KR20150097483A - Holding membrane forming film - Google Patents

Abstract

Provided is a film for forming a protective film which is easy to peel off from a support after curing a protective film forming film fixed on a support and has excellent bonding strength of chips.
The film for forming a protective film according to the present invention is a film for forming a curable protective film having a first surface and a second surface, wherein the adhesive strength of the first surface to the silicon wafer after curing is higher than that of the silicon wafer Adhesive strength.

Description

{HOLDING MEMBRANE FORMING FILM}

The present invention relates to a protective film forming film capable of forming a protective film on a semiconductor wafer or a semiconductor chip and capable of improving the production efficiency of the semiconductor chip. To a film for forming a protective film used for manufacturing a semiconductor chip mounted in a so-called face-down manner.

2. Description of the Related Art Recently, a semiconductor device using a mounting method called a face down method has been manufactured. In the face down system, a semiconductor chip (hereinafter simply referred to as " chip ") having an electrode such as a bump is used on a circuit surface, and the electrode is bonded to the substrate. For this reason, the surface (the back surface of the chip) opposite to the circuit surface of the chip may be exposed.

The back surface of the exposed chip may be protected by the organic film. Conventionally, a chip having a protective film made of this organic film is obtained by applying a liquid resin on the back surface of a wafer by a spin coating method, drying, and curing to cut the protective film together with the wafer. However, since the thickness precision of the protective film thus formed is not sufficient, the yield of the product may be lowered.

In order to solve the above problem, there is disclosed an energy ray-curable chip protective film formed on a release sheet (Patent Document 1).

Conventionally, in the case where the chip itself is sufficiently thick and there is no fear of breakage, the chip protective film disclosed in Patent Document 1 is not used, and the back side of the chip is directly laser-printed. Since the back surface of the chip is smooth, the visibility of characters such as laser-printed characters is excellent.

In recent years, when the chip is thinned and the chip protecting film is attached to the back of the chip for the purpose of preventing breakage and the like, and the protective film is formed by curing, one side of the chip protecting film is cured in the exposed state. For this reason, the smoothness of the surface after curing is not necessarily maintained, and the appearance of the surface is sometimes rough. When the smoothness of the surface of the chip protective film after curing is lowered, the visibility of laser-printed characters and the like may be lowered. Further, since the wafer or the chip is thinned, there is a fear of warping when the chip protective film is cured.

Japanese Laid-Open Patent Publication No. 2009-138026

The smooth chip-protecting film on the surface after curing is obtained by temporarily fixing a smooth surface-supporting member to the exposed surface of the chip or the chip-protecting film attached to the chip, and peeling the support after curing. That is, deformation of the surface of the chip-protecting film caused by the curing reaction can be suppressed by curing the chip-protecting film while keeping the chip-protecting film fixed on the support having a smooth surface. When the cured chip protecting film is peeled from the support, the smoothness of the cured support is transferred to the cured chip protecting film, so that the same surface shape as that of the backside of the chip not using the conventional chip protecting film can be imparted to the cured chip protecting film have. As a result, visibility of characters and the like laser-printed on the chip protective film after curing is improved.

However, if the adhesive force between the chip protective film after curing and the support is excessively high, the chip protective film after curing from the wafer or chip may peel off when peeling the chip protective film from the support.

An object of the present invention is to provide a film for forming a protective film which is easy to peel off from a support after hardening a protective film forming film fixed on a support and has excellent bonding strength to a chip.

The inventors of the present invention have conducted extensive studies to solve the above problems. As a result, it has been found that the above problems can be solved by making a difference in the adhesive force on each surface of the protective film-forming film after curing, thereby completing the present invention.

That is, the gist of the present invention is as follows.

[1] A film for forming a curable protective film having a first surface and a second surface,

Wherein the adhesion of the first surface to the silicon wafer after curing is higher than the adhesion of the second surface to the silicon wafer after curing.

[2] A method for producing a silicon wafer, comprising the steps of: (1) preparing a silicone wafer having a first surface and a second surface, the first surface being bonded to the silicon wafer, Is about 1.2 to 100. The film for forming a protective film according to [1]

[3] The film for forming a protective film according to [1] or [2], wherein the first surface is attached to an adherend forming a protective film.

[4] The protective film forming film according to any one of [1] to [3], wherein the second surface is fixed to the support.

[5] The protective film forming film according to any one of [1] to [4], wherein the adhesion of the second surface to the silicon wafer after curing is 0.01 to 100 N.

[6] The protective film forming film according to any one of [1] to [5], wherein the second surface has a probe tack value of 0.01 to 3 N / 5 mmΦ.

[7] A protective film forming film according to any one of [1] to [6], wherein the protective film comprises two or more resin layers having different compositions.

[8] A method for manufacturing a semiconductor device, comprising the steps of: preparing a resin layer containing at least a second surface containing a releasing agent and containing a releasing agent in the resin layer including the second surface, 7].

[9] The method according to any one of [1] to [9], wherein the content of the releasing agent in the resin layer including the first surface is 0 to 0.001 part by mass based on 100 parts by mass of the solid content excluding the releasing agent among all the solid components constituting the resin layer including the first surface,

The protective film according to [8], wherein the content of the releasing agent in the resin layer including the second surface is 0.001 to 20 parts by mass based on 100 parts by mass of the solid content excluding the releasing agent among all the solid contents constituting the resin layer including the second surface Film.

According to the present invention, even if the film for forming a protective film is cured in a state where the substrate is temporarily fixed, peeling from the substrate is easy, and the protective film forming film after curing from the wafer or chip is not peeled off. For this reason, a desired smoothness can be imparted to the surface of the protective film-forming film after curing. As a result, visibility of letters and the like laser-printed on the protective film-forming film after curing is improved.

Fig. 1 shows a cross-sectional view of a film for forming a protective film according to the present invention.
Fig. 2 shows a first embodiment of a protective film-forming composite sheet formed using a protective film-forming film according to the present invention.
Fig. 3 shows a second embodiment of a protective film-forming composite sheet formed using the protective film-forming film according to the present invention.
Fig. 4 shows a third embodiment of a protective film-forming composite sheet formed using the protective film-forming film according to the present invention.
Fig. 5 shows a fourth embodiment of a protective film-forming composite sheet formed using the protective film-forming film according to the present invention.
6 is a schematic view of a method for evaluating releasability on a second surface of a protective film forming film according to the present invention.
7 shows a schematic view of a method for evaluating the adhesion of a film for forming a protective film according to the present invention.

Hereinafter, the protective film forming film of the present invention will be described in detail.

[Film for forming a protective film]

As shown in Fig. 1, the protective film forming film 10 has a first surface (a) and a second surface (b), and the adhesive strength of the first surface (a) to the silicon wafer after curing (B) of the second surface (b) on the silicon wafer.

The film for forming a protective film is cured in a state where the first surface is attached to an adherend such as a semiconductor wafer or a semiconductor chip. Therefore, the exposed second surface may be deformed due to the curing reaction, making it difficult to maintain the smoothness of the surface. When the smoothness of the second surface in the protective film for forming a protective film (protective film) after curing is lowered, the visibility of the laser-printed characters on the second surface of the protective film sometimes deteriorates in the subsequent laser process.

Here, when the protective film forming film 10 is cured, for example, a silicon wafer or the like is temporarily fixed as a support for imparting smoothness to the second surface, the surface shape of the silicon wafer Transferred. Therefore, the surface shape of the same degree as the back surface of the chip can be imparted to the second surface (b) of the protective film.

A silicon wafer or the like may be attached to the first surface (a) of the protective film forming film 10 as an adherend for forming a protective film. As described above, the second surface (a) of the protective film forming film b, it is necessary to easily peel the fixed silicon wafer or the like on the second surface (b) of the cured protective film forming film after curing the protective film forming film.

According to the protective film forming film of the present invention, since the adhesion of the first surface (a) to the silicon wafer after curing is higher than the adhesion of the second surface (b) to the silicon wafer after curing, When the adherend such as a silicon wafer is attached to the surface a and the support film such as a silicon wafer is temporarily fixed to the second surface b to cure the protective film forming film, Deformation caused by the second surface (b) is suppressed, and the support can be easily peeled off from the second surface (b). Since the smoothness of the surface of the support can be transferred to the second surface (b) by curing the protective film forming film on the support, the smoothness of the second surface (b) after curing is improved and the visibility of laser- A protective film can be formed on the adherend.

The ratio of the adhesion of the first surface to the silicon wafer after curing and the adhesion strength of the second surface to the silicon wafer after curing (adhesion to the silicon wafer on the first surface / adhesion to the silicon wafer on the second surface) Is preferably 1.2 to 100, more preferably 1.3 to 50, still more preferably 1.5 to 30, and particularly preferably 3 to 20. When the ratio of the adhesive force is smaller than 1.2, the difference in adhesion between the first surface and the second surface after curing is small, so that when the support is peeled from the second surface (b), the adherend is also peeled off from the first surface (a) There is a concern. On the other hand, if the ratio of the adhesive force is larger than 100, the adhesion to the support is insufficient, and there is a fear that the protective film forming film peels off from the support during curing of the protective film forming film.

The adhesion of the second surface to the silicon wafer after curing is preferably 0.01 to 100 N, more preferably 0.05 to 20 N, more preferably 0.1 to 5 N, and particularly preferably 0.4 to 5 N. When the adhesive strength of the second surface to the silicon wafer after the curing is in the above range, the adhesion to the support is excellent and peeling of the protective film forming film from the support during the curing reaction and during the conveyance after curing can be suppressed. The adhesive force is an adhesive force of a chip having a protective film of 2 mm x 2 mm size, which is measured by a measuring method in Examples to be described later.

The probe surface value of the second surface of the protective film-forming film is preferably 0.01 to 3 N / 5 mmΦ, more preferably 0.1 to 1.5 N / 5 mmΦ, further preferably 0.3 to 1.5 N / 5 mmΦ. By setting the probe tack value of the second surface within the above range, it is possible to prevent the adherend to adhere to the protective film forming film from the support during the curing reaction. Since the smoothness of the support can be easily imparted to the protective film-forming film after curing, the visibility of characters and the like laser-printed on the protective film-forming film after curing is improved. The probe tack value of the second surface is a probe tack value of the film for forming a protective film before curing, which is measured by a probe at 70 캜, and specifically measured by a measuring method in Examples described later.

The method for producing a protective film having such physical properties as described above includes a method of obtaining two or more resin layers having different compositions by changing the composition of each component constituting the protective film forming film and laminating the resin layers; A method of inclining the composition in the thickness direction of the single-layer protective film-forming film (having a concentration gradient); A method in which only the second surface is previously heated and / or irradiated with energy to form a semi-cured state, and the adhesion on the second surface is lowered to obtain a film for forming a protective film.

In the case where the protective film forming film of the present invention is a laminate of two or more resin layers having different compositions, another layer such as an adhesive layer may be interposed between the resin layers. The adhesive layer is not particularly limited as long as the object of the present invention is not impaired.

At least functions required for the protective film-forming film are (1) sheet shape retainability, (2) initial adhesion, and (3) curability.

The film for forming a protective film can be provided with (1) a sheet-form retaining property and (3) a curing property by adding a binder component, and as the binder component, a first binder containing a polymer component (A) and a curing component Or a second binder component containing a curable polymer component (AB) having properties of the component (A) and the component (B) can be used.

In addition, the initial adhesive property, which is a function for adhering the protective film forming film to the adherend during curing, may be pressure sensitive adhesive property or may be softened and adhered by heat. (2) The initial adhesive property is usually controlled by adjusting the properties of the binder component and the amount of the inorganic filler (C) to be described later.

(First binder component)

The first binder component contains the polymer component (A) and the curing component (B), thereby imparting sheet-like retention and curability to the protective film-forming film. Further, the first binder component does not contain the curable polymer component (AB) for the sake of distinction from the second binder component.

(A) the polymer component

The polymer component (A) is added to a film for forming a protective film with a primary purpose of imparting sheet-like retention to the protective film-forming film.

In order to achieve the above object, the weight average molecular weight (Mw) of the polymer component (A) is usually 20,000 or more, preferably 20,000 to 3,000,000. The value of the weight average molecular weight (Mw) is a value measured by Gel Permeation Chromatography (GPC) (polystyrene standard). For example, a high-speed GPC apparatus "HLC-8120GPC" manufactured by Tosoh Corporation, a high-speed column "TSK gurd column H _XL -H", "TSK Gel GMH _XL ", "TSK Gel G2000 H _XL " (All manufactured by TOSOH CORPORATION) were connected in this order and the detector was set to a differential refractometer at a column temperature of 40 DEG C and a feed rate of 1.0 mL / min.

For the sake of distinction from the curable polymer (AB) described later, the polymer component (A) has no curing functional group which will be described later.

Examples of the polymer component (A) include an acrylic polymer, a polyester, and a phenoxy resin (limited to those having no epoxy group for the sake of clarity from the curable polymer (AB) described later), polycarbonate, polyether, polyurethane, polysiloxane, Polymers and the like can be used. Further, it may be an acryl urethane resin obtained by reacting two or more of these, for example, an urethane prepolymer having an isocyanate group at the molecular end with an acrylic polyol, which is an acrylic polymer having a hydroxyl group. In addition, polymers containing two or more kinds of polymers bonded together may be used, or a combination of two or more of them may be used.

(A1) Acrylic polymer

As the polymer component (A), an acrylic polymer (A1) is preferably used. The glass transition temperature (Tg) of the acrylic polymer (A1) is preferably in the range of -60 to 50 占 폚, more preferably -50 to 40 占 폚, and still more preferably -40 to 30 占 폚. When the glass transition temperature of the acrylic polymer (A1) is high, the proton value of the protective film forming film tends to decrease, and the adhesion after curing tends to deteriorate. In view of this tendency, when a protective film forming film is formed of two or more resin layers, the glass transition temperature (Tg) of the acrylic polymer (A1) used in the resin layer including the second surface (b) And particularly preferably in the range of 40 to -5 占 폚.

The weight average molecular weight of the acrylic polymer (A1) is preferably 100,000 to 1,500,000. When the weight average molecular weight of the acrylic polymer (A1) is high, the value of the proton value of the protective film forming film tends to be lowered, and the adhesiveness after curing tends to decrease. In view of such tendency, when a protective film forming film is formed of two or more resin layers, the weight average molecular weight of the acrylic polymer (A1) used in the resin layer including the second surface (b) is preferably 600,000 to 1,200,000 Is more preferable.

The acrylic polymer (A1) includes at least a monomer constituting (meth) acrylic acid ester.

Examples of the (meth) acrylic esters include alkyl (meth) acrylates having 1 to 18 carbon atoms in the alkyl group, specifically methyl (meth) acrylate, ethyl (meth) acrylate, ) Acrylate, 2-ethylhexyl (meth) acrylate and the like; (Meth) acrylate having a cyclic skeleton, specifically, cycloalkyl (meth) acrylate, benzyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (Meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, imide (meth) acrylate, and the like. Examples of the monomer having a hydroxyl group, the monomer having a carboxyl group and the monomer having an amino group, which will be described later, include (meth) acrylic acid esters.

Further, in the present specification, (meth) acrylic is sometimes used to mean both acryl and methacryl.

A monomer having a hydroxyl group may be used as a monomer constituting the acrylic polymer (A1). When such a monomer is used, the compatibility of the acrylic polymer (A1) with the acrylic polymer (A1) is improved when a hydroxyl group is introduced into the acrylic polymer (A1) and the protective film forming film contains a separate energy ray curable component (B2). Examples of the monomer having a hydroxyl group include (meth) acrylic acid esters having a hydroxyl group such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate; N-methylol (meth) acrylamide, and the like.

As the monomer constituting the acrylic polymer (A1), a monomer having a carboxyl group may be used. When such a monomer is used, the compatibility of the acrylic polymer (A1) with the carboxyl polymer is improved when the carboxyl group is introduced into the acrylic polymer (A1) and the protective film forming film contains a separate energy ray curable component (B2). Examples of the monomer having a carboxyl group include (meth) acrylic acid, maleic acid, fumaric acid, itaconic acid, and the like. When the epoxy-based thermosetting component is used as the curable component (B) to be described later, since the carboxyl group and the epoxy group in the epoxy-based thermosetting component react with each other, the amount of the monomer having a carboxyl group is preferably small.

As the monomer constituting the acrylic polymer (A1), a monomer having an amino group may be used. Examples of such a monomer include a (meth) acrylic acid ester having an amino group such as monoethylamino (meth) acrylate.

As the monomer constituting the acrylic polymer (A1), other vinyl acetate, styrene, ethylene,? -Olefin and the like may be used.

The acrylic polymer (A1) may be crosslinked. The crosslinking is carried out by reacting the acrylic polymer (A1) before crosslinking with a crosslinkable functional group such as a hydroxyl group, and by adding a crosslinking agent to the composition for forming a protective film forming film, by reacting the crosslinkable functional group and the functional group possessed by the crosslinking agent. By crosslinking the acrylic polymer (A1), it is possible to control the cohesive force of the protective film forming film.

Examples of the crosslinking agent include an organic polyvalent isocyanate compound and an organic polyvalent organic compound.

Examples of the organic polyisocyanate compound include an aromatic polyisocyanate compound, an aliphatic polyisocyanate compound, an alicyclic polyisocyanate compound, a trimer of these organic polyisocyanate compounds, and a terminal isocyanate urethane prepolymer obtained by reacting these organic polyisocyanate compounds with a polyol compound .

Specific examples of the organic polyisocyanate compound include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylene diisocyanate, diphenylmethane- Diisocyanate, diphenylmethane-2,4'-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, dicyclohexyl Methane-2,4'-diisocyanate, lysine isocyanate, and polyhydric alcohol adducts thereof.

Specific examples of the organic polyhydric compound include N, N'-diphenylmethane-4,4'-bis (1-aziridinecarboxamide), trimethylolpropane-tri- Ol methane-tri-? - aziridinyl propionate and N, N'-toluene-2,4-bis (1-aziridine carboxamide) triethylene melamine.

The crosslinking agent is used in an amount of usually 0.01 to 20 parts by mass, preferably 0.1 to 10 parts by mass, more preferably 0.5 to 5 parts by mass based on 100 parts by mass of the acrylic polymer (A1) before crosslinking.

In the present invention, when the content of the component (A) is determined on the basis of the content of the component constituting the film for forming a protective film, when the polymer component (A) is a crosslinked acrylic polymer, Is the content of the acrylic polymer before crosslinking.

(A2) Non-acrylic resin

As the polymer component (A), a polyester, a phenoxy resin (limited to those having no epoxy group for the sake of distinction from the curable polymer (AB) described later), polycarbonate, polyether, polyurethane, polysiloxane, Acrylic resin (A2) selected from a combination of two or more thereof, or a combination of two or more thereof. Such a resin preferably has a weight average molecular weight of 20,000 to 100,000, more preferably 20,000 to 80,000.

The glass transition temperature of the non-acrylic resin (A2) is preferably in the range of -30 to 150 占 폚, more preferably -20 to 120 占 폚.

When the non-acrylic resin (A2) is used in combination with the above-mentioned acrylic polymer (A1), when a protective film forming film is transferred to an adherend using a composite sheet for forming a protective film described later, The interlayer delamination can be easily performed, and further, the film for forming the protective film can follow the transfer surface to suppress the occurrence of voids and the like.

When the non-acrylic resin (A2) is used in combination with the acrylic polymer (A1) described above, the content of the non-acrylic resin (A2) is preferably in the range of the mass ratio A2: A1 of the non-acrylic resin (A2) , Usually in the range of 1:99 to 60:40, preferably 1:99 to 30:70. When the content of the non-acrylic resin (A2) is within this range, the above effects can be obtained.

(B) a curable component

The curable component (B) is added to the film for forming a protective film mainly for imparting curability to the protective film forming film. The thermosetting component (B1) or the energy ray-curable component (B2) can be used as the curable component (B). They may be used in combination. The thermosetting component (B1) contains a compound having a functional group which reacts at least by heating. The energy ray curable component (B2) contains a compound (B21) having a functional group which reacts by energy ray irradiation, and undergoes polymerization and curing upon irradiation with energy rays such as ultraviolet rays and electron beams. The functional groups of these curable components react with each other to form a three-dimensional network structure, whereby curing is realized. Since the curable component (B) is used in combination with the polymer component (A), it is preferable that the curable component (B) has a weight average molecular weight Mw) is 10,000 or less, preferably 100 to 10,000.

(B1) Thermosetting component

As the thermosetting component, for example, an epoxy thermosetting component is preferable.

The epoxy-based thermosetting component preferably contains a compound (B11) having an epoxy group and a combination of the compound (B11) having an epoxy group and the thermosetting agent (B12).

(B11) a compound having an epoxy group

As the compound (B11) having an epoxy group (hereinafter occasionally referred to as " epoxy compound (B11) "), conventionally known compounds may be used. Specific examples thereof include polyfunctional epoxy resins, bisphenol A diglycidyl ether and its hydrides, orthocresol novolak epoxy resins, dicyclopentadiene type epoxy resins, biphenyl type epoxy resins, bisphenol A type epoxy resins, Bisphenol F type epoxy resin, and phenylene skeleton type epoxy resin, epoxy compounds having two or more functionalities in the molecule. These may be used alone or in combination of two or more.

When the epoxy compound (B11) is used, the film for forming a protective film preferably contains the epoxy compound (B11) in an amount of 1 to 1,500 parts by mass, more preferably 3 to 1200 parts by mass, per 100 parts by mass of the polymer component (A) Mass part. When the amount of the epoxy compound (B11) is small, the adhesiveness after curing of the protective film forming film tends to be lowered. When only the epoxy compound (B11) which is solid at room temperature is used, the probe tack value of the protective film forming film tends to increase when the amount of the epoxy compound (B11) is small, that is, have. In addition, the room temperature refers to 25 占 폚, and so on.

In the case of forming a film for forming a protective film with two or more resin layers in view of this tendency, only the epoxy compound (B11) which is solid at normal temperature is used in the resin layer including the second surface (b) It is particularly preferable that the epoxy compound (B11) is contained in an amount of 70 to 150 parts by mass based on 100 parts by mass of the polymer component (A).

(B12) Heat curing agent

The thermosetting agent (B12) functions as a curing agent for the epoxy compound (B11). Preferred examples of the heat curing agent include compounds having two or more functional groups capable of reacting with an epoxy group in one molecule. Examples of the functional group include a phenolic hydroxyl group, an alcoholic hydroxyl group, an amino group, a carboxyl group and an acid anhydride. Of these, phenolic hydroxyl groups, amino groups, acid anhydrides and the like are preferable, and phenolic hydroxyl groups and amino groups are more preferable.

Specific examples of the phenol-based curing agent include a polyfunctional phenol resin, a biphenol, a novolac phenol resin, a dicyclopentadiene phenol resin, a xylyl phenol resin, and an aralkyl phenol resin. A specific example of the amine-based curing agent is DICY (dicyandiamide). These may be used singly or in combination of two or more.

The content of the thermosetting agent (B12) is preferably 0.1 to 500 parts by mass, more preferably 1 to 200 parts by mass, per 100 parts by mass of the epoxy compound (B11). If the content of the thermosetting agent is small, the adhesiveness after curing tends to be lowered.

(B13) Curing accelerator

The curing accelerator (B13) may be used for adjusting the thermal hardening rate of the protective film forming film. The curing accelerator (B13) is preferably used particularly when an epoxy-based thermosetting component is used as the thermosetting component (B1).

Preferred curing accelerators include tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol and tris (dimethylaminomethyl) phenol; 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl- Imidazoles such as hydroxymethylimidazole; Organic phosphines such as tributylphosphine, diphenylphosphine and triphenylphosphine; And tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate and triphenylphosphine tetraphenylborate. These may be used singly or in combination of two or more.

The curing accelerator (B13) is contained in an amount of preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, based on 100 parts by mass of the total amount of the epoxy compound (B11) and the thermosetting agent (B12). By containing the curing accelerator (B13) in an amount within the above range, it is possible to achieve high reliability even when exposed to severe reflow conditions, even when exposed to high temperature and high humidity. By adding the curing accelerator (B13), the adhesion after curing of the protective film-forming film can be improved. This action becomes stronger as the content of the curing accelerator (B13) increases.

(B2) Energy ray curable component

Since the film for forming a protective film contains an energy ray curable component, it is possible to cure the protective film forming film without performing a heat curing step requiring a large amount of energy and a long time. As a result, the manufacturing cost can be reduced.

The energy ray curable component may be a compound (B21) having a functional group which reacts by energy ray irradiation alone, but a compound (B21) having a functional group which reacts by energy ray irradiation and a photopolymerization initiator Is preferably used.

(B21) a compound having a functional group which reacts by irradiation of energy rays

Specific examples of the compound (B21) having a functional group which reacts with energy ray irradiation (hereinafter sometimes referred to as "energy ray-reactive compound (B21)") include trimethylolpropane triacrylate, pentaerythritol triacrylate , Pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate or 1,4-butylene glycol diacrylate, and 1,6-hexanediol diacrylate. And acrylate compounds having a polymerization structure such as oligomer ester acrylate, urethane acrylate oligomer, epoxy acrylate, polyether acrylate and itaconic acid oligomer, and the like, And those having a relatively low molecular weight. Such a compound has at least one polymerizable double bond in the molecule.

When the energy ray-reactive compound (B21) is used, the film for forming a protective film preferably contains 1 to 1,500 parts by mass of the energy ray-reactive compound (B21) based on 100 parts by mass of the polymer component (A) Is contained in an amount of 3 to 1200 parts by mass.

(B22) Photopolymerization initiator

By combining the photopolymerization initiator (B22) with the energy ray-reactive compound (B21), the polymerization curing time can be shortened and the amount of light beam irradiation can be reduced.

Specific examples of such a photopolymerization initiator (B22) include benzophenone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, methyl benzoin benzoate , Benzoin dimethyl ketal, 2,4-diethyl thioxanthone,? -Hydroxycyclohexyl phenyl ketone, benzyl diphenyl sulfide, tetramethyl thiuram monosulfide, azobisisobutyronitrile, benzyl, dibenzyl , Diacetyl, 1,2-diphenylmethane, 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propanone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide And? -Cholanthraquinone. The photopolymerization initiator (B22) may be used singly or in combination of two or more.

The blending ratio of the photopolymerization initiator (B22) is preferably 0.1 to 10 parts by mass, more preferably 1 to 5 parts by mass, per 100 parts by mass of the energy ray-reactive compound (B21).

When the blending ratio of the photopolymerization initiator (B22) is less than 0.1 part by mass, photopolymerization is insufficient and satisfactory curing property may not be obtained. When it exceeds 10 parts by mass, residues which do not contribute to photopolymerization are generated, There is a case.

(Second binder component)

By containing the curable polymer component (AB), the second binder component imparts sheet-like retention and curability to the protective film-forming film.

(AB) curable polymer component

The curable polymer component is a polymer having a curing functional group. Curable functional groups are functional groups capable of reacting with each other to form a three-dimensional network structure, and examples thereof include functional groups that react by heating, and functional groups that react with energy rays.

The curing functional group may be added to the unit of the continuous structure which becomes the skeleton of the curable polymer (AB), or may be added to the terminal. When the curing functional group is added to the unit of the continuous structure which becomes the skeleton of the curable polymer component (AB), the curing functional group may be added to the side chain or directly to the main chain. The weight average molecular weight (Mw) of the curable polymer component (AB) is usually 20,000 or more from the viewpoint of achieving the object of imparting sheet-like retention to the protective film forming film.

Examples of the functional group which reacts by heating include an epoxy group. Examples of the curable polymer component (AB) having an epoxy group include a high molecular weight epoxy group-containing compound and a phenoxy resin having an epoxy group.

The same polymer as the above-described acrylic polymer (A1) may be a polymer obtained by polymerization using a monomer having an epoxy group as a monomer (an epoxy group-containing acrylic polymer). Examples of such a monomer include a (meth) acrylic acid ester having a glycidyl group such as glycidyl (meth) acrylate.

When an epoxy group-containing acrylic polymer is used, the preferred embodiment thereof is the same as that of the acrylic polymer (A1).

In the case of using the curable polymer component (AB) having an epoxy group, the heat curing agent (B12) or the curing accelerator (B13) may be used in combination as in the case of using the epoxy thermosetting component as the curable component (B).

Examples of the functional group that reacts with the energy ray include a (meth) acryloyl group. As the curable polymer component (AB) having a functional group which reacts with an energy ray, an acrylate compound having a polymerization structure such as polyether acrylate, etc., can be used.

For example, the functional group Y capable of reacting with the functional group X (for example, an isocyanate group when the functional group X is a hydroxyl group, etc.) is reacted with the raw polymer having the functional group X such as a hydroxyl group in the side chain, A low molecular weight compound having a functional group capable of reacting with a functional group.

In this case, when the raw material polymer corresponds to the above-mentioned acrylic polymer (A1), a preferred embodiment of the raw material polymer is the same as the acrylic polymer (A1).

In the case of using the curable polymer component (AB) having a functional group reacting with the energy ray, the photopolymerization initiator (B22) may be used in combination as in the case of using the energy ray curable component (B2).

The second binder component may contain the above-mentioned polymer component (A) and the curing component (B) together with the curable polymer component (AB).

(A), the curing component (B) and the curing polymer component (AB) constituting the binder component and the curing component (AB) of the binder component in the case where the protective film forming film is formed of two or more resin layers By changing the content ratio, it is possible to adjust the adhesive force on the first surface and the adhesive force on the second surface of the protective film forming film. Further, by changing the content of the thermosetting agent (B12) or the curing accelerator (B13) in each resin layer, it is possible to adjust the adhesive force on the first surface and the adhesive force on the second surface of the protective film forming film.

In this case, the polymer component (A) and the curing component (B) constituting the binder component contained in the resin layer including the resin layer including the first surface (a) and the second surface (b) Depending on the type (content) or content of the curable polymer component (AB) or the content of the thermosetting agent (B12) or the curing accelerator (B13) (hereinafter also referred to as " binder component main composition "), (C), the coupling agent (E), and the releasing agent (F), which are described later, so as not to cause a substantial difference in the adhesive force between the protective film There may be a difference between the adhesive force on the first surface and the adhesive force on the second surface.

For example, first, by adjusting the main composition of the binder component of the resin layer including the second surface (b) and by adding the releasing agent (F), the adhesive force on the second surface of the protective film forming film, To a predetermined range. On the other hand, while the main component of the binder component of the resin layer including the first surface (a) is approximated to the main component of the binder component of the resin layer including the second surface (b) The stripping agent (F) is not added to the layer or added in an amount smaller than that added to the resin layer containing the second surface (b). As a result, the adhesive force on the second surface of the protective film-forming film and the adhesive force on the first surface of the protective film-forming film do not differ substantially depending on the main composition of the binder component. However, since the resin layer containing the second surface (b) contains much of the releasing agent (F) than the resin layer including the first surface (a), the adhesive force on the second surface of the protective film- Can be controlled so as to be lower than the adhesive force on the first surface of the protective film forming film.

As described above, depending on the main composition of the binder component, in order to prevent a difference between the adhesive force on the first surface and the adhesive force on the second surface of the protective film forming film, The strata can be described as follows.

When the acrylic polymer (A1) is used for the resin layer including the first surface (a), the glass transition temperature (Tg) of the acrylic polymer (A1) in the resin layer including the second surface And the glass transition temperature (Tg) thereof is preferably in the range of -40 to -5 ° C.

When the acrylic polymer (A1) is used for the resin layer containing the first surface (a), the weight average molecular weight of the acrylic polymer (A1) in the resin layer including the second surface (b) The average molecular weight is preferably 600,000 to 1,200,000.

In the resin layer containing the first surface (a), when only the epoxy compound (B11) which is solid at room temperature is used, the content of the epoxy compound (B11) in the resin layer including the second surface (b) , It is preferable that 70 to 150 parts by mass of the epoxy compound (B11) is contained relative to 100 parts by mass of the polymer component (A).

In the case where the protective film forming film according to the main composition of the binder component is not substantially different from the adhesive force on the first surface and the adhesive force on the second surface, When the main composition of the binder component and the main component of the binder component of the resin layer including the second surface (b) are approximate, there is a tendency that the difference in volume shrinkage upon curing of both layers tends to be small. Therefore, the effect of suppressing the warp of the protective film forming film at the time of curing may be obtained.

The protective film forming film may contain the following components in addition to the binder component.

(C) Inorganic filler

The protective film-forming film may contain an inorganic filler (C). By adding the inorganic filler (C) to the protective film forming film, the thermal expansion coefficient of the protective film after curing can be adjusted, and the reliability of the semiconductor device can be improved by optimizing the thermal expansion coefficient of the protective film after curing have. In addition, it becomes possible to reduce the hygroscopicity of the protective film after curing.

Further, by performing laser marking on the protective film, the inorganic filler C is exposed to the portion cut by the laser light, and the reflected light is diffused, thereby exhibiting a color close to white. Thus, when the protective film forming film contains a coloring agent (D) described later, a contrast difference is obtained at a portion different from the laser marking portion, and the effect is clarified.

Preferred examples of the inorganic filler include powders of silica, alumina, talc, calcium carbonate, titanium oxide, iron oxide, silicon carbide, boron nitride and the like, spherical beads thereof, single crystal fibers and glass fibers. Among these, silica filler and alumina filler are preferable. The inorganic fillers (C) may be used alone or in combination of two or more.

When the protective film forming film is formed of two or more resin layers, the content of the inorganic filler (C) in the mass of the total solid content constituting the resin layer including the first surface (a) Is preferably 70 to 70 mass%, more preferably 30 to 60 mass%, and the ratio of the total solid content constituting the resin layer including the second surface (b) to the mass thereof is preferably 40 to 80 mass% 50 to 75% by mass. By forming the protective film forming film with two or more resin layers having different compositions as described above, it is possible to adjust the adhesive force on the first surface and the adhesive force on the second surface of the protective film forming film.

When the film for forming a protective film is formed as a single layer, the adhesive force on the first surface and the adhesive force on the second surface of the protective film-forming film are adjusted to have a concentration gradient of the inorganic filler (C) It may be adjusted. In this case, since the concentration of the inorganic filler (C) is lower than that of the second surface side, the first surface side of the protective film-forming film exhibits excellent wettability and adhesion to an adherend such as a semiconductor wafer or chip. Further, since the concentration of the inorganic filler (C) is higher on the second surface side than on the first surface side, the visibility of the laser factor is improved. The content of the inorganic filler (C) is preferably from 50 to 80 mass% in the mass of the total solids constituting the protective film-forming film, because such effect tends to become remarkable, more preferably from 60 to 80 mass% 80% by mass. The method for forming the concentration gradient of the inorganic filler (C) in the thickness direction of the protective film-forming film is not particularly limited, but the following methods can be used. First, the composition for forming a protective film containing the inorganic filler (C) is applied on the release sheet and left for a predetermined time, whereby the inorganic filler (C) precipitates in the protective film formation film. Thereafter, by drying, a film for forming a protective film having an inclined gradient of the inorganic filler (C) is obtained.

(D) Colorant

The film for forming a protective film may contain a colorant (D). By mixing the coloring agent, it is possible to prevent malfunction of the semiconductor device caused by infrared rays or the like generated from the peripheral device when the semiconductor device is mounted on the device. Further, when engraving is performed on the protective film by means such as laser marking, it is easy to recognize marks such as characters and symbols. That is, in the semiconductor device or the semiconductor chip having the protective film formed thereon, the part number or the like is printed on the surface of the protective film by the usual laser marking method (a method of cutting the protective film surface by laser light to perform printing) The difference in contrast between the portion cut by the laser light of the protective film and the portion not cut by the laser light is sufficiently obtained, and the visibility is improved.

As the colorant, organic or inorganic pigments and dyes are used. Among them, a black pigment is preferable in terms of electromagnetic wave shielding and infrared ray shielding. Examples of the black pigment include carbon black, iron oxide, manganese dioxide, aniline black, activated carbon, and the like, but are not limited thereto. From the viewpoint of enhancing the reliability of the semiconductor device, carbon black is particularly preferable. The colorant (D) may be used alone or in combination of two or more.

The blending amount of the colorant (D) is preferably 0.1 to 35 parts by mass, more preferably 0.5 to 25 parts by mass, and particularly preferably 1 to 15 parts by mass, relative to 100 parts by mass of the total solid content of the protective film- to be.

(E) Coupling agent

The coupling agent (E) having a functional group reacting with an inorganic substance and a functional group reacting with an organic functional group may be used for improving adhesion, adhesion and / or cohesiveness of a protective film to an adherend of a protective film forming film. Further, by using the coupling agent (E), the heat resistance of the protective film obtained by curing the protective film-forming film can be prevented, and the water resistance can be improved. Examples of such a coupling agent include titanate-based coupling agents, aluminate-based coupling agents, and silane coupling agents. Among them, a silane coupling agent is preferable.

As the silane coupling agent, a silane coupling agent is preferably used, in which a functional group reactive with the organic functional group is a group which reacts with a functional group contained in the polymer component (A), the curing component (B), the curable polymer component (AB) and the like.

Examples of such silane coupling agents include? -Glycidoxypropyltrimethoxysilane,? -Glycidoxypropylmethyldiethoxysilane,? - (3,4-epoxycyclohexyl) ethyltrimethoxysilane,? - Aminopropyltrimethoxysilane, N-6- (aminoethyl) -? - aminopropyltrimethoxysilane, N-6- (aminoethyl) (Meth) acrylate, N-phenyl-gamma -aminopropyltrimethoxysilane,? -Ureidopropyltriethoxysilane,? -Mercaptopropyltrimethoxysilane,? -Mercaptopropylmethyldimethoxysilane, bis Triethoxysilylpropyl) tetrasulfane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, imidazolylsilane and the like. These may be used singly or in combination of two or more.

The silane coupling agent is used in an amount of usually 0.1 to 20 parts by mass, preferably 0.2 to 10 parts by mass, more preferably 0.2 to 10 parts by mass, per 100 parts by mass of the total of the polymer component (A), the curing component (B) and the curable polymer component (AB) 0.3 to 5 parts by mass. If the content of the silane coupling agent is less than 0.1 part by mass, the above effect may not be obtained. If the content is more than 20 parts by mass, there is a possibility of causing outgas.

When a film for forming a protective film is formed by a resin layer of two or more layers, the content of the coupling agent (E) is preferably 0.03 to 10 mass% in the mass of all the solid components constituting the resin layer including the first surface (a) Is preferably 2% by mass, more preferably 0.05% by mass to 1% by mass, and preferably 0% by mass to 1.5% by mass, more preferably 0% by mass to 5% by mass of the total solid content constituting the resin layer including the second surface (b) 0.01 to 1% by mass. By forming the protective film forming film with two or more resin layers having different compositions as described above, it is possible to adjust the adhesive force on the first surface and the adhesive force on the second surface of the protective film forming film.

When the film for forming a protective film is formed into a single layer, by having the concentration gradient of the coupling agent (E) in the thickness direction, the adhesive force on the first surface and the adhesive force on the second surface It may be adjusted. Since the first surface side of the protective film forming film has a high concentration of the coupling agent (E) as compared with the second surface side, it exhibits excellent adhesion to an adherend such as a semiconductor wafer or chip. The content of the coupling agent (E) in such a case is preferably 0.01 to 2% by mass, more preferably 0.05 to 1% by mass, in the mass of the total solid content constituting the protective film forming film. The method for forming the concentration gradient of the coupling agent (E) in the thickness direction of the protective film-forming film is not particularly limited and is the same as the method for forming the concentration gradient of the inorganic filler (C) described above.

(F) Remover

A releasing agent may be added to adjust the adhesive force on the first surface and the adhesive force on the second surface of the protective film forming film. Examples of the releasing agent include silicone compounds such as polydimethylsiloxane, polyphenylmethylsiloxane and polydiphenylsiloxane, and fluorine compounds.

Among them, a silicone compound is preferable, and as the organopolysiloxane having an aromatic ring-containing group as a side chain, it is more preferable that the kinematic viscosity at 25 캜 is 50 to 100,000 mm 2 / s. The polysiloxane is a compound in which a plurality of unit structures represented by -Si (X) ₂ -O- (X is a side chain) are linked. The number of the unit structures is not particularly limited, but is usually three or more. The value of the kinematic viscosity can be controlled by increasing or decreasing the number of unit structures.

The silicone compound has a high adhesiveness with the other components in the composition for forming a protective film by lowering the adhesiveness to the support by the siloxane moiety of the organopolysiloxane and having the aromatic ring-containing group on the side chain. In addition, the curing component (B) in the composition for forming a protective film often has an aromatic ring in its constituent component, and in such a case, compatibility with the aromatic ring-containing group of the silicone compound is further enhanced.

Examples of the aromatic ring-containing group include a phenyl group and an aralkyl group. The term "aralkyl group" as used herein means an alkyl group in the form of a linear or branched chain, the number of carbon atoms in the alkyl moiety is preferably 1 to 5, more preferably 1 to 3, and the number of carbon atoms in the aryl moiety is preferably 6 to 10, Lt; / RTI > Preferred examples of the aralkyl group include a benzyl group, a phenylethyl group, a phenylpropyl group and a phenylisopropyl group. The aromatic ring-containing group is preferably an aralkyl group.

In the case of forming a film for forming a protective film with two or more resin layers, at least the resin layer containing the second surface (b) contains the releasing agent and the releasing agent (F) in the resin layer including the second surface ) Is preferably larger than the content of the releasing agent (F) in the resin layer including the first surface (a). With such a constitution, it is possible to adjust the adhesive force on the first surface and the adhesive force on the second surface of the protective film forming film. Specifically, the content of the releasing agent (F) is preferably 0 to 0.001 part by mass, more preferably 0 to 100 parts by mass, relative to 100 parts by mass of the solid content excluding the releasing agent among all the solid components constituting the resin layer including the first surface (a) Is preferably from 0.001 to 20 parts by mass, more preferably from 0.01 to 20 parts by mass, based on 100 parts by mass of the solid content excluding the releasing agent, of all the solid components constituting the resin layer including the second surface (b) 10 parts by mass, more preferably 0.05 to 5 parts by mass. By forming the protective film forming film with two or more resin layers having different compositions as described above, it is possible to adjust the adhesive force on the first surface and the adhesive force on the second surface of the protective film forming film. When the content of the releasing agent (F) in the resin layer including the second surface (b) is within the above range, the balance between the re-peeling performance of the support and the adhesive force of the support is excellent, The film for use can be prevented from peeling off from the support.

(G) General purpose additives

In addition to the above, various additives may be added to the protective film forming film. Examples of the various additives include a leveling agent, a plasticizer, an antistatic agent, an antioxidant, an ion trap agent, a gettering agent, and a chain transfer agent.

The film for forming a protective film has initial adhesiveness and curability, and is readily adhered to a semiconductor wafer, chip or the like by pressing it in an uncured state. Further, the protective film forming film may be heated at the time of pressing. And finally cured to give a protective film having a high impact resistance, excellent adhesive strength, and sufficient protection even under severe high temperature and high humidity conditions. The protective film forming film may have a single-layer structure or a multi-layer structure.

The protective film-forming film is obtained, for example, by using a composition (composition for forming a protective film) obtained by mixing the respective components in an appropriate ratio. The protective film forming composition may be diluted with a solvent in advance, or may be added to a solvent at the time of mixing. The composition for forming a protective film may be diluted with a solvent at the time of use.

Examples of such solvents include ethyl acetate, methyl acetate, diethyl ether, dimethyl ether, acetone, methyl ethyl ketone, acetonitrile, hexane, cyclohexane, toluene and heptane.

The thickness of the protective film-forming film is not particularly limited, but is preferably 3 to 300 占 퐉, more preferably 5 to 250 占 퐉, and particularly preferably 7 to 200 占 퐉.

The maximum transmittance at a wavelength of 300 to 1200 nm, which is a measure of the transmittance of visible light and / or infrared and ultraviolet light in the protective film forming film, is preferably 20% or less, more preferably 0 to 15% More preferably more than 0% and not more than 10%, particularly preferably 0.001 to 8%. By setting the maximum transmittance of the protective film forming film at the wavelength of 300 to 1200 nm within the above-mentioned range, the transmittance of the visible light wavelength region and / or the infrared wavelength region is lowered to prevent malfunction of the infrared device of the semiconductor device and improve the print visibility Is obtained. The maximum transmittance of the protective film forming film at a wavelength of 300 to 1200 nm can be adjusted by the colorant (D). The maximum transmittance of the protective film-forming film was measured using a UV-vis spectrum analyzer (manufactured by Shimadzu Corporation) to measure the total light transmittance at 300 to 1200 nm of the protective film-forming film , And the transmittance is the highest value (maximum transmittance).

The protective film forming film of the present invention is used as a protective film by using a semiconductor wafer or a chip made of silicon or gallium-arsenic as an adherend.

The method for producing the protective film forming film according to the present invention is not particularly limited. For example, a film for forming a protective film can be formed on a process film. The film formation is performed by coating a composition for forming a protective film forming film on a process film by a generally known method such as a roll knife coater, a gravure coater, a die coater, a reverse coater, and the like.

The process film can be used as a support sheet or cover film to be described later.

Further, the protective film forming film may be transferred from the process film to the support sheet or the cover film after the film formation. The process film may be either the support sheet or the cover film, and the material to be transferred may be the other one of the support sheet or the cover film.

When a film for forming a protective film is produced by laminating two or more resin layers having different compositions, a resin layer is first formed on the film by the same method as described above. Next, a resin layer having a different composition is formed on another process film. Thereafter, a protective film-forming film can be produced by bonding the obtained resin layers to each other.

[Composite sheet for forming a protective film]

The composite sheet for forming a protective film is obtained by forming the supporting sheet on the second surface side of the protective film forming film so as to be peelable. The shape of the composite sheet for forming a protective film is not limited to one having a sheet-like shape, and may be a long strip-shaped sheet or it may be wound. As the support sheet, a release sheet can be exemplified, and a pressure-sensitive adhesive sheet to be described later can be used.

The composite sheet for forming a protective film is attached to various adherends, and in some cases, the adherend is subjected to necessary processing such as dicing on the composite sheet for forming a protective film. Thereafter, the film for forming a protective film is fixed and remained on the adherend, and the supporting sheet is peeled off. That is, it is used in a process including a step of transferring the protective film forming film from the support sheet to the adherend.

The protective film forming film may have the same shape as the supporting sheet. The composite sheet for forming a protective film is prepared in such a manner that the film for forming a protective film has substantially the same shape as the wafer or a shape that can fully include the shape of the wafer and is formed on a support sheet having a size larger than that of the protective film- Called pre-forming configuration may be adopted.

Examples of the release sheet include a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polymethylpentene film, a polyvinyl chloride film, a vinyl chloride copolymer film, a polyethylene terephthalate film, a polyethylene naphthalate film, (Meth) acrylic acid copolymer film, an ethylene / (meth) acrylic acid ester copolymer film, a polystyrene film, a polycarbonate film, a polypropylene film, a polypropylene film, a polybutylene terephthalate film, , A polyimide film, a fluororesin film, and the like are used. These crosslinked films are also used. These laminated films may also be used.

The surface tension of the surface of the release sheet in contact with the protective film forming film is preferably 40 mN / m or less, more preferably 37 mN / m or less, particularly preferably 35 mN / m or less. The lower limit value is usually about 25 mN / m. Such a release sheet having a relatively low surface tension can be obtained by appropriately selecting a material and can also be obtained by applying a release agent to the surface of the release sheet and carrying out a release treatment.

As the releasing agent to be used for the peeling treatment, an alkyd type, a silicone type, a fluorine type, an unsaturated polyester type, a polyolefin type, a wax type and the like are used, but an alkyd type, a silicone type and a fluorine type releasing agent are particularly preferable because they have heat resistance.

In order to peel off the surface of a film or the like to be the base of the release sheet by using the release agent, the release agent may be directly applied as a solvent or diluted with solvent or emulsified and applied by a gravure coater, a Meyer bar coater, an air knife coater, The release sheet coated with the release agent may be provided at room temperature or under heating or may be cured by electron beam to form the release agent layer.

Further, the surface tension of the release sheet may be adjusted by laminating the films by wet lamination, dry lamination, hot melt lamination, melt extrusion lamination, coextrusion processing or the like. That is, a film having a surface tension of at least one surface which is in contact with the protective film forming film of the above-mentioned peeling sheet is within a preferable range, so that the surface of the film is in contact with the protective film forming film, A release sheet may be produced.

In the case where an adherend is subjected to necessary processing such as dicing on a protective sheet-forming composite sheet, it is preferable to use a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer formed thereon as a supporting sheet. In this embodiment, the protective film-forming film is laminated on the pressure-sensitive adhesive layer formed on the support sheet. As the base material of the adhesive sheet, the above-mentioned films exemplified as the release sheet can be mentioned. The pressure-sensitive adhesive layer may be a weakly adhesive one having an adhesive force enough to peel off the protective film forming film, or an energy ray curable one having an adhesive force lowered by energy ray irradiation.

The pressure-sensitive adhesive layer is formed by a conventionally known various pressure-sensitive adhesives (for example, general-purpose pressure-sensitive adhesives such as rubber, acrylic, silicone, urethane, and vinyl ether adhesives, pressure-sensitive adhesives with surface roughness, energy ray curable pressure sensitive adhesives, can do.

If the composite sheet for forming a protective film has such a constitution, the adhesion between the support sheet and the protective film-forming film is maintained when the protective sheet-forming composite sheet functions as a dicing sheet for supporting the adherend in the dicing step , It is possible to obtain an effect of suppressing peeling of the chip on which the protective film forming film is formed from the supporting sheet in the dicing step. When the protective sheet-forming composite sheet functions as a dicing sheet for supporting an adherend with respect to the dicing step, it is necessary to dice another dicing sheet on the wafer on which the protective film forming film is formed in the dicing step So that the manufacturing process of the semiconductor device can be simplified.

In the case where the composite sheet for forming a protective film has a preforming configuration, the composite sheet for forming a protective film may be the following first, second, or third configuration. Hereinafter, each configuration of the protective sheet-forming composite sheet 100 will be described with reference to Figs. 2 to 4. Fig.

As shown in Fig. 2, the first configuration is a configuration in which a pressure-sensitive adhesive sheet 3 on which a pressure-sensitive adhesive layer 2 is formed on a substrate 1 is removably formed on a second surface side of the protective film- , The pressure-sensitive adhesive layer is energy ray-curable, and the area where the protective film-forming film is laminated is previously subjected to energy ray irradiation to reduce the tackiness, while the other area is kept without being subjected to energy ray irradiation and the adhesive strength is kept high . In order not to irradiate the energy ray only to other regions, for example, an energy ray shielding layer may be formed by printing or the like in a region corresponding to another region of the support sheet, and energy ray irradiation may be performed from the support sheet side.

As shown in FIG. 3, the second structure is a structure in which a separate jig adhesive layer 4 is formed on the pressure-sensitive adhesive layer 2 of the composite sheet 100 for forming a protective film, to be. As the jig adhesive layer, a double-sided pressure-sensitive adhesive sheet having a core material or a single layer of a pressure-sensitive adhesive may be employed.

4, an interfacial adhesion adjustment layer 5 is formed between the protective film forming film 10 and the pressure-sensitive adhesive layer 2 so as to further include the shape of the protective film forming film, . The interfacial adhesion adjustment layer may be a predetermined film or an interfacial adhesion adjustment pressure-sensitive adhesive layer. It is preferable that the interfacial adhesion adjustment pressure-sensitive adhesive layer is formed by curing the energy beam curable pressure-sensitive adhesive with energy ray irradiation in advance.

By forming the composite sheet for forming a protective film with these first to third constitutions, it is possible to adhere the protective sheet-forming composite sheet to the jig by the sufficient adhesiveness of the pressure-sensitive adhesive layer or the jig adhesive layer in the region surrounding the protective film- have. In addition, it is possible to facilitate the pickup of a chip to which a protective film-forming film or a protective film is adhered by controlling the adhesiveness at the interface between the protective film-forming film and the pressure-sensitive adhesive layer or the interfacial adhesion adjusting layer.

5, the protective film forming film 10 and the supporting sheet (in Fig. 5, the pressure-sensitive adhesive layer 2 on the substrate 1) The jig adhesive layer 4 may be formed on the outer peripheral portion of the surface (first surface) of the protective film forming film 10 in the case where the adhesive sheet 3 in which the adhesive film 3 is formed has the same shape. As the jig adhesive layer, the same materials as those described above can be used.

The thickness of the support sheet is usually 10 to 500 mu m, preferably 15 to 300 mu m, particularly preferably 20 to 250 mu m. When the pressure-sensitive adhesive layer is formed, the thickness of the pressure-sensitive adhesive layer is 3 to 50 占 퐉 in the supporting sheet.

A cover film may be adhered to the first surface of the protective film-forming film. The cover film may cover the pressure-sensitive adhesive layer or the jig adhesive layer when the support sheet is an adhesive sheet. The cover film may be the same as the above-mentioned release sheet.

The film thickness of the cover film is usually 5 to 300 mu m, preferably 10 to 200 mu m, particularly preferably 20 to 150 mu m or so.

The film for forming a protective film of such a composite sheet for forming a protective film may be a protective film for an adherend. The film for forming a protective film is attached to the back face of a semiconductor wafer for a face-down chip or a semiconductor chip, and has a function of protecting the semiconductor wafer or the semiconductor chip as a substitute for the sealing resin by being cured by appropriate means. When the semiconductor wafer is attached to the semiconductor wafer, the protective film has a function of reinforcing the wafer, so that damage to the wafer can be prevented.

[Method of Manufacturing Semiconductor Device]

Next, a method of using the protective film forming film of the present invention will be described by taking the case of applying the above-described protective film forming composite sheet to the production of a semiconductor device as an example.

The method for manufacturing a semiconductor device according to the present invention preferably includes a step of attaching the protective film forming film of the composite sheet for forming a protective film to a semiconductor wafer to obtain a semiconductor chip having a protective film. Specifically, a film for forming a protective film of a composite sheet for protecting film is attached to the back surface of a semiconductor wafer having a circuit formed on its surface, and then a semiconductor chip having a protective film on the back surface thereof is obtained. The protective film is preferably a protective film of a semiconductor wafer or a semiconductor chip. The manufacturing method of the semiconductor device according to the present invention preferably further includes the following steps (1) to (5), and the steps (1) to (4) Are performed in an arbitrary order. When the adhesive sheet is used as the support sheet as described above, the step (5) is preferably carried out before the step (1) in order to simplify the manufacturing process of the semiconductor device.

Step (1): The protective film-forming film and the supporting sheet are peeled off.

Step (2): A film for forming a protective film is placed on a support.

Step (3): The film for forming a protective film is cured to obtain a protective film.

Step (4): The protective film and the support are peeled off.

Step (5): A semiconductor wafer and a protective film-forming film or protective film are diced.

The method of manufacturing a semiconductor device according to the present invention may further include the following step (6) in addition to the steps (1) to (5) .

Step (6): laser beam is applied to the protective film.

The semiconductor wafer may be a silicon wafer or a compound semiconductor wafer such as gallium arsenide. The formation of a circuit with respect to the wafer surface can be performed by various methods including a conventionally used method such as an etching method and a lift-off method. Then, the opposite surface (back surface) of the circuit surface of the semiconductor wafer is ground. The grinding method is not particularly limited, and may be ground by a known means using a grinder or the like. When grinding the back side, an adhesive sheet called a surface protection sheet is attached to the circuit surface to protect the circuit on the surface. The back surface grinding is performed by grinding the back surface side on which the circuit is not formed by the grinder while the circuit surface side (i.e., the surface protective sheet side) of the wafer is fixed by a chuck table or the like. The thickness of the wafer after grinding is not particularly limited, but is usually about 50 to 500 mu m.

Thereafter, if necessary, the crushed layer formed during the back grinding is removed. The removal of the crushed layer is performed by chemical etching, plasma etching, or the like.

Then, a film for forming a protective film of the above-mentioned composite sheet for protecting film is pasted on the back surface of the semiconductor wafer. Thereafter, the steps (1) to (4) are performed in this order and the step (5) is performed in an arbitrary order. As an example, the case of performing in the order of steps (5), (1), (2), (3), and (4) will be described.

First, a protective film forming film (first surface) of the above-described composite sheet for protecting film is pasted on the back surface of a semiconductor wafer having a circuit formed on its surface.

Subsequently, the semiconductor wafer and the protective film forming film are diced for each circuit formed on the wafer surface. The dicing is performed to cut the wafer and the protective film forming film together. It is preferable to use an adhesive sheet as a supporting sheet of a composite sheet for forming a protective film when dicing a semiconductor wafer on a protective sheet forming composite sheet (in the case of performing the step (5) before the step (1)), Can fulfill the role of the dicing sheet for supporting the semiconductor wafer via the protective film forming film. In this case, the semiconductor wafer is bonded to the inner peripheral portion of the protective film-forming composite sheet through the protective film forming film, and the outer peripheral portion of the protective film forming composite sheet is bonded to another jig such as a ring frame, Is fixed to the apparatus, and dicing is performed. The dicing of the semiconductor wafer on the protective sheet-forming composite sheet is carried out in the same manner as the conventional method using a dicing sheet.

Thereafter, the dicing chip (chip on which the protective film forming film is formed) is picked up by a general means such as a collet to peel the support sheet from the second surface of the protective film forming film.

Subsequently, the support is temporarily fixed on the protective film-forming film (second surface), and a laminate obtained by laminating the chip, the protective film-forming film and the support in this order is obtained.

The support is not particularly limited as long as its surface is a material having smoothness, and examples thereof include a plate made of an organic resin such as a silicon wafer, a glass plate, and a polymethyl methacrylate plate. The surface roughness (Ra) of these supports is preferably 200 nm or less, and more preferably 0.01 to 100 nm. The surface roughness (arithmetic mean roughness Ra) in the present invention was measured with a surface roughness meter (manufactured by Mitsutoyo Co., Ltd., SV) under the conditions of a measuring length of 10 mm, a scanning speed of 0.1 mm / sec, and a data sampling pitch of 80 탆 based on JIS B0601; -3000S4). When the protective film forming film has a thermosetting property, the support preferably has heat resistance. Examples of the support having heat resistance include a silicon wafer and a glass plate.

Thereafter, the protective film forming film is heat-cured or energy cured to form a protective film on the back surface of the chip. When the protective film forming film is blended with the thermosetting component (B1) or the thermosetting curable polymerizable component (AB) and the energy ray curable component (B2) or the energy ray curable curable polymer component (AB) And curing by energy ray irradiation may be performed at the same time or sequentially. Examples of the energy ray to be irradiated include ultraviolet (UV) rays or electron beams (EB), and ultraviolet rays are preferably used. As a result, a protective film made of a hardened resin is formed on the back surface of the chip, and the strength is improved as compared with the case of a single chip, so that breakage at the time of handling a thin chip can be reduced. In addition, the uniformity of the thickness of the protective film is superior to the coating method in which the coating liquid for the resin film is applied directly to the back surface of the chip.

Then, the support is peeled off from the protective film to obtain a chip on which the protective film is formed. According to the present invention, a protective film having high uniformity in thickness can be easily formed on the back surface of the chip, and cracking after the dicing step or packaging becomes difficult to occur. Further, since the support is temporarily fixed on the protective film-forming film (second surface), and then hardened, the deformation caused by the curing reaction on the second surface is suppressed and the smoothness of the surface of the support can be transferred to the second surface have. As a result, the smoothness of the second surface after curing is improved, and the visibility of the laser-printed characters on the second surface of the protective film is improved in the later-described laser printing process.

Then, it is preferable to laser-coat the protective film (second surface). Laser marking is performed by laser marking, and the surface of the protective film is cut by irradiation with laser light to mark the protective film on the part number or the like. According to the method for manufacturing a semiconductor device of the present invention, since the smoothness of the support is transferred to the second surface of the protective film, the second surface has the same level of smoothness as the support. Therefore, the visibility such as the part number printed on the second surface of the protective film is excellent.

Finally, a semiconductor device can be manufactured by mounting a chip on which a protective film is formed in a face-down manner on a predetermined base. The semiconductor device may also be manufactured by bonding a semiconductor chip having a protective film on its back surface to another member (chip mounting portion) such as a die pad portion or another semiconductor chip.

The protective film-forming film or the protective film-forming composite sheet using the film of the present invention may be used for protecting semiconductor compounds, glass, ceramics, metals, etc., in addition to the above-described methods of use.

Example

Hereinafter, the present invention will be described by way of examples, but the present invention is not limited to these examples. <Re-peelability on the second surface>, <Adhesion of the first and second surfaces>, <Probe tack> and <Laser marking suitability> in the following examples or comparative examples are as follows Respectively.

&Lt; Re-peelability on the second surface &gt;

The first surface of the protective film forming film was affixed to a polished surface (finish No. 2000) of a silicon wafer polished to a thickness of 350 占 퐉 at a table temperature of 60 占 폚 using an adhesive sheet attaching device (Adwill RAD3600F12 manufactured by Lintec Co., Ltd.) , A laminate of a silicon wafer and a film for forming a protective film was obtained.

Subsequently, a dicing tape (D-676H, manufactured by LINTEC CO., LTD.) Was stuck to the protective film forming film side (second surface) of the laminate, and the laminate was diced to 2 mm x 2 mm and picked up A chip having a film for forming a protective film was formed.

6, the second surface of the protective film-forming film of the chip was stuck on the polished surface (finish No. 2000) of the support 7 (500 탆 thick silicon wafer) at 100 캜, 300 g, and 10 seconds. Then, the protective film forming film was thermally cured at 130 캜 for 2 hours to obtain a laminate of the support 7, the protective film 11 and the chip 8.

Thereafter, the support 7 of the laminate was fixed by using a shearing strength measuring tool 6 of a shear strength meter (Dage series Dage series 4000 manufactured by Dage), and the measurement was carried out at a measurement speed of 200 m / A chip was peeled from the support 7 by applying a load from the side to the chip 20 having the protective film formed thereon. The case where the protective film 11 can be peeled off at the interface between the protective film 11 and the support 7 is evaluated as "good", and the protective film 11 causes partial peeling at the interface between the protective film 11 and the chip 8, The case where the chip 8 was exposed or the case where the protective film 11 remained on the support 7 was evaluated as &quot; defective &quot;. The above evaluation was made on 10 stacked bodies of the support 7, the protective film 11 and the chip 8, and the number of evaluations was evaluated as &quot; good &quot;.

&Lt; Adhesion of first surface and second surface &gt;

The first surface of the film for forming a protective film was attached to a polishing surface (finish No. 2000) of a silicon wafer polished to a thickness of 500 mu m at a table temperature of 60 DEG C using an adhesive sheet attaching device (Adwill RAD3600F12 manufactured by Lintec Co., Ltd.) Thus, a laminated body of a silicon wafer and a film for forming a protective film was obtained.

Subsequently, a dicing tape (D-676H, manufactured by LINTEC CO., LTD.) Was stuck to the protective film forming film side (second surface) of the laminate, and the laminate was diced to 2 mm x 2 mm and picked up A chip having a film for forming a protective film was obtained.

Then, the protective film forming film was thermally cured at 130 캜 for 2 hours to obtain a chip having a protective film formed thereon. The protective film (second surface) of the chip with the protective film formed thereon was fixed to the metal plate with an adhesive.

Thereafter, as shown in Fig. 7, the metal plate 9 was fixed by using a shear strength measuring tool 6 of a shear strength measuring instrument (Dage bond tester Dage series4000), and the measurement speed was 200 m / A load is applied to the chip 8 from the side surface of the chip 20 on which the protective film is formed under the condition of 23 캜 so that the adhesive force between the first surface of the protective film 11 and the chip 8 Adhesive force to the wafer) was measured. The adhesive force was set to the maximum value of the load when the chip 8 was peeled from the protective film 11 (at the time of breaking).

The adhesive strength between the second surface of the protective film and the chip (after curing) was measured in the same manner as described above except that the second surface of the protective film-forming film was attached to the silicon wafer and the dicing tape was stuck to the first surface side The adhesion of the second surface to the silicon wafer) was measured.

These ratios (the adhesion of the first surface to the silicon wafer / the adhesion of the second surface to the silicon wafer) were calculated from the adhesive force obtained above.

<Probe value>

Probe values were measured on the second surface of the protective film-forming film prepared in the example or the comparative example using PROBE TACK TESTER manufactured by Rigaku Kogyo Co., Ltd., in accordance with JIS Z0237: 1991 Reference 5. Specifically, a film for forming a protective film before heat curing was cut out with a test piece of 25 mm x 25 mm, and a stainless steel probe having a diameter of 5 mm heated to 70 ° C was applied to the second surface of the test piece at 10 ° C After a contact was made with a contact load of 0.98 N / cm 2, the probe was removed from the test piece at a rate of 10 mm / sec, and the stress at that time was measured.

<Laser marking suitability>

The protective film forming film was thermally cured at 130 DEG C for 2 hours without attaching the chip on which the protective film forming film obtained on the second surface was evaluated to the support body to obtain a laminate of the support, To obtain a sample.

In the evaluation of the re-peelability on the second surface, the evaluation was "good" among the laminate of the protective film and the chip obtained by thermosetting on the support.

Characters of 400 mu m in width and 200 mu m in width were printed by a laser marker (YAG laser marker LM5000, manufactured by Hitachi dry finetech Co., Ltd.) on the protective film of each sample, and the characters were mainly reflected by a microscope And direct light).

The recognition performance was evaluated using a CCD camera equipped with a microscope. The evaluation criteria are as follows.

Good: Contrast value exceeded 70% by CCD camera

Possible: Contrast value by CCD camera is 30 to 70%

Bad: Contrast value less than 30% by CCD camera

[Composition for forming a protective film (?)]

The components constituting the protective film forming composition (?) And the amounts thereof are shown below. The blending amount of each component represents a part by mass in terms of solid content, and in the present invention, the solid content means all the components other than the solvent.

(A) Polymer Component: An acryl-based polymer obtained by copolymerizing 55 parts by mass of n-butyl acrylate, 15 parts by mass of methyl methacrylate, 20 parts by mass of glycidyl methacrylate, and 10 parts by mass of 2-hydroxyethyl acrylate Average molecular weight: 90,000, glass transition temperature: -28 占 폚) / 100 parts by mass

(B) Curable component:

(B11) 50 parts by mass of a bisphenol A type epoxy resin (epoxy equivalent 180-200 g / eq, solid at room temperature) and 50 parts by mass of dicyclopentadiene type epoxy resin (Epiclon HP-7200HH manufactured by Dainippon Ink and Chemicals, 50 parts by mass in a solid state at room temperature) / 100 parts by mass

(B12) A thermally active latent epoxy resin curing agent (dicyandiamide (ADEKA HARDNER 3636 AS, manufactured by Asahi Chemical Co., Ltd.)) / 2.8 parts by mass

(B13) A curing accelerator (2-phenyl-4,5-dihydroxymethylimidazole (Kyuprazole 2PHZ, manufactured by Shikoku Chemical Industry Co., Ltd.)) / 2.8 parts by mass

(C) Inorganic filler: silica filler (fused quartz filler (average particle diameter 3 mu m)) / 300 parts by mass

(D) Colorant: black pigment (carbon black (# MA650, manufactured by Mitsubishi Chemical Corporation, average particle size 28 nm) / 10 parts by mass

(E) Coupling agent: Silane coupling agent (A-1110 manufactured by Japan Unicar Co., Ltd.) / 1 part by mass

(F) Exfoliant: 0.1 part by mass (100 parts by mass) of a total of 100 parts by mass of the silicone compound (XF42-334 manufactured by Momentive Performance Materials, Japan) / (A)

[Composition (β) for forming a protective film]

(Α) except that the amount of the component (F) is 0.5 part by mass relative to 100 parts by mass of the total of the components (A) to (F).

[Composition (γ) for forming a protective film]

Is the same as the composition (?) For forming a protective film except that the amount of the component (F) is 1.5 parts by mass based on 100 parts by mass of the total of the components (A) to (F).

[Composition for forming a protective film (隆)]

Is the same as the protective film forming composition (?) Except that the amount of the component (F) is changed to 3.0 parts by mass relative to 100 parts by mass of the total of the components (A) to (F).

[Composition for forming protective film (?)]

Is the same as the protective film forming composition (?) Except that the polymer component (A ') is used instead of the polymer component (A).

(A ') Polymer component: An acrylic polymer (15 parts by mass) obtained by copolymerizing 15 parts by mass of n-butyl acrylate, 50 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: 90,000, glass transition temperature: -1 DEG C)

[Composition for forming protective film (?)]

Is the same as the protective film forming composition (?) Except that the amount of the component (F) is 0 part by mass relative to 100 parts by mass of the total of (A) to (F).

(Example 1)

As a release sheet, a polyethylene terephthalate film (SP-P502010, manufactured by Lintec Corp., thickness 50 占 퐉) having been subjected to a release treatment on one side thereof was prepared. A methyl ethyl ketone solution (solid content concentration: 61% by weight) of the protective film forming composition (?) Was coated on the exfoliated surface of the release sheet so that the thickness after drying became 25 占 퐉 and dried (drying condition: ), And a resin layer (?) Was formed on the release sheet.

Further, as another release sheet, a polyethylene terephthalate film (SP-P502010, manufactured by Lin Tec Co., Ltd., thickness 50 탆) in which a release treatment was performed on one side was prepared.

Subsequently, a methyl ethyl ketone solution (solid concentration: 61% by weight) of the protective film forming composition (?) Was coated on the exfoliated surface of the release sheet so that the thickness after drying became 25 占 퐉, dried (drying conditions: 3 minutes), and a resin layer (?) Was formed on the release sheet.

Thereafter, the resin layer (alpha) and the resin layer (zeta) were bonded to each other to obtain a protective film-forming film adhered to both sides of the release sheet. The surface on the side of the resin layer (?) Of the protective film forming film is the second surface in the present invention, and the surface on the side of the resin layer (?) Is the first surface in the present invention. The evaluation results are shown in Table 1.

(Example 2)

A film for forming a protective film was obtained in the same manner as in Example 1 except that the protective film forming composition (?) Was used instead of the protective film forming composition (?). The evaluation results are shown in Table 1.

(Example 3)

A film for forming a protective film was obtained in the same manner as in Example 1 except that the protective film forming composition (?) Was used instead of the protective film forming composition (?). The evaluation results are shown in Table 1.

(Example 4)

A film for forming a protective film was obtained in the same manner as in Example 1 except that the protective film forming composition (?) Was used instead of the protective film forming composition (?). The evaluation results are shown in Table 1.

(Example 5)

A film for forming a protective film was obtained in the same manner as in Example 1 except that the protective film forming composition (?) Was used instead of the protective film forming composition (?). The evaluation results are shown in Table 1.

(Comparative Example 1)

A film for forming a protective film was obtained in the same manner as in Example 1 except that the protective film forming composition (?) Was used instead of the protective film forming composition (?). The evaluation results are shown in Table 1.

10: Film for forming a protective film
a: first surface
b: second surface
100: Composite sheet for forming a protective film
1: substrate
2: Pressure-sensitive adhesive layer
3: Pressure sensitive adhesive sheet
4: Jig adhesive layer
5: Interfacial adhesion adjustment layer
6: Shear strength measurement tool
7: Support
8: Chip
9: metal plate
11: Shield
20: Chip formed with a protective film

Claims (9)

A film for forming a curable protective film having a first surface and a second surface,
Wherein the adhesion of the first surface to the silicon wafer after curing is higher than the adhesion of the second surface to the silicon wafer after curing. The method according to claim 1,
The ratio of the adhesion of the first surface to the silicon wafer after curing and the adhesion strength of the second surface to the silicon wafer after curing (adhesion to the silicon wafer on the first surface / adhesion to the silicon wafer on the second surface) Is 1.2-100. 3. The method according to claim 1 or 2,
Wherein the first surface is attached to an adherend forming a protective film. 4. The method according to any one of claims 1 to 3,
And the second surface is fixed to the support. 5. The method according to any one of claims 1 to 4,
Wherein the adhesive force of the second surface to the silicon wafer after curing is 0.01 to 100 N. 6. The method according to any one of claims 1 to 5,
And the second surface has a probe tack value of 0.01 to 3 N / 5 mm PHI. 7. The method according to any one of claims 1 to 6,
Wherein the protective film comprises two or more resin layers having different compositions. 8. The method of claim 7,
Wherein the resin layer containing at least the second surface contains a releasing agent and the content of the releasing agent in the resin layer including the second surface is larger than the content of the releasing agent in the resin layer including the first surface, . 9. The method of claim 8,
The content of the releasing agent in the resin layer including the first surface is 0 to 0.001 part by mass based on 100 parts by mass of the solid content excluding the releasing agent among all the solid components constituting the resin layer including the first surface,
Wherein the content of the releasing agent in the resin layer including the second surface is 0.001 to 20 parts by mass based on 100 parts by mass of the solid content excluding the releasing agent among all the solid components constituting the resin layer including the second surface.

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