JP2600543B2 - Thermosetting resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a cured product having high mechanical strength and high glass transition point, low hygroscopicity, low linear expansion and high adhesiveness, and is suitably used for semiconductor packages and the like. The present invention relates to a thermosetting resin composition.

[0002]

2. Description of the Related Art Conventionally, thermosetting resin compositions containing an epoxy resin, a phenol resin as a curing agent for the epoxy resin, and an inorganic filler have been used for semiconductor packages. .

However, various problems have recently occurred with the reduction in thickness of semiconductor packages. For example, when a flat package is mounted on a printed circuit board, the package is immersed in a high-temperature solder bath. At this time, there is a problem that cracks occur in the package due to thermal shock in a conventional package made of a thermosetting resin composition. It has also been pointed out that if the package absorbs moisture before mounting the flat package on the printed board, a steam explosion occurs in the package when the package is immersed in a high-temperature solder bath, causing cracks.

As a countermeasure against such a problem, improvements have been considered from both sides of the frame and the package resin. In addition to the performance of the resin having high mechanical strength and a high glass transition point, the resin has a low hygroscopic property, Performance such as a low coefficient of linear expansion and good adhesion to a frame is required.

[0005] The present invention has been made in view of the above circumstances,
It is an object of the present invention to provide a thermosetting resin composition which provides a cured product having a high mechanical strength, a high glass transition point, a low hygroscopicity, a low coefficient of linear expansion, and a high adhesiveness.

[0006]

The present inventors have conducted intensive studies to achieve the above object, and as a result, have found that a thermosetting resin composition containing an epoxy resin, a phenolic resin and an inorganic filler is further added. It has been found that it is effective to mix a fluorine-modified resin represented by the following general formula (1) or (2) as an epoxy resin and / or a phenol resin.

[0007]

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That is, an epoxy resin generally used for a semiconductor package has a high glass transition temperature due to a high crosslinking density like a novolak type epoxy resin.
Although it is excellent in heat resistance, there is a problem that the water absorption of the cured product increases when the crosslinking density increases. However, a thermosetting resin composition containing an epoxy resin, a phenol resin, and an inorganic filler is added to the above formulas (1) and (2).
By blending an epoxy resin or a phenolic resin containing a fluorine atom and a naphthalene skeleton represented by
Low moisture absorption, low coefficient of linear expansion, and high adhesion can be added while maintaining the glass transition temperature and mechanical strength of the cured epoxy resin, and therefore, the fluorine represented by the above formulas (1) and (2) can be added. A thermosetting resin composition containing an atom and a naphthalene skeleton-containing epoxy resin, when applied to a semiconductor package, has been found to be able to effectively prevent cracks due to thermal shock or steam explosion when immersed in a solder bath, The present invention has been accomplished.

Hereinafter, the present invention will be described in more detail. The thermosetting resin composition according to the present invention comprises a thermosetting resin composition containing an epoxy resin, a phenol resin, and an inorganic filler represented by the following formula (1): It is obtained by blending a fluorine atom and naphthalene skeleton-containing resin represented by (2).

[0010]

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[0011]

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The fluorine atom and naphthalene skeleton-containing resin is an epoxy resin or a phenol resin having a water repellency derived from a fluorine atom and having a highly hydrophobic naphthalene ring having high rigidity. Examples shown by the structural formulas are as follows.

[0013]

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The fluorine-modified resin of the above formula (1) or (2) according to the present invention is, for example, a fluorine-modified bisphenol A
And mono, di, tri, or tetrahydroxynaphthalene in an appropriate ratio by novolacation to easily synthesize.

In this case, commercially available fluorine-modified bisphenol A and hydroxynaphthalene can be used as raw materials.
A resin corresponding to the desired fluorine-modified resin can be used.

In order to polymerize these raw materials into a novolak compound, a method in which a mixture of the above-mentioned fluorine-modified bisphenol A and hydroxynaphthalene at an appropriate ratio is reacted with an aldehyde compound using a known alkali or acid catalyst. Can be done with

Examples of the aldehyde compound used in the novolakation include formaldehyde and salicylaldehyde. The amount of the aldehyde compound used is not particularly limited, but the ratio of the raw material aldehyde compound / phenol compound is 0.05 to 1 as a molar amount ratio,
In particular, the amount is preferably 0.11 to 0.7.
The molar ratio of aldehyde compound / phenol compound is 0.
If it is less than 05, the molecular weight of the obtained polymer may be small, and if the molar ratio exceeds 1, gelation may occur.

Further, examples of the alkali catalyst used for the novolakation include KOH and NaOH, and examples of the acid catalyst include hydrochloric acid, sulfuric acid, nitric acid, oxalic acid, paratoluenesulfonic acid, acetic acid, butyric acid, propionic acid and the like. The amount of these alkali catalysts or acid catalysts used is a catalytic amount,
Usually, it can be used in the range of 0.5 to 2% by weight based on the phenol compound.

The reaction conditions for this polymerization reaction are not particularly limited, but the fluorine-modified resin and the aldehyde compound are resolulated in an aqueous alkali solution and then acidified, and hydroxynaphthalene is further added thereto at 100 to 150 ° C. for 4 to 8 hours. To obtain a novolak.

When the novolak is formed in this manner, in the above formula (1) or (2), R ¹ is H, at least one of R ^{5 to} R ⁸ is OH, and the phenol resin according to the present invention is H. Can be obtained, and when this is further epoxidized, the epoxy resin according to the present invention can be obtained.

In the composition of the present invention, the same resins as those usually used for semiconductor packages can be blended in addition to the above-mentioned fluorine-modified resin as the epoxy resin and the phenol resin.

Here, as the epoxy resin other than the above, any one having at least two epoxy groups in one molecule can be used. Specifically, bisphenol A type epoxy resin, novolak type epoxy resin ,
An alicyclic epoxy resin and a glycidyl ester type epoxy resin, particularly a polyfunctional epoxy resin and an epoxy resin having a naphthalene ring, are suitable, and these may be used in an appropriate combination.

These epoxy resins have a softening point of 50 to 10.
It is preferable that the epoxy equivalent is 0 ° C. and the epoxy equivalent is 100 to 400. It is also effective to use a brominated epoxy resin for flame retardancy.

The phenol resin acts as a curing agent for the epoxy resin. Examples of other phenol resins include those having two or more phenolic hydroxyl groups such as phenol novolak resin, cresol novolak resin, and triphenolmethane. Can be As the phenol resin, those having a softening point of 60 to 120 ° C and a hydroxyl equivalent of 90 to 150 are preferable.

The phenol resin may be used in any amount as long as the equivalent ratio of epoxy group / hydroxyl group in the thermosetting resin composition is in the range of 0.5 to 2, but usually 100 parts of epoxy resin ( Parts by weight, hereinafter the same)
The range of 0 parts is preferable, and it is desirable to adjust the compounding amount of the fluorine-modified phenol resin and other phenol resins so as to be within this range. If the amount of the phenolic resin is less than 30 parts, sufficient strength may not be obtained in some cases, while if the amount exceeds 70 parts, the moisture resistance may be reduced.

Here, the amount of the fluorine-modified resin represented by the formulas (1) and (2) should be 20 to 100% by weight, especially 50 to 80% by weight in the total amount of 100% by weight of the epoxy resin and the phenol resin. Is preferred. Further, among the fluorine-modified resins of the formulas (1) and (2), the fluorine-modified epoxy resin is preferably used in an amount of 0 to 100% by weight, particularly 50 to 80% by weight of the total amount of the epoxy resin. 0-100% by weight of the total amount of phenolic resin, especially 50-80%
It is preferable to set the weight%.

Next, the inorganic filler compounded in the composition of the present invention reduces the expansion coefficient of the cured product and reduces the stress applied to the semiconductor element. Specifically, fused silica and crystalline silica having a crushed shape and a spherical shape are mainly used, and in addition, alumina, silicon nitride, aluminum nitride, and the like can also be used. Or those mainly composed of spherical products are preferred.

The average particle size of these inorganic fillers is 5 to 20.
μm is preferred, and the amount is preferably 200 to 1600 parts, particularly 300 to 1200 parts, per 100 parts of the epoxy resin. If the amount is less than 200 parts, the expansion coefficient increases, the stress applied to the semiconductor element increases,
In some cases, the device characteristics may be degraded.
If it is added in excess of parts, the viscosity at the time of molding will increase, and the moldability may deteriorate. In addition, it is desirable that these inorganic fillers are surface-treated with a silane coupling agent before use.

The thermosetting resin composition of the present invention preferably contains, in addition to the above components, a silicone-based flexibility-imparting agent or a thermoplastic resin for reducing stress. For example, silicone rubber powder, silicone gel, a block polymer of organic resin and silicone, MBS resin, SEBS, etc. may be mentioned. The surface of the inorganic filler may be treated with a two-part type silicone rubber or silicone gel and added. It is valid.

The amount of the low stress agent used is usually 0.5 to 10% by weight, preferably 1 to 10% by weight of the whole thermosetting resin composition.
~ 5% by weight. If the amount is less than 0.5% by weight, sufficient thermal shock resistance may not be provided. On the other hand, if the amount exceeds 10% by weight, the mechanical strength may decrease.

In addition, the thermosetting resin composition of the present invention may contain, if necessary, a curing accelerator such as imidazole or a derivative thereof, a phosphine derivative or a cycloamidine derivative, and a release agent such as carnauba wax, higher fatty acid or wax. Further, a silane coupling agent, an antimony oxide, a phosphorus compound, a bromo-chlor-containing compound, and the like can be added in a usual amount.

When the thermosetting resin composition of the present invention is produced, the above-mentioned components are uniformly melted and kneaded by a heating roll, kneader, continuous extruder or the like which has been previously heated to 80 to 100 ° C. Can be. There is no particular limitation on the order of compounding the components.

The thermosetting resin of the present invention thus obtained is effective for semiconductor packages such as DIP type, flat pack type, PLCC type and SO type. In this case, a molding method conventionally used, for example, transfer molding, Injection molding, casting and the like can be employed. The molding temperature of the thermosetting resin composition of the present invention is 1
The post-curing is preferably performed at 50 to 180 ° C and 150 to 180 ° C for 2 to 16 hours.

[0034]

As described above, the thermosetting resin composition of the present invention uses the phenol resin or the epoxy resin containing a fluorine atom and a naphthalene skeleton as the epoxy resin or the phenol resin, thereby reducing the epoxy resin. It provides a cured product having low hygroscopicity, low coefficient of linear expansion, and high adhesiveness while maintaining the glass transition point, and is suitably used for semiconductor packages.

[0035]

EXAMPLES The present invention will be described below in detail with reference to examples and comparative examples, but the present invention is not limited to the following examples. In the following examples, all parts are parts by weight.

Examples and Comparative Examples In addition to the components shown in Tables 1-3, 1.5 parts of γ-glycidoxypropyltrimethoxysilane, 1.5 parts of wax E, and carbon black 1.
0 parts and 0.8 parts of triphenylphosphine were added, and the resulting blend was uniformly melt-mixed with a hot two-roll mill to obtain 19 types of thermosetting resin compositions (Examples 1 to 14, Comparative Example 1). ~
5) was produced.

The following various tests (a) to (e) were conducted on these thermosetting resin compositions. The results are shown in Tables 1 to 3. (A) Spiral flow value Using a mold conforming to EMMI standard, 175 ° C, 70
It was measured under the condition of kg / cm ² . (B) Mechanical strength (flexural strength and flexural modulus) 175 ° C, 70 kg / c according to JIS K6911
A bending rod of 10 × 4 × 100 mm was molded under the conditions of m ² and a molding time of 2 minutes, and post-cured at 180 ° C. for 4 hours, and measured at 215 ° C. (C) Using a test piece having a glass transition temperature and an expansion coefficient of 4 mmφ × 15 mm, values measured when the temperature was increased at a rate of 5 ° C. per minute by a dilatometer were measured. (D) Water absorption rate A disk having a diameter of 30 mm and a thickness of 3 mm is molded at 175 ° C for 2 minutes, post-cured at 180 ° C for 4 hours, and then heated at 85 ° C.
The increase in water absorption after standing at / 85% RH for 24 hours was measured. (E) A cylindrical product having a diameter of 15 mm and a height of 5 mm is formed on a 42 alloy plate having an adhesive property of 17 mm × 17 mm (thickness 1 mm) at 175 ° C.
After molding at 180 ° C for 4 hours,
The peeling force between the molded product and the 42 alloy plate was measured with a pushable gauge (n = 8).

[0038]

[Table 1]

[0039]

[Table 2]

[0040]

[Table 3] *: The following were used as epoxy resin and phenol resin.

[0041]

Embedded image (Note 1) Orthocresol novolak epoxy resin (softening point 65 ° C, epoxy equivalent 200) Trade name EOCN1020 (65) (manufactured by Nippon Kayaku Co., Ltd.) (Note 2) Phenol novolak epoxy resin (softening point 100 ° C, OH equivalent 110) Trade name TD2093 (Dai Nippon Ink Co., Ltd.) (Note 3) Brominated phenol novolak type epoxy resin (Softening point 85 ° C, Epoxy equivalent 280) Trade name BREN-S (Nippon Kayaku Co., Ltd.) )

From the results of Tables 1 to 3, the thermosetting resin composition according to the present invention in which an epoxy resin, a phenol resin and an inorganic filler are blended with a phenol resin or an epoxy resin containing a fluorine atom and a naphthalene skeleton (Examples) )
Compared to a thermosetting resin composition containing no phenolic or epoxy resin containing a fluorine atom and a naphthalene skeleton (comparative example), the mechanical strength such as bending strength and bending elastic modulus is not impaired, and the glass transition is high. It can be seen that it has a low coefficient of expansion, a low water absorption, and excellent adhesiveness.

Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication location C08G 59/62 NJF C08G 59/62 NJF C08K 3/00 C08K 3/00 H01L 23/29 H01L 23/30 R 23 / 31

Claims (1)

(57) [Claims] 1. A thermosetting resin composition containing an epoxy resin, a phenol resin and an inorganic filler, wherein a fluorine-modified resin represented by the following general formula (1) or (2) is blended. Curable resin composition. Embedded image