JP2007284461A - Flame-retardant and epoxy resin composition for sealing semiconductor comprising the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flame-retardant that is non-toxic and does not reduce the reliability of a semiconductor apparatus and a composition for sealing a semiconductor device comprising the flame-retardant. <P>SOLUTION: The flame-retardant comprises inorganic porous fine particles, a phosphazene compound, represented by average compositional formula (1), supported on the porous inorganic fine particles, and a resin layer covering the porous inorganic fine particles supporting the phosphazene compound, where the resin has, by a thermobalance, a 10% weight-loss temperature of 300-500°C by thermal decomposition when its temperature is raised from room temperature at a rate of 10°C/min. In the formula, X is a single bond or a group selected from the group consisting of CH<SB>2</SB>, C(CH<SB>3</SB>)<SB>2</SB>, SO<SB>2</SB>, S, O and O(CO)O; n is an integer satisfying 3≤n≤1,000; and d and e are each a number satisfying 2d+e=2n. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a flame retardant for a semiconductor sealing resin. Specifically, the phosphazene compound is supported on porous particles, and the particles are coated with a predetermined thermally decomposable resin layer, and The present invention also relates to a semiconductor sealing resin composition containing the flame retardant.

  Semiconductor elements such as diodes, transistors, ICs, LSIs, and super LSIs are mainly sealed with an epoxy resin composition. The obtained semiconductor device is used everywhere in the living environment such as home appliances and computers, so that it is required to have flame resistance in preparation for an emergency fire.

  In order to impart flame retardancy, a halogenated epoxy resin and antimony trioxide are generally blended. The combination of the halogenated epoxy resin and antimony trioxide has a large radical trap and air blocking effect in the gas phase, and as a result, a high flame retardant effect can be obtained.

  However, halogenated epoxy resins have the problem of generating toxic gases during combustion, and antimony trioxide is also toxic. Therefore, considering the effects on the human body and the environment, these flame retardants are completely contained in the resin composition. It is preferably not included. Further, in the halogenated epoxy resin, the Br radical generated at a high temperature reacts with the Au—Al alloy at the bonding portion between the Au wire and the Al wire of the semiconductor device to form an Al—Br compound. Inferior to

As alternatives to halogenated epoxy resins or antimony trioxide, studies have been made on hydroxides such as Al (OH) ₃ and Mg (OH) ₂ , phosphorus flame retardants such as red phosphorus and phosphate esters, and the like. However, since these hydroxides have a low flame retardant effect, in order to obtain a flame retardant composition, a large amount of hydroxide must be added to the epoxy resin composition, resulting in a viscosity of the composition. As a result, there is a problem in that molding defects such as voids and wire flow occur during molding. Phosphorus flame retardants such as red phosphorus and phosphate esters are hydrolyzed when semiconductor devices are placed under high humidity to produce phosphoric acid, which corrodes aluminum wiring and lowers reliability. There was a big problem.

In order to solve this problem, there has been proposed an epoxy resin composition using a compound in which the surface of red phosphorus is coated with a coating layer composed of a Si _X O _Y composition as a flame retardant (Patent Document 1). The current situation is that reliability has not been improved.

  An epoxy resin composition using a cyclic phosphazene compound as a phosphorus-based flame retardant has also been proposed (Patent Document 2). As described above, a phosphoric acid compound is generated, which affects the high-temperature operation of a semiconductor element. May have an effect.

On the other hand, a capsule-type flame retardant composed of a core material and a film material is known (Patent Document 3). The core material has a flame retardant action, and the film material is an organic material having a flexural modulus at 30 ° C. of 2000 kg / mm ² or less, such as an epoxy resin or an acrylic resin. The core material is a metal hydroxide or zinc borate, but as described above, these flame retardant effects are low. The capsule flame retardant is prepared by a mechanofusion method, but the combination of a core material and a film material that can be applied to the method is limited.
Japanese Patent No. 2843244 JP-A-10-259292 JP 11-255955 A

  Then, an object of this invention is to provide the composition for semiconductor element sealing containing a flame retardant and this flame retardant which does not reduce the reliability of a semiconductor device without toxicity.

That is, the present invention is as follows.
Porous inorganic fine particles,
The phosphazene compound represented by the following average composition formula (1) supported on the porous inorganic fine particles, and
A resin layer covering porous inorganic fine particles carrying the phosphazene compound;
The resin has a temperature of 300 to 500 ° C. at which the weight loss due to thermal decomposition becomes 10% by weight when heated from room temperature to 10 ° C./min under air on a thermobalance.
Flame retardants.

［但し、Ｘは単結合、又はＣＨ_２、Ｃ（ＣＨ_３）_２、ＳＯ_２、Ｓ、Ｏ及びＯ（ＣＯ）Ｏからなる郡より選ばれる基であり、ｎは３≦ｎ≦１０００の整数であり、ｄ及びｅは２ｄ＋ｅ＝２ｎを満たす数である。］

[However, X is a single bond or a group selected from the group consisting of CH ₂ , C (CH ₃ ) ₂ , SO ₂ , S, O and O (CO) O, and n is an integer of 3 ≦ n ≦ 1000. And d and e are numbers satisfying 2d + e = 2n. ]

The present invention also provides:
(A) Flame retardant (B) Epoxy resin (C) Curing agent (D) An epoxy resin composition for semiconductor encapsulation containing an inorganic filler,
(A) The flame retardant is the flame retardant of the present invention,
(A) Flame retardant is contained in 5 to 50 parts by mass with respect to a total of 100 parts by mass of (B) epoxy resin and (C), and the epoxy resin composition for semiconductor encapsulation is brominated and antimony compound Not including,
An epoxy resin composition for semiconductor encapsulation characterized by the above.
Furthermore, the present invention provides a semiconductor device sealed with the resin composition.

  Unlike the antimony and halogen, the flame retardant of the present invention has no toxicity. Further, since it is covered with a resin layer, it does not hydrolyze even when placed under high humidity, and the reliability of the semiconductor device is not impaired. The resin layer has an appropriate thermal decomposability for exhibiting the flame retardancy of the phosphazene compound, and the semiconductor device encapsulated with the resin composition of the present invention is flame retardant standard UL-94, V- 0 can be achieved.

Hereinafter, the present invention will be described in more detail.
The flame retardant of the present invention comprises a phosphazene compound represented by the following average composition formula (1) as an active ingredient.

［但し、Ｘは単結合、又はＣＨ_２、Ｃ（ＣＨ_３）_２、ＳＯ_２、Ｓ、Ｏ及びＯ（ＣＯ）Ｏからなる群より選ばれる基であり、ｎは３≦ｎ≦１０００の整数であり、ｄ及びｅは２ｄ＋ｅ＝２ｎを満たす数である。］

[Wherein X is a single bond or a group selected from the group consisting of CH ₂ , C (CH ₃ ) ₂ , SO ₂ , S, O and O (CO) O, and n is an integer of 3 ≦ n ≦ 1000. And d and e are numbers satisfying 2d + e = 2n. ]

  In the formula (1), n is preferably 3 to 10, and particularly preferably n = 3 in terms of synthesis.

  Preferably, d and e are 0 ≦ d ≦ 0.25n and 1.5n ≦ e ≦ 2n. When X is a single bond, the following structure:

は下記構造、

Is the following structure,

を表す。

Represents.

  The resin which seals or coats the particles carrying the phosphazene compound represented by the average composition formula (1) is a weight due to thermal decomposition when the temperature is raised from room temperature to 10 ° C./min under air on a thermobalance. The temperature at which the reduction is 10% by weight is 300 to 500 ° C, preferably 340 to 500 ° C.

  If the temperature at which the weight loss is 10% by weight is below the lower limit value, the particles can be exposed before being exposed to combustion, and the phosphazene compound supported on the particles contacts the semiconductor component and damages the component. This is not preferable. On the other hand, when it is above the upper limit, the phosphazene compound remains covered with the resin layer even during combustion, and the flame retardancy effect cannot be exhibited.

  The resin or resin composition constituting the coating resin layer includes an epoxy resin, a bismaleimide resin, a silicone resin, a cyanate ester resin, a methyl methacrylate / butadiene / styrene resin, or a polystyrene resin and, if necessary, these curing agents. A resin composition is used, preferably an epoxy resin, a composition containing a phenol resin curing agent, and a bismaleimide resin. The coating resin or composition depends on the specific surface area of the porous fine particles, but is typically 0.05 to 1.5 parts by weight, more typically 0.1 parts by weight with respect to 1 part by weight of the phosphazene compound. ~ 0.5 parts by weight are used.

Examples of the porous inorganic fine particles supporting the phosphazene compound include silicon dioxide, calcium silicate, apatite, alumina, zeolite, and the like, and preferably silicon dioxide. The average particle diameter is 0.5 to 20 μm, preferably 1 to 10 μm, and the specific surface area is 100 to 600 m ² / g, preferably 150 to 400 m ² / g.

Production of the flame retardant of the present invention can be made by the following steps.
(1) A solution is prepared by dissolving a phosphazene compound in a solvent.
(2) The phosphazene solution is added to the porous inorganic fine particles under reduced pressure and stirred for a predetermined time, and then the organic solvent is distilled off.
(3) Separately, a coating layer resin or composition is dissolved in a solvent to prepare a solution. (4) The coating resin solution is added to the porous fine particles carrying the phosphazene compound obtained in step (2), After stirring under heating for hours, the solvent is distilled off.
(5) The fine particles coated with the resin composition layer obtained in step (4) are heated as necessary to cure the coated resin layer.
Step (3) may be performed in parallel with (1).

  Here, the degree of decompression is within the range of the pressure at which the phosphazene compound does not evaporate, and it is desirable to adjust it according to the nature of the solvent used and the pore diameter of the porous fine particles.

The phosphazene compound represented by (1) is preferably present in the flame retardant in a proportion of 10 to 60% by mass, more preferably 30 to 60% by mass. When the amount is 10% by mass or less, since the flame retardant effect per unit mass is low, the amount added to the composition for sealing a semiconductor described later becomes large, which is disadvantageous in cost. On the other hand, although it depends on the specific surface area of the porous fine particles, it is usually difficult to carry an amount of the phosphazene compound exceeding the upper limit.

  Since the obtained flame retardant of the present invention is coated with a heat-stable resin or resin composition, it has high heat resistance, and at a temperature of 300 ° C. or lower, the phosphazene compound is decomposed to generate a phosphate compound. There is nothing. Moreover, the water resistance is high, and phosphate ions and the like do not leak out even in a water extraction test. And when exposed to high temperature at the time of combustion, a coating resin layer will be thermally decomposed and a phosphazene compound will be exposed and the flame-retardant effect will be exhibited.

  This invention relates also to the composition for epoxy resin semiconductor sealing containing the said flame retardant (henceforth (A) flame retardant). (A) A flame retardant is mix | blended in 5-50 mass parts with respect to 100 mass parts of (B) epoxy resin and (C) hardening | curing agent mentioned later, Preferably it is 5-30 mass parts. (A) The fluidity and moldability of the composition can be adjusted by adjusting the particle size of the porous particles of the flame retardant.

[(B) Epoxy resin]
In the composition of the present invention, as the epoxy resin (B), a novolak type epoxy resin, a cresol novolak type epoxy resin, a triphenolalkane type epoxy resin, an aralkyl type epoxy resin, a biphenyl skeleton-containing aralkyl type epoxy resin, a biphenyl type epoxy resin, Examples include dicyclopentadiene type epoxy resins, heterocyclic type epoxy resins, naphthalene ring-containing epoxy resins, bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, stilbene type epoxy resins, and the like. Can be used together. Among these, an epoxy resin containing an aromatic ring, for example, a cresol novolac type or a triphenolalkane type is preferable. In the present invention, a brominated epoxy resin is not blended.

  The epoxy resin has a hydrolyzable chlorine content of 1000 ppm or less, particularly 500 ppm or less, and sodium and potassium are each preferably 10 ppm or less. When hydrolyzable chlorine exceeds 1000 ppm or sodium or potassium exceeds 10 ppm, the sealed semiconductor device may be inferior in moisture resistance when left under high temperature and high humidity for a long time.

[(C) Curing agent]
(C) The curing agent is preferably a phenol resin, specifically, a phenol novolac resin, a naphthalene ring-containing phenol resin, an aralkyl type phenol resin, a triphenolalkane type phenol resin, a biphenyl skeleton-containing aralkyl type phenol resin, or a biphenyl type. Examples include phenol resins, alicyclic phenol resins, heterocyclic phenol resins, naphthalene ring-containing phenol resins, bisphenol A type resins, bisphenol F type resins and the like, and one or more of these. Can be used in combination.

  It is preferable that the said hardening | curing agent shall make sodium and potassium each 10 ppm or less similarly to an epoxy resin. When sodium or potassium exceeds 10 ppm, moisture resistance may deteriorate if the semiconductor device is left under high temperature and high humidity for a long time.

  The blending ratio of the component (C) with respect to the component (B) is not particularly limited, and may be an effective amount capable of curing an epoxy resin that has been generally employed conventionally, but when a phenol resin is used as a curing agent, (B) The molar ratio of the phenolic hydroxyl group contained in the curing agent with respect to 1 mol of the epoxy group contained in the component is usually in the range of 0.5 to 1.5, particularly 0.8 to 1.2. It is preferable to do.

    In the present invention, it is preferable to use a curing accelerator in order to accelerate the curing reaction between the epoxy resin and the curing agent. The curing accelerator is not particularly limited as long as it accelerates the curing reaction. For example, triphenylphosphine, tributylphosphine, tri (p-methylphenyl) phosphine, tri (nonylphenyl) phosphine, triphenylphosphine / triphenyl. Phosphorus compounds such as borane, tetraphenylphosphine / tetraphenylborate, an adduct of triphenylphosphine and 1,4-benzoquinone, triethylamine, benzyldimethylamine, α-methylbenzyldimethylamine, 1,8-diazabicyclo (5.4 0.0) Tertiary amine compounds such as undecene-7, imidazole compounds such as 2-ethyl-4-methylimidazole, 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, etc. are used. Door can be.

    When a phenol resin is used as a curing agent, the curing accelerator is 0.1 to 5 parts by mass, particularly 0.5 to 2 parts by mass with respect to 100 parts by mass of the total amount of the components (B) and (C). It is preferable to do.

[(D) Inorganic filler]
As the inorganic filler (D) blended in the epoxy resin composition of the present invention, those usually blended in the epoxy resin composition can be used. Examples thereof include silicas such as fused silica and crystalline silica, alumina, silicon nitride, aluminum nitride, boron nitride, titanium oxide, glass fiber, and the like.

  The average particle diameter and shape of these inorganic fillers and the filling amount of the inorganic filler are not particularly limited, but in order to increase the flame retardancy, the amount is as large as possible within the range that does not impair the moldability in the epoxy resin composition. Is preferably filled. In this case, spherical fused silica having an average particle diameter of 5 to 30 μm is particularly preferable as the average particle diameter and shape of the inorganic filler, and the filling amount of the inorganic filler as the component (D) is (B), ( C) It is preferable to set it as 300-1200 mass parts with respect to 100 mass parts of total amounts of component, especially 500-1000 weight part.

  In the present invention, the average particle diameter can be determined as, for example, a weight average particle diameter (or median diameter) by a laser diffraction method or the like.

  The inorganic filler is preferably blended in advance with a surface treatment with a coupling agent such as a silane coupling agent or a titanate coupling agent in order to increase the bond strength with the resin. As this coupling agent, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-isocyanatopropyltriethoxysilane, γ-ureidopropyltriethoxysilane, β- (3,4) Epoxy silanes such as -epoxycyclohexyl) ethyltrimethoxysilane; N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane It is preferable to use a silane coupling agent such as an aminosilane such as γ-mercaptopropyltrimethoxysilane. These can be used singly or in combination of two or more. Further, the blending amount of the coupling agent used for the surface treatment and the surface treatment method are not particularly limited.

[Other ingredients]
The flame-retardant epoxy resin composition for semiconductor encapsulation of the present invention can be blended with various additives within a range that does not impair the object of the present invention. Examples of the additive include other flame retardants excluding antimony compounds such as antimony trioxide, such as hydroxides such as aluminum hydroxide and magnesium hydroxide, zinc borate, zinc stannate, zinc molybdate; thermoplastic resin, Low stress agents such as thermoplastic elastomers, organic synthetic rubbers and silicones; mold release agents such as carnauba wax, higher fatty acids and synthetic waxes; colorants such as carbon black; hydrotalcite compounds, zirconium phosphate compounds, hydroxylation A halogen trapping agent such as a bismuth compound and a silane coupling agent for enhancing the adhesion to a semiconductor element can also be added.

  Examples of the release agent component include carnauba wax, rice wax, polyethylene, polyethylene oxide, montanic acid, montanic acid and saturated alcohol, 2- (2-hydroxyethylamino) -ethanol, ethylene glycol, glycerin and the like. A certain montan wax; stearic acid, stearic acid ester, stearic acid amide, ethylene bis-stearic acid amide, a copolymer of ethylene and vinyl acetate, and the like. These may be used alone or in combination of two or more. Can do. The mixing ratio of the release agent is preferably 0.1 to 5 parts by mass, more preferably 0.3 to 4 parts by mass with respect to 100 parts by mass of the total amount of the components (B) and (C).

  As the silane coupling agent, in addition to those which can be used for the surface treatment of the above filler, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane , Γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-acryloxypropyltrimethoxysilane, N-β (Aminoethyl) γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-mercapto B pills methyldimethoxysilane, bis (triethoxysilylpropyl) tetrasulfide, .gamma. isocyanatepropyltriethoxysilane and the like.

[Preparation of epoxy resin composition, etc.]
The epoxy resin composition of the present invention is prepared by, for example, blending the above components (A) to (D) and other additives in a predetermined composition ratio, mixing them sufficiently uniformly by a mixer, a ball mill or the like, and then heating rolls. Using a kneader, an extruder or the like, the mixture can be mixed under heating, then cooled and solidified, and pulverized to an appropriate size as desired to obtain a molding material. Since the (A) flame retardant is coated with the resin layer, the phosphazene compound does not come out in the (B) epoxy resin in the mixing step.

  The epoxy resin composition of the present invention thus obtained can be effectively used for sealing various semiconductor devices. Examples of the sealing method include a low-pressure transfer molding method. In addition, when hardening and shaping | molding of the epoxy resin composition of this invention, it processes for 30 to 180 second at 150-180 degreeC, for example, and postcure (postcure) is performed on the conditions for 2 to 16 hours at 150-180 degreeC. It is desirable.

  The epoxy resin composition of the present invention is excellent in continuous moldability. Further, as will be described later, even if the cured product is left in water, the phosphazene compound is not decomposed.

  Hereinafter, (A) Examples of flame retardant synthesis, examples of epoxy resin compositions and comparative examples will be shown, and the present invention will be specifically shown. However, the present invention is not limited to the following examples.

Synthesis Example 1 Synthesis of Phosphazene Compound A-1 Under a nitrogen atmosphere, 8.6 g (214 mmol) of sodium hydride was suspended in 50 ml of THF at 0 ° C., and a solution of 19.8 g (211 mmol) of phenol in 75 ml of THF was added dropwise thereto. . After stirring for 30 minutes, a solution of 12.0 g (34.5 mmol) of hexachlorotriphosphazene in 75 ml of THF was added dropwise, and the mixture was heated to reflux for 18 hours. The solvent was distilled off under reduced pressure, methanol was added, and the precipitated crystals were washed with methanol and water to obtain 23.8 g of phosphazene compound (A-1) white crystals represented by the following formula.

[Synthesis Example 2] Synthesis of phosphazene compound B-1 Under a nitrogen atmosphere, 4.8 g (119 mmol) of sodium hydride was suspended in 50 ml of THF at 0 ° C., and 10.2 g (108 mmol) of phenol, 4,4′- A solution of 0.45 g (1.8 mmol) of sulfonyldiphenol in 50 ml of THF was added dropwise. After stirring for 30 minutes, a solution of 12.5 g (36.0 mmol) of hexachlorotriphosphazene in 50 ml of THF was added dropwise, and the mixture was heated to reflux for 5 hours. Thereto was added dropwise sodium hydride (5.2 g, 130 mmol) suspended in THF (50 ml) at 0 ° C. Then, phenol (11.2 g, 119 mmol) in THF (50 ml) was added dropwise, and the mixture was further heated to reflux for 19 hours. . After the solvent was distilled off under reduced pressure, chlorobenzene was added and dissolved, and extracted with 5% NaOH aqueous solution 200 ml x 2 times, 5% sulfuric acid aqueous solution 200 ml x 2 times, 5% sodium hydrogen carbonate aqueous solution 200 ml x 2 times, and water 200 ml x 2 times. Went. The solvent was distilled off under reduced pressure to obtain 20.4 g of a phosphazene compound (B-1) represented by the following formula as tan crystals.

[Example 1]
In a vacuum chamber, 50 parts by mass of porous silica fine particles SS-150 (manufactured by Mitsubishi Rayon Co., Ltd.) having an average particle size of 8.8 μm and a specific surface area of 155 m ² / g were prepared. Separately, 40 parts by mass of (A-1) as a supported substance was dissolved in 100 parts by mass of acetone, and 6 parts by mass of epoxy resin GTR-1800 (manufactured by Nippon Kayaku Co., Ltd.) in 100 parts by mass of acetone. Curing agents MEH-7500 (Maywa Kasei Co., Ltd.) 4 parts by mass and triphenylphosphine 0.3 parts by mass were added to prepare uniform solutions. Next, while keeping the inside of the vacuum chamber at a reduced pressure of 0.5 to 1 Torr, 140 parts by mass of the solution (A-1) prepared previously is dropped from the sealed mouth so that the porous silica fine particles are sufficiently infiltrated. After being left for a minute, the mixture was stirred for 30 minutes and returned to atmospheric pressure. Next, acetone was evaporated and separated with stirring while being heated to 60 ° C. while the vacuum chamber was kept under reduced pressure. Next, 110.3 parts by mass of the epoxy resin solution was added while the pressure in the vacuum chamber was reduced, and the mixture was allowed to stand for 30 minutes so as to sufficiently penetrate the porous silica fine particles containing (A-1), followed by stirring for 30 minutes and atmospheric pressure. Returned to. Next, acetone was evaporated and separated with stirring while being heated to 60 ° C. while the vacuum chamber was kept under reduced pressure. Subsequently, the flame retardant a which carries 40 mass% of A-1 coat | covered with the epoxy resin was prepared by making it harden | cure at 180 degreeC for 4 hours in dryer.

  In addition, 6 parts by mass of epoxy resin GTR-1800 (manufactured by Nippon Kayaku Co., Ltd.), 4 parts by mass of curing agent MEH-7500 (manufactured by Meiwa Kasei Co., Ltd.) and 0.3 part by mass of triphenylphosphine are added in 100 parts by mass of acetone. 10% by weight measured by thermogravimetric analysis (Thermo plus TG 8120, manufactured by Rigaku Corporation) in the atmosphere of a cured product obtained by curing a solid obtained by evaporating and separating acetone by stirring at 60 ° C. under reduced pressure at 180 ° C. for 4 hours. The thermal decomposition temperature was 345 ° C.

[Example 2]
40 parts by mass of porous silica fine particles SE-MCB-FP-2 (manufactured by Enex Co., Ltd.) having an average particle size of 3.2 μm and a specific surface area of 242 m ² / g were prepared in a vacuum chamber. Separately, 55 parts by mass of (B-1) as a supported substance was added and dissolved in 100 parts by mass of acetone. Further, in 100 parts by mass of acetone, 4.8 parts by mass of bismaleimide resin BMI (manufactured by KI Kasei Co., Ltd.) and 0.2 part of AIBN (manufactured by Nippon Oil & Fats Co., Ltd.) were added to obtain a uniform solution. Next, 155 parts by mass of the previously prepared solution (B-1) was added while leaving the vacuum chamber under reduced pressure, and the mixture was allowed to stand for 30 minutes so as to sufficiently penetrate the porous silica fine particles, and then stirred for 30 minutes to atmospheric pressure. Returned. Next, acetone was evaporated and separated with stirring while being heated to 60 ° C. while the vacuum chamber was kept under reduced pressure. Next, 105.0 parts by mass of the bismaleimide resin solution was added while the pressure in the vacuum chamber was reduced, and the mixture was left for 30 minutes so as to sufficiently penetrate the porous silica fine particles containing (B-1). Returned to atmospheric pressure. Next, acetone was evaporated and separated while being stirred and heated to 100 ° C. while the vacuum chamber was kept under reduced pressure. Subsequently, the flame retardant b carrying 55% by mass of B-1 coated with a bismaleimide resin was prepared by drying in a dryer at 180 ° C. for 2 hours and then at 220 ° C. for 2 hours.

  In 100 parts by mass of acetone, 4.8 parts by mass of bismaleimide resin BMI (manufactured by Nippon Kayaku Co., Ltd.) and 0.2 parts by mass of AIBN (manufactured by Nippon Oil & Fats Co., Ltd.) were added and acetone was stirred while stirring at 60 ° C. under reduced pressure. 10% by weight pyrolysis temperature measured by thermogravimetric analysis (Thermoplus TG 8120 manufactured by Rigaku Corporation) in the atmosphere of the cured product obtained by curing the solid separated by evaporation at 180 ° C. for 2 hours and then at 220 ° C. for 2 hours. Was 360 ° C.

[Reference Example 1]
In a vacuum chamber, 50 parts by mass of porous silica fine particles SS-150 (manufactured by Mitsubishi Rayon Co., Ltd.) having an average particle size of 8.8 μm and a specific surface area of 155 m ² / g were prepared. Separately, 40 parts by mass of (A-1) as a supported substance was added to 100 parts by mass of acetone and dissolved. Similarly, 10 parts by mass of PES resin 4100M (manufactured by Sumitomo Chemical Co., Ltd.) in 100 parts by mass of N-methyl 2-pyrrolidone was added and heated to 60 ° C. to obtain a uniform solution. Next, while placing the vacuum chamber under reduced pressure, 140 parts by mass of the solution (A-1) prepared above was added and impregnated so as to sufficiently permeate the porous silica fine particles, and then stirred for 30 minutes to return to atmospheric pressure. It was. Next, acetone was evaporated and separated with stirring while being heated to 60 ° C. while the vacuum chamber was kept under reduced pressure. Next, the vacuum chamber was again heated to 60 ° C. under reduced pressure, 110 parts by mass of the PES resin solution was added, and the mixture was allowed to stand for 30 minutes so as to sufficiently permeate the porous silica fine particles containing (A-1). The mixture was stirred for a minute and returned to atmospheric pressure. After removing excess N-methyl-2-pyrrolidone by filtration, the flame retardant c carrying 40% by mass of A-1 coated with PES resin was prepared by drying at 200 ° C. for 2 hours in a dryer. .

  In addition, the 10 weight% thermal decomposition temperature which measured PES resin 4100M (made by Sumitomo Chemical Co., Ltd.) in air | atmosphere in the thermogravimetric analysis (Thermoplus TG 8120 made by Rigaku) was 500 degreeC or more.

[Reference Example 2]
In a vacuum chamber, 50 parts by mass of porous silica fine particles SS-150 (manufactured by Mitsubishi Rayon Co., Ltd.) having an average particle size of 8.8 μm and a specific surface area of 155 m ² / g were prepared. Separately, 40 parts by mass of (A-1) as a supported substance was added to 100 parts by mass of acetone and dissolved. Similarly, 10 parts by mass of PMMA resin (manufactured by Soken Chemical Co., Ltd.) in 100 parts by mass of acetone was added and heated to 60 ° C. to obtain a uniform solution. Next, 140 parts by mass of the previously prepared solution (A-1) was added while the vacuum chamber was kept under reduced pressure, and the mixture was allowed to stand for 30 minutes so as to sufficiently penetrate the porous silica fine particles, and then stirred for 30 minutes to atmospheric pressure. Returned. Next, acetone was evaporated and separated with stirring while being heated to 60 ° C. while the vacuum chamber was kept under reduced pressure. Next, the vacuum chamber was again heated to 60 ° C. under reduced pressure, 110 parts by mass of the PMMA resin solution was added, and the mixture was allowed to stand for 30 minutes so as to sufficiently penetrate the porous silica fine particles containing (A-1). The mixture was stirred for a minute and returned to atmospheric pressure. Next, the vacuum chamber was again heated to 60 ° C. under reduced pressure, and acetone was evaporated and separated while stirring to prepare flame retardant d carrying 40% by mass of A-1 coated with PMMA resin.

  The 10% by weight pyrolysis temperature of PMMA resin (Soken Chemical) measured in the atmosphere by thermogravimetric analysis (Thermoplus TG 8120 manufactured by Rigaku Corporation) was 240 ° C.

[Comparative Example 1]
Magnesium hydroxide Kisuma 8N (manufactured by Kyowa Chemical Co., Ltd.) 80 parts by mass, epoxy resin GTR-1800 (manufactured by Nippon Kayaku Co., Ltd.) 6 parts by mass, curing agent MEH-7500 (manufactured by Meiwa Kasei Co., Ltd.) 3.5 parts by mass The epoxy resin composition obtained by melt-mixing 0.5 parts by mass of triphenylphosphine at 80 ° C. and finely pulverized to 10 to 50 μm is subjected to a high-speed air current impact method using a mechanofusion system (manufactured by Hosokawa Micron Corporation) Thus, a flame retardant e containing 80% by mass of magnesium hydroxide was prepared.

[Examples 3-7, Reference Examples 4-6, Comparative Examples 2-3]
The components shown in Table 1 were uniformly melt-mixed with two hot rolls, cooled and pulverized to obtain an epoxy resin composition for semiconductor encapsulation. With respect to these compositions, the following properties (i) to (vii) were measured. The results are shown in Table 1.

[Comparative Example 4]
Epoxy resin GTR-1800 (manufactured by Nippon Kayaku Co., Ltd.) 36 parts by mass, curing agent MEH-7500 (manufactured by Meiwa Kasei Co., Ltd.) 23 parts by mass, and triphenylphosphine 3 parts by mass were melt-mixed at 80 ° C. Was pulverized to 10 to 50 μm and 40 parts by mass of the phosphazene compound (A-1) were mixed with a mechanofusion system (manufactured by Hosokawa Micron Co., Ltd.) using the impact method in high-speed air current. However, both A-1 and the epoxy resin composition were uniformly mixed, and the same type of flame retardant as Comparative Example 1 was not obtained.

Measuring method of various properties (i) Fluidity Using a mold conforming to the EMMI standard, it was measured under the conditions of 175 ° C., 6.9 N / mm ² and molding time of 120 seconds.

(Ii) Molding hardness According to JIS-K6911, the hardness at 175 ° C when a 10 × 4 × 100 mm rod was molded under the conditions of 175 ° C., 6.9 N / mm ² and molding time of 90 seconds was measured with a Barkol hardness meter. did.

(Iii) Flame retardance Based on the UL-94 standard, a 1/16 inch thick plate was molded from each resin composition under molding conditions of 175 ° C., 6.9 N / mm ² , molding time of 120 seconds, and 180 ° C. The flame retardancy of the molded product obtained by post-curing for 4 hours was examined.

(Iv) Ionic Impurities Each composition was molded at 175 ° C., 6.9 N / mm ^{2 with} a molding time of 90 seconds, and post-cured at 180 ° C. for 4 hours to obtain a disc of 50 mm × 3 mm. The disk was stored in an atmosphere at 175 ° C. for 1000 hours, and then pulverized by a disk mill. 10 g of a pulverized product having a particle size of 63 μm to 212 μm was added to 50 ml of pure water and left at 125 ° C. for 20 hours. Thereafter, pure water was filtered, and the phosphate ion concentration in the filtrate was measured by ion chromatography.

(V) High-temperature electrical resistance characteristics A 70φ × 3 mm disk was molded from each resin composition under the conditions of a temperature of 175 ° C., a molding pressure of 6.9 N / mm ² and a molding time of 120 seconds, and post-cured at 180 ° C. for 4 hours. did. The volume resistivity of the disc was measured in an atmosphere at 150 ° C.

(Vi) Moisture resistance A silicon chip having a size of 6 × 6 mm formed with aluminum wiring of 5 μm width and 5 μm spacing is bonded to a 14 pin-DIP frame (42 alloy), and the aluminum electrode on the chip surface and the lead frame are further bonded to 25 μmφ. After being wire-bonded with a gold wire, the composition was sealed with each composition under molding conditions of 175 ° C., 6.9 N / mm ² , time 120 seconds, and post-cured at 180 ° C. for 4 hours. Twenty of these packages were left in an atmosphere of 130 ° C./85% RH with a DC bias voltage of −20 V for 500 hours, and then the number of packages in which aluminum corrosion occurred was examined.

(Vii) Heat resistance A silicon chip having a size of 6 × 6 mm formed with aluminum wiring having a width of 5 μm and an interval of 5 μm is bonded to a 14 pin-DIP frame (42 alloy), and the aluminum electrode on the chip surface and the lead frame are 25 μmφ. After wire bonding with a gold wire, the composition was sealed with each composition under molding conditions of 175 ° C., 6.9 N / mm ² , time 120 seconds, and post-cured at 180 ° C. for 4 hours. Twenty of these packages were left for 1000 hours in a 175 ° C. atmosphere with a DC bias voltage of −5 V, and the average resistance value was examined.

The components (B) to (D) and additives shown in Table 1 are as follows.
(B) Component epoxy resin (I): o-cresol novolac type epoxy resin, EOCN1020-55 (manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 200)
Epoxy resin (b): triphenylmethane type epoxy resin, EPPN-501H (manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 165)
(C) Component curing agent (C) Phenol novolac resin: DL-92 (Maywa Kasei Co., Ltd., phenolic hydroxyl group equivalent 110)
Curing agent (d) Triphenylmethane type phenol resin: MEH-7500 (Maywa Kasei Co., Ltd., phenolic hydroxyl group equivalent 97)
Component (D) inorganic filler: spherical fused silica (manufactured by Tatsumori Co., Ltd., average particle size 20 μm)

Additive <br/> Curing catalyst: Triphenylphosphine (made by Hokuko Chemical Co., Ltd.)
Mold release agent: Carnauba wax (manufactured by Nikko Fine Products Co., Ltd.)
Carbon black: Denka Black (manufactured by Denki Kagaku Kogyo Co., Ltd.)
Silane coupling agent: KBM-403 (manufactured by Shin-Etsu Chemical Co., Ltd.)

  As is apparent from the results in Table 1, the epoxy resin composition for semiconductor encapsulation containing the flame retardant of the present invention is excellent in moldability and gives a cured product excellent in flame retardancy, moisture resistance and heat resistance. The flame retardant of Reference Example 1 could not obtain the flame retardant effect of the phosphazene compound because the thermal decomposition temperature of the coating resin was too high. On the other hand, since the thermal decomposition temperature of the coating resin is too low, the flame retardant of Reference Example 2 is in contact with water as in Comparative Example 2 in which the phosphazene compound is mixed with the resin, and phosphate ions are generated. , High temperature volume low efficiency decreased. Since the flame retardant of Comparative Example 1 was magnesium hydroxide and was inferior in flame retardancy, 150 parts by mass were required to achieve V-0. In Comparative Example 3, the wiring was disconnected by bromine radicals generated by decomposition of the brominated epoxy resin.

  The flame retardant of the present invention is suitably used for an epoxy resin composition for semiconductor encapsulation. The resin composition is excellent in moldability and suitable for the production of a semiconductor device excellent in flame retardancy, moisture resistance and heat resistance.

Claims (6)

Porous inorganic fine particles,
The phosphazene compound represented by the following average composition formula (1) supported on the porous inorganic fine particles, and
A resin layer covering porous inorganic fine particles carrying the phosphazene compound;
The resin has a temperature of 300 to 500 ° C. at which the weight loss due to thermal decomposition becomes 10% by weight when heated from room temperature to 10 ° C./min under air on a thermobalance.
Flame retardants.

[Wherein X is a single bond or a group selected from the group consisting of CH ₂ , C (CH ₃ ) ₂ , SO ₂ , S, O and O (CO) O, and n is an integer of 3 ≦ n ≦ 1000. D and e are numbers satisfying 2d + e = 2n. ] The porous inorganic fine particles are selected from the group consisting of silicon dioxide, calcium silicate, apatite, alumina, and zeolite having an average particle size of 0.5 to 20 μm and a specific surface area of 100 to 600 m ² / g. The flame retardant according to claim 1.   The flame retardant according to claim 1, wherein the resin layer contains an epoxy resin or a bismaleimide resin.   The flame retardant according to any one of claims 1 to 3, wherein the phosphazene compound is contained in the flame retardant in an amount of 10 to 60% by mass. (A) Flame retardant (B) Epoxy resin (C) Curing agent (D) An epoxy resin composition for semiconductor encapsulation containing an inorganic filler,
(A) The flame retardant is the flame retardant according to any one of claims 1 to 4,
(A) Flame retardant is contained in 5 to 50 parts by mass with respect to a total of 100 parts by mass of (B) epoxy resin and (C), and the epoxy resin composition for semiconductor encapsulation is brominated and antimony compound Not including,
An epoxy resin composition for semiconductor encapsulation characterized by the above-mentioned.   The semiconductor device sealed with the hardened | cured material of the epoxy resin composition for semiconductor sealing of Claim 5.