JPH07165889A - Resin composition for sealing - Google Patents

Abstract

PURPOSE:To obtain a compsn. which has excellent releasability, high heat resistance, low water-absorbing properties, high adhesive properties, and high toughness and gives a sealed semiconductor device with good resistance to soldering crack by specifying the ratio of a dicyanate compd. to a specific mold releasing agent. CONSTITUTION:This compsn. comprises a dicyanate compd. of formula I (wherein R1 is-CH2-, a group of formula II, III, or IV,-O-,-S-, or a direct bond; and R2 and R3 are each-H,-CH3,-C2H5, or-CF3) and/or its prepolymer, at least one modified resin selected from the group consisting of a phenol-modified petroleum resin, a phenol-modified coal resin, and a phenol-modified polybutadiene resin, an epoxy resin, 3-amino-4-chlorobenzamide, and an inorg. filler provided the wt. ratio of 3-amino-4-chlorobenzamide to the dicyanate compd. or its prepolymer is 0.01-0.2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a heat for semiconductor encapsulation which has excellent releasability at the time of taking out a mold, a high glass transition point (hereinafter referred to as Tg), low water absorption, high adhesiveness and excellent toughness. The present invention relates to a curable resin composition.

[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 higher integration, thinner 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.

[0004]

The object of the present invention is to provide excellent releasability at the time of taking out a mold, high heat resistance, low water absorption, high adhesiveness, high toughness, and solderability. An object of the present invention is to provide a resin composition for semiconductor encapsulation which is very excellent in reliability after immersion.

[0005]

The present invention is selected from the group consisting of a dicyanate ester represented by the formula (1) and / or a prepolymer thereof, a phenol-modified petroleum resin, a phenol-modified coal resin and a phenol-modified polybutadiene resin. In the resin composition for encapsulation, which comprises an epoxy resin, 3-amino-4-chlorobenzamide, and an inorganic filler, one or two or more modified resins
The encapsulating resin composition is characterized in that the proportion of chlorobenzamide is 1 part by weight or more and less than 20 parts by weight with respect to 100 parts by weight of the dicyanate ester and / or its prepolymer.

[0006]

[Chemical 2]

The dicyanate ester represented by the general formula (1) and / or its prepolymer used in the present invention means an organic compound having two or more cyanate ester groups in the molecule. In the present invention, the dicyanate ester itself or a prepolymer derived therefrom can be used. These compounds are, if necessary, catalysts such as zinc naphthenate, cobalt naphthenate, copper naphthenate, lead naphthenate, zinc octylate, tin octylate, lead acetylacetonate, copper acetylacetonate, and dibutyltin maleate. By using, the cyanate ester group can be trimerized, and the reaction can be appropriately adjusted to form a prepolymer. The cyanate ester group can form a sym-triazine ring in the molecule by trimerization and can be finally heat-cured. The cured product of the dicyanate ester and / or its prepolymer alone has excellent heat resistance and relatively low water absorption, but is still insufficient in terms of toughness and adhesiveness, and phenol-modified A sealing composition having excellent curability, adhesiveness, and toughness can be provided only by blending a petroleum resin, a phenol-modified coal resin, a phenol-modified polybutadiene resin, or a benzotriazole compound and heating and curing.

The dicyanate ester and / or its prepolymer used in the present invention is represented by the formula (1). Examples of preferred dicyanate ester compounds of formula (1) include 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) -1,1,1,1,3,3,3-hexafluoropropane, di (4-cyanatephenyl) ether, di (4-cyanatephenyl) thioether, 4,4-
Examples include dicyanate-diphenyl and the like.

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. Further, the phenol-modified polybutadiene resin is obtained by addition-polymerizing polybutadiene having a molecular weight of 300 to 2000 with phenols. When the molecular weight of polybutadiene is lower than 300, good toughness cannot be obtained, and when it is higher than 2000, heat resistance is lowered.

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, 5
It is preferably 0% by weight or less and an average of 1 to 3 added per molecule. If the content of the phenols is less than 5% by weight, the curability is poor and the Tg is low, so that good toughness cannot be obtained. On the other hand, if it exceeds 50% by weight, the water absorption rate of the molded product increases.

Phenol-modified petroleum resin, phenol-modified coal resin or phenol-modified polybutadiene resin is a dicyanate ester and / or its prepolymer 100.
It is preferably 5 parts by weight or more and 50 parts by weight or less with respect to parts by weight. If it is less than 5 parts by weight, the curability will be poor and the water absorption of the molded article will be large. On the other hand, if it exceeds 50 parts by weight, the heat resistance is lowered and good toughness cannot be obtained.

The dicyanate ester and / or its prepolymer and the phenol-modified petroleum resin, phenol-modified coal resin or phenol-modified polybutadiene resin are 1
When heated to 00 to 200 ° C, the melting point is 50 ° C or higher and 100 ° C.
The reaction may be performed in advance so that it becomes as follows.

The epoxy resin is not particularly limited, but examples thereof include diglycidyl ether of bisphenol A, 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 phloroglysin diglycidyl ether 3,3 ', 5,5'-tetra Methyl-biphenyl-4,4'-diglycidyl ether, biphenyl-4,
Bifunctional epoxy compounds such as 4'-diglycidyl ether and naphthalene-1,6-diglycidyl ether, phenol-formaldehyde novolac polyglycidyl ether, trimethylolpropane triglycidyl ether, glycerin triglycidyl ether 1,3,3, 5-
Trifunctional or higher functional epoxy compounds such as tri (1,2-epoxyethyl) benzene, polyallyl glycidyl ether, and triglycidyl ether of para-aminophenol are used. It is also possible to use an epoxy resin having a halogen atom such as Cl or Br in the molecule. These compounds can be used alone or in combination.

The epoxy resin is 3 to 3 parts by weight based on 100 parts by weight of the dicyanate ester and / or its prepolymer.
0 parts by weight is preferred. If it is less than 3 parts by weight, the adhesiveness will be lowered, and if it exceeds 30 parts by weight, Tg will be lowered.

The amount of 3-amino-4-chlorobenzamide added is preferably 1 part by weight or more and 20 parts by weight or less with respect to 100 parts by weight of the dicyanate ester and / or its prepolymer. If it is less than 1 part by weight, the releasability at the time of taking out the mold is poor, and if it is 20 parts by weight or more, the water absorption becomes large.
Adhesion is reduced.

Examples of the inorganic filler include silica powder, alumina, antimony trioxide, aluminum hydroxide hydrate, titanium oxide and the like, and these may be used alone or in combination of two or more. Of these inorganic fillers,
Silica powder is preferably used as the semiconductor encapsulating material composition. The amount of the inorganic filler compounded is preferably 100 to 1000 parts by weight with respect to 100 parts by weight of the dicyanate ester and / or its prepolymer. If it is less than 100 parts by weight, the linear expansion coefficient of the molded product will be large, and if it exceeds 1000 parts by weight, the moldability will be reduced and it will not be suitable for practical use.

In addition to these essential components, a curing catalyst, a lubricant, a flame retardant,
A colorant, a silane coupling agent, and the like can be appropriately added and added.

As a general method for producing the encapsulating composition of the present invention as a molding material, a composition in which various additives are added to these essential components and uniformly mixed is prepared by a kneader, a heat roll or the like. A kneading process is performed, and after cooling, pulverization is performed to obtain a molding material.

[0020]

【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 90 seconds. A molded product having good releasability at the time of taking out the mold and a good appearance was obtained. The molded product was further post-cured at 175 ° C. for 8 hours to evaluate the characteristics. The results are shown in Table 1. Example 1
The molding materials Nos. 3 to 3 have high Tg, high toughness (breaking energy), high adhesiveness, and low water absorption. 65
Solder crack resistance was also good in the moisture absorption treatment at a temperature of 95% RH for 72 hours.

(Comparative Examples 1 to 3) According to the formulations shown in Table 1, molding materials were obtained in the same manner as in Examples 1 to 3. In Comparative Examples 1 and 2, the releasability at the time of taking out the mold was not so good.
In Comparative Example 3, the water absorption rate was high and the solder crack resistance after the moisture absorption treatment was poor.

[0022]

[Table 1]

(Note) * 1: Phenol-modified C ₅ petroleum resin; phenol content 23%, 2.2 phenols per molecule * 2: Phenol-modified coal resin; phenol content 23
%, 2.2 phenols per molecule * 3: Phenol-modified polybutadiene resin; polybutadiene molecular weight 700, phenol content 23%, 2.2 phenols per molecule * 4: Bisphenol A type manufactured by Yuka Shell Epoxy Co., Ltd. Epoxy resin * 5: Orthocresol novolac type epoxy resin manufactured by Nippon Kayaku Co., Ltd. * 6: Bis (3,5-dimethyl-4-cyanatephenyl) methane * 7: Cobalt naphthenate * 8: Stress in bending strength test- Calculated from strain curve * 9: Moisture absorption treatment: 85 ° C, 85% RH, 72 hours * 10: Molded body 10 in which a 6 mm square element is mounted on a lead frame of a flat package (thickness 2.7 mm) and transfer molded. Moisture absorption (65 ℃, 95% R)
Immediately after (H, 72 hours), the number of cracks on the surface of the molded product after immersion in a solder bath at 260 ° C. for 10 seconds is shown. * 11: The molded body (good product) after the solder crack resistance test was cut, and the cross section was observed with a scanning electron microscope.

[0024]

The encapsulating resin composition according to the present invention has a good releasability when the mold is taken out, and the cured product has a high Tg.
It has a low water absorption rate, high adhesion, and excellent 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.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location C08L 63/00 NKA H01L 23/29 23/31

Claims (1)

[Claims] 1. A dicyanate ester represented by the formula (1) and / or a prepolymer thereof, and one or more selected from the group consisting of a phenol-modified petroleum resin, a phenol-modified coal resin and a phenol-modified polybutadiene resin. In the resin composition for encapsulation, which comprises an epoxy resin, 3-amino-4-chlorobenzamide, and an inorganic filler, the ratio of 3-amino-4-chlorobenzamide is dicyanate ester and / or its prepolymer. A resin composition for encapsulation, which is 1 part by weight or more and less than 20 parts by weight with respect to 100 parts by weight of a polymer. [Chemical 1]