Electrically insulating and thermally conductive particles, electrically insulating and thermally conductive polymers containing the same, and producing methods of the electrically insulating and thermally conductive particles

Abstract

An electrically insulating and thermally conductive particle includes a cross-linked modified-boron nitride. The cross-linked modified-boron nitride includes a reaction product of boron nitride particles, a coupling agent, and a cross-linking agent, wherein the weight ratio of the boron nitride accounts for at least 92wt% of the cross-linked modified-boron nitride. The average particle size of the electrically insulating and thermally conductive particles is

Description

[Technical Field]

[0001] This invention relates to the field of heat conduction, and to an insulating thermally conductive particle, an insulating thermally conductive polymer comprising the same, and a method for manufacturing the insulating thermally conductive particle. [Previous Technology]

[0002] With the development of various electronic components, the increase in high-frequency applications and the improvement of computing power are accompanied by an increase in heat generation. At the same time, due to the miniaturization and thinning of modern electronic devices, the internal space of the devices has been reduced and the density of electronic components has increased, making it easier for electronic components to overheat and fail. Therefore, heat dissipation has become an increasingly important issue.

[0003] The housings of electronic components or the molding materials of special packaging often enhance the heat conduction effect by adding thermally conductive particles. Metal particles are commonly used, but they are prone to metal shielding effect or short circuit problems. If ceramic thermally conductive particles are used instead, there is a limit to the proportion that can be added. Otherwise, the molding material will be difficult to form. However, if the proportion added is not enough, the improvement in heat dissipation effect is still limited. [Summary of the Invention]

[0004] An insulating and thermally conductive particle is provided herein. The insulating and thermally conductive particle comprises cross-linked modified boron nitride. The cross-linked modified boron nitride comprises boron nitride particles, a coupling agent, and a product of the cross-linking agent reaction, wherein the boron nitride accounts for at least 92 wt% of the total weight of the cross-linked modified boron nitride. The coupling agent is selected from the group consisting of oxysilane coupling agents, titanate coupling agents, isocyanate coupling agents, and phosphate coupling agents, and the cross-linking agent is selected from the group consisting of aromatic or aliphatic compounds containing two or more reactive functional groups, the reactive functional groups including carboxy group, anhydride group, amine group, hydroxy group, or isocyanate group. The average particle size of the insulating and thermally conductive particle is 1800 to 4200 nm, and 90% of the total particle size (D90) is less than 6000 nm. The density of the insulating and thermally conductive particles ranges from 2.8 g / cm³ to 3.5 g / cm³.

[0005] Hereinafter, an insulating and thermally conductive polymer is also provided, comprising the aforementioned insulating and thermally conductive particles and a polymer material as a substrate. The insulating and thermally conductive particles are dispersed in the polymer material, accounting for 70 to 90 wt% of the total weight of the insulating and thermally conductive polymer, and the thermal conductivity of the insulating and thermally conductive polymer is greater than 2.25 W / m*K.

[0006] In some embodiments, a method for manufacturing insulating and thermally conductive particles is further provided. The method for manufacturing insulating and thermally conductive particles includes a delamination step, a modification step, a crosslinking step, and a pulverization step. The delamination step involves adding boron nitride particles and a first solvent to a reaction flask and ultrasonically agitating for at least three hours to obtain a plurality of delamination boron nitride particles. The modification step involves adding a coupling agent to a reaction flask and heating it to reflux with the delamination boron nitride particles to react and obtain a plurality of modified boron nitride particles. The weight ratio of the coupling agent to the boron nitride particles is 0.01 to 0.1, and the coupling agent is selected from the group consisting of oxysilane coupling agents, titanate coupling agents, isocyanate coupling agents, and phosphate coupling agents.

[0007] The crosslinking step involves adding modified boron nitride particles, a second solvent, and a crosslinking agent to a reaction flask, mixing, and heating under reflux to obtain crosslinked modified boron nitride particles. The weight ratio of the crosslinking agent to the modified boron nitride particles is 0.03 to 0.08. The crosslinking agent is selected from the group consisting of aromatic or aliphatic compounds containing two or more reactive functional groups, including carboxy, anhydride, amine, hydroxy, or isocyanate groups. The pulverization step involves removing the crosslinked modified boron nitride particles, drying them, and pulverizing them to obtain a plurality of insulating and thermally conductive particles with an average particle size of 1800 to 4200 nm and a cumulative total particle size (D90) of less than 6000 nm.

Implementation Method

[0008] Exemplary embodiments will now be described in detail with reference to the accompanying drawings to facilitate implementation by those skilled in the art. The overall inventive concept can be embodied in various forms, and is not limited to the exemplary embodiments described herein.

[0009] In addition, the terms "first", "second", and "third" are used only to distinguish one element, component, region, layer or part from another element, component, region, layer or part, and do not indicate their necessary order.

[0010] Figure 1 is a flowchart of a method for manufacturing insulating and thermally conductive particles. As shown in Figure 1, a method S1 for manufacturing insulating and thermally conductive particles is provided herein. The method S1 for manufacturing insulating and thermally conductive particles includes a delamination step S10, a modification step S20, a crosslinking step S30, and a pulverization step S40.

[0011] The delamination step S10 involves adding boron nitride particles and a first solvent to a reaction flask, and then shaking it in an ultrasonic oscillator for at least three hours to generate delamination boron nitride particles. This change can be inferred from the increase in the average particle size of the boron nitride particles, as the oscillation disrupts the van der Waals forces between the layers of boron nitride. Here, boron nitride can be of different crystal forms, such as hexagonal boron nitride (α-BN), cubic boron nitride (β-BN), zincblende boron nitride, or wurtzite boron nitride.

[0012] The modification step S20 involves adding a coupling agent to a reaction flask and heating it to create a reflux between the coupling agent and the delaminated boron nitride particles, thereby modifying the surface of the delaminated boron nitride particles and obtaining a plurality of modified boron nitride particles. The weight ratio of the coupling agent to the boron nitride particles can be from 0.01 to 0.1, for example, 0.01 to 0.08, 0.01 to 0.05, 0.02 to 0.08, or 0.03 to 0.06; and the coupling agent contains a modifying functional group selected from the group consisting of siloxane, titanate, isocyanate, and phosphate groups. After modification step S20, the modified boron nitride particles are more plump than the delaminated boron nitride particles, and the overall particle size is increased.

[0013] In some embodiments, the modification step is a modification reaction carried out by heating and refluxing at a temperature above 60 degrees Celsius for at least 1.5 hours. However, this is only an example and not intended to limit the scope.

[0014] More specifically, in some embodiments, the coupling agent system may be an oxysilane coupling agent, a titanate coupling agent, an isocyanate coupling agent, a phosphate coupling agent, or a combination thereof. For example, the coupling agent system can be 3-Aminopropyltriethoxysilane (APTES), γ-3-Aminopropyltriethoxysilane (γAPTES), γ-3-Methacryloxypropyltrimethoxysilane, γ-3-Aminopropyltrimethoxysilane, Vinyltriethoxysilane, (3-Glycidyloxypropyl)trimethoxysilane (GPTMS), Tetra-isopropyl titanate, Tetra-butyl titanate, Toluene diisocyanate (TDI), or Methylenediphenyl diisocyanate. diisocyanate (MDI), ethoxy phosphate, or combinations thereof.

[0015] The crosslinking step S30 involves mixing a plurality of modified boron nitride particles, a second solvent, and a crosslinking agent, causing the crosslinking agent and modified boron nitride particles to undergo a crosslinking reaction. The mixture is then heated (e.g., above 80°C) and refluxed (e.g., for 1.5 hours or more) to obtain crosslinked modified boron nitride particles. Here, the crosslinked modified boron nitride particles can be in large lumps. The weight ratio of the crosslinking agent to the modified boron nitride particles can be from 0.03 to 0.08, for example, from 0.03 to 0.07. The crosslinking agent can be selected from the group consisting of aromatic or aliphatic compounds containing two or more reactive functional groups, including carboxy, anhydride, amine, hydroxy, or isocyanate groups. The pulverizing step S40 involves removing the crosslinked modified boron nitride particles, drying them, and then pulverizing them to obtain insulating and thermally conductive particles. The insulating and thermally conductive particles obtained in the pulverization step S40 have an average particle size of 1800 to 4200 nm, and 90% of the total particle size (D90) is 5000 to 7000 nm. In addition, the particle size (D10) is 1500 to 2000 nm, and 50% of the total particle size (D50) is 2000 to 3000 nm.

[0016] In some embodiments, the first solvent does not react with the coupling agent. For example, in some embodiments, the first solvent may be water, alcohol, isopropanol, acetone, isoacetone, or a combination thereof. The second solvent may be toluene or ethylbenzene.

[0017] More specifically, in some embodiments, the crosslinking agent system may be N-(oxiranylmethyl)-N-phenyl-Oxiranemethanamine, 1,3-propanediol, 2,3,4-trimethyl-1,3-pentanediol, 2-butene-1,4-diol, 1,4-butanediol, 1,3-butanediol, or 1,5-pentanediol. diol), 1,6-hexanediol, 1,2-cyclohexanedimethanol, 1,2-hexanediol, 1,3-hexanediol, 2-methyl-1,3-propanediol, 2,5-hexanediol, 2-methyl-1,3-pentanediol, 2-methyl-2,4-pentanediol, ethylene glycol The following are alcohols: glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, tripropylene glycol, glycerol, polyglycerol, ethylene carbonate, and 1,2-propylene carbonate, or combinations thereof.

[0018] Insulating and thermally conductive particles can be obtained by the above manufacturing method. The insulating and thermally conductive particles comprise cross-linked modified boron nitride. The cross-linked modified boron nitride comprises boron nitride, a coupling agent, and the product of the reaction of the cross-linking agent, wherein the boron nitride accounts for at least 92 wt% of the total weight of the cross-linked modified boron nitride, the coupling agent is selected from the group consisting of oxysilane coupling agents, titanate coupling agents, isocyanate coupling agents, and phosphate coupling agents, and the cross-linking agent is selected from the group consisting of aromatic or aliphatic compounds containing two or more reactive functional groups, wherein the reactive functional groups include carboxy group, anhydride group, amine group, hydroxy group, or isocyanate group.

[0019] According to an embodiment of the present invention, the density of the insulating and thermally conductive particles disclosed in the present invention is tested and found to be in the range of 2.8 g / cm3 to 3.5 g / cm3.

[0020] Through particle size analysis, the average particle size of the insulating and thermally conductive particles is 1800 to 4200 nm, and 90% of the total particle size (D90) is less than 6000 nm. In some embodiments, the average particle size of the insulating and thermally conductive particles is 3750 nm. In some embodiments, 10% of the total particle size (D10) of the insulating and thermally conductive particles is less than 1750 nm, and 50% of the total particle size (D50) of the insulating and thermally conductive particles is less than 2500 nm.

[0021] In some embodiments, the specific surface area of ​​the insulating thermally conductive particles ranges from 2 to 25 m² / g.

[0022] Further, by mixing the insulating and thermally conductive particles into a polymer material, an insulating and thermally conductive polymer can be obtained. More specifically, the insulating and thermally conductive polymer comprises the aforementioned insulating and thermally conductive particles, and a polymer material. The insulating and thermally conductive particles are dispersed in the polymer material, accounting for 50 to 90 wt% (e.g., 70 to 90 wt%) of the total weight of the insulating and thermally conductive polymer, and the thermal conductivity of the insulating and thermally conductive polymer is greater than 2.25 W / m*K.

[0023] In some embodiments, the polymer material is selected from the group consisting of polydimethylsiloxane (PDMS), thermoplastic polyurethane (TPU), butyl rubber (IIR), ethylene propylene rubber (EPDM), styrene-butadiene rubber (SBR), acrylic rubber (ACM), and fluororubber (FKM).

[0024] In some embodiments, the density of the insulating and thermally conductive polymer is between 2.75 and 3.25 g / cm3.

[0025] In some embodiments, the thermal diffusivity of the insulating and thermally conductive polymer is greater than 0.95 mm² / s.

[0026] In some embodiments, the specific heat capacity of the insulating and thermally conductive polymer is between 0.78 and 1.10 J / g*K.

[0027] In order to make the above-mentioned contents and other objects, features and advantages of this disclosure more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings.

[0028] Manufacturing of insulating and thermally conductive particles

[0029] Example 1

[0030] First, 15g of hexagonal boron nitride particles and 3kg of 50% IPA aqueous solution are placed in a reaction flask, and then placed in an ultrasonic oscillating tank for 6 hours to carry out the delamination step S10 to obtain delaminated boron nitride.

[0031] Next, epoxypropyltrimethoxysilane ((3-Glycidyloxypropyl)trimethoxysilane, GPTMS) is added to modify the surface of the delaminated boron nitride, wherein the weight ratio of GPTMS to boron nitride is 0.045:1.5. The mixture is heated under reflux for two hours to carry out the modification step S20. After filtration and drying, modified boron nitride particles are obtained.

[0032] Next, 1.5 g of the filtered and dried modified boron nitride particles were mixed with 0.05 g of N-(epoxypropyl)-N-phenyl-epoxyethylene methylamine and added to 100 g of toluene for crosslinking step S30. The mixture was heated under reflux for about two hours. Finally, the crosslinked modified boron nitride particles were obtained by filtration and drying, and then pulverized using a pulverizer at a speed of 12000 rpm to obtain insulating and thermally conductive particles (I).

[0033] The boron nitride particles obtained in each stage of Example 1 were analyzed using a particle size analyzer (model nanoSAQLA+AS50, Otsuka Technology). The results are shown in Table 1 below.

[0034] Table 1 Average particle size (nm) (Cumulative calculation) Average particle size (nm) (Histogram distribution) D10(nm) D50(nm) D90(nm) Hexagonal boron nitride particles 500 550 275 325 475 Delamination of boron nitride particles 700 700 350 850 850 Modified boron nitride particles 950 950 550 750 1000 Insulating and thermally conductive particles (I) 3000 3750 1750 2500 6000

[0035] It is understandable that the hexagonal boron nitride particles, through delamination, modification, and cross-linking processes, result in a larger overall particle structure. This can be verified by the increased particle size of boron nitride particles at each stage, as shown in Table 1. Specifically, hexagonal boron nitride particles account for at least 92 wt% (weight percentage) of the total cross-linked modified boron nitride, with the remainder being coupling agent, or residual components from the reaction between the cross-linking agent and the boron nitride raw material. Furthermore, the overall density decreases due to the increased particle size of the boron nitride molecules.

[0036] Example 2

[0037] Example 2 was carried out according to the steps and conditions described in Example 1, but 1.5 g of the filtered and dried modified boron nitride particles were mixed and reacted with 0.1 g of N-(epoxypropyl)-N-phenyl-epoxymethylamine. Insulating and thermally conductive particles (II) were obtained.

[0038] Example 3

[0039] The above-delaminated boron nitride was modified with 3-Aminopropyltriethoxysilane (APTES) as a coupling agent, wherein the weight ratio of APTES to boron nitride was 0.045:1.5. The mixture was heated and refluxed at 80°C for two hours to carry out the modification step S20. After filtration and drying, modified boron nitride particles were obtained.

[0040] Next, 1.5 g of the filtered and dried modified boron nitride particles were mixed with 0.05 g of N-(epoxypropyl)-N-phenyl-epoxyethylene methylamine, and added to 100 g of toluene for crosslinking step S30. The mixture was heated and refluxed at 80 °C for about two hours. Finally, the filtered and dried crosslinked modified boron nitride particles were pulverized in a pulverizer at a speed of 12000 rpm to obtain insulating and thermally conductive particles (III).

[0041] Example 4

[0042] Example 4 was carried out according to the steps and conditions described in Experiment 3, but 1.5 g of the filtered and dried modified boron nitride particles were mixed with 0.1 g of N-(epoxypropyl)-N-phenyl-epoxymethylamine and reacted to obtain insulating and thermally conductive particles (IV).

[0043] Manufacturing of insulating and thermally conductive polymers

[0044] Examples 5-Examples 10

[0045] The above insulating and thermally conductive particles (I)-(IV) were mixed in polydimethylsiloxane (PDMS, purchased from Ziyue Silicon Photonics) polymer material with different doping ratios, wherein the proportion of PDMS was adjusted according to the particle filling rate (as shown in Table 2 below) to obtain insulating and thermally conductive polymers (1)-(6).

[0046] Comparative Examples 1-6

[0047] The boron nitride particles in Comparative Examples 1 and 2 were modified boron nitride particles from Examples 1 and 3 (reacted with GPTMS and APTES coupling agents respectively), but were uncrosslinked modified hexagonal boron nitride particles that were not crosslinked; Comparative Example 3 consisted of undelaminated, unmodified, and uncrosslinked boron nitride particles; the S-BN (S-boron nitride) in Comparative Examples 4 and 5 consisted of hexagonal boron nitride particles that were only delaminated but not modified or crosslinked. Comparative Example 6 involved mixing the insulating and thermally conductive particles of the present invention into PDMS, but the particle filling rate was only 60%.

[0048] The test results of the relevant properties of various insulating and thermally conductive particles are shown in Table 2. Density was measured using an Ohaus PX223ZH density meter. First, the liquid (Heptane) density was set, then the weight of the sample in air was measured, and finally the weight of the sample in the liquid was measured to calculate the sample density. Thermal diffusivity was measured using a Netzsch LFA 447 laser scanner. First, the sample thickness was measured and the dimensions confirmed; then, graphite was uniformly sprayed onto the test sample; finally, the instrument measurement parameters were set, and the thermal diffusivity was calculated using software. Specific heat capacity was measured using a TA DSC 250 specific heat capacity meter. First, the sample was weighed and placed in a platinum pan for ingot forming; then, the DSC heating conditions were set (20℃ / min) and the test was conducted; finally, three data points were measured: the empty pan, the standard (sapphire), and the sample, and the specific heat capacity was calculated using software. Thermal conductivity is calculated using the formula K(W / m*K)=α(mm2 / s)*ρ(g / cm3)*Cp(J / g*K), where α is the thermal diffusivity, ρ is the density, and Cp is the specific heat capacity.

[0049] Table 2 Insulating thermally conductive particles Particle filling rate (%) Weight of insulating and thermally conductive particles (g) PDMS weight (g) Insulating and thermally conductive polymers Density (g / cm³) 3 ) Thermal diffusivity (mm) 2 / s) Specific heat capacity (J / g*K) Thermal conductivity (W / m*K) Example 5 (I) 75 7.5 2.5 (1) 3.013 0.957 0.798 2.30 Example 6 (II) 75 7.5 2.5 (2) 2.897 0.954 0.886 2.45 Example 7 (II) 80 8.0 2.0 (3) 2.974 0.984 1.096 3.21 Example 8 (III) 75 7.5 2.5 (4) 2.825 1.036 0.803 2.35 Example 9 (IV) 75 7.5 2.5 (5) 2.904 0.962 0.956 2.67 Example 10 (IV) 80 8.0 2.0 (6) 3.021 1.127 1.096 3.45 Comparative Example 1 Uncrosslinked modified BN particles 75 7.5 2.5 (7) 2.893 0.905* 0.802 2.10* Comparative Example 2 Uncrosslinked modified BN particles 75 7.5 2.5 (8) 2.833 0.943* 0.805 2.15* Comparative Example 3 Undelaminated / uncrosslinked / unmodified BN particles 75 7.5 2.5 (9) 2.526 0.953 0.831 2.00* Comparative Example 4 S-BN particles 75 7.5 2.5 (10) 2.531 0.957 0.879 2.13* Comparative Example 5 S-BN particles 80 8.0 2.0 (11) 2.534 Membrane material rupture cannot be measured Comparative Example 6 (I) 60 6.0 4.0 (12) 2.857 0.957 0.794 2.17*

[0050] Here, the particle filling rate is the weight percentage of insulating and thermally conductive particles to insulating and thermally conductive polymer (insulating and thermally conductive particles / (insulating and thermally conductive particles + polymer material) x 100%). Furthermore, the insulating and conductive polymer must meet thermal conductivity specifications such as a thermal conductivity greater than 2.25 (W / m*K), a thermal diffusivity greater than 0.95 mm² / s, and / or a specific heat capacity between 0.78 and 1.10 J / g*K to be of practical value. Comparative Examples 1-6 failed to meet the thermal conductivity standards (indicated by * in Table 2). In addition, regarding the material formulation, if the filling rate of the insulating and thermally conductive particles in the comparative examples is increased to slightly more than 75%, for example, to between 78% and 80%, it will result in the polymer failing to form a film (e.g., Comparative Example 5), and thus cannot be formed. Therefore, the required thermal conductivity effect cannot be achieved by filling with more thermally conductive particles.

[0051] In summary, by delaminating, modifying, and crosslinking boron nitride particles to produce insulating and conductive particles, the spacing between boron nitride layers can be increased (this can be inferred from the increase in the average particle size of boron nitride particles at each stage in Table 1). This makes it easier for the insulating and conductive particles to form bonds with polymer materials and improves the compatibility between the insulating and thermally conductive particles and polymer materials. As a result, the weight ratio of the insulating and thermally conductive particles added to the polymer matrix can reach more than 70%, thereby effectively improving the thermal conductivity of the thermally conductive polymer and enhancing its thermal conductivity properties, making it more suitable for application in high-frequency, high-power electronic devices.

[0052] Although the technical content of the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any modifications and refinements made by those skilled in the art without departing from the spirit of the present invention should be included within the scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims. [Simplified Explanation of the Diagram]

[0053] Figure 1 is a flowchart of the manufacturing method of insulating thermally conductive particles.

Claims

1. An insulating and thermally conductive particle, comprising: The cross-linked modified boron nitride is a product comprising boron nitride particles, a coupling agent, and a cross-linking agent, wherein the boron nitride particles account for at least 92 wt% of the total weight of the cross-linked modified boron nitride; wherein the coupling agent is selected from the group consisting of oxysilane coupling agents, titanate coupling agents, isocyanate coupling agents, and phosphate coupling agents; and the cross-linking agent is selected from the group consisting of aromatic or aliphatic compounds containing two or more reactive functional groups, wherein the reactive functional groups include carboxyl, acid anhydride, amino, hydroxyl, or isocyanate groups; wherein the average particle size of the insulating and thermally conductive particles is 1800 to 4200 nm, and 90% of the total particles have a size (D90) of less than 6000 nm.

2. The insulating thermally conductive particles as described in claim 1, wherein the average particle size of the insulating thermally conductive particles is 3500 to 4000 nm.

3. The insulating thermally conductive particles as described in claim 1, wherein 10% of the total number of the insulating thermally conductive particles has a particle size (D10) of less than 1750 nm, and 50% of the total number of the insulating thermally conductive particles has a particle size (D50) of less than 2500 nm.

4. The insulating thermally conductive particles as claimed in claim 1, wherein the specific surface area of ​​the insulating thermally conductive particles is 2 to 25 m² / g and the density is 2.8 g / cm³ to 3.5 g / cm³.

5. An insulating and thermally conductive polymer, comprising: a plurality of insulating and thermally conductive particles as described in any one of claims 1 to 4, wherein the insulating and thermally conductive particles account for 70 to 90 wt% of the total weight of the insulating and thermally conductive polymer; and a polymer material, wherein the insulating and thermally conductive particles are dispersed in the polymer material; wherein the thermal conductivity of the insulating and thermally conductive polymer is greater than 2.25 W / m*K.

6. The insulating and thermally conductive polymer as claimed in claim 5, wherein the polymer material is selected from the group consisting of polydimethylsiloxane, thermoplastic polyurethane, butyl rubber, ethylene propylene rubber, styrene-butadiene rubber, acrylic rubber, and fluororubber.

7. The insulating and thermally conductive polymer as described in claim 5, wherein the density of the insulating and thermally conductive polymer is between 2.75 and 3.25 g / cm3, the thermal diffusivity of the insulating and thermally conductive polymer is greater than 0.95 mm2 / s, and the specific heat capacity of the insulating and thermally conductive polymer is between 0.78 and 1.10 J / g*K.

8. The insulating and thermally conductive polymer as claimed in claim 5, wherein the insulating and thermally conductive particles account for 70 to 80 wt% of the total weight of the insulating and thermally conductive polymer.

9. A method for manufacturing insulating and thermally conductive particles, comprising: a delamination step, wherein a plurality of boron nitride particles and a first solvent are added to a reactor and ultrasonically vibrated for at least three hours to obtain a plurality of delaminated boron nitride particles; and a modification step, wherein a coupling agent is added to the reactor and heated under reflux with the delaminated boron nitride particles to obtain a plurality of modified boron nitride particles, wherein the weight ratio of the coupling agent to the boron nitride particles is 0.01 to 0.1, and wherein the coupling agent is selected from the group consisting of oxysilane coupling agents, titanate coupling agents, isocyanate coupling agents, and phosphate coupling agents; A crosslinking step involves mixing the modified boron nitride particles, a second solvent, and a crosslinking agent, and heating under reflux to obtain crosslinked modified boron nitride particles, wherein the weight ratio of the crosslinking agent to the modified boron nitride particles is 0.03 to 0.08, and the crosslinking agent is selected from the group consisting of aromatic or aliphatic compounds containing two or more reactive functional groups, including carboxy groups, acid anhydrides, amino groups, hydroxyl groups, or isocyanate groups; and a pulverizing step involves removing the crosslinked modified boron nitride particles, drying them, and pulverizing them to obtain a plurality of insulating and thermally conductive particles with an average particle size of 1800 to 4200 nm and a cumulative total of 90% of the particles having a particle size (D90) of 5000 to 7000 nm.

10. A method for manufacturing insulating thermally conductive particles as claimed in claim 9, wherein 10% of the total number of insulating thermally conductive particles has a particle size (D10) of 1500 to 2000 nm, and 50% of the total number of insulating thermally conductive particles has a particle size (D50) of 2000 to 3000 nm.

11. The method for manufacturing insulating and thermally conductive particles as described in claim 9, wherein the first solvent does not react with the coupling agent, and the second solvent is toluene or ethylbenzene.

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