TWI801541B - Phenolic resin and method for producing same, epoxy resin composition and hardened product thereof - Google Patents

Abstract

（式中，R為碳數1～4之烷基，n為0以上之整數）The phenolic resin of the present invention is an ortho-substituted phenolic resin represented by the following general formula (1), and has a melt viscosity of 0.20 Pa·s or less at 150°C. The substituent R of the general formula (1) is preferably a methyl group. The weight average molecular weight (Mw) obtained by gel permeation chromatography (GPC) analysis is less than 1000, and the n=0 component in the resin is also preferred based on the area ratio of gel permeation chromatography (GPC) analysis 12-30%.

(In the formula, R is an alkyl group with 1 to 4 carbon atoms, and n is an integer of 0 or more)

Description

Phenolic resin and method for producing same, epoxy resin composition and hardened product thereof

The present invention relates to a kind of phenolic resin and its preparation method. Also, the present invention relates to an epoxy resin composition including the phenol resin and a cured product of the epoxy resin composition. Furthermore, the present invention relates to a semiconductor device including the cured product.

Epoxy resin compositions are widely used in the fields of electrical properties, electronic parts, structural materials, adhesives, coatings, etc. due to workability and excellent electrical properties, heat resistance, adhesiveness, and moisture resistance of cured products.

This year, with the development of thinner and thinner semiconductor packages, the package is exposed to high temperature due to the heating of the reflow step of substrate mounting. When the package absorbs moisture, due to the reflow step, cracks will be generated, which will affect the reliability of the semiconductor. Therefore, development of a sealing material excellent in solder heat resistance (reflow resistance) is desired. Therefore, as a sealing material, in addition to low water absorption, a sealing material with low thermal stress and high adhesion is sought. Conventionally, an epoxy resin composition obtained by using a phenol aralkyl resin as a hardener is used as one of such sealing materials (Patent Document 1). However, an epoxy resin composition using a phenol aralkyl resin as a hardener cannot meet the demand for cost reduction required by the current market. Also, the solder heat resistance (reflow resistance) commensurate with the cost is insufficient.

Furthermore, in recent years, a semiconductor device with a structure of a laminated chip in a single package or a thinner wire diameter than conventional ones has been launched. In this kind of semiconductor device, due to the thinner wall thickness of the conventional resin sealing part, it is easy to cause underfilling, or easy to cause lead wire deviation during molding, etc. to reduce the sealing step. Sudden yield concerns. Therefore, in order to improve the flow characteristics of the resin composition, it is easy to think of a method of using a low molecular weight phenolic resin hardener, but due to the same method, there are cases where the following abnormalities occur: Poor storage caused by it; or poor transport in the molding process caused by the fixation of the resin composition (tablet) when making the epoxy resin composition; it is easy to cause the equipment to stop (reduction in handling); Any one of properties such as solder resistance, flame retardancy, and formability (also referred to as moldability) is impaired due to reduction in hardenability.

As mentioned above, through the thinning and thinning of the semiconductor package, the fluidity of the resin composition is improved to more than conventional ones, and the handleability, Handa resistance, flame retardancy, and formability are ensured and balanced, and the low cost is realized. etc. are important subjects.

prior art literature patent documents

Patent Document 1: Japanese Patent Application Laid-Open No. 8-258077

The object of the present invention is to provide a phenolic resin at low cost. When the phenolic resin is used as a hardener for epoxy resin, the hardened product obtained has low water absorption, low elastic modulus when heated, and a well-balanced and good performance. Hardening, formability, flame retardancy. Furthermore, it is to provide an epoxy resin composition and its hardened|cured product including this phenol resin excellent in heat resistance (reflow resistance) and handleability. Further, it is to provide a semiconductor device having the cured product.

The present invention relates to the following matters.

1. A phenolic resin, which is an ortho-substituted phenolic resin represented by the following general formula (1), and has a melt viscosity of 0.20 Pa at 150°C. below s.

(In the formula, R is an alkyl group with 1 to 4 carbons, and n is an integer of 0 or more)

2. The phenol resin according to the above 1, wherein the substituent R in the general formula (1) is a methyl group.

3. The phenol resin as described in the above 1 or 2, wherein the weight average molecular weight (Mw) obtained by gel permeation chromatography (GPC) analysis is 1000 or less, and the weight average molecular weight (Mw) analyzed by gel permeation chromatography (GPC) is In terms of the area ratio, the n=0 component in the resin is 12~30%.

4. The phenol resin according to any one of the above 1 to 3, wherein the weight average molecular weight (Mw) obtained by gel permeation chromatography (GPC) is 500 or more and 700 or less. According to the area ratio of GPC analysis, the n=0 component in the resin is more than 26% and less than 28%.

5. The phenolic resin as described in 4 above, wherein the substituent R in the general formula (1) is a methyl group, and the melt viscosity at 150° C. is 0.01 Pa. More than s and less than 0.04Pa. s, the softening point is not less than 60°C and not more than 65°C.

6. An epoxy resin composition comprising the phenol resin and epoxy resin described in any one of 1 to 5 above.

7. The epoxy resin composition as described in 6 above, which comprises the phenol resin as described in 4 above and contains a biphenyl type epoxy resin.

8. The epoxy resin composition as described in 6 above, which contains the phenol resin described in 5 above and contains a biphenyl type epoxy resin.

9. The epoxy resin composition according to the above 6, comprising the phenol resin described in the above 4, and providing a cured product having a storage elastic modulus at 270° C. of 0.2 GPa or more and 0.7 GPa or less.

10. The epoxy resin composition according to the above 6, comprising the phenol resin described in the above 5, and providing a cured product having a storage elastic modulus at 270° C. of 0.2 GPa or more and 0.7 GPa or less.

11. A cured product obtained by curing the epoxy resin composition described in any one of 6 to 10 above.

12. A semiconductor device comprising the cured product described in 11 above.

According to the present invention, a phenolic resin can be obtained at low cost. When the phenolic resin is used as a hardening agent for epoxy resin, the hardened product obtained has low water absorption, low elastic modulus when heated, and has good properties in a well-balanced manner. Hardening, formability, flame retardancy. In addition, an epoxy resin composition and a cured product thereof having excellent heat resistance (reflow resistance) and handleability including the phenol resin can be obtained. Furthermore, a semiconductor device having the cured product can be obtained.

〔Phenolic resin〕

The phenolic resin of the present invention is characterized in that it is an ortho-substituted phenolic resin represented by the following general formula (1), and its melt viscosity at 150°C is 0.20Pa. below s.

(In the formula, R is an alkyl group with 1 to 4 carbons, and n is an integer of 0 or more)

The phenol resin of the present invention has a substituent R at the ortho-position with respect to the phenolic hydroxyl group. Therefore, the phenol resin of the present invention and the phenol having no substituent at the ortho-position Compared with the resin, the melt viscosity relative to the softening point becomes lower. If it is a phenol resin without a substituent R (unsubstituted), the molecular weight becomes smaller and the melt viscosity decreases, and the softening point also decreases. If the softening point is low, there will be problems in handling due to the phenol resin itself or the adhesion when it is made into an epoxy resin composition.

On the other hand, the phenol resin having a substituent R at a meta-position or a para-position other than the ortho position has a lower molecular weight than a phenol resin having a substituent R at an ortho position. Nucleosome composition (n=0) increased. Therefore, problems arise in the formability of the epoxy resin composition and in cured properties such as the bending strength of the obtained cured product.

The phenolic resin of the present invention has a substituent R at the ortho-position relative to the phenolic hydroxyl group, and when made into an epoxy resin composition, it has higher fluidity and formability. Also, the cured product obtained by curing the epoxy resin composition has good cured properties such as bending strength and flame retardancy.

The upper limit of the melt viscosity of the phenolic resin of the present invention at 150°C is 0.20Pa. below s. Since the melt viscosity at 150°C is 0.20Pa. s or less, so that when it is made into an epoxy resin composition, it has high fluidity (low viscosity). The upper limit of the melt viscosity at 150°C is more preferably 0.10Pa. s below, the best is 0.05Pa. below s.

Furthermore, the lower limit of the melt viscosity at 150°C is preferably lower in terms of fluidity when making epoxy resin compositions. In terms of rationality in use caused by adhesion, etc., it is preferably 0.01Pa. s or more. Therefore, the range of melt viscosity at 150°C for the phenolic resin of the present invention is preferably 0.01Pa. More than s and 0.20Pa. s or less, more preferably 0.01Pa. More than s and 0.10Pa. s below, the best is 0.01Pa. More than s and 0.05Pa. below s. Furthermore, the melt viscosity at 150° C. can be obtained by the method described in the following examples.

In the phenol resin of the present invention represented by the above-mentioned general formula (1), the substituent R is a linear or branched alkyl group having 1 to 4 carbon atoms. The substituent R is not limited, for example, methyl, ethyl, Propyl, isopropyl, n-butyl, secondary butyl, isobutyl and tertiary butyl. In terms of rationality in use and ease of acquisition caused by the phenol resin itself or adhesion when it is made into an epoxy resin composition, the substituent R is preferably methyl, ethyl, propylene, etc. group, or n-butyl group, more preferably methyl or ethyl, most preferably methyl. The said substituent R in said general formula (1) may be the same substituent, or may be respectively different substituents as long as it falls within the range of the effect of this invention.

In the phenol resin of the present invention represented by the above general formula (1), n represents the number of repetitions and is an integer of 0 or more. The phenolic resin represented by the above general formula (1) is an aggregate of compounds having various repetition numbers n, so the value of n can be expressed as the average value n' of the aggregate.

The above average value n' is 0.20Pa when the melt viscosity of phenolic resin is 150℃. Values below s. The range of the above-mentioned average value n' is preferably 0.01Pa. More than s and 0.20Pa. s or less, more preferably 0.01Pa. More than s and 0.15Pa. s or less, more preferably 0.01Pa. More than s and 0.10Pa. s below, the best is 0.01Pa. More than s and 0.05Pa. Values below s. The average n' can be calculated based on the following weight average molecular weight (Mw).

In the phenol resin of the present invention, the weight average molecular weight (Mw) in terms of standard polystyrene measured by gel permeation chromatography (GPC) is preferably 400 to 1000, more preferably 500 to 800 Below, preferably 500 or more and 700 or less. In terms of rationality in use caused by phenol resin itself or adhesion when it is made into an epoxy resin composition, or the rationality of mixing operations with inorganic fillers when it is made into an epoxy resin composition In other words, it is preferable to set the weight average molecular weight (Mw) within the above-mentioned range. In addition, the weight average molecular weight (Mw) can be measured by GPC (gel permeation chromatography), and can be calculated|required by the method described in the following Example.

In the phenolic resin of the present invention represented by the above-mentioned general formula (1), the content of the dinuclear body (n=0) (that is, the content of the compound with n=0 in the above-mentioned general formula (1)) is equal to that of the gel permeable layer In terms of the area ratio of GPC analysis, it is preferably 12% or more and 30% or less, more preferably 15% or more and 30% or less, further preferably 22% or more and 30% or less, most preferably 26% Above and below 29%, the best 26% or more and 28% or less. Also, in the phenol resin of the present invention, the content of dinuclear bodies (n=0) is analyzed by gel permeation chromatography (GPC), and it is preferably 12% by weight or more and 30% by weight or less, more preferably 15% by weight or less. % by weight to 30% by weight, more preferably not less than 22% by weight and not more than 30% by weight, most preferably not less than 26% by weight and not more than 29% by weight. In terms of the rationality of use caused by the phenol resin itself or the adhesion when it is made into an epoxy resin composition, and the high fluidity (low viscosity) when it is made into an epoxy resin composition, It is preferable to set the dinuclear content within the above-mentioned range. In addition, the content rate of a dinucleosome can be measured by GPC (gel permeation chromatography), and it can be calculated|required by the method described in the following Example.

In the phenol resin of the present invention, the softening point is preferably not less than 50°C and not more than 90°C, more preferably not less than 60°C and not more than 80°C, most preferably not less than 60°C and not more than 70°C. In terms of rationality in use caused by phenol resin itself or adhesion when it is made into an epoxy resin composition, or the rationality of mixing operations with inorganic fillers when it is made into an epoxy resin composition In other words, it is preferable to set the softening point to the above-mentioned range. A softening point can be adjusted by making weight average molecular weight (Mw) into the said range.

Among the phenol resins of the present invention represented by the above general formula (1), one of the preferred forms is a phenol resin in which the substituent R is a methyl group, and the melt viscosity at 150°C is 0.20Pa. s or less, the weight average molecular weight (Mw) obtained by gel permeation chromatography (GPC) is less than 1000, and based on the area ratio of gel permeation chromatography (GPC) analysis, the n=0 component in the resin is Above 12% and below 30%. In the above preferred mode, it is possible to take into account the rationality of use caused by the phenol resin itself or the adhesion when it is made into an epoxy resin composition, and the mixing with inorganic fillers when it is made into an epoxy resin composition. The rationality of operation and the higher fluidity (low viscosity) when making epoxy resin compositions, and then, the formability when making epoxy resin compositions, or the mechanical properties such as the bending strength of the obtained cured products change. High, in addition, the water absorption of the cured product becomes lower, and the flame retardancy becomes higher.

Among the phenol resins of the present invention represented by the above-mentioned general formula (1), one of the most preferred forms is a phenol resin in which the weight average molecular weight (Mw) obtained by gel permeation chromatography (GPC) is 500 or more And below 700, the area ratio analyzed by gel permeation chromatography (GPC) Calculated, the n=0 component in the resin is more than 26% and less than 28%, and it is more preferably a phenolic resin, in which the substituent R is a methyl group under this condition, and the melt viscosity at 150°C is 0.01Pa. More than s and less than 0.04Pa. s, the softening point is not less than 60°C and not more than 65°C. In this particularly good form, the formability, low water absorption, flame retardancy, heat resistance, and low storage modulus of elasticity can be improved in a well-balanced manner when made into an epoxy resin composition, and when made into an epoxy resin composition The fluidity (low viscosity) is exceptionally excellent.

The above is the description of the phenol resin of the present invention, and a preferred production method of the phenol resin will be described below.

[Manufacturing method of phenolic resin]

<Phenolic compound (a1)>

The phenolic resin of the present invention represented by the above general formula (1) can be obtained by polycondensing the phenolic compound (a1) represented by the following general formula (2) and formaldehyde (a2) under an acidic catalyst. That is, the phenolic resin of this invention is a phenolic novolac type resin.

(In the general formula (2), R has the same definition as in the above general formula (1))

The phenolic compound (a1) represented by the above-mentioned general formula (2) is not particularly limited, and examples include: 2-methylphenol (o-cresol), 2-ethylphenol, 2-propylphenol, 2- Isopropylphenol, 2-n-butylphenol, 2-secondary butylphenol, and 2-tertiary butylphenol. The phenolic compound represented by the above-mentioned general formula (2) is preferable from the viewpoints of practicality in use caused by the phenolic resin itself or adhesion when it is made into an epoxy resin composition, and ease of acquisition. 2-methylphenol, 2-ethylphenol, 2-propylphenol, or 2-n-butylphenol, more preferably 2-methylphenol or 2-ethylphenol, most preferably 2-methylphenol . These phenolic compounds can be used individually by 1 type or in combination of 2 or more types within the range of the effect of this invention.

<Formaldehyde (a2)>

烷等於酸存在下分解而成為甲醛之聚合物。較佳為使用較容易之甲醛水溶液，例如可直接較佳地使用市售之42%甲醛水溶液。 Also, formaldehyde (a2) is not particularly limited, and formaldehyde aqueous solution can be used, and paraformaldehyde, tris

Alkanes are decomposed in the presence of acids to become polymers of formaldehyde. It is preferable to use an aqueous formaldehyde solution that is easier to use, for example, a commercially available 42% formaldehyde solution can be directly and preferably used.

<Molar ratio of phenolic compound (a1) to formaldehyde (a2) (a2/a1)>

In the production of the phenol resin of the present invention represented by the above-mentioned general formula (1), when the phenolic compound (a1) is reacted with formaldehyde (a2), formaldehyde (a2) is preferably used relative to 1 mole of the phenolic compound (a1) It is preferably 0.4 to 1.0 mol, more preferably 0.5 to 0.8 mol, and still more preferably 0.5 to 0.7 mol. By setting the molar ratio of the phenolic compound (a1) to the formaldehyde (a2) in the above range, the melt viscosity at 150° C. or the weight average molecular weight (Mw) of the phenol resin of the present invention can be set in a predetermined range.

<acid catalyst>

In the production method of phenolic resin, the polycondensation reaction can be carried out under the acidic catalyst. The acid catalyst used for the polycondensation reaction is not particularly limited, and known ones such as hydrochloric acid, oxalic acid, sulfuric acid, phosphoric acid, and p-toluenesulfonic acid can be used alone, or two or more of them can be used in combination, and sulfuric acid, oxalic acid, or p-toluene is particularly preferred. sulfonic acid.

<Reaction solvent>

In the production method of the phenol resin, a solvent may be used for the purpose of smoothing the reaction. As a solvent in this case, water, a lower alcohol (aliphatic alcohol whose carbon number is 1-6), etc. are mentioned. Specifically, methanol, ethanol, propanol, butanol, pentanol, hexanol, cyclohexanol, etc. are mentioned. The usage amount of the solvent is not particularly limited, but in terms of removal cost or recovery cost of the solvent, it is preferably less than 50% by weight relative to the phenolic compound, more preferably less than 30% by weight, and more preferably less than 10% by weight. %. On the other hand, the amount of the solvent is preferably 0.1% by weight or more with respect to the phenol compound from the viewpoint of fully exerting the effect obtained by using the solvent.

<reaction temperature>

The reaction temperature of the polycondensation reaction is not particularly limited, and is usually 50-200°C, preferably 70-180°C, more preferably 80-170°C. If it is 50° C. or higher, the reaction can be easily carried out, and if it is 200° C. or lower, it can be It is easy to control the reaction and obtain the target phenolic resin of the present invention stably.

<Reaction time, reaction pressure>

The reaction time of the polycondensation reaction also depends on the reaction temperature, but it is usually about 0.1 to 20 hours. In addition, the reaction pressure of the polycondensation reaction is usually carried out under normal pressure, but may be carried out under increased pressure or reduced pressure.

<post-processing>

It is preferable to add an alkali to neutralize the acid catalyst in order to completely stop the reaction as a post-treatment after completion of the polycondensation reaction, and then to add water to remove the acid catalyst and perform water washing.

The base used to neutralize the acid catalyst is not particularly limited, and any base that neutralizes the acid catalyst to form a water-soluble salt can be used. Examples thereof include inorganic bases such as metal hydroxides and metal carbonates, organic bases such as organic amines, ammonia, and the like. Specific examples of the inorganic base include sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, sodium bicarbonate, calcium carbonate and the like. Specific examples of organic amines include trimethylamine, triethylamine, diethylamine, tributylamine, and the like. Among these, it is preferable to use an organic amine. The amount used also depends on the amount of acid catalyst, but it is preferably used in an amount within the range of pH 4-8 after entering the reaction system after neutralizing the acid catalyst.

The amount of water used for washing and the number of times of washing are not particularly limited, and the number of times of washing is preferably about 1 to 5 in order to remove the acid catalyst to an amount that does not affect actual use, including economical viewpoints. Moreover, the temperature of the water used for washing with water is not specifically limited, It is preferable to carry out at 40-95 degreeC from the viewpoint of the efficiency and workability of removing a catalyst species. In water washing, when the separation of phenol resin and washing water is insufficient, it is effective to increase the temperature of water used for washing or to add a solvent other than water in order to reduce the viscosity of the mixture. The solvents other than water are not particularly limited, and those that dissolve the phenol resin and lower the viscosity can be used.

After removing the acid catalyst, usually, raise the temperature of the reaction system to 130~230°C, for example, under a reduced pressure of 20~50torr, distill and remove volatile components such as unreacted raw materials or organic solvents remaining in the reaction mixture, thereby The target phenolic resin can be preferably separated and recovered.

〔Epoxy resin composition and its cured product〕

The epoxy resin composition of the present invention contains the above-mentioned phenol resin of the present invention as a hardener for the epoxy resin.

Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, cresol novolak type epoxy resin, phenol novolac type epoxy resin, trisphenol methane type epoxy resin Epoxy resins with two or more epoxy groups in the molecule, such as glycidyl ether epoxy resins, glycidyl ester epoxy resins, glycidylamine epoxy resins, and halogenated epoxy resins, such as biphenyl epoxy resins . These epoxy resins can be used individually or in mixture of 2 or more types. Among these, glycidyl ether type epoxy resin is mentioned as preferable epoxy resin, and biphenyl type epoxy resin is mentioned as especially preferable epoxy resin.

The phenol resin is used as a hardener for the epoxy resin in the epoxy resin composition of the present invention, and the epoxy resin composition of the present invention may also contain other hardeners other than the phenol resin of the present invention. The types of curing agents other than the phenol resin of the present invention are not particularly limited, and various curing agents can be used depending on the purpose of use of the epoxy resin composition. For example, other phenolic resins, amine-based curing agents, amide-based curing agents, acid anhydride-based curing agents, etc. other than the general formula (1) can be used.

In the epoxy resin composition of the present invention, the proportion of the phenolic resin composition of the present invention among all the hardeners can sufficiently increase the thermal elastic modulus and molding shrinkage of the cured product obtained from the epoxy resin composition From the point of view of the ratio, a higher ratio is preferable. Specifically, the ratio of the phenolic resin composition of the present invention in all hardeners is preferably at least 30% by mass, more preferably at least 50% by mass, more preferably at least 70% by mass, and even more preferably at least 90% by mass. % or more, especially 100% by mass.

In an epoxy resin composition using a phenolic resin as a hardener, the ratio of the hydroxyl equivalents of the phenolic resin to the epoxy equivalents of the epoxy resin (hydroxyl equivalents/epoxy equivalents) is preferably 0.5 or more and 2.0 or less, more preferably 0.8 or more and 1.2 or less, most preferably 1. Furthermore, functional group equivalents such as hydroxyl equivalents or epoxy group equivalents are defined as A (g/eq) for the functional group equivalents and B as the added amount. In the case of (g), it can be determined by B/A ([B×C/100]/A when the purity of the compound is C%). That is, functional group equivalents such as hydroxyl equivalents or epoxy equivalents represent the molecular weight of the compound per functional group, and functional group equivalents represent the number (equivalents) of functional groups per compound mass (addition).

As the hardening accelerator, known hardening accelerators for hardening epoxy resins with phenol resins can be used. For example, organic phosphine compounds and their boron salts, tertiary amines, quaternary ammonium salts, imidazoles and their tetraphenyl boron salts, etc., are listed. phenylphosphine. In addition, in order to further improve the fluidity, a heat-latent hardening accelerator exhibiting activity by heat treatment is preferable, and tetraphenylphosphonium derivatives such as tetraphenylphosphonium and tetraphenylborate are preferable. The ratio of the hardening accelerator added to the epoxy resin composition may be the same as that in known epoxy resin compositions, for example, may be 0.1 to 10 parts by mass based on 100 parts by mass of the epoxy resin.

The epoxy resin composition of the present invention may preferably contain organic or inorganic fillers. The filler is not particularly limited and can be selected according to the application. For example, amorphous silica, crystalline silica, alumina, calcium silicate, calcium carbonate, talc, mica, barium sulfate, Inorganic fillers such as magnesium oxide. Especially when an epoxy resin composition is used as a semiconductor sealing material, it is preferable to use amorphous silica, crystalline silica, etc. as an inorganic filler.

When blending the inorganic filler, the mixing ratio in the epoxy resin composition [mass of the inorganic filler/mass of the epoxy resin composition including the inorganic filler × 100] is not limited, but is 30~98% by mass, Preferably it is about 40-95 mass %. In applications such as sealing materials for semiconductor devices, the blending ratio of the inorganic filler is 60-95% by mass, preferably 70-95% by mass, more preferably 75-90% by mass, and still more preferably 80-90% by mass. % by mass, the blending ratio of the inorganic filler can also be set to the higher one. When the ratio of the inorganic filler is more than the lower limit of the above-mentioned range, the water absorption rate of the cured product of the epoxy resin composition can be reduced. Moreover, when the ratio of an inorganic filler is below the upper limit of the said range, it becomes easy to obtain the fluidity of the epoxy resin composition for semiconductor sealing.

The epoxy resin composition of the present invention can further contain common epoxy resin composition Additives such as mold release agents, colorants, coupling agents, flame retardants, and solvents are used.

For example, the epoxy resin composition of the present invention can be preferably obtained by melting and mixing at least an epoxy resin and a phenolic resin, if necessary, using a mixing device such as a twin-shaft kneader or a two-roll mill. The obtained epoxy resin composition can be powderized preferably by a pulverizer.

For example, the epoxy resin composition of the present invention can be cured by heat treatment at 100° C. to 350° C. for 0.01 to 20 hours for hardening reaction. By setting the temperature of the curing reaction at 100°C or higher, it can be easily cured, and by setting it at 350°C or lower, performance degradation due to thermal decomposition can be prevented. Moreover, the reaction can be easily completed by setting the time of the hardening reaction to 0.01 hour or more, and productivity can be improved by setting it to 20 hours or less.

The elastic modulus (storage elastic modulus at 270°C) of the hardened epoxy resin using the phenol resin of the present invention as a hardening agent becomes lower when heated. The elastic modulus in heat (storage elastic modulus at 270° C.) is preferably from 0.2 GPa to 0.7 GPa, more preferably from 0.3 GPa to 0.6 GPa. Since the storage elastic modulus at 270°C of the hardened product is in the above range, it has excellent solder heat resistance (reflow resistance), and can achieve high flame retardancy. Also, the phenol resin of the present invention is preferably: for example, the epoxy resin represented by the formula equal to the equivalent number of the phenol resin and the phenol resin, relative to the total mass of the epoxy resin composition, is 83% by mass Inorganic filler (manufactured by Longsen Co., Ltd., high-purity true spherical silica MSR-2212 (Top size 75μm, average particle size 25.5μm, specific surface area 3.0m ² /g, sieve ON 75μ ON 0.0%) ), a hardening accelerator (triphenylphosphine manufactured by Beixing Chemical Co., Ltd.) kneaded at 0.33% by mass relative to the total mass of the epoxy resin composition. The storage modulus of elasticity in the above range.

The epoxy resin composition of the present invention can be blended with inorganic fillers at a high ratio, has excellent fluidity and formability, and its hardened product has excellent low water absorption and flame retardancy. Therefore, the epoxy resin composition of the present invention can be used particularly preferably in semiconductor devices as a semiconductor sealing material.

Example

Hereinafter, the present invention will be further specifically described by means of examples, but the present invention is not limited to these examples.

[1] Synthesis and evaluation of phenolic resin

The analysis method and evaluation method of the resin used in the following examples are explained.

[Measurement of Melt Viscosity]

Use the following machine to measure the melt viscosity (Pa.s) at 150°C.

Machine used: B-type viscometer DV2T Yinghong Seiki Co., Ltd. manufactured by BROOKFIELD

Measuring temperature: 150°C

Measuring method: Set the furnace temperature of the B-type viscometer to 150°C, and weigh a specified amount of sample into the cup.

Put the cup with the sample weighed into the furnace to melt the resin, and put it into the spindle from the top. Rotate the spindle, and read the displayed viscosity where the stable value is the melt viscosity.

[Determination of softening point]

The softening point was measured using the following machine.

Machine used: FP83HT dropping point and softening point measuring system manufactured by Mettler-Toledo Co., Ltd.

Measuring conditions: heating rate 2°C/min

Measuring method: inject molten sample into the sample cup, cool and solidify. The cup filled with the sample is inserted up and down, and the cassette is inserted into the furnace. The resin softens and flows down from the orifice, and the temperature when the lower end passes through the optical path is the softening point (°C), which is detected by the photodetector.

[Weight average molecular weight (Mw), content of dinuclear bodies (n=0)]

The molecular weight distribution was measured using the following apparatus, and the weight average molecular weight (Mw) was calculated|required by polystyrene conversion. Also, the content rate (%) of the dinuclear body (n=0) was determined from the area ratio (peak area of the dinuclear body (n=0)/peak area of the entire phenolic resin×100) obtained by GPC measurement.

2 The calculation of the area ratio of nuclei is based on the straight line before and after the peak (0 value), and the peaks of each component are divided by the longitudinal section at the lowest point.

Machine used: Waters Alliance 2695 (gel permeation chromatography analysis)

String: Made by SHODEX

KF-804×1 piece

KF-803×1 piece

KF-802×1 piece

KF-802.5×1 piece

KF-801×1 piece

Protection column: KF-G manufactured by SHODEX

Dissolving solution: Tetrahydrofuran (THF)

Detector: UV meter with a wavelength of 254nm

Flow rate: 1mL/min

Column oven temperature: 40°C

Analysis software: manufactured by Empower3 Waters

[hydroxyl equivalent]

The hydroxyl equivalent (g/eq) was calculated|required by the hydroxyl equivalent measurement based on JISK0070.

[Determination of melting point]

The melting point was determined using the following machine.

Machine used: Q-2000 manufactured by TA Instruments

Measuring temperature range: -20°C~150°C, heating rate is 10°C/min

Measurement environment: N ₂ (50mL/min) atmosphere

Determination method: The temperature at which melting begins is taken as the melting point (°C).

[Example 1]

[Synthesis of Resin A]

216 parts by mass (2.0 moles) of 2-methylphenol (o-Cr), 92 mass % paraformaldehyde ( Hereinafter, it is also referred to as paraformaldehyde) 39.1 parts by mass (1.2 moles), 0.47 parts by mass of water, and 0.65 parts by mass of oxalic acid. After reacting at 100° C. for 7 hours under reflux, the internal temperature was raised to 160° C., and a decompression-steaming treatment was performed to remove unreacted components, thereby obtaining 187 parts by mass of resin A. Table 1 shows the evaluation results of this resin.

[Example 2]

[Synthesis of Resin B]

Except that the compounding quantity of the 92 mass % paraformaldehyde used in Example 1 was 42.78 mass parts (1.3 mol), the resin B of 204 mass parts was obtained by the operation similar to Example 1 in all. Table 1 shows the evaluation results of this resin.

[Example 3]

[Synthesis of Resin C]

Except that the compounding quantity of the 92 mass % paraformaldehyde used in Example 1 was 48.91 mass parts (1.5 mol), the resin C of 222 mass parts was obtained by the operation similar to Example 1 in all. Table 1 shows the evaluation results of this resin.

[Comparative Example 1]

[Synthesis of Resin D]

The blending amount of 92% by mass of paraformaldehyde used in Example 1 is set to 51.46 parts by mass (1.6 mol ear), except that, all obtained 242 parts by mass of resin D by the same operation as in Example 3. Table 1 shows the evaluation results of this resin.

[Comparative Example 2]

[Synthesis of Resin E]

864 parts by mass (8.0 moles) of 3-methylphenol (m-Cr), 39.1 parts by mass of 92 mass % paraformaldehyde were placed in a 1000 mL glass flask equipped with a thermometer, an inlet, a distillation outlet, a cooler, and a stirrer. parts by mass (1.2 moles), 46.6 parts by mass of water, and 0.86 parts by mass of oxalic acid. After reacting at 100° C. for 7 hours under reflux, the internal temperature was raised to 160° C., and a decompression-steaming treatment was performed to remove unreacted components, thereby obtaining 243 parts by mass of resin E. Table 1 shows the evaluation results of this resin.

[Comparative Example 3]

[Synthesis of Resin F]

432 parts by mass (4.0 moles) of 4-methylphenol (p-Cr) and 40.4 parts by mass of 92 mass % paraformaldehyde were placed in a glass flask with a capacity of 1000 mL equipped with a thermometer, an inlet, a distillation outlet, a cooler, and a stirrer. parts by mass (1.2 moles), 21.0 parts by mass of water, and 0.42 parts by mass of oxalic acid. After reacting at 100° C. for 7 hours under reflux, the internal temperature was raised to 160° C., and a decompression-steaming treatment was performed to remove unreacted components, thereby obtaining 187 parts by mass of resin F. Table 1 shows the evaluation results of this resin.

[Comparative Example 4]

As the resin G, a phenolic novolak resin "HF-1M" (manufactured by Meiwa Chemical Co., Ltd.) was used. Resin G is an unsubstituted phenol resin. Table 1 shows the evaluation results of this resin.

[Comparative Example 5]

As the resin H, a phenol aralkyl resin "MEHC-7800SS" (manufactured by Meiwa Kasei Co., Ltd.) was used. Resin H is an unsubstituted phenolic resin. Table 1 shows the evaluation results of this resin.

[2] Preparation and evaluation of epoxy resin composition and cured product

The analysis method and evaluation method used in the evaluation of the epoxy resin composition and cured product are described below.

[Evaluation of formability]

The epoxy resin composition was evaluated according to the following evaluation criteria.

○: A molded body of suitable size can be obtained by transfer molding.

×: A molded body of suitable size cannot be obtained by transfer molding.

[Measurement of Liquidity]

Taking the epoxy resin composition as an object, the fluidity was measured using the following equipment.

Machine used: 60 t transfer molding machine manufactured by Takara Seisakusho Co., Ltd.

Measuring conditions: mold temperature is 175°C, injection pressure is 6.8MPa, holding time is 120 seconds

Measuring method: inject the epoxy resin composition into the mold for spiral flow measurement according to EMMI-1-66, and measure the flow length (cm). A flow length of 200 cm or more is referred to as "200 over".

[Measurement of Mechanical Properties (Bending Strength)]

The bending strength (MPa) was measured in accordance with JIS K 7171 on a test piece of a hardened epoxy resin composition.

Test piece size: 80mm×10mm×4mm

[Measurement of Water Resistance (Water Absorption)]

The water absorption (%) was measured in accordance with JIS C6481 on a test piece of a hardened epoxy resin composition.

Test piece size: diameter 50mm × thickness 3mm

[Determination of flammability]

The test piece of the cured product of the epoxy resin composition is used as the object, and the judgment is made according to UL-94.

Test piece size: 127mm×13mm×1mm

[Determination of heat resistance and storage elastic modulus]

The glass transition point (Tg) and storage modulus of elasticity were measured using the following equipment for the test piece of the hardened epoxy resin composition.

Machine used: RSA-G2 manufactured by TA Instruments

Measuring conditions: 30°C~270°C heating rate is 3°C/min

Measuring method: use a test piece of hardened epoxy resin with a size of 40mm×12mm×1mm, measure it with a dynamic viscoelasticity measuring device, and obtain the storage elastic modulus (GPa) at 270°C. Also, let the peak temperature of Tan δ be Tg (°C).

[Example 4~6] and [Comparative Example 6~10]

Resins A to H obtained in Examples 1 to 3 and Comparative Examples 1 to 5 were used as hardeners, and the hardener and epoxy resin (YX-4000 manufactured by Mitsubishi Chemical Co., Ltd.) were mixed in the ratio shown in Table 2. , epoxy group equivalent: 187g/eq), filler (KiCROSS MSR-2212 manufactured by Longsen Co., Ltd.), hardening accelerator (TPP manufactured by Beixing Chemical Industry Co., Ltd.), after mixing by a twin-shaft kneader, Cooling and pulverization are performed to obtain an epoxy resin composition. Fluidity was measured using this epoxy resin composition. Also, a test piece was produced by a transfer molding machine using a 40Φ tablet produced from the obtained epoxy resin composition. The formability at this time was evaluated by the above-mentioned evaluation criteria. Furthermore, the test piece was post-cured at 180° C. for 8 hours to obtain a cured epoxy resin. Physical property evaluation was performed using this cured epoxy resin. These evaluation results are shown in Table 3.

From the results shown in Tables 1 and 3, it can be seen that the epoxy resin composition obtained by using the phenol resin of the present invention (Examples 1-3) having a substituent at the ortho position and adjusting the specific molecular weight and dinuclear content rate (Examples 4-6) Compared with each comparative example, various physical properties, such as formability, were satisfied. Also, it can be seen that the cured products of the epoxy resin composition (Examples 4 to 6) have water resistance (low water absorption) equal to or lower than that of Comparative Examples 9 and 10, and have a low modulus of elasticity when heated.

On the other hand, in Comparative Example 6 having a molecular weight exceeding the preferable range of the phenol resin of the present invention, a decrease in fluidity, or poor flammability and heat resistance were obtained. Also, in Comparative Examples 7 and 8, which were used for phenol resins having substituents at the meta-position or para-position, the formability was significantly lowered, and a cured epoxy resin could not be obtained. In order to obtain a hardened epoxy resin, a high molecular weight is required, so it is impossible to obtain a high fluidity epoxy resin composition by increasing the viscosity and softening point. Therefore, it can be seen that by using the phenol resin of the present invention, a high-fluidity epoxy resin composition having good curability and formability in a well-balanced balance can be obtained, and by curing the composition, low water absorption can be obtained. Hardened product with low elastic modulus when heated.

[Industrial availability]

As described above, by using the phenol resin of the present invention, it is possible to obtain an epoxy resin composition and its cured product having excellent moldability and cured physical properties and high fluidity. Therefore, according to the present invention, there can be provided a phenol resin that can be preferably used for an epoxy resin composition for a semiconductor device including a semiconductor sealing material that is light, thin, and small.

Claims (10)

A phenolic resin, which is an ortho-substituted phenolic resin represented by the following general formula (1), and has a melt viscosity of 0.20Pa at 150°C. s or less, the weight average molecular weight obtained by gel permeation chromatography (GPC) is 500 or more and 800 or less, based on the area ratio of gel permeation chromatography (GPC) analysis, the n=0 component in the resin is 22 More than 29% and less than 29%, the softening point is more than 50°C and less than 70°C,

(In the formula, R is an alkyl group having 1 to 4 carbon atoms, and n is an integer of 0 or more). The phenolic resin as described in claim 1, wherein the weight average molecular weight obtained by gel permeation chromatography (GPC) is 500 or more and 700 or less, based on the area ratio of gel permeation chromatography (GPC) analysis, The n=0 component in the resin is not less than 26% and not more than 28%, and the softening point is not more than 65°C. The phenolic resin as claimed in item 1 or 2, wherein the substituent R of the general formula (1) is a methyl group, and the melt viscosity at 150°C is 0.01Pa. More than s and less than 0.04Pa. s, the softening point is above 60°C. The phenol resin according to claim 1 or 2, wherein the ortho-substituted phenol resin represented by general formula (1) is an epoxy resin hardener. A method for producing a phenolic resin, which is a method for producing a phenolic resin according to any one of claims 1 to 3, wherein the phenolic compound represented by general formula (2) and formaldehyde are in a solvent relative to the phenolic compound. 10% by weight of the environment and the polycondensation reaction under the acidic catalyst,

(In the formula, R is an alkyl group with 1 to 4 carbon atoms, and n is an integer of 0 or more),

(In the formula, R is an alkyl group with 1 to 4 carbon atoms). An epoxy resin composition comprising the phenol resin and epoxy resin described in any one of claims 1 to 4. The epoxy resin composition as described in claim 6, which comprises a biphenyl type epoxy resin. The epoxy resin composition according to claim 6 or 7, which provides a hardened product having a storage elastic modulus at 270° C. of 0.2 GPa or more and 0.7 GPa or less. A cured product obtained by curing the epoxy resin composition described in any one of claims 6 to 8. A semiconductor device comprising the cured product described in Claim 9.