JP5382971B2 - 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.

The use of lead-free solder has become common as part of environmental measures, but the melting point of lead-free solder is usually higher than the melting point of tin-lead solder, so it is necessary to increase the reflow temperature when mounting a semiconductor package on a substrate. There is. Here, when the reflow temperature becomes high, peeling and cracks are likely to occur in the semiconductor package during reflow, so that the constituent material of the semiconductor package needs to have higher reflow resistance.
Here, in the case of a package using an organic substrate typified by PBGA or the like, a part to which a semiconductor chip is bonded is often covered with a solder resist, and in order to give a high reflow resistance to a die attach material, a die attach is used. Although it is necessary to further increase the adhesive strength of the material itself to the solder resist, it is described in Patent Document 1 and the like, but at the same time, it absorbs thermal stress based on the difference in thermal expansion coefficient between the semiconductor chip and the organic substrate, so that low stress In the case of epoxy resin-based die attach paste, which is currently the mainstream, it is difficult to achieve both good adhesion to the solder resist and good low stress. In some cases, it progressed to cracks in the semiconductor product and was unsatisfactory in terms of reliability.
JP 2002-184793 A

  The present invention provides a resin composition exhibiting good adhesion to a solder resist, a lead frame, etc. and at the same time exhibiting good low stress, and particularly reliability such as solder crack resistance using the present invention as a semiconductor die attach material. It is to provide a semiconductor device having excellent properties.

Such an object is achieved by the present invention described in the following [1] to [ 4 ].
[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) epoxy compound liquid at room temperature, (D) imidazole derivative represented by general formula (2), (E) organic peroxidation (F) Flakes silver powder as an essential component as a filler, component (A) is 100 to 500% by weight with respect to component (C), and component (D) is 0.5 to 5 with respect to component (C) A resin composition characterized by comprising 0.5% by weight and component (E) in an amount of 0.5 to 5% by weight based on the sum of component (A) and component (B) and no photopolymerization initiator. Alcohol in the molecule Having sex hydroxyl (meth) acrylate compound is 2-hydroxyethyl (meth) acrylate, compounds both terminals are hydroxyl groups of the repeating unit represented by the general formula (1) is Ri Ah with polytetramethylene glycol diol The resin composition whose component (C) is a compound shown by General formula (3) .

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.

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.

[ 2 ] R _{1 of the} imidazole derivative (D) represented by the general formula (2) is a methyl group, R ₂ , R
The resin composition according to item [1], wherein ₃ is hydrogen.
[ 3 ] A semiconductor device manufactured using the resin composition according to [1] or [2] as a die attach material.

  The resin composition of the present invention exhibits good adhesive strength with a solder resist, a lead frame, etc. on an organic substrate and can absorb stress based on the difference in thermal expansion coefficient between the semiconductor chip and the organic substrate. By using as a die attach material, it is possible to provide an unprecedented highly reliable semiconductor package.

  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, an epoxy compound (C) that is liquid at room temperature is used, but this is because only when an epoxy compound is used in combination, sufficient adhesion 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 (C) 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 (D) represented by the general formula (2) is used as a curing agent for the compound (C). 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 (D) is 0.5 to 5 weight% with respect to a compound (C). 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 this invention, an organic peroxide (E) is used as a reaction initiator of the diluent (B) which has urethane acrylate (A) and (meth) acryl group. 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). 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 reduced.

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. Further, various polymerization inhibitors and antioxidants may be added in advance in order to improve the storage stability of the resin composition.
As the filler (F) 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.

[Examples 1 and 2]
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) is Epicoat 630 (Japan Epoxy Resin Co., Ltd., R _{4 in the} general formula (3) is hydrogen. , Hereinafter referred to as E-630) as component (D), Curazole 2MZ-A (manufactured by Shikoku Kasei Kogyo Co., Ltd., R _{1 in the} general formula (2) is a methyl group, R ₂ and R ₃ are each hydrogen, and the following 2MZ- A), dicumyl peroxide (manufactured by NOF Corporation, Park Mill D, decomposition temperature in rapid heating test: 126 ° C., as component (E) Hereinafter, flaky silver powder (hereinafter referred to as silver powder) having an average particle diameter of 3 μm and a maximum particle diameter of 20 μm was used as the component (F). 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 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 (C) 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 PBGA substrate (BT core, solder resist is PSR4000AUS308 manufactured by Taiyo Ink Manufacturing Co., Ltd.), and cured in a 150 ° C. oven 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 80 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 50 μm or less was accepted. Similarly, the die-bonded substrate was sealed with a sealing material (Sumicon EME-G770, manufactured by Sumitomo Bakelite Co., Ltd.), subjected to moisture absorption treatment at 85 ° C. and relative humidity 60% for 168 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: 35x35mm PBGA
Substrate: BT core, 0.56 mm thickness Solder resist: manufactured by Taiyo Ink Manufacturing Co., Ltd., PSR4000AUS308
Chip size: 10x10mm
Die attach paste curing conditions: 150 ° C in oven, 15 minutes

  The resin composition of the present invention exhibits good adhesive strength with a solder resist, a lead frame, etc. on an organic substrate and can absorb stress based on the difference in thermal expansion coefficient between the semiconductor chip and the organic substrate. As a die attach material, it is possible to provide an unprecedented highly reliable semiconductor package by using it as a die attach material, particularly for die attach applications such as PBGA using an organic substrate. .

Claims (3)

(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) a reactive diluent having a (meth) acrylic group, (C) an epoxy compound that is liquid at room temperature, (D) an imidazole derivative represented by the general formula (2), (E) an organic peroxide, F) As a filler, flaky silver powder is an essential component, the component (A) is 100 to 500 wt% with respect to the component (C), the component (D) is 0.5 to 5 wt% with respect to the component (C), A resin composition characterized in that the component (E) is contained in an amount of 0.5 to 5% by weight based on the sum of the components (A) and (B) and does not contain a photopolymerization initiator, Inside alcoholic hydroxide The a (meth) acrylic acid ester compound is 2-hydroxyethyl (meth) acrylate, compounds both terminals are hydroxyl groups of the repeating unit represented by the general formula (1) is Ri Ah with polytetramethylene glycol diol component The resin composition whose (C) is a compound shown by General formula (3) .

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.

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.
is there. The resin composition according to claim 1, wherein R ₁ of the imidazole derivative (D) 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 claim 1 or 2.