JP2000344858A - Epoxy resin composition and semiconductor device sealed therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition excellent in moldability and curable into a product having a low modulus, high adhesion, and excellent soldering- crack resistance by using an epoxy resin of a specified structure, a polyfunctional phenolic resin curing agent, an inorganic filler, and a cure accelerator as the essential components. SOLUTION: This composition essentially consists of an epoxy resin (A) prepared by mixing a polyfunctional phenolic resins represented by formula I (wherein R is a 1-5C hydrocarbon group or a halogen; m=0-4; n=0-3; and k=1-10) and/or formula II (wherein R and m are as defined in formula I) with a phenol being a precursor of a crystalline epoxy resin in a weight ratio of 1-19 and glycidyl-etherifying the mixture, a polyfunctional phenolic resin curing agent (B) represented by formula III (wherein R, m, n, and k are each as defined in formula I; and l=0-2), an inorganic filler (c), and a cure accelerator (D). Component A has a softening point of 70-120 deg.C, and the equivalent ratio of the phenolic hydroxyl groups of the curing agent to the epoxy groups is 0.5-2.0. Component C is used in an amount of 250-400 pts.wt. per 100 pts.wt. total of components A and B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an area-mount type semiconductor device, which has a small warpage after molding or soldering, has a low elastic modulus, high adhesion, excellent solder crack resistance, and excellent moldability. The present invention relates to an epoxy resin composition for semiconductor encapsulation and a semiconductor device using the same.

[0002]

2. Description of the Related Art In recent years, in the market trend of miniaturization, weight reduction and high functionality of electronic equipment, high integration of semiconductors has been progressing year by year, and surface mounting of semiconductor devices has been promoted. Packaging semiconductor devices have been developed and are beginning to shift from conventional semiconductor devices. A ball grid array (hereinafter, referred to as BGA) or a chip size package (hereinafter, referred to as CSP) pursuing further miniaturization is typical of the area mounting type semiconductor device, and these are conventionally represented by QFP and SOP. The surface mount semiconductor device has been developed to meet the demand for higher pin count and higher speed, which is approaching the limit. As a structure,
A semiconductor element is mounted on one side of a hard circuit board represented by a bismaleimide / triazine (hereinafter referred to as BT) resin / copper circuit board or a flexible circuit board represented by a polyimide resin film / copper circuit board, Only the element mounting surface, that is, only one surface of the substrate is molded and sealed with a resin composition or the like. Also, on the surface opposite to the element mounting surface of the substrate, solder balls are formed two-dimensionally in parallel so as to be joined to a circuit board on which a semiconductor device is mounted. Further, as a substrate on which a semiconductor element is mounted, a structure using a metal substrate such as a lead frame has been devised in addition to the organic circuit substrate.

[0003] In many of these area-mounted semiconductor device structures, only the element mounting surface of the substrate is sealed with a resin composition and the solder ball forming surface side is not sealed. In some cases, a sealing resin layer is also formed on the solder ball forming surface as seen in a board-on-chip (hereinafter referred to as BOC). thin. Therefore, due to the mismatch of thermal expansion and thermal contraction between the organic substrate or the metal substrate and the cured product of the resin composition, or the influence of the curing shrinkage at the time of molding and curing the resin composition, these semiconductor devices are used. Warpage tends to occur immediately after molding. In addition, when soldering is performed on a circuit board on which these semiconductor devices are mounted, a heating step of 200 ° C. or more is performed. At this time, warpage of the semiconductor device occurs, and many solder balls do not become flat, There is also a problem that the semiconductor device floats up from the circuit board on which the semiconductor device is mounted, and the electrical connection reliability is reduced. In these area-mounted semiconductor devices,
In order to reduce the warpage, it is important to make the coefficient of linear expansion of the substrate close to the coefficient of linear expansion of the cured product of the resin composition and to reduce the curing shrinkage of the resin composition by two methods. As the substrate, in an organic substrate, a resin having a high glass transition temperature (hereinafter, referred to as Tg) such as a BT resin or a polyimide resin is widely used, and these are higher than around 170 ° C. which is a molding temperature of the resin composition. It has a Tg. Accordingly, during the cooling process from the molding temperature to room temperature, the organic substrate contracts only in the region of α1. Therefore, if the cured product of the resin composition also has a high Tg, α1 is the same as that of the circuit board, and further, if the curing shrinkage is zero, the warpage is considered to be almost zero. Therefore, the combination of a triphenolmethane-type epoxy resin and a triphenolmethane-type phenol resin results in a Tg
Has been proposed, and α1 is adjusted by the amount of the inorganic filler.

When soldering is performed by soldering by means such as infrared reflow, vapor phase soldering, and solder immersion, moisture present inside the semiconductor device due to moisture absorption from the cured resin composition and the organic substrate. Cracks may occur in the package due to the stress caused by rapid vaporization at high temperatures, and peeling may occur at the interface between the element mounting surface of the substrate and the cured product of the resin composition. Along with stress reduction and low moisture absorption, high adhesion to a substrate is also required. A resin composition containing a triphenolmethane-type epoxy resin and a triphenolmethane-type phenol resin as resin components has been used in conventional area-mounted semiconductor devices such as BGA and CSP to reduce warpage.
The cured product of this resin composition has a high Tg, curability, and properties having excellent flexural strength when heated, but has a high moisture absorption rate of the cured product and a relatively high melt viscosity of the resin composition. , There is a limit to high filling of inorganic filler, insufficient moisture absorption,
There was a problem in solder crack resistance. On the other hand, the conventional QF
In surface-mount type semiconductor devices such as P and SOP, a crystalline epoxy resin typified by a biphenyl type epoxy resin is used to prevent cracks at the time of solder mounting and peeling at each material interface. There was a problem that, when compared with a cured product of a resin composition using a triphenolmethane-type epoxy resin, the flexural strength when heated was low and curing was slow. Therefore, in order to obtain a resin composition having a small warpage, excellent curability, excellent bending strength when heated, and low hygroscopicity, low elastic modulus, high adhesion, and excellent solder crack resistance, a triphenolmethane epoxy resin is used. In order to take advantage of the characteristics of crystalline epoxy resin, triphenolmethane epoxy resin can be used even when both epoxy resins are used together in an appropriate amount during the production of the resin composition, or when both epoxy resins are melt-mixed in advance. Features low warpage when cured, excellent curability, excellent bending strength when heated, and low moisture absorption, low elastic modulus, high adhesion when using crystalline epoxy resin, and excellent solder crack resistance. Were not compatible with each other.

[0005]

SUMMARY OF THE INVENTION The present invention has a small warpage after molding or soldering in an area mounting type semiconductor device.
An object of the present invention is to provide an epoxy resin composition for semiconductor encapsulation having a low elastic modulus, high adhesion, excellent solder crack resistance, and excellent moldability, and a semiconductor device.

[0006]

Means for Solving the Problems The present invention relates to [1] (A) a polyfunctional phenol resin (a) represented by the general formula (1) and / or (2), and a precursor of a crystalline epoxy resin. Glycidyl etherified epoxy resin mixed with phenol (b) as a solid, (B) polyfunctional phenol resin curing agent represented by general formula (3), (C)
Inorganic filler, and (D) curing accelerator as essential components,
The weight ratio (a / b) of (a) and (b) is 1 to 19, the softening point of the epoxy resin (A) is 70 to 120 ° C, and the curing of all phenolic resins to the epoxy groups of all epoxy resins. The equivalent ratio of the phenolic hydroxyl group of the agent is 0.5 to
2.0, and the content of the inorganic filler is 2 per 100 parts by weight of the total amount of all epoxy resins and all phenolic resin curing agents.
50 to 1400 parts by weight of an epoxy resin composition for semiconductor encapsulation,

Embedded image (However, R in the formula is a group or atom selected from a hydrocarbon having 1 to 5 carbon atoms and a halogen, and they may be the same or different from each other; m = 0 to 4, n
= 0 to 3, k is an average value and a positive number of 1 to 10)

[0007]

Embedded image (However, R in the formula is a group or atom selected from hydrocarbons having 1 to 5 carbon atoms and halogens, and they may be the same or different from each other; m = 0 to 4)

Embedded image (However, R in the formula is a group or atom selected from a hydrocarbon having 1 to 5 carbon atoms and a halogen, and they may be the same or different from each other; m = 0 to 4, n
= 0 to 3, l = 0 to 2, k is an average value and a positive number of 1 to 10.) [2] Polyfunctional phenol resin (a) represented by general formula (1) and / or general formula (2) [1] The semiconductor according to [1], wherein the glycidyl etherified epoxy resin (A) obtained by mixing phenols (b), which is a precursor of a crystalline epoxy resin, is mixed with a heat of fusion of 5-35 mJ / mg. Epoxy resin composition for sealing, [3] one or more phenols (b) which are precursors of the crystalline epoxy resin are selected from general formula (4), general formula (5), or general formula (6) The epoxy resin composition for semiconductor encapsulation according to [1] or [2],

[0008]

Embedded image (However, R in the formula is a group or atom selected from hydrocarbons having 1 to 5 carbon atoms and halogens, and they may be the same or different from each other; m = 0 to 4)

[0009]

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[0010]

Embedded image (However, R in the formula is a group or atom selected from a hydrocarbon having 1 to 5 carbon atoms and a halogen, and they may be the same or different from each other; m = 0 to 4, R
₂ is a group or atom selected from hydrogen, hydrocarbons having 1 to 5 carbon atoms, and halogen, which may be the same or different. [4] The phenol (b) which is a precursor of the crystalline epoxy resin is 4,4′-dihydroxybiphenyl,
4'-dihydroxy-3,3 ', 5,5'-tetramethylbiphenyl, bis (3,5-dimethyl-4-hydroxyphenyl) methane, 2,2-bis (3', 5'-dimethyl-4 ' -Hydroxyphenyl) propane, bis (2
-Tert-butyl-5-methyl-4-hydroxyphenyl) sulfide or 3-tert-butyl-2,
4'-dihydroxy-3 ', 5', 6-trimethylstilbene, 3-tert-butyl-4,4'-dihydroxy-3 ', 5', 6-trimethylstilbene, 3-tert-butyl-4,4 ' -Dihydroxy-3 ', 5
At least one member selected from the group consisting of 5′-trimethylstilbene and 4,4′-dihydroxy-3,3 ′, 5,5′-tetramethylstilbene, 4,4′-dihydroxy-3,
3′-ditertiarybutyl-6,6′-dimethylstilbene, 2,2′-dihydroxy-3,3′-ditertiarybutyl-6,6′-dimethylstilbene, 2,4′-
Dihydroxy-3,3'-ditert-butyl-6,
6'-dimethylstilbene, 2,2'-dihydroxy-
3,3 ′, 5,5′-tetramethylstilbene, 4,
4'-dihydroxy-3,3'-ditert-butyl-
The epoxy resin composition for semiconductor encapsulation according to the item [1], [2], or [3], which is a mixture with one or more kinds selected from six kinds of 5,5′-dimethylstilbene. A semiconductor device characterized in that a semiconductor element is sealed using the epoxy resin composition for semiconductor sealing according to [1], [2], [3], or [4]. In addition, the warpage of the area-mounted semiconductor device after molding or soldering is small, the solder crack resistance is excellent, and the moldability is excellent.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION A polyfunctional phenol resin (a) represented by the general formula (1) or (2) used in the present invention.
An epoxy resin obtained by glycidyl-etherifying a mixture (hereinafter, referred to as a mixed polyphenol) having a weight ratio (a / b) of 1 to 19 with phenols (b), which is a precursor of a crystalline epoxy resin, is crystalline. A low viscosity derived from the reactive epoxy resin has been achieved, which makes it possible to increase the filling of the inorganic filler, and thus reduce the moisture absorption of the cured product of the resin composition, and the Tg of the cured product of the resin composition is almost reduced. Not drop,
In addition, the cured product of the resin composition using the polyfunctional epoxy resin has the same elasticity as that of the cured product, a low elastic modulus, and the same curability. The epoxy resin obtained by this method is considered to improve the curing reactivity, which is a problem when using a crystalline epoxy resin, by making the polyfunctional epoxy resin and the crystalline epoxy resin more uniform. Can be Therefore, a semiconductor device using the resin composition of the present invention can achieve high reliability even under soldering during mounting.

The polyfunctional phenolic resin represented by the general formula (1) or (2) includes, for example, formulas (7), (8), (9), (10), and (11) And the like, but polyfunctional phenol resins of the formulas (7) and (10) are preferable from the viewpoint of availability, performance, raw material price and the like.

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[0013]

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[0014]

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[0015]

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[0016]

Embedded image Examples of the phenols (b) which are precursors of the crystalline epoxy resin used in the present invention include a biphenyl type represented by the general formula (4), a bisphenol type represented by the general formula (5), and a stilbene type represented by the general formula (6). No.

Examples of the biphenyl type phenols represented by the general formula (4) include 4,4'-dihydroxybiphenyl, 4,4'-dihydroxy-3,3 ', 5,5'-tetramethylbiphenyl, 4,4 '-Dihydroxy-3,
3′-ditert-butyl-6,6′-dimethylbiphenyl, 2,2′-dihydroxy-3,3′-ditert-butyl-6,6′-dimethylbiphenyl, 4,4′-
Dihydroxy-3,3'-ditert-butyl-5,
5'-dimethylbiphenyl, 4,4'-dihydroxy-
3,3 ′, 5,5′-tetratert-butylbiphenyl and the like (including isomers having different substitution positions).
Examples of bisphenol-type phenols of the general formula (5) include bis (4-hydroxyphenyl) methane,
Bis (3-methyl-4-hydroxyphenyl) methane,
Bis (3,5-dimethyl-4-hydroxyphenyl) methane, bis (2,3,5-trimethyl-4-hydroxyphenyl) methane, 1,1-bis (3 ′, 5′-dimethyl-4′-hydroxy Phenyl) ethane, 2,2-bis (4′-hydroxyphenyl) propane, 2,2-bis (3′-methyl-4′-hydroxyphenyl) propane, 2,2-bis (3 ′, 5′-dimethyl) -4'-hydroxyphenyl) propane, 2,2-bis (3'-tert-butyl-4'-hydroxyphenyl) propane,
Bis (2-tert-butyl-5-methyl-4-hydroxyphenyl) sulfide and the like can be mentioned.

The stilbene-type phenols of the general formula (6) include, for example, 3-tert-butyl-4,4'-
Dihydroxy-5,3'-dimethylstilbene, 3-tert-butyl-4,4'-dihydroxy-3 ', 6-
Dimethyl stilbene, 3-tert-butyl-2,4 '
-Dihydroxy-3 ', 5', 6-trimethylstilbene, 3-tert-butyl-4,4'-dihydroxy-
3 ′, 5 ′, 6-trimethylstilbene, 3-tert-butyl-4,4′-dihydroxy-3 ′, 5,5′-
Trimethylstilbene, 4,4'-dihydroxy-3,
3'-dimethylstilbene, 4,4'-dihydroxy-
3,3 ′, 5,5′-tetramethylstilbene, 4,
4'-dihydroxy-3,3'-ditertiarybutylstilbene, 4,4'-dihydroxy-3,3'-ditertiarybutyl-6,6'-dimethylstilbene, 2,
2'-dihydroxy-3,3'-ditert-butyl-
6,6′-dimethylstilbene, 2,4′-dihydroxy-3,3′-ditert-butyl-6,6′-dimethylstilbene, 2,2′-dihydroxy-3,3 ′,
5,5′-tetramethylstilbene, 4,4′-dihydroxy-3,3′-ditert-butyl-5,5′-dimethylstilbene, 4,4′-dihydroxy-3,
3 ', 5,5'-tetratert-butylstilbene and the like (including isomers having different substitution positions).

Among them, 4,4'-dihydroxybiphenyl, 4,4'-dihydroxy-3,3 ', 5,5'-tetramethyl are preferred in view of availability, performance, raw material price and the like. Biphenyl, bis (3,5-dimethyl-4-
Hydroxyphenyl) methane, bis (2,3,5-trimethyl-4-hydroxyphenyl) methane, 2,2-bis (3′-methyl-4′-hydroxyphenyl) propane, 2,2-bis (3 ′, 5'-dimethyl-4'-hydroxyphenyl) propane, bis (2-tert-butyl-5-methyl-4-hydroxyphenyl) sulfide (the above seven phenols are hereinafter referred to as group a), 3-
Tert-butyl-2,4'-dihydroxy-3 ',
5 ', 6-trimethylstilbene, 3-tert-butyl-4,4'-dihydroxy-3', 5 ', 6-trimethylstilbene, 3-tert-butyl-4,4'-dihydroxy-3', 5 5′-trimethylstilbene (the above three phenols are hereinafter referred to as group b), 4,
4′-dihydroxy-3,3 ′, 5,5′-tetramethylstilbene, 4,4′-dihydroxy-3,3′-ditert-butyl-6,6′-dimethylstilbene,
2,2′-dihydroxy-3,3′-ditert-butyl-6,6′-dimethylstilbene, 2,4′-dihydroxy-3,3′-di-tert-butyl-6,6′-dimethylstilbene, 2, 2'-dihydroxy-3,
3 ', 5,5'-tetramethylstilbene, or 4,
4'-dihydroxy-3,3'-ditert-butyl-
One or more selected from 5,5'-dimethylstilbene (the above six phenols are hereinafter referred to as group c) are preferred.

Among the group a, biphenyl-type phenols are 4,4 'which have a large effect of lowering the viscosity and are highly reactive.
Those containing -dihydroxybiphenyl are particularly preferred. In other group a, bis (3,5-dimethyl-
4-hydroxyphenyl) methane, 2,2-bis (3 ′, 5′-dimethyl-4′-hydroxyphenyl)
Propane, bis (2-tert-butyl-5-methyl-
4-Hydroxyphenyl) sulfide is particularly preferred.
In the stilbene-type phenols, a mixture of at least one selected from the group b and at least one selected from the group c is
It is preferable because the softening point is lowered. The mixing ratio, mixing method, and the like are not particularly limited.

The weight ratio (a / b) of the polyfunctional phenolic resin (a) of the present invention to the phenols (b) as a precursor of the crystalline epoxy resin is preferably from 1 to 19,
1.5 to 9 is preferred. If the weight ratio is less than 1, high Tg derived from the polyfunctional epoxy resin formed upon glycidyl etherification and bending strength at the time of heating cannot be sufficiently exhibited, which is not preferable. On the other hand, when the weight ratio is more than 19, the properties such as low viscosity, low elasticity, high adhesion, and excellent solder crack resistance derived from the crystalline epoxy resin formed when glycidyl etherified cannot be sufficiently exhibited. Absent. The method for synthesizing the epoxy resin of the present invention is not particularly limited. For example, after dissolving a mixed polyhydric phenol in an excess of epichlorohydrin, sodium hydroxide, 50 to 50 in the presence of an alkali metal hydroxide such as potassium hydroxide. 150 ° C., preferably 1 to 1 at 60 to 120 ° C.
A method of reacting for 0 hours is exemplified. After completion of the reaction, excess epichlorohydrin is distilled off, and the residue is dissolved in a solvent such as toluene or methyl isobutyl ketone, filtered, washed with water to remove inorganic salts, and then obtained by distilling off the solvent. it can. It is desirable that chlorine ions, sodium ions and other free ions of the produced epoxy resin be as small as possible. The softening point of the epoxy resin of the present invention is preferably in the range of 70 to 120C,
Particularly, 80 to 110 ° C is preferable. If the temperature is lower than 70 ° C., the composition is liquid or semi-solid at room temperature, and there is a problem in workability after the glycidyl etherification treatment, a decrease in storage stability at room temperature of a resin composition using the same, or Tg and heat of a cured product thereof. This is not preferable because there is a possibility that the bending strength may decrease. 120 ° C
If the ratio exceeds the above range, the viscosity of the polyfunctional epoxy resin itself produced at the time of glycidyl etherification increases, and the effect of lowering the viscosity of the crystalline epoxy resin component produced at the same time becomes undesirably low. The measuring method of the softening point of the epoxy resin conformed to the ring and ball method of JIS K 7234.

As the epoxy resin of the present invention, those having a heat of fusion of 5 to 35 mJ / mg are particularly preferred. This heat of fusion originates from the crystalline epoxy resin generated by glycidyl etherification of the phenols (b) used. If the amount is less than 5 mJ / mg, the epoxy resin has a low softening point, and the workability is remarkably reduced. 3
If it exceeds 5 mJ / mg, it behaves like a crystalline epoxy resin and cannot maintain high Tg and curing reactivity derived from the polyfunctional epoxy resin, which is not preferable. The heat of fusion of the epoxy resin indicates the calorific value of the endothermic peak when the temperature is raised from room temperature at a temperature rising rate of 5 ° C./min using a differential scanning calorimeter (manufactured by Seiko Instruments Inc.).
Further, other epoxy resins can be used together as long as the properties of the epoxy resin of the present invention are not impaired. Examples of the epoxy resin that can be used in combination include a novolak-type epoxy resin, a bisphenol A-type epoxy resin, a naphthalene-type epoxy resin, a dicyclopentadiene-modified phenol-type epoxy resin, and the like, and these may be used alone or in combination.

In the resin curing agent represented by the molecular structure of the formula (3), the cured product of the resin composition exhibits a low elastic modulus due to the influence of p-xylylene. Further, the amount of moisture absorption is relatively suppressed, and the adhesion to metals such as a lead frame and a silicon chip is excellent. Further, other phenol resin curing agents can be used in combination as long as the properties of the phenol resin of the present invention are not impaired. Examples of the phenol resin curing agent that can be used in combination include, for example, phenol novolak resin, cresol novolak resin, dicyclopentadiene-modified phenol resin, phenol aralkyl resin, naphthol aralkyl resin, terpene-modified phenol resin, and the like. May be used. Further, from the viewpoint of long-term reliability of the semiconductor device, it is desirable that chlorine ions, sodium ions, and other free ions contained as impurities be as small as possible. The equivalent ratio between the number of epoxy groups in all epoxy resins and the number of phenolic hydroxyl groups in all phenolic resins is 0.5 to 2.0.
Outside of this range, the curability of the resin composition may decrease, or the Tg of the cured product may decrease.

The kind of the inorganic filler used in the present invention is not particularly limited, and those generally used for a sealing material can be used. For example, fused silica,
Examples thereof include fused spherical silica, crystalline silica, secondary aggregated silica, alumina, titanium white, aluminum hydroxide, talc, clay, and glass fiber, with fused spherical silica being particularly preferred. It is preferable that the shape of the spherical silica is infinitely spherical in order to improve the fluidity, and that the particle size distribution is broad. The compounding amount of the inorganic filler is a total amount of 10 parts of all epoxy resins and all phenol resins.
250 to 1400 parts by weight per 0 parts by weight is preferred. 2
If it is less than 50 parts by weight, low thermal expansion and low hygroscopicity cannot be obtained, and the solder crack resistance is insufficient. If it exceeds 1400 parts by weight, the fluidity is reduced and poor filling or the like occurs during molding, It is not preferable because inconvenience such as gold wire deformation in the semiconductor device due to the increase in viscosity may occur. It is preferable that the inorganic filler used in the present invention is sufficiently mixed in advance. If necessary, the inorganic filler may be treated with a coupling agent, an epoxy resin or a phenol resin in advance, and may be used as a treatment method. There is a method of adding to a filler and treating with a mixer.

The curing accelerator used in the present invention may be any one which promotes a crosslinking reaction between an epoxy resin and a phenol resin. For example, 1,8-diazabicyclo (5,
(4,0) Amidine compounds such as undecene-7, organic phosphorus compounds such as triphenylphosphine and tetraphenylphosphonium / tetraphenylborate salts, and imidazole compounds such as 2-methylimidazole. It is not limited. These curing accelerators may be used alone or as a mixture.

The resin composition of the present invention comprises, in addition to the components (A) to (D), if necessary, a flame retardant such as a brominated epoxy resin, antimony oxide, and a phosphorus compound; and an inorganic ion such as bismuth oxide hydrate. Exchangers, coupling agents such as γ-glycidoxypropyltrimethoxysilane, coloring agents such as carbon black and red bean, low-stress components such as silicone oil and silicone rubber, natural waxes, synthetic waxes, higher fatty acids and their metals Various additives such as a release agent such as salts or paraffin, and an antioxidant may be appropriately compounded. The resin composition of the present invention comprises (A) to (D) components,
And other additives are mixed at room temperature using a mixer,
It is obtained by melt-kneading with a kneading machine such as a roll, kneader, extruder, etc., cooling and pulverizing. Using the resin composition of the present invention,
In order to manufacture a semiconductor device by encapsulating an electronic component such as a semiconductor element, it may be cured by a molding method such as transfer molding, compression molding, or injection molding.

[0027]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the present invention. The resins used for synthesizing the epoxy resins A to E of the examples and comparative examples are represented by the formula (10) described above.
And formula (12) (hydroxyl equivalent 98 g / eq). The structure of formula (12) is shown below.

Embedded image

As phenols which are precursors of the crystalline epoxy resin, 4,4'-dihydroxy-3,3 ',
5,5'-tetramethylbiphenyl, 4,4'-dihydroxy-3,3 ', 5,5'-tetramethylstilbene, 3-tert-butyl-4,4'-dihydroxy-
3 ', 5', 6-trimethylstilbene was used. For the epoxy resins A to E used in Examples and Comparative Examples,
The characteristics are shown in Table 1. Epoxy resins A to E were obtained by glycidyl etherification according to a conventional method at the mixing ratios shown in Table 1. The mixing ratio is by weight. The softening point and heat of fusion were measured by the methods described above.

[0029]

[Table 1]

Example 1 Epoxy resin A 52.9 parts by weight 47.1 parts by weight of phenolic resin curing agent of formula (13) (hydroxyl equivalent 130 g / eq)

Embedded image Fused spherical silica (average particle size: 15 μm) 860.0 parts by weight γ-glycidoxypropyltrimethoxysilane 3.0 parts by weight 1,8-diazabicyclo (5,4,0) undecene-7 (hereinafter referred to as DBU) 4 3.0 parts by weight Carbon black 3.0 parts by weight Carnauba wax 5.0 parts by weight Brominated phenol novolak type epoxy resin (epoxy equivalent 275 g / eq) 10.0 parts by weight Antimony trioxide 10.0 parts by weight Inorganic ion exchanger 5 Was mixed with a mixer at room temperature, kneaded at 70 to 120 ° C. with a biaxial roll, cooled and pulverized to obtain a resin composition. The obtained resin composition was evaluated by the following method. Table 2 shows the evaluation results.

Spiral flow: EMMI-I-66
The measurement was performed at a mold temperature of 175 ° C., an injection pressure of 70 kg / cm ² , and a curing time of 2 minutes using a mold for spiral flow measurement according to the above. The unit is cm. Curing torque: Using a curast meter (manufactured by Orientec Co., Ltd., JSR curast meter IVPS type)
The torque was determined at a mold temperature of 175 ° C. and 90 seconds after the start of heating. The torque in the curast meter is a parameter of curability, and the larger the numerical value, the better the curability. The unit is kgf · cm. -Moisture absorption: mold temperature 1 using a transfer molding machine
A molded product having a diameter of 50 mm and a thickness of 3 mm was formed at 75 ° C., an injection pressure of 75 kg / cm ² , and a curing time of 2 minutes, and was treated as a post cure at 175 ° C. for 8 hours. It was left for 696 hours in an environment with a humidity of 60%, and the change in weight was measured to determine the moisture absorption. The unit is% by weight. -Hot strength, hot elastic modulus: The hot flexural strength and the hot flexural modulus were measured (at 240 ° C) according to JIS K 6911. The unit is N / mm ² .・ Package warpage: Using a transfer molding machine
Mold temperature 180 ° C., injection pressure 75 kg / cm ² , curing time 2 minutes, 225 pBGA (substrate 0.36 mm thick, bismaleimide triazine resin / glass cloth substrate, package size 24 × 24 mm, thickness 1.17 mm) ,
Silicon chip is 9 × 9mm in size and 0.35m in thickness
m, 25 μm between the chip and the bonding pad of the circuit board
It is bonded with a gold wire of m diameter. ) Was molded. Further, post-curing was performed at 175 ° C. for 8 hours. After cooling to room temperature, the displacement in the height direction was measured diagonally from the gate of the package using a surface roughness meter, and the largest value of the displacement difference was defined as the amount of warpage. The unit is μm. Evaluation of substrate adhesion: A molded article was molded using a transfer molding machine at a mold temperature of 180 ° C., an injection pressure of 75 kg / cm ² , and a curing time of 2 minutes. After treating this molded article as post cure at 175 ° C. for 8 hours, the molded article portion and the base material portion are sandwiched by a jig using a tensile tester, and the molded product portion is fixed. Was pulled upward, and the substrate adhesion was measured. The target substrate is a 42 alloy frame and a surface of the 42 alloy frame coated with polymethyl methacrylate solder resist (PMMA). The unit is N / mm ² . -Solder crack resistance: Using a transfer molding machine
Mold temperature 180 ° C., injection pressure 75 kg / cm ² , curing time 2 minutes, 225 pBGA (substrate 0.36 mm thick, bismaleimide triazine resin / glass cloth substrate, package size 24 × 24 mm, thickness 1.17 mm ,
Silicon chip is 9 × 9mm in size and 0.35m in thickness
m, 25 μm between the chip and the bonding pad of the circuit board
It is bonded with a gold wire of m diameter. ) Was molded. Eight packages which were post-cured at 175 ° C. for 8 hours were processed at 30 ° C. and a relative humidity of 60% for 696 hours, and then subjected to IR reflow processing (240 ° C.). After the treatment, the presence or absence of internal peeling and cracks was observed with an ultrasonic flaw detector, and the number of defective packages was counted. When the number of defective packages is n, it is displayed as n / 8.

Examples 2 to 3 and Comparative Examples 1 to 5 In the same manner as in Example 1, the resin compositions prepared according to the compositions shown in Tables 2 and 3 were evaluated. The evaluation results are shown in Tables 2 and 3. In Comparative Examples 1 and 5, a phenol novolak resin curing agent (hydroxyl equivalent: 104 g / eq) was used. In Comparative Examples 4 and 5, an epoxy resin of the formula (14) (epoxy equivalent: 154 g / eq) was used. In Comparative Example 4,
4'-bis (2,3-epoxypropoxy) -3,
Resins containing 3 ', 5,5'-tetramethylbiphenyl as a main component (epoxy equivalent: 197 g / eq; hereinafter, (E-
1)).

[0033]

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[0034]

[Table 2]

[0035]

[Table 3]

[0036]

According to the present invention, an epoxy resin composition having excellent moldability can be obtained, and a semiconductor device using the same has a small warpage after molding or soldering, has a low elastic modulus, has high adhesion, and has excellent resistance. Excellent solder cracking properties.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) H01L 23/31 F term (reference) 4J002 CC03X CD00W CD04W CD05W CD06W DE136 DE146 DJ016 DJ036 DJ046 DL006 EU117 EU137 EW017 EW177 FA086 FD016 FD14X FD157 GJ02 GQ05 4J036 AD07 AD08 AD10 AD15 AD20 AE05 AE07 AF06 DC41 DC46 DD07 FA02 FA03 FA05 FA10 FA13 FB08 FB16 JA07 4M109 AA01 BA01 CA21 EA04 EA06 EB03 EB04 EB06 EB07 EB08 EB09 EB12 EB18 EB19 EC03 EC04 EC04 EC09

Claims (5)

[Claims] (A) A polyfunctional phenol resin (a) represented by the general formula (1) and / or the general formula (2) is mixed with a phenol (b) which is a precursor of a crystalline epoxy resin. Glycidyl etherified epoxy resin, (B)
A polyfunctional phenolic resin curing agent represented by the general formula (3),
(C) An inorganic filler and (D) a curing accelerator are essential components, and the weight ratio (a / b) between (a) and (b) is 1 to 19
The softening point of the epoxy resin (A) is 70 to 120 ° C., and the equivalent ratio of the phenolic hydroxyl group of all phenolic resin curing agents to the epoxy group of all epoxy resins is 0.5 to
2.0, and the content of the inorganic filler is 2 per 100 parts by weight of the total amount of all epoxy resins and all phenolic resin curing agents.
50 to 1400 parts by weight of an epoxy resin composition for semiconductor encapsulation. Embedded image (However, R in the formula is a group or atom selected from hydrocarbons having 1 to 5 carbon atoms and halogens, and they may be the same or different from each other; m = 0 to 4) ,
n = 0 to 3, k is an average value and a positive number of 1 to 10) (However, R in the formula is a group or atom selected from hydrocarbons having 1 to 5 carbon atoms and halogens, and they may be the same or different from each other; m = 0 to 4) Embedded image (However, R in the formula is a group or atom selected from a hydrocarbon having 1 to 5 carbon atoms and a halogen, and they may be the same or different from each other; m = 0 to 4, n
= 0 to 3, l = 0 to 2, k is an average value and a positive number of 1 to 10) 2. A polyfunctional phenol resin (a) represented by the general formula (1) and / or the general formula (2) is mixed with a phenol (b) which is a precursor of a crystalline epoxy resin,
The epoxy resin composition for semiconductor encapsulation according to claim 1, wherein the glycidyl etherified epoxy resin (A) has a heat of fusion of 5 to 35 mJ / mg. 3. The phenol (b) which is a precursor of the crystalline epoxy resin is at least one selected from the general formula (4), the general formula (5), and the general formula (6). Or the epoxy resin composition for semiconductor encapsulation according to 2. Embedded image (However, R in the formula is a group or atom selected from hydrocarbons having 1 to 5 carbon atoms and halogens, and they may be the same or different from each other; m = 0 to 4) Embedded image Embedded image (However, R in the formula is a group or atom selected from a hydrocarbon having 1 to 5 carbon atoms and a halogen, and they may be the same or different from each other; m = 0 to 4, R
2 is a group or atom selected from hydrogen, hydrocarbons having 1 to 5 carbon atoms, and halogen, which may be the same or different from each other. ) 4. A phenol (b), which is a precursor of a crystalline epoxy resin, comprises 4,4′-dihydroxybiphenyl, 4,4′-dihydroxy-3,3 ′, 5,5′-tetramethylbiphenyl, Bis (3,5-dimethyl-4-
Hydroxyphenyl) methane, 2,2-bis (3 ′,
5′-dimethyl-4′-hydroxyphenyl) propane, bis (2-tert-butyl-5-methyl-4-hydroxyphenyl) sulfide, or 3-tert-butyl-2,4′-dihydroxy-3 ′, 5 ', 6-trimethylstilbene, 3-tert-butyl-4,4'
-Dihydroxy-3 ', 5', 6-trimethylstilbene, 3-tert-butyl-4,4'-dihydroxy-
3 ′, 5,5′-trimethylstilbene, and at least one member selected from the group consisting of 4,4′-dihydroxy-3,3 ′,
5,5'-tetramethylstilbene, 4,4'-dihydroxy-3,3'-ditert-butyl-6,6'-dimethylstilbene, 2,2'-dihydroxy-3,3 '
-Ditertiarybutyl-6,6'-dimethylstilbene, 2,4'-dihydroxy-3,3'-ditertiarybutyl-6,6'-dimethylstilbene, 2,2'-dihydroxy-3,3 ', 5 3, 5'-tetramethylstilbene, 4,4'-dihydroxy-3,3'-ditert-butyl-5,5'-dimethylstilbene and a mixture with at least one selected from the group consisting of six kinds. Or 3
The epoxy resin composition for semiconductor encapsulation according to the above. 5. A semiconductor device wherein a semiconductor element is encapsulated with the epoxy resin composition for encapsulating a semiconductor according to claim 1, 2, 3 or 4.