JP5931700B2 - Protective film for semiconductor wafer and method for manufacturing semiconductor chip - Google Patents

Description

  The present invention relates to a protective film for a semiconductor wafer and a method for manufacturing a semiconductor chip.

  In order to reduce the mounting area of the semiconductor chip and reduce the height, a flip chip connection method is used. In this connection method, a semiconductor chip is obtained by dicing a wafer having a circuit and connection bumps formed on the surface, and after the surface of the chip is connected to a substrate, resin sealing or the like is used to protect the semiconductor chip. To do.

  A chip protective film forming sheet that prevents the chip from being damaged by the vibration of the rotary blade in the dicing process (hereinafter referred to as “chipping”) and acts as a sealing film instead of resin sealing is known ( Patent Document 1 and Patent Document 2).

  Also known are those using a reinforcing material having a low linear expansion coefficient to prevent twisting of the IC card (Patent Document 3) and those using a reinforcing material to prevent cracking of the semiconductor chip in the IC card. (Patent Document 4).

  The chip protective film is used by being attached to the back surface of the wafer. Therefore, it is this protective film that is finally cut by the rotary blade in the dicing process. However, since the resin component contained in the protective film has stretchability, it is difficult to cut, and there is a problem that the rotary blade is clogged to vibrate the rotary blade and damage the wafer.

  When a reinforcing material having a high elastic modulus is used to prevent the twisting of the IC card, it is possible to prevent the twisting due to the high elastic modulus of the reinforcing material when the IC card is subjected to twisting or bending stress. However, when a high-temperature curing thermosetting adhesive is used to bond the high elastic modulus reinforcing material to the semiconductor chip, it is large due to the strain at curing and the thermal strain generated from the temperature difference between the curing temperature and room temperature. Warpage occurs and a thin semiconductor chip is cracked by bending stress.

  In the method of sticking the reinforcing material to the semiconductor chip in the IC card, due to multiple times of curing process, sticking out of the adhesive, displacement and inclination of the reinforcing material, variation in bending strength due to uneven thickness of the adhesive, Variations in quality and a significant decrease in productivity occur.

JP 2002-280329 A JP 2004-260190 A Japanese Patent Laid-Open No. 10-24686 JP 2000-268152 A

Hiroshima Institute of Technology Bulletin 43 (2009) p57-64

  Moreover, in the method of sticking and curing a protective film on a semiconductor wafer, high temperature curing conditions are required, and therefore the semiconductor wafer is greatly warped due to the difference in linear expansion coefficient between the semiconductor wafer and the protective film. In Non-Patent Document 1, a detailed study is performed when an epoxy resin composition layer is bonded to a printed circuit board or steel, and the thickness of the epoxy resin composition layer, the reaction temperature, and the linear expansion until gelation. It is described that the magnitude of warpage varies depending on the coefficient and elastic modulus, the linear expansion coefficient and elastic modulus after gelation, and the linear expansion coefficient and elastic modulus of printed circuit boards and steel materials. A semiconductor wafer that has greatly warped cannot be transported mechanically, and since the internal stress strain is large, variations in quality and productivity are significantly reduced due to variations in bending strength.

  The present invention has been made in view of the above circumstances, and a semiconductor wafer protective film capable of reducing the warpage of the semiconductor wafer so that the warpage of the semiconductor wafer is small, the bending strength is high, and the variation in the bending strength can be reduced. An object of the present invention is to provide a semiconductor chip manufacturing method with high productivity.

In order to solve the above problems, according to the present invention,
A protective film for a semiconductor wafer comprising a base film and a protective film formed on the upper side of the base film,
The protective film comprises an adhesive layer and a reinforcing layer,
The adhesive layer contains the following components (A) to (D), the peak temperature measured by DSC after heating at 10 ° C./min is 190 ° C. or less, and the reinforcing layer is the following ( Provided is a protective film for a semiconductor wafer comprising components E) and (F) and having a coefficient of linear expansion of 30 ppm or less at a temperature not higher than the glass transition temperature after curing.
(A) At least one selected from the group consisting of phenoxy resin, polyimide resin, and (meth) acrylic resin: 100 parts by mass,
(B) Epoxy resin: 5-200 parts by mass,
(C) Fillers other than the network-like inorganic filler: 100 to 500 parts by mass,
(D) Epoxy resin curing catalyst: catalyst amount,
(E) Thermosetting resin: 300 to 4000 parts by mass, and (F) Reticulated inorganic filler: 300 to 4000 parts by mass.

  Thus, if the protective film of the protective film for a semiconductor wafer is composed of two layers of a low linear expansion coefficient reinforcing layer and a low-temperature curable adhesive layer, the bending strength is high and the bending strength variation is high. The warpage of the semiconductor wafer can be reduced. Therefore, no problem occurs during machine conveyance, and chipping when a semiconductor chip is obtained by dicing the semiconductor wafer can be prevented.

  Moreover, the phenoxy resin in the component (A) is a bisphenol A type phenoxy resin or a bisphenol F type phenoxy resin, and the epoxy resin of the component (B) is a liquid bisphenol A type epoxy resin or a liquid bisphenol F type epoxy resin. Preferably there is.

  If it is a combination of such (A) component and (B) component, the protective film for semiconductor wafers will become further excellent in adhesiveness with respect to a semiconductor wafer.

  In addition, the thermosetting resin in the component (E) is heated at 10 ° C./min and the peak temperature measured by DSC is 250 ° C. or more. The calorific value of the reinforcing layer when the adhesive layer is cured is 20 J / g. The following is preferable.

  With such a component (E) and a reinforcing layer, it is possible to suppress curing warpage and thermal warpage of the entire protective film, and to further reduce variations in warpage and bending strength of the semiconductor wafer.

  The present invention also relates to a method of manufacturing a semiconductor chip by dicing a semiconductor wafer, wherein the protective film for a semiconductor wafer is attached to the semiconductor wafer, cured, and then dicing in a lump. A semiconductor chip manufacturing method for manufacturing a semiconductor chip having a protective film of the same size as the semiconductor chip is provided.

  With such a method for manufacturing a semiconductor chip, since the bending strength is high and the variation is small, the variation in the quality of the obtained semiconductor chip is reduced, and further the warp of the semiconductor wafer is reduced. In addition, the machine can be easily transported, chipping during dicing can be prevented, and high productivity of the semiconductor chip can be realized.

  The semiconductor wafer protective film of the present invention has a low-temperature curing type adhesive layer and a low linear expansion coefficient reinforcing layer on the protective film, so that the bending strength is high, the variation in the bending strength is small, and the warp of the semiconductor wafer is small. High productivity can be realized due to the small size.

As a result of intensive studies to achieve the above object, the present inventors
A protective film for a semiconductor wafer comprising a base film and a protective film formed on the upper side of the base film, wherein the protective film comprises an adhesive layer and a reinforcing layer, and the adhesive layer comprises the following (A) -(D) component is included, the peak temperature measured by DSC by heating at 10 ° C./min is 190 ° C. or less, and the reinforcing layer contains the following components (E) and (F): It has been found that if it has a linear expansion coefficient of 30 ppm or less at a temperature not higher than the glass transition temperature after curing, it will be a good protective film for a semiconductor wafer.
(A) At least one selected from the group consisting of phenoxy resin, polyimide resin, and (meth) acrylic resin: 100 parts by mass,
(B) Epoxy resin: 5-200 parts by mass,
(C) Fillers other than the network-like inorganic filler: 100 to 500 parts by mass,
(D) Epoxy resin curing catalyst: catalyst amount,
(E) Thermosetting resin: 300 to 4000 parts by mass, and (F) Reticulated inorganic filler: 300 to 4000 parts by mass.

(A) At least one phenoxy resin selected from the group consisting of a phenoxy resin, a polyimide resin, and a (meth) acrylic resin is a resin derived from epichlorohydrin and bisphenol A or bisphenol F or the like. Preferably, the polystyrene equivalent weight average molecular weight measured by GPC is 10,000 to 200,000, more preferably 20,000 to 100,000, and most preferably 30,000 to 80,000. If the weight average molecular weight is 10,000 or more, it is easy to form a film. On the other hand, if it is 200,000 or less, sufficient softness along the unevenness of the substrate surface having a fine circuit pattern is obtained. This is preferable.

  Examples of the phenoxy resin include those sold under the trade names PKHC, PKHH, and PKHJ (all manufactured by Sakai Chemical Co., Ltd.), and trade names Epicoat 4250, Epicoat 4275, and Epicoat 1255HX30 of mixed types of bisphenol A and bisphenol F. (All manufactured by Nippon Kayaku Co., Ltd.), Epicoat 5580BPX40 (all manufactured by Nippon Kayaku Co., Ltd.) using brominated epoxy, bisphenol A type trade names YP-50, YP-50S, YP-55, Examples include those commercially available as YP-70 (all manufactured by Tohto Kasei Co., Ltd.), those sold under the trade names JER E1256, E4250, E4275, YX6954BH30, and YL7290BH30 (all manufactured by Japan Epoxy Resin Co., Ltd.). it can. JER E1256 is preferably used in that it has the above-described weight average molecular weight. The phenoxy resin has an epoxy group at the terminal, which reacts with the component (B) described later.

（式中、Ｘは芳香族環又は脂肪族環を含む四価の有機基、Ｙは二価の有機基、ｑは１〜３００の整数である。） As a polyimide resin, what contains the following repeating unit can be used.

(In the formula, X is a tetravalent organic group containing an aromatic ring or an aliphatic ring, Y is a divalent organic group, and q is an integer of 1 to 300.)

  As said polyimide resin, Preferably the weight average molecular weight of polystyrene conversion measured by GPC is 10,000-200,000, More preferably, it is 20,000-100,000, Most preferably, it is 30,000-80,000. It is. If the weight average molecular weight is 10,000 or more, it is easy to form a film. On the other hand, if it is 200,000 or less, sufficient softness along the unevenness of the substrate surface having a fine circuit pattern is obtained. This is preferable.

（式中、Ｘ、Ｙ、ｑは上記と同様である。） The polyimide resin can be obtained by dehydrating and ring-closing a polyamic acid resin having the following repeating units by a conventional method.

(In the formula, X, Y and q are the same as above.)

（式中、Ｘは上記と同様である。）
で表されるテトラカルボン酸二無水物と、下記構造式（４）
Ｈ_２Ｎ−Ｙ−ＮＨ_２ （４）
（式中、Ｙは上記と同様である。）
で表されるジアミンを、常法に従ってほぼ等モルで有機溶剤中で反応させることによって得ることができる。 The polyamic acid resin represented by the above formula has the following structural formula (3)

(Wherein X is the same as above)
A tetracarboxylic dianhydride represented by the following structural formula (4)
_{H 2 N-Y-NH 2} (4)
(In the formula, Y is the same as above.)
Can be obtained by reacting in a substantially equimolar amount in an organic solvent according to a conventional method.

  Here, the following can be mentioned as an example of the tetracarboxylic dianhydride represented by the said Formula (3), You may use combining these.

  Among the diamines represented by the above formula (4), it is preferable that 1 to 80 mol%, more preferably 1 to 60 mol% is a diaminosiloxane compound represented by the following structural formula (5). It is preferable from the viewpoints of solubility in a solvent, adhesion to a substrate film, low elasticity, and flexibility.

（式中、Ｒ^１は互いに独立に炭素数３〜９の二価の有機基であり、Ｒ^２及びＲ^３は、それぞれ独立に、非置換もしくは置換の炭素原子数１〜８の一価炭化水素基であり、ｍは１〜２００の整数である。）

(In the formula, R ¹ is a divalent organic group having 3 to 9 carbon atoms independently of each other, and R ² and R ³ are each independently an unsubstituted or substituted monovalent carbon atom having 1 to 8 carbon atoms. It is a hydrogen group, and m is an integer of 1 to 200.)

The ^{R 1} is a divalent organic group having the carbon number 3-9, for _{example, - (CH 2) 3 -} , - (CH 2) 4 -, - CH 2 CH (CH 3) -, - ( Alkylene groups such as CH ₂ ) ₆ — and — (CH ₂ ) ₈ —,

のいずれかで表されるアリーレン基、アルキレン・アリーレン基、−（ＣＨ_２）_３−Ｏ−、−（ＣＨ_２）_４−Ｏ−等のオキシアルキレン基、下記式

An arylene group represented by any one of the following: an alkylene / arylene group, an oxyalkylene group such as — (CH ₂ ) ₃ —O—, — (CH ₂ ) ₄ —O—, and the following formula

のいずれかで表されるオキシアリーレン基、下記式

An oxyarylene group represented by any of the following formulae

で表されるオキシアルキレン・アリーレン基等のエーテル結合を含んでもよい二価炭化水素基を挙げることができる。

And a divalent hydrocarbon group which may contain an ether bond such as an oxyalkylene / arylene group represented by the formula:

Examples of R ² or R ³ in the above formula (5) include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a hexyl group, a cyclohexyl group, and a 2-ethylhexyl group. , Alkyl groups such as octyl group, allyl group, propenyl group, isopropenyl group, butenyl group, isobutenyl group, hexenyl group and other alkenyl groups, phenyl group, tolyl group, xylyl group and other aryl groups, benzyl group, phenylethyl group An aralkyl group such as, a group in which some or all of the hydrogen atoms bonded to the carbon atoms of these hydrocarbon groups are substituted with a halogen atom such as fluorine, bromine or chlorine, such as a chloromethyl group, a bromoethyl group, 3 Halogen-substituted alkyl groups such as 1,3,3-trifluoropropyl group, etc., among which methyl group and Eniru group is preferred. A combination of two or more diaminosiloxane compounds can also be used.

  Examples of the diamine represented by the above formula (4) other than the diaminosiloxane compound represented by the above formula (5) include p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, and 4,4. '-Diaminodiphenyl ether, 2,2'-bis (4-aminophenyl) propane, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfide, 1,4-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 1,4-bis (p-aminophenylsulfonyl) benzene, 1,4-bis (m-aminophenylsulfonyl) benzene, 1,4-bis (p-amino) Phenylthioether) benzene, 1,4-bis (m-aminophenylthioether) benzene, 2,2- [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [3-methyl-4- (4-aminophenoxy) phenyl] propane, 2,2-bis [3-chloro-4- (4) -Aminophenoxy) phenyl] propane, 1,1-bis [4- (4-aminophenoxy) phenyl] ethane, 1,1-bis [3-methyl-4- (4-aminophenoxy) phenyl] ethane, 1, 1-bis [3-chloro-4- (4-aminophenoxy) phenyl] ethane, 1,1-bis [3,5-dimethyl-4- (4-aminophenoxy) phenyl] ethane, bis [4- (4 -Aminophenoxy) phenyl] methane, bis [3-methyl-4- (4-aminophenoxy) phenyl] methane, bis [3-chloro-4- (4-aminophenoxy) phenyl] methane, bi [3,5-dimethyl-4- (4-aminophenoxy) phenyl] methane, bis [4- (4-aminophenoxy) phenyl] sulfone, 2,2-bis [4- (4-aminophenoxy) phenyl] per Aromatic ring-containing diamines such as fluoropropane can be mentioned, and preferably p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, 1,4-bis ( 3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [3-methyl-4- (4-aminophenoxy) phenyl] propane and the like.

式中、Ａは下記のいずれかの基

式中、Ｂは下記のいずれかの基

（式中、Ｒ^４は、互いに独立に、水素原子又はフッ素、臭素、ヨウ素などのハロゲン原子、あるいはアルキル基、アルケニル基、アルキニル基、トリフルオロメチル基、フェニル基などの非置換又は置換の炭素原子数１〜８の一価炭化水素基であり、各芳香環に付いている置換基は同一であっても異なっていてもよく、ｎは０〜５の整数である。Ａ、Ｂはおのおの１種単独でも、２種以上の組み合わせでもよい。Ｒは水素原子、ハロゲン原子又は非置換もしくは置換の一価炭化水素基である。） The polyimide resin preferably has a phenolic hydroxyl group from the viewpoint of adhesiveness. The phenolic hydroxyl group can be prepared by using a diamine compound having a phenolic hydroxyl group, and examples of such a diamine include those having the following structures.

In the formula, A is any of the following groups:

In the formula, B is any of the following groups:

(Wherein R ⁴ is independently of each other a hydrogen atom or a halogen atom such as fluorine, bromine or iodine, or an unsubstituted or substituted carbon such as an alkyl group, alkenyl group, alkynyl group, trifluoromethyl group or phenyl group. It is a monovalent hydrocarbon group having 1 to 8 atoms, and the substituents attached to each aromatic ring may be the same or different, and n is an integer of 0 to 5. A and B are each 1 type may be individual, or 2 or more types may be combined, R is a hydrogen atom, a halogen atom, or an unsubstituted or substituted monovalent hydrocarbon group.)

Examples of the unsubstituted or substituted monovalent hydrocarbon group having 1 to 8 carbon atoms of R ⁴ are the same as those exemplified for R ² and R ³ , and an ethynyl group, a propynyl group, and a butynyl group. And alkynyl groups such as a hexynyl group.

（式中、Ｒ’は水素原子、フッ素、臭素、ヨウ素などのハロゲン原子、又は炭素数１〜８の、アルキル基、アルケニル基、アルキニル基、トリフルオロメチル基、フェニル基などの非置換又はハロゲン置換の１価炭化水素基であり、各芳香族環に付いている置換基は同一であっても異なっていてもよく、Ｘは単結合、メチレン基、又はプロピレン基である。ｎは上記と同様である。） Moreover, the following can be mentioned as diamine which has another phenolic hydroxyl group.

(In the formula, R ′ is a hydrogen atom, a halogen atom such as fluorine, bromine or iodine, or an unsubstituted or halogenated alkyl group, alkenyl group, alkynyl group, trifluoromethyl group, phenyl group or the like having 1 to 8 carbon atoms. A substituted monovalent hydrocarbon group, the substituents attached to each aromatic ring may be the same or different, and X is a single bond, a methylene group or a propylene group, and n is as described above. The same is true.)

  Among the diamine compounds having a phenolic hydroxyl group, a diamine compound represented by the following formula (6) is particularly preferable.

（式中、Ｒ^４は上記と同様である。）

(In the formula, R ⁴ is the same as above.)

  As a compounding quantity of the diamine compound which has the said phenolic hydroxyl group, it is preferable that it is 5-60 mass% of the whole diamine compound, and it is especially 10-40 mass%. When a polyimide silicone resin having a blending amount within this range is used, a composition having a high adhesive force and forming a flexible adhesive layer can be obtained.

  A monoamine having a phenolic hydroxyl group can also be used for introduction of the phenolic hydroxyl group, and examples thereof include a monoamine having the following structure.

（式中、Ｒ^４は上記と同様であり、各芳香環に付いている置換基は同一であっても異なっていても構わない。Ｄは１種単独で用いても２種以上を併用してもよい。また、ｐは１〜３の整数である。）

(In the formula, R ⁴ is the same as above, and the substituents attached to each aromatic ring may be the same or different. D may be used alone or in combination of two or more. In addition, p is an integer of 1 to 3.)

  When a monoamine having a phenolic hydroxyl group is used, the amount is preferably 1 to 10 mol% based on the entire diamine compound.

  The polyamic acid resin can be synthesized by dissolving the above starting materials in a solvent under an inert atmosphere and reacting them usually at 80 ° C. or lower, preferably 0 to 40 ° C. The obtained polyamic acid resin is usually heated to 100 to 200 ° C., preferably 150 to 200 ° C., thereby dehydrating and ring-closing the acid amide portion of the polyamic acid resin to synthesize the target polyimide resin. it can.

  The solvent may not be one that can completely dissolve the starting material as long as it is inert to the resulting polyamic acid. For example, tetrahydrofuran, 1,4-dioxane, cyclopentanone, cyclohexanone, γ-butyrolactone, N-methylpyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide and dimethyl sulfoxide can be mentioned, preferably non- Protic polar solvents, particularly preferably N-methylpyrrolidone, cyclohexanone and γ-butyrolactone. These solvents can be used singly or in combination of two or more.

  In order to facilitate the dehydration ring closure, it is preferable to use an azeotropic dehydrating agent such as toluene or xylene. Further, dehydration ring closure can be performed at a low temperature using an acetic anhydride / pyridine mixed solution.

  In order to adjust the molecular weight of polyamic acid and polyimide resin, dicarboxylic acid anhydrides such as maleic anhydride and phthalic anhydride and / or aniline, n-butylamine, monoamines having the above-mentioned phenolic hydroxyl groups are added. You can also However, the addition amount of dicarboxylic anhydride is usually 0 to 2 parts by mass per 100 parts by mass of tetracarboxylic dianhydride, and the addition amount of monoamine is usually 0 to 2 parts by mass per 100 parts by mass of diamine. Part.

  Examples of the (meth) acrylic resin include a (meth) acrylic acid ester copolymer composed of a structural unit derived from a (meth) acrylic acid ester monomer and a (meth) acrylic acid derivative. Here, the (meth) acrylic acid ester monomer is preferably a (meth) acrylic acid alkyl ester having an alkyl group having 1 to 18 carbon atoms, such as methyl (meth) acrylate, ethyl (meth) acrylate, (meth ) Propyl acrylate, butyl (meth) acrylate, etc. are used. Examples of the (meth) acrylic acid derivative include (meth) acrylic acid, glycidyl (meth) acrylate, and hydroxyethyl (meth) acrylate.

  By copolymerizing glycidyl methacrylate and the like and introducing a glycidyl group into the (meth) acrylic resin, compatibility with the epoxy resin as a thermosetting adhesive component described later is improved, and the glass transition temperature after curing. (Tg) is increased and the heat resistance is also improved. Further, by introducing a hydroxyl group into the acrylic polymer with hydroxyethyl acrylate or the like, it becomes easy to control the adhesion to the chip and the physical properties of the adhesive.

  The weight average molecular weight of the (meth) acrylic resin is preferably 100,000 or more, more preferably 150,000 to 1,000,000. Moreover, it is preferable that Tg of a (meth) acrylic resin is 20 degrees C or less, More preferably, it is about -70 to 0 degreeC, and has adhesiveness at normal temperature (23 degreeC).

(B) Epoxy resin The epoxy resin is a resin different from the component (A), and preferably has an epoxy equivalent of 50 to 5000 g / eq, more preferably 100 to 500 g / eq.
Examples of such epoxy resins include bisphenol A-type epoxy resins, bisphenol F-type epoxy resins (particularly liquid bisphenol A-type epoxy resins or liquid bisphenol F-type epoxy resins); phenols such as resorcinol, phenylanol novolak, and cresol novolak. Glycidyl ethers; glycidyl ethers of alcohols such as butanediol, polyethylene glycol, and polypropylene glycol; glycidyl ethers of carboxylic acids such as phthalic acid, isophthalic acid, and tetrahydrophthalic acid; active hydrogen bonded to nitrogen atoms such as aniline isocyanurate Group-substituted glycidyl or alkyl glycidyl type epoxy resins; vinylcyclohexane diepoxide, 3,4-epoxycyclohexyl Carbon-carbon in the molecule, such as til-3,4-dicyclohexanecarboxylate, 2- (3,4-epoxy) cyclohexyl-5,5-spiro (3,4-epoxy) cyclohexane-m-dioxane Examples include so-called alicyclic epoxides in which an epoxy is introduced by oxidizing a double bond, for example. In addition, an epoxy resin having a biphenyl skeleton, a dicyclohexadiene skeleton, or a naphthalene skeleton can be used.

  Among these, bisphenol A type epoxy resin, bisphenol F type epoxy resin (particularly liquid bisphenol A type epoxy resin or liquid bisphenol F type epoxy resin), o-cresol novolak type epoxy resin and phenol novolak type epoxy resin are preferably used. . Two or more of these epoxy resins may be used in combination.

  (B) An epoxy resin is 5-200 mass parts with respect to 100 mass parts of (A) component, Preferably it is 10-200 mass parts, More preferably, 50-150 mass parts is mix | blended. When the component (A) and the component (B) are blended at such a ratio, an appropriate tack is exhibited before curing, and a sticking operation to the wafer can be stably performed. An excellent protective film can be obtained.

  In the combination of the component (A) and the component (B), the phenoxy resin in the component (A) is bisphenol A type phenoxy resin or bisphenol F type phenoxy resin, and the epoxy resin of the component (B) is liquid bisphenol A It is preferably a type epoxy resin or a liquid bisphenol F type epoxy resin.

(C) Filler other than reticulated inorganic filler (C) As the filler of component (C), inorganic fillers other than reticulated inorganic filler (non-reticulated inorganic filler) such as silica, alumina, titanium oxide, carbon Conductive particles such as black and silver particles, and silicone resin powder, for example, a crosslinked spherical dimethylpolysiloxane fine powder having a structure in which dimethylpolysiloxane is crosslinked (Japanese Patent Laid-Open No. 3-93834), a crosslinked spherical polymethylsilsesquioxide Oxane fine powder (Japanese Patent Laid-Open No. 3-47848), fine powder obtained by coating the surface of a crosslinked spherical polysiloxane rubber with polymethylsilsesquioxane particles (Japanese Patent Laid-Open No. 7-196815, Japanese Patent Laid-Open No. 9-20631) Gazette) can be used.

  The blending amount of the filler is 100 to 500 parts by mass, preferably 200 to 400 parts by mass with respect to 100 parts by mass of the component (A). When the blending amount is 100 parts by mass or more, low water absorption, low linear expansion, and the like, which are blending purposes of the filler, can be sufficiently achieved. If low water absorption cannot be achieved, the semiconductor device will fail the moisture absorption reliability test, and if the low linear expansion coefficient cannot be achieved, the linear expansion coefficient mismatch will occur when the composite of the protective film for semiconductor wafer and silicon wafer is cured. Occurs, causing a large warp and subsequent dicing becomes impossible. On the other hand, if it is 500 parts by mass or less, there is no fear that the viscosity of the protective layer-forming composition will be excessively increased, there is no possibility that the fluidity when applied to the base film will be deteriorated, and the protective film is applied to the silicon wafer. There is no possibility that sticking at a low temperature becomes difficult, and it is possible to prevent the composite of the wafer and the protective film for a semiconductor wafer from warping greatly. It is preferable that the content rate of a filler is 30-80 mass% of a protective film.

  As the silica, fused silica or crystalline silica is used. The average particle diameter of silica is preferably 0.1 to 10 μm, and more preferably 0.5 to 7 μm. When the average particle diameter of silica is within this range, good smoothness of the surface of the applied protective film (adhesive layer) can be obtained. Further, in recent years, the thickness of the adhesive layer is often required to be 15 to 50 μm. However, if the average particle diameter of silica is within the above range, even if secondary agglomerated particles are present, the requirement is satisfied. Easy to fill.

  The fine powder obtained by coating the surface of the crosslinked spherical polysiloxane rubber with polymethylsilsesquioxane particles was described in the above-mentioned publications (JP-A-7-196815, JP-A-9-20631). It can be made by a method, or a commercially available silicone composite powder KMP600 series (manufactured by Shin-Etsu Chemical Co., Ltd.) can be used. KMP600 is preferably used from the viewpoint of particle size.

  As the filler of the component (C), an inorganic filler, more preferably silica, and most preferably silica produced by a deflagration method is used. The silica is easily wetted by the resin component and is surface-treated according to a conventional method. As the surface treatment agent, a silane (silane coupling agent) is preferable because of its versatility and cost merit. As the silane coupling agent, the alkoxysilane includes glycidoxymethyltrimethoxysilane, glycidoxymethyltriethoxysilane, α-glycidoxyethyltrimethoxysilane, α-glycidoxyethyltriethoxysilane, β- Glycidoxyethyltrimethoxysilane, β-glycidoxyethyltriethoxysilane, α-glycidoxypropyltrimethoxysilane, α-glycidoxypropyltriethoxysilane, β-glycidoxypropyltrimethoxysilane, β- Glycidoxypropyl-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, α-glycidoxybutyltrimethoxysilane, α-glycidoxybutyl Triethoxysilane, -Glycidoxybutyltrimethoxysilane, β-glycidoxybutyltriethoxysilane, γ-glycidoxybutyltrimethoxysilane, γ-glycidoxybutyltriethoxysilane, δ-glycidoxybutyltrimethoxysilane, δ -Glycidoxybutyltriethoxysilane, (3,4-epoxycyclohexyl) methyltrimethoxysilane, (3,4-epoxycyclohexyl) methyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltripropoxysilane, β- (3,4-epoxycyclohexyl) ethyltributoxysilane, β- (3, 4-epoxycyclohexyl) ethyl Riphenoxysilane, γ- (3,4-epoxycyclohexyl) propyltrimethoxysilane, γ- (3,4-epoxycyclohexyl) propyltriethoxysilane, δ- (3,4-epoxycyclohexyl) butyltrimethoxysilane, δ Trialkoxysilanes such as-(3,4-epoxycyclohexyl) butyltrimethoxysilane, N-β- (aminoethyl) γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) γ-aminopropylmethyldiethoxy Silane, γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, trimethoxysilylpropyl nadic acid anhydride, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane are preferably used Is .

(D) Epoxy resin curing catalyst As the epoxy resin curing catalyst of component (D), a type that is cured by heating, that is, a so-called thermally activated latent epoxy resin curing agent is preferable. Examples of such an epoxy resin curing catalyst include dicyandiamide, imidazole compounds, various onium salts, dibasic acid dihydrazide compounds, and the like, and two or more of these may be used in combination. Specific examples thereof include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, and imidazole compounds. -Phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2 -Ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino- -[2'-methylimidazolyl- (1 ')]-ethyl-s-triazine, 2,4-diamino-6- [2'-methylimidazolyl- (1')]-ethyl-s-triazine, 2,4 -Diamino-6- [2'-undecylimidazolyl- (1 ')]-ethyl-s-triazine, 2,4-diamino-6- [2'-ethyl-4'-methylimidazolyl- (1')] -Ethyl-s-triazine, 2,4-diamino-6- [2'-methylimidazolyl- (1 ')]-ethyl-s-triazine isocyanuric acid adduct, 2,4-diamino-6- [2'- Methylimidazolyl- (1 ′)]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5 Hydroxymethylimidazole, 2,3-dihydro -1H- pyrrolo [1,2-a] benzimidazole, it can be mentioned 1-dodecyl-2-methyl-3-benzyl-imidazolium chloride.

  Moreover, a phosphorus catalyst can also be used as an epoxy resin curing catalyst, and examples thereof include triphenylphosphine, triphenylphosphonium triphenylborate, tetraphenylphosphonium tetraphenylborate, and compounds as shown below.

（式中、Ｒ^８〜Ｒ^１５は水素原子又はフッ素、臭素、ヨウ素などのハロゲン原子、あるいは炭素原子数１〜８のアルキル基、アルケニル基、アルキニル基、又は炭素原子数１〜８のアルコキシ基、トリフルオロメチル基、フェニル基などの非置換もしくは置換一価炭化水素基であり、総ての置換基が同一であっても互いに異なっていてもよい。）

(Wherein R ^{8 to} R ¹⁵ are a hydrogen atom or a halogen atom such as fluorine, bromine or iodine, or an alkyl group, alkenyl group, alkynyl group, or alkoxy group having 1 to 8 carbon atoms. , An unsubstituted or substituted monovalent hydrocarbon group such as a trifluoromethyl group and a phenyl group, and all the substituents may be the same or different from each other.)

  An imidazole compound is preferably used as the epoxy resin curing catalyst in that the adhesive layer is heated at 10 ° C./min and the peak temperature measured by DSC is 190 ° C. or less. The amount of the epoxy resin curing catalyst may be an amount effective as a catalyst (catalytic amount), but is usually used in an amount of 0.1 to 20 parts by mass, preferably 1 to 100 parts by mass with respect to 100 parts by mass of the epoxy resin. 12 parts by mass are used.

  The peak temperature (DSC peak temperature) measured by DSC of the adhesive layer containing the above components (A) to (D) is 190 ° C. or lower, preferably 180 ° C. or lower. When the DSC peak temperature is higher than 190 ° C., the thermal warpage due to the temperature difference between the curing temperature of the semiconductor wafer protective film adhesive layer and the curing temperature of the semiconductor wafer protective film adhesive layer and the reinforcing layer and the room temperature increases. When the wafer is greatly warped, it becomes impossible to transport the machine, and the variation in the bending strength of the semiconductor chip increases, making it unsuitable as an industrial product.

  The lower limit of the DSC peak temperature is not specifically defined, but the volatility temperature of the diluting solvent used when forming the adhesive layer, the flash point of the diluting solvent, the storage stability of the adhesive layer itself and the semiconductor wafer protective film when used at room temperature In view of the above, it is preferably 100 ° C. or higher.

(E) Thermosetting resin The thermosetting resin used in the present invention is softened by heating, has a film-forming ability, and further has characteristics required for an interlayer insulating material such as heat resistance and electrical characteristics by thermosetting at a high temperature. When the temperature of the cured thermosetting resin layer is raised at 10 ° C./min and the peak temperature measured by DSC is 250 ° C. or more and the reinforcing layer described below is produced, the calorific value Is preferably 20 J / g or less.

  When the DSC peak temperature of the thermosetting resin is higher than 250 ° C., there is no reaction at the same time when the adhesive layer of the protective film of the semiconductor wafer is cured, and expansion due to heat generation of the reinforcing layer at the time of gelation of the adhesive layer This is preferable because it is possible to prevent the curing warpage and thermal warpage of the entire protective film, and to further reduce variations in warpage and bending strength of the semiconductor wafer.

  Examples of the thermosetting resin include epoxy resin, acrylic resin, polyimide resin, polyamideimide resin, polycyanate resin, polyester resin, and thermosetting polyphenylene ether resin. Two or more of these may be used in combination, or an adhesive film layer having a multilayer structure may be used. Especially, the epoxy resin composition excellent in reliability and cost as an interlayer insulation material is preferable.

  The thermosetting resin is preferably 300 to 4000 parts by mass with respect to 100 parts by mass of the component (A). More preferably, it is 500 to 3000 parts by mass. When the blending amount is 300 parts by mass or more, the protective film has a high coefficient of linear expansion and is not likely to be greatly warped, and it is preferable that the bending strength is not lowered due to chipping during dicing. Further, when the blending amount is 4000 parts by mass or less, there is no fear that the smoothness of the adhesion surface of the protective film to the silicon wafer is lowered, there is no possibility that the adhesion force is lowered, and the bending strength is high. .

(F) Reticulated inorganic filler As the reticulated inorganic filler, glass cloth, glass paper, carbon cloth, and metal mesh can be preferably used. In particular, as the mesh-like inorganic filler, those in which long fibers are knitted in a mesh shape (IPC standard 1280 glass cloth, metal mesh of SUS304, etc. manufactured by Nittobo Co., Ltd.) or those in a random mesh shape are preferable. There is no particular limitation. For the purpose of reducing the stress after curing of the protective film, it is possible to produce a reinforcing layer with a low linear expansion coefficient by adding a large amount of spherical or flaky inorganic filler, but this is because the tensile strength and bending strength are poor. It is not suitable for improving the bending strength, which is one of the objects of the invention.

  The network-like inorganic filler is preferably 300 to 4000 parts by mass with respect to 100 parts by mass of the component (A). More preferably, it is 500 to 3000 parts by mass. When the blending amount is 4000 parts by mass or less, the protective film has a high linear expansion coefficient and is not likely to be greatly warped, and chipping is not caused at the time of dicing, so that the bending strength is not lowered. Further, when the blending amount is 300 parts by mass or more, there is no fear that the smoothness of the adhesion surface of the protective film to the silicon wafer is lowered, there is no possibility that the adhesion force is lowered, and the bending strength is high. .

  The reinforcing layer of the present invention is a thermosetting resin composition containing the above network-like inorganic filler. The linear expansion coefficient at a temperature of Tg or less after curing is 30 ppm or less.

  When the reinforcing layer of the present invention is filled with a filler other than the reticulated inorganic filler, the bending strength is not improved, and when the linear expansion coefficient after curing is 30 ppm or more, there is a difference between the linear expansion coefficient and the silicon wafer. It becomes large and generates a large warp, making it impossible to transport the machine. Further, the internal stress due to the warp increases and the variation in bending strength increases, making it unsuitable as an industrial product.

Other Components The protective film of the present invention may contain an epoxy resin curing agent and various additives in addition to the components described above. As the curing agent, phenol resins, for example, condensates of phenols such as alkylphenols, polyhydric phenols, naphthols, and aldehydes are used, preferably phenol novolak resins, o-cresol novolak resins, p-cresol novolak resins. T-butylphenol novolak resin, dicyclopentadiene cresol resin, polyparavinylphenol resin, bisphenol A type novolak resin, bisphenol F type novolak resin, or modified products thereof.

  Examples of the additive include pigments and dyes. When these are blended and the protective film in the present invention is colored, the laser mark performance is improved. Furthermore, a silane coupling agent can be added for the purpose of improving the adhesion and adhesion between the protective film and the chip back surface. In addition, you may mix | blend a flame retardant, an antistatic agent, etc.

  The elastic modulus after curing of the protective film for a semiconductor wafer of the present invention is preferably 10 to 100 GPa. If the elastic modulus after curing is 10 GPa or more, the protective film for a semiconductor wafer can sufficiently withstand bending stress at the time of bending, and there is no possibility of causing a decrease in bending strength. In addition, when the elastic modulus is 100 GPa or less, when the composite cured product of the protective film for a semiconductor wafer and the silicon wafer is warped, a large stress is generated on the silicon wafer side, and there is no fear that a lot of chipping occurs. There is no risk of lowering the bending strength.

Protective Film for Semiconductor Wafer As a method for producing the protective film for semiconductor wafer of the present invention, the following methods can be mentioned, but the method is not limited to these methods.
(E) A film prepared from a film-like reinforcing layer made of a network-like inorganic filler impregnated with a thermosetting resin, and an adhesive layer composition (components (A) to (D)) by the following method. A protective film for a semiconductor wafer having a protective film having a two-layer structure in which an adhesive layer in a shape is bonded is prepared.
Alternatively, (E) an adhesive layer composition (components (A) to (D)) prepared by the following method on a film-like reinforcing layer made of a network-like inorganic filler impregnated with a thermosetting resin (F) ) To produce a semiconductor wafer protective film having a two-layer protective film.

  The adhesive layer is a comma coater, gravure coater, or a composition obtained by mixing the above components (A) to (D) on a base film so that the thickness is 5 to 100 μm, preferably 10 to 60 μm. It can be obtained by a known method such as a die coater. In addition, said composition can be apply | coated by disperse | distributing to a solvent, for example, cyclohexanone, as needed.

  As the base film, a polyethylene film, a polypropylene film, a polyvinyl chloride film, a polyethylene terephthalate film, a polyimide film, or the like can be used. When the base film is peeled after the protective film is cured, a polyethylene terephthalate film or a polyimide film excellent in heat resistance is preferably used. At that time, a silicone resin or the like may be applied to the surface of the base film to perform a release treatment, or a peelable layer may be formed between the base film and the protective film.

  The thickness of the base film is preferably 5 to 200 μm, more preferably 10 to 150 μm, and particularly preferably about 20 to 100 μm.

The protective film for a semiconductor wafer is used, for example, by the following method.
(1) The process of sticking the protective film of the protective film for semiconductor wafers in this invention on the back surface of the semiconductor wafer in which the circuit was formed in the surface,
(2) The process of peeling the base film of the protective film for semiconductor wafers,
(3) a step of curing the protective film by heating,
(4) A step of dicing the semiconductor wafer and the protective film.
Here, the steps (2) and (3) may be performed in the reverse order.

  The dicing step (4) can be performed according to a conventional method using a dicing sheet. A semiconductor chip having a protective film on the back surface is obtained by dicing. The chip is picked up by a general-purpose means such as a collet and placed on the substrate. By using the protective film for a semiconductor wafer of the present invention, it is difficult for minute damage to occur on the cut surface of the chip, and a semiconductor device can be manufactured with a high yield.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not restrict | limited to the following Example.

Preparation of Composition for Forming Protective Layer In about 50 parts by mass of cyclohexane, the part (A) component shown in Table 1 was dissolved. The obtained solution was mixed with other components in the amounts shown in Table 1 to obtain a composition having a solid content of about 70% by mass.

The components shown in Tables 1 and 2 and the components used below are as follows.
(A) component Phenoxy resin: Mw about 60,000, JER 1256 (made by Japan Epoxy Resin Co., Ltd.)
Polyimide resin 1: A synthesis method will be described later.
Acrylic resin 1: 55 parts by weight of butyl acrylate, 15 parts by weight of methyl methacrylate, 20 parts by weight of glycidyl methacrylate, and 15 parts by weight of 2-hydroxyethyl acrylate (weight average molecular weight 900,000, glass transition temperature − 28 ℃)
(B) Component Epoxy resin: RE310S (manufactured by Nippon Kayaku Co., Ltd.), viscosity at 25 ° C. and 15 Pa. s
(C) Component Silica: SE2050, average particle size 0.5 μm, maximum particle size 5 μm, KBM-403 treated product, (D) component 2P4MHZ-PW (2-phenyl-4-methyl-5) manufactured by Admatechs Co., Ltd. -Hydroxymethylimidazole): Shikoku Kasei Co., Ltd. 2PHZ-PW (2-phenyl-4,5-dihydroxymethylimidazole): Shikoku Kasei Co., Ltd. DICY-7 (dicyandiamide): Japan Epoxy Resin Co., Ltd. (E) + (F) Ingredients Epoxy impregnated glass cloth Type 1: Manufacturing method described below Epoxy impregnated glass cloth Type 1 ': Manufacturing method described below Epoxy impregnated glass cloth Type 2: Manufacturing method described below Epoxy impregnated nylon cloth: Manufacturing method described below

次に、下記式：

で示されるフェノール性水酸基を有するジアミン（ＨＡＢ、和歌山精化製）８．３１質量部と１００質量部の２−メチルピロリドンを、還流冷却器が連結されたコック付きの２５ｍｌ水分定量受器、温度計、攪拌器を備えた１リットルのセパラブルフラスコに仕込み、分散させ、前出の酸無水物リッチのアミック酸オリゴマーを滴下した後、室温で１６時間攪拌し、ポリアミック酸溶液を合成した。その後、キシレン２５ｍｌを投入してから温度を上げ、約１８０℃で２時間還流させた。水分定量受器に所定量の水がたまっていること、水の流出が見られなくなっていることを確認し、水分定量受器にたまっている流出液を除去しながら、１８０℃でキシレンを除去した。反応終了後、大過剰のメタノール中に得られた反応液を滴下し、ポリマーを析出させ、減圧乾燥して、骨格中にフェノール性の水酸基を有するポリイミド樹脂を得た。
得られたポリイミド樹脂の赤外吸光スペクトルを測定したところ、未反応の官能基があることを示すポリアミック酸に基づく吸収は現れず、１７８０ｃｍ−１及び１７２０ｃｍ−１にイミド基に基づく吸収を確認し、３５００ｃｍ−１にフェノール性水酸基に基づく吸収を確認した。得られた樹脂のポリスチレン換算の重量平均分子量は５５，０００であり、官能基当量は７６０ｇ／ｅｑであった。 A diaminosiloxane (KF-8010, Shin-Etsu) represented by the following structural formula was placed in a 1-liter separable flask equipped with a 25 ml moisture determination receiver with a cock connected to a synthetic reflux condenser of polyimide resin 1, a thermometer, and a stirrer. (Chemical Co., Ltd.) 49.01 parts by mass and 100 parts by mass of 2-methylpyrrolidone as a reaction solvent were added and stirred at 80 ° C. to disperse the diamine. A solution of 42.68 parts by mass of 6FDA (2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane) and 100 parts by mass of 2-methylpyrrolidone as an acid anhydride was added dropwise thereto at room temperature for 2 hours. By carrying out a stirring reaction, an acid anhydride-rich amic acid oligomer was synthesized.

Next, the following formula:

25 ml moisture determination receiver with a cock connected with a reflux condenser, 8.31 parts by mass of a diamine having a phenolic hydroxyl group (HAB, manufactured by Wakayama Seika) and 100 parts by mass of 2-methylpyrrolidone, A 1-liter separable flask equipped with a total and a stirrer was charged and dispersed, and the above-mentioned acid anhydride-rich amic acid oligomer was added dropwise, followed by stirring at room temperature for 16 hours to synthesize a polyamic acid solution. Thereafter, 25 ml of xylene was added, the temperature was raised, and the mixture was refluxed at about 180 ° C. for 2 hours. Confirm that the specified amount of water has accumulated in the moisture meter and that no water has flowed out, and remove xylene at 180 ° C while removing the effluent collected in the meter. did. After completion of the reaction, the reaction solution obtained in a large excess of methanol was added dropwise to precipitate a polymer and dried under reduced pressure to obtain a polyimide resin having a phenolic hydroxyl group in the skeleton.
When the infrared absorption spectrum of the obtained polyimide resin was measured, absorption based on polyamic acid indicating that there was an unreacted functional group did not appear, and absorption based on imide groups was confirmed at 1780 cm-1 and 1720 cm-1. Absorption based on a phenolic hydroxyl group was confirmed at 3500 cm-1. The obtained resin had a polystyrene equivalent weight average molecular weight of 55,000 and a functional group equivalent of 760 g / eq.

Adhesive layer varnish adjustment 60% by weight of solid content from (A) phenoxy resin, polyimide resin, acrylic resin, (B) epoxy resin, (C) silica filler, (D) curing catalyst, diluent solvent The adhesive layer resin varnish was prepared. As a diluting solvent, methyl ethyl ketone was used, and the compositions (A) to (D) were dissolved or dispersed at 80 ° C. and returned to room temperature, followed by filtration with a # 400 wire mesh to obtain an adhesive layer varnish.

Adhesive layer preparation The adhesive layer varnish prepared as shown in Table 1 was applied at 2 m / min with a blade coater to one side of the release film layer side of the PET film that had been subjected to a release treatment as a base film, and then at 110 ° C. for 10 minutes. It heat-dried, the 20-micrometer-thick adhesive layer was formed, and the sheet | seat for adhesive layers coated on the whole surface on the base film was produced.

Reinforcing layer resin varnish adjustment A reinforcing layer resin varnish having a solid content of 50% by mass was prepared from the thermosetting resin and dilution solvent according to the formulation shown in Table 2. As the diluting solvent, methyl ethyl ketone was used. (E) The thermosetting resin composition was dissolved or dispersed at 80 ° C., and returned to room temperature, followed by filtration with a # 400 wire mesh to obtain a resin varnish for a reinforcing layer. .

Reinforcing layer preparation Each of the reinforcing layer resin varnishes described in Table 2 was collected in a bath, and a glass cloth having a thickness of 50 um (IPC standard: # 1280, yarn used: ECD450 1/0, weaving density: 60/25 mm in length and width), After passing a 50 um thick nylon cloth (material nylon 66, opening 36 um, thread diameter 33 um, opening ratio 28%) while immersing and scraping off the excess resin varnish with a 120 micron wide slit , And dried for 2 minutes in a continuous drying furnace adjusted to 165 ° C. Thereafter, the reinforcing layer type 1 and the nylon prepreg were dried again in a continuous drying furnace adjusted to 150 ° C. for 30 minutes, and the reinforcing layer type 1 ′ was dried at 150 ° C. for 60 minutes. A reinforcing layer was produced. For the reinforcing layer type 1 ″, five reinforcing layers 1 were laminated and pressure-applied at 180 kg / cm 2, 70 ° C. for 60 seconds to prepare a 400 μm thick reinforcing layer.

Preparation of protective film for semiconductor wafer (Examples 1-7 and Comparative Examples 1-5)
Adhesive layers (Coating liquids 1 to 5) shown in Table 1 and reinforcing layers shown in Table 2 are attached with a hot roll in the combinations shown in Examples 1 to 7 in Table 3 and Comparative Examples 1 to 5 in Table 4. In addition, a protective film for a semiconductor wafer was formed. The hot roll conditions were: roll speed: 0.6 m / min, roll pressure: 0.15 MPa, thermocompression bonding at 50 ° C., and then thermocompression bonding at 100 ° C. again.

DSC measurement The DSC curve was obtained with the following apparatus and measurement conditions. The exothermic peak from 150 ° C to 300 ° C was defined as the DSC peak temperature, and the integrated calorific value of the peak was defined as the DSC exothermic amount.
Rigaku's differential scanning calorimeter: Thermo Plus
Sample weight: 10mg
Reference: Alumina Temperature rising rate: 10 ° C / min
Sampling: 1.0s
Atmosphere: Nitrogen Temperature range: 25-400 ° C

TMA measurement The TMA curve was acquired with the following apparatus and measurement conditions, and the average linear expansion coefficient in the section from Tg temperature −60 ° C. to Tg temperature −10 ° C. was taken as the linear expansion coefficient equal to or lower than Tg.
Rigaku thermomechanical analyzer: Thermo Plus
Sample shape: 50um thickness, 4.85mm width, 15mm length Heating rate: 10 ° C / min
Sampling: 1.0s
Atmosphere: Air Temperature range: 25-300 ° C
Measurement mode: Tensile load method

The protective film obtained by the dicing test was obtained by using a Technovision FM-114 at a temperature of 50 ° C. and a 75 μm-thick silicon wafer (8-inch (200 mm) unpolished wafer, manufactured by Disco Corporation, DAG-810). And then grinded to a wafer having a thickness of 75 μm. A silicon wafer with a protective film was cured with a dryer in Examples 1 to 5 and Comparative Examples 1 to 4 at 150 ° C./2 hours, and Examples 6, 7 and Comparative Example 5 were cured at 175 ° C./4 hours to produce a semiconductor. The wafer protective film was cured. The silicon wafer with the protective film was diced into 10 mm × 10 mm square chips under the following conditions.
Device: DISCO Dicer DAD-341
Cutting method: Single dicing blade: ZH05-SD3500-N1-70EE
Blade rotation speed: 30000 rpm
Blade speed: 30 mm / sec
Dicing film thickness 110 μm, cutting into dicing film: 50 μm

Folding strength, bending strength standard deviation measurement test Folding strength of 40 chips of 10 mm x 10 mm square obtained by the dicing test of the test destination is measured under the following conditions, the average value is bending strength, and the standard deviation is bent The intensity standard deviation was taken as the measurement result. The results are shown in Tables 3 and 4.
Equipment: Shimadzu Corporation Autograph
Anti-folding jig: 4mm width Wedge shape Distance between fulcrums: 6mm
Wedge jig speed: 0.01 m / min

The protective film obtained by the wafer warpage test was obtained by using a Technovision FM-114 at 50 ° C. and a 75 μm-thick silicon wafer (8-inch (200 mm) unpolished wafer, manufactured by DISCO Corporation, DAG-810 And then grinded to a wafer having a thickness of 75 μm. A silicon wafer with a protective film was cured with a dryer in Examples 1 to 5 and Comparative Examples 1 to 4 at 150 ° C./2 hours, and Examples 6, 7 and Comparative Example 5 were cured at 175 ° C./4 hours to produce a semiconductor. The protective film was cured. The silicon wafer with the protective film was placed on a flat surface so as to protrude downward, and the point farthest from the flat surface at the edge of the wafer was measured to obtain a wafer warp.

  The protective film for semiconductors comprising the protective film of Examples 1 to 7 having a low linear expansion coefficient reinforcing layer and a low-temperature curing type adhesive layer has high bending strength, small variation, and wafer warpage. Since it is small, high productivity of the semiconductor chip can be realized. On the other hand, the protective film for a semiconductor including the reinforcing layer which is not the low linear expansion coefficient of Comparative Examples 1 to 3 has inferior bending strength, and warpage of the wafer is large. Moreover, the protective film for a semiconductor including the adhesive layer which is not a low-temperature curable type of Comparative Examples 4 and 5 had a large variation in bending strength and a large amount of warpage of the wafer.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits the same effects. Are included in the technical scope.

Claims (4)

A protective film for a semiconductor wafer comprising a base film and a protective film formed on the upper side of the base film,
The protective film comprises an adhesive layer and a reinforcing layer,
The adhesive layer contains the following components (A) to (D), the peak temperature measured by DSC after heating at 10 ° C./min is 190 ° C. or less, and the reinforcing layer is the following ( A protective film for a semiconductor wafer comprising components E) and (F) and having a linear expansion coefficient of 30 ppm or less at a temperature not higher than the glass transition temperature after curing.
(A) At least one selected from the group consisting of phenoxy resin, polyimide resin, and (meth) acrylic resin: 100 parts by mass,
(B) Epoxy resin: 5-200 parts by mass,
(C) Fillers other than the network-like inorganic filler: 100 to 500 parts by mass,
(D) Epoxy resin curing catalyst: catalyst amount,
(E) Thermosetting resin: 300 to 4000 parts by mass, and (F) Reticulated inorganic filler: 300 to 4000 parts by mass.   The phenoxy resin in the component (A) is a bisphenol A type phenoxy resin or a bisphenol F type phenoxy resin, and the epoxy resin in the component (B) is a liquid bisphenol A type epoxy resin or a liquid bisphenol F type epoxy resin. The protective film for a semiconductor wafer according to claim 1.   The peak temperature measured by DSC by heating the thermosetting resin in the component (E) at 10 ° C./min is 250 ° C. or higher, and the heating value of the reinforcing layer when the adhesive layer is cured is 20 J / g or lower. The semiconductor wafer protective film according to claim 1, wherein the protective film is a semiconductor wafer protective film.   A method for manufacturing a semiconductor chip by dicing a semiconductor wafer, wherein the protective film for a semiconductor wafer according to any one of claims 1 to 3 is attached to the semiconductor wafer, cured, and then collectively. A semiconductor chip manufacturing method comprising manufacturing a semiconductor chip having a protective film of the same size as the semiconductor chip on the back surface by performing dicing.