JP2009029843A - Semiconductor adhesive material and semiconductor adhesive tape - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor adhesive material, which is used for bonding a semiconductor chip to another semiconductor chip or a substrate, reducing a warp of the bonded objects, giving a cured object having excellent reflow heat resistance and to provide a semiconductor adhesive tape using the semiconductor adhesive material. <P>SOLUTION: The semiconductor adhesive material contains an epoxy compound, a curing agent with molecular weight of 500 or less, and a hydrogenated acrylonitrile-butadiene copolymer. The semiconductor adhesive tape has an adhesive layer comprising the semiconductor adhesive material and a base material layer stuck to one side of the adhesive layer. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a semiconductor adhesive used for bonding a semiconductor chip onto a substrate or another semiconductor chip, for example, and more specifically, can suppress warping of the semiconductor chip or the substrate after bonding, and The present invention relates to a semiconductor adhesive that gives a cured product excellent in reflow heat resistance, and a semiconductor adhesive tape using the semiconductor adhesive.

  A semiconductor device in which a semiconductor chip is bonded to a substrate or another semiconductor chip via an adhesive is known. In this type of semiconductor device, high integration is progressing, and semiconductor chips and substrates are becoming thinner.

  Patent Document 1 below discloses an adhesive including an epoxy resin, an epoxy resin curing agent, an epoxy group-containing acrylic copolymer, and a curing accelerator as an example of the adhesive.

  However, when, for example, a semiconductor chip and a substrate having greatly different linear expansion coefficients are joined using the adhesive described in Patent Document 1, stress is generated due to the difference in linear expansion coefficient, and the substrate or the semiconductor chip warps. It was apt. Although semiconductor chips and substrates have been made thinner, when these thicknesses are small, large warpage is particularly likely to occur on the substrate or the semiconductor chip.

  On the other hand, in order to suppress the warpage, conventionally, an adhesive containing acrylic rubber, which is a low-elasticity material, has been used. However, the adhesive containing acrylic rubber has low adhesive force, and peeling at the adhesive interface is likely to occur in the reflow process.

Moreover, in order to suppress the said curvature, the adhesive agent containing the acrylonitrile butadiene rubber which is a low elasticity material has also been used. However, since acrylonitrile-butadiene rubber has a double bond, its heat resistance after bonding is low, and when it is exposed to a high temperature for a long period of time, the adhesive strength may be greatly reduced. Furthermore, impurities are often incorporated into acrylonitrile-butadiene rubber during the emulsion polymerization, and the impurities may cause corrosion of electrodes provided on the substrate or the semiconductor chip.
Japanese Patent No. 3453390

  An object of the present invention is an adhesive used to bond a semiconductor chip onto a substrate or another semiconductor chip, for example, in view of the above-described state of the prior art, and suppresses warping of the bonded adherend. It is an object of the present invention to provide an adhesive for semiconductors that can provide a cured product excellent in reflow heat resistance, and an adhesive tape for semiconductors using the adhesive for semiconductors.

  The semiconductor adhesive according to the present invention includes an epoxy compound, a curing agent having a molecular weight of 500 or less, and a hydrogenated acrylonitrile-butadiene copolymer.

  Various curing agents can be used as the curing agent, but an acid anhydride is preferably used. The fluidity | liquidity of the adhesive agent for semiconductors can be improved further as a hardening | curing agent is an acid anhydride.

  On the specific situation with the adhesive for semiconductors which concerns on this invention, the said acrylonitrile butadiene copolymer is contained in the ratio of 10-200 weight part with respect to 100 weight part of said epoxy compounds. When the hydrogenated acrylonitrile-butadiene copolymer is included at this ratio, the fluidity of the adhesive for semiconductor is excellent, and the warpage of the adherend can be further suppressed.

  In another specific aspect of the adhesive for semiconductor according to the present invention, the ratio of the amount of acrylonitrile in the acrylonitrile-butadiene copolymer is 10 to 40% by weight. In this case, the semiconductor adhesive can be easily formed into a sheet shape, and the fluidity of the semiconductor adhesive is excellent. Moreover, the cured | curing material of the adhesive agent more excellent by reflow heat resistance can be obtained.

  The adhesive according to the present invention preferably further includes a crosslinking agent in addition to the epoxy compound, the curing agent having a molecular weight of 500 or less, and the hydrogenated acrylonitrile-butadiene copolymer. When the crosslinking agent is included, the reflow heat resistance can be further enhanced. In addition, the adhesive according to the present invention more preferably further includes a crosslinking aid. When the crosslinking aid is included, the reflow heat resistance can be further enhanced.

  In still another specific aspect of the semiconductor adhesive according to the present invention, the amount of chlorine ion impurities in the extracted water obtained by adding 10 g of water to 1 g of the cured semiconductor adhesive and extracting it is 50 ppm or less. is there. In this case, it is possible to reduce the influence of impurities on an adherend such as a bonded substrate or semiconductor chip. For example, corrosion of electrodes provided on a substrate or a semiconductor chip can be suppressed.

  The adhesive tape for a semiconductor according to the present invention has an adhesive layer made of an adhesive for a semiconductor constituted according to the present invention, and a base material layer attached to one surface of the adhesive layer.

  Since the adhesive for semiconductors according to the present invention includes an epoxy compound, a curing agent having a molecular weight of 500 or less, and a hydrogenated acrylonitrile-butadiene copolymer, the adherend is bonded using the adhesive. And the curvature of a to-be-adhered body can be suppressed. In particular, when adherends having different linear expansion coefficients are joined, warpage of the adherend can be effectively suppressed. Moreover, since the adhesive for semiconductors according to the present invention includes an epoxy compound, a curing agent having a molecular weight of 500 or less, and a hydrogenated acrylonitrile-butadiene copolymer, the cured product has excellent reflow heat resistance. Is expressed.

  Since the adhesive tape for semiconductor according to the present invention has an adhesive layer made of an adhesive for semiconductor constituted according to the present invention and a base material layer attached to one side of the adhesive layer, for example, the adhesive layer After the semiconductor chip or the like is attached to the substrate, the adhesive layer to which the semiconductor chip is attached is peeled from the base material layer, whereby the semiconductor chip can be easily joined to the substrate or another semiconductor chip.

  Details of the present invention will be described below.

  In order to achieve the above-mentioned problems, the inventors of the present invention have intensively studied the compounding components of the adhesive for semiconductors. As a result, an epoxy compound, a curing agent having a molecular weight of 500 or less, and a hydrogenated acrylonitrile-butadiene copolymer. That the adhesive is combined to suppress warping of the adherend bonded using the adhesive, and the cured product of the adhesive is excellent in reflow heat resistance. The headline and the present invention were made.

  The adhesive for semiconductors according to the present invention includes an epoxy compound, a curing agent having a molecular weight of 500 or less, and a hydrogenated acrylonitrile-butadiene copolymer.

(Epoxy compound)
The epoxy compound is not particularly limited. For example, bisphenol type epoxy resins such as bisphenol A type, bisphenol F type, bisphenol AD type, and bisphenol S type, novolac type epoxy resins such as phenol novolak type and cresol novolak type, and trisphenolmethane. Examples thereof include aromatic epoxy resins such as triglycidyl ether, naphthalene type epoxy resins, fluorene type epoxy resins, dicyclopentadiene type epoxy resins, and water additives thereof.

  As the epoxy compound, in addition to the above-described epoxy compound, a high molecular polymer having an epoxy group may be used. When a high molecular polymer having an epoxy group is used, the cured product of the adhesive for semiconductor exhibits excellent flexibility, and the bonding reliability with the adherend can be improved.

  The polymer having an epoxy group is not particularly limited as long as it is a polymer having an epoxy group at the terminal and / or side chain (pendant position). For example, epoxy group-containing acrylic rubber, epoxy group-containing Examples thereof include butadiene rubber, bisphenol type high molecular weight epoxy resin, epoxy group-containing phenoxy resin, epoxy group-containing acrylic resin, epoxy group-containing urethane resin, and epoxy group-containing polyester resin. Especially, since the mechanical strength and heat resistance of hardened | cured material are improved, an epoxy-group-containing acrylic resin is preferable. These polymer polymers having an epoxy group may be used alone or in combination of two or more.

  A preferred lower limit of the weight average molecular weight of the polymer having an epoxy group is 10,000. If the weight average molecular weight is less than 10,000, the flexibility of the cured product may not be sufficiently improved.

  The preferable lower limit of the epoxy equivalent of the polymer having an epoxy group is 200, and the preferable upper limit is 1000. If the epoxy equivalent is less than 200, the flexibility may not be sufficiently improved. Conversely, if it exceeds 1000, the mechanical strength and heat resistance of the cured product may be reduced.

  As a compounding quantity of the high molecular polymer which has the said epoxy group, 10-100 weight% is preferable in the total 100 weight% of an epoxy compound. When there are too few high molecular polymers which have an epoxy group, fluidity | liquidity may become high too much, and when too large, fluidity | liquidity may become too low.

(Curing agent)
The semiconductor adhesive according to the present invention includes a curing agent having a molecular weight of 500 or less.

  When the molecular weight of the curing agent exceeds 500, the fluidity of the adhesive for semiconductor may become too low, and the reflow heat resistance after bonding may decrease.

  As the curing agent, a conventionally known curing agent can be appropriately selected and used as long as the molecular weight is 500 or less, and is not particularly limited. For example, an acid anhydride curing agent, a phenol curing agent, an amine Examples of the curing agent include a latent curing agent such as dicyandiamide, and a cationic catalyst-type curing agent. Especially, since the fluidity | liquidity of the adhesive agent for semiconductors can be improved further, an acid anhydride is preferable. These curing agents may be used alone or in combination of two or more.

  Examples of the acid anhydride curing agent include acid anhydride curing agents such as methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic acid anhydride, and trialkyltetrahydrophthalic anhydride. However, since it is hydrophobized, methylnadic acid anhydride or trialkyltetrahydrophthalic anhydride is preferably used. On the other hand, methyltetrahydrophthalic anhydride and methylhexahydrophthalic anhydride are less preferred because they have poor water resistance. These acid anhydride curing agents may be used alone or in combination of two or more.

  Although it does not specifically limit as a compounding quantity of the said hardening | curing agent, When using the hardening | curing agent which reacts equivalently with the functional group of an epoxy compound, 70-110 equivalent is preferable with respect to the functional group amount of an epoxy compound. Moreover, when using the hardening | curing agent which functions as a catalyst, the preferable minimum of a hardening | curing agent is 1 weight part with respect to 100 weight part of epoxy compounds, and a preferable upper limit is 20 weight part.

  Since the curing rate and the physical properties of the cured product can be adjusted, the adhesive for semiconductors may contain a curing accelerator.

  It does not specifically limit as said hardening accelerator, For example, an imidazole type hardening accelerator and a tertiary amine type hardening accelerator are mentioned. Among these, an imidazole-based curing accelerator is preferable because the reaction system is easily controlled to adjust the curing speed and the physical properties of the cured product. These curing accelerators may be used alone or in combination of two or more.

  The imidazole curing accelerator is not particularly limited. For example, 1-cyanoethyl-2-phenylimidazole in which the 1-position of imidazole is protected with a cyanoethyl group, or a basic group protected with isocyanuric acid (Shikoku Chemical Industry) Product name "2MA-OK") and the like. These imidazole type hardening accelerators may be used independently and may use 2 or more types together.

  The blending amount of the curing accelerator is not particularly limited and is preferably in the range of 1 to 10 parts by weight with respect to 100 parts by weight of the epoxy compound.

  When using the said hardening | curing agent and a hardening accelerator together, it is preferable that the compounding quantity of a hardening | curing agent shall be below an equivalent theoretically required with respect to an epoxy group. If the compounding amount of the curing agent exceeds the theoretically required equivalent, chlorine ions may be easily eluted by moisture after curing. That is, if the curing agent is excessive, for example, when the elution component is extracted from the cured product of the semiconductor adhesive with hot water, the pH of the extracted water becomes about 4 to 5, so that a large amount of chlorine from the epoxy resin. Ions may elute. Therefore, the pH of the pure water after 1 g of the cured product of the adhesive for semiconductor is immersed in 10 g of pure water at 100 ° C. for 2 hours is preferably 6-8, more preferably 6.5-7.5.

(Hydrogenated butadiene-acrylonitrile copolymer)
The adhesive for semiconductors according to the present invention contains a hydrogenated acrylonitrile-butadiene copolymer.

  The hydrogenated butadiene-acrylonitrile copolymer is obtained by hydrogenating a copolymer having both a butadiene skeleton and an acrylonitrile skeleton. By containing a hydrogenated butadiene-acrylonitrile copolymer, it is possible to suppress warping of the adherend. In particular, when adherends having different linear expansion coefficients are joined, warpage of the adherend can be effectively suppressed. Furthermore, since the hydrogenated butadiene-acrylonitrile copolymer is hydrogenated, the reflow heat resistance of the cured product of the adhesive for semiconductor is enhanced.

  The hydrogenated butadiene-acrylonitrile copolymer is not particularly limited, and examples thereof include acrylonitrile-butadiene copolymer, isoprene-acrylonitrile-butadiene copolymer, acrylonitrile-methyl acrylate-butadiene copolymer, and acrylonitrile- Examples thereof include hydrogenated ethylene-butadiene copolymer and carboxyl group-containing butadiene-acrylonitrile copolymer.

  Although it does not specifically limit as a commercial item of the said hydrogenated butadiene- acrylonitrile copolymer, For example, Zetpol0010, Zetpol1010, Zetpol1020, Zetpol1020S, Zetpol2000L, Zetpol2010, Zetpol2010p, Zetpol2010p, Zetpol2010p, Zetpol20p, Zetpol2010p, Zetpol20p Zetpol 3110X50, Zetpol 3310, Zetpol 4110, Zetpol 4310, Zetpol 4320 (manufactured by Nippon Zeon), THERBAN 1706, THERBAN 1706S, THERBAN 1707, THERBAN 1707S, THERBAN 1907, THER RBAN1907S, THERBAN2207, THERBAN2207S, THERBANXTVPKA8805 (manufactured by Bayer AG), CHEMISAT (manufactured by Goodyear Co., Ltd.).

  The amount of acrylonitrile in the hydrogenated butadiene-acrylonitrile copolymer is preferably in the range of 10 to 40% by weight. More preferably, it is in the range of 15 to 35% by weight. If the amount of acrylonitrile is too small, the hydrogenated butadiene-acrylonitrile copolymer and the epoxy compound may be phase-separated macroscopically, and it may be difficult to form into a sheet. The fluidity of the agent may decrease, and the adhesion to the adherend may decrease.

  The iodine value of the hydrogenated butadiene-acrylonitrile copolymer is preferably in the range of 5-50. If the iodine value is too small, the number of unsaturated bonds may be too small to obtain a sufficient crosslinking effect. If the iodine value is too large, the number of unsaturated bonds will be too large, resulting in long-term heat resistance. May be inferior.

  In this specification, the iodine value means the number of grams of iodine that can be added to 100 g of hydrogenated butadiene-acrylonitrile copolymer. It means that the smaller the iodine value, the smaller the number of unsaturated bonds contained in the hydrogenated butadiene-acrylonitrile copolymer.

The Mooney viscosity (ML _{1 + 4} 100 ° C.) of the hydrogenated butadiene-acrylonitrile copolymer is preferably in the range of 30-80. If the Mooney viscosity is less than 30, it may be difficult to produce a sheet, and if it exceeds 80, the fluidity during bonding may be insufficient.

  In addition, the iodine value of Zetpol0020, which is a commercial product of a hydrogenated butadiene-acrylonitrile copolymer, is 23, the Mooney viscosity is 65, the iodine value of Zetpol 1020 is 24, the Mooney viscosity is 78, and Zetpol 2020L. The iodine value is 28, the Mooney viscosity is 57.5, the iodine value of Zetpol 3310 is 15, the Mooney viscosity is 80, the iodine value of Zetpol 4320 is 27, and the Mooney viscosity is 70.

  By the way, in the production of the hydrogenated butadiene-acrylonitrile copolymer, a water vapor washing step is performed in the production process. Accordingly, the hydrogenated butadiene-acrylonitrile copolymer contains relatively few impurities. Therefore, if a hydrogenated butadiene-acrylonitrile copolymer is used, a system with a small amount of impurities can be constructed.

  Further, when a hydrogenated butadiene-acrylonitrile copolymer having a carboxyl group is used, the water absorption rate of the copolymer is relatively high, so that the reflow heat resistance tends to decrease. In this case, by introducing a radical crosslinking reaction, the degree of crosslinking can be increased and the reflow heat resistance can be increased.

  The blending amount of the hydrogenated butadiene-acrylonitrile copolymer is preferably in the range of 10 to 200 parts by weight with respect to 100 parts by weight of the epoxy compound. More preferably, it is the range of 30-150 weight part. If the amount of the butadiene-acrylonitrile copolymer that is hydrogenated is too small, the warping of the adherend may not be sufficiently suppressed. If the amount is too large, the fluidity may be extremely lowered.

(Crosslinking agent)
The semiconductor adhesive according to the present invention preferably contains a crosslinking agent. When the adhesive for semiconductor contains a crosslinking agent, the remaining double bond can be crosslinked, and the heat resistance can be further enhanced. A crosslinking agent may be used independently and 2 or more types may be used together.

  The crosslinking agent is not particularly limited, and organic peroxides such as dicumyl peroxide and di-t-butyl peroxide, sulfur such as powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, and highly dispersible sulfur, Sulfur halides such as sulfur chloride and sulfur dichloride, p-quinonedioxime, quinonedioximes such as p, p'-dibenzoylquinonedioxime, triethylenetetramine, hexamethylenediamine carbamate, 4,4'-methylenebis- Examples thereof include organic polyvalent amine compounds such as o-chloroaniline, alkylphenol resins having a methylol group, and the like. Among these, a peroxide crosslinking agent is preferable because a residue is hardly generated at the time of crosslinking and the electrical characteristics are excellent.

  The peroxide crosslinking agent is not particularly limited, but di-t-butyl peroxide, dicumyl peroxide, t-butyl cumyl peroxide, t-butyl peroxide, 1,1-di (t-butylperoxy) -3, 3,5-trimethylcyclohexane, 1,1-di (t-butylperoxy) cyclododecane, 2,5-dimethyl-di (t-butylperoxy) hexane, 2,5-dimethyl-di (t-butylperoxy) hexyne -3,1,3-di (t-butylperoxyisopropyl) benzene, 2,5-dimethyl-di (benzoylperoxy) hexane, t-butylperoxyisopropyl carbonate, n-butyl-4,4-di (t-butyl) Peroxy) palerate, di-t-butylperoxypropylbenzene and the like. Of these, di-t-butylperoxypropylbenzene is preferred because of excellent storage stability and crosslinking reactivity.

  The amount of the crosslinking agent is preferably in the range of 1 to 10 parts by weight with respect to 100 parts by weight of the epoxy compound. More preferably, it is the range of 2-8 weight part. When the amount of the crosslinking agent is too small, the heat resistance may not be sufficiently improved. When the amount is too large, molecular cleavage by radicals may be a problem.

(Crosslinking aid)
The semiconductor adhesive according to the present invention preferably contains a crosslinking aid. When the semiconductor adhesive contains a crosslinking aid, the remaining double bond can be effectively crosslinked, and the heat resistance can be further enhanced.

  Although it does not specifically limit as said crosslinking aid, A sulfenamide type crosslinking aid (a), a guanidine type crosslinking aid (b), a thiourea type crosslinking aid (c), a thiazole type crosslinking aid (d), thiuram Examples thereof include a crosslinking aid (e), a dithiocarbamic acid crosslinking aid (f), and a xanthogenic acid crosslinking aid (g). The crosslinking aids may be used alone or in combination of two or more.

  Examples of the sulfenamide crosslinking aid (a) include N-cyclohexyl-2-benzothiazole sulfenamide, Nt-butyl-2-benzothiazole sulfenamide, N-oxyethylene-2-benzothiazole. Examples thereof include sulfenamide, N-oxyethylene-2-benzothiazole sulfenamide, N, N′-diisopropyl-2-benzothiazole sulfenamide and the like.

  Examples of the guanidine-based crosslinking aid (b) include diphenyl guanidine, diortolyl guanidine, orthotolyl biguanidine, and the like.

  Examples of the thiourea-based crosslinking aid (c) include thiocarboanilide, diortolylthiourea, ethylenethiourea, diethylthiourea, and trimethylthiourea.

  Examples of the thiazole-based crosslinking aid (d) include 2-mercaptobenzothiazole, dibenzothiazyl disulfide, 2-mercaptobenzothiazole zinc salt, 2-mercaptobenzothiazole sodium salt, 2-mercaptobenzothiazole cyclohexylamine salt, 2 -(2,4-dinitrophenylthio) benzothiazole and the like.

  Examples of the thiuram-based crosslinking aid (e) include tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, dipentamethylenethiuram tetrasulfide and the like.

  Examples of the dithiocarbamate crosslinking aid (f) include sodium dimethyldithiocarbamate, sodium diethyldithiocarbamate, sodium di-n-butyldithiocarbamate, lead dimethyldithiocarbamate, zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, di-n. -Zinc butyldithiocarbamate, zinc pentamethylenedithiocarbamate, zinc ethylphenyldithiocarbamate, tellurium diethyldithiocarbamate, selenium dimethyldithiocarbamate, selenium diethyldithiocarbamate, copper dimethyldithiocarbamate, iron dimethyldithiocarbamate, diethylamine diethyldithiocarbamate, pentamethylene Piperidine dithiocarbamate, pipette of methylpentamethylenedithiocarbamate Phosphorus, and the like.

  Examples of the xanthogenic acid crosslinking aid (g) include sodium isopropyl xanthate, zinc isopropyl xanthate, zinc butyl xanthate, and the like.

  The amount of the crosslinking aid is preferably in the range of 1 to 10 parts by weight with respect to 100 parts by weight of the epoxy compound. If the amount of the crosslinking aid is too small, the heat resistance may not be sufficiently improved. If the amount is too large, molecular cleavage by radicals may be a problem.

(Other ingredients)
The semiconductor adhesive according to the present invention preferably contains an ion scavenger. When the adhesive for semiconductor contains an ion scavenger, corrosion of the electrode provided on the adherend can be suppressed.

  The ion scavenger is not particularly limited as long as it can reduce the amount of ionic impurities. For example, aluminosilicate, hydrous titanium oxide, hydrous bismuth oxide, zirconium phosphate, phosphorus Examples include titanium oxide, hydrotalcite, ammonium molybdophosphate, hexacyanozinc, organic ion exchange resin, and the product name "IXE" series manufactured by Toa Gosei Co., Ltd., which is commercially available as an ion scavenger with excellent properties at high temperatures. It is done. These ion scavengers may be used alone or in combination of two or more.

  The adhesive for semiconductors according to the present invention may further contain a silane coupling agent, a thixotropic agent, and the like.

  Although it does not specifically limit as said silane coupling agent, For example, an aminosilane coupling agent, an epoxy silane coupling agent, a ureido silane coupling agent, an isocyanate silane coupling agent, a vinyl silane coupling agent, an acrylic silane cup Examples thereof include a ring agent and a ketimine silane coupling agent. Among them, an aminosilane coupling agent is suitably used because of excellent curing speed and affinity with an epoxy resin. These silane coupling agents may be used alone or in combination of two or more.

  The thixotropy imparting agent is not particularly limited, and examples thereof include fine metal particles, calcium carbonate, fumed silica, inorganic fine particles such as aluminum oxide, boron nitride, aluminum nitride, and aluminum borate. Of these, fumed silica is preferable.

  The thixotropy-imparting agent may be surface-treated as necessary. As the thixotropic agent, particles having a hydrophobic group on the surface are preferable, and fumed silica having a hydrophobic surface is more preferable.

(Semiconductor adhesive)
The semiconductor adhesive according to the present invention is used, for example, for bonding a semiconductor chip onto a substrate or another semiconductor chip.

  For example, after a semiconductor chip is bonded onto a substrate or another semiconductor chip via the semiconductor adhesive according to the present invention, the semiconductor adhesive is cured by heating, and the semiconductor chip is bonded to the substrate or another semiconductor. It can be bonded on the chip.

  It is preferable that the chlorine ion impurity amount in the extracted water obtained by adding 10 g of water to 1 g of the cured product of the adhesive for semiconductor according to the present invention and extracting it is 50 ppm or less. When the chlorine ion impurity amount is 50 ppm or less, it is possible to reduce the influence of impurities on an adherend such as a bonded substrate or semiconductor chip. For example, corrosion of electrodes provided on a substrate or a semiconductor chip can be suppressed.

  The extraction operation is performed, for example, by putting 1 g of a cured product of a semiconductor adhesive and 10 g of water in a container, sealing it, and extracting by heating at 110 ° C. for 12 hours. The amount of chlorine ion impurities in the extracted water can be measured using, for example, ion chromatography.

  Although it does not specifically limit as an aspect of the adhesive agent for semiconductors which concerns on this invention, A paste form may be sufficient and a sheet form may be sufficient. The method for processing the semiconductor adhesive into a sheet is not particularly limited, but for example, a solvent casting method, an extrusion film forming method, or the like is preferable.

  In addition, when the semiconductor adhesive according to the present invention is in the form of a sheet, it has an adhesive layer made of this sheet-like adhesive for semiconductor, and a base material layer attached to one side of the adhesive layer A semiconductor adhesive can be applied to the semiconductor adhesive tape.

  The above-mentioned adhesive tape for a semiconductor, for example, after a semiconductor chip or the like is attached to an adhesive layer, the adhesive layer to which the semiconductor chip is attached is peeled off from the base material layer, so that the semiconductor chip substrate or other semiconductor chips Bonding can be performed easily. Alternatively, after attaching a semiconductor wafer to the adhesive layer, dicing into individual semiconductor chips, and peeling the adhesive layer to which the semiconductor chips are attached from the base material layer to the substrate of the semiconductor chip or other semiconductor chips Can be easily joined.

  Since the peelability between the adhesive layer and the base material layer is improved, the surface of the base material layer to which the adhesive layer is affixed or the base material layer itself preferably has no tackiness. But the base material layer may have adhesiveness.

  The base material layer is not particularly limited, but a polyester film such as a polybutylene terephthalate film or a polyethylene terephthalate film, a polyolefin film such as a polytetrafluoroethylene film, a polyethylene film, a polypropylene film, a polymethylpentene film or a polyvinyl acetate film. And a plastic film such as a polyvinyl chloride film and a polyimide film, an LDPE film, an LDPE-LLDPE film, an LDPE-HDPE film, an LDPE-HDPE-LLLDPE film, an LLDPE film, and an HDPE film. The base material layer may be a laminate of these films.

  Moreover, the said base material layer may contain a (meth) acrylic resin as a main component.

  As the (meth) acrylic resin, a (meth) acrylic acid ester polymer is preferable. As the (meth) acrylic acid ester polymer, a (meth) acrylic acid alkyl ester monomer having an alkyl group in the range of 1 to 12 carbon atoms as a main monomer, this and a functional group-containing monomer, and further, if necessary, these And those obtained by copolymerizing with other modifying monomers that can be copolymerized with a conventional method. Of these, an alkyl group having 6 or more carbon atoms is particularly preferred. The weight average molecular weight of the (meth) acrylic acid ester polymer is about 200,000 to 2,000,000.

  Although it does not specifically limit as said (meth) acrylic-acid alkylester monomer, What is obtained by esterification reaction of the primary or secondary alkyl alcohol whose carbon number of an alkyl group is 1-12, and (meth) acrylic acid. Is preferred.

  Specific examples of the (meth) acrylic acid alkyl ester monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, and (meth) acrylic acid. (Meth) acrylic acid such as n-butyl, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, octyl (meth) acrylate, lauryl (meth) acrylate, etc. Is mentioned.

  The base material layer may function as a dicing layer, but preferably has a dicing layer on the surface opposite to the surface on which the adhesive layer of the base material layer is affixed separately from the base material layer. preferable. When a dicing layer is provided separately from the base material layer, a semiconductor wafer can be affixed to an adhesive tape for a semiconductor and can be easily diced into individual semiconductor chips.

  The dicing layer is not particularly limited. Polyester films such as polyethylene terephthalate, polytetrafluoroethylene films, polyethylene films, polypropylene films, polymethylpentene films, polyolefin films such as polyvinyl acetate films, polyvinyl chloride films, polyimides For example, a substrate made of an appropriate synthetic resin film such as a film is coated with an adhesive such as an acrylic adhesive or a rubber adhesive. These dicing layers are stuck to the base material layer from the pressure-sensitive adhesive side.

  EXAMPLES Hereinafter, although an Example is hung up and this invention is demonstrated in more detail, this invention is not limited only to these Examples.

(Examples 1-14 and Comparative Examples 1-4)
Each component shown in Table 1 below was blended in the proportions shown in Table 1 (units are parts by weight), stirred with a homodisper, and then applied onto a PET film whose surface was release-treated using an applicator. The film was coated to a thickness and dried by heating in an oven at 110 ° C. for 3 minutes to produce a sheet as an adhesive for semiconductor.

(Evaluation)
(1) Degree of crosslinking after heating Each sheet was heated and cured in an oven at 170 ° C. for 30 minutes, and then the sheet was immersed in an ethyl acetate solvent and shaken for 24 hours. Thereafter, it was dried in an oven at 110 ° C. for 60 minutes, and the dry weight was measured. The ratio between the weight of the sheet after drying and the weight of the sheet before immersion in the solvent was calculated as a percentage (weight after drying / weight before immersion in solvent × 100 (%)), and used as an index of the degree of crosslinking.

(2) Chlorine ion impurity amount Each sheet was thermally cured in an oven at 170 ° C. for 30 minutes. Next, 1 g of the cured sheet is finely cut into a glass test tube, 10 g of distilled water is added, the test tube is sealed with a burner, and heated for 12 hours with occasional shaking in an oven at 110 ° C. Extraction was performed. Thereafter, the amount of chlorine ion impurities (ppm) in the extracted water was measured using ion chromatography.

(3) Fluidity Each sheet was bonded to a 10 mm square Si chip (thickness 80 μm) to obtain a Si chip with a sheet. A substrate having irregularities on the surface, a maximum height difference between the concave and convex portions of 8 μm, and a thickness of 180 μm was prepared. On this substrate, using a die bonder set to conditions of 5N, 1 second and 100 ° C., a Si chip with a sheet is bonded on the substrate, and the three-layer structure of Si chip / sheet (adhesive for semiconductor) / substrate A joined body was obtained.

  Using an ultrasonic peeling flaw detector mi-scope (manufactured by Hitachi Construction Machinery Finetech Co., Ltd.), the embedding degree of the adhesive in the concavo-convex portion on the substrate was determined by area ratio. When the adhesive is embedded in 90% of the concavo-convex part, “◯”, and when the adhesive is embedded in 70% or more and less than 90% of the concavo-convex part, “△”, less than 70% of the concavo-convex part The case where the adhesive was embedded was evaluated as “x”, and the fluidity was evaluated.

(4) Warpage amount A Si chip / sheet / substrate bonded body was obtained in the same manner as in the evaluation of fluidity. The height on the diagonal of the upper surface of the Si chip of the joined body was measured using a laser displacement meter. The difference in height between the end and the center of the Si chip was taken as the amount of warpage.

(5) Reflow heat resistance A Si chip / sheet / substrate joined body was obtained in the same manner as in the evaluation of fluidity. The joined body was placed in a constant temperature and humidity oven having a temperature of 85 ° C. and a relative humidity of 85%, and the joined body was subjected to moisture absorption. Furthermore, the presence or absence of peeling at the bonding interface of the bonded body was evaluated using the ultrasonic peeling flaw detector mi-scope. In each of the six joined bodies, the number of joined bodies in which peeling did not occur was counted.

  The results are shown in Table 1 below.

Claims (8)

  A semiconductor adhesive comprising an epoxy compound, a curing agent having a molecular weight of 500 or less, and a hydrogenated acrylonitrile-butadiene copolymer.   The adhesive for semiconductors of Claim 1 whose said hardening | curing agent is an acid anhydride.   The adhesive for semiconductors of Claim 1 or 2 which contains the said acrylonitrile-butadiene copolymer in the ratio of 10-200 weight part with respect to 100 weight part of said epoxy compounds.   The adhesive agent for semiconductors of any one of Claims 1-3 whose ratio of the amount of acrylonitrile in the said acrylonitrile-butadiene copolymer is 10 to 40 weight%.   The adhesive for semiconductors of any one of Claims 1-4 which further contains a crosslinking agent.   The adhesive for semiconductors of any one of Claims 1-5 which further contains a crosslinking adjuvant.   The amount of chlorine ion impurities in the extracted water obtained by adding 10 g of water to 1 g of the cured product of the adhesive for semiconductor and extracting it is 50 ppm or less for a semiconductor according to claim 1. adhesive.   An adhesive tape for semiconductor, comprising: an adhesive layer comprising the adhesive for semiconductor according to any one of claims 1 to 7; and a base material layer attached to one surface of the adhesive layer. .