WO2019017435A1

WO2019017435A1 - Silicate compound microparticles and method for producing same

Info

Publication number: WO2019017435A1
Application number: PCT/JP2018/027107
Authority: WO
Inventors: 加藤　博和; 忠之伊左治; 谷本　健二
Original assignee: 日産化学株式会社
Priority date: 2017-07-20
Filing date: 2018-07-19
Publication date: 2019-01-24
Also published as: TW201908241A

Abstract

These silicate compound microparticles have a ratio (d5 0 /ds) of dispersed particle diameter (d50) to primary particle diameter (ds) of at least 1.0 but less than 3.0, where d50 and ds are derived from conversion to spherical particles from the specific surface area measured by the nitrogen adsorption method. The particles also have a crystal particle diameter of 45 to 100 nm as calculated from the X-ray diffraction peak attributed to the (102) plane of the β-eucryptite phase.

Description

Silicate compound fine particles and method for producing the same

The present invention relates to silicate compound fine particles and a method of producing the same.

With the spread of electronic devices, the demand for printed wiring boards, which are the main components of the electronic devices, is increasing. When the CTE of the semiconductor sealing material increases with respect to the coefficient of thermal expansion (CTE) of the substrate while circuit integration and layering progress, circuit destruction will occur. Therefore, in order to reduce the CTE of the sealing material, a technique is used in which a heat-resistant resin such as an epoxy resin constituting the material is filled with an inorganic material (such as amorphous silica fine particles) having a small CTE as a filler. .

Not only as a filler of the above sealing materials, the technique which utilizes amorphous silica fine particles as a filler of underfilling is also used. That is, a circuit mounted on a base material by wire bonding, flip chip bonding or the like is likely to be broken by a relatively small force because it is often fragile to external force or stress. Under the circumstances, it has been practiced to infiltrate a liquid curable resin (epoxy resin or the like) called an underfill between substrate parts to secure connection reliability. Here, it is expected that thermal expansion and contraction of the resin may cause bond breakage, and therefore, for the purpose of suppressing such thermal expansion and contraction of the resin, an inorganic substance having a small CTE (amorphous silica A technique of filling fine particles etc. as a filler is used.

However, in the technology of filling such amorphous silica fine particles, amorphous silica exhibits a “positive” CTE although it has a small CTE compared to, for example, an epoxy resin. There is room for improvement in terms of effectively reducing the CTE of the stop material and the material for forming the underfill (composite resin containing epoxy resin or the like as the main component).

Here, β-eucryptite (β-LiAlSiO ₄ ), which is one of silicate compounds, is known as a material having a negative CTE, and it is considered to use it as a filler. On the other hand, in order to use β-eucryptite as a filler for sealing materials and underfilling, it is necessary to reduce the particle size and increase the dispersibility in the resin so that the resin can be filled at a high density. In addition, since the negative CTE is derived from the specific crystal structure of β-eucryptite, it is essential to have high crystallinity, particularly in underfilling applications.

In addition to the purpose of reducing the CTE as described above, the epoxy resin or the like may be filled with amorphous silica fine particles for the purpose of reducing the dielectric loss and exhibiting the insulating function.

For example, magnesium-containing forsterite (Mg ₂ SiO ₄ ) or enstatite (MgSiO ₃ ), which is one of silicate compounds, is known as a material having a small dielectric loss in a high frequency region and exhibiting high insulation. There is. These compounds are used as materials for dielectric ceramics used in the microwave region, but to be used as a filler to reduce the dielectric loss of the resin, as in the case of β-eucryptite, the resin In order to be able to be packed at high density, it is necessary to reduce the particle size and increase the dispersibility in the resin. Furthermore, in order to reduce dielectric loss in a high frequency region, it is essential to have high crystallinity.

With respect to the above points, a method of producing a ceramic filler of eucryptite by a powder synthesis method in which LiO ₂ , Al ₂ O ₃ and SiO ₂ are used as starting materials and these are mixed at a predetermined molar ratio and then heat treated is disclosed (See, for example, Patent Document 1). Patent Document 1 describes that heat treatment at 1000 to 1400 ° C. is preferable when synthesizing single phase eucryptite.

Also disclosed is a method of mixing each aqueous solution of LiCl, AlCl and Na ₂ SiO ₃ to precipitate or precipitate to form fine particles, and heat treating the fine particles at 700 to 1300 ° C. to produce eucryptite filler. (See, for example, Patent Document 2).

Also disclosed is a method of producing β-eucryptite fine particles in the range of 600 to 1300 ° C. by spray-drying a solution containing a water-soluble lithium salt, a water-soluble aluminum salt and colloidal silica and then firing in air. (See, for example, Patent Document 3).

In addition, after mixing and grinding Mg (OH) ₂ powder or MgO powder and SiO ₂ powder with an average primary particle diameter of 10 μm or less in water, spray drying with a spray drier, and firing at 1100 ° C., wet grinding and spray drying A method of producing forsterite powder having an average primary particle diameter of 0.05 to 0.15 μm by carrying out the method is disclosed (see, for example, Patent Document 4).

Furthermore, a solution containing a water-soluble magnesium salt and colloidal silica is spray-dried and then fired at a temperature of 800 to 1000 ° C. in the air, so that the primary particle diameter by electron microscope observation is 1 without passing through the pulverizing step. A method of producing forsterite fine particles in the range of ̃200 nm is disclosed (see, for example, Patent Document 5).

JP, 2008-255004, A JP, 2014-131042, A International Publication No. 2016/117248 JP 2003-327470 A International Publication No. 2015/146961

However, in patent document 1, since eucryptite is heat-processed and manufactured at comparatively high temperature, the strong aggregation and melt | fusion of particle | grains which resulted from this heat processing were not avoided. In this case, in order to obtain a filler with a small particle size, it was necessary to grind it with strong energy. When such pulverization is carried out, since the particle shape is in the form of a square particle having an irregular size and shape, the dispersibility in the resin is lowered, and the filling amount is excessively limited. Furthermore, there is a case where the crystallinity is reduced and the formation of an amorphous phase occurs due to the pulverization, and the effect of reducing the CTE as a composite resin can not be sufficiently obtained.

Moreover, in patent document 2, since the neutralization reaction of LiCl or AlCl and Na ₂ SiO ₃ occurs, precipitates or precipitates are formed, the distribution of each element becomes uneven, and the filler of eucryptite is formed. There was a possibility that the temperature of the heat treatment required to obtain it might become high. When the temperature of the heat treatment becomes high, strong aggregation and fusion between particles can not be avoided, and the dispersibility in the resin may be insufficient. Moreover, the process of removing a part of sodium ion and lithium ion was complicated. And, the case where the obtained eucryptite is mixed with the crystal phase (α phase) having a positive CTE can not be avoided, and in this case, the effect of reducing the CTE can not be sufficiently obtained.

Further, in Patent Document 3, since the obtained β-eucryptite is not excellent in crushing property and crushing property, when making the particle diameter smaller, it has to be crushed with strong energy. Similar to the above-mentioned Patent Document 1, when such pulverization is carried out, the particle shape is in the form of rectangular particles having irregular sizes and shapes, so that the dispersibility in the resin is lowered, and the filling amount is excessively limited. .

Moreover, in patent document 4, in order to obtain forsterite, it was necessary to carry out wet grinding after baking. Through such pulverization, there is a case where the crystallinity is reduced and the formation of an amorphous phase occurs, and the effect of reducing the dielectric loss may not be sufficiently obtained.

Furthermore, in Patent Document 5, since the heat treatment causes strong fusion between particles, sufficient dispersibility in the resin can not be obtained. In order to improve the dispersibility, it is conceivable to reduce the particle size by wet pulverization or the like. However, similar to Patent Document 4, by undergoing such pulverization, the reduction of crystallinity and the formation of an amorphous phase occur, and the dielectric In some cases, the effect of reducing the loss can not be obtained sufficiently.

The present invention has been made in view of such circumstances, and it is an object of the present invention to provide silicate compound fine particles having a small particle diameter, excellent dispersibility in a resin, and high crystallinity, and a method for producing the same. .

As a result of intensive studies to solve the above problems, the present inventors have crushed a silicate compound as a raw material to a particle diameter within a predetermined range, and then grind the finely divided particles at a relatively low temperature. It has been found that by firing in a temperature range, it is possible to produce silicate compound fine particles having a small particle size, excellent in dispersibility in a resin, and high crystallinity.

That is, the present invention relates to fine particles of a silicate compound as described in any one of the following first to fourth aspects and a method for producing the same.

As a first aspect, the ratio (d ₅₀ / d _S ) of the primary particle diameter (d _S ) converted to spherical particles from the specific surface area by nitrogen adsorption method and the dispersed particle diameter (d ₅₀ ) is 1.0 or more It is less than 3.0, and the crystallite diameter calculated from the X-ray diffraction peak belonging to the (102) plane of the β-eucryptite phase is 45 nm or more and 100 nm or less. .

As the second aspect, the specific surface area measured by the nitrogen adsorption method and the primary particle diameter in terms of spherical particles _{(d S),} and the dispersion particle diameter _{(d 50),} of (the ratio _{_d} 50 / _d _S) is 1.0 or more It is less than 3.0, and the crystallite diameter calculated from the X-ray diffraction peak belonging to the (112) plane of the forsterite phase is 30 nm or more and 100 nm or less.

As a third aspect, in the step (A) of pulverizing the silicate compound so that the dispersed particle diameter (d ₅₀ ) is in the range of 0.1 μm to 2.0 μm, and the fine particles of the pulverized silicate compound And (B) a step of firing at a temperature of 750 ° C. or more and less than 950 ° C., which is a method of producing fine particles of a silicate compound.

According to a fourth aspect, the method further comprises the step (C) of dispersing the fired fine particles such that the dispersed particle diameter (d ₅₀ ) is in the range of 0.1 μm to 2.0 μm. It is a manufacturing method of the silicate compound fine particles as described in three viewpoints.

According to the present invention, it is possible to provide silicate compound fine particles having a small particle size, excellent dispersibility in a resin, and high crystallinity. Such fine particles of the silicate compound of the present invention can be suitably used as a filler for semiconductor sealing materials and underfilling.

Electron microscope image of silicate compound particles according to Examples 1 and 2 Electron microscope image of fine particles of silicate compound according to Examples 3 and 4 Electron microscope image of silicate compound particles according to Comparative Examples 1 and 4

The silicate compound fine particles according to the present invention and the method for producing the same will be described. The following description shows one aspect of the present invention, and can be arbitrarily changed within the scope of the present invention.

The present invention relates to silicate compound fine particles and a method of producing the same. The silicate compound is, for example, a compound used as a filler for a semiconductor sealing material or underfilling, and examples thereof include β-eucryptite and forsterite. Therefore, the modes for carrying out the present invention will be described in detail by dividing the case where the silicate compound is β-eucryptite and the case where it is forsterite.

(1) Silicate compound (β-eucryptite) fine particles The silicate compound (β-eucryptite) fine particles of the present invention are dispersed in primary particle diameter d _S converted to spherical particles from specific surface area by nitrogen adsorption method, and dispersed A crystal calculated from an X-ray diffraction peak belonging to the (102) plane of the β-eucryptite phase which has a ratio (d ₅₀ / d _S ) of the particle diameter d ₅₀ of 1.0 to less than 3.0. The diameter is 45 nm or more and 100 nm or less.

Such β-eucryptite microparticles can be produced through a process including specific (A) steps and (B) steps. That is, in the step (A), the silicate compound as the raw material is pulverized to a small particle size (for example, the dispersed particle size d ₅₀ is 0.1 μm or more and 2.0 μm or less). In the subsequent step (B), the fine particles pulverized in the previous step (A) are fired in a specific temperature range.

The temperature range in the step (B) is lower than the temperature range such as "sintering" in which a sintered body is obtained by sintering an aggregate of fine particles. Conventionally, in general, a sintering process for obtaining a sintered body of pulverized particles is often performed after the process of pulverizing the raw material. However, in the step (B), a temperature range lower than the temperature for such sintering is set. Then, in relation to the temperature range in the step (B), it is determined in the above-mentioned step (A) whether or not the raw material is crushed to any particle size.

As described above, in the step (B), since sintering is performed in a specific temperature range lower than conventional sintering, it is possible to avoid that the particles are strongly fused. Of course, the temperature range of the step (B) does not deviate from the temperature at which firing can be carried out, so in the step (B), an effect normally expected as firing, for example, an effect such as particle growth can be naturally obtained .

Therefore, even if the crystallinity of the silicate compound is lost by the pulverization of the raw material in the step (A), the lost crystallinity is recovered and improved by the subsequent firing in the step (B). Can. In addition, according to the temperature range of the step (B), it is possible to avoid that the particles are firmly fused. Therefore, when the fine particles are re-dispersed after firing, the fine particles can be easily crushed without giving strong energy.

In other words, the particles can be broken down with relatively weak energy, so there is no loss of crystallinity with the breaking up. Therefore, the fine particles pulverized to the small particle size in the (A) step recover crystallinity while undergoing the slight growth by the firing in the (B) step, and maintain the high crystallinity while still maintaining the small particle size. At the time of redispersion, it exhibits excellent dispersibility.

Such fine particles of the silicate compound of the present invention have a ratio (d ₅₀ / d _S ) of a primary particle diameter d _S converted to a spherical particle from a specific surface area by a nitrogen adsorption method and a dispersed particle diameter d ₅₀ of 1. It is 0 or more and less than 3.0.

The primary particle diameter d _S converted to spherical particles is calculated by the reciprocal of the product of the specific surface area (surface area per unit mass) measured by the nitrogen adsorption method and the density of the silicate compound, as shown in the formula (1). it can. The specific surface area by the nitrogen adsorption method can be measured according to a known method, and the density of the silicate compound can be derived based on the pycnometer method, the Archimedes method or the like.
d _S = n 1/1 (specific surface area (m ² / g) density (g / m ³ )) (1)
(Wherein, d _S is the primary particle diameter converted to spherical particles and n is a constant)

The primary particle diameter d _S converted to spherical particles represents the diameter of the primary particles regardless of the aggregation state of the fine particles in the dispersion medium. That is, according to the primary particle diameter d _S converted to spherical particles, even when the fine particles are not much aggregated in the dispersion medium to become secondary particles, the same value as the value corresponding to the diameter of unaggregated primary particles A value will be obtained. Therefore, ideally, the value of the denominator of the ratio (d ₅₀ / d _S ) does not depend on the degree of aggregation or fusion of the fine particles in the dispersion medium.

The dispersed particle size d ₅₀ is an average particle size when the dried fine particles are dispersed in a dispersion medium. The particle diameter can be measured by various methods such as laser diffraction method, dynamic light scattering method and centrifugal sedimentation method, but in the present invention, the value measured by laser diffraction method is adopted as dispersed particle diameter as adopted in the examples. d ₅₀ As a dispersion medium, although water is mentioned typically, it does not specifically limit.

In the case where the fine particles aggregate into secondary particles in the dispersion medium without much, the dispersed particle size d ₅₀ roughly corresponds to the secondary particle size. The higher the degree to which the particles are strongly aggregated or fused in the dispersion medium, the larger the dispersed particle diameter d ₅₀ which is a molecule of the ratio (d ₅₀ / d _S ), and as a result, the ratio (d ₅₀ / d d _S ) becomes large. Conversely, as the degree of dispersion of the fine particles in the dispersion medium is higher, the dispersed particle diameter d ₅₀ has a value closer to the primary particle diameter d _S converted to spherical particles. That is, the ratio (d ₅₀ / d _S ) approaches 1.0 as the degree of dispersion of the fine particles in the dispersion medium is higher.

Thus, the ratio (d ₅₀ / d _s ) is an indicator of the dispersibility of the particles and, from its principle, is 1.0 or more. When the ratio (d ₅₀ / d _S ) is close to 1.0 as in the silicate compound fine particles of the present invention, it means that the fine particles are well dispersed in the dispersion medium.

On the other hand, when the ratio (d ₅₀ / d _S ) is less than 3.0 and the degree to which the fine particles are well dispersed in the dispersion medium is low, sufficient dispersibility in the resin can not be obtained. . If sufficient dispersibility in the resin can not be obtained, these fine particles can not be packed into the resin at a high density, so that the desired effect can not be obtained even when used as a filler.

Next, in the silicate compound fine particles of the present invention, the crystallite diameter calculated from the X-ray diffraction peak belonging to the (102) plane of the β-eucryptite phase is 45 nm or more and 100 nm or less. This type of X-ray diffraction peak can be measured by a known method.

The strongest line of the β-eucryptite phase is an X-ray diffraction peak belonging to the (102) plane near 2θ = 25 °. Therefore, in the present invention, the crystallite diameter calculated from the X-ray diffraction peak by the Scherrer formula is within the above range.

If the crystallite diameter is smaller than the above range, the original characteristics of the crystalline material can not be obtained. That is, with β-eucryptite, the effect of reducing CTE can not be obtained. On the other hand, when the crystallite diameter exceeds the above range, the progress of particle growth at the time of firing becomes remarkable, and it becomes difficult to maintain the diameter of the broken fine particles such that the diameter becomes small.

The crystallite diameter in the direction perpendicular to the diffractive surface is in the relationship of Formula (2) when it is expressed by 2θ (half width β, unit is Rad) corresponding to the peak width at half intensity. Where L is the crystallite diameter, λ is the X-ray wavelength (0.154 nm), and K is the form factor constant. Usually, 0.9 is used for K.
L = Kλ / (β · cos θ) (2)

(2) Silicate Compound (Forsterite) Fine Particles The silicate compound (forsterite) fine particles of the present invention have a primary particle diameter d _S converted to spherical particles from the specific surface area by a nitrogen adsorption method, a dispersed particle diameter d ₅₀ , Ratio (d ₅₀ / d _S ) is 1.0 or more and less than 3.0, and the crystallite diameter calculated from the X-ray diffraction peak belonging to the (112) plane of the forsterite phase is 30 nm or more and 100 nm or less .

Such forsterite fine particles can also be produced through processes including the steps (A) and (B), as in the case of the β-eucryptite fine particles. Even if the crystallinity of the silicate compound is lost by the pulverization of the raw material in the step (A), the lost crystallinity can be recovered and further improved by the subsequent firing of the step (B). In addition, according to the temperature range of the step (B), it is possible to avoid that the particles are firmly fused. Therefore, when the particles are redispersed after firing, the particles can be broken down with relatively weak energy, so that the crystallinity is not lost along with the crushing.

As described above, the fine particles pulverized to the small particle size in the (A) step recover crystallinity while undergoing the slight growth by the firing in the (B) step, and the high particle size still remains with the small particle size. Exerts excellent dispersibility at the time of re-dispersion while maintaining the

Such fine particles of the silicate compound of the present invention have a ratio (d ₅₀ / d _S ) of a primary particle diameter d _S converted to a spherical particle from a specific surface area by a nitrogen adsorption method and a dispersed particle diameter d ₅₀ of 1. It is 0 or more and less than 3.0. The primary particle diameter d _S and the dispersed particle diameter d ₅₀ converted to spherical particles can be derived based on the same method as in the case of the β-eucryptite fine particles.

When the ratio (d ₅₀ / d _S ) is in the range close to 1.0, it means that the fine particles are well dispersed in the dispersion medium. On the other hand, when the ratio (d ₅₀ / d _S ) is less than 3.0 and the degree to which the fine particles are well dispersed in the dispersion medium is low, sufficient dispersibility in the resin can not be obtained. In this case, since these fine particles can not be packed into the resin at high density, the desired effect can not be obtained even when used as a filler.

Next, in the silicate compound fine particles of the present invention, the crystallite diameter calculated from the X-ray diffraction peak belonging to the (112) plane of the forsterite phase is 30 nm or more and 100 nm or less. This type of X-ray diffraction peak can be measured by a known method.

In the forsterite fine particles, the crystallite diameter calculated as described above is preferably 30 nm or more and 50 nm or less. When the crystallite diameter is in this range, it is easy to form fine particles of a silicate compound having a small particle diameter, excellent dispersibility in a resin, and high crystallinity.

The strongest line of the forsterite phase is an X-ray diffraction peak belonging to the (112) plane near 2θ = 36.5 °. Therefore, in the present invention, the crystallite diameter calculated from the X-ray diffraction peak by the Scherrer formula is within the above range.

If the crystallite diameter is smaller than the above range, the original characteristics of the crystalline material can not be obtained. That is, in the forsterite, the effect of reducing the dielectric loss can not be obtained. On the other hand, when the crystallite diameter exceeds the above range, the progress of particle growth at the time of firing becomes remarkable, and it becomes difficult to maintain the diameter of the broken fine particles such that the diameter becomes small.

Incidentally, even in the case of forsterite, as in the case of β-eucryptite, the crystallite diameter can be calculated by the above equation (2).

(3) Method for Producing Silicate Compound Fine Particles In the method for producing silicate compound fine particles of the present invention, the silicate compound (raw material) is added so that the dispersed particle diameter d ₅₀ is in the range of 0.1 μm to 2.0 μm. It has the process (A) which grind | pulverizes, and the process (B) which bakes the microparticles | fine-particles of this ground silicate compound at the temperature of 750 degreeC or more and less than 950 degreeC. Each step will be described below.

The silicate compound used as a raw material can be manufactured by a well-known method in a process (A), and a commercial item can also be used. For example, as β-eucryptite, one manufactured by the method described in WO 2016/117248, or FE-200 manufactured by Marusu Gakuen Co., Ltd. can be used. In addition, as forsterite, one manufactured by the method described in WO2016 / 117248, or one manufactured by Marusu Gakuen Co., Ltd. can be used. Even if it is any silicate compound, you may use together what was manufactured and a commercial item.

In the step (A), the particle diameter to which the raw material is to be ground is related to the dispersed particle diameter d ₅₀ of the silicate compound fine particles finally obtained through the next step (B). Therefore, when the dispersed particle diameter d ₅₀ of the raw material pulverized in the step (A) exceeds 2.0 μm, the particle diameter of the finally obtained silicate compound also becomes large. On the other hand, when the dispersed particle diameter d ₅₀ is reduced to less than 0.1 μm in the step (A), the particles are likely to be firmly fused in the next step (B).

Examples of the method of pulverizing the raw material in the step (A) include wet pulverization such as a bead mill and dry pulverization such as a jet mill. In wet grinding using a bead mill or the like, as the dispersion medium, general-purpose materials such as water, isopropanol and methyl ethyl ketone can be used, but are not particularly limited. In view of the ease of drying, it is desirable to use an organic solvent having a low boiling point. In order to grind the raw material down to a small particle size, wet grinding may be advantageous in some cases, but dry grinding may, of course, also be suitably employed.

When the grinding method is wet grinding, the slurry needs to be dried and powdered before X-ray diffraction analysis is performed. The drying method may be, for example, vacuum drying with a vacuum dryer or the like, heat drying with a hot plate or the like, or lyophilization, but is not particularly limited.

Next, in the step (B), the fine particles pulverized in the previous step (A) are fired at a temperature of 750 ° C. or more and less than 950 ° C. Even if the crystallinity of the silicate compound is lost by the pulverization of the raw material in the step (A), the lost crystallinity can be recovered and thus improved by the step (B), and the crystallite The diameter and x-ray diffraction intensity can also be increased.

If the firing temperature in the step (B) is lower than the above range, the effect of firing can not be obtained. For example, the crystallinity does not improve and the particles do not grow. On the other hand, if the firing temperature in the step (B) is larger than the above range, fusion between particles and particle growth significantly progress, and the silicate compound becomes coarse particles. In this case, fine particles of silicate compound having a ratio (d ₅₀ / d _S ) of less than 3.0 can not be obtained. Not only that, in order to grind such strongly fused coarse particles, strong energy is required, and as a result, a reduction in crystallite diameter accompanying the grinding can not be avoided.

Furthermore, in the step (B), the irregular and angular particle shape is changed to a rounded particle shape. In order to easily obtain the rounded particle form, it is preferable to bake at 800 ° C. or more and less than 950 ° C. in the step (B).

However, the firing method in the step (B) is not particularly limited as long as it can heat the silicate compound fine particles at a temperature of 750 ° C. or more and less than 950 ° C. The baking time of the step (B) is, for example, 30 minutes to 20 hours, but other times may be possible. The production conditions may be varied depending on the type of the silicate compound. For example, when the silicate compound is β-eucryptite, the firing temperature can be 800 ° C. or more and less than 950 ° C. Of course, even when the silicate compound is forsterite, the firing temperature can be 800 ° C. or more and less than 950 ° C.

Through the process including the step (A) and the step (B), the silicate compound fine particles of the present invention can be produced. Such fine particles of the silicate compound of the present invention are in the form of roundness, and the dispersed particle diameter d _S is within a small range (for example, within the range of 0.1 μm to 2.0 μm). There is. As a result, the dispersed particle diameter d ₅₀ is larger than the above range, and excellent dispersibility in the resin can be ensured as compared with fine particles of an irregular shaped angular shape (fine particles as shown in the prior art), and high density It becomes possible to fill.

In addition, the silicate compound fine particles of the present invention have higher crystallinity than the fine particles as shown in the prior art. Therefore, for example, if the silicate compound is β-eucryptite, sufficient effect to reduce CTE as a composite resin can be expected, and if the silicate compound is forsterite, dielectric loss as a composite resin is reduced. Sufficient effects can be expected. Therefore, any silicate compound can be suitably used as a filler for a semiconductor sealing material or underfilling.

Here, in the present invention, the fine particles of the silicate compound calcined in the above-mentioned step (B) are dispersed (C) so that the dispersed particle diameter d ₅₀ is in the range of 0.1 μm to 2.0 μm. It is preferable to have

In the present invention, since the firing temperature in the previous step (B) is suppressed to a relatively low temperature range, strong aggregation and fusion between particles are avoided. Since fine particles can be broken down with relatively weak energy, reduction in crystallite diameter and decrease in X-ray diffraction intensity hardly occur in the step (C), and high crystallinity can be maintained.

Even with relatively weak energy, the particles can be broken down while maintaining high crystallinity until the dispersed particle diameter d ₅₀ is close to the particles (primary particles) that have been crushed in the previous step (A), The fine particles after firing can be dispersed in a dispersion medium. Through the step (C), the ratio (d ₅₀ / d _S ) can be easily made less than 3.0.

Examples of the dispersion method in the step (C) include wet pulverization such as a bead mill and dry pulverization such as a jet mill, but are not particularly limited. In wet grinding such as bead milling, as the dispersion medium, general-purpose dispersion media such as water, isopropanol and methyl ethyl ketone can be used, but this is not particularly limited.

When the fine particles (baked powder) subjected to the previous step (B) are dispersed in a composite resin such as an epoxy resin, they may be directly dispersed, or may be dispersed in another dispersion medium and then mixed. May be In the case of dispersion in a resin, a three-roll mill or the like can be preferably used, but it is not particularly limited.

Hereinafter, the present invention will be described by way of examples and comparative examples, but the present invention is not limited to these examples. In Examples and Comparative Examples, various evaluations were performed as follows.

<X-ray diffraction analysis>
X-ray source: Cu, voltage: 40 kV, current: 15 mA, step width: 0.01 °, scan rate: 5 ° / min, divergence angle slit (DS), using Rigaku X-ray diffractometer MiniFlex 600 0.625 °, scattering slit (SS); 8.0 mm, light receiving slit (RS); OPEN, incident solar slit; 2.5 °, light receiving solar slit; measured at 2.5 °, X-ray diffraction I got the data.

<X-ray diffraction intensity>
The X-ray diffraction data of each sample was subjected to background processing with automatic setting using analysis software PDXL-2 to measure the X-ray diffraction intensity. In β-eucryptite, the intensity of the diffraction peak of the strongest line (102) appearing near 2θ = 25 ° (unit: counts), and forsterite the strongest line appearing near 2θ = 36.5 ° (112) The intensity (in units of counts) of the diffraction peak of the surface was adopted.

<Calculation of crystallite diameter>
The X-ray diffraction data of each sample was subjected to background processing by automatic setting using analysis software PDXL-2, and the crystallite diameter was calculated based on Scherrer's equation. In β-eucryptite, the crystallite diameter in the direction perpendicular to the (102) plane was adopted, and in the case of forsterite, the crystallite diameter in the direction perpendicular to the (112) plane was adopted.

<Measurement of dispersed particle size by laser diffraction method>
The dispersed particle diameter d ₅₀ (dispersed particle diameter d ₅₀ by laser diffraction method) was measured using a laser diffraction type particle size distribution measurement device Mastersizer 2000 manufactured by Malvern. In the measurement, pure water was used as a dispersion medium, and ultrasonic waves were irradiated for 1 minute. For β-eucryptite, an average particle diameter calculated using a refractive index of 1.55 and an absorption coefficient (imaginary part) of 0.1 was employed. For forsterite, an average particle diameter calculated using a refractive index of 1.65 and an absorption coefficient (imaginary part) of 0.1 was employed.

<Calculation of primary particle diameter>
The specific surface area of the silicate compound powder was measured by a nitrogen adsorption method using MONOSORB manufactured by Kantachrome Corporation. Then, assuming that the density of β-eucryptite is 2.35 and the density of forsterite is 3.0, the primary particle diameter d _S when converted to spherical particles is calculated.

Production Example 1
Based on the method described in WO 2016/117248, β-eucryptite powder was synthesized according to the following procedure.

<Production of aluminum oxalate aqueous solution>
378.8 g (3 moles) of oxalic acid dihydrate (special grade, 99.5% by mass, manufactured by Kanto Chemical Co., Inc.) was dissolved in 1469.6 g of pure water to obtain an oxalic acid aqueous solution. While stirring the obtained aqueous solution of oxalic acid, 191.3 g (1 mol) of dry aluminum hydroxide gel (Kyowa Chemical Co., Ltd., trade name; Kyoward 200 S, 53.3 mass% of Al ₂ O ₃ ) is added, Heat at 85 ° C. for 2 hours.

Since part of the water was volatilized during heating, 45 g of pure water was added to adjust to 2039.2 g. The resultant was passed through glass filter paper (GA-100, manufactured by Advantec Co., Ltd.) and filter paper (No. 5C manufactured by Advantech Co., Ltd.) to obtain a pale yellow and transparent aqueous solution of aluminum oxalate. The solid content concentration (Al ₂ O ₃ conversion) of the obtained aqueous solution of aluminum oxalate was 5.00% by mass.

<Production of lithium oxalate aqueous solution>
Dissolve 42.0 g (1 mole) of lithium hydroxide monohydrate (special grade, 98.0 mass%, manufactured by Kanto Chemical Co., Ltd.) in 819.1 g of pure water, and oxalic acid dihydrate (manufactured by Kanto Chemical Co., Ltd.) The aqueous solution of lithium oxalate was obtained by adding 63.0 g (0.5 mol) of a special grade, 99.5 mass%) and stirring for 10 minutes at room temperature. The solid content concentration (in terms of Li ₂ O) of the obtained aqueous solution of lithium oxalate was 1.62% by mass.

<Production of β-eucryptite powder>
Colloidal silica (Snowtex (registered trademark) OXS, Nissan Chemical Industries, Ltd., silica concentration 10.5 mass%, primary particle diameter 5 nm by transmission electron microscope observation) 572.2 g (SiO ₂ 1 mol), aluminum oxalate An aqueous solution of 1019.6 g (Al ₂ O ₃ 0.5 mol) and an aqueous solution of lithium oxalate 924.1 g (Li ₂ O 0.5 mol) were added, and the mixture was stirred at room temperature for 10 minutes to obtain a mixture. The specific gravity of the obtained mixed solution was 1.068, the pH was 2.0, and the electric conductivity was 22.3 mS / cm.

The obtained mixture was subjected to an inlet temperature of 185 ° C., an atomizing air pressure of 0.14 MPa, an aspirator flow rate of 0.50 m ³ / min, using a spray dryer (Palvis Mini Spray GB 210-A, manufactured by Yamato Scientific Co., Ltd.). The mixture was dried under the conditions of a liquid transfer rate of 4 g / min to obtain a dry powder. The outlet temperature at this time was 80 ± 3 ° C.

300 g of the obtained dried powder was put in an alumina crucible and baked at a temperature of 850 ° C. for 5 hours in the atmosphere using a tabletop electric furnace to obtain 103 g of a white powder. When the obtained white powder is identified by X-ray diffraction analysis, it is a β-eucryptite single phase, and the diffraction peak intensity of the strongest line (102) surface appearing near 2θ = 25 ° is 28054, and the crystallite diameter is It was 52 nm. Primary particle diameter _{d S} by nitrogen adsorption method 2.72Myuemu, dispersed particles size _{d 50} by a laser diffraction method was 11.2 .mu.m.

Production Example 2
Forsterite powder was synthesized according to the following procedure based on the method described in WO2015 / 146961.

<Production of magnesium citrate aqueous solution>
In 2058.8 g of pure water, 253.5 g of citric acid monohydrate (special grade, 99.5 mass%, manufactured by Kanto Chemical Co., Ltd.) was dissolved to obtain a 10.0 mass% citric acid aqueous solution. While stirring the obtained citric acid aqueous solution, 105.7 g of magnesium hydroxide (Kanto Chemical Co., Ltd., first grade, 95.0%) is added, and stirring is carried out at room temperature for 1 hour to obtain a magnesium citric acid aqueous solution. The The solid content concentration (in terms of MgO) of the obtained aqueous solution of magnesium citrate was 2.9% by mass.

<Production of forsterite powder>
After mixing 1196.1 g of pure water with 283.4 g of colloidal silica (Snowtex (registered trademark) OXS, manufactured by Nissan Chemical Industries, Ltd., silica concentration 10.6 mass%, primary particle diameter 5 nm by electron microscope observation), Production Example 1 The aqueous solution of 1334.8 g of the aqueous solution of magnesium citrate obtained in the above was added, and the mixture was stirred at room temperature for 30 minutes to obtain a mixture. The specific gravity of the obtained mixed solution was 1.04, the viscosity was 1.8 mPa · s, and the pH was 5.2.

An inlet temperature of 180 ° C., an atomizing air pressure of 1.35 kgf / cm ² , and an aspirator flow rate of 0.30 m using a spray dryer (Palvis Mini Spray GA-22, manufactured by Yamato Scientific Co., Ltd.). It dried on the conditions of ³ / minute and the sending speed of a liquid mixture 5 g / min. The outlet temperature at this time was 80 ± 2 ° C. to obtain 99.6 g of a white dry powder.

43.1 g of the obtained dry powder is put in an alumina crucible and fired at a temperature of 500 ° C. in the atmosphere for 2 hours in the atmosphere using a tabletop electric furnace and then fired at a temperature of 800 ° C. in the atmosphere for 2 hours, 12.4 g of white powder was obtained. The white powder obtained was identified by X-ray diffraction analysis, and the product phase is almost single phase of forsterite, and the diffraction peak intensity of the strongest line (112) plane near 2θ = 36.5 ° is 2808, crystal The child diameter was 35 nm. Primary particle diameter _{d S} by nitrogen adsorption method 0.11 .mu.m, dispersed particles size _{d 50} by a laser diffraction method was 7.43Myuemu.

Example 1
40 g of β-eucryptite powder produced in Production Example 1, 160 g of isopropanol, and 900 g of φ 0.5 mm zirconia beads were placed in a grinding container, and wet-milled under conditions of 1000 rpm using a bead mill apparatus Easy Nano RMB type manufactured by Imex. After grinding for 5 hours, the zirconia beads were removed and the slurry was recovered.

The slurry was then placed in an eggplant flask and dried at 10 Torr using a rotary evaporator until volatiles were eliminated to obtain a dry powder. The dry powder is identified by X-ray diffraction analysis to be β-eucryptite single phase, and the intensity of the diffraction peak of the strongest line (102) surface appearing near 2θ = 25 ° is 15361, and the crystallite diameter is 40 nm. there were. Primary particle diameter _{d S} by a nitrogen adsorption method is 0.20 [mu] m, dispersed particles size _{d 50} by a laser diffraction method was 0.39 .mu.m.

The dried powder was put in an alumina sagger, heated to 850 ° C. at 3 ° C./min in a table electric furnace, and fired for 5 hours to obtain a fired powder. The obtained calcined powder is identified by X-ray diffraction analysis to be β-eucryptite single phase, and the diffraction peak intensity of the strongest line (102) surface appearing near 2θ = 25 ° is 35714, and the crystallite diameter is It was 61 nm.

Next, 8 g of the above-mentioned calcined powder, 32 g of isopropanol and 85 g of φ1 mm zirconia beads are placed in a 100 cc plastic container, placed on a universal ball mill UB32 manufactured by Yamato Scientific Co., and crushed for 24 hours at 200 rpm to contain β-eucryptite fine particles. A slurry was obtained.

The slurry was dried by the same method as described above to obtain a powder of β-eucryptite fine particles. As a result of identification by X-ray diffraction analysis, the diffraction peak intensity of the strongest line (102) surface which is a β-eucryptite single phase and appears near 2θ = 25 ° was 32843, and the crystallite diameter was 59 nm. Primary particle diameter _{d S} by a nitrogen adsorption method was 0.33 .mu.m, dispersed particles size _{d 50} by a laser diffraction method was 0.35 .mu.m. Further, when the particle morphology was observed with an electron microscope, rounded fine particles were confirmed.

Example 2
A slurry obtained by adding 100 g of the β-eucryptite powder produced in Production Example 1 to 400 g of isopropanol was prepared using a bead mill Ultra Apex Mill UAM 015 manufactured by Hiroshima Metal & Machinery Co., Ltd. The slurry was ground for 5 hours and 30 minutes under the condition of 5 m / sec in peripheral speed.

The slurry was then placed in an eggplant flask and dried at 10 Torr using a rotary evaporator until volatiles were eliminated to obtain a dry powder. The dry powder is identified by X-ray diffraction analysis to be β-eucryptite single phase, and the intensity of the diffraction peak of the strongest line (102) surface appearing near 2θ = 25 ° is 8931, and the crystallite diameter is 31 nm. there were. The primary particle diameter d _S by the nitrogen adsorption method was 0.16 μm, and the dispersed particle diameter d ₅₀ by the laser diffraction method was 0.30 μm.

The dried powder was put into an alumina sagger, heated to 850 ° C. at 3 ° C./min in a table electric furnace, and fired for 3 hours to obtain a fired powder. The obtained calcined powder is identified by X-ray diffraction analysis to be β-eucryptite single phase, the diffraction peak intensity of the strongest line (102) surface appearing near 2θ = 25 ° is 33,394, and the crystallite diameter is It was 58 nm.

The slurry was dried by the same method as described above to obtain a powder of β-eucryptite fine particles. As a result of identification by X-ray diffraction analysis, the diffraction peak intensity of the strongest line (102) plane which is a β-eucryptite single phase and appears near 2θ = 25 ° is 30718, and the crystallite diameter is 60 nm. The primary particle diameter d _S by the nitrogen adsorption method was 0.28 μm, and the dispersed particle diameter d ₅₀ by the laser diffraction method was 0.28 μm. Further, when the particle morphology was observed with an electron microscope, rounded fine particles were confirmed.

[Example 3]
40 g of commercially available β-eucryptite powder FE-200 (manufactured by Marusu Gakuen Co., Ltd.), 160 g of isopropanol, and 900 g of φ 0.5 mm zirconia beads are placed in a grinding container, and a bead mill apparatus Easy Nano RMB type manufactured by Imex Co., Ltd. Wet grinding was performed under the conditions. After grinding for 5 hours, the zirconia beads were removed and the slurry was recovered.

The slurry was then placed in an eggplant flask and dried at 10 Torr using a rotary evaporator until volatiles were eliminated to obtain a dry powder. The dry powder is identified by X-ray diffraction analysis to be β-eucryptite single phase, and the diffraction peak intensity of the strongest line (102) surface appearing near 2θ = 25 ° is 14295, and the crystallite diameter is 40 nm. there were. The primary particle diameter d _S by the nitrogen adsorption method was 0.19 μm, and the dispersed particle diameter d ₅₀ by the laser diffraction method was 0.39 μm.

The dried powder was put in an alumina sagger, heated to 850 ° C. at 3 ° C./min in a table electric furnace, and fired for 5 hours to obtain a fired powder. The obtained calcined powder is identified by X-ray diffraction analysis to be β-eucryptite single phase, and the diffraction peak intensity of the strongest line (102) surface appearing near 2θ = 25 ° is 32006, and the crystallite diameter is It was 58 nm.

The slurry was dried by the same method as described above to obtain a powder of β-eucryptite fine particles. As a result of identification by X-ray diffraction analysis, the diffraction peak intensity of the strongest line (102) plane which is a β-eucryptite single phase and appears near 2θ = 25 ° was 25166, and the crystallite diameter was 52 nm. Primary particle diameter _{d S} by a nitrogen adsorption method was 0.34 .mu.m, dispersed particles size _{d 50} by a laser diffraction method was 0.42 .mu.m. Further, when the particle morphology was observed with an electron microscope, rounded fine particles were confirmed.

Example 4
40 g of forsterite powder produced in Production Example 2, 160 g of methanol, and 900 g of φ 0.5 mm zirconia beads were placed in a grinding container, and wet ground under conditions of 1000 rpm using a bead mill apparatus Easy Nano RMB type manufactured by Imex. After grinding for 5 hours, the zirconia beads were removed and the slurry was recovered.

The slurry was then placed in an eggplant flask and dried at 10 Torr using a rotary evaporator until volatiles were eliminated to obtain a dry powder. The dry powder was identified by X-ray diffraction analysis to be a forsterite single phase, and the diffraction peak intensity of the strongest line (112) plane near 2θ = 36.5 ° was 1379, and the crystallite diameter was 23 nm. Primary particle diameter _{d S} by a nitrogen adsorption method was 0.03 .mu.m, dispersed particles size _{d 50} by a laser diffraction method was 0.22 [mu] m.

The dried powder was put in an alumina sagger, heated to 900 ° C. at 3 ° C./min in a table-top electric furnace, and fired for 5 hours to obtain a fired powder. The obtained calcined powder is identified by X-ray diffraction analysis to be a forsterite single phase, and the diffraction peak intensity of the strongest line (112) plane near 2θ = 36.5 ° is 2450, and the crystallite diameter is 31 nm. The

Next, 8 g of the above-mentioned calcined powder, 32 g of isopropanol and 85 g of φ1 mm zirconia beads are placed in a 100 cc plastic container, placed on a universal ball mill UB32 manufactured by Yamato Scientific Co., and crushed for 24 hours at 200 rpm to obtain a slurry containing fine forsterite particles. The

The slurry was dried by the same method as described above to obtain a powder of forsterite fine particles. As a result of identification by X-ray diffraction analysis, the diffraction peak intensity of the strongest line (112) plane which is forsterite single phase and appears near 2θ = 36.5 ° is 2369, and the crystallite diameter is 33 nm. Primary particle diameter _{d S} by a nitrogen adsorption method was 0.07 .mu.m, dispersed particles size _{d 50} by a laser diffraction method was 0.19 .mu.m. Further, when the particle morphology was observed with an electron microscope, rounded fine particles were confirmed.

Comparative Example 1
The synthesis of β-eucryptite powder was performed in the same manner as in Production Example 1. 40 g of this β-eucryptite powder, 160 g of isopropanol, and 900 g of φ 0.5 mm zirconia beads were placed in a crushing container, and wet-milled under conditions of 1000 rpm using a bead mill apparatus Easy Nano RMB type manufactured by Imex. After grinding for 5 hours, the zirconia beads were removed to obtain a slurry containing β-eucryptite fine particles.

The slurry was then placed in an eggplant flask and dried at 10 Torr using a rotary evaporator until free of volatiles to prepare a dry powder. As a result of identification by X-ray diffraction analysis, the diffraction peak intensity of the strongest line (102) plane which is a β-eucryptite single phase and appears near 2θ = 25 ° was 15361, and the crystallite diameter was 40 nm. Primary particle diameter _{d S} by a nitrogen adsorption method is 0.20 [mu] m, dispersed particles size _{d 50} by a laser diffraction method was 0.39 .mu.m. In addition, when the particle form was observed with an electron microscope, irregular and angular fine particles were confirmed.

Comparative Example 2
A slurry obtained by adding 100 g of the β-eucryptite powder produced in Production Example 1 to 400 g of isopropanol was prepared using a bead mill Ultra Apex Mill UAM 015 manufactured by Hiroshima Metal & Machinery Co., Ltd. The slurry was ground for 5 hours and 30 minutes under the condition of 5 m / sec in peripheral speed.

The slurry was then placed in an eggplant flask and dried at 10 Torr using a rotary evaporator until volatiles were eliminated to obtain a dry powder. The dry powder is identified by X-ray diffraction analysis to be β-eucryptite single phase, and the intensity of the diffraction peak of the strongest line (102) surface appearing near 2θ = 25 ° is 8931, and the crystallite diameter is 31 nm. there were. The primary particle diameter d _S by the nitrogen adsorption method was 0.16 μm, and the dispersed particle diameter d ₅₀ by the laser diffraction method was 0.30 μm. In addition, when the particle form was observed with an electron microscope, irregular and angular fine particles were confirmed.

Comparative Example 3
60 g of the β-eucryptite powder produced in Production Example 1, 240 g of isopropanol, and 1200 g of φ 0.5 mm zirconia beads were placed in a grinding container, and wet ground under conditions of 1000 rpm using a bead mill apparatus Easy Nano RMB type manufactured by Imex. After grinding for 5 hours, the zirconia beads were removed to obtain a slurry containing β-eucryptite fine particles.

The slurry was then placed in an eggplant flask and dried at 10 Torr using a rotary evaporator until volatiles were eliminated to obtain a dry powder. The dry powder is identified by X-ray diffraction analysis to be β-eucryptite single phase, and the intensity of the diffraction peak of the strongest line (102) surface appearing near 2θ = 25 ° is 11149, and the crystallite diameter is 35 nm. there were. The primary particle diameter d _S by the nitrogen adsorption method was 0.17 μm, and the dispersed particle diameter d ₅₀ by the laser diffraction method was 0.32 μm.

The dried powder was put in an alumina sagger, heated to 700 ° C. at 3 ° C./min in a table-top electric furnace, and fired for 5 hours to obtain a fired powder. The obtained calcined powder is identified by X-ray diffraction analysis to be β-eucryptite single phase, and the diffraction peak intensity of the strongest line (102) surface appearing near 2θ = 25 ° is 18786, and the crystallite diameter is It was 37 nm and the improvement of crystallinity was insufficient. In addition, when the particle form was observed with an electron microscope, irregular and angular fine particles were confirmed.

Comparative Example 4
A fired powder was obtained in the same manner as in Comparative Example 3 except that the temperature of the firing step was changed to 950 ° C. The obtained calcined powder is identified by X-ray diffraction analysis to be β-eucryptite single phase, and the diffraction peak intensity of the strongest line (102) surface appearing near 2θ = 25 ° is 42042, and the crystallite diameter is It was 69 nm.

Next, 8 g of the calcined powder, 32 g of isopropanol, and 85 g of φ1 mm zirconia beads are placed in a 100 cc plastic container, placed on a universal ball mill UB32 manufactured by Yamato Scientific Co., and crushed for 24 hours at 200 rpm to obtain a slurry containing β-eucryptite. I got

The slurry was then placed in an eggplant flask and dried at 10 Torr using a rotary evaporator until volatiles were eliminated to obtain a dry powder. The dry powder is identified by X-ray diffraction analysis to be β-eucryptite single phase, and the diffraction peak intensity of the strongest line (102) surface appearing near 2θ = 25 ° is 32008, and the crystallite diameter is 64 nm. there were. Primary particle diameter _{d S} by a nitrogen adsorption method was 0.95 .mu.m, dispersed particles size _{d 50} by a laser diffraction method is 78 .mu.m, was dispersed in a range of 0.1 [mu] m ~ 2.0 .mu.m. In addition, when the particle form was observed with an electron microscope, irregular and angular fine particles were confirmed.

Comparative Example 5
40 g of forsterite powder produced in Production Example 2, 160 g of isopropanol, and 900 g of φ 0.5 mm zirconia beads were placed in a grinding container, and wet ground under conditions of 1000 rpm using a bead mill apparatus Easy Nano RMB type manufactured by Imex. After grinding for 5 hours, the zirconia beads were removed to obtain a slurry containing forsterite fine particles.

The slurry was then placed in an eggplant flask and dried at 10 Torr using a rotary evaporator until volatiles were eliminated to obtain a dry powder. The dry powder was identified by X-ray diffraction analysis to be a forsterite single phase, and the diffraction peak intensity of the strongest line (112) plane near 2θ = 36.5 ° was 1379, and the crystallite diameter was 23 nm. Primary particle diameter _{d S} by a nitrogen adsorption method is 0.03 .mu.m, the dispersed particles size _{d 50} by a laser diffraction method was 0.22 [mu] m.

The dried powder was put in an alumina sagger, heated to 700 ° C. at 3 ° C./min in a table-top electric furnace, and fired for 5 hours to obtain a fired powder. The obtained calcined powder is identified by X-ray diffraction analysis to be a forsterite single phase, the diffraction peak intensity of the strongest line (112) plane near 2θ = 36.5 ° is 912, and the crystallite diameter is 24 nm, The improvement in crystallinity was insufficient. In addition, when the particle form was observed with an electron microscope, irregular and angular fine particles were confirmed.

The above results are summarized in Table 1. “BET particle diameter” in the table is an abbreviation of “primary particle diameter d _S converted to spherical particles from specific surface area by nitrogen adsorption method”. Further, electron microscope images of the silicate compound fine particles according to Examples 1 to 4 are shown in FIGS. 1 and 2, and electron microscope images of the silicate compound fine particles according to Comparative Examples 1 and 4 are shown in FIG.

Here, the fine particles of the silicate compound (β-eucryptite) of Examples 1 to 3 each have a crystallite diameter of about 1.5 times (Example 1), after undergoing calcination (Step (B)), It was confirmed to grow 1.9 times (Example 2) and 1.5 times (Example 3). On the other hand, in Comparative Example 3 in which the firing temperature was 700 ° C., almost no particle growth was observed, and the particle growth was 1.1 times or less. In Comparative Example 4 in which the firing temperature was 950 ° C., it was confirmed that the particles grew up to about twice.

Moreover, it was confirmed that the crystallite diameter of the silicate compound (forsterite) fine particles of Example 4 grows to about 1.3 times after passing through the firing (step (B)). On the other hand, in Comparative Example 5 in which the firing temperature was 700 ° C., almost no particle growth was observed.

In the silicate compound fine particles of Examples 1 to 4, the rounded particle shape was observed by the electron microscope, whereas in Comparative Examples 1 and 4, the irregularly shaped angular fine particles were observed.

As described above, in the β-eucryptite fine particles of Examples 1 to 3, the ratio (d ₅₀ / d) of the primary particle diameter d _S converted to the spherical particle from the specific surface area by the nitrogen adsorption method and the dispersed particle diameter d ₅₀ d _S ) was 1.0 or more and less than 3.0, and the crystallite diameter calculated from the X-ray diffraction peak belonging to the (102) plane of the β-eucryptite phase was 45 nm or more and 100 nm or less.

Moreover, forsterite particles of Example 4, the primary particle diameter _{d S} in terms of spherical particles from the specific surface area by nitrogen adsorption method, the dispersed particle size _{d 50,} of (the ratio _{_d} 50 / _d _S) of 1.0 The crystallite diameter is not less than 3.0 and is not less than 30 nm and not more than 100 nm, which is calculated from the X-ray diffraction peak belonging to the (112) plane of the forsterite phase.

The fine particles of the silicate compound of the present invention have a small particle diameter and are excellent in dispersibility in a resin, so that the resin can be filled at a higher density than in the past. In addition, since the fine particles of the silicate compound of the present invention have high crystallinity, the original characteristics of the material can be sufficiently exhibited. Therefore, for example, β-eucryptite fine particles can be suitably used as a filler for reducing CTE in applications such as semiconductor sealing materials and underfills. Moreover, if it is a forsterite fine particle, it can be conveniently used as a filler for reducing a dielectric loss in uses, such as a semiconductor sealing material.

Claims

The ratio (d 50 / d S ) of the primary particle diameter (d S ) converted to the spherical particles from the specific surface area by the nitrogen adsorption method and the dispersed particle diameter (d 50 ) is 1.0 or more and less than 3.0 ,
A silicate compound fine particle characterized in that a crystallite diameter calculated from an X-ray diffraction peak belonging to the (102) plane of a β-eucryptite phase is 45 nm or more and 100 nm or less.
(Ratio d 50 / d S ) of primary particle diameter (d S ) converted to spherical particles from specific surface area by nitrogen adsorption method and dispersed particle diameter (d 50 ) is 1.0 or more and less than 3.0 ,
A silicate compound fine particle characterized in that a crystallite diameter calculated from an X-ray diffraction peak belonging to the (112) plane of the forsterite phase is 30 nm or more and 100 nm or less.
(A) grinding the silicate compound so that the dispersed particle size (d 50 ) is in the range of 0.1 μm to 2.0 μm.
(B) firing the pulverized fine particles of the silicate compound at a temperature of 750 ° C. or more and less than 950 ° C .;
A method for producing silicate compound fine particles characterized by having:
The silica according to claim 3, further comprising a step (C) of dispersing the fired fine particles such that the dispersed particle size (d 50 ) is in the range of 0.1 μm to 2.0 μm. Method of producing salt compound fine particles.