JP2955013B2 - Epoxy resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an epoxy resin composition excellent in solder heat resistance, moldability and moisture resistance reliability.

<Conventional technology> Epoxy resins are excellent in heat resistance, moisture resistance, electrical properties, adhesiveness, etc., and can be imparted with various properties by formulation, so they are used as industrial materials such as paints, adhesives, and electrical insulating materials. Have been.

For example, as a method of sealing an electronic circuit component such as a semiconductor device, a hermetic seal made of metal or ceramic and a resin seal made of phenol resin, silicone resin, epoxy resin or the like have been conventionally proposed. However, resin sealing with epoxy resin is mainly used in terms of balance between economy, productivity, and physical properties.

On the other hand, recently, the density and automation of component mounting on printed circuit boards have been increasing, and instead of the conventional “insertion mounting method” in which lead pins are inserted into holes in the board, “components are soldered to the board surface” “Surface mounting method” has become popular. Along with this, packages are also being transferred from conventional DIPs (dual inline packages) to thin FPPs (flat plastic packages) suitable for high-density mounting and surface mounting.

With the shift to the surface mounting method, the soldering process has become a major problem that has not been a problem in the past. In the conventional pin insertion mounting method, the lead portion is only partially heated in the soldering process, but in the surface mounting method, the entire package is immersed in a heating medium and heated. As a soldering method in the surface mounting method, a solder bath immersion, heating with a saturated vapor of an inert gas (permaphase method), an infrared reflow method, and the like are used. In any case, the entire package is heated to a high temperature of 210 to 270 ° C. It will be heated. Therefore, the package sealed with the conventional sealing resin has a problem that the resin portion is cracked at the time of soldering, the reliability is reduced, and the package cannot be used for manufacturing.

It is said that the occurrence of cracks in the soldering process is due to the fact that the moisture absorbed during the post-curing and mounting process explosively turns into steam and expands during soldering heating. A method is used in which the package is stored in a completely dried and sealed container and shipped.

Various studies have been made on improvements in the sealing resin. For example,
A method of adding an epoxy resin having a biphenyl skeleton (JP-A-63-251419, JP-A-1-87616)
And so on. In addition, in order to improve the moisture resistance of the sealing resin, a sila coupling agent is usually added. Specifically, an aminosilane coupling agent having a primary amino group is added to an ordinary epoxy resin. Addition method (Japanese Patent Publication No. Sho 57-1557)
No. 53) has been proposed.

<Problem to be Solved by the Invention> However, the method of enclosing a container with a dry package has a drawback that the manufacturing process and the handling of the product are complicated, and the manufacturing cost is high.

In addition, resins improved by various methods have each been effective little by little, but are still not sufficient. The method of adding an epoxy resin having a biphenyl skeleton (JP-A-63-251419, JP-A-1-87616)
(Quat flat packages) and other relatively thick packages have the effect of improving solder heat resistance, but TSOP
(Thin small outline package) and other thin packages have a problem that the soldering heat resistance is not sufficient.

The method of adding an aminosilane coupling agent having a primary amine group, which is conventionally used to improve the moisture resistance reliability, has the effects of improving the moisture resistance reliability and simultaneously improving the mechanical strength of the resin. However, it is not practical because the fluidity is reduced.

An object of the present invention is to solve the problem of cracks generated in the soldering step and to provide an epoxy resin composition excellent in moisture resistance reliability and moldability.

<Means for Solving the Problems> The present inventors have achieved the above object by adding an aminosilane coupling agent containing a secondary amino group to an epoxy resin having a naphthalene skeleton. The present inventors have found that a matched epoxy resin composition can be obtained, and have reached the present invention.

That is, the present invention relates to an epoxy resin composition comprising an epoxy resin (A), a curing agent (B), a filler (C), and a silane coupling agent (D),
The epoxy resin (A) has the following general formula (I) (However, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , and R ⁶ each represent a hydrogen atom, a halogen atom, or a group selected from an alkyl group having 1 to 4 carbon atoms.) An epoxy resin composition comprising an epoxy resin (a) as an essential component, wherein the silane coupling agent (D) contains an amino group, and all of the amino groups are secondary.

 Hereinafter, the configuration of the present invention will be described in detail.

The epoxy resin (A) in the present invention has the formula (I)
It is important that the epoxy resin (a) represented by the following formula is contained as an essential component. When the epoxy resin (a) is not contained, the effect of preventing the occurrence of cracks in the soldering step and the effect of heat resistance are not exhibited. In the above formula (I), R ¹ , R ² , R ³ , R ⁴ , R ⁵ , and R ⁶ each represent a hydrogen atom, a halogen atom, or a group selected from an alkyl group having 1 to 4 carbon atoms. Preferred specific examples of R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ include a hydrogen atom, a methyl group, an ethyl group, a propyl group,
i-propyl group, n-butyl group, sec-butyl group, tert
-A butyl group, a chlorine atom, a bromine atom and the like.

Preferred specific examples of the epoxy resin (a) in the present invention include 1,5-diglycidylnaphthalene, 1,5-diglycidyl-7-methylnaphthalene, 1,6-diglycidylnaphthalene, and 1,6-diglycidyl-2-. Methylnaphthalene, 1,6-diglycidyl-8-methylnaphthalene, 1,6-
Examples thereof include diglycidyl-4,8-dimethylnaphthalene, 2-bromo-1,6-diglycidylnaphthalene, and 8-bromo-1,6-diglycidylnaphthalene.

The epoxy resin (A) in the present invention can contain the above-mentioned epoxy resin (a) in combination with another epoxy resin other than the epoxy resin (a). Other epoxy resins that can be used in combination include, for example, cresol novolak epoxy resin, phenol novolak epoxy resin, biphenyl epoxy resin, various novolak epoxy resins synthesized from bisphenol A and resorcinol, bisphenol A epoxy resin, wire Aliphatic epoxy resin, alicyclic epoxy resin, heterocyclic epoxy resin, halogenated epoxy resin and the like.

The ratio of the epoxy resin (a) contained in the epoxy resin (A) is not particularly limited, and the effect of the present invention is exhibited if the epoxy resin (a) is contained as an essential component, but a more sufficient effect is obtained. In order to exert the effect, the epoxy resin (a) is usually added to the epoxy resin (A) by 50% by weight.
As described above, it is necessary that the content is preferably 70% by weight or more.

In the present invention, the compounding amount of the epoxy resin (A) is usually 3 to 30% by weight, preferably 5 to 20% by weight.

The curing agent (B) in the present invention is an epoxy resin (A)
There is no particular limitation as long as it reacts and cures. Specific examples thereof include, for example, phenol novolak resin, cresol novolak resin, various novolak resins synthesized from bisphenol A and resorcin, various polyphenol compounds, and anhydrous polyphenol compounds. Maleic acid, phthalic anhydride,
Acid anhydrides such as pyromellitic anhydride and aromatic amines such as metaphenylenediamine, diaminodiphenylmethane, and diaminodiphenylsulfone are exemplified.
For sealing semiconductor devices, novolak resins such as phenol novolak and cresol novolak are preferably used from the viewpoint of heat resistance, moisture resistance and storage stability, and two or more curing agents may be used in combination depending on the application.

In the present invention, the amount of the curing agent (B) is usually 1 to 20.
% By weight, preferably 2 to 15% by weight. Furthermore, the mixing ratio of the epoxy resin (A) and the curing agent (B) is such that the chemical equivalent ratio of (B) to (A) is in the range of 0.6 to 1.5, particularly 0.8 to 1.2 from the viewpoint of mechanical properties and moisture resistance. Is preferred.

In the present invention, a curing catalyst may be used to accelerate the curing reaction between the epoxy resin (A) and the curing agent (B). The curing catalyst is not particularly limited as long as it promotes the curing reaction. For example, 2-methylimidazole, 2,4-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methyl Imidazole compounds such as imidazole and 2-heptadecyl imidazole, triethylamine, benzyldimethylamine, α-methylbenzyldimethylamine,
Tertiary amine compounds such as-(dimethylaminomethyl) phenol, 2,4,6-tris (dimethylaminomethyl) phenol, 1,8-diazabicyclo (5,4,0) undecene-7, zirconium tetramethoxide, zirconium Organometallic compounds such as tetrapropoxide, tetrakis, (acetylacetonato) zirconium, tri (acetylacetonato) aluminum and triphenylphosphine, trimethylphosphine, triethylphosphine;
Organic phosphine compounds such as tributylphosphine, tri (p-methylphenyl) phosphine, and tri (nonylphenyl) phosphine are exemplified. Of these, organic phosphine compounds are preferred from the viewpoint of moisture resistance, and triphenylphosphine is particularly preferably used. Two or more of these curing catalysts may be used in combination depending on the application, and the amount added is preferably in the range of 0.1 to 10 parts by weight based on 100 parts by weight of the epoxy resin (A).

The filler (C) in the present invention is not particularly limited, and is not particularly limited to fused silica, crystalline silica, calcium carbonate, magnesium carbonate, alumina, magnesia, clay, talc, calcium silicate, titanium oxide, antimony oxide, asbestos,
Glass fiber and the like can be mentioned. Among them, fused silica is preferred. In the present invention, the proportion of the filler (C) is
75-90% by weight. If the filler (C) is less than 75% by weight, the solder heat resistance is insufficient, and if it exceeds 90% by weight, the flow is insufficient. Further, in the present invention, the filler (C) is 90 to 40% by weight of crushed fused silica (C ') having an average particle size of 10 μm or less and spherical fused silica (C ″) having an average particle size of 40 μm or less.
It is preferable to contain 10 to 60% by weight of fused silica from the viewpoint of solder heat resistance. Here, the average particle diameter means a particle diameter (median diameter) at which the cumulative weight becomes 50%.

It is important that the silane coupling agent (D) used in the present invention is an aminosilane compound containing an amino group and in which all amino groups are secondary amino groups. Specific examples of these silane coupling agents (D) include those represented by the following formula (II) or (III).

(However, R ⁷ , R ⁸ , R ⁹ , R ¹¹ , R ¹² , R ¹³ each represents a group selected from monovalent hydrocarbon groups having 1 to 20 carbon atoms,
R ¹⁰ , R ¹⁴ , and R ¹⁵ each represent a group selected from divalent hydrocarbon groups having 1 to 20 carbon atoms, and n represents an integer of 1 to 3. Among them, a group in which a group having a large steric hindrance, for example, an isopropyl group, a t-butyl group, a diphenylmethane group, a triphenylmethane group or a phenyl group, is bonded to the amine from the viewpoint of the life of the composition is most preferable. Preferred is N-phenylaminopropyltrimethoxysilane in which the phenyl group in the formula (II) is bonded to an amine.

The addition amount of the silane coupling agent (D) used in the present invention is usually 0.1 to 5 parts by weight, preferably 0.2 to 3 parts by weight, particularly preferably 0.2 to 3 parts by weight with respect to 100 parts by weight of the filler from the viewpoint of moldability and reliability. 0.3 to 1.5 parts by weight. Depending on the application, a silane coupling agent such as epoxy silane or mercapto silane can be used in combination.

In the present invention, the addition method of the silane coupling agent (D) is not particularly limited, but the addition method of preliminarily surface-treating the filler (C) with the silane coupling agent (D) is most effective in improving the moisture resistance reliability. preferable.

In the present invention, a modified silicone oil (E) can be added to reduce stress and improve reliability.

The modified silicone oil (E) used herein has an organopolysiloxane structure, and specific examples include those represented by the following formula (IV).

(R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , and R ²⁰ each represent a hydrogen atom,
X to Y are an alkyl group having 1 to 20 carbon atoms, a phenyl group, a vinyl group, a hydroxyl group, an amino group, an epoxy group, and a carboxyl group. A functional group having at least one group and / or an atom selected from a group, a mercapto group, a polyoxyalkylene group, an alkoxy group and a fluorine atom, and Y may be a hydrogen atom. M represents an integer of 1 or more, and n represents an integer of 0 or more. The amount of addition of the modified silicone oil (E) is usually 0.01 to 5% by weight, preferably 0.1 to 5% by weight from the viewpoint of reducing stress and reliability.
-3% by weight, particularly preferably 0.3-2% by weight.

The epoxy resin composition of the present invention includes a halogen compound such as a halogenated epoxy resin, a flame retardant such as a phosphorus compound, a flame retardant auxiliary such as antimony trioxide, a colorant such as carbon black and iron oxide, a silicone rubber, and an olefin. Elastomers such as copolymers, modified nitrile rubber and modified polybutadiene rubber, thermoplastic resins such as polyethylene, long-chain fatty acids, metal salts of long-chain fatty acids, esters of long-chain fatty acids, amides of long-chain fatty acids, and paraffin wax. A releasing agent and a crosslinking agent such as an organic peroxide can be optionally added.

The epoxy resin composition of the present invention is preferably melt-kneaded, and is produced by melt-kneading using a known kneading method such as a Banbury mixer, a kneader, a roll, a single-screw or twin-screw extruder and a co-kneader. You.

<Example> Hereinafter, the present invention will be specifically described with reference to examples.

Examples 1 to 7, Comparative Examples 1 to 4 Components shown in Table 1, silane coupling agent (D) shown in Table 2, fused silica (C) shown in Table 3, modified silicone oil shown in Table 4 (E) was dry-blended with a mixer at a composition ratio shown in Table 5 using a mixer. This is mixed with a mixing roll having a roll surface temperature of 90 ° C. for 5 minutes.
After heating and kneading for minutes, the mixture was ground and pulverized to produce an epoxy resin composition.

Using this composition, low-pressure transfer molding
The composition was molded under the conditions of 175 ° C. × 2 minutes, and each composition and moldability were measured by the following physical property and moldability measurement methods. Table 5 shows the results
Shown in

Solder heat resistance: Mold 28 pins and 16 TSOPs with simulated elements, post cure at 180 ° C for 5 hours, and 12 at 85 ° C / 85% RH
After humidification for a period of time, the mixture was heated to 245 ° C. for 10 seconds using an IR reflow furnace, and the ratio of the number of TSOPs without cracks was determined.

PCBT after solder immersion: TSOP after solder immersion at 125 ° C, 85% R
H, USPCBT was performed at a bias voltage of 10 V, and the time until the cumulative failure rate became 50% was obtained.

Resin flash: molded by flash measurement using a low pressure transfer molding method under the conditions of 175 ° C. × 90 seconds, the length of the composition flowing out into a groove having a width of 5 μm in the mold is determined, and the value of the resin flash is determined. And This value is preferably smaller.

Hot hardness: 10cm diameter by low pressure transfer molding method
Was molded under the conditions of 175 ° C. × 90 seconds, and its hardness (Shore D) was measured to obtain the hardness when heated.

As can be seen from Table 5, the epoxy resin compositions of the present invention (Examples 1 to 7) are excellent in moldability such as solder heat resistance and moisture resistance reliability, hot hardness, and resin flash. On the other hand, the epoxy resin (a) is contained in the epoxy resin (A).
Comparative Examples 1 and 2, which do not contain, have inferior solder heat resistance.
Furthermore, Comparative Examples 3 and 4 containing no silane coupling agent of the present invention are inferior in solder heat resistance, moisture resistance reliability and resin flash. In particular, in Comparative Example 4 using a silane coupling agent containing no amino group, sufficient hot hardness cannot be obtained.

Further, the ratio of the fused silica (C) is 75% by weight to 90% of the whole.
90 to 40% by weight of a crushed fused silica (C ') having an average particle size of 10 μm or less and an average particle size
Examples 3 to 7 containing fused silica composed of spherical fused silica (C ″) of 40 μm or less are particularly excellent in solder heat resistance and PCBT after solder immersion.

Examples further containing a modified silicone oil
6,7 further improve the humidity resistance reliability.

<Effect of the Invention> Since the epoxy resin composition of the present invention contains a specific epoxy resin, a curing agent, a specific silane coupling agent, and a filler, solder heat resistance, moisture resistance reliability and heat hardness, Excellent moldability such as burrs.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI H01L 23/29 H01L 23/30 R 23/31 (56) References JP-A-2-218735 (JP, A) JP-A-2 -218736 (JP, A) JP-A-2-265916 (JP, A) JP-A-2-88621 (JP, A) JP-A-1-268712 (JP, A)

Claims (9)

(57) [Claims] 1. An epoxy resin composition comprising an epoxy resin (A), a curing agent (B), a filler (C) and a silane coupling agent (D), wherein the epoxy resin (A) Is the following general formula (I) (However, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , and R ⁶ each represent a hydrogen atom, a halogen atom, or a group selected from an alkyl group having 1 to 4 carbon atoms.) An epoxy resin composition comprising an epoxy resin (a) as an essential component, wherein the silane coupling agent contains an amino group, and the amino groups are all secondary. 2. The epoxy resin (a) is an epoxy resin (A).
The epoxy resin composition according to claim 1, which is 50% by weight or more. 3. The proportion of the filler (C) is 75 to 90% by weight of the whole.
The epoxy resin composition according to claim 1 or 2, wherein 4. The filler (C) is 90 to 40% by weight of crushed fused silica (C ') having an average particle size of 10 μm or less, and the average particle size is 40 μm.
The epoxy resin composition according to any one of claims 1 to 3, further comprising fused silica comprising 10 to 60% by weight of the following spherical fused silica (C "). 5. An epoxy resin (A) having a compounding amount of 3
-30% by weight, the amount of the curing agent (B) is such that the chemical equivalent ratio of the curing agent (B) to the epoxy resin (A) is 0.6-1.5, and the amount of the silane coupling agent (D) is filled. The amount is 0.1 to 5 parts by weight per 100 parts by weight of the material.
5. The epoxy resin-based composition according to any one of items 1 to 4, 6. The epoxy resin composition according to claim 1, wherein the composition further comprises a modified silicone oil (E). 7. The epoxy resin composition according to claim 1, wherein the composition further comprises an organopolysiloxane represented by the following formula (IV). (R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , and R ²⁰ are each a hydrogen atom, and have 1 to 2 carbon atoms.
X or Y is an alkyl group having 1 to 20 carbon atoms, a phenyl group, a vinyl group, a hydroxyl group, an amino group, an epoxy group, or a carboxyl group. , A mercapto group, a polyoxyalkylene group, an alkoxy group and a functional group having at least one atom selected from a fluorine atom, and Y may be a hydrogen atom. M represents an integer of 1 or more, and n represents an integer of 0 or more. ) 8. The epoxy resin composition according to claim 1, which is used for encapsulating a semiconductor. 9. A semiconductor device encapsulated with the epoxy resin composition according to claim 8.