JP6121845B2 - Surface-treated silica powder, slurry composition and resin composition using the same - Google Patents

Description

The present invention relates to silica powder.

In recent years, with the increase in speed, size, weight, and functionality of electronic devices, printed wiring boards that support high-density mounting and wiring miniaturization have been developed. Multilayer build-up boards have problems such as cracking due to differences in thermal expansion coefficient between insulating layers and copper wiring and IC chips, and heat resistance during manufacturing. Therefore, low thermal expansion is required.

In order to reduce the coefficient of thermal expansion of the substrate, there are known methods such as a method of highly filling a matrix resin such as an epoxy resin with a filler such as silica powder, and a method using a rigid resin. However, when the filler is highly filled in the resin, the fluidity and moldability are significantly reduced. Further, in the case of thinning, there is a problem that the insulation reliability is lowered because the rigidity of the substrate itself is low.

In order to cause the filler to be highly filled and flowable in the resin, it is effective to adjust the particle size distribution to obtain the closest packed state and to control the surface treatment state. In Patent Document 1, a slurry composition obtained by dispersing spherical silica particles having an average particle size of 0.1 μm to 5 μm and a sphericity of 0.8 or more and silica nanoparticles having an average particle size of 1 nm to 50 nm in an organic solvent. A varnish composition is disclosed. In this case, the optimization of the particle size is insufficient, the effect of improving the fluidity associated with the formation of the close-packed state is poor, and there is no description regarding the surface treatment state, and the problem has not been solved. In Patent Document 2, an average particle diameter D50 and a 100% equivalent diameter D100 are defined, but high fluidity is not realized.

It is known that silanol groups exist as reaction sites on the particle surface of silica particles, and the wettability to the resin can be controlled by surface modification using a surface treatment agent such as a silane coupling agent. That is, it is important to control the amount of surface modifying groups. Patent Document 3 discloses a basic silica powder in which a specific amount of silazanes is treated, but the treatment amount alone is insufficient.

JP 2006-36916 A JP 2003-13002 A JP 2004-161900 A

It is an object of the present invention to provide a spherical silica powder that has good dispersion when the spherical silica powder is highly filled into the resin, the fluidity of the resin composition before curing is extremely high, and the substrate strength of the resin composition after curing is high. To provide powder.

The present invention employs the following means in order to solve the above problems.
(1) The volume average particle diameter is 0.80 to 1.3 μm, and the ratio (D10 / D50) of the cumulative volume 10% value (D10) to the cumulative volume 50% value (D50) in the particle size distribution = 0.20 to 0.00. 50, spherical silica powder having a BET specific surface area value of 3.5 to 5.5 m ² / g and a degree of hydrophobicity of 1.0 to 5.0%.
(2) A slurry composition comprising the spherical silica powder according to (1).
(3) A resin composition using the slurry composition according to (2).

By using the spherical silica powder of the present invention, when the resin is highly filled, the fluidity of the resin composition before curing can be extremely increased, and the substrate strength of the resin composition after curing can be increased.

In the present invention, the volume average particle size is 0.80 to 1.3 μm, and the ratio (D ₁₀ / D ₅₀ ) = 0 of the cumulative volume 10% value (D ₁₀ ) and the cumulative volume 50% value (D ₅₀ ) in the particle size distribution = 0. Spherical silica powder having a BET specific surface area value of 3.5 to 5.5 m ² / g and a degree of hydrophobicity of 1.0 to 5.0%.
The volume average particle diameter of the spherical silica powder is 0.80 to 1.3 μm, and if it exceeds 1.3 μm, silica agglomerates are generated, resulting in poor moldability, and if it is less than 0.80 μm, high fluidity is obtained. Cannot be obtained. A preferred range is 0.90 to 1.2 μm.

The ratio (D ₁₀ / D ₅₀ ) of the cumulative volume 10% value (D ₁₀ ) and the cumulative volume 50% value (D ₅₀ ) in the particle size distribution of the spherical silica powder is 0.20 to 0.50. When (D ₁₀ / D ₅₀ ) = 0.50 is exceeded, high fluidity accompanying an increase in the maximum filling rate of the spherical silica powder cannot be obtained. When (D ₁₀ / D ₅₀ ) = 0.20 or less, the system becomes thermodynamically unstable with an increase in specific surface area, so that the particles aggregate and fluidity is impaired. A preferable range of (D ₁₀ / D ₅₀ ) is 0.28 to 0.42.

The particle size distribution, the cumulative volume 10% value (D ₁₀ ), and the cumulative volume 50% value (D ₅₀ ) of the spherical silica powder are values based on the particle size measurement by the laser diffraction light scattering method. It can be measured by “Model LS-230” (manufactured by Beckman Coulter). In the measurement, an organic solvent to be used is used as a solvent, and as a pretreatment, dispersion treatment is performed by applying an output of 200 W using an ultrasonic homogenizer for 20 seconds. Moreover, it prepared so that PIDS (PolarizationIntensity Differential Scattering) density | concentration might be 45-55 mass%. In addition, the refractive index of the solvent to be used was used for the refractive index, and the refractive index of the powder material was taken into consideration for the refractive index of the powder. For example, amorphous silica was measured with a refractive index of 1.50. The measured particle size distribution was converted so that the particle diameter channel had a width of log (μm) = 0.04.

The specific surface area of the spherical silica powder is a value based on the BET method, and can be measured using “Macsorb HM model-1208” (manufactured by MACSORB) as a specific surface area measuring machine.

The BET specific surface area value of the spherical silica powder is 3.5 to 5.5 m ² / g. If it is less than 3.5 m ² / g, the moldability becomes poor due to the presence of coarse particles, and if it exceeds 5.5 m ² / g, silica aggregates are generated and the moldability becomes poor.

The degree of hydrophobicity of the spherical silica powder of the present invention is 1.0 to 5.0%. When it exceeds 5.0, the reaction amount with the surface treating agent used at the time of slurry composition manufacture may fall, and board | substrate intensity | strength may fall. If it is less than 1.0, high fluidity and dispersibility of the resin composition cannot be obtained.

The method for producing the spherical silica powder constituting the present invention includes, for example, supplying a metal powder slurry into a high-temperature flame composed of a combustible gas and an auxiliary combustible gas in a production furnace, and vaporizing and oxidizing the metal powder in the flame. Is obtained.

A surface treatment with a silane coupling agent is performed before using the spherical silica as a slurry composition. It is preferable to perform a surface treatment in advance so that the degree of hydrophobicity resulting from the surface state is 1.0 to 5.0%. Thereby, a silica particle can be further disperse | distributed favorably in a resin composition by performing wet surface treatment in the state which the dispersibility to the organic solvent improved the silica particle. Examples of the silane coupling agent include aminosilanes such as N-phenylaminopropyltrimethoxysilane, vinylsilanes such as vinyltrimethoxysilane, and acrylic silanes such as acryloxytrimethoxysilane.

  An ultrasonic atomizer is not specifically limited, What is necessary is just to use a well-known thing. The spray size during ultrasonic spraying depends on the frequency of ultrasonic vibration, and the higher the frequency, the smaller the spray size. A preferred spray size is 1 μm or less.

A surface treatment agent is adsorbed on the surface of silica particles in advance using an ultrasonic atomizer, and then pressure treatment using an autoclave is performed. The treatment temperature is preferably 120-180 ° C., the treatment pressure is 1-2 atm, and the treatment time is 1-3 hr. Thereby, a surface silanol group and a surface treating agent can be made to react uniformly.

The slurry composition will be described.
The spherical silica powder can be suitably used as a slurry composition dispersed in water or an organic solvent. The type of the organic solvent in which the silica particles are dispersed is not particularly limited. What is necessary is just to select according to resin. For example, polar solvents such as methyl alcohol, ethyl alcohol, isopropyl alcohol, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, and ethyl acetate are used.
Of these, methyl ethyl ketone is particularly preferable.

  Content of the spherical silica powder contained in a slurry composition is 72.0-75.0 mass% from a viewpoint of the moldability of a resin composition. When it exceeds 75.0 mass%, a dispersion process cannot be performed. When the content is less than 72.0% by mass, the resin varnish viscosity becomes low, and the moldability deteriorates.

The slurry composition of the present invention preferably has a yield value in the CASSON viscosity formula of 0.4 to 1.9 Pa and an apparent viscosity coefficient of 0.01 to 0.05.

The resin composition will be described.
When manufacturing a resin substrate such as a package substrate or an interlayer insulating film using the slurry composition, it is preferable to employ an epoxy resin as the resin.

The epoxy resin used in the resin composition is not particularly limited, and examples thereof include bisphenol A type epoxy resin, bisphenol F type epoxy resin, biphenyl type epoxy resin, phenol novolac type epoxy resin, naphthalene type epoxy resin, and phenoxy type epoxy resin. Can be mentioned. One of these can be used alone, two or more having different important molecular weights can be used in combination, and one or two or more can be used.
Among these epoxy resins, bisphenol A type epoxy resins are particularly preferable.

  Although the resin composition of this invention should just use a well-known hardening | curing agent, a phenol type hardening | curing agent can be used. As the phenolic curing agent, a phenol novolac resin, an alkylphenol novolac resin, polyvinylphenols and the like can be used alone or in combination of two or more.

  As for the compounding quantity of the said phenol hardening | curing agent, the equivalent ratio (phenolic hydroxyl group equivalent / epoxy group equivalent) with an epoxy resin is less than 1.0, and 0.1 or more are preferable. As a result, there remains no unreacted phenol curing agent, and the moisture absorption heat resistance is improved.

The amount of spherical silica powder blended in the resin composition is preferably large from the viewpoints of heat resistance and coefficient of thermal expansion. It is desirable that it is 80 mass% or more with respect to the whole mass of a resin composition.

Examples 1-10 Comparative Examples 1-10
(1) From the outermost part of the production of spherical silica powder, a burner having a triple-winding tube structure assembled in the order of a combustible gas supply pipe, an auxiliary combustible gas supply pipe, and a metal powder slurry supply pipe is installed at the top of the production furnace, A metal oxide powder was produced using an apparatus in which the lower part of the production furnace was connected to a collection system (product powder was sucked with a blower and collected with a bag filter). In addition, three outer peripheral burners for forming an outer peripheral flame are installed on the outer periphery of the burner. LPG was supplied at 10 Nm ³ / hr from the combustible gas supply pipe, and oxygen was supplied at 15 Nm ³ / hr from the auxiliary combustible gas supply pipe to form a high-temperature flame in the production furnace. A slurry having a concentration of 55% by mass prepared by dispersing metal silicon powder in methyl alcohol was supplied from a metal powder slurry supply pipe using a slurry pump, and spherical silica powder was collected by a bag filter.
(2) Manufacture of silica-containing slurry Using an ultrasonic sprayer on spherical silica powder manufactured by the metal powder slurry method, the spray amount is 2.5 L / min, the frequency is 1.6 MHz, and the N ₂ pressure is 0.04 MPa. The surface treatment agent was sprayed on the silica powder. Thereafter, the autoclave was filled with silica powder and treated at 2 atm and 180 ° C. for 2 hr to obtain a surface-treated spherical silica powder. As the surface treating agent, N-phenyltrimethoxysilane “KBM-573” (manufactured by Shin-Etsu Chemical Co., Ltd., molecular weight 255.4) was used. Next, the obtained silica powder was dispersed in a methyl ethyl ketone (MEK) solvent to prepare a slurry having a solid content concentration of 75% by mass.
(3) Production of cured resin: 10.0 parts by mass of bisphenol A type epoxy resin “EPICLON-850” (manufactured by DIC Corporation, epoxy equivalent 186 g / eq) as an epoxy resin, novolak type phenolic resin “PSM-4261 as a curing agent ”5.9 parts by mass (manufactured by Gunei Chemical Industry Co., Ltd., hydroxyl group equivalent 106 g / eq, softening point 80 ° C.), 2-phenylimidazole (2PZ)“ manufactured by Shikoku Kasei Kogyo Co., Ltd. ”0.2 mass as a curing accelerator Parts, vinyltrimethoxysilane “KBM-1003” (manufactured by Shin-Etsu Chemical Co., Ltd., molecular weight 148.2) as a surface treating agent (SC agent) was dissolved in 100 parts by mass of the resulting slurry composition. A resin composition (epoxy resin varnish) was prepared. This resin composition was applied to a substrate using an applicator, vacuum degassed at 50 ° C., and then dried at a temperature of 150 ° C. for 2 hours to obtain a cured resin. The fluidity and dispersibility of the obtained resin composition and the moldability of the cured resin were evaluated according to the methods shown below. The evaluation results are shown in Tables 1-2.
(4) Example 9
In the surface treatment of Example 1, a cured resin was obtained in the same manner as in Example 1 except that vinyltrimethoxysilane “KBM-1003” (manufactured by Shin-Etsu Chemical Co., Ltd., molecular weight 148.2) was used.
(5) Example 10
A cured resin was obtained in the same manner as in Example 1 except that methyltrimethoxysilane “KBM-13” (manufactured by Shin-Etsu Chemical Co., Ltd., molecular weight 136.2) was used in the surface treatment of Example 1.
(6) Comparative Example 9
In the surface treatment of Example 1, only a surface treatment using an ultrasonic sprayer was performed, and a cured resin was obtained in the same manner as in Example 1 except that the treatment with an autoclave was not performed.
(7) Comparative Example 10
In the surface treatment of Example 1, a cured resin was obtained in the same manner as in Example 1 except that the surface treatment was performed using a spray instead of the ultrasonic atomizer.

Evaluation methods for the surface-treated silica, the resin composition, and the cured resin are shown in the following (1) to (6).
(1) Specific surface area 1.0 g of spherical silica powder was weighed, put into a measurement cell, and after pretreatment, the BET specific surface area value was measured. The measuring machine used was “Macsorb HM model-1208” (manufactured by MACSORB). Pretreatment was performed under the following conditions.
Degassing temperature: 300 ° C
Degassing time: 18 minutes Cooling time: 4 minutes (2) Hydrophobic degree 50 ml of ion exchange water, surface-treated silica powder as a sample was put in a 0.2 g beaker, and methanol was added dropwise from a burette while stirring with a magnetic stirrer. The methanol mass fraction in the methanol water mixed solution at the end point where the total amount of the sample sank was defined as the degree of hydrophobicity.
(3) Fluidity The viscosity of the resin composition after vacuum defoaming was measured with an E-type viscometer (manufactured by Toki Sangyo Co., Ltd .: TVE-10) at 20 rpm (measurement temperature 25 ° C.). At this time, 2.0 Pa · s or more was regarded as defective.
(4) The dispersible resin composition was evaluated as dispersibility by using a grind gauge having a width of 90 mm, a length of 240 mm, and a maximum depth of 100 μm in accordance with JIS-K5101.
Each code is as follows.
◎: The scale where 3 streaks (linear traces) of 1 cm or more are generated is less than 5 μm. ○ The scale where 3 streaks (linear traces) of 3 cm or more are generated is less than 8 μm. The scale at the position where three (linear traces) are generated is 8 μm or more × 1 cm or more where the scale where three lines (linear traces) are generated is 10 μm or more. (5) Formability / silica particle aggregate obtained The number of aggregates of silica particles of 10 μm or more present in an area of 1 cm ^{3 of the} cured resin product is irradiated with a fringe pattern using a surface shape inspection system KURASURF-PH (manufactured by Kurashiki Boseki Co., Ltd.), and phase difference shift is performed. As a result, surface irregularities were detected and evaluated as moldability according to the following criteria.
Each code is the following evaluation criteria.
A: No aggregate less than 10 μm B: Less than 5 aggregates less than 10 μm ×: 5 or more aggregates greater than 10 μm (6) Bending strength Specimen (thickness 1.0 mm × depth 25.25) according to JIS C6481. 0 mm × width 75.0 mm), and the bending strength N / mm ² in the vertical direction was evaluated.

  As is clear from the comparison between Examples and Comparative Examples, when the spherical silica powder of the present invention is highly filled in an epoxy resin, a slurry composition having extremely high fluidity and a resin composition in which spherical silica particles are well dispersed. Can be obtained.

The slurry composition and resin composition of the present invention can be used for a semiconductor package substrate in the field of electronic equipment such as a printed wiring board.

Claims (3)

Volume average particle diameter is 0.80 to 1.3 μm, ratio of cumulative volume 10% value (D10) to cumulative volume 50% value (D50) in particle size distribution (D10 / D50) = 0.20 to 0.50, BET A spherical silica powder having a specific surface area value of 3.5 to 5.5 m ² / g and a degree of hydrophobicity of 1.0 to 5.0%. A slurry composition comprising the spherical silica powder according to claim 1. A resin composition using the slurry composition according to claim 2.