Aluminum oxide including through-holes

Abstract

The present invention relates to aluminum oxide including through-holes and, more specifically, to aluminum oxide having a novel structure in which density is reduced by a plurality of through-holes formed in parallel and adjacent to each other in each particle.

Description

Aluminum oxide containing through holes

[0001] The present invention relates to aluminum oxide including through holes, and to aluminum oxide having a novel structure in which BET increases and density decreases due to a plurality of through holes formed in parallel and adjacent to each other within a particle.

[0002]

[0003] Aluminum oxide (Al2O3) has excellent physical properties such as high heat resistance, chemical resistance, corrosion resistance, and high strength. Aluminum oxide exists in various crystalline forms such as amorphous, gamma, beta, and alpha phases, and among them, alpha-aluminum oxide is a white powder with a molecular weight of 101.96, a specific gravity of about 3.965, and a melting point of about 2,072℃, and is a substance with a hexagonal crystal structure (a=4.758, c=12.991Å).

[0004] These aluminum oxides are widely used for electronic ceramics such as integrated circuit (IC) substrates, components for liquid crystal displays (LCDs) or plasma display panels (PDPs), mechanical and structural ceramics such as grinding equipment and molding / processing machines, energy and environmental ceramics such as fillers, catalysts, and catalyst carriers, and bioceramics such as artificial bones and artificial joints.

[0005] In particular, spherical aluminum oxide is applied in various fields, and due to its excellent thermal conductivity, it has recently been widely used as a heat-dissipating material for electronic devices. The thermal conductivity of spherical aluminum oxide varies depending on its purity, and the higher the purity, the higher the thermal conductivity, and thus the better the heat-dissipating properties.

[0006] Furthermore, when mixing spherical aluminum oxide as a filler into a heat-dissipating resin or other heat-dissipating material, high purity must be used and the filling ratio must be increased to maintain a high density in order to obtain a heat-dissipating material with excellent heat-dissipating properties.

[0007] However, in the case of conventional spherical aluminum oxide, there was a problem in that when mixed with resin and stored with a density of 3.9 or higher, aluminum oxide particles precipitated, reducing heat dissipation properties.

[0008]

[0009] The purpose of the present invention is to provide a novel aluminum oxide structure having a through hole.

[0010]

[0011] The present invention provides aluminum oxide including a through hole.

[0012] In the aluminum oxide including a through hole according to the present invention, the through hole means that both ends, which are the particle boundaries, are open and penetrate the center of the particle.

[0013] In the aluminum oxide including a through hole according to the present invention, the through hole is characterized in that the pore size is constant from one end to the other end. In the aluminum oxide including a through hole according to the present invention, the through hole is characterized in that it is formed in a shape extending straightly in a cylindrical shape.

[0014] The aluminum oxide including through holes according to the present invention is characterized by including a plurality of through holes formed in parallel and adjacent to each other within the particle.

[0015] The aluminum oxide including the through hole according to the present invention has a density of 3.0 g / cm 3 The aluminum oxide including the through hole according to the present invention has a density of 2.8 g / cm 3 3.0 g / cm 3 It is characterized by the following. The true density of conventional aluminum oxide is 3.9 to 4.2 g / cm 3 It is known that the aluminum oxide according to the present invention has a significantly reduced density compared to conventional aluminum oxide due to the through holes included therein.

[0016] In the aluminum oxide including through holes according to the present invention, the pore size of the through holes is characterized by being 20 nm to 300 nm. The aluminum oxide including through holes according to the present invention is manufactured by an anodizing process using an aluminum substrate, and the pore size can be changed depending on the type of acid used in the anodizing process and the applied voltage. In the aluminum oxide including through holes according to the present invention, when manufactured by anodizing using oxal, the pore size of the through holes is characterized by being 30 nm to 40 nm.

[0017] The aluminum oxide including through holes according to the present invention is characterized by a particle size of 10 to 100 μm. The aluminum oxide including through holes according to the present invention is manufactured by manufacturing a membrane through an anodizing process using an aluminum substrate and then pulverizing the membrane. The thickness of the membrane can be controlled by the anodizing process time, and the particle size can be controlled during the pulverizing process.

[0018] Aluminum oxide including a through hole according to the present invention is characterized in that the aspect ratio of the through hole is 100 or more. Aluminum oxide including a through hole according to the present invention is manufactured by manufacturing a membrane through an anodizing process using an aluminum substrate and then pulverizing, so that the thickness of the membrane is controlled by the anodizing process time, and the particle size is controlled during the pulverizing process, so that the aspect ratio of the through hole can be controlled to 100 or more.

[0019] Aluminum oxide including a through hole according to the present invention has a BET of 10 to 15 m 2 / g is characterized. The aluminum oxide including through holes according to the present invention has a BET value greatly expanded by a plurality of through holes formed in parallel within the particles.

[0020] Aluminum oxide including a through hole according to the present invention is characterized in that a peak appears at 800 to 900°C when analyzed by TG.

[0021] The aluminum oxide including the through hole according to the present invention is characterized in that the crystal form is in an amorphous state.

[0022] The aluminum oxide including a through hole according to the present invention is characterized by having an Al2O3 content of 94% or more and an SiO2 content of 0.5% or less. Since the aluminum oxide including a through hole according to the present invention is manufactured by an anodizing process using an aluminum substrate, it is determined according to the properties of the aluminum substrate used, and impurities can be reduced.

[0023]

[0024] The aluminum oxide according to the present invention has a reduced density due to a plurality of through holes formed in parallel and adjacent to each other within the particles, and when used in combination with a resin, such as a thermal interface material, the phenomenon of sinking due to low density is reduced, thereby exhibiting effects such as a greatly improved thermal interface effect.

[0025]

[0026] Figure 1 shows aluminum oxide manufactured according to one embodiment of the present invention.

[0027] Figures 2 and 3 show the results of SEM analysis performed on the pulverized membrane and aluminum oxide manufactured in one embodiment of the present invention.

[0028] Figures 4 and 5 show the results of SEM analysis performed on the pulverized membrane aluminum oxide manufactured in one embodiment of the present invention.

[0029] Figure 6 shows the results of SEM analysis performed on aluminum oxide manufactured in one embodiment of the present invention.

[0030] Figure 7 shows the results of XRD analysis performed on aluminum oxide having a particle structure including through holes manufactured in one embodiment of the present invention.

[0031] FIG. 8 shows the results of TG analysis for aluminum oxide having a particle structure including through holes manufactured according to one embodiment of the present invention.

[0032] Figure 9 shows the results of XRF analysis of aluminum oxide having a particle structure including through holes manufactured according to one embodiment of the present invention.

[0033]

[0034] Hereinafter, the present invention will be described in more detail by way of examples. However, the present invention is not limited to the following examples.

[0035]

[0036] <Example> Preparation of aluminum oxide powder

[0037] <Example 1>

[0038] An aluminum plate with a purity of 99.999% and a size of 100 mm * 150 mm was prepared, and electrolytic polishing was performed in a mixed solution of perchloric acid and ethanol for surface cleaning.

[0039] The first anodic oxidation was performed for 60 minutes to form a seed layer in 0.5 M oxalic acid, a solution temperature of 30°C, an applied voltage of 40 V, and a maximum current limit of 10 A, thereby forming a first anodic oxidation layer.

[0040] Afterwards, a mixed solution of chromic acid (1.8 wt%) and phosphoric acid (6 wt%) was used as an etchant, and the aluminum substrate was immersed in the solution at a temperature of 60°C for 3 hours to completely remove the first anodic oxidation layer and form a regular seed array.

[0041] Afterwards, the aluminum substrate was washed in distilled water and then subjected to a second anodization for 60 minutes at 0.5 M oxalic acid, a solution temperature of 30°C, an applied voltage of 40 V, and a maximum current limit of 10 A to form a second anodized layer. Thereafter, the aluminum substrate on which the second anodized layer was formed was heat-treated at 800°C for 5 hours.

[0042] After washing the aluminum plate on which the first layer of the anodic oxidation membrane was formed with distilled water, pulse anodic oxidation was performed by applying 40 cycles of 12M sulfuric acid, solution temperature 0 ℃, 55 V for 3 seconds, and 40 V for 5 seconds as one cycle, thereby forming a third anodic oxidation layer having high solubility in the etching solution under the second anodic oxidation layer.

[0043] The obtained substrate was washed in distilled water and then dried in an oven at 45°C for 20 minutes.

[0044] Afterwards, the sample was immersed in a phosphoric acid (6 wt%) solution at a solution temperature of 40°C for 10 minutes as an etchant to remove the highly soluble third anodic oxidation layer.

[0045] The thin film separated from the aluminum substrate by removing the third anodic oxide layer was washed with distilled water and then dried to obtain a membrane with through holes.

[0046] The membrane thus obtained was pulverized using a ball mill for 24 hours to obtain aluminum oxide of Example 1.

[0047]

[0048] <Example 2>

[0049] Aluminum oxide of Example 2 was obtained in the same manner as in Example 1, except that the voltage applied during the first and second anodic oxidations was 80 V, and that the ball mill was used for 48 hours during the pulverization process after membrane formation.

[0050]

[0051] <Example 3>

[0052] Aluminum oxide of Example 3 was obtained in the same manner as in Example 1, except that an aluminum plate having a purity of 99.5% was used.

[0053] The manufactured aluminum oxide powders of Examples 1 to 3 are shown in Fig. 1.

[0054]

[0055] <Experimental Example> SEM Measurement

[0056] SEM analysis was performed on the pulverized membrane and pulverized aluminum oxide manufactured in Example 1, and the results are shown in FIGS. 2 and 3.

[0057] As shown in FIG. 2, the membrane manufactured according to the embodiment of the present invention has a membrane shape including through holes with a pore size of 30 to 50 nm, and as shown in FIG. 3, it can be confirmed that the aluminum oxide manufactured by crushing the membrane manufactured according to the embodiment of the present invention has a particle structure including a plurality of through holes formed in parallel within the particle.

[0058]

[0059] <Experimental Example> SEM Measurement

[0060] SEM analysis was performed on the pulverized membrane and pulverized aluminum oxide manufactured in Example 2 above, and the results are shown in FIGS. 4 and 5.

[0061] As shown in FIG. 4, the membrane manufactured according to the embodiment of the present invention has a membrane shape including through holes with a pore size of 130 to 170 nm, and as shown in FIG. 5, it can be confirmed that the aluminum oxide manufactured by crushing the membrane manufactured according to the embodiment of the present invention has a particle structure including a plurality of through holes formed in parallel within the particle.

[0062]

[0063] <Experimental Example> SEM Measurement

[0064] SEM analysis was performed on the pulverized aluminum oxide prepared in Example 3 above, and the results are shown in Fig. 6.

[0065] As shown in Fig. 6, it can be confirmed that the aluminum oxide manufactured by crushing the membrane manufactured in the embodiment of the present invention has a particle structure including a plurality of through holes formed in parallel within the particle.

[0066]

[0067] <Experimental Example> Density measurement

[0068] The density of aluminum oxide particles having a structure including through holes of Examples 1 to 3 as shown in Fig. 1 was measured, and the results are shown in Table 1 below.

[0069] As a comparative example, the density of spherical aluminum oxide powder was measured.

[0070] True density is the density in an absolutely dense state, i.e., after eliminating internal pores or voids between particles. It refers to the actual mass of a solid substance per unit volume that exhibits the corresponding physical properties, and was measured using a Gas Pycnometer at the Korea Testing Laboratory.

[0071] [Table 1]

[0072]

[0073] In the above Table 1, the aluminum oxide particles having a structure including through holes according to the embodiment of the present invention have a density of 3.0 g / cm due to the through holes being created in parallel. 3 Below, it can be confirmed that the density is greatly reduced compared to that of conventional spherical aluminum oxide.

[0074]

[0075] <Experimental Example> BET Measurement

[0076] BET was measured for the aluminum oxide particles having a particle structure including through holes manufactured in Examples 1 to 3 above, and the results are shown in Table 2 below.

[0077] BET was measured using the BET method at the Korea Testing Laboratory.

[0078] [Table 2]

[0079]

[0080] <Experimental Example> Measurement of pore volume and pore size

[0081] The pore volume and pore size of the aluminum oxide particle structure including the through holes manufactured in Examples 1 to 3 above were measured, and the results are shown in Tables 3 and 4 below.

[0082] Pore ​​volume and pore size were measured using the gas adsorption method using a surface area and porosimetry analyzer from Micromeritics at the Korea Testing Laboratory.

[0083] [Table 3]

[0084]

[0085]

[0086] [Table 4]

[0087]

[0088]

[0089] <Experimental Example> Phase Analysis by XRD

[0090] XRD analysis was performed on aluminum oxide having a particle structure including through holes manufactured using 99.5% pure aluminum manufactured in Example 3 above, and the results are shown in Fig. 7.

[0091] As can be seen in Fig. 7, the aluminum oxide powder having a particle structure including through holes manufactured according to an embodiment of the present invention is an amorphous Al2O3.

[0092]

[0093] <Experimental Example> TG Analysis

[0094] TG analysis was performed on aluminum oxide having a particle structure including through holes manufactured using 99.5% pure aluminum manufactured in Example 3 above, and the results are shown in Fig. 8.

[0095] As shown in Fig. 8, it can be confirmed that the aluminum oxide particle structure including the through hole manufactured according to the embodiment of the present invention exhibits a peak at 800 to 900°C in TG analysis.

[0096]

[0097] <Experimental Example> XRF Analysis

[0098] XRF analysis was performed on aluminum oxide having a particle structure including through holes manufactured using 99.5% pure aluminum manufactured in Example 3 above, and the results are shown in Fig. 9.

[0099] As shown in Fig. 9, it can be confirmed that the aluminum oxide particle structure including the through hole manufactured according to the embodiment of the present invention has an Al2O3 content of 90% or more and a SiO2 content of 0.5% or less.

[0100]

[0101] CROSS-REFERENCE TO RELATED APPLICATION

[0102] This patent application claims priority under 35 USC §119(a) to Korean Patent Application No. 10-2024-0023627, filed in Korea on February 19, 2024, and Korean Patent Application No. 10-2025-0021502, filed in Korea on February 19, 2025, the entire contents of which are incorporated herein by reference. In addition, this patent application claims priority in countries other than the United States for the same reasons, the entire contents of which are incorporated herein by reference.

Claims

1. Aluminum oxide including through holes with open ends 2. In paragraph 1, The above through hole has a pore size that is constant from one end to the other. Aluminum oxide containing through holes 3. In paragraph 1, The above through holes are formed in multiple numbers adjacent to and parallel to each other within the particle. aluminum oxide 4. In paragraph 1, The above aluminum oxide has a density of 3.0 g / cm 3 Characterized by the following Aluminum oxide containing through holes 5. In paragraph 1, The above aluminum oxide has a density of 2.8 g / cm 3 3.0 g / cm 3 Characterized by the following Aluminum oxide containing through holes 6. In paragraph 1, The pore size of the through hole is 20 nm to 300 nm. aluminum oxide 7. In paragraph 1, Particle size is 10 to 100 um Aluminum oxide containing through holes 8. In paragraph 1, The aspect ratio of the above through hole is 100 or more. Aluminum oxide containing through holes 9. In paragraph 1, BET is 10 to 15 m 2 / g is Aluminum oxide containing through holes 10. In paragraph 1, When analyzing TG, a peak appears at 800 to 900 ℃. Aluminum oxide containing through holes 11. In paragraph 1, The crystal form is in an amorphous state Aluminum oxide containing through holes 12. In paragraph 1, Al2O3 content is 94% or more and SiO2 content is 0.5% or less Aluminum oxide containing through holes

Images