JP2007099819A - Liquid epoxy resin composition and semiconductor device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid epoxy resin composition good in fluidity and giving a cured product reduced in warpage and high in impact resistance, and to provide a semiconductor device obtained using the liquid epoxy resin composition. <P>SOLUTION: The liquid epoxy resin composition essentially comprises (A) an epoxy resin liquid at room temperature, (B) a curing agent and (C) a urethane resin, wherein the urethane resin C is a hydroxyl-terminated one. In this liquid epoxy resin composition, the terminal hydroxy group of the urethane resin C is obtained by reaction between an isocyanate compound as the main constituent component of the urethane resin and a hydroxyl-compound and, as necessary, a chain extender. This liquid epoxy resin composition may optionally contain (D) a filler, being suitable as a resin composition for underfill materials. The semiconductor device sealed with the above composition's cured product is also provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid epoxy resin composition and a semiconductor device using the same.

    In an integrated circuit package, a gap between a chip and a substrate is sealed with an underfill material. Among them, a liquid resin composition for underfill material (hereinafter referred to as U / F material) is used particularly for large package applications. The chip warps due to the effect of curing shrinkage, which causes stress on the solder bumps and may cause defects such as bump cracks.

  In general, the cause of warpage is caused by the high elastic modulus of the U / F material itself and the internal stress generated from the difference in the linear expansion coefficient between the U / F material and the mounting substrate. Among them, it is conceivable to lower the elastic modulus of the resin composition to impart toughness and reduce stress.

  In reducing the stress of a liquid epoxy resin composition as a U / F material, a number of methods have been reported, such as a method using a modified epoxy resin and a method using an additive with a flexible composition as a toughening epoxy resin. ing. For example, Akimoto et al. Of Asahi Denka Kogyo Co., Ltd. have reported a method of modifying an epoxy resin with a urethane prepolymer for the purpose of toughening a cured epoxy resin (for example, see Non-Patent Document 1). However, the urethane-modified epoxy resin is obtained by an addition reaction between the secondary hydroxyl group in the epoxy resin and the isocyanate group in the urethane-based prepolymer, and although the resin viscosity is too high although it is effective in improving toughness, This causes a defect that it cannot be injected into the gap of the solder bump connection, making it unsuitable for casting.

  Also disclosed is a resin composition comprising a liquid epoxy resin, a phenol novolak resin and a curing agent used in combination with aliphatic diamines, and a stress reducing agent having a hydroxyl group at the molecular end as constituents (see, for example, Patent Document 1). ). However, the hydroxyl-terminated compound as a stress-reducing agent of this resin composition does not form a phase separation structure with the epoxy resin and the curing agent. As a result, there is a risk of lowering the reliability in the thermal shock test, so there is a restriction on the amount of addition. In addition, when only the hydroxyl-terminated polyol-based compound is added, since there is a risk that the resin bleeds out, that is, the reliability decreases due to the occurrence of bleeding, the amount of addition is limited. In either case, there was a problem for further improvement in stress reduction.

Akimoto et al., Thermosetting resin 1990. Vol. 4P35-47 JP 2002-241484 A (Claim 1)

  In view of such circumstances, the present invention provides a liquid epoxy resin composition excellent in fluidity, capable of reducing warpage after curing, and excellent in thermal shock resistance, and a semiconductor device using the same. It is in.

  That is, the present invention is an epoxy resin composition comprising an epoxy resin (A), a curing agent (B), and a urethane resin (C) that are liquid at room temperature as essential components, and the urethane resin (C) is at the end. It is a liquid epoxy resin composition characterized by having a hydroxyl group.

  In the liquid epoxy resin composition of the present invention, the hydroxyl terminal of the urethane resin (C) is obtained by reacting an isocyanate compound as a main component of the urethane resin with a hydroxyl group-containing compound and, if necessary, a chain extender. The curing agent (B) is preferably in a liquid state, and more preferably a compound having at least two amino groups in one molecule. Moreover, the said liquid epoxy resin composition can contain a filler (D) and is suitable for the resin composition for underfill materials.

  Moreover, this invention is the semiconductor device sealed with the hardened | cured material of the said epoxy resin composition. In the semiconductor device, it is preferable that the gap between the electronic component and the electronic component mounting substrate is underfill sealed with a cured product of the liquid epoxy resin composition.

  According to the present invention, a liquid epoxy resin composition excellent in fluidity, capable of reducing warpage after curing, and excellent in thermal shock resistance can be obtained. The liquid epoxy resin composition of the present invention is suitable as an underfill material because it is excellent in fluidity and facilitates the filling and bonding work of the gap between the electronic component and the electronic component mounting substrate in the semiconductor device. Moreover, the semiconductor device using the liquid epoxy resin composition of the present invention improves the connection reliability in the bump connection method accompanying the reduction in stress.

  Examples of the epoxy resin (A) which is liquid at room temperature used in the present invention include, for example, bisphenol A diglycidyl ether type epoxy resins and hydrogenated products thereof, bisphenol F diglycidyl ether type epoxy resins and hydrogenated products thereof, and bisphenol S. Diglycidyl ether type epoxy resin, 3,3 ′, 5,5′-tetramethyl-4,4′-dihydroxybiphenyl diglycidyl ether type epoxy resin, 4,4′-dihydroxybiphenyl diglycidyl ether type epoxy resin, aminophenol Triglycidyl ether type epoxy resin, 1,6-dihydroxybiphenyl diglycidyl ether type epoxy resin, phenol novolac type epoxy resin, bromine type phenol novolac type epoxy resin, diallyl bisphenol A diglycidyl type epoxy resin Carboxymethyl and the like resins may be used one or more Korara.

  The curing agent (B) used in the present invention is not limited as long as it is a curing agent generally used for a liquid epoxy resin composition. In particular, in the solder bump connection method, the gap between the electronic component and the electronic component mounting substrate is not limited. From the viewpoint of filling adhesion and connection reliability, a liquid is preferable, and a polyamine compound or an acid anhydride compound is more preferable.

Examples of the polyamine compound include alicyclic polyamine compounds such as isophorone diamine, norbornene diamine and 1,2-diaminocyclohexane, m-xylylenediamine, 3,3′-dimethyl-4,4′-diaminodiphenylmethane, and 3,3. Examples include aromatic polyamine compounds such as'-diethyl-4,4'-diaminodiphenylmethane. Examples of the acid anhydride compound include phthalic anhydride compounds such as tetrahydrophthalic anhydride and hexahydrophthalic anhydride, methylnadic acid anhydride, dodecenyl succinic anhydride, and the like. The said hardening | curing agent may be used independently and may be used in combination of 2 or more type.
As for the content of the curing agent, in the case of a polyamine compound, the ratio of the active hydrogen equivalent of the polyamine compound to the epoxy equivalent of 1.0 of the epoxy resin is preferably 0.8 to 1.2. In the case of an acid anhydride compound, it is preferable that the ratio of the acid anhydride equivalent to the epoxy equivalent 1.0 of the epoxy resin is 0.5 to 1.0.

  The urethane resin (C) used in the present invention has a hydroxyl group at its terminal, and examples thereof include a hydroxyl-terminated urethane prepolymer. Examples of the production method include reacting an isocyanate compound and a hydroxyl group-containing compound. As the soft segment, the hydroxyl group-containing compound, such as a polyether polyol compound or a polyester polyol compound, and the hard segment as an isocyanate compound, such as an aromatic isocyanate compound or an aliphatic isocyanate compound, etc. In this reaction, the reaction molar ratio of the hydroxyl group-containing compound is excessively reacted to synthesize a prepolymer. If necessary, it can be obtained by increasing the molecular weight with a chain extender.

  The content of the urethane resin (C) is preferably 5% by weight to 30% by weight with respect to the total of the epoxy resin (A) and the curing agent (B). Is not sufficient, and the desired result may not be obtained in the thermal shock test. Moreover, when it exceeds 30% by weight, the workability is lowered due to the increase in the viscosity of the resin composition, and the addition amount when an additive such as a filler (D) is added may be restricted. It may not be preferable.

  Examples of the isocyanate compound include aromatic isocyanate compounds and aliphatic isocyanate compounds. Examples of the aromatic isocyanate compound include 4,4′-diphenylmethane diisocyanate and tolylene diisocyanate. Examples of the aliphatic isocyanate compound include 1,6-hexamethylene diisocyanate and 4,4'-dicyclohexylmethane diisocyanate.

  Examples of the hydroxyl group-containing compound include polyether polyol compounds and polyester polyol compounds. Specific examples of the polyether polyol compound include diols such as polyoxypropylene glycol, polyoxytetramethylene glycol, and neopentyl glycol. And triols such as polyoxypropylene triol and polyoxypropylene polyoxyethylene triol.

  The polyester polyol compound is synthesized from a general polybasic acid and a hydroxy compound. Specific examples of the polybasic acid include organic compounds such as phthalic acid, adipic acid, dimerized linolenic acid and maleic acid. Acids are exemplified, and examples of hydroxy compounds include glycols such as ethylene glycol, propylene glycol, butylene glycol and diethylene glycol, trimethylolpropane, hexanetriol, glycerin, trimethylolethane and pentaerythritol.

  Examples of the chain extender used arbitrarily include polyhydric alcohol compounds, polyhydric amine compounds, aminoethanol and aminophenol. Examples of the polyhydric alcohol compounds include ethylene glycol, 1,4-butanediol, 2,3-butanediol, trimethylolpropane, glycerin and the like are exemplified, and examples of the polyvalent amine compound include 4,4′-diaminodiphenylmethane, ethylenediamine, triethanolamine, 3,3′-dichloro-4,4 ′. -Diaminodiphenylmethane and the like are exemplified.

The liquid epoxy resin composition of the present invention can further contain a filler (D), and specific examples thereof include silica powder, alumina, talc, calcium carbonate, clay and mica, and particularly silica. The powder is preferably fused silica. These fillers (D) may be used alone or in combination of two or more.
Further, the amount added is not particularly limited as long as the properties (moisture resistance, workability, etc.) as the liquid sealing resin are maintained, but the content of the filler is not limited to the total liquid epoxy resin composition. The amount is preferably 50% by weight to 80% by weight. If the filler content is less than 50% by weight, the desired characteristics may not be obtained. If the filler content is more than 80% by weight, the resin viscosity becomes too high and injection into the gaps between the solder bumps is performed. It may be difficult and may be unsuitable for casting.

  In addition to the above components, the liquid epoxy resin composition of the present invention includes a curing accelerator, a stress reducing agent, a reactive diluent, a pigment, a coupling agent, a flame retardant, a leveling agent, and an antifoaming agent as necessary. In the art, additives known to those skilled in the art can be blended.

  As a manufacturing method of the liquid epoxy resin composition of the present invention, an epoxy resin (A), a curing agent (B), a urethane resin (C), optionally a filler (D), and, if necessary, other components and And a method of obtaining a liquid epoxy resin composition after defoaming by mixing them at a predetermined composition ratio and performing uniform kneading with a three roll or the like.

The liquid epoxy resin composition of the present invention can be used to seal an electronic component such as a semiconductor element with a cured product to form a semiconductor device. As a manufacturing method thereof, known methods such as casting, injection, and dipping are known. The method can be used.
In addition, the liquid epoxy resin composition of the present invention can be used as an underfill material that fills a gap between an electronic component such as a semiconductor element and an electronic component mounting substrate, and by using this, a cured product thereof can be used as a semiconductor element or the like. In the manufacturing method of underfill sealing the gap between the electronic component and the electronic component mounting substrate to form a semiconductor device, a known method such as sealing by injecting a resin composition into the gap between the electronic component and the substrate is also known. This method can be used.

  Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited by these examples. For the characteristic evaluation, the amount of warpage of the package and the thermal shock test were measured using the liquid epoxy resin composition obtained in the examples. For the package evaluation, the flip chip connected to the bismaleimide triazine substrate was used. It was. The specifications and measurement methods of the flip chip are as follows, and the measurement results are collectively shown in Table 1 (warping amount, thermal shock test).

(1) Specification of flip chip Chip size: 20 mm square.
Passivation: Polyimide resin.
Bump height: 80 μm.
Bump pitch: 250 μm.
Bump arrangement: Full array Bump: Eutectic solder.
Connection test by daisy chain is possible.
(2) Warpage amount For sealing, the package is placed on a 100 ° C hot platen, liquid epoxy resin is applied to one side of the chip and sealed, and then a hot air circulating dryer is used to cure at a curing temperature of 150 ° C. Curing was performed for 90 minutes. Next, the displacement was examined in the diagonal direction using a contact surface roughness meter of the package, and the maximum displacement was taken as the amount of warpage.
(3) Thermal shock test The thermal shock test was conducted after exposing the package obtained above to a thermal shock test (temperature conditions: -55 ° C / 30 minutes to 125 ° C / 30 minutes, 500, 1000, 1500 cycles). The connectivity by daisy chain was examined (number of test pieces: 10).
The criteria for the determination were the number of chip cracks, and the number of chip cracks that occurred even at one location in the package.

[Synthesis Example 1]
[Synthesis example of hydroxyl-terminated urethane prepolymer]
The blending ratio of polypropylene glycol having a number average molecular weight of 800 (manufactured by Sanyo Kasei Kogyo Co., Ltd.) and tolylene diisocyanate (Coronate T-80 manufactured by Nippon Polyurethane Industry Co., Ltd.) is the same as the former hydroxyl group (OH) and the latter isocyanate (NCO ) The molar ratio of the groups was charged so that OH / NCO = 1.8 mol / 1.0 mol, and the chain extender was 1,4-butanediol (manufactured by Kanto Chemical Co., Inc.) at 80 ° C. × 2 The reaction was carried out for a period of time under nitrogen reflux to obtain a hydroxyl group-terminated urethane prepolymer (I) having a number average molecular weight (Mn) of 2,000 and a hydroxyl value of 46.

[Synthesis Example 2]
[Synthesis example of hydroxyl-terminated urethane prepolymer]
In Synthesis Example 1, the number average molecular weight is 4,600 and the hydroxyl value is 24 in the same manner as in Synthesis Example 1, except that the number average molecular weight of polypropylene glycol (manufactured by Sanyo Chemical Industries) is changed to 2,000. A hydroxyl-terminated urethane prepolymer (II) was obtained.

Example 1
Bisphenol A-type and F-type mixed epoxy resin (epoxy equivalent = 160, manufactured by Dainippon Ink & Chemicals, trade name EXA-830LVP) and aminophenol type epoxy resin (epoxy equivalent = 83, manufactured by Sumitomo Chemical Co., Ltd.) , Trade name ELM-100) 50.0 parts by weight, 3,3′-diethyl-4,4′-diaminodiphenylmethane (active hydrogen equivalent = 63.5, manufactured by Nippon Kayaku Co., Ltd., trade name Kayahard AA) 58.0 parts by weight, 15.0 parts by weight of the hydroxyl-terminated urethane prepolymer (I) obtained in Synthesis Example 1, 0.5 parts by weight of 2-phenyl-4-methylimidazole as a curing accelerator, coupling 3.0 parts by weight of γ-glycidoxypropyltrimethoxysilane as an agent, 177 parts by weight of spherical silica having a maximum particle size of 10 μm and an average particle size of 2 μm as an inorganic filler After kneading in a three-roll to obtain a liquid epoxy resin composition was defoamed. The obtained liquid epoxy resin composition was evaluated by the above method, and the results are shown in Table 1.

(Example 2)
In Example 1, a liquid epoxy resin composition was prepared in the same manner as in Example 1 except that the addition amount of the hydroxyl-terminated urethane prepolymer (I) was 35.0 parts by weight, and was used for property evaluation. did.

(Example 3)
In Example 1, except that the hydroxyl-terminated urethane prepolymer was replaced with the hydroxyl-terminated urethane prepolymer (I), and the hydroxyl-terminated urethane prepolymer (II) obtained in Synthesis Example 2 was changed to 15.0 parts by weight. All were carried out similarly to Example 1, the liquid epoxy resin composition was created, and it used for characteristic evaluation.

Example 4
In Example 1, instead of 3,3′-diethyl-4,4′-diaminodiphenylmethane (manufactured by Nippon Kayaku Co., Ltd., trade name Kayahard AA) as the curing agent, 4-methylhexahydrophthalic anhydride (new) Nippon Rika Co., Ltd. (MH-700) A liquid epoxy resin composition was prepared in the same manner as in Example 1 except that 146.0 parts by weight and spherical silica were changed to 265.0 parts by weight. Provided.

(Comparative Example 1)
In Example 1, except for the hydroxyl-terminated urethane prepolymer (I), 3,3′-diethyl-4,4′-diaminodiphenylmethane (active hydrogen equivalent = 63.5, manufactured by Nippon Kayaku Co., Ltd., trade name Kayahard) A-A) A liquid epoxy resin composition was prepared in the same manner as in Example 1 except that 40.0 parts by weight and spherical silica were changed to 162.0 parts by weight, and subjected to characteristic evaluation.

(Comparative Example 2)
In Example 1, instead of the hydroxyl-terminated urethane prepolymer (I), polypropylene glycol (number average molecular weight = 2,000, hydroxyl value = 56, manufactured by Wako Pure Chemical Industries, Ltd.) was changed to 15.0 parts by weight. Except for the above, a liquid epoxy resin composition was prepared in the same manner as in Example 1 and subjected to characteristic evaluation.

  The liquid epoxy resin composition of the present invention is excellent in fluidity, and the cured product has good thermal shock property due to reduction of warpage without occurrence of bleeding, and is equipped with a semiconductor device using this. The possibility of use in many industrial fields such as the electronic equipment field, communication equipment field, and computer field is conceivable.

Claims (10)

It is an epoxy resin composition having an epoxy resin (A), a curing agent (B) and a urethane resin (C) that are liquid at room temperature as essential components, and the urethane resin (C) has a hydroxyl group at the terminal. A liquid epoxy resin composition characterized by the above. The liquid epoxy resin composition according to claim 1, wherein the urethane resin (C) having a hydroxyl group at the terminal is obtained by reacting an isocyanate compound with a hydroxyl group-containing compound. The liquid epoxy resin composition according to claim 1, wherein the urethane resin (C) having a hydroxyl group at the terminal is obtained by reacting an isocyanate compound, a hydroxyl group-containing compound and a chain extender. The liquid epoxy resin composition according to claim 2, wherein the hydroxyl group-containing compound is a polyether polyol compound or a polyester polyol compound. The liquid epoxy resin composition according to claim 3 or 4, wherein the chain extender is a glycol compound, a diamine compound, an amino alcohol compound, or an aminophenol compound. The liquid epoxy resin composition according to any one of claims 1 to 5, wherein the curing agent (B) is a compound having at least two amino groups in one molecule. The liquid epoxy resin composition according to any one of claims 1 to 6, wherein the epoxy resin composition contains a filler (D). The liquid epoxy resin composition according to claim 1, wherein the epoxy resin composition is a resin composition for an underfill material. A semiconductor device sealed with a cured product of the epoxy resin composition according to claim 1. The semiconductor device according to claim 9, wherein a gap between the electronic component and the electronic component mounting substrate is underfill sealed with a cured product of the liquid epoxy resin composition.