JP2014209621A - Three-dimensional packaging semiconductor device, resin composition and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a three-dimensional packaging semiconductor device having high performance.SOLUTION: A three-dimensional packaging semiconductor device comprises two and more semiconductor devices arranged at a distance of 30 μm and under between the closest parts; and a heat transfer interposed material interposed between the semiconductor devices. The heat transfer interposed material has silica particles and a resin material in which the silica particles are dispersed, in which a contained amount of each of uranium and thorium in the silica particles is 1.0 ppb and under, a contained amount of each of natrium and kalium is 500 ppm and under, and a mean volume diameter of the silica particles is within a range of 2 nm-200 nm, and a real density is 2.1 g/cmand over.

Description

  The present invention relates to a three-dimensional mounting type semiconductor device.

  In recent years, as a technique for reducing the mounting area of a plurality of semiconductor devices, many techniques for three-dimensional mounting by stacking semiconductor devices have been proposed. For example, as a representative example, there is a three-dimensional mounting technique disclosed in Patent Document 1 (see FIG. 1).

  As a specific example of three-dimensional mounting, a method of forming one three-dimensional mounting type semiconductor device by interposing an intermediary material such as an underfill or a film between a plurality of semiconductor devices has been studied. The intervening material realizes insulation between the semiconductor devices and improvement of the reliability of the semiconductor devices, and further exhibits an effect of quickly transferring the heat generated in each semiconductor device.

  By the way, the integration of each semiconductor device is also progressing. In such an integrated semiconductor device, the amount of heat generated by the operation is large, and it is required to improve the heat dissipation even by itself. Yes. Of course, in order to stably operate continuously when such semiconductor devices are stacked to form a three-dimensionally mounted semiconductor device, it is necessary to improve the heat dissipation of the entire three-dimensionally mounted semiconductor device.

  And in order to suppress the volume change accompanying heat transfer, the filler which consists of inorganic materials is made to contain. Conventionally, silica particles have been widely used as fillers made of inorganic materials, and resin compositions containing silica particles in a resin such as a thermosetting resin are known. By including and dispersing silica particles in the resin, the heat resistance of the resin composition can be improved and the physical strength can be improved.

  Here, since the interposition material itself does not directly contribute to the development of the function of the semiconductor, it is desired to be as thin as possible (to reduce the distance between adjacent semiconductor devices). Then, it is necessary to form the filler contained in the interposing material interposed between them with a filler that does not contain coarse particles larger than the distance as the distance between the semiconductor devices decreases. In recent years, particles having a very small particle size of 200 nm or less are required as fillers.

  Furthermore, if the filler contains an α-ray source, the generated α-rays are likely to affect the operation of the semiconductor device (soft error). Therefore, it is desirable that the content of impurities such as the α-ray source is small.

  Here, as a method for producing silica particles having a particle size of submicron to micrometer order, a method called VMC method is widely used, but particles having a particle size of about several nanometers to several tens of nanometers smaller than that. As a method for producing silica particles having a diameter, a method of producing water glass as a raw material (Patent Document 1), a method using alkoxide as a silica precursor as a raw material, and the like are known.

  In the method using water glass as the raw material, the amount of impurities is large, and as a method for producing silica particles with high purity, a highly pure silicon compound such as high-purity metal silicon or silicon tetrachloride is produced. A method of producing silica particles from a pure silicon compound has been adopted. For example, it is possible to suitably obtain sub-micrometer to micrometer order silica particles from a method of oxidizing metal silicon to obtain silica particles, and from a method via alkoxide to a nanometer to several tens of nanometer order. Even a product could be obtained suitably.

Japanese Patent No. 3463328

  In the above circumstances, the present inventors evaluated the properties after dispersing nanometer-order silica particles in the resin composition. As a result, it was found that the nanometer order silica particles having a high purity produced by the conventional method may not have sufficient physical properties, and an invention capable of solving the problem has been completed.

  The present invention has been devised to solve the above-described problems, and utilizes the above-described invention that can provide a production method capable of producing silica particles having high purity and high physical properties and surface-modified silica particles. An object to be solved is to provide a high-performance inorganic filler obtained in this way, and to provide a three-dimensional mounting type semiconductor device employing an interposition material using the inorganic filler.

(1) A three-dimensional mounting type semiconductor device that solves the above problem includes two or more semiconductor devices in which the distance between the closest portions is 30 μm or less;
A heat transfer interposition material interposed between the semiconductor devices;
Have
The heat transfer medium has inorganic material particles and a resin material in which the inorganic material particles are dispersed,
The inorganic material particles have uranium and thorium contents of 1.0 ppb or less,
Each of sodium and potassium content is 500 ppm or less,
The volume average particle size is 2 nm to 200 nm,
Silica particles having a true density of 2.1 g / cm ³ or more.

  Conventionally, when trying to obtain silica particles having a volume average particle diameter in the range of 2 nm to 100 nm and reducing the α-ray generation range or reducing the concentration of impurities such as uranium and thorium, After obtaining high purity, a method for obtaining high purity silica by producing alkoxide from high purity metal silicon, silicon silicon produced by producing a silicon compound such as silicon tetrachloride from silicon silicon that is easy to purify. By improving the purity of the compound, silica particles having a high purity were produced by a method of obtaining silica after reducing the amount of α-ray source such as uranium.

  As a result of intensive studies by the present inventors, it has been clarified that although silica particles produced from an alkoxide can produce an α-ray source with a satisfactory amount and particle size, the water absorption is not sufficient. If the water absorption is high, the moisture when the moisture in the atmosphere is sucked and dispersed in a resin or the like is not sufficient and sufficient performance may not be obtained when applied to a three-dimensional mounting type semiconductor device.

  However, silica particles produced from water glass have not been freed of α-ray sources such as uranium, and generation of α-rays cannot be avoided. Here, since it was difficult to remove ionic substances such as sodium and α-ray sources such as uranium in the state of water glass, silica particles are produced by producing water glass from naturally occurring silica. It was difficult to obtain silica particles with high purity.

  However, conventionally, there is no requirement to obtain silica particles having a low water absorption, even if silica particles having a small particle size and a small amount of ionic substances and α-rays are required. No attempt has been made to reconcile these properties.

  As a result of intensive studies by the present inventors for the purpose of solving this problem, high purity and low hygroscopicity are produced by producing silica particles from high-purity metallic silicon via silicic acid or silicate. The present invention has been completed by finding that high physical characteristics can be realized. In this case, it was discovered that the true density of particles can be used as an index for evaluating water absorption, and it was found that water absorption can also be controlled by controlling the value within a certain range.

  In addition, when manufacturing a three-dimensional mounting type semiconductor device, it may be manufactured by interposing a heat transfer material formed in a film shape between semiconductor devices. In that case, the heat transfer material is used. It is necessary to perform positioning between the film constituting the semiconductor device and the semiconductor device. In that case, if the heat transfer interposing material is transparent, positioning becomes easy. Silica particles having a small particle size have transparency to visible light even in the resin composition, and thus are highly effective in applications where a film-like heat transfer medium is used.

The above-described three-dimensional mounting type semiconductor device (1) can further include one or more constituent elements of the following (2) and (3).
(2) The content of sodium and potassium is 250 ppm or less. (3) The content of uranium and thorium is 0.5 ppb or less.

The heat transfer interposing material in the above-described three-dimensional mounting type semiconductor device (1) to (3) can be obtained by curing the resin composition described in the following (4). In addition, the heat transfer interposing material in the three-dimensional mounting type semiconductor device of (1) to (3) is formed by filling the following resin composition between the semiconductor devices and then curing it (as a so-called underfill material) Use), or after being formed into a film shape. It is possible to improve the filling property by applying a vacuum at the time of filling, or to dispose the heat transfer interposing material before bringing the semiconductor device close to each other, and then place the semiconductor device close to it.
(4) The resin composition of the present invention that solves the above-mentioned problem is a composition before curing of the heat transfer interstitial material of the above-described three-dimensional mounting semiconductor device,
The inorganic material particles and the resin material in which the inorganic material particles are dispersed are included.

The following component (5) can be added to the resin composition (4) described above. When selecting (5), one or more components of (6) to (8) can be added. When selecting (8), the component of (9) can be added.
(5) An alkaline silicate solution production step of producing an alkaline silicate solution by dissolving 5 mass% or more of a silicon-containing material, which is either metal silicon or a silicon compound, in the silica particles, and producing an alkaline silicate solution; An aqueous silica sol forming step of forming an aqueous silica sol from the obtained alkaline silicate solution;

A solution corresponding to water glass is obtained by preparing an alkali silicate solution by dissolving a silicon-containing material in an alkali solution. Thus, impurities can be concentrated in the silicon-containing material not dissolved, and the content of uranium and thorium contained in the produced nanosilica can be reduced.
(6) The silicon-containing material is metallic silicon. This is because metallic silicon is easy to purify.
(7) The alkaline solution contains a volatile alkaline substance as a main component. When a volatile alkaline substance (for example, ammonia) is employed, the subsequent removal of the alkaline substance is facilitated, and the alkaline substance remaining in the finally produced silica particles can be reduced.
(8) A surface treatment step of surface-treating the aqueous silica sol with a silane coupling agent and an organosilazane,
The silane coupling agent has three alkoxy groups, a phenyl group, a vinyl group, an epoxy group, a methacryl group, an amino group, a ureido group, a mercapto group, an isocyanate group, or an acrylic group,
The molar ratio of the silane coupling agent to the organosilazane is the silane coupling agent: the organosilazane = 1: 2 to 1:10. The surface-modified silica particles obtained by performing this surface treatment are less cohesive.
(9) The surface treatment step
A first treatment step of treating the silica particles with the silane coupling agent;
A second treatment step of treating the silica particles with the organosilazane,
The second processing step is performed after the first processing step.

3 is a SEM photograph of the aqueous silica sol obtained in Test Example 1. 3 is a SEM photograph of the aqueous silica sol obtained in Test Example 1. 3 is a SEM photograph of the aqueous silica sol obtained in Test Example 1. It is the graph which showed the result of having conducted the thermogravimetric analysis about the sample of Test Example 1 and Test Example 15. FIG.

  The three-dimensional mounting type semiconductor device of the present invention will be described in detail based on the following embodiments. In addition, the resin composition and the method for producing the resin composition will also be described.

  The three-dimensional mounting type semiconductor device according to the present embodiment is obtained by stacking two or more semiconductor devices via a heat transfer medium. The distance between the stacked semiconductor devices is 30 μm or less. As long as there is no contact between the semiconductor devices, it is desirable that it be small. In order to reduce the possibility of contact of the semiconductor device, it is desirable to define a minimum value, for example, 10 μm can be adopted as the lower limit value.

The semiconductor device to be employed is not particularly limited. By integrating three-dimensionally, the degree of integration can be dramatically improved. Here, as a method generally assumed as a method for realizing a three-dimensional mounting type semiconductor device, a required number of semiconductor devices are stacked (parts where wiring is necessary are electrically connected by a conventional method). Then, there is a method in which a resin composition in which an inorganic filler is dispersed is infiltrated into the gap (a reflow process or the like can be used) and cured as it is. In order to realize this method, it is desired that the permeability of the resin composition into the gap is high. Moreover, a thin film can be formed from a resin composition, and a semiconductor device can be laminated | stacked by interposing the thin film between semiconductor devices.
It is desirable that the heat conduction intercalating material to be interposed has a thermal conductivity of 0.7 W / mK or more when the thickness is 10 μm to 30 μm.

  As a resin composition capable of forming a heat transfer material, inorganic material particles (silica particles or the like. Particles formed from other materials may be included. Hereinafter, the filler is appropriately referred to as “filler”) and the filler. It is desirable that the resin material is dispersed. As the resin material, an epoxy resin or the like having high fluidity before curing and high mechanical and thermal durability after curing is desirable. A curing agent (a curing agent for the resin material) can be contained as necessary.

The filler preferably has a sphericity of 0.85 or more. The sphericity is preferably 0.90 or more, and more preferably 0.95 or more. The sphericity is measured by taking a photograph with an SEM, and calculating from the observed particle area and circumference as a value calculated by (sphericity) = {4π × (area) ÷ (perimeter) ² }. The closer to 1, the closer to a true sphere. Specifically, an average value measured for 100 particles using an image processing apparatus (Sysmex Corporation: FPIA-3000) is employed. The particle size can be measured by a laser diffraction / scattering particle size distribution analyzer. Further, the content of coarse particles of 20 μm or more is preferably 0 ppm, and the flow rate of coarse particles of 10 μm or more is preferably 100 ppm or less.

  Hereinafter, the inorganic material particles employed for the filler of the heat transfer medium will be described. The inorganic material particles have silica particles. Inorganic particles are not inhibited from containing other inorganic material particles (for example, alumina particles).

Silica particles The silica particles have a true density of 2.1 g / cm ³ or more, desirably 2.2 g / cm ³ or more. In this specification, the true density is measured after standing for 72 hours in an atmosphere of 40 ° C. and 80% relative humidity, and then a true density meter (true density meter. An apparatus that measures using a gas such as helium gas or air). It calculated using. Hygroscopicity was determined from Karl Fischer moisture content measurement and thermogravimetry. Before the measurement, surface treatment is performed using hexamethyldisilazane so as to be 4 μmol per unit surface area.

For example, silica particles produced via silane, which is a conventional production method, have a true density of 2.0 g / cm ³ or less, exhibiting a hygroscopic value of about 9%, and can be clearly identified. It is presumed that silica particles produced via silane have high hygroscopicity because the crystal structure is not dense. Here, what can be manufactured with the manufacturing method of the silica particle of this embodiment demonstrated later is one of the silica particles of this embodiment.

  The silica particles of this embodiment have a uranium and thorium content of 1.0 ppb or less, respectively, and a sodium and potassium content of 500 ppm or less. The contents of uranium and thorium are each desirably 0.5 ppb or less. Moreover, it is desirable that the content of sodium and potassium is 250 ppm or less, respectively. That is, it means that the generation amount of α rays and the abundance of ionic substances are limited. Such a range is a value that can hardly be achieved unless the purity is improved.

  Moreover, the silica particle of this embodiment has a volume average particle diameter of 2 nm to 200 nm. The volume average particle size is measured by a laser scattering method. As the lower limit of the desirable volume average particle diameter, 5 nm, 3 nm, and 2 nm can be adopted. As an upper limit of a desirable volume average particle diameter, 100 nm, 150 nm, and 200 nm can be adopted. Furthermore, it is desirable that particles (coarse particles) of a certain size or larger are not included. For example, it is desirable that coarse particles having a particle size larger than a value set as a distance between semiconductor devices are not contained. Further, it is desirable that coarse particles having a particle size of 5 μm or more, 3 μm or more, or 1 μm or more are not included. In principle, the silica particles contained in the resin composition obtained by employing the production method of the present invention are unlikely to contain particles having a large particle diameter, and may be completely absent depending on conditions.

-Manufacturing method of a silica particle The manufacturing method of a silica particle is a method of manufacturing the silica particle mentioned above. This production method includes an alkaline silicate solution production step and an aqueous silica sol formation step.

  The alkaline silicate solution production process is a process for producing an alkaline silicate solution by dissolving a silicon-containing material in an alkaline solution. The silicon-containing material is dissolved by leaving 5% or more based on the total mass before dissolution. As a method of controlling so that 5% or more remains, it can be realized by controlling the dissolution temperature, the dissolution time, the amount of the alkaline solution, and the like. The silicon-containing material is either metal silicon or a silicon compound. The alkaline solution is preferably an aqueous solution of an alkaline substance. It is desirable to use a volatile compound as the alkaline substance (especially, it is desirable to use it as a main component). For example, one or more compounds selected from ammonia, primary amines, secondary amines, tertiary amines, inorganic base compounds composed of sodium, potassium, lithium, and ammonium and inorganic salts. When ammonia is employed as the alkaline substance of the alkaline solution and metal silicon is employed as the silicon-containing material, it is desirable that the concentration be about 3 to 15% based on the mass of the silica finally produced. . Moreover, it is desirable to add about 0.5% to 2.0% ammonia. When the silicon-containing material is dissolved, the particle size can be controlled by adjusting the temperature. For example, it can be controlled to about 30 to 60 ° C. Further, by adding the silica particles produced by the method described here in this step or the aqueous silica sol formation step described later, the added particles become seed particles, which can form larger particles than the added seed particles. it can.

  Metallic silicon can be dissolved directly in an alkaline solution, or after reacting metallic silicon with oxygen to form silica. In particular, the use of amorphous silica can improve the solubility. Even crystalline silica can be used by improving the solubility by making it amorphous for the purpose of improving the solubility.

  As a method for obtaining silica by reacting metallic silicon and oxygen, a method called deflagration method (VMC method) can be adopted. The VMC method has a large specific surface area (particulate) and can obtain amorphous silica. In the VMC method, a chemical flame is formed by a burner in an atmosphere containing oxygen, and metal silicon powder is introduced into the chemical flame in such an amount that a dust cloud is formed, and deflagration is caused to obtain spherical oxide particles. Is the method. When preparing the aluminum content, the aluminum content is controlled with respect to the silicon-containing material in the above-described purification step, or the aluminum content in the alkaline silicate solution is adjusted in this step. Do.

  It is possible to employ a purification process in which metal silicon is purified before being subjected to an alkaline silicate solution production process. A conventional method can be employed for the purification step. In particular, the purification process is a particularly effective process for reducing the amount of α-ray source (uranium, thorium) in metallic silicon. The purification method is not particularly limited. For example, a method using a silicon compound that is easy to purify, a zone melting method, a method of depositing a single crystal, and the like can be mentioned. Further, these methods can be performed a plurality of times or combined.

  The aqueous silica sol forming step is a step of forming an aqueous silica sol from the obtained alkaline silicate solution (including the alkaline silica sol). Colloidal silica is produced by adding acid to the alkaline silicate solution. For example, the pH is preferably 2-9. PH 4-7 is particularly preferable. This silica sol having a pH of 4 to 7 is prepared by treating an alkaline silicate solution with a cation exchange resin or a cation exchange resin and an anion exchange resin to produce an acidic silica sol having a pH of 2 to 5, an alkali metal hydroxide aqueous solution, It can be produced by adding a base such as aqueous ammonia, amine, or aqueous quaternary ammonium hydroxide and adjusting the pH to 4-7. This sol is preferably used immediately after production.

Here, the SiO ₂ concentration contained in the alkaline silicate solution is not particularly limited, but is preferably 5 to 50% by mass. The particle size of the produced colloidal silica can be exemplified as 4 to 30 nm in terms of the converted particle size from the specific surface area by the BET method or the specific surface area by the Sears method. The Sears method is a particle converted from a specific surface area by titration with sodium hydroxide as described in ANALYTIC CHEMISTRY Vol. 28 No. 12 (December 1956) p. 1981. This is a diameter measurement method.

Use of aluminate: An aluminate addition step of adding aluminate and / or aluminate to the obtained aqueous silica sol can be provided. By adding aluminate, the stability as a water-dispersed product is improved. The addition of aluminate and / or aluminate can be performed by adding an alkali solution (alkali aluminate aqueous solution). As the aluminate used, an aqueous solution of sodium aluminate, potassium aluminate, quaternary ammonium aluminate, guanidine aluminate or the like can be used, but an aqueous sodium aluminate solution commercially available as an industrial chemical is particularly preferable. The Na ₂ O / Al ₂ O ₃ molar ratio of the aqueous sodium aluminate solution is preferably 1.2 to 2.0.

Addition of the alkali aluminate aqueous solution to the silica sol can be performed at 0 to 80 ° C., preferably 5 to 60 ° C. with stirring after adjusting the pH to 2 to 9. Stirring can be performed by a Satake type, a Faudler type, a Disper type stirrer, a homomixer, or the like, but a stronger stirring speed is preferred. The alkali aluminate aqueous solution to be added is preferably used at an Al ₂ O ₃ concentration of 0.5 to 10% by weight. Although the addition time of the alkali aluminate aqueous solution may be long, it is usually within 10 minutes.

The amount of alkali aluminate aqueous solution (for example, ammonium aluminate aqueous solution) added to the silica sol exceeds 0.0006 in terms of the Al ₂ O ₃ / SiO ₂ molar ratio of the silica sol after the addition, but is preferably 0.004 or less. In particular, it exceeds 0.0008 but is preferably 0.004 or less. The silica sol obtained has a pH of 5-11, preferably 6-10.

  It is desirable to have the process of heat-processing the obtained silica sol, and heating temperature is 80-250 degreeC, Especially 100-200 degreeC is preferable. The heating time is preferably 0.5 to 20 hours. For this heating, a SUS or glass device and a pressurizing device can be used.

  Furthermore, about silica sol, it is possible to contact a cation exchange resin or a cation exchange resin and an anion exchange resin, and the temperature at that time can be used at 0-60 degreeC, However, 5-50 degreeC is especially preferable. The cation exchange resin is preferably a hydrogen-type strongly acidic cation exchange resin, and is easily obtained as a commercial industrial product. As an example, the trade name Amberlite IR-120B can be mentioned. As the anion exchange resin, a hydroxyl type strongly basic anion exchange resin is preferable, and it is easily obtained as a commercial industrial product. An example of this is the trade name Amberlite IRA-410.

  The contact between the silica sol and the ion exchange resin can be preferably performed by passing the silica sol through a column filled with the ion exchange resin, and the speed of passing the silica sol through the column is 1 to 10 space velocity per hour. The degree is preferred. In the contact of the silica sol with the cation exchange resin and the anion exchange resin, it is preferable that the silica sol is first contacted with the cation exchange resin, and then contacted with the anion exchange resin. Further preferred.

It strikes the contact of the ion exchange resins, without diluting the resulting silica sol, but intact SiO ₂ concentration can be liquid permeation, and if you passed is diluted, is SiO ₂ concentration of the resulting silica sol decreased In such a case, the SiO ₂ concentration can be increased by concentration by a method such as an evaporation method or a method using a microporous film. The pH of the acidic silica sol obtained by contact with the ion exchange resin is 2-5.

Surface treatment step surface treatment process, the silica particles obtained by the above-mentioned method, the formula (1): - a functional group represented by OSiX ¹ X ² X ^3, formula (2): - OSiY ^This is a step of obtaining surface-modified silica particles in which a functional group represented by ¹ Y ² Y ³ is bonded to the surface. Hereinafter, the functional group represented by the formula (1) is referred to as a first functional group, and the functional group represented by the formula (2) is referred to as a second functional group.

X ¹ in the first functional group is a phenyl group, vinyl group, epoxy group, methacryl group, amino group, ureido group, mercapto group, isocyanate group, or acrylic group. X ² and X ³ are —OSiR ₃ or —OSiY ⁴ Y ⁵ Y ⁶ , respectively. Y ⁴ is R. Y ⁵ and Y ⁶ are each R or —OSiR ₃ .

Y ¹ in the second functional group is R. Y ² and Y ³ are each —OSiR ₃ or —OSiY ⁴ Y ⁵ Y ⁶ .

The more —OSiR ₃ contained in the first functional group and the second functional group, the more R on the surface of the surface-modified silica particles. The more R (alkyl group having 1 to 3 carbon atoms) contained in the first functional group and the second functional group, the less the surface-modified silica particles of the present invention are aggregated.

Regarding the first functional group, when X ² and X ³ are each —OSiR ₃ , the number of R is minimized. Further, ^{X 2} and ^{X 3} is -OSiY ⁴ Y ⁵ Y ^6, respectively, ^and, if Y 5, ^{Y 6} is -OSiR ₃ respectively, the number of R is maximized.

Regarding the second functional group, when Y ² and Y ³ are each —OSiR ₃ , the number of R is minimized. Further, ^{Y 2} and ^{Y 3} are -OSiY ⁴ Y ⁵ Y ^6, respectively, ^and, if Y 5, ^{Y 6} is -OSiR ₃ respectively, the number of R is maximized.

The number of X ¹ contained in the first functional group, the number of R contained in the first functional group, and the number of R contained in the second functional group are the abundance ratio between R and X ¹ , the surface What is necessary is just to set suitably according to the particle size and use of a modified silica particle.

^{Incidentally, X 2, X 3, Y} 2, Y 3, Y 5, and any of ^{Y 6, X} 2 of the adjacent ^{functionality, X 3, Y 2, Y} 3, Y 5, and any ^{Y 6} You may combine with heel -O-. For example, any one of the first functional group X ² , X ³ , Y ⁵ , and Y ⁶ is the first functional group adjacent to the first functional group X ² , X ³ , Y ⁵ , and It may be bonded to any of Y ⁶ by —O—. Similarly, any of Y ² , Y ³ , Y ⁵ , and Y ⁶ of the second functional group is replaced with Y ² , Y ³ , Y ⁵ , Y ² of the second functional group adjacent to the second functional group. And Y ⁶ may be bonded to each other by —O—. Furthermore, any one of the first functional groups X ² , X ³ , Y ⁵ , and Y ⁶ is the second functional group adjacent to the first functional group, Y ² , Y ³ , Y ⁵ , And Y ⁶ may be bonded to each other by —O—.

In the surface-modified silica particles of the present invention, if the ratio of the number of the first functional group and the second functional group is 1:12 to 1:60, X ¹ and R are present on the surface of the surface-modified silica particles. Exist in a well-balanced manner. For this reason, the surface-modified silica particles having an abundance ratio of the first functional group to the second functional group of 1:12 to 1:60 are particularly excellent in the affinity for the resin and the aggregation suppressing effect. Further, when X ¹ is 0.5 to 2.5 per unit surface area (nm ² ) of the surface-modified silica particles, a sufficient number of first functional groups are bonded to the surface of the surface-modified silica particles. There are also a sufficient number of R derived from the first functional group and the second functional group. Therefore, also in this case, the affinity for the resin and the effect of suppressing aggregation of the surface-modified silica particles are sufficiently exhibited.

In any case, R per unit surface area (nm ² ) of the surface-modified silica particles is preferably 1 to 10. In this case, the balance between the number of X ^{1 and} the number of R existing on the surface of the surface-modified silica particles is improved, and both the affinity for the resin and the aggregation suppressing effect of the surface-modified silica particles are well balanced. Demonstrated.

In the surface-modified silica particles of the present invention, it is preferable that all of the hydroxyl groups present on the surface of the silica particles are substituted with the first functional group or the second functional group. If the sum of the first functional group and the second functional group is 2.0 or more per unit surface area (nm ² ) of the surface-modified silica particles, the silica particles in the surface-modified silica particles of the present invention It can be said that almost all of the hydroxyl groups present on the surface of the surface are substituted with the first functional group or the second functional group.

The surface-modified silica particles of the present invention have R on the surface. This can be confirmed by an infrared absorption spectrum. Specifically, when the infrared absorption spectrum of the surface-modified silica particles of the present invention is measured by a solid diffuse reflection method, there is a maximum absorption of C—H stretching vibration at 2962 ± 2 cm ⁻¹ .

  Further, as described above, the surface-modified silica particles of the present invention are hardly aggregated.

  Note that the surface-modified silica particles of the present invention can be dispersed again by ultrasonic treatment even if they are slightly aggregated. Specifically, the surface-modified silica particles of the present invention are substantially converted into primary particles by irradiating the surface-modified silica particles of the present invention dispersed in methyl ethyl ketone with ultrasonic waves having an oscillation frequency of 39 kHz and an output of 500 W. Can be dispersed. The ultrasonic irradiation time at this time may be 10 minutes or less. Whether or not the surface-modified silica particles of the present invention are dispersed to primary particles can be confirmed by measuring the particle size distribution. Specifically, the surface-modified silica particles of the present invention are primary particles if the surface-modified silica particles are measured with a particle size distribution measuring device such as a microtrack device and the surface-modified silica particles have a particle size distribution. It can be said that it was even distributed.

  Since the surface-modified silica particles of the present invention hardly aggregate, they can be provided as surface-modified silica particles that are not dispersed in a liquid medium such as water or alcohol. In this case, since no liquid medium is brought in, it is preferably used as a filler for a resin material.

  Moreover, since the surface-modified silica particles of the present invention hardly aggregate, they can be easily washed with water. For this reason, the surface-modified silica particles of the present invention can be applied to surface-modified silica particles for electronic parts.

The method for producing surface-modified silica particles of the present invention has a step (surface treatment step) of subjecting silica particles to surface treatment with a silane coupling agent and organosilazane in a liquid medium containing water. The silane coupling agent has three alkoxy groups and a phenyl group, a vinyl group, an epoxy group, a methacryl group, an amino group, a ureido group, a mercapto group, an isocyanate group, or an acrylic group (that is, X ¹ described above).

By performing the surface treatment with the silane coupling agent, the hydroxyl group present on the surface of the silica particles is substituted with a functional group derived from the silane coupling agent. The functional group derived from the silane coupling agent is represented by the formula (3); —OSiX ¹ X ⁴ X ⁵ . The functional group represented by the formula (3) is referred to as a third functional group. X ¹ in the third functional group is the same as X ¹ in the functional group represented by the formula (1). X ⁴ and X ⁵ are each an alkoxy group. By surface-treating with organosilazane, the third functional group X ⁴ and X ⁵ are derived from organosilazane —OSiY ¹ Y ² Y ³ (the functional group represented by the formula (2), the second functional group ). When all of the hydroxyl groups present on the surface of the silica particles are not substituted with the third functional group, the hydroxyl groups remaining on the surface of the silica particles are substituted with the second functional group. Therefore, on the surface of the surface-modified surface-modified silica particles, the functional group represented by the formula (1): —OSiX ¹ X ² X ³ (that is, the first functional group) and the formula (2): The functional group represented by —OSiY ¹ Y ² Y ³ is bonded to the functional group (that is, the second functional group). In addition, since the molar ratio of the silane coupling agent to the organosilazane is silane coupling agent: organosilazane = 1: 2 to 1:10, the first functional group and the first functional group in the obtained surface-modified silica particles. The abundance ratio with the functional group of 2 is theoretically from 1:12 to 1:60.

In the surface treatment step, the silica particles may be simultaneously surface treated with a silane coupling agent and an organosilazane. Alternatively, the silica particles may first be surface treated with a silane coupling agent and then surface treated with organosilazane. Alternatively, the silica particles may be first surface treated with organosilazane, then surface treated with a silane coupling agent, and then surface treated with organosilazane. In any case, the amount of organosilazane may be adjusted so that all the hydroxyl groups present on the surface of the silica particles are not substituted with the second functional group. The hydroxyl groups present on the surface of the silica particles may all be substituted with the third functional group, or only a part may be substituted with the third functional group, and the other part may be substituted with the second functional group. It may be replaced. All of X ⁴ and X ⁵ contained in the third functional group may be substituted with the second functional group.

A part of organosilazane may be replaced with the second silane coupling agent. As the second silane coupling agent, one having three alkoxy groups and one alkyl group can be used. In this case, X ⁴ and X ⁵ contained in the third functional group are substituted with the fourth functional group derived from the second silane coupling agent. The fourth functional group has the formula (4); - represented by OSiY ¹ X ⁶ X ^7. Y ¹ is the same R as ^{Y 1} in the second functional ^{group, X 6,} X ⁷ is an alkoxy group or a hydroxyl group, respectively. X ⁶ and X ⁷ contained in the fourth functional group are substituted with the second functional group derived from organosilazane, or are substituted with another fourth functional group. In this case, the amount of R present on the surface of the surface-modified silica particles can be further increased. When a part of the organosilazane is replaced with the second silane coupling agent, it is necessary to surface-treat with the organosilazane again after the surface treatment with the second silane coupling agent. This is because X ⁶ and X ⁷ contained in the fourth functional group are finally substituted with the second functional group derived from organosilazane.

When a part of the organosilazane is replaced with the second silane coupling agent, X ⁴ and X ⁵ contained in the first functional group described above are substituted with the second functional group derived from the organosilazane, Substitution with a fourth functional group derived from the second silane coupling agent. When X ⁴ and X ⁵ are substituted with the fourth functional group, X ⁶ and X ⁷ contained in the fourth functional group are substituted with the second functional group or another fourth functional group. Is replaced by If X ^6, X ⁷ contained in the fourth functional group has been replaced by another fourth functional group, X ^6, X ⁷ contained in the fourth functional groups is substituted with the second functional group The For this reason, the second silane coupling agent is an organosilazane set when the surface treatment is performed only with the first coupling agent and organosilazane (when the organosilazane is not replaced with the second silane coupling agent). A maximum of 5a / 3 mol can be substituted for the amount (a) mol. The amount of organosilazane required in this case is 8a / 3 mol.

  The alkoxy groups of the silane coupling agent and the second silane coupling agent are not particularly limited, but those having a relatively small carbon number are preferred, and those having 1 to 12 carbon atoms are preferred. Considering the hydrolyzability of the alkoxy group, the alkoxy group is more preferably any one of a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.

  Specific examples of silane coupling agents include phenyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and 3-glycidoxypropyltrimethoxysilane. 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-phenyl-3 -Aminopropyltrimethoxysilane.

  Any organosilazane may be used as long as it can replace the hydroxyl group present on the surface of the silica particles and the alkoxy group derived from the silane coupling agent with the second functional group described above. preferable. Specific examples include tetramethyldisilazane, hexamethyldisilazane, pentamethyldisilazane, and the like.

  Examples of the second silane coupling agent include methyltrimethoxysilane, methyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, and hexyltriethoxysilane.

  In the surface treatment step, a polymerization inhibitor may be added in order to suppress polymerization of the silane coupling agent or polymerization of the second silane coupling agent. As the polymerization inhibitor, common ones such as 3,5-dibutyl-4-hydroxytoluene (BHT) and p-methoxyphenol (methoquinone) can be used.

  The method for producing surface-modified silica particles of the present invention may include a solidification step after the surface treatment step. The solidification step is a step of precipitating the surface-modified silica particles after the surface treatment with a mineral acid and washing and drying the precipitate with water to obtain a solid of the surface-modified silica particles. As described above, since general silica particles are very likely to aggregate, it is very difficult to disperse once solidified silica particles. However, since the surface-modified silica particles of the present invention are difficult to aggregate, they are difficult to aggregate even when solidified, and are easily redispersed even if aggregated. In addition, as above-mentioned, the surface modification silica particle used for uses, such as an electronic component, can be easily manufactured by wash | cleaning the surface modification silica particle with water. In the cleaning step, it is preferable to repeat the cleaning until the electrical conductivity of the water extracted from the surface-modified silica particles (specifically, the water in which the silica particles are immersed at 121 ° C. for 24 hours) is 50 μS / cm or less. .

  Examples of the mineral acid used in the solidification step include hydrochloric acid, nitric acid, sulfuric acid, and phosphoric acid, and hydrochloric acid is particularly desirable. The mineral acid may be used as it is, but is preferably used as a mineral acid aqueous solution. The concentration of the mineral acid in the aqueous mineral acid solution is preferably 0.1% by mass or more, and more preferably 0.5% by mass or more. The amount of the mineral acid aqueous solution can be about 6 to 12 times based on the mass of the surface-modified silica particles to be cleaned.

  The cleaning with the mineral acid aqueous solution can be performed a plurality of times. The washing with the mineral acid aqueous solution is preferably performed after the surface-modified silica particles are immersed in the mineral acid aqueous solution. Further, it can be left in the immersed state for 1 to 24 hours, and further for about 72 hours. When it is allowed to stand, stirring can be continued or not stirred. When washing in the mineral acid-containing liquid, it can be heated to room temperature or higher.

  Thereafter, the surface-modified silica particles washed and suspended are collected by filtration and then washed with water. It is desirable that the water used does not contain ions such as alkali metals (for example, 1 ppm or less on a mass basis). For example, ion exchange water, distilled water, pure water and the like. Washing with water is the same as washing with an aqueous mineral acid solution. Surface-modified silica particles can be dispersed and suspended, and then filtered, or water can be continuously passed through the filtered surface-modified silica particles. This is also possible. The end of washing with water may be determined based on the electrical conductivity of the extracted water described above, or may be the time when the alkali metal concentration in the wastewater after washing the surface-modified silica particles becomes 1 ppm or less. And it is good also as the time of the alkali metal concentration of extraction water becoming 5 ppm or less. When washing with water, it can be heated to a room temperature or higher.

  The surface-modified silica particles can be dried by a conventional method. For example, heating or leaving under reduced pressure (vacuum).

  As a method of dehydrating the surface-modified silica particles other than drying, a mixed material that can be dissolved in the aqueous organic solvent after adding an aqueous organic solvent having a boiling point higher than that of water to the surface-modified silica particles that contain water Can be used to remove water. Examples of aqueous organic solvents include propylene glycol monomethyl ether (propylene glycol-1-methyl ether, boiling point of about 119 ° C .; propylene glycol-2-methyl ether, boiling point of about 130 ° C.), butanol (boiling point of 117.7 ° C.), N-methyl- Examples include 2-pyrrolidone (boiling point of about 204 ° C.) and γ-butyrolactone (boiling point of about 204 ° C.).

  The mixed material is an organic compound having a boiling point higher than that of the aqueous organic solvent. Since the boiling point is higher than that of the water-based organic solvent and water, it finally remains together with the surface-modified silica particles. The mixed material can be made into a polymer as it is or by reacting. The mixed material can also form a matrix in which the surface modified silica particles are dispersed. The mixed material is a compound that can be dispersed or dissolved in a state in which an aqueous organic solvent is added to the surface-modified silica particles containing water. The mixed material may be a polymer or a low molecule. The mixed material desirably has an epoxy group, an oxetane group, a hydroxyl group, a blocked isocyanate group, an amino group, a half ester group, an amic group, a carboxy group, and a carbon-carbon double bond group in the chemical structure. These functional groups are functional groups (polymerizable functional groups) that can be bonded to each other by setting suitable reaction conditions, and the molecular weight of the mixed material can be improved. Suitable reaction conditions include simple heating and light irradiation, generation of reactive species such as radicals and ions (anions and cations) by heat and light irradiation, and a reaction initiator that binds between these functional groups. (Polymerization initiator) is added and heating or light irradiation is performed. A compound necessary for the polymerization reaction can be added as a curing agent, or a catalyst for the reaction can be added.

  Preferred examples of the mixed material include a monomer that forms a polymer material by polymerization and a polymer material modified with a polymerizable functional group as described above. For example, a prepolymer such as an epoxy resin, an acrylic resin, or a urethane resin before curing is suitable.

  By removing water (and also an aqueous organic solvent), the surface-modified silica particles can be mixed or dispersed in the mixed material.

(Filler-containing composition)
The filler-containing composition of the present embodiment is a mixture of the above-described surface-modified silica particles and a resin material (and / or a resin material precursor, hereinafter referred to as “resin material or the like”). The mixing ratio between the surface-modified silica particles and the resin material is not particularly limited, but the larger the amount of the surface-modified silica particles, the better the thermal stability.

  Furthermore, since the above-mentioned surface-modified silica particles have high sphericity, they have high filling properties in resin materials and the like, and it is easy to suitably control the content of metal materials and the amount of ionic substances such as Na and K. Therefore, the water extract does not exhibit electrical conductivity and can be suitably used for electronic equipment.

  The resin material or the like is a composition that can be cured under some conditions. For example, a mixture of a prepolymer and a curing agent. The curing agent may be mixed immediately before curing. The type of resin material is not particularly limited. For example, it is desirable to have an epoxy group, oxetane group, hydroxyl group, blocked isocyanate group, amino group, half ester group, amic group, carboxy group and carbon-carbon double bond group in the chemical structure. These functional groups are functional groups (polymerizable functional groups) that can be bonded to each other by setting suitable reaction conditions, and resin materials and the like can be cured by selecting appropriate reaction conditions. Suitable reaction conditions for curing include simple heating and light irradiation, generation of reactive species such as radicals and ions (anions and cations) by heat and light irradiation, and bonding between these functional groups. For example, adding a reaction initiator (polymerization initiator) to perform heating or light irradiation. A compound necessary for the polymerization reaction can be added as a curing agent, or a catalyst for the reaction can be added.

  Preferred examples of the resin material include a monomer that forms a polymer material by polymerization and a polymer material modified with a polymerizable functional group as described above. For example, a prepolymer such as an epoxy resin, an acrylic resin, or a urethane resin before curing is suitable. In particular, when the thermal stability is high, it is desirable that the composition is composed mainly of an epoxy resin.

  The following tests revealed that the density of silica particles and water absorption are related. According to the method of the present invention, silica particles having low water absorption could be obtained. Although the purity of the silica particles obtained by the alkoxide method can be increased, the density cannot be increased compared with the silica particles obtained by the method of the present invention, and the water absorption is large. It has been found that silica particles having low water absorption have high stability when dispersed in a resin composition. Here, since the three-dimensional mounting type semiconductor is disposed between the semiconductor devices as described above, the performance required for the interposition material that is a cured product of the resin composition disposed therebetween is It will be expensive. Silica particles having high water absorption even when dispersed in the resin may ultimately contain water up to the limit of water absorption, and there is a possibility that the physical properties may be insufficient due to water absorption.

(Test Example 1)
A mixed solution of 100 parts by mass of metallic silicon, 70 parts by mass of thorium, 30 ppb of uranium, 10 ppm of sodium, 500 ppm of aluminum, 50 ppm of potassium and 100 ppm of iron, 2000 parts by mass of ion-exchanged water, and 5 parts by mass of 5% aqueous sodium hydroxide solution Were heated and stirred (alkaline silicate solution production step and aqueous silica sol formation step).

  Unreacted (undissolved) metallic silicon was separated by filtration. Unreacted metal silicon was 16 parts by mass. The dissolved metallic silicon became an aqueous silica sol. The obtained aqueous silica sol had thorium of 0.2 ppb, uranium of 0.1 ppb, sodium of 10 ppm, aluminum of 20 ppm, potassium and iron of less than 1 ppm (below detection limit), and volume average particle size of 5 nm. SEM photographs of the obtained aqueous silica sol are shown in FIGS.

The unreacted metal silicon was 260 ppb for thorium, 150 ppb for uranium, 130 ppm for sodium, 3600 ppm for aluminum, 300 ppm for potassium, and 600 ppm for iron. The true specific gravity was 2.2 g / cm ³ and the hygroscopicity was 2%.

  From the above results, it was found that the purity of the aqueous silica sol produced by interrupting dissolution can be improved.

(Test Example 2)
A test similar to Test Example 1 was conducted except that a 5% aqueous ammonia solution was used instead of the aqueous sodium hydroxide solution.

(Test Example 3)
A test similar to Test Example 1 was conducted except that a 5% aqueous potassium hydroxide solution was used instead of the aqueous sodium hydroxide solution.

(Test Example 4)
A test similar to Test Example 1 was conducted except that a 5% aqueous ammonia solution was used in addition to the aqueous sodium hydroxide solution.

(Test Example 5)
Tests similar to those of Test Example 1 were performed except that the contents of thorium and uranium of silicon metal were set to 1.0 ppb or less.

(Test Example 6)
Tests similar to those in Test Example 2 were performed except that the contents of thorium and uranium in silicon metal were not more than 1.0 ppb.

(Test Example 7)
The same test as in Test Example 3 was performed except that the contents of thorium and uranium in silicon metal were not more than 1.0 ppb.

(Test Example 8)
The same test as in Test Example 4 was performed except that the contents of thorium and uranium in silicon metal were not more than 1.0 ppb.

(Test Example 9)
The same test as in Test Example 1 was performed except that 10 parts by mass of the aqueous silica sol (volume average particle diameter 5 nm) obtained in Test Example 1 was added to the raw material.

(Test Example 10)
The same test as in Test Example 1 was performed except that 10 parts by mass of the aqueous silica sol (volume average particle size 10 nm) obtained in Test Example 9 was added to the raw material.

(Test Example 11)
A test was conducted in the same manner as in Test Example 4 except that 1/3 of metal silicon was added every 2 hours after the start of the reaction.

(Test Example 12)
A test similar to Test Example 1 was conducted except that the amount of the aqueous sodium hydroxide solution was 100 parts by mass.

(Test Example 13)
A test similar to Test Example 12 was conducted except that a 5% aqueous potassium hydroxide solution was used instead of the aqueous sodium hydroxide solution.

(Test Example 14)
Tests similar to those of Test Example 1 were performed except that the contents of thorium and uranium of metal silicon were 1000 ppb or more.

(Test Example 15: alkoxide method)
A first liquid was obtained by mixing 100 parts by mass of tetramethylorthosilicate and 1200 parts by mass of pure water. 1 part by mass of 1% tetramethylammonium hydroxide and 1800 parts by mass of pure water were mixed to obtain a second liquid. The first liquid was added at a constant rate while heating and stirring the second liquid.
(Test Example 16: Sodium aluminate treatment) 100 parts by mass of the aqueous silica sol obtained in Test Example 9 and 2 parts by mass of a 1% sodium aluminate aqueous solution were mixed and heated at 80 ° C. for 72 hours. Aluminum contained in the obtained aqueous silica sol increased from less than 1 ppm to 1200 ppm before and after the reaction.

-Evaluation Table 1 shows the silica particles obtained in each test example. The amounts of U, Th, Na, and K were measured by ICP-MS. The particle size was calculated from the BET specific surface area. The results of thermogravimetric analysis (heating rate: 5 ° C./min) for Test Example 1 and Test Example 15 are shown in FIG. As is clear from FIG. 4, the silica particles of Test Example 15 produced by the conventional method have a weight reduction (that is, the amount containing water) compared to the silica particles of Test Example 1 produced by one of the methods of the present invention. I found it big. As a result of examining the silica particles of other test examples in the same manner, the true density was 2.1 g / m ³ or more and the water absorption was also low.

  As is apparent from the table, the amounts of uranium and thorium were all 1 ppb or less except for Test Example 14. Even when the uranium and thorium concentrations of the raw material exceeded 1000 ppb, the uranium concentration in the obtained aqueous silica sol was 10 ppb and the thorium concentration was 1 ppb, and sufficiently effective uranium and thorium removal was possible.

  Both Na and K showed low values except for Test Example 12 in which a large amount of Na was added as an alkaline substance contained in the alkaline solution and Test Example 13 in which a large amount of K was added. Therefore, it has been found that the target concentrations of Na and K can be realized by reducing the amounts of Na and K to a necessary level.

The particle diameter of the obtained aqueous silica sol was controllable by adding silica (aqueous silica sol) (Test Examples 9 and 10). From the results of both, it was found that the particle size of the aqueous silica sol obtained also changed according to the particle size of the added aqueous silica sol. An aqueous silica sol having a particle size smaller than that of the alkoxide method was obtained. Further, the aqueous silica sol of Test Example 15 obtained by the alkoxide method had a hygroscopicity of 9%, and showed a larger water absorption than other aqueous silica sols. The high water absorption of the sample in this test example is presumed to be due to the disorder of the crystal structure forming silica, and it was found that the degree of the disorder appears in the density value. That is, in Test Example 15 in which the density is 2.0 g / cm ³ , the water absorption is as high as 9%, whereas in the Test Example in which the density is 2.1 g / cm ³ and 2.2 g / cm ³ , the water absorption is 2 % Significantly decreased. It has been found that silica particles having high water absorption have low stability when dispersed in a resin material to form a resin composition.

  Uranium and thorium contained in the aqueous silica sol obtained in any of Test Examples 1 to 14 were lower than the raw material concentration.

Resin composition (Test Example A)
The aqueous silica sol obtained in Test Example 1 was surface-treated with epoxy silane. 20 parts by mass of this surface-treated silica was uniformly dispersed in 80 parts by mass of an epoxy resin to obtain a resin composition of this test example, and the transmittance was measured. The transmittance was measured by adding 1 g of a resin dispersion to a quartz glass cell, and using a spectrophotometer (Hitachi U-2910) at 589 nm. U, Th, Na and K amounts were also measured.

(Test Example B)
The test was performed in the same manner as in Test Example A except that the aqueous silica sol obtained in Test Example 5 was used.

(Comparative Example A)
The test was conducted in the same manner as in Test Example A except that the aqueous silica sol obtained in Test Example 14 was used.

(Comparative Example B)
The test was conducted in the same manner as in Test Example A, except that the surface-treated silica was changed to SE2050-SEJ (manufactured by Admatechs, average particle size 0.5 μm).

  As is apparent from the table, Test Examples A and B, which are resin compositions of the method of the present invention, also had high transmittance and high purity. In comparison, the resin composition of Comparative Example A contained a large amount of impurities such as Na depending on the purity of the raw material. In Comparative Example B employing silica particles having a large particle size, the transparency was not sufficient.

Claims (9)

Two or more semiconductor devices in which the distance between the closest parts is 30 μm or less;
A heat transfer interposition material interposed between the semiconductor devices;
Have
The heat transfer medium has inorganic material particles and a resin material in which the inorganic material particles are dispersed,
The inorganic material particles have uranium and thorium contents of 1.0 ppb or less,
Each of sodium and potassium content is 500 ppm or less,
The volume average particle size is 2 nm to 200 nm,
Silica particles having a true density of 2.1 g / cm ³ or more,
Three-dimensional mounting type semiconductor device. The three-dimensional mounting type semiconductor device according to claim 1, wherein the silica particles have a sodium and potassium content of 250 ppm or less.   The three-dimensionally mounted semiconductor device according to claim 2, wherein the silica particles have a uranium and thorium content of 0.5 ppb or less. It is a composition before hardening of the said heat-transfer intervention material of the three-dimensional mounting type semiconductor device of any one of Claims 1-3,
A resin composition comprising the inorganic material particles and the resin material in which the inorganic material particles are dispersed. A method for producing the resin composition according to claim 4,
The silica particles are obtained by an alkaline silicate solution production process in which an alkali silicate solution is produced by dissolving 5% by mass or more of a silicon-containing material, which is either metal silicon or a silicon compound, in an alkaline solution. It has an aqueous silica sol forming step of forming an aqueous silica sol from an alkaline silicate solution.   The method for producing a resin composition according to claim 5, wherein the silicon-containing material is metallic silicon.   The method for producing a resin composition according to claim 5 or 6, wherein the alkaline solution contains a volatile alkaline substance as a main component. In the manufacturing method of the resin composition of any one of Claims 5-7,
For the aqueous silica sol, having a surface treatment step of surface treatment with a silane coupling agent and organosilazane,
The silane coupling agent has three alkoxy groups, a phenyl group, a vinyl group, an epoxy group, a methacryl group, an amino group, a ureido group, a mercapto group, an isocyanate group, or an acrylic group,
The molar ratio of the silane coupling agent to the organosilazane is characterized in that the silane coupling agent: the organosilazane = 1: 2 to 1:10. The surface treatment step includes
A first treatment step of treating the silica particles with the silane coupling agent;
A second treatment step of treating the silica particles with the organosilazane,
The method for producing a resin composition according to claim 8, wherein the second treatment step is performed after the first treatment step.