JP2015137287A - Protective film for semiconductor wafer and method for producing semiconductor chip with protective film for semiconductor wafer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a protective film for a semiconductor wafer which has few voids present between a semiconductor wafer, an adhesive layer and a reinforcing film layer and is well-balanced in a flexural strength of a semiconductor wafer.SOLUTION: There is provided a protective film for a semiconductor wafer which comprises a base film and a protective film formed on the upper side of the base film, where the protective film comprises an adhesive layer and a reinforcing film layer, the adhesive layer comprises (A) to (D) components, the reinforcing film layer comprises (E) and (F) components and the content ratio (the content in the flow direction/the content in the direction perpendicular to the flow direction) of (F) component in a cross-sectional area at the same width of the reinforcing film layer is more than 100% and 190% or less. (A) At least one selected from the group consisting of a phenoxy resin, a polyimide resin and a (meth)acrylic resin, (B) an epoxy resin part, (C) a filler other than a mesh-like inorganic filler, (D) an epoxy resin curing catalyst, (E) a thermosetting resin and (F) a mesh-like inorganic filler.

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.

  In the method of sticking and curing a protective film on a semiconductor wafer, high temperature curing conditions are required, so that 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.

  In order to prevent wrinkling of the film during transport of the protective film for semiconductor wafers, it is required to produce a reinforcing film layer that is strong in the film transport direction (flow direction: major axis direction) by applying tension to the film. It has been.

  In addition, since an air layer (void) that is a defect existing between each of the semiconductor wafer, the adhesive layer, and the reinforcing film layer is a starting point for cracking the semiconductor chip, in the process of manufacturing the semiconductor wafer protective film, When sticking a protective film on a semiconductor wafer, it is required that voids be reduced as much as possible.

  Furthermore, in general, a semiconductor chip has a long side and a short side. When a stress is applied perpendicular to the long side when compared by a three-point bend, the stress is applied perpendicular to the short side. Since it is easier to break than the case, a balanced reinforcing film layer is required.

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

  The present invention has been made in view of the above circumstances, and there are few voids existing between a semiconductor wafer, an adhesive layer, and a reinforcing film layer in a semiconductor wafer with a protective film, and the resistance perpendicular to the long side and the short side of the semiconductor chip. It is an object of the present invention to provide a semiconductor wafer protective film and a semiconductor chip manufacturing method having a balanced folding strength.

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 film layer,
The adhesive layer contains the following components (A) to (D), the reinforcing film layer contains the following components (E) and (F), and is perpendicular to the flow direction and flow of the reinforcing film layer. When the directions are compared, the content ratio of the component (F) in the cross-sectional area with the same width (content in the flow direction / content in the direction perpendicular to the flow) is higher than 100% and not higher than 190% A protective film for a semiconductor wafer is provided.
(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.

  With such a protective film for a semiconductor wafer, wrinkles are less likely to occur in the transport direction, so that voids existing between the semiconductor wafer, the adhesive layer, and the reinforcing film layer can be reduced. And the bending strength perpendicular to the short side can be balanced.

Further, a method of manufacturing a semiconductor chip by dicing a semiconductor wafer,
When the protective film for a semiconductor wafer according to the present invention is attached to the semiconductor wafer, the operation direction of a heat roller and the flow direction of the reinforcing film layer are attached together and then diced to produce a semiconductor chip. A method for manufacturing a semiconductor chip is preferable.

  If it is such a manufacturing method, by making the flow direction of the protective film for semiconductor wafers coincide with the operating direction of the heat roller, it is possible to provide a semiconductor chip in which voids are less likely to occur in a semiconductor chip with a protective film.

Further, a method of manufacturing a semiconductor chip by dicing a semiconductor wafer,
The ratio of the long side to the short side (long side / short side) of the semiconductor chip is 100% or more, and the flow direction of the reinforcing film layer of the protective film for semiconductor wafer of the present invention is parallel to the long side of the semiconductor chip. The semiconductor chip having a protective film in which the direction of the long side of the semiconductor chip and the flow direction of the reinforcing film layer are matched on the back surface is manufactured by performing pasting and curing, and then dicing in a lump. A method for manufacturing a semiconductor chip is preferable.

  With such a manufacturing method, it is possible to provide a more balanced semiconductor chip with the bending strength of the semiconductor chip being long and short.

  According to the protective film for a semiconductor wafer and the method for producing a semiconductor chip using the same according to the present invention, the void strength is small because the void is difficult to enter between the semiconductor wafer and the protective film for the semiconductor wafer. Semiconductor chips with a balanced ratio can be manufactured.

It is sectional drawing which shows an example of the protective film for semiconductor wafers of this invention. It is a schematic diagram which shows an example of the bending strength measurement test of the chip | tip which affixed the protective film for semiconductor wafers of this invention. It is a schematic diagram which shows an example of the bending strength measurement test of the chip | tip which affixed the protective film for semiconductor wafers of this invention.

As a result of intensive studies to achieve the above object, the present inventor,
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 film layer,
The adhesive layer contains the following components (A) to (D), the reinforcing film layer contains the following components (E) and (F), and is perpendicular to the flow direction and flow of the reinforcing film layer. When the direction is compared, the content ratio of the component (F) in the cross-sectional area with the same width (content in the flow direction / content in the direction perpendicular to the flow) is higher than 100% and not higher than 190% Then, it discovered that it became a good protective film for semiconductor wafers.
(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.

  Further, the present inventor is a method for manufacturing a semiconductor chip provided with a protective film on the non-circuit surface of the semiconductor chip, and a device for taking out the semiconductor chip is the same on the non-circuit surface side of the semiconductor wafer formed on one side. A protective film for semiconductor wafer having a content ratio (content in the flow direction / content in the direction perpendicular to the flow) of the network-like inorganic filler in the cross-sectional area in the width is higher than 100% and not higher than 190% In addition, when the protective film for the semiconductor wafer is bonded, the flow direction of the protective film for the semiconductor wafer and the operating direction of the heat roller are made to coincide with each other, or the flow direction of the protective film for the semiconductor wafer and the semiconductor chip are manufactured. By making the long sides parallel to each other, a semiconductor chip with a small variation in bending strength and a balanced aspect ratio of bending strength can be obtained. Found a method for manufacturing a semiconductor chip, characterized in that the granulation.

(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.) and 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 in 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 of excessively increasing the viscosity of the composition for forming a protective film, and there is no possibility of deterioration in fluidity when applied to the base film, 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.)

(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 thermosetting resin layer is cured at a temperature of 10 ° C./min and the peak temperature measured by DSC is 250 ° C. or more and the reinforcing film layer described below is produced, heat is generated. The amount 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 the heat is generated by the reinforcing film layer when the adhesive layer is gelled. This is preferable because expansion can be further prevented, curing warpage and thermal warpage of the entire protective film can be suppressed, and variations in warpage and bending strength of the semiconductor wafer can be further reduced.

  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 a reinforcing 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 film layer with a low linear expansion coefficient by adding a large amount of spherical or scale-like inorganic filler, but 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 present 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 film layer that can be used in the present invention is a thermosetting resin composition containing the above-described network-like inorganic filler, and has a linear expansion coefficient of 30 ppm or less at a temperature of Tg or less after curing. Can do.

  If the reinforcing film layer used in the present invention contains a network-like inorganic filler, the bending strength is improved, and if the linear expansion coefficient after curing is 30 ppm or less, the linear expansion coefficient with the silicon wafer. Since the divergence is small, it is difficult for large warp to occur.

  In the present invention, the content ratio of the network-like inorganic filler in the flow direction of the protective film for semiconductor wafer (content in the flow direction / content in the direction perpendicular to the flow) is higher than 100% and not higher than 190%. A reinforcing film layer is used. When the content of the network-like inorganic filler in the flow direction of the reinforcing film layer is 100% or less, wrinkles parallel to the flow direction (conveying direction) are generated when the reinforcing film layer is produced or transported. When it is provided, it causes wrinkles and causes a decrease in bending strength. When the cross-sectional area ratio of the mesh filler is higher than 190%, the vertical / horizontal balance of the bending strength is biased to one side, and large irregularities are generated perpendicular to the flow direction (conveying direction). Cause voids and lowers the bending strength.

  A semiconductor wafer in which the content ratio (content in the flow direction / content in the direction perpendicular to the flow) of the network-like inorganic filler in the flow direction of the protective film for a semiconductor wafer is higher than 100% and 190% or less. When the protective film for semiconductor and the semiconductor wafer are bonded together, even if an air layer is included, the protective film for semiconductor wafer has unevenness parallel to the flow direction, so it is parallel to the moving direction of the bonding roller. There is an air escape route, voids are unlikely to occur, and bending strength is unlikely to decrease.

  Further, the content ratio (content in the flow direction / content in the direction perpendicular to the flow) of the network-like inorganic filler in the flow direction of the protective film for a semiconductor wafer is higher than 100% and not higher than 190%. When the semiconductor wafer protective film and the semiconductor wafer are bonded, the flow direction of the semiconductor wafer protective film and the long side of the semiconductor chip are made parallel so that the network-like inorganic filler is parallel to the long side. Since there are many, it is possible to provide a method of manufacturing a semiconductor chip in which the bending strength is balanced between the long side and the short side when three-point bending is performed.

  When the flow direction used in the present invention and the direction perpendicular to the flow are compared, the content ratio of the component (F) in the cross-sectional area with the same width (content in the flow direction / content in the direction perpendicular to the flow) is As a mesh-like inorganic filler that is higher than 100% and 190% or less, glass cloth is preferably used as an example, and IPC specifications of the glass cloth are 106, 1080, 2116, 1504, 1501, 7628, and the like. It is done. The present invention is not limited to glass cloth or the IPC specifications.

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) impregnated with thermosetting resin (F) content ratio of components in cross-sectional area with the same width (content in flow direction / content in direction perpendicular to flow) is higher than 100%, 190% A film-like reinforcing film layer composed of the following network-like inorganic filler and a film-like adhesive layer prepared from the adhesive layer composition (components (A) to (D)) by the following method were bonded together. A protective film for a semiconductor wafer having a protective film having a two-layer structure is produced.
Alternatively, (E) an adhesive layer composition ((A) to (D)) prepared by the following method on a film-like reinforcing film layer made of a network-like inorganic filler impregnated with a thermosetting resin. Component) is applied to produce a protective film for a semiconductor wafer having a protective film having a two-layer structure.

  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.

  Thus, as shown in FIG. 1, a protective film for a semiconductor wafer comprising a base film 1 and a protective film 2 on the upper side of the base film 1, wherein the protective film 2 is an adhesive layer 3 and a reinforcing film layer 4. The protective film 5 for semiconductor wafer which consists of these can be produced.

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.

The thickness of the semiconductor wafer is preferably 25 μm to 250 μm.
If the thickness of the semiconductor wafer is 25 μm or more, a device structure using a semiconductor wafer protective film is applicable, and if it is 250 μm or less, when the semiconductor wafer protective film is used, for example, 200 mm (8 It is possible to suppress the occurrence of warping larger than 20 mm at both ends of the wafer. Therefore, the present invention is preferably used when the thickness of the semiconductor wafer is 25 μm to 250 μm.

Method of manufacturing a semiconductor chip by dicing a semiconductor wafer A method of manufacturing a semiconductor chip by dicing a semiconductor wafer, wherein when the protective film for a semiconductor wafer is attached to the semiconductor wafer, the operating direction and reinforcement of the heat roller A method for manufacturing a semiconductor chip is preferred, in which the film layers are attached in the flow direction and then diced to manufacture a semiconductor chip.

  If it is such a manufacturing method, by making the flow direction of the protective film for semiconductor wafers coincide with the operating direction of the heat roller, it is possible to provide a semiconductor chip in which voids are less likely to occur in a semiconductor chip with a protective film.

  Further, a method for manufacturing a semiconductor chip by dicing a semiconductor wafer, wherein the ratio of the long side to the short side (long side / short side) of the semiconductor chip is 100% or more, and the semiconductor wafer protective film is reinforced. The flow direction of the film layer and the long side of the semiconductor chip are pasted in parallel and cured, and then dicing in a lump so that the direction of the long side of the semiconductor chip and the flow direction of the reinforcing film layer on the back surface A semiconductor chip manufacturing method for manufacturing a semiconductor chip having a protective film matched with the above is preferable.

  With such a manufacturing method, it is possible to provide a more balanced semiconductor chip with the bending strength of the semiconductor chip being long and short.

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

Preparation of Composition for Forming Semiconductor Wafer Protective Film In about 50 parts by mass of cyclohexanone, parts by mass (A) shown in Table 1 were 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 50,000, JER 1256 (made by Japan Epoxy Resin Co., Ltd.)
(B) Component Epoxy resin: RE310S (manufactured by Nippon Kayaku Co., Ltd.), viscosity at 25 ° C. and 15 Pa. s
Component (C) Silica: SC2050, average particle size 0.5 μm, maximum particle size 5 μm, KBM-403 treated product, manufactured by Admatechs Co., Ltd. (D) component DICY-7 (Dicyandiamide): manufactured by Japan Epoxy Resin Co., Ltd. ( E) + (F) component Epoxy impregnated glass cloth: description of production method below

Adjustment of adhesive layer varnish (A) Phenoxy resin (B) Epoxy resin, (C) Silica filler, (D) Curing catalyst, Dilution solvent adjusts the adhesive layer resin varnish with a solid content of 60% by mass. did. 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. By heating and drying, an adhesive layer having a thickness of 20 μm was formed, and an adhesive layer 1 coated on the entire surface of the base film was produced.

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

Reinforcing film layer preparation Each of the reinforcing film layer resin varnishes described in Table 2 was collected in a bath and allowed to pass continuously while immersing the glass cloth described in Table 3, and the excess resin varnish was scraped off with a 120 μm wide slit. Then, it was dried for 2 minutes in a continuous drying furnace adjusted to 165 ° C. Thereafter, the film was dried again in a continuous drying furnace adjusted to 150 ° C. for 30 minutes, and 120 μm reinforcing film layer compositions 1 to 3 shown in Table 2 were produced.

Cross section%
Regarding the cross-sectional area% of the network-like inorganic filler shown in Table 3, the reinforcing film layer produced by the method shown in Table 2 was cured at 175 ° C./4 hrs, and then cut out to 10 mm × 10 mm 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
After cutting out, the cross-sectional area of the mesh-like inorganic filler contained in the 1 mm-wide visual field was measured with a microscope, and the cross-sectional area% was measured from the ratio of the flow direction and the direction perpendicular to the flow.

Production of Protective Film for Semiconductor Wafer The adhesive layer shown in Table 1 and the reinforcing film layer shown in Table 2 were bonded together with a hot roll to form a protective film for semiconductor wafer (protective film). The hot roll conditions were thermocompression bonding at a roll speed of 0.5 m / min, a roll pressure of 0.5 MPa, and 100 ° C.

A protective film obtained by pasting a protective film for a semiconductor wafer was bonded to a silicon wafer (8-inch (200 mm) unpolished wafer, DAG-810, manufactured by Disco Corporation) at 70 ° C. using Technovision FM-114. And then grinded to a wafer having a thickness of 75 μm. The direction of attachment is “parallel attachment” when the operating direction of the heat roller and the flow direction of the protective film layer for the semiconductor wafer are matched, and when the operation direction of the heat roller and the flow direction of the protective film layer for the semiconductor wafer are perpendicular. Was defined as “vertical paste”.

Curing of protective film for semiconductor wafer The protective film for semiconductor wafer was cured at 175 ° C. for 4 hours on the wafer with the protective film for semiconductor wafer obtained by the preliminary dicing.

Dicing The following UV-sensitive dicing film having a total thickness of 110 μm is pasted on the protective film surface of the semiconductor wafer with the protective film for semiconductor wafer produced as described above, and the silicon wafer with protective film is 10 mm × 10 mm square ( Examples 1 to 4 and Comparative Example 1) were diced into 8 mm × 12.5 mm square (Example 5 and Comparative Example 2). Regarding the 10 mm × 10 mm square, when the number of terminals on the back side of the chip is not line symmetric, the case where the parallel fibers of the reinforcing film layer 4 are rich as shown in FIG. As shown in FIG. 3, the case where the vertical fibers of the reinforcing film layer 4 are rich is defined as “vertical cut”. For 8mm x 12.5mm square, "parallel cut" when the 8mm short side and the flow direction of the reinforcing film layer are parallel, and "vertical cut" when the 8mm short side and the flow direction of the reinforcing film layer are vertical. It was.
Device: DISCO Dicer DAD-341
Cutting method: Single dicing blade: ZH05-SD3500-N1-70EE
Blade rotation speed: 30000 rpm
Blade speed: 30 mm / sec

Folding strength measurement test The bending strength of 40 chips of 10 mm × 10 mm square and 8 mm × 12.5 mm square obtained by the dicing test described above was measured under the following conditions, and the average value was taken as the bending strength measurement. For the 10 mm × 10 mm square, as shown in FIGS. 2 and 3, a bending jig 8 was used for the reinforcing film layer 4 attached to the chip 7 provided with the terminals 6 on the back side. The wedge shapes are arranged in an autograph so as to be parallel to the short sides of 10 mm and 8 mm, respectively, and the results are shown in Tables 3 to 5.
Equipment: Shimadzu Corporation Autograph
Anti-folding jig: 4mm width Wedge shape Distance between fulcrums: 6mm
Wedge jig speed: 0.01 m / min

Void-containing observation test The number of voids having a width of 20 μm or more, which was found on the short sides of 10 mm and 8 mm of the 10 mm × 10 mm square and 8 mm × 12.5 mm square chips obtained in the dicing test described above, was measured.

  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.

1 ... base film, 2 ... protective film, 3 ... adhesive layer,
4 ... Reinforcing film layer, 5 ... Protective film for semiconductor wafer,
6 ... Terminal, 7 ... Chip, 8 ... Folding jig.

Claims (3)

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 film layer,
The adhesive layer contains the following components (A) to (D), the reinforcing film layer contains the following components (E) and (F), and is perpendicular to the flow direction and flow of the reinforcing film layer. When the directions are compared, the content ratio of the component (F) in the cross-sectional area with the same width (content in the flow direction / content in the direction perpendicular to the flow) is higher than 100% and not higher than 190%. A protective film for semiconductor wafers.
(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 method of manufacturing a semiconductor chip by dicing a semiconductor wafer,
When the protective film for a semiconductor wafer according to claim 1 is attached to the semiconductor wafer, the operating direction of the heat roller and the flow direction of the reinforcing film layer are attached together and then diced to manufacture a semiconductor chip. A method for manufacturing a semiconductor chip. A method of manufacturing a semiconductor chip by dicing a semiconductor wafer,
The ratio of the long side to the short side (long side / short side) of the semiconductor chip is 100% or more, and the flow direction of the reinforcing film layer of the protective film for a semiconductor wafer according to claim 1 and the long side of the semiconductor chip are A semiconductor chip having a protective film in which the direction of the long side of the semiconductor chip and the flow direction of the reinforcing film layer are matched on the back surface by pasting and curing in parallel, and then dicing in a lump. A method of manufacturing a semiconductor chip, characterized by manufacturing.

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