JP2010163597A - Pressure-sensitive adhesive film for surface protection of silicon oxide film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure-sensitive adhesive film for surface protection of a silicon oxide film, which pressure-sensitive adhesive film has high adhesion to a surface of the silicon oxide film while attached thereto, is easily released without performing complicated treatment when peeled off and removed, and does not generate adhesive deposits derived from the pressure-sensitive adhesive film upon processing, such as cutting. <P>SOLUTION: The pressure-sensitive adhesive film for surface protection of the silicon oxide film is obtained by adjusting a compounding ratio of two or more M-A-M type triblock copolymers and a phthalic acid ester-based plasticizer included in a pressure-sensitive adhesive layer, the two or more M-A-M type triblock copolymers having different composition ratios of a methylmethacrylate polymer block (M) and a butyl acrylate polymer block (A). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a non-contaminating adhesive film for protecting a silicon oxide film surface, which has excellent adhesion to the silicon oxide film surface and does not generate glue residue derived from an adhesive film by cutting.

  In general, a semiconductor integrated circuit forms a circuit pattern on the surface of a wafer obtained by cutting, grinding, polishing, etc. a single crystal ingot that has been crystal-grown, and then grinding the back surface of the wafer for thinning. Manufactured by dicing to divide into individual chips. In such a manufacturing process, the thinned wafer may be damaged or the wafer may be contaminated with polishing scraps, chemicals, and the like. For the purpose of preventing these problems, an adhesive film for protecting the wafer surface is used. Since the adhesive film for protecting the wafer surface is finally peeled off from the wafer surface, water is placed between the wafer and the adhesive film during chemical treatment while it is affixed to the wafer surface. In addition, it is desirable to have high adhesion and adhesiveness that do not allow chemicals to enter, and to have easy peelability that does not damage the wafer when peeling and removing from the wafer surface.

  As an adhesive film for protecting the wafer surface having such characteristics, a radiation curable adhesive layer and an adhesive layer having a storage elastic modulus in a specific range are provided on one surface of a base film (see Patent Document 1). ) And those having an expanded layer containing a thermally decomposable hydrazide compound between the base film layer and the adhesive layer (see Patent Document 2).

  However, according to the above adhesive film, it has high adhesion to the wafer surface during grinding of the wafer back surface, chemical treatment, etc., and easy peeling when removing the adhesive film from the wafer surface. However, when the adhesive film is peeled and removed from the wafer surface, a complicated process such as radiation irradiation or heating is required, and the workability is not good.

JP 2002-53819 A JP 2005-332900 A

  By the way, even if it is generally referred to as an adhesive film for protecting a wafer surface, characteristics required for the adhesive film differ depending on the state of the wafer surface. For example, a silicon oxide film surface in which a silicon dioxide film is formed on the surface of a silicon wafer is an object to be adhered, which is inferior in adhesiveness and adhesion of an adhesive film as compared to a normal wafer surface. Further, such an adhesive film is cut into the shape of a wafer in order to be attached to the silicon oxide film surface, but the glue residue derived from the adhesive film at that time causes contamination of the wafer, which causes a problem.

  The present invention has been made in view of the above-mentioned problems, and the object is to have high adhesion to the silicon oxide film surface while sticking, and at the time of peeling and removal, Silicon oxide film surface protection that can be easily peeled off without complicated processing as reported in the above-mentioned patent document, and does not generate glue residue derived from an adhesive film during processing such as cutting It is to provide an adhesive film for use.

  The present inventor has intensively studied to create a pressure-sensitive adhesive film suitable for protecting a silicon oxide film surface, and as a main component of the pressure-sensitive adhesive layer, a methyl methacrylate polymer block (M) and a butyl acrylate polymer block ( A) A triblock copolymer mixture containing two or more types of MAM type triblock copolymers comprising: The present inventors have found that an adhesive film having three characteristics of adhesion and high adhesion, easy peeling at the time of peeling and removal, and non-fouling at the time of processing can be obtained, and the present invention has been completed. Specifically, the following are provided.

  (1) In an adhesive film in which an adhesive layer and a release layer are sequentially formed on a substrate, the adhesive layer comprises a methyl methacrylate polymer block (M) and a butyl acrylate polymer block (A). A triblock copolymer mixture comprising two or more types of MAM type triblock copolymers having a mass average molecular weight of 10,000 to 200,000, and a phthalate ester plastic having a mass average molecular weight of 300 to 1000 A triblock copolymer (X) in which the proportion of the butyl acrylate polymer block (A) is 70% by mass or more, and the butyl acrylate A triblock copolymer (Y) in which the proportion of the polymer block (A) is 60% by mass or less, and the triblock copolymer in the triblock copolymer mixture X) is 50% by mass or more, and the phthalate ester plasticizer is blended in an amount of 15 to 32.5 parts by mass with respect to 100 parts by mass of the triblock copolymer mixture. An adhesive film for protecting the silicon oxide film surface.

  (2) The triblock copolymer mixture comprises a triblock copolymer (X) in which the proportion of the butyl acrylate polymer block (A) is 72 to 80% by mass, and the butyl acrylate polymer block. The pressure-sensitive adhesive film for protecting a silicon oxide film according to (1), comprising a triblock copolymer (Y) having a proportion of (A) of 45 to 55% by mass.

  (3) The silicon according to (1) or (2), wherein the proportion of the triblock copolymer (X) in the triblock copolymer mixture is 50 to 97.5% by mass Oxide film protective film.

  (4) The peel strength after 0.5 hours has elapsed after being attached to the silicon oxide film surface measured under 180 ° peel test conditions with a peel speed of 300 mm / min, a peel distance of 150 mm, and a specimen width of 20 mm. The adhesive film for protecting a silicon oxide film according to any one of (1) to (3), wherein the pressure-sensitive adhesive film is 0.000 N / 20 mm.

  According to the pressure-sensitive adhesive film of the present invention, as a main component of the pressure-sensitive adhesive layer, two or more types of M-A-M types having different ratios of the methyl methacrylate polymer block (M) and the butyl acrylate polymer block (A) are used. Uses a triblock copolymer mixture containing a triblock copolymer and is blended with a phthalate ester plasticizer to obtain good adhesion and adhesion even on the silicon oxide film surface. Can do. Therefore, water and chemicals do not enter between the wafer and the adhesive film. Moreover, according to the adhesive film of this invention, when peeling and removing from a silicon oxide film surface, it can peel easily, without performing a special process. Furthermore, according to the pressure-sensitive adhesive film of the present invention, no adhesive residue derived from the pressure-sensitive adhesive film is generated during processing such as cutting, so that the wafer is not contaminated. Therefore, the adhesive film is suitable for protecting the silicon oxide film surface.

  Hereinafter, specific embodiments of the present invention will be described in detail.

  The pressure-sensitive adhesive film for protecting a silicon oxide film of the present invention (hereinafter referred to as a pressure-sensitive adhesive film) is formed by sequentially forming a pressure-sensitive adhesive layer and a release layer on a substrate, and the pressure-sensitive adhesive layer is a methyl methacrylate polymer. A triblock copolymer mixture comprising two or more types of MAM type triblock copolymers having a weight average molecular weight of 10,000 to 200,000 comprising the block (M) and the butyl acrylate polymer block (A). And a phthalate ester plasticizer having a mass average molecular weight of 300 to 1000, and the triblock copolymer mixture has a occupying ratio of the butyl acrylate polymer block (A) of 70% by mass or more. A triblock copolymer (X) and a triblock copolymer (Y) in which the proportion of the butyl acrylate polymer block (A) is 60% by mass or less. The proportion of the triblock copolymer (X) in the copolymer mixture is 50% by mass or more, and the phthalate plasticizer is 15 to 32 with respect to 100 parts by mass of the triblock copolymer mixture. .5 parts by mass is blended.

  In the present invention, a triblock copolymer mixture containing two or more types of MAM type triblock copolymers having different proportions of the butyl acrylate polymer block (A) and a phthalate ester plasticizer are used. It is characterized in that it is used for the adhesive layer and the physical properties of the adhesive film are adjusted. The proportion of the butyl acrylate polymer block (A) in the triblock copolymer (X) and the triblock copolymer (Y), the proportion of the triblock copolymer (X) in the triblock copolymer mixture, By adjusting the blending amount of the phthalate ester plasticizer, the adhesive film has characteristics such as high adhesion to the silicon oxide film surface, easy peelability at the time of peeling and removal, and non-contamination at the time of processing such as cutting. Can be granted. Hereinafter, the adhesive film of the present invention will be described in the order of the substrate, the adhesive layer, and the release layer.

[Base material]
The substrate is not particularly limited as long as it has necessary strength and flexibility, and a synthetic resin film is generally used. As the material of the synthetic resin film, polyester resin, polypropylene resin, poly (4-methyl-pentene-1) resin, ethylene-vinyl acetate copolymer, ethylene-propylene copolymer, polyvinyl chloride resin, Vinyl chloride-vinyl acetate copolymer, polyvinylidene chloride resin, fluorine resin, polystyrene resin, poly (meth) acrylic resin, polyvinyl butyral resin, polyacrylonitrile resin, cellulose acetate resin, polycarbonate resin, Known resins such as polyamide resins, polyester resins, polyvinyl alcohol resins, polyphenylene sulfide resins, polyether ether ketone resins, para aramid resins, polyurethane resins and the like can be mentioned. In the present invention, among these, it is particularly preferable to use a polyester-based resin from the viewpoint of chemical resistance such as rigidity, extensibility, dimensional stability, flexibility, and stackability.

  Examples of the polyester-based resin include polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polybutylene naphthalate, polyarylate, polytetramethylene terephthalate, etc. Among them, from the viewpoint of ease of handling, low cost, etc. Polyethylene terephthalate is particularly preferred.

  Although the thickness of a base material is not specifically limited, Preferably it is 12-188 micrometers, More preferably, it is 25-100 micrometers. If it is the said range, since the form of an adhesive film can be maintained, workability | operativity, such as sticking and peeling of an adhesive film, will become favorable.

[Adhesive layer]
The pressure-sensitive adhesive layer forming the pressure-sensitive adhesive film of the present invention contains a triblock copolymer mixture and a phthalate ester plasticizer. The triblock copolymer mixture is composed of two or more types of MAM type triblock copolymers having different proportions of the methyl methacrylate polymer block (M) and the butyl acrylate polymer block (A). Containing. And, at least two of the M-A-M type triblock copolymers are a triblock copolymer (X) in which the proportion of the butyl acrylate polymer block (A) is 70% by mass or more, and an acrylic The proportion of the acid butyl polymer block (A) is 60% by mass or less, and the proportion of the triblock copolymer (X) in the triblock copolymer mixture is 50%. It is at least mass%, preferably 50 to 97.5 mass%, more preferably 50 to 85 mass%. The triblock copolymer (X) and the triblock copolymer (Y) in which the proportion of the butyl acrylate polymer block (A) is in the above range, and the triblock copolymer (X) If the proportion is within the above range, by adjusting the blending ratio with the phthalate ester plasticizer described later, it has high adhesion to the silicon oxide film surface, so it is possible to prevent the penetration of chemicals and the like. In addition, when removing and removing, the wafer can be easily peeled without being damaged, and further, when processing such as cutting, no adhesive residue derived from an adhesive film is generated. And a non-staining adhesive film can be formed.

  The triblock copolymer mixture contained in the pressure-sensitive adhesive layer is composed of a triblock copolymer (X) in which the proportion of the butyl acrylate polymer block (A) is 72 to 80% by mass, butyl acrylate heavy It is preferable that it consists of a triblock copolymer (Y) whose proportion of the combined block (A) is 45 to 55% by mass. If it is the said range, the adhesive film which has favorable adhesiveness, adhesiveness, and non-contamination property with respect to a silicon oxide film surface will be formed by adjusting the compounding ratio with the phthalate ester plasticizer mentioned later. be able to.

  The triblock copolymer (X) satisfying the above-mentioned mass average molecular weight and the proportion of the butyl acrylate polymer block (A) is not particularly limited, but specifically, for example, LA2140e (manufactured by Kuraray Co., Ltd.), What is marketed with brand names, such as LA410L (made by Kuraray), can be used conveniently. Further, the triblock copolymer (Y) satisfying the above-mentioned mass average molecular weight and the proportion of the butyl acrylate polymer block (A) is not particularly limited, and specifically, for example, LA4285 ( What is marketed by the brand name of Kuraray Co., Ltd. can be used conveniently.

  The mass average molecular weight (measured by GPC) of the MAM type triblock copolymer is 10,000 to 200,000, preferably 45,000 to 200,000. If it is the said range, cohesion force sufficient as an adhesive layer is shown.

  Examples of the phthalate ester plasticizer included in the pressure-sensitive adhesive layer include di-2-ethylhexyl phthalate (DOP), dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), and phthalate. Heptylnonyl acid (HNP), di-n-octyl phthalate (DNOP), di-i-octyl phthalate (DCapP), di-i-decyl phthalate (DIDP), ditridecyl phthalate (DTDP), dicyclohexyl phthalate ( DCHP), butyl benzyl phthalate (BDP), ethyl phthalyl ethyl glycolate (EPEG), butyl phthalyl butyl glycolate (BPBG) and the like, and one or more of these may be used in combination. In the present invention, among these, di-2-ethylhexyl phthalate (DOP) is preferably used from the viewpoint of versatility.

  The compounding quantity of a phthalate ester plasticizer is 15-32.5 mass parts with respect to 100 mass parts of a triblock copolymer mixture, Preferably it is 15-30 mass parts. In addition, when using 2 or more types together, the compounding quantity as a whole is meant. If it is the said range, the adhesive film which has high adhesiveness with respect to a silicon oxide film surface, the easy peelability in the case of peeling removal, and the non-contamination property with respect to the wafer in the case of cutting can be formed. In addition, the mass average molecular weight (measurement by GPC) of a phthalate ester plasticizer is 300-1000, Preferably it is 300-700. If it is the said range, the solubility to an adhesive solution is favorable.

  In addition, a metal chelating agent, a surfactant, an antioxidant, a tackifier, an ultraviolet absorber, a pigment, a dye, a colorant, an antistatic agent, an antiseptic, as necessary, as long as the object of the present invention is not impaired. Various additives such as an antifoaming agent and a wettability adjusting agent can be blended.

  Although it does not specifically limit as a formation method of an adhesive layer, For example, the method by printing, coating, etc. are mentioned. Further, the thickness of the pressure-sensitive adhesive layer can be appropriately selected within a range that does not impair the adhesion and adhesion to the silicon oxide film surface in consideration of the state, shape and the like of the silicon oxide film surface, and is usually 10 to 60 μm. The thickness is preferably 20 to 50 μm. If it is the said range, it can form the adhesive film which has high adhesiveness with respect to a silicon oxide film surface in the case of sticking, and has easy peelability in the case of peeling removal.

[Peeling layer]
A peeling layer consists of a peeling member which has the peelability laminated | stacked on the adhesive layer, and has a function which protects the surface of an adhesive layer. The release member is not particularly limited as long as it has necessary strength and flexibility, and a synthetic resin film subjected to silicone release treatment is generally used. As a material of the synthetic resin film, for example, polyester resins such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polybutylene naphthalate, polyarylate, polytetramethylene terephthalate are preferable. The thickness of the release layer is not particularly limited, but is preferably 25 to 125 μm.

  In the pressure-sensitive adhesive film of the present invention, a pressure-sensitive adhesive (hereinafter referred to as pressure-sensitive adhesive solution) dissolved in an organic solvent is applied to a substrate and dried to form a pressure-sensitive adhesive layer having a desired thickness. Can be manufactured. The organic solvent is not particularly limited, and examples thereof include toluene, methyl ethyl ketone, ethyl acetate, methyl isobutyl ketone (MIBK), butyl acetate, acetone, and a mixed solution thereof. As a method of applying the adhesive solution to the substrate, conventionally known methods such as a roll coating method, a gravure coating method, a micro gravure coating method, a reverse coating method, a roll brush method, a spray coating method, an air knife coating method, impregnation Method, curtain coating method, die coating method, doctor blade method, comma coating method and the like. Although the drying conditions of the applied adhesive are not specifically limited, Usually, it dries for 30 seconds-3 minutes in the temperature range of 40-120 degreeC. Although the thickness of the adhesive film of this invention can be suitably selected according to the objective, Usually, it is 47-373 micrometers.

  The pressure-sensitive adhesive film of the present invention is applied to a silicon oxide film surface measured under the 180 ° peel test (in accordance with “JIS Z0237”) conditions of a peel rate of 300 mm / min, a peel distance of 150 mm, and a specimen width of 20 mm. The peel strength after elapse of time is preferably 0.01 to 1.00 N / 20 mm, and more preferably 0.01 to 0.30 N / 20 mm. If it is in the above range, it is possible to prevent the intrusion of a chemical solution between the silicon oxide film surface and the adhesive film, and to peel easily without performing a special treatment when peeling and removing the adhesive film. Can do.

  In the pressure-sensitive adhesive film of the present invention, other layers such as a printing layer may be laminated as long as the effects of the present invention are not impaired.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these Examples.

[material]
<Triblock polymer (X)>
LA2140e (manufactured by Kuraray Co., Ltd.): The proportion of butyl acrylate polymer block (A) is 72 to 80% by mass, the solid content is 100%, and the molecular weight is about 80,000.
LA410L (manufactured by Kuraray Co., Ltd.): The proportion of butyl acrylate polymer block (A) is 72 to 80% by mass, the solid content is 100%, and the molecular weight is about 160,000.
<Triblock polymer (Y)>
LA4285 (manufactured by Kuraray Co., Ltd.) The proportion of butyl acrylate polymer block (A) is 45 to 55 mass%, the solid content is 100%, and the molecular weight is about 67,000.
<Phthalate ester plasticizer>
Di-2-ethylhexyl phthalate (DOP) (manufactured by J-Plus), molecular weight 390.6

[Method of forming adhesive film]
Compositions shown in Tables 1 and 2 so that the film thickness after drying on the corona-treated surface of the substrate (PET film, trade name “S105”, film thickness 50 μm, manufactured by Toray Industries, Inc.) is 40 μm using an applicator. The pressure-sensitive adhesive solution (diluted solvent: dissolved in 100 g of toluene) was applied to form a pressure-sensitive adhesive layer. Next, the diluted solvent in the pressure-sensitive adhesive layer was volatilized in an oven (90 ° C., 1 minute), and a release layer (PET separator film, trade name “0010BD”, film thickness 50 μm, Fujimori on the coated surface of the pressure-sensitive adhesive layer after drying. The peel-treated surface of Kogyo Kogyo Co., Ltd. was laminated and subjected to an aging treatment for 1 day at room temperature and humidity to form an adhesive film.

  About each adhesive film formed by the said method, the following items were evaluated. The results are shown in Table 1 (Comparative Examples 1-37), Table 2 (Examples 1-15, Comparative Examples 38-52), and Table 3 (Examples 16-30, Comparative Examples 53-68).

[Peel strength]
The adhesive film was cut into a width of 20 mm to prepare a test piece. A CVD oxide film is formed on the surface of the single crystal silicon wafer by the CZ method on the test piece in a CVD furnace under the conditions: target: 20 mm, atmosphere: helium gas base, monosilane, oxygen gas, temperature: 400 ° C., holding time: 15 seconds The surface of the oxide film was laminated using a 2 kg roller, and allowed to stand at normal humidity and room temperature for 0.5 hour. Then, using a tensile tester (RTF-1150-H), the peel strength at normal temperature and normal temperature was measured (speed: 300 mm / min, peel distance: 150 mm, peel angle: 180 °) (based on JIS Z0237) ). And, when the peel strength is 0.01 to 0.30 N / 20 mm, ◎, when exceeding 0.30 N / 20 mm and up to 1.00 N / 20 mm, ○, less than 0.01 N / 20 mm, etc. The case and the case of exceeding 1.00 N / 20 mm were evaluated as x.

[Confirmation of interference fringe width at silicon oxide film edge after hydrofluoric acid treatment]
In order to investigate the adhesion between the adhesive film and the silicon oxide film surface, the width of the interference fringes at the edge of the silicon oxide film after the hydrofluoric acid treatment was measured. If the adhesiveness between the adhesive film and the silicon oxide film surface is low, the width of the interference fringe at the end of the silicon oxide film becomes wide due to the penetration of the chemical solution.
The adhesive film was cut into a size of 2 cm × 10 cm with a cutter knife to prepare a test piece. This test piece was affixed to the oxide film surface in which the CVD oxide film was formed on the single crystal silicon wafer surface using a 2 kg roller in a CVD furnace. The oxide film was formed by the CZ method (target: 20 mm, atmosphere: helium gas base, monosilane, oxygen gas, temperature: 400 ° C., holding time: 15 seconds). A test piece was affixed to the oxide film and allowed to stand at normal humidity and room temperature for 0.5 hours, and then treated with hydrofluoric acid. Then, the test piece was peeled off, and the interference fringe width at the oxide film end was confirmed with a high magnification microscope (VHX-600, manufactured by Keyence Corporation, magnification 2,000), and the width was measured. The case where the interference fringe width was less than 30 μm was evaluated as “◯”, the case of 30-40 μm as “Δ”, and the case of exceeding 40 μm as “X”. The test piece was peeled off using a tensile tester (RTF-1150-H) under conditions of a speed of 300 mm / min, a peel distance of 150 mm, and a peel angle of 180 °.

[Confirmation of glue residue after Gakushin friction test]
The presence or absence of occurrence of adhesive residue (width of 1 mm or more) derived from the adhesive after the Gakushin friction test (JIS L0849 compliant) was confirmed. AB-301 Gakushin type friction fastness tester (manufactured by Tester Sangyo) conforming to JIS L0849 was used for the test apparatus, and the size of the test piece of the adhesive film was 3 cm × 22 cm. Cover the tip of the friction piece with JIS L0803 JIS dyeing fastness test cotton (made by the Japanese Standards Association) and fix it on the test stand (surface radius: 200 mm, shape: kamaboko plate type) with a load of 200 g. The test piece was rubbed 20 times between 22 cm at a reciprocating speed of 30 times per minute, and then the presence or absence of glue residue on the test piece was confirmed. The confirmation was performed visually and with an optical microscope (VHX-600, manufactured by Keyence Corporation, magnification 100).

  From the results of the peel strength against wafer, the width of interference fringes, and the generation of glue residue shown in Tables 1 to 3, a triblock polymer (X ) Adjust the blending ratio of LA2140e or LA410L, triblock polymer (Y) LA4285 whose butyl acrylate polymer block (A) occupies 60 mass% or less, and DOP which is a phthalate ester plasticizer By doing so, it was confirmed that an adhesive film having characteristics such as high adhesion to the silicon oxide film surface, easy peeling at the time of peeling and removal, and non-contamination at the time of processing such as cutting can be formed. Moreover, it was confirmed that the adhesive film using LA410L as the triblock polymer (X) has an excellent evaluation result of the peel strength against the wafer as compared with the adhesive film using LA2140e.

Claims (4)

In the adhesive film in which the adhesive layer and the release layer are sequentially formed on the substrate,
The MAM type triblock copolymer having a mass average molecular weight of 10,000 to 200,000, wherein the pressure-sensitive adhesive layer comprises a methyl methacrylate polymer block (M) and a butyl acrylate polymer block (A). A triblock copolymer mixture containing two or more of the above and a phthalate ester plasticizer having a mass average molecular weight of 300 to 1,000,
The triblock copolymer mixture comprises a triblock copolymer (X) in which the proportion of the butyl acrylate polymer block (A) is 70% by mass or more and the butyl acrylate polymer block (A). A triblock copolymer (Y) having a proportion of 60% by mass or less,
The proportion of the triblock copolymer (X) in the triblock copolymer mixture is 50% by mass or more,
The adhesive film for protecting a silicon oxide film, wherein the phthalate ester plasticizer is blended in an amount of 15 to 32.5 parts by mass with respect to 100 parts by mass of the triblock copolymer mixture.   The triblock copolymer mixture comprises a triblock copolymer (X) in which the proportion of the butyl acrylate polymer block (A) is 72 to 80% by mass, and the butyl acrylate polymer block (A). The silicon oxide film surface-protective pressure-sensitive adhesive film according to claim 1, comprising a triblock copolymer (Y) having a proportion of 45 to 55% by mass.   3. The silicon oxide film surface protecting material according to claim 1, wherein a proportion of the triblock copolymer (X) in the triblock copolymer mixture is 50 to 97.5 mass%. Adhesive film.   A peel strength of 0.5 to 10 hours after being applied to a silicon oxide film surface measured under a 180 ° peel test condition with a peel speed of 300 mm / min, a peel distance of 150 mm, and a specimen width of 20 mm. The pressure-sensitive adhesive film for protecting a silicon oxide film according to claim 1, wherein the pressure-sensitive adhesive film is 20 mm.