TWI457281B - Silica powder, process for its production and its use - Google Patents

Description

Oxide powder, its production method and use

The present invention relates to a cerium oxide powder, a method for producing the same, and a use thereof.

In response to the demand for miniaturization, weight reduction, and high performance of electronic equipment, the miniaturization, thinning, and high density of semiconductors are rapidly progressing. Further, a semiconductor package method or a preferred surface package for a high-density package such as a wiring board has become mainstream. In recent years, in order to reduce the package height of the wiring substrate, the surface mount type semiconductor has a very thin package thickness because the ultrathin semiconductor package can be used. Further, on the semiconductor, a PoP (Package On Package) encapsulation method for packaging another semiconductor is put into practical use, and the thinning of semiconductors is progressing further.

In addition, in recent years, the awareness of environmental issues has increased, and in the packaging of semiconductor wiring boards, the temperature at the time of packaging has been 10 ° C higher than that of the prior art by using a lead-free solder that does not contain lead having a large environmental burden. In other words, in a state where the semiconductor package is thinner than the conventional one, the package is cracked more frequently than in the conventional high-temperature package. Therefore, in terms of the semiconductor package material, further improvement in bending strength and solder resist turtle are required. Cracking and so on.

In order to satisfy this requirement, a method of improving the bending strength and reducing the stress is proposed by a method of improving the epoxy resin or the phenol resin curing agent used in the semiconductor packaging material, etc. (see Patent Document 1 and Patent Document 2). However, in these methods, the effect of improving the bending strength is insufficient, and in the conventionally thin package, there is no semiconductor packaging material which is resistant to the package temperature of the lead-free solder and which can significantly improve the solder crack resistance.

In addition, in order to improve the high-temperature placement characteristics (reliability) of the semiconductor package material, an example of controlling the amount of chemical adsorption of ammonia and trapping impurities in the semiconductor package material is exemplified. (Refer to Patent Document 3)

[Patent Document 1] JP-A-2001-233937

[Patent Document 2] Japanese Patent Publication No. Hei 10-279669

[Patent Document 3] WO/2007/132771

An object of the present invention is to provide a cerium oxide powder which is prepared by a semiconductor encapsulating material or the like which is suitable for improving bending strength and further improving solder crack resistance.

The present inventors conducted research on the intent to achieve the above object, and found a cerium oxide powder which achieves the object. The present invention is based on related knowledge and has the following points.

(1) A cerium oxide powder characterized by a Freundlich adsorption constant K of pyridine of from 1.3 to 5.0.

(2) The cerium oxide powder according to the above (1), wherein the content of SiO ₂ , Al ₂ O ₃ , and B ₂ O ₃ (in terms of oxide) is 99.5 mass% or more in total, and Al ₂ O ₃ The content of B ₂ O ₃ is 0.1 to 20% by mass in total.

(3) The cerium oxide powder according to the above (1) or (2), wherein the specific surface area is from 0.5 to 5 m ² /g, and the average particle diameter is from 1 to 60 μm.

(4) An inorganic powder containing the cerium oxide powder according to any one of the above (1) to (3).

(5) The inorganic powder according to the above (4), wherein the inorganic powder is a cerium oxide powder and/or an alumina powder.

(6) A method for producing a cerium oxide powder according to any one of the above (1) to (3), wherein at least two of the two are disposed at an angle of 2 to 10 with respect to a central axis of the furnace body. The burner is in the furnace body, and the raw material is oxidized by a burner to the flame, and the aluminum source material and/or the boron source material are sprayed toward the flame by at least one burner.

(7) The method for producing a cerium oxide powder according to the above (6), wherein the aluminum source material is alumina powder, and the raw material cerium oxide powder has a content of Al ₂ O ₃ of 1% by mass or less.

(8) The method for producing a cerium oxide powder according to the above (7), wherein the alumina powder has an average particle diameter of 0.01 to 10 μm.

(9) A resin composition containing the cerium oxide powder according to any one of the above (1) to (3), or the inorganic powder according to (4) or (5) above.

(10) The resin composition according to (9) above, wherein the resin of the resin composition is an epoxy resin.

(11) A semiconductor encapsulating material using the resin composition according to (9) or (10) above.

According to the present invention, it is possible to provide a resin composition for improving bending strength and flux crack resistance, particularly a resin composition as a conductor encapsulating material, and a cerium oxide powder suitable for preparing the resin composition.

Hereinafter, the present invention will be described in detail.

The cerium oxide powder of the present invention is a cerium oxide powder having a Freundlich adsorption constant K of 1.3 to 5.0 of pyridine. Since the pyridine which is an alkaline substance is adsorbed on the acid point on the surface of the cerium oxide powder, the larger the adsorption constant K value of the substance means the more the number of acid spots on the surface of the cerium oxide powder. When the acid point of the cerium oxide powder is large, the number of bonding points with the basic decane coupling agent such as amino decane or anilino decane increases. Therefore, the resin component of the epoxy resin, the phenol resin, and the like in the semiconductor encapsulating material and the adhesion to the surface of the cerium oxide powder become more stable, and the bending strength is increased, and the moisture becomes difficult to enter the resin component and the cerium oxide powder. The interface, therefore, also leap to enhance the packaging resistance.

When the Freundlich adsorption constant K of pyridine is less than 1.3, since the bonding point between the decane coupling agent and the cerium oxide powder is small, the bending strength or the solder crack resistance of the semiconductor packaging material cannot be remarkably improved. Sex. Further, when the Freundlich adsorption constant K of pyridine exceeds 5.0, the number of acid sites on the surface of the cerium oxide powder becomes excessive, and the epoxy resin is hardened. Therefore, in order to use a semiconductor encapsulating material to enhance the viscosity of the encapsulating material when the semiconductor is packaged, there is a problem that the formability is impaired. The preferred pyridine has a Freundlich adsorption constant K of from 1.5 to 4.5, particularly preferably from 2.0 to 4.3. These values are unique when compared to the Freundlich adsorption constant K value of 0.07 to 0.8 for conventional cerium oxide powders.

The Freundlich adsorption constant K of pyridine can be determined by the following procedure.

(1) Preparation of pyridine standard solution: Spectroscopic analysis was carried out in a 500 ml measuring flask with 0.1 mol of pyridine, and the volume was made up to n-heptane by spectroscopic analysis. Next, 0.25 ml, 0.50 ml, and 1.00 ml of the above pyridine solution were separately taken in a 200 ml measuring flask, and the volume was adjusted to n-heptane to prepare a pyridine standard of 0.25 mmol/l, 0,50 mmol/l, and 1.00 mmol/l. Solution.

(2) Adsorption of cerium oxide powder: It was previously dried at 200 ° C for 2 hours, and the fine scale was allowed to stand in a desiccator to cool each of 4.00 g of the cooled cerium oxide powder in three 25 ml measuring flasks. 20 ml of a 0.25 mmol/l, 0.50 mmol/l, 1.00 mmol/l pyridine standard solution was placed in each of the measuring flasks, and the mixture was shaken for 3 minutes. The measuring flask was placed in a thermostat set at 25 ° C for 2 hours to adsorb pyridine to the cerium oxide powder.

(3) Determination of the amount of pyridine adsorption: From the above-mentioned measuring flask in which the pyridine standard solution and the cerium oxide powder were mixed, the supernatant liquid was separately taken out and placed in a measuring element of an ultraviolet-visible spectrophotometer, and the residue was quantified by absorbance. The residual pyridine concentration.

(4) Calculation of the Freundlich adsorption constant K of pyridine: Fronidrich of pyridine was calculated by the Freundlich adsorption formula of logA=logK+(1/n)logC Freundlich) adsorption constant K. That is, when plotting logA as the Y-axis and (1/n) logC as the X-axis, K can be calculated by obtaining the logK from the Y-axis segment. Here, A is a pyridine amount (μmol/g) adsorbed to 1 g of cerium oxide powder, C is a residual pyridine concentration (μmol/ml) in the supernatant, and K and n are constant.

In addition, if it is used for the measurement of the ultraviolet-visible spectrophotometer, the product name "UV-Vis spectrophotometer UV-1800 type" manufactured by Shimadzu Corporation is available. For example, a pyridine (grade for spectroscopic analysis) and n-heptane (gradation for spectroscopic analysis) manufactured by Wako Pure Chemical Industries, Ltd. are used as an agent for preparing a pyridine standard solution. Further, background compensation was performed by measuring only n-heptane at a measurement wavelength of 251 nm as the absorbance. In the preparation of the calibration curve, a pyridine standard solution of 0.00 mmmol/l, 0.25 mmol/l, 0.50 mmol/l, and 1.00 mmol/l was used.

Further, the characteristics of the cerium oxide powder of the present invention are SiO ₂ , Al ₂ O ₃ , and B ₂ O ₃ (the oxide equivalent) in a total amount of 99.5% by mass or more, and Al ₂ O ₃ and B ₂ O ₃ . The content ratio is 0.1 to 20% by mass in total. When the content ratio of SiO ₂ , Al ₂ O ₃ , and B ₂ O ₃ is less than 99.5% by mass in total, that is, when the content ratios other than SiO ₂ , Al ₂ O ₃ , and B ₂ O ₃ exceed 0.5% by mass, they are formed. In the case of semiconductor packaging materials, it is not preferable to add unnecessary impurities. For example, Na ₂ O, Fe ₂ O _{3 ,} etc., are partially dissolved as ions, causing damage to the semiconductor wafer or wiring. MgO, K ₂ O, CaO, etc. increase the thermal expansion coefficient of the cerium oxide powder and adversely affect the encapsulation resistance.

The total content of SiO ₂ , Al ₂ O ₃ , and B ₂ O ₃ is preferably 99.6% by mass or more, and more preferably 99.7% by mass or more.

Further, the total content of Al ₂ O ₃ and B ₂ O _{3 in the} cerium oxide powder is preferably from 0.1 to 20% by mass. When Al and B are present in the cerium oxide powder, the positions of Al and B become strong acid sites. By the acid point, since the bonding point between the basic decane coupling agent and the surface of the cerium oxide powder is increased, the bending strength and the solder crack resistance are improved. When the total content of the content ratio of Al ₂ O ₃ and B ₂ O ₃ is less than 0.1% by mass, the increase in the acid point is insufficient, and when it exceeds 20% by mass, the thermal expansion coefficient of the cerium oxide powder is excessively large. Flux cracking has an adverse effect. The total content of Al ₂ O ₃ and B ₂ O ₃ is preferably 0.2 to 18% by mass, more preferably 0.3 to 15% by mass.

The SiO ₂ content (oxidation conversion) of the cerium oxide powder of the present invention is a mass reduction method; the Al ₂ O ₃ content (oxide conversion) is an atomic absorption spectrometry; and the B ₂ O ₃ content (oxide) The conversion is performed by ICP luminescence analysis and can be measured by the following procedure.

(1) Measurement of SiO ₂ content: 2.5 g of oxidized enamel powder of fine scale was placed in a white gold dish, and 20 g, 1 ml, and 1 ml were separately added to the test drug-grade hydrofluoric acid, the test drug-grade sulfuric acid, and pure water. The platinum dish was placed on a sand bath heated to 300 ° C for 15 minutes to dissolve and dry the powder. Next, the platinum dish was placed in a Monfort furnace heated to 1000 ° C for 10 minutes to evaporate the hydrofluoric acid. After standing in a desiccator to cool to room temperature, the mass of the platinum scale was measured, and the SiO ₂ content of the cerium oxide powder was calculated from the mass reduction rate.

(2) Measurement of the content of Al ₂ O ₃ : 1 g of the oxidized enamel powder of the fine scale was placed in a white gold dish, and the special grade hydrofluoric acid and the test substance super perchloric acid were added to 20 ml and 1 ml, respectively. The platinum dish was placed on a sand bath heated to 300 ° C for 15 minutes and then cooled to room temperature, transferred to a 25 ml measuring flask and made up to volume with pure water. The amount of Al in the solution was quantified by a calibration line method using an atomic absorption spectrophotometer. The content of Al was converted into Al ₂ O ₃ to calculate the content in the cerium oxide powder. For example, an atomic absorption photometer is available under the trade name "Atomic Absorbance Photometer AA-969" manufactured by Japan's Jarrell-Ash Company. For example, the standard solution used in the calibration line is prepared, and the Al standard solution for atomic absorption by Toki Chemical Co., Ltd. (concentration: 1000 ppm) is used. Further, in the case of the flame at the time of measurement, an acetylene-laugh gas was used, and the absorbance at a wavelength of 309.3 nm was measured and quantified.

(3) Determination of the content of B ₂ O ₃ : 1 g of oxidized enamel powder of fine scales was placed in a white gold dish, and 20 ml, 1 ml, and 1 ml were separately added to the test drug super hydrofluoric acid, the test drug special grade nitric acid, and the test drug super mannitol. A 1% aqueous solution was placed on a sand bath heated to 300 ° C for 15 minutes to dissolve and dry the powder. Next, in the dried material of the platinum dish, an average of 1 ml of the test drug-grade nitric acid and pure water was separately added, and after dissolving, it was transferred to a 25 ml measuring flask and then made up to a volume of pure water. The amount of B in the solution was quantified by a calibration line method using an ICP emission spectroscopic analyzer. The content of B in the cerium oxide powder was calculated by converting the B amount into B ₂ O ₃ . When the ICP emission spectroscopic analyzer is exemplified, the product name "SPS-1700R" manufactured by Seiko Instruments Inc. is used, and the luminous intensity at a wavelength of 249.8 nm is measured. For example, if the standard solution used in the calibration curve is prepared, the standard solution for atomic absorption of Dong Chemical Co., Ltd. (concentration: 1000 ppm) is used.

When the specific surface area of the cerium oxide powder is in the range of 0.5 to 5 m ² /g and the average particle diameter is in the range of 1 to 60 μm, the bending strength and the solder crack resistance in the resin composition of the present invention are further promoted. Improve the effect. When the specific surface area is less than 0.5 m ² /g, the bonding area between the decane coupling agent and the surface of the cerium oxide powder is too small, and it is difficult to improve the bending strength and the solder crack resistance. Further, when the specific surface area exceeds 5 m ² /g, the cerium oxide powder contains a large amount of small particles, indicating that some or all of the surface of the particles has irregularities, and the viscosity of the sealing material when the semiconductor is encapsulated by using a semiconductor packaging material is increased to form Impaired. The preferred specific surface area ranges from 0.6 to 4.8 m ² /g, more preferably from 0.7 to 4.7 m ² /g.

In addition, even if the average particle diameter of the cerium oxide powder is less than 1 μm, the viscosity of the sealing material when the semiconductor is packaged by using the semiconductor packaging material is increased, and the moldability is impaired. On the other hand, in the case where the average particle diameter exceeds 60 μm, the thickness of the semiconductor package becomes extremely thin, causing a problem of damage to the semiconductor wafer, or a problem of obtaining a package having unevenness and unevenness. The preferred average particle size ranges from 2 to 55 μm, more preferably in the range of from 3 to 50 μm. Further, the maximum particle diameter is preferably 196 μm or less, more preferably 128 μm or less.

The average particle diameter of the cerium oxide powder of the present invention is determined based on particle size measurement by a laser diffraction scattering method. For the measuring machine to be used, for example, the product name "Hills Particle Size Analyzer Model 920" manufactured by Cirrus Co., Ltd. is used, and the cerium oxide powder is dispersed in water, and further, the ultrasonic homogenizer is used at a power of 200 W. Dispersion treatment was carried out for 1 minute and then measured. Further, the particle size distribution measurement was carried out with particle diameter channels of 0.3, 1, 1.5, 2, 3, 4, 6, 8, 12, 16, 24, 32, 48, 64, 96, 128, and 196 μm. In the particle size distribution measured, the particle diameter at which the cumulative mass is 50% is the average particle diameter, and the particle diameter at which the cumulative mass is 100% is the maximum particle diameter.

The specific surface area of the cerium oxide powder of the present invention is determined based on the specific surface area measurement by the BET method. For example, a specific surface area measuring machine is available under the trade name "Make Thorpe HM-1208" manufactured by MOUNTECH.

The cerium oxide powder of the present invention can be found to have an effect even when it is mixed with other inorganic powders. The content of the cerium oxide powder of the present invention in the inorganic powder is preferably 0.5% by mass or more, and more preferably 2% by mass or more. The type of the inorganic powder is preferably a cerium oxide powder and/or an alumina powder. These powders may be used singly or in combination of two. When the thermal expansion coefficient of the semiconductor package material is lowered or the wear resistance of the mold is lowered, when the enamel powder is given thermal conductivity, the alumina powder is selected. Further, the cerium oxide powder is preferably an amorphous ratio value of 95% or more as measured by the method described later.

The oxidized enamel powder of the present invention preferably has an amorphous ratio of 95% or more, particularly preferably 98% or more, measured by the following method. The amorphous ratio is a X-ray diffraction analysis using a powder X-ray diffraction apparatus (for example, the product name "Mini Flex type" manufactured by RIGAKU Co., Ltd.) in the range of 26 to 27.5 ° of the CuKα line. The peak intensity ratio is measured. In the case of cerium oxide powder, the crystalline lanthanum oxide has a main peak at 26.7°, while there is no spike in the amorphous yttrium oxide. When the amorphous cerium oxide is mixed with the crystalline cerium oxide, the X-ray intensity of the sample from the X-ray intensity relative to the crystalline cerium oxide standard sample is obtained because a peak height of 26.7° corresponding to the ratio of the crystalline cerium oxide is obtained. Ratio, calculation of the mixing ratio of crystalline cerium oxide (X-ray diffraction intensity of sample / X-ray diffraction intensity of crystalline cerium oxide), by general formula, amorphous ratio (%) = (1-crystalline oxidation矽 mixing ratio) × 100 to obtain the amorphous ratio.

The average sphericity of the cerium oxide powder, the inorganic powder, and the alumina powder of the present invention is preferably 0.80 or more, and particularly preferably 0.85 or more. Therefore, the viscosity of the resin composition is lowered, and the formability can be improved. The average sphericity is obtained by taking a particle image photographed by a solid microscope (for example, a product name "SMZ-10" manufactured by Nikon Co., Ltd.) into a screen analysis device (for example, a product name by MOUNTECH). MacVieW") is determined by the projected area (A) and perimeter (PM) of the particles from the photo. When (B) is a true circular area corresponding to the circumference (PM), since the sphericity of the particle is A/B, it is assumed that there is a true circle having the same circumference as the sample circumference (PM). PM=2πr, B=πr ² , then B=π×(PM/2π) ² , and the sphericity of each particle is sphericity=A/B=A×4π/(PM) ² . The sphericity of 200 particles of any of the particles thus obtained was obtained, and the average value thereof was an average sphericity.

Next, a method for producing the cerium oxide powder of the present invention will be described.

The manufacturing method of the present invention is a method for producing a cerium oxide powder, characterized in that at least two burners are disposed in the furnace body at an angle of 2 to 10°, and the raw material is oxidized by a burner to the flame. The Al source material and/or the B source material are sprayed toward the flame by at least one burner. When the raw material oxidizes the cerium powder and the Al source material and/or the B source material from the same burner toward the flame, since the injected material is necessarily diffused into a conical shape, the Al source is fused to the surface of the raw material oxidized cerium powder. The ratio of the substance and/or the B source material is small, and the cerium oxide powder of the present invention in which the total content of Al ₂ O ₃ and B ₂ O ₃ is 0.1 to 20% by mass cannot be produced. Further, even if the raw material oxidized enamel powder and the Al source material and/or the B source material are mixed in advance and diffused into a conical shape at the time of spraying, the composition becomes heterogeneous due to dispersion and separation.

Having an angle of 2 to 10° with respect to the central axis of the furnace body, at least two burners are disposed in the furnace body in a manner of combining the focal points, so that at least one of the cerium powder is sprayed toward the flame by one burner toward the flame. The burner sprays the Al source material and/or the B source material toward the flame, and the cerium oxide powder of the present invention can be efficiently produced. The composition homogeneity of the cerium oxide powder of the present invention can be further improved by making the burner for ejecting the Al source material and/or the B source material into a plurality of branches. Preferably, the number of burners is one in relation to the jet burner of the raw material cerium oxide powder, and the ratio of the jet burner of the Al source material and/or the B source material is two. Further, the arrangement angle of the burner must be 2 to 10 degrees with respect to the central axis of the furnace body. When the arrangement angle of the burner is less than 2°, the position at which the focus is combined becomes the outside of the flame, and the ratio of the Al source material and/or the B source material to the surface of the raw material oxidized enamel powder is less. Further, even if the burner arrangement angle exceeds 10°, it is not preferable to bond the focus of the Al source material and/or the B source material before the melt adhesion on the surface of the raw material cerium oxide powder. Preferred burner configurations are in the range of 3 to 8 degrees.

In the present invention, the Al source material is preferably an alumina powder. In terms of Al source material, aluminum oxide, aluminum hydroxide, aluminum sulfate, aluminum chloride, aluminum organic compound, etc. are mentioned, but since alumina has a melting point close to that of the raw material oxidized enamel powder, it is easily melted when sprayed by a burner. Adhered to the surface of the raw material cerium oxide powder, it is best because the impurity content is small. Further, the average particle diameter of the alumina powder is preferably 0.01 to 10 μm. When the average particle diameter is less than 0.01 μm, the powder tends to aggregate, and the composition tends to become heterogeneous when it is fused with the cerium oxide powder. When it exceeds 10 μm, the composition also becomes heterogeneous when it is fused to the cerium oxide powder. The average particle diameter is preferably from 0.03 to 8 μm, more preferably from 0.05 to 5 μm.

In the present invention, the Al ₂ O ₃ content of the raw material cerium oxide powder is preferably 1% by mass or less. Among the Al and B in the cerium oxide powder, a strong acid point is formed only on the surface of the powder, and it can be bonded to a basic decane coupling agent. Therefore, Al ₂ O ₃ existing in the raw material cerium oxide powder causes an adverse effect such as an increase in the thermal expansion coefficient of the cerium oxide powder. The Al ₂ O ₃ content of the raw material cerium oxide powder is preferably 0.8% by mass or less, more preferably 0.5% by mass or less.

The raw material cerium oxide powder may contain Fe ₂ O ₃ , Na ₂ O, MgO, CaO, B ₂ O ₃ or the like in addition to the above Al ₂ O ₃ , and the SiO ₂ content of the raw material oxidized enamel powder is 97 mass. More preferably, it is 98% by mass or more.

For the device which sprays, melts, and collects the raw material oxidized enamel powder and the Al source material and/or the B source material, for example, a device in which a trap device is connected to a furnace having a burner is used. The furnace body may be of an open type or a closed type, or a vertical type or a horizontal type. In the collection device, one or more of a gravity sedimentation chamber, a cyclone separator, a bag filter, and an electrostatic precipitator are provided, and by adjusting the collection conditions, the produced cerium oxide powder can be collected. For example, Japanese Laid-Open Patent Publication No. Hei 11-57451, No. Hei 11-71107, and the like.

Further, in the present invention, the Freundlich adsorption constant K of the ruthenium oxide powder may be melted by adhering to the Al source material and/or the B source material on the surface of the raw material cerium oxide powder. The size and the content of Al ₂ O ₃ in the cerium oxide powder, the B ₂ O ₃ content, the specific surface area of the cerium oxide powder, and the average particle diameter increase or decrease. The Al ₂ O ₃ content and the B ₂ O ₃ content in the cerium oxide powder can be individually increased or decreased by adjusting the ratio of the raw material oxidized cerium powder to the Al source material and/or the B source material to the burner. . The specific surface area, the average particle diameter, and the like of the cerium oxide powder can be adjusted by the particle size composition of the raw material oxidized enamel powder, the flame temperature, and the like. Further, the average sphericity and the amorphous ratio can be adjusted by the supply amount of the raw material oxidized enamel powder to the flame, the flame temperature, and the like. In addition, it is possible to produce a cerium oxide powder having various specific surface areas, an average particle diameter, an Al ₂ O ₃ content, a B ₂ O ₃ content, and the like, and it is possible to produce a further specific genus by appropriately mixing the two or more kinds thereof. Freundlich oxidized enamel powder having a constant K, an Al ₂ O ₃ content, a B ₂ O ₃ content, a specific surface area, and an average particle diameter.

The resin composition of the present invention is a resin composition containing the cerium oxide powder or the inorganic powder of the present invention. The content of the cerium oxide powder or the inorganic powder in the resin composition is from 10 to 95% by mass, more preferably from 30 to 90% by mass.

As the resin, an epoxy resin, a decyloxy resin, a phenol resin, a melamine resin, a urea resin, an unsaturated polyester, a fluororesin, a polyimine, a polyamidamine, a polyether-imine, or the like can be used. Polyamide; polybutylene terephthalate, polyester such as polyethylene terephthalate; polyphenylene sulfide, aromatic polyester, polyfluorene, liquid crystal polymer, polyether oxime, polycarbonate , maleic acid imide modified resin, ABS resin, AAS (acrylonitrile, acrylic rubber, styrene) resin, AES (acrylonitrile, ethylene, propylene, diene rubber, styrene) resin. Among them, epoxy resin, oxime resin, phenol resin and the like are particularly preferred.

Among them, in terms of a semiconductor encapsulating material, an epoxy resin having two or more epoxy groups in one molecule is preferable. For example, there are phenol novolak type epoxy resin; o-cresol novolak type epoxy resin; epoxidized by phenolic and aldehyde novolak resin; bisphenol A, bisphenol F and bisphenol S, etc. a epoxidized propyl ether; a glycidyl ester acid epoxy resin obtained by reacting a polybasic acid such as phthalic acid or a dibasic acid with epichlorohydrine; a chain aliphatic epoxy resin; a cyclic fat Group epoxy resin; heterocyclic epoxy resin; alkyl modified polyfunctional epoxy resin; β-naphthol novolak epoxy resin; 1,6-dihydroxynaphthalene epoxy resin; 2,7-dihydroxy A naphthalene type epoxy resin; a bishydroxybiphenyl type epoxy resin; and an epoxy resin which introduces a halogen atom such as bromine to impart flame retardancy. Among them, from the viewpoint of moisture resistance and solder reflow resistance, an o-cresol novolac type epoxy resin, a bishydroxybiphenyl type epoxy resin, an epoxy resin of a naphthalene skeleton, or the like is preferable.

The epoxy resin used in the present invention is a hardener comprising an epoxy resin, or a hardener of an epoxy resin and a hardening accelerator for an epoxy resin. The epoxy resin hardener may be exemplified by a simultaneous oxidation catalyst of formaldehyde, paraformaldehyde or p-xylene, and the reaction is selected from the group consisting of phenol, cresol, xylenol, resorcinol, chlorophenol, and third butyl. a novolac type resin obtained by one or more of a group consisting of phenol, indophenol, propofol, and octylphenol; a poly-p-hydroxystyrene resin; a double bisphenol A or a bisphenol S a phenolic compound; a trifunctional phenol such as gallic phenol or phloroglucin; an acid anhydride such as maleic anhydride, phthalic anhydride or pyromellitic anhydride; m-phenylenediamine, diaminodiphenylmethane, and diamine-based An aromatic amine such as phenylhydrazine.

In order to promote the reaction of the epoxy resin with the hardener, a hardening accelerator such as triphenylphosphine, benzyldimethylamine or 2-methylimidazole can be used.

In the resin composition of the present invention, the following components may be further blended as necessary.

Examples of the low stress agent include rubbery materials such as a silicone rubber, a polysulfide rubber, an acrylic rubber, a butadiene rubber, a styrene block polymer, and a saturated elastomer; and various thermoplastic resins. A resinous substance such as a phthalic acid resin; or a modified epoxy resin such as an amine siloxane, an epoxy siloxane or an alkoxy siloxane or a resin of a part or all of a phenol resin.

Examples of the decane coupling agent include an epoxy decane such as γ-glycidoxypropyltrimethoxydecane or β-(3,4-epoxycyclohexyl)ethyltrimethoxydecane; Amino decane such as ethoxy decane, urea propyl triethoxy decane, N-aniline propyl trimethoxy decane; phenyl trimethoxy decane, methyl trimethoxy decane, octadecyl trimethoxy A hydrophobic decane compound such as decane; a thiol decane or the like.

As the surface treatment agent, a Zr chelate compound, a titanate coupling agent, an aluminum coupling agent, or the like.

Examples of the flame retardant auxiliary include Sb ₂ O ₃ , Sb ₂ O ₄ , and Sb ₂ O ₅ .

Examples of the flame retardant include halogenated epoxy resins or phosphorus compounds.

Examples of the colorant include carbon black, iron oxide, a dye, a pigment, and the like.

Further, examples of the release agent include natural waxes, synthetic waxes, metal salts of linear fatty acids, acid amides, esters, and paraffin waxes.

The resin composition of the present invention may be kneaded by a heating roll, a kneader, a uniaxial or biaxial extruder, or the like by blending the above materials with a blender or a Henschel mixer or the like. After cooling, it is produced by pulverization.

The semiconductor encapsulating material-based resin composition of the present invention comprises an epoxy resin, and is composed of a composition comprising a curing agent for an epoxy resin and a curing accelerator for an epoxy resin. In the case of encapsulating a semiconductor by using the semiconductor encapsulating material of the present invention, a forming method using a normal method such as a transfer mold method or a vacuum printing mold method is employed.

[Examples]

Although explained in more detail by the following examples of the invention, it is not limited by those explained.

[Examples 1 to 9 and Comparative Examples 1 to 7]

The raw material cerium oxide powder, the Al source material, and the B source material having different average particle diameters and different Al ₂ O ₃ content ratios are prepared in the apparatus described in JP-A-11-57451. There is a device for adjusting a plurality of burners which are mounted at an angle of 0 to 15° with respect to the central axis of the furnace body, and are melted, melted, and spheroidized in a flame to produce various cerium oxides shown in Table 1. Quality powder. Further, these powders are suitably blended to produce cerium oxide powders and inorganic powders shown in Table 2.

Further, the adjustment of the Freundlich adsorption constant K of the cerium oxide powder is carried out by changing the average particle diameter of the Al source material and/or the B source material which are melt-attached to the surface of the raw material cerium oxide powder. The amount of Al ₂ O ₃ contained in the cerium oxide powder, the B ₂ O ₃ content, the specific surface area of the cerium oxide powder, and the average particle diameter are carried out. The Al ₂ O ₃ content and the B ₂ O ₃ content in the cerium oxide powder are adjusted by adjusting the ratio of the amount of the raw material oxidized cerium powder to the Al source material and/or the B source material to the burner. get on. The adjustment of the specific surface area, the average particle diameter, and the like of the cerium oxide powder is carried out by adjusting the particle size composition of the raw material oxidized enamel powder, the flame temperature, and the like. Further, the adjustment of the average sphericity, the amorphous ratio, and the like of the cerium oxide powder is carried out by adjusting the supply amount of the raw material oxidized cerium powder to the flame, the flame temperature, and the like. Also, the maximum temperature of the flame is in the range of about 2,000 ° C to 2,300 ° C.

The amorphous ratio of the cerium oxide powder was 99.5% or more.

Determination of the pyridine Frondrich adsorption constant K, SiO ₂ content, Al ₂ O ₃ content, B ₂ O ₃ content, specific surface area, average particle diameter, average sphericity of the oxidized enamel powder Etc. and shown in Table 2.

In order to evaluate the characteristics of the obtained cerium oxide powder and the filler of the inorganic powder as a semiconductor encapsulating material, 4,4'-bis (2,3-ring) was added to 86.5 parts by mass (the same by mass). 6.7 parts of oxypropoxy)-3,3',5,5'-tetramethylbiphenyl type epoxy resin, 5.5 parts of phenol resin, 0.3 parts of triphenylphosphine, 0.6 parts of anilinodecane, 0.1 part of carbon black, And 0.3 parts of palm wax, dry blending with a Hanschel mixer. Then, the kneading was performed by a double-axis extrusion kneading machine (thread diameter D = 25 mm, kneading disk length 10 Dmm, stirring blade rotation number 80 to 120 rpm, discharge amount 2.5 kg/Hr, kneaded material temperature 100 to 101 ° C) which were engaged in the same direction. The kneaded material (discharged material) was cast by a casting press, cooled, and pulverized to produce a semiconductor encapsulating material, and bending strength, solder crack resistance, and formability (spiral flow) were evaluated in accordance with the following. These results are shown in Table 2.

(1) bending strength

The bending strength of the hardened body of the semiconductor package obtained above was measured as follows. Specifically, each of the semiconductor package materials was molded into a shape having a width of 10 mm, a length of 80 mm, and a height of 4 mm by using a transfer molding machine at 175 ° C for 120 seconds, and was cured at a temperature of 175 ° C for 6 hours, and then five evaluations were prepared. Test piece. Then, the product name "autoclave AG-5000A type" manufactured by Shimadzu Corporation was used, and the bending strength was measured in accordance with JIS K 7171. Further, the distance between the fulcrums was 64 mm, the weighting speed was 5 mm/min, and the measurement environment was 25 ° C and 50% RH, and the average value of each measured value (n = 5) was obtained as the bending strength.

The larger the numerical value (MPa) is, the more the bending strength is.

(2) solder resist cracking

The solder resist crackability of the semiconductor package material obtained above was measured as follows. That is, a semiconductor wafer was irradiated with a silver paste followed by 9.6 mm × 9.6 mm × 0.4 mm on a copper lead frame having a thickness of 150 μm. Next, each of the above semiconductor package materials was used, and after molding at 175 ° C for 120 seconds using a transfer molding machine, the film was cured at a temperature of 175 ° C for 6 hours to prepare a solder paste cracking property of 15 mm × 19 mm × A 1.8 mm 60-pin QFP (Quad Flat Package) sample. Next, the evaluation samples were treated for 10 hours each for 72 hours under the environmental conditions of 85 ° C and 85% RH, and then heated by a flux reflow device at a temperature of 250 ° C. Then, the evaluation sample was cut in half, and after grinding the cut surface, the size of the crack was observed by a microscope. If the crack is too small to be 70 μm or more, the number of defects is 10. The results are shown in Table 2.

(3) Spiral flow

Determination of spirals of semiconductor packaging materials using a transfer molding machine equipped with a mold for spiral flow measurement according to EMMI-I-66 (Epoxy Molding Material Institute; Society of Plastic Industry) Flow value. The transfer molding conditions were a mold temperature of 175 ° C, a molding pressure of 7.4 MPa, and a dwell time of 120 seconds. The larger the spiral flow value, the superior fluidity is indicated.

As is apparent from comparison between the examples and the comparative examples, the cerium oxide powder according to the present invention can prepare a resin composition superior to the comparative example in bending strength and solder resist crack resistance, particularly a semiconductor encapsulating material.

The cerium oxide powder of the present invention is used for a semiconductor packaging material used in automobiles, mobile electronic devices, personal computers, home electric products, and the like; a laminate for mounting semiconductors; and a putty, a sealing material, various rubbers, and various materials. Filling materials for engineering plastics, etc. Further, in addition to the semiconductor encapsulating material, the resin composition of the present invention can be used as a prepreg such as a glass woven fabric, a glass non-woven fabric, or a hardened other organic substrate and hardened, for example, a printed substrate, or various engineering plastics. Wait.

In addition, the entire contents of the specification, the scope of the patent application, and the abstract of the Japanese Patent Application No. 2008-018973, filed on Jan.

Claims (11)

A cerium oxide powder characterized by a Fraundlich adsorption constant K of pyridine at an adsorption temperature of 25 ° C of 1.3 to 5.0, and a content ratio of SiO ₂ , Al ₂ O ₃ , and B ₂ O ₃ ( The total amount of Al ₂ O ₃ and B ₂ O ₃ is 0.1 to 20% by mass, the specific surface area is 0.5 to 5 m ² /g, and the average particle diameter is 1 to 60 μm. The cerium oxide powder according to claim 1, wherein the average sphericity is 0.80 or more. For example, the cerium oxide powder of the first application of the patent scope, wherein the amorphous ratio is 95% or more. An inorganic powder characterized by containing the cerium oxide powder according to any one of claims 1 to 3. The inorganic powder according to claim 4, wherein the inorganic powder is a cerium oxide powder and/or an alumina powder. A method for producing a cerium oxide powder according to any one of claims 1 to 3, characterized in that at least two burners are disposed in the furnace body at an angle of 2 to 10° with respect to the central axis of the furnace body. The raw material oxidizes the enamel powder by a burner toward the flame, and the aluminum source material and/or the boron source material are sprayed toward the flame by at least one burner. The method for producing a cerium oxide powder according to claim 6, wherein the aluminum source material is alumina powder, and the raw material cerium oxide powder has an Al ₂ O ₃ content of 1% by mass or less. The method for producing a cerium oxide powder according to claim 7, wherein the alumina powder has an average particle diameter of 0.01 to 10 μm. A resin composition characterized by containing the cerium oxide powder according to any one of claims 1 to 3, or the inorganic powder according to claim 4 or 5. The resin composition of claim 9, wherein the resin of the resin composition is an epoxy resin. A semiconductor encapsulating material using the resin composition of claim 9 or 10.