Composite useful for the management of heat and / or electromagnetic interference (EMI), and method of decreasing hardness and / or reducing spreading of material(s), if any, migrating from a composite

Abstract

This invention discloses exemplary thermal interface materials (generally, composites) comprising silane coupling agents for reducing material hardness and / or for reducing the diffusion of material migrating therefrom (if any). Exemplary methods for reducing material hardness and / or reducing the diffusion of material migrating from the composite (if any) are also disclosed, the composite being used to manage thermal and / or electromagnetic interference (EMI). In an exemplary specific example, the composite comprises a matrix, one or more functional fillers within the matrix, and a silane coupling agent within the matrix. Based on the total weight of the composite, the composite contains at least about 0.5% by weight of the silane coupling agent, and / or the composite contains an amount of silane coupling agent sufficient to reduce the hardness of the composite, such that the composite is configured to have high resilience and low compressive strength and / or reduced diffusion of material (if any) migrating from the composite.

Description

Technical Field

[0001] This disclosure relates to thermal interface materials (broadly speaking, complexes) including silane coupling agents for reducing material hardness and / or for reducing the diffusion of material (if any) migrating from them (e.g., reducing oil seepage diffusion, etc.). This disclosure also relates to methods for reducing material hardness and / or reducing the diffusion of material (if any) migrating from the complex for managing thermal and / or electromagnetic interference (EMI). The complex may include thermal management and / or EMI mitigation materials such as thermal interface materials (TIMs) (e.g., low oil seepage and high resilience thermal pads, etc.), EMI absorbers, thermally conductive EMI absorbers, electrically-conductive elastomers (ECEs), conductive complexes, combinations thereof, etc. Prior Technology

[0002] This section provides background information related to this disclosure, which is not necessarily prior art.

[0003] Electrical components such as semiconductors, integrated circuit packages, and transistors typically have pre-designed operating temperatures at which they operate optimally. Ideally, these pre-designed temperatures are close to the ambient air temperature. However, the operation of electrical components generates heat. If this heat is not removed, the components may operate at temperatures significantly higher than their normal or desired operating temperatures. Such excessively high temperatures can adversely affect the operating characteristics of the components and the operation of related devices.

[0004] To avoid or at least reduce adverse operating characteristics arising from heat generation, heat should be removed, for example, by conducting heat from the operating electrical components to a heat sink. The heat sink can then be cooled using conventional convection and / or radiation techniques. During conduction, heat can be transferred from the operating electrical components to the heat sink through direct surface contact between the electrical components and the heat sink, and / or through contact between the electrical components and the heat sink surfaces via an intermediate medium or thermal interface material (TIM). Thermal interface materials can be used to fill the gaps between heat transfer surfaces to increase heat transfer efficiency, compared to using air (a relatively poor thermal conductor) to fill the gaps.

[0005] Another common problem in the operation of electronic devices is the generation of electromagnetic radiation within the device's electronic circuitry. This radiation can lead to electromagnetic interference (EMI) or radio frequency interference (RFI), which can interfere with the operation of other electronic devices within a certain distance. Without adequate shielding, EMI / RFI interference can cause degradation or complete loss of critical signals, resulting in inefficient or inoperable electronic devices.

[0006] As used herein, the term "EMI" should be considered to generally include and refer to both EMI emissions and RFI emissions, and the term "electromagnetic" should be considered to typically include and refer to electromagnetic frequencies and radio frequencies from both external and internal sources. Therefore, the term "shielding" (as used herein) broadly includes and refers to mitigating (or limiting) EMI and / or RFI, such as by absorbing, reflecting, blocking, and / or redirecting energy, or a combination thereof, so that EMI and / or RFI no longer interfere with, for example, government compliance and / or internal functionality of electronic component systems. Summary of the Invention

[0007] In one embodiment, this disclosure provides a composite for managing thermal and / or electromagnetic interference (EMI), the composite comprising a matrix, one or more functional fillers within the matrix, and a silane coupling agent within the matrix, wherein: Based on the total weight of the composite, the composite comprises at least about 0.5% by weight of the silane coupling agent; and / or The composite contains a sufficient amount of the silane coupling agent to reduce the hardness of the composite, thereby configuring the composite to have a high recovery rate and low compressive strength and / or reduce the diffusion of material (if any) migrating from the composite.

[0008] In another embodiment, this disclosure provides a method for reducing hardness and / or reducing diffusion of material (if any) migrating from a composite for managing thermal and / or electromagnetic interference (EMI), the method comprising adding a silane coupling agent to the composite such that, based on the total weight of the composite, the composite comprises at least about 0.5% by weight of the silane coupling agent. Simple Explanation of the Diagram

[0009] The accompanying drawings described herein are for illustrative purposes only for selected specific examples, and not for all possible specific examples, and are not intended to limit the scope of this disclosure.

[0010] [Figures 1 and 2] are photographs of an exemplary thermal interface material (generally a composite) according to an exemplary specific example, which includes a silane coupling agent for reducing material hardness and reducing diffusion of material (if any) migrating from it. As shown in Figures 1 and 2, no oil seepage was observed from the thermal interface material on day 1 (Figure 1) and day 7 (Figure 2) as determined by the coarse absorbent paper method. Implementation

[0011] Example embodiments will now be described more fully with reference to the accompanying drawings.

[0012] As is recognized herein, thermal pads (in a broad sense, thermal interface materials) with low oil permeation, high resilience, and low compressibility are advantageous. Therefore, this paper discloses thermal interface materials (in a broad sense, composites) with low oil permeation, high resilience under low compressibility, and high thermal conductivity (e.g., at least 1 watt per meter per gram von (W / mK), 2 W / mK, 3 W / mK, 4 W / mK, 5 W / mK, greater than 5 W / mK, etc.). The thermal interface materials disclosed herein (e.g., thermal pads, etc.) can be advantageously used at the interface between a heat sink (in a broad sense, a heat dissipation / removal structure) and an integrated circuit (IC) (in a broad sense, a heat source).

[0013] Having grasped the foregoing, this document develops and / or discloses exemplary specific examples of thermal interface materials (broadly, composites), including silane coupling agents, for reducing material hardness and / or for reducing the diffusion of material (if any) migrating from it (e.g., reducing oil seepage diffusion, etc.). Exemplary methods for reducing material hardness and / or reducing the diffusion of material (if any) migrating from the composite are also disclosed, the composite being used to manage thermal and / or electromagnetic interference (EMI). The composite may include thermal management and / or EMI mitigation materials, such as thermal interface materials (TIMs) (e.g., low oil seepage and high resilience thermal pads, etc.), EMI absorbers, thermally conductive EMI absorbers, conductive elastomers (ECEs), conductive composites, combinations thereof, etc.

[0014] Exemplary composites for managing thermal and / or electromagnetic interference (EMI) are disclosed. In an exemplary specific instance, the composite comprises a matrix, one or more functional fillers within the matrix, and a silane coupling agent within the matrix. Based on the total weight of the composite, the composite may include at least about 0.5% by weight of the silane coupling agent. Alternatively, the composite may include a sufficient amount (e.g., at least about 0.5% by weight or more) of the silane coupling agent to reduce the stiffness of the composite, thereby configuring the composite to have a high resilience and low compressive strength, and / or reducing the diffusion of material (if any) migrating from the composite.

[0015] In an exemplary specific instance, the silicone coupling agent is operable to wet the particle surface to promote mixing with the silicone resin (broadly, the matrix) and to form bonds between the resin and the different particles. The amount of silicone coupling agent is preferably sufficiently high or increased to reduce the material hardness of the composite, resulting in a high recovery rate of the composite under low compressive forces. The amount of silicone coupling agent is also preferably sufficiently high or increased to ensure that unreacted polymers bind to the particle surface, thereby preventing unreacted polymers from easily diffusing out of and migrating from the composite.

[0016] In an exemplary specific instance, the silane coupling agent preferably promotes adhesion between the different materials of the composite by forming a durable bond between the organic and inorganic materials. The silane coupling agent preferably reacts with the surface of the functional filler and the matrix resin of the composite and forms an interfacial layer therebetween, which can transfer stress, thereby enhancing the bond strength between them and improving the performance of the composite. The silane coupling agent may also preferably improve the dispersibility during the mixing of the resin and functional filler, and improve the mechanical strength, water and heat resistance, transparency, adhesion, and other properties of the composite.

[0017] In an exemplary specific instance, the complex comprises at least about 0.5% by weight but not more than about 1% by weight of a silane coupling agent. The complex also comprises at least about 0.1% by volume of a silane coupling agent. The complex may include at least about 0.1% by volume but not more than about 0.6% by volume of a silane coupling agent. For example, the complex may comprise about 0.93% by weight and about 0.3% by volume of a silane coupling agent.

[0018] In an exemplary specific example, the silane coupling agent comprises hexadecyltrimethoxysilane or trimethoxyhexadecylsilane having the linear formula H3C(CH2)15Si(OCH3)3. In such an exemplary specific example, the complex comprises at least about 0.5% by weight but not more than about 1% by weight (e.g., about 0.93% by weight, etc.) of hexadecyltrimethoxysilane. For example, the complex may comprise about 0.93% by weight and about 0.3% by volume of hexadecyltrimethoxysilane. Hexadecyltrimethoxysilane has a molecular weight of 346.62 and the chemical formula is as follows.

[0019] In other exemplary embodiments, the silane coupling agent comprises doecyltrimethoxysilane. In such exemplary embodiments, the complex comprises at least about 0.5% by weight but not more than about 1% by weight (e.g., about 0.93% by weight, etc.) of doecyltrimethoxysilane. For example, the complex may comprise about 0.93% by weight and about 0.3% by volume of doecyltrimethoxysilane.

[0020] In an exemplary specific instance, the complex contains a sufficient amount (e.g., at least about 0.5% by weight, etc.) of silane coupling agent to ensure that the unreacted polymer of the complex is bound to the particle surface of one or more functional filler particles, thereby reducing or preventing the diffusion of unreacted polymer (if any) migrating from the complex.

[0021] In an exemplary specific instance, the matrix comprises a silicone resin matrix. The composite contains a sufficient amount (e.g., at least about 0.5% by weight) of a silane coupling agent to improve dispersion during mixing of one or more functional fillers within the silicone resin matrix, to promote adhesion between the silicone resin and one or more functional fillers, and to ensure that unreacted polymers bind to the particle surfaces of one or more functional fillers to prevent unreacted polymers (if any) from easily diffusing out, thereby reducing the silicone oil exudation rate from the composite and making the composite substantially or fully usable without silicone oil migrating or being released beyond the scope of the composite.

[0022] In an exemplary specific instance, the complex includes a sufficient amount (e.g., at least about 0.5% by weight, etc.) of a silane coupling agent such that the complex is configured to have a reduced silicone oil exudation rate of less than 2% over time from the complex, thereby making the complex substantially or fully usable without the silicone oil migrating or being released beyond the scope of the complex.

[0023] In an exemplary specific instance, the composite contains a sufficient amount (e.g., at least about 0.5% by weight, etc.) of a silane coupling agent, such that the composite is configured to have a reduced silicone oil permeation rate of less than 1% over time, as determined by the HT method. As background, the HT method for determining silicone oil permeation rate over time typically includes a weight loss test method. The test procedure is as follows: • Select appropriate samples and sample sizes based on product specifications, cut the product into 1 square inch samples using a circular mold, weigh the cut samples and record the initial weight W0; • Cover both sides of the sample with a single layer of glass fiber; • Cover both sides of the sample with three layers of filter paper; • Place the sample into the oil seepage fixture, select a suitable spacer to control sample compression, and assemble the fixture using an electric screwdriver; • Place the fixture in a 125℃ oven and bake for a fixed time; • After baking, remove the sample, weigh it, and record the final weight W1; and The formula for the oil seepage weight loss test is as follows: Oil seepage weight loss = (initial weight W0 - final weight W1) / initial weight W0 * 100%.

[0024] In an exemplary specific instance, the composite contains a sufficient amount (e.g., at least about 0.5% by weight, etc.) of a silane coupling agent, such that the composite is configured to have a reduced silicone oil bleed rate of about 10% over time on day 12, as determined by the rough blotting paper method. For background, the rough blotting paper method used to determine the silicone oil bleed rate over time primarily involves diameter testing as follows: • Select appropriate samples and sample sizes based on product specifications, cut the product into square-inch samples using die-cutting, and place the samples on blotting paper with the rough side; Place the sample and blotting paper into the fixture, and place a shim to control sample compression; • Place the plastic plate on the top clamp and assemble using an electric screwdriver; • Place the fixture in an oven and bake at 125℃ for a fixed time; Remove the clamps after baking; • Use a ruler or gauge to measure the diameter of the sample and the maximum oil diameter; and • Method for calculating oil penetration area ratio: Oil penetration % = (Diameter of oil penetration mark - Diameter of sample after baking) / Diameter of sample after baking * 100%.

[0025] In an exemplary specific instance, the composite exhibits a high thermal conductivity of at least 1 watt per meter per gram ervin (W / mK), as determined by a hot plate thermal constant analyzer. For example, the composite may have thermal conductivity values ​​of 1 W / mK, 2 W / mK, 3 W / mK, 4 W / mK, 5 W / mK, and greater than 5 W / mK. To determine thermal conductivity, a hot plate instrument can be used, which employs a transient planar source method to measure thermal conductivity, thermal diffusivity, and specific heat capacity. For background, this technique is covered under ISO 22007-2:2008; Part II. This technique utilizes a planar sensor and a specific mathematical model describing thermal conductivity, combined to enable the method to measure the heat transfer characteristics of electronic devices. It typically covers a thermal conductivity range from 0.01 to 500 W / m / K. The transient planar source technique typically employs two sample halves of the sensor. The method can also be used in a single-sided configuration. This technique is versatile and rapid, covering measurements of solids, pastes, thin films, and liquids. This technique can evaluate both isotropic and anisotropic materials. The planar sensor comprises a continuous double helix of conductive nickel metal, etched from a thin foil. The nickel helix is ​​situated between two thin polyimide films (Kapton). During measurement, a constant electrical effect propagates through the conductive helix, increasing the sensor temperature. The generated heat dissipates into the sample on either side of the sensor at a rate dependent on the material's thermal transport properties. By recording the temperature response over time within the sensor, the material's thermal conductivity, thermal diffusivity, and specific heat capacity can be calculated.

[0026] In an exemplary specific instance, the composite comprises one or more functional fillers, which include one or more of the following: thermally conductive fillers; electrically conductive fillers; electromagnetic wave absorbing fillers; dielectric absorbing fillers; and fillers having two or more of the properties of thermal conductivity, electrical conductivity, dielectric absorption and electromagnetic wave absorption.

[0027] In an exemplary specific example, the composite comprises one or more functional fillers, which include one or more alumina fillers within a matrix, such that the composite comprises at least 90% by weight of the one or more alumina fillers. The composite also has a thermal conductivity of at least 1 watt per meter per gram waler. The at least one or more alumina fillers within the matrix may comprise at least three different alumina fillers within the matrix. For example, the at least three different alumina fillers may comprise a first alumina filler having a D50 average particle size of about 2 micrometers, a second alumina filler having a D50 average particle size of about 10 micrometers, and a third alumina filler having a D50 average particle size of about 70 micrometers. Continuing this example, the first alumina filler may comprise alumina spherical particles having a D50 average particle size of about 2 micrometers. The second alumina filler may comprise alumina spherical particles having a D50 average particle size of about 10 micrometers. The third alumina filler comprises alumina spherical particles having a D50 average particle size of about 70 micrometers. As background, the D50 of the particle size distribution is also called the median diameter or median of the particle size distribution, and is the particle size value at 50% of the cumulative distribution. 17

[0028] Based on the total weight of the composite, the composite may comprise approximately 93.3% by weight of a first alumina filler, a second alumina filler, and a third alumina filler. For example, the composite may comprise approximately 23.30% by weight of a first alumina filler, approximately 30% by weight of a second alumina filler, and approximately 40% by weight of a third alumina filler. The composite may comprise approximately 16% by volume to approximately 22% by volume of a first alumina filler, approximately 20% by volume to approximately 28% by volume of a second alumina filler, and approximately 28% by volume to approximately 36% by volume of a third alumina filler. In one exemplary specific example, the composite comprises approximately 19% by volume of a first alumina filler, approximately 24% by volume of a second alumina filler, and approximately 32% by volume of a third alumina filler.

[0029] In an exemplary specific instance, the composite is configured to have a recovery rate of greater than 30% for a thickness of 2.5 mm, a peak force of less than 100 psi (per square inch) for 50% compression, and a residual force of less than 20 psi for 50% compression.

[0030] In an exemplary specific instance, the composite is configured to have: a reduced silicone oil exudation rate of less than 2% over time (determined by the HT method); a deflection of greater than 50% at 30 psi for a 2 mm thickness; a thermal resistance of less than 0.45 at 10 psi for a 1 mm thickness; a hardness of less than 45 Shore 00; and a recovery rate of greater than 30% for a 2.5 mm thickness, a peak force of less than 100 psi for 50% compression, and a residual force of less than 20 psi for 50% compression.

[0031] In an exemplary specific instance, the composite is configured to have: a thermal conductivity of at least 3.4 W / m / g eV as determined by a hot plate thermal constant analyzer; a silicone oil exudation rate reduced over time by less than 1% (e.g., as determined by the HT method) and / or about 10% (e.g., as determined by the coarse absorbent paper method) at day 12; a flexural strength of at least 61% at 30 PSI for a thickness of 2 mm; a thermal resistance of less than 0.318 at 10 PSI for a thickness of 1 mm; a hardness of less than 31 Shore 00; and a recovery rate of at least 46% for a thickness of 2.5 mm, wherein the peak force is less than 25 PSI for 50% compression and the residual force is less than 5.6 PSI for 50% compression.

[0032] In an exemplary specific instance, the composite includes a cross-linked thermally conductive gap pad having a thermal conductivity of at least 3.4 W / m / gelvin, as determined by a hot plate thermal constant analyzer, and an oil permeation rate of approximately 10% on day 12, as determined by a coarse absorbent paper method.

[0033] In an exemplary specific example, the matrix comprises: a first silicone vinyl oil having a first viscosity and a first molar concentration; and a second silicone vinyl oil having a second viscosity higher than the first viscosity and a second molar concentration lower than the first molar concentration. For example, the composite may comprise: about 2.47% by weight of a silicone vinyl oil with a viscosity of 1000 centistokes (cSt) and a molar concentration of 0.11 mmol / g; and about 1.67% by weight of a silicone vinyl oil with a viscosity of 5000 centistokes (cSt) and a molar concentration of 0.06 mmol / g.

[0034] In an exemplary specific example, the complex comprises a crosslinking agent, a chain extender, a catalyst, and an inhibitor. For example, the complex may include about 0.47 wt% of a crosslinking agent, about 1.13 wt% of a chain extender, about 0.01 wt% of a catalyst, and about 0.10 wt% of an inhibitor. The crosslinking agent may comprise polysiloxanes di-MeMe hydrogen. The chain extender may comprise dimethylhydrogen-terminated PDMS. The catalyst may comprise a platinum catalyst. And the inhibitor may comprise a silicone inhibitor.

[0035] In one exemplary specific example, the composite comprises: about 23.3 wt% of a first alumina filler comprising spherical alumina particles having an average particle size D50 of 2 micrometers; about 30 wt% of a second alumina filler comprising spherical alumina particles having an average particle size D50 of 10 micrometers; and about 40 wt% of a third alumina filler comprising spherical alumina particles having an average particle size D50 of 70 micrometers. The composite comprises about 23.30 wt% of the first alumina filler, about 30 wt% of the second alumina filler, and about 40 wt% of the third alumina filler. The composite is configured to have: a thermal conductivity of at least 3.4 W / m / g eV as determined by a hot plate thermal constant analyzer; a silicone oil exudation rate reduced over time by less than 1% (e.g., as determined by the HT method) and / or about 10% (e.g., as determined by the coarse absorbent paper method) at day 12; a flexural strength of at least 61% at 30 PSI for a thickness of 2 mm; a thermal resistance of less than 0.318 at 10 PSI for a thickness of 1 mm; a hardness of less than 31 Shore 00; and a recovery rate of at least 46% for a thickness of 2.5 mm, wherein the peak force is less than 25 PSI for 50% compression and the residual force is less than 5.6 PSI for 50% compression. Continuing with this example, the complex comprises: approximately 2.47% by weight of a silicone vinyl oil with a viscosity of 1000 centistokes (cSt) and a molar concentration of 0.11 mmol / g; approximately 1.67% by weight of a silicone vinyl oil with a viscosity of 5000 centistokes (cSt) and a molar concentration of 0.06 mmol / g; approximately 0.47% by weight of a crosslinking agent; approximately 1.13% by weight of a chain extender; approximately 0.93% by weight of a silane coupling agent; approximately 0.01% by weight of a catalyst; and approximately 0.10% by weight of an inhibitor.

[0036] By way of example only, the table below provides a comparative performance of two conventional thermal pad composites A and B, and a specific example of composite C. Composite C contains at least about 0.5% by weight of a silane coupling agent as disclosed herein. Conventional thermal pad composite A contains 15 to 25% by weight of silicone resin, 0.02 to 0.1% by weight of additives, and 70 to 85% by weight of alumina. Conventional thermal pad composite B contains 5 to 10% by weight of silicone resin, 0.02 to 0.2% by weight of additives, and 85 to 95% by weight of alumina.

[0037] As shown in Table 1 below, among the three composites A, B, and C, exemplary composite C exhibits the highest thermal conductivity of 3.6 W / mK, the lowest oil leakage, and the highest recovery rate of 45%. The conventional thermal pad composite A has a lowest thermal conductivity of 1 W / mK. Generally, higher thermal conductivity is more beneficial for heat conduction. However, other properties are also important, including flexural strength, compressive strength, oil leakage, recovery rate, and volatility. As recognized herein, it is desirable to provide materials with high flexural strength, low compressive strength, low or no oil leakage, and high recovery rate. Furthermore, as further recognized herein, adding more filler load to increase thermal conductivity may increase material stiffness, making the material too stiff to flex and exhibiting high compressive strength. Composites A and C have similar flexural strength versus pressure curves, but composite C has a thermal conductivity of 3.6 W / mK, which is significantly higher than the conventional composite A's 1 W / mK thermal conductivity. At the same pressure, composites A and C have approximately equal flexural strengths and higher flexural strengths than composite B. [complex] Thermal conductivity [Coarse Ink Absorption Paper Oil Bleeding Method] [50%] [compression,] [125ºC] [bake] [HT] [French oil seepage] [50%] [compression,] [125º] [bake] [Response Rate] Day 1 oil Oil on the 3rd day Oil on the 7th day Oil on the second day A 1 W / mK 36% 77% 100% 0.77% twenty one% B 3 W / mK twenty three% 43% 46% 3.98% 3% C 3.6 W / mK 0 0 ≤8% 0.49% 45%

[0038] In exemplary specific instances, thermal interface materials comprise composites as disclosed herein. Thermal interface materials include thermal pads, thermally conductive gap fillers, phase change thermal interface materials, dispensable materials, bulk putty, thermal grease, and thermal interface material sheets. For example, thermal interface materials may include thermal pads having rectangular, triangular, circular, oval, or polygonal shapes. Thermal interface materials may include sheets having rectangular, triangular, circular, oval, or polygonal shapes. Thermal interface materials may include die-cut portions having rectangular, triangular, circular, oval, or polygonal shapes.

[0039] In an exemplary specific instance, the composite includes a thermally conductive filler and an EMI-absorbing filler in the matrix, such that the composite includes a multifunctional EMI absorber having a first function of EMI mitigation and a second function of thermal management, and vice versa. For example, the filler may include one or more of functional nanoparticles, conductive fillers, thermally conductive fillers, EMI or microwave absorbing fillers, magnetic fillers, coated fillers, combinations thereof, etc. The filler may be added to and mixed into a bulk material comprising a matrix material, thereby providing a mixture of filler and base or matrix material. Exemplary fillers include carbon black, boron nitride, nickel cobalt, iron carbonyl, iron silicate, iron particles, iron-chromium compounds, silver, alloys containing 85% iron, 9.5% silicon, and 5.5% aluminum, alloys containing approximately 20% iron and 80% nickel, ferrites, magnetic alloys, magnetic powders, magnetic flakes, magnetic particles, nickel-based alloys and powders, chromium alloys, oxides, copper, zinc oxide, alumina, graphite, ceramics, silicon carbide, manganese-zinc, glass fiber, carbon nanotubes (e.g., single-walled carbon nanotubes, multi-walled carbon nanotubes, and / or carbon nanostructures, etc.), and combinations thereof. Fillers may include one or more of the following: particles, spheres, microspheres, ellipsoids, irregular spheres, strands, flakes, powders, nanotubes, and / or any or any combination of all these shapes. Furthermore, exemplary specific examples may also include the same (or different) fillers of different grades (e.g., different sizes, different purities, different shapes, etc.).

[0040] In an exemplary specific instance, the composite comprises a pad having a rectangular, triangular, oval, circular, or polygonal shape. Alternatively, the composite comprises a sheet having a rectangular, triangular, oval, circular, or polygonal shape. Or, the composite comprises a die-cut part having a rectangular, triangular, oval, circular, or polygonal shape.

[0041] In an exemplary specific instance, the composite is a thermal interface material, an EMI absorber, a thermally conductive absorber, a conductive elastomer, a conductive composite, or a combination of two or more thereof. For example, the composite may be a thermal phase change material, a thermal putty, a thermal grease, a dispensable thermal interface material, and / or a thermal gap filler.

[0042] In an exemplary specific instance, the composite comprises one or more functional fillers, which include one or more of zinc oxide, aluminum oxide, boron nitride, aluminum, silicon carbide and / or aluminum nitride.

[0043] In an exemplary specific instance, the device or system includes a complex as disclosed herein for managing the thermal properties of the device or system.

[0044] Exemplary methods for reducing hardness and / or reducing the diffusion of material (if any) migrating from the composite are also disclosed, the composite being used to manage thermal and / or electromagnetic interference (EMI). In an exemplary specific instance, the method includes adding a silane coupling agent to the composite such that, based on the total weight of the composite, the composite contains at least about 0.5% by weight of the silane coupling agent.

[0045] In an exemplary specific instance, the method includes adding a silane coupling agent (e.g., hexadecyltrimethoxysilane, dodecyltrimethoxysilane, etc.) to the complex such that the complex contains at least about 0.5% by weight but not more than about 1% by weight of the silane coupling agent and / or adding a silane coupling agent to the complex such that the complex contains at least about 0.1% by volume of the silane coupling agent.

[0046] In an exemplary specific instance, the method includes adding a silane coupling agent to the complex such that the complex contains at least about 0.1 vol% but not more than about 0.6 vol% of the silane coupling agent.

[0047] In an exemplary specific instance, the method includes adding a silane coupling agent to the complex such that the complex comprises about 0.93 wt% of the silane coupling agent and about 0.3 vol wt% of the silane coupling agent.

[0048] In an exemplary specific instance, the method configures the complex to have a high recovery rate and low compressibility.

[0049] In an exemplary specific instance, the method includes adding a sufficient amount of silane coupling agent to ensure that the unreacted polymer of the complex binds to the particle surface of one or more functional filler particles of the complex, thereby reducing or preventing the diffusion of unreacted polymer (if any) migrating from the complex.

[0050] In an exemplary specific instance, the composite comprises a silicone resin matrix and one or more functional filler particles within the silicone resin matrix. The method includes adding a sufficient amount of silane coupling agent to improve dispersion during the mixing of more functional filler particles within the silicone resin matrix. This promotes adhesion between the silicone resin and the one or more functional filler particles and ensures that unreacted polymers bind to the particle surfaces of the one or more functional filler particles, preventing unreacted polymers from easily diffusing out, thereby reducing the exudation rate of silicone oil from the composite, making the composite substantially or fully usable, while preventing silicone oil from migrating or being released beyond the scope of the composite.

[0051] Furthermore, the exemplary specific examples disclosed herein can be used in a wide range of industries (e.g., automotive, consumer, industrial, data communications / telecommunications, aerospace / defense, etc.) and a wide range of applications (e.g., automotive electronics, advanced driver-assistance systems (ADAS), automotive powertrain / electronic control units (ECUs), automotive infotainment, routers, hard disk drives, solid-state drives, wireless infrastructure, drones / satellites, gaming systems, smart home devices, laptops / tablets / portable devices, etc.).

[0052] In an exemplary specific instance, the electronic device includes a heat source and a composite disclosed herein, which can be used as a thermal interface material (e.g., a thermally conductive pad, a thermally conductive gap filler, a phase change thermal interface material, a dispensable material, bulk putty, thermal grease, and / or a thermal interface material sheet, etc.). The composite is positioned relative to the heat source to establish at least a portion of a conductive thermal path from the heat source through the composite. The composite may also be configured to absorb and / or conduct EMI, such that the composite is also operable to mitigate and / or manage EMI within the electronic device.

[0053] In an exemplary specific instance, the electronic device includes a heat source, a heat dissipation / cooling structure, and a composite as disclosed herein, which can be used as a thermal interface material (e.g., a thermally conductive pad, a thermally conductive gap filler, a phase change thermal interface material, a dispensable material, bulk putty, thermal grease, and / or a thermal interface material sheet, etc.). The composite is positioned relative to the heat source and the heat dissipation / cooling structure to establish at least a portion of a thermally conductive path between the heat source and the heat dissipation / cooling structure. The composite may also be configured to absorb and / or conduct EMI, such that the composite is also operable to mitigate and / or manage EMI within the electronic device.

[0054] In an exemplary specific instance, the electronic device includes a heat source, a board-level shield, and a composite disclosed herein, which can be used as a thermal interface material (e.g., a thermally conductive pad, a thermally conductive gap filler, a phase change thermal interface material, a dispensable material, bulk putty, thermal grease, and / or a thermal interface material sheet, etc.). The composite is positioned relative to the heat source and the board-level shield to establish at least a portion of a thermally conductive path between the heat source and the board-level shield. The composite can also be configured to absorb and / or conduct EMI, such that the composite is also operable to mitigate and / or manage EMI within the electronic device.

[0055] In an exemplary specific example, the electronic device includes a heat source, a board-level shield, a heat dissipation / cooling structure, and a first composite and a second composite, which can be used as thermal interface materials (e.g., thermal pads, thermal gap fillers, phase change thermal interface materials, dispensable materials, bulk putty, thermal grease, and / or thermal interface material sheets, etc.). The first composite is positioned relative to the heat source and the board-level shield to establish at least a portion of a first thermally conductive path between the heat source and the board-level shield. The second composite is positioned relative to the board-level shield and the heat dissipation / cooling structure to establish at least a portion of a second thermally conductive path between the board-level shield and the heat dissipation / cooling structure. The first composite and / or the second composite may also be configured to absorb and / or conduct EMI, such that the first composite and / or the second composite are also operable to mitigate and / or manage EMI within the electronic device.

[0056] In an exemplary specific example, the electronic device includes integrated circuitry, board-level shielding, a heat sink, and a first and a second composite material, which may be used as thermal interface materials (e.g., thermal pads, thermal gap fillers, phase change thermal interface materials, dispensable materials, bulk putty, thermal grease, and / or thermal interface material sheets, etc.). The first composite material is positioned relative to the integrated circuitry and the board-level shielding to establish at least a portion of a first thermally conductive path between the integrated circuitry and the board-level shielding. The second composite material is positioned relative to the board-level shielding and the heat sink to establish at least a portion of a second thermally conductive path between the board-level shielding and the heat sink. The first and / or second composite materials may also be configured to absorb and / or conduct EMI, such that the first and / or second composite materials are also operable to mitigate and / or manage EMI within the electronic device.

[0057] The exemplary specific examples disclosed herein can be used in conjunction with a wide range of heat sources, electronic devices, and / or heat dissipation / cooling structures or components (e.g., radiators, heat sinks, heat pipes, vapor chambers, device housings, enclosures, or chassis, etc.). For example, a heat source may include one or more heat-generating components or devices, such as high-power integrated circuits (ICs), optical transceivers, 5G infrastructure equipment (e.g., base stations, small cells, smart poles, etc.), solid-state drives (SSDs), memory in video cards, set-top boxes, televisions, gaming systems, automotive electronics for advanced driver assistance systems (ADAS) (e.g., radar, multi-domain controllers, cameras, etc.), CPUs, dies within underfill, semiconductor devices, flip-chip devices, graphics processing units (GPUs), digital signal processors (DSPs), multiprocessor systems, integrated circuits (ICs), multi-core processors, etc. Typically, a heat source may include any component or device having a temperature higher than that of the thermal management and / or EMI mitigation material or otherwise providing or transferring heat to or through the thermal management and / or EMI mitigation material, regardless of whether the heat is generated by the heat source or transferred solely through or via the heat source. Therefore, the embodiments disclosed herein should not be limited to use with any single type of heat source, electronic device, heat dissipation / cooling structure, etc.

[0058] Exemplary specific examples are provided so that this disclosure will be thorough and will fully convey the scope to those skilled in the art. Numerous specific details, such as examples of specific components, apparatuses, and methods, are set forth to provide a thorough understanding of the specific examples of this disclosure. It will be apparent to those skilled in the art that specific details are not required, that the exemplary specific examples may be embodied in many different forms, and that nothing should be construed as limiting the scope of this disclosure. In some exemplary specific examples, well-known processes, well-known apparatus structures, and well-known technologies are not described in detail. Furthermore, advantages and improvements achievable with one or more exemplary specific examples of the invention are provided for illustrative purposes only and do not limit the scope of this disclosure (because the exemplary specific examples disclosed herein may provide all or none of the aforementioned advantages and improvements, and still fall within the scope of this disclosure).

[0059] The specific dimensions, materials, and / or shapes disclosed herein are illustrative in nature and do not limit the scope of this disclosure. The disclosure of specific values ​​and ranges of values ​​for a given parameter herein is not an exhaustive list of other values ​​and ranges of values ​​that may be used in one or more of the examples disclosed herein. Moreover, it is contemplated that any two specific values ​​for a specific parameter described herein may define endpoints of a range of values ​​suitable for the given parameter (i.e., the disclosure of a first and second value for a given parameter may be interpreted as the disclosure that any value between the first and second values ​​may also be used for the given parameter). For example, if parameter X is exemplified herein as having a value A and also exemplified herein as having a value Z, then parameter X is contemplated to have a range of values ​​from about A to about Z. Similarly, the disclosure of two or more ranges of values ​​for a parameter (whether such ranges are nested, overlapping, or distinct) encompasses all possible combinations of ranges of values ​​that may be clamped by the endpoints of the disclosed ranges. For example, if parameter X is exemplified here as having a value in the range of 1-10, 2-9, or 3-8, it is also contemplated that parameter X may have other ranges of values ​​including 1-9, 1-8, 1-3, 1-2, 2-10, 2-8, 2-3, 3-10, and 3-9.

[0060] The terminology used herein is for the purpose of describing particular exemplary instances only and is not intended to be limiting. As used herein, the singular forms "a" and "an" may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprising" and "having" are inclusive, thus specifying the presence of the described features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. The steps, processes, and operations described herein are not to be construed as requiring them to be performed in the particular order discussed or illustrated, unless specifically identified as such. It should also be understood that additional or alternative steps may be employed.

[0061] When an element or layer is referred to as being "on," "engaged with," "connected to," or "coupled" to another element or layer, the element or layer may be directly on, directly engaged with, connected to, or coupled to the other element or layer, or an intervening element or layer may be present. Conversely, when an element is referred to as being "directly on," "directly engaged with," "directly connected to," or "directly coupled to" another element or layer, no intervening element or layer may be present. Other terms used to describe relationships between elements should be interpreted in the same manner (e.g., "between" to "directly between," "adjacent" to "directly adjacent," etc.). As used herein, the term "and / or" includes any and all combinations of one or more of the listed items.

[0062] The term "about," when applied to a value, indicates that a calculation or measurement allows for a slight degree of inaccuracy (close to accurate in value; approximately or reasonably close to the value; nearly). If, for some reason, the inaccuracy provided by "about" is not otherwise understood in that general sense in the field, then "about," as used herein, indicates at least the variation that may arise from common measurement methods or the use of such parameters. For example, the terms "approximately," "about," and "roughly" may be used herein to mean within manufacturing tolerances. Whether modified by the term "about," requests include equivalents of quantity.

[0063] While the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers, and / or parts, these elements, components, regions, layers, and / or parts should not be limited by these terms. These terms may only be used to distinguish one element, component, region, layer, or part from another. Terms such as "first," "second," and other numerical terms, when used herein, do not imply order unless the context clearly indicates otherwise. Thus, the first element, component, region, layer, or part discussed below may be referred to as a second element, component, region, layer, or part without departing from the teaching of the exemplary specific examples.

[0064] Spatially relative terms (such as "inside," "outside," "below," "below," "down," "above," "upper," etc.) are used herein for descriptive convenience to describe the relationship between one element or feature and another element or feature, as illustrated in the accompanying drawings. Spatially relative terms may be intended to include not only the orientation depicted in the drawings but also different orientations of the device in use or operation. For example, if the device in the drawings is rotated, then an element described as "below" or "below" other elements or features will be oriented as "above" other elements or features. Thus, the example term "below" may include both the above and below orientations. The device may be oriented in other ways (rotated 90 degrees or in other orientations), thus explaining the spatially relative descriptors used herein.

[0065] The foregoing description has provided specific examples for illustrative and descriptive purposes. It is not intended to be exhaustive or limiting of this disclosure. Independent elements, intended uses, or features of a particular specific example are typically not limited to that particular specific example, but are interchangeable where appropriate and can be used with the selected specific example (even if that specific example is not specifically shown or described). The same content can also be changed in many ways. Such changes are not considered deviations from this disclosure, and all such modifications are intended to be included within the scope of this disclosure. Industrial applicability

[0066] The composites disclosed herein can reduce material hardness and / or reduce the diffusion of materials (if any) migrating from them (e.g., reduce oil seepage diffusion, etc.). The methods disclosed herein can reduce material hardness and / or reduce the diffusion of materials (if any) migrating from composites that can be used to manage heat and / or electromagnetic interference (EMI).

[0067] none

Claims

1. A composite for managing thermal and / or electromagnetic interference (EMI), the composite comprising a matrix, one or more functional fillers within the matrix, and a silane coupling agent within the matrix, wherein: The silane coupling agent comprises hexadecyltrimethoxysilane; based on the total weight of the composite, the composite comprises at least about 0.5% by weight but not more than about 1% by weight of the hexadecyltrimethoxysilane; the composite comprises at least about 0.1% by volume but not more than about 0.6% by volume of the hexadecyltrimethoxysilane; the one or more functional fillers comprise at least 90% by weight of at least three different alumina fillers, the at least three different alumina fillers comprising: a first alumina filler having a D50 average particle size of about 2 micrometers; a second alumina filler having a D50 average particle size of about 10 micrometers; and a third alumina filler having a D50 average particle size of about 70 micrometers.

2. The complex according to claim 1, wherein the complex comprises about 0.5% by weight of the hexadecyltrimethoxysilane.

3. The complex according to claim 1, wherein the complex comprises about 0.1 vol% of the hexadecyltrimethoxysilane.

4. The complex according to claim 1, wherein the complex comprises about 0.6 vol% of the hexadecyltrimethoxysilane.

5. The complex according to claim 1, wherein the complex comprises about 0.93% by weight of the hexadecyltrimethoxysilane.

6. The complex according to claim 1, wherein the complex comprises about 0.3 vol% of the hexadecyltrimethoxysilane.

7. The complex according to claim 1, wherein the complex comprises about 0.93% by weight of the hexadecyltrimethoxysilane and about 0.3% by volume of the hexadecyltrimethoxysilane.

8. The complex according to claim 1, wherein the hexadecyltrimethoxysilane binds the unreacted polymer to the filler surface.

9. The composite of claim 1, wherein the matrix comprises a silicone resin matrix.

10. The complex according to claim 1, wherein the complex comprises the hexadecyltrimethoxysilane, such that the complex is configured to have a reduced silicone oil exudation rate of less than 2% over time from the complex.

11. The complex according to claim 1, wherein the complex comprises the hexadecyltrimethoxysilane, such that the complex is configured to have a reduced silicone oil exudation rate of less than 1% over time.

12. The complex according to claim 1, wherein the complex comprises the hexadecyltrimethoxysilane, such that the complex is configured to have a reduced time-dependent silicone oil exudation rate of about 10% on day 12.

13. The composite according to claim 1, wherein the one or more functional fillers comprise one or more of the following: thermally conductive fillers; electrically conductive fillers; electromagnetic wave absorbing fillers; and dielectric absorbing fillers.

14. The composite according to claim 13, wherein the one or more functional fillers comprise two or more of the following: thermally conductive fillers; electrically conductive fillers; electromagnetic wave absorbing fillers; and dielectric absorbing fillers.

15. The composite of claim 1, wherein the composite has a thermal conductivity of at least 1 watt per meter per gram von.

16. The complex according to claim 1, wherein: The first alumina filler comprises alumina spherical particles having a D50 average particle size of about 2 micrometers; the second alumina filler comprises alumina spherical particles having a D50 average particle size of about 10 micrometers; and the third alumina filler comprises alumina spherical particles having a D50 average particle size of about 70 micrometers.

17. The composite according to claim 1, wherein, based on the total weight of the composite, the composite comprises approximately 93.3% by weight of the first alumina filler, the second alumina filler, and the third alumina filler.

18. The complex according to claim 1, wherein the complex comprises: Approximately 23.30% by weight of the first alumina filler; approximately 30% by weight of the second alumina filler; And approximately 40% by weight of the third alumina filler.

19. The complex according to claim 1, wherein the complex comprises: The first alumina filler comprises approximately 16 vol% to approximately 22 vol%. The second alumina filler comprises about 20% to about 28% by volume; and the third alumina filler comprises about 28% to about 36% by volume.

20. The complex according to claim 19, wherein the complex comprises: Approximately 19% by volume of the first alumina filler; approximately 24% by volume of the second alumina filler; And approximately 32% by volume of the third alumina filler.

21. The composite according to any one of claims 1 to 20, wherein the composite is configured to have a recovery rate of more than 30% for a thickness of 2.5 mm, a peak force of less than 100 PSI for 50% compression, and a residual force of less than 20 PSI for 50% compression.

22. The composite according to any one of claims 1 to 20, wherein the composite has a thermal conductivity of at least 2 watts per meter per gram von.

23. The composite according to any one of claims 1 to 20, wherein the composite is configured to have: a reduced silicone oil exudation rate of less than 2% over time; a deflection of greater than 50% for a thickness of 2 mm at 30 psi; a thermal resistance of less than 0.45 for a thickness of 1 mm at 10 psi; a hardness of less than 45 Shore 00; and a recovery rate of greater than 30% for a thickness of 2.5 mm, a peak force of less than 100 psi for 50% compression, and a residual force of less than 20 psi for 50% compression.

24. The composite according to any one of claims 1 to 20, wherein the composite is configured to have: a thermal conductivity of at least 3.4 W / m / g ervin; a silicone oil exudation rate of less than 1% and / or about 10% at day 12; a flexural strength of at least 61% at 30 PSI for a thickness of 2 mm; a thermal resistance of less than 0.318 at 10 PSI for a thickness of 1 mm; a hardness of less than 31 Shore 00; and a recovery rate of at least 46% for a thickness of 2.5 mm, a peak force of less than 25 PSI for 50% compression, and a residual force of less than 5.6 PSI for 50% compression.

25. The composite according to any one of claims 1 to 20, wherein the composite comprises a cross-linked thermally conductive spacer having a thermal conductivity of at least 3.4 W / m and an oil permeation rate of about 10% on day 12.

26. The composite according to any one of claims 1 to 20, wherein the composite comprises a thermally conductive gap pad.

27. A method for reducing hardness and / or reducing diffusion of material migrating from a composite in the presence of such material, the composite being used to manage thermal and / or electromagnetic interference (EMI), the method comprising adding a silane coupling agent comprising hexadecyltrimethoxysilane to the composite such that, based on the total weight of the composite, the composite comprises at least about 0.5% by weight but not more than about 1% by weight of the hexadecyltrimethoxysilane, and such that the composite comprises at least about 0.1% by volume but not more than about 0.6% by volume of the hexadecyltrimethoxysilane, wherein the composite comprises at least 90% by weight of at least three different alumina fillers, the at least three different alumina fillers comprising: a first alumina filler having a D50 average particle size of about 2 micrometers; a second alumina filler having a D50 average particle size of about 10 micrometers; and a third alumina filler having a D50 average particle size of about 70 micrometers.

28. The method according to request item 27, wherein: The first alumina filler comprises alumina spherical particles having a D50 average particle size of about 2 micrometers; the second alumina filler comprises alumina spherical particles having a D50 average particle size of about 10 micrometers; and the third alumina filler comprises alumina spherical particles having a D50 average particle size of about 70 micrometers.

29. The method of claim 27, wherein the method comprises adding the hexadecyltrimethoxysilane to the complex such that the complex comprises about 0.93% by weight of the hexadecyltrimethoxysilane.

30. The method of claim 27, wherein the method comprises adding the hexadecyltrimethoxysilane to the complex such that the complex comprises about 0.3 vol% of the hexadecyltrimethoxysilane.

31. The method of claim 27, wherein the method comprises adding the hexadecyltrimethoxysilane to the complex such that the complex comprises about 0.93% by weight and about 0.3% by volume of the hexadecyltrimethoxysilane.

32. The method according to claim 27, wherein the composite has a thermal conductivity of at least 2 watts per meter per gram von.

33. The method according to claim 27, wherein the composite is configured to have: a hardness of less than 45 Shore 00; and a recovery rate of more than 30% for a thickness of 2.5 mm, a peak force of less than 100 PSI for 50% compression, and a residual force of less than 20 PSI for 50% compression.

34. The method of claim 27, wherein the hexadecyltrimethoxysilane binds the unreacted polymer to the filler surface.

35. The method according to any one of claims 27 to 34, wherein the composite comprises a silicone resin matrix.

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