JP2006233127A - Liquid resin composition for sealing used for underfill and semiconductor device using the same and manufacturing method for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid resin composition for sealing used for an underfill having reduced cracks and warpages by dispersing silica filler suitably for relieving the stress in the resin. <P>SOLUTION: The liquid-form sealing resin composition for an underfill comprises: (A) an epoxy resin; (B) an aromatic amine hardening agent represented by the formula (1); (C) a silica filler with its surface substantially entirely covered by isolated silanol groups; and (D) a silane coupling agent. In the formula, R<SP>1</SP>is a hydrogen atom or a 1-4C alkyl group and R<SP>2</SP>is either a hydrogen atom, a 1-3C alkyl group or an electron attracting group. R<SP>1</SP>and R<SP>2</SP>can be different and n is a natural number. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid sealing resin composition for underfill, a semiconductor device using the same, and a manufacturing method thereof.

Conventionally, by incorporating silica filler whose surface is covered with isolated silanol groups into a resin composition for semiconductor encapsulation, the fluidity of the resin composition is improved and the mechanical strength of the cured product is improved. Have been made. (Patent Documents 1 and 2).
JP2002-338231A JP2002-201339

However, when the conventional techniques described in Patent Documents 1 and 2 are applied to the underfill, the interface between the silica filler surface and the epoxy resin is firmly bonded. As a result, the strength of the resin composition itself is improved. There remains a problem in that the low adhesion between the resin composition and the resin composition has become apparent.
In addition, the conventional liquid sealing resin composition for underfill is in contact with and compatible with the flux component remaining in the semiconductor device, so that fillers aggregate together, resulting in non-uniform linear expansion coefficient and elastic modulus. The problem was left.
This invention is made | formed in view of the said situation, The place made into the objective is to reduce a crack, peeling, etc., and to relieve stress localization in a resin composition.

[1] (A) epoxy resin,
(B) an aromatic amine curing agent represented by the formula (1),
(C) a silica filler whose substantially entire surface is covered with isolated silanol groups,
(D) a silane coupling agent,
A liquid encapsulating resin composition for underfill, comprising:
(In the formula, R ¹ represents hydrogen or an alkyl group having 1 to 4 carbon atoms, R ² represents any one of hydrogen, an alkyl group having 1 to 3 carbon atoms, and an electron-withdrawing group. R ¹ and R ² represent May be different, n is a natural number.)
[2] The liquid sealing resin composition for underfill according to [1], further comprising (E) a polybutadiene having an epoxy group.
[3] The liquid sealing resin composition for underfill according to [1] or [2], wherein the silane coupling agent contains aminosilane and epoxysilane, or mercaptosilane and epoxysilane.
[4] A substrate, a chip disposed on the substrate, and an underfill filling the gap between the two,
A semiconductor device obtained by curing the underfill liquid encapsulating resin composition according to any one of [1] to [3].
[5] A method of manufacturing a semiconductor device comprising a substrate, a chip disposed on the substrate, and an underfill filling the gap between the two,
(I) A step of filling the gap between the substrate and the chip with the liquid sealing resin composition for underfill according to any one of [1] to [3],
(II) a step of curing the filled underfill liquid sealing resin composition to form an underfill;
A method of manufacturing a semiconductor device including:

  ADVANTAGE OF THE INVENTION According to this invention, the stress in resin can be relieve | moderated because a silica filler disperse | distributes moderately, and the liquid sealing resin composition for underfills by which the crack and curvature were reduced can be provided.

  The present invention includes (A) an epoxy resin, (B) an aromatic amine curing agent represented by formula (1), (C) a silica filler in which substantially the entire surface is covered with isolated silanol groups, and (D) silane. It is related with the liquid sealing resin composition for underfills characterized by including a coupling agent. The following is an example, and the present invention is not limited to the following. Below, each component of the liquid sealing resin composition for underfills of this invention is demonstrated in detail.

The (A) epoxy resin used in the present invention is not particularly limited in molecular weight or structure as long as it has two or more epoxy groups in one molecule. For example, novolak type phenol resins such as phenol novolak resin, cresol novolak resin, bisphenol A novolak resin, phenol resin such as resol type phenol resin, novolak type epoxy resin such as phenol novolak type epoxy resin, cresol novolak type epoxy resin, bisphenol A type Aromatic glycidylamine type such as epoxy resin, bisphenol type epoxy resin such as bisphenol F type epoxy resin, N, N-diglycidylaniline, N, N-diglycidyltoluidine, diaminodiphenylmethane type glycidylamine, aminophenol type glycidylamine Epoxy resin, hydroquinone type epoxy resin, biphenyl type epoxy resin, stilbene type epoxy resin, triphenolmethane type epoxy resin, toner Phenolpropane type epoxy resin, alkyl modified triphenolmethane type epoxy resin, triazine nucleus-containing epoxy resin, dicyclopentadiene modified phenol type epoxy resin, naphthol type epoxy resin, naphthalene type epoxy resin, phenol aralkyl having phenylene and / or biphenylene skeleton Type epoxy resin, epoxy resin such as aralkyl type epoxy resin such as naphthol aralkyl type epoxy resin having phenylene and / or biphenylene skeleton, alicyclic type such as vinylcyclohexene dioxide, dicyclopentadiene oxide, alicyclic diepoxy-adipide Aliphatic epoxy resins such as epoxy are listed.
In this case, those containing a structure in which a glycidyl ether structure or a glycidylamine structure is bonded to an aromatic ring are preferable from the viewpoint of heat resistance, mechanical properties, and moisture resistance, and aliphatic or alicyclic epoxy resins are particularly reliable and adhesive. In view of the above, it is preferable to limit the amount used. These may be used alone or in combination of two or more. In the present invention, because of the mode of the liquid sealing resin composition for underfill, it is preferable that the epoxy resin is finally liquid at room temperature (25 ° C.). And dissolved in a liquid epoxy resin so long as it is in a liquid state.

  The aromatic amine curing agent (B) used in the present invention is represented by the formula (1). A structure in which a primary amine or a secondary amine is bonded to an aromatic ring in one molecule and two or more primary amines and / or secondary amines are included in one molecule Are m-phenylenediamine, diaminodiphenylsulfone, diethyltoluenediamine, trimethylenebis (4-aminobenzoate), polytetramethylene oxide-di-P-aminobenzoate, and those having the structure shown in formula (1). In this case, the aromatic amine represented by the formula (1) is preferable from the viewpoint of stress absorption and thermal shock resistance.

(In the formula, R ¹ represents hydrogen or an alkyl group having 1 to 4 carbon atoms, R ² represents any one of hydrogen, an alkyl group having 1 to 3 carbon atoms, and an electron-withdrawing group. R ¹ and R ² represent May be different, n is a natural number.)

  In the formula (1), when R1 is hydrogen, the resin composition can obtain excellent adhesion and relatively good thermal shock resistance, and when R1 is an alkyl group having 1 to 4 carbon atoms, A resin composition having good adhesion and excellent impact resistance and low stress can be obtained. However, when the number of carbon atoms in R1 is 5 or more, it is not preferable because of a decrease in reactivity due to a steric hindrance effect, a decrease in adhesion, a decrease in glass transition point, and a decrease in heat resistance. R2 in Formula (1) is preferably hydrogen, an alkyl group having 1 to 3 carbon atoms, or an electron-withdrawing group. As the carbon number of R2 is larger, a resin composition having excellent stress absorbability can be obtained. However, when the carbon number is 4 or more, the viscosity of the composition is increased and the heat resistance is lowered, which is not preferable. The electron donating group for R4 includes -NO2, -CF3, and halogen groups (F, Cl, Br, I). In consideration of the corrosion of the metal joint portion of the semiconductor device, R4 is preferably H or having 1 to 3 carbon atoms. R1 and R2 may be different.

  The aromatic amine curing agent (B) used in the present invention may be used alone or in combination of two or more. In addition, other curing agents and catalysts may be used in combination as long as the usable time and storage stability are not impaired. Such curing agents include phenols such as tetramethylbisphenol A, m-phenylenediamine, diaminodiphenylsulfone, diethyltoluenediamine, trimethylenebis (4-aminobenzoate), polytetramethylene oxide-di-P-aminobenzoate, etc. Aromatic polyamines, catechol, resorcin, hydroquinone, xylenol, salicylic acid, methyl toluenesulfonate, citrazic acid, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2- It is an imidazole type curing catalyst such as phenyl-4,5-dihydroxymethylimidazole, 2-phenylimidazole.

  The blending amount of the (B) curing agent used in the present invention is in the range of 0.6 to 1.4, more preferably in the range of 0.7 to 1.3 in terms of the active hydrogen equivalent of the curing agent with respect to the epoxy equivalent of the epoxy resin. Here, when the active hydrogen equivalent of the curing agent is within the range, there is an advantage that the reactivity and the heat resistance of the composition are improved.

  In general, silanol groups exist on the surface of silica filler, and their chemical states are roughly classified into two types: isolated silanol groups (free type) and adjacent silanol groups (hydrogen bond type). The surface of a silica filler usually used as a filler is in a state where adjacent silanol groups and isolated silanol groups are mixed. Adjacent silanol groups are silanol groups in the state where the silanol groups on the same surface are close to each other and hydrogen bonds are formed with each other. The isolated silanol groups are separated from each other on the same surface. It is a silanol group in a state where no hydrogen bond is formed between them. It is known that the silanol groups adjacent to each other have low activity because hydrogen bonds are formed with each other, while isolated silanol groups are known to exhibit high activity because they are not constrained by hydrogen bonds. Both can be distinguished by an absorption spectrum or the like.

(C) Silica filler in which substantially the entire surface is covered with isolated silanol groups used in the present invention means that the isolated silanol accounts for 70% or more of the entire surface among the silanol groups present on the entire surface of the silica filler. Say what you are.
Therefore, (C) Silica filler whose substantially entire surface is covered with isolated silanol groups has a high surface activity and reacts well with the silane coupling agent, resulting in good dispersion stability in the resin composition. Show.
Specifically, when (C) a resin composition containing a silica filler whose substantially entire surface is covered with isolated silanol groups is filled in a semiconductor device, the flux component and resin composition remaining inside the device Silica does not agglomerate even if they are compatible with each other, and as a result, uniformity of stress distribution such as elastic modulus and thermal expansion coefficient in the semiconductor device is maintained, and high reliability of the semiconductor device is maintained.

  (C) As a method for synthesizing a silica filler having substantially the entire surface covered with isolated silanol groups used in the present invention, a normal silica filler is dissolved with water, hydrogen fluoride treatment or alkali treatment, and then the surface is dissolved. There is a method of heating in a temperature range of 1 to 48 hours at a temperature range of 1050C to 1050C. Here, the normal silica filler as a raw material is not particularly limited in the synthesis method and the state of the surface silanol group as long as 99% or more of the components are SiO2. Such silica fillers include fused silica, crystalline silica, or synthetic silica powder starting from natural silica stone, but synthetic silica in that the amount of impurities such as uranium and thorium that cause soft errors is small. Is preferred. Methods for dissolving the silica filler surface include immersing and stirring the silica filler in water, hydrofluoric acid aqueous solution or alkaline aqueous solution, spraying water, hydrofluoric acid aqueous solution or alkaline aqueous solution on the silica surface, ammonia, etc. There is a method in which an alkaline gas or hydrogen fluoride gas is brought into contact with the silica surface, and these treatments may be carried out at a high temperature and high pressure in order to perform dissolution efficiently. Examples of the alkaline aqueous solution include aqueous solutions of sodium hydroxide, calcium hydroxide, ammonia and the like, and the concentration is preferably 0.1% or more because it can be efficiently dissolved. In the case where adsorbed water is sufficiently adhered to the surface of the silica filler as a raw material, only the heat treatment may be performed without passing through the surface dissolution step. When the heating temperature is 600 ° C or higher, the dehydration condensation reaction occurs between adjacent silanol groups, so the adjacent silanol disappears and decreases.When the heating temperature is 1050 ° C or lower, the isolated silanol group does not disappear due to reaction or melting. As a result, the temperature range of 600 ° C. to 1050 ° C. is preferable because substantially only isolated silanol remains on the surface. For the purpose of removing residual components (ionic impurities) of the alkaline aqueous solution remaining after dissolution treatment or heat treatment, neutralization reaction treatment or washing with ion exchange water / distilled water may be performed, and water is removed after washing. Therefore, a decompression process or a drying process may be performed.

As an evaluation method of such a silanol group, there is an infrared absorption spectrum by the stirring reflection method described above. Isolated silanol has a sharp peak near 3745 cm ⁻¹ , and adjacent silanol has a broad peak at 3500 to 3700 cm ^−1. Indicates. By measuring a standard substance having a known silanol group, the concentration of the isolated silanol group in the sample can be quantified. A preferable silanol concentration in this case is 0.008 to 0.08 mmol / g, more preferably 0.01 to 0.05 mmol / g. When the silanol group concentration is 0.008 mmol / g or more, it reacts favorably with the silane coupling agent, and as a result, the silica filler is preferable in order to exhibit good dispersion stability in the resin composition. In the case of g or less, silica is not aggregated due to hydrogen bonds between isolated silanols between silica particles, and as a result, the initial dispersibility and mixing properties when producing the resin composition are improved, which is preferable.
In addition to the infrared absorption spectrum, the isolated silanol group can be observed and quantified by, for example, near infrared spectroscopy, nuclear magnetic resonance, electron spin resonance, and the like.

  The shape of the silica filler of the present invention is preferably spherical from the viewpoint of viscosity and flow characteristics. The average particle size of the silica filler is preferably 0.1 to 30 microns, and particularly preferably 0.2 to 5 microns. When the average particle diameter exceeds 0.1 microns, the viscosity of the resin composition is lowered and the fluidity is improved. When it is less than 30 microns, it becomes difficult to cause partial unfilling / filling failure due to filler clogging when the composition flows to the semiconductor device.

  The content of the silica filler in the total resin composition is in the range of 30 to 80% by weight, more preferably 40 to 75% by weight. When the content is 30% by weight or more, the thermal expansion coefficient of the resin composition is small and the reliability of the semiconductor device can be maintained. When the content is 80% by weight or less, the gaps in the semiconductor device are not clogged with fillers. Can flow.

  The (D) silane coupling agent used in the present invention is, as long as the chemical structure has a chemical structure including a silicon atom to which an alkoxy group is bonded and a hydrocarbon part to which a functional group is bonded in one molecule, In particular, the molecular weight and structure are not limited. For example, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylethyldiethoxysilane, 2- (3,4 epoxy cyclohexyl) ) Epoxy silane coupling agent such as ethyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylethyldiethoxysilane, Silane coupling agents having an acrylate group bonded thereto such as 3-acryloxypropyltrimethoxysilane, N-aminoethylated aminopropylmethyl dialkoxysilane, N-aminoethylated aminopropyltri Lucoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltriethoxysilane, N-phenyl-γ-aminobutyl Aminosilane coupling agents such as trimethoxysilane, N-phenyl-γ-aminobutyltriethoxysilane, N- (1,3-dimethylbutylidene) -3- (triethoxysilyl) propylamine, N- (benzylidene)- Latent aminosilane coupling agents in which the primary amino group of an aminosilane coupling agent such as 3- (triethoxysilyl) propylamine is protected by reaction with a ketone or aldehyde, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxy Like silane A silane cup that exhibits the same function as a mercaptosilane coupling agent by thermal decomposition such as a mercaptosilane coupling agent, bis (3-triethoxysilylpropyl) tetrasulfide, bis (3-triethoxysilylpropyl) disulfide There are ring agents. Further, these silane coupling agents may be blended in advance by hydrolysis.

  These may be used alone or in combination of two or more. In the case of the present invention, the epoxy silane coupling agent is preferable from the viewpoint of relatively good adhesion to the substrate and the semiconductor device member surface (solder resist on the substrate surface, polyimide on the silicon chip surface, side surface of the silicon chip). . Aminosilane coupling agents, latent aminosilane coupling agents and mercaptosilane coupling agents are preferred because of their very good adhesion to the polyimide on the silicon chip surface and the “silicon nitride surface”. From the viewpoint of adhesion to the entire semiconductor device, (1) a combination of an epoxy silane coupling agent and an amino silane coupling agent or a latent amino silane coupling agent, or (2) an epoxy silane coupling agent and a mercapto silane coupling. Combinations with agents are preferred. Aminosilane coupling agent and mercaptosilane coupling agent may be combined, but amine and mercapto may react and impair the fluidity of the resin composition. It is preferable to blend by taking a method such as preparing and blending a masterbatch, or individually modifying the silica surface layer.

  The blending amount of the (D) silane coupling agent used in the present invention is 0.03 to 5.0% by weight, more preferably 0.1 to 3.0% by weight, based on the total resin amount. Here, the total resin amount means the total weight of all components excluding the silica filler in the resin composition. (D) When the addition amount of the coupling agent of the silane coupling agent exceeds 0.03% by weight, the dispersibility of the silica filler in the resin composition is improved, and the adhesion of the semiconductor device to the silicon chip is further improved. Therefore, it is preferable, and when it does not exceed 5.0% by weight, bubbles due to alcohol generated from the silane coupling agent during resin curing can be suppressed, which is preferable.

  As a blending method of the silane coupling agent, an integral blend formula in which a silica filler and an organic material are mixed, mixed, dispersed, and mixed at the same time in the process of producing a resin composition, (A) epoxy resin , (B) Masterbatch method, in which a coupling agent is dispersed and dissolved in advance in an aromatic amine curing agent and / or other organic additive other than silica filler, and then blended into the resin composition, coupling agent in advance There is a method of chemically modifying the surface of the silica filler, and the above object can be achieved even if any blending method is used or a blending method combining these is performed. More preferably, it is possible to obtain a resin composition having a uniform master batch method or a combination method in which the master batch method and a method of chemically modifying the silica surface layer are combined.

The (E) polybutadiene having an epoxy group used as necessary in the present invention is a polymer containing a 1,3-butadiene monomer as a repeating unit in the molecule and having an epoxy group in the molecule. The molecular weight and bonding structure are not particularly limited. The number average molecular weight is preferably in the range of 400 to 4000, and more preferably 600 to 3000. When the molecular weight is 400 or more, the resin composition can maintain the glass transition temperature, and when the molecular weight does not exceed 4000, the viscosity of the resin composition does not become excessively high and exhibits good workability. can do. In addition, a number average molecular weight here is a styrene conversion molecular weight by GPC method. The epoxy group content is preferably 3 to 10%. If it exceeds 3%, it can be mixed and compatible with the epoxy resin and aromatic amine curing agent without separation. If it does not exceed 10%, a sea-island structure can be formed after curing, resulting in low stress and flexibility. A sex-imparting effect can be obtained.
The introduction site of the epoxy group may be any of main chain skeleton, side chain, and terminal of polybutadiene. The bond structure of the butadiene main chain skeleton may be a cis isomer, a trans isomer, or a vinyl isomer, but the total of the cis isomer and the trans isomer is preferably at least 20% or more. When the sum of the cis form and the trans form is 20% or more, the mobility of the molecule is maintained, and a stress absorption effect can be expressed in the resin composition.

  In addition, a random copolymer or a block copolymer containing other monomers in the structure may be used as long as the above requirements are satisfied, but in this case, the repeating unit of 1,3 butadiene monomer should be 30% by weight or more. Is preferred. Examples of such polymers include epoxidized SBR (styrene butadiene rubber), NBR (nitrile rubber), and ABS.

  The compounding amount of the polybutadiene (C) having an epoxy group used in the present invention is in the range of 0.5 to 10% by weight of the total resin composition, and more preferably in the range of 1.0 to 5.0% by weight. Here, when 0.5% by weight or more, there is an effect of imparting sufficient flexibility to the resin composition, and when not exceeding 10% by weight, the viscosity of the resin composition does not become excessively high, Good workability can be expressed.

  The semiconductor device of the present invention is not particularly limited as long as it uses a flux. Specifically, a flip chip type semiconductor device can be given. A flip chip semiconductor device is a device in which a chip and a substrate are electrically connected via solder bumps. Solder bumps are often made of an alloy consisting of tin, lead, silver, copper, bismuth, etc., and as a method of electrical connection, metal pads on the board and metal bumps on the chip using a flip chip bonder, etc. After the alignment, the metal bump is heated to the melting point or higher by using an IR reflow device, a hot plate, or other heating device, and the metal pad and the metal bump on the substrate are formed by fusion bonding. At this time, a solder paste or a metal layer having a relatively low melting point may be formed in advance on the metal pad portion on the substrate. Prior to this electrical joining step, flux is applied to the metal bumps and / or the surface layer of the metal pad portion of the substrate. In addition to this bonding step, flux may be used when forming metal bumps on the chip (wafer) surface. Any flux may be used as long as it has a function of removing the oxide film on the metal surface that hinders fusion bonding and improving the melt wettability between metals. The semiconductor device to which electrical connection is made has a form in which metal bumps exist in a columnar shape in a parallel gap between the chip and the substrate, and this gap is filled and sealed with the resin composition of the present invention.

  In the present invention, additives such as a diluent, a pigment, a flame retardant, a surfactant, a leveling agent, and an antifoaming agent may be used as necessary in addition to the above components. As a method for producing the resin composition of the present invention, each component, additive, etc. is dispersed and kneaded using a planetary mixer, three rolls, two hot rolls, a laika machine, etc., and then defoamed under vacuum. To manufacture. For the purpose of removing volatile components in the raw material in advance or in the middle of production, a temperature range in which the reaction between the epoxy resin and the curing agent and the decomposition reaction of each component does not occur under atmospheric pressure or a reduced pressure atmosphere, for example, 50 ° C. to 200 ° C. It does not matter even if the heat treatment is performed. Further, curing may be performed at a temperature of 5 ° C. to 35 ° C. for 12 to 96 hours in the middle or final stage of the dispersion mixing process.

  As a method for filling and sealing the gap of the semiconductor device of the present invention, it is usual to apply the resin composition to the end of the chip while heating the semiconductor device and the resin composition, and to spread the gap by the capillary phenomenon. Although it is a method, for the purpose of shortening the production cycle, a method of inclining the semiconductor device or accelerating the implantation using a pressure difference may be used in combination. The filled resin is cured by heating in a temperature range of 100 ° C. to 170 ° C. for 1 to 12 hours. Here, for example, the temperature profile may be heat-cured while changing the temperature stepwise, such as heating at 100 ° C. for 1 hour and then heating at 150 ° C. for 2 hours.

(Example 1) Please correspond to the table.
100 parts by weight of bisphenol F type epoxy resin (specific compounds are described in the notes in Table 1. The same applies hereinafter) as the epoxy resin (A), and (D) 2 epoxy silane coupling agents as silane coupling agents 3 parts by weight of 5 parts by weight, 5 parts by weight of diluent and 0.05 part by weight of pigment were mixed and stirred at 7 rpm at 27 ° C. for 7 hours using a planetary mixer. 219.2 parts by weight of silica and 39.1 parts by weight of an aromatic primary amine curing agent as the amine curing agent (B) are mixed, mixed using three rolls, and vacuum stirred using a planetary mixer and a vacuum pump. A liquid sealing resin composition for underfill was prepared by defoaming treatment. Here, the silanol group amount of the isolated silanol silica used in Example 1 is 0.02 mmol / g, and the IR spectrum chart is shown in FIG.

  The viscosity was measured using a Brookfield viscometer equipped with a CP-51 type cone at 25 ° C. and 5 rpm. The viscosity measurement result of the resin composition obtained in Example 1 was 12.1 Pa · s. The viscosity of the composition is preferably 35 Pa.sec or less in consideration of the stability of quantitative supply to the semiconductor device, the coating supply property to the semiconductor device, and the flow characteristics into the gap.

  Fill and seal the resin composition obtained in Example 1 in a semiconductor device, (1) fluidity evaluation, (2) filler separation phenomenon evaluation and reliability test moisture absorption (3) reflow test (peeling resistance) Evaluation) and (4) Temperature cycle test (peeling resistance test) was conducted. The components of the semiconductor device used for testing and evaluation are as follows. The chip is a PHASE-2TEG wafer manufactured by Hitachi VLSI, with a circuit protection film made of polyimide and a solder bump with Sn / Pb composition eutectic solder cut to 15mm x 15mm x 0.8mmt. did. The substrate is based on a 0.8mmt glass epoxy substrate equivalent to Hitachi Chemical FR5, and a solder resist PSR4000 / AUS308 made by Taiyo Ink Co., Ltd. is formed on both sides, and a gold-plated pad corresponding to the above solder bump arrangement is arranged on one side. The product was cut into a size of 50 mm × 50 mm and used. TSF-6502 (manufactured by Kester, rosin flux) was used as a flux for connection. To assemble the semiconductor device, first apply a uniform flux of about 50 microns on a sufficiently smooth metal or glass plate using a doctor blade, and then use a flip chip bonder to lightly contact the circuit surface of the chip with the flux film. After that, the flux is transferred to the solder bump, and then the chip is pressed onto the substrate. A heat treatment was performed in an IR reflow furnace, and solder bumps were melted and produced. The resin composition is filled and sealed by heating the prepared semiconductor device on a hot plate at 110 ° C., applying the resin composition prepared on one side of the chip, filling the gap, and then using a 120 ° C. oven. The resin was heat-cured for a minute to obtain a semiconductor device for evaluation tests.

For evaluation of fluidity to a semiconductor device, the prepared semiconductor device was observed with an ultrasonic flaw detector, and the presence or absence of voids (bubbles) in the resin composition was confirmed. In the semiconductor device produced using the resin composition obtained in Example 1, no voids were observed and good fluidity was exhibited.

  As a method for measuring the filler separation phenomenon, the dispersion state of the filler in the resin composition in the semiconductor device is observed and evaluated using an electron microscope (SEM) by cutting and polishing perpendicularly to the chip surface of the prepared semiconductor device. did. In the semiconductor device produced using the resin composition obtained in Example 1, the filler was uniformly present in the resin composition and was in a good dispersion state. The obtained cross-sectional photograph is shown in FIG.

  As a test method for the moisture absorption reflow test, the manufactured semiconductor device was subjected to a JEDEC level 3 moisture absorption treatment (treated at 30 ° C. and 60% relative humidity for 168 hours), followed by IR reflow treatment (peak temperature 220 ° C.) three times. The presence or absence of peeling of the resin composition inside the semiconductor device was observed with an ultrasonic flaw detector, and the appearance of the underfill on the outer periphery of the chip was observed with an optical microscope to confirm the presence or absence of cracks on the resin surface. In the semiconductor device produced using the resin composition obtained in Example 1, peeling and cracking were not observed, and good reliability was shown.

  As the temperature cycle test, the semiconductor device subjected to the above-described moisture absorption reflow test was subjected to 1000 cycles of (−55 ° C./30 minutes) and (125 ° C./30 minutes) cooling / heating cycle processing, and then with an ultrasonic flaw detector. The presence or absence of peeling between the chip and the resin composition interface inside the semiconductor device was observed with an optical microscope to observe the appearance of the underfill on the outer periphery of the chip to check for cracks on the resin surface. In the semiconductor device produced using the resin composition obtained in Example 1, peeling and cracking were not observed, and good reliability was shown. The above results are summarized in Table 1.

(Examples 2-5, Comparative Examples 1-3)
The experiment and evaluation were performed in the same manner as in Example 1 except that the formulation was as shown in Table 1. The results are shown in Table 1. In addition, Examples 1-5 of a table | surface and Comparative Examples 1-3 were prepared so that content of the silica filler which occupies in all the resin compositions might be 60 weight%. The IR measurement result of the general silica used in Comparative Example 2 is shown in FIG.

Comparing the IR charts of FIG. 1 and FIG. 2, the peak derived from isolated silanol silica in the vicinity of 3750 cm ⁻¹ is larger in FIG. 1 (isolated silanol silica) than in FIG. 2 (general silica). Recognize. Actually, some isolated silanol groups also exist in general silica, so that a peak derived from the isolated silanol groups is observed as shown in FIG. Further, although the surface of the isolated silanol silica is substantially covered with the isolated silanol group, since adjacent silanol groups which are not present on the surface of the silica are detected in the IR measurement, also in FIG. 1, 3500-3700 cm ^−1. A peak derived from the adjacent silanol group is observed in the vicinity.

The terms in Table 1 are explained below.
Bisphenol F type epoxy resin: manufactured by Dainippon Ink and Chemicals, EXA-830LVP, bisphenol F type liquid epoxy resin, epoxy equivalent 161
Methyl group-containing trifunctional glycidylamine: Sumitomo Chemical Co., Ltd., Sumiepoxy ELM-100, 4- (2,3-epoxypropoxy) -N, N-bis (2,3-epoxypropyl) -2-methylaniline , Epoxy equivalent 100
Trifunctional glycidylamine: manufactured by Japan Epoxy Resin, Epicoat E-630, N, N-bis (2,3-epoxypropyl) -4- (2,3-epoxypropoxy) aniline, epoxy equivalent 98
Aromatic secondary amine type curing agent: having a structure in which R1 is a methyl group, R2 is hydrogen, and the average of n is 0.3 in the formula (1). Amine equivalent weight 116
Aromatic primary amine type curing agent: Nippon Kayaku Co., Ltd. Kayahard AA 3,3'-diethyl-4,4'-diaminodiphenylmethane amine equivalent 63.5
Imidazole catalyst: Shikoku Kasei Kogyo Co., Ltd., Curazole C17Z, 2-heptadecylimidazole anhydride anhydride curing agent: Nippon Zeon Co., Ltd. Fine SO-E3 (synthetic spherical silica, average particle size: 1.0um) immersed in aqueous sodium hydroxide and surface-dissolved, then heat-treated at 700 ° C for 8 hours, washed with ion-exchanged water, dried and ground . Isolated silanol concentration 0.02 mmol / g (IR spectrum diffuse reflection method).
General silica: Admatechs Co., Ltd., Admafine SO-E3, synthetic spherical silica, average particle size 1.0 um, isolated silanol concentration 0.005 mmol / g (IR spectrum diffuse reflection method).
Secondary aminosilane coupling agent: Shin-Etsu Chemical Co., Ltd. KBM-573: N-phenyl-3-aminopropyltrimethoxysilane, molecular weight 255.4, theoretical coverage 307m ^ 2 / g)
Primary aminosilane coupling agent: Shin-Etsu Chemical Co., Ltd. KBM-903: 3-aminopropyltrimethoxysilane, molecular weight 179.3, theoretical coverage 436m ^ 2 / g)
Mercaptosilane coupling agent: Shin-Etsu Chemical Industrial Co., Ltd. KBM-803 3-mercaptopropyltrimethoxysilane, molecular weight 196.4, theoretical coverage 398m ^ 2 / g
Epoxysilane coupling agent: Shin-Etsu Chemical Industrial Co., Ltd. KBM-403: 3-glycidoxypropyltrimethoxysilane, molecular weight 236.3, theoretical coverage 330m ^ 2 / g
Low stress agent: Shin-Nippon Petrochemical Co., Ltd. E-1000-6.5, number average molecular weight 1000, epoxy equivalent 246
Diluent: Reagents manufactured by Tokyo Chemical Industry Co., Ltd. Ethylene glycol mono-normal-butyl ether acetate pigment: MA-600 carbon black pigment manufactured by Mitsubishi Chemical

In Examples 1 to 5 in which isolated silanol silica (D) is blended in Table 1, even if the blending of the epoxy resin (A), the curing agent (B), the silane coupling agent (E), and the low stress agent is changed, the void is formed. It showed good fluidity with no filler and no filler separation phenomenon was observed. 2 that is a cross-sectional photograph of Example 1, it can be seen that the silica filler is well dispersed in the underfill (the resin composition of the present invention). Furthermore, in the moisture absorption reflow test and temperature cycle test evaluation of the semiconductor device, there was no peeling or cracking, and good results could be obtained.
Next, in the case of the combination (Comparative Example 1) in which the amine curing agent (B) of Example 5 was replaced with an acid anhydride curing agent and an imidazole catalyst, peeling was observed when the semiconductor device was assembled and a moisture absorption reflow test was performed. Insufficient adhesion characteristics. Such peeling becomes a problem because it reduces the operational reliability of the semiconductor device.
In the case of the combination in which the isolated silanol silica of Example 3 was replaced with general silica (Comparative Example 2), a filler separation phenomenon was observed. When FIG. 3 which is a cross-sectional photograph of the comparative example 2 is seen, the portion 6 where the filler settles on the upper part of the underfill and becomes only the resin can be observed in black. There is a risk that stress due to non-uniformity inside the resin composition may impair the reliability of the semiconductor device.
In the case of the combination (Comparative Example 3) in which the silane coupling agent (D) of Example 3 was replaced with a diluent, voids were observed in the fluidity evaluation, and filler separation was observed in the cross-sectional observation. When a semiconductor device was assembled and a moisture absorption reflow test was performed, peeling and cracking were observed, and adhesion characteristics and resin strength were insufficient. Such voids / peeling / cracks are problematic because they significantly reduce the operational reliability of the semiconductor device.

  INDUSTRIAL APPLICATION This invention is used suitably for the liquid sealing resin composition for underfill which a crack, the stress of curvature, etc. do not generate | occur | produce easily, the semiconductor device using the same, and its assembly method.

FIG. 1 shows the IR spectrum of the isolated silanol silica used in the examples.

FIG. 1 shows an IR spectrum of general silica used in Comparative Example 2.

FIG. 3 shows a cross-sectional photograph of the semiconductor device of Example 1.

FIG. 4 shows a cross-sectional photograph of the semiconductor device of Comparative Example 2.

Explanation of symbols

1 Solder bump (95% tin / 5% silver)
2 Silicon chip 3 Underfill 4 Gold pad 5 Solder resist 6 Part with a lot of resin made by separation and sedimentation of filler and little silica

Claims (5)

(A) epoxy resin,
(B) an aromatic amine curing agent represented by the formula (1),
(C) a silica filler whose substantially entire surface is covered with isolated silanol groups,
(D) a silane coupling agent,
A liquid encapsulating resin composition for underfill, comprising:
(In the formula, R ¹ represents hydrogen or an alkyl group having 1 to 4 carbon atoms, R ² represents any one of hydrogen, an alkyl group having 1 to 3 carbon atoms, and an electron-withdrawing group. R ¹ and R ² represent May be different, n is a natural number.)   The liquid sealing resin composition for underfill according to claim 1, further comprising (E) a polybutadiene having an epoxy group.   The liquid sealing resin composition for underfill according to claim 1 or 2, wherein the silane coupling agent contains aminosilane and epoxysilane, or mercaptosilane and epoxysilane. A substrate, a chip disposed on the substrate, and an underfill filling the gap between the two,
A semiconductor device obtained by curing the underfill liquid encapsulating resin composition according to claim 1. A method of manufacturing a semiconductor device comprising a substrate, a chip disposed on the substrate, and an underfill filling the gap between the two,
(I) a step of filling the gap between the substrate and the chip with the liquid sealing resin composition for underfill according to any one of claims 1 to 3,
(II) a step of curing the filled underfill liquid sealing resin composition to form an underfill;
A method of manufacturing a semiconductor device including: