JPH1160688A - Epoxy resin composition and its cured item - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject compsn. which is resistant to moisture and solder reflow, has a low permittivity, and is useful for electric and electronic parts, molding materials, coating materials, etc., by incorporating a specific epoxy resin into the same. SOLUTION: This compsn. contains an epoxy resin represented by formula I, pref. in an amt. of at least 30 wt.%, still pref. at least 40 wt.%. Pref., a polyhydric phenol compd. (e.g. a phenol-novolak resin) having a hydroxyl equivalent of 160 g/eq or higher is incorporated as a curative in an amt. of 0.5-1.5 equivalents. pref. 0.6-1.2 equivalents, per equivalent of epoxy group of the epoxy resin. If necessary, a cure accelerator (e.g. triphenylphosphine) and/or fused silica is also incorporated. In the formula, (n) is 1-10; and X is H or a 1-4C alkyl. The epoxy resin of formula I is produced by reacting a compd. of formula II with an epihalohydrin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulating material for electric and electronic parts such as a high-reliability semiconductor encapsulation, and various kinds of materials such as a laminate (printed wiring board) and CFRP (carbon fiber reinforced plastic). The present invention relates to an epoxy resin useful for composite materials, adhesives, paints, etc., an epoxy resin composition containing the same, and a cured product thereof.

[0002]

2. Description of the Related Art Epoxy resins are used in the fields of electric and electronic parts, structural materials, adhesives, paints, etc. due to workability and excellent electrical properties, heat resistance, adhesiveness, moisture resistance (water resistance), etc. of the cured product. Widely used in

However, in recent years, particularly in the electric and electronic fields, with the development thereof, various properties of the resin such as high purity, low hygroscopicity, adhesiveness, low dielectric constant, and low viscosity for highly filling the filler, etc. Is required to be further improved. Further, as a structural material, a lightweight material having excellent mechanical properties is required for aerospace materials, leisure and sports equipment applications, and the like. To meet these requirements, many proposals have been made on epoxy resins and resin compositions containing them, but they have not been satisfactory yet.

[0004]

DISCLOSURE OF THE INVENTION The present invention relates to an insulating material for electric and electronic parts which exhibits excellent low moisture absorption (low water absorption), excellent solder reflow resistance, and low dielectric constant (low dielectric loss tangent) in the cured product. Epoxy resins, epoxy resin compositions and cured products useful for adhesives, paints, etc. for various composite materials such as laminated boards (printed wiring boards, etc.) and CFRP, etc. Is what you do.

[0005]

Means for Solving the Problems The present inventors have made intensive studies on an epoxy resin composition having the above-mentioned properties and a method for applying the same to a cured product thereof, and have completed the present invention. That is, the present invention provides the following equation (1):

[0006]

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(Wherein, n represents an average value and represents a positive number of 1 to 10; X represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms). A resin composition, (2) the epoxy resin composition according to the above (1) prepared for semiconductor encapsulation, and (3) a polyphenol compound having a hydroxyl equivalent of 160 g / eq or less as a curing agent. ) Or (2), (4) a cured product obtained by curing the epoxy resin composition according to any one of (1), (2) and (3); (5) The present invention relates to a semiconductor device using the epoxy resin composition of the above (2) or (3) as a sealing agent.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The epoxy resin contained in the epoxy resin composition of the present invention has the following formula (2)

[0009]

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(Wherein, n represents an average value and represents a positive number of 1 to 10; X represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms), and is reacted with an epihalohydrin compound. By doing so, the epoxy resin of the formula (1) described in the above (1) is obtained. Examples of the epihalohydrins used in this reaction include epichlorohydrin, epibromohydrin, epiiodohydrin, β-methylepichlorohydrin, β-methylepibromohydrin, β-ethylepichlorohydrin, etc. Easy and inexpensive epichlorohydrin is preferred. This reaction can be performed according to a conventionally known method.

For example, the reaction is carried out at 20 to 120 ° C. for 1 to 20 hours while adding a solid of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide to the mixture of the compound of the formula (2) and epihalohydrin at once or gradually. Let it. At this time, the alkali metal hydroxide may use an aqueous solution,
In that case, the alkali metal hydroxide is continuously added, and water and epihalohydrins are continuously distilled off under reduced pressure or normal pressure from the reaction system, and further separated to separate water to remove epihalohydrins. A method of continuously returning to the system may be used.

In the above method, the amount of the epihalohydrin used is usually 0.5 to 20 mol, preferably 0.7 to 10 mol, per equivalent of the hydroxyl group of the compound of the formula (2). The amount of the alkali metal hydroxide to be used is generally 0.5 to 1.5 mol, preferably 0.7 to 1.2 mol, per 1 equivalent of the hydroxyl group of the compound of the formula (2). Further, by adding an aprotic polar solvent such as dimethyl sulfone, dimethyl sulfoxide, dimethylformamide, and 1,3-dimethyl-2-imidazolidinone in the above reaction, an epoxy resin having a low hydrolyzable halogen concentration can be obtained, Suitable for use as a sealing material for electronic materials, for example, 800 ppm or less in total chlorine concentration, 1800 pp in total bromine concentration
m or less. The amount of the aprotic polar solvent used is in the range of 5 to 200% by weight, preferably 10 to 100% by weight, based on the weight of the epihalohydrin. In addition, the reaction can easily proceed by adding an alcohol such as methanol or ethanol in addition to the above-mentioned solvent. Further, toluene, xylene, dioxane and the like can also be used.

Further, tetramethylammonium chloride, tetramethylammonium bromide, a mixture of the compound represented by the formula (2) and an excess epihalohydrin are added to the mixture.
Using a quaternary ammonium salt such as trimethylbenzylammonium chloride as a catalyst,
A solid or aqueous solution of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide is added to the halohydrin ether of the compound of the formula (2) obtained by reacting at 20 ° C. for 1 to 20 hours. The epoxy resin of the present invention can also be obtained by reacting for 1 to 20 hours to close the ring of the halohydrin ether. In this case, the amount of the quaternary ammonium salt used is usually 0.001 to 0.2 mol, preferably 0.05 to 0.1 mol per equivalent of the hydroxyl group of the compound of the formula (2).
Is a mole.

Usually, these reactants are washed with water or without water, after removing excess epihalohydrin under heating and reduced pressure, and dissolved in a solvent such as toluene, xylene, methyl isobutyl ketone, and the like. Then, an aqueous solution of an alkali metal hydroxide is added to react again. In this case, the amount of the alkali metal hydroxide used is usually from 0.01 to 1 equivalent of the hydroxyl group of the compound of the formula (2).
It is 0.2 mole, preferably 0.05-0.1 mole.
The reaction temperature is usually 50 to 120 ° C, and the reaction time is usually 0.5.
~ 2 hours.

After the completion of the reaction, salts produced as by-products are removed by filtration, washing with water, and the like, and further, solvents such as toluene, xylene and methyl isobutyl ketone are distilled off under reduced pressure under heating to obtain an epoxy resin having a low hydrolyzable halogen. Can be.

In the epoxy resin composition of the present invention, the epoxy resin of the formula (1) of the present invention can be used alone or in combination with another epoxy resin. When used in combination, the proportion of the epoxy resin of the present invention in the total epoxy resin is 3
It is preferably at least 0% by weight, particularly preferably at least 40% by weight.

Specific examples of epoxy resins that can be used in combination with the epoxy resin of the formula (1) include novolak type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins,
Examples include, but are not limited to, alicyclic epoxy resins, biphenyl type epoxy resins, glycidylamine type epoxy resins, glycidyl ester type epoxy resins, and the like. These may be used alone or as a mixture of two or more.

The epoxy resin composition of the present invention contains a curing agent in a preferred embodiment. As the curing agent, amine compounds, acid anhydride compounds, amide compounds, phenol compounds and the like can be used. Specific examples of the curing agent that can be used include diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, dicyandiamide, a polyamide resin synthesized from a dimer of linolenic acid and ethylenediamine, phthalic anhydride, and trianhydride. Mellitic acid, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, bisphenols, phenols (phenol, alkyl substitution Polycondensates of phenol, naphthol, alkyl-substituted naphthol, dihydroxybenzene, dihydroxynaphthalene, etc.) with various aldehydes, polymerization of phenols with various diene compounds , Polycondensates of phenols with aromatic dimethylol, biphenols and modified products thereof, imidazo -
BF ₃ -amine complex, guanidine derivative and the like. The amount of the curing agent used is preferably 0.5 to 1.5 equivalents to 1 equivalent of the epoxy group of the epoxy resin,
-1.2 equivalents is particularly preferred. If the amount is less than 0.5 equivalents or more than 1.5 equivalents with respect to 1 equivalent of the epoxy group, curing may be incomplete and good cured physical properties may not be obtained. Further, in the epoxy resin composition for semiconductor encapsulation, it is preferable to use a phenolic compound as a curing agent from the viewpoint of its reliability. In particular, a phenolic compound curing agent having a hydroxyl equivalent of 160 g / eq or less is heat resistant. And it is more preferable from the point of curability.

The epoxy resin composition of the present invention optionally contains a curing accelerator. Specific examples of the curing accelerator that can be used include known imidazole compounds such as 2-methylimidazole and 2-ethylimidazole, tertiary amine compounds such as tris- (dimethylaminomethyl) phenol, and triphenylphosphine compounds. Examples include a curing accelerator, but are not particularly limited thereto. The curing accelerator is 0.01 to 100 parts by weight of the epoxy resin.
15 parts by weight are used as needed.

Further, the epoxy resin composition of the present invention may contain, if necessary, fused silica, crystalline silica, porous silica, alumina, zircon, calcium silicate, calcium carbonate, silicon carbide, silicon nitride, boron nitride, zirconia,
Aluminum nitride, forsterite, steatite,
Powders such as spinel, mullite, titania, talc, etc., or various fillers such as inorganic fillers, silane coupling agents, mold release agents, pigments, etc., made of these spherical or crushed, and various thermosetting resins are added. can do. In particular, when an epoxy resin composition for semiconductor encapsulation is obtained, the amount of the inorganic filler used is usually 8% in the epoxy resin composition.
The range is 0 to 92% by weight, preferably 83 to 90% by weight.

The epoxy resin composition of the present invention is obtained by uniformly mixing the above components at a predetermined ratio, and is usually precured at a temperature of 130 to 180 ° C. for 30 to 500 seconds. By post-curing at a temperature of 150 to 200 ° C. for 2 to 15 hours, a sufficient curing reaction proceeds, and the cured product of the present invention is obtained. In addition, the components of the epoxy resin composition can be uniformly dispersed or dissolved in a solvent or the like, and the solvent can be removed and then cured.

The cured product of the present invention thus obtained has moisture resistance, solder reflow resistance, and a low dielectric constant (low dielectric loss tangent). Therefore, the epoxy resin composition of the present invention can be used in a wide range of fields where moisture resistance and low dielectric constant (low dielectric loss tangent) are required. Specifically, insulating materials, laminates,
It is useful as a material for all electric and electronic parts such as a sealing material. In addition to molding materials and composite materials, they can be used in the fields of coating materials, adhesives and the like. Particularly, in semiconductor encapsulation, solder reflow resistance is beneficial.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to embodiments. Note that the present invention is not limited to these examples.

First, the epoxy resin used in the present invention will be described in detail with reference to production examples. The epoxy resin used in the present invention is not limited to these production examples. In the production examples, epoxy equivalent, melt viscosity, softening point,
The total chlorine concentration was measured under the following conditions. Epoxy equivalent Measured in accordance with JIS K-7236, unit is g
/ Eq. Melt viscosity Melt viscosity in cone plate method at 150 ° C Measurement machine: cone plate (ICI) high temperature viscometer (RESE)
ARCH EQUIPMENT (LONDON) LTD. : 3 (measurement range 0 to 20 poise) Sample amount: 0.15 ± 0.005 (g) Softening point Measured by a method according to JIS K-7234 Total chlorine concentration 1N-KOH propylene glycol in butyl carbitol solution of sample The amount of chlorine released by adding the solution and refluxing for 10 minutes was measured by silver nitrate titration, and the value was divided by the weight of the sample.

Production Example 1 192 parts by weight of the compound of the formula (2) having a softening point of 94 ° C., 555 parts by weight of epichlorohydrin (ECH, the same applies hereinafter),
140 parts by weight of dimethyl sulfoxide (DMSO, the same applies hereinafter) was charged into a reaction vessel, heated, stirred and dissolved, and then heated to a temperature of 4 parts.
While maintaining the temperature at 5 ° C., while maintaining the inside of the reaction system at 45 Torr, 100 parts by weight of a 40% aqueous sodium hydroxide solution was continuously dropped over 4 hours. At this time, ECH and water distilled off by azeotropic distillation are cooled and separated, and then the organic layer EC is removed.
The reaction was performed while returning only H into the reaction system. After the completion of the dropwise addition of the aqueous sodium hydroxide solution, the reaction was carried out at 45 ° C. for 2 hours and at 70 ° C. for 1 hour. Subsequently, washing with water was repeated to remove by-product salts and dimethyl sulfoxide. Then, excess epichlorohydrin was distilled off from the oil layer under heating and reduced pressure, and 500 parts by weight of methyl isobutyl ketone was added to the residue to dissolve the residue. The solution of methyl isobutyl ketone was heated to 70 ° C., and 12 parts by weight of a 30% aqueous sodium hydroxide solution was added. After reacting for 1 hour, the reaction solution was repeatedly washed with water until the washing solution became neutral. Subsequently, 240 parts by weight of an epoxy resin (E1) was obtained by distilling off methyl isobutyl ketone from the oil layer under heating and reduced pressure. The obtained epoxy resin (E1) has an epoxy equivalent of 258, a total chlorine concentration of 560 ppm, a melt viscosity of 1.5 ps, and a softening point of 6
5 ° C.

Preparation Example 2 The same operation as in Preparation Example 1 was carried out except that the compound of the formula (2) was changed to 180 parts by weight having a softening point of 73 ° C., whereby 227 parts by weight of an epoxy resin (E2) was obtained. Was. The obtained epoxy resin (E2) had an epoxy equivalent of 250, a total chlorine concentration of 600 ppm, a melt viscosity of 0.2 ps, and a softening point of 46 ° C.

Production Example 3 The same operation as in Production Example 1 was carried out except that the compound of the formula (2) was changed to 93 parts by weight with a softening point of 73 ° C. + 93 parts by weight with a softening point of 94 ° C. Epoxy resin (E
3) 235 parts by weight were obtained. The obtained epoxy resin (E
Epoxy equivalent of 3) is 253, total chlorine concentration is 590 pp
m, melt viscosity was 0.6 ps, and softening point was 55 ° C.

Examples 1-3, Comparative Examples 1-4 Epoxy resins (E1)-(E) obtained in Production Examples 1-3.
3) and XD-1000-L (manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 248, softening point 65 ° C, melt viscosity 1.0 poise) (hereinafter XD-L), XD-1000- as comparative examples
2L (Nippon Kayaku Co., Ltd. epoxy equivalent 240, softening point 56 ° C, melt viscosity 0.5 poise) (hereinafter XD-2L),
EOCN-1020 (Nippon Kayaku Co., Ltd. epoxy equivalent 195, softening point 54 ° C, melt viscosity 0.8 poise) (hereinafter EOCN), YX-4000 (Yuka Kasper Epoxy Co., Ltd. epoxy equivalent 193, softening point) 105 ° C., melt viscosity 0.1 poise) (hereinafter referred to as YX), and a curing agent (phenol novolak resin (manufactured by Nippon Kayaku Co., Ltd., PN-80, ICI viscosity at 150 ° C.) with respect to 1 epoxy equivalent of epoxy resin. 1.5 ps, softening point 86 ° C., hydroxyl equivalent 106), 1 hydroxyl equivalent, 1 part by weight of a curing accelerator (triphenylphosphine) per 100 parts by weight of epoxy resin, and transfer molding to give a resin molded product. It was prepared and cured at 160 ° C. for 2 hours and further at 180 ° C. for 8 hours.

The results of measuring the physical properties of the cured product thus obtained are shown in Table 1. The measurement of the physical properties was performed by the following methods. -Water absorption: Weight increase rate (%) before and after boiling a disc-shaped test piece of 5 cm in diameter x 4 mm in water at 100 ° C for 24 hours-Hygroscopicity: 85 disc-shaped test pieces of 5 cm in diameter x 4 mm in thickness C./85% RH and 121.degree. C./100% RH for 24 hours before and after humidification (%). Dielectric constant, dielectric loss tangent: Measured in accordance with JIS-6911.

[0030]

Table 1 Example 1 Comparative Example 1 2 3 1 2 3 4 Epoxy resin E1 E2 E3 XD-L XD-2L EOCN YX Water absorption (%) 0.75 0.75 0.75 0.90 0.90 1.15 1.30 Moisture absorption (%) 85 ° C / 85% RH 0.45 0.45 0.45 0.60 0.60 0.70 0.75 121 ° C / 100% RH 1.00 1.05 1.00 1.25 1.25 1.60 1.80 Dielectric constant 3.6 3.6 3.6 3.8 3.8 4.0 3.9 Dielectric tangent 0.012 0.012 0.012 0.014 0.013 0.021 0.020

Example 4, Comparative Examples 5 to 7 The epoxy resin of Production Example 3 (E3) was used as the epoxy resin.
And, as a comparative example, the above-mentioned epoxy resin XD-2L, EO
CN, YX, curing agent (phenol novolak resin (Nippon Kayaku Co., Ltd., PN-80, softening point 86 ° C.)), curing accelerator (triphenylphosphine), silane coupling agent (Shin-Etsu Chemical Co., Ltd. KBM403) ), Release agent (fine carnauba manufactured by Toa Kasei Co., Ltd.), antimony trioxide, brominated epoxy resin (BRE manufactured by Nippon Kayaku Co., Ltd.)
NS), spherical silica as an inorganic filler (average particle size 30
μm) and crushed silica (average particle size: 5 μm) were blended in the ratio (parts by weight) shown in Table 2, kneaded by a biaxial roll, pulverized, and tableted. Then, the tablet was used to transfer a 16-pin 42-alloy lead frame with a silicon chip to it at 175 ° C and 120 ° C by transfer molding.
For ² seconds at 70 ° C.
S obtained by post-curing at 180 ° C. for 8 hours
The following characteristics were measured using the OP simulation device. Reflow cracking property: After humidification at 85 ° C./85% RH for a predetermined time, immersion in a solder bath at 260 ° C. for 10 seconds, cracks in appearance and peeling of the front and back surfaces of the die pad were observed, and the number of defects was counted.

[0032]

Table 2 Example Comparative Example 4 5 6 7 Epoxy resin E3 XD-2L EOCN YX 79 78 73 72 Curing agent 33 34 39 39 Curing accelerator 1.2 1.2 1 1.8 Silane coupling agent 7 7 7 7 Release agent 4 4 4 4 Antimony trioxide 6 6 6 6 Brominated epoxy resin 30 30 30 30 Spherical silica 590 590 590 590 Crushed silica 250 250 250 250 250 Reflow crackability (defective number / number of test pieces) Humidification time 24H 0/20 0/20 1/20 0/20 72H 0/20 2/20 4/20 1/20 168H 0/20 6/20 19/20 5/20

[0033]

The epoxy resin composition of the present invention has excellent low water absorption (low moisture absorption) in the cured product. Therefore, when used as a semiconductor encapsulant, it is possible to obtain a semiconductor device having extremely excellent solder reflow resistance, and it is also useful as a paint (such as a rust preventive paint) and an adhesive. In addition, since it has a low dielectric constant and a low dielectric loss tangent, it is suitable for use as an insulating material for various electric and electronic components such as semiconductors that generate high frequencies.

Claims (5)

[Claims] (1) Formula (1) (In the formula, n represents an average value and represents a positive number of 1 to 10. X
Represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. )
The epoxy resin composition containing the epoxy resin represented by these. 2. The epoxy resin composition according to claim 1, which is prepared for encapsulating a semiconductor. 3. The epoxy resin composition according to claim 1, which contains a polyhydric phenol compound having a hydroxyl equivalent of 160 g / eq or less as a curing agent. 4. A cured product obtained by curing the epoxy resin composition according to any one of claims 1, 2 and 3. 5. A semiconductor device using the epoxy resin composition according to claim 2 as a sealant.