JP2009242719A - Phenolic novolac resin, epoxy resin composition and cured product therefrom, and semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low-cost phenolic novolac resin excellent in flowability, curability and formability, an epoxy resin composition, and a reliable semiconductor device using them. <P>SOLUTION: This phenolic novolac resin is adjusted so that the content of monomer components is 0.5 mass% or less, the binuclear compound component is 10 to 25 mass%, the trinuclear compound component is 20 to 40 mass%, and the tetranuclear compound component be 15 to 20 mass%. The semiconductor device is obtained by sealing a semiconductor element using the phenolic novolac resin, the epoxy resin composition containing the phenolic novolac resin, and the epoxy resin composition. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a phenol novolac resin, an epoxy resin composition and a cured product thereof, and a semiconductor device.

  In recent years, as electronic components such as integrated circuits (ICs), large scale integrated circuits (LSIs), and very large scale integrated circuits (VLSIs) and semiconductor devices have been increased in density and integration, their mounting methods have been changed from insertion mounting. It is changing to surface mounting. Along with this, there is a demand for a multi-pin lead frame and a narrow lead pitch. Surface mount type QFP (Quad Flat Package), which is small, light, and compatible with multi-pin use, is used in various semiconductor devices. It has been. And since the semiconductor device is excellent in the balance of productivity, cost, reliability and the like, it is mainly sealed with an epoxy resin composition.

  In recent years, in consideration of environmental burden, an epoxy resin composition capable of imparting flame retardancy without using a halogen compound has been studied. For example, an epoxy resin composition using a composite metal hydroxide as a flame retardant has been proposed. The flame retardant mechanism using a composite metal hydroxide releases water at a high temperature. However, when used in a semiconductor device, there is a concern that reliability at a high temperature may be reduced. Moreover, in order to maintain high reliability, it is necessary to use an expensive composite metal hydroxide because a high-purity composite metal hydroxide with reduced ionic impurities is required.

Further, an epoxy resin composition using a phenol aralkyl type epoxy resin having a biphenylene skeleton imparting flame retardancy to a resin skeleton without using a flame retardant has been studied (for example, Patent Document 2). The phenol aralkyl type epoxy resin having a biphenylene skeleton has a high viscosity and fluidity may be lowered.

  Therefore, for the purpose of improving fluidity, focusing on the phenol resin that is a curing agent, an epoxy resin composition using a low molecular weight phenol novolac resin as a curing agent has been studied in order to lower the viscosity at the time of melting. (For example, Patent Document 3). However, these low molecular weight phenol novolak resins have a problem in that the curable composition of the epoxy resin composition is lowered because the component ratio of the binuclear structure is increased due to the structure. In addition, the softening point of the resin also decreases, making handling difficult. A low molecular weight phenol novolac resin having a low dinuclear component ratio has been proposed for the purpose of achieving both fluidity and curability (for example, Patent Document 4), but the yield of the raw materials used is low. There was a problem with production costs.

JP 2002-53737 A JP-A-11-140277 JP 2004-339258 A JP 2006-233197 A

  The phenol novolac resin of the present invention exhibits excellent fluidity, curability and moldability when used in an epoxy resin composition for semiconductor encapsulation, and is sufficient without using a brominated epoxy resin or an antimony compound. A phenol novolak resin that has the same flame retardancy even when the curing agent of the epoxy resin composition for semiconductor encapsulation showing flame resistance is replaced with the phenol novolak resin of the present invention, and can be produced at low cost, and An epoxy resin composition using a phenol novolac resin and excellent in fluidity, curability and moldability, and a semiconductor device excellent in reliability are provided.

  As a result of intensive studies in view of the above problems, the present inventors have found that the phenol novolac resin of the present invention has excellent fluidity, curability and molding when used in an epoxy resin composition for semiconductor encapsulation. Even if the hardener of the epoxy resin composition for semiconductor encapsulation which exhibits sufficient properties and exhibits sufficient flame resistance without using brominated epoxy resin or antimony compound is replaced with the phenol novolac resin of the present invention, the same flame retardant And a phenol novolac resin that can be manufactured at low cost, and an epoxy resin composition using the phenol novolac resin is excellent in fluidity, curability, and moldability, and is a semiconductor using the epoxy resin composition The apparatus has been found to be excellent in reliability, and the present invention has been completed.

（ただし、上記一般式（１）において、Ｒ₁、Ｒ₂は炭素数１〜６の炭化水素基であり、互いに同じであっても異なっていてもよい。Ｒ₃は炭素数１〜４の炭化水素基である。ａは０〜５の整数であり、ｂは０〜３の整数である。ｍは０〜２０の整数であり、ｎは１〜２０の整数であり、かつｍ／ｎの平均は１／１０〜１／１である。アルコキシ基を有するｍ個の繰り返し単位とグリシジルエーテル基を有するｎ個の繰り返し単位は、それぞれが連続で並んでいても、お互いが交互もしくはランダムに並んでいてもよいが、それぞれの間には必ず−ＣＨ₂−を有する構造をとる。）
［３］ ［１］項に記載のいずれかのフェノールノボラック樹脂と、下記一般式（２）で表されるエポキシ樹脂を必須成分とするエポキシ樹脂組成物。

（ただし、上記一般式（２）において、Ｒ₄、Ｒ₅、及びＲ₆は、それぞれ、炭素数１〜４の炭化水素基であり、互いに同じであっても異なっていてもよい。また、ｎは１〜１０の整数である。）
［４］ ［１］項に記載のフェノールノボラック樹脂、上記一般式（１）、および上記一般式（２）で表されるエポキシ樹脂を必須成分とするエポキシ樹脂組成物。
［５］ ［２］ないし［４］項のいずれかに記載のエポキシ樹脂組成物の硬化物により半導体素子を封止してなる半導体装置。 The above-mentioned subject is achieved by the present invention described in the following [1] to [5].
[1] A phenol novolac resin obtained by a reaction between phenol and formaldehyde, the phenol monomer content being 0.5 mass% or less as measured by the gel permeation chromatography area method, and the dinuclear component is 10 A phenol novolac resin characterized by having a nucleoside component of ˜25% by mass, a trinuclear component of 20-40% by mass, a tetranuclear component of 15-20% by mass, and a softening point of the resin of 65 ° C.-80 ° 2] An epoxy resin composition comprising the phenol novolac resin according to the item [1] and an epoxy resin represented by the following general formula (1) as essential components.

(However, in the above general formula _{(1), R 1, R} 2 is a hydrocarbon group having 1 to 6 carbon atoms, good .R ₃ is from 1 to 4 carbon atoms optionally substituted by one or more identical to each other A is an integer of 0-5, b is an integer of 0-3, m is an integer of 0-20, n is an integer of 1-20, and m / n. The average number of the repeating units is 1/10 to 1 / 1.The m repeating units having an alkoxy group and the n repeating units having a glycidyl ether group are alternately or randomly selected from each other even if they are continuously arranged. (Although they may be arranged side by side, a structure having —CH ₂ — is always present between them.)
[3] An epoxy resin composition comprising the phenol novolac resin described in the item [1] and an epoxy resin represented by the following general formula (2) as essential components.

(However, in the above general formula _{(2), R 4, R} 5, and R ₆ are each a hydrocarbon group having 1 to 4 carbon atoms, or. Also be different be the same as each other, n is an integer of 1 to 10.)
[4] An epoxy resin composition comprising, as an essential component, the phenol novolac resin according to the item [1], the epoxy resin represented by the general formula (1), and the general formula (2).
[5] A semiconductor device formed by sealing a semiconductor element with a cured product of the epoxy resin composition according to any one of [2] to [4].

  The phenol novolac resin of the present invention exhibits excellent fluidity and curability when used in an epoxy resin composition for semiconductor encapsulation, and is sufficient without using a brominated epoxy resin or an antimony compound. Even if the curing agent of the epoxy resin composition for semiconductor encapsulation showing flame resistance is replaced with the phenol novolac resin of the present invention, it has the same flame retardancy and can be produced at a lower cost.

  Hereinafter, the phenol novolac resin of the present invention will be described.

  The present invention relates to a phenol novolac resin obtained by a reaction between phenol and formaldehyde, and the phenol content is 0.5 mass% or less as measured by gel permeation chromatography area method, and the dinuclear component is 10 or less. ˜25 mass%, trinuclear component is 20 to 40 mass%, tetranuclear component is 15 to 20 mass%, and softening point of the resin is 65 ° C. to 80 ° C.

  When the content of phenol is more than 0.5% by mass, curing of the phenol novolac resin and the epoxy resin does not proceed and crosslinking is not sufficient, which is not preferable.

  When the content of the binuclear component is less than 10% by mass, the fluidity may decrease due to an increase in the softening point, and this is not preferable. When the content of the binuclear component exceeds 25% by mass, The workability is lowered due to the lowering of the softening point, and the curability may be lowered.

  When the trinuclear component is less than 20% by mass, or the tetranuclear component is less than 15% by mass, the curing rate with the epoxy resin is slow, and when used in an epoxy resin composition for semiconductor encapsulation, the specified molding It may not be cured over time, which is not preferable. When the trinuclear component exceeds 40% by mass, or the tetranuclear component exceeds 20% by mass, the viscosity of the phenol novolac resin increases, and when used in an epoxy resin composition for semiconductor encapsulation, Since fluidity | liquidity falls, it is not preferable.

  The phenol novolac resin of the present invention is obtained by polycondensing phenol and formaldehyde in the presence of an acid catalyst, followed by operations such as distillation, washing with water, and solvent extraction. It is obtained by adjusting the amount of the nuclear component. Further, a phenol monomer, a binuclear phenol novolac resin, a trinuclear phenol novolac resin, and a tetranuclear phenol novolac resin prepared in advance can be appropriately adjusted to the phenol novolac resin by reaction. Furthermore, the phenol novolak resin of the present invention can also be obtained by mixing a phenol novolak resin whose phenol monomer component amount, binuclear component amount, trinuclear component amount, and tetranuclear component amount can be identified in advance.

Although it does not specifically limit as phenol novolak resin by which each component was identified, The thing obtained by distillation, extraction, etc. can be used. By appropriately using these methods, the phenol novolac resin of the present invention can be produced at low cost.
As the phenol, phenol or a solution containing phenol can be used. Usually, it is preferable from a cost viewpoint to use industrial phenol.

  The dinuclear component, the trinuclear component, and the tetranuclear component are not particularly limited with respect to their isomers. It has a structure with methylene bridges bonded at three positions in the ortho and para positions with respect to phenol. For example, in a binuclear body, three isomers of ortho-ortho position, ortho-para position, and para-para position are formed. Exists.

  The gel permeation chromatograph is a method for analyzing phenol novolac resin, which can separate components of phenol resin having 4 nuclei or less by retention time, and can indicate mass% by area method. For example, in accordance with JIS K0124, analysis can be performed using gel permeation chromatography, and a column (TSKgel G1000HXL × 1, G2000HXL × 2, G3000HXL × 1 manufactured by Tosoh Corporation) is placed in a column oven set at 40 ° C. The solvent is tetrahydrofuran and the flow rate is 1.0 ml / min. In the retention time, 4 nuclei or less can be separated and mass% can be shown by the area method.

  The softening point refers to the temperature at which the resin softens, and can generally be measured by the method shown in JIS K-2531. When the softening point is lower than 65 ° C., workability such as resin consolidation may be reduced. When the softening point is higher than 80 ° C., when used in an epoxy resin composition for semiconductor encapsulation, fluidity at the time of molding. May decrease.

  As the formaldehyde used in the synthesis of the phenol novolac resin of the present invention, it is possible to use a source substance such as paraformaldehyde, trioxane, an aqueous formaldehyde solution, or a solution of these formaldehydes. Usually, it is preferable from the viewpoint of cost to use an aqueous formaldehyde solution.

  As the acid catalyst used for the synthesis of the phenol novolac resin of the present invention, an acid catalyst that is generally known in the synthesis of novolak phenol resins can be used. For example, inorganic acids such as sulfuric acid, hydrochloric acid, phosphoric acid, phosphorous acid, or organic acids such as oxalic acid, formic acid, organic phosphonic acid, paratoluenesulfonic acid, dimethylsulfuric acid, zinc acetate, nickel acetate, etc. may be used. These can be used alone or in combination of two or more. Usually, it is preferable to use oxalic acid or hydrochloric acid because the catalyst can be easily removed.

  The polycondensation of the phenol and formaldehyde is performed by setting the reaction molar ratio (F / P molar ratio) of formaldehyde (F) to phenol (P), for example, in the range of 0.05 to 0.7 mole. It is possible to make it react by making temperature into the range of 50-150 degreeC.

In the step of adjusting the amount of phenol component, amount of binuclear component, amount of trinuclear component, amount of tetranuclear component by operations such as distillation, washing with water, solvent extraction from the polycondensation of phenol and formaldehyde, When the operation is performed, the temperature is preferably 50 to 250 ° C., and the distillation and extraction can be removed from the reaction product by a distillation operation such as atmospheric distillation, vacuum distillation, steam distillation or the like. When the temperature is lower than 50 ° C., the efficiency by distillation deteriorates and the productivity deteriorates, which is not preferable. When it exceeds 250 ° C., the phenol novolac resin is decomposed and the molecular weight is increased, which is not preferable.
As a specific example of the operation of distillation, for example, distillation removal of water can be removed by atmospheric distillation at a temperature of 100 to 150 ° C., and phenol distillation removal is 5.0 × 10 ³ at a temperature of 150 to 200 ° C. It can be removed by Pa vacuum distillation, and dinuclear removal by distillation can be removed by vacuum steam distillation at a temperature of 200 to 250 ° C. and 5.0 × 10 ³ Pa.

  In the case of the washing operation, the novolac phenol resin or the novolac phenol resin dissolved in an organic solvent is mixed with water and stirred at a temperature of 20 to 150 ° C. at normal pressure or under pressure. The aqueous phase and the organic phase containing the novolak phenol resin are separated by standing or centrifugation, and the aqueous phase is removed from the system to remove low molecular weight components dissolved in the aqueous phase. It is possible to adjust the binuclear component amount, the trinuclear component amount, and the tetranuclear component amount.

  In the case of the solvent extraction operation, a phenolic resin in which a nonpolar solvent such as toluene or xylene having low solubility in a novolak phenol resin is dissolved in a novolak phenol resin, a novolak phenol resin aqueous solution, or a polar solvent such as alcohol The mixture is stirred at normal temperature or under pressure at a temperature of 20 to 150 ° C., then allowed to stand or centrifuged to separate the nonpolar solvent phase from the organic phase containing the phenol resin, and the nonpolar solvent phase is separated. By removing the high molecular weight component dissolved in the nonpolar solvent phase by removing it out of the system, the amount of phenol monomer component, the amount of binuclear component, the amount of trinuclear component, and the amount of tetranuclear component are adjusted. Is possible.

Hereinafter, the epoxy resin composition using the phenol novolac resin of the present invention will be described.

[Epoxy resin (A)]
An epoxy resin composition containing the phenol novolac resin of the present invention and an epoxy resin (A) represented by the following general formula (1) is preferable as a sealing material for a semiconductor device.

（ただし、上記一般式（１）において、Ｒ₁、Ｒ₂は炭素数１〜６の炭化水素基であり、互いに同じであっても異なっていてもよい。Ｒ₃は炭素数１〜４の炭化水素基である。ａは０〜５の整数であり、ｂは０〜３の整数である。ｍは０〜２０の整数であり、ｎは１〜２０の整数であり、かつｍ／ｎの平均は１／１０〜１／１である。アルコキシ基を有するｍ個の繰り返し単位とグリシジルエーテル基を有するｎ個の繰り返し単位は、それぞれが連続で並んでいても、お互いが交互もしくはランダムに並んでいてもよいが、それぞれの間には必ず−ＣＨ₂−を有する構造をとる。）

(However, in the above general formula _{(1), R 1, R} 2 is a hydrocarbon group having 1 to 6 carbon atoms, good .R ₃ is from 1 to 4 carbon atoms optionally substituted by one or more identical to each other A is an integer of 0-5, b is an integer of 0-3, m is an integer of 0-20, n is an integer of 1-20, and m / n. The average of 1 to 10 to 1/1 is m. (Although they may be arranged side by side, a structure having —CH ₂ — is always present between them.)

  The epoxy resin (A) represented by the general formula (1) has many aromatic ring carbons in the molecule, and the cured product of the epoxy resin composition using the epoxy resin has excellent flame resistance and low water absorption. have. Moreover, as a lower limit of the average value of m / n, it is preferable that it is 1/10, and it is more preferable that it is 1/9. When the lower limit value of the average value of m / n is within the above range, an effect of improving flame resistance can be obtained. Further, the upper limit of the average value of m / n is not particularly limited, but is preferably 1/1 and 1/2 from the viewpoint of the viscosity of the epoxy resin and the fluidity of the resin composition. Is more preferable.

  The epoxy resin (A) having the structure represented by the general formula (1) is an epichlorohydrin obtained by co-condensing phenols, aldehydes, and a compound represented by the following general formula (3). Can be obtained by glycidyl etherification.

（ただし、上記一般式（３）において、Ｒ₁は炭素数１〜６の炭化水素基であり、互いに同じであっても異なっていてもよい。Ｒ₃は炭素数１〜４の炭化水素基である。ａは０〜５の整数である。）

(However, in the above general formula (3), R ₁ represents a hydrocarbon group having 1 to 6 carbon atoms, good .R ₃ be different be the same as each other hydrocarbon radical having 1 to 4 carbon atoms A is an integer of 0 to 5)

The compound represented by the general formula (3) is characterized in that an alkoxy group (—OR ₃ ) is bonded to a naphthalene ring to which a glycidyl ether group is not bonded. Since the compound represented by the general formula (3) is polar due to the bonding of the alkoxy group, and this improves the reactivity, the compound is included in the structure of the novolak resin composed of phenols and aldehydes. The structure can be introduced. The epoxy resin (A) has the advantage that the raw material cost is lower than that of the phenol aralkyl type epoxy resin having a biphenylene skeleton having excellent flame resistance and low water absorption, and the raw material is easily available. It can be manufactured or obtained.

  Although it does not specifically limit as phenols used for manufacture of an epoxy resin (A), For example, phenol, o-cresol, p-cresol, m-cresol, phenylphenol, ethylphenol, n-propylphenol , Iso-propylphenol, t-butylphenol, xylenol, methylpropylphenol, methylbutylphenol, dipropylphenol, dibutylphenol, nonylphenol, mesitol, 2,3,5-trimethylphenol, 2,3,6-trimethylphenol, etc. It is done. Among these, phenol and o-cresol are preferable, and o-cresol is more preferable. These may be used alone or in combination of two or more.

  Examples of aldehydes used in the production of the epoxy resin (A) include formaldehyde and paraformaldehyde.

The compound represented by the general formula (2) used for the production of the epoxy resin (A) is not particularly limited as long as it has the structure of the general formula (2). For example, 1-methoxynaphthalene, 2 -Methoxynaphthalene, 1-methyl-2-methoxynaphthalene, 1-methoxy-2-methylnaphthalene, 1,3,5-trimethyl-2-methoxynaphthalene, 1-ethoxynaphthalene, 2-ethoxynaphthalene, 1-t-butoxy Naphthalene, 1,4-dimethoxynaphthalene, 2,6-dimethoxynaphthalene, 2,7-dimethoxynaphthalene and the like can be mentioned. Among these, in view of flame resistance, low water absorption, etc., it is more preferable that —OR ₃ in the general formula (3) is a methoxy group.

  Examples of aldehydes used in the production of the epoxy resin (A) include formaldehyde and paraformaldehyde.

The compound represented by the general formula (2) used for the production of the epoxy resin (A) is not particularly limited as long as it has the structure of the general formula (3). For example, 1-methoxynaphthalene, 2 -Methoxynaphthalene, 1-methyl-2-methoxynaphthalene, 1-methoxy-2-methylnaphthalene, 1,3,5-trimethyl-2-methoxynaphthalene, 1-ethoxynaphthalene, 2-ethoxynaphthalene, 1-t-butoxy Naphthalene, 1,4-dimethoxynaphthalene, 2,6-dimethoxynaphthalene, 2,7-dimethoxynaphthalene and the like can be mentioned. Among these, in view of flame resistance, low water absorption, etc., it is more preferable that —OR ₃ in the general formula (3) is a methoxy group.

[Epoxy resin (B)]
An epoxy resin composition containing the phenol novolac resin of the present invention and an epoxy resin (B) represented by the following general formula (2) is preferable as a sealing material for a semiconductor device. Thermal decomposition start temperature is higher than other epoxy resins, thermal decomposition rate is slow, and heat resistance is excellent.

（ただし、上記一般式（２）において、Ｒ₄、Ｒ₅、及びＲ₆は、それぞれ、炭素数１〜４の炭化水素基であり、互いに同じであっても異なっていてもよい。また、ｎは１〜１０の整数である。）

(However, in the above general formula _{(2), R 4, R} 5, and R ₆ are each a hydrocarbon group having 1 to 4 carbon atoms, or. Also be different be the same as each other, n is an integer of 1 to 10.)

  The epoxy resin (B) having the structure represented by the general formula (2) is obtained by glycidyl etherifying a phenol resin obtained by cocondensing phenols and bis (methoxymethyl) biphenyl with epichlorohydrin. Can be obtained.

In the general formula (2), R ₁ is a hydrogen atom, an alkyl group such as a methyl group having 1 to 4 carbon atoms, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, or a t-butyl group; They are selected from phenyl groups and may be the same or different. Although n is 0-10, it is preferable that it is 0-2.

  The epoxy resin composition using the phenol novolac resin of the present invention includes an epoxy resin (A) having a structure represented by the general formula (2), and an epoxy resin having a structure represented by the general formula (3) ( B) is preferably used in combination. When used in combination, sufficient fluidity and curability can be maintained and flame retardancy can be exhibited.

The amount of the phenol novolak resin of the present invention, the epoxy resin (A) having the structure represented by the general formula (1), and / or the epoxy resin (B) having the structure represented by the general formula (2) is Although it is not particularly limited, it is usually used in such an amount that the active hydrogen of the phenol resin is 0.5 to 1.5, preferably 0.8 to 1.2 equivalents relative to the epoxy equivalent of the epoxy resin. .

The epoxy resin composition using the phenol novolac resin of the present invention preferably contains an inorganic filler. As an inorganic filler, what is generally used for the resin composition for semiconductor sealing can be used, for example, fused silica, spherical silica, crystalline silica, alumina, silicon nitride, aluminum nitride, etc. are mentioned. The particle size of the inorganic filler is preferably 0.01 μm or more and 150 μm or less in consideration of the filling property to the mold.

  As a lower limit of the content rate of the said inorganic filler, it is preferable that it is 80 mass% or more of the whole said epoxy resin composition, It is more preferable that it is 82 mass% or more, It is especially that it is 84 mass% or more. preferable. When the lower limit value of the content ratio of the inorganic filler is within the above range, the amount of moisture absorption of the cured product of the epoxy resin composition increases, and there is little possibility of causing a decrease in solder crack resistance due to a decrease in strength. Moreover, as an upper limit of the content rate of an inorganic filler, it is preferable that it is 92 mass% or less of the whole said epoxy resin composition, It is more preferable that it is 91 mass% or less, It is 90 mass% or less. Particularly preferred. When the upper limit value of the content ratio of the inorganic filler is within the above range, there is little possibility of causing defects on the molding surface due to the loss of fluidity.

  In addition to the components described above, the epoxy resin composition of the present invention includes a curing accelerator, a coupling agent, a colorant such as carbon black, bengara, and titanium oxide; a low-stress additive such as silicone oil and silicone rubber; a bismuth oxide water Inorganic ion exchangers such as hydrates; additives such as metal hydroxides such as aluminum hydroxide and magnesium hydroxide, and flame retardants such as zinc borate, zinc molybdate, and phosphazene may be appropriately blended.

  The epoxy resin composition of the present invention has the structure represented by the phenol novolak resin of the present invention, the epoxy resin (A) having the structure represented by the general formula (1), and / or the general formula (3). Epoxy resin (B), inorganic filler, other additives, etc., mixed uniformly at room temperature using a mixer, etc., and then melted using a kneader such as a heating roll, kneader or extruder. What knead | mixed, followed by cooling and grinding | pulverization etc. which adjusted the dispersity, fluidity | liquidity, etc. suitably can be used as needed.

  Next, the semiconductor device of the present invention will be described. To manufacture a semiconductor device by sealing a semiconductor element with a cured product of the epoxy resin composition for semiconductor sealing of the present invention, for example, a lead frame mounted with a semiconductor element, a circuit board or the like is placed in a mold cavity. Then, what is necessary is just to shape-harden the epoxy resin composition for semiconductor sealing by shaping | molding methods, such as a transfer mold, a compression mold, and an injection mold.

  The semiconductor element encapsulated with the cured product of the epoxy resin composition for encapsulating a semiconductor according to the present invention is not particularly limited, and examples thereof include an integrated circuit, a large-scale integrated circuit, a transistor, a thyristor, a diode, and a solid-state imaging. An element etc. are mentioned.

The form of the semiconductor device of the present invention is not particularly limited. For example, the dual in-line package (DIP), the plastic lead chip carrier (PLCC), the quad flat package (QFP), the low profile package, and the like. Quad Flat Package (LQFP), Small Outline Package (SOP), Small Outline J Lead Package (SOJ), Thin Small Outline Package (TSOP), Thin Quad Flat Package (TQFP), Examples include a tape carrier package (TCP), a ball grid array (BGA), and a chip size package (CSP).

  The semiconductor device of the present invention in which a semiconductor element is encapsulated with a cured product of an epoxy resin composition for encapsulating a semiconductor by a molding method such as transfer molding is used as it is or at a temperature of about 80 ° C. to 200 ° C. for about 10 minutes to 10 hours. After being fully cured over a period of time, it is mounted on an electronic device or the like.

The preferred embodiments of the phenol novolac resin, the epoxy resin composition, and the semiconductor device of the present invention have been described above, but the present invention is not limited to this.
EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited to this.

[Synthesis of phenol novolac resin]

[Phenol novolac (binuclear) resin (A)]
A reactor equipped with a stirrer, a thermometer, and a cooler was charged with 1700 g of phenol and 590 g of 37% formalin, added with 17 g of oxalic acid, and then reacted for 4 hours while maintaining the reaction temperature at 95 ° C to 105 ° C. Thereafter, the temperature was raised to 180 ° C., and distillation under reduced pressure was performed at a reduced pressure of 5.0 × 10 ³ Pa to remove unreacted phenol. Then, the temperature was raised to 220 ° C. and a reduced pressure of 5.0 × 10 ³ Pa. The novolak phenol resin (A) containing 97.0% dinuclear component content and 3.0% trinuclear component is obtained by performing steam distillation at a water vapor amount of 2 g / min. ) Was obtained.

[Phenol novolac (trinuclear) resin (B)]
A reactor equipped with a stirrer, a thermometer, and a cooler was charged with 1700 g of phenol and 75 g of 37% formalin, added with 17 g of oxalic acid, and then reacted for 4 hours while maintaining the reaction temperature at 95 ° C to 105 ° C. Then, the temperature was raised to 180 ° C., distilled under reduced pressure at a reduced pressure of 5.0 × 103 Pa to remove unreacted phenol, heated to 220 ° C., and the amount of water vapor at a reduced pressure of 5.0 × 103 Pa. A novolac containing a dinuclear component content of 2.0%, a trinuclear component of 82.0%, and a tetranuclear component of 12.0% by removing the dinuclear component by steam distillation at 2 g / min. 35 g of a phenol resin (B) was obtained.

[Phenol novolac (tetranuclear) resin (C)]
A reactor equipped with a stirrer, thermometer and cooler was charged with 3400 g of phenol novolac resin (A) and 150 g of 37% formalin, and after adding 17 g of oxalic acid, the reaction temperature was kept at 95 ° C. to 105 ° C. for 4 hours. Reacted. Then, the temperature was raised to 180 ° C., vacuum distillation was performed at a reduced pressure of 5.0 × 103 Pa to remove unreacted phenol, the temperature was raised to 220 ° C., and the dinuclear component was reduced to 0.5% by mass. Until it becomes, it is removed by steam distillation at a steam pressure of 2 g / min at a reduced pressure of 5.0 × 10 3 Pa, the content of the binuclear component content is 0.3%, the trinuclear 1.0%, the tetranuclear 10 g of a novolak phenol resin (C) containing 89.7% was obtained.

Example 1
[Synthesis of phenol novolac resin D]
A reactor equipped with a stirrer, a thermometer, and a cooler was charged with 1700 g of phenol and 590 g of 37% formalin, added with 17 g of oxalic acid, and then reacted for 4 hours while maintaining the reaction temperature at 95 ° C to 105 ° C. Thereafter, the temperature was raised to 180 ° C., and distillation under reduced pressure was performed at a reduced pressure of 5.0 × 10 ³ Pa to remove unreacted phenol. Then, the temperature was raised to 220 ° C. and a reduced pressure of 5.0 × 10 ³ Pa. The dinuclear component content is adjusted to 20.1% by steam distillation at a water vapor amount of 2 g / min. 730 g of novolak phenol resin D containing 1% was obtained. The obtained resin had a softening point of 73 ° C.

(Example 2)
[Phenol novolac resin E]
A reactor equipped with a stirrer, a thermometer, and a cooler was charged with 1700 g of phenol and 590 g of 37% formalin, added with 17 g of oxalic acid, and then reacted for 4 hours while maintaining the reaction temperature at 95 ° C to 105 ° C. Thereafter, the temperature was raised to 180 ° C., and distillation under reduced pressure was performed at a reduced pressure of 5.0 × 10 ³ Pa to remove unreacted phenol. Then, the temperature was raised to 220 ° C. and a reduced pressure of 5.0 × 10 ³ Pa. The dinuclear component content is adjusted to be 11.2% by steam distillation at a water vapor amount of 2 g / min. 650 g of novolak phenol resin E containing 9% was obtained. The softening point of the obtained resin was 79 ° C.

(Example 3)
[Phenol novolac resin F]
A reactor equipped with a stirrer, a thermometer, and a cooler was charged with 1700 g of phenol and 590 g of 37% formalin, added with 17 g of oxalic acid, and then reacted for 4 hours while maintaining the reaction temperature at 95 ° C to 105 ° C. Thereafter, the temperature was raised to 180 ° C., and distillation under reduced pressure was performed at a reduced pressure of 5.0 × 10 ³ Pa to remove unreacted phenol. Then, the temperature was raised to 220 ° C. and a reduced pressure of 5.0 × 10 ³ Pa. The dinuclear component content is adjusted to 24.4% by steam distillation at a water vapor amount of 2 g / min at a temperature of 22.2% for the trinuclear component and 15.4 for the tetranuclear component. 790 g of novolak phenol resin F containing 2% was obtained. The softening point of the obtained resin was 70 ° C.

Example 4
[Phenol novolac resin G]
A reactor equipped with a stirrer, a thermometer, and a cooler was charged with 1700 g of phenol and 890 g of 37% formalin, added with 17 g of oxalic acid, and then reacted for 4 hours while maintaining the reaction temperature at 95 ° C to 105 ° C. Thereafter, the temperature was raised to 220 ° C., and distillation under reduced pressure was performed at a reduced pressure of 5.0 × 10 3 Pa to remove unreacted phenol, and 1075 g of phenol novolac resin G was obtained. The obtained phenol novolak resin contained 19.8% dinuclear component, 13.2% trinuclear component, 13.2% tetranuclear component, and had a softening point of 82 ° C. It was. 60 g of this resin, 10 g of phenol novolac resin A, 20 g of phenol novolac resin B, and 10 g of phenol novolac resin C were charged, and heated to 200 ° C. to melt and mix to obtain 100 g of phenol novolac resin G. The obtained phenol novolak resin contained 21.4% dinuclear component, 25.5% trinuclear component, 18.1% tetranuclear component, and had a softening point of 71 ° C. .

(Comparative Example 1)
[Phenol novolac resin H]
A reactor equipped with a stirrer, a thermometer, and a cooler was charged with 1700 g of phenol and 890 g of 37% formalin, added with 17 g of oxalic acid, and then reacted for 4 hours while maintaining the reaction temperature at 95 ° C to 105 ° C. Thereafter, the temperature was raised to 220 ° C., and distillation under reduced pressure was performed at a reduced pressure of 5.0 × 10 ³ Pa to remove unreacted phenol, thereby obtaining 1075 g of phenol novolac resin H. The obtained phenol novolak resin contained 19.8% dinuclear component, 13.5% trinuclear component, 13.2% tetranuclear component, and had a softening point of 82 ° C. It was.

(Comparative Example 2)
[Phenol novolac resin I]
A reactor equipped with a stirrer, a thermometer, and a cooler was charged with 1700 g of phenol and 950 g of 37% formalin. After 17 g of oxalic acid was added, the reaction was carried out for 4 hours while maintaining the reaction temperature at 95 ° C to 105 ° C. Thereafter, the temperature was raised to 220 ° C., and distillation under reduced pressure was performed at a reduced pressure of 5.0 × 10 3 Pa to remove unreacted phenol, thereby obtaining 1150 g of phenol novolac resin I. The obtained phenol novolak resin contained 18.0% dinuclear component, 14.4% trinuclear component, and 13.8% tetranuclear component, and had a softening point of 91 ° C. It was.

(Comparative Example 3)
[Phenol novolac resin J]
After adding 1700 g of phenol and 590 g of 37% formalin and adding 17 g of oxalic acid, the reaction was carried out for 4 hours while maintaining the reaction temperature at 95 ° C to 105 ° C. Thereafter, the unreacted phenol content was adjusted to 9.1% by distillation under reduced pressure to obtain 1400 g of phenol novolac resin I. The obtained phenol novolac resin contained 23.5% dinuclear component, 21.0% trinuclear component, 15.4% tetranuclear component, and had a softening point of 63 ° C. It was.

(Comparative Example 4)
[Phenol novolac resin K]
A reactor equipped with a stirrer, a thermometer, and a cooler was charged with 1700 g of phenol and 890 g of 37% formalin, added with 17 g of oxalic acid, and then reacted for 4 hours while maintaining the reaction temperature at 95 ° C to 105 ° C. Thereafter, the temperature was raised to 180 ° C., and distillation under reduced pressure was performed at a reduced pressure of 5.0 × 10 ³ Pa to remove unreacted phenol. Then, the temperature was raised to 220 ° C. and a reduced pressure of 5.0 × 10 ³ Pa. The dinuclear component content was adjusted to 9.0% by steam distillation at a water vapor amount of 2 g / min at a temperature of 27.2% for the trinuclear component and 18. for the tetranuclear component. 650 g of novolak phenol resin K containing 2% was obtained. The softening point of the obtained resin was 82 ° C.

(Comparative Example 5)
[Phenol novolac resin L]
A reactor equipped with a stirrer, a thermometer, and a cooler was charged with 1700 g of phenol and 890 g of 37% formalin, added with 17 g of oxalic acid, and then reacted for 4 hours while maintaining the reaction temperature at 95 ° C to 105 ° C. Thereafter, the temperature was raised to 180 ° C., and distillation under reduced pressure was performed at a reduced pressure of 5.0 × 10 ³ Pa to remove unreacted phenol. Then, the temperature was raised to 220 ° C. and a reduced pressure of 5.0 × 10 ³ Pa. The dinuclear component content is adjusted to be 27.5% by steam distillation at a water vapor amount of 2 g / min. 845 g of novolak phenol resin L containing 1% was obtained. In addition, the softening point of the obtained resin was 68 degreeC.

(Comparative Example 6)
[Phenol novolac resin M]
A reactor equipped with a stirrer, a thermometer and a condenser was charged with 80 g of phenol novolac resin G, 5 g of phenol novolac resin A, 5 g of phenol novolac resin B, and 10 g of phenol novolac resin C, and heated to 200 ° C. Then, 100 g of phenol novolac resin M was obtained. The obtained phenol novolac resin contained 20.2% dinuclear component, 16.0% trinuclear component, and 18.4% tetranuclear component, and had a softening point of 79 ° C. It was.

(Comparative Example 7)
[Phenol novolac resin N]
A reactor equipped with a stirrer, a thermometer, and a cooler was charged with 1700 g of phenol and 140 g of 37% formalin, and after adding 17 g of oxalic acid, the reaction was carried out for 4 hours while maintaining the reaction temperature at 95 ° C to 105 ° C. Thereafter, the temperature was raised to 180 ° C., and distillation under reduced pressure was performed at a reduced pressure of 5.0 × 10 ³ Pa to remove unreacted phenol. Then, the temperature was raised to 220 ° C. and a reduced pressure of 5.0 × 10 ³ Pa. The dinuclear component content is adjusted to 12.4% by steam distillation at a water vapor amount of 2 g / min at a temperature of 45.3% for the trinuclear component and 15.5 for the tetranuclear component. 250 g of novolak phenol resin N containing 6% was obtained. The softening point of the obtained resin was 75 ° C.

(Comparative Example 8)
[Phenol novolac resin O]
A reactor equipped with a stirrer, a thermometer, and a condenser was charged with 1700 g of phenol and 500 g of 37% formalin, and after adding 17 g of oxalic acid, the reaction was carried out for 4 hours while maintaining the reaction temperature at 95 ° C to 105 ° C. Thereafter, the temperature was raised to 180 ° C., and distillation under reduced pressure was performed at a reduced pressure of 5.0 × 10 ³ Pa to remove unreacted phenol. Then, the temperature was raised to 220 ° C. and a reduced pressure of 5.0 × 10 ³ Pa. The dinuclear component content was adjusted to 21.7% by steam distillation at a water vapor amount of 2 g / min. 450 g of novolak phenol resin O containing 2% was obtained. The obtained resin had a softening point of 77 ° C.

(Comparative Example 9)
[Phenol novolac resin P]
A reactor equipped with a stirrer, a thermometer, and a cooler was charged with 60 g of phenol novolac resin H, 20 g of phenol novolak resin B, and 20 g of phenol novolac resin C, heated to 200 ° C., melted and mixed, and phenol novolac. 100 g of resin P was obtained. The obtained phenol novolac resin contained 12.1% dinuclear component, 25.3% trinuclear component, 26.7% tetranuclear component, and had a softening point of 87 ° C. It was.

Table 1 shows the results of confirming the characteristics of the obtained phenol novolac resin.

The method for confirming the characteristics of the phenol novolac resin will be described below.

(1) Confirmation of phenol content, dinuclear content, trinuclear content, and tetranuclear content in phenol novolac resin: Tetrahydrofuran was used as an elution solvent, flow rate was 1.0 ml / min, column temperature was 40 The measurement was performed under the condition of ° C. The apparatus used was: main body: HLC-8020 manufactured by Tosoh, analytical column: two TSKgel G1000HXL manufactured by Tosoh, and one G3000HXL.
(2) Softening point of phenol novolac resin: Measured according to JIS JIS K-2531.
(3) Yield of phenol novolac resin: It was determined by the ratio of the yield (weight) of the resin to the phenol weight of the raw material. Moreover, when it mixed, the yield at the time of each synthesis | combination was calculated | required by carrying out the weighted average by the mixing ratio.

[Preparation of epoxy resin composition and manufacture of semiconductor device]
An epoxy resin composition using the raw materials shown below and the phenol novolac synthesized above was prepared to manufacture a semiconductor device.

(Epoxy resin)
Epoxy resin 1: Epoxy resin having a structure represented by the following formula (4) (EXA-7320, manufactured by Dainippon Ink & Chemicals, Inc.)

Epoxy resin 2: epoxy resin having a structure represented by the following formula (5) (Nippon Kayaku Co., Ltd., NC-3000)

(Inorganic filler)
Inorganic filler 1: 100 parts by mass of fused spherical silica FB560 (average particle size 30 μm) manufactured by Denki Kagaku Kogyo, 6.5 parts by mass of synthetic spherical silica SO-C2 (average particle size 0.5 μm) manufactured by Admatex, synthesized by Admatex A blend of 7.5 parts by mass of spherical silica SO-C5 (average particle size 30 μm) in advance.

(Curing accelerator)
Curing accelerator: Triphenylphosphine (manufactured by Hokuko Chemical Co., Ltd., TPP)

(Composite metal hydroxide)
Composite metal hydroxide: Magnesium hydroxide / zinc hydroxide solid solution composite metal hydroxide (Echo Mug Z-10, manufactured by Tateho Chemical Co., Ltd.)

(Silane coupling agent)
Silane coupling agent 1: γ-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-403)
Silane coupling agent 2: γ-mercaptopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-803)

(Coloring agent)
Colorant 1: Carbon black (Mitsubishi Chemical Industry Co., Ltd., MA600)

(Release agent)
Mold release agent 1: Carnauba wax (Nikko Fine Co., Ltd., Nikko Carnauba, melting point 83 ° C.)

Example 4
Epoxy resin 1 9.44 parts by mass Phenol novolac resin 1 3.73 parts by mass Inorganic filler 1 86.0 parts by mass Curing accelerator 1 0.23 parts by mass Silane coupling agent 1 0.10 parts by mass Silane coupling agent 2 0.10 parts by weight Colorant 1 0.30 parts by weight Release agent 1 0.10 parts by weight are mixed at room temperature with a mixer, melt-kneaded with a heating roll at 80 to 100 ° C., cooled and ground, and epoxy resin composition I got a thing. It evaluated by the following method using the obtained epoxy resin composition. The evaluation results are shown in Table 2.

  Spiral flow: Using a low-pressure transfer molding machine (KTS-15, manufactured by Kotaki Seiki Co., Ltd.), a spiral flow measurement mold according to EMMI-1-66 was applied at 175 ° C., injection pressure 6.9 MPa, holding pressure The epoxy resin composition was injected under the condition of time 120 seconds, and the flow length was measured. The spiral flow is a fluidity parameter, and the larger the value, the better the fluidity. The unit is cm.

  Flame resistance: Epoxy resin using a low pressure transfer molding machine (KTS-30, manufactured by Kotaki Seiki Co., Ltd.) under conditions of a mold temperature of 175 ° C., an injection time of 15 seconds, a curing time of 120 seconds, and an injection pressure of 9.8 MPa. The composition was injection molded to produce a 3.2 mm thick flame proof test piece. About the obtained test piece, the flame resistance test was done according to the specification of UL94 vertical method. The table shows Fmax, ΣF and the fire resistance rank after the determination. The epoxy resin composition obtained in Example 1 exhibited good flame resistance such as Fmax: 7 seconds, ΣF: 24 seconds, and flame resistance rank: V-0.

  Curing torque ratio: Using a curast meter (manufactured by Orientec Co., Ltd., JSR curast meter IVPS type), the mold temperature was 175 ° C., the torque after 90 seconds from the start of heating, and after 300 seconds, the curing torque ratio: ( Torque after 90 seconds) / (torque after 300 seconds) × 100 (%) was calculated. The torque in the curast meter is a parameter of thermal rigidity, and a larger curing torque ratio is better from the viewpoint of fast curing. Units%.

Semiconductor device appearance test: epoxy resin composition using a low-pressure transfer molding machine (Daiichi Seiko Co., Ltd., GP-ELF) under conditions of a mold temperature of 180 ° C., an injection pressure of 7.4 MPa, and a curing time of 120 seconds. The lead frame on which the semiconductor element (silicon chip) is mounted is sealed and molded, and 80 pQFP (Cu lead frame, the size is 14 × 20 mm × thickness 2.00 mm, the semiconductor element is 7 × 7 mm × thickness) N = 12 semiconductor devices each having a thickness of 0.35 mm and the semiconductor element and the inner lead portion of the lead frame are bonded by a gold wire with a diameter of 25 μm), and post-cure heat treatment at 175 ° C. for 4 hours. did. If the appearance of the heat-treated semiconductor device is observed with a magnifying glass, and one or more of voids, unfilled, burrs / bleeds on the lead frame are observed, the failure mode is listed in the table. Is marked as ○.

  Solder resistance test 1: Each N = 6 semiconductor devices were humidified at 60 ° C. and a relative humidity of 60% for 120 hours, and then subjected to IR reflow treatment (260 ° C., according to JEDEC Level 3 conditions). The presence or absence of peeling and cracks inside these semiconductor devices was observed with an ultrasonic flaw detector (manufactured by Hitachi Construction Machinery Finetech Co., Ltd., mi-scope 10), and the occurrence of either peeling or cracking was regarded as defective. The number of defective semiconductor devices in n = 6 is displayed. The epoxy resin composition obtained in Example 1 showed a good reliability with a defective number of 0/6.

  Solder resistance test 2: Solder resistance test 1 except that each N = 6 semiconductor devices were humidified at 85 ° C. and 60% relative humidity for 168 hours in the solder resistance test 1 described above. The test was conducted in the same manner as above. The epoxy resin composition obtained in Example 1 showed a good reliability with a defective number of 0/6.

(Examples 5-12 and Comparative Examples 10-20)
(Examples 5-12 and Comparative Examples 10-20)
Examples 5 to 12 were prepared in accordance with the formulations in Table 2, and Comparative Examples 10 to 20 were prepared in the same manner as in Example 4 in accordance with the formulations in Table 3 and were evaluated in the same manner as in Example 1. . The evaluation results of the examples are shown in Table 2, and the evaluation results of the comparative examples are shown in Table 3.

As is apparent from the results shown in Table 2, the epoxy resin compositions containing the phenol novolac resins of Examples 1 to 4 shown in Table 1 are excellent in fluidity and curability in Examples 4 to 12. It showed flame resistance, continuous formability, and solder resistance. Moreover, it turned out that sufficient fluidity | liquidity is shown from Example 7 even if a composite metal hydroxide is added.
On the other hand, Comparative Examples 10 to 20 using the phenol novolak resins of Comparative Examples 1 to 9 were not obtained to satisfy all of fluidity, curability, heat resistance, continuous moldability, and solder resistance. Phenol novolac resins containing many low nucleophilic components have good fluidity and flame resistance, but the curability is poor, and phenol novolak resins containing many high nucleophilic components are curable. Is good, but fluidity and flame resistance are reduced. Further, sufficient results were not obtained for continuous formability and solder resistance.

  The epoxy resin composition using the phenol novolac resin of the present invention is excellent in fluidity and curability and excellent in moldability.

Claims (5)

A phenol novolak resin obtained by a reaction between phenol and formaldehyde, wherein the phenol monomer content is 0.5 mass% or less as measured by an area method of gel permeation chromatography, and the dinuclear component is 10 to 25 mass. %, A trinuclear component is 20 to 40% by mass, a tetranuclear component is 15 to 20% by mass, and a softening point of the resin is 65 ° C. to 80 ° C. An epoxy resin composition comprising the phenol novolac resin according to claim 1 and an epoxy resin (A) represented by the following general formula (1) as essential components.

(However, in the above general formula _{(1), R 1, R} 2 is a hydrocarbon group having 1 to 6 carbon atoms, good .R ₃ is from 1 to 4 carbon atoms optionally substituted by one or more identical to each other A is an integer of 0-5, b is an integer of 0-3, m is an integer of 0-20, n is an integer of 1-20, and m / n. The average number of the repeating units is 1/10 to 1 / 1.The m repeating units having an alkoxy group and the n repeating units having a glycidyl ether group are alternately or randomly selected from each other even if they are continuously arranged. (Although they may be arranged side by side, a structure having —CH ₂ — is always present between them.) An epoxy resin composition comprising the phenol novolac resin according to claim 1 and an epoxy resin (B) represented by the following general formula (2) as essential components.

(However, in the above general formula _{(2), R 4, R} 5, and R ₆ are each a hydrocarbon group having 1 to 4 carbon atoms, or. Also be different be the same as each other, n is an integer of 1 to 10.)   An epoxy resin composition comprising, as an essential component, the phenol novolac resin (A) according to claim 1, the epoxy resin represented by the general formula (1), and the general formula (2).   A semiconductor device formed by sealing a semiconductor element with a cured product of the epoxy resin composition according to claim 2.