JPH048740A - Filler for resin - Google Patents

Abstract

PURPOSE:To provide a filler capable of giving resin compositions markedly improved in spiral flow and burr characteristics and heat releasability, containing each specific nitride powder and/or oxynitride powder. CONSTITUTION:The objective inorganic filler containing (A) nitride and/or oxynitride powder with the particle size distribution expressed as follows: (1) <=1mu= 5-10wt.%; (2) <=2mu=6-12wt.%; (3) <=3mu =10-16wt.%; (4) <=8mu=35-47wt.%; (5) <=24mu=51-63wt.%; <=48mu=67-75wt.%; <=96mu=88-92wt.%; (6) mean size =9-22mum; (7) (RRS-n value) <=0.80. Said (oxy)nitride is prepared by e.g. directly nitriding a metal such as metallic silicon or metallic aluminum, (reductive) nitriding said metal, oxynitride, nitride and/or oxide, and its purity being >=70 (esp. >=90)%.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to fillers for resins, specifically capacitors 5 to 10.
% 6-12% 10-16% 35-47% 51-63% 67-75% 88-92% 9-22 μm ≦0.80, sealing material for electronic components such as connectors, resistors, semiconductors, etc.
This invention relates to resin fillers useful for insulation pastes, heat dissipation sheets, etc.

[Prior art] Resin encapsulants made of fillers such as fused silica and chemical silica, and epoxy resins and polyphenylene resins have significantly improved reliability and are excellent in moldability and mass production. Approximately 90% is used as a resin sealant.

However, in recent years, in the electrical and electronic equipment industry,
In order to promote miniaturization and weight reduction, electrical and electronic components are required to be highly integrated, and sealing materials, insulating pastes, heat dissipation sheets, etc. for electrical and electronic components need to further improve their heat dissipation properties. It has become.

Therefore, nitride powders such as silicon nitride and aluminum nitride have been proposed as fillers with superior heat dissipation properties compared to fused silica and silica oxide (Japanese Unexamined Patent Publication No. 60-4522, No. 61-101522). , No. 62-43415).

Resin compositions using these nitride powders as fillers certainly have improved heat dissipation, but when transferred or injection molded, compared to conventional fused silica or raw silica fillers. However, there were disadvantages in that the spiral flow was significantly reduced, causing mold wear, and the heat dissipation properties of these nitride powders could not be fully utilized because high filling was not possible.

[Problem to be solved by the invention]

In order to improve the above-mentioned drawbacks, the present inventors have conducted a detailed study on the effect that the particle size of nitride powder and/or oxynitride powder has on flow characteristics, and as a result, the inventors have found that nitride powder and/or oxynitride powder having a certain particle size distribution and The present invention has been completed based on the discovery that flow characteristics are specifically improved when oxynitride powder is used as a filler.

[Means to solve the problem]

That is, the present invention is a filler for resin characterized by being made of an inorganic powder containing a nitride powder and/or an oxynitride powder having the following particle size characteristics.

(particle size distribution) 1μ 5-10% 2μ　　　　6～12% 3μ　　　　10~16% 8μ 35-47% 24μ 51~63% 48μ 67-75% -96μ　　　88~92% (Average particle size) 9 to 22 μm (RR5-n value) ≦0.80 The present invention will be explained in more detail below.

Examples of nitrides and oxynitrides in the present invention include nitrides such as silicon nitride and aluminum nitride, and oxynitrides such as silicon oxynitride, aluminum oxynitride, and sialon. When it is desired to impart higher thermal conductivity to the resin composition, aluminum nitride, silicon nitride, and sialon are selected, and when it is desired to impart higher thermal shock resistance, silicon oxynitride and aluminum oxynitride are selected. Note that silicon nitride and Sialon have two types of crystal forms, α type and β type, and either type may be used, and of course, a mixture of the two types may be used. Furthermore, in the case of oxynitrides of silicon oxynitride and aluminum oxynitride, not only crystalline substances but also amorphous substances may coexist.

The nitride powder and oxynitride powder according to the present invention can be produced by (1) directly nitriding metals such as metal silicon, metal aluminum, and silicon-aluminum alloys, (2) oxidizing metals such as silica, alumina, kaolin, and mullite. (3) Method of (reducing) nitriding the aforementioned metal and oxynitride, nitride and/or metal oxide, (4) (Reducing) nitriding metal oxide and nitride. Method, (5) Direct vapor phase synthesis from metal halides such as silicon tetrachloride and aluminum chloride and/or organometallic compounds such as methyl silicate and triethoxyaluminum and ammonia or via metal imide or metal amide. It can be obtained by a method etc.

Among the above production methods, methods (1) and (3) are preferable in that they are easy to adjust the particle size and specific surface area and can further improve the heat dissipation, thermal shock resistance, and moldability of the resin composition.
The method (5) is preferable in that it is easy to obtain a linearized filler. In addition, when obtaining nitrides and/or oxynitrides by the methods (1) to (5) above, if necessary, oxides, carbonates, and At least one selected from oxalates and the like may be blended.

The purity of the nitride powder and/or oxynitride powder that is the filler of the present invention is 70% or more, preferably 80% or more, particularly preferably 90% or more. If the purity is less than 90%, at least one of electrical insulation, thermal conductivity, and thermal shock resistance of the resulting resin composition will be impaired.

When the filler of the present invention is obtained by the method (1) or (3) described above, in order to ensure good electrical insulation and thermal shock resistance, the residual rate of unreacted metal must be 1% or less, preferably 0. ．．
It is important to determine the nitriding conditions so that the content is 5% or less, particularly preferably 0.3% or less.

The purity of the filler of the present invention is represented by the ratio of the peak of the filler of the present invention to the sum of the peak heights of various impurity crystalline powders and the filler of the present invention at predetermined positions obtained from an X-ray diffraction chart. shall be allowed to do so.

In the case of silicon oxynitride and aluminum oxynitride, not only crystalline products but also amorphous products may exist, but broad peaks due to amorphous products should be excluded from purity calculations. do.

The residual rate of unreacted metal in the present invention is the peak of the metal powder of the unreacted metal relative to the phase of the peak height of the metal powder and the nitride powder and/or oxynitride powder at a predetermined position obtained from the X-ray diffraction chart. shall be represented by the ratio of The specific peaks are as follows.

(210) plane of the filler α-sialon of the present invention
(101) face of β-Sialon
Silicon oxynitride (110)
(440) plane of aluminum oxynitride (440) plane of α-silicon nitride (
210) plane (101) plane of β-silicon nitride (101) plane impurity of aluminum nitride
(101) plane of cristobalite α-quartz (101) plane α-alumina (113 plane) Mullite (120 plane metal silicon (111 plane) Metal aluminum (111 plane) β-5iC (111 plane of the present invention Ionic impurities contained in the filler include F
e"5000 ppm or less, Na"1100 ppm or less, cp50 ppm or less, preferably Fe"10
00 ppm or less, Na-30 ppm or less, C1-20
ppm or less, particularly preferably Fe"100 ppm or less, Na"10 ppm or less, C/! -10 ppm or less. Especially when Na” exceeds 1100pp and Cf- is 5
If it exceeds 0 ppm, moisture resistance will be poor.

The filler of the present invention has a particle size distribution, average particle diameter, and
It is necessary to have an RRS-n value, preferably,
As shown in the same table.

When the particle size distribution and average particle size exceed the range of the present invention shown in Table 1 and become fine particles, the fine particle content becomes too thick and the resin viscosity increases, resulting in a decrease in flow and insufficient kneading. This makes it impossible to suppress the occurrence of firmness. On the other hand, if the particle size distribution and average particle size exceed the range of the present invention shown in Table 1 and become coarse particle size, or even if the particle size distribution and average particle size
Even within the scope of the present invention, the RRS-n value is 0.80.
When it exceeds , dilatancy becomes stronger and the flow decreases.

Table 1 The particle size of the filler of the present invention is measured by a laser diffraction method, but particle size measurement using other measurement principles, such as light transmission natural sedimentation, centrifugal sedimentation, electron microscopy, gasket invactor method, coulter method, etc. It goes without saying that there is no problem in using particle size measurement using a counter method or the like, as long as it is corrected with the laser diffraction method. Please note that currently commercially available laser diffraction particle size measuring needles use different wavelengths,
Particles smaller than 0.1 μm cannot be detected. therefore,
The content of particles of 0.1 μm or less in the filler of the present invention may be any amount, but if the content of particles of 0.16 m or less is too large, the filler will become very bulky, resulting in poor workability and easy generation of dust. Since drawbacks may occur in some cases, if this becomes a problem, the content of particles of 0.1 μm or less may be limited.

The RRS-n value refers to one point where the cumulative weight% from the maximum particle size on the RRS particle size diagram is 10 to 30% by weight and 70 to 90% by weight.
Ros inRam is represented by a straight line connecting one point of
It refers to the n value in the mler formula. In addition, in actual particle size measurement, if two or more straight lines can be drawn connecting one point in the range of 10 to 30 weight % and one point in the range of 70 to 90 weight % of the cumulative weight % from the maximum particle size, , are represented by the minimum gradient among these straight lines.

Here, the RR3 particle size diagram is Rosin-Rammle
This is a particle size diagram showing the particle size distribution of r according to the following equation.

R (Dp) = 100 exp (-b Dp") (wherein R (Dp) is the cumulative weight % from the maximum particle size to the particle size Dp, Dp is the particle size, and b and n are constants) The particle size of the filler of the invention can be adjusted only by controlling the crushing conditions, but if necessary, dry classification using a gravity settling type, centrifugal type, or inertial force type such as an air sieve or cyclone, a water sieve, Fine particles can also be removed by sedimentation classification, wet classification using a liquid cyclone, decanter, etc., or sieving.

10 times the weight or less, preferably 3 times the weight or less, particularly preferably 1 times the weight or less (all including 0) of the total weight of the nitride powder and/or oxynitride powder of the present invention, and the shape is crushed; Other fillers such as spherical, whisker-like, fibrous or scale-like fused silica, raw silica, silica titania glass, cristobalitized silica, aluminum silicate, alumina, titanium nitride, boron nitride, etc. may be used in combination. If it exceeds 10 times the weight, at least one of the characteristics of heat dissipation, thermal shock resistance, and moisture resistance reliability will be impaired. In addition, when using fillers other than nitride powder and/or oxynitride powder,
It is important to use fillers appropriately depending on the required properties of the sealant. In other words, if thermal shock resistance and moisture resistance reliability are important, choose fused silica or silica titania glass, and if thermal conductivity is important, choose titanium nitride, boron nitride, or alumina. Raw silica, cristobalitized silica, aluminum silicate, etc. are selected for thermal conductivity and cost reduction.

The smaller the maximum particle size of the filler of the present invention, the less likely it is to damage or damage wiring, passivation films, bonding wires, etc. on the element surface during molding, but it is less likely to cause gate clogging during transfer molding. The maximum particle size considered is 500 μm or less, preferably 149
It is preferably 74 μm or less, particularly preferably 74 μm or less.

The content of the filler of the present invention in the resin composition is 20 to 97
% by weight, preferably 30-95% by weight, particularly preferably 40% by weight
~90% by weight. When the content of the filler is less than 20% by weight, the moldability of the resin composition is excellent, but thermal stress is large and heat shock resistance and moisture resistance reliability are reduced. On the other hand, if it exceeds 97% by weight, the moldability of the resin composition will be impaired, unfilled areas and voids will occur frequently, and electrical insulation and reliability will be impaired.

Resins for which the filler of the present invention can be used include bisphenol-type epoxy resins, phenol novolak-type epoxy resins, alicyclic-type epoxy resins, heterocyclic-type epoxy resins, glycidyl ester-type epoxy resins, glycidylamine-type epoxy resins, and halogenated epoxy resins. Epoxy resins such as epoxy resins, polybenzimidazole, polybenzoxazole, polybenzthiazole, polyoxadiazole, polypyrazole, polyquinoxaline, polyquinazolinedione, polybenzoxazinone, polyindolone, polyquinazolone, polyindoxyl, silicone resin, Silicone-epoxy resin, phenolic resin, melamine resin, urea resin, unsaturated polyester, polyamino bismaleimide, diallyl phthalate resin, fluororesin, TPχ resin (methylpentene polymer (trade name manufactured by Mitsui Petrochemicals)), polyimide, polyamideimide , polyetherimide, polyamides such as 6-row nylon and MXD-nylon, amorphous nylon, polyesters such as polybutylene terephthalate and polyethylene terephthalate,
Polyphenylene sulfide, modified polyphenylene ether, polyarylate, fully aromatic polyester, polysulfone, liquid crystal polymer, polyether ether ketone, polyether sulfone, polycarbonate, maleimide modified resin, ABS resin, 8AS (acrylonitrile/acrylic rubber/styrene) resin, Examples include AES (acrylonitrile-ethylene-propylene-diene rubber-styrene) resin, but for sealing materials, electrical insulation pastes, etc., epoxy resins, silicone epoxy resins, and adhesives that adhere to metals at higher temperatures are usually used. In order to maintain strength and bending strength, kerimide (trade name manufactured by Mitsubishi Gas Chemical Co., Ltd.), BT
Polyamino bismaleimide resins such as resin (trade name manufactured by Mitsubishi Gas Chemical Co., Ltd.), sealing resins that can reuse gates and runners include polyphenylene sulfide, alloys of polyphenylene sulfide, liquid crystal polymers, and/or epoxy group-containing polymers. etc. are preferred.

The resin composition using the filler of the present invention may contain a rubber component such as butyl rubber, acrylic rubber, ethylene propylene rubber, silicone rubber, polyester elastomer, or polybutadiene in order to improve thermal shock resistance. You can also do it. Furthermore, as necessary, benzoguanamine, 2゜4-dihydrazine-6-methylamino-S-)riazine, 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2ethyl-4-methylimidazole imidazole derivatives such as, various amine complexes of boron fluoride, trisdimethylaminomethylphenol, 1,8-diaza bicyclo(5,4
, O)-Undecene-7° tertiary amine compounds such as benzyl dimethylamine, dicyandiamide, amino alcohol compounds obtained by the reaction of bisphenol type epoxy resins or talezol novolac type epoxy resins with ammonia, and adipic acid hydrazide. Nitrogen curing (accelerator) agents, phenolic curing agents such as phenol novolak and cresol novolak, acid anhydride curing agents such as tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, triphenylphosphine , tricyclohexylphosphine, methyldiphenylphosphine, tritolylphosphine, 1,2-bis(
organic phosphine curing (accelerator) agents such as diphenylphosphino)ethane and bis(diphenylphosphino)methane;
Curing catalysts such as bis-(tributyltin) oxide, silver dioctate, antimony octoate, silver butyrate, lead oxide, lead sulfide, lead carbonate, polymerization catalysts such as platinum compounds, vulcanization of benzoyl peroxide, dicumyl peroxide, etc. agent, carnauba wax, centana wax, polyester oligomer, silicone oil, low molecular weight polyethylene, paraffin, metal salts of straight chain fatty acids, acid amides, esters, etc.
Mold release agent, 2,6-di-t-butyl-4-methylphenol, 1,3.5-)lis(2-methyl-4-hydroxy-5-t-butylphenol)butane, distearylthiodipropionate, Stabilizers such as trinonylphenyl phosphite and tridecyl phosphite, 2,2'-dihydroxy-4=methoxybenzophenone, 2(2'-hydroxy-5-methylphenyl)benzotriazole,
4-t-7” tylphenyl salicylate, ethyl-2-
Light stabilizers such as cyano-3,3-diphenylacrylate, colorants such as red iron, carbon black, antimony trioxide, antimony tetroxide, triphenylstibine, hydrated alumina, ferrocene, phosphazene, hexabromobenzene, tetrabromophthal. Acid anhydrides, tricresyl phosphate, flame retardants such as tetrabromobisphenol A1 brominated epoxy derivatives, vinyltrimethoxysilane, T-glycidoxypropyltrimethoxysilane, T-
ureidopropyltriethoxysilane, N-β-(aminoethyl)-T-aminopropyltrimethoxysilane,
Silane coupling agents such as β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, isopropyltriine stearoyl titanate, dicumylphenyloxyacetate titanate, bis(dioctylpyrophosphate)oxyacetate nathanate, isopropyltridecylbenzene A titanium-based coupling agent such as sulfonyl titanate, an aluminum-based coupling agent such as acetalkoxyaluminum diisopropylate, etc. can be blended.

The resin composition containing the filler of the present invention can be prepared by thoroughly mixing predetermined amounts of each of the above-mentioned components using a Henschel mixer or the like.
Roll, Banbury mixer, kneader 1 leveler,
It can be produced by heating and kneading using a known mixing means such as an Ajihomo mixer, a twin-screw extruder, and a single-screw extruder.

C Example] The present invention will be specifically explained below with reference to Examples, but the present invention is not limited to these Examples. In Examples and Comparative Examples, "parts" and "%" mean "parts by weight" and "% by weight."

β- conversion, powder production of metal Si powder (maximum particle size 149μm, average particle size 10u+
n, purity 99.9%), 70 parts of lamp black, 30 parts of Aerosil 0X-50 (manufactured by Nippon Aerosil Co., Ltd.), and 13 parts of a 5% aqueous solution of ammonium salt of carboxymethylcellulose were mixed in a blender for 20 minutes, and then gold was mixed. After mold press molding, drying, and degreasing, 250″C/hr in a nitrogen stream
The temperature was raised to 1450°C at a heating rate of
Powders A1~ as shown in Table 2 are obtained by removing coarse particles and classifying them using a sieve screen of
I got 3. As a result of X-ray diffraction of these powders, metallic Si
0.08%, silicon oxynitride 0.6%, α
- 14.3% silicon nitride, and the remainder was β-silicon nitride.

Further, Powders A-1 to A-3 were classified using a Turbo Brush Fire (manufactured by Nisshin Engineering Co., Ltd.) air classifier with different classification points to obtain Powders A-4 to A-12.

Production of α-silicon nitride powder Metallic Si powder (maximum particle size 149 μm, average particle size 10 μm
, M degree 99.9%) and 10 parts of a 5% aqueous solution of ammonium salt of carboxymethylcellulose were mixed in a blender for 20 minutes, mold press-molded, dried, and degreased, then heated to 1000°C in a nitrogen stream for 20''. The temperature was raised at a rate of C/hr, the temperature was raised between 1000 and 1450°C at a rate of 10°C/hr, and the reaction was further carried out at 1450°C for 10 hours to obtain a reaction mass. After crushing this reaction mass, The powders A-13 and A-14 shown in Table 2 were obtained by finely pulverizing them in a ball mill for 6 hours and 2 hours, and removing coarse particles with a sieve screen with an opening of 141 μm.X
As a result of line diffraction, metallic Si 0.04%, α-silicon nitride 9
1.2%, and the remainder was β-silicon nitride.

Further, Powder A-13 was classified using a Turbo Brush Fire (manufactured by Nissin Engineering Co., Ltd.) air classifier with different classification points to obtain Powder A-15.

Production of crushed aluminum nitride powder Atomized aluminum powder (maximum particle size 200 am
, purity 99.99%) in a graphite tray with a thickness of 3 cm.
After reacting for 3 hours at 650°C and 2 hours at 750°C in a nitrogen atmosphere of 0.3 atm, the temperature was further raised to 1000°C at a rate of 30°C/hr. At that temperature, the reaction was carried out in a nitrogen atmosphere of 1 atm for 5 hours to obtain a reaction mass. After removing coarse particles, this was classified into powder A-16 in the same manner as in the production of α-silicon nitride powder.
I got it. As a result of X-ray diffraction, unreacted aluminum 0.13
% aluminum nitride.

- Production of Sialon Metallic Si powder (maximum particle size 149μ, average particle size 10un)
, purity 99.9%) 42 parts, fused silica powder (maximum particle size 44 μm steel, average particle size 5 μm, purity 99.9%) 29 parts,
Metal Si powder (maximum particle size 44μm, average particle size 1oμm mist,
47 parts (purity 99.9%) and 68 parts α-alumina were blended.

After mixing this in a Type B blender for 20 minutes, 8% of a 10% aqueous solution of ammonium salt of carboxymethylcellulose was added by external grinding, kneaded in a roll mill, and then shaped. A nitrided sintered body was produced by heating for 15 hours, and after being crushed for 6 hours, it was classified.
Powder A-17 was obtained. As a result of X-ray diffraction, metal 510.0
6%, metallic aluminum 0.11%, α-alumina 2.
5%, and the remainder was β-sialon.

Production of silicon oxynitride crystals Metallic Si powder (
Maximum particle size 74μm, average particle size 12μm, purity 99.9%
) and 40 parts of raw silica powder (maximum particle size 44 μm, average particle size 10 μm, purity 99.9%) were mixed in a ■ type blender for 20 minutes, and then mixed with a 10% aqueous solution of ammonium salt of carboxymethyl cellulose. 8% was added and kneaded using a roll mill. This was molded by press molding, dried, and then heated at 1450 to 1500''C for 5 hours in a nitrogen gas atmosphere to produce a nitride.

This nitride was firstly crushed with a crusher, then finely pulverized with a ball mill, coarse particles were removed with a 149μ sieve, and the powder A-18 was obtained by classification and particle size adjustment. As a result of X-ray diffraction, metal Si
0.11%, β-silicon nitride 2.2%, α-silicon nitride 1
．． 3%, and the remainder was silicon oxynitride.

Production of epoxy resin composition Cresol novolak epoxy resin (epoxy equivalent: 21
5) A resin composition consisting of 150 parts, 45 parts of brominated cresol novolak epoxy resin (epoxy equivalent: 350), and 87 parts of phenol novolac resin (phenol equivalent: 107) was mixed with the fillers shown in Table 2, and 5.5 parts of antimony dioxide.
6 parts, carbon black 3 parts, carnauba wax 4.4
2.5 parts of 2-undecylimidazole as a curing accelerator, and 5 parts of T-glycidoxypropyltrimethoxysilane were kneaded with a mixing roll and pulverized to prepare an epoxy resin composition. These resin compositions were subjected to the following evaluation tests. The results are shown in Table-3.

The measured values listed in Tables 2 and 3 were determined by the following method.

(1) Particle size measurement by laser diffraction method (Gra
nuloo+eter model 715).

(2) Formability (spiral flow) Molding temperature is 170°C using a mold that complies with EMMI standards.
1 Measured at a molding pressure cuff of 0 kg/c-d.

(3) Paris 2, 5.10. Using a mold with a slit of a predetermined thickness of 30 μm, molding temperature: 170°C, molding pressure: 0 kg/c
The flow length was measured at tll, and its maximum value was shown.

(4) Heat dissipation thermal conductivity measuring device (“RC-TC-1 type” manufactured by Agne)
) was measured by the temperature gradient method at room temperature.

(5) Heat shock resistance evaluation (T/S resistance) A 16-pin lead frame with an island size of 4 x 7.5 m was transfer molded using each composition, and the 16-pin DIP
The molded body was immersed 200 times in a liquid at -196°C and a liquid at 260°C for 30 seconds each, and the occurrence rate of cranks on the surface of the molded body was determined from 50 samples.

〔Effect of the invention〕

By using the filler of the present invention, it is possible to obtain a resin composition that is excellent in all of spiral flow properties, firmness properties, and heat dissipation properties.

Claims (1)

[Scope of Claims] 1. A filler for resin, characterized in that it is made of an inorganic powder containing nitride powder and/or oxynitride powder having the following particle size characteristics. (Particle size distribution) -1μ: 5-10% -2μ: 6-12% -3μ: 10-16% -8μ: 35-47% -24μ: 51-63% -48μ: 67-75% -96μ: 88 ~92% (average particle size) 9-22 μm (RRS-n value) ≦0.80