JP4590883B2 - Resin composition and semiconductor device produced using resin composition - Google Patents

Description

  The present invention relates to a resin composition and a semiconductor device manufactured using the resin composition.

As a part of environmental measures, lead removal from semiconductor products is being promoted, and the lead frame plating is increasingly changed to Ni-Pd for the purpose of deleading from the exterior plating of the semiconductor package. Here, Ni—Pd plating is performed by thin gold plating (gold flash) for the purpose of improving the stability of the Pd layer on the surface. However, due to the smoothness of the Ni—Pd plating itself and the presence of gold on the surface, ordinary silver is used. Compared with a plated copper frame or the like, the adhesive strength is reduced. Also, since lead-free solder is used as the solder for mounting on the board, the reflow temperature needs to be higher than in the case of tin-lead solder. Due to an increase in stress due to a decrease in adhesive force and an increase in reflow temperature, the constituent material of the semiconductor package needs to have higher reflow resistance because peeling and cracking are likely to occur in the semiconductor package during reflow.
Therefore, a low-stress material that is superior in adhesiveness to a Ni-Pd plating frame in particular than a conventionally used die attach paste (see, for example, Patent Document 1) and can withstand increasing stress at the same time is desired. But nothing was satisfactory.
JP 2000-273326 A

  INDUSTRIAL APPLICABILITY The present invention provides a resin composition exhibiting good adhesion to a Ni-Pd plating frame and at the same time good low stress properties, and particularly reliability such as solder crack resistance using the present invention as a semiconductor die attach material. It is to provide an excellent semiconductor device.

Such an object is achieved by the present invention described in the following [1] to [6].
[1] (A) A (meth) acrylic acid ester compound having an alcoholic hydroxyl group in the molecule, a compound in which both ends of the repeating unit represented by the general formula (1) are hydroxyl groups, and isophorone diisocyanate are reacted. Urethane acrylate obtained, (B) reactive diluent having (meth) acrylic group, (C) bismaleimide compound, (D) epoxy compound liquid at room temperature, (E) imidazole derivative represented by general formula (2) , (F) an organic peroxide, (G) a filler as an essential component, the component (C) with respect to the component (A) is 16 to 100% by weight, and the component (D) with respect to the component (A) is 20 to 100% by weight. %, The component (E) is 0.5 to 5% by weight based on the component (D), and the component (F) is 0.5 to 5% based on the sum of the component (A), the component (B), and the component (C). 5% by weight and light weight A resin composition containing no initiator.

R in the general formula (1) is a hydrocarbon having 3 to 6 carbon atoms, and n is an integer of 2 to 50.

R ₁ in the general formula (2) is a hydrocarbon having 1 to 20 carbon atoms, R _2, R ₃ are each hydrogen or a methyl group.

[2] The resin composition according to item [1], wherein the (meth) acrylic acid ester compound having an alcoholic hydroxyl group in the molecule is 2-hydroxyethyl (meth) acrylate.
[3] The resin composition according to [1] or [2], wherein the compound in which both ends of the repeating unit represented by the general formula (1) are hydroxyl groups is polytetramethylene glycol diol.
[4] The resin composition according to [1], [2] or [3], wherein the epoxy compound (D) which is liquid at room temperature is a compound represented by the general formula (3).

R ₄ in the general formula (3) is hydrogen or a hydrocarbon group having 1 to 4 carbon atoms, and G is a glycidyl group.

[5] R ₁ is a methyl group of the general formula imidazole derivative represented by (2) (E), R 2, R 3 are each hydrogen [1] to [4] according to any one of items Resin composition.
[6] A semiconductor device manufactured using the resin composition according to any one of [1] to [5] as a die attach material.

  Since the resin composition of the present invention exhibits good adhesion with the Ni-Pd plating frame and can absorb stress based on the difference in thermal expansion coefficient between the semiconductor chip and the lead frame, the present invention is used as a die attach material. By using it, an unprecedented highly reliable semiconductor package can be provided.

  In the present invention, urethane acrylate obtained by reacting the following raw materials is used. A (meth) acrylic acid ester compound having an alcoholic hydroxyl group in the molecule is used for the purpose of introducing (meth) acrylic groups at both ends of urethane acrylate. A typical example is 2-hydroxyethyl (meth) acrylate, but is not limited thereto. The compound in which both ends of the repeating unit represented by the general formula (1) are hydroxyl groups is limited to a hydrocarbon having 3 to 6 carbon atoms in the R part, but this has a strong polarity when the carbon number is 2. This is because the resin composition obtained too much is not preferable because the moisture resistance is deteriorated, and when the number of carbon atoms is more than 6, the polarity becomes too low, and the desired adhesive strength cannot be obtained. As the diisocyanate, isophorone diisocyanate is used. This is because, for example, it exhibits better adhesive strength than toluene diisocyanate.

  As the reactive diluent (B) having a (meth) acryl group used in the present invention, a general acrylic reactive diluent can be used. For example, alicyclic (meth) acrylic acid ester, aliphatic (meth) acrylic acid ester, aromatic (meth) acrylic acid ester, aliphatic dicarboxylic acid (meth) acrylic acid ester, aromatic dicarboxylic acid (meth) acrylic acid ester And the like.

  In the present invention, the bismaleimide compound (C) is used. This is because the combined use of the bismaleimide compound can particularly improve the adhesion to the Ni-Pd frame, so the amount of the component (C) to the compound (A) Is limited to 16 to 100% by weight. This is because when the amount of the compound (A) is less than this, the low stress property is deteriorated, and when it is large, the adhesive force is reduced.

  In the present invention, an epoxy compound (D) that is liquid at room temperature is used, but this is because only when an epoxy compound is used in combination, sufficient adhesive force and low stress can be achieved at the same time. A sufficient adhesive strength cannot be obtained. Moreover, although it is limited to liquid at room temperature, this is because if it is not liquid at room temperature, the viscosity of the resin composition becomes too high and there is a practical problem. Here, the liquid epoxy compound at room temperature can be used without any problem if it is liquid by mixing with other epoxy compounds. The structure is not particularly limited as long as it is a liquid epoxy compound at room temperature, but a glycidylamine type liquid compound represented by the general formula (3) is preferable because it exhibits better adhesion. Moreover, the compounding quantity of the compound (D) with respect to a compound (A) is limited to 20 to 100 weight%. This is because if the amount of the compound (A) is less than this, the low stress property is deteriorated, and if the amount is large, sufficient adhesive strength cannot be obtained.

  In the present invention, the imidazole derivative (E) represented by the general formula (2) is used as a curing agent for the compound (D). When imidazoles other than those represented by the general formula (2) are blended with a liquid epoxy at room temperature, the reaction proceeds at room temperature and the life deteriorates, so that it cannot be used. Further, in the case of imidazoles having a latent property, there is no problem of life, but the curability is deteriorated and the adhesive force is also lowered, which is not preferable. The compounding quantity of an imidazole derivative (E) is 0.5 to 5 weight% with respect to a compound (D). This is because if the amount is less than this, the curability is poor, and if it is more, the adhesive strength is deteriorated.

  In the present invention, the organic peroxide (F) is used as a reaction initiator for the diluent (B) having a urethane acrylate (A) and a (meth) acryl group and the bismaleimide compound (C). Although it is not particularly limited as long as it is an organic peroxide usually used for radical polymerization, a rapid heating test (decomposition when a sample 1 g is placed on an electric heating plate and heated at 4 ° C./min.) The decomposition temperature at the starting temperature is preferably 40 to 140 ° C. If the decomposition temperature is less than 40 ° C., the preservability of the resin composition at normal temperature is deteriorated, and if it exceeds 140 ° C., the curing time is extremely long, which is not preferable.

Specific examples of the organic peroxide satisfying this include methyl ethyl ketone peroxide, methylcyclohexanone peroxide, methyl acetoacetate peroxide, acetylacetone peroxide, 1,1-bis (t-butylperoxy) 3,3,5- Trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis (t-hexylperoxy) 3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) Cyclohexane, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane, 1,1-bis (t-butylperoxy) cyclododecane, n-butyl 4,4-bis (t-butyl) Peroxyvalerate, 2,2-bis (t-butylperoxy) butane, 1 1-bis (t-butylperoxy) -2-methylcyclohexane, t-butyl hydroperoxide, P-menthane hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, t-hexyl hydroper Oxide, dicumyl peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane, α, α′-bis (t-butylperoxy) diisopropylbenzene, t-butylcumyl peroxide, Di-t-butyl peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3, isobutyryl peroxide, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide Oxide, lauroyl peroxide, cinnamic acid peroxide, m-tolu Ile peroxide, benzoyl peroxide, diisopropyl peroxydicarbonate, bis (4-t-butylcyclohexyl) peroxydicarbonate, di-3-methoxybutyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di -Sec-butylperoxydicarbonate, di (3-methyl-3-methoxybutyl) peroxydicarbonate, α, α'-bis (neodecanoylperoxy) diisopropylbenzene, cumylperoxyneodecanoate, 1 , 1,3,3-tetramethylbutylperoxyneodecanoate, 1-cyclohexyl-1-methylethylperoxyneodecanoate, t-hexylperoxyneodecanoate, t-butylperoxy Neodecanoate, t-hex Ruperoxypivalate, t-butylperoxypivalate, 2,5-dimethyl-2,5-bis (2-ethylhexanoylperoxy) hexane, 1,1,3,3-tetramethylbutylperoxy-2 -Ethylhexanoate, 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t -Butylperoxyisobutyrate, t-butylperoxymaleic acid, t-butylperoxylaurate, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxyisopropyl monocarbonate , T-butylperoxy-2-ethylhexyl monocarbonate, 2,5-dimethyl 2,5-bis (benzoylperoxy) hexane, t-butylperoxyacetate, t-hexylperoxybenzoate, t-butylperoxy-m-toluoylbenzoate, t-butylperoxybenzoate, bis (t -Butylperoxy) isophthalate, t-butylperoxyallyl monocarbonate, 3,3 ', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone, and the like. Two or more types can be mixed and used for control. The organic peroxide is blended in an amount of 0.5 to 5% by weight based on the component (A) + component (B) + component (C). If it is less than this, the curability expected can not be exhibited, and if it is more, the life is deteriorated and the adhesive force is also lowered.

The resin composition of the present invention is usually used under illumination such as a fluorescent lamp. Therefore, if a photopolymerization initiator is contained in the resin composition, an increase in viscosity is observed due to a reaction during use. I can't.
Furthermore, various polymerization inhibitors may be added in advance in order to improve the storage stability of the resin composition.

As the filler (G) used in the present invention, silver powder is usually used, but gold powder, aluminum nitride, calcium carbonate, silica, alumina and the like can also be used.
If necessary, additives such as a coupling agent, an antifoaming agent, and a surfactant can be used in the resin composition of the present invention.
The resin composition of the present invention can be produced, for example, by premixing the components, kneading using three rolls, and degassing under vacuum.
As a method of manufacturing a semiconductor device using the resin composition of the present invention, a known method can be used.

[Example 1]
As compound (A), NK Oligo UA160TM (manufactured by Shin-Nakamura Chemical Co., Ltd., reaction product of 2-hydroxyethyl acrylate, polytetramethylene glycol diol and isophorone diisocyanate, hereinafter referred to as urethane acrylate), component (B) Lauryl acrylate (manufactured by Kyoeisha Chemical Co., Ltd., light ester LA, hereinafter LA), and component (C) as a polyether bismaleimide acetate (manufactured by Dainippon Ink Industries, Ltd., LumiCure MIA-200, below) BMI-1), Epicote 630 (manufactured by Japan Epoxy Resin Co., Ltd., R _{4 in the} general formula (3) is hydrogen, hereinafter referred to as E-630) as component (D), and Curazole 2MZ-A as component (E) (Shikoku Chemicals Co., Ltd., R ₁ is a methyl group of the formula 2, R _2, hydrogen R ₃ are each less 2MZ- ) As a component (F), dicumyl peroxide (manufactured by NOF Corporation, Park Mill D, decomposition temperature in rapid heating test: 126 ° C., hereinafter initiator), and component (G) having an average particle size of 3 μm, maximum A flaky silver powder (hereinafter referred to as silver powder) having a particle diameter of 20 μm was used. Silane coupling agent having methacrylic group (Shin-Etsu Chemical Co., Ltd., KBM-503, hereinafter referred to as methacrylic silane), silane coupling agent having glycidyl group (Shin-Etsu Chemical Co., Ltd., KBM-403E, hereinafter referred to as epoxy silane) ) Were blended as shown in Table 1, kneaded using three rolls, and defoamed to obtain a resin composition. The blending ratio is parts by weight.

[Example 2]
Example except that 2,2-bis [4- (4-maleimidophenoxy) phenyl] propane (manufactured by Kei-I Kasei Co., Ltd., BMI-80, hereinafter BMI-2) is used as the component (C) to be used. A resin composition was prepared in the same manner as in 1.
[Example 3]
Example 1 except that diglycidyl bisphenol A (epoxy equivalent 180, liquid at room temperature, hereinafter bis A epoxy) obtained by reaction of bisphenol A and epichlorohydrin was used as the liquid epoxy compound (D) at room temperature to be used. A resin composition was prepared.

[Comparative Examples 1 and 2]
The resin composition was obtained in the same manner as in Example 1 by blending at the ratio shown in Table 1.
[Comparative Example 3]
A resin composition was prepared in the same manner as in Example 1 except that Cureazole 2MZ (manufactured by Shikoku Chemicals Co., Ltd., hereinafter 2MZ) was used.

[Example 4]
A resin composition was prepared in the same manner as in Example 1 using cresyl glycidyl ether (epoxy equivalent 185, hereinafter CGE) and phenol novolac resin (hydroxyl equivalent 104, softening point 85 ° C., hereinafter PN).
The obtained resin composition (die attach paste) was evaluated by the following methods. The evaluation results are shown in Table 1.

Evaluation method Viscosity: Using an E-type viscometer (3 ° cone), the values at 25 ° C. and 2.5 rpm were measured immediately after the die attach paste was prepared and after being left at 25 ° C. for 48 hours. The viscosity immediately after production is 15 to 25 Pa.s. The case where the viscosity increase rate after 48 hours was less than 20% within the range of s was regarded as acceptable. The unit of viscosity increase rate is%.
Adhesive strength: Using a paste, a 6 × 6 mm silicon chip was mounted on a gold-flashed Ni-Pd frame and cured in an oven at 150 ° C. for 15 minutes. After curing and after moisture absorption (85 ° C., 85%, 72 hours), the hot die shear strength at 260 ° C. was measured using an automatic adhesive force measuring apparatus. The case where the die shear strength when heated at 260 ° C. was 30 N / chip or more was regarded as acceptable. The unit of adhesive strength is N / chip.
-Warpage amount and reflow resistance: Using the resin composition shown in Table 1, the following substrate and silicon chip were cured and bonded at 150 ° C for 15 minutes. The amount of warpage of the chip surface after curing was measured with a surface roughness meter, and the amount of warpage of 40 μm or less was accepted. Similarly, the die-bonded lead frame was sealed with a sealing material (Sumicon EME-7026, manufactured by Sumitomo Bakelite Co., Ltd.), subjected to moisture absorption treatment at 60 ° C. and a relative humidity of 60% for 192 hours, and then subjected to IR reflow treatment ( 260 ° C., 10 seconds, 3 reflows). The degree of peeling of the treated package was measured with an ultrasonic flaw detector (transmission type). The case where the peeling area of the die attach part was less than 10% was regarded as acceptable. The unit of peeling area is%.
Package: QFP (14x20x2.0mm)
Lead frame: Ni-Pd frame flashed with gold Chip size: 6 x 6 mm
Die attach paste curing conditions: 150 ° C in oven, 15 minutes

  Since the resin composition of the present invention exhibits good adhesion with various lead frames and the like and can absorb stress based on the difference in thermal expansion coefficient between the semiconductor chip and the organic substrate, the present invention is used as a die attach material. By doing so, it is possible to provide an unprecedented highly reliable semiconductor package.

Claims (5)

(A) Urethane obtained by reacting a (meth) acrylic acid ester compound having an alcoholic hydroxyl group in the molecule, a compound in which both ends of the repeating unit represented by the general formula (1) are hydroxyl groups, and isophorone diisocyanate Acrylate, (B) Reactive diluent having (meth) acrylic group, (C) Bismaleimide compound, (D) Epoxy compound represented by general formula (3) or diglycidyl bisphenol A , (E) General formula (2 ), Imidazole derivative, (F) organic peroxide, (G) filler as essential components, component (C) with respect to component (A) is 16 to 100% by weight, component (A) (D) ) Is 20 to 100% by weight, component (E) is 0.5 to 5% by weight based on component (D), and component (F) is the sum of component (A), component (B) and component (C). A resin composition characterized in that it is contained in an amount of 0.5 to 5% by weight and does not contain a photopolymerization initiator.



R in the general formula (1) is a hydrocarbon having 3 to 6 carbon atoms, and n is an integer of 2 to 50.

R ₁ in the general formula (2) is a hydrocarbon having 1 to 20 carbon atoms, R _2, R ₃ are each hydrogen or a methyl group.
In the general formula (3), R ₄ is hydrogen, and G is a glycidyl group.   The resin composition according to claim 1, wherein the (meth) acrylic acid ester compound having an alcoholic hydroxyl group in the molecule is 2-hydroxyethyl (meth) acrylate.   The resin composition according to claim 1 or 2, wherein the compound in which both ends of the repeating unit represented by the general formula (1) are hydroxyl groups is polytetramethylene glycol diol. The resin composition according to any one of claims 1 to 3 , wherein R ₁ of the imidazole derivative (E) represented by the general formula (2) is a methyl group, and R ₂ and R ₃ are each hydrogen. Wherein a fabricated by using the resin composition according as die-attach material to any of claims 1-4.