JP2002053643A - Curing agent for epoxy resin and composition for encapsulating semiconductor using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curing agent for an epoxy resin for obtaining a composition for semiconductor encapsulation having a low viscosity, a low hygroscopicity, a high glass transition point and a good molding curability, and a semiconductor encapsulation using the same. Provision of a stopping composition. SOLUTION: A monofunctional condensed polycyclic oxazine compound (A) in which an oxazine ring and an aromatic hydrocarbon ring are condensed, such as benzoxazine, and polyphenols (B) having a phenol-substituted tricyphenylmethane structure such as the following exemplified compounds: ) As a curing agent for an epoxy resin, and a composition containing (C) an epoxy resin, (D) an inorganic filler, and (E) a curing accelerator as a resin for semiconductor encapsulation. Used. Ph (OH)-(-CH (Ph) OH- (Ph) OH)-) _n -CH (Ph) OH- (Ph) OH (Ph is a benzene residue such as phenylene, n ≧ 0)

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a low-viscosity, low-hygroscopic, high Tg (glass transition point), low cure shrinkage,
The present invention relates to a curing agent for an epoxy resin for obtaining a semiconductor sealing composition having good molding curability, and a semiconductor sealing composition using the same. In particular, epoxy resin curing agent suitable for encapsulation of thin surface mount packages that require high solder heat resistance, fine pitch BGA that requires low warpage and high fluidity, and CSP (chip size package) of package encapsulation. And a semiconductor encapsulating composition using the same.

[0002]

2. Description of the Related Art In recent years, resin sealing using an epoxy resin has been widely used as a semiconductor sealing material. Particularly, an epoxy resin molding material using an epoxy resin and phenol novolak as a curing agent is often used.

However, recently, as electronic components have become smaller, LSIs have become more highly integrated, and semiconductor devices have become larger, high-density packaging has been required.
TQFP (Thin Quad Flat Package), which is suitable for surface mounting, is being shifted to a thinner package and more pins, and solder heat resistance during surface mounting is more demanding. ing.

[0004] Also, due to environmental problems, the mounting temperature rises with the use of lead-free solder, so that the sealing resin is required to have better solder heat resistance. In addition, the package structure is also diverse, and with the increase in the number of pins, the conventional TQ
In addition to FPs, BGA (ball grid array) types have also increased.

BGAs are also becoming smaller and thinner, and it is expected that CSPs (chip size packages) such as fine pitch BGAs with a ball gap of 0.8 mm or less will increase in the future, and the sealing method will be MAP (matrix).・ As seen in arrays and packages, the method of sealing many chips at once has been adopted, and low warpage, low viscosity, high fluidity, and moldability are required for sealing materials. I have.
In contrast to the properties required for such a sealant, the following properties are required from the viewpoint of the base resin (epoxy resin and curing agent).

(1) Solder heat resistance → low water absorption, low viscosity (incorporation of a large amount of inorganic filler), high adhesion, high Tg (2) High fluidity → low viscosity, heat potential of curing reaction (3) Low warpage → High hardness during molding and demolding (rapid curing), low thermal expansion / shrinkage, low curing shrinkage, low viscosity (shrinkage expansion is possible because a large amount of inorganic fillers can be incorporated. (Temperature can be reduced), high Tg (the glass region with low thermal expansion extends to high temperatures) (4) Formability → High curing speed, little deterioration of curing speed and fluidity over time.

[0007]

However, the above-mentioned required properties of the base resin are contradictory, and at present, none of them can satisfy these properties at the same time. For example, if the number of functional groups is reduced and the molecular weight is reduced in order to obtain low water absorption and low viscosity, there are problems such as a decrease in hardness, curing speed and Tg at the time of demolding. On the other hand, when polyfunctional to increase Tg and curability, water absorption increases and viscosity also increases. In addition to the use of epoxy resin as a sealing resin, the use of a polymaleimide resin or the like has been studied, but has drawbacks in terms of toughness, adhesion, cost, and the like.

The inventors of the present invention have focused on condensed polycyclic oxazine compounds such as benzoxazine as a method for solving these problems and providing excellent solder heat resistance and moldability, high fluidity and low warpage. However, the use of this and a specific polyphenol as an essential component in a curing agent for an epoxy resin was studied.

Benzoxazine compounds, which are heteropolycyclic compounds of a benzene nucleus and an oxazine nucleus, are already known (for example, JP-A-49-47387). Of these benzoxazine compounds, thermosetting polyfunctional benzoxazine resins have been proposed for application mainly to printed circuit boards, taking advantage of flame retardancy and low water absorption. It has also been proposed to use this as a composition for semiconductor encapsulation (JP-A-6-322121, JP-A-11-140278, JP-A-11-140278).

However, in these proposals, a multifunctional benzoxazine having a plurality of oxazine rings in one molecule is used, and a thermosetting product of itself is used as a base resin. Such a polyfunctional benzoxazine has a large drawback in that the viscosity is high and the viscosity is further increased by a reaction of itself during the production of the sealing material. Also, because the curability is poor,
It is completely unsatisfactory for high performance encapsulant applications that meet the objectives of the present invention.

[0011] In these patent applications, there is also described an example in which a polyfunctional benzoxazine compound is used in combination with a phenol resin or an epoxy resin for the purpose of improving curability and the like. Since the three-dimensional cured product is a base resin, and the epoxy resin and phenol resin are positioned as mixed additives or copolymer modifiers, the blending ratio is also high with the ratio of benzoxazine, and the ratio of OH groups to epoxy groups is properly maintained. For this reason, it is not blended with the idea of controlling the ratio of (benzoxazine + phenolic resin) / epoxy resin, so that a semiconductor encapsulant of the present invention that requires both high fluidity and rapid curability is required. It is completely inadequate for the task, and practicality cannot be expected even if it is used for the purpose of the present invention.

It has also been proposed to synthesize a phenol compound using an oxazine compound having one oxazine ring, for example, 6-methyldihydrobenzoxazine as an intermediate, and to use the phenol compound in combination with an epoxy resin or the like for semiconductor encapsulation applications. However, in this method, a ring-opening polymerization of an oxazine compound is performed once to produce a polyfunctional phenol resin having a high molecular weight (the number of structural units of the phenol compound is at least 3). It is used as a curing agent for epoxy resin. For this reason, the curing agent itself has a high viscosity and is not suitable for semiconductor encapsulant applications that require high fluidity.

[0013]

Means for Solving the Problems The inventors of the present invention use a monofunctional type condensed polycyclic oxazine compound which does not itself form a three-dimensional network and has no thermosetting property, By using a curing agent containing polyphenols as an essential component as a curing agent for an epoxy resin, it simultaneously satisfies the above properties required for a base resin, has excellent solder heat resistance and moldability, and has high fluidity and low warpage. It was found that a composition for use was obtained, and the present invention was reached.

That is, the monofunctional condensed polycyclic oxazine compound of the present invention has a low molecular weight and a low viscosity because there is no hydrogen bond of an OH group. Properties / low viscosity. If this is combined with a specific polyphenol, the monofunctional condensed polycyclic benzoxazine compound has a low viscosity, so that it is easily filled in a mold, and after the post-molding curing, the polyphenol and, for example, the formula (6) Reaction occurs quickly, and O
A polymer compound having an increased number of H groups is produced, which acts as a curing agent for an epoxy resin having excellent curability and demoldability,
It was found that a cured product having a high Tg and a low water absorption was obtained.
In addition, it was found that the resin composition of the present invention exhibited surprising effects that could not be predicted from the known knowledge of conventional oxazine compounds, such as the ability to prevent the deterioration of the molding and curing characteristics over time.

[0015]

Embedded image (Wherein R ¹ , R ² and n are the same as defined in formulas (1) and (2))

The present invention relates to a curing agent for an epoxy resin comprising a monofunctional condensed polycyclic oxazine compound represented by the formula (1) (A) and a polyphenol (B) selected from the formulas (2) and (3). is there.

[0017]

Embedded image (Where [Aro] represents a monocyclic or condensed polycyclic aromatic hydrocarbon ring which forms a condensed ring by sharing an adjacent carbon atom with the oxazine nucleus, and R ¹ is a phenyl group, an alkyl having 1 to 4 carbons. A cyclohexyl group, and R ² has 1 carbon atom
To 4 alkyl groups, phenyl groups, benzyl groups or phenoxy groups, and m ≧ 0. )

[0018]

Embedded image (Where n ≧ 0, R ³ is hydrogen or an alkyl group having 1 to 3 carbon atoms, and R ⁴ , R ⁵ , and R ⁶ are the same or different alkyl groups, phenyl groups, or benzyl groups; Is an integer of 0 or 1 to 3, and q, r, and s are integers of 0 or 1 to 4. When p, q, r, and s are 2 or more, a plurality of substituents substituted on one benzene nucleus May be the same or different from each other.)

[0019]

Embedded image (Wherein n, R ³ , R ⁴ , R ⁵ , R ⁶ and p, q, r, s are the same as defined in formula (2), R ⁷ is a direct bond,-
CH ₂ —, —C (CH ₃ ) ₂ —, —O—, —S—, or —
Represents SO ₂ —. )

The present invention also provides a resin composition for semiconductor encapsulation comprising the above-mentioned curing agent comprising (A) and (B), (C) an epoxy resin, (D) an inorganic filler and (E) a curing accelerator. Things.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Monofunctional condensed polycyclic oxazine compound (A)) The monofunctional condensed polycyclic oxazine compound (A) used in the present invention (hereinafter referred to as "monofunctional oxazine compound" or "oxazine compound") ) Is represented by the formula (1), and is a heteropoly group obtained by condensing an oxazine nucleus with a monocyclic or condensed polycyclic aromatic hydrocarbon nucleus such as a benzene nucleus or a naphthalene nucleus or an anthracene nucleus. It is a cyclic compound. As an example of such an oxazine compound,
Examples include a benzoxazine compound of the formula (7) in which an oxazine nucleus and a benzene nucleus are condensed, and a naphthoxazine compound of the formula (8) in which a naphthalene nucleus is condensed. More specifically, examples of the benzoxazine compound of the formula (7) include 3-phenyl-3,4-dihydro-2H-benzo [e] [1,3] oxazine and 3-methyl-3,4-dihydro -2H-benzo [e] [1,
3] Oxazine, 6-tert-butyl-3-phenyl-3,4-
Dihydro-2H-benzo [e] [1,3] oxazine, 6-tert-butyl-3-cyclohexyl-3,4-dihydro-2H-benzo [e] [1,3] oxazine, 3-6-diphenyl- 3,4-dihydro-
2H-benzo [e] [1,3] oxazine, 6-benzyl-3-naphthyl-3,4-dihydro-2H-benzo [e] [1,3] oxazine, 6-
Benzyl-3-phenyl-3,4-dihydro-2H-benzo [e] [1,
3] Oxazine and the like, as an example of the naphthoxazine compound of the formula (8), 3-phenyl-3,4-dihydro-2H-naphtho [2,1-e]
[1,3] oxazine, 2-cyclohexyl-2,3-dihydro-1H
-Naphtho [1,2-e] [1,3] oxazine and the like. These condensed polycyclic oxazine compounds have one oxazine nucleus in the molecule and have one —O— bond derived from the raw material monohydric phenol in the oxazine nucleus, but other phenolic hydroxyl groups Is a monofunctional compound having no.

[0022]

Embedded image

[0023]

Embedded image (R ¹ , R ² and m in the formulas (7) and (8) are the same as defined in the formula (1))

The polyfunctional oxazine resin, which has been proposed to be used as a sealing material, has a higher melt viscosity than a monofunctional monooxazine compound. Due to the reaction, the viscosity as a sealing material further increases, high fluidity, regarding low viscosity,
It has major drawbacks. In addition, the composition comprising these polyfunctional oxazine resins has insufficient curability, and is difficult to remove, or has a large warpage of the BGA package, and is not practical. Hard to say.

(Synthesis of Monofunctional Condensed Polycyclic Oxazine Compound) The monofunctional oxazine compound used in the present invention comprises:
Monocyclic or condensed polycyclic phenols (a), formaldehyde (b), and amino groups having one phenolic hydroxyl group in one molecule and at least one ortho position to the hydroxyl group are not substituted from primary amine (c) to one closed in, can be synthesized by a known method, by the selection of the phenol (a) and primary amine (c), R ^1, R of formula (1)
Various oxazine compounds having different ² and n can be obtained.

The phenols (a) as raw materials include phenol, p-cresol, m-cresol, o-cresol, p-tert-butylphenol, m-tert-butylphenol, o-tert-butylphenol, p-phenylphenol, m-phenylphenol,
o-phenylphenol, p-benzylphenol, m-
Monosubstituted phenols such as benzylphenol, o-benzylphenol, p-phenoxyphenol, m-phenoxyphenol, o-phenoxyphenol, p-bromophenol, m-bromophenol, o-bromophenol, 1-naphthol, 2-naphthol And its substitutes,
Condensed polycyclic phenols having one phenolic hydroxyl group in one molecule such as hydroxyanthracene, hydroxyphenanthrene and a substituted product thereof are used. In particular, phenol, p-cresol, p-tert-butylphenol, p-phenylphenol, 1-phenylphenol, Naphthol, 2-
Naphthol is preferred.

Benzoxazine using phenol novolak resin or polyphenols such as various bisphenols, trisphenols and tetraphenols as raw materials has a relatively high viscosity, and reacts during kneading for complexation to increase the viscosity. Not easy to use.

As formaldehyde, formalin which is an aqueous solution thereof, polymer paraform, trioxane and the like are used.

Examples of the primary amine (b) having one amino group in one molecule include aromatic amines such as aniline, substituted aniline and naphthylamine, and aliphatic amines such as cyclohexylamine and methylamine. An oxazine compound obtained by using an aromatic amine is less advantageous in reacting with the other curing agent component, polyphenol, during kneading than when an aliphatic amine is used, and is therefore advantageous and preferable for lowering the viscosity. It is also possible to use an aliphatic amine in combination with an aromatic amine in balance with the curability in the mold.

The monofunctional condensed polycyclic oxazine compound (A) can be prepared from the above raw materials by a known method (for example, JP-A-49-473).
87). That is, phenols are dissolved in a suitable solvent such as dioxane, toluene, methanol, ethylene glycol dimethyl ether, or the phenols are melted by heating, and a primary amine and formaldehyde are added thereto. Or
The phenol and the primary amine are dissolved in the above solvent or melted by heating, and formaldehyde is added therein. Alternatively, any method can be used, such as dissolving phenols in a solvent or melting by heating, and adding a preliminarily reacted primary amine and formaldehyde thereto. Usually, the reaction proceeds without a catalyst, but a hydroxide of an alkali metal or an alkaline earth metal, a tertiary amine, or the like can be used as a catalyst. The feed ratio of the raw materials is usually phenols / primary amine / formaldehyde = 1 /
The reaction condition is usually a temperature of 60 to 1 (molar ratio).
The reaction is carried out at 20 ° C. for about 2 to 24 hours. The desired oxazine compound can be obtained by separating the organic layer, which is a reaction product, from the condensed water generated by the reaction, or removing the condensed water out of the system by distillation, and taking out the organic layer. Alternatively, the precipitated oxazine compound is separated and removed by filtration or the like.

The oxazine compound obtained by the above reaction usually contains, as impurities, an oligomer formed by ring-opening of the oxazine compound, for example, a polyhydroxy compound having a structure represented by the following formula (9) as a repeating unit. If the number of ring oligomers is large, the viscosity will be high. Therefore, it is desirable that the condensed polycyclic oxazine compound used as the composition for semiconductor encapsulation of the present invention has less than 50% of the above impurities. The formation of the above-mentioned ring-opened oligomer can be suppressed by reaction conditions for the synthesis of the oxazine compound, for example, selection of the reaction temperature and the reaction solvent.

[0032]

Embedded image

As another impurity, it is desirable that the unreacted monohydroxy compound is 2% or less, the primary amine is 2% or less, and the reaction product of only the primary amine and formaldehyde is 10% or less.

If necessary, the oxazine compound is washed repeatedly with an aqueous solution of an alkali metal hydroxide and pure water, and then the remaining oligomer and impurities are removed by drying under reduced pressure. Can be reduced.

(Polyphenols (B)) The polyphenols (B) used as curing agents for epoxy resins are as follows:
A phenol resin having phenol in the side chain of the triphenylmethane structure represented by the formula (2) or a phenol resin having a triphenylmethane structure in which phenol is bonded to the side chain represented by the formula (3) via a benzene nucleus These are used alone or in combination. In the formula (2), n ≧ 0 and usually obtained as a mixture of compounds having different molecular weights are used as they are, but n is preferably 2 or less as an average value. If n is a high molecular weight phenolic resin larger than this range, the viscosity increases and the fluidity is impaired, which is not preferable.

Of the above polyphenols, the polyphenol of the formula (2) is obtained by the reaction of phenol with hydroxybenzaldehyde such as salicylaldehyde, and the compound of the formula (3)
Is obtained by the reaction of phenol with benzaldehydes to which phenol is bound.

As the polyphenols, in addition to the polyphenols (B) represented by the formulas (2) to (3), phenol aralkyl resins, phenol novolak resins, cresol novolak resins, bisphenol A, bisphenol F,
A phenol resin such as polyparavinylphenol or decalin-modified phenol resin can be used in combination as long as the properties of the resin composition of the present invention are not affected.

(Epoxy resin (C)) As the epoxy resin (C) cured by the curing agent of the present invention, any epoxy resin having two or more epoxy groups in one molecule can be used. For example, triphenol epoxy resin, tetraphenolethane epoxy resin, biphenyl epoxy resin, phenol novolak epoxy resin, orthocresol novolak epoxy resin, dihydroxynaphthalene novolak epoxy resin, dicyclopentadiene epoxy resin, stilbene epoxy resin,
Bisphenol A or F type epoxy resin, halogenated epoxy resin, hydroquinone type epoxy resin and the like can be mentioned, and in particular, triphenol type epoxy having a glycidyl ether group-substituted phenyl group represented by the formula (4) or (5) When a resin is used, the structure is similar to the component (B) of the curing agent of the present invention, and therefore, there is an advantage that the resin has high Tg, rapid curability, and high heat resistance.

[0039]

Embedded image (Wherein n, R ³ , R ⁴ , R ⁵ , R ⁶ and p, q, r, s are the same as defined in the formula (2), and OG represents a glycidyl ether group.)

[0040]

Embedded image (Where n, R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and p, q, r,
s is the same as defined in formula (3), and OG represents a glycidyl ether group. )

(Oxazine compound / polyphenols /
The composition ratio of the epoxy resin) The oxazine compound and the polyphenol compound of the present invention act as a curing agent for the epoxy resin. The mixing ratio of the two components of the curing agent, oxazine compound (A) / polyphenol compound (B), is as follows: The weight ratio is preferably from 5/95 to 30/70. This ratio is 5
If it is less than / 95, the effects of using the oxazine compound (low viscosity, high fluidity, low water absorption, high Tg, low curing shrinkage, etc.) cannot be sufficiently exhibited. This ratio is 30/70
If it exceeds, the curing speed is reduced, the moldability is poor, or the sealing material composition manufactured by combining with an epoxy resin, an inorganic filler, a curing accelerator, etc., may be likely to cause cold flow. is there.

The mixing ratio of the curing agent component ((A) + (B)) to the epoxy resin (C) is 1.2 / 1 to 1 in an equivalent ratio of epoxy group / (oxazine ring + hydroxyl group). /1.2
It is preferable to be within the range. This ratio is 1.2
When the ratio exceeds / 1, the epoxy groups react with each other and 1 /
If it is less than 1.2, unreacted hydroxyl groups remain in the cured product, causing an increase in water absorption. Also, the curing speed tends to decrease slightly.

(Inorganic Filler (D)) The resin composition for semiconductor encapsulation of the present invention contains an inorganic filler as an essential component. As the inorganic filler, silica, alumina,
Examples include titanium white, silicon nitride, silicon carbide, calcium carbonate, magnesium carbonate, aluminum hydroxide, magnesia, clay, talc, calcium silicate, and titanium oxide. Among them, silica and alumina are preferred. Either spherical or crushed shapes can be used, but those having a spherical particle size distribution that can be finely packed are more preferable.

The filling amount of the inorganic filler is preferably 70 to 95% by weight, particularly preferably 80 to 93% by weight based on the total amount of the resin composition for semiconductor encapsulation. The amount of the inorganic filler is 70
%, It is inferior in moisture resistance and also has an adverse effect on solder heat resistance and warpage. On the other hand, if it exceeds 95%, the fluidity is lost or the viscosity is greatly increased, resulting in poor moldability. As long as the moldability (melt viscosity, fluidity) is not impaired, it is preferable that the amount of the inorganic filler is large from the viewpoint of low stress and low hygroscopicity.

(Curing Accelerator (E)) As the curing accelerator (E), a known curing accelerator for curing an epoxy resin with a phenolic curing agent can be used. These curing accelerators also promote the ring-opening polymerization reaction between the oxazine compound represented by the formula (4) and the phenol resin. Examples of such curing accelerators include tertiary amines such as tributylamine, triethylamine, 1,8-diazabicyclo (540) undecene-7, triethylamine, benzyltrimethylammonium chloride, benzyltrimethylammonium hydroxide, and triethylammonium tetraphenylborate. Quaternary ammonium salts, imidazoles such as 2-methylimidazole, 2,4-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, and 2-phenyl4-methylimidazole;
Examples thereof include tetraphenylboron salts with imidazoles such as ethyl 4-methylimidazole tetraphenylborate, organic phosphine compounds such as triphenylphosphine and tetraphenylphosphonium tetraphenylborate, and boron salts thereof. Among them, 1,8-diazabicyclo (540) undecene-7 (DBU) and imidazoles are preferable from the viewpoint of curability and moisture resistance. In order to achieve higher fluidity, a heat-latent curing accelerator that exhibits activity upon heating is more preferable, and tetraphenylphosphonium / tetraphenylborate (TPP / TPB) or a tetra-substituted phosphonium organic acid is preferred. Salts, such as tetraphenylphosphonium tetrakis (naphthalenecarboxylate) borate, are preferred.

(Other Additives) The composition for encapsulating a semiconductor of the present invention may contain, if necessary, natural wax,
Synthetic wax, higher fatty acids and their metal salts, paraffin, etc., carbon black and the like as coloring agents, silane coupling agents and titanate coupling agents as coupling agents, brominated epoxy resins, phosphorus compounds, antimony trioxide as flame retardants, Melamine or the like may be blended. Also, various elastomers such as polybutadiene, butadiene-acrylonitrile copolymer, silicone rubber, and silicone oil can be added or reacted in advance as a low stress agent. The amounts of these additives used may be the same as the amounts used in conventional epoxy resin compositions for semiconductor encapsulation.

(Mixing method) The epoxy resin composition of the present invention comprises the above-mentioned oxazine compound (A), polyphenols (B), epoxy resin (C), inorganic filler (D), curing accelerator (E) and other components. Is sufficiently mixed with a mixer or the like, and further kneaded with a hot roll, kneader, extruder, or the like, and then solidified by cooling and pulverized to an appropriate size.

[0048]

Since the monofunctional condensed polycyclic benzoxazine compound used in the present invention has a low viscosity, a low-viscosity / high-flowability composition can be obtained by blending it with a specific polyphenol. It reacts quickly with polyphenols at the time of molding and curing to increase the molecular weight and generate hydroxyl groups, so it acts as a curing agent for epoxy resins with excellent curability and demoldability, and has high fluidity and rapid curability, and low water absorption. And a practical encapsulating resin composition which simultaneously satisfies a high Tg at a high level. Furthermore, the resin composition of the present invention has less deterioration with time of the molding and curing properties. Especially for TQFP sealant and fine pitch BGA, fluidity, solder heat resistance,
High Tg, excellent in curability and curability over time, and high Tg compatible with BGA for regular size and MPA method
Fluidity and solder heat resistance are imparted to the sealing agent, and it is extremely useful as a semiconductor sealing material suitable for high-density mounting and surface mounting.

[0049]

EXAMPLES The present invention will be specifically described below with reference to examples. The types of the raw material compounds used in the examples,
The methods for evaluating the properties of the sealant are as follows.

1. Raw Materials (A) Condensed polycyclic oxazine compound (1) Benzoxazine (BO): synthesized according to Production Example 1 below. (2) Benzoxazine (BO): synthesized according to Production Example 2 below. (3) Polyfunctional condensed polycyclic oxazine compound: synthesized according to Production Example 3 below. (4) Monobenzoxazine polymer: synthesized according to Production Example 4 below.

(B) Polyphenols The following two types of polyphenols were used. (1) P. Ph Polyphenol represented by the following formula (10)

[0052]

Embedded image n = 0.3 (average) OH group equivalent: 98 g / eq Melt viscosity: 7.7 poise (150 ° C.) Ph Polyphenol represented by the following formula (11)

[0053]

Embedded image n = 0.2 (average) OH group equivalent: 154 g / eq

(C) Epoxy resin (1) Epoxy resin: epoxy resin represented by the following formula (12)

[0055]

Embedded image n = 0.3 (average) Epoxy group equivalent: 168 g / eq (2) Epoxy resin: epoxy resin represented by the following formula (13)

[0056]

Embedded image n = 1.6 (average) Epoxy group equivalent: 213 g / eq

2. Physical property evaluation method [Physical properties of sealing material] (1) Melt viscosity: The viscosity at 175 ° C was measured by a flow tester. (2) Spiral flow: Spiral flow is measured by transfer molding. (3) Curast meter curability: The torque rise speed by curing at 175 ° C. is measured with a curast meter, and the torque of 60 seconds, 90 seconds and 120 seconds is measured. read. (4) Removability: The removability after transfer molding at 175 ° C. for 120 seconds was evaluated based on the following three grades based on the presence or absence of deformation, hot rigidity and the like. ：: good △: slightly poor × poor

[Physical Properties of Cured Sealing Material] 175 ° C., 120
After transfer molding in seconds, a post cure at 180 ° C. for 6 hours was performed to prepare a cured product, which was evaluated by the following method. (4) Tg: Tg was determined from the inflection point of the linear expansion coefficient by TMA. (5) Water absorption: 85 disks with a diameter of 50 mm and a thickness of 3 mm
24 hours when left in air at 85 ° C and 85% humidity, 7
It was determined from the weight increase after 2 hours and 168 hours.

[Preparation Example 1] (Synthesis of benzoxazine) 50 parts (parts by weight, the same applies hereinafter) of phenol were dissolved in 25 parts of a dioxane solvent and heated to 90 ° C. 49.5 parts of aniline and 86.2 parts of formaldehyde were each added dropwise over 2 hours. The temperature was raised to the reflux temperature, and kept in that state for 4 hours. After completion of the reaction, the condensed water and water in formalin were removed from the organic layer, and then the organic layer was washed with water and separated.
After washing with water, dioxane and unreacted monomers are removed at 40 to 60 ° C. under reduced pressure to remove 89.5 parts of benzoxazine (3-phenyl-3,4-dihydro-2H-benzo [e] [1,3]. Oxazine) was obtained. The properties of the obtained benzoxazine are as follows. Purity 81% (by GPC) Phenol 0.1% (by GC) Aniline 0.2% (by GC) Aniline formaldehyde polymer 5.5% (by GC) Ring-opening polymer 13% (by GPC) Viscosity (30 ° C) 2.5 poise Oxazine ring Equivalent (calculated including those already opened): 224 g / eq

[Production Example 2] (Production of benzoxazine) 150 parts of p-tert-butylphenol were dissolved in 80 parts of a methanol solvent. Paraformaldehyde 80
And 0.58 parts of KOH were dissolved in 80 parts of a methanol solvent, and 99 parts of aniline was added to the solution while cooling. Thereafter, a paraformaldehyde / aniline / KOH methanol solution was added to the p-tert-butylphenol solution, and reacted at 70 ° C. for 4 hours while stirring. After the reaction, 129 parts of benzoxazine (6-tert-butyl-3-phenyl-3,4-dihydro-2H-benzo [e] [1,3] oxazine) was obtained in the same manner as in Production Example 1. The benzoxazine obtained had an oxazine ring equivalent (calculated including that of the ring opened) of 267 g / eq.

[Production Example 3] (Production of polyfunctional benzoxazine) 6,6- (1-methylethylidene) bis (3,4-dihydro-3-phenyl) was prepared from bisphenol A and aniline / formaldehyde in the same manner as in Production Example 1. -2H-1,3-benzoxazine) was synthesized. The oxazine ring equivalent was 232 g / eq (calculated including that of the ring opened).

[Production Example 4] (Production of Monobenzoxazine Polymer) To 20 g of the benzoxazine obtained in Production Example 1 was added 1 g of phenol, and heat treatment was performed in MIBK at 100 ° C. for 300 minutes to obtain a molecular weight of 2500 or more. A high molecular weight polymer was obtained.

Examples 1 to 8 The benzoxazines obtained in Production Examples 1 and 2 as condensed polycyclic oxazine compounds, polyphenols as polyphenols, epoxy resins as epoxy resins, and 2-ethyl-4 as a curing accelerator -Methylimidazole or tetraphenylphosphonium / tetraphenylborate (TP
P.TPB), silica treated with a silane coupling agent as an inorganic filler, and carnauba wax as a release agent were used in the mixing ratio shown in Table 1. First, a polyphenol and an epoxy resin in which a predetermined amount of a benzoxazine compound and a predetermined amount of a curing accelerator were melted were weighed and sufficiently pulverized and mixed by a mixer. Further, the mixture was mixed with silica treated with a silane coupling agent and carnauba wax, and thoroughly mixed with a mixer. The mixture was kneaded with a two-roll kneader at 90 ° C. for 3 to 5 minutes, and then pulverized to 5 mm under with a cutter mill to prepare a sealing material sample, and the physical properties thereof were measured. The results are shown in Tables 1 and 2.

[Comparative Example 1] In Example 1, only the polyphenol was used as an epoxy resin curing agent in the mixing ratio shown in Table 1 without using a benzoxazine compound.
A sealing material sample was prepared in the same manner as described above, and its physical properties were measured. Table 2 shows the results.

Comparative Example 2 In Comparative Example 1, a sealing material sample was prepared in the same manner as in Example 1 except that polyphenol was used instead of polyphenol, and its physical properties were measured. Table 2 shows the results.

Comparative Example 3 A sealing material sample was prepared in the same manner as in Example 1 except that the polyfunctional benzoxazine obtained in Production Example 3 was used in place of benzoxazine, and the physical properties thereof were measured. It was measured. Table 3 shows the results.

Comparative Example 4 In Comparative Example 3, a sealing material sample was prepared in the same manner as in Comparative Example 3 except that polyphenol was used instead of polyphenol and epoxy resin was used instead of epoxy resin, and the physical properties were measured. did. Table 3 shows the results.

Comparative Example 5 Example 1 was repeated using only the polyfunctional benzoxazine compound obtained in Production Example 3 as a curing agent.
A sealing material sample was prepared by curing the epoxy resin in the same manner as described above, and the physical properties were measured. Table 3 shows the results.

Comparative Example 6 Using only the benzoxazine polymer obtained in Production Example 4 as a curing agent, an epoxy resin was cured in the same manner as in Example 1 to prepare a sealing material sample, and the physical properties thereof were measured. It was measured. Table 3 shows the results.

Comparative Example 7 An epoxy resin was cured with a curing agent composed of a polymer of benzoxazine and polyphenol in the same manner as in Example 1, a sealing material sample was prepared, and its physical properties were measured. Table 3 shows the results.

[0071]

[Table 1] TPP ・ TPB ： Tetraphenylphosphonium ・ Tetraphenylborate

[0072]

[Table 2] TPP ・ TPB ： Tetraphenylphosphonium ・ Tetraphenylborate

[0073]

[Table 3] TPP ・ TPB ： Tetraphenylphosphonium ・ Tetraphenylborate

The epoxy resin of each of the examples cured by using the monofunctional condensed polycyclic oxazine compound of the present invention and a curing agent composed of polyphenols has a low viscosity, a fast curing property, a moldability, a low Tg, and a low Tg. It has a good balance of physical properties such as water absorption, and is excellent as a molding material for sealing. On the other hand, in Comparative Examples 1 and 2 in which no monofunctional condensed polycyclic oxazine compound was used, the melt viscosity was high and the fluidity was insufficient. Further, in the results of Comparative Examples 3 and 4 using a polyfunctional benzoxazine as the benzoxazine compound, the melt viscosity was increased and the fluidity was poor. In the result of Comparative Example 5 in which the epoxy resin was cured only with the above polyfunctional benzoxazine compound without using the phenol resin, the curability was remarkably low and the water absorption resistance was also poor. Furthermore, in Comparative Example 6 in which a polymer (polyfunctional polyphenol) obtained by pre-polymerizing the monofunctional benzoxazine compound used in the present invention was used as a curing agent, the melt viscosity was remarkably increased and the water absorption resistance was poor. The result is.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 23/31 (72) Inventor Masato Ohira 3 Oji Hikari, Kashima City, Ibaraki Pref. Sumikin Chemical Co., Ltd. 72) Inventor Kunio Ichihara 3, Oaza, Kashima, Ibaraki Pref. F-term (reference) 4J002 CC03X CC06X CC07X CD00W CD07W CE00X EJ017 EJ047 EU236 FD018 FD14X FD146 FD147 FD159 GQ05 DA05 AF03 DA06 DB05 DC38 FB07 JA07 4M109 AA01 BA01 BA03 CA21 EA02 EA03 EB02 EB03 EB04 EB12 EC01 EC05 EC20

Claims (5)

[Claims] A curing agent for an epoxy resin comprising a monofunctional condensed polycyclic oxazine compound represented by the formula (1) (A) and a polyphenol (B) selected from the formulas (2) and (3). Embedded image (Where [Aro] represents a monocyclic or condensed polycyclic aromatic hydrocarbon ring which forms a condensed ring by sharing an adjacent carbon atom with the oxazine nucleus, and R ¹ is a phenyl group, an alkyl having 1 to 4 carbons. Or a cyclohexyl group, and R ² has 1 to 1 carbon atoms.
4 is an alkyl group, a phenyl group, a benzyl group or a phenoxy group, and m ≧ 0. ) (Where n ≧ 0, R ³ is hydrogen or an alkyl group having 1 to 3 carbon atoms, and R ⁴ , R ⁵ , and R ⁶ are the same or different alkyl groups, phenyl groups, or benzyl groups; Is an integer of 0 or 1 to 3, and q, r, and s are integers of 0 or 1 to 4. When p, q, r, and s are 2 or more, a plurality of substituents substituted on one benzene nucleus May be the same or different from each other.) (Wherein n, R ³ , R ⁴ , R ⁵ , R ⁶ and p, q, r, s are the same as defined in formula (2), R ⁷ is a direct bond,-
CH ₂ —, —C (CH ₃ ) ₂ —, —O—, —S—, or —
Represents SO ₂ —. ) 2. A weight ratio (A) / (B) of a monofunctional condensed polycyclic oxazine compound (A) and a polyphenol compound (B).
Is from 5/95 to 30/70. 3. A monofunctional condensed polycyclic oxazine compound according to claim 1, (B) a polyphenol according to claim 1, (C) an epoxy resin, (D) an inorganic filler, and (E) a curing accelerator. A resin composition for semiconductor encapsulation comprising: 4. The resin composition for semiconductor encapsulation according to claim 3, wherein the epoxy resin is an epoxy resin represented by the formula (4) or (5). Embedded image (Where n, R ³ , R ⁴ , R ⁵ , R ⁶ and p, q, r, s are
As defined in (2), OG represents a glycidyl ether group. ) (Where n, R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and p, q, r,
s is the same as defined in formula (3), and OG represents a glycidyl ether group. ) 5. The compounding ratio of the condensed polycyclic oxazine compound (A) and polyphenol compound (B) to the epoxy resin (C) is equivalent to epoxy group / (oxazine ring of condensed polycyclic oxazine compound + hydroxyl group of polyphenols). The resin composition for semiconductor encapsulation according to claim 3, wherein the ratio is 1.5 / 1 to 1 / 1.2.