Silicon-containing aluminum nitride particles, sintered body, resin composition, and method for producing silicon-containing aluminum nitride particles

Abstract

To provide silicon-containing aluminum nitride particles, a sintered body, a resin composition, and a method for producing silicon-containing aluminum nitride particles.SOLUTION: Provided are silicon-containing aluminum nitride particles, wherein, when the total of a mass of aluminum and a mass of silicon analyzed from the particles by an inductively coupled plasma optical emission spectrometer and a mass of oxygen and a mass of nitrogen analyzed from the particles by an oxygen-nitrogen analyzer is set to 100 mass%, a total mass ratio of the aluminum and the nitrogen is 90 mass% or more, a mass ratio of the silicon is within a range of 1.5 mass% or more and 10.0 mass% or less, a mass ratio of the oxygen is X mass%, a specific surface area of the particles measured by a BET method is Y 2 / g, and a ratio (X / Y) is within a range of 0.40 or more and 0.85 or less.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to silicon-containing aluminum nitride particles, a sintered body, a resin composition, and a method for producing the silicon-containing aluminum nitride particles.

Background Art

[0002] A light-emitting device that emits white, incandescent, or orange light by combining a light-emitting element and a phosphor has been developed. To form a light-emitting device, a die bond material for fixing the light-emitting element to a support or a lead electrode, an underfill material disposed between the light-emitting element and a support substrate or a lead electrode during flip-chip mounting, a package material that fixes and holds the light-emitting element and serves as a reflector, etc. are used. As a material constituting a member of the light-emitting device such as a die bond material, an underfill material, or a package material, a resin material containing a filler or the like is used. Further, aluminum nitride particles are known to have a higher thermal conductivity than oxides such as aluminum oxide. A sintered body formed by sintering aluminum nitride particles has excellent heat dissipation properties and may be used as a support for electronic components or the like. Fillers and sintered bodies are required to have a high thermal conductivity for heat dissipation and a high reflectance for light in a specific wavelength range.

[0003] Patent Document 1 discloses a resin material for a molded body that serves as a support for a semiconductor light-emitting element, containing a polyorganosiloxane, boron nitride or aluminum nitride having a primary particle size of 0.1 μm or more and 7.0 μm or less, and a curing catalyst.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When aluminum nitride particles are used as a filler, when the aluminum nitride particles come into contact with the resin, the moisture contained in the resin reacts with the aluminum nitride, generating ammonia (NH3), which may inhibit the curing of the resin. Further, when the aluminum nitride particles and moisture contained in the cured product or sintered body react to generate ammonia (NH3), the cured product or sintered body may deteriorate.

[0006] An object of the present disclosure is to provide silicon-containing aluminum nitride particles, a sintered body, a resin composition, and a method for producing the silicon-containing aluminum nitride particles, which have high moisture resistance and are difficult to react with moisture while maintaining the high thermal conductivity of aluminum nitride.

Means for Solving the Problems

[0007] In a first aspect, when the total of the mass of aluminum and the mass of silicon analyzed from the particles by an inductively coupled plasma optical emission spectrometer and the mass of nitrogen and the mass of oxygen analyzed from the particles by an oxygen-nitrogen analyzer is 100% by mass, the total mass ratio of the aluminum and the nitrogen is 90% by mass or more, the mass ratio of the silicon is in the range of 1.5% by mass or more and 10.0% by mass or less, the mass ratio of the oxygen is X% by mass, and the specific surface area of the particles measured by the BET method is Ym 2 / g, and the ratio (X / Y) of the numerical value X of the X% by mass to the numerical value Y of the Ym 2 / g is in the range of 0.40 or more and 0.85 or less, the particles are silicon-containing aluminum nitride particles.

[0008] In a second aspect, when the total of the mass of aluminum and the mass of silicon analyzed from the particles by an inductively coupled plasma optical emission spectrometer and the mass of nitrogen and the mass of oxygen analyzed from the particles by an oxygen-nitrogen analyzer is 100% by mass, the total mass ratio of the aluminum and the nitrogen is 90% by mass or more, the mass ratio of the silicon is in the range of 1.5% by mass or more and 10.0% by mass or less, and the atomic percentage O of oxygen P to the atomic percentage N of nitrogen P analyzed from the particles by X-ray photoelectron spectroscopy, the ratio OP / N P Silicon-containing aluminum nitride particles having an / N exceeding 2.0.

[0009] A third aspect is a sintered body containing the silicon-containing aluminum nitride particles.

[0010] A fourth aspect is a resin composition containing the silicon-containing aluminum nitride particles and a resin.

[0011] A fifth aspect includes obtaining a raw material mixture containing aluminum nitride and silicon nitride, wherein when the total of aluminum nitride and silicon nitride is 100% by mass, silicon nitride is contained in the range of 2% to 15% by mass; subjecting the raw material mixture to a first heat treatment at a pressure of 0.101 MPa or more and a temperature in the range of 1600°C to 2100°C to obtain a first heat-treated product; and subjecting the obtained first heat-treated product to a second heat treatment at a temperature of 850°C or more and less than 1000°C to obtain a second heat-treated product. This is a method for producing silicon-containing aluminum nitride particles.

Advantages of the Invention

[0012] According to the above aspects, it is possible to provide silicon-containing aluminum nitride particles, a sintered body, a resin composition, and a method for producing silicon-containing aluminum nitride particles that are highly moisture-resistant and difficult to react with moisture while maintaining high thermal conductivity and high reflectivity.

Brief Description of the Drawings

[0013]

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Mode for Carrying Out the Invention

[0014] Hereinafter, the silicon-containing aluminum nitride particles, sintered body, resin composition, and method for producing silicon-containing aluminum nitride particles according to the present disclosure will be described. However, the embodiments shown below are examples for embodying the technical idea of the present invention, and the present invention is not limited to the following silicon-containing aluminum nitride particles, sintered body, resin composition, and method for producing silicon-containing aluminum nitride particles. The relationship between color names and chromaticity coordinates, the relationship between the wavelength range of light and the color names of monochromatic light, etc. follow JIS Z8110.

[0015] When the total of the mass of aluminum and the mass of silicon analyzed from the silicon-containing aluminum nitride particles by an inductively coupled plasma optical emission spectrometer (hereinafter also referred to as "ICP") and the mass of nitrogen and the mass of oxygen analyzed from the particles by an oxygen / nitrogen analyzer is 100% by mass, the total mass ratio of aluminum and nitrogen is 90% by mass or more, the mass ratio of silicon is in the range of 1.5% by mass or more and 10.0% by mass or less, the mass ratio of oxygen is X% by mass, and the specific surface area of the particles measured by the BET method is Ym 2 / g, and the ratio (X / Y) of the numerical value X of X% by mass to the numerical value Y of Ym 2 / g is in the range of 0.40 or more and 0.85 or less.

[0016] When the total of the mass of aluminum and the mass of silicon analyzed from the silicon-containing aluminum nitride particles by ICP and the mass of nitrogen and the mass of oxygen analyzed from the particles by an oxygen / nitrogen analyzer is 100% by mass, the total mass ratio of aluminum and nitrogen is 90% by mass or more, the mass ratio of silicon is in the range of 1.5% by mass or more and 10.0% by mass or less, and the atomic percentage O P of oxygen to the atomic percentage N P of nitrogen analyzed from the particles by X-ray photoelectron spectroscopy P is such that the ratio O P / N exceeds 2.0.

[0017] The mass of aluminum and the mass of silicon in the silicon-containing aluminum nitride particles are analyzed by ICP. Also, the mass of nitrogen and the mass of oxygen in the silicon-containing aluminum nitride particles are analyzed by an oxygen-nitrogen analyzer. When the total of the mass of aluminum, the mass of silicon, the mass of nitrogen, and the mass of oxygen analyzed by the above-described apparatuses for the silicon-containing aluminum nitride particles is taken as 100% by mass, the total mass ratio of aluminum and nitrogen is 90% by mass or more, and the mass ratio of silicon is within the range of 1.5% by mass or more and 10.0% by mass or less. When the total amount of the mass of aluminum, the mass of nitrogen, the mass of silicon, and the mass of oxygen analyzed from the particles by the above-described apparatuses is taken as 100% by mass, if the total mass ratio (mass%) of aluminum and nitrogen and the mass ratio (mass%) of silicon are within the above-described ranges, while maintaining the crystal structure of aluminum nitride, a part of the aluminum in the crystal structure of aluminum nitride is substituted with silicon. When a part of the aluminum in the crystal structure of aluminum nitride is substituted with silicon, the silicon-containing aluminum nitride has a high reflectance. The high reflectance that the silicon-containing aluminum nitride has means, in this specification, that the reflectance of light within a wavelength range of, for example, 380 nm or more and 730 nm or less (hereinafter, also referred to as "within the wavelength range of the visible light region") is 50% or more. Aluminum nitride particles usually have a high thermal conductivity of 150 W / m·K to 200 W / m·K at 20°C. On the other hand, aluminum nitride usually has a reflectance within the wavelength range of the visible light region of about 70%. The silicon-containing aluminum nitride particles can increase the reflectance of light within the wavelength range of the visible light region while maintaining the high thermal conductivity that the aluminum nitride particles have, by substituting a part of the aluminum in the crystal structure with silicon while maintaining the crystal structure of aluminum nitride.In addition, when the total amount of the mass of aluminum, the mass of nitrogen, the mass of silicon, and the mass of oxygen analyzed from the silicon-containing aluminum nitride particles by each of the above-described apparatuses is 100% by mass, if the mass ratio of silicon is within the above-described range, the reaction between aluminum and oxygen in the silicon-containing aluminum nitride particles can be suppressed, and a film containing oxygen can be formed while suppressing the formation of aluminum oxide (Al2O3). The silicon-containing aluminum nitride particles may have a total mass ratio of aluminum and nitrogen of 92% by mass or more, 93% by mass or more, and preferably 98% by mass or less when the total amount of the mass of aluminum, the mass of silicon, the mass of nitrogen, and the mass of oxygen analyzed from the particles by each of the above-described apparatuses is 100% by mass. The silicon-containing aluminum nitride particles preferably have a silicon mass ratio in the range of 1.5% by mass or more and 8.0% by mass or less, more preferably in the range of 1.5% by mass or more and 5.0% by mass or less, still more preferably in the range of 1.5% by mass or more and 4.0% by mass or less, even more preferably in the range of 2.0% by mass or more and 4.0% by mass or less, and particularly preferably in the range of 2.5% by mass or more and 3.5% by mass or less when the total of the mass of aluminum, the mass of silicon, the mass of nitrogen, and the mass of oxygen analyzed from the particles by each of the above-described apparatuses is 100% by mass.

[0018] When the total of the mass of aluminum, the mass of silicon, the mass of nitrogen, and the mass of oxygen analyzed from the silicon-containing aluminum nitride particles by each of the above-described apparatuses is 100% by mass, the mass ratio of oxygen is X% by mass, and the specific surface area of the particles measured by the BET method is Ym 2 / g, and the ratio (X / Y) of the numerical value X of the mass ratio of oxygen in X% by mass to the numerical value Y of the specific surface area of the particles in Ym 2 / g of the numerical value Y is in the range of 0.40 or more and 0.85 or less. The ratio (X / Y) is the Ym of the specific surface area of the silicon-containing aluminum nitride particles 2It is the ratio of the numerical value X of X mass % of the mass ratio of oxygen in the silicon-containing aluminum nitride particles to the numerical value Y of / g. When the ratio (X / Y) is within the range of 0.40 or more and 0.85 or less, a film containing oxygen is formed on the surface of the silicon-containing aluminum nitride particles while suppressing the formation of aluminum oxide. When a film containing oxygen is formed on the surface of the silicon-containing aluminum nitride particles, the reaction between the silicon-containing aluminum nitride particles and water is suppressed, for example, it is difficult to react with moisture contained in the air or resin, and the moisture resistance of the silicon-containing aluminum nitride particles can be improved. Since the reaction with moisture is suppressed in the silicon-containing aluminum nitride particles having the ratio (X / Y) within the above range, even when contained in a resin, the generation of ammonia (NH3) generated by the reaction between aluminum nitride (AlN) contained in the silicon-containing aluminum nitride and moisture (H2O) can be suppressed. When the silicon-containing aluminum nitride particles are contained in a resin, deterioration of the resin due to ammonia can be suppressed. The mass ratio of oxygen in the silicon-containing aluminum nitride particles varies depending on the size of the silicon-containing aluminum nitride particles (for example, the average particle diameter). The silicon-containing aluminum nitride particles have a numerical value X of X mass % of the mass ratio of oxygen when the total of the mass of aluminum, the mass of silicon, the mass of nitrogen, and the mass of oxygen analyzed from the particles by each of the above devices is 100 mass %, and the specific surface area Ym of the particles measured by the BET method 2If the ratio (X / Y) divided by the numerical value Y of / g is within the range of 0.40 or more and 0.85 or less, even if the silicon-containing aluminum nitride particles have a small average particle size, a film containing oxygen that can suppress the reaction between the silicon-containing aluminum nitride particles and moisture is formed on the surface of the silicon-containing aluminum nitride particles. Since a film containing oxygen that can suppress the reaction with moisture is formed substantially uniformly on the surface of the silicon-containing aluminum nitride particles, the ratio (X / Y) of the silicon-containing aluminum nitride particles is preferably in the range of 0.41 or more and 0.84 or less, more preferably in the range of 0.42 or more and 0.83 or less, and even more preferably in the range of 0.43 or more and 0.82 or less. The average particle size of the silicon-containing aluminum nitride particles can be measured by the Fisher Sub-Sieve Sizer method (hereinafter also referred to as the "FSSS method"). The silicon-containing aluminum nitride particles with a small average particle size refer to, for example, silicon-containing aluminum nitride particles having an average particle size of 3.0 μm or less measured by the FSSS method. The silicon-containing aluminum nitride particles with a small average particle size may be in the range where the average particle size measured by the FSSS method is 0.1 μm or more and 3.0 μm or less, 0.2 μm or more and 3.0 μm or less, or 0.5 μm or more and 3.0 μm or less. The average particle size D by the FSSS method can be, for example, the Fisher Sub-Sieve Sizer’s Number measured using a Fisher Model 95 Sub-Sieve Sizer (manufactured by Fisher Scientific) as the average particle size D. The FSSS method is a kind of air permeability method, which measures the specific surface area using the flow resistance of air and mainly determines the particle size of primary particles.

[0019] If the ratio (X / Y) of silicon-containing aluminum nitride particles is in the range of 0.40 or more and 0.85 or less, a film containing oxygen in which the reaction between aluminum and oxygen in the silicon-containing aluminum nitride is suppressed and the formation of aluminum oxide (Al2O3) is inhibited is formed on the surface of the particles. As described above, the thermal conductivity of aluminum nitride particles is usually as high as 150 W / m·K to 200 W / m·K at 20°C. On the other hand, the thermal conductivity of aluminum oxide particles is usually 30 W / m·K at 20°C, which is considerably lower than that of aluminum nitride particles. If the ratio (X / Y) of silicon-containing aluminum nitride particles is in the range of 0.40 or more and 0.85 or less, a film containing oxygen can be formed on the surface of the particles while suppressing the formation of aluminum oxide. If the ratio (X / Y) of silicon-containing aluminum nitride particles is in the range of 0.40 or more and 0.85 or less, the high thermal conductivity and high reflectivity of the silicon-containing aluminum nitride particles can be maintained while suppressing the reaction between the silicon-containing aluminum nitride particles and moisture.

[0020] When the total mass of aluminum, silicon, nitrogen, and oxygen analyzed from the particles by each of the aforementioned apparatuses is 100% by mass, the silicon-containing aluminum nitride particles have a total mass ratio of aluminum and nitrogen of 90% by mass or more and a silicon mass ratio in the range of 1.5% by mass or more and 10.0% by mass or less. As a result, compared to aluminum nitride particles that do not contain silicon or aluminum nitride particles with a silicon mass ratio of less than 1.5% by mass, a film containing oxygen is more likely to be formed while suppressing the formation of aluminum oxide. The silicon-containing aluminum nitride particles can form a film containing oxygen on the surface of the silicon-containing aluminum nitride particles while suppressing the formation of aluminum oxide by subjecting the raw material mixture to a first heat treatment to obtain the silicon-containing aluminum nitride particles and then further subjecting the obtained silicon-containing aluminum nitride particles to a second heat treatment. The reason why the silicon-containing aluminum nitride particles can form a film containing oxygen while suppressing the formation of aluminum oxide more than aluminum nitride particles that do not contain silicon or aluminum nitride particles with a silicon mass ratio of less than 1.5% by mass is presumably that since silicon is more easily oxidized than aluminum, silicon reacts with oxygen before aluminum, forming a film containing oxygen. For example, in the case of aluminum nitride particles with a silicon mass ratio of less than 1.5% by mass, when the aluminum nitride particles are subjected to a second heat treatment, the oxygen analyzed from the particles increases, and the ratio (X / Y) exceeds 0.85 and becomes 1 or more. When the ratio (X / Y) of the silicon-containing aluminum nitride particles exceeds 1 and increases, the oxygen content per specific surface area is high, and it is presumed that aluminum and oxygen in the silicon-containing aluminum nitride particles react to form a film containing aluminum oxide (Al2O3) on the surface of the silicon-containing aluminum nitride particles.

[0021] When the total of the mass of aluminum, the mass of silicon, the mass of nitrogen, and the mass of oxygen analyzed by each of the aforementioned apparatuses is 100% by mass, the total mass ratio of aluminum and nitrogen is 90% by mass or more, the mass ratio of silicon is in the range of 1.5% by mass or more and 10.0% by mass or less, and the atomic percentage N P of nitrogen analyzed from the particles by X-ray photoelectron spectroscopy (hereinafter also referred to as "XPS") P and the atomic percentage O P of oxygen (at%) P has a ratio O P / N P exceeding 2.0. When the ratio O P / N P exceeds 2.0, a film containing oxygen is formed on the surface of the silicon-containing aluminum nitride particles while suppressing the formation of aluminum oxide. When the ratio O P / N P exceeds 2.0, even for silicon-containing aluminum nitride particles having a large average particle size, a film containing oxygen that can suppress the reaction between the silicon-containing aluminum nitride particles and moisture is formed on the surface of the silicon-containing aluminum nitride particles. Silicon-containing aluminum nitride particles having a large average particle size refer to silicon-containing aluminum nitride particles having an average particle size measured by the FSSS method exceeding 3.0 μm. The silicon-containing aluminum nitride particles having a large average particle size may be in the range of exceeding 3.0 μm and 100 μm or less, may be in the range of exceeding 3.0 μm and 80 μm or less, or may be in the range of 3.5 μm or more and 80 μm or less, as measured by the FSSS method.

[0022] For the silicon-containing aluminum nitride particles, the ratio O P / N PIf it exceeds 2.0, even if the silicon-containing aluminum nitride particles have an average particle size exceeding 3.0 μm, a film containing oxygen is formed on the surface of the silicon-containing aluminum nitride particles, and the reaction between the silicon-containing aluminum nitride particles and moisture can be suppressed. Silicon-containing aluminum nitride particles having a film containing oxygen on the surface can suppress an increase in the mass of the silicon-containing aluminum nitride particles when a pressure cooker test (hereinafter also referred to as "PCT") described later is performed, and are difficult to react with moisture while maintaining high thermal conductivity and high reflectivity, and have excellent moisture resistance. The silicon-containing aluminum nitride particles have a ratio of O P / N P preferably 10.0 or less, more preferably 9.0 or less, and even more preferably 8.0 or less. When the ratio of O P / N P of the silicon-containing aluminum nitride particles becomes too large, aluminum in the silicon-containing aluminum nitride particles may react with oxygen to form aluminum oxide, and the high thermal conductivity may not be maintained. Further, when the ratio of O P / N P of the silicon-containing aluminum nitride particles becomes too large, the film containing oxygen formed on the surface of the silicon-containing aluminum nitride particles may become too thick, and the reflectivity may decrease.

[0023] When the total of the mass of aluminum, the mass of silicon, the mass of nitrogen, and the mass of oxygen analyzed from the particles by each of the aforementioned apparatuses is 100% by mass, the mass ratio of oxygen is preferably in the range of 0.9% by mass or more and 3.5% by mass or less. When the total of the mass of aluminum, the mass of silicon, the mass of nitrogen, and the mass of oxygen analyzed from the aforementioned particles is 100% by mass, when the mass ratio of oxygen is within the aforementioned range, the ratio (X / Y) is within the range of the silicon-containing aluminum nitride particles within the range of 0.40 or more and 0.85 or less, and it is easy to form a film containing oxygen while suppressing the formation of aluminum oxide on the surface of the silicon-containing aluminum nitride particles. Further, when the total of the mass of aluminum, the mass of silicon, the mass of nitrogen, and the mass of oxygen analyzed from the aforementioned particles is 100% by mass, when the mass ratio of oxygen is in the range of 0.9% by mass or more and 3.5% by mass or less, the ratio O P / N P exceeds 2.0, and it is easy to form a film containing oxygen while suppressing the formation of aluminum oxide on the surface of the silicon-containing aluminum nitride particles. When the total of the mass of aluminum, the mass of silicon, the mass of nitrogen, and the mass of oxygen analyzed from the particles by each of the aforementioned apparatuses is 100% by mass, the mass ratio of oxygen is more preferably in the range of 1.0% by mass or more and 3.5% by mass or less, even more preferably in the range of 1.1% by mass or more and 3.4% by mass or less, and particularly preferably in the range of 1.2% by mass or more and 3.3% by mass or less.

[0024] The silicon-containing aluminum nitride particles can form a film containing oxygen while suppressing the formation of aluminum oxide on the surface of the silicon-containing aluminum nitride particles by subjecting the raw material mixture to a first heat treatment to obtain the silicon-containing aluminum nitride particles and then subjecting the obtained silicon-containing aluminum nitride particles to a second heat treatment. Hydroxyl groups (OH) may adhere to the surface of the silicon-containing aluminum nitride particles obtained by heat-treating the raw material mixture, and oxygen may be contained. When the total of the mass of aluminum, the mass of silicon, the mass of nitrogen, and the mass of oxygen analyzed from the particles by the above-described apparatuses is 100% by mass, even if the mass ratio of oxygen is in the range of 0.9% by mass or more and 3.5% by mass or less, if a film containing oxygen is not formed on the surface of the silicon-containing aluminum nitride particles, it is difficult to suppress the reaction between the silicon-containing aluminum nitride particles and moisture, and the moisture in the air or in the resin reacts with the components in the silicon-containing aluminum nitride particles, and for example, the generation of ammonia (NH3) may not be suppressed. Even when the silicon-containing aluminum nitride particles are not subjected to the second heat treatment and a film containing oxygen is not formed on the surface of the particles, hydroxyl groups (OH) may bind to the surface of the particles, and the mass ratio of oxygen may be in the range of 0.9% by mass or more and 3.5% by mass or less. However, if a film containing oxygen is not formed on the surface of the particles, the particle size becomes slightly smaller and the numerical value Y of the specific surface area Ym 2 / g becomes larger. Therefore, even when the X mass% of oxygen is in the range of 0.9% by mass or more and 3.5% by mass or less, the ratio (X / Y) becomes smaller than 0.40. Even when the silicon-containing aluminum nitride particles are not subjected to the second heat treatment and a film containing oxygen is not formed on the surface of the particles, hydroxyl groups (OH) may bind to the surface of the particles, and the mass ratio of oxygen may be in the range of 0.9% by mass or more and 3.5% by mass or less. However, if a film containing oxygen is not formed on the surface of the particles, the ratio O P / N P analyzed from the particles by XPS becomes less than 2.0.

[0025] The silicon-containing aluminum nitride particles have a specific surface area measured by the BET method of 2.5 m 2 / g or more and 4.5 m 2It is preferably within the range of 2.5 m 2 / g or more and 4.5 m 2 / g or less. When the specific surface area of the silicon-containing aluminum nitride particles measured by the BET method is within the range of 2.6 m 2 / g or more and 4.4 m 2 / g or less, it is presumed that a film containing oxygen is formed almost evenly on the surface of the silicon-containing aluminum nitride particles with a ratio (X / Y) within the range of 0.40 or more and 0.85 or less. Since the reaction between the components of the silicon-containing aluminum nitride particles, particularly aluminum and moisture, is suppressed, even when contained in a resin, the generation of ammonia (NH3) produced by the reaction between aluminum nitride (AlN) and moisture (H2O) contained in the silicon-containing aluminum nitride can be suppressed. The silicon-containing aluminum nitride particles preferably have a specific surface area measured by the BET method within the range of 2.7 m 2 / g or more and 4.2 m 2 / g or less, and more preferably within the range of 2.7 m

[0026] The silicon-containing aluminum nitride particles have a peak intensity N of the Kα line of nitrogen analyzed from the particles by X-ray fluorescence analysis (hereinafter also referred to as "XRF") Kα The ratio of the peak intensity Al of the Kα line of aluminum to Kα Al Kα / N Kα is preferably more than 740. The peak intensity of the Kα line of nitrogen measured from the silicon-containing aluminum nitride particles by XRF is the peak intensity of the Kα line of the nitrogen element. Also, the peak intensity of the Kα line of aluminum measured from the silicon-containing aluminum nitride particles by XRF is the peak intensity of the Kα line of the aluminum element. Since the silicon-containing aluminum nitride particles are covered with a film containing oxygen, the peak intensity N of the Kα line of nitrogen that forms the crystal structure of the silicon-containing aluminum nitride particles Kα is the peak intensity Al of the Kα line of aluminum, which is more likely to bind with oxygen than the nitrogen element KαRather, it is more likely to decrease due to the increase of the oxygen-containing film. By analyzing the silicon-containing aluminum nitride particles with XRF, the state of the oxygen-containing film covering the silicon-containing aluminum nitride particles can be evaluated. The silicon-containing aluminum nitride particles have a peak intensity N of the Kα line of nitrogen analyzed from the particles by XRF Kα with respect to the peak intensity Al of the Kα line of aluminum Kα The ratio Al Kα / N Kα If it exceeds 740, an oxygen-containing film is formed on the surface of the silicon-containing aluminum nitride particles. The silicon-containing aluminum nitride particles have a peak intensity N of the Kα line of nitrogen analyzed from the particles by XRF Kα with respect to the peak intensity Al of the Kα line of aluminum Kα The ratio Al Kα / N Kα is more preferably 745 or more, even more preferably 750 or more, even more preferably 760 or more, and may be 810 or less. If the aforementioned ratio Al Kα / N Kα is 810 or less, an oxygen-containing film can be formed on the surface of the silicon-containing aluminum nitride while suppressing the formation of aluminum oxide.

[0027] The silicon-containing aluminum nitride particles have a composition represented by Al 1-x Si x N (where x is a number satisfying 0.02 ≦ x ≦ 0.2). It is preferable that the silicon-containing aluminum nitride particles contain oxygen. When the silicon-containing aluminum nitride particles have a composition represented by Al 1-x Si x N (where x is a number satisfying 0.02 ≦ x ≦ 0.2), since a part of aluminum in the crystal structure is substituted with silicon while maintaining the crystal structure of aluminum nitride, the reflectivity can be increased while maintaining the high thermal conductivity of aluminum nitride. The silicon-containing aluminum nitride particles have Al 1-x Si xIt has a composition represented by N (where x is a number satisfying 0.02 ≤ x ≤ 0.2), and because the aforementioned ratio (X / Y) is within the range of 0.40 or more and 0.85 or less, it has a film containing oxygen on the surface of the silicon-containing aluminum nitride particles, can suppress the reaction with moisture, and can suppress the generation of ammonia (NH3). The silicon-containing aluminum nitride particles are Al 1-x Si x It has a composition represented by N (where x is a number satisfying 0.02 ≤ x ≤ 0.2), and because the aforementioned ratio O P / N P exceeds 2.0, it has a film containing oxygen on the surface of the silicon-containing aluminum nitride particles. When performing PCT, it is possible to suppress an increase in the mass of the silicon-containing aluminum nitride particles, is difficult to react with moisture while maintaining high thermal conductivity and high reflectivity, and has excellent moisture resistance. Al 1-x Si x The variable x in the composition represented by N represents the molar ratio of Si in 1 mole of the composition. The variable x is more preferably a number satisfying the range of 0.02 or more and 0.15 or less (0.02 ≤ x ≤ 0.15), even more preferably a number satisfying the range of 0.02 or more and 0.10 or less (0.02 ≤ x ≤ 0.10), still more preferably a number satisfying the range of 0.02 or more and 0.08 or less (0.02 ≤ x ≤ 0.08), particularly preferably a number satisfying the range of 0.02 or more and 0.07 or less (0.02 ≤ x ≤ 0.07), and even more particularly preferably within the range of 0.03 or more and 0.06 or less (0.03 ≤ x ≤ 0.06).

[0028] The silicon-containing aluminum nitride particles preferably have an average particle size measured by the FSSS method within the range of 0.1 μm or more and 100 μm or less. The silicon-containing aluminum nitride particles may have an average particle size of the particles measured by the FSSS method within the range of 0.5 μm or more and 3.0 μm or less, and may be silicon-containing aluminum nitride particles with a small average particle size. The silicon-containing aluminum nitride particles may have an average particle size of the particles measured by the FSSS method within the range of 0.1 μm or more and 3.0 μm or less, within the range of 0.2 μm or more and 3.0 μm or less, or within the range of 0.5 μm or more and 3.0 μm or less. The silicon-containing aluminum nitride particles may have an average particle size measured by the FSSS method within the range of more than 3.0 μm and 100 μm or less, and may be silicon-containing aluminum nitride particles with a large average particle size. The silicon-containing aluminum nitride particles may have an average particle size measured by the FSSS method within the range of more than 3.0 μm and 80 μm or less, within the range of 3.5 μm or more and 80 μm or less, within the range of 5.0 μm or more and 75 μm or less, or within the range of 10 μm or more and 70 μm or less.

[0029] Silicon-containing aluminum nitride particles with an average particle size measured by the FSSS method in the range of 0.5 μm or more and 3.0 μm or less, when the total of the mass of aluminum and the mass of silicon analyzed from the particles by ICP and the mass of nitrogen and the mass of oxygen analyzed from the particles by an oxygen-nitrogen analyzer is taken as 100% by mass, the total mass ratio of aluminum and nitrogen is 90% by mass or more, the mass ratio of silicon is in the range of 1.5% by mass or more and 10.0% by mass or less, and the ratio (X / Y) is in the range of 0.40 or more and 0.85 or less. When the silicon-containing aluminum nitride particles have a relatively small average particle size in the range of 0.5 μm or more and 3.0 μm or less measured by the FSSS method, if the ratio (X / Y) is in the range of 0.40 or more and 0.85 or less, it is presumed that a film containing oxygen is formed almost evenly on the surface of the silicon-containing aluminum nitride particles. Even when a film containing oxygen is formed on the surface, the moisture resistance can be improved while maintaining high thermal conductivity and high reflectivity. Silicon-containing aluminum nitride particles suppress the reaction of the components of the silicon-containing aluminum nitride particles, particularly the reaction between aluminum and moisture. Therefore, even when contained in a resin, the generation of ammonia (NH3) produced by the reaction of aluminum nitride (AlN) contained in the silicon-containing aluminum nitride with moisture (H2O) is suppressed, and it has excellent moisture resistance.

[0030] Silicon-containing aluminum nitride particles with an average particle size measured by the FSSS method in the range exceeding 3.0 μm and 100 μm or less, when the total of the mass of aluminum and the mass of silicon analyzed from the particles by ICP and the mass of nitrogen and the mass of oxygen analyzed from the particles by an oxygen-nitrogen analyzer is taken as 100% by mass, the total mass ratio of aluminum and nitrogen is 90% by mass or more, the mass ratio of silicon is in the range of 1.5% by mass or more and 10.0% by mass or less, and the ratio O P / N P exceeds 2.0. When the silicon-containing aluminum nitride particles have a relatively large average particle size in the range exceeding 3.0 μm and 100 μm measured by the FSSS method, the ratio O P / N PIf it exceeds 2.0, it is presumed that a film containing oxygen is formed almost evenly on the surface of the silicon-containing aluminum nitride particles even when the average particle size is relatively large. The silicon-containing aluminum nitride particles can improve moisture resistance while maintaining high thermal conductivity and high reflectivity even when the average particle size is relatively large and a film containing oxygen is evenly formed on the surface of the particles. When the silicon-containing aluminum nitride particles are subjected to PCT, an increase in the mass of the silicon-containing aluminum nitride particles can be suppressed, the particles are less likely to react with moisture, and they have excellent moisture resistance.

[0031] In the powder X-ray diffraction pattern measured using CuKα radiation (1.5418 Å), the peak intensity at a diffraction angle 2θ of 43.3 ± 0.5° is preferably 5% or less relative to the peak intensity of 100% at a diffraction angle 2θ of 33.2 ± 0.5° for the silicon-containing aluminum nitride particles. The peak that appears at a diffraction angle 2θ of 33.2 ± 0.5° in the powder X-ray diffraction pattern of the silicon-containing aluminum nitride particles is a peak derived from the crystal structure of aluminum nitride (AlN). The peak that appears at a diffraction angle 2θ of 43.3 ± 0.5° in the powder X-ray diffraction pattern of the silicon-containing aluminum nitride particles is a peak derived from the crystal structure of aluminum oxide (Al2O3). If the peak intensity at a diffraction angle 2θ of 43.3 ± 0.5° is 5% or less relative to the peak intensity of 100% at a diffraction angle 2θ of 33.2 ± 0.5° in the powder X-ray diffraction pattern of the silicon-containing aluminum nitride particles, it can be confirmed that the reaction between aluminum and oxygen in the silicon-containing aluminum nitride particles is suppressed and the formation of aluminum oxide on the surface of the silicon-containing aluminum nitride particles is suppressed. If the formation of aluminum oxide on the surface of the silicon-containing aluminum nitride particles is suppressed, the formation of aluminum oxide, which has a lower thermal conductivity than aluminum nitride, is suppressed, so it can be confirmed that the crystal structure of aluminum nitride partially substituted with silicon, which has a high thermal conductivity of aluminum nitride, is maintained. The peak intensity at a diffraction angle 2θ of 43.3 ± 0.5° relative to the peak intensity of 100% at a diffraction angle 2θ of 33.2 ± 0.5° in the powder X-ray diffraction pattern of the silicon-containing aluminum nitride particles is more preferably 4% or less, still more preferably 3% or less, and may be 0.1% or more, may be 0.2% or more, or may be 0.5% or more. The powder X-ray diffraction patterns representing the crystal structures of aluminum nitride (Si3N4) and aluminum oxide (Al2O3) can refer to the values of the International Center for Diffraction Data (ICDD).

[0032] The silicon-containing aluminum nitride particles preferably have a light reflectance of 50% or more within the wavelength range of 380 nm or more and 730 nm or less. Even when the silicon-containing aluminum nitride particles contain silicon and have a film containing oxygen on the surface, they can maintain a light reflectance of 50% or more within the wavelength range of the visible light region while maintaining a high thermal conductivity.

[0033] The silicon-containing aluminum nitride particles preferably have a light reflectance of 80% or more within the wavelength range of 380 nm or more and 730 nm or less. The thermal conductivity of the aluminum nitride particles is usually as high as 150 W / m·K to 200 W / m·K at 20°C. On the other hand, the reflectance of aluminum nitride within the wavelength range of the visible light region is usually as low as about 70% to 80%. Since a part of the aluminum in the crystal structure of the silicon-containing aluminum nitride particles is replaced by silicon while maintaining the crystal structure of the aluminum nitride, the light reflectance within the wavelength range of the visible light region can be maintained as high as 80% or more while maintaining the high thermal conductivity of the aluminum nitride particles. Also, even when a thin film containing oxygen is formed on the surface of the silicon-containing aluminum nitride particles, the crystal structure of the aluminum nitride partially substituted with silicon is maintained, so that a high thermal conductivity and a high reflectance are maintained. The silicon-containing aluminum nitride particles more preferably have a light reflectance of 81% or more within the wavelength range of the visible light region, and still more preferably 82% or more. The silicon-containing aluminum nitride particles may have a light reflectance of 99% or less, 98% or less, or 95% or less within the wavelength range of the visible light region.

[0034] The silicon-containing aluminum nitride particles preferably have a light reflectance of 40% or less at a wavelength of 250 nm. If the silicon-containing aluminum nitride particles have a light reflectance of 40% or less at a wavelength of 250 nm, the silicon-containing aluminum nitride particles are likely to absorb light having a wavelength in the ultraviolet region near 250 nm, that is, a wavelength of 200 nm to less than 380 nm. For example, when the silicon-containing aluminum nitride is dispersed in a polymer such as a resin and used, deterioration of the polymer containing the resin due to ultraviolet rays can be suppressed.

[0035] When 1.0 g of silicon-containing aluminum nitride particles is brought into contact with 50 mL of a 6 mol / L hydrochloric acid aqueous solution that has been boiled, it is preferable that the amount of ammonia generated in the hydrochloric acid aqueous solution is 120 mass ppm or less. Silicon-containing aluminum nitride particles are obtained by subjecting a raw material mixture to a first heat treatment to obtain silicon-containing aluminum nitride particles that are a first heat treatment product, and then subjecting the obtained silicon-containing aluminum nitride particles, which are the first heat treatment product, to a second heat treatment at a temperature lower than the first heat treatment, thereby forming a film containing oxygen while suppressing the formation of aluminum oxide (Al2O3) on the surface of the silicon-containing aluminum nitride particles. The silicon-containing aluminum nitride particles may have hydroxyl groups attached to the surface of the silicon-containing aluminum nitride particles obtained by the first heat treatment, and the oxygen content may be in the range of 0.9 mass% or more and 3.5 mass% or less. When the silicon-containing aluminum nitride particles have no film containing oxygen formed on the surface and have hydroxyl groups attached, the reaction between the components (e.g., aluminum and nitrogen) in the silicon-containing aluminum nitride particles and moisture is not suppressed, and the reaction of aluminum, nitrogen, and water proceeds, and ammonia (NH3) may be generated. When a film containing oxygen is formed on the surface of the silicon-containing aluminum nitride particles by the second heat treatment, the reaction between the components (e.g., aluminum and nitrogen) in the silicon-containing aluminum nitride particles and water is suppressed, and when 1.0 g of the silicon-containing aluminum nitride particles is brought into contact with 50 mL of a 6 mol / L hydrochloric acid aqueous solution that has been boiled, the amount of ammonia generated in the hydrochloric acid aqueous solution is 120 mass ppm or less. When 1.0 g of the silicon-containing aluminum nitride particles is brought into contact with 50 mL of a 6 mol / L hydrochloric acid aqueous solution that has been boiled, if the amount of ammonia generated in the hydrochloric acid aqueous solution is 120 mass ppm or less, it can be confirmed that the silicon-containing aluminum nitride particles do not have hydroxyl groups attached to the surface, but rather have a film containing oxygen formed on the surface, and the reaction between the silicon-containing aluminum nitride particles and water is suppressed.The amount of ammonia generated can be measured by bringing 1.0 g of the silicon-containing aluminum nitride particles into contact with 50 mL of a boiling 6 mol / L hydrochloric acid aqueous solution, contacting them for 10 minutes with stirring, and measuring the concentration of ammonia in the hydrochloric acid aqueous solution, which is the filtrate obtained by filtration, as the amount of ammonia generated. When 1.0 g of the silicon-containing aluminum nitride particles is brought into contact with 50 mL of a boiling 6 mol / L hydrochloric acid aqueous solution, it is more preferable that the amount of ammonia generated in the hydrochloric acid aqueous solution is 115 mass ppm or less, and even more preferable that it is 110 mass ppm or less. When 1.0 g of the silicon-containing aluminum nitride particles is brought into contact with 50 mL of a boiling 6 mol / L hydrochloric acid aqueous solution, the amount of ammonia generated contained in the hydrochloric acid aqueous solution may be 0.5 mass ppm or more, or may be 1.0 mass ppm or more. Specifically, the measurement of the amount of ammonia generated can be carried out by referring to the method in the examples described later and measuring the amount of ammonia contained in the hydrochloric acid aqueous solution when 1.0 g of the silicon-containing aluminum nitride particles is brought into contact with 50 mL of a 6 mol / L hydrochloric acid aqueous solution, for example, with an ion meter (manufactured by Toa DKK Corporation).

[0036] The silicon-containing aluminum nitride particles preferably have a mass change rate of 50% or less before and after PCT (Pressure Cooker Test) when exposed for 24 hours at 130°C and a relative humidity of 100% using a pressure cooker tester. Specifically, when the mass of the sample of the silicon-containing aluminum nitride particles before PCT is 100% by mass, the mass of the sample of the silicon-containing aluminum nitride particles after PCT is preferably 150% by mass or less. The mass change rate of the silicon-containing aluminum nitride particles before and after PCT refers to the value obtained by subtracting the mass ratio of the silicon-containing aluminum nitride particles after PCT when the silicon-containing aluminum nitride particles before PCT are taken as 100% by mass. If the mass change rate before and after PCT is 50% or less, even when placed under a high temperature of 130°C and a high humidity of 100% relative humidity, the mass change rate is small, the reaction between the elements in the silicon-containing aluminum nitride particles and moisture is suppressed, and the moisture resistance is improved. The mass change rate of the silicon-containing aluminum nitride particles before and after PCT tends to be larger with a larger specific surface area for silicon-containing aluminum nitride particles with a smaller average particle size. Silicon-containing aluminum nitride particles with a smaller average particle size in the range of 0.5 μm or more and 3.0 μm or less in average particle size measured by the FSSS method preferably have a mass change rate before and after PCT of 50% or less, more preferably 48% by mass or less, and even more preferably 46% by mass or less. Silicon-containing aluminum nitride particles with a larger average particle size in the range of more than 3.0 μm and 100 μm or less in average particle size measured by the FSSS method preferably have a mass change rate before and after PCT of 50% or less, more preferably 10% by mass or less, even more preferably 5% by mass or less, and even more preferably 1% by mass or less.

[0037] The sintered body contains silicon-containing aluminum nitride particles. The sintered body may contain silicon-containing aluminum nitride particles, and the content of the silicon-containing aluminum nitride particles may be 90% by mass or more and 99% by mass or less. The sintered body may be obtained by molding a raw material powder containing silicon-containing aluminum nitride particles to obtain a molded body, and then firing the obtained molded body to obtain a sintered body. The sintered body contains silicon-containing aluminum nitride particles. The silicon-containing aluminum nitride particles contained in the sintered body, when the total of the mass of aluminum, the mass of silicon, the mass of nitrogen, and the mass of oxygen analyzed from the particles by each of the aforementioned apparatuses is 100% by mass, the mass ratio of oxygen is X% by mass, and the specific surface area of the particles measured by the BET method is Ym 2 / g, and the ratio (X / Y) of the numerical value X of the mass ratio X% by mass of oxygen to the numerical value Y of the specific surface area Ym 2 / g of the particles is within the range of 0.40 or more and 0.85 or less. The silicon-containing aluminum nitride particles contained in the sintered body, when the total of the mass of aluminum, the mass of silicon, the mass of nitrogen, and the mass of oxygen analyzed by each of the aforementioned apparatuses is 100% by mass, the total mass ratio of aluminum and nitrogen is 90% by mass or more, the mass ratio of silicon is within the range of 1.5% by mass or more and 10.0% by mass or less, and the ratio O P / N PIt exceeds 2.0. The silicon-containing aluminum nitride particles have a film containing oxygen on the surface, and since the reaction between the silicon-containing aluminum nitride particles and water is suppressed, the generation of ammonia (NH3) is suppressed and the moisture resistance is improved. The silicon-containing aluminum nitride particles have a film containing oxygen on the surface, and since the reaction between the silicon-containing aluminum nitride particles and water is suppressed, the mass change rate before and after PCT is 50% or less, and the moisture resistance is improved. The sintered body containing the silicon-containing aluminum nitride particles has a high reflectance of light in the visible light region while maintaining the high thermal conductivity of aluminum nitride, and since the moisture resistance is improved, it can be used, for example, as a support for arranging the light source of a light-emitting device. Further, the sintered body containing the silicon-containing aluminum nitride particles can also be used as a heat sink or a support for electronic components. Examples of the method for obtaining a molded body by molding a raw material containing silicon-containing aluminum nitride particles include die pressing, cold isostatic pressing (CIP) in which terms are defined in JIS Z2500:2000, No. 2109, and the like. The atmosphere for firing the molded body is preferably an inert atmosphere containing nitrogen, and the nitrogen gas in the inert atmosphere may preferably be an atmosphere of 70% by volume or more, or an atmosphere of 80% by volume or more. The temperature for firing the molded body may be in the range of 1600°C or higher and 1800°C or lower, or may be in the range of 1650°C or higher and 1750°C or lower.

[0038] The resin composition contains silicon-containing aluminum nitride particles and a resin. The resin composition containing silicon-containing aluminum nitride particles can use the silicon-containing aluminum nitride particles, for example, as a filler. As the resin contained in the resin composition, a thermoplastic resin and a thermosetting resin can be used. The resin composition containing silicon-containing aluminum nitride particles can be used as a light-emitting device, for example, a molded body having a recess and also functioning as a reflector, or a sealing material disposed in the recess of the molded body. Further, the resin composition containing silicon-containing aluminum nitride particles can also be used as a bonding member such as an underfill material, a die bond material for bonding a light-emitting element or a semiconductor element to a support body. As the thermoplastic resin as the resin contained in the resin composition, at least one resin selected from the group consisting of an acrylic resin, a polycarbonate resin, a cyclic polyolefin resin, a polyethylene terephthalate resin, and a polyester resin can be used. As the thermosetting resin as the resin contained in the resin composition, at least one resin selected from the group consisting of an epoxy resin and a silicone resin can be used.

[0039] FIG. 1 is a schematic cross-sectional view showing an example of a light-emitting device using a resin composition containing silicon-containing aluminum nitride particles.

[0040] The light-emitting device 100 includes a molded body 40 which is a support having a recess, a light-emitting element 10 serving as a light source, and a fluorescent member 50 which is a sealing material disposed in the recess and covering the light-emitting element 10. The molded body 40 is integrally formed by a pair of leads 20, 30 and a resin portion 42 containing a thermoplastic resin or a thermosetting resin. In the molded body 40, a pair of leads 20, 30 constituting the bottom surface of the recess are disposed, and a resin portion 42 constituting the side surface of the recess is disposed. The side surface of the recess formed by the resin portion 42 also functions as a reflector of the light-emitting device. The light-emitting element 10 is die-bonded by a bonding member 13 to the upper surface of one of the pair of leads 20, 30 constituting the bottom surface of the recess of the molded body 40. The light-emitting element 10 has a pair of positive and negative electrodes, and the pair of positive and negative electrodes are electrically connected to the pair of leads 20, 30 via wires 60, respectively. The light-emitting element 10 is covered by the fluorescent member 50. The fluorescent member 50 contains a phosphor 70 that wavelength-converts the light-emitting element 10. The phosphor 70 may include a first phosphor and a second phosphor having emission peak wavelengths in different wavelength ranges.

[0041] The resin composition containing silicon-containing aluminum nitride particles is preferably included in the resin portion constituting the molded body which is the support of the light-emitting device. The silicon-containing aluminum nitride particles suppress the reaction with moisture in the resin while maintaining a high reflectance, and the resin composition containing silicon-containing aluminum nitride particles can suppress the reaction between the silicon-containing aluminum nitride particles and the moisture contained in the resin and suppress the generation of ammonia (NH3). The resin composition containing silicon-containing aluminum nitride particles can form the resin portion without inhibiting the curing of the resin composition and suppressing the deterioration of the cured product after curing. Since the resin portion constituting the molded body of the light-emitting device also functions as a reflector, the resin portion formed using the resin composition containing silicon-containing aluminum nitride particles can improve the light extraction efficiency due to the high reflectance of the silicon-containing aluminum nitride particles.

[0042] A resin composition containing silicon-containing aluminum nitride particles is preferably included in a bonding member for die-bonding a light-emitting element to one lead. The silicon-containing aluminum nitride particles suppress the reaction with moisture in the resin while maintaining high thermal conductivity. The resin composition containing silicon-containing aluminum nitride particles suppresses the reaction between the silicon-containing aluminum nitride particles and the moisture contained in the resin, suppresses the generation of ammonia (NH3), reduces the mass change rate before and after PCT to 50% or less, and can improve the moisture resistance. The resin composition containing silicon-containing aluminum nitride particles can form a resin part without inhibiting the curing of the resin composition and suppressing the deterioration of the cured product after curing. By using the resin composition containing silicon-containing aluminum nitride particles in a bonding member for die-bonding a light-emitting element to a lead, the heat dissipation of the light-emitting device can be improved due to the high thermal conductivity of the silicon-containing aluminum nitride particles.

[0043] A method for producing silicon-containing aluminum nitride particles includes mixing aluminum nitride and silicon nitride to obtain a raw material mixture containing silicon nitride in the range of 2% by mass or more and 15% by mass or less when the total of aluminum nitride and silicon nitride is 100% by mass; subjecting the raw material mixture to a first heat treatment at a pressure of 0.101 MPa or more and a temperature in the range of 1600°C or more and 2100°C or less to obtain a first heat-treated product; and subjecting the obtained first heat-treated product to a second heat treatment at a temperature of 850°C or more and less than 1000°C to obtain a second heat-treated product. The method for producing silicon-containing aluminum nitride particles preferably includes wet-dispersing the obtained first heat-treated product before the second heat treatment.

[0044] In the raw material mixture, with respect to a total amount of 100% by mass of aluminum nitride and silicon nitride, the silicon nitride is in the range of 2% by mass or more and 15% by mass or less, preferably in the range of 3% by mass or more and 14% by mass or less, more preferably in the range of 4% by mass or more and 13% by mass or less, still more preferably in the range of 5% by mass or more and 12% by mass or less, even more preferably in the range of 5% by mass or more and 11% by mass or less, and particularly preferably in the range of 5% by mass or more and 10% by mass or less. As long as the raw material mixture contains silicon nitride in the range of 2% by mass or more and 15% by mass or less with respect to a total amount of 100% by mass of aluminum nitride and silicon nitride, by performing the first heat treatment, while maintaining the crystal structure of aluminum nitride, a part of aluminum in the crystal structure is substituted with silicon, and a first heat-treated product having a high reflectance of light in the wavelength range of 380 nm or more and 730 nm or less can be obtained.

[0045] The mixing of aluminum nitride and silicon nitride is preferably performed using a mixer. In addition to a ball mill commonly used industrially, crushers such as a vibration mill, a roll mill, and a jet mill can also be used as the mixer. Further, aluminum nitride and silicon nitride can also be classified using wet separators such as a sedimentation tank, a hydrocyclone, and a centrifuge, and dry classifiers such as a cyclone and an air separator, which are commonly used industrially, in order to make the specific surface area of the particles within a certain range.

[0046] The obtained raw material mixture is first heat-treated at a pressure of 0.101 MPa or more and a temperature in the range of 1600 °C or more and 2100 °C or less to obtain a first heat-treated product. By the first heat treatment, while maintaining the crystal structure of aluminum nitride, a part of aluminum in the crystal structure is substituted with silicon, and a first heat-treated product which is silicon-containing aluminum nitride particles can be obtained.

[0047] The raw material mixture is preferably subjected to a first heat treatment under a pressure of 0.101 MPa or more and within a range exceeding 0.101 MPa and not exceeding 1 MPa. By subjecting the raw material mixture to the first heat treatment under a pressure of 0.101 MPa or more, even if a part of aluminum in the crystal structure of aluminum nitride is substituted with silicon, the crystal structure of aluminum nitride is difficult to break, and the crystal structure of aluminum nitride with high thermal conductivity is maintained, and a first heat-treated product which is silicon-containing aluminum nitride particles can be obtained.

[0048] The temperature of the first heat treatment is within a range of 1600 °C or more and 2100 °C or less, preferably within a range of 1650 °C or more and 2050 °C or less, more preferably within a range of 1700 °C or more and 2050 °C or less, and still more preferably within a range of 1750 °C or more and 2000 °C or less. If the temperature of the first heat treatment is within a range of 1600 °C or more and 2100 °C or less, the crystal structure of aluminum nitride can be maintained, a part of aluminum in the crystal structure can be substituted with silicon, and silicon-containing aluminum nitride particles with high reflectivity within a wavelength range of 380 nm or more and 730 nm or less can be obtained while maintaining the high thermal conductivity of aluminum nitride.

[0049] The atmosphere of the first heat treatment is preferably a nitrogen atmosphere. The atmosphere of the first heat treatment only needs the nitrogen gas in the atmosphere to be 80% by volume or more. The content of nitrogen gas in the atmosphere is preferably 90% by volume or more, more preferably 95% by volume or more, still more preferably 98% by volume or more, and most preferably 100% by volume. The atmosphere during the first heat treatment may contain 15% by volume or less of oxygen, but when oxygen is contained, aluminum is oxidized, the crystal structure changes, and it becomes difficult to maintain high thermal conductivity. The lower the content of oxygen gas in the atmosphere, the higher the reflectivity while maintaining high thermal conductivity, and silicon-containing aluminum nitride particles can be obtained. The content of oxygen gas in the atmosphere of the first heat treatment is preferably 10% by volume or less, more preferably 5% by volume or less, and still more preferably 1% by volume or less.

[0050] The time for performing the first heat treatment, specifically, the holding time at the heat treatment temperature of the raw material mixture, is preferably 1 hour or more and 10 hours or less, more preferably 2 hours or more and 8 hours or less. If the holding time at the heat treatment temperature of the raw material mixture is 1 hour or more and 10 hours or less, while maintaining the crystal structure of aluminum nitride, a part of aluminum in the crystal structure is substituted with silicon, and silicon-containing aluminum nitride particles having a high reflectance in the wavelength range of the visible light region can be obtained while maintaining the high thermal conductivity of aluminum nitride. In the method for producing silicon-containing aluminum nitride particles, obtaining the raw material mixture and subjecting the raw material mixture to the first heat treatment to obtain a first heat-treated product may refer to the description in JP-A-2020-100543.

[0051] The obtained first heat-treated product is preferably wet-dispersed before the second heat treatment. By wet-dispersing the obtained first heat-treated product before the second heat treatment, the first heat-treated product that has aggregated into secondary particles during the first heat treatment can be dispersed into individual primary particles, and the second heat treatment can be performed after the wet dispersion, and a film containing oxygen can be evenly formed on the surface of the primary particles by the second heat treatment. The wet dispersion can be carried out by dispersing the obtained first heat-treated product in a solvent having a mass (g) 2 to 5 times the mass (g) of the first heat-treated product and stirring. The solvent used for the wet dispersion can be at least one selected from the group consisting of, for example, water, methanol, ethanol, isopropyl alcohol, n-butyl alcohol, propylene glycol, diethyl ether, dimethyl ether, ethyl methyl ether, ethylene glycol, methyl ethyl ketone, cyclohexane, cyclohexanone, n-hexane, toluene, benzene, acetone, chloroform, dimethylformamide, and dichloromethane. The solvent may be used alone or in combination of two or more. The solvent preferably contains at least one of water and ethanol, and preferably contains water. Deionized water may be used for the water. The temperature of the solvent when performing the wet dispersion is preferably room temperature, and preferably in the range of 15°C or higher and 25°C or lower. In order to disperse the first heat-treated product that has aggregated into secondary particles so as to contain a large number of primary particles, the time for wet-dispersing the first heat-treated product is preferably 0.5 hours or more and 10 hours or less, and more preferably 1 hour or more and 8 hours or less. Also, the wet dispersion can be carried out using, for example, a mixer, and stirring can also be carried out using, for example, a ball mill. As the medium when using a ball mill, alumina balls having a size in the range of, for example, a diameter (φ) of 1 mm or more and 5 mm or less can be used.

[0052] The method for producing silicon-containing aluminum nitride particles preferably includes subjecting the first heat-treated product to wet dispersion, followed by solid-liquid separation, and drying at a temperature in the range of 80°C or higher and 120°C or lower. By subjecting the first heat-treated product to wet dispersion, followed by solid-liquid separation, and drying at a temperature in the range of 80°C or higher and 120°C or lower, the first heat-treated product formed as primary particles by wet dispersion can be dried as primary particles, making it easier to form a film containing oxygen on the surface of each particle. The temperature for drying the first heat-treated product after wet dispersion may be in the range of 90°C or higher and 110°C or lower.

[0053] The first heat-treated product after wet dispersion preferably has a particle size ratio D / Dm of the average particle size D measured by the FSSS method to the volume median diameter Dm measured by the laser diffraction particle size distribution measurement method in the range of 0.2 or more and 0.95 or less. The first heat-treated product after the final wet separation is preferably dried after solid-liquid separation. When the particle size ratio D / Dm of the first heat-treated product after wet dispersion is 0.2 or more and 0.95 or less, the average particle size measured by the FSSS method of the first heat-treated product after wet dispersion is preferably in the range of 0.1 μm or more and 100 μm or less. The volume median diameter Dm measured by the laser diffraction particle size distribution measurement method is the volume median diameter at 50% cumulative volume in the volume-based particle size distribution measured by the laser diffraction particle size distribution measurement method. The volume median diameter Dm measured by the laser diffraction particle size distribution measurement method is a method of measuring the particle size without distinguishing primary particles and secondary particles by using the scattered light of the laser light irradiated on the particles. The volume median diameter Dm after wet dispersion is preferably in the range of 0.2 μm or more and 200 μm or less, and more preferably in the range of 0.5 μm or more and 180 μm or less. The particle size ratio D / Dm of the average particle size D to the volume median diameter Dm indicates that the closer the numerical value for distinguishing primary particles and secondary particles is to 1, the fewer the aggregated secondary particles and the more the number of primary particles. That D / Dm is less than 1 indicates the presence of secondary particles. When the particle size ratio D / Dm of the first heat-treated product after wet dispersion is in the range of 0.2 or more and 0.5 or less, it indicates that by wet dispersion after the first heat treatment, the aggregated secondary particles are dispersed and the proportion of primary particles contained increases.

[0054] The first heat-treated product after wet dispersion preferably has a particle size ratio D / Dm in the range of 0.2 or more and 0.5 or less. When the particle size ratio D / Dm of the first heat-treated product after wet dispersion is in the range of 0.2 or more and 0.5 or less, the average particle size of the first heat-treated product after wet dispersion measured by the FSSS method may be in the range of 0.1 μm or more and 3.0 μm or less, or may be in the range of 0.5 μm or more and 3.0 μm or less. When the particle size ratio D / Dm of the first heat-treated product after wet dispersion is in the range of 0.2 or more and 0.5 or less, the volume median diameter Dm of the first heat-treated product after wet dispersion measured by the laser diffraction particle size distribution measurement method may be in the range of 0.3 μm or more and 6.0 μm or less, or may be in the range of 0.5 μm or more and 5.0 μm or less. Even if the average particle size D of the first heat-treated product after wet dispersion measured by the FSSS method is in the range of 0.1 μm or more and 3.0 μm or less and the first heat-treated product has a small average particle size, if the particle size ratio D / Dm is in the range of 0.2 or more and 0.5 or less, the proportion of primary particles contained is large, and by the second heat treatment described later, an oxygen-containing film can be formed on the surface of the silicon-containing aluminum nitride particles while suppressing the formation of aluminum oxide while maintaining the crystal structure of the silicon-containing aluminum nitride particles. The first heat-treated product after wet dispersion more preferably has a particle size ratio D / Dm in the range of 0.25 or more and 0.5 or less, and even more preferably in the range of 0.30 or more and 0.45 or less.

[0055] The first heat-treated product after wet dispersion preferably has a particle size ratio D / Dm in the range of 0.55 or more and 0.95 or less. When the particle size ratio D / Dm of the first heat-treated product after wet dispersion is in the range of 0.55 or more and 0.95 or less, the average particle size of the first heat-treated product measured by the FSSS method may be in the range of more than 3.0 μm and 100 μm or less, may be in the range of more than 3.0 μm and 80 μm or less, may be in the range of 3.5 μm or more and 80 μm or less, may be in the range of 5.0 μm or more and 75 μm or less, or may be in the range of 10 μm or more and 70 μm or less. When the particle size ratio D / Dm of the first heat-treated product after wet dispersion is in the range of 0.55 or more and 0.95 or less, the volume median diameter Dm of the first heat-treated product after wet dispersion measured by the laser diffraction particle size distribution measurement method may be in the range of 5 μm or more and 105 μm or less, or may be in the range of 6 μm or more and 100 μm or less. Even if the average particle size D of the first heat-treated product measured by the FSSS method is in the range of more than 3.0 μm and 100 μm or less and the first heat-treated product has a large average particle size, if the particle size ratio D / Dm is in the range of 0.55 or more and 0.95 or less, a larger proportion of primary particles is contained, and by the second heat treatment described later, while maintaining the crystal structure of the silicon-containing aluminum nitride particles, an oxygen-containing film can be formed on the surface of the silicon-containing aluminum nitride particles with a large average particle size while suppressing the formation of aluminum oxide. The particle size ratio D / Dm of the first heat-treated product after wet dispersion is more preferably in the range of 0.6 or more and 0.9 or less, and even more preferably in the range of 0.65 or more and 0.85 or less.

[0056] The obtained first heat-treated product is second heat-treated at a temperature of 850°C or higher and lower than 1000°C to obtain a second heat-treated product. By subjecting the first heat-treated product to the second heat treatment, it is possible to obtain a second heat-treated product which is silicon-containing aluminum nitride particles having a film containing oxygen formed on the surface of the silicon-containing aluminum nitride particles which are the first heat-treated product, while suppressing the formation of aluminum oxide. The film containing oxygen formed on the surface of the silicon-containing aluminum nitride particles by the second heat treatment is different from the hydroxyl group (OH) attached to the surface of the silicon-containing aluminum nitride particles, suppresses the reaction between the silicon-containing aluminum nitride particles and water, and is, for example, difficult to react with moisture contained in the atmosphere or resin, and the moisture resistance of the silicon-containing aluminum nitride particles can be improved. The temperature of the second heat treatment is more preferably a temperature of 900°C or higher and 980°C or lower. The temperature of the second heat treatment is lower than the temperature of the first heat treatment, and the difference between the temperature of the first heat treatment and the temperature of the second heat treatment is preferably 500°C or higher, more preferably 700°C or higher, and preferably 1250°C or lower.

[0057] The atmosphere of the second heat treatment is preferably an air atmosphere. The air atmosphere means an atmosphere containing 20% by volume or more of oxygen in the atmosphere. The pressure of the second heat treatment is preferably in the range of 0.09 MPa or higher and 0.12 MPa or lower, and preferably 0.101 MPa which is the standard atmospheric pressure.

[0058] The time for performing the second heat treatment is preferably 0.5 hours or more and 20 hours or less, and more preferably 1 hour or more and 15 hours or less. The time for performing the second heat treatment specifically refers to the holding time of the first heat-treated product at the second heat treatment temperature. If the time of the second heat treatment is 0.5 hours or more and 15 hours or less, it is possible to form a film containing oxygen on the surface of the silicon-containing aluminum nitride particles while suppressing the formation of aluminum oxide while maintaining the crystal structure of the silicon-containing aluminum nitride particles.

[0059] The obtained second heat-treated product may be subjected to a classification process. As the classification process, for example, at least one of wet dispersion, wet sieving, dehydration, drying, and dry sieving may be performed.

[0060] The obtained second heat-treated product is silicon-containing aluminum nitride particles having a film containing oxygen on the surface. When the total of the mass of aluminum and the mass of silicon analyzed from the particles by ICP and the mass of nitrogen and the mass of oxygen measured from the particles by an oxygen-nitrogen analyzer is set to 100% by mass, the total mass ratio of aluminum and nitrogen is 90% by mass or more, the mass ratio of silicon is in the range of 1.5% by mass or more and 10.0% by mass or less, oxygen is X% by mass, and the specific surface area of the particles measured by the BET method is Ym 2 / g, and the ratio (X / Y) of the numerical value X of X% by mass of oxygen to the numerical value Y of Ym 2 / g of the specific surface area is preferably in the range of 0.40 or more and 0.85 or less, and is silicon-containing aluminum nitride particles.

[0061] When the total of the mass of aluminum and the mass of silicon analyzed from the particles by ICP and the mass of nitrogen and the mass of oxygen measured from the particles by an oxygen-nitrogen analyzer is set to 100% by mass for the obtained second heat-treated product, the total mass ratio of aluminum and nitrogen is 90% by mass or more, the mass ratio of silicon is in the range of 1.5% by mass or more and 10.0% by mass or less, and the atomic percentage N P (at%) of nitrogen analyzed from the particles by XPS to the atomic percentage O P (at%) of oxygen, the ratio O P / N P is preferably more than 2.0, and is silicon-containing aluminum nitride particles.

Examples

[0062] Hereinafter, the present invention will be specifically described with reference to examples. The present invention is not limited to these examples.

[0063] Example 1 With respect to a total of 100% by mass of aluminum nitride powder and silicon nitride powder, 94.5% by mass of aluminum nitride powder and 5.5% by mass of silicon nitride powder are mixed to obtain a raw material mixture. The obtained raw material mixture is filled into a container made of boron nitride. The raw material mixture filled in the container is subjected to a first heat treatment at 1800 °C for 4 hours under a pressure of 0.92 MPa in a nitrogen atmosphere of 100% by volume of nitrogen gas to obtain a first heat-treated product. 100 g of the obtained first heat-treated product is dispersed in 400 g of deionized water, and wet-dispersed using 200 g of alumina balls with a diameter (φ) of 2 mm at a room temperature of 20 °C for 6 hours using a ball mill. The first heat-treated product after wet dispersion is subjected to solid-liquid separation and dried at 100 °C for 10 hours. The first heat-treated product after wet dispersion and drying is subjected to a second heat treatment at 900 °C for 10 hours under atmospheric pressure (0.101 MPa) in an air atmosphere to obtain a second heat-treated product. The second heat-treated product is subjected to a classification treatment by a dry sieve to obtain silicon-containing aluminum nitride particles that are the second heat-treated product. Table 1 shows the presence or absence of silicon nitride (Si3N4) in the raw material mixture, the first heat treatment temperature, the wet dispersion time, the average particle diameter D measured by the Fisher sub-sieve sizer method of the first heat-treated product after wet dispersion and drying, the volume median diameter Dm measured by the laser diffraction particle size distribution measurement method, the particle size ratio D / Dm of the average particle diameter D to the volume median diameter Dm, the temperature and time of the second heat treatment, and the presence or absence of an SiO2 film attached to the surface of the second heat-treated product. In Table 1, when there is no silicon nitride (Si3N4) in the raw material mixture, when there is no coating layer containing silicon dioxide (SiO2), and when no specific treatment is performed, it is described as "none".

[0064] Examples 2 to 5 Silicon-containing aluminum nitride particles that are the second heat-treated product are obtained in the same manner as in Example 1, except that the first heat treatment temperature, the wet dispersion time, the second heat treatment temperature, and the time are changed as shown in Table 1.

[0065] Comparative Example 1 In Example 1, the aluminum nitride particles used as raw materials are used as the aluminum nitride particles in Comparative Example 1.

[0066] Comparative Example 2 The aluminum nitride powder of Comparative Example 1 is first heat-treated at the first heat-treatment temperature shown in Table 1 in the same manner as in Example 1 to obtain a first heat-treated product. The obtained first heat-treated product is wet-dispersed for the time shown in Table 1 and then wet-dispersed and dried in the same manner as in Example 1. The first heat-treated product after wet dispersion and drying is second heat-treated at the second heat-treatment temperature and for the time shown in Table 1 in the same manner as in Example 1 to obtain a second heat-treated product. The obtained second heat-treated product is classified in the same manner as in Example 1 to obtain aluminum nitride particles of Comparative Example 2, which are the second heat-treated product.

[0067] Comparative Example 3 The first heat-treated product after wet dispersion and drying obtained in the same manner as in Example 1, except that the second heat treatment is not performed, is used as the silicon-containing aluminum nitride particles of Comparative Example 3.

[0068] Comparative Example 4 Silicon-containing aluminum nitride particles, which are the second heat-treated product, are obtained in the same manner as in Example 1, except that the time for wet-dispersing the first heat-treated product, the temperature and time for the second heat treatment are as shown in Table 1.

[0069] Comparative Example 5 Without performing the second heat treatment, a coating layer containing silicon dioxide (SiO2) was disposed on the surface of the first heat-treated product after wet dispersion and drying obtained in the same manner as in Example 1. Specifically, 10.4 g of an ethanol solution of tetraethoxysilane (Si(OC2H5)4) (tetraethoxysilane concentration: 28% by mass) was used as a solution containing a metal ion alkoxide. The solution containing a metal alkoxide contained tetraethoxysilane such that SiO2 was 3.0% by mass with respect to 100% by mass of the first heat-treated product. 180 mL of an alcohol preparation (Solmix AP-7) containing ethanol, 1-propanol, and 2-propanol and 63 mL of aqueous ammonia containing 11.0% by mass of ammonia as a basic catalyst were mixed to obtain a reaction solution. 100 g of the first heat-treated product after wet dispersion and drying obtained in the same manner as in Example 1 was placed in the reaction solution, stirred at room temperature, and the first heat-treated product was dispersed. While stirring the reaction solution, the solution containing a metal alkoxide was dropped into the reaction solution over 150 minutes. After completion of the dropping of the solution containing a metal alkoxide, the reaction solution was stirred for 60 minutes, and the first heat-treated product was brought into contact with the solution containing a metal alkoxide in the presence of ammonia which is a basic catalyst. Then, stirring was stopped, and the product having a coating layer containing Si disposed on the surface of the first heat-treated product was taken out from the reaction solution and dried in a dryer at a temperature of 60°C or higher and lower than 120°C for 15 hours or longer to form a film of silicon dioxide (SiO2) on the surface of the first heat-treated product, thereby obtaining the silicon-containing aluminum nitride particles of Comparative Example 5. The content of the coating layer was obtained by comparing the Si and O contents (mass%) of the silicon-containing aluminum nitride particles according to Comparative Example 5 obtained by the composition analysis described below with the Si and O contents (mass%) of the silicon-containing aluminum nitride particles according to Comparative Example 3 which is the first heat-treated product before forming the coating layer, and comparing the total content (mass%) of Si and O of the silicon-containing aluminum nitride particles according to Comparative Example 3 with the total content (mass%) of Si and O of the silicon-containing aluminum nitride particles according to Comparative Example 5, and taking the increase as the amount of the coating layer with respect to the total amount of the silicon-containing aluminum nitride particles according to Comparative Example 5. The content of the coating layer of the silicon-containing aluminum nitride particles according to Comparative Example 5 was 0.8% by mass with respect to 100% by mass of the silicon-containing aluminum nitride of Comparative Example 5.

[0070] Average particle diameter D For the wet-dispersed and first heat-treated products after drying of the examples and comparative examples, the average particle diameter was determined using a Fisher Sub-Sieve Sizer Model 95 (manufactured by Fisher Scientific). Specifically, a 1 cm 3 portion of the sample was weighed, packed into a dedicated tubular container, and then dried air at a constant pressure was passed through. From the relational expression between the permeated air pressure and the porosity of the packed sample, the average particle diameter by the FSSS method was determined. The results are shown in Table 1. The average particle diameter by the FSSS method is also referred to as the Fisher sub-sieve sizer’s number.

[0071] Volume median diameter Dm For the wet-dispersed and first heat-treated products after drying of the examples and comparative examples, the volume median diameter Dm was measured by the laser diffraction particle size distribution measurement method using a laser diffraction particle size distribution measuring device (MASTER SIZER 3000, manufactured by MALVERN). The results are shown in Table 1.

[0072] [Table 1]

[0073] For each of the silicon-containing aluminum nitride particles according to Examples 1 to 5 and Comparative Examples 3 to 5, and the aluminum nitride particles according to Comparative Examples 1 and 2, the following evaluations were performed. The results are shown in Table 2.

[0074] Composition analysis For each of the silicon-containing aluminum nitride particles according to Examples 1 to 5 and Comparative Examples 3 to 5, and each of the aluminum nitride particles according to Comparative Examples 1 and 2, compositional analysis was performed. The mass of aluminum (Al) and the mass of silicon (Si) in each particle were quantitatively analyzed using an inductively coupled plasma atomic emission spectrometer (ICP-AES, manufactured by Perkin Elmer). Also, for the mass of oxygen (O) and the mass of nitrogen (N) in each particle, quantitative analysis was performed using an oxygen-nitrogen analyzer (manufactured by HORIBA). The numerical values of Al, Si, O, and N in Table 2 are the mass ratios of each element when the total of the mass of aluminum, the mass of silicon, the mass of nitrogen, and the mass of oxygen is 100% by mass. Each silicon-containing aluminum nitride particle has a composition represented by Al 1-x Si x N, contains oxygen, and with the molar ratio of N in 1 mole of the composition being 1, the variable x representing the molar ratio of Si was determined. Each of the silicon-containing aluminum nitride particles according to Examples 1 to 5 and each of the silicon-containing aluminum nitride particles according to Comparative Examples 3 and 4 has a composition represented by Al 1-x Si x N, and x in this composition is 0.05 (x = 0.05), and it has a composition represented by Al 0.95 Si 0.05 N and contains oxygen. The aluminum nitride particles according to Comparative Examples 1 and 2 have a composition represented by AlN with a molar ratio of silicon being 0. The silicon-containing aluminum nitride particles according to Comparative Example 5 have a composition represented by Al 1-x Si x N, and x in this composition is 0.06 (x = 0.06), and it has a composition represented by Al 0.94 Si 0.06 N and contains oxygen.

[0075] Specific surface area by BET method For each of the silicon-containing aluminum nitride particles according to Examples 1 to 5 and Comparative Examples 3 to 5, and each of the aluminum nitride particles according to Comparative Examples 1 and 2, measurement was performed using a fully automatic specific surface area measuring device (Macsorb, manufactured by Mountech) by the BET method.

[0076] Ratio (X / Y) For each silicon-containing aluminum nitride particle according to Examples 1 to 5 and Comparative Examples 3 to 5 and each aluminum nitride particle according to Comparative Examples 1 and 2, the specific surface area Ym 2 The ratio (X / Y) of the numerical value X of the mass% of oxygen determined by the composition analysis to the numerical value Y of / g was determined.

[0077] X-ray diffraction pattern and peak intensity For each silicon-containing aluminum nitride particle according to Examples 1 to 5 and Comparative Examples 3 to 5 and each aluminum nitride particle according to Comparative Examples 1 and 2, a sample horizontal multi-purpose X-ray diffractometer (Ultima IV, manufactured by Rigaku Corporation), X-ray source: CuKα ray (λ = 1.5418 Å, tube voltage 40 kV, tube current 40 mA) was used to measure the X-ray diffraction pattern. Fig. 2 shows the X-ray diffraction patterns of each silicon-containing aluminum nitride particle according to Examples 1 to 5 and Comparative Examples 3 to 5 and the X-ray diffraction patterns of each aluminum nitride particle according to Comparative Examples 1 and 2. In the X-ray diffraction patterns of each silicon-containing aluminum nitride particle according to Examples 1 to 5 and Comparative Examples 3 to 5 and the X-ray diffraction patterns of the aluminum nitride particles according to Comparative Examples 1 and 2, the peak intensity ratio of diffraction angle 2θ of 43.3 ± 0.5° to the peak intensity of 100% of diffraction angle 2θ of 33.2 ± 0.5° was determined.

[0078] Average particle size D For each silicon-containing aluminum nitride particle according to Examples 1 to 5 and Comparative Examples 3 to 5 and each aluminum nitride particle according to Comparative Examples 1 and 2, the average particle size was determined using a Fisher Sub-Sieve Sizer Model 95 (manufactured by Fisher Scientific). Specifically, 1 cm 3 The sample was weighed, packed in a dedicated tubular container, and then dry air at a constant pressure was passed through. From the relational expression between the permeated air pressure and the porosity of the packed sample, the average particle size by the FSSS method was determined.

[0079] Reflection spectrum For each of the silicon-containing aluminum nitride particles according to Examples 1 to 5 and Comparative Examples 3 to 5, and each of the aluminum nitride particles according to Comparative Examples 1 and 2, using a spectrofluorophotometer (F-7100, manufactured by Hitachi High-Tech Corporation), at room temperature (25 °C ± 5 °C), light from a halogen lamp serving as an excitation light source was irradiated onto the silicon-containing aluminum nitride particles or aluminum nitride particles serving as samples, and the reflection spectrum within a wavelength range of 250 nm or more and 730 nm or less was measured by scanning while matching the wavelengths of the spectrofluorophotometer on the excitation side and the fluorescence side. Using a standard reflector (Spectralon (registered trademark), manufactured by Labsphere), with the reflectance of the standard reflector with respect to the excitation light with an excitation wavelength of 450 nm as a reference, the reflectance of the silicon-containing aluminum nitride particles or aluminum nitride was determined as the relative reflectance. FIG. 3 shows the reflection spectra of each of the silicon-containing aluminum nitride particles according to Examples 1 to 3 and the aluminum nitride particles according to Comparative Example 1. FIG. 4 shows the reflection spectra of each of the silicon-containing aluminum nitride particles according to Examples 4 and 5 and the aluminum nitride particles according to Comparative Example 1. Further, the reflectances of each of the silicon-containing aluminum nitride particles according to Examples 1 to 5 and Comparative Examples 3 to 5, and each of the aluminum nitride particles according to Comparative Examples 1 and 2 at 250 nm, 380 nm, 450 nm, and 730 nm are shown in Table 2.

[0080] Generation amount of ammonia (NH3) (mass ppm) For each of the silicon-containing aluminum nitride particles according to Examples 1 to 5 and Comparative Examples 3 to 5, and each of the aluminum nitride particles according to Comparative Examples 1 and 2, 1.0 g of each silicon-containing aluminum nitride particle or each aluminum nitride particle was brought into contact with 50 mL of a 6 mol / L hydrochloric acid aqueous solution, and the generation amount of ammonia generated in the hydrochloric acid aqueous solution was measured. Specifically, it was measured by the following method. (1) Add 50 mL of a boiling 6 mol / L hydrochloric acid (HCl) aqueous solution to 1.0 g of the silicon-containing aluminum nitride particles. (2) Bring the silicon-containing aluminum nitride particles into contact with the hydrochloric acid aqueous solution for 10 minutes while stirring at 450 rpm using a stirrer. (3) Filter the hydrochloric acid aqueous solution after stirring to separate it from the silicon-containing aluminum nitride particles, and measure the ammonium ion concentration (volume concentration mg / L) in the hydrochloric acid aqueous solution obtained by filtration as the ammonia generation amount (mass ppm) using an ion meter (MM-60R, manufactured by Toa DKK Corporation).

[0081] SEM photograph Using a scanning electron microscope (SEM), SEM photographs of each silicon-containing aluminum nitride particle according to Examples 1 to 5 and Comparative Examples 3 to 5, and each aluminum nitride particle according to Comparative Examples 1 and 2 were obtained. FIG. 5 is an SEM photograph of the silicon-containing aluminum nitride particle according to Example 1. FIG. 6 is an SEM photograph of the silicon-containing aluminum nitride particle according to Example 4. FIG. 7 is an SEM photograph of the aluminum nitride particle according to Comparative Example 1.

[0082]

Table 2

[0083] As shown in Table 2, the silicon-containing aluminum nitride particles according to Examples 1 to 5 have a ratio (X / Y) within the range of 0.40 or more and 0.85 or less, and a film containing oxygen is formed on the surface of the silicon-containing aluminum nitride particles while suppressing the formation of aluminum oxide.

[0084] When the total of the mass of aluminum, the mass of silicon, the mass of nitrogen, and the mass of oxygen analyzed from the particles of the silicon-containing aluminum nitride particles according to Examples 1 to 5 is 100% by mass, the mass ratio of oxygen is within the range of 0.9% by mass or more and 3.5% by mass or less, and the specific surface area measured by the BET method is 2.5 m 2 / g or more and 4.5 m 2 / g or less. Further, the silicon-containing aluminum nitride particles according to Examples 1 to 5 have a composition represented by Al 1-x Si x N (x = 0.05).

[0085] As shown in Table 2, the silicon-containing aluminum nitride particles according to Examples 1 to 5 had an ammonia generation amount of 120 mass ppm or less, a film containing oxygen was formed on the surface of the silicon-containing aluminum nitride particles, and it was confirmed that the reaction between the silicon-containing aluminum nitride particles and moisture was suppressed.

[0086] As shown in Table 2 and FIG. 2, in the powder X-ray diffraction pattern measured using CuKα rays (1.5418 Å), the silicon-containing aluminum nitride particles according to Examples 1 to 5 had a peak intensity at a diffraction angle 2θ of 43.3 ± 0.5° of 5% or less, specifically 3% or less, with respect to the peak intensity of 100% at a diffraction angle 2θ of 33.2 ± 0.5°, and the formation of aluminum oxide on the surface of the silicon-containing aluminum nitride particles was suppressed.

[0087] As shown in Table 2, FIG. 3, and FIG. 4, the silicon-containing aluminum nitride particles according to Examples 1 to 5 had a light reflectance of 80% or more in the visible light region of 380 nm or more and 730 nm or less, and a high reflectance was maintained. Further, the silicon-containing aluminum nitride particles according to Examples 1 to 5 had a light reflectance of 40% or less at a wavelength of 250 nm, and the silicon-containing aluminum nitride particles easily absorbed light having a wavelength in the ultraviolet region around 250 nm and less than 380 nm. For example, when the silicon-containing aluminum nitride is dispersed in a polymer such as a resin and used, deterioration of the polymer containing the resin due to ultraviolet rays can be suppressed.

[0088] As shown in the SEM photograph of FIG. 5, the silicon-containing aluminum nitride particles according to Example 1 are presumed to have few aggregated secondary particles and many primary particles, and a film containing oxygen is evenly formed on the surface of the primary particles.

[0089] As shown in the SEM photograph of FIG. 6, the silicon-containing aluminum nitride particles according to Example 4 had a wet dispersion time of the first heat-treated product of 1 hour, and since the wet dispersion time of the first heat-treated product was shorter than that of the silicon-containing aluminum nitride particles according to Example 1, aggregated secondary particles were also included.

[0090] The aluminum nitride particles according to Comparative Example 1 have a reflectance of less than 80% for light in the visible light region of 380 nm or more and 730 nm or less, and the reflectance is low. Also, the reflectance of light with a wavelength of 250 nm exceeds 40%. The aluminum nitride particles according to Comparative Example 1 have a low oxygen content and are presumed to contain some oxygen due to the attachment of hydroxyl groups (OH) to the surface. The specific surface area of the aluminum nitride particles according to Comparative Example 1 is not significantly different from that of the silicon-containing aluminum nitride particles according to Example 5, but because the oxygen content is low, the ratio (X / Y) is 0.230 which is less than 0.40. Since no film containing oxygen is formed on the surface of the aluminum nitride particles according to Comparative Example 1, aluminum in the aluminum nitride reacts with moisture, and the ammonia generation amount exceeds 120 mass ppm and is 620 mass ppm, and the ammonia generation amount increases. Since no film containing oxygen is formed on the surface of the aluminum nitride particles according to Comparative Example 1, the mass change rate exceeds 50% before and after PCT, and the moisture resistance is not improved. As shown in the SEM photograph of Fig. 7, the aluminum nitride particles according to Comparative Example 1 have few aggregated secondary particles and many primary particles. The appearance shown in the SEM photograph does not change significantly from that of the silicon-containing aluminum nitride particles according to Example 1.

[0091] The aluminum nitride particles according to Comparative Example 2 have a reflectance of light with a wavelength of 250 nm exceeding 40%. The aluminum nitride particles according to Comparative Example 2 have a relatively high reflectance of light with wavelengths in the ultraviolet region from 200 nm to less than 380 nm per 250 nm, and are less likely to absorb light in the ultraviolet region. By the second heat treatment, a film containing aluminum oxide (Al2O3) is formed on the surface of the particles. The aluminum nitride particles according to Comparative Example 2 have, in the powder X-ray diffraction pattern, the peak intensity at a diffraction angle 2θ of 43.3 ± 0.5° is as large as 169.54% with respect to the peak intensity of 100% at a diffraction angle 2θ of 33.2 ± 0.5°. Also, for the aluminum nitride particles according to Comparative Example 2, since aluminum oxide is formed on the surface of the particles, the oxygen content increases, and the ratio (X / Y) exceeds 0.85 and is 4.419. It is presumed that the aluminum nitride particles according to Comparative Example 2 have a low thermal conductivity because aluminum oxide is formed on the surface.

[0092] Since the silicon-containing aluminum nitride particles according to Comparative Example 3 have not been subjected to the second heat treatment, a film containing oxygen is not formed on the surface of the particles. For the aluminum nitride particles according to Comparative Example 3, since the oxygen content has not increased significantly, it is presumed that hydroxyl groups are attached to the surface of the particles. The silicon-containing aluminum nitride particles according to Comparative Example 3 have a larger specific surface area than the silicon-containing aluminum nitride particles according to Examples 1 to 5 because a film containing oxygen is not formed on the surface, and the ratio (X / Y) is 0.304 which is less than 0.40. Since the silicon-containing aluminum nitride particles according to Comparative Example 3 do not have a film containing oxygen formed on the surface, the silicon-containing aluminum nitride reacts with moisture, and the ammonia generation amount exceeds 120 mass ppm and is 170 mass ppm, and the ammonia generation amount increases.

[0093] The silicon-containing aluminum nitride particles according to Comparative Example 4 are heat-treated at a temperature of 750 °C in the second heat treatment, and the second heat treatment is performed at a low temperature of less than 850 °C. Therefore, it is presumed that the oxygen-containing film formed on the surface of the silicon-containing aluminum nitride particles is very thin, or the oxygen-containing film is not evenly formed on the particle surface. The silicon-containing aluminum nitride particles according to Comparative Example 4 have an oxygen content lower than that of the silicon-containing aluminum nitride according to Comparative Example 3, and the ratio (X / Y) is 0.394, which is less than 0.40. Since the oxygen-containing film formed on the surface of the silicon-containing aluminum nitride particles according to Comparative Example 4 is very thin or the oxygen-containing film is not evenly formed, aluminum in the silicon-containing aluminum nitride reacts with moisture, and the ammonia generation amount exceeds 120 mass ppm and is 280 mass ppm, and the ammonia generation amount increases.

[0094] Since the silicon-containing aluminum nitride particles according to Comparative Example 5 are not subjected to the second heat treatment, an oxygen-containing film is not formed on the particle surface. Since the silicon-containing aluminum nitride particles according to Comparative Example 5 have a relatively large oxygen content, it is presumed that hydroxyl groups are attached to the particle surface. Since the silicon-containing aluminum nitride particles according to Comparative Example 5 do not have an oxygen-containing film formed on the surface, the specific surface area is larger than that of the silicon-containing aluminum nitride particles according to Examples 1 to 5, and the ratio (X / Y) is 0.226, which is less than 0.40. Since the silicon-containing aluminum nitride particles according to Comparative Example 5 do not have an oxygen-containing film formed on the surface, the silicon-containing aluminum nitride reacts with moisture, and the ammonia generation amount exceeds 120 mass ppm and is 260 mass ppm, and the ammonia generation amount increases.

[0095] For each of the silicon-containing aluminum nitride particles according to Examples 1, 2, and 4 and the aluminum nitride particles according to Comparative Example 1, PCT was performed and the following evaluations were made.

[0096] PCT (Pressure Cooker Test) Using a high-acceleration sub-life test device (PC-422R8, manufactured by Hirayama Manufacturing Co., Ltd.), each silicon-containing aluminum nitride particle according to Examples 1, 2, and 4 and the aluminum nitride particle according to Comparative Example 1 were subjected to PCT (Pressure Cooker Test) for 24 hours under the conditions of 130°C and a relative humidity of 100%. The mass of the sample before PCT was taken as 100% by mass, and the mass of the sample after PCT was expressed as a mass ratio to 100% by mass of the mass before PCT. The value obtained by subtracting the mass ratio (%) after PCT from 100% of the mass before PCT was defined as the mass change rate (%). Also, regarding oxygen (O) in the sample after PCT, the mass of oxygen (O) in the sample after PCT was detected by quantitative analysis using an oxygen-nitrogen analyzer (manufactured by HORIBA). The numerical value of the mass of oxygen (O) in the sample after PCT detected by the oxygen-nitrogen analyzer was divided by the numerical value of the mass of the silicon-containing aluminum nitride particles (samples) introduced into the oxygen-nitrogen analyzer and multiplied by 100, and expressed as a mass ratio (mass%).

[0097] When the mass before PCT of the silicon-containing aluminum nitride particles according to Examples 1 and 2 is set to 100% by mass, the mass after 24 hours of PCT of the silicon-containing aluminum nitride particles according to Example 1 is 146.9% by mass, and the mass of the silicon-containing aluminum nitride particles according to Example 2 is 140.9% by mass. The mass change rate of the silicon-containing aluminum nitride particles according to Example 1 is 46.9% by mass before and after PCT, and the mass change rate of the silicon-containing aluminum nitride particles according to Example 2 is 40.9% by mass before and after PCT. The mass change rates of the silicon-containing aluminum nitride particles according to Examples 1 and 2 are 50% or less before and after PCT, and the mass change rate is suppressed even after PCT under high temperature and high humidity, and the moisture resistance is improved. Further, the mass ratio of oxygen (O) by an oxygen-nitrogen analyzer after 24 hours of PCT of the silicon-containing aluminum nitride particles according to Example 1 is 15.9% by mass, and the mass ratio of oxygen (O) of the silicon-containing aluminum nitride particles according to Example 2 after 24 hours of PCT is 32.3% by mass. The silicon-containing aluminum nitride particles according to Examples 1 and 2 contain oxygen (O) even after PCT. The mass ratio of oxygen (O) by an oxygen-nitrogen analyzer after PCT of the silicon-containing aluminum nitride particles according to Examples 1 and 2 is higher than the mass ratio of oxygen (O) before PCT, and it is presumed that hydroxyl groups (OH) are attached to the surface of the particles while suppressing the reaction between the silicon-containing aluminum nitride particles and moisture.

[0098] When the mass before PCT of the silicon-containing aluminum nitride particles according to Example 4 is set to 100% by mass, the mass after 24 hours of PCT is 100.5% by mass. The silicon-containing aluminum nitride particles according to Example 4 have a mass change rate of 0.5% by mass before and after PCT, the mass change rate is small, and the moisture resistance is further improved. Further, the silicon-containing aluminum nitride particles according to Example 4 have a mass ratio of oxygen (O) of 2.0% by mass as measured by an oxygen-nitrogen analyzer after 24 hours of PCT. The silicon-containing aluminum nitride particles according to Example 4 contain oxygen (O) even after PCT. The mass ratio of oxygen (O) of the silicon-containing aluminum nitride particles according to Example 4 as measured by an oxygen-nitrogen analyzer after PCT is not more than that of the silicon-containing aluminum nitride particles according to Examples 1 and 2 compared with the mass ratio of oxygen before PCT, and it can be confirmed that the reaction between the silicon-containing aluminum nitride particles and moisture is suppressed.

[0099] When the mass before PCT of the aluminum nitride particles according to Comparative Example 1 is set to 100% by mass, the mass after 24 hours of PCT is 152.1% by mass. The aluminum nitride particles according to Comparative Example 1 have a mass change rate of more than 52.1% by mass and 50% by mass before and after PCT, and the moisture resistance is not improved. Further, the aluminum nitride particles according to Comparative Example 1 have a mass ratio of oxygen (O) of 16.2% by mass as measured by an oxygen-nitrogen analyzer after 24 hours of PCT. The mass ratio of oxygen (O) of the aluminum nitride particles according to Comparative Example 1 as measured by an oxygen-nitrogen analyzer after 24 hours of PCT is considerably larger than the mass ratio of oxygen (O) before PCT, and it is presumed that the silicon-containing aluminum nitride particles react with moisture and the amount of oxygen (O) increases.

[0100] The aluminum nitride particles according to Comparative Example 1 and the silicon-containing aluminum nitride particles according to Comparative Example 3 were mixed with a silicone resin to produce a bulk sample, and the thermal conductivity was measured as follows.

[0101] Thermal conductivity (W / m·K) Fifty mass% of the aluminum nitride particles according to Comparative Example 1 and 50 mass% of the silicone resin were mixed to make 100 mass% of a mixed sample for measuring thermal conductivity. The mixed sample was cured to a size within the range of 10 mm in length, 10 mm in width, and 0.5 mm or more and 1 mm or less in thickness to obtain a bulk sample for measuring the thermal conductivity of Comparative Example 1. Further, using the silicon-containing aluminum nitride particles according to Comparative Example 3, in the same manner as in the case of using Comparative Example 1, a bulk sample for measuring the thermal conductivity of Comparative Example 3 was obtained. For each of the obtained bulk samples for measuring thermal conductivity, the thermoelectric power was measured using a laser flash analyzer (manufactured by NETZSCH). The thermal conductivity of a bulk sample obtained by curing only the silicone resin (100 mass% of the silicone resin) is 0.17 W / m·K.

[0102] The thermal conductivity of the bulk sample for measuring the thermal conductivity of Comparative Example 1 is 0.39 W / m·K, and the thermal conductivity of the bulk sample for measuring the thermoelectric power of Comparative Example 3 is 0.40 W / m·K. In Example 1, the thermal conductivity of the bulk sample according to Comparative Example 1 using the aluminum nitride particles according to Comparative Example 1 as a raw material and the thermal conductivity of the bulk sample according to Comparative Example 3 using the silicon-containing aluminum nitride particles according to Comparative Example 3 in the same manner as in Example 1 except that the second heat treatment was not performed are very close values. Therefore, while maintaining the crystal structure of aluminum nitride, a part of aluminum is replaced by silicon to form silicon-containing aluminum nitride particles, and high thermal conductivity is maintained. The silicon-containing aluminum nitride particles according to Examples 1 to 5 have a ratio (X / Y) within the range of 0.40 or more and 0.85 or less, and a film containing oxygen is formed on the surface of the silicon-containing aluminum nitride particles while suppressing the formation of aluminum oxide. Therefore, it is presumed that the high thermal conductivity of the silicon-containing aluminum nitride particles is maintained.

[0103] The silicon-containing aluminum nitride particles according to Example 4 and the silicon-containing aluminum nitride particles according to Comparative Example 3 were mixed with the silicone resin, and the heat generation behavior was measured as follows.

[0104] Heat generation behavior Using the silicon-containing aluminum nitride particles according to Example 4 and the silicon-containing aluminum nitride particles according to Comparative Example 3, the heat generation behavior when added to a silicone resin was confirmed with a differential scanning calorimeter (DSC). A silicone resin of 100% by mass was designated as Sample 1, a resin composition obtained by mixing 50% by mass of the silicone resin and 50% by mass of the silicon-containing aluminum nitride particles according to Example 4 was designated as Sample 2, and a resin composition obtained by mixing 50% by mass of the silicone resin and 50% by mass of the silicon-containing aluminum nitride particles according to Comparative Example 3 was designated as Sample 3. For each sample, using a differential scanning calorimeter (DSC2500, manufactured by TA Instruments), a DSC curve from 40°C to 200°C was measured when the temperature was raised from 30°C to 299°C at a rate of 10°C / min. Figure 7 shows the DSC curves of each sample.

[0105] As shown in Figure 8, since the silicone resin of Sample 1 and the resin composition containing the silicon-containing aluminum nitride particles according to Example 4 of Sample 2 have peaks in the heat generation amount at the same temperature, they have the same heat generation behavior as the silicone resin. Since the silicone resin of Sample 1 and the resin composition containing the silicon-containing aluminum nitride particles according to Example 4 of Sample 2 have peaks in the heat generation amount at the same temperature and exhibit the same heat generation behavior, it is presumed that the curing of the resin composition of Sample 2 is not inhibited and the reaction between the silicon-containing aluminum nitride particles according to Example 4 contained in Sample 2 and moisture is suppressed. On the other hand, the resin composition containing the silicon-containing aluminum nitride particles according to Comparative Example 3 of Sample 3 has a peak in the heat generation amount at a temperature different from that of the silicone resin of Sample 1, and the heat generation behavior is different from that of the silicone resin of Sample 1.

[0106] Example 6 With respect to a total of 100% by mass of aluminum nitride powder and silicon nitride powder, 94.7% by mass of aluminum nitride powder and 5.3% by mass of silicon nitride powder are mixed to obtain a raw material mixture. The obtained raw material mixture is filled into a container made of boron nitride. The raw material mixture filled in the container is subjected to a first heat treatment at 1700°C for 4 hours under a pressure of 0.92 MPa in a nitrogen atmosphere of 100% by volume of nitrogen gas to obtain a first heat-treated product. Disperse 100 g of the obtained first heat-treated product in 400 g of deionized water, and perform wet dispersion using 200 g of alumina balls with a diameter (φ) of 2 mm at room temperature of 20°C for 1 hour using a ball mill. Separate the solid and liquid of the first heat-treated product after wet dispersion, and dry it at 100°C for 10 hours. Perform a second heat treatment on the first heat-treated product after wet dispersion and drying at 900°C for 10 hours under atmospheric pressure (0.101 MPa) in an air atmosphere to obtain a second heat-treated product. Classify the second heat-treated product by dry sieving to obtain silicon-containing aluminum nitride particles as the second heat-treated product. Table 3 shows the presence or absence of silicon nitride (Si3N4) in the raw material mixture, the first heat treatment temperature, the wet dispersion time, the average particle diameter D measured by the Fisher sub-sieve sizer method of the first heat-treated product after wet dispersion and drying, the volume median diameter Dm measured by the laser diffraction particle size distribution measurement method, the particle size ratio D / Dm of the average particle diameter D to the volume median diameter Dm, the temperature and time of the second heat treatment, and the presence or absence of the SiO2 film attached to the surface of the second heat-treated product. In Table 3, when there is no silicon nitride (Si3N4) in the raw material mixture, when there is no coating layer containing silicon dioxide (SiO2), and when no specific treatment is performed, it is described as "none".

[0107] Example 7 Silicon-containing aluminum nitride particles as the second heat-treated product are obtained in the same manner as in Example 6, except that 89.4% by mass of aluminum nitride powder and 10.6% by mass of silicon nitride powder are mixed to obtain a raw material mixture with respect to a total of 100% by mass of the aluminum nitride powder and the silicon nitride powder.

[0108] Comparative Example 6 The first heat-treated product after wet dispersion and drying obtained in the same manner as in Example 6, except that the second heat treatment is not performed, is obtained as silicon-containing aluminum nitride particles of Comparative Example 6.

[0109] Comparative Example 7 In Example 6, the aluminum nitride particles used as the raw material are used as the aluminum nitride particles of Comparative Example 7.

[0110] Average particle diameter D, volume median diameter Dm In Examples 6 and 7, and Comparative Examples 6 and 7, for the first heat-treated product after wet dispersion and drying, in the same manner as the first heat-treated product in Example 1, the average particle diameter by the FSSS method and the volume median diameter Dm by the laser diffraction particle size distribution measurement method were measured. The results are shown in Table 3.

[0111]

Table 3

[0112] For each silicon-containing aluminum nitride particle according to Examples 6 and 7, and Comparative Example 6, and the aluminum nitride particle according to Comparative Example 7, the following evaluations were performed. The results are shown in Tables 4 and 5. In Table 4, the symbol "-" indicates that the numerical value of the corresponding item was not obtained.

[0113] For each of the obtained silicon-containing aluminum nitride particles according to the examples and comparative examples, in the same manner as in Example 1, a composition analysis was performed. Aluminum (Al) and silicon (Si) in each particle were quantitatively analyzed for the mass of aluminum (Al) and the mass of silicon (Si) in each silicon-containing aluminum nitride particle using an inductively coupled plasma optical emission spectrometer (ICP-AES). Also, for the mass of oxygen (O) and the mass of nitrogen (N) in each particle, a quantitative analysis was performed using an oxygen-nitrogen analyzer (manufactured by HORIBA). The numerical values of Al, Si, O, and N in Table 4 are the mass ratios of each element when the total of the mass of aluminum, the mass of silicon, the mass of nitrogen, and the mass of oxygen is 100% by mass. When the silicon-containing aluminum nitride particle has a composition represented by Al 1-x Si x N and contains oxygen, a variable x representing the molar ratio of Si was determined with the molar ratio of N in 1 mole of the composition being 1. The silicon-containing aluminum nitride particle according to Example 6 has Al 1-x Si x The x in the composition represented by N is 0.04 (x = 0.04), and Al 0.96 Si 0.04It has a composition represented by N and contains oxygen. The silicon-containing aluminum nitride particles according to Example 7 are Al 1-x Si x In the composition represented by N, x is 0.07 (x = 0.07), and Al 0.93 Si 0.07 It has a composition represented by N and contains oxygen. The silicon-containing aluminum nitride particles according to Comparative Example 6 are Al 1-x Si x In the composition represented by N, x is 0.04 (x = 0.04), and Al 0.96 Si 0.04 It has a composition represented by N and contains oxygen. The aluminum nitride particles according to Comparative Example 7 have x = 0 and a composition represented by AlN.

[0114] X-ray photoelectron spectroscopy Using an X-ray photoelectron spectrometer (PHI Quantera II, manufactured by ULVAC-PHI, Inc.), by X-ray photoelectron spectroscopy (XPS: X-Ray Photoelectron Spectroscopy), the atomic percentage N P (at%) of nitrogen and the atomic percentage O P (at%) of oxygen in each of the silicon-containing aluminum nitride particles according to the examples and comparative examples were measured, and the ratio O P (at%) of oxygen to the atomic percentage N P (at%) of oxygen, O P / N P was determined. For the silicon-containing aluminum nitride particles according to Example 7, the measurement was not performed.

[0115] X-ray fluorescence analysis Using an X-ray fluorescence spectrometer (ZSX Primus II, manufactured by Rigaku Corporation), by X-ray fluorescence elemental analysis (XRF: X-Ray Fluorescence spectrometry), the peak intensity of the Kα line of the aluminum (Al) element and the peak intensity of the Kα line of the nitrogen (N) element in each of the silicon-containing aluminum nitride particles according to the examples and comparative examples were measured, and the ratio Al Kα / N Kαwas obtained. For the silicon-containing aluminum nitride particles according to Example 7, measurements have not been performed.

[0116] X-ray diffraction pattern and peak intensity For each of the silicon-containing aluminum nitride particles according to Examples 6 and 7 and Comparative Example 6, and the aluminum nitride particles according to Comparative Example 7, the X-ray diffraction pattern was measured in the same manner as in Example 1. FIG. 9 shows the X-ray diffraction patterns of each of the silicon-containing aluminum nitride particles according to Examples 6 and 7 and Comparative Example 6, and the aluminum nitride particles according to Comparative Example 7. In the X-ray diffraction patterns of each of the silicon-containing aluminum nitride particles according to Examples 6 and 7 and Comparative Example 6, and the aluminum nitride particles according to Comparative Example 7, the peak intensity ratio of diffraction angle 2θ of 43.3 ± 0.5° to the peak intensity of diffraction angle 2θ of 33.2 ± 0.5° with respect to 100% was determined.

[0117] Average particle size D For each of the silicon-containing aluminum nitride particles according to Examples 6 and 7 and Comparative Example 6, and the aluminum nitride particles according to Comparative Example 7, the average particle size D was determined by the FSSS method in the same manner as in Example 1.

[0118] Reflection spectrum For each of the silicon-containing aluminum nitride particles according to Examples 6 and 7 and Comparative Example 6, and the aluminum nitride particles according to Comparative Example 7, the reflectance was determined in the same manner as in Example 1. FIG. 10 shows the reflection spectra of each of the silicon-containing aluminum nitride particles according to Examples 6 and 7 and Comparative Example 6, and the aluminum nitride particles according to Comparative Example 7. Also, the reflectances of each of the silicon-containing aluminum nitride particles according to Examples 6 and 7 and Comparative Example 6 at 250 nm, 380 nm, 450 nm, and 730 nm are shown in Table 4.

[0119] PCT (Pressure Cooker Test) For each of the silicon-containing aluminum nitride particles according to Examples 6 and 7 and Comparative Example 6, and the aluminum nitride particles according to Comparative Example 7, a PCT (Pressure Cooker Test) was conducted in the same manner as in Example 1. Similar to the case of measuring the silicon-containing aluminum nitride particles according to Example 1 described above, the mass ratio of the samples before and after PCT was measured. The value obtained by subtracting the mass ratio before PCT (100%) from the mass ratio after PCT was defined as the mass change rate (%). Also, similar to the case of measuring the silicon-containing aluminum nitride particles according to Example 1 described above, for oxygen (O) in the samples before and after PCT, the mass of oxygen (O) in the samples before and after PCT was detected by quantitative analysis using an oxygen-nitrogen analyzer (manufactured by HORIBA). The numerical value of the mass of oxygen (O) in the samples before and after PCT detected by the oxygen-nitrogen analyzer was divided by the numerical value of the mass of the silicon-containing aluminum nitride particles (sample) introduced into the oxygen-nitrogen analyzer and multiplied by 100 to represent the mass ratio (mass %). The results are shown in Table 5.

[0120] Thermal conductivity (W / m·K) 80% by mass of the aluminum nitride particles according to Examples 6 and 7 and 20% by mass of the silicone resin were mixed to make 100% by mass of a mixed sample for measuring thermal conductivity. The mixed sample was cured to a size within the range of 10 mm in length, 10 mm in width, and 0.5 mm or more and 1 mm or less in thickness to make a bulk sample for measuring thermal conductivity in the same manner as in Comparative Example 1. For the obtained bulk sample for measuring thermal conductivity, the thermal conductivity was measured in the same manner as in Comparative Example 1.

[0121] SEM photograph For the silicon-containing aluminum nitride particles according to Example 6 and the aluminum nitride particles according to Comparative Example 7, SEM photographs were obtained in the same manner as in Example 1. FIG. 11 is an SEM photograph of the silicon-containing aluminum nitride particles according to Example 6. Also, FIG. 12 is an SEM photograph of the aluminum nitride particles according to Comparative Example 7.

[0122]

Table 4

[0123]

Table 5

[0124] As shown in Table 4, for the silicon-containing aluminum nitride particles according to Example 6, the atomic percentage O of oxygen with respect to the atomic percentage N of nitrogen analyzed from the particles by XPS P (at%) P (at%) ratio O P / N P exceeds 2.0. The silicon-containing aluminum nitride particles according to Examples 6 and 7 have an average particle size by the FSSS method in the range exceeding 3.0 μm and not exceeding 100 μm. The silicon-containing aluminum nitride particles according to Examples 6 and 7 have a film containing oxygen formed on the surface of the silicon-containing aluminum nitride particles with a large average particle size while suppressing the formation of aluminum oxide.

[0125] For the silicon-containing aluminum nitride particles according to Examples 6 and 7, when the total of aluminum, silicon, nitrogen, and oxygen analyzed from the particles is 100% by mass, the total mass ratio of aluminum and nitrogen is 90% by mass or more, and the mass ratio of silicon is in the range of 1.5% by mass or more and 10.0% by mass or less. Further, the silicon-containing aluminum nitride particles according to Examples 6 and 7 have a composition represented by Al 1-x Si x N (x = 0.04 or x = 0.07) and contain oxygen.

[0126] For the silicon-containing aluminum nitride particles according to Example 6, the ratio Al of the peak intensity of the Kα line of aluminum to the peak intensity of the Kα line of nitrogen analyzed from the particles by XRF Kα / N Kα is 740 or more. It can be confirmed that the silicon-containing aluminum nitride particles according to Example 6 are covered with a film containing oxygen.

[0127] As shown in Table 5, the silicon-containing aluminum nitride particles according to Examples 6 and 7 had a mass change rate of 1% or less before and after PCT, and had almost no mass change rate even after PCT under high temperature and high humidity, indicating that the moisture resistance of the silicon-containing aluminum nitride particles with a large average particle size was improved.

[0128] As shown in Table 4 and FIG. 9, in the powder X-ray diffraction pattern measured using CuKα radiation (1.5418 Å), the silicon-containing aluminum nitride particles according to Examples 6 and 7 had a peak intensity at a diffraction angle 2θ of 43.3 ± 0.5° that was 2% or less relative to the peak intensity of 100% at a diffraction angle 2θ of 33.2 ± 0.5°, indicating that the formation of aluminum oxide on the surface of the silicon-containing aluminum nitride particles was suppressed.

[0129] The silicon-containing aluminum nitride particles according to Examples 6 and 7 had a large average particle size exceeding 25 μm by the FSSS method. The bulk samples containing the silicon-containing aluminum nitride particles according to Examples 6 and 7 and silicone resin had a thermal conductivity that was 7 to 10 times higher than that of the bulk sample obtained by curing only the silicone resin. The thermal conductivity of the bulk sample obtained by curing only the silicone resin (100% by mass of silicone resin) was 0.17 W / m·K. The bulk sample using the silicon-containing aluminum nitride particles according to Example 6 had a thermal conductivity of 1.69 W / m·K. The bulk sample using the silicon-containing aluminum nitride particles according to Example 7 had a thermal conductivity of 1.24 W / m·K.

[0130] As shown in Table 4 and FIG. 10, the silicon-containing aluminum nitride particles according to Examples 6 and 7 had a light reflectance of 60% or more in the visible light region of 380 nm or more and 730 nm or less, maintaining a high reflectance. Also, the silicon-containing aluminum nitride particles according to Examples 6 and 7 had a light reflectance of 40% or less at a wavelength of 250 nm, and the silicon-containing aluminum nitride particles were likely to absorb light with wavelengths in the ultraviolet region around 250 nm, i.e., wavelengths from 200 nm to less than 380 nm. For example, when the silicon-containing aluminum nitride is dispersed in a resin and used, deterioration of the resin due to ultraviolet rays can be suppressed.

[0131] As shown in the SEM photograph of FIG. 11, the silicon-containing aluminum nitride particles according to Example 6 have an average particle size by the FSSS method in the range exceeding 3.0 μm and not exceeding 100 μm, specifically 42.5 μm. Even when the average particle size is large, there are few secondary particles and many primary particles, and it is presumed that a film containing oxygen is evenly formed on the surface of the primary particles. Since a film containing oxygen is formed on the surface of the primary particles of the silicon-containing aluminum nitride particles according to Example 6, the unevenness on the surface of the particles can be confirmed more clearly than the surface of the aluminum nitride particles according to Comparative Example 7, which is the raw material, shown in the SEM photograph of FIG. 12 described later.

[0132] Since the silicon-containing aluminum nitride particles according to Comparative Example 6 have not been subjected to the second heat treatment, a film containing oxygen is not formed on the surface of the particles. Since the content of oxygen in the aluminum nitride particles according to Comparative Example 6 has not increased significantly, it is presumed that hydroxyl groups are attached to the surface of the particles. Since the silicon-containing aluminum nitride particles according to Comparative Example 6 do not have a film containing oxygen on the surface, the atomic percentage O P (at%) of oxygen with respect to the atomic percentage N P (at%) of nitrogen analyzed from the particles by XPS is such that the ratio O P / N P is 2.0 or less, the mass change rate after PCT at high temperature and high humidity is 1%, and compared with Examples 6 and 7 having a film containing oxygen on the surface of the silicon-containing aluminum nitride particles, the mass change rate is large and the moisture resistance is not improved.

[0133] For the silicon-containing aluminum nitride particles according to Comparative Example 6, the ratio Al Kα / N Kα of the peak intensity of the Kα line of aluminum to the peak intensity of the Kα line of nitrogen analyzed from the particles by XRF is less than 740, and the surface of the silicon-containing aluminum nitride particles according to Comparative Example 6 is not covered with a film containing oxygen.

[0134] The aluminum nitride particles according to Comparative Example 7 are the raw materials of the silicon-containing aluminum nitride particles according to Examples 6 and 7 and Comparative Example 6, and since the first heat treatment and the second heat treatment are not performed, a film containing oxygen is not formed on the surface of the particles. Since the oxygen content of the aluminum nitride particles according to Comparative Example 7 has not increased significantly, it is presumed that hydroxyl groups are attached to the surface of the particles. Since the aluminum nitride particles according to Comparative Example 7 do not have a film containing oxygen formed on the surface, the atomic percentage O of oxygen with respect to the atomic percentage N of nitrogen analyzed from the particles by XPS P (at%) P (at%) of the ratio O P / N P is 2.0 or less, and the mass change rate after PCT at high temperature and high humidity is as large as 2.5%, and the moisture resistance is not improved.

[0135] For the aluminum nitride particles according to Comparative Example 7, the ratio Al of the peak intensity of the Kα line of aluminum to the peak intensity of the Kα line of nitrogen analyzed from the particles by XRF Kα / N Kα is 817.1, which exceeds 810. The aluminum nitride particles according to Comparative Example 7 are aluminum nitride particles used as raw materials without performing the first heat treatment and the second heat treatment, and it is presumed that aluminum and oxygen in the aluminum nitride react to form aluminum oxide on the surface of the particles.

[0136] Although the reflectance of the aluminum nitride particles according to Comparative Example 7 for light with a wavelength of 250 nm is 40% or less, the reflectance for light with wavelengths in the range of 280 nm to 320 nm or less, which are wavelengths in the ultraviolet region, exceeds 40% and is large, and it is presumed that it is difficult to suppress the deterioration of polymers containing resins and the like by ultraviolet rays because it is difficult to absorb light with wavelengths in the ultraviolet region.

[0137] As shown in the SEM photograph of FIG. 12, the surface of the aluminum nitride particles according to Comparative Example 7 has not changed significantly compared to the silicon-containing aluminum nitride particles according to Example 6 shown in FIG. 11. Since no film containing oxygen is formed on the surface of the aluminum nitride particles according to Comparative Example 7, the surface is smoother than the silicon-containing aluminum nitride particles according to Example 6 shown in the SEM photograph of FIG. 11, and the surface appears to have less height difference between unevenness.

[0138] Embodiments according to the present disclosure include the following silicon-containing aluminum nitride particles, sintered bodies, resin compositions, and methods for producing silicon-containing aluminum nitride particles. [Item 1] When the total of the mass of aluminum and the mass of silicon analyzed from the particles by an inductively coupled plasma optical emission spectrometer and the mass of oxygen and the mass of nitrogen analyzed from the particles by an oxygen / nitrogen analyzer is 100% by mass, the total mass ratio of the aluminum and the nitrogen is 90% by mass or more, the mass ratio of the silicon is in the range of 1.5% by mass or more and 10.0% by mass or less, the mass ratio of the oxygen is X% by mass, the specific surface area of the particles measured by the BET method is Ym 2 / g, the ratio (X / Y) of the numerical value X of the X% by mass to the numerical value Y of the Ym 2 / g is in the range of 0.40 or more and 0.85 or less. Silicon-containing aluminum nitride particles. [Item 2] When the total of the mass of aluminum and the mass of silicon analyzed from the particles by an inductively coupled plasma optical emission spectrometer and the mass of oxygen and the mass of nitrogen analyzed from the particles by an oxygen / nitrogen analyzer is 100% by mass, the total mass ratio of the aluminum and the nitrogen is 90% by mass or more, the mass ratio of the silicon is in the range of 1.5% by mass or more and 10.0% by mass or less, the atomic percentage O of oxygen relative to the atomic percentage N of nitrogen analyzed from the particles by X-ray photoelectron spectroscopy P P of P O PSilicon-containing aluminum nitride particles having a value exceeding 2.0. [Item 3] The silicon-containing aluminum nitride particles according to Item 1 or 2, wherein when the total of the mass of aluminum, the mass of silicon, the mass of nitrogen, and the mass of oxygen is 100% by mass, the mass ratio of oxygen is in the range of 0.9% by mass or more and 3.5% by mass or less. [Item 4] The specific surface area of the particles measured by the BET method is 2.5 m 2 / g or more and 4.5 m 2 / g or less. The silicon-containing aluminum nitride particles according to Item 1 or Item 3 that cites Item 1. [Item 5] The silicon-containing aluminum nitride particles according to Claim 1 or Claims 3 to 4 that cite Claim 1, wherein when the total of the mass of aluminum, the mass of silicon, the mass of nitrogen, and the mass of oxygen is 100% by mass, the mass ratio of silicon is in the range of 1.5% by mass or more and 4.0% by mass or less. [Item 6] The peak intensity N of the Kα line of nitrogen analyzed from the particles by fluorescent X-ray analysis Kα The ratio Al of the peak intensity Al of the Kα line of aluminum to Kα Is more than 740. The silicon-containing aluminum nitride particles according to Item 2 or Item 3 that cites Item 2. Kα / N Kα The silicon-containing aluminum nitride particles according to any one of Items 1 to 7, having a composition represented by Al [Item 7] Al 1-x Si x N (where x is a number satisfying 0.02 ≦ x ≦ 0.2) and containing oxygen. [Item 8] The silicon-containing aluminum nitride particles according to any one of Items 1 to 7, having an average particle size measured by the Fischer sub-sieve sizer method of 0.1 μm or more and 100 μm or less. [Item 9] The silicon-containing aluminum nitride particles according to claim 1 or claims 3 to 5 and 7, which cite claim 1, wherein the average particle size measured by the Fisher sub-sieve sizer method is 0.5 μm or more and 3.0 μm or less. [Claim 10] The silicon-containing aluminum nitride particles according to claim 2 or claims 3, 6, and 7, which cite claim 2, wherein the average particle size measured by the Fisher sub-sieve sizer method is more than 3.0 μm and 80 μm or less. [Claim 11] In the powder X-ray diffraction pattern measured using CuKα radiation (1.5418 Å), the peak intensity at a diffraction angle 2θ of 43.3 ± 0.5° with respect to the peak intensity of 100% at a diffraction angle 2θ of 33.2 ± 0.5° is 5% or less, for the silicon-containing aluminum nitride particles according to any one of claims 1 to 10. [Claim 12] The silicon-containing aluminum nitride particles according to any one of claims 1 to 11, wherein the reflectance of light in the wavelength range of 380 nm or more and 730 nm or less is 50% or more. [Claim 13] The silicon-containing aluminum nitride particles according to claim 1 or claims 3 to 5, 7, 8, 9, and 11, which cite claim 1, wherein the reflectance of light in the wavelength range of 380 nm or more and 730 nm or less is 80% or more. [Claim 14] The silicon-containing aluminum nitride particles according to any one of claims 1 to 13, wherein the reflectance of light with a wavelength of 250 nm is 40% or less. [Claim 15] When 1.0 g of the silicon-containing aluminum nitride particles is brought into contact with 50 mL of a 6 mol / L hydrochloric acid aqueous solution that has been boiled, the amount of ammonia generated in the hydrochloric acid aqueous solution is 120 mass ppm or less, for the silicon-containing aluminum nitride particles according to claim 1 or claims 3 to 5, 7, 8, 9, 11, and 13, which cite claim 1. [Claim 16] A sintered body containing the silicon-containing aluminum nitride particles according to any one of claims 1 to 15. [Claim 17] A resin composition containing the silicon-containing aluminum nitride particles according to any one of claims 1 to 15 and a resin. [Claim 18] Mix aluminum nitride and silicon nitride to obtain a raw material mixture containing silicon nitride in the range of 2% by mass or more and 15% by mass or less when the total of aluminum nitride and silicon nitride is 100% by mass. Subject the raw material mixture to a first heat treatment at a pressure of 0.101 MPa or more and a temperature in the range of 1600 °C or more and 2100 °C or less to obtain a first heat-treated product. Subject the obtained first heat-treated product to a second heat treatment at a temperature of 850 °C or more and less than 1000 °C to obtain a second heat-treated product. A method for manufacturing silicon-containing aluminum nitride particles, comprising the above steps. [Item 19] The method for manufacturing silicon-containing aluminum nitride particles according to item 18, further comprising wet-dispersing the first heat-treated product before the second heat treatment. [Item 20] The method for manufacturing silicon-containing aluminum nitride particles according to claim 18 or 19, further comprising subjecting the first heat-treated product to the second heat treatment in an oxygen-containing atmosphere for 1 hour or more and 15 hours or less. [Item 21] The method for manufacturing silicon-containing aluminum nitride particles according to item 19 or item 20 that cites item 19, further comprising subjecting the first heat-treated product to solid-liquid separation after the wet dispersion and drying in the range of 80 °C or more and 120 °C or less. [Item 22] The method for manufacturing silicon-containing aluminum nitride particles according to claim 19 or item 20 or 21 that cites item 19, wherein the particle size ratio D / Dm of the average particle size D measured by the Fisher subsieve sizer method to the volume median diameter Dm measured by the laser diffraction particle size distribution measurement method of the first heat-treated product after the wet dispersion is in the range of 0.2 or more and 0.5 or less. [Item 23] The method for manufacturing silicon-containing aluminum nitride particles according to claim 19 or item 20 or 21 that cites item 19, wherein the particle size ratio D / Dm of the average particle size D measured by the Fisher subsieve sizer method to the volume median diameter Dm measured by the laser diffraction particle size distribution measurement method of the first heat-treated product after the wet dispersion is in the range of 0.55 or more and 0.95 or less. [Item 24] The second heat-treated product is particles of silicon-containing aluminum nitride. When the total of the mass of aluminum and the mass of silicon analyzed from the particles by an inductively coupled plasma optical emission spectrometer and the mass of nitrogen and the mass of oxygen analyzed from the particles by an oxygen / nitrogen analyzer is 100% by mass, the total mass ratio of aluminum and nitrogen is 90% by mass or more, the mass ratio of silicon is in the range of 1.5% by mass or more and 10.0% by mass or less, the mass ratio of oxygen is X% by mass, and the specific surface area of the particles measured by the BET method is Ym 2 / g, and the ratio (X / Y) of the numerical value X of X% by mass to the numerical value Y of Ym 2 / g is in the range of 0.40 or more and 0.85 or less. The method for producing silicon-containing aluminum nitride particles according to any one of items 18 to 22. [Item 25] The second heat-treated product is particles of silicon-containing aluminum nitride. When the total of the mass of aluminum and the mass of silicon analyzed from the particles by an inductively coupled plasma optical emission spectrometer and the mass of nitrogen and the mass of oxygen analyzed from the particles by an oxygen / nitrogen analyzer is 100% by mass, the total mass ratio of aluminum and nitrogen is 90% by mass or more, the mass ratio of silicon is in the range of 1.5% by mass or more and 10.0% by mass or less, and the atomic percentage N of nitrogen analyzed from the particles by X-ray photoelectron spectroscopy P to the atomic percentage O of oxygen P The ratio O P / N P exceeds 2.0. The method for producing silicon-containing aluminum nitride particles according to any one of items 18 to 20 and 23.

Industrial Applicability

[0139] The silicon-containing aluminum nitride particles of the present disclosure can be used as a sintered body or a resin composition. The sintered body containing the silicon-containing aluminum nitride particles can be used as a heat sink or a support for electronic components. Further, the resin composition containing the silicon-containing aluminum nitride can be used, for example, as a molded body or a sealing material of a light-emitting device. Further, the resin composition containing the silicon-containing aluminum nitride can be used for joining members such as a die bond material and an underfill material for die-bonding a light-emitting element or a semiconductor element to a support.

Description of Reference Numerals

[0140] 10: Light-emitting element, 13: Joining member, 20, 30: Lead, 40: Molded body, 42: Resin part, 50: Fluorescent member, 60: Wire, 70: Phosphor, 100: Light-emitting device.

Claims

1. when the sum of the mass of aluminum and the mass of silicon analyzed from the particles by an inductively coupled plasma optical emission spectrometer and the mass of oxygen and the mass of nitrogen analyzed from the particles by an oxygen / nitrogen analyzer is taken as 100 mass%, the total mass ratio of the aluminum and the nitrogen is 90 mass% or more and the mass ratio of the silicon is within the range of 1.5 mass% or more and 10.0 mass% or less, The mass percentage of oxygen is X mass%, The specific surface area of ​​the particles measured by the BET method is Ym ２ / g, The Ym ２ The ratio (X / Y) of the numerical value X of X mass% to the numerical value Y of X mass% / g is in the range of 0.40 or more and 0.85 or less.

2. when the sum of the mass of aluminum and the mass of silicon analyzed from the particles by an inductively coupled plasma optical emission spectrometer and the mass of oxygen and the mass of nitrogen analyzed from the particles by an oxygen / nitrogen analyzer is taken as 100 mass%, the total mass ratio of the aluminum and the nitrogen is 90 mass% or more and the mass ratio of the silicon is within the range of 1.5 mass% or more and 10.0 mass% or less, The atomic percentage of nitrogen, N, analyzed from the particles by X-ray photoelectron spectroscopy Ｐ The atomic percentage of oxygen to Ｐ Ratio of Ｐ / N Ｐ Silicon-containing aluminum nitride particles having a surface roughness of greater than 2.

0.

3. 3. The silicon-containing aluminum nitride particle according to claim 1 or 2, wherein the mass ratio of the oxygen is in the range of 0.9 mass% or more and 3.5 mass% or less when the sum of the mass of the aluminum, the mass of the silicon, the mass of the nitrogen, and the mass of the oxygen is 100 mass%.

4. The specific surface area of ​​the particles measured by the BET method is 2.5 m ２ / g or more 4.5m ２ The silicon-containing aluminum nitride particles according to claim 1, wherein the surface area of ​​the silicon-containing aluminum nitride particles is in the range of 0.1 to 1.0 μm / g or less.

5. 2. The silicon-containing aluminum nitride particle according to claim 1, wherein the mass ratio of the silicon is in the range of 1.5 mass% or more and 4.0 mass% or less when the sum of the mass of the aluminum, the mass of the silicon, the mass of the nitrogen, and the mass of the oxygen is 100 mass%.

6. The peak intensity N of Kα radiation of nitrogen analyzed from the particles by X-ray fluorescence analysis Ｋα Peak intensity of aluminum Kα radiation Al Ｋα The ratio of Al Ｋα / N Ｋα The silicon-containing aluminum nitride particles of claim 2 , wherein the MnO 2 is greater than 740.

7. A １－ｘ S ｘ 3. The silicon-containing aluminum nitride particle according to claim 1 or 2, which has a composition represented by N (x is a number satisfying 0.02≦x≦0.2) and contains oxygen.

8. 3. The silicon-containing aluminum nitride particles according to claim 1, having an average particle size of 0.1 μm or more and 100 μm or less as measured by a Fisher subsieve sizer method.

9. 2. The silicon-containing aluminum nitride particles according to claim 1, having an average particle size of 0.5 μm or more and 3.0 μm or less as measured by a Fisher subsieve sizer method.

10. 3. The silicon-containing aluminum nitride particles according to claim 2, having an average particle size of more than 3.0 μm and not more than 80 μm as measured by a Fisher subsieve sizer method.

11. 3. The silicon-containing aluminum nitride particle according to claim 1 or 2, wherein in a powder X-ray diffraction pattern measured using CuKα radiation (1.5418 Å), the peak intensity at a diffraction angle 2θ of 43.3±0.5° is 5% or less relative to the peak intensity at a diffraction angle 2θ of 33.2±0.5° (100%).

12. 3. The silicon-containing aluminum nitride particles according to claim 1, having a reflectance of 50% or more for light in a wavelength range of 380 nm or more and 730 nm or less.

13. 2. The silicon-containing aluminum nitride particles according to claim 1, having a reflectance of 80% or more for light in a wavelength range of 380 nm or more and 730 nm or less.

14. 3. The silicon-containing aluminum nitride particles according to claim 1 or 2, having a reflectance of 40% or less for light having a wavelength of 250 nm.

15. 2. The silicon-containing aluminum nitride particles according to claim 1, wherein when 1.0 g of the silicon-containing aluminum nitride particles is contacted with 50 mL of a boiled 6 mol / L aqueous hydrochloric acid solution, the amount of ammonia generated in the aqueous hydrochloric acid solution is 120 mass ppm or less.

16. A sintered body comprising the silicon-containing aluminum nitride particles according to claim 1 or 2.

17. A resin composition comprising the silicon-containing aluminum nitride particles according to claim 1 or 2 and a resin.

18. mixing aluminum nitride and silicon nitride to obtain a raw material mixture containing silicon nitride in a range of 2 mass% to 15 mass% when the total of aluminum nitride and silicon nitride is 100 mass%; performing a first heat treatment on the raw material mixture at a pressure of 0.101 MPa or more and at a temperature of 1600° C. or more and 2100° C. or less to obtain a first heat-treated product; and subjecting the obtained first heat-treated product to a second heat treatment at a temperature of 850°C or higher and lower than 1000°C to obtain a second heat-treated product.

19. The method for producing silicon-containing aluminum nitride particles according to claim 18, further comprising wet-dispersing the first heat-treated product prior to the second heat treatment.

20. The method for producing silicon-containing aluminum nitride particles according to claim 18, further comprising subjecting the first heat-treated product to the second heat treatment in an oxygen-containing atmosphere for 1 hour or more and 15 hours or less.

21. The method for producing silicon-containing aluminum nitride particles according to claim 19, further comprising: subjecting the first heat-treated product to solid-liquid separation after the wet dispersion, and drying the product at a temperature in the range of 80°C or higher and 120°C or lower.

22. The method for producing silicon-containing aluminum nitride particles according to claim 19, wherein the particle size ratio D / Dm of the average particle size D measured by a Fisher subsieve sizer method to the volume median diameter Dm measured by a laser diffraction particle size distribution measurement method of the first heat-treated product after the wet dispersion is in the range of 0.2 to 0.

5.

23. The method for producing silicon-containing aluminum nitride particles according to claim 19, wherein the particle size ratio D / Dm of the average particle size D measured by a Fisher subsieve sizer method to the volume median diameter Dm measured by a laser diffraction particle size distribution measurement method of the first heat-treated product after the wet dispersion is in the range of 0.55 to 0.

95.

24. The second heat-treated product is a silicon-containing aluminum nitride particle, and when the sum of the mass of aluminum and the mass of silicon analyzed from the particle by an inductively coupled plasma optical emission spectrometer and the mass of nitrogen and the mass of oxygen analyzed from the particle by an oxygen / nitrogen analyzer is taken as 100 mass%, the total mass ratio of the aluminum and the nitrogen is 90 mass% or more, the mass ratio of the silicon is within a range of 1.5 mass% or more and 10.0 mass% or less, the mass ratio of the oxygen is X mass%, and the specific surface area of ​​the particle measured by a BET method is Ym ２ / g, and the Ym ２ The method for producing silicon-containing aluminum nitride particles according to claim 18, wherein the ratio (X / Y) of the numerical value X of X mass% to the numerical value Y of X mass% / g is within the range of 0.40 or more and 0.85 or less.

25. The second heat-treated product is particles of silicon-containing aluminum nitride, and when the sum of the mass of aluminum and the mass of silicon analyzed from the particles by an inductively coupled plasma optical emission spectrometer and the mass of nitrogen and the mass of oxygen analyzed from the particles by an oxygen / nitrogen analyzer is taken as 100 mass%, the total mass ratio of the aluminum and the nitrogen is 90 mass% or more, the mass ratio of the silicon is within a range of 1.5 mass% to 10.0 mass%, and the atomic percentage N of nitrogen analyzed from the particles by X-ray photoelectron spectroscopy is 1.5 mass% or more and 1.5 mass% or less. Ｐ The atomic percentage of oxygen to Ｐ Ratio of Ｐ / N Ｐ The method for producing silicon-containing aluminum nitride particles according to claim 18, wherein the σ is greater than 2.0.

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