JP3317745B2 - Resin composition for sealing - Google Patents

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 having excellent curability, high glass transition temperature (hereinafter referred to as Tg), excellent toughness, and excellent adhesiveness. It is.

[0002]

2. Description of the Related Art In recent years, epoxy resin compositions have been generally used for sealing semiconductor devices such as ICs, LSIs, transistors, diodes, and the like, electronic circuits, and the like, from the viewpoint of characteristics and cost. However, the trend toward mass production of electronic components, high integration, and surface mounting has been progressing, and accordingly, requirements for sealing resins have become strict. In particular, cracks are likely to occur in the equipment due to the increase in the size of chips due to high integration, thinning of packages and solder immersion (200 to 300 ° C) during surface mounting. As a resin, heat resistance, high toughness and low water absorption are strongly desired.

[0003] Epoxy resins are currently the mainstream as semiconductor encapsulation resins. However, there is a limit in improvement of epoxy resin in terms of heat resistance and low water absorption, and a highly reliable epoxy resin after solder immersion during surface mounting has not been obtained. As a resin having high heat resistance in place of epoxy resin, maleimide resin has been attracting attention, but has a disadvantage that it has a high water absorption rate, cracks due to solder immersion during moisture absorption, and has poor reliability.

[0004]

SUMMARY OF THE INVENTION The object of the present invention is to provide fast curing, high heat resistance, high toughness, good adhesion to a lead frame, and extremely low reliability after solder immersion. An object of the present invention is to provide an excellent resin composition for semiconductor encapsulation.

[0005]

The present invention provides (A) a dicyanate ester compound represented by the formula (1) and / or a prepolymer thereof, (B) a phenol-modified petroleum resin,
One or more modified resins selected from the group consisting of phenol-modified coal resins and phenol-modified polybutadiene resins, (C) epoxy resins, (D) 3- (2H-benzotriazole-2-yl) -1 ′ A sealing resin composition comprising 1,1 ′, 1′-tris (4-hydroxyphenyl) ethane and (E) an inorganic filler.

[0006]

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[0007]

The dicyanate ester compound represented by the general formula (1) and / or a prepolymer thereof used in the present invention means an organic compound having two cyanate ester groups in a molecule. In the present invention, the bifunctional cyanate ester itself or a prepolymer derived therefrom can be used. These compounds, if necessary, may be a catalyst such as zinc naphthenate, cobalt naphthenate, copper naphthenate, lead naphthenate, zinc octylate, tin octylate, lead acetylacetonate, copper acetylacetonate, dibutyltin maleate, etc. 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 compound and / or its prepolymer alone has excellent heat resistance and relatively low water absorption, but is still insufficient in toughness and adhesiveness, Only by blending a modified petroleum resin, a phenol-modified coal resin, a phenol-modified polybutadiene resin or a benzotriazole compound with an epoxy resin and curing by heating, a sealing composition excellent in curability, heat resistance, adhesion and toughness can be obtained. It can be provided.

Examples of preferred dicyanate ester compounds of the formula (1) used in the present invention include bis (4
-Cyanate phenyl) 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
-Cyanate phenyl) thioether, 4,4-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 ₅ C ₉ copolymerized petroleum resin or petroleum resin obtained by adding phenols to dicyclopentadiene resin obtained from dicyclopentadiene obtained by thermal dimerization of cyclopentadiene contained in C ₅ fraction. .

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

As phenols, phenol, cresol, xylenol and the like are used. The phenol content is at least 5% by weight in the phenol-modified resin, 50%
It is preferable that the content is not more than 1% by weight and an average of 1 to 3 is added per molecule. If the content of phenols is less than 5% by weight,
The curability is poor, the Tg is low, and good toughness cannot be obtained.
If it exceeds 50% by weight, the releasability at the time of molding is poor, and the water absorption of the molded article is increased.

The phenol-modified petroleum resin, phenol-modified coal resin or phenol-modified polybutadiene resin is preferably used in an amount of 5 to 50 parts by weight based on 100 parts by weight of the dicyanate ester compound. If the amount is less than 5 parts by weight, the curability and the releasability will be poor, and the water absorption of the molded article will also increase. 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.
The reaction can be performed in advance so that the melting point is 50 ° C. or higher and 100 ° C. or lower.

Examples of the epoxy resin include, but are not limited to, diglycidyl ether of bisphenol A, 4,4'-di (1,2-epoxyethyl) diphenyl ether, and 4,4'- (1,2-epoxyethyl) diphenyl ether, glycidyl ether of resorcinol, butadiene epoxyside, bis- (2,3-epoxycyclopentyl) ether propane, diglycidyl ether of phloroglysin, diglycidyl ether of methylphloroglysin, 3,3 Bifunctional epoxy compounds such as', 5,5'-tetramethyl-biphenyl-4,4'-diglycidyl ether, biphenyl-4,4'-diglycidyl ether, naphthalene-1,6-diglycidyl ether, phenol- Polyglycidyl ether of formaldehyde novolak, triglycidyl ether of trimethylolpropane, glycerin Epoxy compounds having three or more functions such as triglycidyl ether, 1,3,5-tri (1,2-epoxyethyl) benzene, polyallyl glycidyl ether, and triglycidyl ether of paraaminophenol 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 preferably used in an amount of 5 to 50 parts by weight based on 100 parts by weight of the dicyanate ester compound. If the amount is less than 5 parts by weight, the releasability is poor and the water absorption of the molded article is large. If it exceeds 50 parts by weight, Tg will decrease.

3- (2H-benzotriazol-2-yl) -1 ', 1',
1'-Tris (4-hydroxyphenyl) ethane is extremely effective in improving the adhesion to a lead frame or chip. Although the reason is not clear, it is thought that the complex is formed in some form. The rate of addition is 100 parts of the dicyanate ester compound.
It is preferably 3 to 30 parts by weight based on parts by weight. If it is less than 3 parts by weight, the adhesion to the lead frame or chip is not sufficient,
If it exceeds 30 parts by weight, the toughness decreases.

The addition amount of the curing catalyst such as copper acetylacetonate is preferably 0.05 to 5 parts by weight based on 100 parts by weight of the dicyanate ester compound. If less than 0.05 parts by weight,
If the curability is not sufficient, and if the amount exceeds 5 parts by weight, the gel time becomes 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, and titanium oxide. These can be used alone or as a mixture of two or more. Of these inorganic fillers,
As a semiconductor sealing material composition, silica powder is preferably used. The amount of the inorganic filler is preferably 100 to 1000 parts by weight based on 100 parts by weight of the dicyanate ester compound. If the amount is less than 100 parts by weight, the water absorption and the coefficient of linear expansion of the molded article will be large.

Other than these essential components, a lubricant, a flame retardant, a release agent, a silane coupling agent,
A coloring agent and the like can be appropriately compounded and added.

As a general method for producing the sealing composition of the present invention as a molding material, a composition obtained by adding various additives to these essential components and uniformly mixing the mixture with a kneader, a hot roll or the like is used. A kneading process is performed, and after cooling, pulverized to obtain a molding material.

[0021]

【Example】

(Examples 1 to 3) According to the composition shown in Table 1, kneading was performed with a hot roll to obtain a molding material. The obtained molding material was molded at 175 ° C. for 1.5 minutes by transfer molding, and a molded article having good appearance was obtained. The molded article was further cured at 180 ° C. for 8 hours, and the characteristics were evaluated. Table 1 shows the results. The molding materials of Examples 1 to 3 have high Tg, high toughness (breaking energy), and low water absorption. Solder crack resistance and adhesion were also good.

(Comparative Examples 1 to 3) According to the composition shown in Table 1, molding materials were obtained in the same manner as in Examples 1 to 3. The epoxy resin of Comparative Example 1 had a low Tg and poor solder crack resistance. Comparative Examples 2 and 3 do not have sufficient adhesiveness to the chip.

[0023]

[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 resin resin; molecular weight of 700 phenol, 23% phenol content, 2.2 phenols per molecule * 4: Hypheno manufactured by Yuka Shell Ethoxy Co., Ltd. -A-type epoxy resin * 5: Orthocreso-Renophorac-type epoxy resin manufactured by Nippon Kayaku Co., Ltd. * 6: Copper acetylacetonate * 7: Triphenylphosphine * 8: Pulse (3,5-dimethyl-4-) Cyanate phenyl) methane * 9: Hoechst 3- (2H-benzotriazole-2-yl) -1 ', 1', 1'-tris (4-
Human peroxyphenyl) ethane * 10: Phenolnophorac resin manufactured by Sumitomo Turres * 11: Higher fatty acid ester * 12: Calculated from stress-strain curve of bending strength test * 13: Moisture absorption treatment: 85 ° C, 85% RH, 72 hours * 14 : Mount a 6mm square element on a flat package (2.7mm thick) reed frame, transfer molded 10 molded products, moisture absorption treatment (65 ℃, 95% RH, 72 hours) Immediately afterwards in 260 ° C solder bath
The number of cracks generated on the surface of the molded body after immersion for 0 seconds is shown. * 15: 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 sealing resin composition of the present invention is fast-curing, the cured product has a high Tg, low water absorption, and excellent toughness. When this is used for semiconductor encapsulation, the solder crack resistance and adhesiveness of the encapsulant are good, and the resin composition for semiconductor encapsulation is highly reliable and excellent.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI C08L 63/00 C08L 63/00 Z // H01L 23/29 H01L 23/30 R 23/31 (56) References JP 6 -256625 (JP, A) JP-A-6-136096 (JP, A) JP-A-5-339372 (JP, A) JP-A-63-113014 (JP, A) JP-A-1-158039 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 79/04 C08K 5/3472 C08L 9/00 C08L 45/00 C08L 63/00 H01L 23/29

Claims (1)

(57) [Claims] 1. A dicyanate ester compound represented by formula (1) and / or a prepolymer thereof, (B) a phenol-modified petroleum resin, a phenol-modified coal resin, and a phenol-modified polybutadiene resin. One or more modified resins, (C) an epoxy resin,
(D) A sealing resin composition comprising 3- (2H-benzotriazole-2-yl) -1 ′, 1 ′, 1′-tris (4-hydroxyphenyl) ethane and (E) an inorganic filler. Embedded image