JPH06256625A - Resin composition for sealing - Google Patents

Abstract

PURPOSE:To obtain the subject composition improved in heat resistance by mixing a dicyanate ester compound represented by a specified formula, a phenol- modified resin, an epoxy resin, bis(2,4-pentanedionato)copper and an inorganic filler. CONSTITUTION:This resin composition for high-temperature use is obtained by kneading a mixture of 100 pts.wt. dicyanate ester compound represented by the formula (wherein R1 is CH2, C(CH3)2, C(CF3)2, CHCH3, O, S, or direct linkage; and R2 and R3 are each H, CH3, C2H5 or CF3), such as bis(4- dicyanatophenyl)methane, 5-50 pts.wt. of at least one modified resin selected from phenol-modified petroleum resin, phenol-modified coal resin and phenol- modified polybutadiene resin, 5-50 pts.wt. epoxy resin comprising, e.g. bisphenol A glycidyl ether, 0.05-5 pts.wt. curing catalyst comprising, e.g. bis(2,4- pentanedionato)copper, and 100-1,000 pts.wt. inorganic filler such as silica powder. This composition is used for semiconductor sealing and has good soldering crack resistance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosetting resin composition for semiconductor encapsulation which is fast-curing, has a high glass transition point (hereinafter referred to as Tg), has a low water absorption property and is excellent in toughness. Is.

[0002]

2. Description of the Related Art In recent years, epoxy resin compositions have been generally used for sealing semiconductor elements such as ICs, LSIs, transistors and diodes, electronic circuits, etc. in terms of characteristics, cost, and the like. However, with the trend toward mass production of electronic components, high integration and surface mounting, the demands for the sealing resin have become stricter accordingly. In particular, cracks are likely to occur in the device due to chip size increase due to high integration, thin package, and solder dipping (200 to 300 ° C) during surface mounting, and for semiconductor encapsulation to improve reliability. As a resin, heat resistance, high toughness, and low water absorption are strongly desired.

Epoxy resins are currently the mainstream resin for semiconductor encapsulation. However, there is a limit to the improvement of the epoxy resin in terms of heat resistance and low water absorption, and a highly reliable epoxy resin after solder dipping during surface mounting has not been obtained. As a resin having a high heat resistance, which is an alternative to an epoxy resin, a maleimide resin has been attracting attention, but it has a drawback that it has a large water absorption rate, cracks are generated when solder is dipped during moisture absorption, and reliability is poor. In addition to the above, cyanate ester resin is known as a resin having high heat resistance instead of the epoxy resin.
This resin has a high Tg and becomes a cured product having a relatively low water absorption when a long pressing time is applied as in the case of molding a laminated plate. However, when this is used for short-time molding of a sealing material or the like, the curing speed is very slow and the releasability from the mold is poor. When a curing catalyst such as nonylphenol, cobalt naphthenate, or zinc naphthenate is increased in order to improve the curability, there are problems such as a decrease in Tg, brittleness, and an increase in water absorption.

[0004]

SUMMARY OF THE INVENTION The object of the present invention is to provide a semiconductor which has fast curing property, high heat resistance, low water absorption property, high toughness, and excellent reliability after solder immersion. It is to provide a resin composition for sealing.

[0005]

The present invention provides one or two selected from the group consisting of a dicyanate ester compound represented by the formula (1), a phenol-modified petroleum resin, a phenol-modified coal resin and a phenol-modified polybutadiene resin. A resin composition for encapsulation comprising at least one modified resin, an epoxy resin, bis (2,4-pentanedionato) copper, and an inorganic filler.

[Chemical 1]

[0006]

The dicyanate ester compound used in the present invention is represented by the formula (1). Formula (1)
Examples of preferred dicyanate ester compounds of bis (4-cyanatephenyl) methane, bis (3-methyl-4-cyanatephenyl) methane, bis (3-ethyl-4-cyanatephenyl) methane, bis (3,5 -Dimethyl-4-cyanatephenyl) methane, 1,1-bis (4-cyanatephenyl) ethane, 2,2-bis (4-cyanatephenyl) propane, 2,2-
Bis (4-cyanatephenyl) -1,1,1,3,3,3-hexafluoropropane, di (4-cyanatephenyl) ether, di
(4-Cyanatephenyl) thioether, 4,4-dicyanate-diphenyl and the like can be mentioned.

The phenol-modified petroleum resin used in the present invention is obtained by copolymerizing diolefins and monoolefins contained in a cracked oil fraction of petroleum with phenols. More specifically, among the cracked oil fraction, C ₅ system in which the C ₅ fraction in material (aliphatic) petroleum resins, C ₉ system in which a C ₉ fraction to the raw material (aromatic) petroleum resin, C _A petroleum resin obtained by adding phenols to a ₅ C ₉ copolymerized petroleum resin or a dicyclopentadiene resin obtained by dimerizing cyclopentadiene contained in a C ₅ fraction as a raw material. .

The phenol-modified coal resin used in the present invention is obtained by addition-polymerizing styrene, vinyltoluene, coumarone, indene and the like contained in the cracked oil fraction of coal with phenols. The phenol-modified polybutadiene resin is obtained by addition-polymerizing polybutadiene having a molecular weight of 300 to 2000 with phenols. If the molecular weight of polybutadiene is lower than 300, good toughness cannot be obtained and
If it is higher than 0, the heat resistance decreases.

As the phenols, phenol, cresol, xylenol and the like are used. The content of phenols is 5% by weight or more in the phenol-modified resin, 50
It is preferable that the amount is 1% or less by weight and an average of 1 to 3 added per molecule. When the content of phenols is less than 5% by weight,
Curability is poor, Tg is low, and good toughness cannot be obtained.
On the other hand, if it exceeds 50% by weight, the releasability at the time of molding is poor and the water absorption rate of the molded product increases.

The amount of the phenol-modified petroleum resin, phenol-modified coal resin or phenol-modified polybutadiene resin is preferably 5 parts by weight or more and 50 parts by weight or less based on 100 parts by weight of the dicyanate ester compound. If it is less than 5 parts by weight, the curability and releasability are poor, and the water absorption of the molded product is large. Also
If it exceeds 50 parts by weight, the heat resistance is lowered and good toughness cannot be obtained.

The dicyanate ester compound and the phenol-modified petroleum resin, phenol-modified coal resin or phenol-modified polybutadiene resin are heated to 100 to 200 ° C. and pre-reacted so that the melting point is from 50 ° C. to 100 ° C. You can also

The epoxy resin is bisphenol A.
Glycidyl ether, 4,4'-di (1,2-epoxyethyl)
Diphenyl ether, 4,4 '-(1,2-epoxyethyl) diphenyl ether, resorcin glycidyl ether, butadiene epoxyside, bis- (2,3-epoxycyclopentyl) ether propane, phloroglysin diglycidyl ether, methyl phloglycine Diglycidyl ether, 3,3 ', 5,5'-tetramethyl-biphenyl-4,4'-diglycidyl ether, biphenyl-4,4'-diglycidyl ether, naphthalene-1,6-diglycidyl ether, etc. Bifunctional epoxy compound, polyglycidyl ether of phenol-formaldehyde novolac, triglycidyl ether of trimethylolpropane, triglycidyl ether of glycerin, 1,3,5-tri (1,2-epoxyethyl)
Trifunctional or higher functional epoxy compounds such as benzene, polyallyl glycidyl ether, and triglycidyl ether of para-aminophenol are used. These compounds can be used alone or in combination.

The amount of the epoxy resin is preferably 5 parts by weight or more and 50 parts by weight or less based on 100 parts by weight of the dicyanate ester compound. If it is less than 5 parts by weight, the releasability is poor and the water absorption of the molded product is high. Further, if it exceeds 50 parts by weight, Tg is lowered.

The curing catalyst is bis (2,4-pentanedionato).
Copper is preferably used. Generally known zinc naphthenate and cobalt naphthenate are not very curable, and unless the curing temperature is raised or the curing time is extended,
A homogeneous molded product cannot be obtained. Therefore, the productivity is significantly reduced. Further, when the amount of these catalysts added is increased, Tg is lowered, resulting in brittleness and increased water absorption. The amount of bis (2,4-pentanedionato) copper added is 100% of the dicyanate compound.
It is preferably 0.05 to 5 parts by weight with respect to parts by weight. If it is less than 0.05 parts by weight, the curability will be insufficient, and if it is more than 5 parts by weight, the gel time will be short and defects such as defective filling may occur in the molded product.

Examples of the inorganic filler include silica powder, alumina, antimony trioxide, aluminum hydroxide hydrate, titanium oxide and the like, and these can be used alone or in combination of two or more kinds. Among these inorganic fillers, silica powder is preferably used as the semiconductor sealing material composition. The inorganic filler is preferably added in an amount of 100 to 1000 parts by weight based on 100 parts by weight of the dicyanate compound. If it is 100 parts by weight or less, the water absorption rate and the linear expansion coefficient of the molded product will be large, and if it is 1000 parts by weight or more, the moldability will be reduced, which is not suitable for practical use.

The composition for encapsulant of the present invention is formed into a molding material by appropriately mixing and adding a lubricant, a flame retardant, a release agent, a silane coupling agent, a colorant and the like, and kneading with heating. be able to.

[0017]

【Example】

(Examples 1 to 3) According to the formulation shown in Table 1, kneading was performed with a hot roll to obtain a molding material. The obtained molding material was molded by transfer molding at 175 ° C. for 1.5 minutes, and a molded product having a good appearance was obtained. The molded product was further post-cured at 180 ° C. for 8 hours to evaluate the characteristics. The results are shown in Table 1. The molding materials of Examples 1 to 3 have high Tg, high toughness (breaking energy), fast curing property, and low water absorption. The solder crack resistance after the moisture absorption treatment was also good.

(Comparative Examples 1 and 2) According to the formulations shown in Table 1, molding materials were obtained in the same manner as in Examples 1 to 3. In Comparative Example 1, the curability was poor and it was difficult to mold at 175 ° C for 1.5 minutes.
Molded at ℃ for 3 minutes. In Comparative Example 2 in which the amount of the curing catalyst (cobalt naphthenate) was increased, the curability was good, but the Tg was low and the water absorption rate was high, so the solder crack resistance after the moisture absorption treatment was poor.

[0019]

[Table 1] Note * 1: phenol - le modified C ₅ petroleum resin; phenol - le content 23%, 1 molecule per phenol - Le 2.2 pieces * 2: phenol - le modified coal resin; phenol - le content 23%, 2.2 phenols per molecule * 3: phenol-modified polybutadiene resin; molecular weight of polypolydiene 700, phenol content 23%, phenols per molecule 2.2 phenols * 4: Vespheno manufactured by Yuka Shell Epoxy Co., Ltd. -A type epoxy resin * 5: Nippon Kayaku Co., Ltd. ortho-cresol-nornovolak type epoxy resin * 6: Vise (2,4-pentanionate) copper * 7: Cobalt naphthenate * 8: Vice (3,5) -Dimethyl-4-cyanatephenyl) methane * 9: Higher fatty acid ester * 10: Calculated from stress-strain curve in bending strength test * 11: Moisture absorption treatment: 85 ° C, 85% RH, 72 hours * 12: Flat pack A 6mm square element is mounted on a lead frame (2.7mm thick). Und synthesis, transfer - a shaped body 10 molded, moisture absorption treatment (65 ℃, 95% RH, 72 hours) in a solder bath immediately after 260 ° C. 1
The number of cracks on the surface of the molded product after immersion for 0 second is shown.

[0020]

The encapsulating resin composition of the present invention is fast-curing, has a high Tg, has a low water absorption rate, and is excellent in toughness. When this is used for semiconductor encapsulation, the solder crack resistance of the encapsulant is also good, and it is a highly reliable and excellent resin composition for semiconductor encapsulation.

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Claims (1)

[Claims] 1. A dicyanate ester compound represented by the formula (1), one or more modified resins selected from the group consisting of a phenol-modified petroleum resin, a phenol-modified coal resin and a phenol-modified polybutadiene resin, and an epoxy. A sealing resin composition comprising a resin, bis (2,4-pentanedionato) copper, and an inorganic filler. [Chemical 1]