interconnect 40 and / or the traces 36 may enable Figure 10 the components shown to be fabricated and / or operated while eliminating or reducing problems associated with material fatigue, material creep, current action between multiple conductors, etc.

[0069] Figure 10 The embodiments shown may be used in bioelectric sensors such as electrocardiogram (ECG or EKG), electromyogram (EMG), etc. In such embodiments, the conductive material 30 may be made of conductive silicone, copper cladding, or other materials suitable for implementing electrodes suitable for contacting a patient's body. The first substrate 32 and the second substrate 34 may be made of, for example, a material that is rigid enough to carry one or more electronic components but flexible enough to comfortably conform to a patient's body. Examples include TPU, polyamide, thermosetting epoxy resin, thermosetting plastics, etc.

[0070] In some example embodiments, the conductive material 30 may be implemented as conductive silicone, which has good tolerance for skin contact, while the second substrate 34 may be implemented with epoxy resin to form a substrate for electronic components and / or other trace layers for a circuit board. The first substrate 32 may be implemented with TPU, which may protect the patient from contacting the epoxy resin substrate 34, which may be irritating to some patients.

[0071] Although the conductive traces 36 are shown on the bottom of the second substrate 34, in some embodiments, the conductive traces 36 may pass through the second substrate 34, which may be used as, for example, an in-place stencil to form the traces 36 that may be enclosed between the first substrate 32 and the sealant 38.

[0072] Some embodiments may include additional substrate layers having additional through-holes, traces, etc. to form a functional circuit having one or more electrical and / or electronic components.

[0073] In some embodiments, Figure 10The structure shown may include an interface 44 to connect the component to one or more other devices. For example, in some embodiments, the conductive traces 36 may transition to one or more terminals to couple the component to a cable or other conductive device, such as to read data from a sensor in which the component is integrated. In other embodiments, the interface 44 may transition to another hetero-junction (e.g., Figure 4 the hetero-junction shown) to transition to a conductive component with a relatively high elongation rate to connect the component to other devices.

[0074] In some embodiments, Figure 10 one or more of the substrates shown may be implemented as a fabric layer, or a fabric layer may be added as an additional layer. For example, in the case of a bioelectric sensor, such a fabric layer may be included to provide patient comfort. Additionally or alternatively, such a fabric layer may be used to integrate the component into a piece of clothing or apparel, or into other wearable devices (such as a brace). Further, a plurality of components, such as Figure 10 those shown, may be integrated into a piece of clothing or apparel or other wearable device having one or more flexible and / or stretchable substrates to form electrical and / or electronic interconnections between the components.

[0075] Figure 11 is a cross-sectional view of another exemplary embodiment of a hetero-structure according to the present disclosure. Figure 11 The embodiment shown may include components similar to those shown in the Figure 4 embodiment, but Figure 11 the embodiment may further include a third substrate, substrate C (166), which forms a second junction with substrate B (112). Traces 168, traces and / or pads 170, vias 172 and / or vias 174 may continue the continuous interconnection formed by the interconnecting medium 114 through traces 122 and / or pads 124, vias 116, and traces 118 and / or pads 120. Another sealant C (176) may encapsulate the interconnecting portion within or on substrate C. In some embodiments, any one of sealants A, B, and / or C may be formed as a single layer.

[0076] In some embodiments, Figure 11The structure shown can be used, for example, in an application where the structure can provide continuous functional interconnection between components X and Y. For example, component X can be implemented as a sensor, a display, an actuator, and / or any other type of component that can be carried on substrate A, which can be implemented, for example, with a material that is relatively rigid enough to carry the sensor, display, actuator, etc. of component X (such as a medical or other biosensor, an industrial sensor, etc.), but still flexible and / or stretchable enough to conform to the body of a subject, an industrial device, a parachute, a piece of clothing, or other soft item, etc. Then, substrate A can transition to substrate B, which can be implemented as, for example, a relatively more flexible and / or stretchable (e.g., high elongation) material that can conduct one or more signals and / or operate as a sensor while extending along a certain distance to component Y. For example, substrate B can be sewn or glued or otherwise attached to items such as clothing, parachute cords, pipes, conduits, cables, etc. Substrate B can then transition to substrate C, which can be implemented, for example, with a relatively rigid material (such as a fiberglass or polyamide circuit board) that can carry a data collection and / or processing unit, which can display data received from component X, send data to be displayed by component X, control one or more sub-components in component X, etc.

[0077] Thus, in some embodiments, depending on the implementation details, a component (such as the Figure 11 component shown) can provide a complete end-to-end interconnection solution between two components, which can span multiple junctions between heterogeneous materials, while in turn the heterogeneous materials can span multiple environments when utilizing a continuous interconnection.

[0078] Some techniques that can be used to fabricate continuous interconnections between heterogeneous materials (such as those shown in Figure 10 and Figure 11 according to some inventive principles disclosed in this patent) include those disclosed in the above-mentioned U.S. Patent Application Publication No. 2020 / 0066628, which is incorporated by reference, and which discloses methods for directly attaching surface-mounted components to vias filled with conductive gels and other interconnection media, and stencil printing methods for fabricating multi-layer PCBs that can be compatible with conductive gels and other interconnection media.

[0079] Embodiments disclosed herein may be described in the context of various implementation details, but the principles of the present disclosure are not limited to these or any other specific details. Some functions have been described as being implemented by certain components, but in other embodiments, the functions may be distributed among different systems and components at different locations and have various user interfaces. Certain embodiments have been described as having specific components, processes, steps, combinations thereof, etc., but these terms may also include embodiments in which the specific processes, steps, combinations thereof, etc. may be implemented by: using multiple components, processes, steps, combinations thereof, and / or the like, or in which multiple processes, steps, combinations thereof, and / or the like may be integrated into a single process, step, combination thereof, and / or the like. A reference to a component or element may refer only to a part of the component or element. The use of terms such as "first" and "second" in the present disclosure and claims may merely be for the purpose of distinguishing the things they modify and may not indicate any spatial or temporal order, unless it is apparent from the context. The mention of a first thing does not imply the existence of a second thing. Additionally, in accordance with the inventive principles disclosed in this patent, the various details and embodiments described above may be combined to produce additional embodiments.

[0080] Since the inventive principles disclosed in this patent may be modified in arrangement and detail without departing from the inventive concept, such changes and modifications are considered to fall within the scope of the appended claims.

Claims

1. A structure for continuous interconnection between heterogeneous materials, comprising: A first material; A second material, the second material being connected to the first material at a first joint between the first material and the second material; And One or more dielectrics, the dielectrics extending across the first joint to form a continuous interconnection between the first material and the second material; Wherein the one or more dielectrics include a fluid-phase material; Wherein the one or more dielectrics are conductive; A first electrical component electrically connected to the one or more dielectrics; A second electrical component electrically connected to the one or more dielectrics; Wherein the first material and the second material are heterogeneous, having at least one different mechanical property or processing parameter.

2. The structure according to claim 1, further comprising a transition portion at the first joint between the first material and the second material.

3. The structure according to claim 2, wherein the transition portion includes an overlap portion.

4. The structure according to claim 1, wherein the one or more dielectrics include a functional material.

5. The structure according to claim 4, wherein the functional material is conductive.

6. The structure according to claim 5, wherein the functional material includes a conductive gel.

7. The structure according to claim 1, wherein the rigidity of the first material is higher than the rigidity of the second material.

8. The structure according to claim 1, wherein the elasticity of the first material is higher than the elasticity of the second material.

9. The structure according to claim 1, further comprising a first sealant disposed on the first material to enclose a portion of the dielectric.

10. The structure according to claim 1, further comprising a second sealant disposed on the second material to enclose a portion of the dielectric.

11. The structure according to claim 1, wherein the first material includes a through hole through which at least a portion of the dielectric passes.

12. The structure according to claim 11, wherein: The structure includes an overlap portion at the first joint between the first material and the second material; and The through hole passes through the overlap portion.

13. The structure according to claim 5, further comprising an electrical component attached to the first material and electrically coupled to the dielectric.

14. The structure according to claim 1, wherein: The structure further includes a third material, the third material being connected to the second material at a second joint between the second material and the third material; The dielectric extends across the second joint to form a continuous interconnection between the first material, the second material, and the third material; And The second material and the third material are heterogeneous.

15. The structure according to claim 14, wherein, The first electrical component is attached to the first material; and The second electrical component is attached to the third material.

16. A sensor structure, comprising: A first substrate, the first substrate including a first material; A conductive contact layer, the conductive contact layer including a second material disposed on the first substrate; A second substrate, the second substrate including a third material disposed on the first substrate; And A fluid-phase conductor, which is arranged in a pattern on the second substrate and forms a continuous electrical interconnection with the conductive contact layer; wherein at least two of the first material, the second material, and the third material are heterogeneous by having at least one mechanical property or processing parameter that is different relative to each other.

17. The sensor structure according to claim 16, further comprising an electrical component disposed on the second substrate and electrically connected to the continuous electrical interconnection.

18. The sensor structure according to claim 16, wherein the first substrate includes a through hole, and the continuous electrical interconnection is connected to the conductive contact layer through the through hole.

19. A method for continuous interconnection between heterogeneous materials, comprising: connecting a first material to a second material at a first joint; and forming a continuous interconnection between the first material and the second material that spans the first joint; wherein the continuous interconnection includes a fluid-phase material; wherein the continuous interconnection is conductive; electrically connecting a first electrical component to the continuous interconnection; electrically connecting a second electrical component to the continuous interconnection; wherein the first material and the second material are heterogeneous and have at least one different mechanical property or processing parameter.

20. The method according to claim 19, further comprising encapsulating the continuous interconnection.

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