JP2001316566A - One pack epoxy resin composition and epoxy resin composition for semiconductor sealing use using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-viscosity one-pack epoxy resin composition stable to moisture, good in storage stability and capable of giving the corresponding cured products with high heat resistance, moisture resistance and adhesion. SOLUTION: This one-pack epoxy resin composition comprises (A) an epoxy compound, (B) an aromatic amine, and (C) a compound having in the molecule at least one ester linkage formed by reaction an 1-alkoxyethanol and a carboxylic acid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a one-part composition using a compound having at least one ester bond formed by a reaction between 1-alkoxyethanol and a carboxylic acid in a molecule as a curing accelerator using an aromatic amine as a curing agent. The present invention relates to a conductive epoxy resin composition and an epoxy resin composition for semiconductor encapsulation using the same. More specifically, a one-pack type epoxy resin composition that is stable against moisture, has low viscosity and good storage stability, and has excellent heat resistance, moisture resistance, and adhesion when cured. The present invention relates to a resin composition and an epoxy resin composition for semiconductor encapsulation using the same.

[0002]

2. Description of the Related Art Liquid epoxy resin compositions are preferably used for sealing semiconductors as liquid resin compositions for tape carrier packages and the like because of their excellent workability. Have been.

However, the epoxy resin composition for semiconductor encapsulation peels off at the interface between the chip and the encapsulating resin during heating due to the stress generated by the difference between the coefficient of thermal expansion of the silicon chip and that of the encapsulating resin. In order to prevent such problems as above, the inorganic filler is generally contained in a high ratio. By containing the inorganic filler, the coefficient of thermal expansion of the resin composition can be made closer to that of the silicon chip. For this reason, the composition before the inorganic filler is filled must have a low viscosity.

[0004] Epoxy resin compositions for semiconductor encapsulation are used as one-pack type resin compositions in order to suppress variations in the compounding ratio and increase productivity. Sex matters. Generally, -40 to-
It is a practical level that there is no large increase in viscosity even when stored at a low temperature of 20 ° C. for 1 year or more, and the rate of increase in viscosity after 1 day at room temperature is 2 times or less.

Further, the epoxy resin composition for semiconductor encapsulation must have a high level of heat resistance, moisture resistance and adhesiveness when cured.

Heretofore, as a curing agent for an epoxy resin composition for encapsulating a semiconductor, a curing agent having a low viscosity and relatively good storage stability can be obtained, so that an acid anhydride such as methylhexahydrophthalic anhydride is used. Many are used.

However, when an acid anhydride is used as a curing agent, it is easily affected by moisture because of its high hygroscopicity, and is not suitable for producing a stable composition.
In addition, a PCT for evaluating the moisture resistance of the cured product is easy to be hydrolyzed because an ester bond is generated by the curing reaction.
Moisture easily penetrates during testing. The infiltrated water causes hydrolysis of the ester bond, corrosion of the semiconductor element, cracking of the sealing component due to vaporization of the water during heating, and the like. Further, the adhesiveness to metal is not sufficient.

On the other hand, when a liquid amine compound is used as a curing agent, there is no problem as described above. However, many liquid amine compounds are aliphatic, and in this case, heat resistance of the cured product is expected. However, it has been considered that it is difficult to obtain a one-pack type resin composition having high heat resistance when a cured product is obtained, because it has drawbacks such as inability to store and low storage stability.

Further, it is possible to use a liquid aromatic amine compound as a curing agent, but in this case, there is a disadvantage that the curing reaction requires heating at a high temperature for a long time.

[0010]

Means for Solving the Problems In view of the above-mentioned circumstances, the present inventors have made intensive studies and as a result, have found that 1-alkoxyethanol and 1-alkoxyethanol have not been used as a curing accelerator in epoxy resin compositions. The present invention has found that when a compound having at least one ester bond generated by a reaction with a carboxylic acid is used as a curing accelerator, the above-described problem when an aromatic amine compound is used as a curing agent can be solved. Was completed.

That is, the present invention comprises (A) an epoxy compound, (B) an aromatic amine, and (C) a compound having at least one ester bond formed in the molecule by the reaction between 1-alkoxyethanol and a carboxylic acid. The one-part epoxy resin composition (Claim 1), the epoxy resin composition according to Claim 1, further comprising (D) an inorganic filler (Claim 2), and the composition according to Claim 1 or Claim 2. The present invention relates to an epoxy resin composition for semiconductor encapsulation comprising:

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The one-part epoxy resin composition of the present invention contains an epoxy compound (A) as a main component and an aromatic amine (B) as a curing agent, and further contains an intramolecular molecule as a curing accelerator. Containing a compound (C) having at least one ester bond generated by the reaction between 1-alkoxyethanol and a carboxylic acid (hereinafter, also referred to as compound (C)) (hereinafter, this composition is referred to as Epoxy resin composition (I)).

In the present invention, since an aromatic amine (B) is used as a curing agent, a stable composition which is hardly affected by moisture can be obtained, the cured product is hardly hydrolyzed, and a metal or the like is used. And the adhesiveness with the resin is also improved. Further, since the compound (C) is used as the curing accelerator, the curing reaction can be performed at a lower temperature and in a shorter time than when the compound (C) is not used. As a result, a one-pack type epoxy resin composition that is stable to moisture, has low viscosity and good storage stability, and does not require high-temperature and long-time heating during the curing reaction. It is suitable for products, especially epoxy resin compositions for semiconductor encapsulation, and when it is made into a cured product, a cured product having excellent heat resistance, moisture resistance and adhesiveness can be obtained.

The epoxy compound (A) can be used without any particular limitation as long as it is an epoxy compound conventionally used in a one-pack type epoxy resin composition, preferably an epoxy resin composition for encapsulating a semiconductor. . Examples of such epoxy compounds include various epoxy resins as well as other epoxy compounds such as reactive diluents. These may be used alone or in combination of two or more. The other epoxy compound such as the reactive diluent is a component usually used for adjusting the viscosity of the composition and the elastic modulus of the cured product.

The epoxy resin having two or more epoxy groups in the molecule is preferable from the viewpoint that a crosslinked structure capable of exhibiting sufficient heat resistance can be formed. Further, four or less, and more preferably three or less are preferable in that a low-viscosity resin composition can be obtained. If the number of epoxy groups contained in the molecule is too small, the heat resistance of the cured product tends to be low, the strength tends to be weak, etc., and if the number is too large, the viscosity of the resin composition increases, and curing shrinkage occurs. Tend to increase.

The number average molecular weight of the epoxy resin is preferably from 200 to 5,500, more preferably from 200 to 1,000, particularly preferably from 300 to 400, from the viewpoint of a good balance of physical properties. If the number average molecular weight is too small, the strength of the cured product will be weak, and the tendency to decrease the moisture resistance will tend to occur.If the number average molecular weight is too large, the viscosity of the resin composition will be high, and the diluent will be used for workability adjustment. Tend to increase, for example.

Further, the epoxy equivalent of the epoxy resin is preferably 100 to 2750, more preferably 100 to 500, and particularly preferably 150 to 200, from the viewpoint that the compounding amount of the curing agent falls within an appropriate range. If the epoxy equivalent is too small, the compounding amount of the curing agent becomes too large, and the properties of the cured product tend to deteriorate, and if too large, the compounding amount of the curing agent decreases and the molecular weight of the epoxy resin itself increases. Tend to increase and the viscosity of the resin composition tends to increase.

Specific examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, naphthalene type epoxy resin, biphenyl type epoxy resin, glycidylamine type epoxy resin, alicyclic type Epoxy resins, dicyclopentadiene-type epoxy resins, phenol novolak-type epoxy resins, polyester-modified epoxy resins, copolymers with other polymers such as silicone-modified epoxy resins, and the like can be given. Among these, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, naphthalene type epoxy resin, phenol novolak type epoxy resin, etc. have relatively low viscosity, and have excellent heat resistance and moisture resistance. It is preferable from the point of being performed.

Examples of the reactive diluent among the other epoxy compounds include tert-butylphenylglycidyl ether, 2-ethylhexylglycidylether, allylglycidylether, phenylglycidylether, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 1- (3-glycidoxypropyl) 1,1,3,
3,3-pentamethyldisiloxane, N-glycidyl-
Monoglycidyl compounds such as N, N-bis [3- (trimethoxysilyl) propyl] amine and monoalicyclic epoxy compounds such as 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane.

Other epoxy compounds other than the reactive diluent include resorcin diglycidyl ether, hydroquinone diglycidyl ether,
5-di-tert-butylhydroquinone diglycidyl ether, butanediol diglycidyl ether, butenediol diglycidyl ether, butynediol diglycidyl ether, glycerin triglycidyl ether,
Alkylene glycidyl ethers such as trimethylolpropane triglycidyl ether and pentaerythritol tetraglycidyl ether; 1,3-diglycidyl-
5,5-dialkylhydantoin, 1-glycidyl-3
Glycidyl group-containing hydantoin compounds such as-(glycidoxyalkyl) -5,5-dialkylhydantoin;
Diglycidyl phthalate, diglycidyl tetrahydrophthalate, glycidyl esters such as dimer acid diglycidyl ester, tetraglycidyl diaminodiphenylmethane, triglycidyl-p-aminophenylmethane,
Glycidyl group-containing amino compounds such as triglycidyl-m-aminophenylmethane, diglycidylaniline, diglycidyltoluidine, tetraglycidyl-m-xylylenediamine, and 1,3-bis (3-glycidoxypropyl) -1,1 , 3,3-tetramethyldisiloxane,
Glycidyl group-containing siloxanes such as α, β-bis (3-glycidoxypropyl) polydimethylsiloxane are exemplified.

If a large amount of other epoxy compounds such as the reactive diluent is used, the moisture resistance and heat resistance of the cured product are reduced, so that 30% by weight (hereinafter, referred to as%) in the component (A), It is preferable to use 15% or less.

The aromatic amine (B) contained in the epoxy resin composition (I) is an amine compound and does not form an ester bond by a curing reaction, so that the resin composition has a higher hygroscopic property than an acid anhydride. A cured product having low moisture resistance and excellent moisture resistance can be obtained. In addition, since the resin composition is an aromatic amine, the storage stability of the resin composition is improved and the heat resistance of the cured product is higher than that of the case of the aliphatic amine compound. Furthermore, since the reactive group is an amino group, compared with the case where an acid anhydride is used as a curing agent,
Excellent adhesion to metals. Further, although many aromatic amines are solid, when diethyltoluenediamine or the like described below is used, the viscosity of the resin composition is reduced because the liquid is a low-viscosity liquid despite being an aromatic amine. Can be lower.

As the aromatic amine (B), any aromatic amine which has been conventionally used in a one-pack type epoxy resin composition, preferably an epoxy resin composition for encapsulating a semiconductor, can be used without any particular limitation. it can. Examples of such aromatic amines include, for example, diethyltoluenediamine (hereinafter, also referred to as DETDA), 3,3′-diethyl-4,4′-diaminodiphenylmethane, and the like. The DETDA is an aromatic amine compound having a structure in which a phenyl group of toluene is substituted with two amino groups and two ethyl groups, for example, a structure shown in Japanese Patent Application No. 10-271965. Among them, 3,5-diethyl-2,6-toluenediamine (hereinafter, referred to as 2,6-T)
DA), 3,5-diethyl-2,4-toluenediamine (hereinafter, also referred to as 2,4-TDA), and a mixture thereof are preferable. Of the above mixtures, especially 2,
6-TDA / 2,4-TDA is 30/70 to 10/90
(Hereinafter, also referred to as component (B-1)) is preferable from the viewpoint of easy availability.

The amount of the component (B) to be used with respect to the component (A) is not particularly limited as long as the compounding ratio can exhibit the characteristics of the composition of the present invention. It is preferable that the active hydrogen of the component (B) is blended in a range of 0.7 to 1.3 equivalents, more preferably 0.8 to 1.2 equivalents. When the amount of active hydrogen is more than 1.3 equivalents, the content of the epoxy compound in the composition becomes too low, which tends to cause poor curing, weakened cured product, and the like. If the amount is less than the equivalent, a tendency such as an increase in the viscosity of the resin composition tends to occur.

The epoxy resin composition (I) of the present invention is a one-part type and has good workability, so that it can be used for semiconductor encapsulation. Therefore, the mixture of the components (A) and (B) has a viscosity at 25 ° C. of 500 to 150,000 mPa · s.
s, more preferably 500 to 10000 mPa · s, especially 800 to 2000 mPa · s, from the viewpoint that a large amount of inorganic filler can be blended.

The epoxy resin composition (I) of the present invention comprises
The compound (C) which acts as a curing accelerator for promoting the curing reaction between the component (A) and the component (B) is contained.

The compound (C) is a compound having at least one ester bond generated by the reaction between 1-alkoxyethanol and carboxylic acid in the molecule, and is at room temperature (about 25 ° C.).
In the temperature range below -20 ° C, the composition does not act as a curing accelerator and has sufficient storage stability.
0 ° C, further 130-175 ° C, sometimes 130-16
When the temperature reaches 0 ° C., it acts as a curing accelerator and causes the curing reaction to proceed promptly.

The compound (C) is, for example, a compound represented by the following general formula (I): R ¹ (COO—CH (OR ² ) —CH ₃ ) _n (I) (wherein R ¹ has 2 to 10 carbon atoms and nitrogen An n-valent hydrocarbon group which may contain one or more atoms such as atoms and oxygen atoms, R ² has 1 to 6 carbon atoms, and may contain one or more kinds of nitrogen atoms and oxygen atoms. A good monovalent hydrocarbon radical, n
Is an integer of 1 to 6), and specific examples thereof include, for example, formula (1):

[0029]

Embedded image

Wherein R ¹ is a divalent phenyl group and R ² is a propyl group, R ¹ is a trivalent phenyl group and R ² is a propyl group, and R ¹ is a tetravalent phenyl group Wherein R ² is a propyl group. These may be used alone or in combination of two or more. Among them, the compound represented by the formula (1) is preferable from the viewpoint of a balance between curing reactivity and storage stability.

The amount of the compound (C) used is not particularly limited as long as the above-mentioned effect of accelerating curing can be obtained.
The amount is preferably from 0.3 to 12 parts, more preferably from 2 to 8 parts, per 100 parts of the component (A) from the viewpoint of heat resistance and storage stability of the cured product. When the amount of the compound (C) used is less than 0.3 part, a tendency that a sufficient curing promoting effect cannot be obtained tends to occur. Instead, undesirable tendencies such as poor storage stability tend to occur.

Since the amount of the component (C) contained in the epoxy resin composition (I) of the present invention is small, the viscosity at 25 ° C. is 500 to 150,000 mPa · s, and more preferably 500 to 100,000 mPa · s.
00mPa · s, especially 800-2000mPa · s
Often a liquid.

The epoxy resin composition (I) of the present invention comprises:
In order to reduce the coefficient of thermal expansion of the cured product, increase the strength, and the like, an inorganic filler as the component (D) can be blended.

As the inorganic filler (D), any conventionally used inorganic filler can be used without particular limitation. Specific examples thereof include fused silica powder, quartz glass powder, crystalline silica powder, glass fiber, alumina powder, and talc. Of these, the use of spherical fused silica powder having an average particle size of 10 to 20 μm can effectively suppress the increase in viscosity of the resin composition due to filling, and is effective because the coefficient of thermal expansion of itself is small. This is preferable in that the thermal expansion coefficient of the cured product can be reduced.

When the inorganic filler (D) is used, the filling rate is 5 to 80% in the composition comprising the components (A) to (C) and the inorganic filler (D), and more preferably 30 to 7%.
Generally, it is set to 0%.

The epoxy resin composition of the present invention comprises the components (A), (B) and (C), if necessary, an inorganic filler (D), a diluent for adjusting workability, and other components. It can be obtained by uniformly mixing additives (eg, colorant, defoamer, surface treatment agent, flame retardant, etc.) with a kneader, a mixer, a three-roll mill, or the like. The resin composition thus obtained has fluidity suitable for encapsulating a semiconductor by a method such as coating with a dispenser, screen printing, potting, and underfill, has a small hygroscopic property, and has excellent heat resistance. A cured product having water resistance and moisture resistance can be provided.

The heating conditions for thermally curing the uniformly mixed resin composition are not particularly limited as long as the characteristics of the present invention can be exhibited, and are not particularly limited. 190 ° C, further 130 ~
It can be cured at 160C for 1 to 4 hours. In order to suppress curing shrinkage and reduce residual stress,
It is preferable to perform step curing in which the temperature is gradually raised to the temperature range in several steps.

The cured product thus obtained has, for example, a glass transition temperature (Tg) of 110 ° C. or higher, and
30 ° C. or higher.

In a preferred embodiment of the resin composition of the present invention, in the case of a resin composition containing the component (A), the component (B) and the component (C), for example, a bisphenol F type epoxy is used as the component (A). (B) for 100 parts of resin
20-40 parts of DETDA as a component, furthermore 25-3
5 parts (equivalent ratio of component (A) / component (B) = 1 / 0.7 to
1 / 1.3, and even 1 / 0.8 to 1 / 1.2),
As the component (C), 0.3 to 12 parts, more preferably 2 to 8 parts, of a compound having at least one ester bond formed by a reaction between 1-alkoxyethanol and a carboxylic acid in the molecule is exemplified. In the case of the composition, the viscosity at 25 ° C. is 500 to 10000 mPa · s, and further 800
2,000 mPa · s, Tg as cured product is 11
The temperature is 0 ° C. or higher, and further 130 ° C. or higher.

[0040]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

The relationships between the components used in the following Examples and Comparative Examples and their abbreviations are summarized below.

(A) Component EPC830 LVP: bisphenol F type epoxy resin (epoxy equivalent: 162, Dainippon Ink and Chemicals, Inc.)
(B) Component Epicure-W: a mixture of 3,5-diethyl-2,6-toluenediamine / 3,5-diethyl-2,4-toluenediamine in 20/80 (active hydrogen equivalent: 45, oiled shell) (C) Component of formula (1): a compound produced from 1-propoxyethanol and tris (2-carboxyethyl) isocyanurate, specific gravity (20 ° C) 1.118, viscosity (25)
° C) 300 mPa · s, refractive index 1.46 (20 ° C) Other components BPA: 2,2'-bis (4-hydroxyphenyl) propane, manufactured by Mitsui Chemicals, Inc., bisphenol A 2P4MHZ: 2-phenyl-4 , 5-Dihydroxymethylimidazole, manufactured by Shikoku Chemicals Co., Ltd., Cureazole 2P4MHZ 2MZ: 2-methylimidazole, Shikoku Chemicals Co., Ltd.
2MZ SL-A-187: γ-glycidoxypropyltrimethoxysilane (manufactured by Nippon Unicar Co., Ltd., epoxy silane coupling agent) ML501C: Spherical fused silica powder having an average particle size of 18.5 μm (Tokuyama Corporation) )

The evaluation methods used in the following examples and comparative examples are summarized below.

(Viscosity) Examples 1-4 and Comparative Examples 1-4
, The viscosity (initial viscosity) of the composition immediately after preparation with an E-type viscometer and the viscosity of the composition after standing at 25 ° C. for 24 hours (1
(Viscosity after standing for one day). In the fifth embodiment, S
The initial viscosity and the viscosity after standing at 25 ° C. for 24 hours were measured with a SA viscometer at rotation speeds of 5 rpm and 50 rpm. All measurements were performed at 25 ° C.

(Viscosity increase rate) The viscosity / initial viscosity after standing for one day was defined as the viscosity increase rate.

(Gel Time (150 ° C.)) 2.0 cc of the resin composition was placed in a test tube and measured with a gel time tester (manufactured by Yasuda Seiki Co., Ltd.) set at 150 ° C.

(DSC) The temperature of the unreacted resin composition was raised from 25 ° C. to 300 ° C. at a rate of 10 ° C./min using a DSC device, and the reaction behavior was examined from the obtained specific heat curve. The rising temperature and the peak temperature were obtained from the intersection of the baseline and the extrapolation line of the obtained specific heat curve and the maximum heat generation temperature, respectively.

(Glass transition temperature (Tg) of cured product) The cured product obtained by heating the composition at 150 ° C for 3 hours was subjected to DSC.
The Tg was determined from the inflection point of the specific heat curve obtained by analyzing at a heating rate of 10 ° C./min using an apparatus (differential scanning calorimeter).

(Fluidity) 0.2 g of the composition was molded on a slide glass which had been washed with acetone,
After leaving the mixture to flow for a period of time and allowing it to flow and spread naturally, it was cured, and then the height of the top of the cured product (glove height (GH)) was measured with a vernier caliper. G. FIG. H. The smaller the value, the better the fluidity.

(Adhesiveness) The composition was applied to a plate-shaped square silicon mirror chip having a thickness of 0.5 mm and a side of 5 mm so as to have a thickness of 50 μm, and bonded to the same silicon mirror chip substrate. After bonding at 3 ° C for 3 hours, the shear strength (Chip) was measured using a die shear tester.
-Bonding-Strength (CBS)) was measured on a hot plate set at 120 ° C.

(Hygroscopicity of the composition)
mφ iron can, left in a constant temperature / humidity bath at 25 ° C / 90 RH% for a predetermined period of time, and the rate of weight increase was determined for each time period.
The composition was made hygroscopic.

(Moisture resistance of cured product)
40mmφ × 5mm cured product obtained by heating for hours,
In a PCT test, the substrate was exposed to a condition of 120 ° C./2 atm for a predetermined time, and Tg was measured at each time in the same manner as described above.
A decrease in Tg indicates that the cured product has low moisture resistance and the cured product has deteriorated.

Examples 1 to 4 and Comparative Examples 1 to 4 The components shown in Table 1 were mixed so as to have the compositions shown in Table 1 to prepare uniform resin compositions.

The evaluation items shown in Table 1 were evaluated using the obtained composition. Table 1 shows the results.

[0055]

[Table 1]

The results of DSC evaluated in Example 2 and Comparative Example 1 are shown in FIG. 1 for reference.

Example 5 Each component shown in Table 2 was mixed so as to have a composition shown in Table 2 to prepare a uniform resin composition.

The evaluation items shown in Table 2 were evaluated using the obtained composition. Table 2 shows the results.

[0059]

[Table 2]

[0060]

Since the epoxy resin composition of the present invention uses an aromatic amine as a curing agent, it is stable against moisture, and has a low viscosity and good storage stability. Since a compound having at least one ester bond generated by the reaction between 1-alkoxyethanol and a carboxylic acid in the molecule is used as a curing accelerator, the composition is cured at a relatively low temperature and in a short time to obtain a heat resistant product. It is highly resistant, has high moisture resistance, and exhibits excellent adhesion.

[Brief description of the drawings]

FIG. 1 shows DS measured in Example 2 and Comparative Example 1.
It is a graph which shows the result of C.

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Claims (3)

[Claims] 1. A one-part epoxy comprising (A) an epoxy compound, (B) an aromatic amine, and (C) a compound having at least one ester bond formed by a reaction between 1-alkoxyethanol and a carboxylic acid in a molecule. Resin composition. 2. The epoxy resin composition according to claim 1, further comprising (D) an inorganic filler. 3. An epoxy resin composition for semiconductor encapsulation comprising the composition according to claim 1.