JP2001261932A - Red phosphorus for epoxy resin sealing and epoxy resin composition for semiconductor sealing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a red phosphorus that has sound and stabilized inorganic coating layers for sealing the inorganic coating layers with an epoxy resin. SOLUTION: The red phosphorus for sealing epoxy resin is a stabilized red phosphorus in which an inorganic coating layer of a three-dimensional structure is formed on the surface of the particles of red phosphorus and has the following physical properties: the average particle sizes (MA) of 0.1-50 μm, the BET specific surface area (A) of >=5 m2/g and the rate of the BET specific surface area (A) to the theoretical specific surface area (B) calculated by the following formula (1): B (m2/g)=6/(ρ.MA) (1) (wherein ρ is a specific weight of the red phosphorus in g/cm3) is >=50.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a red phosphorus-based flame retardant which is particularly useful for flame retarding electric parts such as sealing materials for semiconductors, laminates, connectors and the like, and an epoxy resin composition containing the same. is there.

[0002]

2. Description of the Related Art Conventionally, most electronic components such as semiconductor circuits are used.
Are sealed with an epoxy resin composition. This composition
Some flame retardants include halogen-based flame retardants or halo flame retardants.
A combination of a gen-based flame retardant and antimony trioxide
Inorganic fillers such as fused spherical silica and crystalline silica as fillers
Has a high concentration. However, dioxin, etc.
Halogen flame retardants and triacids
Flame-retardant epoxy resin composition not using antimony bromide
Has been requested. There are various proposals for those issues
For example, SixOy (X and Y are positive numbers and X: Y
= 1: 2 to 1: 4) using a red phosphorus flame retardant
Epoxy resin composition for conductor encapsulation (Japanese Unexamined Patent Publication No.
Report), use a red phosphorus-based flame retardant whose surface layer is TixOy
Epoxy resin composition for semiconductor encapsulation (JP-A-7-173372)
Gazette), bismuth oxide, bismuth hydroxide,
Includes red phosphorus-based flame retardant that is coated and adhered to a mixture of
Epoxy resin composition having (JP-A-8-100108)
Semiconductor encapsulation containing red phosphorus flame retardant and ion scavenger
Epoxy resin composition (JP-A-8-151427), red resin
Flame retardant and boron flame retardant (2ZnO.3B _TwoO_Three・
3.5H_TwoO) Epoxy resin set for semiconductor encapsulation
Hydroxide on the surface of the product (JP-A-8-151505), red phosphorus
After coating with aluminum, further coating with phenyl resin
Having an average particle size of 2 to 8 μm and a maximum particle size of 20 μm.
m for semiconductor encapsulation containing a red phosphorus-based flame retardant
And oxy resin compositions (JP-A-10-152599).

[0003]

However, at present, the stabilized red phosphorus-based flame retardant has not yet reached the level where it can be used in epoxy resin compositions for semiconductor encapsulation. Thus, the present inventors have conducted intensive studies in view of the above problem, and found that 3
The present inventors have found that stabilized red phosphorus having a three-dimensionally structured inorganic coating layer can provide extremely excellent flame retardancy to epoxy resins, and completed the present invention.

[0004]

That SUMMARY OF THE INVENTION The present invention provides a stabilized red phosphorus inorganic coating layer of the three-dimensional structure surface is formed of the red phosphorus particles, an average particle diameter (M _A) is 0. 1 to
50 μm, BET specific surface area (A) is 5 m ² / g or more, and BET specific surface area (A) and the following formula (1): B (m ² / g) = 6 / (ρ · M _A ) (1) (Where ρ represents the specific gravity of red phosphorus (g / cm ³ )) and the specific surface area (A) / the theoretical specific surface area (B) calculated by
(B) The red phosphorus for epoxy resin sealing characterized by having 50 or more.

Further, the present invention provides (A) an epoxy resin,
An epoxy resin for semiconductor encapsulation comprising (B) a phenolic resin, (C) a curing accelerator, (D) red phosphorus, and (D) an inorganic filler, wherein the red phosphorus is the above-mentioned red for epoxy resin encapsulation. The present invention relates to an epoxy resin composition for semiconductor encapsulation using phosphorus.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The stabilized red phosphorus of the present invention has the following properties. That is,
The stabilized red phosphorus of the present invention has a particle diameter of at most 100 μm.
m and an average particle diameter of 1 to 50 μm, preferably 5 to 20 μm. Further, the BET specific surface area is 5 m ² / g or more, preferably 10 m ² / g or more. The BET specific surface area (A) of the stabilized red phosphorus of the present invention is considerably higher than the theoretical specific surface area (B) calculated from the average particle size. The ratio (A) / (B) is 50 or more, preferably 100
That is all. This means that the inorganic powder stabilizing the red phosphorus is agglomerated to form a three-dimensional structure and is covered. This coating increases the stabilization of red phosphorus and reduces the generation of phosphine and the like practically. The average particle size of the stabilized red phosphorus is measured by a laser method using Microtrack. Moreover, the theoretical specific surface area (B) is specifically obtained by ^{B (m 2 / g) =} 6 / ρ · M A. In the formula, ρ indicates the specific gravity of red phosphorus, and M
_A indicates the average particle diameter (μm) calculated from the average particle diameter measured by the laser method. BET specific surface area is
It is a result measured by a nitrogen adsorption method.

[0007] The stabilized red phosphorus of the present invention is obtained by coating the surface of red phosphorus particles with an inorganic powder. The inorganic powder is S
i, A1, Mg, Ti, Zn, Fe, Sb, Co, Z
At least one or two or more selected from oxides or hydroxides of r, V, Ca and the like, and phosphates. Specifically, titanium hydroxide, titanium oxide, condensed aluminum obtained by hydrolyzing polyaluminum chloride, aluminum oxide, aluminum hydroxide, magnesium hydroxide, silicon dioxide, zinc white, calcium phosphate, apatite, etc. And preferably, titanium hydroxide, titanium oxide, aluminum hydroxide and the like.

In the method for producing stabilized red phosphorus according to the present invention, a metal salt is added to an aqueous suspension of red phosphorus and stirred, and then an alkali is added to the aqueous suspension of red phosphorus to convert the metal salt to red. It is characterized by a first step of precipitating on the surface of phosphorus particles, and a second step of adding a flocculant to the aqueous solution and stirring. Metal salts are Si, A1, Mg, Ti, Zn, Fe, Sb,
A water-soluble metal salt such as Co, Zr, V, and Ca may be used. The alkali is ammonia gas, ammonia water, caustic soda, caustic potash, NaHCO ₃ , Na ₂ CO ₃ , K ₂ CO ₃ , K
At least one selected from inorganic alkali agents such as HCO ₃ and Ca (OH) ₂ or organic alkali agents such as ethanolamine is used, but ammonia gas and ammonia which can easily wash and remove by-products are used. Water is preferred. The end point of the neutralization is in the range of pH 6-8, preferably pH 7.0 ± 0.5. The flocculant is not particularly limited as long as it is commercially available, but polyaluminum chloride and aluminum sulfate are preferred. When coating red phosphorus with aluminum hydroxide, it is only necessary to neutralize polyaluminum chloride or aluminum sulfate with an alkali. The slurry concentration of red phosphorus may be at least 2 times or more, preferably 5 to 110 times the weight of red phosphorus in weight ratio. The temperature at the time of deposition on the red phosphorus surface may be room temperature to 100 ° C, and after neutralization is 60 ° C or more,
Preferably, 80 to 90 ° C is good. The features of the production method of the present invention are as follows:
In order to enhance the workability during filtration, after coating the surface of red phosphorus with a metal, a coagulant is added to capture fine particles present in the solution into the red phosphorus coating and deposit the coating three-dimensionally. Thereby, the filterability is improved. As a result, the BET relative to the average particle diameter is larger than that of the ordinary coated red phosphorus.
The specific surface area becomes a value higher than the specific surface area calculated from the particle diameter. After the above steps, the stabilized red phosphorus of the present invention can be produced by filtering and then washing the solution. The stabilized red phosphorus of the present invention can be used for semiconductor encapsulation. The amount of the stabilized red phosphorus added is 0.1 to 10% by weight, preferably 1 to 10% by weight, based on the semiconductor encapsulant.
5% by weight.

The epoxy resin used in the encapsulating material for semiconductors includes all monomers, oligomers and polymers having at least two epoxy groups in one molecule, such as bisphenol A type epoxy, bisphenol F type epoxy and bisphenol S type epoxy. N-glycidyl compounds from phenol novolak type epoxy, cresol novolak type epoxy, naphthalene type epoxy, biphenyl type epoxy, aromatic amine and heterocyclic nitrogen base such as N, N-diglycidylaniline, triglycidyl isocyanurate, N , N, N ', N'-tetraglycidyl-bis (p-aminophenyl) -methane and the like, but are not particularly limited thereto. These can be used in combination of several types.

As the curing agent, any of those known to those skilled in the art can be used. In particular, C2 to C20 linear aliphatic diamines such as ethylenediamine, trimethylenediamine, tetramethylenediamine, hexamethylenediamine, and the like can be used. Phenylenediamine, paraphenylenediamine, paraxylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenylether, 4,
4'-diaminodiphenylsulfone, 4,4'-diaminodicyclohexane, bis (4-aminophenyl) phenylmethane, 1,5-diaminonaphthalene, meta-xylylenediamine, para-xylylenediamine, 1,1-bis (4 Amines such as -aminophenyl) cyclohexane and dicyanodiamide; phenol novolak resins; cresol novolak resins; tert-butylphenol novolak resins; novolac phenol resins such as nonylphenol novolak resins; resole phenol resins; A phenolic compound in which a hydrogen atom bonded to a benzene ring, a naphthalene ring or another aromatic ring is substituted with a hydroxyl group, such as a phenol aralkyl resin, a naphthol aralkyl resin, and a carbohydrate. And phenolic resins obtained by co-condensation with Le compound, an acid anhydride is exemplified, but the invention is not particularly limited thereto.

[0011] Examples of the filler include fused silica powder, crystalline silica powder, alumina, silicon nitride and the like. The mixing ratio of these fillers is 60 to 90% by weight in the resin composition.
It is. Also, if necessary, release agents such as natural waxes, synthetic waxes, metal salts of linear fatty acids, acid amides, esters, paraffins, coloring agents such as carbon black and red iron, various curing accelerations It can be used as a sealing resin composition by using additives known to those skilled in the art, such as an agent, and is suitably used for sealing a semiconductor element by transfer molding, injection molding, or the like.

[0012]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

(Production of Stabilized Red Phosphorus)
And then a particle diameter of 3-44 μm and an average particle diameter of 18
200 g of a red phosphorus powder of 200 μm was added and stirred. Then, a titanium tetrachloride solution (containing 8.5 wt% as Ti,
30.6 g of the product was added. Next, a 5 wt% aqueous ammonia solution was added to the solution to adjust the pH to 7 to 7.
Adjusted to 8. Next, polyaluminum chloride (trade name, Taipec, manufactured by Daimei Chemical, containing 33% as Al ₂ O ₃ )
2.0 g was added and stirred. After the addition, the solution was heated with stirring to a temperature of 85 ° C., and heating and stirring were continued for 2 hours. The final pH at this time was 6.8. After completion of the reaction, filtration, washing and drying were performed to obtain stabilized red phosphorus of the present invention (sample A).

(Evaluation of Physical Properties of Stabilized Red Phosphorus) For the obtained stabilized red phosphorus (Sample A), the material of the coating layer, the average particle diameter, the BET specific surface area (A), the theoretical specific surface area (B) and the specific surface area The ratio (A / B) was measured. In addition, the measurement of the physical properties was performed as follows. Table 1 shows the results.・ Measurement of average particle diameter (D50) MICROTRAC particle size analyzer (model: 9320-X100, manufactured by Nikkiso Co., Ltd.)
Was measured by a laser method. -Measurement of BET specific surface area It was measured by a nitrogen adsorption method using Flowsorb (manufactured by Shimadzu Corporation). Measurement above formula of the theoretical specific surface area (1), 2.2 [rho (g / cm ^3), the M _A
It was determined by substituting the value of (D50).

[0015]

[Table 1]

(Evaluation of Amount of Phosphine Generated from Stabilized Red Phosphorus) A 50 ml sealed container was filled with an N ₂ gas atmosphere, and the stabilized red phosphorus (sample A) obtained in the container was filled with P.
(Phosphorus), 2.0 g was sealed as a component and kept at 250 ° C. for 1 hour. Then, the gas in the container was sampled with a Tedlar bag, and a phosphine gas detector tube (Gastec detector tube: detection concentration 0.150 ppm, Kitazawa Sangyo Co., Ltd. )) Was used to measure the phosphine (PH ₃ ) concentration in the Tedlar bag. As a result, the amount of generated phosphine was 20 μg / g.

Examples 1 and 2 Various additives were added so as to obtain the compositions shown in Table 2, and mixed at room temperature with a mixer. Subsequently, the mixture was kneaded with a biaxial roll at 70 to 100 ° C., cooled and pulverized to obtain a molding material, and tested for flame retardancy, moisture resistance, and high-temperature storage characteristics under the following conditions. Table 2 shows the results.

<Flame Retardancy Test> The obtained molding material was tableted and subjected to low-pressure transfer molding at 175 ° C. and 7 ° C.
Under the conditions of 0 kg / cm ² and 120 seconds, a test piece for flame retardancy test was prepared. UL94 (V-0, V-1, V-2)
A flame-retardant test was carried out based on.

<Moisture resistance test> Line width 10 μm, thickness 1 μm
External dimensions 19 × 14 × 2.7 equipped with a 6 × 6 × 0.4 mm test silicone chip with aluminum wiring
An 80-mm flat package having a thickness of 80 mm was manufactured by transfer molding, pre-processed, humidified, and the number of disconnection defects due to corrosion of aluminum wiring was checked at predetermined time intervals. The flat package is 180 ± 3 by transfer press.
The molding material was molded under the conditions of 90 ° C., 6.9 ± 0.17 MPa, and then cured at 180 ± 5 ° C. for 5 hours. In the pretreatment, the flat package was humidified under the conditions of 85 ° C. and 85% RH for 72 hours, and a vapor phase reflow treatment was performed at 215 ° C. for 90 seconds. Thereafter, the humidification test was performed under the conditions of 2.02 × 105 Pa and 121 ° C.

<High Temperature Leaving Characteristics> Partial silver plating was performed using a test element in which an aluminum wiring having a line / space of 10 μm was formed on a silicon substrate having an outer size of 5 × 9 mm and an oxide film of 5 μm. The lead pad of the alloy was connected with silver paste, and the bonding pad of the element and the inner lead were connected with an Au wire at 200 ° C. by a thermonic wire bonder. Then, by transfer molding, a 16-pin type DIP (Dual
Inline Package) was prepared, and the obtained test IC was stored in a high-temperature bath at 200 ° C., taken out at predetermined time intervals, and subjected to a continuity test to determine the number of defects. The test IC was transferred at 180 ± 3 ° C. using a transfer press.
The molding material was molded under the conditions of 9 ± 0.17 MPa and 90 seconds, and then cured by post-curing at 180 ° C. ± 5 ° C. for 5 hours.

[0021]

[Table 2]

[0022]

[Table 3]

[0023]

As described above, the red phosphorus for epoxy resin encapsulation of the present invention is obtained by forming a three-dimensional inorganic coating layer firmly on the surface of red phosphorus particles. It is useful as a flame-retardant resin.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09K 3/10 C09K 3/10 L Z Q 21/04 21/04 H01L 23/29 H01L 23/30 R 23 / 31 (72) Inventor Takahiro Nagayama 4th Floor, Ibasen Building, 4-1, Nihonbashi Kobunacho, Chuo-ku, Tokyo Japan Chemical Industry Co., Ltd. Sales Headquarters F term (reference) 4H017 AA04 AA22 AA27 AA29 AA31 AA39 AB08 AB17 AC01 AD06 AE05 4H028 AA07 AA08 AA42 AB02 BA06 4J002 CC03X CD00W DA056 FB076 FD136 FD157 GQ01 GQ05 4J036 AA01 DA01 DA02 FA04 FB07 JA07 JA08 4M109 AA01 BA01 CA21 EA02 EB03 EB04 EB07 EB12 EC20

Claims (2)

[Claims] 1. A stabilized red phosphorus in which an inorganic coating layer having a three-dimensional structure is formed on the surface of red phosphorus particles, having an average particle diameter (M _A ) of 0.1 to 50 μm and a BET specific surface area (A). Is not less than 5 m ² / g, and the BET specific surface area (A) and the following formula (1): B (m ² / g) = 6 / (ρ · M _A ) (1) (wherein ρ is red phosphorus Specific surface area (A) / theoretical specific surface area (B) calculated by the specific gravity (g / cm ³ )
(B) the red phosphorus for epoxy resin sealing characterized by being 50 or more. 2. An epoxy resin for semiconductor encapsulation comprising (A) an epoxy resin, (B) a phenol resin, (C) a curing accelerator, (D) red phosphorus, and (D) an inorganic filler,
2. An epoxy resin composition for semiconductor encapsulation using the red phosphorus for epoxy resin encapsulation according to claim 1.