JP2012201696A - Liquid epoxy resin composition for electronic component and electronic device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid epoxy resin composition for electronic components which gives a cured product having chemical resistance, can be used as a one-part composition because of good storage stability, and can also suppress cure shrinkage, and to provide an electronic device using the same.SOLUTION: The liquid epoxy resin composition includes an epoxy resin which is liquid at ordinary temperature, a curing agent for the epoxy resin, a curing accelerator for the epoxy resin, and a hydrosilylation reaction product of a room temperature curing, two-part addition reaction curing type silicone rubber composition obtained by mixing two liquids of a base resin component and a curing agent component.

Description

  The present invention relates to a liquid epoxy resin composition for electronic components used for sealing, adhesion, protection, etc. of electronic components and an electronic device using the same.

In electronic components such as semiconductor elements, resin compositions are used for sealing and protection and adhesion to substrates and the like in mounting on various electronic devices.
For example, in the flip-chip mounting of semiconductor elements that have been increasingly used in recent years, a gap between a semiconductor element and an interposer is sealed with an underfill that is filled and cured with a liquid resin composition underfill material.

  This underfill protects the bumps, increases the bonding strength between the semiconductor element and the interposer, and prevents moisture in the air from entering between the semiconductor element and the interposer, thereby improving the moisture resistance of the package of the semiconductor device. Can be improved.

  The flip chip mounting type semiconductor device having such a structure has a small mounting area, and it is not necessary to encapsulate the resin up to the wire as in the case of wire bonding connection, so the height after mounting can be reduced and the size can be reduced. It is possible to meet demands for thinning.

  As an underfill material used for such flip chip mounting, a liquid epoxy resin composition is widely used (see Patent Documents 1 and 2).

  In addition, the liquid epoxy resin composition is also used as a sealing material for wafer level CSP.

Such a liquid epoxy resin composition may be required to have high chemical resistance depending on the use of an electronic device in which an electronic component is sealed. Such a situation is the same not only for sealing applications but also for adhesion and protection of various electronic components.
Therefore, conventionally, when chemical resistance is required, a two-component liquid epoxy resin composition having high reactivity is mainly used.

JP 2010-144144 A JP 2004-027005 A

  However, the two-pack type is low in storage stability and has limited workability. Further, the curing shrinkage rate is large and the stress applied to the member tends to increase.

  Even if a one-pack type liquid epoxy resin composition satisfying chemical resistance is prepared, it is difficult to satisfy physical properties required for the cured product, for example, suppression of curing shrinkage.

  The suppression of curing shrinkage is the same in the adhesion and protection of various electronic components, but is particularly important for sealing electronic components. For example, solder bumps may cause stress due to the effect of filling and contraction of the liquid epoxy resin composition during the flip-chip mounting process, and warping of the semiconductor element, which may cause defects such as bump cracks.

  Particularly in recent years, low-k (low dielectric constant) has been increasing due to high integration and high speed of semiconductor elements. In addition, from the viewpoint of environmental protection, lead-free requirements are increasing, lead removal of solder bumps is progressing, and terminal connection temperatures are also increasing. As a result, the solder terminal material has become brittle and it has become difficult to ensure connectivity. Depending on the selection of the underfill material, the joint is not sufficiently protected when subjected to repeated thermal shocks in temperature cycle tests, etc. As a result, the joint may fatigue. Such low-k applications and lead-free solder applications are required to further suppress the stress at the bump joint caused by shrinkage due to curing.

  In addition to the liquid epoxy resin composition, as a one-component thermosetting resin composition having chemical resistance, a liquid silicone resin composition and the like have been developed, but the heat resistance is higher than that of the liquid epoxy resin composition. Inferior in terms of adhesiveness and adhesion.

  Therefore, the present invention is useful for sealing, adhesion, protection, etc. of electronic components, the cured product has chemical resistance, good storage stability, can be used in a one-pack type, and suppresses curing shrinkage. It is an object of the present invention to provide a liquid epoxy resin composition for electronic parts. Another object of the present invention is to provide an electronic device using such a liquid epoxy resin composition for electronic components.

  In order to solve the above problems, the liquid epoxy resin composition for electronic parts of the present invention includes an epoxy resin that is liquid at room temperature, an epoxy resin curing agent, an epoxy resin curing accelerator, and a main component and a curing agent component. It is characterized by containing a hydrosilylation reaction product of a room temperature curable two-component addition reaction curable silicone rubber composition obtained by mixing these two solutions.

  In this liquid epoxy resin composition for electronic parts, the content of the hydrosilylation reaction product of the two-component addition reaction curable silicone rubber composition is equal to the total amount of the epoxy resin that is liquid at room temperature and the epoxy resin curing agent. It is preferable that it is 30-60 mass% with respect to it.

  In this liquid epoxy resin composition for electronic parts, the epoxy resin curing agent is preferably a phenolic curing agent.

  The electronic device of the present invention includes an electronic component and a cured layer of the liquid epoxy resin composition for an electronic component formed on at least a part of the surface of the electronic component.

According to the liquid epoxy resin composition for electronic parts of the present invention, the cured product has chemical resistance, good storage stability, can be used in a one-pack type, and curing shrinkage can also be suppressed.
According to the electronic device of the present invention, it has chemical resistance, is excellent in workability when forming a hardened layer on at least a part of the surface of the electronic component, and can also suppress the stress of the hardened layer due to hardening shrinkage. .

  The present invention is described in detail below.

  In the liquid epoxy resin composition for electronic parts of the present invention, an epoxy resin that is liquid at room temperature is blended as an epoxy resin.

  As the epoxy resin that is liquid at room temperature, various epoxy resins that are liquid in a temperature range of 5 to 28 ° C. under atmospheric pressure, particularly around room temperature of 18 ° C. can be used.

  Examples of epoxy resins that are liquid at room temperature include hydrogenated bisphenol types such as bisphenol F type epoxy resins and bisphenol A type epoxy resins, hydrogenated bisphenol F type epoxy resins, and hydrogenated bisphenol A type epoxy resins. Epoxy resin, naphthalene ring-containing epoxy resin, alicyclic epoxy resin, biphenyl type epoxy resin, dicyclopentadiene type epoxy resin, polyalkylene glycol skeleton containing epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, triphenylmethane Type epoxy resin, aliphatic epoxy resin, triglycidyl isocyanurate and the like can be used. These may be used alone or in combination of two or more.

  By using a liquid epoxy resin at room temperature as described above, reliability such as reflow heat resistance can be improved.

  Moreover, the glass transition temperature (Tg) which affects the viscosity which influences workability | operativity, and the curvature after hardening can be appropriately adjusted by using combining an epoxy resin liquid at normal temperature as mentioned above suitably.

  In particular, bisphenol-type epoxy resins and hydrogenated bisphenol-type epoxy resins are preferred as epoxy resins that are liquid at room temperature. By using these, it is possible to lower the viscosity of the liquid epoxy resin composition for electronic parts, and the Tg of the cured product can be adjusted to an appropriate range, and the adhesiveness of the cured product is good. Can be maintained. The epoxy equivalent of the bisphenol type epoxy resin and the hydrogenated bisphenol type epoxy resin is preferably 150 to 200.

  Moreover, as long as the whole liquid epoxy resin composition for electronic components becomes liquid at normal temperature, you may use together an epoxy resin solid at normal temperature.

  In consideration of the reliability of an electronic device such as a semiconductor device, it is desirable to use an epoxy resin that contains as few impurities as possible, such as Na ions, Cl ions, and Br ions.

  The liquid epoxy resin composition for electronic parts of the present invention is blended with an epoxy resin curing agent. As a curing agent for the epoxy resin, for example, a phenol-based curing agent, an acid anhydride-based curing agent, an amine-based curing agent, or the like can be used.

  Among these, considering the chemical resistance, a phenolic curing agent is preferable. Since the phenolic curing agent does not cause hydrolysis of the cured product, the moisture resistance is improved. For example, in the case of a wafer level CSP, the reinforcing effect of the post electrode protruding from the wafer surface is easily maintained. In addition, when the liquid epoxy resin composition for electronic parts is cured in a thinly spread state, the curing agent component may volatilize and cause curing failure, but the phenolic curing agent suppresses vaporization. Can do.

  As a phenol type hardening | curing agent, the compound which has multiple phenolic hydroxyl groups in 1 molecule, especially a liquid thing can be used. For example, novolak type phenol resins such as phenol novolak and cresol novolak, bisphenols, aralkyl type phenol resins such as phenol aralkyl resin, naphthol aralkyl resin, dicyclopentadiene type phenol novolak resin, dicyclopentadiene type naphthol novolak resin, etc. A dicyclopentadiene type phenol resin, a terpene-modified phenol resin, or the like can be used. These may be used alone or in combination of two or more.

  When the phenolic curing agent as described above is used, the cured product has excellent adhesion and high sealing performance can be realized.

  As the phenolic curing agent, a compound having an allylated phenol structure can be particularly preferably used. A compound having an allylated phenol structure is a compound typified by an allylated phenol novolak, but has excellent adhesiveness of a cured product, can realize high sealing performance, and further has a viscosity of a liquid epoxy resin composition for electronic components. Can be lowered.

  As the allylated phenol novolak, for example, a compound in which 2 to 4 structural units of the following formula are bonded can be used.

  As the acid anhydride-based curing agent, an acid anhydride-based curing agent that is liquid at room temperature is preferable in consideration of improving the workability by lowering the viscosity of the liquid epoxy resin composition for electronic components. Examples of the acid anhydride curing agent that is liquid at room temperature include phthalic anhydride compounds such as methyltetrahydrophthalic anhydride and methylhexahydrophthalic anhydride, methylnadic acid anhydride, dodecenyl succinic anhydride, and the like. . As the amine curing agent, for example, a liquid aromatic amine can be used.

  Although content of the hardening | curing agent in the liquid epoxy resin composition for electronic components is not specifically limited, The ratio (hardening agent / epoxy resin) with respect to an epoxy resin liquid at normal temperature will be 0.6-1.4 by an equivalent ratio. A range is preferred. When the content of the curing agent is within such a range, the curability, the strength of the cured product, and the adhesion can be improved.

  The liquid epoxy resin composition for electronic parts of the present invention is blended with an epoxy resin curing accelerator. As the curing accelerator for the epoxy resin, it is preferable to use a latent curing accelerator. Although the latent curing accelerator is highly reactive in liquid epoxy resin compositions for electronic parts in a certain temperature range when heated, it is excellent in a lower temperature range, generally room temperature or lower temperature range. It has a high storage stability.

  As the curing accelerator, for example, an imidazole compound, a tertiary amine compound, an organic phosphorus compound, a quaternary ammonium compound, or the like can be used.

  Examples of the imidazole compound include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl- 4-methylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl- 2-phenolimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazolium trimellitate, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2 , 4-Diamino-6- [2'-methylimidazolyl- (1 ')]-ethyl-striazine, 2,4-diamino-6- (2'-undecylimidazolyl) -ethyl-s-triazine, 2, 4-Diamino-6- [2'-ethyl-4-methylimidazolyl- (1 ')]-ethyl-s-triazine, 2,4-diamino-6- [2'-methylimidazolyl- (1')]- Ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-methylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxydimethylimidazole, 2-phenyl-4-methyl-5- Hydroxymethylimidazole, 1-cyanoethyl-2-phenyl-4,5-di (2-cyanoethoxy) methylimidazole, etc. can be used. That.

  An imidazole-based microcapsule-type latent catalyst (microencapsulated imidazole) can also be used. Here, the imidazole-based microcapsule-type latent catalyst is obtained by coating a compound having an imidazole skeleton as a core and coating the periphery of the core with a thermosetting resin such as a phenol resin, a melamine resin, or an epoxy resin. It refers to fine sphere particles.

  As the tertiary amine compound, for example, 1,8-diazabicyclo (5,4,0) -7-undecene (DBU) can be used. Also, amine adduct particles can be used.

  As the organic phosphorus compound, for example, phosphines such as triphenylphosphine, diphenylphosphine, and tributylphosphine can be used. As the quaternary ammonium compound, for example, tetramethylammonium phosphonium salt, teratobutylammonium salt and the like can be used.

  Among these, imidazole compounds and tertiary amine compounds are preferred as epoxy resin curing accelerators. These suppress pot life reduction and are suitable for making the liquid epoxy resin composition for electronic parts into a one-pack type.

  As for content of a hardening accelerator, 0.1-5.0 mass parts is preferable with respect to a total of 100 mass parts of an epoxy resin and a hardening | curing agent. By setting the content of the curing accelerator within such a range, the gelation time is not delayed and it is possible to suppress the progress of curing too quickly.

  The liquid epoxy resin composition for electronic parts of the present invention has a hydrosilylation reaction product of a room temperature curable two-component addition reaction curable silicone rubber composition obtained by mixing two components of a main component and a curing agent component. Is blended.

  The room temperature curable two-component addition reaction curable silicone rubber composition includes a main component containing a diorganopolysiloxane having at least two alkenyl groups on average in one molecule, and at least two on average in one molecule. A two-component type with a curing agent component containing an organohydrogenpolysiloxane having a silicon atom-bonded hydrogen atom can be used. The silicone rubber composition contains a curing accelerator for hydrosilylation reaction.

  The diorganopolysiloxane having at least two alkenyl groups on average in one molecule constitutes the main component of the silicone rubber composition. Examples of the alkenyl group in the diorganopolysiloxane include a vinyl group, an allyl group, a butenyl group, a pentenyl group, a hexenyl group, and a heptenyl group. Among these, a vinyl group is preferable.

  Examples of the organic group bonded to the silicon atom other than the alkenyl group in the diorganopolysiloxane include, for example, an unsubstituted or halogen-substituted monovalent group having 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, excluding an aliphatic unsaturated bond. A hydrocarbon group etc. can be mentioned. Specifically, for example, alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, isopropyl group, isobutyl group, tert-butyl group, cyclohexyl group; phenyl group, tolyl group, xylyl group Aryl groups such as groups; halogenated alkyl groups such as 3-chloropropyl group and 3,3,3-trifluoropropyl group. Of these, a methyl group and a phenyl group are preferable.

  The molecular structure of the diorganopolysiloxane is generally a linear structure in which the main chain is composed of repeating diorganosiloxane units and both ends of the molecular chain are blocked with triorganosiloxy groups. A part of the molecular chain may be somewhat branched as long as the effect is not impaired.

  The viscosity of the diorganopolysiloxane at 25 ° C. is not particularly limited, but is preferably 100 to 1,000,000 mPa · s, more preferably 100 to 500,000 mPa · s as measured by a rotational viscometer.

  Examples of such diorganopolysiloxane include dimethylpolysiloxane blocked with dimethylvinylsiloxy group at both ends of the molecular chain, dimethylsiloxane / methylvinylsiloxane copolymer blocked with dimethylvinylsiloxy group at both ends of the molecular chain, and trimethylsiloxy at both ends of the molecular chain. Block-capped dimethylsiloxane / methylvinylsiloxane copolymers, and some or all of the methyl groups of these diorganopolysiloxanes: alkyl groups such as ethyl and propyl groups; aryl groups such as phenyl and tolyl groups; Diorganopolysiloxane substituted with halogenated alkyl groups such as 1,3-trifluoropropyl group, and diorganopolysiloxane wherein a part or all of vinyl groups of these diorganopolysiloxanes are substituted with alkenyl groups such as allyl group and propenyl group Use polysiloxane, etc. It can be. These may be used alone or in combination of two or more.

  An organohydrogenpolysiloxane having an average of at least two silicon-bonded hydrogen atoms in one molecule constitutes the curing agent component of the silicone rubber composition. This organohydrogenpolysiloxane has an average of 2 or more (usually about 2 to 300), preferably 3 or more (for example, about 3 to 200) silicon-bonded hydrogen atoms (SiH groups) in one molecule. .

  The molecular structure of the organohydrogenpolysiloxane is not particularly limited, and may be any of linear, branched, cyclic, and three-dimensional network resinous materials, for example.

  The organic group bonded to the silicon atom in the organohydrogenpolysiloxane is, for example, an unsubstituted or halogen-substituted monovalent carbon atom having 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, excluding aliphatic unsaturated bonds. A hydrogen group etc. can be mentioned. Specifically, for example, alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, isopropyl group, isobutyl group, tert-butyl group, cyclohexyl group; phenyl group, tolyl group, xylyl group An aryl group such as a group; an aralkyl group such as a benzyl group and a phenethyl group; and a halogenated alkyl group such as a 3-chloropropyl group and a 3,3,3-trifluoropropyl group. Of these, a methyl group is preferable.

  The viscosity of such organohydrogenpolysiloxane at 25 ° C. is not limited, but is preferably 0.5 to 1,000,000 mPa · s, more preferably 1 to 100,000 mPa · s. The organohydrogenpolysiloxane preferably has 2 to 500 silicon atoms (or polymerization degree) in one molecule, more preferably 3 to 300 silicon atoms.

Examples of such organohydrogenpolysiloxane include 1,1,3,3-tetramethyldisiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, methylhydrogencyclopolysiloxane, and methylhydrogen. Siloxane / dimethylsiloxane cyclic copolymer, tris (dimethylhydrogensiloxy) methylsilane, tris (dimethylhydrogensiloxy) phenylsilane, dimethylhydrogensiloxy group-blocked dimethylsiloxane / methylhydrogensiloxane copolymer, molecule Dimethylhydrogensiloxy group-blocked methylhydrogenpolysiloxane at both ends of the chain, Trimethylsiloxy group-blocked methylhydrogenpolysiloxane at both ends of the molecular chain, Dimethylhydro at both ends of the molecular chain Benzyloxy-blocked dimethylpolysiloxane, dimethylhydrogensiloxy-blocked dimethylsiloxane / diphenylsiloxane copolymer at both ends, trimethylsiloxy-blocked dimethylsiloxane / methylhydrogensiloxane copolymer at both ends, trimethyl at both ends Siloxy group-blocked dimethylsiloxane / diphenylsiloxane / methylhydrogensiloxane copolymer, molecular chain both ends dimethylhydrogensiloxy group-blocked dimethylsiloxane / methylhydrogensiloxane copolymer, H (CH ₃ ) ₂ SiO _1/2 unit and Copolymers with SiO ₂ units, copolymers of H (CH ₃ ) ₂ SiO _1/2 units, (CH ₃ ) ₃ SiO _1/2 units, and SiO ₂ units can be used. These may be used alone or in combination of two or more.

  In the silicone rubber composition, the content of the organohydrogenpolysiloxane is such that the ratio of the number of moles of hydrogen atoms bonded to silicon atoms in the organohydrogenpolysiloxane to the alkenyl groups in the diorganopolysiloxane is 0.01-20. The amount within the range is preferable, the amount within the range of 0.1 to 10 is more preferable, and the amount within the range of 0.1 to 5 is more preferable. Within such a range, the silicone rubber composition can be sufficiently cured and the physical properties of the resulting silicone rubber can be improved.

  The silicone rubber composition contains a curing accelerator for hydrosilylation reaction for accelerating the curing of the silicone rubber composition. As the curing accelerator for hydrosilylation reaction, for example, a platinum catalyst, a rhodium catalyst, an iridium catalyst, a palladium catalyst, a ruthenium catalyst, or the like can be used. Of these, platinum-based catalysts are preferred.

Specific examples of the curing accelerator for hydrosilylation reaction include platinum fine powder, platinum black, chloroplatinic acid, platinum tetrachloride, alcohol-modified chloroplatinic acid, platinum olefin complexes, platinum alkenylsiloxane complexes. , Platinum carbonyl complexes, platinum-based catalysts such as thermoplastic organic resin powders such as methyl methacrylate resin, polycarbonate resin, polystyrene resin and silicone resin containing these platinum-based catalysts; Formula: [Rh (O ₂ CCH ₃ ) ₂ ] ₂ , Rh (O ₂ CCH ₃ ) ₃ , Rh ₂ (C ₈ H ₁₅ O ₂ ) ₄ , Rh (C ₅ H ₇ O ₂ ) ₃ , Rh (C ₅ H ₇ O ₂ ) (CO) ₂ , Rh ( CO) [Ph ₃ P] (C ₅ H ₇ O ₂ ), RhX ₃ [(R) ₂ S] ₃ , (R ² ₃ P) ₂ Rh (CO) X, (R ² ₃ P) ₂ Rh (CO _{) H, Rh 2 X 2 Y} 4, H a Rh b (En) c Cl d Or a rhodium-based catalyst represented by Rh [O (CO) R] _3-n (OH) _n (wherein X represents a hydrogen atom, a chlorine atom, a bromine atom, or an iodine atom, Y represents a methyl group, An alkyl group such as an ethyl group, CO, C ₈ H ₁₄ , or 0.5 C ₈ H ₁₂ ; R represents an alkyl group, a cycloalkyl group, or an aryl group; R ² represents an alkyl group, an aryl group, an alkyloxy group, A group, or an aryloxy group, En represents an olefin, a represents 0 or 1, b represents 1 or 2, c represents an integer of 1 to 4, d represents 2, 3, or 4; N represents 0 or 1.); Formula: Ir (OOCCH ₃ ) ₃ , Ir (C ₅ H ₇ O ₂ ) ₃ , [Ir (Z) (En) ₂ ] ₂ , or [Ir (Z) (Dien)] Iridium catalyst represented by ₂ (wherein Z is a chlorine atom, a bromine atom, An iodine atom or an alkoxy group, En represents an olefin, Dien represents cyclooctadiene), and the like.

  The content of the curing accelerator for hydrosilylation reaction in the silicone rubber composition is not particularly limited as long as it is an amount sufficient to accelerate the curing of the silicone rubber composition, but is 1,000,000 parts by mass of diorganopolysiloxane. On the other hand, the quantity in which the metal atom in the curing agent for hydrosilylation reaction is in the range of 0.01 to 1,000 parts by mass is preferred, and the quantity in the range of 0.1 to 500 parts by mass is more preferred.

  Silicone rubber compositions usually store a main component containing a diorganopolysiloxane and a curing accelerator for hydrosilylation reaction separately from a curing agent component containing an organohydrogenpolysiloxane, and mix these during use. It is prepared as a two-part type. The curing agent component may contain diorganopolysiloxane in addition to the organohydrogenpolysiloxane.

  The silicone rubber composition can be blended with various additives as required within a range not impairing the effects of the present invention. Examples of such additives include fillers, pigments, dyes, antioxidants, and organic solvents.

  Each said component of a silicone rubber composition can be manufactured by a well-known method. Moreover, what is marketed as a two-component addition reaction curable silicone rubber composition of room temperature curable type (RTV) can be used for the silicone rubber composition.

  The hydrosilylation reaction product blended in the liquid epoxy resin composition for electronic parts of the present invention is obtained by mixing the main ingredient component and the curing agent component to form a silicone rubber composition and proceeding the hydrosilylation reaction. is there.

  Curing by the hydrosilylation reaction is preferably performed at 80 to 200 ° C, more preferably 80 to 150 ° C. The reaction time is preferably 0.1 to 4 hours.

  Moreover, the compounding ratio of the main ingredient component and the curing agent component is preferably in the range of 100: 70 to 100: 150 by mass ratio. By making a compounding ratio into such a range, the chemical resistance of the hardened | cured material of the liquid epoxy resin composition for electronic components can be improved.

  The content of the hydrosilylation reaction product in the liquid epoxy resin composition for electronic parts is preferably 30 to 60% by mass with respect to the total amount of the epoxy resin that is liquid at room temperature and the epoxy resin curing agent. When the content is within this range, the storage stability can be enhanced, and curing shrinkage can be particularly suppressed. Moreover, the heat resistance and adhesiveness of the cured product can be improved.

  The liquid epoxy resin composition for electronic parts of the present invention can further contain other components within a range not impairing the effects of the present invention. As such other components, for example, a filler, a colorant, a silane coupling agent, an antifoaming agent, and the like can be used.

  As the filler, for example, silica, alumina, aluminum nitride, boron nitride, silicon nitride, silicon carbide, calcium carbonate, or the like can be used. When spherical amorphous silica having a maximum particle size of 1 to 40 μm is used, the liquid epoxy resin composition for electronic parts can be filled into a narrow gap by utilizing capillary action without significantly increasing the viscosity.

  As the colorant, for example, carbon black, organic dyes, organic pigments, titanium oxide, red lead, bengara and the like can be used.

  Examples of the silane coupling agent include epoxy silanes such as γ-glycidoxypropyltrimethoxysilane and γ-glycidoxypropyltriethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ -Aminosilane such as ureidopropyltriethoxysilane, mercaptosilane such as γ-mercaptopropyltrimethoxysilane, vinylsilane and the like can be used.

  The liquid epoxy resin composition for electronic parts of the present invention is blended with each of the above components, and stirred, dissolved, mixed, dispersed while performing heat treatment or cooling treatment as necessary, and defoamed as necessary. Can be prepared. In addition, a disper, a planetary mixer, a ball mill, a bead mill, three rolls, etc. can be used in combination in the steps such as stirring, dissolution, mixing and dispersion.

  The liquid epoxy resin composition for electronic parts of the present invention has good storage stability and can be used in a one-pack type. And since the cured product has chemical resistance against methanol, IPA (isopropanol), MEK (methyl ethyl ketone), NMP (N-methylpyrrolidone), hydrochloric acid, sulfuric acid, etc., it is suitable for applications that require chemical resistance. It is. Moreover, the stress of the hardened layer by hardening shrinkage | contraction can also be suppressed by mix | blending the hydrosilylation reaction product of room temperature hardening type 2 liquid addition reaction hardening type silicone rubber composition.

  The liquid epoxy resin composition for electronic parts of the present invention can be used for sealing, adhesion, protection and the like of electronic parts such as semiconductor elements such as IC and LSI. Specifically, an electronic device such as a semiconductor device including an electronic component and a cured layer of a liquid epoxy resin composition for electronic components formed on at least a part of the surface of the electronic component is configured, and the cured layer is It can function as a sealing material, an adhesive layer, or a protective layer.

  The liquid epoxy resin composition for electronic parts according to the present invention can be used, for example, in applications that require less warping after curing, specifically, WL (wafer level) or WS including a process of sealing and curing the entire wafer. (Wafer scale) CSP, underfilled flip-chip connected CSP, BGA semiconductor device, printer thermal transfer or thermal head portion (thermal head) and the like.

  As a method of applying the liquid epoxy resin composition for electronic parts to the surface of various members, in addition to vacuum printing, atmospheric pressure screen printing, application by a spin coater, or a method by dispensing, a molding method by a mold, or the like is used. Can do.

  However, in the spin coating method (coating with a spin coater), the viscosity is preferably suppressed to 10 Pa · s or less by increasing the amount of the solvent added. In the molding method using the mold, conversely, if a solvent is added, voids are formed in the cured product. Therefore, it is preferable to suppress the viscosity to about 200 Pa · s without containing a solvent.

  The best method for avoiding inclusion of voids in the resin layer is a method using a vacuum printer. In this case, it is necessary to ensure continuous printability by shifting the boiling point of the solvent to the high boiling point side.

  Moreover, when using the method using printing, it is preferable that the viscosity of the liquid epoxy resin composition for electronic components is 200 Pa.s or less. If it exceeds 200 Pa · s, the transfer of the resin to the printing object may not be sufficient, and it may be necessary to repeat squeezing. Moreover, even if it can be suppressed to 200 Pa · s or less by adding a solvent, if the addition amount exceeds 10% by mass, the solvent remains after curing and the cured product becomes brittle, or a large amount of solvent volatilizes. May cause voids in the cured product.

  In order to reduce this void due to solvent volatilization during curing, it is common to add multiple types of solvents with different boiling points and gradually evaporate in order from the low boiling point solvent, but this is not particularly the case with methods using vacuum printing. . The low boiling point solvent volatilizes during printing, and the viscosity increases during printing, so that quality variations are likely to occur when printing is performed continuously. Further, if the boiling point of the solvent is 50 to 100 ° C. higher than the upper limit of the curing temperature, rapid volatilization is suppressed, and since the solvent is gradually volatilized, it is difficult to form voids, and there is no need to change the time required for curing.

  In order to manufacture WL-CSP using the liquid epoxy resin composition for electronic parts of the present invention, first, a resin layer is penetrated into a pad portion on a wafer at a position where a bump is formed when becoming a CSP. Form the metal as a post that will do.

  As a method for forming the post, specifically, a flux is printed on the pad portion, a solder ball is placed thereon using a metal mask and reflowed, or a solder paste is printed on the pad portion and reflowed. Alternatively, there is a method of growing a metal such as copper on the pad portion by a plating method.

  Next, the liquid epoxy resin composition for electronic parts of the present invention is printed on a wafer on which a metal as a post is formed, and is cured by heating. Printing may be atmospheric printing or vacuum printing. In the case of normal pressure printing, it is preferable to carry out a treatment for removing voids in the composition by placing it under reduced pressure after printing.

  The heat curing may be performed under normal pressure or under pressure, but the voids in the cured product can be reduced under pressure. Moreover, after curing the first stage curing at 80 to 120 ° C. for 30 minutes to 2 hours, the second stage curing is applied at 150 to 170 ° C. for 1 to 6 hours. Can do. When a phenol-based curing agent is used, in addition to such two-step curing, one-step curing at 100 to 170 ° C. for 30 minutes to 6 hours can also be applied.

  Next, the wafer after curing of the liquid epoxy resin composition for electronic components is polished from the resin layer side, and the height of the post and the resin layer is made uniform. If necessary, a step of polishing the back surface of the wafer to reduce the total thickness may be employed. In addition, the liquid epoxy resin composition for electronic parts of the present invention and other resins may be applied and cured on the back surface of the wafer in order to protect the back surface of the semiconductor element and improve the marking property.

  Next, CSP bumps are formed using solder or the like. Specifically, a flux is printed on the end face of the post exposed on the surface of the resin layer, a solder ball is placed on the post using a metal mask, and reflow is performed, or a solder paste is printed on the post and reflowed. The method etc. can be mentioned.

  When the wafer thus obtained is separated into pieces by dicing, a CSP having metal electrodes composed of posts and bumps can be obtained. This CSP uses a liquid epoxy resin composition for electronic parts with good adhesion and appropriate linear expansion coefficient, and has low warpage and low internal stress, and is excellent in temperature cycleability and moisture resistance reliability.

  Further, as an electronic device of the present invention, a semiconductor device by flip chip mounting can be manufactured by sealing between a semiconductor element and a circuit board (interposer) with a liquid epoxy resin composition for electronic components.

  For example, a bare chip semiconductor element is connected to a pad electrode on an upper surface portion of an interposer such as an FR grade or ceramic substrate formed with a circuit via a bump. For example, solder bump bonding between an electronic component such as a surface mounting IC chip having a solder bump and an electronic component mounting substrate is performed by a reflow apparatus using far infrared rays.

  Next, a liquid epoxy resin composition for electronic parts is applied and filled in the gaps between the bumps. For example, application and filling can be performed by potting sealing by discharging from a dispenser, underfill sealing, pressure sealing that performs pressurization and heating simultaneously, sealing by printing using a mask or a screen, and the like.

  And after completion | finish of filling, the liquid epoxy resin composition for electronic components with which it filled is heat-hardened with a hot air circulation dryer, a tunnel furnace, etc., and the clearance gap between a semiconductor element and an interposer is sealed. Thereby, a semiconductor device by flip chip mounting can be manufactured. The conditions for heat-curing the liquid epoxy resin composition for electronic parts are not particularly limited, and can be, for example, 100 to 170 ° C. and 0.5 to 5 hours.

  EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

  The liquid epoxy resin compositions for electronic parts of Examples and Comparative Examples were prepared by blending each component in the blending amounts (parts by mass) shown in Table 1 and stirring, dissolving, mixing, and dispersing according to a conventional method.

  As the blending components shown in Table 1, the following were used.

(Epoxy resin)
Bisphenol F-type epoxy resin that is liquid at normal temperature, “Epicoat 806” manufactured by Japan Epoxy Resin Co., Ltd., epoxy equivalent 165
(Epoxy resin curing agent)
Phenol-based curing agent, allylated phenol novolak, “MEH8000-4L” manufactured by Meiwa Kasei Kogyo Co., Ltd., hydroxyl equivalent 141
(Epoxy resin curing accelerator)
2-Ethyl-4-methylimidazole, “CURESOL 2E4MZ” manufactured by Shikoku Kasei Kogyo Co., Ltd.
(Two-component addition reaction curable silicone rubber composition)
A room temperature curable two-component addition reaction curable silicone rubber composition (manufactured by Shin-Etsu Chemical Co., Ltd., main component “KE-1031A”, hardener component “KE-1031B”) was used. A curing agent component of 50 to 200 parts by mass was added to 100 parts by mass of the main component heated to 80 to 150 ° C., and the reaction was stirred for 90 to 120 minutes to obtain a hydrosilylation reaction product. The silicone rubber composition a is 50 parts by mass of the curing agent component, the silicone rubber composition b is 70 parts by mass of the curing agent component, the silicone rubber composition c is 150 parts by mass of the curing agent component, and the silicone rubber composition is 100 parts by mass of the main component. The thing d added 200 mass parts of hardening | curing agent components.

  The following evaluation was performed using the thus obtained liquid epoxy resin compositions for electronic parts of Examples and Comparative Examples.

[Storage stability]
Using a B8H type viscometer (manufactured by Tokyo Keiki Co., Ltd.), the viscosity immediately after preparing the liquid epoxy resin composition for electronic parts (initial viscosity) and the viscosity after standing at room temperature (25 ° C.) for 24 hours are measured. And
The viscosity increase rate was calculated by the following formula.
(Viscosity increase rate) = (viscosity after standing for 24 hours) / (initial viscosity)

The storage stability was evaluated according to the following criteria based on the rate of increase in viscosity.
○: Viscosity increase rate less than 2 times Δ: Viscosity increase rate 2 times or more and less than 2.5 times

[Curing shrinkage]
The liquid epoxy resin composition for electronic parts was molded into a disk shape of φ50 × 3 mm at 100 ° C. for 1 hour. The initial mass of the obtained disk and the mass in water were measured, the cure shrinkage was calculated, and evaluated according to the following criteria.
○: Curing shrinkage rate less than 2.0% Δ: Curing shrinkage rate 2.0% or more and less than 2.5% ×: Curing shrinkage rate 2.5% or more

[chemical resistance]
A disk was formed in the same manner as the measurement of the curing shrinkage rate, immersed in NMP, and allowed to stand at room temperature for 336 hours. The mass change rate after standing was calculated and evaluated according to the following criteria.
○: Mass change rate −1.0% or more and less than 1.0% Δ: Mass change rate −2.0% or more and less than −1.0% or 1.0% or more and less than 2.0%

The evaluation results are shown in Table 1.

  From Table 1, room temperature curable two-component addition reaction curing obtained by mixing two liquids of epoxy resin, epoxy resin curing agent, epoxy resin curing accelerator, and main component and curing agent component at room temperature. Examples 1 to 10 in which a liquid epoxy resin composition for an electronic component was prepared by blending a hydrosilylation reaction product of a type silicone rubber composition were cured as compared with Comparative Example 1 in which no hydrosilylation reaction product was blended The chemical resistance and storage stability of the product were generally good, and curing shrinkage was also suppressed.

  In particular, in Examples 1 to 8 in which the mixing ratio of the main ingredient component and the curing agent component is in the range of 100: 70 to 100: 150, the chemical resistance of the cured product of the liquid epoxy resin composition for electronic parts can be improved. did it.

  Furthermore, the content of the hydrosilylation reaction product in the liquid epoxy resin composition for electronic components was set in the range of 30 to 60% by mass with respect to the total amount of the epoxy resin liquid at room temperature and the epoxy resin curing agent. In Examples 1 to 4, the storage stability could be increased, and curing shrinkage could be particularly suppressed.

Claims (4)

  Room temperature curable two-component addition reaction curable silicone rubber composition obtained by mixing two liquids of epoxy resin, epoxy resin curing agent, epoxy resin curing accelerator, and main component and curing agent component at room temperature A liquid epoxy resin composition for electronic parts, comprising a product hydrosilylation reaction product.   The content of the hydrosilylation reaction product of the two-component addition reaction curable silicone rubber composition is 30 to 60% by mass with respect to the total amount of the epoxy resin that is liquid at normal temperature and the epoxy resin curing agent. The liquid epoxy resin composition for electronic parts according to claim 1.   The liquid epoxy resin composition for electronic parts according to claim 1 or 2, wherein the epoxy resin curing agent is a phenolic curing agent.   An electronic device comprising: an electronic component; and a cured layer of the liquid epoxy resin composition for an electronic component according to any one of claims 1 to 3 formed on at least a part of a surface of the electronic component. .