Apparatus, system and method for producing or using highly sustainable circuits

Abstract

Apparatus, systems, and methods for manufacturing and using highly sustainable circuit assemblies are disclosed. In various embodiments, the highly sustainable circuit assemblies include a substrate layer and a contact pattern supported by the substrate layer. The contact pattern may be configured to correspond to at least one terminal of an electrical component. The contact pattern may include a modified conductive material. The modified conductive material may be a non-hazardous, readily renewable, and readily recyclable material.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Provisional Application No. 63 / 154,665, filed February 26, 2021, entitled "HIGHLY SUSTAINABLE CIRCUITS AND METHODS FOR MANUFACTURING SAME," the disclosure of which is incorporated herein by reference in its entirety.

[0002] (Technical field) The present disclosure relates generally to electronic circuits. More specifically, the present disclosure relates to highly sustainable electronic circuit assemblies having conductive materials, layers, and / or connections that can be easily separated, reused, and / or recycled. In various configurations, the electronic circuit assemblies are substantially free of toxic or volatile organic compounds and can be manufactured using processes that consume low energy and produce minimal waste. Summary of the Invention

[0003] The following summary is provided for the purpose of facilitating an understanding of some of the innovative features unique to the technology disclosed herein, and is not intended to be a complete description, with the specification, claims, and abstract taken as a whole to provide a comprehensive understanding of the various aspects.

[0004] In various aspects, a method of reclaiming material from a highly sustainable circuit assembly is disclosed. In one aspect, the highly sustainable circuit assembly includes an electrical component, a substrate layer, and a transformed conductive material. In another aspect, the method includes removing the electrical component from the circuit assembly, heating the highly sustainable circuit assembly to a melting point of the substrate layer to form a molten substrate layer, and separating the transformed conductive material from the molten substrate layer to obtain a reclaimed transformed conductive material and a reclaimed substrate layer material.

[0005] In various embodiments, a method for recycling a regenerated transformed conductive material is disclosed. In one embodiment, the method includes providing a regenerated transformed conductive material including a metal alloy and a metal oxide formed by exposing the metal alloy to air, exposing the regenerated transformed conductive material to an acid solution, whereby the metal oxide and the acid solution react to obtain a clean liquid metal alloy, and removing the clean liquid metal alloy from the acid solution.

[0006] In various embodiments, a highly sustainable circuit assembly is disclosed. In one embodiment, the circuit assembly includes a substrate and a contact pattern supported by the substrate. In another embodiment, the contact pattern is configured to correspond to at least one terminal of an electrical component, the contact pattern including a modified conductive material. The modified conductive material includes a material that is readily renewable.

[0007] In various embodiments, a method for manufacturing a highly sustainable circuit assembly is disclosed. In one embodiment, the method includes providing a substrate layer and depositing a modified conductive material onto the substrate layer to form a contact pattern corresponding to at least one terminal of an electrical component. In another embodiment, the modified conductive material includes a readily renewable material.

[0008] In various embodiments, a highly sustainable circuit assembly is disclosed. In one embodiment, the circuit assembly includes a substrate layer and a first stack layer having a first routing pattern formed thereon. In another embodiment, the first routing pattern extends through a thickness of the first stack layer, the first routing pattern including a modified conductive material, the modified conductive material including a readily renewable material.

[0009] In various embodiments, a method for manufacturing a highly sustainable circuit assembly is disclosed. In one embodiment, the method includes providing a substrate layer and disposing a first stack layer on a surface of the substrate layer, the first stack layer having a first routing pattern formed thereon, the first routing pattern extending through a thickness of the first stack layer. In another embodiment, the method includes overfilling the first routing pattern with a deformed conductive material, removing excess deformed conductive material from the circuit assembly, and recovering the excess deformed conductive material.

[0010] These and other objects, configurations, and features of the present disclosure, as well as methods of operation, functions relating to elements of structure, combinations of parts, efficiency of manufacture, and the like, will become more apparent from a consideration of the following description, appended claims, and the accompanying drawings, which form part of this specification, while it is to be understood that the drawings are for purposes of illustration and description only, and are not intended to define or define the invention.

[0011] The various aspects described herein are particularly defined in the appended claims, and will become apparent from the following description, both as to organization and method of operation, including the advantages thereof, taken in conjunction with the accompanying drawings. [Brief description of the drawings]

[0012] [Figure 1] FIG. 2 is an exploded perspective view of a circuit assembly according to at least one non-limiting aspect of the present disclosure. [Diagram 2] FIG. 2 is a partially exploded perspective view of a circuit assembly according to at least one non-limiting embodiment of the present disclosure. [Figure 3A] 3 is a cross-sectional view taken along line AA of FIG. 2 illustrating details and aspects of an exemplary embodiment of the circuit assembly of FIG. 2 according to at least one non-limiting aspect of the present disclosure. [Figure 3B] 3 is a cross-sectional view taken along line AA of FIG. 2 illustrating details and aspects of an exemplary embodiment of the circuit assembly of FIG. 2 according to at least one non-limiting aspect of the present disclosure. [Figure 3C] 3 is a cross-sectional view taken along line AA of FIG. 2 illustrating details and aspects of an exemplary embodiment of the circuit assembly of FIG. 2 according to at least one non-limiting aspect of the present disclosure. [Figure 3D] 3 is a cross-sectional view taken along line AA of FIG. 2 illustrating details and aspects of an exemplary embodiment of the circuit assembly of FIG. 2 according to at least one non-limiting aspect of the present disclosure. [Figure 3E] 3 is a cross-sectional view taken along line AA of FIG. 2 illustrating details and aspects of an exemplary embodiment of the circuit assembly of FIG. 2 according to at least one non-limiting aspect of the present disclosure. [Figure 4] FIG. 2 is a partially exploded perspective view of a circuit assembly according to at least one non-limiting embodiment of the present disclosure. [Figure 5A] 5 is a cross-sectional view taken along line BB in FIG. 4 illustrating exemplary embodiment details and aspects of the circuit assembly of FIG. 4 according to at least one non-limiting aspect of the present disclosure. [Figure 5B] 5 is a cross-sectional view taken along line BB in FIG. 4 illustrating exemplary embodiment details and aspects of the circuit assembly of FIG. 4 according to at least one non-limiting aspect of the present disclosure. [Figure 5C] 5 is a cross-sectional view taken along line BB in FIG. 4 illustrating exemplary embodiment details and aspects of the circuit assembly of FIG. 4 according to at least one non-limiting aspect of the present disclosure. [Figure 6] FIG. 2 is a partially exploded perspective view of a circuit assembly according to at least one non-limiting embodiment of the present disclosure. [Figure 7A] 1A-1D illustrate various aspects of a laminated circuit assembly and a method for manufacturing the same in accordance with at least one non-limiting embodiment of the present disclosure. [Figure 7B] 1A-1D illustrate various aspects of a laminated circuit assembly and a method for manufacturing the same in accordance with at least one non-limiting embodiment of the present disclosure. [Figure 8A] 1A-1D illustrate various aspects of a laminated circuit assembly and a method for manufacturing the same in accordance with at least one non-limiting embodiment of the present disclosure. [Figure 8B]1A-1D illustrate various aspects of a laminated circuit assembly and a method for manufacturing the same in accordance with at least one non-limiting embodiment of the present disclosure. [Figure 9A] 1A-1D illustrate various aspects of a laminated circuit assembly and a method for manufacturing the same in accordance with at least one non-limiting embodiment of the present disclosure. [Figure 9B] 1A-1D illustrate various aspects of a laminated circuit assembly and a method for manufacturing the same in accordance with at least one non-limiting embodiment of the present disclosure. [Figure 10A] 1A-1D illustrate various aspects of a laminated circuit assembly and a method for manufacturing the same in accordance with at least one non-limiting embodiment of the present disclosure. [Figure 10B] 1A-1D illustrate various aspects of a laminated circuit assembly and a method for manufacturing the same in accordance with at least one non-limiting embodiment of the present disclosure. [Figure 11A] 1A-1D illustrate various aspects of a laminated circuit assembly and a method for manufacturing the same in accordance with at least one non-limiting embodiment of the present disclosure. [Figure 11B] 1A-1D illustrate various aspects of a laminated circuit assembly and a method for manufacturing the same in accordance with at least one non-limiting embodiment of the present disclosure. [Figure 12A] 1A-1D illustrate various aspects of a laminated circuit assembly and a method for manufacturing the same in accordance with at least one non-limiting embodiment of the present disclosure. [Figure 12B] 1A-1D illustrate various aspects of a laminated circuit assembly and a method for manufacturing the same in accordance with at least one non-limiting embodiment of the present disclosure. [Figure 13A] 1A-1D illustrate various aspects of a laminated circuit assembly and a method for manufacturing the same in accordance with at least one non-limiting embodiment of the present disclosure. [Figure 13B] 1A-1D illustrate various aspects of a laminated circuit assembly and a method for manufacturing the same in accordance with at least one non-limiting embodiment of the present disclosure. [Figure 14A] 1A-1D illustrate various aspects of a laminated circuit assembly and a method for manufacturing the same in accordance with at least one non-limiting embodiment of the present disclosure. [Figure 14B] 1A-1D illustrate various aspects of a laminated circuit assembly and a method for manufacturing the same in accordance with at least one non-limiting embodiment of the present disclosure. [Figure 15A]1A-1D illustrate various aspects of a laminated circuit assembly and a method for manufacturing the same in accordance with at least one non-limiting embodiment of the present disclosure. [Figure 15B] 1A-1D illustrate various aspects of a laminated circuit assembly and a method for manufacturing the same in accordance with at least one non-limiting embodiment of the present disclosure. [Figure 16] FIG. 1 is a cross-sectional view of a circuit assembly according to at least one non-limiting embodiment of the present disclosure. [Figure 17] FIG. 1 is a cross-sectional view of a circuit assembly according to at least one non-limiting embodiment of the present disclosure. [Figure 18] FIG. 1 is a flow diagram of a method for recovering materials from a highly sustainable circuit assembly in accordance with at least one non-limiting embodiment of the present disclosure. [Figure 19] FIG. 1 is a flow diagram of a method for recycling regenerated transformed conductive material in accordance with at least one non-limiting embodiment of the present disclosure.

[0013] Corresponding reference numbers throughout the several views indicate corresponding parts. Lettered reference numbers (e.g., 20A, 20B, etc.) may indicate variations of corresponding parts throughout the several views. The examples set forth below illustrate various aspects of the present disclosure in one embodiment, and these examples are not to be construed as limiting the scope of the present disclosure.

[0014] (Detailed Description) This application is related to the following co-pending patent applications, the disclosures of which are incorporated herein by reference in their entireties: International patent application PCT / US2017 / 019762, filed February 27, 2017, and published as International Publication WO2017 / 151523A1 on September 8, 2017, entitled "Liquid Wire"; U.S. Application No. 16 / 548379, entitled "Structure with Deformed Conductor," filed Aug. 22, 2019, and patented Aug. 10, 2021 as U.S. Patent No. 11,088,063; U.S. Application No. 17 / 192,725, filed March 14, 2021, titled "Modified Inductor"; International patent application PCT / US2021 / 071374, filed September 3, 2021, entitled "Wearable Device with Flexible Inductive Pressure Sensor"; U.S. Provisional Application No. 63 / 243,206, filed September 13, 2021, for an invention entitled "Sustainable Inflatable Circuit and Method for Manufacturing Same"; U.S. Provisional Application No. 63 / 261,266, filed Sep. 21, 2021, titled "Stretchable and Flexible Metal Film Structure"; U.S. Provisional Application No. 63 / 270,589, filed October 22, 2021, entitled "Flexible Three-Dimensional Electronic Components"; and The invention is titled "Apparatus, Systems, and Methods for Creating or Using Fluid-Filled Circuits" and is U.S. Provisional Application No. 3 / 272,487, filed October 27, 2021.

[0015] This application is also related to U.S. application Ser. No. 11 / 107,354, entitled "FLUID-FILLED BLADDER FOR FOOTWEAR AND OTHER USE," filed Apr. 14, 2004, and patented July 22, 2009 as U.S. Patent No. 7,401,369, the entire disclosure of which is incorporated herein by reference.

[0016] Numerous specific details described herein provide a detailed understanding of the overall structure, function, manufacture, and use of the embodiments described in this disclosure and illustrated in the accompanying drawings. Well-known operations, components, and elements are not described in detail so as not to obscure the embodiments described in the specification. The reader of this description will understand that the embodiments described and illustrated in this disclosure are non-limiting embodiments, and the specific structural and functional details described in this disclosure are representative and exemplary. Variations and modifications thereto may be made without departing from the scope of the claims of this application.

[0017] In the following description, the same reference characters refer to the same or corresponding parts throughout the drawings. In addition, in the following description, expressions such as "front", "rear", "left", "right", "upper", and "lower" are used for convenience and should not be understood as limiting expressions.

[0018] A portion of the disclosure of this patent document contains material protected by copyright law. The copyright owner agrees to the facsimile reproduction of this patent disclosure in the form in which it appears in the patent office files or records, but otherwise reserves his or her right to any and all copyrights disclosed in this application.

[0019] Traditional methods for laminating conductive materials onto a typical printed circuit board are unsustainable because they require multiple processes that consume many resources and create a lot of waste. For example, creating FR4 / copper circuit boards typically involves curing, etching, stripping, and soldering processes that consume electricity and water and generate used materials and waste. In the case of etching, for example, excess copper conductors are often treated as waste after being removed from the circuit board assembly. Furthermore, used materials such as etchants, stripping solvents, solder dross, and wastewater treatment sludge often become hazardous waste.

[0020] Furthermore, even circuit board manufacturing methods using conductive adhesives (e.g., conductive epoxies containing silver epoxy) instead of soldering can lack sustainability. For example, conductive epoxies are typically applied to circuit board assemblies and cured immediately. Due to this curing reaction, reworking the epoxy after curing will degrade its conductivity, so excess conductive epoxy cannot be reworked or reused. Thus, excess conductive epoxy is often wasted. In addition, cleaning solutions are also consumed when removing the conductive epoxy from the circuit board.

[0021] Various attempts have been made to improve the sustainability of conventional circuit boards. For example, the Environmental Protection Agency (EPA) has published a summary entitled "Workshop Materials on WEEE Management in Taiwan, Handout 10, Oct. 2012," the entire contents of which are incorporated herein by reference, providing details regarding waste generation and recycling processes associated with conventional printed circuit boards. However, these recycling processes are costly, time-consuming, and inefficient. Thus, there is a need for apparatus, systems, and methods for manufacturing and using highly sustainable circuit assemblies. The manufacturing and use of such highly sustainable circuit assemblies can not only reduce resource consumption, but also minimize waste and produce virtually no harmful by-products during manufacturing compared to conventional methods, and such highly sustainable circuit boards can include non-hazardous, readily renewable, and / or readily recyclable elements. These non-hazardous, readily renewable, and / or readily recyclable materials can be reused in the creation of additional circuit assemblies, reducing the need for new raw materials. This disclosure describes apparatus, systems, and methods for making and using such highly sustainable circuit assemblies.

[0022] Disclosed are several aspects of apparatus, systems, and methods for manufacturing and using circuit assemblies having various components, such as substrates, layers, laminates, contacts, traces, and electrical components (e.g., integrated circuits). Various aspects (e.g., features, components, materials, methods) disclosed with respect to specific circuit assemblies disclosed herein may be applied to and combined with other circuit assemblies and / or methods disclosed herein.

[0023] 1 shows an exploded perspective view of a circuit assembly 10 according to at least one non-limiting embodiment of the present disclosure. The circuit assembly 10 includes a substrate layer 100 including a contact pattern 102. According to the non-limiting embodiment of FIG. 1, two contacts 102 are shown. However, according to alternative embodiments, the contact pattern 102 may include various arrangements of contacts, including a single contact structure. The contact pattern 102 may be supported by the substrate 100. The contact pattern 102 may be formed of a conductive material that is easily reproducible and deformable.

[0024] In this disclosure, the term "readily renewable" means that the material can be reclaimed from the circuit assembly using techniques or methods that (i) do not use significant resources such as water, (ii) use relatively low energy inputs, and / or (iii) do not generate significant waste or material loss. A method that does not generate significant waste and / or material loss may mean that 60% or more of the material by weight, such as 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, 99.5%, or 99.9% or more by weight of the material is not discarded and / or lost during the reclaiming process. The reclaiming process is exemplified below with reference to FIG. 18. A readily renewable material may be a readily recyclable material.

[0025] The term "readily recyclable" as used herein may mean that the material can be processed for reuse in further manufacturing. A material is easily recyclable if 55% or more by weight of the material originally used to generate the next recycled material can be reprocessed and reused, such as 60%, 65%, 70%, 75%, 80%, 85%, or 90% or even 95% or more by weight. Regenerating and reprocessing easily renewable and easily recyclable materials can generally reduce the need to create new substrates. An exemplary recycling process for easily recyclable materials is described below with reference to FIG. 19.

[0026] The term "modified conductive material" as used herein may refer to the material disclosed in International Patent Application PCT / US2017 / 019762, entitled "Liquid Wire," filed February 27, 2017, and published September 8, 2017 as International Publication WO2017 / 151523A1, the entire disclosure of which is incorporated herein by reference. For example, the modified conductive material may be in various states, such as liquid, paste, gel, and / or powder, or may otherwise have deformability (e.g., soft, flexible, bendable, stretchable, flowing viscoelastic, Newtonian, or non-Newtonian viscosity, etc.).

[0027] In various configurations, the modified conductive material may include an electroactive material, such as a modified conductor (such as a gallium indium alloy) that includes a conductive gel. The conductive gel may have a shear thinning composition, and in some configurations may include a mixture of materials in desired ratios.

[0028] In some embodiments, the viscosity of the deformed conductive material under high shear (e.g., during motion) may be in the range of about 10 to 500 Pascal seconds (Pa*s), such as in the range of 50 Pa*s to 300 Pa*s, and / or may be about 50 Pa*s, about 60 Pa*s, about 70 Pa*s, about 80 Pa*s, about 90 Pa*s, about 100 Pa*s, about 110 Pa*s, about 120 Pa*s, about 130 Pa*s, about 140 Pa*s, about 150 Pa*s, about 160 Pa*s, about 170 Pa*s, about 180 Pa*s, about 190 Pa*s, or about 200 Pa*s. In some embodiments, the viscosity of the deformed conductive material may be in the range of 1,000,000 Pa*s to 40,000,000 Pa*s under low shear (e.g., at rest), and / or may be about 10,000,000 Pa*s, about 20,000,000 Pa*s, about 30,000,000 Pa*s, or about 40,000,000 Pa*s.

[0029] In various embodiments, the conductive gel may include a mixture of a eutectic gallium alloy and gallium oxide, the mixture including a eutectic gallium alloy in a weight percent (wt%) range of 59.9% to 99.9%, such as 67% to 90%, and a gallium oxide in a weight percent range of 0.1% to 2.0%, such as 0.2% to 1%. For example, mixtures of eutectic gallium alloys and gallium oxides have the following melting points: 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, and 95%. It may contain 95%, 96%, 97%, 98%, 99% or more (e.g., 99.9%) eutectic gallium alloy and may contain 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2.0% gallium oxide.

[0030] In various embodiments, the eutectic gallium alloy may include gallium-indium or gallium-indium-tin in a desired elemental ratio. In some embodiments, the eutectic gallium alloy includes gallium and indium. In some embodiments, the gallium-indium alloy may include gallium in a weight percent range of 40-95%, such as 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 100%, 101%, 102%, 103%, 104%, 105%, 106%, 107%, 108%, 109%, 109%, 109%, 108%, 109%, 1010%, 109, 102%, 103%, 104%, 105%, 106%, 107%, 108%, 109%, 109, 109, 1010%, 102%, 103%, 104%, 105%, 106%, 107%, 108%, 109, Contains 3%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, or 95%. In one embodiment, the gallium-indium alloy contains indium in a weight percent range of 5-60%, for example 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28% , 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, or 60%. In some embodiments, the eutectic gallium alloy contains gallium and tin.In one embodiment, the alloy contains tin in a weight percentage range of 0.001 to 50%, for example, 0.001%, 0.005%, 0.01%, 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.5%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13% , 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, or 50%.

[0031] In various forms, the modified conductive material may be a non-hazardous material. As used herein, the term "non-hazardous" may mean that the material is RoHS compliant under European Union Directive 2002 / 95 / EC, Directive 2011 / 65 / EU, and / or Directive 2015 / 863 (i.e., RoHS, RoHS2, RoHS3). For example, in some embodiments, the non-hazardous materials may contain, by weight, less than 0.01% cadmium (Cd), less than 0.1% lead (Pb), less than 0.1% mercury (Hg), less than 0.1% hexavalent chromium (Cr VI), less than 0.1% polybrominated biphenyls (PBBs), less than 0.1% polybrominated diphenyl ethers (PBDEs), less than 0.1% bis(2-ethylhexyl) phthalate (DEHP), less than 0.1% benzyl butyl phthalate (BBP), less than 0.1% dibutyl phthalate (DBP), and less than 0.1% diisobutyl phthalate (DIBP).

[0032] The transformed conductive materials disclosed herein may be readily renewable and readily recyclable. In some embodiments, the transformed conductive materials disclosed herein may be highly sustainable. As used herein, "highly sustainable" may refer to materials and / or products that are readily renewable and / or contain readily renewable content, require relatively little energy and other resources to manufacture, are non-hazardous and / or contain non-hazardous materials, do not generate hazardous substances during manufacture, and / or do not generate other waste during manufacture. In some embodiments, a highly sustainable transformed conductive material may be readily renewable, non-hazardous, have no substantial VOC emissions during manufacture, be layerable with relatively little energy consumption, be layerable in a single step, be manufactured, regenerated, and recycled without consuming natural resources (e.g., water), generate substantially no waste during manufacture, or combinations thereof. In some forms, the highly sustainable circuit assembly may include a highly sustainable modified conductive material, may have one or more layers (e.g., a substrate layer, a stencil layer, an insulating layer) that include a highly sustainable material, and / or may be fabricable using a variety of manufacturing techniques, as described below with reference to Figures 7A, 7B through 19.

[0033] In various configurations, the modified conductive material may be adhesive to the various layers of a circuit assembly and the terminals / contacts of electrical components, as determined by a "smear test." The smear test is performed by smearing approximately 1 cm3 of the modified conductive material onto a test coupon of layer material or terminal / contact material. The modified conductive material may be applied with a cotton swab (i.e., a Q-Tip). TM) onto the test coupon. If the modified conductive material coats the test coupon without forming any air bubbles, then the modified conductive material is adhesive to the test coupon material. On the other hand, if applying the modified conductive material to the test coupon causes a bead to form in the modified conductive material, thereby leaving air bubbles on the test coupon, then the modified conductive material is not adhesive. For example, some modified conductive material formulations may have a surface tension that causes a bead to form in the modified conductive material. A smear test should be performed on all materials (e.g., terminals, channels, leads, contact walls) that have mating surfaces with the modified conductive material to be tested for adhesion. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] Returning again to FIG. 1 , the circuit assembly 10 may include an electrical component 104. The electrical component 104 may be supported by a substrate 100 and may include one or more terminals 106. As will be described in more detail below, the one or more terminals 106 may be configured in various arrangements depending on the type of electrical component 104 used. The contact pattern 102 may be configured based on the number and arrangement of the terminals 106 of the electrical component 104 such that the contact pattern 102 aligns with or corresponds to the one or more terminals 106. According to a non-limiting embodiment of FIG. 1 , the one or more terminals 106 are shown in dashed lines (partial perspective view) and are located on a side of the electrical component 104 that is not visible in the perspective view shown in FIG. 1 . The one or more terminals 106 of the electrical component 104 may connect to a corresponding one or more portions of the contact pattern 102 to form one or more electrical connections between the electrical component 104 and the contact pattern 102. In a configuration in which the electrical component 104 is adhered, attached, proximate, or supported by the substrate 100, one or more terminals 106 may contact a corresponding portion or portions of the contact pattern 102, as indicated by arrows 108. Thus, various embodiments of the circuit assembly 10 may be capable of forming electrical connections without the need for soldering or conventional processes to form electrical connections.

[0035] In various embodiments, the contact pattern 102 may be supported by the substrate 100, for example, by being formed directly on the surface of the substrate, by being recessed into the substrate 100, by being formed in another layer of material above the substrate 100, or in other manners. The electrical component 104 may be supported by the substrate 100, for example, by being attached directly to the surface of the substrate 100, by being attached to another component supported by the substrate 100, for example, by being glued to the contact pattern 102, or in other manners.

[0036] In various embodiments, the circuit assembly 10 may include a pattern of reusable conductive traces (not shown) formed from a modified conductive material and supported by the substrate 100. In some embodiments, the pattern of reusable conductive traces may be similar to the traces disclosed below. The pattern of reusable conductive traces may be interconnected with the contact pattern 102. In some configurations, the contact pattern 102 and the reusable conductive traces may be formed from the same modified conductive material.

[0037] 1 may include one or more of a wide variety of readily renewable and / or readily recyclable materials. In various embodiments, the substrate 100 may include, for example, a thermoset plastic material, a thermoplastic material (such as a thermoplastic polymer), such as thermoplastic polyurethane (TPU), high density polyethylene (HDPE), polyethylene terephthalate (PET), polyvinyl chloride (PVC), low density polyethylene (LDPE), polypropylene (PP), polystyrene (PS), or the like, textile, wood, paper, or other insulating materials, or combinations thereof.

[0038] With further reference to FIG. 1 , the electrical component 104 may be any electrical, electronic, electromechanical, and / or electrical device or function, such as an integrated circuit, a semiconductor, a transistor, a diode, an LED, a capacitor, a resistor, an inductor, a switch, a terminal, a connector, a display, a sensor, a printed circuit board, or other device or function. In some embodiments, the electrical component 104 may include exposed components. In some embodiments, the electrical component 104 may be partially or fully encapsulated in various types of packages. In some embodiments where the electrical component 104 includes an integrated circuit and / or a semiconductor, various types of packages may be used, as described in more detail below. For example, the electrical component 104 may include an integrated circuit in bare die form. As another example, the electrical component may include a die that is attached to a substrate but not fully encapsulated in a package, such as a chip-scale device.

[0039] With further reference to FIG. 1, the circuit assembly 10 can be a highly sustainable circuit assembly. The highly sustainable circuit assembly 10 can include a substrate layer 100 including a readily renewable material, such as, for example, a thermoplastic polymer or one or more of the various substrate materials disclosed above. The highly sustainable circuit assembly 10 can include contacts 102 including a readily renewable modified conductive material (e.g., a highly sustainable modified conductive material), such as, for example, one or more of the various modified conductive materials disclosed above. In various embodiments, the circuit assembly 10 can be manufactured and / or processed using various manufacturing, remanufacturing, and recycling techniques, which are described in detail below with respect to any of FIGS. 7A and 7B through 19. Thus, the highly sustainable circuit assembly 10 can include components that can be formed and / or laminated, remanufactured, and recycled without consuming natural resources (e.g., water) and / or without generating substantial waste.

[0040] Although a general embodiment of the circuit assembly 10 has been described that may, in some aspects, result in a highly sustainable circuit 10, various other circuit assemblies are described. Any of the aspects of the circuit assembly 10 described above (e.g., the substrate layer 100, the contact pattern 102, the electrical components 104, the one or more terminals 106, etc.) may be applied to any of the various other circuit assemblies described below. Similarly, any of the aspects of the various other circuit assemblies described below may be applied to the circuit assembly 10. Thus, any of the circuit assemblies described below may result in a highly sustainable circuit assembly.

[0041] Referring now to FIG. 2, a partially exploded perspective view of a circuit assembly 12 is shown in accordance with at least one non-limiting embodiment of the present disclosure. According to the non-limiting embodiment of FIG. 2, the circuit assembly 12 may include an integrated circuit (IC) 116 configured in a surface mount package having terminals in the form of leads 118A-118F (collectively referred to as leads 118; leads 118E-118F not shown). The circuit assembly 12 may include a substrate layer 110 including a modified conductive material and including a pattern of contacts 112A-112F (collectively referred to as contacts 112) arranged to correspond to the footprints of the leads 118 of the IC 116. In various embodiments, the contacts 112 may be formed in the shape of solder pads conventionally used to make electrical connections between the IC 116 and a printed circuit board. The reusable conductive traces 114A-114F (collectively reusable conductive traces 114) may be formed from modified conductive material and may each be connected to a contact 112A-112F and extend to an edge of the substrate layer 110. As described in further detail herein, the contact pattern 112 and / or the reusable conductive traces 114 may be specifically configured for reuse via methods 1000, 2000 of FIGS. 18 and 19. The reusable traces 114 may be used, for example, to connect the integrated circuit 116 to other electrical components, circuits, terminals, and the like. The leads 118A-118F contact the corresponding contacts 112A-112F, respectively, when the integrated circuit 116 is adhered to, attached to, proximate to, disposed on, or otherwise supported by the substrate 110, as indicated by arrow 120. In the non-limiting embodiment of FIG. 2, the contacts 112 and reusable traces 114 are formed on a surface of the substrate layer 110 and protrude above the substrate layer 110, for example, by flexographic printing, block printing, jet printing, 3D printing, stencil transfer, spray masking, extrusion, rolling, brushing, screen printing, pattern deposition, or any other suitable technique.

[0042] 3A-3E are cross-sectional views taken along line AA in FIG. 2 showing an exemplary embodiment of circuit assembly 12 according to a non-limiting embodiment of the present disclosure. Although specific contacts (i.e., contacts 112C, 112D), leads (i.e., leads 114C, 114D), and terminals (i.e., terminals 118C, 118D) are depicted in FIG. 3A-3E, the various details presented may apply to any example of contacts, leads, and / or terminals. Accordingly, these components are referred to below as contacts 112, leads 114, and terminals 118.

[0043] 3A, circuit assembly 12 is shown prior to bringing IC 116 into proximity with substrate layer 110 in accordance with at least one non-limiting embodiment of the present disclosure.

[0044] 3B, a circuit assembly 12 is shown in which an IC 116 is supported by a substrate layer 110 and forms ohmic contacts between leads 118 and contacts 112 in accordance with at least one non-limiting embodiment of the present disclosure. The IC 116 is secured to the substrate layer 110 by an adhesive layer 122. In the non-limiting embodiment of FIG. 3B, the leads 118 displace a portion of the deformed conductive material of the contacts 112. The displacement of the deformed conductive material by the leads 118 can cause the deformed conductive material to conform to the shape of the leads 118, providing additional contact surface area and improved electrical connection between the contacts 112 and the IC 116.

[0045] 3C, the circuit assembly 12 has an encapsulant 124 covering all or a portion of the integrated circuit 116, the leads 118, the contacts 112, or the reusable traces 114, or any combination thereof, in accordance with at least one non-limiting embodiment of the present disclosure. The encapsulant 124 may further fill spaces between the integrated circuit 116, the leads 118, and the substrate layer 110. The encapsulant 124 may include, for example, a silicon-based material such as polydimethylsiloxane (PDMS), urethane, epoxy, polyester, polyamide, varnish, and other materials that can form a protective coating and / or can be used to hold the circuit assembly 12 together. In various embodiments, the encapsulant 124 may be a thermoplastic polymer (e.g., a polymeric material similar to the substrate layer 110). Thus, the encapsulant 124 may include a highly sustainable material.

[0046] 3D, circuit assembly 12 is illustrated in which IC 116 directly contacts substrate layer 110 in accordance with at least one non-limiting embodiment of the present disclosure. In some embodiments, substrate layer 110 may include an inherently tacky or adhesive material having sufficient adhesive properties to secure IC 116 to substrate layer 110. In some configurations, encapsulant 124, as described above in connection with FIG. 3C, may directly secure IC 116 to substrate layer 110 without the need for adhesive 122. In some configurations, configuring circuit assembly 12 such that IC 116 directly contacts substrate layer 110 may allow leads 118 to be pressed further into contacts 112 as compared to non-limiting embodiments of circuit assembly 12 in which adhesive 122 is used.

[0047] 3E, the circuit assembly 12 includes a layer 126 of material attached to the surface of the substrate layer 110 and located between the contact pattern 112 and the substrate layer 110. The layer 126 can perform a variety of functions. For example, the substrate layer 110 can be made of a flexible or stretchable material, while the layer 126 can be made of a relatively stiff or less stretchable material to inhibit bending or stretching of the region of the substrate 110 proximate the IC 116 or other electrical component. Thus, the layer 126 can serve to inhibit poor connection between the terminal 118 of the integrated circuit 116 and the contact 112 that may occur due to bending or stretching of the substrate 110. As another example, the layer 126 can perform a heat sinking or heat dissipation function for the IC 116 or other electrical component. As yet another example, the layer 126 can have adhesive or high tack properties greater than those of the substrate layer 110. Thus, layer 126 can serve to secure ICs 116 or other electrical components to substrate layer 110, with or without the use of adhesive 122. In some embodiments, layer 126 may additionally or alternatively be disposed on a surface of substrate layer 110 opposite a surface of substrate layer 110 to which ICs 116 are attached. In some embodiments, layer 126 may additionally or alternatively be disposed within the substrate. In some embodiments, layer 126 may additionally or alternatively be disposed elsewhere in circuit assembly 12. Layer 126 may be formed as a continuous sheet of material or may be patterned to have openings for, for example, any or all of contacts 112, reusable traces 114, integrated circuits 116, or other components. Layer 126 may include materials such as, for example, TPU, fiberglass, PET, polyimide (PI), or B-stage resin film. In various embodiments, layer 126 may include a thermoplastic polymer (e.g., a polymeric material similar to substrate layer 110). In this manner, layer 126 may include a highly sustainable material.

[0048] 4, a partially exploded perspective view of a circuit assembly 14 is shown in accordance with at least one non-limiting embodiment of the present disclosure. The circuit assembly 14 may include a substrate layer 128, contact patterns 126A-F (collectively, contacts 126), reusable traces 130A-F (collectively, reusable traces 130), and an IC 132 including terminals 134A-F (collectively, terminals 134). The circuit assembly 14 may be similar to the circuit 12 of FIG. 2, except that the contacts 126 and traces 130 of the circuit assembly 14 may be formed by recesses in the substrate layer 128 that are partially or completely filled with a deformed conductive material. The recesses in the contacts 126 in the substrate layer 128 may be formed by removing a portion of the sheet material of the substrate layer 128 by drilling, routing, etching, cutting, or other methods of removing material using mechanical-optical devices (e.g., lasers), chemical devices, electrical devices, ultrasonic devices, or other devices or combinations thereof. Alternatively or additionally, the substrate layer 128 may be formed with the recesses of the contacts 126 via molding, casting, 3D printing, or other forming processes. The modified conductive material may be deposited within the recesses of the contacts 126 via any of the processes described above, including printing, stencil transfer, spraying, rolling, brushing, and any other technique for depositing material within a recess. Additionally, the recesses of the contacts 126 may be overfilled with the modified conductive material, after which excess material may be removed using any suitable technique, including scraping, rolling, brushing, and the like, such that the modified conductive material is flush with, protrudes beyond (i.e., overfilled) or recessed within (i.e., underfilled) the surrounding surface of the substrate layer 128. This is described in more detail below.

[0049] 5A-5C are cross-sectional views taken along line BB in FIG. 4 showing an exemplary embodiment of a circuit assembly 14 according to a non-limiting embodiment of the present disclosure. Although specific contacts (i.e., contacts 126C, 126D), leads (i.e., leads 130C, 130D), and terminals (i.e., terminals 134C, 134D) are shown in FIG. 5A-5C, in some cases, the various details presented may apply to any example of the contacts, leads, and / or terminals. Accordingly, these components are hereinafter referred to as contacts 126, leads 130, and terminals 134.

[0050] Referring to FIG. 5A, circuit assembly 14 is shown prior to bringing IC 132 into proximity with substrate layer 128 in accordance with at least one non-limiting embodiment of the present disclosure.

[0051] 5B, a circuit assembly 14 is illustrated in which an IC 132 is supported by a substrate layer 128 and forms ohmic contacts between the leads 134 and the contacts 126 in accordance with at least one non-limiting embodiment of the present disclosure. In some embodiments, the IC 132 is directly attached to the substrate layer 128, which may include, for example, an adhesive surface, as described above with respect to the substrate layer 110 of FIG. 3D. Alternatively, the IC 132 may be attached to the substrate using an adhesive or other suitable technique, for example, as described above with respect to FIGS. 3B-3E. In the non-limiting embodiment of FIG. 5B, the leads 134 protrude toward the contacts 126, displacing a portion of the deformed conductive material. The displacement of the deformed conductive material by the leads 134 can cause the deformed conductive material to conform to the shape of the leads 134, providing additional contact surface area and improved electrical connection between the contacts 126 and the IC 132.

[0052] In the non-limiting embodiments of Figures 2, 3A-3E, 4, and 5A-5B, each IC is illustrated as a surface mount package, such as a SOT23-6 (Small Outline Transistor, 6-lead) package. Of course, any other type of IC package and electronic component may be used with the circuit assemblies disclosed herein (e.g., as disclosed above with respect to electrical component 104 of Figure 1). For example, referring now to Figure 5C, circuit assembly 14 uses chip-scale package 136 as an integrated circuit (instead of IC 132) in accordance with at least one non-limiting embodiment of the present disclosure. Chip-scale package 136 includes solder bumps 138. Similar to leads 134, solder bumps 138 can form ohmic contacts with contacts 126.

[0053] In various embodiments, leadless chip carriers may be used with the circuit assemblies disclosed herein. Leadless chip carriers may have terminals with flat lead surfaces that provide a good interface to any of the disclosed contacts without disturbing the deformed conductive material pattern. In other embodiments, packages with protruding solder structures, such as ball grid arrays (BGAs) and wafer level chip scale packages (WL-CSPs), such as the chip scale package 136 shown in FIG. 5C, as well as packages with slightly protruding leads, such as leaded chip carriers, may be used with the circuit assemblies disclosed herein. Packages with protruding solder structures or leads may be used because the deformed conductive material can sink the protruding solder structures or leads into the contacts to form a reliable ohmic connection without displacing the deformed conductive material enough to destroy the pattern.

[0054] Referring to FIG. 6, a partially exploded perspective view of a circuit assembly 16 is shown in accordance with at least one non-limiting embodiment of the present disclosure. The circuit assembly 16 can include a substrate layer 140, contact patterns 144A-F (collectively, contacts 144), reusable traces 146A-F (collectively, reusable traces 146), and an IC 148 including terminals 150A-F (collectively, terminals 150). The circuit assembly 16 can be similar to the circuit assembly 14 of FIG. 4, except that a layer of material 142 is attached to the surface of the substrate layer 140 after formation of the pattern of contacts 144 and reusable traces 146, but before attachment of the integrated circuit 148. The layer 142 can be similar to, for example, the layer 126 in the non-limiting embodiment of FIG. 3E. According to the non-limiting embodiment of FIG. 6, the layer 142 includes openings 152A and 152B for the contacts 144. However, layer 142 may include any number and pattern of openings to expose various patterns of contacts 144 that may be implemented.

[0055] In addition to packaged integrated circuits and other devices, exposed integrated circuit dies and other components may be used with the circuit assemblies disclosed herein. For example, an IC die containing bonding or contact pads can be mounted to a substrate layer having a flush or protruding contact pattern that corresponds to the pattern of bonding or contact pads on the die. In some forms, a bare integrated circuit die may be mounted such that the bonding or contact pads face the surface of the substrate that contains the contacts (e.g., the die may be mounted upside down). Such mounting allows the deformed conductive material of the contacts to form an ohmic connection with the bonding or contact pads.

[0056] Although the modified conductive material is generally shown to be flush with the surface of the substrate, such as in circuit assemblies 14 and 16 in Figures 4, 5A-5C, and 6, the modified conductive material may additionally or alternatively be formed inboard (i.e., recessed into) or higher than (i.e., protruding out of) the surface of substrate layer 128, 140. In some embodiments, the modified conductive material may be formed lower than the surface of substrate layer 128, 140, for example, by only partially filling some or all of the recesses of contacts 126, 144 with material, or by removing some material by scraping, brushing, gouging, etching, evaporation, etc. In some embodiments, the modified conductive material may be formed higher than the surface of substrate layer 128 by pattern lamination, stencil transfer, various forms of printing, etc. In some non-limiting embodiments, the modified conductive material may be formed higher than the surface of the substrate layer 126, 144 by using a release layer having a pattern that matches the recessed pattern of the contacts 126, 144. The release layer may be disposed over the substrate layer 128, 140, and the recessed pattern may be overfilled and then ground flush with the top surface of the release layer. The release layer may then be removed to form the protruding modified conductive material in a manner described below.

[0057] 2, 3A-3E, 4, 5A-5C, and 6 generally depict the contacts and reusable traces of the circuit assemblies 12, 14, 16 extending partially on the surface of or into the substrate layers. In various aspects of the disclosure, the circuit assemblies described herein may be configured such that some or all of the contacts and / or reusable traces extend through the entire thickness of the substrate layers. For example, the contacts may be implemented as vias that extend through the substrate layers, which may function as stack layers, as described below.

[0058] Although general embodiments of circuit assemblies 10, 12, 14, and 16 that can be highly sustainable in some aspects have been described, the present disclosure also describes various other circuit assemblies and methods of manufacturing them. Various other circuit assemblies described below have stack layers that include paths configured to include modified conductive materials. Any of the aspects of circuit assemblies 10, 12, 14, and 16 described above (e.g., substrate layers, contact patterns, electrical components (e.g., ICs), one or more terminals, etc.) may be applied to any of the various other circuit assemblies described below. Similarly, any of the aspects of the various other circuit assemblies described below and methods of manufacturing them may be applied to circuit assemblies 10, 12, 14, and 16 described above.

[0059] 7A and 7B through 15A and 15B show various intermediate circuit assemblies and final circuit assemblies according to non-limiting embodiments of the present disclosure. In some embodiments, 7A and 7B through 15A and 15B may correspond to various steps for a method of manufacturing the intermediate circuit assemblies and the final circuit assemblies. 7B, 8B, 9B, 10B, 11B, 12B, 13B, 14B, and 15B are cross-sectional views of 7A, 8A, 9A, 10A, 11A, 12A, 13A, 14A, and 15A, respectively.

[0060] Referring now to FIG. 7A, a perspective view of the circuit assembly 20A is shown prior to laminating the substrate layer 250 to the first stack layer 252 according to at least one non-limiting embodiment of the present disclosure. In the non-limiting embodiment of FIG. 7, the first stack layer 252 is shown as a stencil layer. In other embodiments, the first stack layer 252 may be an insulating layer. In some embodiments, the circuit assembly 20A may include a release layer 254 disposed on the first stack layer 252. FIG. 7B is a cross-sectional view taken along line CC in FIG. 7A. FIGS. 7A and 7B may correspond to initial or intermediate steps for producing a highly sustainable circuit assembly. The substrate layer 250 and the first stack layer 252, as well as any additional stack layers (e.g., layers 270, 276, 282, etc.) shown in FIGS. 8A and 8B through 15A and 15B may be made from materials disclosed in the above description with respect to the substrate layer 100 of FIG. 1. For example, the substrate layer 250 and the first stack layer 252 may be made of a readily recyclable polymeric material such as TPU. The substrate layer 250 may be a generally continuous sheet of material, while the first stack layer 252 and the release layer 254 may include one or more pathway patterns (e.g., openings, channels 256, 258) configured to accommodate the deformed conductive material. In various embodiments, the pathways 256, 258 may be channels cut through the thickness of a sheet of material used to create a mask or stencil, thereby creating the first stack layer 252 (e.g., a stencil layer). The release layer 254 may be thinner than the first stack layer 252 and may be laminated on top of the first stack layer 252.

[0061] In various configurations, release layers, such as release layer 254, may be applied and removed during the manufacturing process of the various circuit assemblies disclosed herein. In some embodiments, the release layer may be the only substantial "waste" generated during the manufacturing process of the circuit assemblies. As such, circuit assembly designs and materials that do not include a release layer may be preferred.

[0062] However, in various embodiments, it may be desirable to manufacture the various circuit assemblies disclosed herein with, for example, a release layer to achieve the contact configurations described below. If a release layer is used during manufacture, the release layer can be formed from a readily recyclable material, for example, siliconized or non-siliconized PET film, or siliconized or non-siliconized paper-based release film. Methods for recycling these release layers are described in U.S. Patent Publication No. 8,842,840, published September 30, 2014, entitled "Process for Recycling Waste Film and Articles Manufactured Therefrom," the entire disclosure of which is incorporated herein by reference. Methods for these recycling processes are also described, for example, by Mitsubishi in the Reprocessing Process for Waste Film and Articles Manufactured Therefrom. TM Accordingly, a circuit assembly that includes and / or is manufactured using a readily recyclable release liner can be a highly sustainable circuit assembly.

[0063] 7A and 7B, the pathways 256, 258 may be formed in the first stack layer 252 and possibly the release layer 254 using subtractive techniques, such as, for example, laser cutting, drilling, routing, die cutting, water jet cutting, etc. In other embodiments, the first stack layer 252 and / or the release layer 254, and thus the pathways 256, 258, may be formed using additive manufacturing techniques, such as 3D printing, pattern deposition, molding (injection, pressing), etc. These techniques may be similarly applied to form additional stack layers (e.g., stack layers 270, 276, 282, etc.) disclosed below with respect to FIGS. 8A and 8B through 15A and 15B.

[0064] In various forms, the techniques used to form the layers of the circuit assemblies disclosed herein may generate scrap (e.g., due to cutting paths, etc.). The amount of scrap generated may be relatively small since only a small amount of material needs to be removed due to the small dimensions of the paths (e.g., the path dimensions may generally have widths and / or depths on the micron scale, e.g., widths and / or depths in the range of 80-400 microns). Notwithstanding the above, because the layers of the circuit assemblies disclosed herein may include readily renewable and readily recyclable materials, scrap generated during the formation of the layers may be salvaged, reprocessed, and used in subsequent manufacturing of the layers and / or circuit assemblies.

[0065] Referring to FIG. 8A, a perspective view of the circuit assembly 20B after laminating the substrate layer 250 to the first stack layer 252 is shown according to at least one non-limiting embodiment of the present disclosure. FIG. 8B is a cross-sectional view taken along line DD in FIG. 8A. FIGS. 8A and 8B may correspond to steps for manufacturing a highly sustainable circuit assembly. Prior to subsequent manufacturing steps, the substrate layer 250 and the first stack layer 252 may be bonded, fused, or cured together, or otherwise connected to each other using any suitable process and / or material. For example, in some embodiments, the substrate layer 250 and the first stack layer 252 may be positioned in a lamination position (e.g., using an index pin). In some forms, the substrate layer 250 and the first stack layer 252 may be made of TPU or other thermoplastic material and may be bonded together using heat and pressure. In some embodiments, the substrate layer 250 and / or the first stack layer 252 are made of an inherently tacky material, such as a b-stage resin material or an aliphatic TPU film (e.g., Huntsman Krystalflex TM). In some embodiments, the substrate layer 250 and the first stack layer 252 can be bonded together by self-adhesion and pressure. In some embodiments, the substrate layer 250 and / or the first stack layer 252 can be made of a UV-curable material and can be exposed to a UV light source after lamination. Bonding the substrate layer 250 and the first stack layer 252 during lamination may seal the channels 256 and 258 at the interface between the substrate layer 250 and the first stack layer 252, ensuring no leakage when laminating the deformed conductive material, as described below. Leakage of the deformed conductor may additionally or alternatively be inhibited by other methods, such as configuring the formulation of the deformed conductive material to inhibit leakage (e.g., adjusting the rheological parameters of the deformed conductive material), using tools (e.g., clamping the layers and / or using pins), and adjusting the operating parameters used during the manufacture of the circuit assembly (e.g., adjusting the applied pressure of the wiping operation).

[0066] Referring to FIG. 9A, a perspective view of the circuit assembly 20C is shown after overfilling the channels 256 and 258 of the first stack layer 252 with a modified conductive material 260. FIG. 9B is a cross-sectional view taken along line EE of FIG. 9A. FIGS. 9A and 9B may correspond to steps for manufacturing a highly sustainable circuit assembly. The modified conductive material 260 may include any of the modified conductive materials disclosed above with respect to FIG. 1. In various embodiments, the modified conductive material 260 may be easily renewable and / or highly sustainable, thus making the circuit assembly 20 a highly sustainable circuit lay-up. For example, the modified conductive material 260 may include a conductive gel (e.g., gallium indium alloy) as disclosed above. Overfilling the channels 256, 258 with the modified conductive material 260 may be performed using any suitable technique, such as extrusion, rolling, swabbing, spraying, printing, brushing, deposition. In some embodiments, the channels 256, 258 may be overfilled with the deformed conductive material 260 using a cotton swab. The step of using a cotton swab may include driving the deformed conductive material 260 completely into the channels 256, 258.

[0067] 10A, a perspective view of a circuit assembly 20D is shown in a process of wiping off excess deformed conductive material 260, according to at least one non-limiting embodiment of the present disclosure. FIG. 10B is a cross-sectional view taken along line FF in FIG. 10A. FIG. 10A and FIG. 10B may correspond to steps for manufacturing a highly sustainable circuit assembly. After the deformed conductive material 260 is laminated to the circuit assembly 20 (e.g., overfilled into the channels 256, 258), the excess deformed conductive material 260 may be wiped off from the surface of the first stack layer 252, or from the release layer 254 as shown in the non-limiting embodiment of FIG. 10A and FIG. 10B. The wiping process may be performed by wiping in the direction indicated by the arrow 264 using a wiping tool 262. The wiping tool 262 may optionally be a squeegee with a resilient blade configured to apply downward pressure to the surface of the first stack layer 252 and / or the release layer 254 while moving horizontally over the surface of the layer. This wiping action may cause excess deformed conductive material 260 to form a mound 266 in front of the tool 262 and help fill underfilled areas of the channels 256 and 258. The excess deformed conductive material 260 may be collected and used to fill channels or to form reusable traces and / or contacts in another circuit assembly. Various lamination methods described herein may perform a single operation to apply the deformed conductive material 260 to each layer of the circuit assembly. In some embodiments, no further operations are required to produce functional, reusable traces and / or contacts in the circuit assembly.

[0068] To evaluate the feasibility of salvaging and reusing deformed conductive materials in a manufacturing environment, the inventors salvaged reclaimed deformed conductive materials from several lamination and wiping operations (i.e., the same bulk material is reclaimed and reused across several circuit assembly lamination operations) and tested their performance. Experiments have shown that the excess material reclaimed from prior operations performs substantially indistinguishably compared to virgin material, as shown in Examples 1 and 2 below. Thus, compared to conventional circuit boards and related methods, the various circuit assemblies and their related methods disclosed herein can reduce or eliminate waste generation and / or reduce or eliminate resource consumption due to lamination of conductive materials. For example, as described in detail above, conventional methods of manufacturing FR4 / copper circuit boards often include various resource-consuming curing, etching, and stripping steps that generate waste, such as etched excess copper conductors and other used materials. Furthermore, epoxy-based conductive adhesives used in place of soldering are often wasted due to reduced reusability after curing. In contrast, in various embodiments, the transformed conductive materials described herein can be laminated onto a circuit assembly and the excess can be recovered and reused without consuming resources (e.g., water), without consuming energy (e.g., without consuming electricity, without applying heat, without soldering), without wasting the transformed conductive material (e.g., because it can be recovered and reused), without generating other waste (e.g., without using cleaning solvents, without chemical etching), and / or without producing harmful by-products (e.g., because the transformed conductive material can be non-hazardous).

[0069] 11A, a perspective view of a circuit assembly 20E is shown in which the deformed conductive material 260 is generally flush with the surface 267 of the release layer 254 and all or most of the excess deformed conductive material 260 has been removed, according to at least one non-limiting embodiment of the present disclosure. FIG. 11B is a cross-sectional view along line GG in FIG. 11A. FIGS. 11A and 11B may correspond to steps for producing a highly sustainable circuit assembly that occur after the lamination step (e.g., overfilling step and / or wiping step). Depending on the technique used to remove the excess material, a thin patch of deformed conductive material may remain on the surface 267 of the release layer 254. Thus, the release layer 254 may be removed, for example, by peeling it from the circuit assembly 20E, to expose a clean top surface 268 on the first stack layer 252 as shown in FIGS. 12A and 12B. The removed release layer 254 may be salvaged and reprocessed to form new release layers or other articles, such as plastic bottles.

[0070] Referring to FIG. 12A, a perspective view of a circuit assembly 20F is shown in which the deformed conductive material 260 is generally flush with the surface 268 of the first stack layer 252 and all or most of the excess deformed conductive material 260 has been removed, in accordance with at least one non-limiting embodiment of the present disclosure. FIG. 12B is a cross-sectional view taken along line HH in FIG. 12A. The deformed conductive material 260 in the channels 256 and 258 is shown to be generally flush with the surface 268. This may be accomplished, for example, by not using a release layer or by using a release liner 254 that is thin enough (e.g., within a thickness range of 1-10 microns, 10-100 microns, or thousandths of an inch) to allow the remaining deformed conductive material 260 to be substantially flush with the surface 268 after its removal. Thus, in some embodiments, the thickness of the release layer 254 may be shown exaggerated in FIGS. 7A and 7B through 11A and 11B. In various embodiments, where even slight protrusions of the deformed conductive material 260 must be avoided, the slight protrusions of the deformed conductive material 260 may be removed from the channels 256 and 258 by wiping, scraping, brushing, etc. This allows the deformed conductive material 260 to be flush with the surface 268 of the first stack layer 252. Thus, in some embodiments where a release layer 254 is used, Figures 12A and 12B may correspond to steps for producing a highly sustainable circuit assembly that occur after removing the release layer 254. Also, in some embodiments where a release layer is not used, Figures 12A and 12B may correspond to steps for producing a highly sustainable circuit assembly that occur after a lamination step (e.g., an overfill step and / or a wiping step).

[0071] In various embodiments, the deformed conductive material 260 may remain slightly protruding from the surface 168. Thus, in one form, the thickness of the release layer 254 may be purposefully set to a value that causes the deformed conductive material 260 to protrude a predetermined amount above the top surface 268 of the first stack layer 252.

[0072] The circuit assembly 20F of Figures 12A and 12B may have utility as fabricated or may serve as a base for additional layers. For example, the circuit assembly 20F may include a contact pattern (e.g., contacts 102 of Figure 1) for engaging terminals (e.g., terminals 106 of Figure 1) of an electrical device (e.g., electrical component 104 of Figure 1) that may be attached, affixed, mounted, or otherwise supported on the first stack layer 252, similar to the circuit assemblies 10, 12, 14, and 16 described above with respect to Figures 1 to 6. In some configurations, in such applications, the deformed conductive material 260 may protrude above the top surface 268 of the first stencil layer 252. This protrusion may allow the deformed conductive material 260 to better engage with the terminals of the electrical device. The configuration of the channels 256, 258 may be modified to include conductive paths of different numbers, sizes, shapes, etc. Thus, the channels 256, 258 containing the modified conductive material 260 may function as contacts and / or reusable traces (eg, the various contacts and reusable traces disclosed above with respect to Figures 1-6).

[0073] As another example, the fabricated circuit assembly 20F can be used as a circuit element itself. For example, one or more channels 256, 258 filled with the modified conductive material 260 may function as a transmission line, such as a strip line, or as a circuit capacitor. In such an embodiment, an insulating layer (e.g., the second stack layer 270 in Figures 13A and 13B) may be laminated on top of the first stack layer 252 to surround and protect the modified conductive material 260.

[0074] In various embodiments, the circuit assembly 20F may include additional layers to create a laminated circuit assembly. For example, referring now to FIG. 13A, a circuit assembly 20G is illustrated in which a second stack layer 270 is laminated on a first stack layer 252 in accordance with at least one non-limiting embodiment of the present disclosure. FIG. 13B is a cross-sectional view taken along line JJ in FIG. 13A. FIG. 13A and FIG. 13B may correspond to a step for producing a highly sustainable circuit assembly that occurs after the lamination step (e.g., after laminating the second stack layer 270 on the first stack layer 252). The second stack layer 270 may be an insulating layer or a stencil layer. In the non-limiting embodiment of FIG. 13A and FIG. 13B, the second stack layer 270 acts as an insulating layer and covers at least a portion of the routing pattern of the first stack layer 252 (e.g., covers at least a portion of the channels 256, 258). The second stack layer 270 may include a routing pattern. The routing pattern may be, for example, vias 272, 274 that respectively align with portions of the reusable traces formed by channels 256, 258 of the first stack layer 252. The second stack layer 270, vias 272, 274, and modified conductive material 260 may be formed, deposited, and laminated using any of the materials and techniques described above with respect to the first stack layer 252, channels 256, 258, and modified conductive material 260 of the circuit assemblies 20A-20F. For example, the circuit assembly 20G may include a release layer (not shown) (e.g., similar to the release layer 254) attached to the second stack layer 270.

[0075] As shown by the non-limiting embodiment of FIG. 13B, the via 272 of the second stack layer 270 aligns with a portion of the channel 256 of the first stack layer 252. Thus, when the via 272 is filled with the deformed conductive material 260, it forms a continuous conductive structure with the channel 256. The vias 272, 274 of the second stack layer 270 can serve various functions. For example, the vias 272, 274 may function as contacts (e.g., similar to the contacts 102 of FIG. 1) for one or more electrical devices (e.g., the electrical component 104 of FIG. 1). Thus, as shown by the non-limiting embodiment of FIG. 13A and FIG. 13B, the vias 272, 274 may be used as contacts for an electrical component (e.g., a resistor, a capacitor, or any other electrical component) having two connecting leads or terminals. As another example, the vias 272, 274 may function as a circuit element itself, such as a transmission line or a sensor. As yet another example, the vias 272, 274 may electrically connect reusable traces formed by the channels 256, 258 in the first stack layer 252 to reusable traces in another layer above the second stack layer 270. The pattern of vias 272, 274 shown in Figures 13A and 13B is merely an example and the pattern may be modified to include any number, shape, arrangement, etc. of conductive paths.

[0076] 14A, a perspective view of a circuit assembly 20H having a third stack layer 276 laminated on the second stack layer 252 is shown in accordance with at least one non-limiting embodiment of the present disclosure. FIG. 14B is a cross-sectional view taken along line KK in FIG. 14A. FIGS. 14A and 14B may correspond to steps occurring after the lamination step (e.g., after laminating the third stack layer 276 on the second stack layer 270) for producing a highly sustainable circuit assembly. The third stack layer 276 may be an insulating layer or a stencil layer. The third stack layer 276 may include a routing pattern (e.g., channels 278, 280) that aligns with the vias 272, 274 of the second stack layer 270. The third stack layer 276, the channels 278, 280, and the modified conductive material 260 may be formed, deposited, laminated, etc. using any of the materials and techniques disclosed above with the circuit assemblies 20A-20G. For example, the circuit assembly 20H may include a release layer (not shown) attached to the third stack layer 276 (eg, similar to release layer 254).

[0077] Similar to the routing patterns of the first stack layer 252 and the second stack layer 270, the routing patterns of the third stack layer 276 (e.g., channels 278 and 280) can serve a variety of functions. For example, the routing patterns of the third stack layer 276 may serve as contacts for one or more electrical devices, the routing patterns may serve as circuit elements themselves, such as transmission lines or sensors, or the routing patterns may serve as reusable traces that are electrically connected to the vias 272, 274 of the second stack layer 270. The routing patterns (i.e., channels 278 and 280) shown in Figures 14A and 14B are merely an example, and the patterns may be modified to include conductive paths of any number, shape, arrangement, etc.

[0078] Referring now to FIG. 15A, a perspective view of a circuit assembly 20J is shown having a fourth stack layer 282 laminated on the third stack layer 276 in accordance with at least one non-limiting embodiment of the present disclosure. FIG. 15B is a cross-sectional view taken along line LL in FIG. 15A. FIG. 15A and FIG. 15B may correspond to steps for producing a highly sustainable circuit assembly that occur after a lamination step (e.g., after laminating the fourth stack layer 282 on the third stack layer 276). The fourth stack layer 282 may be an insulating layer or a stencil layer. The fourth stack layer 282 may include a routing pattern (e.g., channels 284, 286) that aligns with the channels 278, 280 of the third stack layer 276. The fourth stack layer 282, the channels 284, 286, and the modified conductive material 260 may be formed, deposited, laminated, etc. using any of the materials and techniques disclosed above with the circuit assemblies 20A-20H. For example, the circuit assembly 20J may include a release layer (not shown) attached to the fourth stack layer 282 (eg, similar to release layer 254).

[0079] Similar to the routing patterns of the first stack layer 252, the second stack layer 270, and the third stack layer 276, the routing pattern of the fourth stack layer 282 (e.g., channels 284 and 286) can serve multiple functions. For example, the routing pattern of the fourth stack layer 282 may serve as a contact for one or more electrical devices, the routing pattern may serve as a circuit element itself, e.g., a transmission line or a sensor, the routing pattern may serve as a via that electrically connects the channels 278 and 280 of the third stack layer 276 with a second circuit assembly (not shown), the routing pattern may serve as a contact for making a "hard-soft connection between the hard external terminals of an electrical component." The routing pattern (i.e., channels 278 and 280) shown in Figures 14A and 14B is merely an example, and the pattern may be modified to include conductive paths of any number, shape, arrangement, etc.

[0080] As is evident from the non-limiting embodiment of FIG. 15B, there is a continuous conductive path through the channels 256, the vias 272, the channels 278, and the channels 284 (e.g., pads 284) in the first stack layer 252. The stack layers and paths shown in the non-limiting embodiments of FIGS. 7A and 7B through 15A and 15B are illustrative and can be modified to create any type of circuit device when combining multiple stacks as a complete layup or as a modular assembly. For example, the order of layers containing vias and connection points (e.g., pads) and layers containing reusable traces can be changed. Additionally, the total number and relative positions of stack layers and substrate layers can also be changed. Some layers can contain reusable traces, vias, pads, or any combination thereof.

[0081] Considering the numerous configurations of paths that can be implemented, one skilled in the art will understand that any stack layer of the circuit assembly 20 can perform not only an electrical circuit function, but also an insulating function for the stack layer or adjacent stack layers. For example, referring back to the non-limiting embodiment of FIG. 15A, the fourth stack layer 282 is shown as an insulating layer that at least partially covers the third stack layer 276, which is shown as a stencil layer. In some embodiments, any of the stack layers of the circuit assembly 20 that function as an insulating layer (e.g., the fourth stack layer 282 as shown in FIG. 15A) is configured so that minimal deformed conductive material 260 is exposed when the circuit assembly 20 is installed for its final application. This can help prevent the deformed conductive material from being removed from the circuit assembly 20 (e.g., by being pulled out of the channels of the stack layer by foreign objects or by inertial forces). In other aspects, if any of the various non-limiting aspects of the circuit assembly 20 (e.g., 20A, 20B, 20C, 20D, 20E, 20F, 20G, 20H, 20J) are not in their final form but are intermediate products, the amount of contact of the deformed conductor with the surroundings may not be limited. For example, the circuit assembly 20J of FIG. 15A,B may function as a subassembly that is joined with a second circuit subassembly (not shown) to form the final circuit assembly. Such non-limiting aspects of the circuit layup may optionally have one or more electrical components attached to form the circuit assembly. It should be understood that such embodiments illustrate a modular method of designing circuit layups and electrical assemblies. Additionally, it should be noted that any of the circuit assemblies 20 (e.g., 20A, 20B, 20C, 20D, 20E, 20F, 20G, 20H, 20J) may exist as a circuit assembly in its final form.

[0082] 16, a cross-sectional view of a circuit assembly 20K according to at least one non-limiting embodiment of the present disclosure is shown. For illustrative purposes, the non-limiting embodiment of FIG. 16 is shown having layers similar to those of FIG. 15B. However, in other embodiments, the circuit assembly 20K may have any number and combination of layers as described above. According to the non-limiting embodiment of FIG. 16, the circuit assembly 20K may include a layer 277, a sublayer 277, or a portion of a layer 277 (collectively referred to as a sublayer 277). The sublayer may include a conductive element pattern (e.g., reusable traces 288, 290) formed thereon and / or therein. In this embodiment, the sublayer 277 is interposed between a portion of the second stack layer 270 and a portion of the third stack layer 276. A step may be formed in the third stack layer 276 and the fourth stack layer 282 to accommodate the sublayer 277. In other embodiments, sublayer 277 can replace some or all of the stack layers, or can be added as an entire separate layer. The thickness of sublayer 277 can be less than, greater than, or the same as the thickness of the other layers.

[0083] In some embodiments, any or all of the conductive elements on and / or contained in layer 277 may include a deformed conductive material (e.g., deformed conductive material 260) and may be laminated using various lamination methods described herein. In some embodiments, the conductive element pattern on and / or contained in layer 277 may include a mixture of deformable and non-deformable conductive elements. Sublayer 277 may be formed from any of the stack layer and / or substrate layer materials disclosed above and may be attached to other layers as described above. The element pattern may include reusable traces, vias, pads, or circuit elements including transmission lines and sensors, or any combination thereof. The element pattern may be formed on sublayer 277 via any of the techniques described above. In some forms, some or all of the conductive elements of sublayer 277 may be formed using a printing process, such as a reel-to-reel (R2R) process. By using a printing process to form sublayer 277, it is possible to create finer conductive elements, accommodating smaller electrical components or interconnects, or generally accommodating components or interconnects with different properties.

[0084] According to the non-limiting embodiment of FIG. 16, the sublayer 277 includes a conductive element pattern including reusable traces 288 and 290. The reusable traces 288, 290 can be connected to pads 292, 294 that align with terminals 296, 298, respectively, on an electrical component 300. Vias 302 and 304 through the third stack layer 276 can conductively couple the pads 292, 294 to the terminals 296, 298. In one form (as shown in the non-limiting embodiment of FIG. 16), the electrical component 300 can be a bare integrated circuit die with the terminals 296 and 298 formed as bond or contact pads. In other embodiments, any other type of electrical component (e.g., electrical component 104 of FIG. 1) may be used. The electrical component 300 may be attached to the third layer 276 using any suitable technique, such as the connection methods described above with respect to the electrical component 104 and / or IC 116 of FIGS.

[0085] The conductive element patterns (e.g., reusable traces 288, 290) formed on or in the sublayer 277 may be interconnected with any other type of reusable trace, via, pad, component, etc. In the non-limiting embodiment of FIG. 16 , the reusable trace 290 on the sublayer 277 is electrically connected to the reusable trace 278 in the third stack layer 276 through a hybrid and reusable trace / via 308 formed in a stepped portion of the third stack layer 276 corresponding to the thickness of the sublayer 277. In other non-limiting embodiments, the portion of the third stack layer 276 above the sublayer 277 may be omitted, and the fourth stack layer 282 may be formed on a plane defined by the remaining portion of the third stack layer 276 and the sublayer 277.

[0086] Referring to FIG. 17, a cross-sectional view of a circuit assembly 20L is shown in accordance with at least one non-limiting embodiment of the present disclosure. The circuit assembly 20L of FIG. 17 may be similar to the circuit assembly 20K of FIG. 16, except that the portion of the third stack layer 276 that underlies the electrical component 300 is omitted. Additionally, the vias 302 and 304 may also be omitted. In some embodiments, the electrical component 300 may be attached to a surface of the sublayer 277 with a layer of adhesive 306. In some embodiments, the terminals 296, 298 may directly contact the pads 292, 294 formed from the deformed conductive material.

[0087] In various embodiments, any of the non-limiting embodiments of circuit assembly 20 described above may include electrical components (e.g., any of the types of electrical components described above with respect to FIG. 1) integrated within, for example, the laminate, e.g., between stack layers. In some embodiments, one or more of the interior stack layers may have cutouts to accommodate the height of the electrical components (e.g., to accommodate the height of an integrated circuit package). In still other embodiments, the electrical components (e.g., resistors, capacitors, smaller IC packages, bare IC dies, etc.) may be small enough to be placed between layers, especially if the layers are relatively soft or flexible.

[0088] In various embodiments, one or more of the stack layers and / or substrate layers of any of the circuit assemblies disclosed herein may be formed from a resilient and stretchable TPU, such as Lubrizol® Estane® 58000 series, e.g., 58238. In other embodiments, one or more of the stack layers and / or substrate layers of any of the circuit assemblies disclosed herein may be formed from a relatively stiff material, such as by injection molding using Lubrizol® Estane® S375D.

[0089] In various embodiments, any of the circuit assemblies disclosed herein may include an epoxy-based material, such as, for example, a B-stage resin film. The epoxy-based material may be used as an additional separate component to provide an adhesive surface for adhering electrical components to any layer and / or to bond layers together. In various other embodiments, all of the sustainable layers, adhesives, and encapsulants of any of the circuit assemblies disclosed herein may be made from heat-activated adhesives, such as thermoplastic polyurethane (PU) adhesives (e.g., those manufactured by Bemis and Framis). In still other embodiments, any of the layers, adhesives, and / or encapsulants of the circuit assembly may include thermosetting adhesives, such as silicone, acrylic, and pressure sensitive adhesives of any chemistry. In the case of encapsulants (e.g., encapsulants applied to terminals of electrical components), the encapsulant may include a minimal concentration of thermosetting materials, which may allow the material to be easily recycled. In one embodiment, the circuit assemblies disclosed herein may include a filler material that includes a thermosetting material. Fillers containing thermosetting materials may be reused in a "regrinded" form to strengthen, modify, or reduce the cost of molded articles made from similar thermosetting materials.

[0090] The various materials, methods, and components described herein can provide highly sustainable circuit assemblies. The various circuit assemblies disclosed herein can be highly sustainable, for example, compared to etched FR4 / copper circuit boards or circuit boards employing epoxy-based conductive adhesives. Additionally, the circuit assemblies disclosed herein, including circuit assemblies including modified conductive materials and stacked layers, may not require the use of reinforcements (e.g., chopped fiber reinforcements) in the layer materials themselves. The reinforcements used in conventional circuit boards make recycling and reuse of the circuit board materials difficult, cumbersome, and harmful for workers who process discarded electronics made from these types of circuit boards. For example, conventional circuit board materials typically must be ground, and the resulting "reground" is rarely used in consumer products. The apparatus, systems, and methods discussed herein can enable a circular manufacturing chain, and / or the readily recyclable circuit assemblies including the materials may be recycled and used again in other circuit assemblies or other consumer products.

[0091] Circuit assemblies constructed according to various aspects disclosed herein can provide high-performance circuit assemblies that can reduce the cost of assembly. For example, some aspects of the circuit assemblies disclosed herein can enable the use of less expensive unpackaged electrical devices. Additionally, other aspects of the circuit assemblies disclosed herein can eliminate the need for soldering. Additionally, other aspects of the circuit assemblies disclosed herein can improve reliability by eliminating the need for soldering, thereby reducing associated energy consumption (e.g., heating). Additionally, other aspects of the circuit assemblies disclosed herein can improve cooling performance by eliminating device packaging that can be a barrier to heat dissipation.

[0092] Referring to FIG. 18, a flow diagram of a method 1000 of recovering material from a highly sustainable circuit assembly according to at least one non-limiting embodiment of the present disclosure is shown. The highly sustainable circuit assembly described with respect to FIG. 18 may be any of the highly sustainable circuit assemblies 10, 12, 14, 16, and 20 described above with respect to FIGS. 1 through 17. The highly sustainable circuit assembly may include electrical components, a substrate layer, and a modified conductive material. In some embodiments, the highly sustainable material may include one or more stack layers. In other embodiments, the highly sustainable circuit assembly may include an encapsulant and / or an adhesive. The method 1000 may begin by performing a step 1002 of removing electrical components from the circuit assembly. The method 1000 may further include a step 1004 of heating the highly sustainable circuit assembly to a melting point of the substrate layer to form a molten substrate layer. In one embodiment, heating the substrate layer to its melting point, step 1004, can cause the substrate layer to separate from or melt and flow with other layers (e.g., stack layers) included in the circuit assembly. The modified conductive material (e.g., conductive gels disclosed herein; gallium-indium alloy gels disclosed herein, etc.) can have extremely high temperature resistance and remain in a fluid state up to about 1300°C.

[0093] The method 1000 may further include a step 1006 of separating the deformed conductive material from the molten substrate layer to obtain a regenerated deformed conductive material and a regenerated substrate layer material. In an experiment, the inventors heated a highly sustainable circuit assembly including a deformed conductive material (i.e., a gallium-indium alloy gel material) and a TPU substrate and stack layer to a flow temperature of the layers. The inventors found that by heating the layers to a flow temperature, the deformed conductive material can be easily separated from the molten layer material due to its surface tension characteristics.

[0094] In another aspect, the method 1000 may include heating the highly sustainable circuit assembly to a melting point of the stack layer to form a molten stack layer, and separating the deformed conductive material from the molten stack layer to obtain a regenerated deformed conductive material and a regenerated stack layer material.

[0095] In another embodiment, the method 1000 may include heating the circuit assembly to the melting point of the encapsulant, and removing the electrical components from the circuit assembly occurs after heating the circuit assembly to the glass transition temperature of the encapsulant. In yet another embodiment, the method 1000 may include heating the circuit assembly to the glass transition temperature of the adhesive material, and removing the electrical components from the circuit assembly occurs after heating the circuit assembly to the glass transition temperature of the adhesive material. Heating the circuit assembly to the melting point and / or glass transition temperature allows the electrical components to be easily removed for reuse in other circuit assemblies. The temperature required for heating may be lower than the temperatures experienced by electrical components in the manufacture of standard circuit assemblies, and therefore does not damage the components.

[0096] Referring to Figure 19, a flow diagram of a method 2000 for recycling regenerated transformed conductive material is shown in accordance with at least one non-limiting embodiment of the present disclosure. The transformed conductive material discussed with respect to Figure 19 may be any of the various transformed conductive materials described above with respect to Figures 1-18. The method 2000 may begin by performing step 2002 of providing a regenerated transformed conductive material including a metal alloy and a metal oxide formed upon exposure of the metal alloy to air. In one embodiment, the regenerated transformed conductive material may be regenerated according to method 1000 described above with respect to Figure 18.

[0097] 19, the method 2000 may further include exposing the regenerated, transformed conductive material to an acid solution 2004, thereby reacting the metal oxide with the acid solution to obtain a clean liquid metal alloy. In one embodiment, exposing the regenerated, transformed conductive material to an acid solution may cause the metal oxide to react with the acid to form metal salts and water. This reaction may remove the metal oxide from the metal alloy to obtain a clean liquid metal alloy.

[0098] The method 2000 may further include a step 2006 of removing the clean liquid metal alloy from the acid solution. In some embodiments, the amount of clean liquid metal alloy removed from the acid solution is 55% or more by weight of the metal alloy used to originally create the regenerated transformed conductive material, such as 55% or more by weight, 60% or more by weight, 65% or more by weight, 70% or more by weight, 75% or more by weight, 80% or more by weight, 85% or more by weight, 90% or more by weight, or 95% or more by weight. In another embodiment, the method 2000 may further include a step of creating a new transformed conductive material from the clean liquid metal alloy. In this manner, recycling the regenerated transformed conductive material allows the transformed conductive material to be reused in the manufacture of new circuits without degradation of electrical properties.

[0099] In another embodiment, exposing the regenerated deformed conductive material to an acid solution 2004 may further include agitating the deformed conductive material in the acid solution to obtain a clean liquid metal alloy. In one embodiment, the regenerated deformed conductive material includes fine particles. Agitating the deformed conductive material in the acid solution can remove the fine particles to obtain a clean liquid metal alloy. In another embodiment, agitating the deformed conductive material in the acid solution can cause the fine particles to float on the surface of the acid solution, and the liquid metal can be extracted. In one embodiment, agitating the deformed conductive material in the acid solution to obtain a clean liquid metal alloy includes agitating the deformed conductive material in the acid solution for more than one day. An exemplary process for recycling the regenerated deformed conductive material, which is carried out using the above method, is detailed below with respect to Example 3.

[0100] In another embodiment, the method 2000 can include extracting the particulate from the acid solution. In yet another embodiment, the method 2000 can include creating new transformed conductive material from the extracted particulate.

[0101] In another embodiment, the method 2000 can include recovering the acid solution for reuse in a subsequent process for recycling the regenerated transformed conductive material. For example, the acid solution can be reused after extracting the clean liquid metal alloy and particulates.

[0102] In another aspect, the modified conductive material may include a conductive gel. In one form, the modified conductive material may include a gallium alloy having particulates suspended therein. In another aspect, the clean liquid metal alloy may include a gallium alloy. In yet another aspect, the acid solution may include hydrochloric acid.

[0103] (Example) (Examples 1 and 2) (The resistance value of the deformable conductive material reproduced during the manufacture of the circuit assembly) Examples 1 and 2 in Table 1 below compare experimentally measured resistance values ​​for virgin samples of deformed conductive material with samples of deformed conductive material that were reclaimed during a circuit assembly manufacturing process. Specifically, the reclaimed deformed conductive material was recovered after a wiping process similar to the wiping process described with respect to Figures 10A and 10B. Examples 1 and 2 show that the resistance values ​​of the reclaimed material and virgin are within the typical margin of variation of virgin resistance measurements.

[0104] [Table 1]

[0105] Example 3 (Recycling of deformed conductive gel regenerated from circuit assemblies) (overview) A deformable conductive gel, named MG5 (Metal Gel 5) and having a composition including a eutectic alloy of gallium (68.5 wt%), indium (21.5 wt%) and tin (10 wt%) with particulates suspended therein, was reclaimed from the circuit assembly using the reclaiming process described above with respect to FIG. 18. The reclaimed MG5 was processed to obtain a clean liquid gallium-indium-tin metal alloy, as described in detail below. The resulting clean liquid metal alloy can then be used to produce more (i.e., reclaimed) MG5 or another formulation of a similar deformed conductive material. The "waste" resulting from this recycling process includes only small amounts of residual gallium oxide and gallium chloride. The recycling process also produces particulates that were originally contained in MG5, which can be reused to produce more (i.e., recycled) MG5 or another formulation of a similar deformed conductive material.

[0106] (Production of MG5 and formation of gallium oxide) Generally, a thin layer of gallium oxide may form on the surface gallium in the presence of air. To produce the MG5 conductive gel, gallium oxide is formed and dispersed in a gallium-indium-tin liquid metal alloy, causing novel micro / nanostructures to form within the liquid metal alloy, forming a Bingham plastic. The micro and nanostructures are blended within the mixture, for example, by sonication or other mechanical means that draws air into the mixture. In some embodiments, sonication can create cavitation at the surface of the mixture, drawing air into the mixture. In this manner, the mixture may include a colloidal suspension of micro and nanostructures within the gallium alloy / gallium oxide mixture. For a detailed description of MG5 and similar conductive gel formulations and methods of manufacture, see International Patent Application PCT / US2017 / 019762, entitled "LIQUID WIRE," filed February 27, 2017, and published September 8, 2017 as International Publication WO2017 / 151523A1.

[0107] MG5 gel is a stiff paste that can be patterned into complex shapes. Thus, MG5 can be used, for example, to form electrical circuit assemblies, circuit lay-ups, stacks, etc. MG5 is more mechanically stable and has better adhesion than unmodified liquid metal alloys. Over extended periods of time (usually months or years), or through repeated patterning and handling, or after being reclaimed from a circuit lay-up, the amount of oxide in the gel can increase, causing degradation of its mechanical and electrical properties. In such cases, the oxide structure can be broken down to form unmodified liquid metal alloys, which can then be reprocessed to form "new" MG5 or other formulations. This method utilizes vigorous agitation in an acidic solution to break down the gallium oxide, as described below.

[0108] (Acid treatment of regenerated MG5) The regenerated MG5 gel was immersed in a bath of 3M hydrochloric acid (HCl). Initially, the HCl appeared to have little effect on the gel's mechanical properties. This is in contrast to liquid metals, which react immediately to HCl. Upon exposure to HCl, the gallium oxide on the surface of MG5 forms gallium chloride primarily via the following reaction:

[0109]

number

[0110] When the gallium oxide is removed, the high surface tension of the liquid metal alloy becomes the dominant mechanical force, which causes the liquid metal alloy to tend to bead up as nearly spherical as possible, pushing any small particles inside the metal outwards.

[0111] To achieve this result with regenerated MG5, a solution of MG5 gel and acid was stirred using a stir bar rotating at 500 rpm in the solution bed. Initially, the metal alloy was unaffected by the acid. It was shiny and still exhibited the mechanical properties characteristic of a moldable, highly viscous gel. After two days of stirring, it was observed that the MG5 gel structure had been destroyed. After this stirring, the metal alloy components had adopted an approximately spherical shape, more characteristic of a liquid metal alloy in an acidic solution. Particles were also observed suspended throughout the solution.

[0112] (Recovery of liquid metal alloys) In earlier experiments (prior to the experiment described herein as Experiment 3), the recovery of the initial liquid metal alloy used to form MG was 66 wt. %. Implementation of the acid treatment technique described in this Experiment 3 achieved recovery of over 80 wt. % of the initial liquid metal used to form MG5.

[0113] No harmful or toxic by-products were generated, and even the "waste" materials filtered from the acid solution were non-toxic and non-hazardous materials in very small quantities. Furthermore, the acid solution was not substantially degraded and could be used to process additional regenerated conductive material from other discarded circuit lay-ups.

[0114] Thus, the methods described above (e.g., the manufacturing process described above with respect to Figures 1 through 17, the regeneration process described above with respect to Figure 18, the recycling process described above with respect to Figure 19, and / or the acid agitation technique described above with respect to Example 3) can enable recovery of electrical components from discarded circuit assemblies, reprocessing of layer materials, and reprocessing of conductive materials. The recovered and reprocessed materials can be reused to manufacture new circuit assemblies.

[0115] Example 4 The liquid metal alloy recovered in Example 3 can be used as the basis for producing more modified conductive materials (e.g., new MG5 or another modified conductive material). With further refinements to the acid treatment method, it is expected that virtually any liquid metal can be regenerated using the same basic principles, augmented, for example, by developing custom equipment.

[0116] Example 5 (Regeneration efficiency of circuit assembly elements) Two highly sustainable circuit assemblies embodied as two sensors have been fabricated using the principles taught herein, and various tables and descriptions are provided to summarize the regenerative efficiency of the various components.

[0117] Table 1 below summarizes the results of comparing the total weight of all untreated layers (stack layers and release layers) used to manufacture a circuit assembly with the weight of just the release layer.

[0118] [Table 2]

[0119] Thus, 35.5% by weight of the original layer of material becomes waste in the form of the release liner, and 64% by weight of the material is carried over to the next stage.

[0120] Table 3 below compares the total amount of TPU material used to form the stack layers and the weight of material cut from the TPU material from the circuit assembly.

[0121] [Table 3]

[0122] Therefore, for every 4.485 g of TPU used, 1.39 g are "excess." In other words, for every 1 g of TPU used, 0.31 g of TPU is excess. However, the TPC can be fully regenerated and used to manufacture additional circuit assemblies.

[0123] Table 4 below shows the weight of the circuit assembly after adding the MG5 modified conductive material compared to the weight of the circuit assembly before adding the MG5. Additionally, Table 5 shows, for each sensor, the amount of MG5 actually used in the circuit assembly (calculated based on Table 4), the total amount of MG5 that is typically deposited during the manufacturing process, and therefore the amount of excess MG5.

[0124] [Table 4]

[0125] [Table 5]

[0126] Thus, for every 28.8 mg of final sensor product, 435 mg of excess MG5 is used. In other words, for every mg of MG5 contained in the final circuit assembly element, 0.015 g of excess MG5 is used. However, the excess MG5 may be subsequently reclaimed and used in subsequent circuit assembly manufacturing steps.

[0127] Table 6 below shows the total weight of the final circuit assembly components.

[0128] [Table 6]

[0129] In particular, circuit assembly components that can be regenerated using the methods described herein include the TPC layer (83.71% by weight), the electrical components (3.23% by weight), and MG5 (1.71% by weight). These components account for as much as 88.65% of the weight of the circuit assembly. Furthermore, in some configurations, the thermoset adhesive may be reground and recycled.

[0130] Also noteworthy is that the circuit assemblies contained only 1.71% modified conductive material (MG5) and the "extra" conductive material was fully renewable and used to manufacture additional circuit assemblies, resulting in virtually no waste in respect of the modified conductive material.

[0131] Example 6 A typical circuit assembly may contain up to 10% by weight of the modified conductive material in the final assembly, such as up to 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, or 1% by weight. Furthermore, 95% or more of the "excess" modified conductive material, such as 96%, 97%, 98%, 99%, 99.5%, or 99.9% by weight of the excess modified conductive material, may be recovered from the manufacturing process and used in future manufacturing processes.

[0132] Various aspects of the subject matter described herein are set forth in the following numbered clauses:

[0133] Clause 1: A method for reclaiming material from a highly sustainable circuit assembly comprising an electrical component, a substrate layer, and a deformed conductive material, the method comprising the steps of: removing the electrical component from the circuit assembly; heating the highly sustainable circuit assembly to a melting point of the substrate layer to form a molten substrate layer; and separating the deformed conductive material from the molten substrate layer to obtain a reclaimed deformed conductive material and a reclaimed substrate layer material.

[0134] Clause 2: The method of clause 1, wherein the highly sustainable circuit assembly further comprises a stack layer, the method further comprising the steps of heating the highly sustainable circuit assembly to a melting point of the stack layer to form a molten stack layer, and separating the deformed conductive material from the molten stack layer to obtain a recycled deformed conductive material and a recycled substrate layer material.

[0135] Clause 3: The method of clause 1 or 2, wherein the circuit assembly comprises an encapsulant, and the method further comprises the step of heating the circuit assembly to a melting point of the encapsulant, and the step of removing the electrical component from the circuit assembly occurs after the step of heating the circuit assembly to a glass transition temperature of the encapsulant.

[0136] Clause 4: The method of any one of clauses 1 to 3, wherein the circuit assembly comprises an adhesive material, and the method further comprises the step of heating the circuit assembly to a glass transition temperature of the adhesive material, and the step of removing the electrical component from the circuit assembly occurs after the step of heating the circuit assembly to the glass transition temperature of the adhesive material.

[0137] Clause 5: The method of any one of clauses 1 to 4, wherein the modified conductive material comprises a conductive gel.

[0138] Clause 6: The method of any one of clauses 1 to 5, wherein the modified conductive material comprises a gallium alloy.

[0139] Clause 7: The method of any one of clauses 1 to 6, further comprising recycling the regenerated deformed conductive material.

[0140] Clause 8: A method for recycling regenerated deformed conductive material, the method comprising the steps of: providing a regenerated deformed conductive material comprising a metal alloy and a metal oxide formed by exposing the metal alloy to air; exposing the regenerated deformed conductive material to an acid solution, whereby the metal oxide and the acid solution react to obtain a clean liquid metal alloy; and removing the clean liquid metal alloy from the acid solution.

[0141] Clause 9: The method of clause 8, further comprising creating new deformed conductive material from the clean liquid metal alloy.

[0142] Clause 10: The method of clause 8 or 9, wherein exposing the regenerated deformed conductive material to an acid solution includes agitating the deformed conductive material in the acid solution to obtain a clean liquid metal alloy.

[0143] Clause 11: The method of any one of clauses 8 to 11, wherein the amount of clean liquid metal alloy removed from the acid solution is 55% or more by weight of the metal alloy used to originally make the regenerated transformed conductive material.

[0144] Clause 12: The method of any one of clauses 8 to 11, wherein the amount of clean liquid metal alloy removed from the acid solution is 80% or more by weight of the metal alloy used to originally make the regenerated transformed conductive material.

[0145] Clause 13: The method of any one of clauses 8 to 12, wherein the regenerated deformed conductive material includes particulates, and the step of agitating the deformed conductive material in the acid solution removes the particulates to obtain a clean liquid metal alloy.

[0146] Clause 14: The method of any one of clauses 8 to 13, wherein the step of stirring the deformed conductive material in the acid solution to obtain a clean liquid metal alloy comprises stirring the deformed conductive material in the acid solution for two or more days.

[0147] Clause 15. The method of any one of clauses 8 to 14, wherein the metal alloy comprises a gallium-indium-tin alloy and the metal oxide comprises a gallium oxide.

[0148] Clause 16: A highly sustainable circuit assembly comprising: a substrate; and a contact pattern supported on the substrate, the contact pattern configured to correspond to at least one terminal of an electrical component, the contact pattern comprising a modified conductive material, the modified conductive material comprising a readily renewable material.

[0149] Clause 17: A highly sustainable circuit assembly of clause 16, wherein the modified conductive material comprises a material that is readily recyclable.

[0150] Clause 18: A highly sustainable circuit assembly of clauses 16 or 17, wherein the substrate comprises readily renewable materials and the substrate layers comprise readily recyclable materials.

[0151] Clause 19: A highly sustainable circuit assembly of any one of clauses 16 to 18, wherein the deformed conductive material is configured to adhere to at least one terminal of the electrical component, thereby electrically coupling at least a portion of the contact pattern to at least one terminal of the electrical component.

[0152] Clause 20: A highly sustainable circuit assembly according to any one of clauses 16 to 19, wherein the electrical component is supported by the circuit assembly such that the deformed conductive material conforms to the shape of at least one terminal of the electrical component.

[0153] Clause 21: A highly sustainable circuit assembly according to any one of clauses 16 to 20, wherein the contact pattern is formed on a surface of the substrate layer.

[0154] Clause 22: A highly sustainable circuit assembly of clauses 16 to 21, wherein the contact pattern is at least partially recessed into the substrate layer.

[0155] Clause 23: A highly sustainable circuit assembly according to any one of clauses 16 to 22, wherein the substrate comprises a flexible and / or stretchable material.

[0156] Clause 24: The highly sustainable circuit assembly of any one of clauses 16 to 23, further comprising an insert layer configured to inhibit flexure and / or stretching of a portion of the substrate layer adjacent the contact pattern, to dissipate heat from the electrical component, to adhere the electrical component to the substrate layer, or any combination thereof.

[0157] Clause 25: The highly sustainable circuit assembly of any one of clauses 16 to 24, further comprising a conductive trace pattern supported on the substrate layer, the conductive trace pattern electrically coupled to the contact pattern, the contact pattern comprising a deformed conductive material.

[0158] Clause 26: The highly sustainable circuit assembly of any one of clauses 16 to 25, wherein the modified conductive material comprises a conductive gel.

[0159] Clause 27: The highly sustainable circuit assembly of any one of clauses 16 to 26, wherein the modified conductive material comprises a gallium alloy.

[0160] Clause 28: A highly sustainable circuit assembly according to any one of clauses 16 to 27, further comprising an electrical component.

[0161] Clause 29: A method for producing a highly sustainable circuit assembly, comprising the steps of providing a substrate layer and laminating a modified conductive material to the substrate layer to form a contact pattern corresponding to at least one terminal of an electrical component, the modified conductive material comprising a readily renewable material.

[0162] Clause 30: The method of clause 29, wherein the modified conductive material comprises a readily recyclable material.

[0163] Clause 31: The method of clause 29 or 30, wherein the substrate layer comprises a readily renewable material, the substrate layer comprises a readily recyclable material.

[0164] Clause 32: The method of any one of clauses 29 to 31, further comprising the steps of bringing the electrical component into proximity with the substrate layer and adhering the deformed conductive material to at least one terminal of the electrical component, thereby forming an ohmic contact between at least a portion of the contact pattern and at least one terminal of the electrical component, wherein the step of bringing the electrical component into proximity with the substrate layer conforms the deformed conductive material to a shape of the at least one terminal of the electrical component.

[0165] Clause 33: The method of any one of clauses 29 to 32, further comprising the step of fixing an electrical component to an adhesive layer adhesively attached to a surface of the substrate layer.

[0166] Clause 34: The method of any one of clauses 29 to 33, further comprising covering at least a portion of the circuit assembly with an encapsulant.

[0167] Clause 35: The method of any one of clauses 29 to 34, further comprising attaching an electrical component directly to a surface of the substrate layer.

[0168] Clause 36: The method of any one of clauses 29 to 35, comprising attaching an insert layer to the substrate layer, the insert layer configured to inhibit flexure and / or elongation of a portion of the substrate layer adjacent the contact pattern, to dissipate heat from an electrical component, to adhere the electrical component to the substrate layer, or any combination thereof.

[0169] Clause 37: The method of any one of clauses 29 to 36, wherein the step of depositing the deformed conductive material on the substrate layer to form a contact pattern further comprises depositing the deformed conductive material such that the deformed conductive material protrudes from a surface of the substrate layer.

[0170] Clause 38: The method of any one of clauses 29 to 37, wherein the step of depositing the deformed conductive material on the substrate layer to form a contact pattern further comprises at least partially filling recesses formed in the substrate layer with the deformed conductive material.

[0171] Clause 39: The method of any one of clauses 29 to 38, further comprising laminating a modified conductive material to the substrate layer to form a conductive trace pattern electrically coupling with the contact pattern.

[0172] Clause 40: The method of any one of clauses 29 to 39, wherein the substrate layer comprises a flexible or stretchable material.

[0173] Clause 41: The method of any one of clauses 29 to 40, wherein the modified conductive material comprises a conductive gel.

[0174] Clause 42: The method of any one of clauses 29 to 41, wherein the modified conductive material comprises a gallium alloy.

[0175] Clause 43: A highly sustainable circuit assembly comprising: a substrate layer; and a first stack layer having a first path pattern formed thereon, the first path pattern extending through a thickness of the first stack layer, the first path pattern comprising a modified conductive material, the modified conductive material comprising a readily renewable material.

[0176] Clause 44: The circuit assembly of clause 43, wherein the modified conductive material comprises a readily recyclable material.

[0177] Clause 45: The circuit assembly of clause 43 or 44, wherein the substrate layer comprises a first material, the first stack layer comprises a first material, the first material is a readily renewable material, and the first material is a readily recyclable material.

[0178] Clause 46: The circuit assembly of any one of clauses 43 to 45, wherein the first stack layer is bonded to a substrate layer.

[0179] Clause 47: A circuit assembly of any one of clauses 43 to 46, wherein the first stack layer includes a first surface adjacent to the substrate layer and a second surface opposite the first surface, and the surface of the deformed conductive material is flush with the second surface of the first stack layer.

[0180] Clause 48: The circuit assembly of any one of clauses 43 to 47, wherein a surface of the deformed conductive material protrudes beyond a surface of the first stack layer.

[0181] Clause 49: A circuit assembly of any one of clauses 43 to 48, wherein the first routing pattern including the deformed conductive material includes a contact pattern, a trace pattern, or a combination thereof configured to correspond to at least one terminal of an electrical component.

[0182] Clause 50: A circuit assembly according to any one of clauses 43 to 49, further comprising an electrical component.

[0183] Clause 51: A circuit assembly of any one of clauses 43 to 50, further comprising a second stack layer having a second path pattern formed thereon, the second path pattern extending through a thickness of the second stack layer, and a third path pattern comprising a deformed conductive material.

[0184] Clause 52: A circuit assembly according to any one of clauses 43 to 51, further comprising a sublayer interposed between the first stack layer and the second stack layer, the sublayer including a conductive element pattern.

[0185] Clause 53: A circuit assembly of any one of clauses 43 to 52, wherein the conductive element pattern is electrically coupled to a second path pattern extending through the thickness of the second stack layer, the second path pattern being configured to correspond to at least one terminal of an electrical component.

[0186] Clause 54: A circuit assembly of any one of clauses 43 to 53, wherein a first portion of the second path pattern is aligned with a first portion of the first path pattern, and the deformed conductive material forms a continuous structure extending from the first portion of the first path pattern to the first portion of the second path pattern.

[0187] Clause 55: A circuit assembly of any one of clauses 43 to 54, further comprising a third stack layer having a third path pattern formed thereon, the third path pattern extending through a thickness of the third stack layer, and the third path pattern comprising a deformed conductive material.

[0188] Clause 56: A circuit assembly of any one of clauses 43 to 55, wherein a first portion of the third path pattern is aligned with a second portion of the second path pattern, and the deformed conductive material forms a continuous structure extending from the first portion of the first path pattern to the first portion of the third path pattern.

[0189] Clause 57: A circuit assembly of any one of clauses 43 to 56, further comprising a fourth stack layer having a fourth path pattern formed thereon, the fourth path pattern extending through a thickness of the fourth stack layer, and the fourth path pattern comprising a deformed conductive material.

[0190] Clause 58: A circuit assembly of any one of clauses 43 to 57, wherein a first portion of the fourth path pattern is aligned with a second portion of the third path pattern, and the deformed conductive material forms a continuous structure extending from the first portion of the first path pattern to the first portion of the fourth path pattern.

[0191] Clause 59: The circuit assembly of any one of clauses 43 to 58, wherein the modified conductive material comprises a conductive gel.

[0192] Clause 60: The circuit assembly of any one of clauses 43 to 59, wherein the modified conductive material comprises a gallium alloy.

[0193] Clause 61: A method for manufacturing a highly sustainable circuit assembly, the method comprising the steps of: providing a substrate layer; disposing on a surface of the substrate layer a first stack layer having a first path pattern formed thereon, the first path pattern extending through a thickness of the first stack layer; overfilling the first path pattern with deformed conductive material; removing excess deformed conductive material from the circuit assembly; and recovering the excess deformed conductive material.

[0194] Clause 62: The method of clause 61, comprising using the recovered excess deformed conductive material to fill a second routing pattern included in a second stack layer, using the recovered excess deformed conductive material to fabricate another circuit assembly, or a combination thereof.

[0195] Clause 63: The method of clause 61 or 62, further comprising bonding the first stack layer to a substrate layer.

[0196] Clause 64: The method of any one of clauses 61 to 63, wherein the step of removing excess deformed conductive material from the circuit assembly includes a step of wiping the excess deformed conductive material from a release liner attached to the surface of the first stack layer, and the method further includes a step of removing the release liner from the surface of the first stack layer.

[0197] Clause 65: The method of any one of clauses 61 to 64, wherein removing excess deformed conductive material from the circuit assembly comprises wiping the excess deformed conductive material from the surface of the first stack layer.

[0198] Clause 66: The method of any one of clauses 61 to 65, further comprising the step of attaching an electrical component to the circuit assembly, wherein at least one terminal of the electrical component corresponds to the first routing pattern formed in the first stack layer.

[0199] Clause 67: The method of any one of clauses 61 to 66, further comprising the steps of: disposing a second stack layer on a surface of the first stack layer, the second stack layer including a second path pattern formed in the second stack layer and extending through a thickness of the second stack layer; overfilling the second path pattern with deformed conductive material; removing excess deformed conductive material from the circuit assembly; and recovering the excess deformed conductive material.

[0200] Clause 68: The method of any one of clauses 61 to 67, further comprising interposing a sublayer including a conductive element pattern between the first stack layer and the second stack layer.

[0201] Clause 69: The method of any one of clauses 61 to 68, wherein the second path pattern is configured to correspond to at least one terminal of the electrical component, and the method further includes a step of electrically coupling the conductive element pattern to the deformed conductive material filled in the second path pattern.

[0202] Clause 70: The method of any one of clauses 61 to 69, wherein the step of disposing the second stack layer on the surface of the first stack layer includes a step of aligning a first portion of the second path pattern with a first portion of the first path pattern, and the step of overfilling the second path pattern with the deformed conductive material includes a step of forming a continuous structure extending from the first portion of the first path pattern to the first portion of the second path pattern.

[0203] Clause 71: The method of any one of clauses 61 to 70, further comprising the steps of: disposing a third stack layer on a surface of the second stack layer, the third stack layer including a third routing pattern formed in the third stack layer and extending through a thickness of the third stack layer; overfilling the third routing pattern with deformed conductive material; removing excess deformed conductive material from the circuit assembly; and recovering the excess deformed conductive material.

[0204] Clause 72: The method of any one of clauses 61 to 71, wherein the step of disposing the third stack layer on the surface of the second stack layer includes a step of aligning a first portion of the third path pattern with a second portion of the second path pattern, and the step of overfilling the third path pattern with the deformed conductive material includes a step of forming a continuous structure extending from the first portion of the first path pattern to the first portion of the third path pattern.

[0205] Clause 73: The method of any one of clauses 61 to 72, further comprising the steps of: disposing a fourth stack layer on a surface of the third stack layer, the fourth stack layer including a fourth routing pattern formed in the fourth stack layer and extending through a thickness of the fourth stack layer; overfilling the fourth routing pattern with deformed conductive material; removing excess deformed conductive material from the circuit assembly; and recovering the excess deformed conductive material.

[0206] Clause 74: The method of any one of clauses 61 to 73, wherein the step of disposing the fourth stack layer on the surface of the third stack layer includes a step of aligning a first portion of the fourth path pattern with a second portion of the third path pattern, and the step of overfilling the fourth path pattern with the deformed conductive material includes a step of forming a continuous structure extending from the first portion of the first path pattern to the first portion of the fourth path pattern.

[0207] Clause 75: The method of any one of clauses 61 to 74, wherein the modified conductive material comprises a conductive gel.

[0208] Clause 76: The method of any one of clauses 61 to 75, wherein the modified conductive material comprises a gallium alloy.

[0209] Clause 77: A highly sustainable circuit lay-up may include a combination of a non-hazardous and easily renewable modified conductive material and at least one layer of a readily recyclable material. The conductive material may form a pattern of reusable traces and / or contacts on the layer. The method of forming the reusable traces on the layer may include a single step that generates substantially no waste (whether hazardous or not) and consumes no additional natural resources beyond those that make up the lay-up material. The method consumes substantially less energy than methods used to make conventional circuit boards.

[0210] Clause 78: A highly sustainable circuit assembly may include at least one electrical component provided with terminals corresponding to the contact pattern of the circuit lay-up. The electrical component may include one or more terminals that contact the one or more contacts. The electrical component is assembled to the lay-up using a method that provides a stable electrical connection without the need for soldering, eliminates the need for substantial energy consumption, produces substantially no waste, and emits substantially no volatile organic compounds (VOCs).

[0211] Clause 79: A highly sustainable circuit lay-up may be formed from at least one laminate including at least one substrate layer, one or more stencil layers, and one or more insulating layers. One or more layers of the laminate may be formed from readily recyclable materials. The laminate may include at least one pattern of reusable traces and / or contacts and / or vias formed from non-hazardous and readily renewable conductive materials. The pattern of reusable conductive traces may be interconnected with the pattern of contacts and / or vias. A first pattern of reusable traces, vias, and contacts may be formed on or recessed into the surface of the substrate layer. One or more stencil layers may be supported on the substrate layer with a second pattern of reusable traces and / or vias and / or contacts extending through the thickness of the stencil layer. At least a portion of the pattern of the stencil layer may correspond to the pattern of the substrate layer. At least one insulating layer may be supported on the substrate layer and / or on the at least one stencil layer. The insulating layer may have a contact pattern and / or vias on or extending through its surface. At least a portion of the pattern of the insulating layer may correspond to the pattern of the substrate and / or stencil layer. The conductive material may be laid up in one or more layers of the laminate by a single process that produces substantially no waste (whether hazardous or not), consumes no additional natural resources other than those that make up the layup material, has relatively low energy consumption, and emits substantially no VOCs. The various layers may be connected to form the laminate. A circuit layup may include multiple laminates, and two or more laminates may be connected together. The vias and contacts of one laminate may be connected to the vias and contacts of another laminate, thereby forming a connection between the laminates. The vias may extend through a combination of one or more substrate layers, stencil layers, and insulating layers of each laminate, thereby connecting between reusable traces of each laminate.

[0212] Clause 80: The highly sustainable circuit layup or circuit assembly may optionally include an encapsulant covering at least a portion of the electrical components, vias, and / or contacts. The encapsulant, as well as one or more layers of the layup or laminate, may be formed from a readily recyclable material.

[0213] Clause 81: The substrate layer, the stencil layer, and the insulating layer may include a flexible material. These layers may include a stretchable material. At least a portion of these layers may have adhesive properties. These layers may be connected to each other by their adhesive properties.

[0214] Clause 82: The at least one electrical device may include a surface mount component. The at least one electrical device may include a packaged integrated circuit. The at least one electrical device may include a bare integrated circuit die. The at least one electrical component may be attached to the circuit layup by adhesion of any layer or by an adhesive to any layer.

[0215] Clause 83: At least one electrical component may be attached to the insulating layer. The insulating layer may have sufficient adhesive properties to stably attach the electrical component to the circuit lay-up. The conductive material may be deformable and have adhesive properties that provide a stable electrical connection without the need for soldering, eliminate the need for substantial energy consumption, generate substantially no waste, and emit substantially no volatile organic compounds (VOCs).

[0216] Clause 84: The method may include providing a substrate layer, forming one or more vias in the substrate layer, depositing a modified conductive material in at least one of the vias, and depositing an insulating layer on the substrate layer, the insulating layer at least partially encapsulating the modified conductive material. Depositing the modified conductive material in the at least one via may include wiping the conductive material on the at least one via to remove excess conductive material from the surrounding substrate surface.

[0217] Clause 85: The method may include the steps of providing a substrate layer, selectively forming one or more vias in the substrate layer, depositing a modified conductive material in at least one of the substrate layer vias, successively stacking at least one stencil layer having one or more vias on the substrate layer, depositing a modified conductive material in at least one via of the stencil layer after each stacking of the stencil layers, and depositing an insulating layer on the last stacked stencil layer. The at least one via of each stencil layer may extend through the thickness of the layer. The successively stacked stencil layers may at least partially encapsulate the modified conductive material of the previously stacked layer. The insulating layer may at least partially encapsulate the modified conductive material in at least one via of the last stacked stencil layer. The step of depositing the modified conductive material may include wiping the conductive material on at least one via to remove excess conductive material from the surface surrounding the layer in which the via is formed.

[0218] Clause 86: The substrate surface and at least one of the stencil layer surfaces may include a release layer. The release layer may be removed after the modified conductive material is laminated to the respective layer surface.

[0219] Clause 87: At least one via in the substrate layer or at least one stencil layer may be in communication with at least one via in another layer. A via in a stencil layer may extend through the thickness of that layer.

[0220] Clause 88: The method may include forming at least one contact in a circuit lay-up comprising an adhesive deformed conductive material, and supporting an electrical component having at least one terminal in the circuit lay-up, the at least one terminal of the electrical component contacting the at least one contact to form at least one electrical connection between the electrical component and the contact. The at least one terminal may include a plurality of terminals arranged in a pattern, the at least one contact may include a plurality of contacts comprising the deformed conductive material and arranged in a pattern corresponding to the pattern of the terminals of the electrical component, the plurality of terminals of the electrical component may contact the plurality of contacts, and the adhesive properties of the deformed conductor form a stable electrical connection between the electrical component and the contact.

[0221] Clause 89: The method includes heating the circuit assembly to a melting point of the encapsulant, extracting the electrical components, heating the circuit assembly to a melting point of one or more of the substrate layer, the stencil layer, and the insulating layer, separating the conductive material from the circuit assembly, and purifying the conductive material. The method may further include reusing the electrical components and reprocessing the one or more layer materials and the conductive material for reuse.

[0222] Clause 90: A method of making a circuit layup comprising the steps of: providing a substrate layer; forming one or more paths in the substrate layer; recovering scrap material generated in the steps of forming the substrate layer and the paths; laminating a deformed conductive material to at least one of the paths; providing an insulating layer and stacking the insulating layer on the substrate layer; and recovering scrap material generated in the step of providing the insulating layer, wherein laminating the deformed conductive material to at least one of the paths includes removing excess deformed conductive material from the surrounding substrate surface by wiping the conductive material from the at least one path, the insulating layer at least partially encapsulating the deformed conductive material, and the scrap of the substrate layer and the insulating layer are reprocessed and the excess conductive material is incorporated into the making of one or more subsequent circuit layups.

[0223] All patents, patent applications, publications, or other disclosure materials mentioned herein are incorporated herein by reference in their entirety, as if each individual reference material were expressly incorporated by reference. All references and their materials, or portions thereof, that are incorporated herein by reference are incorporated herein only to the extent that the incorporated materials do not contradict existing definitions, descriptions, or other disclosure materials set forth in this disclosure. Therefore, to the extent necessary, the disclosure set forth herein supersedes any conflicting materials incorporated herein by reference, and the disclosure expressly set forth in this application controls.

[0224] The present invention has been described with reference to various exemplary and schematic embodiments. The embodiments described herein are understood to provide illustrative features of various details of the various embodiments of the disclosed invention. Thus, unless otherwise specified, it is understood that, to the extent possible, one or more features, elements, components, ingredients, structures, modules, and / or aspects of the disclosed embodiments may be combined, separated, exchanged, and / or rearranged with one or more other features, elements, components, ingredients, structures, modules, and / or aspects of the disclosed embodiments without departing from the scope of the disclosed invention. Thus, it will be understood by those skilled in the art that various substitutions, modifications, or combinations of any of the exemplary embodiments may be made without departing from the scope of the invention. Moreover, those skilled in the art will recognize, or be able to ascertain with no more than routine experimentation, many equivalents to the various embodiments of the invention described herein upon review of this specification. Thus, the present invention is not limited by the description of the various embodiments, but rather by the scope of the claims.

[0225] Those of skill in the art will generally recognize that the terms used herein, and particularly in the appended claims (e.g., the body of the appended claims), are generally intended as "open-ended" terms (e.g., the term "comprises" should be interpreted as "including, but not limited to," the term "having" should be interpreted as "having at least," the term "including" should be interpreted as "including, but not limited to," etc.). Those of skill in the art will further appreciate that if a specific number of introduced claim recitations is intended, such intent will be expressly set forth in the claim, and in the absence of such recitation, no such intent exists. For example, as an aid to understanding, the appended claims below may use the introductory phrases "at least one" and "one or more" to introduce the claim recitations. However, the use of such phrases should not be construed as meaning that the introduction of a claim recitation with the indefinite article "a" or "an" limits a particular claim that includes such an introduced claim recitation to claims that include only one of such introduced claim recitation, even if that same claim includes the introductory phrase "one or more" or "at least one" and an indefinite article such as "a" or "an" (e.g., "a" and / or "an" should normally be construed to mean "at least one" or "one or more").

[0226] Furthermore, even if a particular number in an introduced claim is explicitly recited, one of ordinary skill in the art will recognize that such recitation should generally be interpreted to mean at least the recited number (e.g., an exposed recitation of "two recitations" without other modifiers generally means at least two recitations, or more than two recitations). Furthermore, when a convention similar to "such as at least one of A, B, and C" is used, such a configuration is generally intended in the sense that one of ordinary skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" includes, but is not limited to, systems having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, and C, etc.). When a convention similar to "at least one of A, B, or C, etc." is used, such a configuration is generally intended in the sense that one of ordinary skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" includes, but is not limited to, systems having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, and C, etc.). As will be further understood by one of ordinary skill in the art, disjunctive words and / or phrases, whether in the description, claims, or drawings, that typically present two or more alternative terms, should be understood to contemplate the possibility of including one of the terms, either of the terms, or both terms, unless the context dictates otherwise. For example, the phrase "A or B" is typically understood to include the possibility of "A" or "B," or "A and B."

[0227] With respect to the appended claims, those skilled in the art will appreciate that the operations described therein may generally be performed in any order. Also, while the claims are presented in a sequential order, it should be understood that various operations may be performed in orders other than those described, or may be performed simultaneously. Examples of such alternative orders include overlapping, interleaved, interrupted, reordered, incremented, preparatory, supplemental, concurrent, reversed, or other variant orders, unless the context dictates otherwise. Moreover, terms such as past tense adjectives, such as "according to" and "related to," are generally not intended to exclude such variants, unless the context dictates otherwise.

[0228] It should be noted that references to "one embodiment," "an embodiment," "exemplary embodiment," "one exemplary embodiment," etc. mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment. Thus, the appearances of the phrases "in one embodiment," "in an embodiment," "in an example," and "in one example" in various places throughout this specification do not necessarily all refer to the same embodiment. Furthermore, particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0229] As used herein, the singular forms "a", "an" and "the" include the plural forms as well, unless the context clearly indicates otherwise.

[0230] Directional terms used herein, such as, but not limited to, up, down, left, right, below, over, front, back, and variations thereof, refer to the orientation of the elements as shown in the accompanying drawings and do not limit the scope of the claims, unless expressly stated otherwise.

[0231] The term "about" or "approximately" as used in this disclosure, unless otherwise specified, refers to an acceptable error for a particular value as determined by a person skilled in the art, which depends in part on how the value is measured or determined. In certain embodiments, the term "about" or "approximately" refers to within 1, 2, 3, or 4 standard deviations. In certain embodiments, the term "about" or "approximately" refers to within 50%, 200%, 105%, 100%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, or 0.05% of a given value or range.

[0232] As used herein, unless otherwise indicated, all numerical parameters are understood to be prefaced and modified in all instances by the term "about," in which case the numerical parameters have the inherent variability inherent in the underlying measuring techniques employed to determine the numerical value of the parameter. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter set forth herein should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0233] Numerical ranges mentioned herein include all subranges subsumed within the mentioned range. For example, a range of "1-100" includes all subranges between (and including) the implied minimum of 1 and the implied maximum of 100, i.e., with a minimum equal to or greater than 1 and a maximum equal to or less than 100. Also, all ranges mentioned herein include the endpoints of the mentioned range. For example, a range of "1-100" includes the endpoints 1 and 100. Any maximum numerical limitation stated herein is intended to include all lower numerical limitations subsumed therein, and any minimum numerical limitation stated herein is intended to include all higher numerical limitations subsumed therein. Accordingly, applicants reserve the right to amend this specification, including the claims, to explicitly state any subranges subsumed within the expressly stated ranges. All such ranges are inherently described herein.

[0234] Any patent applications, patents, non-patent publications, or other disclosure materials mentioned herein and / or set forth in the Application Data Sheet are incorporated herein by reference to the extent that the incorporated materials do not conflict with the present specification. Therefore, to the extent necessary, the disclosures expressly set forth herein supersede any conflicting materials incorporated herein by reference. Any material, or portions thereof, that is intended to be incorporated herein by reference that conflicts with existing definitions, descriptions, or other disclosure materials set forth herein is incorporated only to the extent that no conflict arises between the incorporated materials and the existing disclosure materials.

[0235] "Comprise" (and any form of comprise, such as "comprises" or "comprising"), "have" (and any form of have, such as "has" or "having"), "include" (and any form of include, such as "includes" or "including"), and "contain" (and any form of contain, such as "contains" or "containing") are open-ended linking verbs. As a result, a system that "contains," "has," "contains," or "contains" one or more elements may possess one or more of those elements, but is not limited to possessing only those one or more elements.

Claims

1. A method for producing a highly sustainable circuit assembly, comprising: providing a substrate layer; placing a first stack layer having a first path pattern formed thereon on a surface of the substrate layer; depositing a deformed conductive material so as to at least partially fill the first routing pattern; removing excess deformed conductive material from the first stack layer; and reusing the excess deformed conductive material removed from the first stack layer; the electrical resistance of the reused excess deformed conductive material is equal to the electrical resistance of the laminated deformed conductive material; method.

2. The step of reusing the excess deformed conductive material comprises: at least partially filling a second routing pattern provided in a second stack layer of the circuit assembly with the excess deformed conductive material; using the excess deformed conductive material to fabricate another circuit assembly; or The method of claim 1 comprising a combination thereof.

3. removing the excess deformed conductive material from the first stack layer comprises wiping the excess deformed conductive material from a surface of the first stack layer or wiping the excess deformed conductive material from a release layer attached to the surface of the first stack layer; The method of claim 1.

4. mounting an electrical component to the circuit assembly, at least one terminal of the electrical component corresponding to the first routing pattern; and electrically coupling the at least one terminal of the electrical component to at least a portion of the first routing pattern without soldering, without generating waste, and without emitting volatile organic compounds. The method of claim 1.

5. disposing a second stack layer having a second path pattern formed thereon on the first stack layer; depositing the modified conductive material so as to at least partially fill the second routing pattern; removing excess deformed conductive material from the second stack layer; and reusing the excess deformed conductive material removed from the second stack layer. The method of claim 1.

6. further comprising interposing a sublayer comprising a conductive element pattern between the first stack layer and the second stack layer. The method according to claim 5.

7. the modified conductive material comprises a non-hazardous and easily recyclable conductive gel; The method of claim 1.

8. the modified conductive material comprises a gallium alloy; The method of claim 1.

9. A highly sustainable circuit assembly, A substrate layer; a first stack layer having a first path pattern formed thereon, the first path pattern extending through a thickness of the first stack layer, the first path pattern comprising a modified conductive material; the modified conductive material comprises a non-hazardous and easily recyclable material; Circuit assembly.

10. The first path pattern comprising the modified conductive material comprises: a contact pattern configured to correspond to at least one terminal of an electrical component; Trace pattern, or With a combination of these, 10. The circuit assembly of claim 9.

11. The circuit assembly of claim 10 further comprising the electrical component.

12. a second stack layer having a second path pattern formed thereon, the second path pattern extending through a thickness of the second stack layer, the second path pattern comprising the modified conductive material; 10. The circuit assembly of claim 9.

13. a sublayer interposed between the first stack layer and the second stack layer, the sublayer comprising a conductive element pattern; 13. The circuit assembly of claim 12.

14. the conductive element pattern is electrically coupled to the second path pattern; the second path pattern is configured to correspond to at least one terminal of an electrical component; 14. The circuit assembly of claim 13.

15. a first portion of the second path pattern aligned with a first portion of the first path pattern; the modified conductive material forms a continuous structure extending from the first portion of the first routing pattern to the first portion of the second routing pattern; 13. The circuit assembly of claim 12.

16. a third stack layer having a third path pattern formed thereon, the third path pattern extending through a thickness of the third stack layer, the third path pattern comprising the modified conductive material; 16. The circuit assembly of claim 15.

17. a first portion of the third path pattern aligned with a second portion of the second path pattern; the modified conductive material forms a continuous structure extending from the first portion of the first routing pattern to the first portion of the third routing pattern.

17. The circuit assembly of claim 16.

18. a fourth stack layer having a fourth path pattern formed thereon, the fourth path pattern extending through a thickness of the fourth stack layer, the fourth path pattern comprising the modified conductive material; 20. The circuit assembly of claim 17.

19. a first portion of the fourth path pattern aligned with a second portion of the third path pattern; the modified conductive material forms a continuous structure extending from the first portion of the first routing pattern to the first portion of the fourth routing pattern.

20. The circuit assembly of claim 18.

20. the modified conductive material comprises a conductive gel; 10. The circuit assembly of claim 9.

21. the modified conductive material comprises a gallium alloy; 10. The circuit assembly of claim 9.

22. 1. A method of recovering materials from a highly sustainable circuit assembly comprising an electrical component, a substrate layer, and a modified conductive material, comprising: removing the electrical component from the circuit assembly; heating the highly sustainable circuit assembly to a melting point of the substrate layer to form a molten substrate layer; separating the deformed conductive material from the fused substrate layer to obtain a regenerated deformed conductive material and a regenerated substrate layer material; and recycling the regenerated deformed conductive material. method.

23. the circuit assembly comprising an adhesive material; The method further comprises heating the circuit assembly to a glass transition temperature of the adhesive material; the step of removing the electrical component from the circuit assembly occurs after the step of heating the circuit assembly to the glass transition temperature of the adhesive material.

23. The method of claim 22.

24. the modified conductive material comprises a conductive gel; 23. The method of claim 22.

25. the modified conductive material comprises a gallium alloy; 23. The method of claim 22.

26. The regenerated deformable conductive material comprises a metal alloy and a metal oxide formed by exposing the metal alloy to air; The step of recycling the regenerated deformed conductive material includes: exposing the regenerated transformed conductive material to an acid solution, thereby reacting the metal oxide with the acid solution to obtain a clean liquid metal alloy; and removing the clean liquid metal alloy from the acid solution.

23. The method of claim 22.

27. and recycling the regenerated deformed conductive material further comprises creating a new deformed conductive material from the clean liquid metal alloy.

27. The method of claim 26.

28. The step of exposing the regenerated deformed conductive material to the acid solution comprises agitating the deformed conductive material in the acid solution to obtain the clean liquid metal alloy.

27. The method of claim 26.

29. the amount of the clean liquid metal alloy removed from the acid solution is greater than or equal to 55% by weight of the metal alloy originally used to make the regenerated transformed conductive material; 30. The method of claim 28.

30. The regenerated conductive material comprises fine particles; agitating the deformed conductive material in the acid solution removes the particulates to obtain the clean liquid metal alloy; 30. The method of claim 28.

31. the metal alloy comprises a gallium-indium-tin alloy; the metal oxide comprises gallium oxide; 27. The method of claim 26.

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