Thermal interface materials comprising liquid metal droplets and solid thermally conductive particles, circuit assemblies formed therefrom, and methods of manufacture thereof

Abstract

Thermal interface materials (TIMS) comprising liquid metal droplets and solid thermally conductive particles, circuit assemblies formed therefrom, and methods of manufacture thereof are provided. The TIM comprises 5% to 80% by volume of a polymer component based on a total volume of the TIM and 20% to 95% by volume of a conductive component based on the total volume of the TIM. The conductive component is dispersed through the polymer component. The conductive component comprises 25% to 99% by volume of liquid metal droplets based on a total volume of the conductive component and 1% to 75% by volume of solid thermally conductive particles based on the total volume of the conductive component. The liquid metal droplets and solid thermally conductive particles are dispersed through the polymer component.

Description

THERMAL INTERFACE MATERIALS COMPRISING LIQUID METAL DROPLETS AND SOLID THERMALLY CONDUCTIVE PARTICLES, CIRCUIT ASSEMBLIES FORMED THEREFROM, AND METHODS OF MANUFACTURE THEREOFInventors: Keyton Feller, Swagata Mondal, Benjamin Dorau, Hing Jii Mea, Navid KazemCROSS-REFERENCE

[0001] This Application claims priority to U.S. Provisional Patent Application No. 63 / 609,440, entitled, “THERMAL INTERFACE MATERIALS COMPRISING LIQUID METAL DROPLETS AND SOLID METAL PARTICLES, CIRCUIT ASSEMBLIES FORMED THEREFROM, AND METHODS OF MANUFACTURE THEREOF” which was filed on December 13, 2023, U.S. Provisional Patent Application No. 63 / 568,584, entitled, “THERMAL INTERFACE MATERIALS COMPRISING LIQUID METAL DROPLETS AND SOLID THERMALLY CONDUCTIVE PARTICLES, CIRCUIT ASSEMBLIES FORMED THEREFROM, AND METHODS OF MANUFACTURE THEREOF”, which was filed on March 22, 2024, and U.S. Provisional Patent Application No. 63 / 655,731, which was filed on June 4, 2024, entitled, “THERMAL INTERFACE MATERIALS COMPRISING LIQUID METAL DROPLETS AND SOLID THERMALLY CONDUCTIVE PARTICLES, CIRCUIT ASSEMBLIES FORMED THEREFROM, AND METHODS OF MANUFACTURE THEREOF”. The contents of each is hereby incorporated by reference into this specification in their entirety.FIELD

[0002] The present disclosure relates to thermal interface materials comprising liquid metal droplets and solid thermally conductive particles, circuit assemblies formed therefrom, and methods of manufacture thereof.BACKGROUND

[0003] A thermal interface material (TIM) can be used to thermally connect two or more layers together. For example, TIMs are often used in CPU packages to thermally connect the integrated heat spreader (IHS) of a CPU package to a heat sink. There are various types of TIMs that can be used. However, current TIMs present challenges.SUMMARY

[0004] In one general aspect, the present disclosure is directed to a thermal interface material comprising 5% to 80% by volume of a polymer component based on a total volume of the thermal interface material and 20% to 95% by volume of a conductive component based on the total volume of the thermal interface material. In various examples, the polymer component comprises a polymer selected from the group consisting of an acrylic polymer, an acrylate polymer, a vinyl polymer, a polyester polymer, a polyurethane polymer, a polybutadiene polymer, a polyamide polymer, a polyether polymer, a polysiloxane polymer, a silicon hydride polymer, a fluoropolymer, a polyisoprene polymer, and a copolymer of any two or more thereof. The conductive component is dispersed through the polymer component. The conductive component comprises 25% to 99% by volume of liquid metal droplets based on a total volume of the conductive component and 1% to 75% by volume of solid thermally conductive particles based on the total volume of the conductive component. The liquid metal droplets are dispersed through the polymer component. The liquid metal droplets comprise a melting point of no greater than 30 degrees Celsius. In various examples, the liquid metal droplets comprise a metal selected from the group consisting of gallium, a gallium alloy, indium, an indium alloy, tin, a tin alloy, mercury, and a mercury alloy. The solid thermally conductive particles are dispersed through the polymer component. The solid thermally conductive particles comprise a melting point of at least 100 degrees Celsius. In various examples, the solid thermally conductive particles comprise a metal selected from the group consisting of a metal, a metal alloy, a ceramic, an oxide, carbon based materials, or a combination thereof. In certain examples, the liquid metal droplets comprise a D90 in a range of 1 micron to 300 microns and the solid thermally conductive particles comprise a D90 in a range of 1 micron to 300 microns. In various examples, the thermal interface material may optionally further comprise at least one of a catalyst, rigid spacer particles, a coupling agent, fumed silica, an additive, and a surfactant.

[0005] In another general aspect, the present disclosure is directed to an assembly comprising a first layer, a second layer, and the thermal interface material as described in the present disclosure compressed and disposed in contact with and between the first layer and the second layer.

[0006] In another general aspect, the present disclosure is directed to a method comprising applying the thermal interface material as described in the present disclosure on a first layer of an assembly at a first thickness and compressing the assembly to decrease the first thickness to a second thickness. The second thickness is no greater than a D90 of the liquid metal droplets prior to compressing the assembly.

[0007] In another general aspect, the present disclosure is directed to a method of manufacture of a thermal interface material. The method comprises mixing a first polymer component and solid thermally conductive particles together, thereby dispersing the solid thermally conductive particles throughout the first polymer component to create a first mixture. The solid thermally conductive particles comprise a melting point of at least 50 degrees Celsius. In various examples, the solid thermally conductive particles comprise a metal, a metal alloy, a ceramic, an oxide, carbon based materials, or a combination thereof. The method comprises mixing a second polymer component and liquid metal together, thereby forming liquid metal droplets from the liquid metal and dispersing the liquid metal droplets throughout the second polymer component. In various examples, the first polymer component and / or the second polymer component comprises a polymer selected from the group consisting of an acrylic polymer, an acrylate polymer, a vinyl polymer, a polyester polymer, a polyurethane polymer, a polybutadiene polymer, a polyamide polymer, a polyether polymer, a polysiloxane polymer, a silicon hydride polymer, a fluoropolymer, a polyisoprene polymer, and a copolymer of any two or more thereof. The liquid metal droplets comprise a melting point of no greater than 30 degrees Celsius. In various examples, the liquid metal droplets comprise a metal selected from the group consisting of gallium, a gallium alloy, indium, an indium alloy, tin, a tin alloy, mercury, and a mercury alloy. The method comprises mixing the first mixture and second mixture together, thereby forming the thermal interface material. In certain examples, the liquid metal droplets comprise a D90 in a range of 1 micron to 300 microns and the solid thermally conductive particles comprise a D90 in a range of 1 micron to 300 microns. In various examples, the thermal interface material may optionally further comprise at least one of a catalyst, rigid spacer particles, a coupling agent, fumed silica, an additive, and a surfactant.

[0008] In another general aspect, the present disclosure is directed to a method of manufacture of a thermal interface material. The method comprises mixing a first polymer component and solid thermally conductive particles together, thereby dispersing the solidthermally conductive particles throughout the first polymer component to create a first mixture. The solid thermally conductive particles comprise a melting point of at least 50 degrees Celsius. In various examples, the solid thermally conductive particles comprise a metal, a metal alloy, a ceramic, an oxide, carbon based materials, or a combination thereof. The method comprises mixing the first mixture, a second polymer component, and liquid metal together, thereby forming liquid metal droplets from the liquid metal and dispersing the liquid metal droplets throughout the first and second polymer components to create the thermal interface material. In various examples, the first polymer component and / or the second polymer component comprises a polymer selected from the group consisting of an acrylic polymer, an acrylate polymer, a vinyl polymer, a polyester polymer, a polyurethane polymer, a polybutadiene polymer, a polyamide polymer, a polyether polymer, a polysiloxane polymer, a silicon hydride polymer, a fluoropolymer, a polyisoprene polymer, and a copolymer of any two or more thereof. The liquid metal droplets comprise a melting point of no greater than 30 degrees Celsius. In various examples, the liquid metal droplets comprise a metal selected from the group consisting of gallium, a gallium alloy, indium, an indium alloy, tin, a tin alloy, mercury, and a mercury alloy. In certain examples, the liquid metal droplets comprise a D90 in a range of 1 micron to 300 microns and the solid thermally conductive particles comprise a D90 in a range of 1 micron to 300 microns. In various examples, the thermal interface material may optionally further comprise at least one of a catalyst, rigid spacer particles, a coupling agent, fumed silica, an additive, and a surfactant, which may be added at various times during the method of manufacture.

[0009] The present invention can provide both a low contact resistance at the material interfaces and a low thermal resistance through the TIM. The low contact resistance can be enabled by the application of the polymer in a conformable state, so that the polymer and liquid metal droplets can adapt to the surface of the layer to achieve a desired contact resistance. The low thermal resistance through the TIM can be enabled by the liquid metal droplets and solid thermally conductive particles, including the size and / or shape of the liquid metal droplets and / or solid thermally conductive particles. The use of the solid thermally conductive particles can lead to manufacturing efficiencies, reductions in cost, and / or improvements in the use of the TIM, such as, for example, resistance to liquid metal coalescence. These and other benefits realizable from various embodiments of the present invention will be apparent from the description that follows.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The features and advantages of various examples of the present invention, and the manner of attaining them, will become more apparent, and the examples will be better understood by reference to the following description of examples taken in conjunction with the accompanying drawing, wherein:

[0011] FIG. l is a perspective view of an assembly according to the present disclosure after deposition of the thermal interface material; and

[0012] FIG. 2 is a side view of an assembly formed by compressing the first and second layer of FIG. 1.

[0013] Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate certain examples, in one form, and such exemplifications are not to be construed as limiting the scope of the examples in any manner.DETAILED DESCRIPTION

[0014] Certain exemplary aspects of the present invention will now be described to provide an overall understanding of the principles of the composition, function, manufacture, and use of the compositions and methods disclosed herein. An example or examples of these aspects are illustrated in the accompanying drawing. Those of ordinary skill in the art will understand that the compositions, articles, and methods specifically described herein and illustrated in the accompanying drawing are non-limiting exemplary aspects and that the scope of the various examples of the present invention is defined solely by the claims. The features illustrated or described in connection with one exemplary aspect may be combined with the features of other aspects. Such modifications and variations are intended to be included within the scope of the present invention.

[0015] Pressure values as used herein refer to gauge pressure unless stated otherwise.

[0016] Properly formulating a thermal interface material (TIM) that is applied to a circuit assembly between an integrated heat spreader (IHS) and a heat sink can require balancing the thermal resistance through the TIM and the contact resistance at the material interfaces. For example, a polymeric material may have a low contact resistance at the material interfacesbut a high thermal resistance through the material. A solid metal may have a low thermal resistance through the material but a high contact resistance at the material interfaces.

[0017] Thus, the present disclosure provides, in various examples, a thermal interface material comprising 5% to 80% by volume of a polymer component based on a total volume of the thermal interface material and 20% to 95% by volume of a conductive component based on the total volume of the thermal interface material. The conductive component comprises 25% to 99% by volume of liquid metal droplets based on a total volume of the conductive component and 1% to 75% by volume of solid thermally conductive particles based on the total volume of the conductive component. The liquid metal droplets are dispersed through the polymer component. The liquid metal droplets comprise a melting point of no greater than 30 degrees Celsius. The solid thermally conductive particles are dispersed through the polymer component. The solid thermally conductive particles comprise a melting point of at least 50 degrees Celsius.

[0018] As used in this specification, particularly in connection with layers, films, or materials, the terms “on,” “onto,” “over,” and variants thereof (e.g., “applied on,” “formed on,” “deposited on,” “provided on,” “located on,” and the like) mean applied, formed, deposited, provided, or otherwise located over a surface of a substrate but not necessarily in contact with the surface of the substrate. For example, a TIM “deposited on” a substrate or “deposited between” two elements does not preclude the presence of another layer or other layers of the same or different composition located between the applied TIM and the substrate or layers. Likewise, a second layer “deposited on” a first layer does not preclude the presence of another layer or other layers of the same or different composition located between the deposited second layer and the deposited TIM.

[0019] As used in this specification, the terms “polymer” and “polymeric” means prepolymers, oligomers, and both homopolymers and copolymers. As used in this specification, “prepolymer” means a polymer precursor capable of further reactions or polymerization by a reactive group or reactive groups to form a higher molecular mass and / or cross-linked state.

[0020] The polymer component can comprise a polymeric binder, a thermosetting polymer, and / or a thermoplastic polymer. As used herein, the term “thermosetting” refers to polymers that “set” irreversibly upon curing or cross-linking, where the polymer chains of thepolymeric components are joined together by covalent bonds, which is often induced, for example, by heat or radiation. In various examples, curing or a cross-linking reaction can be carried out under ambient conditions. Once cured or cross-linked, a thermosetting polymer may not flow upon the application of heat, may otherwise irreversibly increase in viscosity, and / or can be insoluble in conventional solvents. As used herein, the term “thermoplastic” refers to polymers that include polymeric components in which the constituent polymer chains are not joined (e.g., crosslinked) by covalent bonds and thereby can undergo liquid flow upon heating and are soluble in conventional solvents. In certain embodiments, the polymer can be elastomeric (e.g., rubbery, soft, stretchy), or rigid (e.g., glassy) For example, the polymer component can be elastomeric and may have a ultimate tensile strain of at least 100%, such as, for example at least 200% or at least 300%. Ultimate tensile strain can be measured according to ASTM D3039.

[0021] Thermosetting polymers may include at least one of a cross-linking agent that may comprise, for example, aminoplasts, polyisocyanates (including blocked isocyanates), polyepoxides, beta-hydroxyalkylamides, polyacids, anhydrides, organometallic acidfunctional materials, polyamines, polyvinyls, polysilicon hydrides, polyalcohols, polyacid chlorides, polyhalides, and polyamides. A polymer may have functional groups that are reactive with the cross-linking agent.

[0022] The polymer component in the TIMs described herein may be selected from any of a variety of polymers well known in the art. For example, the thermosetting polymer may comprise at least one of an acrylic polymer (e.g., an acrylate polymer), a vinyl polymer, a polyester polymer, a polyurethane polymer, polybutadiene, a polyamide polymer, a polyether polymer, a polysiloxane polymer (e.g., poly(dimethylsiloxone)), a silicon hydride polymer, a fluoropolymer, a polyisoprene polymer (e.g., rubber), and a copolymer of two or more thereof. The functional groups on a thermosetting polymer may be selected from any of a variety of reactive functional groups, including, for example, at least one of a carboxylic acid group, an amine group, an epoxide group, a hydroxyl group, a thiol group, a carbamate group, an amide group, a urea group, an isocyanate groups (including a blocked isocyanate group), a vinyl group, a silicon hydride group, an acid chloride group, an acrylate group, a halide group, and a mercaptan group.

[0023] The thermoplastic polymer can comprise at least one of propylene-ethylene copolymer, styrene-butadiene-styrene, polyether, and styrene ethylene butylene styrene. The polymer can comprise a melting point of at least 100 degrees Celsius, such as, for example, at least 120 degrees Celsius, at least 150 degrees Celsius, or at least 200 degrees Celsius.

[0024] The polymeric binder can be a polyether binder, a polyether modified binder (e.g., an ethoxylate of an alcohol, a propoxylate of an alcohol), a carboxylic acid, an amine, a phenol, a sorbitan, a sorbitan ester, or a combination thereof.

[0025] The polymer component can optionally comprise other components such as, for example, fumed silica, a coupling agent, and an additive.

[0026] In various examples, the polymer component can comprise 0.1% by weight to 0.5% by weight of a coupling agent, if present, based on a total weight of the polymer component. For example, the coupling agent can comprise at least one of 3- Glycidoxypropyltrimethoxy silane, 3 -Glycidoxypropyltri ethoxy silane, 3- Aminopropyltrimethoxy silane, and Bis(3 -trimethoxy silylpropyl)amine. The coupling agent can promote adhesion to substrates.

[0027] In certain examples, the polymer component can comprise 0.1% by weight to 5% by weight of a fumed silica, if present, based on a total weight of the polymer component.

[0028] In various examples, the polymer component can comprise 0.1% by weight to 40% by weight of an additive, if present, based on a total weight of the polymer component. The additive can be used to adjust mechanical and / or chemical properties of the polymer component and / or resulting TIM. The additive can comprise a diluent, a plasticizer, or a combination thereof. In various examples, the additive can comprise an ethylene glycol oligomer, a propylene glycol oligomer, a diethylene glycol, a dipropylene glycol, a diethylene glycol mono-alkyl ether, a diethlyene glycol di-alkyl ether, a dipropylene glycol mono-alkyl ether, a dipropylene glycol di-alkyl ether, a triethylene glycol, tripropylene glycol, a triethylene glycol mono-alkyl ether, a triethlyene glycol di-alkyl ether, a tripropylene glycol mono-alkyl ether, a tripropylene glycol di-alkyl ether, or a combination thereof.

[0029] The additive can be used to configure the viscosity of the polymer component, configure the compliance of the polymer component, and / or adjust a concentration of a component in the polymer component to enhance stability. For example, the amount of shearimparted to the TIM during mixing can affect the formation of the liquid metal droplets. It is believed, that the viscosity of the polymer component, among other factors, can contribute to the amount of shear that can be imparted to the TIM. Thus, by configuring the TIM with a desirable viscosity, the amount of shear imparted during mixing of the TIM can be adjusted.

[0030] The TIM can comprise at least 5% polymer component by total volume of the TIM, such as, for example, at least 7% polymer component, at least 10% polymer component, at least 15% polymer component, at least 20% polymer component, at least 25% polymer component, at least 30% polymer component, at least 40% polymer component, at least 50% polymer component, or at least 60% polymer component, all based on the total volume of the TIM. The TIM can comprise no greater than 80% polymer component by total volume of the TIM, such as, for example, no greater than 70% polymer component, no greater than 60% polymer component, no greater than 50% polymer component, no greater than 40% polymer component, no greater than 30% polymer component, no greater than 25% polymer component, no greater than 20% polymer component, no greater than 15% polymer component, or no greater than 10% polymer component, all based on the total volume of the TIM. The TIM can comprise a range of 5% to 80% polymer component by total volume of the TIM, such as, for example, 5% to 70% polymer component, 5% to 60% polymer component, 5% to 50% polymer component, 5% to 40% polymer component, 5% to 30% polymer component, 7% to 30% polymer component, 10% to 30% polymer component, 5% to 25% polymer component, 5% to 20% polymer component, or 5% to 10% polymer component, all based on the total volume of the TIM. The amount of the polymer component can be selected while balancing a desired elasticity, adhesiveness, and a desired effective thermal conductivity of the TIM.

[0031] The conductive component (e.g., thermally conductive component) is dispersed throughout the polymer component. The TIM can comprise at least 20% conductive component by total volume of the TIM, such as, for example, at least 25% conductive component, at least 30% conductive component, at least 40% conductive component, at least 50% conductive component, at least 60% conductive component, at least 70% conductive component, at least 80% conductive component, or at least 90% conductive component, all based on the total volume of the TIM. The TIM can comprise no greater than 95% conductive component by total volume of the TIM, such as, for example, no greater than 93% conductive component, no greater than 90% conductive component, no greater than 80%conductive component, no greater than 70% conductive component, no greater than 60% conductive component, no greater than 50% conductive component, no greater than 40% conductive component, or no greater than 30% conductive component, all based on the total volume of the TIM. The TIM can comprise a range of 20% to 95% conductive component by total volume of the TIM, such as, for example, 30% to 95% conductive component, 40% to 95% conductive component, 50% to 95% conductive component, 50% to 93% conductive component, 60% to 93% conductive component, 70% to 95% conductive component, or 70% to 93% conductive component, all based on the total volume of the TIM. The amount of conductive component can be selected while balancing a desired elasticity and a desired effective thermal conductivity of the TIM.

[0032] The liquid metal droplets are dispersed throughout the polymer component and the liquid metal droplets can be emulsified therein. The liquid metal droplets for the TIM can comprise at least one of gallium, a gallium alloy, indium, an indium alloy, tin, a tin alloy, mercury, and a mercury alloy. The liquid metal droplets can comprise a melting point of no greater than 30 degrees Celsius, such as, for example, no greater than 25 degrees Celsius, no greater than 20 degrees Celsius, no greater than 15 degrees Celsius, no greater than 10 degrees Celsius, no greater than 5 degrees Celsius, no greater than 0 degrees Celsius, or no greater than -10 degrees Celsius. The liquid metal droplets can comprise a melting point of at least -40 degrees Celsius, such as, for example, at least -20 degrees Celsius, at least -19 degrees Celsius, at least -10 degrees Celsius, at least 0 degrees Celsius, at least 5 degrees Celsius, at least 10 degrees Celsius, at least 15 degrees Celsius, at least 20 degrees Celsius, or at least 25 degrees Celsius. The liquid metal droplets can comprise a melting point in a range of -40 degrees Celsius to 30 degrees Celsius, such as, for example, -20 degrees Celsius to 30 degrees Celsius, -19 degrees Celsius to 30 degrees Celsius, or -19 degrees Celsius to 25 degrees Celsius. The determination of the melting point can be made at a pressure of 1 atmosphere absolute. In certain embodiments, the TIM can comprise Gallium Indium Tin (Galinstan) and a melting point of -19 degrees Celsius.

[0033] The conductive component can comprise at least 25% liquid metal droplets by total volume of the conductive component, such as, for example, at least 30% liquid metal droplets, at least 35% liquid metal droplets, at least 40% liquid metal droplets, at least 45% liquid metal droplets, at least 50% liquid metal droplets, at least 55% liquid metal droplets, at least 60% liquid metal droplets, at least 70% liquid metal droplets, at least 80% liquid metaldroplets, or at least 85% liquid metal droplets, all based on the total volume of the conductive component. The conductive component can comprise no greater than 99% liquid metal droplets by total volume of the conductive component, such as, for example, no greater than 95% liquid metal droplets, no greater than 93% liquid metal droplets, no greater than 90% liquid metal droplets, no greater than 80% liquid metal droplets, no greater than 70% liquid metal droplets, no greater than 60% liquid metal droplets, no greater than 50% liquid metal droplets, no greater than 40% liquid metal droplets, or no greater than 30% liquid metal droplets, all based on the total volume of the conductive component. The conductive component can comprise a range of 25% to 99% liquid metal droplets by total volume of the conductive component, such as, for example, 25% to 95% liquid metal droplets, 40% to 95% liquid metal droplets, 50% to 95% liquid metal droplets, 50% to 90% liquid metal droplets, 55% to 85% liquid metal droplets, 60% to 80% liquid metal droplets, or 65% to 75% liquid metal droplets, all based on the total volume of the conductive component. The amount of liquid metal droplets can be selected while balancing a desired elasticity and a desired effective thermal conductivity of the TIM.

[0034] The composition and / or mixing techniques can be selected to achieve a desired Dso and / or D90 of the liquid metal droplets in the TIM prior to compressing. The D50 of the liquid metal droplets can be at least 1 micron prior to compressing, such as, for example, at least 5 microns, at least 10 microns, at least 15 microns, at least 20 microns, at least 30 microns, at least 35 microns, at least 40 microns, at least 50 microns, at least 60 microns, at least 70 microns, at least 80 microns, at least 90 microns, at least 100 microns, at least 120 microns, at least 150 microns, or at least 200 microns, all prior to compressing. The D50 of the liquid metal droplets can be no greater than 300 micron, such as, for example, no greater than 250 microns, no greater than 200 microns, no greater than 150 microns, no greater than 120 microns, no greater than 100 microns, no greater than 90 microns, no greater than 80 microns, no greater than 70 microns, no greater than 60 microns, no greater than 50 microns, no greater than 40 microns, no greater than 35 microns, no greater than 30 microns, no greater than 20 microns, no greater than 10 microns, or no greater than 5 microns, all prior to compressing. For example, the D50 of the liquid metal droplets can be in a range of 1 microns to 300 microns, such as, for example, 5 microns to 300 microns, 150 microns to 250 microns, 5 microns to 150 microns, 15 to 150 microns, 35 microns to 150 microns, 35 microns to 70 microns, or 5 microns to 100 microns, all measured prior to compressing.

[0035] As used herein, Dxcan be measured using microscopy (e.g., optical microscopy or electron microscopy). The size can be the diameter of spherical particles or the length along the largest dimension of ellipsoidal or otherwise irregularly shaped particles. As used herein, “Dx” of particles refers to the diameter at which X% of the particles have a smaller diameter.

[0036] The D90 of the liquid metal droplets can be at least 1 micron, such as, for example, at least 5 microns, at least 10 microns, at least 15 microns, at least 20 microns, at least 30 microns, at least 35 microns, at least 40 microns, at least 50 microns, at least 60 microns, at least 70 microns, at least 80 microns, at least 90 microns, at least 100 microns, at least 120 microns, at least 150 microns, or at least 200 microns, all prior to compressing. The D90 of the liquid metal droplets can be no greater than 300 micron, such as, for example, no greater than 250 microns, no greater than 200 microns, no greater than 150 microns, no greater than 120 microns, no greater than 100 microns, no greater than 90 microns, no greater than 80 microns, no greater than 70 microns, or no greater than 50 microns, all prior to compressing. For example, the D90 of the liquid metal droplets can be in a range of 1 microns to 300 microns, such as, for example, 5 microns to 300 microns, 150 microns to 250 microns, 10 microns to 200 microns, 15 to 150 microns, 35 microns to 150 microns, 35 microns to 120 microns, or 50 microns to 100 microns, all measured prior to compressing.

[0037] At least a portion of the liquid metal droplets can comprise an exterior surface comprising a metal oxide. The metal oxide can comprise at least one of gallium oxide, indium oxide, tin oxide, iron oxide, mercury oxide, aluminum oxide, nickel oxide, zinc oxide, copper oxide, and other metal oxides. For example, in examples when the liquid metal droplets comprises gallium or a gallium alloy, a film of gallium oxide may be formed on the liquid metal droplets by oxidation due to exposure to water and / or air. In various examples, a film of a metal oxide can be formed by inclusion of metal oxide particles (e.g., aluminum oxide, zinc oxide) into the polymeric binder or into the liquid metal droplets.

[0038] The solid thermally conductive particles are dispersed throughout the polymer component and can be suspended therein. The solid thermally conductive particles can be separate from the liquid metal droplets in the TIM. For example, the solid thermally conductive particles can be in a first dispersion, the liquid metal droplets can be a second dispersion separate from the first dispersion, and the polymer component can be the continuous phase. The solid thermally conductive particles may not be suspended within theliquid metal droplets and / or may not be coated with liquid metal. The solid thermally conductive particles can be substantially in contact with the polymer component.

[0039] The solid thermally conductive particles can comprise a metal, a metal alloy, a ceramic, an oxide, carbon based materials, or a combination thereof. The metal or metal alloy can comprise aluminum, an aluminum alloy, titanium, a titanium alloy, manganese, a manganese alloy, iron, an iron alloy, nickel, a nickel alloy, copper, a copper alloy (e.g., bronze), zinc, a zinc alloy, lead, a lead alloy, silver, a silver alloy, gold, a gold alloy, indium, an indium alloy, tin, a tin alloy, bismuth, a bismuth alloy, tungsten, a tungsten alloy, and a combination thereof. For example, the solid thermally conductive particles can comprise at least of aluminum, an aluminum alloy, iron, an iron alloy, copper, a copper alloy, zinc, and a zinc alloy. In various examples, the solid thermally conductive particles comprise a copper alloy, such as, for example, a copper alloy comprising tin (e.g., bronze).

[0040] The ceramic can comprise boron nitride, aluminum nitride, or a combination thereof. The carbon based material can comprise a carbide, graphite, graphene, diamond, or a combination thereof. The carbide can comprise silicon carbide, tungsten carbide, aluminum carbide, or a combination thereof. The oxide can comprise aluminum oxide, iron oxide, or a combination thereof.

[0041] The solid thermally conductive particles can comprise a melting point of at least 50 degrees Celsius, such as, for example, at least 75 degrees Celsius, at least 100 degreesCelsius, at least 110 degrees Celsius, at least 120 degrees Celsius, at least 150 degreesCelsius, at least 200 degrees Celsius, at least 250 degrees Celsius, at least 300 degreesCelsius, at least 350 degrees Celsius, at least 400 degrees Celsius, or at least 500 degreesCelsius. The solid thermally conductive particles can comprise a melting point in a range of 100 degrees Celsius to 3,500 degrees Celsius, such as, for example, 100 degrees Celsius to 2,000 degrees Celsius, 200 degrees Celsius to 2,000 degrees Celsius, or 500 degrees Celsius to 1,500 degrees Celsius.

[0042] The conductive component can comprise at least 1% solid thermally conductive particles by total volume of the TIM, such as, for example, at least 5% solid thermally conductive particles, at least 10% solid thermally conductive particles, at least 20% solid thermally conductive particles, at least 25% solid thermally conductive particles, at least 30% solid thermally conductive particles, at least 40% solid thermally conductive particles, at least50% solid thermally conductive particles, at least 60% solid thermally conductive particles, at least 70% solid thermally conductive particles, at least 80% solid thermally conductive particles, or at least 90% solid thermally conductive particles, all based on the total volume of the TIM. The TIM can comprise no greater than 75% solid thermally conductive particles by total volume of the TIM, such as, for example, no greater than 70% solid thermally conductive particles, no greater than 60% solid thermally conductive particles, no greater than 50% solid thermally conductive particles, no greater than 40% solid thermally conductive particles, no greater than 35% solid thermally conductive particles, no greater than 30% solid thermally conductive particles, no greater than 20% solid thermally conductive particles, or no greater than 10% solid thermally conductive particles, all based on the total volume of the conductive component. The conductive component can comprise a range of 1% to 75% solid thermally conductive particles by total volume of the conductive component, such as, for example, 5% to 75% solid thermally conductive particles, 10% to 75% solid thermally conductive particles, 20% to 75% solid thermally conductive particles, 5% to 50% solid thermally conductive particles, 10% to 50% solid thermally conductive particles, 20% to 50% solid thermally conductive particles, or 25% to 35% solid thermally conductive particles, all based on the total volume of the conductive component. The amount of solid thermally conductive particles can be selected while balancing a desired elasticity and a desired effective thermal conductivity of the TIM.

[0043] The composition and / or mixing techniques can be selected to achieve a desired Dso and / or D90 of the solid thermally conductive particles in the TIM prior to compressing. The D50 of the solid thermally conductive particles can be at least 1 micron prior to compressing, such as, for example, at least 5 microns, at least 10 microns, at least 15 microns, at least 20 microns, at least 30 microns, at least 35 microns, at least 40 microns, at least 50 microns, at least 60 microns, at least 70 microns, at least 80 microns, at least 90 microns, at least 100 microns, at least 120 microns, at least 150 microns, or at least 200 microns, all prior to compressing. The D50 of the solid thermally conductive particles can be no greater than 300 micron, such as, for example, no greater than 250 microns, no greater than 200 microns, no greater than 150 microns, no greater than 120 microns, no greater than 100 microns, no greater than 90 microns, no greater than 80 microns, no greater than 70 microns, no greater than 60 microns, no greater than 50 microns, no greater than 40 microns, no greater than 35 microns, no greater than 30 microns, no greater than 20 microns, no greater than 10 microns, or no greater than 5 microns, all prior to compressing. For example, the D50 of the solidthermally conductive particles can be in a range of 1 microns to 300 microns, such as, for example, 5 microns to 300 microns, 150 microns to 250 microns, 5 microns to 150 microns, 15 to 150 microns, 35 microns to 150 microns, 30 microns to 60 microns, 5 microns to 70 microns, or 5 microns to 100 microns, all measured prior to compressing.

[0044] The D90 of the solid thermally conductive particles can be at least 1 micron, such as, for example, at least 5 microns, at least 10 microns, at least 15 microns, at least 20 microns, at least 30 microns, at least 35 microns, at least 40 microns, at least 50 microns, at least 60 microns, at least 70 microns, at least 80 microns, at least 90 microns, at least 100 microns, at least 120 microns, at least 150 microns, or at least 200 microns, all prior to compressing. The D90 of the solid thermally conductive particles can be no greater than 300 micron, such as, for example, no greater than 250 microns, no greater than 200 microns, no greater than 150 microns, no greater than 120 microns, no greater than 100 microns, no greater than 90 microns, no greater than 80 microns, no greater than 70 microns, or no greater than 50 microns, all prior to compressing. For example, the D90 of the solid thermally conductive particles can be in a range of 1 microns to 300 microns, such as, for example, 5 microns to 300 microns, 150 microns to 250 microns, 10 microns to 200 microns, 15 to 150 microns, 35 microns to 150 microns, 35 microns to 120 microns, or 50 microns to 100 microns, all measured prior to compressing.

[0045] The D90 of the liquid metal droplets can be less than, equal to, or greater than the D90 of the solid thermally conductive particles. In various examples, the D90 of the liquid metal droplets can be at least 20% greater than a width of the solid thermally conductive particles prior to compressing, such as, for example, at least 25% greater, at least 30% greater, at least 35% greater, or at least 40% greater. The D90 of the liquid metal droplets can no greater than 200% more than a width of the solid thermally conductive particles prior to compressing, such as, for example, no greater than 100% more, or no greater than 50% more than a width of the solid thermally conductive particles prior to compressing.

[0046] The solid thermally conductive particles can comprise a spherical shape, a shape of a rod, a shape of a cylinder, or a combination thereof.

[0047] The solid thermally conductive particles can be non-reactive with the metal oxide on the liquid metal droplets. For example, the solid thermally conductive particles may not cause the liquid metal droplets to coalesce and / or aggregate. The solid thermally conductiveparticles can comprise a coating. For example, the coating can be bonded (e.g., covalent bond, ionic bond, coordination bond, metallic bond) to at least a portion of a surface of the solid thermally conductive particles. The coating can comprise a bimetallic compound, a polymer, an organic compound (e.g., a surfactant), or a combination thereof. The polymer can comprise a polymer chain having a molecular weight of at least 100 g / mol as measured by gel permeation chromatography (GPC), such as, for example, at least 200 g / mol, at least 300 g / mol, at least 400 g / mol, at least 500 g / mol, at least 1,000 g / mol, at least 2,000 g / mol, or at least 5,000 g / mol, all as measured by GPC. In various examples, the polymer chain can comprises at least one of an acrylic polymer, an acrylate polymer, a vinyl polymer, a polyester polymer, a polyurethane polymer, a polybutadiene polymer, a polyamide polymer, a polyether polymer, a polysiloxane polymer, a polysilane polymer, a silicon hydride polymer, a fluoropolymer, a polyisoprene polymer, polystyrene polymer, polyepoxide polymer, and a copolymer of any two or more thereof. In certain examples the coating comprises an acid functionalized polymer. The polymer can comprise a polysilane polymer. The polysilane polymer can comprise a silicon atom bonded to four substituents where at least one substituent is of silyl ether functionality (Si-0-R) ( e.g., (methoxy)silyl ether, (ethoxy)silyl ether, (propoxy)sily ether, (isopropoxy)silyl ether, (tert-butoxy) silyl ether, (phenoxy)silyl ether) and may comprise other substituents which do not have silyl ether functionality (e.g., vinyl, amine, alcohol, acrylate, phenyl, carboxylic acid, thiol, azide, alkyne, haloalkane, anhydride, aldehyde, imide) with at least 2 carbon atoms between a functional group and a silicon atom.

[0048] The acid for functionalizing the liquid metal may be a Bronsted-Lowry acid. The acid can comprise at least one of an acid comprising a sulfate group, an acid comprising a nitrate group, an acid comprising a phosphate group, an acid comprising a chloride group, an acid comprising a bromide group, an acid comprising an iodide group, a carboxylic acid, and an acid comprising a sulfonic group. For example, the acid can comprise at least one of sulfuric acid, nitric acid, phosphoric acid, hydrochloric acid, hydrobromic acid, hydroiodic acid, and carboxylic acid. The acid can be a monoprotic acid or a polyprotic acid.

[0049] The amount of coating bonded to at least a portion of the solid thermally conductive particles can be sufficient to achieve an enhanced resistance of the solid thermally conductive particles to move through the polymer component by at least one of steric hindrances and charge repulsion compared to solid thermally conductive particles not bonded to the coating;and / or an enhance resistant for the solid thermally conductive particles to interact with the metal oxide on the liquid metal droplets; enhanced affinity of the solid thermally conductive particles towards the polymer component compared to solid thermally conductive particles not bonded to the coating; enable crosslinking of the solid thermally conductive particles into the polymer component; and / or enhanced surface wetability of the solid thermally conductive particles compared to solid thermally conductive particles not bonded to the coating. In various examples, the liquid metal droplets can comprise a coating and / or a surface functionalizing component.

[0050] The solid thermally conductive particles can comprise a thermal conductivity greater than a thermal conductivity of the liquid metal droplets. For example, the solid thermally conductive particles can comprise a thermal conductivity of at least 5 W / m*K, at least 10 W / m*K, at least 20 W / m*K , at least 30 W / m*K , at least 40 W / m*K , at least 50 W / m*K, at least 60 W / m*K, at least 70 W / m*K, at least 75 W / m*K, at least 100 W / m*K, or at least 150 W / m*K. The solid thermally conductive particles can comprise a thermal conductivity value in a range of 5 W / m*K to 500 W / m*K, such as, for example, 10 W / m*K to 300 W / m*K, 20 W / m*K to 500 W / m*K or 100 W / m*K to 300 W / m*K.

[0051] The solid thermally conductive particles comprise an electrical conductivity of at least 103Siemens per meter (S / m) as measured according to ASTM Bl 92-20, such as, for example, at least 104S / m, or at least 105S / m, all as measured according to ASTM Bl 92-20.

[0052] The solid thermally conductive particles can comprise a D90 sphericity of at least 0.5, such as, for example, at least 0.6 or at least 0.7. The solid thermally conductive particles can comprise a D90 sphericity of no greater than 0.95, such as, for example, no greater than 0.9, or no greater than 0.8. As used herein, D90 sphericity can be measured using microscopy (e.g., optical microscopy or electron microscopy). The sphericity measurement is the degree to which a particle approximates a sphere by comparing a surface area of a sphere having the same volume of an element to the surface area of the element. As used herein, “D90 sphericity” refers to the mean average sphericity of particles having a diameter no greater than the D90 particle size of the particles. The sphericity can enhance the uniformity of the solid thermally conductive particles and thereby enhance control of a bond line thickness.

[0053] In various examples, the solid thermally conductive particles can comprise a Young’s modulus of at least 100 MPa (megapascals), such as, for example, at least 110 MPa, at least150 MPa, at least 200 MPa, at least 250 MPa, at least 500 MPa, at least 750 MPa, at least 1GPa (gigapascals), or at least 2 GPa. Young’s Modulus can be measured according to ASTMEl 11-17.

[0054] The TIM can optionally comprise other components such as, for example, rigid spacer particles, a catalyst, fumed silica, a coupling agent, an additive, and a surfactant. The rigid spacer particles can comprise at least one of iron, an iron alloy (e.g., steel), vanadium, a vanadium alloy, niobium, a niobium alloy, titanium, a titanium alloy, copper, a copper alloy (e.g., bronze), a rigid polymer, a glass, and a ceramic. The rigid spacer particles can be resistant to deformation and / or corrosion by the liquid metal droplets. For example, the rigid spacer particles can comprise a Young’s modulus of at least 100 MPa (megapascals), such as, for example, at least 110 MPa, at least 150 MPa, at least 200 MPa, at least 250 MPa, at least 500 MPa, at least 750 MPa, at least 1 GPa (gigapascals), or at least 2 GPa. Young’s Modulus can be measured according to ASTM El 11-17. The TIM can comprise a range of 0.1% to 5% rigid spacer particles by total volume of the TIM, such as, for example, 0.1% to 4% rigid spacer particles, 0.1% to 3% rigid spacer particles, 1% to 4% rigid spacer particles, or 1% to 3% rigid spacer particles, all based on the total volume of the TIM.

[0055] The D90 and / or D50 of the rigid spacer particles in the TIM can be selected to achieve a desired bondline thickness in the assembly. For example, the D90 of the rigid spacer particles can be at least 1 micron, such as, for example, at least 5 microns, at least 10 microns, at least 20 microns, at least 30 microns, at least 35 microns, at least 40 microns, at least 50 microns, at least 60 microns, at least 70 microns, at least 80 microns, at least 90 microns, at least 100 microns, at least 120 microns, at least 200 microns, or at least 300 microns. The D90 of the rigid spacer particles can be no greater than 350 microns, such as, for example, no greater than 300 microns, no greater than 200 microns, no greater than 125 microns, no greater than 120 microns, no greater than 100 microns, no greater than 90 microns, no greater than 80 microns, no greater than 70 microns, no greater than 60 microns, no greater than 50 microns, no greater than 40 microns, no greater than 35 microns, no greater than 30 microns, no greater than 20 microns, no greater than 10 microns, or no greater than 5 microns. For example, the D90 of the rigid spacer particles can be in a range of 1 microns to 350 microns, such as, for example, 10 microns to 200 microns, 15 microns to 150 microns, 5 microns to 125 microns, 35 microns to 125 microns, 35 microns to 70 microns, or 50 microns to 70 microns.

[0056] The TIM can be manufactured by mixing a first polymer component and solid thermally conductive particles together, thereby dispersing the solid thermally conductive particles throughout the first polymer component to create a first mixture. The first mixture can be a dispersion (e.g., a solid dispersed phase in a liquid continuous phase).

[0057] A second polymer component and liquid metal can be mixed together, thereby forming liquid metal droplets from the liquid metal and dispersing the liquid metal droplets throughout the second polymer component to create a second mixture. The second mixture can be an emulsion (e.g., liquid dispersed phase in liquid continuous phase).

[0058] The first polymer component and the second polymer component, can be the same or different, and each, individually, can be configured as the polymer component described herein above and together form the polymer component of the TIM.

[0059] The respective polymer component and bulk liquid metal or bulk solid thermally conductive particles can be mixed together with at least one of stirring, a high shear mixer, low-shear mixing, a centrifugal mixer, by shaking in a container, a mortar and pestle, and sonication to form an emulsion or dispersion, as the case may be. More details about exemplary ways to form an emulsion of the second polymer component and the liquid metal droplets are described in (1) published PCT WO / 2019 / 136252, entitled “Method of Synthesizing a Thermally Conductive and Stretchable Polymer Composite”, (2) published U.S. application US 2017 / 0218167, entitled “Polymer Composite with Liquid Phase Metal Inclusions,” (3) U.S. Patent No. 10,777,483, entitled “Method, apparatus, and assembly for thermally connecting layers”, (4) U.S. Provisional Patent No. 63 / 268,134, entitled “Thermal interface material, an integrated circuit assembly, and a method for thermally connecting layers”, (5) published PCT WO 2022 / 204689 entitled “A method, apparatus, and assembly for thermally connecting layers with thermal interface materials comprising rigid particles”, and (6) U.S. provisional application 63 / 479,879, entitled “A method of Manufacture of a Thermal Interface Material, a Thermal Interface Material Formed Therefrom, and an Integrated Circuit Formed Therefrom”, all of which are incorporated herein by reference in their entirety.

[0060] The first mixture may be formed prior to, during, and / or after forming the second mixture. The first mixture and the second mixture can be separately formed. For example, the first mixture and the second mixture can be formed in separate vessels and / or separatemixing zones of the same vessel. The polymer components, liquid metal, and solid thermally conductive particles can be added in quantities to achieve a desired composition of the TIM as described above.

[0061] The method comprises mixing the first mixture and second mixture together, thereby forming the TIM. Mixing the first mixture and the second mixture together can comprise at least one of stirring, a high shear mixer, low-shear mixing, a centrifugal mixer, by shaking in a container, a mortar and pestle, and sonication to form an emulsion and / or dispersion, thereby forming the TIM. Mixing the first polymer component and the solid thermally conductive particles together, mixing the second polymer component and the liquid metal together, and / or mixing the first mixture and the second mixture together can comprise dualaxis centrifugal mixing. Mixing the first mixture and the second mixture together can comprise adding the first mixture to a vessel comprising the second mixture, adding the second mixture to a vessel comprising the first mixture, adding both the first mixture and a second mixture to a third vessel, or other mixing step. The TIM can comprise a hybrid emulsion dispersion (e.g., a liquid dispersed phase and a solid dispersed phase in a liquid continuous phase). Combining all components at once without separately forming the first mixture, may result in an interaction between the liquid metal droplets and the solid thermally conductive particles that could fail to create a stable dispersion.

[0062] In certain examples, the second mixture may not be formed and liquid metal and optionally a second polymer component can be added directly to the first mixture to form the thermal interface material. Mixing the second mixture, the liquid metal, and the second polymer component can comprise at least one of stirring, a high shear mixer, low-shear mixing, a centrifugal mixer, by shaking in a container, a mortar and pestle, and sonication to form an emulsion and / or dispersion, thereby forming the TIM. Mixing the first mixture, the liquid metal, and the second polymer component together can comprise dual-axis centrifugal mixing. Mixing the first mixture, the liquid metal, and the second polymer component together can comprise adding the first mixture to a vessel comprising the liquid metal, adding the liquid metal to a vessel comprising the first mixture, adding both the first mixture and the liquid metal to a third vessel, or other mixing step. The TIM can comprise a hybrid emulsion dispersion (e.g., a liquid dispersed phase and a solid dispersed phase in a liquid continuous phase). Combining all components at once without separately forming the first mixture, may result in an interaction between the liquid metal droplets and the solid thermally conductiveparticles. In various examples, all components can be added at once without forming separate mixtures based on mixing techniques and components used.

[0063] The other components such as, for example, rigid spacer particles, a catalyst, fumed silica, a coupling agent, an additive, and a surfactant can be added to the first mixture, the second mixture, during the formation of the TIM, and / or after mixing the first mixture and the second mixture, as the application may require. In certain examples, a first portion of the first mixture may be reserved, while a second portion of the first mixture and the second mixture are mixed together to form a third mixture. Then, the first portion of the first mixture can be mixed with the third mixture to form the TIM and adjust the viscosity, compliance, and / or concentration of a component.

[0064] The composition and / or mixing techniques can be chosen such that the viscosity of the TIM is less than 2,000,000 cP (centipoise), such as, for example, less than 750,000 cP, less than 500,000 cp, less than 250,000 cP, 200,000 cP, less than 150,000 cP, less than 100,000 cP, less than 50,000 cP, less than 15,000 cP, less than 14,000 cP, less than 13,000 cP, less than 12,000 cP, less than 11,000 cP, or less than 10,000 cP. For example, the composition and / or mixing techniques can be chosen such that the viscosity of the TIM is at least 1,000 cP, such as, for example, at least 2,000 cP, at least 5,000 cP, or at least 10,000 cP.

[0065] The composition and / or mixing techniques can be chosen such that the viscosity of the TIM is in a range of 1,000 cP to 2,000,000 cP, such as, for example, 2,000 cP to 750,000 cP, or 2,000 cP to 500,000 cP. The viscosity of the TIM emulsion can be measured by a parallel plate (40mm) rheometer at 25 degrees Celsius, a frequency of 10 radians per second, and a strain of 5%. Selecting the viscosity can require a balance of installation pressure, which may increase with a high viscosity, an ability to resist undesirably fast spreading during application of the TIM and pump out during operation, and viscosity of the polymer component.

[0066] The TIM can be applied to various layers and devices, and it is described below with reference to FIGs. 1-2 with reference to a circuit assembly, but is not limited to only a circuit assembly and could be applied to other devices. Referring to FIG. 1, the method according to the present disclosure comprises depositing a TIM 104 according to the present disclosure between a first layer 106 of an assembly 102 and a second layer 108 of the assembly 102.The thickness of the TIM can be selected based on the desired application. As illustrated, theTIM 104 comprises a hybrid emulsion dispersion of a polymer component 110 (e.g., continuous phase), liquid metal droplets 112 (e.g., liquid dispersed phase), solid thermally conductive particles 114 (e.g., solid dispersed phase), and optionally rigid spacer particles 116. Collectively, the liquid metal droplets 112 and the solid thermally conductive particles 114 form the conductive component.

[0067] Depositing the TIM 104 can comprise, for example, at least one of auger or air controlled dispensing, extruding (e.g., through a nozzle, such as, a circular nozzle, a fan nozzle, or other nozzle shape), applying with a utensil (e.g., brush, spatula), stencil printing, 3D printing, and screen printing. The TIM 104 can be deposited in a conformable state such that the TIM 104 can adapt to the surfaces of the first layer 106 and the second layer 108 to achieve a desired level of surface contact therebetween. In various examples, the TIM 104 can be applied directly to the first layer 106 and, thereafter, the second layer 108 can be applied directly to the TIM 104. In various other examples, the TIM 104 can be applied directly to the second layer 108 and, thereafter, the first layer 106 can be applied directly to the TIM 104. In certain examples, the TIM 104 can be applied to both the first layer 106 and the second layer 108 and then the first layer 106 and the second layer 108 can be applied together. In various examples, after deposition of the TIM 104 and compression of the assembly 102, the TIM 104 can be in direct contact with and between the first layer 106 and the second layer 108. In certain examples, the application of the TIM 104 may be limited to the surfaces of the first layer 106 such that the TIM 104 can be efficiently used.

[0068] The TIM 104 can be dispensed from a container and applied to a layer in a conformable state. The TIM 104 can be stored in a container prior to use. The TIM 104 can be in a conformable state in the container. The container can comprise at least one of a pillow pack, a syringe, a beaker, a jar, a bottle, and a drum. In various examples, the container can be a ready to use dispensing device, such as, for example, a pillow pack or a syringe. In certain examples, the TIM 104 may not be stored and can be used after creation of the emulsion without storage.

[0069] The TIM 104 can be applied to at least 1% of a surface area of an exposed side 106a of the first layer 106 prior to compressing the assembly 102, such as, for example, at least 2%, at least 5%, at least 10%, at least 20%, at least 30%, at least 40%, or at least 50%, all of the surface area of the exposed side 106a of the first layer 106. For example, the TIM 104can be applied to a range of 1% to 100% of the surface area of an exposed side 106a of the first layer 106 prior to compressing the assembly 102, such as, for example 2% to 100%, 5% to 90%, or 5% to 80%, all of the surface area of the exposed side 106a of the first layer 106.

[0070] Referring to FIG. 1, the TIM 104 can be deposited at a first thickness, ti, between a first layer 106 of the assembly 102 and the second layer 108 of the assembly 102. The first thickness, ti, can be selected to enhance the effective thermal conductivity of the TIM 104 and / or spatial uniformity of the liquid metal droplets 112 packing within the TIM 104. The first thickness, ti, can be at least 1.1 times a D90 of the liquid metal droplets 112 prior to compression, such as, for example, at least 2.5 times, at least 3 times, at least 4 times, at least 5 times, at least 6 times, at least 10 times, at least 20 times, at least 50 times, or at least 100 times, all of a D90 of the liquid metal droplets 112 prior to compressing the assembly 102. The first thickness, ti, can be no greater than 1,000 times a D90 of the liquid metal droplets 112, such as, for example, no greater than 500 times, no greater than 250 times, no greater than 150 times, no greater than 100 times, no greater than 50 times, no greater than 15 times, no greater than 10 times, no greater than 6 times, or no greater than 5 times, all of a D90 of the liquid metal droplets 112 prior to compressing the assembly 102. The first thickness, ti, can be in a range of 1.1 times to 1,000 times a D90 of the liquid metal droplets 112 prior to compressing the assembly 102, such as, for example, 2 times to 500 times, 2 times, to 150 times, 2 times to 100 times, 2 times to 50 times, 2 times to 10 times, 3 times to 10 times, or 3 times to 6 times, all of a D90 of the liquid metal droplets 112 prior to compressing the assembly 102. Because the first thickness, ti, can be at least 1.1 times the D90 of the liquid metal droplets 112 prior to compression, a desired distribution of the liquid metal droplets on the assembly 102 and spatial uniformity of the liquid metal droplets 112 packing within the TIM 104 can be achieved, thereby enhancing the effective thermal conductivity of the TIM 104.

[0071] The first layer 106 can be a heat-generating electronic component (e.g., a battery, memory, a data storage unit, a power inverter, a thermoelectric generator, a motor winding, an integrated circuit) and / or thermally connected to the heat-generating electronic component. The integrated circuit can comprise a processor (e.g., central processing unit(CPU), tensor processing unit (TPU), graphics processing unit (GPU), artificial intelligence focused processor, an ASIC, and / or a system-on-a-chip (SOC)). The second layer 108 can be an upper layer that can be thermally conductive. The first layer 106 and thesecond layer 108, individually, can be at least one of a battery, a processor, a heat sink (e.g., fins, fan, liquid cooling, cold plate, heat sink, heat wick, heat pipe), an integrated heat spreader, and packaging. In various examples, the first layer 106 can comprise a processor and the second layer 108 can comprise at least one of a heat sink, an integrated heat spreader, and packaging. In certain examples, the first layer 106 can comprise an integrated heat spreader and the second layer 108 can comprise at least one of a heat sink, an integrated heat spreader, and packaging. In various examples, the first layer 106 can comprise a battery and the second layer 108 can comprise at least one of a heat sink, an integrated heat spreader, and packaging.

[0072] After deposition of the TIM 104, the method comprises compressing the assembly 102, thereby deforming the liquid metal droplets 112 and forming an assembly 202. For example, referring to the detailed views in FIGs. 1-2, the first layer 106 and the second layer 108 can be urged together. Compressing the assembly 102 can comprise applying a pressure to the first layer 106 and the second layer 108 of at least 3 kPa, such as, for example, at least 10 kPa, at least 70 kPa, at least 100 kPa, or at least 300 kPa. Compressing the assembly 102 can comprise applying a pressure to the first layer 106 and the second layer 108 of no greater than 350 kPa. In various examples, compressing the assembly 102 comprises a first compression process based on displacement where a pressure is applied to the first layer 106 and the second layer 108 until the TIM 104 is compressed to a desired bondline thickness, tm. As illustrated in FIGs. 1-2, the pressure can be applied by a first plate 120 and a second plate 122.

[0073] In various examples, the relative liquid metal surface area coverage between the TIM 104, and the first layer 106 and the second layer 108 can be increased by compression. For example, the relative liquid metal surface area coverage after compression can be in a range of 1% to 100%, such as, for example, 1% to 5%, 5% to 10%, 10% to 30%, 30% to 50%, or increasing until the liquid metal surface area coverage achieves 100%. As used herein, “relative liquid metal area coverage” is the surface area covered by the liquid metal normalized by the total contact surface area between the TIM 104 and the first layer 106 and second layer 108. Relative liquid metal area coverage can be measured using crosssectioning followed by optical imaging using a ZEISS Axio Zoom.V16 or confocal scanning acoustic microscopy using a Hitachi FineSAT III for CSAM.

[0074] After compression, the bondline thickness, tm, of the assembly 102 can be no greater than 300 microns, such as, for example, no greater than 250 microns, no greater than 200 microns, no greater than 150 microns, no greater than 145 microns, no greater than 140 microns, no greater than 125 microns, no greater than 100 microns, no greater than 80 microns, no greater than 70 microns, no greater than 50 microns, no greater than 40 microns, no greater than 35 microns, or no greater than 30 microns. The bondline thickness, tm, of the assembly 102 can be at least 1 microns, such as, for example, at least 10 microns, at least 15 microns, at least 30 microns, at least 35 microns, at least 40 microns, at least 50 microns, at least 70 microns, at least 75 microns, at least 80 microns, at least 100 microns, at least 120 microns, at least 140 microns, at least 145 microns, or at least 200 microns. The bondline thickness, tBL, of the assembly 102 can be in a range of 1 micron to 300 microns, such as, for example, 1 microns to 250 microns, 10 microns to 300 microns, 10 microns to 250 microns, 1 micron to 200 microns, 15 microns to 200 microns, 15 microns to 150 microns, 30 microns to 150 microns, 50 microns to 120 microns, 75 microns to 125 microns, or 15 microns to 100 microns.

[0075] The D90 of the liquid metal droplets 112 in the TIM 104 prior to applying can be greater than the bondline thickness, tm. For example, the D90 of the liquid metal droplets 112 prior to applying and / or a compressing process can be greater than the bondline thickness, tm, such as, for example, 1% greater than the bondline thickness, tm, 2% greater than the bondline thickness, tm, 5% greater than the bondline thickness, tm, 10% greater than the bondline thickness, tm, 15% greater than the bondline thickness, tm, 20% greater than the bondline thickness, tm, 30% greater than the bondline thickness, tm, 40% greater than the bondline thickness, tm, 50% greater than the bondline thickness, tm, or 75% greater than the bondline thickness, tm. The D90 of the liquid metal droplets 112 prior to applying and / or a compressing process can be no more than 100% greater than the bondline thickness, tm, such as, for example, no more than 75% greater than the bondline thickness, tm, no more than 50% greater than the bondline thickness, tm, no more than 40% greater than the bondline thickness, tm, no more than 30% greater than the bondline thickness, tm, no more than 20% greater than the bondline thickness, tm, no more than 15% greater than the bondline thickness, tm, no more than 10% greater than the bondline thickness, tm, no more than 5% greater than the bondline thickness, tm, or no more than 2% greater than the bondline thickness, tm. The D90 of the liquid metal droplets 112 in the TIM 104 prior to applying can be equal to or less than the bondline thickness, tm. For example, the D90 of the liquid metaldroplets 112 prior to applying and / or a compressing process can be 1% or less than the bondline thickness, tm, such as, for example, 2% or less than the bondline thickness, tm, 3% or less than the bondline thickness, tm, 5% or less than the bondline thickness, tm, 10% or less than the bondline thickness, tm, 15% or less than the bondline thickness, tm, or 20% or less than the bondline thickness. The D90 of the liquid metal droplets 112 prior to applying and / or a compressing process can be in a range of 20% less than to 100% greater than the bondline thickness, tm, such as, for example, 10% less than to 100% greater than the bondline thickness, tm, 10% less than to 50% greater than the bondline thickness, tm, 5% less than to 50% greater than the bondline thickness, tm, 1% greater than to 100% greater than the bondline thickness, tm, 1% greater than to 50% greater than the bondline thickness, tm, 1% to 30% greater than the bondline thickness, tm, 2% greater than to 30% greater than the bondline thickness, tm, or 5% greater than to 20% greater than the bondline thickness, tm. In certain examples, the D90 of the liquid metal droplets 112 in the TIM 104 prior to applying can be no greater than the bondline thickness, tm.

[0076] The D90 of the liquid metal droplets 112 in the TIM 104 prior to applying can be equal to or less than the bondline thickness, tm. For example, the D90 of the liquid metal droplets 112 prior to applying and / or a compressing process can be 1% or less than the bondline thickness, tm, such as, for example, 2% or less than the bondline thickness, tm, 3% or less than the bondline thickness, tm, 5% or less than the bondline thickness, tm, 10% or less than the bondline thickness, tm, 15% or less than the bondline thickness, tm, or 20% or less than the bondline thickness.

[0077] The TIM can cover at least 90% of a surface area of an exposed side 106a of the first layer 106 after compressing the circuit assembly, such as, for example, at least 95% of the surface area of the exposed side 106a.

[0078] In examples where the TIM 104 (e.g., polymer component 110) is curable, the cure time of the TIM 104 can be sufficient to enable the compression to occur and to achieve the bondline thickness, tm. Cure time of the TIM 104 can be in a range of 1 minute to 48 hours, such as, for example, 1 minute to 24 hours, 1 minute to 12 hours, 1 minute to 1 hour, 2 minutes to 1 hour, 2 minutes to 30 minutes, 5 minutes to 1 hour, 10 minutes to 1 hour, 30 minutes to 2 hours, 1 minute to 10 minutes, or 1 hour to 2 hours.

[0079] Before curing, the TIM 104 can comprise mechanical properties of a Bingham plastic and after curing the TIM 104 can comprise mechanical properties of an elastic solid. For example, the TIM 104 can be elastomeric and may have a ultimate tensile strain of at least 100%, such as, for example at least 200% or at least 300%. Ultimate tensile strain can be measured according to ASTM D3039. In the uncured state, the TIM 104 can comprise a storage modulus (G’) greater than the loss modulus (G”) of the TIM 104 over relevant frequencies (e.g., less than 100 rad / s). In various examples, the TIM 104 can behave more like a solid than a liquid).

[0080]

[0081] Compressing the assembly 102 can apply a force to the TIM 104 and can deform the liquid metal droplets 112 dispersed within the polymer component 110 of the TIM 104. Because the polymer component 110 is still liquid and conformable and moveable, the compressing force can deform the liquid metal droplets 112. The liquid metal droplets 112 can be in the liquid phase during deformation, such that a lower pressure is required for the compression and a desired deformation can be achieved.

[0082] In various examples, the liquid metal droplets 112 prior to compressing can have a first average aspect ratio and after compressing the liquid metal droplets 112 can have a second average aspect ratio. The second average aspect ratio can be different than the first average aspect ratio. For example, the second average aspect ratio can be greater than the first average aspect ratio. The average aspect ratio can be a mean ratio of the width to the height of the liquid metal droplets 112. In various examples, the first aspect ratio can be 1 and the second aspect ratio can be greater than 1. In certain examples, the first aspect ratio can be in a range of 1 to 1.5. In certain examples, the second aspect ratio can be at least 0.5 greater than the first aspect ratio, such as, for example, at least 1 greater than the first aspect ratio, at least 2 greater than the first aspect ratio, or at least 5 greater than the first aspect ratio. In certain examples, the second aspect ratio can be at least 2 after compressing the assembly 102, such as, for example, at least 3, or at least 4 after compressing the assembly 102. In various examples, the aspect ratio of the solid thermally conductive particles can be 1, at least 2, at least 3, or at least 4. The aspect ratio of the solid thermally conductive particles may not change after compressing.

[0083] The width (e.g., longest dimension) of the liquid metal droplets 112 can be substantially aligned with the longitudinal plane of the TIM 104 in the assembly 102 and the height of the liquid metal droplets 112 can be substantially aligned with the thickness of the TIM 104 (e.g., the bondline thickness, dni). The width of the liquid metal droplets 112 can increase upon compression of the assembly 102. For example, in certain examples, the diameter of liquid metal droplets 112 prior to compressing can be 200 pm (with a first aspect ratio of 1) and after compression to a bondline thickness of 100 pm, the liquid metal drop can be deformed to an ellipsoidal shape with a 400 pm width (e.g., second aspect ratio of 4).

[0084] In certain examples, the liquid metal droplets 112, the solid thermally conductive particles 114, and / or the rigid spacer particles 116 can be aligned substantially in a monolayer as shown in FIG. 2 after compressing. The monolayer can be achieved by selecting the Dso and / or D90 of the liquid metal droplets 112, the solid thermally conductive particles 114, and / or the rigid spacer particles 116, and the bondline thickness, tm. Configuring the liquid metal droplets 112, the solid thermally conductive particles 114, and / or the rigid spacer particles 116 in a monolayer can reduce the thermal resistance of the TIM 104.

[0085] The D50 and / or D90 of the liquid metal droplets 112, the solid thermally conductive particles 114, and / or the rigid spacer particles 116, deformation of the liquid metal droplets 112, and controlled compression of the TIM 104 can improve the thermal resistance value of the TIM 104. For example, the TIM 104 can comprise a thermal resistance value of at least 0.5 (°K*mm2) / W, such as, for example, at least 1 (°K*mm2) / W, at least 2 (°K*mm2) / W, at least 3 (°K*mm2) / W, at least 5 (°K*mm2) / W, or at least 10 (°K*mm2) / W. The TIM 104 can comprise a thermal resistance value of no greater than 30 (°K*mm2) / W, such as, for example, no greater than 20 (°K*mm2) / W, no greater than 15 (°K*mm2) / W, no greater than 10 (°K*mm2) / W, no greater than 9 (°K*mm2) / W, no greater than 8 (°K*mm2) / W, no greater than 7 (°K*mm2) / W, or no greater than 5(°K*mm2) / W. The TIM 104 can comprise a thermal resistance value in a range of 0.5 (°K*mm2) / W to 30 (°K*mm2) / W, such as, for example, 0.5 (°K*mm2) / W to 20 (°K*mm2) / W, 0.5 (°K*mm2) / W to 15 (°K*mm2) / W, 1 (°K*mm2) / W to 10 (°K*mm2) / W, 2 (°K*mm2) / W to 10 (°K*mm2) / W, or 2 (°K*mm2) / W to 8 (°K*mm2) / W. The thermal resistance value can be measured using a TIMA 5 instrument from NanoTest (Germany).

[0086] The Dso and / or D90 of the liquid metal droplets 112, the solid thermally conductive particles 114, and / or the rigid spacer particles 116, deformation of the liquid metal droplets 112, and controlled compression of the TIM 104 can improve the thermal conductivity value of the TIM 104. For example, the TIM 104 can comprise an effective thermal conductivity value of at least 1 W / m*K, such as, for example, at least 5 W / m*K, at least 10 W / m*K, at least 12 W / m*K, at least 15 W / m*K, at least 17 W / m*K, or at least 20 W / m*K. The TIM 104 can comprise an effective thermal conductivity value in a range of 1 W / m*K to 50 W / m*K, such as, for example, 5 W / m*K to 50 W / m*K, 10 W / m*K to 40 W / m*K or 10 W / m*K to 30 W / m*K. As used herein, the effective thermal conductivity is a thickness of the TIM divided by a thermal resistance of the TIM.

[0087] The TIM 104 can be cured or may not be cured, depending on the application. For example, the TIM 104 may be cured to thicken the TIM 104, which may increase the viscosity of the polymer component 110. In certain examples, the TIM 104 may be cured to a solid. In various examples, the TIM 104 is cured after compressing the first layer 106 and the second layer 108 of the assembly 102. Applying the TIM 104 at a lower viscosity can enable a more efficient installation and ability to wet surfaces of the first layer 106 and the second layer 108. Increasing the viscosity after application can enable the TIM 104 to resist pump out and enhance removal of the TIM 104. In various examples, the TIM 104 may not be cured. In various examples, the TIM 104 may be cured prior to application to the first layer 106 and the second layer 108.

[0088] In various examples, the polymer component 110 after curing is elastomeric. Curing the polymer component 110 can inhibit pump out of the liquid metal droplets 112 during thermal cycling of the assembly 102 and can provide a mechanical bond between the first layer 106 and the second layer 108.

[0089] Curing the TIM 104 can comprise at least one of heating the TIM 104 (e.g., in examples with a thermosetting polymer), adding a catalyst to the TIM 104 (e.g., platinum catalyst, moisture), exposing the TIM 104 to air, cooling the TIM 104 (e.g., in examples with a thermoplastic polymer), applying electromagnetic radiation (e.g., photo-polymerization), and applying pressure to the TIM 104. Curing the TIM 104 can increase the viscosity of the TIM 104. For example, the TIM 104 can comprise a viscosity after curing that is at least double of the TIM prior to curing, such as, for example, at least triple, at least quadrupole, orten times a viscosity of the TIM prior to curing. For example, the TIM 104 can comprise a viscosity after curing of greater than 15,000 cP, such as, for example, greater than 20,000 cP, greater than 30,000 cP, greater than 50,000 cP, greater than 100,000 cP, greater than 150,000 cP, greater than 200,000 cP, greater than 250,000 cP, greater than 500,000 cP, greater than 750,000 cP, greater than 850,000 cP, greater than 1,000,000 cP, greater than 1,500,000 cP, greater than 2,500,000 cP, greater than 4,000,000 cP, or greater than 5,000,000 cP. In various examples, the TIM 104 can be an adhesive. The polymer in the TIM 104 can be selected to reduce off-gasing of the TIM 104 during curing. In certain examples, the TIM 104 can be removed with a solvent and / or scrapping. In various examples, the method of manufacturing the assembly 102 can be a snap-cure process, a reflow oven, a bake process, and / or a high- force magazine.

[0090] For example, in examples comprising a snap-cure process, the first plate 120 and the second plate 122 are urged into contact with the first layer 106 and the second layer 108 of the assembly 102. The temperature of the first plate 120 and / or second plate 122 can be in a range of 80 degrees Celsius to 200 degrees Celsius and can be displaced at various rates.

[0091] EXAMPLES

[0092] Various aspects, benefits and features that are potentially realizable through implementation of the present invention will be more fully understood by reference to the following examples, which provide illustrative non-limiting aspects of the invention. It is understood that the invention described in this specification is not necessarily limited to the examples described in this section.

[0093] Example 1

[0094] A first blend of poly ether polymers was created by mixing 45.0 g of Pluronic L-35 block copolymer surfactant with 45.0 g polypropylene glycol having a number average molecular weight of 1,000 g / mol and 10.0 g Jeffamine ED-2003, all purchased from Sigma Aldrich.

[0095] 2.24 g of the first blend was combined with 117.76 g Galinstan from Indium Corp and mixed together under high shear to create a first emulsion that was 90% Galinstan droplets by volume.

[0096] 21.36 g of the first blend was combined with 78.64 g of aluminum particles having a particle size of < 30 micron from Sigma Aldrich and mixed together under high shear to create a first dispersion that was 60% aluminum particles by volume. The first dispersion was separately formed from the first emulsion.

[0097] 120.0 g of the first emulsion was combined with 20.93 g of the first dispersion and mixed together under high shear to create a first TIM. The conductive component in the first TIM comprised aluminum particles and Galinstan droplets and the conductive compound occupied 80% by volume of the first TIM. The conductive component in the first TIM was 25% aluminum particles by volume and 75% Galinstan droplets by volume. The first TIM was successfully formed.

[0098] Example 2

[0099] A second blend of poly ether polymers was created by mixing 45.0 g of Pluronic L-64 block copolymer surfactant with 45.0 g polypropylene glycol having a number average molecular weight of 1,000 g / mol and 10.0 g Jeffamine ED-2003, all purchased from Sigma Aldrich.

[0100] 2.24 g of the second blend was combined with 117.76 g Galinstan from Indium Corp and mixed together under high shear to create a second emulsion that was 90% Galinstan droplets by volume.

[0101] 10.93 g of the second blend was combined with 89.07 g of copper particles having a particle size of 10 - 25 micron from Sigma Aldrich and mixed together under high shear to create a second dispersion that was 50% copper particles by volume. The second dispersion was separately formed from the second emulsion.

[0102] 120.0 g of the second emulsion was combined with 34.05 g of the second dispersion and mixed together under high shear to create a second TIM. The conductive component in the second TIM comprised copper particles and Galinstan droplets and the conductive compound occupied 80% by volume of the first TIM. The conductive component in the second TIM was 15.6% copper particles by volume and 84.4% Galinstan droplets by volume. The second TIM was successfully formed.

[0103] Example 3

[0104] A third blend of poly ether polymers was created by mixing 50.0 g of Pluronic L-35 block copolymer surfactant with 45.0 g polypropylene glycol having a number average molecular weight of 1,000 g / mol and 5.0 g Jeffamine ED-2003, all purchased from Sigma Aldrich.

[0105] 2.24 g of the third blend was combined with 117.76 g Galinstan from Indium Corp and mixed together under high shear to create a third emulsion that was 90% Galinstan droplets by volume.

[0106] 15.50 g of the third blend was combined with 184.50 g of 325 mesh bronze particles from Metal Powders USA and mixed together under high shear to create a third dispersion that was 60% bronze particles by volume. The third dispersion was separately formed from the third emulsion.

[0107] 120.0 g of the third emulsion was combined with 57.69 g of the third dispersion and mixed together under high shear to create a third TIM. The conductive component in the third TIM comprised bronze particles and Galinstan droplets and the conductive compound occupied 80% by volume of the third TIM. The conductive component in the third TIM was 25.0% bronze particles by volume and 75.0% Galinstan droplets by volume. The third TIM was successfully formed.

[0108] Properties of Examples 1-3 were measured and are shown in Table 1 below:

[0109] Table 1 : Properties of Examples 1-3* Measured with a TIMA-5 instrument

[0110] Example 4[OHl] A fourth blend of poly ether polymers was created by mixing 45.0 g of Pluronic L-35 block copolymer surfactant with 45.0 g polypropylene glycol having a number averagemolecular weight of 1,000 g / mol and 10.0 g Jeffamine ED-2003, all purchased from Sigma Aldrich.

[0112] 21.36 g of the fourth blend was combined with 78.64 g of aluminum particles having a particle size of < 30 micron from Sigma Aldrich and mixed together under high shear to create a fourth dispersion that was 60% aluminum particles by volume.

[0113] 2.21g of the fourth dispersion was combined with 2.37 g of the fourth blend and 145.42 g Galinstan from Indium Corp and mixed under high shear to create a fourth TIM. The conductive component in the fourth TIM comprised aluminum particles and Galinstan droplets. The fourth TIM was composed of 10% polyether, 2.5% aluminum particles, and 87.5% Galinstan by volume. The fourth TIM was successfully formed.

[0114] Example 5

[0115] A fifth blend of poly ether polymers was created by mixing 50.0 g of Pluronic L-35 block copolymer surfactant with 45.0 g polypropylene glycol having a number average molecular weight of 1,000 g / mol and 5.0 g Jeffamine ED-2003, all purchased from Sigma Aldrich.

[0116] 21.36 g of the fifth blend was combined with 78.64 g of aluminum particles having a particle size < 30 micron from Sigma Aldrich and mixed together under high shear to create a fifth dispersion that was 60% aluminum particles by volume.

[0117] 2.21g of the fifth dispersion was combined with 2.37 g of the fifth blend and 145.42 g Galinstan from Indium Corp and mixed under high shear to create a fifth TIM. The conductive component in the fifth TIM comprised aluminum particles and Galinstan droplets. The TIM was composed of 10% poly ether, 2.5% aluminum particles, and 87.5% Galinstan droplets by volume. The fifth TIM was successfully formed.

[0118] Example 6

[0119] A sixth blend of poly ether polymers was created by mixing 45.0 g of Pluronic L-35 block copolymer surfactant with 45.0 g polypropylene glycol having a number average molecular weight of 1,000 g / mol and 10.0 g Jeffamine ED-2003, all purchased from Sigma Aldrich.

[0120] 21.36 g of the sixth blend was combined with 78.64 g of aluminum particles having an average particle size of < 30 micron from Sigma Aldrich and mixed together under high shear to create a sixth dispersion that was 60% aluminum particles by volume.

[0121] 4.50 g of the sixth dispersion was combined with 1.92 g of the sixth blend and 143.58 g Galinstan from Indium Corp and mixed under high shear to create a sixth TIM. The conductive component in the sixth TIM comprised aluminum particles and Galinstan droplets. The TIM was composed of 10% poly ether, 5% aluminum particles, and 85% Galinstan droplets by volume.

[0122] Example 7

[0123] A seventh blend of polyether polymers was created by mixing 50.0 g of Pluronic L-35 block copolymer surfactant with 45.0 g polypropylene glycol having a number average molecular weight of 1,000 g / mol and 5.0 g Jeffamine ED-2003, all purchased from Sigma Aldrich.

[0124] 21.36 g of the seventh blend was combined with 78.64 g of aluminum particles having an average particle size of < 30 micron from Sigma Aldrich and mixed together under high shear to create a seventh dispersion that was 60% aluminum particles by volume.

[0125] 4.50 g of the seventh dispersion was combined with 1.92 g of the seventh blend and 143.58 g Galinstan from Indium Corp and mixed under high shear to create a seventh TIM. The conductive component in the seventh TIM comprised aluminum particles and Galinstan droplets. The seventh TIM was composed of 10% poly ether, 5% aluminum particles, and 85% Galinstan droplets by volume.

[0126] Example 8

[0127] An eighth blend of polyether polymers was created by mixing 1.61 g of fumed silica, 4.00 g of polypropylene glycol) bis(2-aminopropyl ether) having a number average molecular weight of 2000 g / mol, 14.42 g of polypropylene glycol) having a number average molecular weight of 2000 g / mol, and 47.99 g Polysorbate 80, all purchased from Sigma Aldrich. The seventh blend was subjected to high speed dual-axis centrifugal mixing to enhance uniformity.

[0128] 5.67 g of the eighth blend was combined with 19.82 g of copper particles having an average particle size in a range of 15 microns to 45 microns. The eighth blend and copper particles were mixed together under high shear using a high-speed dual-axis centrifugal mixing to disperse the copper particles and create an eight dispersion.

[0129] To the eighth dispersion, 223.31 g of gallium-indium-tin eutectic purchased from 5N Plus was added to the eight dispersion and mixed under high shear using a high-speed dual axis centrifugal mixing to create an intermediate dispersion.

[0130] To the intermediate dispersion of liquid metal droplets and solid metal particles was added 0.50 g of di(ethylene glycol) hexyl ether and 0.50 g of triethylene glycol monomethyl ether was added to the intermediate dispersion and mixed with low-speed dual-axis centrifugal mixing to create an eighth TIM.

[0131] The properties of Examples 1-8 were measured and are shown in Table 2 below:

[0132] Table 2: Properties of Examples 1-8* Measured with a TIMA-5 instrument

[0133] As used in this specification, the terms “cure” and “curing” refer to the chemical cross-linking of components in an emulsion or material applied over a substrate, or the increase of viscosity of the components in the emulsion or material applied over the substrate. Accordingly, the terms “cure” and “curing” do not encompass solely physical drying of an emulsion or material through solvent or carrier evaporation. In this regard, the term “cured,” as used in this specification in examples comprising a thermosetting polymer, refers to thecondition of an emulsion or material in which a component of the emulsion or material has chemically reacted to form new covalent bonds in the emulsion or material (e.g., new covalent bonds formed between a binder resin and a curing agent). The term “cured”, as used in this specification in examples comprising a thermoplastic polymer, refers to the condition of an emulsion or material in which the temperature of the thermoplastic polymer decreases below the melting point of the thermoplastic polymer such that the viscosity of the emulsion or material increases. In examples comprising both a thermosetting polymer and a thermoplastic polymer, the term “cured” refers to one of or both of the polymers curing as described herein.

[0134] In various other examples, the TIM according to the present disclosure can be used in a system on a package. For example, a single horizontal TIM layer can be in contact with multiple dies on one side (e.g., the integrated circuit can comprise multiple dies, or multiple integrated circuits can be in contact with the same side of the TIM) and an upper layer or layers on a different side.

[0135] Those skilled in the art will recognize that the herein described compositions, articles, methods, and the discussion accompanying them are used as examples for the sake of conceptual clarity and that various configuration modifications are contemplated.Consequently, as used herein, the specific examples set forth and the accompanying discussion are intended to be representative of their more general classes. In general, use of any specific exemplar is intended to be representative of its class, and the non-inclusion of specific components (e.g., operations), devices, and objects should not be taken as limiting.

[0136] With respect to the appended claims, those skilled in the art will appreciate that recited operations therein may generally be performed in any order. Also, although various operational flows are presented in a sequence(s), it should be understood that the various operations may be performed in other orders than those that are illustrated or may be performed concurrently. Examples of such alternate orderings may include overlapping, interleaved, interrupted, reordered, incremental, preparatory, supplemental, simultaneous, reverse, or other variant orderings, unless context dictates otherwise. Furthermore, terms like “responsive to,” “related to,” or other past-tense adjectives are generally not intended to exclude such variants, unless context dictates otherwise.

[0137] Although various examples have been described herein, many modifications, variations, substitutions, changes, and equivalents to those examples may be implemented and will occur to those skilled in the art. Also, where materials are disclosed for certain components, other materials may be used. It is therefore to be understood that the foregoing description and the appended claims are intended to cover all such modifications and variations as falling within the scope of the disclosed examples. The following claims are intended to cover all such modification and variations.

[0138] Various aspects of the invention according to the present disclosure include, but are not limited to, the aspects listed in the following numbered clauses.

[0139] Clause 1. A thermal interface material comprising: 5% to 80% by volume of a polymer component based on a total volume of the thermal interface material; 20% to 95% by volume of a conductive component based on the total volume of the thermal interface material, the conductive component is dispersed through the polymer component, wherein the conductive component comprises: 25% to 99% by volume of liquid metal droplets based on a total volume of the conductive component, the liquid metal droplets dispersed through the polymer component, wherein the liquid metal droplets comprise a melting point of no greater than 30 degrees Celsius; and 1% to 75% by volume of solid thermally conductive particles based on the total volume of the conductive component, the solid thermally conductive particles dispersed through the polymer component, wherein the solid thermally conductive particles comprise a melting point of at least 100 degrees Celsius.

[0140] Clause 2. The thermal interface material of clause 1, wherein the conductive component comprises: 65% to 75% by volume of liquid metal droplets based on a total volume of the conductive component; and 25% to 35% by volume of solid thermally conductive particles based on the total volume of the conductive component.

[0141] Clause 3. The thermal interface material of any of clauses 1-2, wherein the solid thermally conductive particles comprise a metal, a metal alloy, a ceramic, an oxide, carbon based materials, or a combination thereof.

[0142] Clause 4. The thermal interface material of any of clauses 1-3, wherein the solid thermally conductive particles comprise a metal or metal alloy selected from the group consisting of aluminum, an aluminum alloy, titanium, a titanium alloy, manganese, amanganese alloy, iron, an iron alloy, nickel, a nickel alloy, copper, a copper alloy, zinc, a zinc alloy, lead, a lead alloy, silver, a silver alloy, gold, a gold alloy, indium, an indium alloy, tin, a tin alloy, bismuth, a bismuth alloy, tungsten, a tungsten alloy, and a combination thereof.

[0143] Clause 5. The thermal interface material of any of clauses 1-4, wherein the solid thermally conductive particles comprise a ceramic selected from the group consisting of boron nitride, aluminum nitride, and a combination thereof.

[0144] Clause 6. The thermal interface material of any of clauses 1-5, wherein the solid thermally conductive particles comprise a carbon based material selected from the group consisting of a carbide, graphite, graphene, diamond, and a combination thereof.

[0145] Clause 7. The thermal interface material of any of clauses 1-6, wherein the solid thermally conductive particles comprise a carbide selected from the group consisting of silicon carbide, tungsten carbide, aluminum carbide, and a combination thereof.

[0146] Clause 8. The thermal interface material of any of clauses 1-7, wherein the solid thermally conductive particles comprise an oxide selected from the group consisting of aluminum oxide, iron oxide, and a combination thereof.

[0147] Clause 9. The thermal interface material of any of clauses 1-8, wherein at least a portion of the liquid metal droplets comprise an exterior surface comprising a metal oxide.

[0148] Clause 10. The thermal interface material of clause 9, wherein the solid thermally conductive particles are non-reactive with the metal oxide.

[0149] Clause 11. The thermal interface material of any of clauses 1-10, wherein solid thermally conductive particles comprise a thermal conductivity greater than a thermal conductivity of the liquid metal droplets.

[0150] Clause 12. The thermal interface material of any of clauses 1-11, wherein solid thermally conductive particles comprise a thermal conductivity value of at least 5 W / m*K.

[0151] Clause 13. The thermal interface material of any of clauses 1-12, wherein solid thermally conductive particles comprise a thermal conductivity value of at least 20 W / m*K.

[0152] Clause 14. The thermal interface material of any of clauses 1-13, wherein the solid thermally conductive particles are coated with a coating comprising a bimetallic compound, a polymer, an organic compound, a surfactant, or a combination thereof.

[0153] Clause 15. The thermal interface material of any of clauses 1-14, wherein the solid thermally conductive particles comprise an electrical conductivity of at least 103S / m.

[0154] Clause 16. The thermal interface material of any of clauses 1-15, wherein the conductive component comprises solid thermally conductive particles that have D90 sphericity greater than 0.5.

[0155] Clause 17. The thermal interface material of any of clauses 1-16, wherein the solid thermally conductive particles comprises an aspect ratio of at least 2.

[0156] Clause 18. The thermal interface material of any of clauses claim 1-17, wherein the solid thermally conductive particles comprise a shape of at least one of a rod and a cylinder.

[0157] Clause 19. The thermal interface material of any of clauses 1-18, wherein the solid thermally conductive particles comprise a sphericity of no greater than 0.95.

[0158] Clause 20. The thermal interface material of any of clauses 1-19, wherein the solid thermally conductive particles comprise a Young’s modulus of at least 100 MPa.

[0159] Clause 21. The thermal interface material of any of clauses 1-20, wherein a D90 of the liquid metal droplets is at least 20% greater than a width of the solid thermally conductive particles.

[0160] Clause 22. The thermal interface material of any of clauses 1-21, wherein the liquid metal droplets comprise a metal selected from the group consisting of gallium, a gallium alloy, indium, an indium alloy, tin, a tin alloy, mercury, and a mercury alloy.

[0161] Clause 23. The thermal interface material of any of clauses 1-22, wherein the polymer component comprises a polymer selected from the group consisting of an acrylic polymer, a vinyl polymer, a polyester polymer, a polyurethane polymer, a polybutadiene polymer, a polyamide polymer, a polyether polymer, a polysiloxane polymer, a siliconhydride polymer, a fluoropolymer, a polyisoprene polymer, and a copolymer of any two or more thereof.

[0162] Clause 24. The thermal interface material of any of clauses 1-23, wherein the liquid metal droplets comprise a D90 in a range of 1 micron to 300 microns and the solid thermally conductive particles comprise a D90 in a range of 1 micron to 300 microns.

[0163] Clause 25. The thermal interface material of any of clauses 1-24, wherein the liquid metal droplets comprise a D90 in a range of 15 microns to 150 microns and the solid thermally conductive particles comprise a D90 in a range of 10 microns to 100 microns.

[0164] Clause 26. The thermal interface material of any of clauses 1-25, wherein the thermal interface material comprises a viscosity in a range of 1,000 cP to 2,000,000 cP measured at 25 °C.

[0165] Clause 27. The thermal interface material of any of clauses 1-26, further comprising at least one of a catalyst, rigid spacer particles, a coupling agent, fumed silica, an additive, and a surfactant.

[0166] Clause 28. An assembly comprising: a first layer; a second layer; and the thermal interface material of any of clauses 1-27 compressed and disposed in contact with and between the first layer and the second layer.

[0167] Clause 29. The assembly of clause 28, wherein a bondline thickness formed between the first layer and the second layer is less than a D90 of the liquid metal droplets prior to compression of the thermal interface material in the assembly.

[0168] Clause 30. The assembly of any of clauses 28-29, wherein a bondline thickness formed between the first layer and the second layer is no greater than 300 microns.

[0169] Clause 31. The assembly of any of clauses 28-30, wherein the first layer and the second layer, individually, comprise at least one of a battery, a processor, a heat sink, an integrated heat spreader, and packaging.

[0170] Clause 32. The assembly of any of clauses 28-31, wherein the thermal interface material is cured.

[0171] Clause 33. The assembly of any of clauses 28-32, wherein the thermal interface material comprises an effective thermal conductivity value of at least 1 W / m*K.

[0172] Clause 34. A method comprising: applying the thermal interface material of any of clauses 1-27 on a first layer of an assembly at a first thickness; and compressing the assembly to decrease the first thickness to a second thickness, wherein the second thickness is no greater than a D90 of the liquid metal droplets prior to compressing the assembly.

[0173] Clause 35. The method of clause 34, further comprising, after compressing the assembly, curing the thermal interface material thereby forming a cured assembly.

[0174] Clause 36. The method of any of clauses 34-35, wherein the first thickness is at least 1.1 times a D90 of the liquid metal droplets in the thermal interface material prior to compressing the assembly.

[0175] Clause 37. An assembly produced by the method of any of clauses 34-36.

[0176] Clause 38. A method of manufacture of a thermal interface material, the method comprising: mixing a first polymer component and solid thermally conductive particles together, thereby dispersing the solid thermally conductive particles throughout the first polymer component to create a first mixture, wherein the solid thermally conductive particles comprise a melting point of at least 100 degrees Celsius; mixing a second polymer component and liquid metal together, thereby forming liquid metal droplets from the liquid metal and dispersing the liquid metal droplets throughout the second polymer component to create a second mixture, wherein the liquid metal droplets comprise a melting point of no greater than 30 degrees Celsius; and mixing the first mixture and second mixture together, thereby forming the thermal interface material.

[0177] Clause 39. The method of clause 38, wherein mixing the second polymer component and the liquid metal together comprises a dual-axis centrifugal mixing.

[0178] Clause 40. The method of any of clauses 38-39, wherein the first polymer component, the second polymer component, the liquid metal, and the solid thermally conductive particles are added in quantities to achieve: 5% to 80% by volume of the first and second polymer components based on a total volume of the thermal interface material; 20% to 95% by volume of a conductive component based on the total volume of the thermalinterface material, wherein the conductive component comprises: 60% to 90% by volume of the liquid metal droplets based on a total volume of the conductive component; and 10% to 40% by volume of the solid thermally conductive particles based on the total volume of the conductive component.

[0179] Clause 41. The method of any of clauses 38-40, wherein the solid thermally conductive particles comprise a metal, a metal alloy, a ceramic, an oxide, carbon based materials, or a combination thereof.

[0180] Clause 42. The method of any of clauses 38-41, wherein the liquid metal droplets comprise a metal selected from the group consisting of gallium, a gallium alloy, indium, an indium alloy, tin, a tin alloy, mercury, and a mercury alloy.

[0181] Clause 43. The method of any of clauses 38-42, wherein the first and second polymer components each, individually, comprise a polymer selected from the group consisting of an acrylic polymer, an acrylate polymer, a vinyl polymer, a polyester polymer, a polyurethane polymer, a polybutadiene polymer, a polyamide polymer, a polyether polymer, a polysiloxane polymer, a silicon hydride polymer, a fluoropolymer, a polyisoprene polymer, and a copolymer of any two or more thereof.

[0182] Clause 44. The method of any of clauses 38-43, wherein the liquid metal droplets comprise a D90 in a range of 1 micron to 300 microns and the solid thermally conductive particles comprise a D90 in a range of 1 micron to 300 microns.

[0183] Clause 45. A method of manufacture of a thermal interface material, the method comprising: mixing a first polymer component and solid thermally conductive particles together, thereby dispersing the solid thermally conductive particles throughout the first polymer component to create a first mixture, wherein the solid thermally conductive particles comprise a melting point of at least 100 degrees Celsius; mixing the first mixture with a second polymer component and liquid metal together, thereby forming liquid metal droplets from the liquid metal and dispersing the liquid metal droplets throughout the first and second polymer components to create the thermal interface material, wherein the liquid metal droplets comprise a melting point of no greater than 30 degrees Celsius.

[0184] Clause 46. The method of clause 45, wherein mixing the first mixture, the second polymer component, and the liquid metal together comprises a dual-axis centrifugal mixing.

[0185] Clause 47. The method of any of clauses 45-46, wherein the first polymer component, the second polymer component, the liquid metal, and the solid thermally conductive particles are added in quantities to achieve: 5% to 80% by volume of the first and second polymer components based on a total volume of the thermal interface material; 20% to 95% by volume of a conductive component based on the total volume of the thermal interface material, wherein the conductive component comprises: 60% to 90% by volume of the liquid metal droplets based on a total volume of the conductive component; and 10% to 40% by volume of the solid thermally conductive particles based on the total volume of the conductive component.

[0186] Clause 48. The method of any of clauses 45-47, wherein the solid thermally conductive particles comprise a metal, a metal alloy, a ceramic, an oxide, carbon based materials, or a combination thereof.

[0187] Clause 49. The method of any of clauses 45-48, wherein the liquid metal droplets comprise a metal selected from the group consisting of gallium, a gallium alloy, indium, an indium alloy, tin, a tin alloy, mercury, and a mercury alloy.

[0188] Clause 50. The method of any of clauses 45-49, wherein the first and second polymer components each, individually, comprise a polymer selected from the group consisting of an acrylic polymer, an acrylate polymer, a vinyl polymer, a polyester polymer, a polyurethane polymer, a polybutadiene polymer, a polyamide polymer, a polyether polymer, a polysiloxane polymer, a silicon hydride polymer, a fluoropolymer, a polyisoprene polymer, and a copolymer of any two or more thereof.

[0189] Clause 51. The method of any of clauses 45-50, wherein the liquid metal droplets comprise a D90 in a range of 1 micron to 300 microns and the solid thermally conductive particles comprise a D90 in a range of 1 micron to 300 microns.

[0190] Clause 52. A method of manufacture of a thermal interface material, the method comprising: mixing a polymer component, solid thermally conductive particles, and liquid metal together, thereby dispersing the solid thermally conductive particles and the liquid metal throughout the polymer component, wherein the solid thermally conductive particles comprise a melting point of at least 100 degrees Celsius and wherein the liquid metal droplets comprise a melting point of no greater than 30 degrees Celsius.

[0191] Clause 53. The thermal interface material of any of clauses 1-27, wherein the polymer component further comprises a polyether modified binder, a carboxylic acid, an amine, a phenol, a sorbitan, a sorbitan ester, or a combination thereof.

[0192]

[0193] As used herein, “at least one of’ a list of elements means one of the elements or any combination of two or more of the listed elements. As an example “at least of A, B, and C” means A only; B only; C only; A and B; A and C; B and C; or A, B, and C.

[0194] Various features and characteristics are described in this specification to provide an understanding of the composition, structure, production, function, and / or operation of the invention, which includes the disclosed compositions, TIMs, assemblies, and methods. It is understood that the various features and characteristics of the invention described in this specification can be combined in any suitable manner, regardless of whether such features and characteristics are expressly described in combination in this specification. The Inventors and the Applicant expressly intend such combinations of features and characteristics to be included within the scope of the invention described in this specification. As such, the claims can be amended to recite, in any combination, any features and characteristics expressly or inherently described in, or otherwise expressly or inherently supported by, this specification. Furthermore, the Applicant reserves the right to amend the claims to affirmatively disclaim features and characteristics that may be present in the prior art, even if those features and characteristics are not expressly described in this specification. Therefore, any such amendments will not add new matter to the specification or claims and will comply with the written description, sufficiency of description, and added matter requirements. The various non-limiting embodiments disclosed and described in this specification can comprise, consist of, or consist essentially of the features and characteristics as variously described herein.

[0195] Any numerical range recited in this specification describes all sub-ranges of the same numerical precision (z.e., having the same number of specified digits) subsumed within the recited range. For example, a recited range of “1.0 to 10.0” describes all sub-ranges between (and including) the recited minimum value of 1.0 and the recited maximum value of 10.0, such as, for example, “2.4 to 7.6,” even if the range of “2.4 to 7.6” is not expressly recited in the text of the specification. Accordingly, the Applicant reserves the right to amend thisspecification, including the claims, to expressly recite any sub-range of the same numerical precision subsumed within the ranges expressly recited in this specification. All such ranges are inherently described in this specification such that amending to expressly recite any such sub-ranges will comply with the written description, sufficiency of description, and added matter requirements.

[0196] Also, unless expressly specified or otherwise required by context, all numerical parameters described in this specification (such as those expressing values, ranges, amounts, percentages, and the like) may be read as if prefaced by the word “about,” even if the word “about” does not expressly appear before a number. Additionally, numerical parameters described in this specification should be construed in light of the number of reported significant digits, numerical precision, and by applying ordinary rounding techniques. It is also understood that numerical parameters described in this specification will necessarily possess the inherent variability characteristic of the underlying measurement techniques used to determine the numerical value of the parameters.

[0197] Notwithstanding that numerical ranges and parameters setting forth the broad scope of the invention are approximations, numerical values set forth in the specific examples are reported precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard variation found in its respective testing measurements.

[0198] Reference throughout the specification to “various examples,” “some examples,” “one example,” “an example,” or the like means that a particular feature, structure, or characteristic described in connection with the example is included in an example. Thus, appearances of the phrases “in various examples,” “in some examples,” “in one example,” “in an example,” or the like, in places throughout the specification are not necessarily all referring to the same example. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in an example or examples. Thus, the particular features, structures, or characteristics illustrated or described in connection with one example may be combined, in whole or in part, with the features, structures, or characteristics of another example or other examples without limitation. Such modifications and variations are intended to be included within the scope of the present examples.

[0199] Any patent, publication, or other document identified in this specification is incorporated by reference into this specification in its entirety unless otherwise indicated but only to the extent that the incorporated material does not conflict with existing descriptions, definitions, statements, illustrations, or other disclosure material expressly set forth in this specification. As such, and to the extent necessary, the express disclosure as set forth in this specification supersedes any conflicting material incorporated by reference. Any material, or portion thereof, that is incorporated by reference into this specification, but which conflicts with existing definitions, statements, or other disclosure material set forth herein, is only incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material. Applicant reserves the right to amend this specification to expressly recite any subject matter, or portion thereof, incorporated by reference. The amendment of this specification to add such incorporated subject matter will comply with the written description, sufficiency of description, and added matter requirements.

[0200] Whereas particular examples of this invention have been described above for purposes of illustration, it will be evident to those skilled in the art that numerous variations of the details of the present invention may be made without departing from the invention as defined in the appended claims.

[0201] While the present disclosure provides descriptions of various specific aspects for the purpose of illustrating various aspects of the present disclosure and / or its potential applications, it is understood that variations and modifications will occur to those skilled in the art. Accordingly, the invention or inventions described herein should be understood to be at least as broad as they are claimed and not as more narrowly defined by particular illustrative aspects provided herein.

[0202] It is understood that the inventions described in this specification are not limited to the examples summarized in the Summary or Detailed Description. Various other aspects are described and exemplified herein.

Claims

CLAIMSWHAT IS CLAIMED IS:

1. A thermal interface material comprising:5% to 80% by volume of a polymer component based on a total volume of the thermal interface material;20% to 95% by volume of a conductive component based on the total volume of the thermal interface material, the conductive component is dispersed through the polymer component, wherein the conductive component comprises:25% to 99% by volume of liquid metal droplets based on a total volume of the conductive component, the liquid metal droplets dispersed through the polymer component, wherein the liquid metal droplets comprise a melting point of no greater than 30 degrees Celsius; and1% to 75% by volume of solid thermally conductive particles based on the total volume of the conductive component, the solid thermally conductive particles dispersed through the polymer component, wherein the solid thermally conductive particles comprise a melting point of at least 100 degrees Celsius.

2. The thermal interface material of claim 1, wherein the conductive component comprises:65% to 75% by volume of liquid metal droplets based on a total volume of the conductive component; and25% to 35% by volume of solid thermally conductive particles based on the total volume of the conductive component.

3. The thermal interface material of claim 1, wherein the solid thermally conductive particles comprise a metal, a metal alloy, a ceramic, an oxide, carbon based materials, or a combination thereof.

4. The thermal interface material of claim 1, wherein the solid thermally conductive particles comprise a metal or metal alloy selected from the group consisting of aluminum, an aluminum alloy, titanium, a titanium alloy, manganese, a manganese alloy, iron, an iron alloy, nickel, a nickel alloy, copper, a copper alloy, zinc, a zinc alloy, lead, a lead alloy, silver, a silver alloy, gold, a gold alloy, indium, an indium alloy, tin, a tin alloy, bismuth, a bismuth alloy, tungsten, a tungsten alloy, and a combination thereof.

5. The thermal interface material of claim 1, wherein the solid thermally conductive particles comprise a ceramic selected from the group consisting of boron nitride, aluminum nitride, and a combination thereof.

6. The thermal interface material of claim 1, wherein the solid thermally conductive particles comprise a carbon based material selected from the group consisting of a carbide, graphite, graphene, diamond, and a combination thereof.

7. The thermal interface material of claim 1, wherein the solid thermally conductive particles comprise a carbide selected from the group consisting of silicon carbide, tungsten carbide, aluminum carbide, and a combination thereof.

8. The thermal interface material of claim 1, wherein the solid thermally conductive particles comprise an oxide selected from the group consisting of aluminum oxide, iron oxide, and a combination thereof.

9. The thermal interface material of claim 1, wherein at least a portion of the liquid metal droplets comprise an exterior surface comprising a metal oxide.

10. The thermal interface material of claim 9, wherein the solid thermally conductive particles are non-reactive with the metal oxide.

11. The thermal interface material of claim 1, wherein solid thermally conductive particles comprise a thermal conductivity greater than a thermal conductivity of the liquid metal droplets.

12. The thermal interface material of claim 1, wherein solid thermally conductive particles comprise a thermal conductivity value of at least 5 W / m*K.

13. The thermal interface material of claim 1, wherein solid thermally conductive particles comprise a thermal conductivity value of at least 20 W / m*K.

14. The thermal interface material of claim 1, wherein the solid thermally conductive particles are coated with a coating comprising a bimetallic compound, a polymer, an organic compound, or a combination thereof.

15. The thermal interface material of claim 1, wherein the solid thermally conductive particles comprise an electrical conductivity of at least 103S / m.

16. The thermal interface material of claim 1, wherein the conductive component comprises solid thermally conductive particles that have D90 sphericity greater than 0.5.

17. The thermal interface material of claim 1, wherein the solid thermally conductive particles comprises an aspect ratio of at least 2.

18. The thermal interface material of claim 1, wherein the solid thermally conductive particles comprise a shape of at least one of a rod and a cylinder.

19. The thermal interface material of claim 1, wherein the solid thermally conductive particles comprise a sphericity of no greater than 0.95.

20. The thermal interface material of claim 1, wherein the solid thermally conductive particles comprise a Young’s modulus of at least 100 MPa.

21. The thermal interface material of claim 1, wherein a D90 of the liquid metal droplets is at least 20% greater than a width of the solid thermally conductive particles.

22. The thermal interface material of claim 1, wherein the liquid metal droplets comprise a metal selected from the group consisting of gallium, a gallium alloy, indium, an indium alloy, tin, a tin alloy, mercury, and a mercury alloy.

23. The thermal interface material of claim 1, wherein the polymer component comprises a polymer selected from the group consisting of an acrylic polymer, a vinyl polymer, a polyester polymer, a polyurethane polymer, a polybutadiene polymer, a polyamide polymer, a polyether polymer, a polysiloxane polymer, a silicon hydride polymer, a fluoropolymer, a polyisoprene polymer, and a copolymer of any two or more thereof.

24. The thermal interface material of claim 1, wherein the liquid metal droplets comprise a D90 in a range of 1 micron to 300 microns and the solid thermally conductive particles comprise a D90 in a range of 1 micron to 300 microns.

25. The thermal interface material of claim 1, wherein the liquid metal droplets comprise a D90 in a range of 15 microns to 150 microns and the solid thermally conductive particles comprise a D90 in a range of 10 microns to 100 microns.

26. The thermal interface material of claim 1, wherein the thermal interface material comprises a viscosity in a range of 1,000 cP to 2,000,000 cP measured at 25 °C.

27. The thermal interface material of claim 1, further comprising at least one of a catalyst, rigid spacer particles, a coupling agent, fumed silica, an additive, and a surfactant.

28. An assembly comprising: a first layer; a second layer; and the thermal interface material of claim 1 compressed and disposed in contact with and between the first layer and the second layer.

29. The assembly of claim 28, wherein a bondline thickness formed between the first layer and the second layer is less than a D90 of the liquid metal droplets prior to compression of the thermal interface material in the assembly.

30. The assembly of claim 28, wherein a bondline thickness formed between the first layer and the second layer is no greater than 300 microns.

31. The assembly of claim 28, wherein the first layer and the second layer, individually, comprise at least one of a battery, a processor, a heat sink, an integrated heat spreader, and packaging.

32. The assembly of claim 28, wherein the thermal interface material is cured.

33. The assembly of claim 28, wherein the thermal interface material comprises an effective thermal conductivity value of at least 1 W / m*K.

34. A method comprising: applying the thermal interface material of claim 1 on a first layer of an assembly at a first thickness; and compressing the assembly to decrease the first thickness to a second thickness, wherein the second thickness is no greater than a D90 of the liquid metal droplets prior to compressing the assembly.

35. The method of claim 34, further comprising, after compressing the assembly, curing the thermal interface material thereby forming a cured assembly.

36. The method of claim 34, wherein the first thickness is at least 1.1 times a D90 of the liquid metal droplets in the thermal interface material prior to compressing the assembly.

37. An assembly produced by the method of claim 34.

38. A method of manufacture of a thermal interface material, the method comprising: mixing a first polymer component and solid thermally conductive particles together, thereby dispersing the solid thermally conductive particles throughout the first polymer component to create a first mixture, wherein the solid thermally conductive particles comprise a melting point of at least 100 degrees Celsius;mixing a second polymer component and liquid metal together, thereby forming liquid metal droplets from the liquid metal and dispersing the liquid metal droplets throughout the second polymer component to create a second mixture, wherein the liquid metal droplets comprise a melting point of no greater than 30 degrees Celsius; and mixing the first mixture and second mixture together, thereby forming the thermal interface material.

39. The method of claim 38, wherein mixing the second polymer component and the liquid metal together comprises a dual-axis centrifugal mixing.

40. The method of claim 38, wherein the first polymer component, the second polymer component, the liquid metal, and the solid thermally conductive particles are added in quantities to achieve:5% to 80% by volume of the first and second polymer components based on a total volume of the thermal interface material;20% to 95% by volume of a conductive component based on the total volume of the thermal interface material, wherein the conductive component comprises:60% to 90% by volume of the liquid metal droplets based on a total volume of the conductive component; and10% to 40% by volume of the solid thermally conductive particles based on the total volume of the conductive component.

41. The method of claim 38, wherein the solid thermally conductive particles comprise a metal, a metal alloy, a ceramic, an oxide, carbon based materials, or a combination thereof42. The method of claim 38, wherein the liquid metal droplets comprise a metal selected from the group consisting of gallium, a gallium alloy, indium, an indium alloy, tin, a tin alloy, mercury, and a mercury alloy.

43. The method of claim 38, wherein the first and second polymer components each, individually, comprise a polymer selected from the group consisting of an acrylic polymer, anacrylate polymer, a vinyl polymer, a polyester polymer, a polyurethane polymer, a polybutadiene polymer, a polyamide polymer, a polyether polymer, a polysiloxane polymer, a silicon hydride polymer, a fluoropolymer, a polyisoprene polymer, and a copolymer of any two or more thereof.

44. The method of claim 38, wherein the liquid metal droplets comprise a D90 in a range of 1 micron to 300 microns and the solid thermally conductive particles comprise a D90 in a range of 1 micron to 300 microns.

45. A method of manufacture of a thermal interface material, the method comprising: mixing a first polymer component and solid thermally conductive particles together, thereby dispersing the solid thermally conductive particles throughout the first polymer component to create a first mixture, wherein the solid thermally conductive particles comprise a melting point of at least 100 degrees Celsius; mixing the first mixture with a second polymer component and liquid metal together, thereby forming liquid metal droplets from the liquid metal and dispersing the liquid metal droplets throughout the first and second polymer components to create the thermal interface material, wherein the liquid metal droplets comprise a melting point of no greater than 30 degrees Celsius.

46. The method of claim 45, wherein mixing the first mixture, the second polymer component, and the liquid metal together comprises a dual-axis centrifugal mixing.

47. The method of claim 45, wherein the first polymer component, the second polymer component, the liquid metal, and the solid thermally conductive particles are added in quantities to achieve:5% to 80% by volume of the first and second polymer components based on a total volume of the thermal interface material;20% to 95% by volume of a conductive component based on the total volume of the thermal interface material, wherein the conductive component comprises:60% to 90% by volume of the liquid metal droplets based on a total volume of the conductive component; and10% to 40% by volume of the solid thermally conductive particles based on the total volume of the conductive component.

48. The method of claim 45, wherein the solid thermally conductive particles comprise a metal, a metal alloy, a ceramic, an oxide, carbon based materials, or a combination thereof .

49. The method of claim 45, wherein the liquid metal droplets comprise a metal selected from the group consisting of gallium, a gallium alloy, indium, an indium alloy, tin, a tin alloy, mercury, and a mercury alloy.

50. The method of claim 45, wherein the first and second polymer components each, individually, comprise a polymer selected from the group consisting of an acrylic polymer, an acrylate polymer, a vinyl polymer, a polyester polymer, a polyurethane polymer, a polybutadiene polymer, a polyamide polymer, a polyether polymer, a polysiloxane polymer, a silicon hydride polymer, a fluoropolymer, a polyisoprene polymer, and a copolymer of any two or more thereof.

51. The method of claim 45, wherein the liquid metal droplets comprise a D90 in a range of 1 micron to 300 microns and the solid thermally conductive particles comprise a D90 in a range of 1 micron to 300 microns.

52. A method of manufacture of a thermal interface material, the method comprising: mixing a polymer component, solid thermally conductive particles, and liquid metal together, thereby dispersing the solid thermally conductive particles and the liquid metal throughout the polymer component, wherein the solid thermally conductive particles comprise a melting point of at least 100 degrees Celsius and wherein the liquid metal droplets comprise a melting point of no greater than 30 degrees Celsius.

53. The thermal interface material of claim 1, wherein the polymer component comprises a polyether modified binder, a carboxylic acid, an amine, a phenol, a sorbitan, a sorbitan ester, or a combination thereof.

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