KR102205085B1 - Composition for High Strength Aluminum Nitride Sintering and High Strength Aluminum Nitride Sintered Body - Google Patents

Abstract

The problem to be solved by the present invention is to provide a composition for sintering aluminum nitride for making an aluminum nitride sintered body capable of sintering at a low temperature and having high thermal conductivity and excellent strength at the same time, and an aluminum nitride sintered body made by firing the same. One aspect of the present invention for solving the above problems is to provide an amorphous liquid phase sintering aid, a crystalline liquid phase sintering aid, a dispersion reinforced crystalline ceramic additive, and an aluminum nitride sintering composition comprising aluminum nitride powder. Another aspect of the present invention for solving the above problem is to provide a high-strength aluminum nitride sintered body made by firing the aluminum nitride sintering composition.

Description

Composition for high strength aluminum nitride sintering and high strength aluminum nitride sintered body {Composition for High Strength Aluminum Nitride Sintering and High Strength Aluminum Nitride Sintered Body}

The present invention relates to a composition for sintering aluminum nitride and an aluminum nitride sintered body made therefrom, and more particularly, an aluminum nitride sintered body capable of sintering at a temperature of 1700°C or less, obtaining high density and thermal conductivity, and at the same time having excellent strength. It relates to a composition for sintering that can be produced and a sintered body made therefrom.

The basic structure of the crystal structure of aluminum nitride (AlN) is a tetrahedron centered on Al or N. These tetrahedrons cross each other to have a hexagonal wurtzite structure, and interatomic bonds are made of covalent bonds. In an ideal wurtzite structure, the ratio of the c-axis and the a-axis is 1.633, whereas AlN has a wurtzite structure with a lattice constant a = 0.31127nm and c = 0.49816nm with a slightly shifted c/a ratio. .

This aluminum nitride has a thermal conductivity (319W/m·K) 10 times higher than that of alumina (Al ₂ O ₃ ), excellent electrical insulation properties (9×10 ¹³ Ω·cm), and a thermal expansion coefficient similar to that of silicon (Si) ( 4×10 ^-6 ), due to its excellent mechanical strength, it is applied to semiconductor substrates and parts of high thermal conductivity ceramics. Due to these characteristics, aluminum nitride is widely used as a component for semiconductor equipment, and specifically, an aluminum nitride substrate with metal thin film adhesion, a heat sink for a light emitting diode (LED), a heat sink for a high-power Si device, a substrate for a laser device for compound semiconductors, and a hybrid vehicle. It is used for power control boards and the like. Among them, aluminum nitride, which is used for parts for semiconductor manufacturing equipment, has excellent thermal conductivity, thermal expansion, and resistance to plasma, so it is used for heating elements, electrostatic chuck, and ceramic chamber parts. In this case, research on laser diodes or heat sinks for LEDs is being actively conducted.

However, aluminum nitride (AlN) is difficult to sinter due to the characteristic of strong covalent bonds, and high temperature pressure sintering is required to obtain a dense sintered body, and when sintered without atmosphere control, it is oxidized at a high temperature of 1,000°C or higher. In order to compensate for this problem, many studies have been conducted to obtain a dense sintered body at a relatively low temperature through atomization of aluminum nitride as a starting material and addition of sintering aids such as alkaline earth metal oxide or rare earth metal oxide. However, even with such a sintering aid, a high-temperature process of 1900°C or higher is still required, so there are still many limitations in industrial applications. . In addition, although the aluminum nitride sintered body has excellent thermal conductivity, in terms of strength, it exhibits relatively lower properties than the sintered body of other materials, and thus many attempts to improve this have been made.

Korean Patent Registration Publication No. 10-1147029

The problem to be solved by the present invention is to provide a composition for sintering aluminum nitride for making an aluminum nitride sintered body capable of sintering at a low temperature and having high thermal conductivity and excellent strength at the same time, and a high-strength aluminum nitride sintered body made by firing the same.

One aspect of the present invention for solving the above problems is to provide an amorphous liquid phase sintering aid, a crystalline liquid phase sintering aid, a dispersion reinforced crystalline ceramic additive, and an aluminum nitride sintering composition comprising aluminum nitride powder.

Another aspect of the present invention for solving the above problem is to provide a high-strength aluminum nitride sintered body made by firing the aluminum nitride sintering composition.

By using the composition for sintering aluminum nitride according to the present invention, an aluminum nitride sintered body having high thermal conductivity and excellent strength can be obtained through firing at a low temperature.

1 is a scanning electron microscope photograph of the raw material powder used in the experiment.
2 is a graph showing a change in strength of an aluminum nitride sintered body according to the amount of dispersion-reinforced crystalline ceramic additive.
3 is a scanning electron microscope photograph showing a difference in microstructure of an aluminum nitride sintered body according to the presence or absence of a dispersion-reinforced crystalline ceramic additive.
4 is a graph showing the results of X-ray diffraction analysis of an aluminum nitride sintered body with or without a dispersion-reinforced crystalline ceramic additive.

Hereinafter, with reference to the accompanying drawings with respect to an embodiment of the present invention will be described the configuration and operation. In the following description of the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted. In addition, when a part'includes' a certain component, it means that other components may be further included rather than excluding other components unless specifically stated to the contrary.

According to the present invention, there is provided a composition for sintering aluminum nitride comprising an amorphous liquid phase sintering aid, a crystalline liquid phase sintering aid, a dispersion-strengthening crystalline ceramic additive, and aluminum nitride powder. Amorphous liquid phase sintering aid induces sintering of aluminum nitride even at low temperature, and crystalline liquid phase sintering aid induces liquid phase sintering at low temperature and at the same time, it can increase thermal conductivity by lowering the oxygen concentration of aluminum nitride through secondary phase formation. . In addition, the dispersion-reinforced crystalline ceramic additive induces fine crystals in the sintered body to increase the strength of the sintered body after completion of sintering through the dispersion reinforcement effect.

In addition, according to the present invention, the amorphous liquid phase sintering aid is amorphous cordierite glass, amorphous borosilicate glass, amorphous MgO-CaO-Al ₂ O ₃ -SiO ₂ based glass and amorphous CaO-Al ₂ O ₃ -SiO ₂ It provides a composition for sintering aluminum nitride, including at least one selected from the group consisting of glass. The amorphous liquid phase sintering aid is an additive that helps aluminum nitride to be sintered, and induces liquid phase sintering even at low temperatures through an interfacial reaction with aluminum nitride. All of the amorphous liquid phase sintering aids described above have small thermal expansion coefficients and are suitable for sintering aluminum nitride because they have strong properties against thermal shock.

In addition, according to the present invention, the amorphous liquid phase sintering aid provides a composition for sintering aluminum nitride made by a complex polymerization method. In a general solid-phase reaction method, since it relies on mechanical pulverization and mixing, the uniformity and homogeneity of the synthesized powder is inferior, and it is difficult to make particles of 1 micron or less. In order to improve the problems of the solid-phase reaction method, a wet chemistry method is widely used, and among them, a sol-gel method or a coprecipitation method is mainly used. This wet chemistry method has an advantage in micronizing the powder, but has a disadvantage in that it is difficult to maintain a stoichiometric composition in a powder in which several components are mixed. On the other hand, when the complex oxide powder is prepared through the complex polymerization method, the stoichiometric composition of the cations is maintained and the multi-component complex oxide powder composed of homogeneous and fine particles is produced due to the anti-aggregation effect due to the low mobility of the cations. It can be easily obtained. In addition, it exhibits high purity and uniformity, is easy to control the chemical and physical properties of the synthesized powder, is manufactured at a relatively low temperature in the process, and has the advantage of no pulverization and resintering steps required in the solid phase reaction method.

In the present invention, the complex polymerization method uses a glycol-based solvent such as ethylene glycol and an α-hydroxy carboxylic acid such as citric acid to each metal ion. After forming a metal-chelate complex in which the resins are uniformly distributed in the resin, the polyesterization reaction is induced at an appropriate temperature (less than 100℃) to form a polymer resin, which is then at a temperature of 300℃ or higher. It refers to a method of producing a complex oxide powder by removing organic matter by causing decomposition of a polymer by heating at. Such a complex polymerization method has the advantage of being able to maintain a stoichiometric composition ratio of cations in a starting solution state even in an oxide state as a final product, and it is possible to prevent aggregation while forming a powder due to a low mobility of the cations.

According to the present invention, the crystalline liquid phase sintering aid provides a composition for sintering aluminum nitride comprising at least one selected from the group consisting of Y ₂ O ₃ , CaCO ₃ , MgO and Al ₂ O ₃ . The crystalline liquid phase sintering aid serves to lower the sintering temperature by inducing liquid phase sintering through eutectic reaction on the surface of aluminum nitride, and reacts with oxygen present on the surface of aluminum nitride to form a secondary phase. It plays a role in increasing the purity of the final sintered body to increase the thermal conductivity of the final sintered body.

In addition, according to the present invention, the dispersion reinforced crystalline ceramic additive provides a composition for sintering aluminum nitride comprising at least one selected from the group consisting of ZrO ₂ , YSZ (Y ₂ O ₃ -stabilized ZrO ₂ ) and SiC do. The dispersion-reinforced crystalline ceramic additive induces the formation of fine particles during the sintering process in the aluminum nitride sintered body, thereby making the high-strength sintered body through the dispersion strengthening effect.

In addition, the amorphous liquid phase sintering aid according to the present invention provides a composition for sintering aluminum nitride of 0.5 to 5% of the total weight of the composition for sintering aluminum nitride. If the amount of the amorphous ceramic additive is too small, it is difficult to bring the sintering temperature low, and there is a problem that the density of the sintered body is low. Conversely, if the amount is too large, there is a problem that the thermal conductivity decreases. Therefore, the amorphous ceramic additive is preferably 0.5 to 5.0% of the total weight of the composition for sintering aluminum nitride.

According to the present invention, the amorphous ceramic additive provides a composition for sintering aluminum nitride having an average particle size of 1.0 μm or less. This is because the smaller the size of the amorphous ceramic additive, the higher the surface energy, so that smooth sintering is performed even at a low temperature, and the sintering density is increased, thereby improving the thermal conductivity of the sintered body.

According to the present invention, the crystalline liquid phase sintering aid provides a composition for sintering aluminum nitride, which is 0.5 to 5% of the total weight of the composition for sintering aluminum nitride. If the amount of the crystalline liquid sintering aid is too small, the thermal conductivity of the final sintered body is low, and when too much, grain growth of the aluminum nitride particles occurs and the strength of the sintered body decreases. Therefore, the crystalline ceramic additive is preferably 0.5 to 5.0% of the total weight of the composition for sintering aluminum nitride.

In addition, according to the present invention, the dispersion reinforced crystalline ceramic additive provides a composition for sintering aluminum nitride of 0.5 to 3.0% of the total weight of the composition for sintering the aluminum nitride. If the amount of the dispersion strengthening crystalline ceramic additive is too small, it is difficult to obtain the dispersion strengthening effect, and if it is too large, there is a problem of lowering the thermal conductivity. Therefore, the dispersion-reinforced crystalline ceramic additive is preferably 0.3 to 3.0% of the total weight of the composition for sintering aluminum nitride.

In addition, according to the present invention, the amorphous liquid phase sintering aid, the crystalline liquid phase sintering aid, and the dispersion reinforced crystalline ceramic additive provide a composition for sintering aluminum nitride having a weight ratio of 1:2 to 5:0.3 to 3. If the weight ratio of the crystalline liquid sintering aid to the amorphous liquid sintering aid is less than 2, the secondary phase formation is small and the effect of improving the thermal conductivity is low, and when it is greater than 5, the ratio of the amorphous liquid sintering aid is lowered and the sintering temperature is increased. In addition, if the weight ratio of the dispersion-strengthening crystalline ceramic additive to the amorphous liquid sintering aid is less than 0.3, the dispersion strengthening effect does not appear, and if it is greater than 3, the thermal conductivity is significantly lowered, which is not preferable.

According to the present invention, the sum of the weight of the amorphous liquid phase sintering aid, the crystalline liquid phase sintering aid, and the dispersion reinforced crystalline ceramic additive is 3 to 8% of the total weight of the aluminum nitride sintering composition to provide a composition for sintering aluminum nitride do. If the amount of the total additive is too small, a stable sintered body cannot be formed, so that the density of the sintered body is low, resulting in a decrease in thermal conductivity and strength. Conversely, even if it is too large, there is a problem that the amount of aluminum nitride, which acts as a heat conduction, decreases, resulting in a decrease in thermal conductivity. Therefore, the total amount of the additive is preferably 3 to 8% of the total weight of the composition for sintering aluminum nitride.

In addition, in the present invention, the amorphous MgO-CaO-Al ₂ O ₃ -SiO ₂ -based glass is aluminum nitride having a molar ratio of MgO:CaO:Al ₂ O ₃ :SiO ₂ of 1:1 to 5:1 to 3:5 to 11 It provides a composition for sintering. The amorphous MgO-CaO-Al ₂ O ₃ -SiO ₂ -based glass has a lower melting point in the above composition, so that it can exhibit a sufficient density when sintering aluminum nitride.

In addition, the present invention provides an aluminum nitride sintered body made by firing the various aluminum nitride sintering compositions described above. In addition to aluminum nitride, which is the main material, an aluminum nitride sintering composition containing an amorphous liquid sintering aid, a crystalline liquid sintering aid, and a dispersion-reinforced crystalline ceramic additive simultaneously is sintered at a relatively low temperature to produce an aluminum nitride sintered body with high thermal conductivity and excellent strength. Can be obtained. When firing, the temperature is preferably made at 1,400 ~ 1,700 ℃ lower than when using the existing rare earth additives.

Hereinafter, the present invention will be described in more detail through examples. The following examples illustrate the present invention, and the present invention is not limited thereto.

(Example 1)

A mixed powder was prepared by mixing an amorphous liquid sintering aid, a crystalline liquid sintering aid, and a dispersion-strengthening crystalline ceramic additive with aluminum nitride powder. The used aluminum nitride powder (Grade H, Tokuyama, Japan) was a powder prepared by the thermal carbon reduction nitriding method using high-purity alumina, and the physical properties are shown in Table 1 below. A scanning electron microscope photograph of the aluminum nitride powder is shown in Fig. 1(a).

Specific Surface Area (m ² /g) 2.50~2.68 Mean Particle Size (㎛) 1.07~1.17

impurities O(wt%) 0.78~0.86 C(ppm) 130-270 Ca(ppm) 200-240 Si(ppm) 39~48 Fe(ppm) 10-14

Amorphous MgO-CaO-Al ₂ O ₃ -SiO ₂ based glass (MCAS) powder as an amorphous liquid sintering aid in the aluminum nitride powder, crystalline yttria (Y ₂ O ₃ ) powder as a crystalline liquid sintering aid, and dispersion-enhanced crystalline As a ceramic additive, YSZ (Y ₂ O ₃ -stabilized ZrO ₂ ) powder was weighed to be 1.0 wt%, 3.0 wt%, and 0.5 wt%, respectively, and mixed with respect to the total mixed powder. The MCAS powder used was directly manufactured and used (FIG. 1(b)), the yttria powder was purchased from China's Sinocera (FIG. 1(c)), and the yttria powder was European Stark (HC Stark). ) Purchased from the company (Fig. 1 (d))

Mixing was done twice, and the first mixing was carried out for 2 hours at 50 rpm using a 3D mixer, and the zirconia balls used were Ø3. For the second mixing, ball milling was performed at 100 rpm for 24 hours using a Ø3 standard zirconia ball. Thereafter, a sheet was produced through tape casting, and the conditions for tape casting were summarized in Table 2 below.

Application condition Dam height 0.30 mm Feed speed 2 m/min dry 70℃ Lamination condition Table, head temperature 50℃ pressure 10 tons, 10 seconds Crimp condition Temperature 70℃ pressure 200 bar, 10 minutes (isotropic pressure) Cutting condition Table, blade temperature 50℃ Cutting size 3.5cm x 3.5cm

The prepared sheet was held in a box furnace at 580°C for 4 hours to proceed with the debinding process, and then heated at a rate of 5°C/min using a tungsten sintering furnace, and then maintained at 1,600°C for 1 hour to proceed with sintering. N ₂ -4 wt% H ₂ A non-oxidizing atmosphere was maintained by using a mixed gas.

The amorphous MgO-CaO-Al ₂ O ₃ -SiO ₂ based glass (MCAS) powder was made by a complex polymerization method, and as a solvent, citric acid (C ₆ H ₈ O ₇ , a hydroxy carboxylic acid solvent, 99.5%, DAE JUNG), a glycol-based solvent, ethylene glycol (HOCH ₂ CH ₂ OH, 99.0%, DAE JUNG) was used. The starting material is magnesium (Mg) precursor magnesium nitrate hexahydrate (Magnesium Nitrate Hexahydrate) (Mg(NO ₃ ) ₂ ·6H2O, 98%, DAE JUNG), calcium carbonate (Calcium Carbonate) (CaCO ₃ , 99.5%, JUNSEI), aluminum nitrate nonahydrate (Al(NO ₃ ) ₃ 9H ₂ O, 98%, SAMCHUN), a silicon (Si) precursor as an aluminum nitrate Laethyl orthosilicate (Tetraethyl orthosilicate) (Si(OC ₂ H ₅ ) ₄ , 99%, ALDRICH) was used. Ethylene glycol was heated to 90° C., citric acid was added, and the mixture was stirred at 250 rpm for 1 hour to dissolve. At this time, the molar ratio of ethylene glycol and citric acid was set to be 4:1, and the total amount of ME (precursors containing metal) required for synthesis in a mixed solvent of ethylene glycol and citric acid was 1:5 with CA (Citric Acid). It was calculated as the molar ratio of (total amount of ME: CA). Here, the ME is Mg(NO ₃ ) ₂ ·6H ₂ O, CaCO ₃ , Al(NO ₃ ) ₃ ·9H ₂ O and Si(OC ₂ H ₅ ) ₄ Means. In the mixed solvent of ethylene glycol and citric acid, Mg(NO ₃ ) ₂ ·6H ₂ O, CaCO ₃ , Al(NO ₃ ) ₃ ·9H ₂ O and Si(OC ₂ H ₅ ) ₄ were dissolved in the order of 30 minutes. At this time, Mg(NO ₃ ) ₂ ·6H ₂ O, CaCO ₃ , Al(NO ₃ ) ₃ ·9H ₂ O and Si(OC ₂ H ₅ ) ₄ were added and dissolved in a molar ratio of 6.87:18.78:28.25:46.09. , This constitutes a ratio of MgO:CaO:Al ₂ O ₃ :SiO ₂ = 5:19:26:50 when converted to a weight% with respect to the oxide. After the reaction was completed, the solution was heated in a heating mentle at 300° C. for 2 hours to evaporate the liquid to form a powder. These powders were referred to as powder precursors. Even after heating, heat treatment was performed at 400° C. for 5 hours to remove organic matter remaining in the powder precursor. The powder from which the organic matter was removed was calcined at 400-800°C for 5 hours to synthesize amorphous MgO-CaO-Al ₂ O ₃ -SiO ₂ based glass powder. At this time, the particle size of the synthesized amorphous glass powder was 0.1 μm in average particle size.

(Example 2)

An aluminum nitride substrate was prepared in the same manner as in Example 1, but as an amorphous liquid-phase sintering aid in the production of the mixed powder, amorphous MgO-CaO-Al ₂ O ₃ -SiO ₂ -based glass (MCAS) powder and a crystalline liquid phase sintering aid were used. Crystalline yttria (Y ₂ O ₃ ) powder and YSZ (Y ₂ O ₃ -stabilized ZrO ₂ ) powder as dispersion-reinforced crystalline ceramic additives were made to be 1.0 wt%, 3.0 wt% and 1.0 wt%, respectively, to the total mixed powder. Weigh and mix.

(Example 3)

An aluminum nitride substrate was prepared in the same manner as in Example 1, but as an amorphous liquid-phase sintering aid in the production of the mixed powder, amorphous MgO-CaO-Al ₂ O ₃ -SiO ₂ -based glass (MCAS) powder and a crystalline liquid phase sintering aid were used. Crystalline yttria (Y ₂ O ₃ ) powder and YSZ (Y ₂ O ₃ -stabilized ZrO ₂ ) powder as dispersion-reinforced crystalline ceramic additives were made to be 1.0 wt%, 3.0 wt% and 2.0 wt%, respectively, with respect to the total mixed powder. Weigh and mix.

(Example 4)

An aluminum nitride substrate was prepared in the same manner as in Example 1, but as an amorphous liquid-phase sintering aid in the production of the mixed powder, amorphous MgO-CaO-Al ₂ O ₃ -SiO ₂ -based glass (MCAS) powder and a crystalline liquid phase sintering aid were used. Crystalline yttria (Y ₂ O ₃ ) powder and YSZ (Y ₂ O ₃ -stabilized ZrO ₂ ) powder as dispersion-strengthening crystalline ceramic additives were made to be 1.0 wt%, 3.0 wt% and 3.0 wt%, respectively, of the total mixed powder. Weigh and mix.

(Example 5)

An aluminum nitride substrate was prepared in the same manner as in Example 1, but as an amorphous liquid-phase sintering aid in the production of the mixed powder, amorphous MgO-CaO-Al ₂ O ₃ -SiO ₂ -based glass (MCAS) powder and a crystalline liquid phase sintering aid were used. Crystalline yttria (Y ₂ O ₃ ) powder and YSZ (Y ₂ O ₃ -stabilized ZrO ₂ ) powder as dispersion-strengthening crystalline ceramic additives were made to be 1.0 wt%, 4.0 wt% and 1.0 wt%, respectively, to the total mixed powder. Weigh and mix.

(Example 6)

An aluminum nitride substrate was prepared in the same manner as in Example 1, but as an amorphous liquid-phase sintering aid in the production of the mixed powder, amorphous MgO-CaO-Al ₂ O ₃ -SiO ₂ -based glass (MCAS) powder and a crystalline liquid phase sintering aid were used. Crystalline yttria (Y ₂ O ₃ ) powder and YSZ (Y ₂ O ₃ -stabilized ZrO ₂ ) powder as dispersion-reinforced crystalline ceramic additives were made to be 1.0 wt%, 4.0 wt% and 2.0 wt%, respectively, with respect to the total mixed powder. Weigh and mix.

(Example 7)

An aluminum nitride substrate was prepared in the same manner as in Example 1, but as an amorphous liquid-phase sintering aid in the production of the mixed powder, amorphous MgO-CaO-Al ₂ O ₃ -SiO ₂ -based glass (MCAS) powder and a crystalline liquid phase sintering aid were used. Crystalline yttria (Y ₂ O ₃ ) powder and YSZ (Y ₂ O ₃ -stabilized ZrO ₂ ) powder as dispersion-reinforced crystalline ceramic additives were made to be 1.0 wt%, 5.0 wt% and 1.0 wt%, respectively, to the total mixed powder. Weigh and mix.

(Comparative Example 1)

An aluminum nitride substrate was prepared in the same manner as in Example 1, but only the amorphous MgO-CaO-Al ₂ O ₃ -SiO ₂ based glass powder as an amorphous liquid sintering aid in the production of the mixed powder was 1.0 wt% based on the total mixed powder. Weighed and mixed so as to be.

(Comparative Example 2)

An aluminum nitride substrate was prepared in the same manner as in Example 1, but the amorphous MgO-CaO-Al ₂ O ₃ -SiO ₂ -based glass powder and crystalline yttria as a crystalline liquid sintering aid as an amorphous liquid sintering aid when preparing the mixed powder. (Y ₂ O ₃ ) The powder was weighed and mixed to be 1.0 wt% and 3.0 wt%, respectively, with respect to the total mixed powder.

(Comparative Example 3)

An aluminum nitride substrate was prepared in the same manner as in Example 1, but the amorphous MgO-CaO-Al ₂ O ₃ -SiO ₂ -based glass powder and crystalline yttria (Y ₂ O ₃ ) powder were mixed as a whole when preparing the mixed powder. The powder was weighed and mixed to be 1.0 wt% and 4.0 wt%, respectively.

The sintered density and the bending strength of the aluminum nitride sintered body made in the above Examples and Comparative Examples were analyzed, and the results are summarized in Table 3 below.

division Composition (wt%) Sintering density
(g/cm ³ ) Bending strength (MPa) AlN MCAS Y ₂ O ₃ YSZ medium Maximum value Example 1 95.5 1.0 3.0 0.5 3.30 480 543 Example 2 95.0 1.0 3.0 1.0 3.29 608 627 Example 3 94.0 1.0 3.0 2.0 3.34 565 582 Example 4 93.0 1.0 3.0 3.0 3.35 553 596 Example 5 94.0 1.0 4.0 1.0 3.32 638 675 Example 6 93.0 1.0 4.0 2.0 3.34 532 633 Example 7 93.0 1.0 5.0 1.0 3.30 563 582 Comparative Example 1 99.0 1.0 0.0 0.0 3.22 404 435 Comparative Example 2 96.0 1.0 3.0 0.0 3.29 424 445 Comparative Example 3 95.0 1.0 4.0 0.0 3.29 450 462

(MCAS: amorphous MgO-CaO-Al ₂ O ₃ -SiO ₂ glass powder)

As can be seen in Table 3, compared to the case of using only amorphous MCAS powder, which is an amorphous liquid sintering aid, or using MCAS powder and yttria powder, which is a crystalline liquid sintering aid at the same time, MCAS powder and crystalline liquid sintering aid are It can be seen that when yttria powder and YSZ powder, which is a dispersion reinforced crystalline ceramic additive, are used together, the bending strength increases rapidly.

In FIG. 2, comparing the powder in which 1.0 wt% and 3.0 wt% of MCAS powder and yttria powder were mixed (Comparative Example 2) and the powder (Examples 2 to 4) further mixed with YSZ powder, respectively, after sintering It can be seen that the bending strength shows a remarkable difference.

In this way, the reason that the bending strength increases rapidly as the dispersion-reinforced crystalline ceramic additive is used together is that the dispersion-reinforced crystalline ceramic additive finely reacts with itself or with other additives in the sintered body to generate dispersion-reinforced particles This is because the strength of the sintered body is increased. 3(a) shows the cross-section of the aluminum nitride sintered body according to Comparative Example 2, and FIG. 3(b) shows the cross-section of the aluminum nitride sintered body according to Example 2. As can be seen here, as YSZ powder is added, a fine ZrN particles were produced, and it can be seen that these fine particles increase the strength of the entire sintered body through the dispersion strengthening effect.

In the results of X-ray diffraction analysis on the sintered bodies prepared in Comparative Example 2 and Examples 2 to 4, in addition to aluminum nitride, in all the samples analyzed, YAG (Yttrium aluminum), a secondary phase produced by the reaction of aluminum nitride and Y ₂ O ₃ garnet) phase was detected, and in Examples 2 to 4 in which YSZ powder was further mixed, it could be seen that ZrN crystals were formed. MCAS used as an amorphous liquid phase sintering aid was an amorphous phase and was not observed by X-ray diffraction analysis.

In the present specification, the present invention has been described in connection with some embodiments, but it should be understood that various modifications and changes can be made without departing from the spirit and scope of the present invention that can be understood by those skilled in the art to which the present invention belongs. something to do. In addition, such modifications and changes should be considered to fall within the scope of the claims appended to this specification.

Claims (14)

Including an amorphous liquid sintering aid, a crystalline liquid sintering aid, a dispersion-strengthening crystalline ceramic additive, and aluminum nitride powder,
The dispersion-reinforced crystalline ceramic additive is YSZ (Y ₂ O ₃ -stabilized ZrO ₂ ) that forms a ZrN secondary phase during sintering,
The amorphous liquid sintering aid, the crystalline liquid sintering aid, and the dispersion reinforced crystalline ceramic additive have a weight ratio of 1:2 to 5:0.3 to 3,
The sum of the weight of the amorphous liquid sintering aid, the crystalline liquid sintering aid, and the dispersion-enhanced crystalline ceramic additive is 3 to 8% of the total weight of the composition,
Composition for sintering aluminum nitride. The method of claim 1,
The amorphous liquid phase sintering aid is in the group consisting of amorphous cordierite glass, amorphous borosilicate glass, amorphous MgO-CaO-Al ₂ O ₃ -SiO ₂ based glass and amorphous CaO-Al ₂ O ₃ -SiO ₂ based glass Comprising at least one selected, aluminum nitride sintering composition. The method of claim 1,
The amorphous liquid phase sintering aid is made by a complex polymerization method, a composition for sintering aluminum nitride. The method of claim 1,
The crystalline liquid phase sintering aid includes at least one selected from the group consisting of Y ₂ O ₃ , CaCO ₃ , MgO and Al ₂ O ₃ , for sintering aluminum nitride. delete The method of claim 1,
The amorphous liquid phase sintering aid is 0.5 to 5.0% of the total weight of the aluminum nitride sintering composition, aluminum nitride sintering composition. The method of claim 1,
The amorphous liquid phase sintering aid has an average particle size of 1.0 μm or less, a composition for sintering aluminum nitride. The method of claim 1,
The crystalline liquid phase sintering aid is 0.5 to 5.0% of the total weight of the composition for sintering the aluminum nitride, the composition for sintering aluminum nitride. The method of claim 1,
The dispersion reinforced crystalline ceramic additive is 0.5 to 3.0% of the total weight of the aluminum nitride sintering composition, aluminum nitride sintering composition. delete delete The method of claim 2,
The amorphous MgO-CaO-Al ₂ O ₃ -SiO ₂ -based glass has a molar ratio of MgO:CaO:Al ₂ O ₃ :SiO ₂ of 1:1 to 5:1 to 3:5 to 11, and a composition for sintering aluminum nitride . An aluminum nitride sintered body produced by firing the composition for sintering aluminum nitride according to any one of claims 1 to 4, 6 to 9, and 12. 14. The aluminum nitride sintered body according to claim 13, wherein the firing is performed at 1400 to 1700°C.

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