JP5392990B2 - Liquid resin composition and semiconductor device manufactured using the 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.

In recent years, the speed of semiconductor devices has been remarkably increased, and transmission delay due to a decrease in signal propagation speed due to wiring resistance and parasitic capacitance between wirings has become a problem. Such a problem tends to become more prominent because the wiring resistance increases and the parasitic capacitance increases as the wiring width and the wiring interval become finer due to higher integration of semiconductor devices. Therefore, in order to prevent signal delay due to increase in wiring resistance and parasitic capacitance, copper wiring is introduced instead of the conventional aluminum wiring, and the relative dielectric constant of the interlayer insulating film is 3.9 of the silicon dioxide film. A small low dielectric constant insulating film has been applied. In particular, the relative dielectric constant of the interlayer insulating film is strongly demanded to be about 2.0 or less as the design standard is reduced from 65 nm to 45 nm. There is a need for a porous insulating film having a reduced dielectric constant by increasing the porosity.
Such a porous insulating film generally has a problem that its mechanical strength is weak because of its structure. That is, compared with a semiconductor element using a conventional insulating film, it is more sensitive to external stress, and the insulating film may be destroyed even by stress that has not been a problem until now.
In order to reduce the stress generated there, semiconductor constituent materials such as sealing materials and die attach materials are required to have low stress, and the semiconductor production process has been reviewed.
The semiconductor element is bonded to a support such as a lead frame, a glass epoxy substrate (glass fiber reinforced epoxy resin substrate), a BT substrate (a BT resin substrate made of cyanate monomer and oligomer thereof and bismaleimide), and an organic substrate such as a polyimide film. In the die attach process, warpage occurs due to the difference in thermal expansion coefficient between the semiconductor element and the support after die attach. However, excessive warpage causes damage to the interlayer insulating film, and thus warpage is unlikely to occur. There is a need for touch materials.
Here, in order to reduce the warp, it is necessary to lower the elastic modulus of the die attach material. (1) A method of adding a liquid low-stress agent (see, for example, Patent Document 1),
(2) A method of adding a solid low stress agent (for example, see Patent Document 2),
(3) A method of reducing the crosslinking density (for example, see Patent Document 3),
(4) A method of introducing a flexible structure into the resin skeleton (see, for example, Patent Document 4),
(5) A method of adding a polymer having a low glass transition temperature (Tg) (for example, see Patent Document 5) has been studied. For example, in the method of (1), the liquid low-stress agent itself has a high viscosity. Therefore, when a blending amount capable of obtaining a sufficiently low elastic modulus is added, it tends to be difficult to handle due to high viscosity. In the method (2), since the ratio of solid content in the liquid resin composition increases, the viscosity is high. In the method (3), mechanical properties such as strength at high temperatures tend to deteriorate. In the method (4), the viscosity of the resin into which the flexible skeleton is introduced is high. In the method of (5), the liquid resin composition cannot be obtained unless a solvent is used, and the solvent needs to be volatilized during curing of the liquid resin composition, so that the warp is caused. Chip size that can be a problem ( Most warp in the case Ppusaizu is small has been left also disadvantages, such as is not suitable to become not) a problem.
On the other hand, while lead elimination from semiconductor products is being promoted as part of environmental measures, lead-free solder is also used for mounting on the board, so the reflow temperature must be higher than that for tin-lead solder. is there. The reflow treatment at high temperature increases the stress inside the semiconductor package, so that peeling and cracking are likely to occur in the semiconductor product during reflow, and the die attach material is also difficult to peel off. Material is desired. Thus, a liquid resin composition having a low elastic modulus, showing a good adhesive force even at a high temperature and excellent in workability at the time of application is desired as a die attach material, but none has been sufficiently satisfied.
Japanese Patent Laid-Open No. 05-120914 JP 2003-347322 A Japanese Patent Laid-Open No. 06-084974 Japanese Patent Laid-Open No. 08-176409 JP 2005-154687 A

  The present invention is a liquid resin composition having a low elastic modulus and good high-temperature adhesiveness and excellent coating workability, and particularly solder crack resistance when the present invention is used as a semiconductor die attach material or a heat radiation member adhesive. It is to provide a semiconductor device having excellent reliability.

Such an object is achieved by the present invention described in the following [1] to [5].
[1] A liquid resin composition for adhering a semiconductor element or a heat radiating member to a support, comprising (A) a filler and (B) a thermosetting resin, wherein the main chain is the thermosetting resin (B). A liquid resin composition comprising a compound (B1) composed of carbon-carbon bonds, having a molecular weight of 1000 or more and 20000 or less and having at least one radical polymerizable functional group in one molecule.
[2] The liquid according to [1], wherein the compound (B1) is a copolymer containing a (meth) acrylic acid ester compound as a monomer unit and having at least one radical polymerizable functional group in one molecule. Resin composition.
[3] The above [1] or [2], wherein the radically polymerizable functional group of the compound (B1) is at least one selected from the group consisting of a (meth) acryloyl group, a (meth) allyl group, a vinyl group, and a maleimide group. ] The liquid resin composition as described in.
[4] A semiconductor device manufactured using the liquid resin composition according to any one of [1] to [3] above as a die attach material or a heat radiation member bonding material.

  Since the liquid resin composition of the present invention has a low elastic modulus and good adhesion at high temperatures and is excellent in coating workability, the present invention has been used so far by using the present invention as a die attach material or an adhesive for a heat dissipation member. It is possible to provide a highly reliable semiconductor device that does not have a high reliability.

The present invention is a liquid resin composition containing a filler and a thermosetting resin. The thermosetting resin has a main chain composed of carbon-carbon bonds, and has a molecular weight of 1000 or more and 20000 or less and radical polymerization in one molecule. Because it contains a compound having at least one functional functional group, it has a low elastic modulus and exhibits excellent adhesive strength at high temperatures and is excellent in coating workability, so it is used as a liquid resin composition for bonding a semiconductor element or a heat dissipation member By doing so, it becomes possible to provide an unprecedented highly reliable semiconductor device.
Hereinafter, the present invention will be described in detail.

Examples of the filler (A) used in the present invention include silver powder, gold powder, copper powder, aluminum powder, nickel powder, palladium powder and other metal powders, alumina powder, titania powder, aluminum nitride powder, boron nitride powder and the like. Examples thereof include polymer powders such as ceramic powder, polyethylene powder, polyacrylate powder, polytetrafluoroethylene powder, polyamide powder, polyurethane powder, and polysiloxane powder. Since the liquid resin composition may be ejected using a nozzle, the average particle size of the filler is preferably 30 μm or less in order to prevent nozzle clogging, and it is preferable that there are few ionic impurities such as sodium and chlorine. In particular, silver powder is preferably used when electrical conductivity and thermal conductivity are required. If it is the silver powder currently marketed for electronic materials, reduced powder, atomized powder, etc. can be obtained, and as a preferable particle diameter, an average particle diameter is 1 micrometer or more and 30 micrometers or less. Below this, the viscosity of the liquid resin composition becomes too high, and above this causes nozzle clogging during dispensing as described above, and silver powder other than for electronic materials may have a large amount of ionic impurities. So be careful. There are no particular limitations on the shape, such as flakes and spheres, but flakes are preferably used, and are usually contained in the liquid resin composition in an amount of 65% by weight to 95% by weight. This is because when the proportion of silver powder is less than this, the conductivity deteriorates, and when it is more than this, the viscosity of the liquid resin composition becomes too high.

As the thermosetting resin (B) used in the present invention, the reaction proceeds by heating to increase the molecular weight, and the main chain is composed of carbon-carbon bonds as the thermosetting resin, and the molecular weight is 1000. The compound (B1) having at least one radical-polymerizable functional group in one molecule is contained in the range of 20,000 to 20,000. This makes it possible to obtain a cured product having a low elastic modulus by using the compound (B1), and the carbon-carbon bond is chemically and thermally stable compared to an ether bond, an ester bond, an amide bond and the like. Because there is. Although the molecular weight is limited to 1000 or more and 20000 or less, when the molecular weight is lower than this, the intended effect of lowering the elastic modulus cannot be sufficiently exhibited, and when it is higher than this, the viscosity of the liquid resin composition is increased. This is because too much application workability is deteriorated.
Further, the compound (B1) is preferably a copolymer containing a (meth) acrylic acid ester compound as a monomer unit and having a radical polymerizable functional group, which has a highly reactive radical polymerizable functional group. This is because a liquid resin composition having excellent curability can be obtained. Here, examples of the radical polymerizable functional group include a (meth) acryloyl group, a (meth) allyl group, a vinyl group, and a maleimide group, and it is preferable to use at least one of these.

Further, the compound (B1) is preferably liquid at room temperature when mixed with a liquid component of the thermosetting resin to be used when a thermosetting resin other than the compound (B1) is used. This is because it is difficult to obtain a liquid resin composition with good coating workability if it does not become liquid at room temperature by mixing with liquid components of liquid or other thermosetting resins at room temperature.
Examples of such a compound (B1) include a first component such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, cyclohexyl (meth) acrylate, hydroxyethyl (meth) acrylate, (meth ) After obtaining a copolymer having a hydroxyl group, a carboxy group or a glycidyl group with a molecular weight of 1000 or more and 20000 or less by copolymerizing with a second component having a functional group such as acrylic acid or glycidyl (meth) acrylate, The compound which introduce | transduced the radically polymerizable functional group is mentioned. It is also preferable to contain styrene as the first component. The method for producing the copolymer is not particularly limited. Generally, the copolymer can be reacted in a solvent by using a polymerization initiator and a chain transfer agent. In particular, the concentrations of the polymerization initiator and the chain transfer agent are reacted. It is preferable that it is 1 weight% or less with respect to all the components used for. Particularly preferred is that it can be obtained by carrying out the reaction at a high temperature and high pressure without using a polymerization initiator and a chain transfer agent, and more preferably without using it. The copolymer thus obtained has a low molecular weight and a narrow molecular weight distribution, so that even when a compound having a radical polymerizable functional group is introduced, there is little increase in viscosity when it is made into a liquid resin composition, and stability at high temperatures. It has the feature of being excellent in.
Such a copolymer is sold by Toagosei Co., Ltd. under the trade name Arufon. If a (meth) acrylate having a hydroxyl group such as hydroxyethyl (meth) acrylate is used as the second component during the preparation of the copolymer, the main chain is composed of carbon-carbon bonds and the molecular weight is 1000 or more and 20000 or less. A radically polymerizable functional group is introduced by reacting this copolymer with a compound having a radically polymerizable functional group such as (meth) acrylic acid, maleimidated amino acid or a derivative thereof. The obtained compound can be obtained.
In addition, if a compound having a carboxy group such as (meth) acrylic acid is used as the second component at the time of preparing the copolymer, the main chain is composed of carbon-carbon bonds and has a molecular weight of 1000 to 20000 and has a carboxy group. A copolymer can be obtained, and radical polymerization is carried out by reacting this copolymer with a compound having a hydroxyl group and a radical polymerizable functional group such as hydroxyethyl (meth) acrylate, hydroxyethyl vinyl ether, (meth) allyl alcohol, etc. A compound into which a functional functional group is introduced can be obtained.
Furthermore, if a (meth) acrylate having a glycidyl group such as glycidyl (meth) acrylate is used as the second component during the preparation of the copolymer, the main chain is composed of carbon-carbon bonds, and the molecular weight is 1000 or more and 20000 or less. A copolymer having a group can be obtained, and a radical polymerizable functional group can be obtained by reacting the copolymer with a compound having a radical polymerizable functional group such as (meth) acrylic acid, maleimidated amino acid or a derivative thereof. Can be obtained.
The number of radically polymerizable functional groups contained in one molecule of the compound into which these radically polymerizable functional groups are introduced is preferably 2 or more and 100 or less, and more preferably 2 or more and 30 or less. More preferred is 2 or more and 10 or less. If the number of radically polymerizable functional groups is less than this, the cohesive force after curing is reduced and the adhesive force is deteriorated, and if it is more than this, the intended effect of lowering the elastic modulus may not be sufficiently exhibited. .
Examples of the compound having a radical polymerizable functional group include (meth) acrylic acid, maleimidated amino acid, hydroxyethyl (meth) acrylate, hydroxyethyl vinyl ether, (meth) allyl alcohol, and the like.

  In the present invention, a thermosetting resin other than the compound (B1) can be used. Examples of the thermosetting resin other than the compound (B1) include an epoxy resin, an acrylic resin, a maleimide resin, and a cyanate resin. Among them, a radical polymerizable acrylic resin and a maleimide resin are preferably used because of their good curability. It is done. These resins can be used in combination.

The acrylic resin is a compound having a (meth) acryloyl group other than the above-mentioned compound (B1) having a (meth) acryloyl group, and the (meth) acryloyl group is heated under heating by using a polymerization initiator described later together. It is a thermosetting resin that has a high molecular weight when reacted. It is not particularly limited as long as it has a (meth) acryloyl group, and a polyether, polyester, polycarbonate, polyurethane, polybutadiene, butadiene acrylonitrile copolymer having a molecular weight of 500 to 10,000 is preferable having a (meth) acryloyl group.
As the polyether, those in which a divalent organic group having 3 to 6 carbon atoms is repeated via an ether bond are preferable, and those having no aromatic ring are preferable. A (meth) acryloyl group can be introduced by a reaction between a polyether polyol and (meth) acrylic acid or a derivative thereof.
As polyester, the thing which the C3-C6 bivalent organic group repeated via the ester bond is preferable, and the thing which does not contain an aromatic ring is preferable. A (meth) acryloyl group can be introduced by a reaction between a polyester polyol and (meth) acrylic acid or a derivative thereof.
As a polycarbonate, what a C3-C6 bivalent organic group repeated via the carbonate bond is preferable, and what does not contain an aromatic ring is preferable. A (meth) acryloyl group can be introduced by a reaction between a polycarbonate polyol and (meth) acrylic acid or a derivative thereof.
As the polyurethane, a reaction product of a bifunctional isocyanate and a diol is preferable, and a (meth) acryloyl group can be introduced by adding a (meth) acrylate having a hydroxyl group such as hydroxy (meth) acrylate during the reaction. As the bifunctional isocyanate, those not containing an aromatic ring are preferable, and isophorone diisocyanate and norbornene diisocyanate are particularly preferable.
As polybutadiene, a (meth) acryloyl group can be introduced by a reaction between a polybutadiene having a carboxy group and a (meth) acrylate having a hydroxyl group, a reaction between a polybutadiene having a hydroxyl group and (meth) acrylic acid or a derivative thereof, In addition, a (meth) acryloyl group can be introduced by a reaction between polybutadiene to which maleic anhydride has been added and (meth) acrylate having a hydroxyl group.
As the butadiene acrylonitrile copolymer, a (meth) acryloyl group can be introduced by a reaction between a butadiene acrylonitrile copolymer having a carboxy group and a (meth) acrylate having a hydroxyl group.

  If necessary, the following compounds can be used in combination. For example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxy Butyl (meth) acrylate, 1,2-cyclohexanediol mono (meth) acrylate, 1,3-cyclohexanediol mono (meth) acrylate, 1,4-cyclohexanediol mono (meth) acrylate, 1,2-cyclohexanedimethanol mono (Meth) acrylate, 1,3-cyclohexanedimethanol mono (meth) acrylate, 1,4-cyclohexanedimethanol mono (meth) acrylate, 1,2-cyclohexanediethanol mono (meth) acrylate 1,3-cyclohexanediethanol mono (meth) acrylate, 1,4-cyclohexanediethanol mono (meth) acrylate, glycerin mono (meth) acrylate, glycerin di (meth) acrylate, trimethylolpropane mono (meth) acrylate, tri (Meth) acrylate having a hydroxyl group such as methylolpropane di (meth) acrylate, pentaerythritol mono (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, neopentyl glycol mono (meth) acrylate, And (meth) acrylate having a carboxy group obtained by reacting a (meth) acrylate 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 (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tertiary butyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, Tridecyl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, isoamyl (meth) acrylate, isostearyl (meth) acrylate, behenyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, other alkyl (meth) ) Acrylate, cyclohexyl (meth) acrylate, tertiary butyl cyclohexyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, benzyl (meth) acrylate, pheno Xylethyl (meth) acrylate, isobornyl (meth) acrylate, glycidyl (meth) acrylate, trimethylolpropane tri (meth) acrylate, zinc mono (meth) acrylate, zinc di (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl ( (Meth) acrylate, neopentyl glycol (meth) acrylate, trifluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate, 2,2,3,3,4,4-hexafluoro Butyl (meth) acrylate, perfluorooctyl (meth) acrylate, perfluorooctylethyl (meth) acrylate, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, 1, 10-decanediol di (meth) acrylate, tetramethylene glycol di (meth) acrylate, methoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxypolyalkylene glycol mono (meth) acrylate, Octoxy polyalkylene glycol mono (meth) acrylate, Lauroxy polyalkylene glycol mono (meth) acrylate, Stearoxy polyalkylene glycol mono (meth) acrylate, Allyloxy polyalkyl Glycol mono (meth) acrylate, nonylphenoxypolyalkylene glycol mono (meth) acrylate, N, N′-methylenebis (meth) acrylamide, N, N′-ethylenebis (meth) acrylamide, 1,2-di (meth) Acrylamide ethylene glycol, di (meth) acryloyloxymethyl tricyclodecane, N- (meth) acryloyloxyethyl maleimide, N- (meth) acryloyloxyethyl hexahydrophthalimide, N- (meth) acryloyloxyethyl phthalimide N-vinyl-2-pyrrolidone, styrene derivatives, α-methylstyrene derivatives and the like can also be used.

Further, a thermal radical polymerization initiator is preferably used 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 a rapid heating test (decomposition start temperature when a sample is placed on an electric heating plate and heated at 4 ° C./min. In which the decomposition temperature is 40 to 140 ° C. When the decomposition temperature is less than 40 ° C., the storage stability of the conductive paste at room temperature is deteriorated, and when it exceeds 140 ° C., the curing time becomes extremely long, which is not preferable. 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-hexyl peroxy Neodecanoate, 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-ethylhexanoate , T-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-butylperoxymaleic acid, t-butylperoxylaurate, t-butylperoxy-3,5, 5-trimethylhexanoate, t-butylperoxyisopropyl monocarbonate, t-butyl Tilperoxy-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) benzophenone, etc. These may be used alone or in combination of two or more in order to control curability. The compounding quantity of a polymerization initiator is 0.1 to 10 weight% with respect to a thermosetting resin (B). More preferably, it is 0.5 to 10% by weight.
Here, since the liquid resin composition of the present invention is usually used under illumination such as a fluorescent lamp, if a photopolymerization initiator is contained, an increase in viscosity is observed due to reaction during use. It is not preferable to contain an initiator. “Substantially” means that a small amount of the photopolymerization initiator may be present to such an extent that no increase in viscosity is observed, and it is preferably not contained.

  The maleimide resin is a compound containing one or more maleimide groups in one molecule other than the above-mentioned compound (B1) having a maleimide group. For example, N, N ′-(4,4′-diphenylmethane) bismaleimide, And bismaleimide resins such as bis (3-ethyl-5-methyl-4-maleimidophenyl) methane and 2,2-bis [4- (4-maleimidophenoxy) phenyl] propane. More preferred maleimide resins 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, and polycarbonate polyol are preferable, and those that do not contain an aromatic ring are particularly preferable. Since the maleimide group can react with an allyl group, the combined use with an allyl ester resin is also preferable. The allyl ester resin is preferably an aliphatic one, and particularly preferred is a compound obtained by transesterification of a cyclohexane diallyl ester and an aliphatic polyol. Furthermore, the above-mentioned thermal radical polymerization initiator is preferably used as the polymerization initiator. Moreover, combined use with cyanate resin, an epoxy resin, and an acrylic resin is also preferable.

  Here, the compounding amount of the compound (B1) is preferably 1% by weight or more and 70% by weight or less with respect to the thermosetting resin (B). A more preferable blending amount is 3% by weight or more and 60% by weight or less. If it is less than this, the intended effect of lowering the elastic modulus may not be sufficiently exhibited. If it is more than this, the viscosity of the liquid resin composition is high, which may cause deterioration in coating workability.

In the present invention, additives such as a coupling agent, an antifoaming agent, and a surfactant can also be used.
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, a liquid resin composition is dispensed on a predetermined portion of a lead frame, and then a semiconductor chip is mounted and heat-cured. Then, a semiconductor device is manufactured by wire bonding and transfer molding using an epoxy resin. Alternatively, after the flip chip bonding, a liquid resin composition is dispensed on the back surface of a semiconductor chip such as a flip chip BGA (Ball Grid Array) sealed with an underfill material, and heat radiation components such as a heat spreader and a lid are mounted and cured.

Preparation compound (B11) of compound (B1)
Acrylic oligomer having a hydroxyl value of 20 mg KOH / g and a molecular weight of 11,000 (manufactured by Toagosei Co., Ltd., Arufon UH-2000, acrylic having a hydroxyl group obtained by continuous bulk polymerization at high temperature and high pressure without using a chain transfer catalyst. 110 g of a main oligomer composed of a carbon-carbon bond in the main oligomer), 5 g of methacrylic acid (reagent) and 500 g of toluene (reagent) as a compound having a radical polymerizable functional group are placed in a separable flask and a Dean-Stark trap is used. Water was removed by stirring for 30 minutes under reflux. After cooling to room temperature, a solution of 10 g of dicyclohexylcarbodiimide dissolved in 50 ml of ethyl acetate was added dropwise over 10 minutes with stirring, and then reacted at room temperature for 6 hours. Excess dicyclohexylcarbodiimide was precipitated by adding 50 ml of ion-exchanged water with stirring after the reaction, and then stirred for 30 minutes under reflux using a Dean-Stark trap to remove water. After cooling to room temperature, the reaction solution was filtered to remove solids, followed by separation and washing three times with ion exchange water at 70 ° C. and twice with ion exchange water at room temperature. The solvent was removed from the filtrate obtained by filtering the solvent layer again with an evaporator and a vacuum dryer to obtain a product. (Yield: about 98%, liquid at room temperature. GPC measurement confirmed that the molecular weight (in terms of styrene) was about 12000 and no methacrylic acid remained. The disappearance of hydroxyl groups by proton NMR measurement using heavy chloroform, The presence of a methacryl group and the formation of an ester bond were confirmed, which was a compound having a main chain composed of carbon-carbon bonds, a molecular weight of 12,000 and about 4 methacryloyl groups which are radically polymerizable functional groups, hereinafter referred to as compound B11).

Compound (B12)
Acrylic oligomer having a hydroxyl value of 33 mg KOH / g and a molecular weight of 5000 (manufactured by Toagosei Co., Ltd., Arufon UH-2130, acrylic having a hydroxyl group obtained by continuous bulk polymerization at high temperature and high pressure without using a chain transfer catalyst. 100 g of a compound comprising a carbon-carbon bond in the main chain and a 7-g methacrylic acid (reagent) and 500 g of toluene (reagent) as a compound having a radical polymerizable functional group in a separable flask and using a Dean-Stark trap Water was removed by stirring for 30 minutes under reflux. After cooling to room temperature, a solution of 17 g of dicyclohexylcarbodiimide dissolved in 50 ml of ethyl acetate was added dropwise over 10 minutes with stirring, and then reacted at room temperature for 6 hours. Excess dicyclohexylcarbodiimide was precipitated by adding 50 ml of ion-exchanged water with stirring after the reaction, and then stirred for 30 minutes under reflux using a Dean-Stark trap to remove water. After cooling to room temperature, the reaction solution was filtered to remove solids, followed by separation and washing three times with ion exchange water at 70 ° C. and twice with ion exchange water at room temperature. The solvent was removed from the filtrate obtained by filtering the solvent layer again with an evaporator and a vacuum dryer to obtain a product. (Yield: about 97%. Liquid at room temperature. GPC measurement confirmed that the molecular weight (in terms of styrene) was about 5500 and no methacrylic acid remained. The disappearance of hydroxyl groups by proton NMR measurement using heavy chloroform, The presence of a methacryl group and the formation of an ester bond were confirmed, which was a compound having a main chain composed of carbon-carbon bonds, a molecular weight of 5500, and about 3 methacryloyl groups which are radically polymerizable functional groups.

Compound (B13)
An acrylic oligomer having an acid value of 108 mgKOH / g and a molecular weight of 4600 (manufactured by Toagosei Co., Ltd., Arufon UC-3900, having a carboxy group obtained by continuous bulk polymerization at high temperature and high pressure without using a chain transfer catalyst. 100 g of an acrylic oligomer having a main chain composed of carbon-carbon bonds), 7.8 g of 2-hydroxyethyl methacrylate (reagent) and 8.9 g of butyl alcohol (reagent) as a compound having a radical polymerizable functional group, toluene (Reagent) 500 g was placed in a separable flask and stirred for 30 minutes under reflux using a Dean-Stark trap to remove water. After cooling to room temperature, a solution prepared by dissolving 37 g of dicyclohexylcarbodiimide in 100 ml of ethyl acetate was added dropwise over 15 minutes with stirring, and then reacted at room temperature for 6 hours. Excess dicyclohexylcarbodiimide was precipitated by adding 50 ml of ion-exchanged water with stirring after the reaction, and then stirred for 30 minutes under reflux using a Dean-Stark trap to remove water. After cooling to room temperature, the reaction solution was filtered to remove solids, followed by separation and washing three times with ion exchange water at 70 ° C. and twice with ion exchange water at room temperature. The solvent was removed from the filtrate obtained by filtering the solvent layer again with an evaporator and a vacuum dryer to obtain a product. (Yield about 95%. Liquid at room temperature. GPC measurement confirmed that the molecular weight (in terms of styrene) was about 5500 and that 2-hydroxyethyl methacrylate did not remain. Methyl methacrylate was measured by proton NMR measurement using deuterated chloroform. The presence of a group and the formation of an ester bond were confirmed, which was a compound having a main chain composed of carbon-carbon bonds, a molecular weight of 5500, and about 3 methacryloyl groups which are radically polymerizable functional groups.

Compound (B14)
An acrylic oligomer having an acid value of 74 mgKOH / g and a molecular weight of 10,000 (manufactured by Toagosei Co., Ltd., Arufon UC-3000, having a carboxy group obtained by continuous bulk polymerization at high temperature and high pressure without using a chain transfer catalyst. 100 g of an acrylic oligomer having a main chain composed of carbon-carbon bonds), 5.2 g of 2-hydroxyethyl methacrylate (reagent) and 6.9 g of butyl alcohol (reagent) as a compound having a radical polymerizable functional group, toluene (Reagent) 500 g was placed in a separable flask and stirred for 30 minutes under reflux using a Dean-Stark trap to remove water. After cooling to room temperature, a solution prepared by dissolving 28 g of dicyclohexylcarbodiimide in 100 ml of ethyl acetate was added dropwise over 15 minutes with stirring, and then reacted at room temperature for 6 hours. Excess dicyclohexylcarbodiimide was precipitated by adding 50 ml of ion-exchanged water with stirring after the reaction, and then stirred for 30 minutes under reflux using a Dean-Stark trap to remove water. After cooling to room temperature, the reaction solution was filtered to remove solids, followed by separation and washing three times with ion exchange water at 70 ° C. and twice with ion exchange water at room temperature. The solvent was removed from the filtrate obtained by filtering the solvent layer again with an evaporator and a vacuum dryer to obtain a product. (Yield: about 95%. Liquid at room temperature. GPC measurement confirmed that the molecular weight (in terms of styrene) was about 11000 and no 2-hydroxyethyl methacrylate remained. The presence of a group and the formation of an ester bond were confirmed, which was a compound having a main chain composed of carbon-carbon bonds, a molecular weight of 11,000, and about 4 methacryloyl groups which are radically polymerizable functional groups.

[Example 1]
The filler (A) is flaky silver powder (hereinafter referred to as silver powder) having an average particle diameter of 8 μm and a maximum particle diameter of 30 μm, and the thermosetting resin (B) is compound B11, polyether bismaleimide acetate (Dainippon). Lumicure MIA-200 manufactured by Ink Industries Co., Ltd., a reaction product of maleimidated glycine and polytetramethylene glycol diol, hereinafter referred to as compound B2), a diallyl ester compound obtained by a reaction of a diallyl ester of cyclohexanedicarboxylic acid and polypropylene glycol ( Molecular weight 1000, but containing about 15% of the diallyl ester of cyclohexanedicarboxylic acid used as a raw material, hereinafter referred to as compound B3), 1,6-hexanediol dimethacrylate (manufactured by Kyoeisha Chemical Co., Ltd., light ester 1, 6HX, hereinafter referred to as compound B6) ), Dicumyl peroxide (Nippon Yushi Co., Ltd., Park Mill D, decomposition temperature in rapid heating test: 126 ° C., hereinafter referred to as Compound B7), silane coupling agent having a glycidyl group (Shin-Etsu Chemical Co., Ltd., KBM-403E, hereinafter) Compound C1), a silane coupling agent having a methacryl group (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-503P, hereinafter referred to as Compound C2) is blended as shown in Table 1, and kneaded and defoamed using three rolls. Table 1 shows the results obtained by obtaining a liquid resin composition with the following evaluation methods. In addition, a mixture ratio is a weight part.

[Examples 2 to 7]
Evaluation was performed after blending at the ratio shown in Table 1 and obtaining a liquid resin composition in the same manner as in Example 1.
In Example 3, diglycidyl bisphenol A obtained by reaction of bisphenol A and epichlorohydrin (epoxy equivalent 180, liquid at room temperature and having two glycidyl groups in one molecule, hereinafter referred to as compound B5), 2-methylimidazole And 2,4-diamino-6-vinyltriazine adduct (Curazole 2MZ-A: manufactured by Shikoku Chemicals Co., Ltd., hereinafter referred to as Compound B8), dicyandiamide (hereinafter referred to as Compound B9), In Example 5, the compound B13 was converted into a polycarbonate diol having a molecular weight of about 900 synthesized from 1,4-dimethanolcyclohexane / 1,6-hexanediol (= 3/1 (weight ratio)) and dimethyl carbonate in Example 6. Polycarbonate obtained by reacting methyl methacrylate Methacrylate compounds (Ube Industries, Ltd., UM-90 (3/1) DM, less compound B4), using the above-mentioned compound B14 in Example 7. In Examples 4 and 6, Compound B2 and Compound B3 were not used.

[Comparative Examples 1-3]
Evaluation was performed after blending at the ratio shown in Table 1 and obtaining a liquid resin composition in the same manner as in Example 1.
In Comparative Example 1, an acrylic oligomer having a molecular weight of 2000 (manufactured by Toagosei Co., Ltd., Arufon UP-1020, having no functional group obtained by continuous bulk polymerization at high temperature and high pressure without using a chain transfer catalyst) A compound composed of a carbon-carbon bond in an acrylic oligomer and the following compound X) was used.

Evaluation Method / Viscosity: Using an E-type viscometer (3 ° cone), the value at 25 ° C. and 2.5 rpm was measured immediately after the production of the liquid resin composition. A viscosity value of 20 ± 10 Pa · S was accepted. The unit of viscosity is Pa · S.
-Dotting test: 1,000 dots were applied using a 22G single nozzle (inner diameter 0.47 mm) with a dot testing machine (manufactured by Musashi Engineering, SHOTMASTER-300) (coating amount: about 0.2 mg / 1 point). After application, the striking points were observed from directly above, and the number of blanks and the number of thread pulls (those in which the thread breakage was bad during application and fell outside the striking point) were measured. A case where the total of the number of blanks and the number of thread draws was 10 or less was marked as ○, a case where it was 3 or less was marked as ◎, and a case where it was larger than 10 was marked as x.
-Adhesive strength: Using the liquid resin composition shown in Table 1, a 6 x 6 mm silicon chip is mounted on a silver ring-plated copper frame (only the inner lead part is silver-plated and the die pad part is not silver-plated), Cured for 120 seconds on a 175 ° C hot plate. After curing and after moisture absorption (85 ° C., 85%, 72 hours), the hot die shear strength at 260 ° C. was measured using an automatic adhesive force measuring apparatus. The case where the die shear strength when heated at 260 ° C. was 30 N / chip or more was regarded as acceptable. The unit of adhesive strength is N / chip.
Elastic modulus: 4 × 20 × 0.1 mm film-shaped test pieces were prepared using the liquid resin composition shown in Table 1 (curing conditions: 150 ° C. for 30 minutes), and the dynamic viscoelasticity measuring machine (DMA) was used. The measurement was performed in the pull mode. The measurement conditions are as follows.
Measurement temperature: room temperature to 300 ° C
Temperature increase rate: 5 ° C / min Frequency: 10Hz
Load: 100mN
The storage elastic modulus at 250 ° C. was regarded as the elastic modulus, and the case of 300 MPa or less was regarded as acceptable. The unit of elastic modulus is MPa.

Reflow resistance: Using the liquid resin composition shown in Table 1, the following substrate (lead frame) and silicon chip were cured and bonded at 175 ° C. for 120 seconds. The die-bonded lead frame is encapsulated with a sealing material (Sumicon EME-G700L, manufactured by Sumitomo Bakelite Co., Ltd.) to form a semiconductor device (package). Treatment (260 ° C., 10 seconds, 3 reflows) was performed. The degree of peeling of the treated package was measured with an ultrasonic flaw detector (transmission type). The case where the peeling area of the die attach part was less than 10% was regarded as acceptable. The unit of the peeled area is%.
Package: QFP (14 x 20 x 2.0 mm)
Lead frame: Silver ring-plated copper frame Chip size: 6 x 6 mm
Liquid resin composition curing conditions: 175 ° C. 120 seconds on hot plate

  Since the liquid resin composition of the present invention has a low elastic modulus and good adhesion at high temperatures and is excellent in coating workability, the present invention has been used so far by using the present invention as a die attach material or an adhesive for a heat dissipation member. It is possible to provide a highly reliable semiconductor device that does not have a high reliability.

Claims (3)

A liquid resin composition for a semiconductor device in which a semiconductor element or a heat radiating member is bonded to a support, the liquid resin composition for a semiconductor device being heat-cured, (A) a filler, (B) thermosetting Resin , (C) a thermal radical polymerization initiator , the main chain of the thermosetting resin (B) is composed of carbon-carbon bonds, the molecular weight is 1000 or more and 20000 or less, and a radical polymerizable functional group is contained in one molecule. A liquid resin composition comprising a compound (B1) having at least one,
The liquid resin composition whose said compound (B1) is a copolymer containing a (meth) acrylic acid ester compound as a monomer unit. 2. The liquid for a semiconductor device according to claim 1, wherein the radically polymerizable functional group of the compound (B1) is at least one selected from the group consisting of a (meth) acryloyl group, a (meth) allyl group, a vinyl group, and a maleimide group. Resin composition. A semiconductor device manufactured using the liquid resin composition for a semiconductor device according to claim 1 as a die attach material or a material for adhering a heat dissipation member.