TWI697518B - Manufacturing method of metal oxide particle material - Google Patents

Abstract

The problem to be solved by the present invention is to provide a method for producing a metal oxide particle material capable of reducing the amount of water contained. The solution of the present invention is a method of manufacturing a metal oxide particle material, which includes: preparing a metal particle material dispersion system having a metal particle material and a dispersion medium for dispersing the metal particle material; and by combining the foregoing The metal particle material dispersion system is supplied to the oxidizing ambient gas to burn the aforementioned metal particle material to produce the combustion step of the metal oxide particle material, wherein the aforementioned manufacturing method includes controlling the moisture contained in the aforementioned dispersion medium and the aforementioned oxidizing ambient gas Steps for controlling moisture content below a certain value.

Description

Manufacturing method of metal oxide particle material

The present invention relates to a method for manufacturing a metal oxide particle material, which can manufacture a metal oxide particle material with a small dielectric loss tangent.

Metal oxide particle materials have been used as packaging materials, substrate materials, and other electronic materials for semiconductor devices. In particular, a resin composition in which metal oxide particles are dispersed in a resin material is known (Patent Documents 1 to 3, etc.) .

A method (VMC method) for preparing a metal oxide particle material by throwing a metal particle material into an oxidizing atmosphere and burning it is known as one of the methods for producing a metal oxide particle material (Patent Document 3 , 4, etc.).

In addition, Patent Document 2 has disclosed that when a resin composition in which a metal oxide particle material is dispersed in a resin material is applied to an electronic material, the amount of the dispersed metal oxide particle material is made to physically adsorb water to 50 ppm or less. Make the results of the pressure cooker test better.

Regarding the method of reducing the amount of physically adsorbed water of the metal oxide particle material in Patent Document 2, it has been disclosed that the heat treatment method is adopted, that is, the produced metal oxide particle material is heated and dried. Also, if silicon dioxide is heated to more than 200°C, the surface OH groups (bound water) will start to be removed (for example, refer to Non-Patent Document 1), so the physical adsorption of silicon dioxide is carried out by heating to 200°C Determination.

In addition, in Patent Document 3, "the metal powder of the metal oxide powder is synthesized by supplying metal powder in a reaction vessel to a high-temperature flame composed of combustible gas and combustion-supporting gas, and oxidizing the metal powder in the flame. The main point of the "Method of Manufacturing Oxide Powder" lies in the invention of obtaining excellent metal oxides by appropriately controlling the amount of water vapor generated by the combustion of combustible gas (Patent Document 3, paragraph [0034]). Here, since the water vapor that is a problem in Patent Document 3 is not supplied from the outside, it is mainly calculated as the theoretical amount of water vapor generated by the combustion of a reactive gas (for example, propane) (Patent Document 3 No. [0035] ]segment). The invention disclosed in Patent Document 3 is an invention aimed at providing "a metal oxide powder that has excellent fluidity and formability improvement effects of semiconductor packaging materials, and can improve mechanical strength and solder heat resistance, and a manufacturing method thereof." [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 58-138740 [Patent Document 2] Japanese Patent Application Laid-Open No. 60-199020 (claim 2 etc.) [Patent Document 3] Japanese Patent Application Publication No. 2005-139295 [Patent Document 4] Japanese Patent Application Publication No. 60-255602 [Non-Patent Literature]

[Non-Patent Document 1] Surface Chemistry and Adhesion Phenomenon of Microsomes, Masatoshi Kinzawa, Takashi Takei, Journal of the Japan Sea Society, 1987, Volume 41, No. 4, p.168-180

[The problem to be solved by the invention]

When the inventors of the present invention applied metal oxide particle materials to electronic materials, they found that in addition to reducing the amount of physically adsorbed water, it was also possible to improve electrical characteristics by reducing the water (bound water, etc.) contained in addition to the physically adsorbed water ( For example, reducing the dielectric loss tangent: Df).

Here, in the invention disclosed in Patent Document 2, as in Claim 1, the particle size is limited to 20 to 100 μm, and it is assumed that particles with a larger particle size are handled. In recent years, with the miniaturization of semiconductor device structures and circuits, the particle size of fillers for electronic materials has decreased from submicron to nanometer level. The content of physically adsorbed water will increase in proportion to the surface area of the particle material. Therefore, as the particle size becomes smaller, the surface area increases, and the amount of physically adsorbed water also increases. For example, in a particle material whose particle size is changed from submicron to nanometer level, the water content equivalent to the "water content of 50 ppm or less" specified in Patent Document 2 becomes several tens of times greater than 1000 ppm. Even if heating is performed for the purpose of reducing the moisture content with such a moisture content as the target, the moisture content cannot be expected to be reduced to the extent that the electrical characteristics can be improved, and sufficient electrical characteristics cannot be achieved. In particular, even if the amount of physically adsorbed water is reduced, the moisture in the air will quickly recombine afterwards.

Furthermore, from the viewpoint of realizing appropriate electrical characteristics, it is known that a lower water content is better, and it is not desirable to actively supply water as in the invention disclosed in Patent Document 3 (for example, paragraph 0034).

The problem to be solved by the inventors is to provide a method for producing a metal oxide particle material capable of reducing moisture contained in addition to physically adsorbed water. [Means to solve the problem]

(1) The inventors of the present invention devoted themselves to research to solve the above-mentioned problems. As a result, they found that the amount of physically adsorbed water and other moisture can be reduced by adjusting the production conditions in the VMC method, and completed the following invention.

That is, the manufacturing method of the metal oxide particle material of the present invention to solve the above-mentioned problems is a method of manufacturing the metal oxide particle material, which has: The step of preparing a metal particle material dispersion system having a metal particle material and a dispersion medium for dispersing the metal particle material; and The combustion step of producing the metal oxide particle material by supplying the metal particle material dispersion system to the oxidizing atmosphere to burn the metal particle material, The aforementioned manufacturing method has a moisture content control step of controlling the moisture contained in the aforementioned dispersion medium and the aforementioned oxidizing ambient gas below a certain value.

The VMC method is a method of manufacturing metal oxides by oxidizing metal particle materials. By reducing the moisture content contained in the environment where the metal particle material is oxidized, the moisture content called bound water contained in the produced metal oxide can be reduced. It is easier to control the moisture content than to remove the moisture after manufacturing the metal oxide particle material.

(2) In the invention of (1) above, at least a part of the dispersion medium and the oxidizing ambient gas is air, and the moisture content control step includes a drying step of removing at least a part of the moisture contained in the air. By having a step of actively removing moisture to reduce the moisture content, the moisture content of the produced metal oxide can be controlled. In addition, "air" in this manual means "outside air".

(3) In the invention of (1) above, at least a part of the dispersion medium and the oxidizing ambient gas is air, and the moisture content control step is to measure the absolute humidity of the air, and the measured absolute humidity is below a specified value In the case of the previous combustion step. By introducing air into an environment where the metal particle material is oxidized and managing the humidity of the introduced air, the moisture content of the produced metal oxide can be controlled.

(4) In the above inventions (1) to (3), in terms of the specific controlled moisture content, the moisture content control step is to control the moisture content contained in the dispersion medium and the oxidizing ambient gas to 10.0 Steps below g/Nm ³ . In addition, in this specification, when the volume is expressed as "Nm ³ ", it means a value converted into a volume in a standard state (25°C, 1 atm).

(5) In the above inventions (1) to (4), the aforementioned moisture content control step may be: control the moisture content of the obtained metal oxide particle material to per unit surface area (m ² ) when heated at 200°C Steps below 40ppm. By keeping the moisture content within this range, electrical characteristics can be improved. The amount of physically adsorbed water was measured by heating at 200°C. The moisture content per unit surface area (m ² ) is calculated as (moisture content when heated at 200°C: ppm)÷(specific surface area: m ² /g). The specific surface area is a value measured by the BET method using nitrogen gas. [Effects of Invention]

The method for producing a metal oxide particle material of the present invention can easily produce a metal oxide particle material whose moisture content can be reduced by having the above-mentioned configuration.

[Form to implement the invention]

According to the following embodiments, the method of manufacturing the metal oxide particle material of the present invention will be described in detail. The manufacturing method of the metal oxide particle material of this embodiment is a method of manufacturing the metal oxide particle material from the metal particle material. The manufacturing method of the metal oxide particle material of this embodiment has a preparation step, a combustion step, and a moisture content control step.

・Preparation procedure The preparation step is a step of preparing the metal particle material dispersion system. The metal particle material dispersion system has a metal particle material and a dispersion medium, wherein the metal particle material is dispersed in the dispersion medium. The metal particle material is a particle material containing simple metals such as silicon and aluminum, alloys made of multiple metal elements, intermetallic compounds, and the like. The particle size of the particle material is not particularly limited, but the particle size (particle size distribution) of the metal particle material may be within a range that can cause combustion (deflagration) in an oxidizing atmosphere. As for the upper limit, it is preferably about 400 μm, more preferably 60 μm or less. This is because the particle size is small and it is easy to convert all the contained metals into oxides due to deflagration. In addition, from the viewpoint of operability, the lower limit can also be limited to about 1 μm. In addition, the upper limit value and the lower limit value are defined in a preferable range for the above-mentioned reasons. Of course, a combination of the upper limit value and the lower limit value outside the range can be adopted for other reasons.

The present invention contains the metal element contained in the produced metal oxide particle material. When multiple metal elements are contained, the abundance ratio and mixing ratio are controlled according to the composition ratio in the metal oxide particle material to be produced. It may also contain metal elements. The elements contained in addition to the metal elements may be elements that are vaporized during oxidation in the combustion step and are not left in the metal oxide particle material produced, or may be trapped in the metal oxide particle material produced element.

The dispersion medium is not particularly limited except for controlling the water content contained. As for the dispersion medium, a gas is preferred. The dispersion medium may contain oxygen that reacts with the metal particle material to form an oxide, or an oxidizing gas that is a compound that releases oxygen through thermal decomposition. As for the gas, in addition to the oxidizing gas, an inert gas having low reactivity with the metal particle material is preferable. Examples of inert gases include nitrogen and argon. In addition to gas, liquid and solid compounds can also be contained in the dispersion medium. As for the dispersing medium, those containing air are preferable, and those composed of air are more preferable.

In the dispersion medium, the content of the compound that generates moisture through combustion is preferably limited or not present. Examples of compounds that generate moisture through combustion include hydrogen-containing compounds such as hydrocarbons, alcohols, ketones, and ethers. Furthermore, nitrogen-containing compounds such as amines and ammonia generate nitrogen oxides through oxidation, and therefore are preferably not contained; sulfur-containing compounds generate sulfur oxides through oxidation, and therefore are preferably not contained.

The mixing ratio of the metal particle material and the dispersion medium is not particularly limited. According to the concentration of the metal particle material in the oxidizing atmosphere described later, the particle size distribution and morphology of the metal oxide particle material produced will change. Therefore, when the metal particle material dispersion system is put into the oxidizing atmosphere, it can be The method of the metal particle material concentration with the necessary particle size distribution and morphology determines the concentration of the metal particle material dispersion system. When the concentration of metal particle materials increases, deflagration is likely to continue; when the concentration decreases, the stability of deflagration can be improved. The concentration of the metal particle material should only be capable of supplying a metal particle material capable of generating a sufficient amount of combustion heat to continue the flame.

The preparation method of the metal particle material dispersion system is not particularly limited. When a mixed gas and liquid are used as a dispersion medium, the order of mixing the metal particle material, the liquid dispersion medium, and the gas dispersion medium is not limited. For example, the metal particle material can be dispersed in a liquid dispersion medium first, and then dispersed in a gas dispersion medium; or the liquid dispersion medium can be dispersed in a gas dispersion medium, and then the metal particle material can be dispersed; or After dispersing the metal particle material in the gas dispersion medium, the liquid dispersion medium is dispersed. Furthermore, as for the metal particle material dispersion system, it is possible to adopt and use those having different composition ratios (different concentrations of metal particle materials, etc.).

・Combustion steps The combustion step is a step of producing a metal oxide particle material by supplying the metal particle material dispersion system to an oxidizing ambient gas and burning the contained metal particle material. Oxidizing ambient gas system is a gas containing oxygen, or a compound that generates oxygen through thermal decomposition. As for the oxidized ambient gas, those containing air are particularly preferred, and those composed of air are more preferred.

As far as the method of burning the metal particles contained in the material is concerned, it is ignited at some ignition source. Examples of ignition sources include chemical flames obtained by burning combustible gases such as hydrocarbons, plasma, sparks, and the like. When a chemical flame is used, it is desirable that the amount of moisture generated through combustion is generally below the limit amount. The metal particle material is burned and finally rapidly cooled to produce the metal oxide particle material. The metal oxide particle material is removed from the area that has reached the combustion state in the oxidizing atmosphere by gravity or the like.

The aforementioned dispersing medium and oxidizing ambient air system are preferably both air. In addition, the amount (A) of oxygen and the like contained in the dispersion medium and the oxidizing ambient gas is preferably more than the amount (B: chemical equivalent) required to oxidize the metal particle material. For example, a preferable lower limit of A/B can be 1.1, 1.2, 1.3, 1.4, 1.5, 1.8, 2.0, 3.0, etc. By increasing the value of A/B, when the aforementioned chemical flame is used and water vapor is generated from the chemical flame, the water vapor generated by the dispersion medium and oxidizing ambient gas with a low water content can be diluted, and overall Reduce the moisture content per unit volume described later.

・Moisture content control procedure The moisture content control step is the step of controlling the moisture contained in the dispersion medium and oxidizing ambient gas below a certain value. The method of controlling the moisture content below a certain value is not particularly limited. For example, it is possible to use a drying step to remove moisture from a dispersion medium or oxidizing ambient gas, or use a dispersion medium or oxidizing ambient gas with an inherently low moisture content. As for the drying method, it is possible to adopt a method of drying by using a desiccant to pass a dispersion medium and oxidizing ambient gas; a method of cooling to make the moisture reach a supersaturated state and agglomerate.

As for the dispersion medium and oxidizing ambient gas, when air is used in at least a part, it is possible to adopt: the step of drying the air; or the measurement step of measuring the absolute humidity of the air (atmosphere) and the absolute humidity is at a specified value In the following, the preparation step and the combustion step are implemented. For example, since the humidity in the air fluctuates with seasons and weather, it is also possible to perform the preparation step and the combustion step when the air with the required moisture content is obtained through the measurement step.

As far as the moisture content is concerned, it is enough as long as it can be controlled below the specified value, but it is better to reduce the moisture content by drying or dehumidification. The specified value of the moisture content is not particularly limited, and 20.0 g/Nm ³ , 10.0 g/Nm ³ , 5.0 g/Nm ³ and the like can be exemplified. In addition, it can also be limited from the moisture content of the metal oxide particle material produced. By controlling the moisture content in the dispersion medium, oxidizing ambient gas, or controlling the amount of combustible gas generated by moisture during combustion, it is also possible to control the moisture content contained in the metal oxide particle material produced (for example, including the surface OH groups and other existing bound water). It is possible to control the moisture content of the dispersion medium and the oxidizing ambient gas or the amount of combustible gas so that the moisture content of the metal oxide particle material is below 40 ppm per unit area. If the amount of combustible gas is reduced, the moisture content of the metal oxide particle material also tends to decrease. Also, especially by reducing the amount of bound water, the amount of physically adsorbed water will also be reduced.

In this specification, the "moisture content of the metal oxide particle material" refers to the water content released by heating the metal oxide particle material to 200°C after the combustion step. In addition, the heating temperature can be set to 500°C as needed. The amount of water generated by heating to 500°C is not only the amount of physically adsorbed water, but also bound water.

・Other steps The metal oxide particle material obtained after the combustion step is separated and recovered by a classification device. As for the classification device, a filter, a centrifugal separator, etc. can be cited. The separated metal oxide particle material is preferably stored under dry conditions. In particular, it is better not to come into contact with liquid moisture, and more preferably not to be exposed to a high-humidity gas environment (for example, 65% RH or more). In particular, when the metal oxide material is dispersed in the resin material as described later, it is preferable not to be exposed to moisture until the dispersion, more preferably not to be exposed to moisture until the resin material is hardened, and even more preferably In order to keep the resin material from being exposed to moisture even in the use state after the resin material is cured. Moreover, in addition to the moisture content control step, the moisture content of the metal oxide particle material can also be reduced by reducing the relative amount of combustible gas.

In addition, the metal oxide particle material system can be surface-treated. Appropriate surface treatment can prevent moisture from penetrating into the metal oxide particle material, so the moisture content can be kept low. In terms of surface treatment, silazane compounds (hexamethyldisilazane, etc.), silane compounds (phenylsilane, alkylsilane, methacrylic silane, aminosilane, epoxy silane, etc.) can be exemplified.

Furthermore, after the metal oxide particle material is produced, it can be quickly dispersed in the resin material to produce a resin composition. The resin material is not particularly limited. Examples include thermosetting resins (either before or after curing), thermoplastic resins and other general resin materials, such as epoxy resin, melamine resin, acrylic Resin, polycarbonate resin, polyester, silicone resin, liquid crystal polymer (LCP), polyimide, cyclic olefin polymer (COP), polyphenylene oxide (PPO). A single type of resin material may be used, or multiple types of resin materials may be mixed (blended, etc.) for use. The resin material preferably has a moisture content of 1000 ppm or less, and more preferably 500 ppm or less. [Example]

According to embodiments, the method for manufacturing the metal oxide particle material of the present invention will be described.

(Test) A metal particle material dispersion system was prepared by dispersing metallic silicon (volume average particle diameter: 15 μm) as a metal particle material in air as a dispersion medium (preparation step). The metal particle material dispersion system was supplied to the air as an oxidizing ambient gas at a rate of ⁴ Nm ³ /hour. The oxidizing atmosphere system is supplied into the reaction furnace at a rate of 15 Nm ³ /hour. In the reaction furnace, propane gas supplied at a rate of 1 Nm ³ /hour is burned as an ignition source, and a metal particle material dispersion system is supplied to this ignition source. The obtained metal oxide particle material is collected with a bag filter.

Air (VMC supply gas) is used as the dispersion medium and oxidizing ambient gas system, and the moisture content is adjusted in two stages by adjusting the humidity (moisture content control step). Regarding the silicon dioxide particles as the material of the obtained metal oxide particles, the water content was measured by the Karl-Fisher method for the case of heating to 200°C and the case of heating to 500°C. The results are shown in Table 1.

[Table 1] Moisture content (ppm) VMC supply gas 200°C 500℃ Temperature(℃) Relative humidity(%) Absolute humidity (g/Nm ³ ) Test example 1 710 1328 33 50 17.79 Test example 2 279 551 20 25 4.3

It is obvious from Table 1 that the moisture content in the obtained silicon dioxide particles also changes with the moisture content in the air used. Therefore, it is found that the environment used in the production of metal oxides can be controlled (reduced) The moisture content contained in it can also control (reduce) the moisture content contained in the produced metal oxide. In addition, this test confirms that the moisture content of the metal oxide particle material can be reduced by reducing the moisture content contained in the VMC supply gas. In the manufacturing conditions this time, the moisture content of the metal oxide particle material will increase due to factors other than the dispersion medium such as the moisture from the combustible gas or the moisture in the cooling gas environment, and the oxidizing ambient gas.

The details are not shown, but it is confirmed that the dielectric loss tangent value can be reduced by reducing the moisture content generated when heated to 200°C and the moisture content generated when heated to 500°C.

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Claims (4)

A manufacturing method of metal oxide particle material, which has the following steps: A step of preparing a metal particle material dispersion system having a metal particle material and a dispersion medium for dispersing the metal particle material; and The combustion step of manufacturing the metal oxide particle material by supplying the metal particle material dispersion system to the oxidizing ambient gas to burn the metal particle material, Wherein the manufacturing method has a moisture content control step of controlling the moisture contained in the dispersion medium and the oxidizing ambient gas below a certain value, At least a part of the dispersion medium and the oxidizing ambient gas is air, The moisture content control step includes a drying step of removing at least a part of the moisture contained in the air. A manufacturing method of metal oxide particle material, which has the following steps: A step of preparing a metal particle material dispersion system having a metal particle material and a dispersion medium for dispersing the metal particle material; and The combustion step of manufacturing the metal oxide particle material by supplying the metal particle material dispersion system to the oxidizing ambient gas to burn the metal particle material, Wherein the manufacturing method has a moisture content control step of controlling the moisture contained in the dispersion medium and the oxidizing ambient gas below a certain value, At least a part of the dispersion medium and the oxidizing ambient gas is air, The moisture content control step is to measure the absolute humidity of the air, and to perform the combustion step when the measured absolute humidity is below a specified value. A method for manufacturing metal oxide particle materials, which is a method for manufacturing metal oxide particle materials with the following steps: Preparation of a metal particle material dispersion system with a metal particle material and a dispersion medium for dispersing the metal particle material Step; and by supplying the metal particle material dispersion system to the oxidizing environment gas to burn the metal particle material to produce a combustion step of metal oxide particle material, wherein the manufacturing method has the dispersion medium and the oxidizing environment The moisture content control step of controlling the moisture contained in the gas below a certain value is a step of controlling the moisture content of the dispersion medium and the oxidizing ambient gas below 10.0 g/Nm ³ . A method for manufacturing metal oxide particle materials, which is a method for manufacturing metal oxide particle materials with the following steps: Preparation of a metal particle material dispersion system with a metal particle material and a dispersion medium for dispersing the metal particle material Step; and by supplying the metal particle material dispersion system to the oxidizing environment gas to burn the metal particle material to produce a combustion step of metal oxide particle material, wherein the manufacturing method has the dispersion medium and the oxidizing environment The moisture content control step in which the moisture contained in the gas is controlled below a certain value. The moisture content control step is to control the moisture content of the obtained metal oxide particle material to a unit surface area (m ² ) when heated at 200°C Steps below 40ppm.