JP5573028B2 - Liquid resin composition and semiconductor device produced using liquid resin composition - Google Patents

Description

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

  The problem of heat generated during the operation of semiconductor products has become more prominent with the increase in capacity, high-speed processing, and fine wiring of semiconductor products. So-called thermal management, which releases heat from semiconductor products, is an increasingly important issue. It has become to. For this reason, a method of attaching a heat dissipating member such as a heat spreader or a heat sink to a semiconductor product is generally adopted, but a material having a higher thermal conductivity has been desired. On the other hand, depending on the form of the semiconductor product, in order to make thermal management more efficient, the heat spreader is bonded to the semiconductor element itself or the die pad part of the lead frame to which the semiconductor element is bonded, or the die pad part is exposed on the package surface. For example, a method for providing a function as a heat radiating plate (for example, Patent Document 1) is adopted. Further, it may be bonded to an organic substrate having a heat dissipation mechanism such as a thermal via. Also in this case, high thermal conductivity is required for the material for bonding the semiconductor element.

As described above, high thermal conductivity is required for materials (such as die attach paste and heat dissipation member bonding material) used for bonding each member of a semiconductor device. It is necessary to withstand this reflow treatment, and there are many cases where adhesion of a large area is required, and it is also necessary to have low stress properties in order to suppress the occurrence of warpage due to the difference in thermal expansion coefficient between the constituent members.

  Here, it is usually necessary to disperse the metal filler such as silver powder and copper powder or ceramic filler such as aluminum nitride and boron nitride with a high content in the organic binder as a filler in the high thermal conductive adhesive, When the viscosity of the binder is high, the viscosity of the high heat conductive adhesive is also high. For this reason, it is necessary to add a large amount of solvent or reactive diluent (for example, Patent Document 2). However, when a large amount of solvent or reactive diluent is contained, sedimentation of the filler is likely to occur during storage, and the coating stability. It was difficult to obtain a stable thickness of the adhesive layer.

JP 2006-86273 A

JP 2006-73811 A

  The present invention relates to a liquid resin composition having low resin composition layer thickness stability during storage, excellent thickness stability of the resin composition layer, low elastic modulus and sufficient low stress, and the die attach for semiconductors. It is to provide a semiconductor device having excellent reliability by being used as a paste or a material for adhering heat dissipation members.

The liquid resin composition according to the present invention is a liquid resin composition containing a compound (A) having one acrylic group and a filler (B), wherein the transmittance of the compound (A) at 50 ° C. is Ta. When the transmittance at 0 ° C. is Tb, Ta and Tb satisfy the following conditional expression 1.
[Conditional Formula 1: (Ta−Tb) /Ta≧0.1]

  The liquid resin composition according to the present invention may further include a compound (C) having two or more functional groups capable of reacting with the compound (A) in one molecule.

In the liquid resin composition according to the present invention, the compound (A) may be represented by the general formula (1).
R ¹ : hydrogen, a hydrocarbon group having 1 to 6 carbon atoms,
R ² : cyclohexylene group,
R ³ : hydrogen, a hydrocarbon group having 1 to 6 carbon atoms.

  The semiconductor device according to the present invention is manufactured using the liquid resin composition as a die attach material or a heat dissipation member bonding material.

  The liquid resin composition of the present invention is excellent in thickness stability of the resin composition layer because the filler content is high and the coating workability is excellent, but the sedimentation of the filler during storage is small, as shown in FIG. By using the resin composition as a die attach paste for a semiconductor or a material for adhering a heat dissipation member, it is possible to provide a semiconductor device having excellent reliability.

It is a schematic sectional drawing which shows an example of the semiconductor device produced using the liquid resin composition which concerns on this invention as a die attach paste.

The present invention includes a compound (A) having one acrylic group and a filler (B), wherein the compound (A) has a transmittance Ta at 50 ° C. and a transmittance at 0 ° C. as Tb (Ta− A liquid resin composition having a value of Tb) / Ta of 0.1 or more, wherein the settling of the filler (B) during storage hardly occurs and the thickness stability of the resin composition layer is improved. The present invention provides a liquid resin composition which is excellent and has a low elastic modulus and high adhesiveness.
Hereinafter, the present invention will be described in detail.

  In the present invention, when the transmittance at 50 ° C. is Ta and the transmittance at 0 ° C. is Tb, the value of (Ta−Tb) / Ta is 0.1 or more. Use (A). In the present specification, an acryl group including a functional group having a substituent at the α-position and / or β-position of the acryloyl group is used.

In the present invention, the transmittance Ta at 50 ° C. of the compound (A) refers to the transmittance measured in a 25 ° C. environment after leaving the compound (A) in a 50 ° C. environment for 168 hours. The transmittance measured in the following procedure.

(Measurement method of transmittance Ta)
The compound (A) was measured by fixing the scale of an Eppendorf pipette (Eppendorf, volume range 0.500 to 10.00 μl) to 3.200 μl, and dropped onto a slide glass (26 mm × 76 mm, soda-lime glass) did. A cover glass (18 mm × 18 mm, soda-lime glass) was placed thereon, and the compound was sandwiched between the slide glass and the cover glass (preparation). This was placed on a 10 cm × 20 cm × 5 cm brass metal block, and the metal block was placed in a constant temperature bath at 50 ° C. and allowed to stand for 168 hours. After leaving, the slide glass with the metal block was taken out and moved to the measuring instrument. The preparation was set in a measuring instrument within 5 minutes to 7 minutes after removal, and the transmittance was measured within 5 minutes to 7 minutes after setting. The apparatus used for this measurement is a spectrophotometer (Shimadzu UV-visible spectrophotometer UV-160A), the measurement conditions are set to room temperature 25 ± 5 ° C., wavelength range 360 to 800 nm, and the transmittance value at 450 nm is defined as transmittance Ta. To do. In addition, as a blank, what put the cover glass on the slide glass in the state which does not pinch | interpose a compound (A) was used.

In the present invention, the transmittance Tb at 0 ° C. of the compound (A) means the transmittance measured in a 25 ° C. environment after leaving the compound (A) in a 0 ° C. environment for 168 hours. Means the transmittance measured in the following procedure.

(Measurement method of transmittance Tb)
According to the above method, the sample whose transmittance was measured after being left in a 50 ° C. environment for 168 hours was placed on the metal block again, placed in a thermostat at 0 ° C. together with the metal block, and left for 168 hours. After leaving in the 0 ° C. environment, the transmittance was measured in the same manner as the above Ta measurement, and the transmittance value at 450 nm was defined as Tb.

  Usually, the compound (A) having one acrylic group is generally used as a reactive diluent because of its low viscosity, but at the same time, due to its low viscosity, sedimentation of the filler (B) occurs during storage of the liquid resin composition. It also has the disadvantage of being easy. Therefore, in the present invention, the compound (A) having one acrylic group is used. When the transmittance at 50 ° C. is Ta and the transmittance at 0 ° C. is Tb, the value of (Ta−Tb) / Ta is 0.00. It is preferably 1 or more, more preferably 0.2 or more, and particularly preferably 0.25 or more. If the value of (Ta-Tb) / Ta is 0.1 or more, the liquid resin composition itself solidifies or thickens at 0 ° C. or less, which is the storage temperature of the resin composition. Thereby, it becomes possible to suppress the sedimentation of the filler, and a stable quality can be obtained. When the value of (Ta-Tb) / Ta is less than 0.1, it is not preferable because the viscosity of the liquid resin composition cannot be sufficiently reduced or the filler (B) is likely to settle at a low temperature. .

  Examples of such a compound include alkoxypolyalkylene glycol acrylate or alkoxypolyalkylene glycol methacrylate such as methoxypolyethylene glycol acrylate, methoxypolyethylene glycol methacrylate, methoxypropylene glycol acrylate, and methoxypropylene glycol methacrylate, and a value of (Ta-Tb) / Ta is 0. .1 or more, alkyl acrylate or alkyl methacrylate such as cetyl acrylate, cetyl methacrylate, stearyl acrylate, stearyl methacrylate, and (Ta-Tb) / Ta value of 0.1 or more, and the following formula (1) The compounds shown, specifically tertiary butyl cyclohexyl acrylate, tertiary butyl cyclohexyl Substituted cyclohexyl acrylates such as sills methacrylate, or the value of the replacement cyclohexyl methacrylate (Ta-Tb) / Ta can be mentioned those is 0.1 or more, it may be used in combination of plural kinds in combination.

R ¹ : hydrogen, a hydrocarbon group having 1 to 6 carbon atoms,
R ² : cyclohexylene group,

R ³ : hydrogen, a hydrocarbon group having 1 to 6 carbon atoms.

  Among these, a particularly preferred compound is a substituted cyclohexyl acrylate or substituted cyclohexyl methacrylate having a (Ta-Tb) / Ta value of 0.1 or more, and particularly preferred are tertiary butyl cyclohexyl acrylate and tertiary butyl cyclohexyl methacrylate. And the value of (Ta-Tb) / Ta is 0.1 or more. This is because when these compounds are used, it is possible to suppress sedimentation of the filler (B) at 0 ° C. or lower and to effectively reduce the viscosity at room temperature.

  The filler (B) used in the present invention is not particularly limited, but preferably has a single thermal conductivity of 10 W / mK or more in order to increase the thermal conductivity of the cured resin composition. Examples of such fillers include metal powders such as silver powder, gold powder, copper powder, aluminum powder, nickel powder, and palladium powder, and ceramic powders such as alumina powder, titania powder, aluminum nitride powder, and boron nitride powder. . Among these, metal powder having a thermal conductivity of 200 W / mK or more as a single substance is more preferable from the viewpoint of thermal conductivity, and particularly preferable is silver powder, gold powder, copper powder, aluminum powder, or beryllium powder. It is at least one filler selected from the group. Since the filler may discharge the resin composition containing it using a nozzle, the average particle size is preferably 30 μm or less in order to prevent clogging of the nozzle, and is less ionic impurities such as sodium and chlorine. Preferably there is. Among these fillers, silver powder is most preferable from the viewpoint of good thermal conductivity and stability to oxidation.

  Here, the silver powder is a fine powder of pure silver or a silver alloy. Examples of the silver alloy include silver-copper alloy, silver-palladium alloy, silver-tin alloy, silver-zinc alloy, silver-magnesium alloy, silver-nickel alloy containing 50% by weight or more, preferably 70% by weight or more of silver. Can be mentioned. If it is the silver powder normally marketed for electronic materials, reduced powder, atomized powder, etc. can be obtained, and an average particle diameter is 0.5 micrometer or more and 30 micrometers or less as a preferable particle size. A more preferable average particle diameter is 1 μm or more and 10 μm or less. This is because the viscosity of the resin composition becomes too high below the lower limit value, and may cause nozzle clogging at the upper limit value or more, and silver powder other than for electronic materials may have a large amount of ionic impurities. is necessary. If necessary, it can be used in combination with metal powder having an average particle size of 1 μm or less. The shape of the silver powder is not particularly limited, such as flaky or spherical, but is preferably flaky, and the addition amount is usually preferably 70% by weight or more and 95% by weight or less in the resin composition. This is because when the proportion of silver powder is less than the lower limit, the thermal conductivity of the cured product is deteriorated, and when it is more than the upper limit, the viscosity of the liquid resin composition becomes too high and the coating workability may be deteriorated. .

  Further, in the present invention, it is possible to include a compound (C) having two or more functional groups capable of reacting with the compound (A) in one molecule. Examples of the functional group capable of reacting with the compound (A) include an acryl group, an allyl group, a vinyl group, a maleate group, a maleimide group, an epoxy group, and an oxetane group. Among them, preferred functional groups are an acrylic group, an allyl group, a vinyl group, a maleate group, and a maleimide group that can be radically polymerized with the compound (A), and particularly preferred are an acrylic group, an allyl group, and a maleimide group. It is preferable that two or more of these functional groups are contained in one molecule, because when only one functional group is present in one molecule, the crosslink density of the cured product does not increase and the mechanical properties deteriorate. is there. Preferred compounds (C) are exemplified below, but are not limited thereto.

  A compound having two or more acrylic groups capable of reacting with the compound (A) in one molecule is preferably a polyether, polyester, polycarbonate, polyacrylate, polymethacrylate, polybutadiene, or butadiene acrylonitrile copolymer having a molecular weight of 500 to 10,000. It is a compound having an acrylic group as a polymer.

  As a polyether, what a C3-C6 organic group repeated via the ether bond is preferable, and what does not contain an aromatic ring is preferable. It can be obtained by reaction of polyether polyols with acrylic acid or methacrylic acid and their derivatives.

  As the polyester, those in which an organic group having 3 to 6 carbon atoms is repeated via an ester bond are preferable, and those having no aromatic ring are preferable. It can be obtained by reaction of polyester polyols with acrylic acid or methacrylic acid and their derivatives. As a polycarbonate, what a C3-C6 organic group repeated via the carbonate bond is preferable, and the thing which does not contain an aromatic ring is preferable. It can be obtained by reaction of polycarbonate polyol with acrylic acid or methacrylic acid and derivatives thereof.

  The polyacrylate or polymethacrylate is preferably a copolymer of acrylic acid or methacrylic acid and acrylate or methacrylate, or a copolymer of acrylate or methacrylate having a hydroxyl group and acrylate or methacrylate having no polar group. When these copolymers react with carboxy groups, they can be obtained by reacting acrylate or methacrylate having a hydroxyl group, and when reacting with hydroxyl groups, acrylic acid or methacrylic acid and derivatives thereof.

  Polybutadiene can be obtained by reaction of polybutadiene having a carboxy group with an acrylate or methacrylate having a hydroxyl group, reaction of a polybutadiene having a hydroxyl group with acrylic acid or methacrylic acid and derivatives thereof, and maleic anhydride is obtained. It can also be obtained by reaction of the added polybutadiene with an acrylate or methacrylate having a hydroxyl group.

  The butadiene acrylonitrile copolymer can be obtained by a reaction between a butadiene acrylonitrile copolymer having a carboxy group and an acrylate or methacrylate having a hydroxyl group.

  A compound having two or more allyl groups capable of reacting with the compound (A) in one molecule is preferably a polyether, polyester, polycarbonate, polyacrylate, polymethacrylate, polybutadiene, or butadiene acrylonitrile copolymer having a molecular weight of 500 to 10,000. Compounds having an allyl group in the polymer, such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, phthalic acid, tetrahydrophthalic acid, Reaction of diallyl ester compounds obtained by reacting dicarboxylic acids such as hexahydrophthalic acid and their derivatives with allyl alcohol with diols such as ethylene glycol, propylene glycol and tetramethylene glycol It is a thing etc.

  Preferred examples of the compound having two or more maleimide groups capable of reacting with the compound (A) in one molecule include N, N ′-(4,4′-diphenylmethane) bismaleimide and bis (3-ethyl- And bismaleimide compounds such as 5-methyl-4-maleimidophenyl) methane and 2,2-bis [4- (4-maleimidophenoxy) phenyl] propane. More preferred are compounds obtained by reaction of dimer acid diamine and maleic anhydride, and compounds obtained by reaction of maleimidated amino acids such as maleimide acetic acid and maleimide caproic acid with polyols. The maleimidated amino acid is obtained by reacting maleic anhydride with aminoacetic acid or aminocaproic acid. As the polyol, polyether polyol, polyester polyol, polycarbonate polyol, polyacrylate polyol, and polymethacrylate polyol are preferable. Those not containing are particularly preferred. This is because when an aromatic ring is contained, it becomes a solid or high viscosity as a compound having two or more maleimide groups in one molecule, and the elastic modulus when it is a cured product becomes too high.

  Moreover, in order to adjust various properties of the liquid resin composition of the present invention, the following compounds can be used within a range not impairing the effects of the compound (A). For example, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, 2-hydroxybutyl acrylate, 2-hydroxybutyl methacrylate 3-hydroxybutyl acrylate, 3-hydroxybutyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, 1,2-cyclohexanediol monoacrylate, 1,2-cyclohexanediol monomethacrylate, 1,3-cyclohexanediol mono Acrylate, 1,3-cyclohexanediol monomethacrylate, 1,4-cyclohexanediol Acrylate, 1,4-cyclohexanediol monomethacrylate, 1,2-cyclohexanedimethanol monoacrylate, 1,2-cyclohexanedimethanol monomethacrylate, 1,3-cyclohexanedimethanol monoacrylate, 1,3-cyclohexanedimethanol monomethacrylate 1,4-cyclohexanedimethanol monoacrylate, 1,4-cyclohexanedimethanol monomethacrylate, 1,2-cyclohexanediethanol monoacrylate, 1,2-cyclohexanediethanol monomethacrylate, 1,3-cyclohexanediethanol monoacrylate, 1, 3-cyclohexanediethanol monomethacrylate, 1,4-cyclohexanediethanol monoacrylate, 1,4-cyclohex Diethanol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate, glycerol diacrylate, glycerol dimethacrylate, trimethylolpropane monoacrylate, trimethylolpropane monomethacrylate, trimethylolpropane diacrylate, trimethylolpropane dimethacrylate, pentaerythritol monoacrylate, Pentaerythritol monomethacrylate, pentaerythritol diacrylate, pentaerythritol dimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, neopentyl glycol monoacrylate, neopentyl glycol monomethacrylate acrylate or methacrylate having a hydroxyl group And acrylates or methacrylates having a carboxy group obtained by reacting these acrylates or methacrylates having a hydroxyl group with a dicarboxylic acid or a derivative thereof. Examples of dicarboxylic acids that can be used here include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, phthalic acid, and tetrahydrophthalic acid. , Hexahydrophthalic acid and derivatives thereof.

In addition to the above, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-butyl acrylate, n-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, tar butyl acrylate, tar butyl methacrylate, isodecyl acrylate, isodecyl methacrylate, Lauryl acrylate, lauryl methacrylate, tridecyl acrylate, tridecyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, other alkyl acrylates or methacrylates, cyclohexyl acrylate, cyclohexyl methacrylate, tetrahydrofurfuryl acrylate, tetrahydrofurfuryl methacrylate, benzyl acrylate Benzyl methacrylate, phenoxyethyl acrylate, phenoxyethyl methacrylate, isobornyl acrylate, isobornyl methacrylate, glycidyl acrylate, glycidyl methacrylate, trimethylol propane triacrylate, trimethylol propane trimethacrylate, zinc monoacrylate, zinc monomethacrylate, Zinc diacrylate, zinc dimethacrylate, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, neopentyl glycol acrylate, neopentyl glycol methacrylate, trifluoroethyl acrylate, trifluoroethyl methacrylate, 2,2, 3, 3 Tetrafluoropropyl acrylate, 2,2,3,3-tetrafluoropropyl methacrylate, 2,2,3,3,4,4-hexafluorobutyl acrylate, 2,2,3,3,4,4-hexafluorobutyl Methacrylate, perfluorooctyl acrylate, perfluorooctyl methacrylate, perfluorooctylethyl acrylate, perfluorooctylethyl methacrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, propylene glycol diacrylate, propylene glycol dimethacrylate, 1,4-butanediol Diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanedio Diacrylate, 1,9-nonanediol dimethacrylate, 1,3-butanediol diacrylate, 1,3-butanediol dimethacrylate, 1,10-decanediol diacrylate, 1,10-decanediol dimethacrylate, tetra Methylene glycol diacrylate, tetramethylene glycol dimethacrylate, methoxyethyl acrylate, methoxyethyl methacrylate, butoxyethyl acrylate, butoxyethyl methacrylate, ethoxydiethylene glycol acrylate, ethoxydiethylene glycol methacrylate, N, N′-methylenebisacrylamide, N, N′-methylene Bismethacrylamide, N, N′-ethylenebisacrylamide, N, N′-ethylenebismethacrylamide, 1,2 Diacrylamide ethylene glycol, 1,2-dimethacrylamide ethylene glycol, diacryloyloxymethyl tricyclodecane, dimethacryloyloxymethyl tricyclodecane, N-acryloyloxyethyl maleimide, N-methacryloyloxyethyl maleimide, N-acryloyloxyethyl hexahydrophthalimide, N-methacryloyloxyethyl hexahydrophthalimide, N-acryloyloxyethyl phthalimide, N-methacryloyloxyethyl phthalimide, n-vinyl-2-pyrrolidone, styrene derivative, α-methyl It is also possible to use styrene derivatives and the like.

  Furthermore, it is also possible to use a thermal radical polymerization initiator as the polymerization initiator. Although it is not particularly limited as long as it is normally used as a thermal radical polymerization initiator, it is desirable that the decomposition start temperature in the rapid heating test (when 1 g of a sample is placed on an electric heating plate and heated at 4 ° C./min) Is preferably 40 to 140 ° C. When the decomposition temperature is less than 40 ° C., the storage stability of the resin composition at normal temperature is deteriorated. Specific examples of the thermal radical polymerization initiator satisfying this include methyl ethyl ketone peroxide, methylcyclohexanone peroxide, methyl acetoacetate peroxide, acetylacetone peroxide, 1,1-bis (t-butylperoxy) 3, 3, 5 -Trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis (t-hexylperoxy) 3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) ) Cyclohexane, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane, 1,1-bis (t-butylperoxy) cyclododecane, n-butyl 4,4-bis (t- Butyl peroxy) valerate, 2,2-bis (t-butylperoxy) Tan, 1,1-bis (t-butylperoxy) -2-methylcyclohexane, t-butyl hydroperoxide, P-menthane hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, t -Hexyl hydroperoxide, dicumyl peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane, α, α'-bis (t-butylperoxy) diisopropylbenzene, t-butyl Cumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3, isobutyryl peroxide, 3,5,5-trimethylhexanoyl peroxide , Octanoyl peroxide, lauroyl peroxide, cinnamic acid peroxide m-toluoyl peroxide, benzoyl peroxide, diisopropyl peroxydicarbonate, bis (4-t-butylcyclohexyl) peroxydicarbonate, di-3-methoxybutyl peroxydicarbonate, di-2-ethylhexyl peroxide Carbonate, di-sec-butylperoxydicarbonate, di (3-methyl-3-methoxybutyl) peroxydicarbonate, di (4-t-butylcyclohexyl) peroxydicarbonate, α, α′-bis (neo) Decanoylperoxy) diisopropylbenzene, cumylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, 1-cyclohexyl-1-methylethylperoxyneodecanoate, t-Hexylpao Cineodecanoate, t-butylperoxyneodecanoate, t-hexylperoxypivalate, t-butylperoxypivalate, 2,5-dimethyl-2,5-bis (2-ethylhexanoylperoxy) ) Hexane, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 1-cyclohexyl-1-methylethylperoxy-2-ethylhexanoate, t-hexylperoxy-2-ethyl Hexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-butylperoxymaleic acid, t-butylperoxylaurate, t-butylperoxy-3 , 5,5-trimethylhexanoate, t-butylperoxyisopropyl monocarbonate, t Butylperoxy-2-ethylhexyl monocarbonate, 2,5-dimethyl-2,5-bis (benzoylperoxy) hexane, t-butylperoxyacetate, t-hexylperoxybenzoate, t-butylperoxy-m- Toluoyl benzoate, t-butylperoxybenzoate, bis (t-butylperoxy) isophthalate, t-butylperoxyallyl monocarbonate, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) Examples thereof include benzophenone, but these may be used alone or in combination of two or more in order to control curability.

  In the present invention, a coupling agent can be used. Generally used silane coupling agents and titanium-based coupling agents can be used. In particular, when a silane coupling agent having an S—S bond is used as a filler (B), silver powder is used. Since the bonding with the surface also occurs, not only the adhesion strength to the adherend surface but also the cohesive strength of the cured product is improved, so that it can be suitably used. Examples of silane coupling agents having an S—S bond include bis (trimethoxysilylpropyl) monosulfide, bis (triethoxysilylpropyl) monosulfide, bis (tributoxysilylpropyl) monosulfide, and bis (dimethoxymethylsilylpropyl) mono. Sulfide, bis (diethoxymethylsilylpropyl) monosulfide, bis (dibutoxymethylsilylpropyl) monosulfide, bis (trimethoxysilylpropyl) disulfide, bis (triethoxysilylpropyl) disulfide, bis (tributoxysilylpropyl) disulfide Bis (dimethoxymethylsilylpropyl) disulfide, bis (diethoxymethylsilylpropyl) disulfide, bis (dibutoxymethylsilylpropyl) disulfide, bis (to Methoxysilylpropyl) trisulfide, bis (triethoxysilylpropyl) trisulfide, bis (tributoxysilylpropyl) trisulfide, bis (dimethoxymethylsilylpropyl) trisulfide, bis (diethoxymethylsilylpropyl) trisulfide, bis ( Dibutoxymethylsilylpropyl) trisulfide, bis (trimethoxysilylpropyl) tetrasulfide, bis (triethoxysilylpropyl) tetrasulfide, bis (tributoxysilylpropyl) tetrasulfide, bis (dimethoxymethylsilylpropyl) tetrasulfide, bis (Diethoxymethylsilylpropyl) tetrasulfide, bis (dibutoxymethylsilylpropyl) tetrasulfide, bis (trimethoxysilylpropyl) poly Rufide, bis (triethoxysilylpropyl) polysulfide, bis (tributoxysilylpropyl) polysulfide, bis (dimethoxymethylsilylpropyl) polysulfide, bis (diethoxymethylsilylpropyl) polysulfide, bis (dibutoxymethylsilylpropyl) polysulfide, etc. Can be mentioned. A combination with other than the silane coupling agent having an S—S bond is also preferred.

  In the liquid resin composition of the present invention, additives such as an antifoaming agent, a surfactant, various polymerization inhibitors and antioxidants can be used as necessary.

  The liquid resin composition of the present invention can be produced, for example, by premixing each component, kneading using three rolls, and degassing under vacuum.

A known method can be used as a method of manufacturing a semiconductor device using the liquid resin composition of the present invention. For example, using a commercially available die bonder, the liquid resin composition is dispensed on a predetermined portion of the lead frame, and then the chip is mounted and heat-cured. Then, a semiconductor device is manufactured by wire bonding and transfer molding using an epoxy resin. Alternatively, the resin composition is dispensed on the back side of a chip such as a flip chip BGA (Ball Grid Array) sealed with an underfill material after flip chip bonding, and a heat dissipation component such as a heat spreader or lid is mounted and cured. Is possible.

Hereinafter, although the liquid resin composition of this invention is demonstrated in detail based on an Example, this invention is not limited to this.
In both Examples and Comparative Examples, the following raw materials were blended in the parts by weight shown in Table 1, and then kneaded and defoamed using three rolls to obtain a liquid resin composition.

(Compound (A))
The following compounds A1 to A5 were used as the compound (A) having one acrylic group.
Compound A1: Tertiary butyl cyclohexyl methacrylate (manufactured by NOF Corporation, Blemmer TBCHMA, (Ta-Tb) /Ta=0.28, hereinafter referred to as Compound A1)
Compound A2: Methoxypolyethylene glycol acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.,
NK ester AM-90G, (Ta-Tb) /Ta=0.21, hereinafter compound A2)
Compound A3: 2-ethylhexyl methacrylate (manufactured by Kyoeisha Chemical Co., Ltd., light ester EH, (Ta-Tb) /Tb=0.04, hereinafter referred to as compound A3)
Compound A4: 1,4-cyclohexanedimethanol monoacrylate (Nippon Kasei Co., Ltd.)
Manufactured by CHDMMA, (Ta-Tb) /Tb=0.07, hereinafter referred to as Compound A4)
Compound A5: 2-methacryloyloxyethyl succinic acid (manufactured by Kyoeisha Chemical Co., Ltd., light ester HO-MS, (Ta-Tb) /Ta=0.02, hereinafter compound A5)

(Filler (B))
As the filler (B), silver powder (hereinafter referred to as silver powder) having an average particle diameter of 7 μm and a tap density of 5.8 g / cm 3 was used.

(Compound (C))
The following compounds C1 to C5 were used as the compound (C) having two or more functional groups capable of reacting with the compound A in the molecule.
Compound C1: Polybutadiene having hydroxyl groups at both ends (Idemitsu Kosan Co., Ltd., R-45HT) 140 g, methacrylic acid (reagent) 10.3 g, hydroquinone monomethyl ether (Kawaguchi Chemical Co., Ltd., MQ-F) 0.03 g And 500 g of toluene (reagent) in a separable flask and stirring at room temperature for 10 minutes to make a uniform solution, 1.0 g of paratoluenesulfonic acid monohydrate (reagent) is added, and stirring is further performed for 5 minutes. It was. Thereafter, the mixture was heated using an oil bath and reacted for 4 hours while dehydrating in a Dean-Stark trap under reflux. After cooling to room temperature, the organic solvent layer which has been subjected to liquid separation washing 5 times with ion-exchanged water is filtered to remove the solid content, and the product obtained by removing the solvent with an evaporator and a vacuum dryer is compounded. C1. (Yield: about 92%. Viscous liquid at room temperature. Disappearance of protons of methylene groups bonded with hydroxyl groups (4.05 to 4.2 ppm), formation of ester bonds (4 .45 to 4.65 ppm), and 4.9 to 5.05 ppm of integrated strength of 1,2-vinyl bond and 1.95 to 2.15 ppm of integrated strength of 1,4-vinyl bond (for 4 protons). From the ratio, it was confirmed that the ratio of all vinyl bonds of 1,4 vinyl bonds (total of 1,2-vinyl bonds and 1,4 vinyl bonds) was about 80%. 3100 and it was confirmed that there was no peak based on methacrylic acid).
Compound C2: Polybutadiene having hydroxyl groups at both ends (Idemitsu Kosan Co., Ltd., R-15HT) 120 g, methacrylic acid (reagent) 17.2 g, hydroquinone monomethyl ether (Kawaguchi Chemical Industry Co., Ltd., MQ-F) 0.06 g The product obtained in the same manner as Compound A1 except that 1.9 g of paratoluenesulfonic acid monohydrate (reagent) was used was defined as Compound C2 (yield: about 94%. A viscous liquid at room temperature. As in compound A1, the ratio of hydroxyl group disappearance, ester bond formation, and 1,4 vinyl bond to the total vinyl bond (total of 1,2-vinyl bond and 1,4 vinyl bond) is about 80 as measured by proton NMR. It was confirmed that the number average molecular weight in terms of styrene by GPC was about 1500, and no peak based on methacrylic acid was present).
Compound C3: 1,6-hexanediol dimethacrylate (manufactured by Kyoeisha Chemical Co., Ltd., light ester 1, 6HX, hereinafter referred to as compound C3)
Compound C4: Bismaleimide compound obtained by reaction of polytetramethylene glycol and maleimidated acetic acid (molecular weight 580, hereinafter referred to as compound C4)
Compound C5: diallyl ester compound obtained by reaction of diallyl ester of cyclohexanedicarboxylic acid and polypropylene glycol (molecular weight 1000, but containing about 15% of diallyl ester of cyclohexanedicarboxylic acid used as a raw material, hereinafter compound C5)

(Additive)
In addition to the compound (A), filler (B), and compound (C), the following additives were used.
Radical polymerization initiator: Dicumyl peroxide (manufactured by NOF Corporation, Park Mill D, decomposition start temperature in rapid heating test: 126 ° C.)
Coupling agent 1: Coupling agent having a glycidyl group (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-403E)
Coupling agent 2: Coupling agent having a methacryl group (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-503P)
Coupling agent 3: bis (trimethoxysilylpropyl) tetrasulfide (manufactured by Daiso Corporation, Cabras 4)

(Evaluation test)
The following evaluation tests were performed on the liquid resin compositions of Examples and Comparative Examples obtained above. The evaluation results are shown in Table 1.

(Settling test)
A syringe (10 cc) filled with 30 g of the liquid resin composition of Examples and Comparative Examples was stored for 30 days in a thermostatic chamber adjusted to 0 ° C. so that the tip of the syringe was down. The appearance after storage was confirmed by visual observation. If there was no change, it was rated as “◯”, when the separation of the silver powder and the resin component was confirmed a little, and when markedly observed, it was marked as “X”. It used for the following thickness stability test 2 after the external appearance confirmation.

(Thickness stability test 1)
A copper heat spreader (25) in which a silicon chip (15 × 15 × 0.5 mm) whose thickness has been measured in advance using a syringe filled with 30 g of the liquid resin composition of Examples and Comparative Examples is plated with Ni (25 × 15 × 0.5 mm). × 25 × 2 mm). Mount the resin composition shown in Table 1 using a dispenser on the heat spreader about 0.02 cc, and then mount the silicon chip using a compact mounter SMT-64RH manufactured by Okuhara Electric Co., Ltd. at room temperature. A load of 2 kgf was applied for 10 seconds. Ten test pieces were prepared immediately after the syringe was set, about 10 g of the resin composition was discarded and another 10 pieces were produced, and about 10 g of the resin composition was discarded again, and a total of 30 test pieces were produced. The test piece after mounting was cured at 150 ° C. for 60 minutes, and then the thickness of the resin composition layer was measured with a contact-type thickness meter. (The thickness of the resin composition layer was determined by measuring the height from the heat spreader to the chip surface at the four corners of the chip and reducing the thickness of the chip). A case where the difference between the maximum thickness and the minimum thickness of 30 test pieces produced was 10 μm or less was regarded as acceptable. The unit of thickness is μm.

(Thickness stability test 2)
The thickness of the resin composition layer was measured in the same manner as in the stability test 1 except that the syringe after the sedimentation test was used. A case where the difference between the maximum thickness and the minimum thickness of 30 test pieces produced was 10 μm or less was regarded as acceptable. The unit of thickness is μm.

(Resin bleed test)
The resin blur of 30 test pieces prepared in the thickness stability test 1 was observed with an optical microscope. (Measure the length of the longest part of the resin that oozes out from the end of the resin composition onto the surface of the Ni-plated copper heat spreader). The case where the resin bleeding length was 100 μm or less was regarded as acceptable. The unit of resin bleeding is μm.

(Elastic modulus)
About each liquid resin composition of an Example and a comparative example, a 4x20x0.1mm film-like test piece is produced (hardening conditions 150 degreeC 30 minutes), and it pulls with a dynamic viscoelasticity measuring machine (DMA). Measurements were made in mode. The measurement conditions are as follows.
Measurement temperature: -100 to 300 ° C
Temperature increase rate: 5 ° C / min Frequency: 10Hz
Load: 100mN
The storage elastic modulus at 25 ° C. was regarded as the elastic modulus, and the case of 1500 MPa or less was regarded as acceptable. The unit of elastic modulus is MPa.

(Thermal conductivity)
A disk-shaped test piece having a diameter of 2 cm and a thickness of 1 mm was prepared using each of the liquid resin compositions of Examples and Comparative Examples. (Curing conditions are 175 ° C. × 2 hours. However, the temperature was increased from room temperature to 30 minutes up to 175 ° C. over 30 minutes.) Thermal diffusion coefficient (α) measured by laser flash method (t1 / 2 method), measured by DSC method The thermal conductivity was calculated using the following equation from the measured specific heat (Cp) and the density (ρ) measured according to JIS-K-6911. The unit of thermal conductivity is W / mK. A sample having a thermal conductivity of 5 W / mK or more was regarded as acceptable.
Thermal conductivity = α × Cp × ρ

(Temperature cycle resistance 1)
The state of peeling before and after temperature cycle treatment (conditions: -65 ° C / 30 minutes ← → 150 ° C / 30 minutes, 100 cycles) of the test piece after the thickness stability test 1 was measured with an ultrasonic flaw detector (reflection type). It was measured. The case where the ratio of the peeled area to the chip area was less than 10% was regarded as acceptable. The unit of the peeled area is%.

(Temperature cycle resistance 2)
The state of peeling before and after the temperature cycle treatment was measured in the same manner as in the temperature cycle resistance 1 except that the test piece after the thickness stability test 2 was used. The case where the ratio of the peeled area to the chip area was less than 10% was regarded as acceptable. The unit of the peeled area is%.

(Reflow resistance)
Using the liquid resin compositions of Examples and Comparative Examples, the following lead frames and silicon chips were cured and bonded at 150 ° C. for 60 minutes. Furthermore, sealing was performed using a sealing material (Sumicon EME-G620A, manufactured by Sumitomo Bakelite Co., Ltd.) to manufacture a semiconductor device. This semiconductor device was subjected to moisture absorption treatment at 30 ° C., relative humidity 60%, 168 hours, and then IR reflow treatment (260 ° C., 10 seconds, 3 times reflow). The degree of peeling of the treated semiconductor device was measured by an ultrasonic flaw detector (transmission type). The case where the ratio of the peeled area to the chip area was less than 10% was regarded as acceptable. The unit of the peeled area is%.
Semiconductor device: QFP (14 x 20 x 2.0 mm)
Lead frame: Ni-Pd / Au plated copper frame Chip size: 6 x 6 mm
Curing conditions for resin composition: 150 ° C. in oven for 60 minutes

  Since the liquid resin according to the present invention has low sedimentation of the filler during low-temperature storage and has excellent thickness stability of the resin composition layer and low elastic modulus and sufficient low stress, it is suitable for die attach paste or heat radiation member adhesion By using it as a material, a highly reliable semiconductor device can be obtained.

DESCRIPTION OF SYMBOLS 1 ... Hardened | cured material layer of liquid resin composition 2 ... Die pad 3 ... Semiconductor element 4 ... Lead 5 ... Sealing material 10 ... Semiconductor device

Claims (4)

A liquid resin composition comprising a compound (A) having one acrylic group and a filler (B),
It is used for die attach paste for semiconductors or heat radiation member bonding materials,
The filler (B) is a metal powder or a ceramic powder,
When the transmittance of light having a wavelength of 450 nm at 50 ° C. of the compound (A) is Ta and the transmittance of light having a wavelength of 450 nm at 0 ° C. is Tb,
Ta and Tb satisfy | fill the following conditional expression 1, The liquid resin composition characterized by the above-mentioned.
[Conditional Formula 1: (Ta−Tb) /Ta≧0.1] The liquid resin composition according to claim 1, further comprising a compound (C) having two or more functional groups capable of reacting with the compound (A) in one molecule. The liquid resin composition according to claim 1 or 2, wherein the compound (A) is represented by the general formula (1).

R ¹ : hydrogen, a hydrocarbon group having 1 to 6 carbon atoms,
R ² : cyclohexylene group,
R ³ : hydrogen, a hydrocarbon group having 1 to 6 carbon atoms. A semiconductor device produced by using the liquid resin composition according to any one of claims 1 to 3 as a die attach material or a heat radiation member bonding material.