JP2003110065A - Spherical inorganic powder and use thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide spherical inorganic powder that can obtain a semiconductor sealing material having excellent flow behavior, filling properties, and forming properties even if a package form is a superthin type when a semiconductor chip is sealed by a resin composition, and to provide the resin composition. SOLUTION: In the spherical inorganic powder, a polymodal frequency grain size distribution for showing the maximum value is provided in a grain size region of at least 2 to 10 μm and 20 to 50 μm, an average grain size is 5 to 35 μm, the maximum grain size is 60 μm or less, and at the same time (d99/modal diameter) is 2.2 or less. Preferably, the ratio (SB/SC) of BET method ratio surface area SB to theoretical ratio surface area SC that is calculated by grain size distribution is 2.5 or less. Preferably, a particle that is less than 50 nm is not contained substantially. Preferably, the average sphericity of a particle having a particle diameter that is less than d75 is 0.90 or more, and that of a particle having a particle diameter that is at least d75 is 0.85 or more. In a resin composition, the spherical inorganic powder is filled.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a spherical inorganic powder and a resin composition filled with the same. Specifically, when a semiconductor chip is sealed with a resin composition, a spherical inorganic powder and a resin for obtaining a semiconductor sealing material having excellent fluidity, filling property and moldability even if the package form is ultrathin It relates to a composition.

[0002]

2. Description of the Related Art In recent years, in response to the trend toward smaller and lighter electronic devices and higher performance, the compounding of devices, the miniaturization, thinning and narrowing of pitch of semiconductor packages have been increasingly accelerated.
As for the mounting method, surface mounting, which is suitable for high-density mounting on a wiring board, is becoming mainstream. As semiconductor packages and their mounting methods have progressed in this way, semiconductor encapsulation materials are also required to have higher performance, in particular, improved functions such as solder heat resistance, moisture resistance, low thermal expansion, mechanical properties, and electrical insulation. ing. In order to meet these requirements, a semiconductor encapsulating material in which an epoxy resin is filled with an inorganic powder, particularly an amorphous silica powder as a filler is generally used, and nearly 90% of the semiconductor encapsulating material is obtained by this resin composition. Is. From the viewpoint of solder heat resistance, moisture resistance, low thermal expansion, and improvement of mechanical strength, it is desirable that the inorganic powder filled in this semiconductor encapsulation material is highly filled in the epoxy resin, and high performance of the semiconductor encapsulation material is achieved. From the above requirement, a resin composition having a high filling rate of the inorganic powder is being shifted.

Regarding the compounding of devices, which has been studied as a response to the demands for reduction in size and weight of electronic equipment and improvement in performance, a laminated package having a structure in which semiconductor chips are stacked back-to-back and having a thickness of 1 mm is used. TSOP
(Thin Small Outline Packa
ge) type and 2.5 mm thick SOJ (Sma
ll Outline J-leaded Packa
ge) type has been developed. As for the miniaturization and thinning of the package, an ultra-thin package thinner than the conventional TSOP, for example, 0.5 mm thick Paper Thin, to enable double-sided mounting and multi-stage mounting.
Package and the like have been proposed.

However, the resin thickness of the laminated package and the ultra-thin package is about 70 μm at the thin portion, which is considerably thinner than the ordinary TSOP of about 230 μm, and the conventional semiconductor encapsulating material is simply used. However, there is a problem that penetration molding (filling) cannot be performed well. In addition, when the package is attached to the wiring board, the entire package is heated to a high temperature of 200 ° C or higher and soldered. At that time, vaporization of moisture absorbed during storage causes cracks inside the package, which is terrible. Sometimes even reached outside.

In order to reduce the water absorption rate of the package and improve the solder heat resistance, it is effective to increase the filler filling rate in the semiconductor encapsulating material. In order to apply this technology to an ultra-thin package, it is necessary to adjust the filler particle size to a maximum of 60 μm or less. In this case, the particle size distribution is smaller than that of a conventional filler having a maximum particle size of 70 to 150 μm. Since it becomes narrower, there is a problem that the fluidity and moldability are lowered, and conversely, the filling rate of the filler is forced to be lowered.

As described above, it is difficult to manufacture an ultra-thin package with the conventional semiconductor encapsulating material, and new technical development is currently awaited. In the future, as the chip becomes larger and the package becomes smaller and thinner, it is desirable to achieve a filler filling rate of 85% or more, and even 90% or more from the viewpoint of solder heat resistance during soldering. However, with the restriction that the maximum particle size should be about 60 μm or less, fillers that do not impair the fluidity, filling property, and moldability of the semiconductor encapsulating material even when highly filled with filler have been reported. Absent.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a semiconductor having excellent fluidity, filling property and moldability when a semiconductor chip is sealed with a resin composition even if the package form is ultrathin. It is to provide a spherical inorganic powder and a resin composition for obtaining a sealing material.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above situation, and various effects of adjusting the maximum particle size of the filler to investigate the influence on the filling property and the fluidity of the resin. As a result, when the filler was highly filled into the resin, it was found that the filler composed of spherical inorganic powder having a specific particle size distribution corresponding to each maximum particle size exhibited high fluidity, and it was used. It was found that the semiconductor encapsulating material has significantly improved moldability in a highly filled region of 90% or more, and exhibits similar behavior regardless of the type and properties of the resin, and has completed the present invention.

That is, the present invention is as follows. (Claim 1) At least 2 to 10 µm and 20 to 5
It has a multimodal frequency particle size distribution showing a maximum value in the particle size range of 0 μm, an average particle size of 5 to 35 μm, a maximum particle size of 60 μm or less, and (d99 / modal diameter) of 2.2 or less. A spherical inorganic powder characterized by the above. (Claim 2) The ratio of the specific surface area S _B measured by the BET method and the theoretical specific surface area S _C calculated by the particle size distribution (S _B /
The spherical inorganic powder according to claim 1, wherein S _C ) is 2.5 or less. (Claim 3) The spherical inorganic powder according to claim 1 or 2, which does not substantially contain particles of less than 50 nm. (Claim 4) The average sphericity of particles having a particle size of less than d75 is 0.90 or more, and the average sphericity of particles having a particle size of d75 or more is 0.85 or more. 2. The spherical inorganic powder according to 2 or 3. (Claim 5) The spherical inorganic powder according to claim 1, 2, 3 or 4, wherein the spherical inorganic powder is amorphous silica. (Claim 6) A resin composition comprising the spherical inorganic powder according to any one of claims 1 to 5.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail below.

When the spherical inorganic powder of the present invention is used as a filler for a resin composition, particularly a semiconductor encapsulating material, it enables high filling, high fluidity and high moldability. That is, since the spherical inorganic powder of the present invention has its specific properties, the resin composition filled with the spherical inorganic powder has high maximum filling property and high fluidity while the maximum particle size cannot be achieved by conventional techniques. And high moldability can be satisfied.

The spherical inorganic powder of the present invention comprises at least 2
It has a multi-modal frequency particle size distribution showing maximum values in the particle size range of 10 to 10 μm and 20 to 50 μm, and an average particle size of 5 to 35 μm.
m, the maximum particle size is 60 μm or less, and (d99 / mode diameter) is 2.2 or less. Further, more preferably, the ratio of the specific surface area S _B measured by the BET method to the theoretical specific surface area S _C calculated by the particle size distribution (S _B /
It is necessary that S _C ) is 2.5 or less. The spherical inorganic powder designed in this way has never existed so far, and is a very important factor in terms of ensuring the fluidity and moldability at the time of high filling into the resin.

The particle component contained in the maximum value of 20 to 50 μm is a particle component which becomes a core when the resin is filled.
If it is less than μm, the fluidity and moldability are remarkably deteriorated. On the contrary, if it exceeds 50 μm, problems such as damage to a semiconductor chip during molding, wire cutting, and die gate blockage may occur. In particular, it is preferably in the region of 30 to 45 μm. On the other hand, the particle component contained in the maximum value of 2 to 10 μm can enter into the gap between the particle components having the maximum value of 20 to 50 μm, and the packed structure of the particles can be made dense, so that high packing can be achieved. It will be possible. In particular, it is 0.1 with respect to the average particle size of the core particle component.
If the average particle size is about 0.2 times, higher filling becomes possible, and among them, the average particle size is preferably 4 to 8 μm. By having these two maximum values at the same time, it is possible to achieve unprecedented high fluidity in the high filling region of the spherical inorganic powder.

More preferably, in the above-mentioned frequency particle size distribution, the maximum value is also set in the region of 0.2 to 1.5 μm. The particle component contained in the maximum value of 0.2 to 1.5 μm enters the gap of the particle filling structure composed of the particle component having the maximum value in 20 to 50 μm and the particle component having the maximum value in 2 to 10 μm. Since it is possible to make the packing structure of the particles more dense, the packing property is improved, and as a result, the fluidity can be significantly improved.

The average particle size of the spherical inorganic powder of the present invention must be 5 to 35 μm. If the average particle diameter deviates from this range, the balance of the above-mentioned particle packing structure is lost, and desired fluidity and packing property cannot be achieved.

What is important in the present invention is that the maximum particle size of the spherical inorganic powder is specified to be 60 μm or less.
99 / modal diameter) is 2.2 or less. If the maximum particle size exceeds 60 μm, filling defects (unfilled, void) and molding defects (chip damage, wire sweep, wire cutting, die shift, die gate clogging) are likely to occur during ultra-thin package molding, making it ultra-thin It becomes difficult to apply it to packaging. By setting (d99 / modal diameter) to 2.2 or less within the limitation of the maximum particle diameter of 60 μm or less, it becomes possible to minimize the deterioration of the fluidity of the semiconductor encapsulating material. Since the burr characteristics are also remarkably improved, high filling can be achieved without impairing the moldability.

Furthermore, the spherical inorganic powder of the present invention is not provided.
The conditions that must be met are the specific surface measured by the BET method.
Product S_BAnd theoretical specific surface area S calculated from the particle size distribution_CRatio with
(S _B/ S_C) Is 2.5 or less, preferably 2.0 or less
It means that This large ratio means that
It seems that it can not be detected with a particle size distribution measuring instrument such as
It means that it contains a large amount of fine ultrafine particles. like this
Ultrafine particles increase the resin composition when the spherical inorganic powder is highly filled.
It causes viscous properties and significantly impairs fluidity and moldability.

The particle size distribution of the spherical inorganic powder of the present invention is a value based on particle size measurement by a laser diffraction light scattering method,
As a particle size distribution measuring device, for example, "model LS-23
0 "(manufactured by Beckman Coulter, Inc.). At the time of measurement, water was used as a solvent, and as a pretreatment, a dispersion treatment was performed by applying an output of 200 W using a homogenizer for 1 minute. In addition, PIDS (Polar
ization intensity difference
ntial Scattering) concentration 45-55
% Was prepared. The refractive index of water is 1.3
3, the refractive index of the material of the powder was taken into consideration for the refractive index of the powder. For example, the refractive index of amorphous silica was measured at 1.50.

The mode diameter referred to in the present invention is the particle size showing the highest frequency value in the frequency particle size distribution of the spherical inorganic powder. Further, d99 is a cumulative value 99% particle diameter in the cumulative particle size distribution of the spherical inorganic powder.

The maximum particle size in the present invention is a particle size in which the ratio of the remaining amount on the sieve by the wet sieving method is 1% or less. For example, the wet sieving shaker "Octagon Model Digita" is used.
1 ”(manufactured by Seishin Enterprise Co., Ltd.). At the time of measurement, JIS standard sieve (for example, 75 μm,
53 μm, 45 μm, etc.), and spherical inorganic powder 1
After shaking 0 ± 0.02 g of the sample in a shower water amount of 9.5 liters / min for 5 minutes, the sieve residue was transferred to an aluminum container and dried at 120 ° C. Calculate the ratio of

The specific surface area S _B is a value based on the BET method.
"SORB U2" (manufactured by Yuasa Ionics) can be used for measurement. The theoretical specific surface area S _C can be automatically calculated by the above particle size distribution measuring device. The principle of this measuring machine is based on the formula: S _C = 6 / (ρ · SD). In the formula, SD is the area average particle diameter (μm), and ρ is the density of the spherical inorganic powder. For example, if the powder is amorphous silica, it is 2.21.

SD is an equation, SD = Σ (ni · ai
・ Di) / Σ (ni · ai). this is,
In a group of one powder, d from the smallest particle size
There are n1, n2, ... Ni, ... nk particles each having a particle size of 1, d2, ... Di, .. .dk, and the surface area per particle is a1, a.
2, ... ai, ... ak, SD is SD =
(N1 ・ a1 ・ d1 + n2 ・ a2 ・ d2 + ... + ni
・ Ai ・ di + ・ ・ ・ + nk ・ ak ・ dk) / (n1 ・
a1 ・ + n2 ・ a2 + ・ ・ ・ + ni ・ ai + ・ ・ ・ + n
k · ak).

The spherical inorganic powder of the present invention preferably contains substantially no particles of less than 50 nm. As described above, the ultrafine particles increase the viscosity of the resin composition when the spherical inorganic powder is highly filled, and significantly impair the fluidity and moldability. Particularly, particles having a size of less than 50 nm have a remarkable tendency, and in the spherical inorganic powder of the present invention,
It is preferable that substantially no such ultrafine particles are contained.

Here, substantially not containing particles of less than 50 nm means that the magnification is 50,000 by an electron microscope.
This means that the number of particles having a size of less than 50 nm in 100 photographs taken at double magnification is counted, and the value converted as an average value per photograph is less than 50. The number of particles of less than 50 nm is preferably smaller, but when the average number of particles is 50 or more, the effect of the present invention is not abruptly lost. Value.

An electron micrograph is taken by a field emission scanning electron microscope such as "FE-SEM, Model JSM-6".
"301F" (made by JEOL Ltd.), acceleration voltage 15k
It is performed under the conditions of V and irradiation current of 3 × 10 ⁻¹¹ A. As a pretreatment for photographing, a vacuum vapor deposition device such as "Model JEE-4" is used.
X ”(manufactured by JEOL Ltd.) is deposited on the spherical inorganic powder for 2 seconds, and then gold-palladium is further deposited for 60 seconds.

“Spherical” in the spherical inorganic powder of the present invention
The average sphericity of particles having a cumulative particle size distribution of less than 75% (d75) is 0.90 or more, d75
It is preferable that the particles having the above particle diameter have an average sphericity of 0.85 or more. Generally, if the average sphericity of the spherical inorganic powder is increased, the fluidity tends to be improved.
The average sphericity of coarse particles with a particle size of 75 or more is 0.8
By setting it to 5 or more, the effect of the present invention can be further enhanced.

The average sphericity is measured by a stereomicroscope (for example, "SM
Z-10 type "manufactured by Nikon Co., Ltd.) or a particle image photographed by a scanning electron microscope or the like can be taken into an image analyzer (for example, manufactured by Japan Avionics Co., Ltd.) and measured as follows. That is, the projected area (A) and perimeter (PM) of the particles are measured from the photograph. When the area of a perfect circle corresponding to the perimeter (PM) is (B), the roundness of the particle can be displayed as A / B. Therefore, assuming a perfect circle with the same perimeter as the perimeter (PM) of the sample particles, P
Since M = 2πr and B = πr ² , B = π × (PM /
2π) ² , and the sphericity of each particle is sphericity = A /
It can be calculated as B = A × 4π / (PM) ² . The roundness of 200 particles thus obtained was determined and the average value was used as the average sphericity.

A circularity measuring method other than the above is a particle image analyzer (for example, "FPIA-1000").
It can also be obtained by converting from the circularity of individual particles quantitatively automatically measured by Sysmex Co., Ltd.) by the formula, circularity = (circularity) ² .

The material of the spherical inorganic powder of the present invention is an inorganic powder such as silica, alumina, titania, magnesia, and calcia, and these powders may be used alone or as a mixture of two or more kinds. In particular, the point of bringing the thermal expansion coefficient of the semiconductor chip and the semiconductor encapsulation material close to each other,
From the viewpoint of solder heat resistance, moisture resistance, and low wear of the mold, amorphous silica produced by a method of melting crystalline silica at a high temperature or a synthetic method is most suitable. In addition, the amorphous rate is measured by a powder X-ray diffractometer (for example, “Mini F
Lex ”manufactured by RIGAKU), and 2K of CuKα ray
Can be measured from the intensity ratio of specific diffraction peaks by performing X-ray diffraction analysis of the sample in the range of 26 ° to 27.5 °. That is, crystalline silica has a main peak at 26.7 °, but amorphous silica has no peak.
When amorphous silica and crystalline silica are mixed, a peak height of 26.7 ° can be obtained according to their ratio, so the X-ray intensity of the sample relative to the X-ray intensity of the crystalline silica standard sample can be obtained.
The crystalline silica mixture ratio (X-ray diffraction intensity of sample / X-ray diffraction intensity of crystalline silica) was calculated from the ratio of the line intensities, and the formula, amorphous rate (%) = (1-crystalline silica mixture ratio ) × 100,
The amorphous rate can be obtained from

Next, the resin composition of the present invention will be described. The resin composition of the present invention contains 10 to 99% of the spherical inorganic powder of the present invention.

The resins used in the present invention include epoxy resins, silicone resins, phenol resins, melamine resins, urea resins, unsaturated polyesters, fluororesins, polyimides, polyamideimides, polyamides such as polyetherimides, and polybutylene terephthalate. , Polyester such as polyethylene terephthalate, polyphenylene sulfide, wholly aromatic polyester, polysulfone, liquid crystal polymer, polyether sulfone, polycarbonate,
Examples thereof include maleimide modified resin, ABS resin, AAS (acrylonitrile-acrylic rubber / styrene) resin, AES (acrylonitrile / ethylene / propylene / diene rubber / styrene) resin.

Among these, the semiconductor sealing material is 1
Epoxy resins having two or more epoxy groups in the molecule are preferred. Specific examples thereof include phenol novolac type epoxy resins, orthocresol novolac type epoxy resins, epoxidized novolac resins of phenols and aldehydes, glycidyl ethers such as bisphenol A, bisphenol F and bisphenol S, phthalic acid and Glycidyl ester acid epoxy resin obtained by reaction of polybasic acid such as dimer acid and epochlorohydrin, linear aliphatic epoxy resin, alicyclic epoxy resin, heterocyclic epoxy resin, alkyl-modified polyfunctional epoxy resin, β-naphthol novolak type Eoxy resin, 1,6-dihydroxynaphthalene type epoxy resin,
Examples thereof include 2,7-dihydroxynaphthalene type epoxy resin, bishydroxybiphenyl type epoxy resin, and epoxy resin into which halogen such as bromine is introduced for imparting flame retardancy. Among them, from the viewpoint of moisture resistance and solder reflow resistance, orthocresol novolac type epoxy resin, bishydroxybiphenyl type epoxy resin, naphthalene skeleton epoxy resin and the like are preferable.

The curing agent for the epoxy resin is not particularly limited as long as it cures by reacting with the epoxy resin, and examples thereof include phenol, cresol, xylenol,
A novolak type obtained by reacting one or a mixture of two or more selected from the group of resorcinol, chlorophenol, t-butylphenol, nonylphenol, isopropylphenol, octylphenol, etc. with formaldehyde, paraformaldehyde or paraxylene under an oxidation catalyst. Resins, polyparahydroxystyrene resins, bisphenol compounds such as bisphenol A and bisphenol S, trifunctional phenols such as pyrogallol and phloroglucinol, maleic anhydride, acid anhydrides such as phthalic anhydride and pyromellitic anhydride, and metaphenylene Aromatic amines such as diamine, diaminodiphenylmethane and diaminodiphenyl sulfone can be exemplified.

The resin composition of the present invention may contain the following components if necessary. That is, as a stress reducing agent, silicone rubber, polysulfide rubber, acrylic rubber, butadiene rubber, rubber-like substances such as styrene block copolymers and saturated elastomers, various thermoplastic resins, silicone resins, etc. Γ-glycidoxy as a silane coupling agent, such as a resinous substance, a resin obtained by modifying a part or all of an epoxy resin, a phenolic resin with an aminosilicone, an epoxysilicone, an alkoxysilicone, or the like. Propyltrimethoxysilane, β
-Epoxysilanes such as (3,4-epoxycyclohexyl) ethyltrimethoxysilane, aminopropyltriethoxysilane, ureidopropyltriethoxysilane,
Zr chelate, titanium cup as a surface treatment agent such as aminosilane such as N-phenylaminopropyltrimethoxysilane, hydrophobic silane compound such as phenyltrimethoxysilane, methyltrimethoxysilane, octadecyltrimethoxysilane and mercaptosilane. Ring agent,
As flame retardant aids such as aluminum-based coupling agents,
Sb ₂ O ₃ , Sb ₂ O ₄ , Sb ₂ O _{5 and the} like are flame retardants, halogenated epoxy resins and phosphorus compounds, and coloring agents such as carbon black, iron oxide, dyes and pigments. Further, a release agent such as wax can be added. Specific examples thereof include natural waxes, synthetic waxes, metal salts of straight chain fatty acids, acid amides, esters and paraffins.

In particular, when high humidity resistance reliability and high temperature storage stability are required, addition of various ion trapping agents is effective. Specific examples of the ion trap agent include trade names “DHF-4A” and “KW-200” manufactured by Kyowa Chemical Co., Ltd.
0 "," KW-2100 ", trade name" IXE-600 "manufactured by Toagosei Chemical Industry Co., Ltd., and the like.

A curing accelerator can be added to the resin composition of the present invention in order to accelerate the reaction between the epoxy resin and the curing agent. Examples of the curing accelerator include 1,8-diazabicyclo (5,4,0) undecene-7, triphenylphosphine, benzyldimethylamine, and 2-methylimidazole.

The resin composition of the present invention is prepared by blending a predetermined amount of each of the above materials with a blender or a Henschel mixer, then kneading with a heating roll, kneader, uniaxial or biaxial extruder, etc. It can be manufactured by

In order to seal a semiconductor using the resin composition of the present invention, known molding methods such as transfer molding and multi-plunger are adopted.

[0039]

EXAMPLES The present invention will be described in more detail below with reference to examples and comparative examples.

Examples 1 to 7 Comparative Examples 1 to 9 Natural silica stone was crushed, and the crushed material was fed into a high temperature flame formed by the combustion of LPG and oxygen, and subjected to melting and spheroidizing treatment to obtain a non-spherical shape. A crystalline silica powder was obtained. 16 kinds of powders A to P shown in Tables 1 and 2 were produced by adjusting flame forming conditions, raw material particle size, raw material supply amount, classification conditions and the like. Specifically, the particle size distribution is adjusted by adjusting the raw material particle size and the multi-step sieving operation of the powder after spheroidization, and the specific surface area is adjusted by adding ultrafine powders having various particle diameters and specific surface areas. Went by. The sphericity was controlled by adjusting the flame forming conditions and the raw material supply amount. The amorphous rate of each of these spherical silica powders was 99% or more. Measure the particle size distribution of powder A to P
The maximum values in the m region and the 20 to 50 μm region are shown as P1 and P2, respectively. Further, the ratio (S _B / S _C ) of the specific surface area S _B measured by the BET method and the theoretical specific surface area S _C calculated by the particle size distribution was determined.

In order to evaluate the characteristics of the spherical amorphous silica powders A to P as the filler of the semiconductor encapsulating material, 90% of the spherical amorphous silica powder (mass%, the same applies hereinafter) was used.
4'-bis (2,3-epoxypropoxy) -3,
3 ', 5,5'-Tetramethylbiphenyl type epoxy resin 4.2%, phenol resin 4.3%, triphenylphosphine 0.2%, γ-glycidoxypropyltrimethoxysilane 0.5%, carbon black After 0.3% and carnauba wax 0.5% were added and dry blended with a Henschel mixer, the resulting blend was intermeshed in a twin-screw extrusion kneader (screw diameter D = 25 mm, kneading disc length 10 Dmm, Paddle speed 100 rp
m, discharge rate 5 kg / h, heater temperature 105-110
The mixture was heated and kneaded. The discharged material was cooled by a cooling press machine and then pulverized to obtain an epoxy resin composition, which was used as a semiconductor sealing material. The fluidity and moldability were evaluated according to the following. The results are shown in Table 1 (Examples) and Table 2 (Comparative Examples).

Fluidity Test (Evaluation of Spiral Flow) EMMI-I-66 (Epoxy Molding M)
aerial Institute; Society
The spiral flow value of the above-mentioned epoxy resin composition was measured using a transfer molding machine equipped with a mold for spiral flow measurement based on of Plastic Industry). Transfer molding conditions are
Mold temperature 175 ° C, molding pressure 7.4 MPa, holding time 9
It was set to 0 seconds.

Burr characteristic test (burr evaluation) Molding was carried out using a mold for burr evaluation having slits of 2 μm, 5 μm, 10 μm and 30 μm, and the length of the burr was measured. The transfer molding conditions were a mold temperature of 175 ° C., a molding pressure of 7.4 MPa, and a holding time of 90 seconds.

Moldability Test (Evaluation of Appearance, Evaluation of Number of Voids) Using a mold having a resin thickness of 70 μm above and below the chip, a transfer molding machine was used to produce 18 48-pin TSOPs with simulated elements sealed, It was visually inspected whether there was any appearance defect such as unfilled. In addition, if the package has a good visual inspection, 0.1% remains in the package.
The number of voids of mm or more was counted using an ultrasonic flaw detector, and the number of voids per package was calculated. In addition,
The transfer molding conditions were a mold temperature of 175 ° C., a molding pressure of 7.4 MPa and a holding pressure of 120 seconds.
Post cure was carried out at 5 ° C. for 5 hours.

[0045]

[Table 1]

[0046]

[Table 2]

As is clear from Tables 1 and 2, the semiconductor encapsulating material of the present invention, which is filled with the spherical inorganic powder, is used in the ultra-thin package in which the maximum particle size of the spherical inorganic powder is restricted. It can be seen that the fluidity and moldability are at a high level even when the filling rate is 90%.

[0048]

According to the present invention, when a semiconductor chip is encapsulated with a resin composition, a semiconductor encapsulating material excellent in fluidity, filling property and moldability is obtained even if the package form is ultrathin. Provided are spherical inorganic powders and resin compositions that can be obtained.

Continued front page    (72) Inventor Hideaki Nagasaka             1 Shinkaimachi, Omuta City, Fukuoka Prefecture             Ceremony company Omuta factory F term (reference) 4J002 BD121 BH001 BN071 BN121                       BN151 CC031 CC161 CC181                       CD001 CF001 CF211 CG001                       CL001 CM041 CN011 CN031                       CP031 DJ016 FA086 FD016                       GJ00 GQ01 GQ05                 4M109 AA01 CA21 EA02 EB12 EC20

Claims (6)

[Claims] 1. At least 2 to 10 μm and 20 to 5
It has a multimodal frequency particle size distribution showing a maximum value in the particle size range of 0 μm, an average particle size of 5 to 35 μm, a maximum particle size of 60 μm or less, and (d99 / modal diameter) of 2.2 or less. A spherical inorganic powder characterized by the above. 2. The ratio (S _B / S _{B of} the specific surface area S _B measured by the BET method and the theoretical specific surface area S _C calculated by the particle size distribution).
The spherical inorganic powder according to claim 1, wherein S _C ) is 2.5 or less. 3. The spherical inorganic powder according to claim 1, which is substantially free of particles of less than 50 nm. 4. The average sphericity of particles having a particle size of less than d75 is 0.90 or more, and the average sphericity of particles having a particle size of d75 or more is 0.85 or more. 2. The spherical inorganic powder according to 2 or 3. 5. The spherical inorganic powder according to claim 1, 2, 3 or 4, wherein the spherical inorganic powder is amorphous silica. 6. A resin composition comprising the spherical inorganic powder according to any one of claims 1 to 5.