JP2012049388A - Sheet for forming semiconductor wafer protective film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet for forming a semiconductor wafer protective film which can be optically oriented without contaminating the surface of a circuit on a wafer.SOLUTION: The sheet for forming a semiconductor wafer protective film used for forming a protective film on a semiconductor wafer includes a base film, a peeling film, and a protective film formation layer arranged between the base film and the peeling film. A plurality of protective film formation layers are formed on the surface of the base film at a constant interval. Each protective film formation layer has a diameter smaller by 100 μm to 5 mm than the diameter of a semiconductor wafer on which the protective film is formed, and elasticity modulus of a hardened protective film formation layer is 1-20 GPa.

Description

  The present invention relates to a semiconductor wafer protective film forming sheet for forming a film (film) for protecting the back surface of a semiconductor wafer when dicing the semiconductor wafer.

  In order to reduce the mounting area of the semiconductor chip, a flip chip connection method is used. In this connection method, usually, (1) a circuit and connection bumps are formed on the surface of a semiconductor wafer, (2) the back surface of the semiconductor wafer is polished to a predetermined thickness, and (3) the semiconductor wafer is diced to form a semiconductor chip. (4) After the chip is connected to the substrate with the circuit forming surface facing the substrate side, (5) resin sealing or the like is performed to protect the semiconductor chip.

  However, in the polishing step (2), minute streak-like scratches are formed on the back surface of the semiconductor wafer, which may cause cracks after the dicing step or packaging. Therefore, a protective film (chip protective film) is formed on the back surface after the polishing step (2) so that even if such a line-shaped scratch occurs in the polishing step, the subsequent step is not adversely affected. Furthermore, as a sheet for forming such a protective film, a sheet comprising a release sheet and a protective film forming layer formed on the release surface is proposed (Patent Document 1, Patent Document). 2).

On the other hand, in the dicing process, it is known that the wafer may be damaged (hereinafter referred to as “chipping”) due to vibration of the rotary blade or the like.
The chip protective film is expected to prevent chipping in such a dicing process.

  The general method for forming a protective film for a chip is as follows: 1) peeling of the release film from the adhesive sheet, 2) sticking of the protective film for chip and the substrate film on the back surface of the wafer circuit, 3) along the outer periphery of the wafer Cutting of the chip protective film and the substrate film, 4) peeling of the substrate film from the chip protective film, and 5) curing of the chip protective film.

  However, in the process of 3), in order to prevent the film cutting blade from contacting the outer periphery of the wafer, the film (chip protective film and base film) is cut larger than the outer periphery of the wafer, and after the base film is peeled off When the wafer of the chip protective film (cured) is handled in the process, the protective film protruding from the wafer is detached and the circuit surface of the wafer is contaminated. Further, when the film is cut, it can be cut only in a circular shape, so that the protective film forming layer covers the orientation flat or the notch, which makes it difficult to align the wafer.

JP 2002-280329 A JP 2004-260190 A

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a semiconductor wafer protective film forming sheet capable of optical orientation without polluting the circuit surface on the wafer.

  In order to solve the above-described problems, the present invention provides a semiconductor wafer protective film forming sheet for forming a protective film on a semiconductor wafer, the base film, the release film, and the base film and the release film. A plurality of protective film forming layers formed at regular intervals on the surface of the base film, and each protective film forming layer is a target for forming the protective film. There is provided a sheet for forming a protective film for a semiconductor wafer, having a diameter smaller than the diameter of the semiconductor wafer by 100 μm to 5 mm and having an elastic modulus of 1 GPa to 20 GPa after the curing.

  Such a semiconductor wafer protective film forming sheet of the present invention is supplied with the protective film forming layer having an outer diameter smaller than the outer diameter of the semiconductor wafer, specifically, a diameter smaller by 100 μm to 5 mm than the diameter of the semiconductor wafer. In addition, since the elastic modulus is 1 GPa to 20 GPa, there is no detachment of the film piece after curing of the protective film forming layer, the circuit piece on the wafer is not contaminated by the film piece, and chipping is prevented. You can also. Moreover, since the protective film forming layer is formed on the surface of the base film at regular intervals, it is possible to easily detect the top of the protective film forming layer by feeding a certain amount of film. In addition, since there are a plurality of protective film forming layers on the base film, it is possible to save the trouble of changing the setup.

  The protective film forming layer preferably has a planar shape similar to the planar shape of the target semiconductor wafer, and an orientation flat or a notch is formed according to the shape of the target semiconductor wafer.

  Thus, if the protective film forming layer has a planar shape similar to the planar shape of the semiconductor wafer and the orientation flat or notch is formed in accordance with the shape of the semiconductor wafer, optical recognition is facilitated.

Further, the composition for forming a protective film to be the protective film forming layer, at least,
(A) 100 parts by mass of at least one resin selected from the group consisting of phenoxy resin, polyimide resin, and (meth) acrylic resin,
(B) 5 to 200 parts by mass of an epoxy resin,
(C) 100-600 parts by weight of filler,
(D) an effective amount of an epoxy resin curing catalyst,
It can be set as the composition containing.

  With such a protective film-forming composition, a semiconductor wafer protective film-forming sheet having excellent protective film properties such as adhesiveness can be easily formed at low cost.

  As described above, since the semiconductor wafer protective film forming sheet of the present invention is supplied with an outer diameter smaller than the outer periphery of the semiconductor wafer, there is no detachment of the film piece after the protective film forming layer is cured. No contamination of the circuit surface on the wafer due to. Further, since the size is maintained to some extent and the elastic modulus after curing is appropriate, chipping can be prevented. In addition, since a plurality of protective film forming layers are formed on the surface of the base film at regular intervals, it is possible to easily detect the top of the protective film forming layer and to save the trouble of setup change. . Furthermore, by forming the protective film forming layer in a planar shape similar to the planar shape of the semiconductor wafer, and in particular by forming an orientation flat or a notch, optical recognition is easy and wafer alignment can be performed with high accuracy.

It is a flowchart which shows an example of the preparation methods of the semiconductor wafer protective film formation sheet of this invention. It is the schematic which shows an example of the sheet | seat for semiconductor wafer protective film formation of this invention.

Hereinafter, the present invention will be described in detail.
As described above, the conventional protective film forming sheet has a problem in that the protective film protruding from the wafer is detached and the circuit surface of the wafer is contaminated when the wafer having the cured protective film forming layer is handled in the process. was there.

  As a result of intensive studies, the present inventors have found that the size of the protective film-forming layer and the elastic modulus after curing are related to the above problems, and further, the size of the protective film-forming layer and the elastic modulus after curing. It was found that the above problems could be solved while preventing chipping, and the present invention was completed.

  That is, the semiconductor wafer protective film forming sheet of the present invention is a semiconductor wafer protective film forming sheet for forming a protective film on a semiconductor wafer, the base film, the release film, and the base film and the above A protective film forming layer disposed between the protective film and the release film, the protective film forming layer being formed in plural on the surface of the base film at regular intervals, and each protective film forming layer includes the protective film; The protective film forming layer after curing has a diameter of 100 to 5 mm smaller than the diameter of a semiconductor wafer to be formed, and has a modulus of elasticity of 1 to 20 GPa after curing.

  Thus, the protective film forming layer in the sheet for forming a semiconductor wafer protective film of the present invention has a diameter that is 100 μm to 5 mm smaller than the target wafer diameter, and is particularly preferably 1 mm to 4 mm smaller.

  Although the protective film forming layer having a diameter of more than 5 mm smaller than the wafer diameter is effective against the removal of the protective film after curing, the generation of chips that are not covered by the protective film layer, and the protective film layer Chipping is likely to occur due to the level difference of the wafer, and the yield decreases. On the contrary, the protective film forming layer having a diameter smaller than 100 μm smaller than the wafer diameter cannot protrude from the outer periphery of the wafer because the protection accuracy of the protective film forming layer cannot be secured. The effect cannot be expected.

  In the semiconductor wafer protective film-forming sheet of the present invention, the elastic modulus of the protective film-forming layer after curing is from 1 GPa to 20 GPa, preferably from 2 GPa to 10 GPa.

  If it is less than 1 GPa, since it is soft, it is difficult for the protective film forming layer to be detached after curing, but chipping is likely to occur due to the softness of the protective film forming layer. When the pressure is higher than 20 GPa, it is effective for chipping, but the edge is fragile and easily chipped, and the protective film forming layer is likely to be detached after curing.

In the semiconductor wafer protective film forming sheet of the present invention, a plurality of the protective film forming layers described above are formed on the surface of the base film at regular intervals.
For this reason, by sending a fixed amount of film, it is possible to easily detect the top of the protective film forming layer, and it is possible to save the trouble of the setup change and improve the productivity.

  As described above, the protective film forming layer in the semiconductor wafer protective film forming sheet of the present invention is effective only by determining the diameter and the elastic modulus after curing. The planar shape is preferably similar to the planar shape. When the orientation flat or notch is formed on the semiconductor wafer, the orientation flat or notch is also preferably formed on the protective film forming layer according to the shape.

  Thus, if the protective film forming layer serving as the protective film is similar to the shape of the semiconductor wafer, particularly if the orientation flat or notch is formed according to the orientation flat or notch shape formed on the semiconductor wafer, the protective film Is easy and optical recognition is facilitated, and the productivity of the silicon chip can be improved, which is useful for manufacturing a semiconductor device.

Hereinafter, although the embodiment of the present invention is described more concretely, the present invention is not limited to these.
[Composition for protective film formation]
First, the protective film forming composition that serves as the protective film forming layer in the present invention will be described. The composition used for forming the protective film for a semiconductor wafer is not particularly limited as long as it is a thermosetting resin composition, but a phenoxy resin composition, a polyimide resin composition, a (meth) acrylic resin composition, an epoxy resin composition. And maleimide resin composition. These usually contain about 5 to 1500 parts by mass of an inorganic filler such as silica and alumina in 100 parts by mass of the resin, and further contain an effective amount of a curing catalyst and / or a curing agent. Resins, fillers, curing catalysts and the like may be used alone or in combination of two or more.

A particularly preferred thermosetting resin composition used in the present invention is at least:
(A) 100 parts by mass of at least one resin selected from the group consisting of phenoxy resin, polyimide resin, and (meth) acrylic resin,
(B) 5 to 200 parts by mass of an epoxy resin,
(C) 100-600 parts by weight of filler,
(D) an effective amount of an epoxy resin curing catalyst,
It is a composition containing.

-(A) Resin selected from the group consisting of phenoxy resin, polyimide resin and (meth) acrylic resin-
Phenoxy resin Phenoxy resin is a resin derived from epichlorohydrin and bisphenols such as bisphenol A or bisphenol resin F. Preferably, the weight average molecular weight in terms of polystyrene is 10,000 to 200,000, more preferably 20,000 to 100,000, and most preferably 30,000 to 80,000. When the weight average molecular weight is equal to or higher than the lower limit value, it is easy to form a film, whereas when the weight average molecular weight is equal to or lower than the upper limit value, the gap is filled following the unevenness of the substrate surface having a fine circuit pattern. It is easy to obtain a sufficient softness.

Examples of the phenoxy resin include those sold under the trade names PKHC, PKHH, and PKHJ (all manufactured by Sakai Chemical Co., Ltd.), and the commercial names Epicoat 4250, Epicoat 4275, and Epicoat 1255HX30 of bisphenol A and bisphenol F mixed types. Products (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, YP -70 (all manufactured by Tohto Kasei Co., Ltd.), and those sold under the trade names JER E1256, E4250, E4275, YX6954BH30, YL7290BH30 (all manufactured by Japan Epoxy Resin Co., Ltd.). Among these, JER E1256 is preferably used in that it has the above-described preferred weight average molecular weight.
The phenoxy resin has an epoxy group at the end, which reacts with the component (B) described later.

  These phenoxy resins can be used alone or in combination of two or more.

（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。） -Polyimide resin As a polyimide resin, what contains the repeating unit represented by following formula (1) 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.)

  The polyimide resin preferably has a weight average molecular weight of 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 equal to or higher than the lower limit value, it is easy to form a film. On the other hand, if the weight average molecular weight is equal to or lower than the upper limit value, the gap is filled by following the unevenness of the substrate surface having a fine circuit pattern. Enough softness can be obtained.

（式中、Ｘ、Ｙ、ｑは上記の通りである。） The polyimide resin can be obtained by dehydrating and ring-closing a polyamic acid resin having a repeating unit represented by the following formula (2) by a conventional method.

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

（式中、Ｘは上記の通りである。）
で表されるテトラカルボン酸二無水物と、下記式（４）：
Ｈ_２Ｎ−Ｙ−ＮＨ_２ （４）
（式中、Ｙは上記の通りである。）
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 (2) is represented by the following formula (3):

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

Here, the following are mentioned as an example of the tetracarboxylic dianhydride represented by the said Formula (3), These may be used individually by 1 type or in combination of 2 or more types.

（式中、Ｒ^１は互いに独立に炭素原子数３〜９の二価の有機基であり、Ｒ^２及びＲ^３は、夫々独立に、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。） Among the diamines represented by the above formula (4), the organic solvent is preferably 1 to 80 mol%, more preferably 1 to 60 mol% is a diaminosiloxane compound represented by the following formula (5). It is desirable from the viewpoint of solubility in water, adhesion to a substrate film, low elasticity, and flexibility.

(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 having 1 to 8 carbon atoms. A hydrocarbon group, and m is an integer of 1 to 200.)

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

のいずれかで表されるオキシアリーレン基、下記式

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が挙げられる。 Examples of the divalent organic group having 3 to 9 carbon atoms of R ¹ include — (CH ₂ ) ₃ —, — (CH ₂ ) ₄ —, —CH ₂ CH (CH ₃ ) —, — (CH _{2) 6 -, - (CH} 2) 8 - alkylene group such as the following formula

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

An oxyarylene group represented by any of the following formulae

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

Examples of the unsubstituted or substituted monovalent hydrocarbon group having 1 to 8 carbon atoms represented by R ² and R ³ include, for example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert. -Alkyl groups such as butyl group, hexyl group, cyclohexyl group, 2-ethylhexyl group, octyl group, allyl group, propenyl group, isopropenyl group, alkenyl group such as butenyl group, isobutenyl group, hexenyl group, phenyl group, tolyl group , Aryl groups such as xylyl groups, aralkyl groups such as benzyl groups and phenylethyl groups, and some or all of the hydrogen atoms bonded to carbon atoms of these hydrocarbon groups are substituted with halogen atoms such as fluorine, bromine and chlorine Group, for example, halogen-substituted alkyl such as chloromethyl group, bromoethyl group, 3,3,3-trifluoropropyl group, etc. Le group, and among them methyl group and phenyl group are preferred.

  The diaminosiloxane compound of the above formula (5) can be used alone or in combination of two or more.

  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 Examples thereof include aromatic ring-containing diamines such as fluoropropane, 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、Ｒ^４は、互いに独立に、水素原子；フッ素、臭素、よう素等のハロゲン原子；又は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、各芳香環に付いている置換基は異なっていてもよく、ｎは１〜５の整数である。Ａは下記のいずれかの基

（式中、Ｒ^４は上記の通りであり、Ｒ^５及びＲ^６は夫々独立に水素原子、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。）
であり、Ｂは下記のいずれかの基

（式中、Ｒ^４は上記の通りである。）
である。或いは、Ａ及びＢは夫々１種単独でも２種以上の組み合わせでもよい。］ Preferably, the polyimide resin has a phenolic hydroxyl group from the viewpoint of adhesiveness of the protective film. The phenolic hydroxyl group can be prepared by using a diamine compound having a phenolic hydroxyl group. Examples of such a diamine include those having a structure represented by the following formula (6). It is done.

[Wherein, R ^{4 s} are each independently a hydrogen atom; a halogen atom such as fluorine, bromine or iodine; or an unsubstituted or substituted monovalent hydrocarbon group having 1 to 8 carbon atoms, and each aromatic ring The substituents attached to may be different, and n is an integer of 1 to 5. A is one of the following groups

(Wherein R ⁴ is as described above, and R ⁵ and R ⁶ are each independently a hydrogen atom, a halogen atom, or an unsubstituted or substituted monovalent hydrocarbon group.)
And B is one of the following groups:

(Wherein R ⁴ is as described above.)
It is. Alternatively, each of A and B may be a single type or a combination of two or more types. ]

Examples of the unsubstituted or substituted monovalent hydrocarbon group having 1 to 8 carbon atoms of R ⁴ include those exemplified for R ² and R ³ , ethynyl group, propynyl group, butynyl group, hexynyl group and the like. And the like.

（式中、Ｒ^４は上記の通りである。） The representative group of B is a group represented by the following formula.

(Wherein R ⁴ is as described above.)

（式中、Ｒ^７は水素原子、フッ素、臭素、よう素等のハロゲン原子、又は炭素原子数１〜８の、アルキル基、アルケニル基、アルキニル基、トリフルオロメチル基、フェニル基等の非置換もしくはハロゲン置換の一価炭化水素基であり、各芳香族環に付いている置換基は異なっていてもよく、Ｚは単結合、メチレン基、又はプロピレン基である。） Moreover, as diamine which has another phenolic hydroxyl group, what is represented, for example by following formula (7) is mentioned.

(In the formula, R ⁷ is a hydrogen atom, a halogen atom such as fluorine, bromine or iodine, or an unsubstituted alkyl group, alkenyl group, alkynyl group, trifluoromethyl group, phenyl group or the like having 1 to 8 carbon atoms. Alternatively, it is a halogen-substituted monovalent hydrocarbon group, and the substituents attached to each aromatic ring may be different, and Z is a single bond, a methylene group, or a propylene group.)

（式中、Ｒ^４は上記の通りである。） Among the diamine compounds having a phenolic hydroxyl group, a diamine compound represented by the following formula (8) is particularly preferable among those represented by the above formula (6).

(Wherein R ⁴ is as described 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 semiconductor wafer protective film forming sheet having a high adhesive force and forming a flexible protective film forming layer can be obtained.

（式中、Ｄは、

を示し、Ｒ^４は上記の通りであり、各芳香環に付いているＲ^４は同一で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 addition, the monoamine which has a phenolic hydroxyl group can also be used for introduction | transduction of a phenolic hydroxyl group, The monoamine which has the following structure is mentioned as the example.

(Where D is

Are shown, R ⁴ are as defined above, R ⁴ attached to the each aromatic ring may be the same or different. D may be used alone or in combination of two or more. P is an integer of 1 to 3. )

  When a monoamine having a phenolic hydroxyl group is used, the blending amount is 1 to 10 mol% with respect to 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. Examples include tetrahydrofuran, 1,4-dioxane, cyclopentanone, cyclohexanone, γ-butyrolactone, N-methylpyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide and dimethyl sulfoxide, preferably aprotic 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 above dehydration ring closure, it is desirable 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 the polyamic acid and the polyimide resin, polycarboxylic acid anhydrides such as maleic anhydride and phthalic anhydride and / or aniline, n-butylamine, and monoamines having the above-mentioned phenolic hydroxyl groups are mixed with polyamic acid. It can also be added in the synthesis of the acid. However, the addition amount of dicarboxylic acid 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.

-(Meth) acrylic resin The (meth) acrylic resin is derived from, for example, two or more monomers selected from (meth) acrylic acid, (meth) acrylic acid ester monomers, and other derivatives of (meth) acrylic acid. (Meth) acrylic acid ester copolymer is mentioned. Here, the (meth) acrylic acid ester monomer is preferably a (meth) acrylic acid alkyl ester having 1 to 18 carbon atoms in the alkyl group, such as methyl (meth) acrylate, ethyl (meth) acrylate, ( For example, propyl (meth) acrylate and butyl (meth) acrylate are used. Examples of other derivatives of (meth) acrylic acid include glycidyl (meth) acrylate and hydroxyethyl (meth) acrylate.

  When a glycidyl group is introduced into a (meth) acrylic resin by copolymerizing glycidyl methacrylate or the like as a comonomer, compatibility with an epoxy resin as a thermosetting adhesive component, which will be described later, is improved. The glass transition temperature (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 of the protective film to the semiconductor 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. The Tg of the (meth) acrylic resin is preferably 20 ° C. or less, more preferably about −70 to 0 ° C., and has adhesiveness at room temperature (23 ° C.).

-(B) Epoxy resin-
The epoxy resin used as the component (B) in the present invention is a compound having at least two epoxy groups in one molecule. In particular, the epoxy equivalent is preferably 50 to 5000 g / eq, more preferably 100 to 500 g / eq.

  The epoxy resin has a weight average molecular weight of usually less than 10,000, preferably 400 to 9,000, more preferably 500 to 8,000.

  Such epoxy resins include, for example, bis (4-hydroxyphenyl) methane, 2,2′-bis (4-hydroxyphenyl) propane, or diglycidyl ethers of these halides; Polymers (so-called bisphenol F type epoxy resin, bisphenol A type epoxy resin, etc.); butadiene diepoxide; vinylcyclohexene dioxide; diglycidyl ether of resorcin; 1,4-bis (2,3-epoxypropoxy) benzene; 4′-bis (2,3-epoxypropoxy) diphenyl ether; 1,4-bis (2,3-epoxypropoxy) cyclohexene; bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate; 1,2-dihydroxy Such as benzene, resorcinol Epoxy glycidyl ether or polyglycidyl ester obtained by condensing monohydric phenol or polyhydric alcohol and epichlorohydrin; condensing novolac type phenol resin (or halogenated novolac type phenol resin) such as phenol novolak and cresol novolak with epichlorohydrin The resulting epoxy novolac (ie, novolak type epoxy resin); epoxidized polyolefin, epoxidized polybutadiene, epoxidized by peroxidation method; naphthalene ring-containing epoxy resin; biphenyl type epoxy resin; phenol aralkyl type epoxy resin; biphenyl aralkyl type epoxy Resin; and cyclopentadiene type epoxy resin.

  Among these, bisphenol F type epoxy resin and bisphenol A type epoxy resin that are liquid at room temperature are preferable as the component (B).

  These epoxy resins can be used alone or in combination of two or more.

  (B) The compounding quantity of the epoxy resin of a component is 5-200 mass parts with respect to 100 mass parts of resin of (A) component, It is preferable that it is especially 10-100 mass parts. If the compounding amount of the epoxy resin is 5 parts by mass or more, the adhesive strength of the protective film forming layer composition is not inferior, and if it is 200 parts by mass or less, the flexibility of the protective film forming layer is not insufficient.

-(C) Filler-
As the filler of component (C), inorganic fillers such as conductive particles such as silica, alumina, titanium oxide, carbon black and silver particles can be used.

  The amount of the filler of the component (C) is 100 to 600 parts by mass, preferably 100 to 400 parts by mass, and more preferably 150 to 350 parts by mass with respect to 100 parts by mass of the component (A). If the blending amount is 100 parts by mass or more, it is not difficult to achieve low water absorption, low linear expansion, etc., which are blending purposes of the filler, and for the softness of the protective film forming layer. Chipping is less likely to occur. On the other hand, if it is 600 parts by mass or less, the viscosity of the composition for forming a protective film is increased, the fluidity when applied to a film substrate is not deteriorated, and the end part is fragile and easily becomes chipped. The problem that the protective film forming layer is detached after curing is less likely to occur.

  Since silica is easily wetted by the resin component, silica surface-treated according to a conventional method may be used. As the surface treatment agent, a silane (silane coupling agent) is preferable because of its versatility and cost merit. As the silane coupling agent, alkoxysilane is preferable, and as the alkoxysilane, glycidoxymethyltrimethoxysilane, glycidoxymethyltriethoxysilane, α-glycidoxyethyltrimethoxysilane, α-glycidoxyethyl Triethoxysilane, β-glycidoxyethyltrimethoxysilane, β-glycidoxyethyltriethoxysilane, α-glycidoxypropyltrimethoxysilane, α-glycidoxypropyltriethoxysilane, β-glycidoxypropyl Trimethoxysilane, β-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, α-glycidoxybutyltrimethoxysilane, α-glycidoxy Butyltriethoxy Run, β-glycidoxybutyltrimethoxysilane, β-glycidoxybutyltriethoxysilane, γ-glycidoxybutyltrimethoxysilane, γ-glycidoxybutyltriethoxysilane, δ-glycidoxybutyltrimethoxy Silane, δ-glycidoxybutyltriethoxysilane, (3,4-epoxycyclohexyl) methyltrimethoxysilane, (3,4-epoxycyclohexyl) methyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltri Methoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltripropoxysilane, β- (3,4-epoxycyclohexyl) ethyltributoxysilane, β- (3,4-epoxycyclohexyl Ethyltriphenoxysilane, γ- (3,4-epoxycyclohexyl) propyltrimethoxysilane, γ- (3,4-epoxycyclohexyl) propyltriethoxysilane, δ- (3,4-epoxycyclohexyl) butyltrimethoxysilane, Trialkoxysilanes such as δ- (3,4-epoxycyclohexyl) butyltrimethoxysilane, N-β- (aminoethyl) γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) γ-aminopropylmethyldi Ethoxysilane, γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, trimethoxysilylpropyl nadic acid anhydride, etc., γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane are preferred for It is.

-(D) Epoxy resin curing catalyst-
Examples of the epoxy resin curing catalyst as component (D) include phosphorus-based curing catalysts and amine-based curing catalysts.

（式中、Ｒ^８〜Ｒ^１５は、夫々独立に、水素原子、フッ素、臭素、よう素等のハロゲン原子、メチル基、エチル基、プロピル基、ブチル基等の炭素原子数１〜８のアルキル基、ビニル基、アリル基等の炭素原子数２〜８のアルケニル基、プロピニル基、ブチニル基等の炭素原子数２〜８のアルキニル基、フェニル基、トルイル基等の炭素原子数６〜８のアリール基等の一価の非置換の炭化水素基、これらの炭化水素基の水素原子の少なくとも１部がフッ素、臭素、よう素等のハロゲン原子で置換された例えばトリフルオロメチル基等の置換炭化水素基が挙げられ、また、メトキシ基、エトキシ基、プロポキシ基、ブトキシ基等の炭素原子数１〜８のアルコキシ基で置換された炭化水素基が挙げられる。置換一価炭化水素基においては総ての置換基が同一でも夫々異なっていても構わない。） Examples of the phosphorus curing catalyst include triphenylphosphine, triphenylphosphonium triphenylborate, tetraphenylphosphonium tetraphenylborate, and a compound represented by the following formula.

(Wherein R ^{8 to} R ¹⁵ are each independently a hydrogen atom, a halogen atom such as fluorine, bromine or iodine, an alkyl having 1 to 8 carbon atoms such as a methyl group, an ethyl group, a propyl group or a butyl group. A alkenyl group having 2 to 8 carbon atoms such as a group, a vinyl group or an allyl group, an alkynyl group having 2 to 8 carbon atoms such as a propynyl group or a butynyl group, a 6 to 8 carbon atom such as a phenyl group or a toluyl group. Monovalent unsubstituted hydrocarbon groups such as aryl groups, substituted carbons such as trifluoromethyl groups in which at least a part of the hydrogen atoms of these hydrocarbon groups are substituted with halogen atoms such as fluorine, bromine, iodine, etc. And a hydrocarbon group substituted with an alkoxy group having 1 to 8 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, or a butoxy group. The Substituent it does not matter even if also each different in the same.)

  Specific examples of particularly preferred phosphorus-based curing catalysts include triphenylphosphine, triphenylphosphonium triphenylborate, tetraphenylphosphonium tetraphenylborate, and the like.

  Examples of amine-based curing catalysts include imidazole derivatives such as dicyandiamide, 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and the like. Is mentioned. Among these, dicyandiamide and 2-phenyl-4,5-dihydroxymethylimidazole are preferable.

  (D) As a curing catalyst of a component, the above-mentioned curing catalyst can be used individually by 1 type or in mixture of 2 or more types. Particular preference is given to using dicyandiamide.

  (D) The compounding quantity of the epoxy resin curing catalyst of a component is an effective amount, and is specifically 5-50 mass parts per 100 mass parts of resin of (A) component.

-Other optional components-
The composition for forming a protective film used in the present invention can contain other components and various additives as necessary in addition to the components described above. One example is shown below, but is not limited thereto.

Monoepoxy Compound In addition to the epoxy resin (B) component (having at least two epoxy groups in one molecule), the monoepoxy compound may be blended in an amount that does not impair the object of the present invention. For example, examples of the monoepoxy compound include styrene oxide, cyclohexene oxide, propylene oxide, methyl glycidyl ether, ethyl glycidyl ether, phenyl glycidyl ether, allyl glycidyl ether, octylene oxide, and dodecene oxide.

・ Epoxy resin curing agent Although a curing agent is not essential, it is possible to control the resin matrix by adding it, and we can expect effects such as low linear expansion, high Tg, and low elastic modulus. it can.

As this curing agent, conventionally known various curing agents for epoxy resins can be used. For example, diethylenetriamine, triethylenetetramine, diethylaminopropylamine, N-aminoethylpiperazine, bis (4-amino-3-methylcyclohexyl) methane, metaxylylenediamine, menthanediamine, 3,9-bis (3-aminopropyl) -Amine compounds such as 2,4,8,10-tetraoxaspiro [5.5] undecane; epoxy resins-modified aliphatic polyamines such as diethylenetriamine adduct, amine-ethylene oxide adduct, cyanoethylated polyamine; bisphenol A, tri Methylol allyloxyphenol, phenol novolak resin with low polymerization degree, epoxidized or butylated phenol resin, “Super Beckite” 1001 [manufactured by Nippon Reichhold Chemical Co., Ltd.], “Hi tanol "4010 [manufactured by Hitachi, Ltd.], Scadoform L. No. 9 (manufactured by Scado Zwoll, The Netherlands), Methylon 75108 (manufactured by General Electric, USA) and the like, and phenolic resins containing at least two phenolic hydroxyl groups in one molecule; “Beckamine” P. 138 [manufactured by Nippon Reichhold Chemical Co., Ltd.], “Melan” [manufactured by Hitachi, Ltd.], “U-Van” 10R [manufactured by Toyo Kodan Kogyo Co., Ltd.], etc. Resin; Amino resin such as melamine resin and aniline resin; Formula HS (C ₂ H ₄ OCH ₂ OC ₂ H ₄ SS) _n C ₂ H ₄ OCH ₂ OC ₂ H ₄ SH (n = 1 regardless of the above description) A polysulfide resin having at least two mercapto groups in one molecule; phthalic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, pyromellitic anhydride, methyl nadic acid And organic acids such as dodecyl succinic anhydride and chlorendic anhydride, or anhydrides (acid anhydrides) thereof.

  Among the curing agents described above, phenolic resins (particularly phenol novolac resins) give good molding workability to the protective film-forming composition used in the present invention, give excellent moisture resistance, and are toxic. It is desirable because it is relatively inexpensive.

  The above curing agents may be used alone or in combination of two or more according to the curing performance of each curing agent.

  The amount of the curing agent is appropriately adjusted according to the type of the curing agent as long as the reaction between the phenoxy resin as the component (A) and the epoxy resin as the component (B) is not hindered. Generally, it is used in the range of 1 to 100 parts by mass, preferably 5 to 50 parts by mass with respect to 100 parts by mass of the epoxy resin. If it is 100 parts by mass or less, in addition to being economical, there is no disadvantage that the epoxy resin is diluted so that it takes a long time for curing, and that the physical properties of the cured product are deteriorated.

-Solvent For the composition for forming a protective film used in the present invention, a solvent, for example, cyclohexanone, MIBK, MEK or the like can be used as necessary, and other components can be dissolved or dispersed to improve the coating property. it can.

-Other additives The composition for forming a protective film used in the present invention includes an inorganic or organic pigment, a dye such as a dye, a silane coupling agent, an oxidation within a range not impairing the effects of the present invention. An inhibitor, a flame retardant, an antistatic agent, a heat stabilizer and the like can be added. For example, when a protective film is colored by blending pigments, dyes, and the like, visibility and optical device recognition performance are improved when a laser mark or the like is engraved.

  The protective film forming layer is a gravure so that the thickness after drying of the composition for forming a protective film obtained by mixing the above components on a base film described later is 5 to 100 μm, preferably 10 to 60 μm. It can be obtained by a known method such as a coater, reverse coater, roll coater or blade coater.

[Base film]
As the base film, a heat resistant film is preferable, and examples of a film having excellent heat resistance include a polyethylene terephthalate film, a polyimide film, a fluororesin film, and the like. The base film may be not only a single layer but also a plurality of layers in order to achieve both peelability and heat resistance.

  The base film needs to have peelability on one side. Although some of the fluororesin film itself has releasability without being subjected to a mold release treatment, it is generally preferable to perform a mold release treatment on the surface of the substrate film to impart the releasability. Specifically, it can be applied by coating a release agent and providing a release agent layer.

  As the release agent, a silicone resin release agent and an alkyd resin release agent are preferable, and conventionally known silicone resin release agents and alkyd resin release agents can be used.

  As the silicone resin release agent, an addition reaction curable type having dimethylpolysiloxane as a basic skeleton is preferable. Further, it is more preferable that no non-functional long-chain silicone oil or silicone rubber is contained.

  The alkyd resin release agent is mainly composed of a polycondensation product (alkyd resin) of a polybasic acid and a polyhydric alcohol, and includes a thermosetting alkyd resin modified with a modifier. Examples of the polybasic acid include aromatic polybasic acids such as phthalic anhydride and terephthalic acid, and aliphatic polybasic acids such as succinic acid, adipic acid, maleic acid, maleic anhydride, and fumaric acid. Examples of the polyhydric alcohol include dihydric alcohols such as ethylene glycol, diethylene glycol, and propylene glycol, trihydric alcohols such as glycerin and trimethylolpropane, and polyhydric alcohols such as pentaerythritol, dipentaerythritol, and sorbitol. Examples of the modifier include stearic acid, oleic acid, linoleic acid and the like.

  The base film preferably used in the present invention is a polyethylene terephthalate film coated with a release agent and provided with a release agent layer.

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

  The average thickness of the release agent layer in the dry state is not particularly limited, but is preferably 0.01 to 10 μm, and more preferably 0.03 to 1 μm. In particular, if the average thickness of the release agent layer is less than or equal to the above upper limit, when the base film is wound into a roll, the surface of the base film provided with the release agent layer and the back surface of the base film are Since they are not in contact with each other and are difficult to block, the release performance of the release agent layer does not deteriorate due to this blocking.

[Peeling film]
As a peeling film, what has peelability simultaneously with adhesiveness with respect to a protective film formation layer is preferable. As what has peelability simultaneously with adhesiveness, the polyethylene terephthalate film which does not have a release agent layer on the surface, a polyimide film, a fluororesin film, a polyolefin film, a polyethylene film etc. are mentioned, for example.
The release film may be not only a single layer but also a plurality of layers in order to achieve both peelability and adhesion.

  Among them, a polyolefin film is preferably used as one having adhesiveness and peelability at the same time for various protective film forming layers.

[Method for producing semiconductor wafer protective film forming sheet]
An example of a method for producing the semiconductor wafer protective film-forming sheet of the present invention using such a protective film-forming composition, base film, and release film will be described with reference to FIG.
The protective film-forming composition prepared from the components (A) to (D) and other desired components is applied to the entire surface of the base film 1 and dried to form the protective film-forming layer 2. Then, the protective film forming layer 2 is covered with a release film 3 (FIG. 1A).

  Next, in accordance with a conventional method (for example, using a die cutter), the release film and the protective film forming layer are half-cut with the release film as an upper surface so as to have a shape similar to the shape of the semiconductor wafer (FIG. 1). (B)). Half-cutting is performed, for example, at intervals of 10 mm. If an orientation flat or notch is formed on the semiconductor wafer, half-cutting may be performed according to the orientation flat or notch shape (see FIG. 2).

  Then, the excess part of all the peeling films 3 and the protective film formation layer 2 is removed (FIG.1 (c)). Then, the protective layer forming layer 2 is covered with a new release film 3 ′ to complete a semiconductor protective film forming sheet (FIG. 1D).

More specifically, the semiconductor wafer protective film-forming sheet of the present invention thus produced can be used, for example, as follows to produce a semiconductor chip.
(1) For protective film formation comprising a base film, a protective film forming layer, and a release film after aligning an orientation flat or notch on the back surface of a semiconductor wafer having a circuit formed on the front surface. A process of peeling the release film of the sheet and attaching the protective film forming layer side,
(2) A process of curing the protective film by heating after peeling the base film,
(3) A step of dicing the semiconductor wafer and the protective film.

  The dicing in the step (3) 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 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 and a comparative example are shown and this invention is demonstrated further in detail, this invention is not limited to these.
<Preparation of composition for forming protective film>
In each Example and each Comparative Example, the component (A) in an amount shown in Tables 1 and 2 was dissolved in about 50 parts by mass of cyclohexane. The obtained solution was mixed with other components in the amounts shown in Tables 1 and 2 to obtain a composition having a solid content of about 70% by mass.

Each component shown in Table 1 and Table 2 is as follows.
-(A) component (A-1) Phenoxy resin: Mw about 60,000, JER E1256 (made by Japan Epoxy Resin Co., Ltd.)
(A-2) Polyimide resin: obtained by the synthesis method described later.
(A-3) Acrylic resin: 55 parts by mass of butyl acrylate, 15 parts by mass of methyl methacrylate, 20 parts by mass of glycidyl methacrylate, and 15 parts by mass of 2-hydroxyethyl acrylate (weight average molecular weight (Mw)) : 900,000, glass transition temperature (Tg): -28 ° C)

Component (B) Epoxy resin: RE310S (manufactured by Nippon Kayaku Co., Ltd.), viscosity at 25 ° C. and 15 Pa. s (Bisphenol A type epoxy resin)
Component (C) Silica: SC2050, average particle size 0.5 μm, maximum particle size 5 μm, KBM-403 treated product, manufactured by Admatechs Co., Ltd. (spherical silica manufactured by deflagration method)
-(D) component Dicyandiamide (DICY-7): Japan Epoxy Resin Co., Ltd.

..Synthesis of polyimide resin (A-2):
In a 1 liter separable flask equipped with a 25 ml water quantitative receiver with a cock connected to a reflux condenser, a thermometer, and a stirrer, 49.01 parts by mass of diaminosiloxane (KF-8010, manufactured by Shin-Etsu Chemical Co., Ltd.), reaction As a solvent, 100 parts by mass of 2-methylpyrrolidone was charged 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.

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。 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 an imide group 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.

<Preparation of protective film-forming sheet>
The composition for forming a protective film prepared as shown in Tables 1 and 2 was applied at 2 m / min with a blade coater to one side of a release agent layer side of a PET film subjected to a release treatment as a base film, and then 110 ° C. And dried for 10 minutes to form a protective film-forming layer having a thickness of 25 μm and coated on the entire surface of the substrate film. And the protective film formation layer top was covered with the polyolefin film as a peeling film.

The protective film-forming layer having the orientation flat or notch shape was half-cut into a shape similar to that of a semiconductor wafer with various diameters by using a punching cutter with the release film as an upper surface at intervals of 10 mm by a conventional method. Then, all the peeling films and the excess part of the protective film were removed. Next, the protective film forming layer was covered with a new release film to complete a semiconductor protective film forming sheet.
For comparison, a protective film forming sheet not pre-cut into a wafer shape was also produced (Comparative Example 1).

<Evaluation test>
Using the protective film-forming sheet, evaluation was performed as follows. Table 1 shows the results of the examples and Table 2 shows the results of the comparative examples.

-Using the protective film-forming sheet obtained by measuring the elastic modulus , the protective film-forming layer was heat-treated at 190 ° C for 2 hours to be cured. The PET film was peeled off, and the dynamic viscoelastic modulus was measured for a cured product of 20 mm × 5 mm × 50 μm. A dynamic viscoelasticity measuring apparatus was used for the measurement, and Young's modulus was measured under the conditions of a tensile mode, a distance between chucks of 10 mm, a measurement temperature of 25 ° C. and a measurement frequency of 1 Hz.

-Using a protective film forming sheet obtained in the chipping test , using a protective film attaching apparatus (FM-114 manufactured by Technovision), a silicon wafer having a thickness of 220 μm (unpolished wafer having a diameter of 200 mm) at 70 ° C. Was affixed to a wafer having a thickness of 220 μm by polishing # 2000 using DAG-810 manufactured by DISCO Corporation. Thereafter, the base sheet is peeled off from the attached protective film and cured at 190 ° C./2 hours, and then the silicon wafer is diced into 10 mm × 10 mm square chips under the following conditions, and a microscope with 8 chips obtained is obtained. A cross-sectional photograph was taken, and the presence or absence of chipping having a length of 25 μm or more in the cross-sectional direction was examined.

The dicing in the chipping test was performed under the following conditions.
Dicing conditions:
Device used: DISCO Dicer DAD-341
Cutting method: Single Blade rotation speed: 30000rpm
Blade speed: 50 mm / sec
Dicing film thickness: 120 μm
Cutting into dicing film: 30 μm

-Using the protective film forming sheet obtained in the protective film detachment test , using a protective film application apparatus (FM-114 manufactured by Technovision), and affixing to the above-mentioned 220 μm thick wafer at 70 ° C. It was. Thereafter, the base sheet was peeled off from the protective film adhered and cured at 190 ° C./2 hours, and then the silicon wafer was inserted into a dicing cassette DTC 2-8H manufactured by DISCO Corporation. The dicing cassette into which the wafer was inserted was shaken in the horizontal direction with a shaker for 10 minutes, and then the shape of the protective film forming layer on the outer peripheral portion was confirmed to confirm whether desorption occurred.

As shown in Table 1, in the semiconductor wafer protective film-forming sheets of Examples 1 to 10, neither protective film was detached nor chipping occurred.
On the other hand, as shown in Table 2, when the diameter of the protective film forming layer is too small (Comparative Example 2) or larger than the semiconductor wafer (Comparative Examples 1, 3, 6, 7, 8), When the elastic modulus after curing of the protective film forming layer was not within the range of 1 GPa to 20 GPa (Comparative Examples 4 and 5), the protective film was detached or chipped.

  Further, in Examples 1 to 10, when the protective film forming sheet was attached to the wafer, optical recognition was easy and the wafer could be accurately aligned, but Comparative Example 1 in which pre-cut was not performed. Then, the orientation flat or notch portion is covered with the protective film forming layer, and it is difficult to align the wafer.

  As described above, the semiconductor wafer protective film-forming sheet of the present invention does not cause the film piece to be detached after the protective film-forming layer is cured, does not cause contamination of the circuit surface on the wafer by the film piece, and is chipped. It was found that can also be prevented.

  In particular, from the difference in results between Example 2 and Comparative Example 2, Example 8 and Comparative Example 8, Example 9 and Comparative Example 4, Example 10 and Comparative Example 5, the “object for forming protective film” of the present invention. It was proved that there is significance in limiting the numerical value to “a diameter smaller than the diameter of the semiconductor wafer by 100 μm to 5 mm than the diameter of the semiconductor wafer” and “the elastic modulus of the protective film forming layer after curing is 1 GPa to 20 GPa”.

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

  DESCRIPTION OF SYMBOLS 1 ... Base film, 2 ... Protective film formation layer, 3, 3 '... Release film.

(B) The compounding quantity of the epoxy resin of a component is 5-200 mass parts with respect to 100 mass parts of resin of (A) component, It is preferable that it is especially 10-100 mass parts. The amount of the epoxy resin is possible without adhesion Ru degradation of the protective film forming layer composition if 5 parts by mass or more, nor insufficient flexibility of the protective film forming layer is not more than 200 parts by mass.

[Method for producing semiconductor wafer protective film forming sheet]
An example of a method for producing the semiconductor wafer protective film-forming sheet of the present invention using such a protective film-forming composition, base film, and release film will be described with reference to FIG.
The protective film-forming composition prepared from the components (A) to (D) and other desired components is applied to the entire surface of the base film 1 and dried to form the protective film-forming layer 2. Then, the protective film forming layer 2 is covered with a release film 3 (FIG. 1A).

Claims (3)

  A semiconductor wafer protective film forming sheet for forming a protective film on a semiconductor wafer, comprising: a base film, a release film, and a protective film forming layer disposed between the base film and the release film A plurality of the protective film forming layers are formed on the surface of the base film at regular intervals, and each protective film forming layer has a thickness of 100 μm to 5 mm from the diameter of the semiconductor wafer on which the protective film is to be formed. A semiconductor wafer protective film-forming sheet having a small diameter and an elastic modulus of the protective film-forming layer after curing of 1 GPa to 20 GPa.   The protective film forming layer has a planar shape similar to the planar shape of the target semiconductor wafer, and an orientation flat or a notch is formed according to the shape of the target semiconductor wafer. Item 8. A semiconductor wafer protective film forming sheet according to Item 1. The protective film forming composition to be the protective film forming layer is at least,
(A) 100 parts by mass of at least one resin selected from the group consisting of phenoxy resin, polyimide resin, and (meth) acrylic resin,
(B) 5 to 200 parts by mass of an epoxy resin,
(C) 100-600 parts by weight of filler,
(D) an effective amount of an epoxy resin curing catalyst,
The sheet for forming a semiconductor wafer protective film according to claim 1, wherein the sheet is a composition containing the semiconductor wafer protective film.

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