Thin thermal interface material and method of manufacturing the same

Abstract

The present disclosure relates to a composition comprising nanoparticles and C s to C 40 thin thermal interface material with alkyl chains. The thermal interface material can fill the defined cavities to increase the contact surface area and improve thermal conductivity. Also described herein are methods for making the thermal interface material.

Description

[0001] Inventors: Kaoru Ueno, J.A. Piceno, and J. Hammarker Technical Field

[0002] This disclosure generally relates to thermal interface materials, and more specifically to, but not limited to, thermal interface materials exhibiting phase change properties. Background Technology

[0003] Thermally conductive and phase change materials, compounds, or compositions (which may be in powder form, for example) can be used as gap fillers and / or bonding materials in the semiconductor industry (and other industries). Some conventional phase change thermally conductive materials rely on polymer technology and can be mixed with phase change fillers such as organic polymer materials, thermally conductive fillers, and paraffin wax. At high temperatures, these materials become liquid, which can lead to contamination of peripheral electronic devices and components.

[0004] In the field of electronic components such as CPUs and GPUs, one or more thermally conductive materials are frequently used, including for attaching heat sinks to provide heat dissipation and thus optimize component functionality. Thermally conductive materials used in this way can include interphase materials, which can be used to transfer excess heat from the electronic component to a heat diffuser, and then to the heat sink. Electronic components can include one or more metals such as aluminum alloys; however, the adhesion of aluminum to other metals present in the electronic component using one or more of the aforementioned interphase materials may provide less than expected thermal conductivity, resulting in reduced heat transfer to the electronic component (e.g., due to increased thermal resistance) and decreased cooling efficiency.

[0005] Based on the above, additional contributions are needed in this technical field, including, for example, providing thermal interface materials that exhibit the desired adhesion, thermal conductivity, thermal resistance, followability, and / or electrical insulation properties. Summary of the Invention

[0006] This disclosure generally relates to thermal interface materials or thermally conductive composite adhesives, and methods for manufacturing them.

[0007] In one embodiment, the thermal interface material can be as shown in the following general formula (1): NP–C5-C 40 alkyl (Formula I).

[0008] In Formula I, NP can be inorganic nanoparticles having a thermal conductivity higher than 5 W / mK. In some embodiments, the thermal interface material may have or exhibit a first phase at a first temperature and a second phase at a second temperature. In one aspect, the difference between the first and second temperatures may be less than about 10 °C. In some embodiments, the thermal interface material may further comprise NP and C3 to C 40Linkers between alkyl groups, although NP and C5-C 40 It is also possible for alkyl chains to be mixed together without being linked by a linker. As a non-limiting example, when present, the linker may include a urethane ester, allowing the NP to be linked or attached to C3 through the urethane ester. 40 Alkyl groups. In some embodiments, the inorganic nanoparticles may include one or more of silicon dioxide (SiO2), aluminum oxide (Al2O3), AlN (aluminum nitride), cBN (cubic boron nitride), MgOH (magnesium hydroxide), and MgO (magnesium oxide). In some embodiments, the inorganic nanoparticles may have a size of about 1 nanometer (1 × 10⁻⁶). -9 From 10 meters to approximately 10 micrometers (10 × 10) -6 The average particle size is (in meters). In one aspect, inorganic nanoparticles can have an average particle size of less than about 30 nm to about 40 nm. In some embodiments, the thermal interface material may also include a primary amine. In some embodiments, the thermal interface material described herein can be disposed within a polymer matrix.

[0009] In some embodiments, the thermal interface material as shown in Formula I may include one of the following: (TIM-1) (TIM-2) (TIM-3) (TIM-4) (TIM-5), and AlN+1,3-Octadecylurea (DODU) (TIM-6).

[0010] In these examples, the thermal interface material may exhibit or have a first phase at a first temperature and exhibit or have a second phase at a second temperature. In some forms where NP is a nitride nanoparticle, it may be at least partially covered by one or more hydroxyl groups and hydroxylation elements, and / or functionalized by hydroxyl groups.

[0011] In some embodiments, the thermal interface material described herein may include one or more of at least one urea compound and at least one amide compound. In some embodiments, the urea compound may include one or more of N-alkylurea and N,N'-dialkylurea. In some embodiments, the amide compound may include alkylene diamides. In some embodiments, the compound may also include a porous material comprising SiO2, Al2O3, MgO, AlN, c-BN, or combinations thereof.

[0012] In one embodiment, the thermally conductive element may include a porous material defining a plurality of cavities, and the thermal interface material herein may be disposed within the cavities defined by the porous material. In some embodiments, the porous material may include copper.

[0013] In another embodiment, a computer structure with a thermal interface material may include a substrate and at least one computer element. The substrate and at least one computer element may define a surface cavity therein, and the thermal interface material may be disposed within the surface cavity to fill the surface cavity and provide a larger contact surface with the substrate, at least one computer element, and / or the thermal interface material and materials disposed thereon. In some embodiments, the computer structure may also include a thermal pad having a first thermal pad surface facing the substrate and at least one computer element defining the surface cavity therein, wherein at least about 75% of the thermal pad surface is in contact with the larger contact surface. In some embodiments, the presence of air gaps within the polymer matrix may be reduced by the presence of the thermal interface material described herein.

[0014] In one embodiment, the computer structure may include a substrate having a substrate surface and one or more computer components disposed on the substrate surface, wherein the substrate and the one or more computer components define a plurality of cavities. The structure may also include a cover and a first layer and a second layer of thermal interface material. The first layer of thermal interface material may be disposed between the substrate and the one or more computer components and the cover to provide an increased contact area between the first layer of thermal interface material and the substrate and the one or more computer components, and the second layer of thermal interface material may be disposed between the cover and the first layer of thermal interface material to provide an increased contact layer between the first layer of thermal interface material and the cover.

[0015] Brief description of the attached figures Figure 1 This is a schematic diagram of a porous sheet containing the thermal interface material described herein.

[0016] Figure 2 This is a schematic diagram of a computer's architecture.

[0017] Figure 3 and Figure 4 The results show the thermal conductivity of the bulk mixture of the modified thermal interface material and the unmodified nanoparticles.

[0018] Figure 5 The thermal conductivity of the composite material of grafted powder and original powder is shown.

[0019] Figure 6 The thermal conductivity of the original powder and the organic compound powder is shown.

[0020] Figure 7 and Figure 8 Various thermal properties of the AlN / 1,3-octadecylurea (DODU) composite material are shown.

[0021] Figure 9 These are the XRD spectra of the modified and unmodified nanoparticle embodiments described herein.

[0022] Figure 10 It is a DSR spectrum showing the melting temperature of various thermal interface materials. Detailed Implementation

[0023] This disclosure generally relates to thermal interface materials, related thermally conductive composite materials, and methods for manufacturing the same. The materials disclosed herein can exhibit melt-like behavior, which allows them to effectively fill gaps or cavities, thereby forming flatter surfaces and / or increased contact areas, which can provide improved thermal conductivity.

[0024] In one embodiment, the thermal interface material (TIM) can be as shown in the following formula (I): NP–(C5-C) 40 alkyl) (Formula I) In formula (I), NP can represent inorganic particles, such as inorganic nanoparticles. In some embodiments, the inorganic particles can have a thermal conductivity higher than 5 W / mK. Furthermore, NP can be connected to and / or grafted to C5-C in formula (I). 40 Alkyl chains, although NP with C5-C 40 It is also possible for alkyl chains to be mixed together without any linkage or grafting. This is in the case of NP linked to C5-C. 40 In some forms of alkyl chains, the linkage may be provided by urethane and / or polyurethane connectors / joints. In some embodiments, the TIM may have a first phase at a first temperature and a second phase at a second temperature. As a non-limiting example, the first phase may be solid and the second phase may be liquid. In some embodiments, the TIM may include one or more of silicon dioxide (SiO3), aluminum oxide (Al2O3), aluminum nitride (AlN), cubic boron nitride (CBNs), magnesium hydroxide (MgOH), and magnesium oxide (MgO). In forms where the TIM comprises nitrides such as aluminum nitride and / or boron nitride, the nitride may be nanoparticles with at least one hydroxyl group partially coated on its surface, such as aluminum nitride coated with aluminum trihydroxyl, and / or hydroxyl groups on its surface such as aluminum nitride coated with aluminum trihydroxyl (Al(OH)3). In some embodiments, the TIM may include primary amines.

[0025] In one embodiment, the composition includes a polymer matrix and the TIM described herein, wherein the TIM may be disposed within the matrix.

[0026] More specific, but non-limiting, examples of TIMs disclosed herein include: , , , , ,and AlN+DODU.

[0027] It is believed that the various properties of the TIM described herein (such as thermal conductivity, cooling efficiency, thermal resistance, etc.) can be provided at least in part by the inclusion of nanoparticles within a specified size range and the interaction between adjacent long alkyl chains of adjacent grafted or functionalized particles, in order to reduce the air gap present therein.

[0028] In some embodiments, the TIM may include one or more of at least one urea compound and at least one amide compound. In some embodiments, the urea compound may include N-alkylurea ( ), N,N'-dialkylurea ( ), or combinations thereof. In some embodiments, the amide compound may include alkylene diamides (... In some embodiments, the TIM described herein may include having according to the following The material of the structure, wherein each n is 5-25. A specific but non-limiting example according to the above is 1,3-octadecylurea. In some aspects of this form, TIM may include NPs mixed with the structure without any joints or connections therebetween. In one particular aspect, the NPs in these forms may be AlN. In other aspects, it is contemplated that the TIM described herein be mixed with compounds according to the structure. For example, in one form, it is contemplated that TIM-4 may be mixed with compounds according to the structure, such as 1,3-octadecylurea.

[0029] In some embodiments, the TIM described herein may also include a porous material, comprising composites such as SiO2, Al2O3, MgO, AlN, c-BN, or combinations thereof. In some embodiments, the porous material may include a copper mesh or a copper mesh comprising copper particles. In some embodiments, the porous material may be filled with composites such as SiO2, Al2O3, MgO, AlN, c-BN, or combinations thereof.

[0030] In one embodiment, the thermally conductive element may include a porous material defining a cavity therein, and the thermal interface material therein may be disposed within the cavity of the porous material. In some embodiments, the porous material may include copper.

[0031] In another embodiment, a computer structure having the thermal interface material described herein may include a substrate and at least one computer element, wherein the substrate and at least one computer element may define a surface cavity therein. The thermal interface material described herein may be disposed within the surface cavity to fill the surface cavity and provide a larger contact surface with the substrate, at least one computer element, and / or the TIM and the material disposed thereon. In some embodiments, the computer structure may further include a thermal pad having a first thermal pad surface, and the thermal pad may be disposed on the substrate and at least one computer element defining the surface cavity therein. In this form, at least about 50%, about 75%, about 80%, or about 90% of the thermal pad surface is in contact with the larger contact surface. In some embodiments, the TIM described herein may reduce the presence of air gaps within the polymer matrix / TIM, which may improve thermal conductivity and reduce thermal resistance. In some embodiments, the introduction of the TIM layer reduces the presence of air gaps between the various layers of the TIM material, polymer, and / or material containing such material.

[0032] As mentioned above, NP in Formula I can represent inorganic particles, such as inorganic nanoparticles or microparticles. In some embodiments, inorganic particles can have a size of 1 nanometer (1 × 10⁻⁶). -9 (meters) to 10 micrometers (10×10) -6 The average particle size is (in meters). In one or more forms, the inorganic particles may have an average particle size of less than about 30 nm to about 40 nm, or between about 1 and 3 micrometers. In some embodiments, the NP may be nanoparticles comprising metal oxides and / or metal nitrides. In some embodiments, the nanoparticles or the TIM containing the nanoparticles may include silicon dioxide (SiO3), aluminum oxide (Al2O3), aluminum nitride (AlN), cubic boron nitride (CBN), magnesium hydroxide (MgOH), magnesium oxide (MgO) particles and / or mixtures or combinations of such particles.

[0033] In some embodiments, the NP and alkyl chain can be linked to each other via urethane bonds or carbamate bonds. In some embodiments, the TIM can include a connector or linker, which can be an urethane bond. In some embodiments, the connector or linker can include an isocyanate coupling. In some embodiments, the connector or linker can include a carbamate linker. In some embodiments, the connector can include: In some approaches, the linker may include a primary amine.

[0034] In some embodiments, the TIM may include alkyl chains, and the alkyl chains may be a factor in providing the material capable of achieving the biphasic function of the TIM (displaying a first phase at a first temperature and a second phase at a second temperature). In some embodiments, several considerations, such as the length of the alkyl group, the presence and / or position of the carbon-carbon double bond, the resulting cis or trans configuration, the presence of crosslinks, the presence or absence of large side groups, the flexibility of the polymer chain, the film thickness, and / or the branching of the carbon chain, can be adjusted to alter or customize the desired glass transition temperature. In some embodiments, the length of the alkyl chain can be C3, C5, C7, C9, C6, C7, C8, C9 ... 11 To C 20 C 23 C 25 C 28 C 30 C 32 C 35 C 38 C 40 and C 40 Between, or any combination of the values, such as C 17 C 18 C 19 In some embodiments, the alkyl chain may not include carbon-carbon double bonds (“saturated”), or may include at least one, two, three, and / or four carbon-carbon double bonds. In some embodiments, the alkyl chain may include trans and / or cis configurations.

[0035] As described above, in some embodiments, the NP can be connected to and / or grafted to C5-C in formula (I). 40 Alkyl chains. In these and other forms, nanoparticles can have a melting temperature T. m (Melting point), at which temperature amorphous polymers change from below T m The hard / rigid / glassy state transforms into, for example, above T m The material's T-state is either soft / leather-like / fluid / flowable or vice versa. m This can be related to the strength, capability, and properties of the selected material, including but not limited to the length of the alkyl segment and / or the number and / or position of cis / trans / carbon double bonds within the alkyl chain. In some embodiments, the nanoparticles may have a T0 between about 5°C and about 80°C (e.g., between about 45°C and about 70°C). m For example, at a first temperature, such as below, for example, for α, β and / or γ type T m At least one of these, TIM can be in an amorphous, glassy, ​​hardened, and / or solid form. In some ways, for example at a second temperature, such as above T... mTIM can be in a softer, liquid, or fluid form. This allows the material to be applied to the defined cavity in a fluid state and remain within the temperature range below T. m The material hardens or solidifies within the defined cavity, thereby achieving a uniform surface area and / or increasing contact between components disposed on an irregularly shaped motherboard / sub-component. In some embodiments, the temperature difference between the first temperature and the second temperature may be less than about 10°C or about 5°C. In some embodiments, the temperature difference may be about 1.0°C, about 2.5°C, about 4°C, about 5°C, about 7.5°C to about 9°C, about 10°C, about 12.5°C, about 15°C and / or about 25°C, or any combination of the above values ​​or the range of the above temperature differences, for example, about 5°C to about 15°C.

[0036] In some methods, NPs can have an average particle size of less than 100 nm. In other methods, NPs can have an average particle size of 100 nanometers (100 × 10⁻⁶). -9 From 0.010 micrometers (0.01010 × 10⁻⁶ meters) to 0.010 micrometers (0.01010 × 10⁻⁶ meters). -6 The average particle size is approximately 1-3 micrometers. In some embodiments, the average particle size can be less than about 30 nm to about 40 nm. In forms where NP includes BN, for example, the average particle size can be about 1-3 micrometers, and in cases where NP includes BN and / or AlN, the average particle size can be about 1 micrometer.

[0037] In some forms where NP is an inorganic particle, it may include SiO2, Al2O3, MgO, MgOH, and / or CuO. In some embodiments, the inorganic particle may include aluminum nitride or cubic boron nitride (cBN). In some embodiments, the inorganic particle may, for example, have a minimum thermal conductivity of about 0.25 W / mK, about 0.35 W / mK, or about 0.40 W / mK to about 1.0 W / mK, about 1.1 W / mK, about 1.2 W / mK, about 1.4 W / mK, about 1.5 W / mK, or about 2.0, or any combination of the above values, without any additions or modifications. The following table provides non-limiting examples of inorganic particles and their related properties:

[0038] In some embodiments, the overall thermal conductivity of grafted or ungrafted nanoparticles, and / or mixtures of grafted and ungrafted nanoparticles, can be greater than about 1.0 W / mK, about 2.0 W / mK, about 2.5 W / mK, about 3.0 W / mK, about 4.0 W / mK, about 5 W / mK, about 7.5 W / mK, or about 10 W / mK, to name just a few non-limiting examples.

[0039] Now refer to Figure 1The diagram illustrates a modified porous sheet 2 comprising a porous material 4 defining a plurality of cavities 6A and 6B therein. Sheet 2 also includes a TIM 8 as described herein, and in the illustrated form, the TIM is disposed within cavity 6B, although it is also possible for the TIM 8 to be disposed within additional or alternative cavities. In some embodiments, the porous material 4 may comprise a mesh-like interwoven material defining the cavities, such as those located between braided filaments and / or within individual structural portions therein. In some embodiments, the porous material 4 may comprise a conductive metal such as copper. In some embodiments, the conductive metal may be in the form of a mesh or sheet. In these embodiments, for example, the length and / or width dimensions of the conductive metal may be greater than its depth or thickness dimensions. By filling one or more cavities in sheet 2, air gaps are reduced or eliminated, thereby increasing the thermal conductivity of sheet 2 while reducing its thermal resistance. In this way, sheet 2 comprising one or more cavities filled with the TIM described herein can be used in situations where a smooth and efficient heat transfer or transmission is desired. Furthermore, sheet 2 can provide reinforcement to TIM where TIM may reach or approach a temperature that makes it flowable or softenable.

[0040] Now refer to Figure 2 The diagram schematically illustrates a computer structure 10, which includes a substrate 12. The substrate 12 may be, for example, a motherboard, backplate, etc., and may comprise resin, plastic, fiberglass, or other non-conductive materials. The structure 10 may include one or more sub-elements, such as sub-elements 14A, 14B, 14C, and 14D, which may represent a computer processing unit, hard disk, memory, and / or power supply, to name just a few. Sub-elements 14A, 14B, 14C, and 14D are arranged on the substrate 12 in an arrangement with cavities and / or spaces positioned between them; for example, located between sub-elements 14A, 14B, 14C, and 14D, and / or between sub-elements 14A, 14B, 14C, and 14D and the substrate 12. In the illustrated form, a thermal interface material 16 is disposed within the cavities and / or spaces, defining a top surface 18 of the thermal interface material 16. Furthermore, as a phase change material exhibiting different phases at different temperatures, the thermal interface material 16 can fill any voids, cavities, or uneven portions of the substrate 12 to increase the surface area of ​​contact between the substrate 12 and the thermal interface material 16, thereby providing enhanced thermal conductivity and lower thermal resistance. Similarly, by filling other voids or cavities between the sub-elements 14A, 14B, 14C, 14D and the substrate 12, the thermal interface material 16 reduces or eliminates associated air gaps, which in turn enhances the overall thermal conductivity and reduces the thermal resistance of the structure 10.

[0041] In the illustrated configuration, the second TIM layer 20 is disposed on top of the thermal interface material 16, or between the thermal interface material 16 and any other layer (such as another TIM layer) and / or the encapsulation cap 22, which is positioned on the second thermal interface material 20. In some embodiments, the top surface 18 of the thermal interface material 16 may be substantially flat, thereby increasing the surface contact area between the top surface 18 and any other material disposed thereon (including the second thermal interface material 20). In some embodiments, the surface contact area may be at least about 25%, about 33%, about 40%, about 50%, about 60%, about 75%, about 80%, and / or about 90% of the surface area of ​​the top surface 18 and the contact surface of the material disposed above the contact surface 18 (such as the second TIM layer 20 or the encapsulation cap 22). Similarly, when a second TIM layer 20 is present, as a phase change material that exhibits different phases at different temperatures, it can fill any gaps, cavities, or uneven portions of the encapsulation cover 22 to increase the surface area of ​​contact between the encapsulation cover 22 and the thermal interface material 20, and provide enhanced thermal conductivity and lower thermal resistance therebetween.

[0042] In one embodiment, a method for thermally protecting an uneven surface and / or increasing the contact surface area between layers may include providing a substrate on which at least one computer element is disposed. The substrate and / or the at least one computer element disposed thereon may define cavities, recesses, or generally uneven areas within a first surface. The method further includes heating a quantity of thermal interface material (TIM) (e.g., a dual-phase material) to above a first temperature and dispersing the heated TIM material within a cavity in a manner sufficient to at least partially fill the cavity. In some embodiments, the cavity may be sufficiently filled to provide a substantially flat surface layer and / or increase the contact surface area between the substrate and at least one computer element and the thermal interface material. In some embodiments, the thermal dual-phase material comprises C5 to C6. 40 Alkyl-surface-functionalized nanoparticles. In some embodiments, the functionalized nanoparticles may include metal oxide particles.

[0043] Other embodiments described herein relate to a thermally conductive layer comprising a thermal interface material and a method of manufacturing the same. The thermal interface material may include a first layer comprising one or more metal oxide particles, and this first layer may be disposed above an uneven surface. A second layer may include metal oxide particles, and the second layer may be disposed under a heat sink and on a housing (HIS). In some embodiments, the thermal conductivity of the bond present in the thermal interface material may exceed 50 W / m². -1 K -1 Other embodiments and methods for manufacturing thermally conductive composite materials are described herein.

[0044] Example The following examples are intended to be illustrative in nature and are not intended to limit the scope or basic principles of this application.

[0045] Preparation of grafted inorganic particles via isocyanate coupling graft SiO 2 Particle grafting (reference or trace experiments) The received SiO2 particles (2.0 g, 10-20 nm, 6807 NM, SkySpring Nanomaterials, Inc., Houston, Texas, USA) were immersed in 30 mL of triethylamine (≥99.5%, 471283, SigmaAldrich, St. Louis, Missouri, USA) containing 1.0 wt.% dibutyltin dilaurate (DBTDL) (95%, 291234, Sigma Aldrich). The flask was purged with argon and then placed in an ultrasonic bath (XUB5, Grant Instruments Ltd., Royston, UK) at 60 °C for 30 minutes. The flask was then transferred to a hot plate with a heating mantle (AREX-6 Digital Pro). A dropping funnel containing 10.0 g of octadecyl isocyanate (ODI) (industrial grade, O1807, Sigma Aldrich) was fixed to a flask, and ODI was added dropwise to the solution while stirring with a magnetic stirrer at 400-600 rpm. Once the ODI had been completely added to the solution, the flask was purged again with argon gas, sealed, and heated to 85°C. The reaction was allowed to proceed for 20 hours.

[0046] Grafting of MgO nanoparticles MgO hydration To provide adequate surface functionalization for isocyanate coupling, 2.0 g of the received MgO nanoparticles (10-30 nm, 4810NH, SkySpring Nanomaterials, Inc.) were immersed in 150 mL of Milli-Q water in a sealed round-bottom flask for 72 hours at room temperature. The particles were then collected, dried, and milled prior to functionalization.

[0047] MgO / Mg(OH) 2 Particle grafting 2.0 g of partially hydrated MgO was impregnated in a two-necked round-bottom flask containing 30 mL of triethylamine (≥99.5%, 471283, Sigma-Aldrich) with 1.0 wt.% dibutyltin dilaurate (DBTDL) (95%, 291234, Sigma-Aldrich). The flask was purged with argon and then placed in an ultrasonic bath (XUB5, Grant Instruments) at 60 °C for 30 minutes. The flask was then transferred to a hot plate with a heating mantle (AREX-6 Digital Pro). A dropping funnel containing 10.0 g of octadecyl isocyanate (ODI) (industrial grade, O1807, Sigma-Aldrich) was attached to the flask, and ODI was added dropwise to the solution while stirring with a magnetic stirrer at 400–600 rpm. Once the ODI had been completely added to the solution, the flask was purged with argon again, sealed, and heated to 85 °C. The reaction was allowed to proceed for 20 hours. It is labeled as ODI-nano-MgO.

[0048] Grafting of MgO micron particles MgO nanoparticles (using micron-sized particles [MgO (US1130M, MgO, 1000 nm, US Research Nanomaterials, Inc.]) were prepared as described above, except that there was no hydration step of soaking in 150 ml of Milli-Q water before grafting. The procedure was performed in the same manner as described above, but without hydration before grafting.

[0049] γ-Al 2 O 3 Particle grafting The received γ-Al₂O₃ particles (2.0 g, 8–12 nm, SkySpring Nanomaterials, Inc.) were immersed in 30 mL of triethylamine (≥99.5%, 471283, Sigma Aldrich) containing 1.0 wt.% dibutyltin dilaurate (DBTDL) (95%, 291234, Sigma Aldrich) in a two-necked round-bottom flask. The flask was purged with argon and then placed in an ultrasonic bath (XUB5, Grant Instruments) at 60 °C for 30 minutes. The flask was then transferred to a hot plate with a heating mantle (AREX-6 Digital Pro). A dropping funnel containing 10.0 g of octadecyl isocyanate (ODI) (industrial grade, O1807, Sigma Aldrich) was fixed to the flask, and ODI was added dropwise to the solution while stirring with a magnetic stirrer at 400–600 rpm. Once ODI has been completely added to the solution, purge the flask again with argon gas, seal it, and heat it to 90°C. Allow the reaction to proceed for 20 hours.

[0050] Grafting of AlN particles AlN hydration Prior to AlN grafting, the surface of the AlN was hydrated as follows: 30 g of AlN (Type H, Tokuyama Corp., Japan) was immersed in 1 L of MilliQ water (room temperature) with stirring for varying durations (0–100 min). The hydrated AlN powder was vacuum filtered through filter paper (Whatmann 1) and washed with isopropanol. The AlN powder was then dried overnight in a convection oven at 80 °C and further dried in a vacuum oven at 80 °C for 2 hours. The hydrated AlN was labeled AlN-OH100 (100 min hydration), AlN-OH60 (60 min hydration), etc.

[0051] AlN grafting AlN and cBN grafted nanoparticles were prepared in the manner described above for grafting γ-Al2O3 and MgO.

[0052] Grafting of cBN (cubic boron nitride) particles hydroxylation of cBN 6 g of cBN (1–3 µm, MSE supplies) was impregnated in 5 mol dm under stirring. -3 The powder was dissolved in an aqueous NaOH solution for 24 hours. It was then washed with MilliQ water by centrifugation until the pH became neutral. Next, the powder was washed twice more with acetone by centrifugation to remove water. The powder was dried overnight in a convection oven at 80°C, and then further dried in a vacuum oven at 80°C for 2 hours. The hydroxylated cBN was labeled as cBN-OH.

[0053] Post-processing of grafted particles After the specified reaction time, the reaction solution was transferred to a 600 mL beaker and cooled to room temperature. The cooled product was then washed under vacuum with alternating rinsing of toluene (500 mL, ≥99.5%, TX0735, Sigma Aldrich), acetone (500 mL, ≥99.5%, AX0120, Sigma Aldrich), and methanol (500 mL, ≥99.8%, MX0485, Sigma Aldrich). After drying, the material was collected, ground, and passed through a 125 μm sieve (Cole Parmer No. 120) at 40% intensity for 45 seconds at 60 Hz (Resodyn LabRAM). The sieved powder was then placed in a vacuum oven (AVO-200V CR) at 70 °C and -0.1 mPa for 5 hours to ensure complete removal of residual solvents.

[0054] Synthesis of 1-alkylurea, 1,3-dialkylurea and alkylene diamide Synthesis of 1-alkylurea Example 1: 1-Hexylurea and 1-Octylurea 6.00 g of urea (Aldrich) and an equimolar amount of alkylamine (13.2 mL of N-hexylamine or 16.5 mL of N-octylamine) were added to a 100 mL two-necked round-bottom flask equipped with a condenser. The flask was heated to 120 °C with gentle stirring on a heating block on a hot plate. After the urea was completely dissolved in the alkylamine, the mixture was stirred for 12 hours. After cooling to room temperature (~20 °C), the resulting solid was dispersed in water. The solid contents were filtered, washed several times with water, and dried in a vacuum oven at 100 °C for 2 hours. The dried powder was dissolved in hot (~70 °C) isopropanol and recrystallized at room temperature.

[0055] Synthesis of 1,3-dialkylurea Example 2: Example 2 (1,3-Dihexylurea): 4-Nitrobenzoyl chloride (25.00 mmol, 5040 mg) and hexane-1-amine (125.0 mmol, 16.5 mL) were stirred in a dry DCE (50 mL) under argon and heated to 60 °C for 30 min, then cooled to room temperature. The mixture was directly loaded onto a 220 g column and purified by rapid silica gel chromatography (0% EtOAc / DCM (2 CV) → 20% (10 CV)). The fraction containing the product was evaporated to dryness under vacuum to give a white solid, 3060 mg (54% yield). MS (APCI): against chemical formula: C 13 H 28 The calculated value for N2O (M+H) is 229; the measured value is also 229. ¹H NMR (400MHz, CDCl3) δ 4.66–4.36 (m, 2H), 3.14 (td, J=7.2, 5.7 Hz, 4H), 1.57–1.41 (m, 4H), 1.38–1.19 (m, 12H), 0.94–0.81 (m, 6H).

[0056] Example 3: Example 3 (1,3-Didodecylurea): CDI (25.00 mmol, 4053 mg) and dodecane-1-amine (75.00 mmol, 13902 mg) were stirred overnight in a dry DCE under argon atmosphere as described above. The DCE was evaporated, the residue was milled with methanol, and the resulting solid was filtered off. The solid was dried by suction to give a white solid, 9918 mg (100% yield). MS (APCI): against chemical formula: C 17 H 36 The calculated value for N2O(m+H) is 397; the measured value is also 397. ¹H NMR (400 MHz, CDCl3) δ 4.17 (d, J=5.8 Hz, 2H), 3.15 (q, J=6.6 Hz, 4H), 1.48 (q, J=7.1 Hz, 4H), 1.27 (d, J=11.6 Hz, 36H), 0.88 (t, J=6.7 Hz, 6H).

[0057] Example 4: Example 4 (1,3-Dioctylurea): CDI (30.00 mmol, 4863 mg), octane-1-amine (75.00 mmol, 12.4 mL), and triethylamine (75.00 mmol, 10.5 mL) were stirred at 60 °C for 60 min in a dry DCE (50 mL) under argon atmosphere. The reaction mixture was evaporated to dryness under vacuum, diluted with DCM / hexane, and ~40 g of rapid silica gel was added. The reaction mixture was evaporated to dryness under vacuum and loaded into a sampler. The mixture was purified by rapid silica gel chromatography (220 g, 0% acetone / DCM (2 CV) → 30% (20 CV)). The fraction containing the product was evaporated to dryness under vacuum to give a white solid, 5174 mg (61% yield). MS (APCI): against chemical formula: C 17 H 36 The calculated value for N₂O (m+H) is 285; the measured value is also 285. ¹H NMR (400 MHz, CDCl₃) δ 4.25 (t, J=5.7 Hz, 2H), 3.15 (td, J=7.1, 5.6 Hz, 4H), 1.49 (p, J=7.0 Hz, 4H), 1.36–1.18 (m, 20H), 0.94–0.83 (m, 6H).

[0058] Example 5: Example 5 (1,3-Didecylurea): CDI (30.00 mmol, 4863 mg), decane-1-amine (75.00 mmol, 15.0 mL), and triethylamine (75.00 mmol, 10.5 mL) were stirred at 60 °C for 30 min in a dry DCE (50 mL) under argon atmosphere, followed by evaporation of the DCE under vacuum. The residue was evaporated under vacuum onto a ~40 g high-speed silica gel, loaded into a sampler, and purified by high-speed silica gel chromatography (220 g, 0% acetone / DCM (2 CV) → 10% (10 CV)). The fraction containing the product was evaporated under vacuum to dryness to give a white solid, 4282 mg (42% yield). MS (APCI): against chemical formula: C 21 H 44 The calculated value for N2O(m+H) is 341; the measured value is also 341. ¹H NMR (400 MHz, CDCl3) δ 4.25 (t, J=5.6 Hz, 2H), 3.15 (td, J=7.2, 5.7 Hz, 4H), 1.49 (p, J=7.1 Hz, 4H), 1.27 (d, J=11.0 Hz, 28H), 0.88 (t, J=6.8 Hz, 6H).

[0059] Example 6: Example 6 (1,3-Ditetradecylurea): CDI (30.00 mmol, 4863 mg), tetradecane-1-amine (75.00 mmol, 16006 mg), and triethylamine (75.00 mmol, 10.5 mL) were stirred at 60 °C for 90 min under argon in a dry DCE (50 mL), and then cooled to room temperature. The reaction mixture was diluted with ~5% v / v hexane, and the resulting white solid was filtered off and washed with 95:5 DCM:hexane. The precipitate was dried by suction to give a white solid, 11291 mg (85% yield). MS (APCI): against chemical formula: C 29 H 60 The calculated value for N2O(m+H) is 453; the measured value is also 453. ¹H NMR (400 MHz, CDCl3) δ 4.14 (d, J=6.0 Hz, 2H), 3.15 (td, J=7.1, 5.6 Hz, 4H), 1.48 (q, J=7.0 Hz, 4H), 1.38–1.18 (m, 44H), 0.88 (t, J=6.7 Hz, 6H).

[0060] Example 7: Example 7 (1-Hexadecylurea): Phenyl carbamate (33.90 mmol), hexadecyl-1-amine (30.00 mmol, 7244 mg), and triethylamine (66.00 mmol, 9.2 mL) were stirred at 60 °C for four hours in dry THF (50 mL) under argon atmosphere, followed by stirring overnight at room temperature. DCE was removed under vacuum, and the product was recrystallized from hot EtOAc and cooled to room temperature. The product was filtered and washed with EtOAc. The product was dried by suction to give a white solid, 7497 mg (88% yield). MS (APCI): against chemical formula: C 17 H 36 The calculated value for N2O(m+H) is 285; the measured value is also 285. ¹H NMR (400 MHz, DMSO) δ 5.85 (s, 1H), 5.32 (s, 2H), 2.92 (d, J=6.8 Hz, 2H), 1.31 (s, 2H), 1.24 (s, 28H), 0.84 (d, J=7.9 Hz, 3H).

[0061] Example 8: Example 8 (1,3-Dihexadecylurea): CDI (30.00 mmol, 4863 mg), hexadecyl-1-amine (75.00 mmol, 18110 mg), and triethylamine (75.00 mmol, 10.5 mL) were stirred at 75 °C for 120 min under argon in 50 mL of dry THF. The reaction was cooled to room temperature, and the THF was evaporated to dryness under vacuum. The residue was dissolved in ~400 mL of EtOAc and heated to boiling, then diluted with 50 mL of hexane. After cooling to room temperature, the precipitate was filtered off, washed with a small amount of EtOAc, then washed with hexane, and dried by suction to give a white solid, 11576 mg (76% yield). MS (APCI): against chemical formula: C 33 H 68 The calculated value for N2O(m+H) is 509; the measured value is also 509. ¹H NMR (400 MHz, CDCl3) δ 4.13 (s, 2H), 3.15 (q, J=6.7 Hz, 4H), 1.50 (d, J=7.2 Hz, 4H), 1.25 (s, 52H), 0.88 (t, J=6.7 Hz, 6H).

[0062] Example 9: Example 9 (1-Decylurea): Phenyl carbamate (55.00 mmol, 7541 mg), decane-1-amine (50.00 mmol, 10.0 mL), and triethylamine (110.0 mmol, 15.3 mL) were stirred at 60 °C for 180 min in dry THF (50 mL) under argon atmosphere, and then cooled to room temperature. The THF was removed under vacuum, and the residue was dissolved in ~200 mL of hot EtOAc. After cooling to room temperature, the residue was filtered, washed with a small amount of EtOAc, and dried by suction to give a white solid, 8860 mg (87% yield). MS (APCI): against chemical formula: C 11 H 24 The calculated value for N2O(m+H) is 201; the measured value is also 201. ¹H NMR (400 MHz, CDCl3) δ 4.45 (s, 1H), 4.30 (s, 2H), 3.15 (td, J=7.2, 5.7 Hz, 2H), 1.50 (p, J=7.1 Hz, 2H), 1.27 (d, J=8.7 Hz, 14H), 0.88 (t, J=6.8 Hz, 3H).

[0063] Example 10: Example 10 (1-Pentylurea): Phenyl carbamate (88.00 mmol, 12065 mg), pentane-1-amine (80.00 mmol, 9.2 mL), and triethylamine (176.0 mmol, 24.5 mL) were stirred at 60 °C for 120 min in dry THF (50 mL) under argon atmosphere, and then cooled to room temperature. THF was removed under vacuum, and the residue was dissolved in hot EtOAc (~100 mL). The mixture was cooled to room temperature and then scraped to induce crystallization. The mixture was diluted with hexane (~80 mL) and allowed to stand overnight. The crystals were filtered off, washed with a 1:1 EtOAc:hexane solution, and dried by suction to give a white solid, 7064 mg (67% yield). MS (APCI): against chemical formula: C6H 14 The calculated value for N₂O (m+H) is 131; the measured value is also 131. ¹H NMR (400 MHz, CDCl₃) δ 4.69 (s, 1H), 4.46 (s, 2H), 3.15 (td, J=7.2, 5.7 Hz, 2H), 1.51 (p, J=7.3 Hz, 2H), 1.41–1.21 (m, 4H), 0.98–0.80 (m, 3H).

[0064] Example 11: Example 11 (1-Dodecylurea): Phenyl carbamate (49.50 mmol, 6786 mg), dodecyl-1-amine (45.00 mmol, 8341 mg), and triethylamine (99.00 mmol, 13.8 mL) were heated at 60 °C for 60 min in dry THF (50 mL), and then cooled to room temperature. The THF was removed under vacuum, and the residue was recrystallized from hot EtOAc. The mixture was cooled to room temperature, and the product was filtered off, washed with EtOAc, and dried by suction to give a white solid, 9319 mg (91% yield). MS (APCI): against chemical formula: C 13 H 28 The calculated value for N2O(m+H) is 229; the measured value is also 229. ¹H NMR (400 MHz, CDCl3) δ 4.39 (s, 1H), 4.26 (s, 2H), 3.15 (td, J=7.2, 5.7 Hz, 2H), 1.51 (h, J=6.7 Hz, 2H), 1.26 (s, 22H), 0.88 (t, J=6.7 Hz, 3H).

[0065] Example 12: Example 12 (1,3-Dipropylurea): CDI (70.00 mmol, 11347 mg), propane-1-amine (175.0 mmol, 14.4 mL), and triethylamine (175.0 mmol, 24.4 mL) were stirred overnight at 60 °C in a dry DCE (50 mL) under argon atmosphere. The reaction mixture was cooled to room temperature, quenched to pH ~1 with 6N HCl, and filtered through a polypropylene sieve to retain water. The mixture was eluted with DCM. The organic filtrate was evaporated to dryness, dissolved in DCM, evaporated under vacuum to ~40 g of rapid silica gel, loaded onto a sampler, and purified by rapid silica gel chromatography (120 g, 10% acetone / DCM (2 CV) → 70% (10 CV)). The fraction containing the product was evaporated under vacuum to dryness to give a white solid, 4663 mg (46% yield). MS (APCI): against chemical formula: C7H 16 The calculated value for N2O(m+H) is 145; the measured value is also 145. 1H NMR (400 MHz, DMSO) δ 6.13 (s, 2H), 2.92 (t, J=7.0 Hz, 4H), 1.35 (h, J=7.3 Hz, 4H), 0.82 (t, J=7.4 Hz, 6H).

[0066] Synthesis of alkylene diamides Example 13 Example 13 (Glutaramide): Glutaryl dichloro (100.0 mmol, 12.8 mL) was dissolved in dry DCE (190 mL) and cooled to 0°C under argon. Without stirring, concentrated ammonium hydroxide (600.0 mmol, 40.0 mL) was added, allowing it to float on top of the DCE layer. After a few minutes, slow stirring was initiated, then gradually increased over ~20 minutes. The organic matter was evaporated, and the residue was dissolved in ~10% MeOH / water. The residue was passed through a C1... 18 Rapid chromatography (meOH / water) with multiple small injections for purification (275 g C) 18 Materials). The fraction containing the pure product was evaporated to dryness under vacuum to give a white solid, 3758 mg (29% yield). It was contaminated with a large amount of amyl acid (major byproduct). MS (APCI): for chemical formula: C5H 10 The calculated value for N2O2 (m+H) is 131; the measured value is also 131. 1H NMR (400 MHz, DMSO) δ 7.23 (s, 2H), 6.70 (s, 2H), 2.03 (t, J=7.5 Hz, 4H), 1.74–1.56 (m, 2H).

[0067] Example 14: Example 14 (Sebacic acid dichloro(50.00 mmol, 10.7 mL)) was dissolved in 100 mL of dry DCE at 0 °C and treated with concentrated ammonium hydroxide (250.0 mmol, 35.7 mL) in a similar manner to the previous steps. The layers were separated by filtration through a polypropylene sieve while retaining water, and DCM was eluted. The DCM was evaporated to dryness under vacuum. The residue was partially dissolved in hot MeOH, cooled in an ice-water bath, then cold filtered, washed with a small amount of MeOH, and dried by suction to give a white solid, 8650 mg (86% yield). MS (APCI): against chemical formula: C 10 H 20 The calculated value for N2O2(m+H) is 201; the measured value is also 201. ¹H NMR (400 MHz, DMF) δ 7.34 (s, 2H), 6.68 (s, 2H), 2.15 (t, J=7.5 Hz, 4H), 1.55 (q, J=7.2 Hz, 4H), 1.28 (d, J=3.1 Hz, 8H).

[0068] Example 15: Example 15 (Octyldiamide): Octyldichlorodichloro (25.00 mmol, 4.5 mL) was dissolved in dry hexane (100 mL) and cooled to -20 °C (meOH / water-ice), then stirring was stopped. Concentrated ammonium hydroxide (125.0 mmol, 8.3 mL) was slowly added to form a layer below the organic layer. Stirring was gradually increased from zero to the maximum RPM over ~15 minutes. The residue was evaporated to dryness, dissolved in methanol, recrystallized / milled with hot MeOH, cooled to room temperature, and the product was filtered off and washed with a small amount of methanol. It contained some ammonium chloride. It was washed with water and then dried by suction to give a white solid, 2879 mg (67% yield). MS (APCI): against chemical formula: C8H 16 The calculated value for N2O2(m+H) is 173; the measured value is also 173. ¹H NMR (400 MHz, DMSO) δ 7.20 (s, 2H), 6.66 (s, 2H), 2.01 (t, J=7.4 Hz, 4H), 1.46 (dq, J=9.6, 6.8 Hz, 4H), 1.23 (p, J=3.6 Hz, 4H).

[0069] Example 16: Example 16 (Azelamide): Azeloyl dichloride (25.00 mmol, 4.9 mL) and concentrated ammonium hydroxide (125.0 mmol, 8.3 mL) were reacted in the same manner as described above, followed by separation and purification in the same manner to give a white solid, 4040 mg (87% yield). MS (APCI): against chemical formula: C9H 18 The calculated value for N₂O₂ (m+H) is 187; the measured value is also 187. ¹H NMR (400 MHz, DMSO) δ 7.20 (s, 2H), 6.65 (s, 2H), 2.01 (t, J=7.4 Hz, 4H), 1.46 (p, J=7.2 Hz, 4H), 1.31–1.12 (m, 6H).

[0070] Example 17: Example 17 (Dodecanoic acid dichloride): Dodecanoic acid dichloride (25.00 mmol, 6.2 mL) and concentrated ammonium hydroxide (125.0 mmol, 8.3 mL) were stirred in dry hexane (100 mL) at -20 °C in the same manner as described above. Separation and purification were performed as before, yielding a white solid, 4040 mg (77% yield). MS (APCI): against chemical formula: C 12 H 24The calculated value for N2O2(m+H) is 229; the measured value is also 229. 1H NMR (400 MHz, DMSO) δ 7.20 (s, 2H), 6.65 (s, 2H), 2.01 (t, J=7.4 Hz, 4H), 1.46 (t, J=7.2 Hz, 4H), 1.23 (s, 12H).

[0071] Preparation of composite materials Composite materials of grafted powder and original inorganic powder Composite materials were prepared by mixing grafted powder with virgin (ungrafted) powder. The grafted powder and virgin (ungrafted) powder were dispersed in ethanol at a desired ratio (0–60 wt% of virgin powder) at a concentration of ~0.1 g / mL. The dispersion was sonicated at room temperature for 30 minutes.

[0072] Composite materials of organic compound powder and original inorganic powder A mixture of inorganic powders such as AlN (Type H, Tokuyama, Japan), h-BN (3–5 µm, 1367HM, SkySpring, USA), and c-BN (1–3 µm, PO6904, MSE Supplies, USA) with an organic compound was ground in acetone using a mortar and pestle. The resulting powder mixture was dried in a vacuum oven at 80 °C for 1–2 hours.

[0073] Preparation of porous Cu / fusible powder composite materials A small amount of the grafted powder or composite dispersion was dropped onto a release PET (2”×2”) sheet (G10JRM, The Tape Casting Warehouse, Inc., Morrisville, PA, USA) placed on a 70°C hot plate. After the EtOH had completely evaporated, a further amount of dispersion was dropped on. A Si wafer was then placed on a 160°C hot plate to melt the powder, and the Si wafer was then placed back on a 70°C hot plate to solidify. Porous Cu (EQ-bccf-80um, MTI corp., Richmond, CA, USA) cut to 1”×1” was sandwiched between the grafted powder-coated PET. The PET / grafted powder / porous Cu / grafted powder / PET was then placed on a 160°C hot plate and manually pressed to melt the powder and fill the pores.

[0074] In some cases, dry powder is directly melted onto a polyimide sheet on a hot plate (~160°C or above the melting point), and a copper mesh is placed on the molten powder. Separately prepared molten powder / polyimide is placed on the copper mesh to form a polyimide / molten powder / copper mesh / molten powder / polyimide structure. This structure is pressed to impregnate the molten powder into the copper mesh, and excess molten powder is extruded.

[0075] Determination of thermal conductivity Thermal conductivity of grafted particles and composite materials k [Wm -1 K -1 The following equation determines the result: Where, α [mm 2 s -1 ]、 C p [JK -1 g -1 ] and ρ [gcm -3 These are thermal diffusivity, specific heat capacity, and bulk density, respectively.

[0076] thermal diffusivity Thermal diffusivity of organic compound powder The thermal diffusivity of the powdered compound was determined using a TWA (Temperature Wave Analyzer, ai-Phase, Japan). The powdered compound was granulated using a 13 mm KBr tableting die (International Crystal Laboratories). The powdered compound was weighed to achieve a final granule thickness of 200–3000 µm, and granulated under vacuum at 100 kN. More specifically, 0.3–0.4 g of the powdered compound was placed into the KBr tableting die, and the die was evacuated for 4 minutes, followed by compression at 100 kN while maintaining vacuum. The thermal diffusivity of the granules was then determined using a TWA.

[0077] Thermal diffusivity of composite materials The composite powder mixture was granulated in the same manner as the powder compound described above. The thermal diffusivity of the granules was then determined using TWA.

[0078] In some cases, thermal diffusivity is determined after the composite powder is melted onto a Si wafer above its melting point and cured at room temperature. The Si wafer / cured powder / glass sample is prepared as follows: The powder is dispersed in ethanol (Aldrich) at a concentration of ~0.1 g / mL, and the dispersion is sonicated at room temperature for 30 minutes. A small amount of dispersion was dropped onto the unpolished side of a Si wafer (2313, University Wafer, 1” diameter, ~280 µm thickness, single-sided polishing) placed on a 70°C hot plate. After the EtOH had completely evaporated, a further amount of dispersion was added. The Si wafer was then placed on a 160°C hot plate to melt the powder, and then placed back on a 70°C hot plate for curing. This process was repeated several times until the amount (thickness) of cured powder was sufficient to create a glass / powder / Si structure with a powder layer thickness of ~200 µm. The Si wafer was then placed in a vacuum oven (160°C) to remove trapped air. Glass beads (150–212 µm) / silicone paste were placed on the Si wafer as spacers, and then a glass plate (~100 µm) was placed on top.

[0079] heat capacity heat capacity ( C p [JK -1 g -1 The samples prepared by the above pressing process were measured using a DSC (TA Instruments Discovery DSC2500).

[0080] Density of organic compound powder The density of the organic compound powder was determined using a gas hydrometer (Ultrapyc 5000 Micro, Anton Paar).

[0081] The density of the composite material was calculated using the mass fraction from thermogravimetric analysis (TA Instruments Discovery TGA550) and the following equation: in, X For quality fraction, and ρ This refers to the specific density of a particular component as determined by a hydrometer.

[0082] result Thermal conductivity of grafted particles The results of the above analysis of the grafted particles are summarized in the table below.

[0083] The results of the thermal conductivity of the bulk mixture of modified TIM and unmodified nanoparticles are shown in the figure. Figure 3 and Figure 4 .

[0084] Thermal conductivity of organic compounds The thermal conductivity of 1-alkylurea, 1,3-dialkylurea and amides is summarized in the table below.

[0085] The thermal conductivity of the composite material of grafted powder and original powder is shown in... Figure 5 The thermal conductivity of the composite material of the original powder and the organic compound powder is shown in Figure 6 .also, Figure 7 and Figure 8 Various thermal properties of the AlN / 1,3-octadecylurea (DODU) composite material are shown.

[0086] Powder XRD characterization: Ungrafted AlN samples received from the supplier, as well as powder samples of AlN with alkyl-linked grafts as described above, were also analyzed by powder X-ray diffraction with Cu K-α radiation (Bruker, D8 Advance [Madison, Wisconsin, USA]) at 1° / min. The X-ray diffraction results are shown in... Figure 7 The appearance of additional diffraction pattern peaks after surface modification with aluminum nitride (AlN) suggests that the TIM layer may have a crystalline structure (most likely, the alkyl chains may be radially aligned). It is believed that the filler is now linked via the high thermal conductivity interface material described herein, thereby achieving high thermal conductivity in the cured fusible powder.

[0087] Powder DSR characterization: Differential scanning calorimetry (DSC) was used to generate thermal analysis data. The sample volume used was between 3 and 5 mg per test. For each test, the temperature was first equilibrated to -20°C. It was then heated to a maximum temperature of 130°C at a rate of 10°C / min. It was then cooled to -10°C at the same rate. From -10°C, it was heated to 130°C at a rate of 10°C / min. This operation was repeated three times.

[0088] Figure 8 The data shown in the graph represents the data generated in the third loop.

[0089] The use of the terms “may” or “may be” should be interpreted as “yes” or “no”, or selectively as a shortened form of “will” or “will not”, etc. For example, the statement “the thermally conductive composite adhesive may further include a backing layer” should be interpreted as, for example, “in some embodiments, the thermally conductive composite adhesive further includes a backing layer”, or “in some embodiments, the thermally conductive composite adhesive does not further include a backing layer”.

[0090] Unless otherwise stated, all figures used in this specification and embodiments to represent the amount, characteristics (such as molecular weight), reaction conditions, etc., of components should be understood to be modified by the term "about" in all cases. Therefore, unless stated to the contrary, the numerical parameters set forth in this specification and the appended embodiments are approximate values ​​and may vary based on the desired characteristics sought. This is not an attempt to limit the application of the principle of equivalence. For the scope of embodiments, each numerical parameter should be interpreted at least according to the number of significant figures reported and by employing conventional rounding methods.

[0091] For the disclosed processes and / or methods, as may be indicated by the context, the functions performed in the processes and methods may be implemented in different orders. Furthermore, the steps and operations outlined are provided by way of example only, and some of the steps and operations may be optional, combined into fewer steps and operations, or extended into additional steps and operations.

[0092] This disclosure may sometimes illustrate different components contained within or connected to different other components. The architecture depicted is merely exemplary, and many other architectures that achieve the same or similar functionality can be implemented.

[0093] The terminology used in this disclosure and the appended embodiments (e.g., the subject of the appended embodiments) is generally intended to be “open” terms (e.g., the term “including” should be interpreted as “including, but not limited to”, the term “having” should be interpreted as “having at least”, the term “includes” should be interpreted as “including, but not limited to”, etc.). Furthermore, if a specific number of elements is introduced, this can be interpreted as meaning at least the number listed, as may be indicated by the context (e.g., in contrast to “two lists” which is a simple list without other modifiers, it means at least two lists or two or more lists). Any transitional words and / or phrases expressing two or more alternative terms as used in this disclosure should be understood to consider the possibility of including one, any, or both of the terms. For example, the phrase “A or B” should be understood to include the possibility of “A” or “B” or “A and B”.

[0094] The terms “a,” “an,” “the,” and similar pronouns used in the context of describing this disclosure (particularly in the context of the following embodiments) should be interpreted to cover both singular and plural forms, unless otherwise stated herein or clearly contradicted by the context. The use of any and all examples or exemplary language (e.g., “such as”) provided herein is intended only to better illustrate this disclosure and does not constitute a limitation on the scope of any embodiment. No language in this specification should be construed as indicating any non-specific element essential for carrying out this disclosure.

[0095] The grouping of alternative elements or embodiments disclosed herein should not be construed as limiting. Each component of a group may be referred to and embodied individually or in any combination with other parts of that group or other elements appearing herein. For convenience and / or patentability reasons, it is contemplated that one or more components of a group may be included in or removed from the group. When any such inclusion or removal occurs, this specification is deemed to contain a modified group, thereby satisfying the written description of the full Markush group used in the appended embodiments.

[0096] This document describes certain embodiments, including the best mode known to the inventors of this application for carrying out this disclosure. Of course, variations of these described embodiments will become apparent to those skilled in the art after reading the foregoing description. The inventors of this application anticipate that those skilled in the art will appropriately employ such variations, and also expect to implement this disclosure in ways different from those specifically described herein. Therefore, embodiments include all variations and equivalents permitted by applicable law of the subject matter listed in the embodiments. Furthermore, unless otherwise stated herein or clearly contradicted by the context, any combination of the foregoing elements in all their possible variations should be considered. Finally, it should be understood that the embodiments disclosed herein are illustrative of the principles of implementation. Other variations that may be employed are within the scope of the embodiments. Therefore, alternative embodiments may be utilized in accordance with the teachings herein, as examples rather than limitations. Therefore, the embodiments are not precisely limited to those shown and described.

Claims

1. Thermal interface material according to formula (1): NP–C5-C 40 alkyl (Equation (1)) Where NP represents inorganic nanoparticles with a thermal conductivity higher than approximately 5 W / mK, and The thermal interface material exhibits a first phase at a first temperature and a second phase at a second temperature.

2. The thermal interface material of claim 1, wherein the ester binds the NP with C3 to C4. 40 Alkyl linkage.

3. The thermal interface material of claim 2, wherein the ester comprises a urethane ester.

4. The thermal interface material of claim 1, wherein the inorganic nanoparticles comprise at least one of silicon dioxide, aluminum oxide, AlN, cBN, MgOH, and MgO.

5. The thermal interface material of claim 4, wherein the inorganic nanoparticles have an average particle size of less than about 30 nm to about 40 nm.

6. The thermal interface material as claimed in claim 1, further comprising a primary amine.

7. The thermal interface material of claim 1, wherein the difference between the first temperature and the second temperature is less than about 10°C.

8. The thermal interface material as claimed in claim 1, comprising one of the following: ， ， ， ， ,and AlN+DODU.

9. The thermal interface material of claim 1, further comprising one or more of at least one urea compound and at least one amide compound.

10. The thermal interface material of claim 9, wherein the urea compound comprises at least one of N-alkylurea and N,N'-dialkylurea, and the amide compound comprises alkylene diamide.

11. The thermal interface material of claim 10, further comprising a porous material selected from at least one of SiO2, Al2O3, MgO, AlN and c-BN.

12. The thermal interface material of claim 1, comprising the NP and C3 to C 40 A mixture of alkyl groups.

13. A polymer matrix comprising a thermal interface material disposed therein according to any one of claims 1-12.

14. Thermally conductive materials, including: Porous materials having one or more cavities; and The thermal interface material according to any one of claims 1-11.

15. The thermally conductive material of claim 14, wherein the porous material comprises copper.

16. A computer structure with dual-phase material, comprising: A substrate having at least a first surface, wherein the first surface includes a surface cavity defined therein; and The thermal interface material according to any one of claims 1-12 is disposed within and fills the surface cavity.

17. The computer structure of claim 16, further comprising a thermal pad having a first thermal pad surface facing the first surface of the substrate, wherein at least 75% of the thermal pad surface is in contact with the first surface of the substrate.

18. A computer structure, which includes: Substrate; At least one computer element located on the substrate; Encapsulation cap; and The first and second layers of thermal interface material; The first layer of thermal interface material is disposed between the substrate and the at least one computer component and the encapsulation cover to provide an increased contact area between the first layer of thermal interface material and the substrate and the at least one computer component; and The second layer of thermal interface material is disposed between the encapsulation cover and the first layer of thermal interface material to provide an additional contact layer between the first layer of thermal interface material and the encapsulation cover.

19. The computer structure of claim 18, wherein the substrate and the at least one computer element have a plurality of cavities.

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