JPH1149934A - Epoxy resin composition and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an epoxy resin composition used for semiconductor sealing and being excellent in flowability, moldability and package cracking resistance by incorporating an epoxy resin with a phenolic resin, a latent cure accelerator having a specified chemical structure, an inorganic filler and a silane coupling agent. SOLUTION: The epoxy resin (A) used has a melting point of 50-150 deg.C, is crystalline and is desirably a mixture comprising a compound of formula III (wherein R3 is a 1-6C alkyl, phenyl or a halogen), etc. The phenolic resin (B) used is one having at least two phenolic hydroxyl groups in the molecule and is used desirably in such an amount that the equivalent ratio of the total epoxy groups of component A to the total phenolic hydroxyl groups is 0.5-2. The cure accelerator (C) used is represented by formula I (wherein R1 is phenyl or naphthyl), used in an amount of 0.4-20 pts.wt. per 100 pts.wt. total of components A and B and is added at 70-150 deg.C. The silane coupling agent (D) used is exemplified by one represented by formula II (wherein R2 is methyl or ethyl), is used in an amount of 0.01-5 pts.wt, per 100 pts.wt. inorganic filler and improves an affinity for the resin component to reduce void formation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to fluidity, moldability,
Epoxy resin composition with excellent package crack resistance,
And a semiconductor device using the same.

[0002]

2. Description of the Related Art In order to reduce the size, density, and function of electronic products, semiconductor packages have come to take various forms. Particularly in recent years, various studies have been made on an epoxy resin composition (hereinafter, referred to as a resin composition) for encapsulating a semiconductor element for surface mounting. In particular, for the above-mentioned surface mounting, prevention of package cracks is a major problem. In order to prevent this package crack, it is necessary to reduce the moisture absorption of the cured product of the resin composition, and the amount of the inorganic filler, which is one of the main components of the resin composition, is increasing to about 90% by weight. . Techniques for high filling of the inorganic filler include changing the particle size distribution and shape of the inorganic filler, reducing the viscosities of the epoxy resin and the phenol resin, and the like. However, when the amount of the inorganic filler increases, it becomes difficult to uniformly disperse the resin component and the inorganic filler during the heating and kneading of each component. As a result, when a semiconductor element is sealed with a resin composition that is insufficiently kneaded, voids occur in a molded product. Further, it has catalytic activity even at a relatively low temperature, such as triphenylphosphine or 1,8.
-When a curing accelerator such as diazabicyclo (5,4,0) undecene-7 is used alone, a predetermined fluidity is exhibited because a crosslinking reaction between an epoxy resin and a phenol resin proceeds during heating and kneading. Disappears. As a result, if the semiconductor element is sealed with a resin composition having poor fluidity, the gold wire inside the molded product may be deformed or may be poorly filled.

[0003]

SUMMARY OF THE INVENTION The present invention provides an epoxy resin composition excellent in fluidity, moldability, and package crack resistance, and a semiconductor device using the same.

[0004]

The present invention is as follows. [1] (A) epoxy resin, (B) phenol resin,
(C) an epoxy comprising, as essential components, a curing accelerator represented by the general formula (1), (D) an inorganic filler, and (E) one or more silane coupling agents selected from the following formulas. Resin composition,

Embedded image (Here, R ₁ is a phenyl group or a naphthyl group.)

[0005]

Embedded image (Here, R ₂ is a methyl group or an ethyl group.) [2] An inorganic filler previously surface-treated with one or more silane coupling agents selected from the formula (E) [1].
The epoxy resin composition described,

[3] The epoxy resin (A) has a melting point of 50
The epoxy resin composition according to [1], wherein the crystalline epoxy resin has a melting point of 50 to 150 ° C.
At least one selected from general formulas (2) and (3),
The epoxy according to [3], which is a stilbene-type epoxy resin represented by the general formula (4) or a mixture of the stilbene-type epoxy resin represented by the general formula (4) and the stilbene-type epoxy resin represented by the general formula (5). Resin composition,

Embedded image (Here, R ₃ is a group or atom selected from a chain or cyclic alkyl group having 1 to 6 carbon atoms, a phenyl group, and a halogen, and they may be the same or different from each other. .)

[0007]

Embedded image (Here, R ₄ is a group or atom selected from a chain or cyclic alkyl group having 1 to 6 carbon atoms, a phenyl group, and a halogen, which may be the same or different. .)

[0008]

Embedded image (Where R _{5 to} R ₁₂ are each independently a hydrogen atom,
A group or atom selected from a chain or cyclic alkyl group having 1 to 6 carbon atoms or halogen. The two aryl groups attached to the carbon-carbon double bond are different from each other. )

[0009]

Embedded image (Here, R _{13 to} R ₁₆ each independently represent a hydrogen atom, a chain or cyclic alkyl group having 1 to 6 carbon atoms, or a group or atom selected from halogen.
The two aryl groups bonded to the carbon double bond are the same. [5] A semiconductor device characterized by being sealed using the epoxy resin composition according to [1], [2], [3], or [4].

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The epoxy resin (A) used in the present invention is a monomer or oligomer having two or more epoxy groups in one molecule,
And polymers in general. For example, ortho-cresol novolak epoxy resin, phenol novolak epoxy resin, triphenolmethane epoxy resin, alkyl-modified triphenolmethane epoxy resin, triazine nucleus-containing epoxy resin, dicyclopentadiene-modified phenol epoxy resin, biphenyl epoxy resin ,
Bisphenol-type epoxy resins, stilbene-type epoxy resins, and the like may be mentioned, and these may be used alone or in combination. Among these epoxy resins, the melting point is 50-1.
A 50 ° C. crystalline epoxy resin is preferred. Such a crystalline epoxy resin has a rigid structure such as a biphenyl skeleton, a bisphenol skeleton, or a stilbene skeleton in a main chain, and is relatively low in molecular weight, and thus exhibits crystallinity. The crystalline epoxy resin is a solid that crystallizes at room temperature, but rapidly melts and changes to a low-viscosity liquid in a temperature range higher than the melting point. The melting point of the crystalline epoxy resin was measured by using a differential scanning calorimeter at a rate of temperature increase from room temperature to 5 ° C. /
2 shows the temperature at the top of the endothermic peak of crystal melting, which was heated in minutes. As the crystalline epoxy resin satisfying these conditions, at least one selected from the general formulas (2) and (3), the stilbene type epoxy resin represented by the general formula (4), or the general formula (4) A mixture of the stilbene type epoxy resin represented by the formula and the stilbene type epoxy resin represented by the general formula (5) is preferable. The substituent R ₃ of the biphenyl type epoxy resin represented by the general formula (2), and the general formula (3)
The substituent R ₄ of the bisphenol type epoxy resin represented by
As, for example, a methyl group, an ethyl group, a propyl group,
Butyl group, cyclohexyl group, phenyl group, chlorine atom,
A bromine atom and the like are mentioned, and a methyl group is particularly preferable. As the substituents R _{5 to} R ₁₆ of the stilbene type epoxy resin represented by the general formulas (4) and (5), for example, a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group, an amyl group, Examples thereof include a hexyl group (including each isomer), a cyclohexyl group, a chlorine atom, and a bromine atom, and particularly, a methyl group, an ethyl group, a propyl group, or a butyl group is preferable from the viewpoint of low melt viscosity of the resin. This epoxy resin
The stilbene epoxy resin of the general formula (4) or a mixture of the stilbene epoxy resin of the general formula (4) and the stilbene epoxy resin of the general formula (5). A stilbene-type epoxy resin represented by the general formula (4);
There are various types of stilbene type epoxy resins having different structures depending on the type of substituents, etc., and each of the stilbene type epoxy resins of the general formulas (4) and (5) has a single structure. However, a mixture of two or more structures may be used. Mixing of the stilbene-type epoxy resin of the general formula (4) and the stilbene-type epoxy resin of the general formula (5) is not particularly limited as long as the melting point is lowered by mixing both compounds. For example,
There is a method of mixing stilbene-type phenols, which are raw materials of the stilbene-type epoxy resin, before glycidyl etherification, or a method of melting and mixing both stilbene-type epoxy resins. In any case, the melting point is 50%.
Adjust so as to be ~ 150 ° C. As the stilbene type epoxy resin of the general formula (4), availability, performance,
From the viewpoint of raw material prices, 5-tert-butyl-4,4'-dihydroxy-2,3 ', 5'-trimethylstilbene, 3-tert-butyl-4,4'-dihydroxy-3', 5,5 ' Glycidyl etherified trimethylstilbene is particularly preferred. As the stilbene type epoxy resin represented by the general formula (5), 4,4′-dihydroxy-3,3 ′, 5,5′-tetramethylstilbene and 4,4′-dihydroxy-3 are preferable in terms of performance and raw material price. Glycidyl etherified products of, 3'-di-tert-butyl-6,6'-dimethylstilbene and 4,4'-dihydroxy-3,3'-di-tert-butyl-5,5'-dimethylstilbene are particularly preferred. .

The phenolic resin (B) used in the present invention
Refers to all monomers, oligomers, and polymers having two or more phenolic hydroxyl groups in one molecule. For example, a phenol novolak resin, a cresol novolak resin, a para-xylylene-modified phenol resin, a para-xylylene / met-xylylene-modified phenol resin, a terpene-modified phenol resin, a dicyclopentadiene-modified phenol resin, and the like may be used, and these may be used alone or in combination. These phenolic resins have molecular weight, softening point,
It can be used without any restriction on the hydroxyl equivalent. The equivalent ratio of the epoxy groups of all epoxy resins used in the present invention to the phenolic hydroxyl groups of all phenolic resins is preferably 0.5 to 2, and particularly preferably 0.7 to 1.5.
If the ratio is out of the range of 0.5 to 2, the curability, moisture resistance and the like are undesirably reduced.

The curing accelerator (C) represented by the general formula (1) used in the present invention has a latent property. Since this curing accelerator does not show catalytic activity in a relatively low temperature range, the curing reaction of the resin composition does not proceed.
That is, when the components are heated and kneaded, a part of the crosslinking reaction does not proceed promptly, so that a predetermined fluidity is maintained, and for the same reason, the resin composition is also excellent in room temperature storage stability. In addition, in the high temperature range during molding, the catalyst exhibits higher catalytic activity than conventional curing accelerators, and cures the resin composition to a high degree. The amount of the curing accelerator used in the present invention is 0.4 to 20 per 100 parts by weight of the total amount of all epoxy resins and all phenol resins.
It is preferable to mix by weight at 70 to 150 ° C. If the amount is less than 0.4 parts by weight, sufficient curability may not be obtained during heat molding.
Exceeding the weight part is not preferred because curing may be too fast and poor filling may occur due to a decrease in fluidity during molding. Also, as long as the properties of this curing accelerator are not impaired,
There is no problem when used in combination with other curing accelerators such as triphenylphosphine and 1,8-diazabicyclo (5,4,0) undecene-7.

The type of the inorganic filler (D) used in the present invention is not particularly limited, and those generally used for a sealing material can be used. For example, fused silica powder, fused spherical silica powder, crystalline silica powder,
Secondary aggregated silica powder, alumina, titanium white, aluminum hydroxide, talc, clay, glass fiber, and the like are listed, and fused spherical silica powder is particularly preferred. The shape is preferably infinitely spherical, and the filling amount can be increased by mixing particles having different particle sizes. The compounding amount of the inorganic filler is preferably 200 to 2400 parts by weight per 100 parts by weight of the total amount of all epoxy resins and all phenol resins. If it is less than 200 parts by weight, the reinforcing effect of the inorganic filler may not be sufficiently exhibited, and if it is more than 2400 parts by weight, the fluidity of the resin composition may be reduced, and poor filling or the like may occur during molding. Absent. In particular, when the blending amount of the inorganic filler is 250 to 1,400 parts by weight per 100 parts by weight of the total amount of all epoxy resins and all phenolic resins, the moisture absorption of the cured product of the resin composition is low, and the occurrence of package cracks is prevented. Since the viscosity of the resin composition at the time of melting becomes lower, there is no possibility of causing gold wire deformation inside the semiconductor package, which is more preferable. It is preferable that the inorganic filler is sufficiently mixed in advance.

The silane coupling agent (E) used in the present invention may be used alone or as a mixture. When the compounding amount of the inorganic filler is large, the resin component and the inorganic filler are difficult to uniformly disperse during the heating and kneading of each component, and thus the kneading becomes insufficient, and the semiconductor element is sealed with such a resin composition. Then, a void is generated in the molded product. But,
Since these silane coupling agents are excellent in improving the compatibility between the inorganic filler and the resin component, the material becomes more uniform at the time of heating and kneading as compared with a system in which the silane coupling agent is not added. The use of an article reduces voids in the molded article. The amount of the silane coupling agent is preferably 0.01 to 5 parts by weight based on 100 parts by weight of the inorganic filler. If the amount is less than 0.01 part by weight, the effect of adding the coupling agent is small, and the effect of reducing voids is small. If the amount exceeds 5 parts by weight, the moisture absorption of the cured product increases, and the package crack resistance remarkably decreases. In addition, the silane coupling agent used in the present invention is preferably present particularly on the surface of the inorganic filler in order to improve the compatibility between the inorganic filler and the resin component. A method of pre-treating with an agent is effective. Examples of the method of treatment include a method of removing the solvent after mixing with a solvent, a method of directly adding to the inorganic filler and treating with a mixer, and the treatment may be performed with or without heating. There is no problem even if there is.

The resin composition of the present invention comprises, in addition to the components (A) to (E), if necessary, a colorant such as carbon black, a flame retardant such as a brominated epoxy resin, antimony oxide, a phosphorus compound, and a silicone oil. And various additives such as a low-stress component such as silicone rubber, a natural wax, a synthetic wax, a higher fatty acid and a metal salt thereof, a releasing agent such as paraffin, and an antioxidant. The resin composition of the present invention is obtained by mixing the components (A) to (E) and other additives at room temperature using a mixer, kneading the mixture with a kneading machine such as a roll or an extruder, cooling, and pulverizing. Can be In order to manufacture a semiconductor device by encapsulating an electronic component such as a semiconductor using the resin composition of the present invention, it is sufficient to cure and mold by a molding method such as a transfer mold, a compression mold, and an injection mold.

[0016]

EXAMPLES Examples of the present invention will be shown below, but the present invention is not limited to these examples. The mixing unit is parts by weight. The abbreviations and structures of the curing accelerators used in Examples and Comparative Examples are shown below.

Embedded image TPPK-NA

[0017]

Embedded image TPPK-BA

Example 1 50.3 parts by weight of a crystalline epoxy resin of the formula (6) (melting point: 105 ° C.)

Embedded image

49.7 parts by weight of a phenolic resin of the formula (7) (softening point: 73 ° C.)

Embedded image

TPPK-NA 5.0 parts by weight Fused spherical silica (average particle size 15 μm) 830 parts by weight Silane coupling agent of formula (8) 3.0 parts by weight

Embedded image Carbon black 2.0 parts by weight Brominated phenol novolak-type epoxy resin 1.7 parts by weight Carnauba wax 2.8 parts by weight was mixed at room temperature using a mixer, then kneaded at 100 ° C. using a biaxial roll, and cooled. Thereafter, the resultant was pulverized to obtain a resin composition. The obtained resin composition was evaluated by the following method. Table 1 shows the results.

Evaluation method Spiral flow: Spiral flow was measured using a mold for measuring spiral flow according to EMMI-I-66 at a mold temperature of 175 ° C., an injection pressure of 70 kg / cm ² , and a curing time of 2 minutes. Spiral flow is a parameter of fluidity, and the larger the value, the better the fluidity. Unit cm. Void: 175 using low pressure transfer molding machine
160pQ at ℃, pressure 70kg / cm ² , curing time 2min
The FP was formed, and the void of the package was observed using an ultrasonic flaw detector. The evaluation was made in three stages of ○, Δ and ×. Package crack resistance: Using a low-pressure transfer molding machine, 175 ° C., pressure 70 kg / cm ² , curing time 2
80pQFP (thickness 1.5mm) in 175 minutes
After curing for 8 hours at 8 ° C., eight packages were obtained.
After absorbing moisture for 168 hours at 85 ° C. and 85% relative humidity, 2
An IR reflow treatment at 40 ° C. was performed twice for 10 seconds, and the number of package cracks was visually observed. When n packages had cracks, the number was indicated as n / 8.

Examples 2 to 6 Compounded according to the formulation shown in Table 1, a resin composition was obtained in the same manner as in Example 1, and evaluated in the same manner as in Example 1. Table 1 shows the results. The silane coupling agent of the formula (9) used in Example 2 and the crystalline epoxy resin of the formula (10) used in Example 5 (melting point: 80 ° C.) are shown below. Example 6
The crystalline epoxy resin X used in Example 1 was composed of 60% by weight of 4,4′-bis (2,3-epoxypropoxy) -3,3 ′, 5,5′-tetramethylstilbene and 4,4′-bis (2 , 3-epoxypropoxy) -5-tert-butyl-2,3 ', 5'-trimethylstilbene as a main component (melting point: 120
° C). The treated silica used in Examples 4 to 6 was prepared by putting 830 parts by weight of fused spherical silica (average particle size: 15 μm) and 3.0 parts by weight of the silane coupling agent of the formula (8) in an aluminum vat, Time-processed.

Embedded image

[0023]

Embedded image

Comparative Examples 1 and 2 The resin composition was prepared according to the formulation shown in Table 1 and a resin composition was obtained in the same manner as in Example 1, and evaluated in the same manner as in Example 1. Table 1 shows the results.

[Table 1]

[0025]

As described above, by using the epoxy resin composition of the present invention, a highly reliable semiconductor device having excellent fluidity, few voids, and excellent package crack resistance can be obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01L 23/31

Claims (5)

[Claims] (A) an epoxy resin, (B) a phenolic resin, (C) a curing accelerator represented by the general formula (1),
An epoxy resin composition comprising (D) an inorganic filler and (E) one or more silane coupling agents selected from the following formulas as essential components. Embedded image (Here, R ₁ is a phenyl group or a naphthyl group.) (Here, R ₂ is a methyl group or an ethyl group.) 2. The epoxy resin composition according to claim 1, which is an inorganic filler previously surface-treated with at least one silane coupling agent selected from the formula (E). 3. An epoxy resin (A) having a melting point of 50 to 15
The epoxy resin composition according to claim 1 or 2, which is a crystalline epoxy resin at 0 ° C. 4. A crystalline epoxy resin having a melting point of 50 to 150 ° C., wherein at least one selected from the general formulas (2) and (3), a stilbene type epoxy resin represented by the general formula (4), or The epoxy resin composition according to claim 3, which is a mixture of a stilbene type epoxy resin represented by the formula (4) and a stilbene type epoxy resin represented by the general formula (5). Embedded image (Here, R ₃ is a group or atom selected from a chain or cyclic alkyl group having 1 to 6 carbon atoms, a phenyl group, and a halogen, and they may be the same or different from each other. ). (Here, R ₄ is a group or atom selected from a chain or cyclic alkyl group having 1 to 6 carbon atoms, a phenyl group, and a halogen, which may be the same or different. ). (Where R _{5 to} R ₁₂ are each independently a hydrogen atom,
A group or atom selected from a chain or cyclic alkyl group having 1 to 6 carbon atoms or halogen. The two aryl groups attached to the carbon-carbon double bond are different from each other. ) (Here, R _{13 to} R ₁₆ each independently represent a hydrogen atom, a chain or cyclic alkyl group having 1 to 6 carbon atoms, or a group or atom selected from halogen.
The two aryl groups bonded to the carbon double bond are the same. ) 5. A semiconductor device encapsulated with the epoxy resin composition according to claim 1, 2, 3, or 4.