TW202218869A - Protective film forming sheet and manufacturing method thereof capable of sufficiently suppressing defects in scrap removal even when the cut width in a hole punching process is relatively narrow - Google Patents

Abstract

The present invention provides a protective film forming sheet capable of sufficiently suppressing defects in scrap removal even when the cut width in a hole punching process is relatively narrow, and a manufacturing method thereof. The protective film forming sheet is a long sheet including a protective film forming film and a first peeling film provided on one surface of the protective film forming film, the protective film forming sheet is characterized in that the adhesive force after attaching two protective film forming films at 23 DEG C with a load of 2kgf for two minutes is 19N/25 mm or less.

Description

Sheet for forming protective film and method for producing the same

The present invention relates to a sheet for forming a protective film and a method for producing the same. In particular, it relates to a protective film forming sheet including a protective film forming film suitable for protecting workpieces such as semiconductor wafers or processed products such as semiconductor wafers obtained by processing the workpieces, and a method for producing the protective film forming sheet.

In recent years, semiconductor devices have been manufactured by a mounting method called flip-chip bonding. In this mounting method, when mounting a semiconductor wafer having a circuit surface on which convex electrodes such as bumps are formed, the side of the circuit surface of the semiconductor wafer is reversed (face down) and bonded to the wafer. department. Therefore, the semiconductor device has a structure in which the back side of the semiconductor wafer on which the circuit is not formed is exposed.

Therefore, in order to protect the semiconductor wafer from impact during transportation or the like, a hard protective film made of an organic material is often formed on the back surface side of the semiconductor wafer. In order to form such a protective film, an uncured resin film (hereinafter referred to as a "protective film-forming film") as a precursor thereof is used. The protective film forming film is attached to the back surface of the semiconductor wafer, and is diced together with the wafer to form a wafer. By curing the protective film forming film, a wafer having a protective film on the back surface can be obtained.

As a product form of the protective film-forming film, there is known a protective film-forming sheet 10 having a double-layer structure in which a protective film-forming film 11 is releasably laminated on a first release film 12 as shown in FIG. 3 shows the sheet 20 for protective film forming of the three-layer structure in which the protective film forming film 11 is sandwiched between two release films (12, 13). In addition, the said sheet for protective film formation is long, and is wound up in a roll shape, and is stored and transported. Such a sheet for forming a protective film may be affixed to the workpiece by pre-punching the protective film forming film into substantially the same shape as the workpiece (general term for adherends such as semiconductor wafers). This punched sheet for forming a protective film is formed by laminating the protective film forming film 16 punched into a predetermined closed shape on the first release film 12 ( FIG. 2 ), or sandwiching it between two release films (12, 13) (Fig. 4).

The punched protective film forming sheet is produced by punching the protective film forming film into a predetermined closed shape with a die, and removes unnecessary portions 17 around the punched protective film forming film 16 and use. In the case of a sheet for forming a protective film having a double-layer structure composed of the protective film forming film 11 and the first peeling film 12, the protective film forming film 11 is completely punched into a predetermined closed shape and the first peeling is not completely punched The cutout 14 is cut out in the manner of the film 12, the protective film forming film 16 of a predetermined closed shape is left on the first release film 12, and the unnecessary portion 17 in the periphery is removed. When the protective film forming film 11 is sandwiched between two peeling films ( 12 , 13 ) for a protective film forming sheet having a three-layer structure, the protective film forming film 11 and the second peeling film 13 on one side are completely The notches 14 are cut out so that the first release film 12 on the other side is not completely punched out in a predetermined closed shape, and the protective film forming film 16 of the predetermined closed shape is left on the first release film 12 and removed. The useless portion 17 and the second release film 13 in the periphery.

Further detailed description will be given by taking the case of the sheet for forming a protective film of a two-layer structure as an example. As shown in FIG. 5 , the protective film forming film 11 is completely punched into a predetermined closed shape, and the first peeling is not completely punched out of the protective film forming sheet 10 composed of the protective film forming film 11 and the first peeling film 12 . The notch 14 was cut out in the way of the film 12, and the sheet for protective film formation which was punched was produced. This step is called "Punching Step".

Then, in order to attach the punched protective film forming sheet to a workpiece, the unnecessary portion 17 around the protective film forming film 16 punched into a predetermined closed shape is removed ( FIG. 6 ). This step is called the "waste removal step". As a result, a laminate having the protective film-forming film 16 punched into a predetermined closed shape on the first release film 12 and can be used for sticking to a workpiece can be obtained.

In the case of a sheet for forming a protective film of a three-layer structure, in addition to having another peeling film 13 (second peeling film 13 ) on the protective film forming film 11 in the punching process step, the second peeling film 13 is also completely The punching to a predetermined closed shape and the removal of the second release film 13 in the scrap removal step are the same as in the case of the sheet for forming a protective film of a two-layer structure.

The sheet for forming a protective film is required to be able to perform the punching process stably (handling stability). In particular, after the punching process of the protective film-forming film, the operational stability of the waste removal step of removing the useless portion is required. More specifically, in the waste removal step, it is required that the protective film-forming film 16 that should remain is not accidentally peeled off from the first release film 12 together with the useless portion 17 (hereinafter, referred to as "defective waste removal"). ).

In order to solve the above-mentioned problems, for example, Patent Document 1 proposes to control the peeling force between the peeling film and the protective film forming film within a predetermined range. [Prior Art Literature] [Patent Literature]

Patent Document 1: International Publication WO2017/145735

[Technical problem to be solved by the present invention]

When a defect in scrap removal occurs, it is necessary to stop the production line and discard the defective product, thereby reducing the productivity of the product and increasing the cost. Therefore, it is required to further suppress the failure of waste removal.

The inventors of the present invention have further studied the cause of poor waste removal, and have obtained the following findings.

After the punching step and before the scrap removal step, the protective film forming sheet 10 passes through a plurality of rollers such as guide rollers for the purpose of controlling the tension of the protective film forming sheet and the like. At this time, as shown in FIG. 7, the sheet 10 for protective film formation may bend so that the upper part side of the slit 14 (the surface of the side into which a die enters) may become the roll 19 side. As a result of the bending, the width of the notches 14 is narrowed, and the protective film-forming film 16 is slightly deformed by being pressed, especially at the portion of the cutout that is almost parallel to the short-side direction of the sheet 10, which may lead to abutment. The protective film-forming film 16 is in contact with and adheres to the useless portion 17 .

After passing through the rollers 19, the protective film-forming film 16 and the adhering portion of the useless portion 17 are often separated again, but there are cases where the adhesion is maintained without being separated. If the scrap removal is performed in a state where the protective film forming film 16 and the useless portion 17 are attached, the protective film forming film 16 that should remain on the first release film 12 may accidentally be removed from the first release film together with the useless portion 17 to be removed. 12 was peeled off, and the waste removal failure occurred.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a sheet for forming a protective film that can sufficiently suppress defects in scrap removal even when the notch width at the time of punching is narrow, and a method for producing the same. [Technical means to solve technical problems]

The aspects of the present invention are as follows. (1) A sheet for forming a protective film, which is an elongated sheet and has a protective film forming film and a first release film provided on one surface of the protective film forming film, wherein, The adhesive force after attaching two protective film-forming films at 23° C. for 2 minutes with a load of 2 kgf was 19 N/25 mm or less. (2) The sheet for forming a protective film according to (1), wherein the surface elastic modulus of the surface of the first release film in contact with the protective film forming film is 17 MPa or less. (3) The sheet for forming a protective film according to (1) or (2), wherein a part of the sheet for forming a protective film has a part of the sheet for forming a protective film in a plan view of the sheet for forming a protective film. A cutout is formed in the manner of a prescribed closed shape, The incision penetrates the protective film forming film in the thickness direction of the protective film forming sheet and reaches a part of the first release film. (4) The sheet for protective film formation as described in (3) whose width|variety of the said notch in the interface of the said protective film formation film and the said 1st peeling film is 8 micrometers or more. (5) A method for producing a punched sheet for forming a protective film, comprising forming a cutout so that a part of the sheet for forming a protective film described in (1) or (2) above has a predetermined closed shape step, The incision penetrates the protective film forming film in the thickness direction of the protective film forming sheet and reaches a part of the first release film. (6) The method for producing a punched sheet for forming a protective film according to (5), wherein the width of the notch at the interface between the protective film forming film and the first release film is 8 μm above. [Inventive effect]

ADVANTAGE OF THE INVENTION According to this invention, even when the notch width at the time of a punching process is narrow, the sheet for protective film formation which can fully suppress the defect of scrap removal, and its manufacturing method can be provided.

First, the main terms used in this specification are explained.

The workpiece is a plate-shaped body to be attached to the protective film forming film of the present embodiment and to be processed. Examples of the workpiece include wafers and panels. Specifically, a semiconductor wafer and a semiconductor panel are mentioned. As a processed product of a workpiece|work, the wafer obtained by singulating a wafer is mentioned, for example. Specifically, a semiconductor wafer obtained by singulating a semiconductor wafer can be exemplified. At this time, the protective film is formed on the back side of the wafer and the wafer.

The “front surface” of a workpiece such as a wafer refers to the surface on which bump electrodes such as circuits and bumps are formed, and the “back surface” refers to the surface on which circuits and electrodes (such as bump electrodes, for example) are not formed.

In this specification, for example, "(meth)acrylate" is used as a term representing both "acrylate" and "methacrylate", and other similar terms are also the same.

The release film is a film that supports the protective film-forming film in a releasable manner. The thickness of the film is not limited, and it is used in the concept of including a sheet.

The mass ratio in the relevant description of the composition for protective film-forming films and the composition for release agent layers is based on the active ingredient (solid content), and unless otherwise specified, the solvent is not included.

Hereinafter, the present invention will be described in detail according to specific embodiments in the following order.

(1. Protective film forming film) As shown in FIGS. 1 and 5 , the sheet 10 for forming a protective film of the present embodiment is a long sheet having a protective film forming film 11 and a first release film 12 provided on one surface of the protective film forming film 11 . Usually rolled up into rolls.

The protective film forming film 11 forms a protective film for protecting the workpiece or the processed product of the workpiece by being attached to the workpiece and forming a protective film.

"To form a protective film" means to bring the protective film forming film 11 into a state having sufficient properties to protect a workpiece or a processed product of the workpiece. Specifically, when the protective film forming film of the present embodiment is curable, "to form a protective film" means that the uncured protective film forming film is made into a cured product. In other words, the protective film-forming film formed into a protective film is a cured product of the protective film-forming film, which is different from the protective film-forming film.

After stacking the workpiece on the curable protective film forming film, the protective film forming film is cured, whereby the protective film can be firmly adhered to the workpiece, and a durable protective film can be formed.

When the protective film forming film 11 does not contain a curable component and is used in a non-cured state, the protective film forming film of the present embodiment is converted into a protective film when the protective film forming film of the present embodiment is attached to a workpiece. In other words, the protective film may be the same as the protective film forming film.

When high protective performance is not required, since the protective film forming film does not need to be cured, the protective film forming film may be non-curable.

In this embodiment, the protective film forming film is preferably curable. Therefore, the protective film is preferably a cured product. As a hardened|cured material, a thermosetting material and an energy ray hardened|cured material can be illustrated, for example. In this embodiment, it is more preferable that the protective film is a thermally cured product.

Moreover, it is preferable that a protective film forming film has adhesiveness at normal temperature (23 degreeC), or it is preferable to exhibit adhesiveness by heating. Thereby, when a workpiece|work and a protective film forming film are laminated|stacked, both can be bonded together. Therefore, positioning can be surely performed before curing the protective film-forming film.

The protective film forming film may be composed of one layer (single layer), or may be composed of a plurality of layers of two or more layers. When the protective film-forming film has a plurality of layers, the plurality of layers may be the same or different from each other, and the combination of the layers constituting the plurality of layers is not particularly limited.

In the present embodiment, the protective film forming film is preferably one layer (monolayer). If the protective film-forming film is composed of a plurality of layers, there is a risk that interlayer peeling may occur due to the difference in thermal expansion and contraction between the layers in the step where the temperature changes (at the time of reflow treatment or when using the apparatus). reduce this risk.

The thickness of the protective film forming film is not particularly limited, but is preferably 100 μm or less, more preferably 70 μm or less, still more preferably 45 μm or less, and particularly preferably 30 μm or less. If the thickness of the protective film-forming film is within the above-mentioned range, even when passing through the rollers after the punching step, the punched protective film-forming film contacts and adheres to the useless parts, and is easily separated again after passing through the rollers . Further, the thickness of the protective film forming film is preferably 5 μm or more, more preferably 10 μm or more, and further preferably 15 μm or more. When the thickness of the protective film-forming film is within the above-mentioned range, the protective performance of the obtained protective film becomes favorable.

In addition, the thickness of a protective film forming film means the thickness of the whole protective film forming film. For example, the thickness of the protective film forming film composed of a plurality of layers refers to the total thickness of all the layers forming the protective film forming film.

Hereinafter, the protective film formed on the wafer which is the processed product which is a workpiece|work is demonstrated. Specifically, the protective film formed by converting the protective film forming film of the present embodiment into a protective film will be described using the wafer 30 with the protective film shown in FIG. 8 .

As shown in FIG. 8 , the wafer 30 with a protective film has a protective film 32 formed on the back side (upper side in FIG. 8 ) of the wafer 31 , and a front side (lower side in FIG. 8 ) of the wafer 31 . convex electrodes 33 .

A circuit is formed on the surface side of the wafer 31, and the convex electrodes 33 are formed on the surface side so as to be electrically connected to the circuit. The wafer 30 with a protective film is arrange|positioned so that the surface on which the convex electrode 33 is formed may oppose the board|substrate for wafer mounting. Then, by a predetermined heat treatment (reflow treatment), it is electrically and mechanically connected to the substrate via the protruding electrodes 33 to be mounted. As the convex electrode 33, a bump, a pillar electrode, or the like can be exemplified.

(1.1 Adhesion between protective film forming films) In the present embodiment, by controlling the adhesive force when the protective film forming films constituting the protective film forming sheet are adhered to each other within a predetermined range, failure of waste removal is suppressed. Specifically, the present embodiment is characterized in that the adhesive force after attaching two protective film forming films under a load of 2 kgf at 23° C. for 2 minutes is 19 N/25 mm or less. The adhesive force is preferably 15 N/25 mm or less, more preferably 11 N/25 mm or less. In addition, if the adhesion force is too small, the holding performance of the workpiece may be deteriorated. Therefore, the adhesion force is preferably 0.1 N/25 mm or more, more preferably 1 N/25 mm or more, and particularly preferably 3 N/25 mm or more. In addition, the reason why the measurement of the adhesive force is made after the protective film forming films are stuck to each other for 2 minutes is that, in the apparatus for performing scrap removal and sticking to the workpiece, in the step of passing the protective film forming sheet through the roller 19 , the cut portion is in contact with the roller 19 and stops for about 2 minutes.

As described above, by controlling the adhesion between the protective film forming films within a predetermined range, even if the protective film forming sheet is bent after the punching step, the punched protective film forming film 16 and the useless portion 17 are formed. In addition, the protective film forming film 16 and the useless portion 17 can be separated again after the protective film forming sheet has passed through the rollers, and it is possible to reduce the defect of scrap removal.

(1.2 Composition for forming a protective film) The composition of the protective film forming film is not particularly limited as long as the protective film forming film has the above-mentioned physical properties. In the present embodiment, the composition (composition for a protective film-forming film) constituting the protective film-forming film is preferably a resin combination containing at least a polymer component (A), a curable component (B), and a filler (E). thing. The polymer component is regarded as a component formed by a polymerization reaction of a polymerizable compound. In addition, a curable component is a component which can undergo a curing (polymerization) reaction. In addition, the polymerization reaction in the present invention also includes a polycondensation reaction.

Moreover, the component contained in a polymer component may also be a curable component. In the present embodiment, when the composition for a protective film-forming film contains such a component that is both a polymer component and a curable component, the composition for a protective film-forming film is regarded as containing a polymer component and a curable component.

(1.2.1 Polymer composition) The polymer component (A) imparts film formability (film-forming properties) to the protective film-forming film, and imparts moderate viscosity to the protective film-forming film, so that the protective film-forming film can be reliably and uniformly attached to the workpiece. The weight average molecular weight of the polymer component is usually in the range of 50,000 to 2,000,000, preferably in the range of 100,000 to 1,500,000, and particularly preferably in the range of 200,000 to 1,000,000. When the weight average molecular weight is too low, the adhesion between the protective film forming films tends to increase. On the other hand, when the weight average molecular weight is too high, the mutual solubility with other components will deteriorate, and as a result, the formation of a uniform film will be prevented. As such a polymer component, for example, acrylic resin, urethane resin, phenoxy resin, silicone resin, saturated polyester resin, etc. can be used, and acrylic resin is particularly preferably used.

In this specification, unless otherwise specified, the "weight average molecular weight" is a polystyrene-equivalent value measured by a gel permeation chromatography (GPC) method. As a measurement by this method, for example, a high-speed GPC apparatus "HLC-8120GPC" manufactured by TOSOH CORPORATION, which is connected to high-speed columns "TSK gurd column H _XL -H", "TSK Gel GMH XL", "TSK Gel GMH _XL ", " TSK Gel G2000 H _XL " (the above are all manufactured by TOSOH CORPORATION), and the measurement was performed with a differential refractometer as a detector under the conditions of a column temperature of 40°C and a liquid feed rate of 1.0 mL/min.

As an acrylic resin, the (meth)acrylate copolymer which consists of a (meth)acrylate monomer and the structural unit derived from a (meth)acrylic acid derivative is mentioned, for example. Among them, as the (meth)acrylate monomer, alkyl (meth)acrylates having 1 to 18 carbon atoms in the alkyl group are preferably used, and specifically, methyl (meth)acrylate is used. , ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, etc. Moreover, as a (meth)acrylic acid derivative, (meth)acrylic acid, glycidyl (meth)acrylate, hydroxyethyl (meth)acrylate, etc. are mentioned, for example.

In this embodiment, a glycidyl group is preferably introduced into the acrylic resin using glycidyl methacrylate or the like. The mutual solubility of the glycidyl group-introduced acrylic resin and the epoxy resin as a thermosetting component to be described later increases, the glass transition temperature (Tg) after curing of the protective film-forming film increases, and heat resistance increases. Moreover, in this embodiment, in order to control the adhesiveness to a workpiece|work and adhesive physical property, it is preferable to introduce a hydroxyl group into an acrylic resin using hydroxyethyl acrylate or the like.

The glass transition temperature of the acrylic resin is preferably -70°C to 40°C, more preferably -35°C to 35°C, more preferably -20°C to 30°C, still more preferably -10°C to 25°C, and particularly preferably -5°C ℃~20℃. By making the glass transition temperature of an acrylic resin into the said range, the fluidity|liquidity at the time of heating of a protective film forming film and a protective film can be suppressed, and it becomes easy to obtain a smooth protective film. When the glass transition temperature is too low, the adhesion between the protective film forming films tends to increase. When the glass transition temperature is too high, the mutual solubility with other components deteriorates, and as a result, the formation of a uniform film is prevented.

式中，Tg為丙烯酸樹脂的玻璃轉化溫度，m為2以上的整數，Tgk為單體m的均聚物的玻璃轉化溫度，Wk為丙烯酸樹脂中的衍生自單體m的結構單元m的質量分數，且Wk滿足下式。 [數學式2]

式中，m及Wk與上述m及Wk相同。 When the acrylic resin has m types (m is an integer of 2 or more) structural units, the glass transition temperature of the acrylic resin can be calculated as follows. That is, when m types of monomers from which the structural units in the acrylic resin are derived, any non-repeating serial number from 1 to m is sequentially assigned to them, and they are named "monomer m", the following can be used. The Fox formula calculates the glass transition temperature (Tg) of acrylic resins. [Mathematical formula 1]

In the formula, Tg is the glass transition temperature of the acrylic resin, m is an integer of 2 or more, Tgk is the glass transition temperature of the homopolymer of the monomer m, and Wk is the mass of the structural unit m derived from the monomer m in the acrylic resin score, and Wk satisfies the following formula. [Mathematical formula 2]

In the formula, m and Wk are the same as the above-mentioned m and Wk.

As Tgk, the value described in Polymer Data Handbook, Adhesion Handbook, Polymer Handbook, or the like can be used. For example, the Tgk of the homopolymer of methyl acrylate is 10°C, the Tgk of the homopolymer of n-butyl acrylate is -54°C, the Tgk of the homopolymer of methyl methacrylate is 105°C, and the Tgk of the homopolymer of methyl methacrylate is 105°C. The Tgk of the ester homopolymer was -15°C, the Tgk of the glycidyl methacrylate homopolymer was 41°C, and the Tgk of 2-ethylhexyl acrylate was -70°C.

When the total weight of the composition for forming a protective film is 100 parts by mass, the content of the polymer component is preferably 5 to 80 parts by mass, more preferably 8 to 70 parts by mass, more preferably 10 to 60 parts by mass, still more preferably Preferably it is 12-55 mass parts, More preferably, it is 14-50 mass parts, Especially preferably, it is 15-45 mass parts. By making the content of the polymer component within the above-mentioned range, the amount of the low molecular weight component that increases the adhesion between the protective film-forming films can be limited to an appropriate range, so that the material design of the composition for protective film-forming films can be achieved. made easy.

(1.2.2 Thermosetting components) The curable component (B) hardens the protective film-forming film to form a hard protective film. As the curable component, a thermosetting component, an energy ray-curable component, or a mixture thereof can be used. When curing by irradiating energy rays, the protective film-forming film of the present embodiment contains a filler, a coloring agent, and the like, which will be described later, so that the light transmittance decreases. Therefore, for example, when the thickness of the protective film forming film becomes thick, the energy ray curing tends to become insufficient.

On the other hand, even if the thickness of the thermosetting protective film-forming film becomes thick, it can be sufficiently cured by heating, so that a protective film with high protective performance can be formed. In addition, by using conventional heating equipment such as a heating oven, a plurality of protective films can be heated at one time to form a film and thermally cured.

Therefore, in this embodiment, the curable component is preferably thermosetting. That is, the protective film forming film of the present embodiment is preferably thermosetting.

Whether or not the protective film forming film is thermosetting can be judged in the following manner. First, the protective film forming film at normal temperature (23° C.) is heated to a temperature higher than normal temperature, and then cooled to normal temperature, thereby forming a protective film forming film after heating and cooling. Next, at the same temperature, the hardness of the protective film-forming film after heating and cooling was compared with the hardness of the protective film-forming film before heating, and when the protective film-forming film after heating and cooling was harder, it was determined that the protective film-forming film was For thermosetting.

As the thermosetting component, for example, epoxy resins, thermosetting polyimide resins, unsaturated polyester resins, and mixtures of these resins are preferably used. In addition, the thermosetting polyimide resin refers to a general term for low molecular weight, low viscosity monomers or precursor polymers that form polyimide resins by thermal curing. Non-limiting specific examples of thermosetting polyimide resins are described, for example, in Journal of Fiber Society "Fiber and Industry", Vol. 50, No. 3 (1994), P106-P118.

The epoxy resin, which is a thermosetting component, has the property of forming a three-dimensional network when heated to form a strong coating. As such an epoxy resin, well-known various epoxy resins can be used. In this embodiment, the molecular weight (formula weight) of the epoxy resin is preferably 300 or more and less than 50,000, 300 or more and less than 10,000, 300 or more and less than 5,000, 300 or more and less than 3,000. In addition, the epoxy equivalent of the epoxy resin is preferably 50 to 5000 g/eq, more preferably 100 to 2000 g/eq, still more preferably 150 to 1000 g/eq.

Specific examples of such epoxy resins include glycidyl ethers of phenols such as bisphenol A, bisphenol F, resorcinol, phenol novolak, and cresol novolak. ; Glycidyl ethers of alcohols such as butanediol, polyethylene glycol, polypropylene glycol, etc.; Glycidyl ethers of carboxylic acids such as phthalic acid, isophthalic acid, tetrahydrophthalic acid; Substitute aniline with glycidyl group Glycidyl-type or alkyl-glycidyl-type epoxy resins composed of active hydrogen bonded to a nitrogen atom such as aniline isocyanurate; vinylcyclohexane diepoxide, 3,4- Epoxycyclohexylmethyl-3,4-bicyclohexanecarboxylate, 2-(3,4-epoxy)cyclohexyl-5,5-spiro(3,4-epoxy)cyclohexane-m What is called an alicyclic epoxide in which an epoxy group is introduced by, for example, oxidizing a carbon-carbon double bond in the molecule, such as dioxane. In addition to this, epoxy resins having a biphenyl skeleton, a dicyclohexadiene skeleton, a naphthalene skeleton, and the like can also be used.

When a thermosetting component is used as the curable component (B), it is preferable to use a curing agent (C) as an auxiliary agent at the same time. As the curing agent for epoxy resins, a thermally active latent epoxy resin curing agent is preferable. "Thermally active latent epoxy resin curing agent" is a type that is difficult to react with epoxy resin at room temperature (23°C), but is activated by heating to a certain temperature or higher, and reacts with epoxy resin of curing agent. As for the activation method of thermally active latent epoxy resin curing agent, there is a method of generating active species (anions, cations) in a chemical reaction based on heating; it is stably dispersed in epoxy resin at around normal temperature, but at high temperature A method of mutually dissolving, dissolving and initiating a curing reaction with epoxy resin at high temperature; a method of using a molecular sieve-encapsulated curing agent to dissolve at a high temperature and initiating a curing reaction; a method based on microcapsules, etc.

Among the exemplified methods, a method in which the epoxy resin is stably dispersed in the epoxy resin at around normal temperature, but dissolves in and dissolves with the epoxy resin at a high temperature and initiates a curing reaction is preferable.

Specific examples of the thermally active latent epoxy resin curing agent include various onium salts, dibasic acid dihydrazide compounds, dicyandiamine, amine adduct curing agents, and high melting point active hydrogen compounds such as imidazole compounds. Wait. These thermally active latent epoxy resin curing agents may be used alone or in combination of two or more. In this embodiment, dicyandiamine is particularly preferable.

Moreover, as a hardening|curing agent for epoxy resins, a phenol resin is also preferable. As the phenol resin, condensates of phenols such as alkylphenols, polyhydric phenols, and naphthols, and aldehydes and the like can be used without particular limitation. Specifically, phenol novolac resins, o-cresol novolac resins, p-cresol novolac resins, t-butylphenol novolac resins, dicyclopentadiene cresol resins, poly-p-vinyl phenolic resins, bisphenols can be used A-type novolak resins, or their modifications, and the like.

The phenolic hydroxyl groups contained in these phenolic resins can be easily subjected to an addition reaction with the epoxy groups of the epoxy resins described above by heating to form cured products with high impact resistance.

The content of the curing agent (C) is preferably 0.01 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, more preferably 0.2 to 15 parts by mass, and particularly preferably 0.3 to 10 parts by mass relative to 100 parts by mass of the epoxy resin . By making content of a hardening|curing agent (C) into the said range, the network structure of a protective film becomes dense, and it becomes easy to obtain the performance which protects a workpiece|work as a protective film.

When dicyandiamide is used as the curing agent (C), it is preferable to further use a curing accelerator (D) at the same time. As the curing accelerator, for example, 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dimethylolimidazole, 2-phenyl- Imidazoles such as 4-methyl-5-hydroxymethylimidazole (imidazoles in which one or more hydrogen atoms are substituted by groups other than hydrogen atoms). Among them, 2-phenyl-4-methyl-5-hydroxymethylimidazole is particularly preferred.

The content of the curing accelerator is preferably 0.01 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, more preferably 0.2 to 15 parts by mass, and particularly preferably 0.3 to 10 parts by mass relative to 100 parts by mass of the epoxy resin. By making content of a hardening accelerator (D) into the said range, the network structure of a protective film becomes dense, and it becomes easy to obtain the performance which protects a workpiece|work as a protective film.

When the total weight of the composition for forming a protective film is 100 parts by mass, the total content of the thermosetting component and the curing agent is preferably 3 to 80 parts by mass, more preferably 5 to 60 parts by mass, and more preferably 7 to 50 parts by mass parts, more preferably 9 to 40 parts by mass, particularly preferably 10 to 30 parts by mass. When the thermosetting component and the curing agent are blended in the above ratio, moderate viscosity is exhibited before curing, and the sticking operation can be performed stably. In addition, after curing, the performance of protecting the workpiece as a protective film is easily obtained.

When a low molecular weight compound is used as a thermosetting component and a hardening|curing agent, the viscosity of a protective film forming film may increase, and the adhesive force of protective film forming films may increase. Therefore, it is preferable to select the kind and compounding quantity of a thermosetting component and a hardening|curing agent in the said range so that viscosity may be controlled to an appropriate value.

(1.2.3 Energy ray curable components) When the curable component (B) is an energy ray curable component, the energy ray curable component is preferably uncured, preferably has adhesiveness, and is more preferably uncured and has adhesiveness.

The energy ray-curable component is a component that is cured by irradiation with an energy ray, and is a component for imparting film formability, flexibility, and the like to the protective film-forming film.

As the energy-ray-curable component, for example, a compound having an energy-ray-curable group is preferable. As such a compound, a well-known energy ray-curable component is mentioned.

When a low molecular weight compound is used as an energy ray-curable component, the viscosity of a protective film-forming film may increase, and the adhesive force of the protective film-forming films may increase. Therefore, it is preferable to select the kind of the energy ray-curable component and its compounding amount so that viscosity may be controlled to an appropriate value.

(1.2.4 Filling material) By making the protective film forming film contain the filler (E), the adjustment of the thermal expansion coefficient of the protective film obtained by making the protective film forming film into a protective film becomes easy. The adhesion reliability of the package obtained by the film-forming film is further improved. In addition, when the protective film forming film contains the filler (E), a hard protective film can be obtained, the moisture absorption rate of the protective film can be further reduced, and the adhesion reliability of the package can be further improved.

The filler (E) may be either an organic filler or an inorganic filler, but an inorganic filler is preferable from the viewpoint of shape stability at high temperature.

Examples of preferable inorganic fillers include powders of silica, alumina, talc, calcium carbonate, red iron oxide, silicon carbide, boron nitride, etc.; beads obtained by spheroidizing these inorganic fillers; Surface modifiers of fillers; single crystal fibers of these inorganic fillers; glass fibers, etc. Among them, silica and surface-modified silica are preferred. The surface-modified silica is preferably surface-modified using a coupling agent, and more preferably surface-modified using a silane coupling agent.

The average particle diameter of the filler is preferably 0.02 to 10 μm, more preferably 0.05 to 5 μm, and particularly preferably 0.10 to 3 μm.

By making the average particle diameter of a filler into the said value, the handleability of the composition for protective film-forming films becomes favorable. Therefore, the quality of the composition for a protective film-forming film and the protective film-forming film tends to be stabilized.

In addition, unless otherwise specified, the "average particle size" in this specification refers to the value of the particle size (D50) at 50% of the cumulative value in the particle size distribution curve obtained by the laser diffraction scattering method.

When the total weight of the composition for forming a protective film is 100 parts by mass, the content of the filler is preferably 15 to 80 parts by mass, more preferably 30 to 75 parts by mass, still more preferably 40 to 70 parts by mass, and particularly preferably It is 45-65 mass parts.

By setting the content of the filler to the above-mentioned value, it becomes easy to control the adhesion between the protective film forming films within an appropriate range. When the content of the filler is too small, the viscosity of the protective film forming films increases, and the adhesion between the protective film forming films increases excessively. On the other hand, if the blending amount of the filler is too large, the shape retention of the protective film-forming film may decrease, the film may not retain its shape due to bending on the roll, the viscosity of the protective film-forming film and the workpiece may be reduced. The adhesion is excessively reduced.

Further, the protective film-forming film preferably contains two or more fillers. That is, the filler (E) is preferably a mixture of two or more fillers. "Containing two or more fillers" may contain two or more fillers with different materials, and may contain two or more fillers with different average particle diameters.

In this embodiment, it is preferable to contain two or more filler materials having different average particle diameters. By including fillers having different average particle diameters in the protective film-forming film, it becomes easy to arrange fillers having smaller average particle diameters in the voids of fillers having larger average particle diameters. As a result, the above-mentioned effects can be obtained, and it becomes easy to set the adhesion between the protective film-forming films within the above-mentioned range.

When two or more filler materials with different average particle sizes are contained, the average particle size of the filler with the largest average particle size is preferably 1.5 to 100 times the average particle size of the filler with the smallest average particle size, more preferably 2 to 100 times the average particle size of the filler with the smallest average particle size. 20 times, more preferably 3 to 18 times.

In addition, by observing the cross section of the protective film or the protective film-forming film, it can be confirmed whether or not the protective film or the protective film-forming film contains two or more fillers having different average particle diameters.

(1.2.5 Coupling agent) The protective film-forming film preferably contains a coupling agent (F). By containing a coupling agent, it is possible to improve the adhesion between the protective film and the workpiece without impairing the heat resistance of the protective film after curing of the protective film-forming film, and to improve the water resistance (moisture and heat resistance). As the coupling agent, a silane coupling agent is preferable from the viewpoint of its versatility and cost advantage.

Examples of the silane coupling agent include γ-glycidyloxypropyltrimethoxysilane, γ-glycidyloxypropylmethyldiethoxysilane, β-(3,4-epoxy Hexyl)ethyltrimethoxysilane, γ-(methacryloyloxypropyl)trimethoxysilane, γ-aminopropyltrimethoxysilane, N-6-(aminoethyl)-γ-aminopropyl Trimethoxysilane, N-6-(aminoethyl)-γ-aminopropylmethyldiethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-ureidopropyltrimethoxysilane Ethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfide, methyltrimethoxy Silane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, imidazolylsilane, etc. These silane coupling agents may be used alone or in combination of two or more.

When the total weight of the composition for forming a protective film is 100 parts by mass, the content of the coupling agent is preferably 0.01 to 20 parts by mass, 0.1 to 10 parts by mass, 0.2 to 5 parts by mass, and 0.3 to 3 parts by mass.

(1.2.6 Colorants) The protective film-forming film preferably contains a colorant (G). As a result, since the back surface of the workpiece such as the wafer is covered, various electromagnetic waves generated in the electronic device can be blocked, and failures of the workpiece such as the wafer can be reduced. In addition, when a defect in waste removal occurs, it can be immediately detected with the naked eye.

As a coloring agent (G), well-known coloring agents, such as an inorganic type pigment, an organic type pigment, and an organic type dye, can be used, for example. In this embodiment, inorganic pigments are preferred.

Examples of inorganic pigments include carbon black, cobalt pigments, iron pigments, chromium pigments, titanium pigments, vanadium pigments, zirconium pigments, molybdenum pigments, ruthenium pigments, platinum pigments, ITO ( Indium tin oxide) dyes, ATO (antimony tin oxide) dyes, etc. Among them, carbon black is particularly preferably used. Electromagnetic waves in a wide wavelength range can be blocked by carbon black.

The blending amount of the colorant (especially carbon black) in the protective film-forming film varies depending on the thickness of the protective film-forming film. For example, when the thickness of the protective film-forming film is 20 μm, the amount of When the total weight is 100 parts by mass, the content of the colorant is preferably 0.01 to 10 parts by mass, more preferably 0.03 to 7 parts by mass, and more preferably 0.05 to 4 parts by mass.

The average particle diameter of the colorant (especially carbon black) is preferably 1 to 500 nm, particularly preferably 3 to 100 nm, and further preferably 5 to 50 nm. If the average particle diameter of the colorant is within the above range, it is easy to control the light transmittance within a desired range.

(1.2.7 Other additives) The composition for forming a protective film may contain, as other additives, a photopolymerization initiator, a crosslinking agent, a plasticizer, an antistatic agent, an antioxidant, a getter, a Adhesives, strippers, etc.

Among them, the content of the release agent in the composition for forming a protective film is preferably less than a predetermined amount. In the present embodiment, it is preferably less than 0.00099 mass % with respect to the total mass of the protective film-forming film. When there is too much content of a release agent, there exists a tendency for the adhesion reliability of a protective film and a workpiece|work to fall. As a release agent, an alkyd type release agent, a silicone type release agent, a fluorine type release agent, an unsaturated polyester type release agent, a polyolefin type release agent, a wax type release agent can be illustrated, for example.

(1.2.8 Control of adhesion between protective film forming films) As described above, the present embodiment is characterized in that, by controlling the adhesion force when the protective film forming films constituting the protective film forming sheet are adhered to each other within a predetermined range, failure of waste removal is suppressed.

The adhesion between the protective film-forming films can be controlled by the kind and blending amount of each component constituting the protective film-forming film.

When the weight average molecular weight of the polymer component (A) is low, the adhesive force tends to increase. When the glass transition temperature of the polymer component (A) is low, the adhesive force tends to increase. Further, when a low molecular weight compound is used as the curable component (B), the curing agent (C), the curing accelerator (D), or the energy ray curable component, the adhesive force tends to increase. When the blending amount of the filler (E) is large, the adhesive force tends to decrease.

Adhesion can also be controlled by partially curing the protective film-forming film. For example, the adhesive force can be lowered by partially curing the curable component (B). The timing for partially curing the protective film-forming film is not particularly limited, and may be, for example, a stage before passing through the roll 19 when punching the sheet for protective film-forming. However, from the viewpoint of setting the peeling forces F1 and F2 described later in an appropriate range and the adhesiveness to the workpiece, it is preferable that the protective film forming film is not partially cured as described in the examples described later.

(2. Sheet for forming protective film) Before use, the protective film-forming film can be wound and stored in the form of a double-layered protective film-forming sheet 10 in which a peelable protective film-forming film 11 is laminated on the first release film 12 as shown in FIG. 1 . . In addition, as shown in FIG. 3, the sheet 20 for protective film formation of the three-layer structure in which the protective film forming film 11 is sandwiched between two release films (the first release film 12, the second release film 13) may be used. The form (another embodiment) is rolled up and stored. The release film is peeled off when the protective film is used to form the film.

The said sheet for protective film formation is long, and is wound up in a roll shape, and is stored and transported. As such a sheet for forming a protective film, there is also known a sheet for forming a protective film in which the protective film forming film is punched in advance to have substantially the same shape as the workpiece. The protective film forming film 16 punched into the punched protective film forming sheet into a predetermined closed shape is laminated on the first release film 12 ( FIG. 2 ), or sandwiched between two release films ( 12, 13) between (Figure 4).

The first release film may be composed of one layer (single layer) or two or more substrates, and the surface of the substrate may be subjected to a release treatment from the viewpoint of controlling the releasability. That is, the surface of the base material may be modified, or a material not derived from the base material may be formed on the surface of the base material. In this embodiment, it is preferable that the 1st release film has a base material and a release agent layer. By having the release agent layer, it becomes easy to control the physical properties of the surface on which the release agent layer is formed in the first release film. In this embodiment, after coating the coating agent containing the composition for release agent layers described later on one surface of the base material, the coating film is dried and cured to form the release agent layer. Thereby, a 1st peeling film can be obtained.

The thickness of the first release film 12 is not particularly limited, but is preferably 30 to 100 μm, more preferably 40 to 80 μm, and more preferably 45 to 70 μm.

By making the lower limit of the thickness of the 1st peeling film 12 into the said value, it can prevent that a dicing blade penetrates the 1st peeling film 12 and cuts the 1st peeling film 12 when a protective film forming film is cut with a dicing blade. In addition, after the protective film forming sheet 10 is unwound and the protective film forming film 11 is cut out, before being transported to the next step, the protective film forming sheet 10 passes through rollers such as guide rollers in the apparatus, but by By setting the upper limit of the thickness of the first release film 12 to the above-mentioned value, the protective film forming film 11 can be prevented from being peeled off from the first release film 12 .

In addition, the thickness of the 1st peeling film 12 means the thickness of the whole 1st peeling film. For example, the thickness of the 1st release film which consists of several layers means the total thickness of all the layers which comprise a 1st release film.

As a base material of the 1st release film 12, a resin film, paper, etc. are mentioned. Examples of the resin of the resin film include polyethylene terephthalate, polyethylene, polypropylene, polybutene, polybutadiene, polymethylpentene, polyvinyl chloride, vinyl chloride copolymer, polyvinyl chloride Butylene terephthalate, polyurethane, ethylene-vinyl acetate copolymer, ionomer resin, ethylene (meth)acrylic acid copolymer, polystyrene, polycarbonate, fluororesin, low density polyethylene, linear Low density polyethylene and triacetyl cellulose, etc. As paper, high-quality paper, coat paper, cellophane, laminated paper, etc. are mentioned. One of these substrates may be used alone, or two or more of them may be used simultaneously. Among them, a polyethylene terephthalate film is preferable because it is inexpensive and has rigidity.

At least one surface (surface laminated with the protective film forming film) of the first release film 12 may be subjected to release treatment with the composition for release agent layers. The thickness of the release agent layer is preferably 30 nm or more and 200 nm or less, and more preferably 50 nm or more and 180 nm or less.

The surface elastic modulus (23° C.) of the surface of the first release film 12 in contact with the protective film forming film 11 is preferably 17 MPa or less, more preferably 14 MPa or less, more preferably 13 MPa or less, particularly preferably 12 MPa or less. The surface modulus of elasticity is an indicator of the ease of deformation of the surface. By setting the surface elastic modulus of the surface of the first release film 12 in contact with the protective film forming film 11 within the above-mentioned range, in the punching process, when the die is pressed and then pulled up, it is possible to suppress the die at the surface. Between the protective film forming film 11 and the first peeling film 12, floating (peeling of about 1 to 4 mm) occurred. This is considered to be because the surface of the first release film 12 is relatively soft, and the surface of the first release film follows the deformation of the protective film-forming film even if there is a pressure release by compression of the die and release thereof. By suppressing the occurrence of floating, it is possible to further reduce the failure of waste removal. The lower limit of the surface elastic modulus of the surface of the first release film 12 in contact with the protective film forming film 11 is not particularly limited, but if the surface elastic modulus is too low, the peeling force may increase, so it is preferably 3 MPa or more , more preferably 4 MPa or more, particularly preferably 5 MPa or more.

The surface elastic modulus of the surface in contact with the protective film forming film 11 of the first release film 12 at 23° C. can be measured using an atomic force microscope equipped with a cantilever. That is, the surface of the first release film 12 in contact with the protective film forming film 11 is pressed and pulled away by a cantilever to obtain a force curve. Fitting based on the JKR theoretical formula was performed on the obtained force curve, and the elastic modulus was calculated|required as the surface elastic modulus of this invention. A specific measurement method will be described in detail in the examples to be described later.

In order to set the peeling force F1 to be described later in an appropriate range and to set the surface elastic modulus of the first release film 12 within the above-mentioned range, in the present embodiment, as the composition for the release agent layer, for example, an alkyd-based composition is preferable. Release agent, silicone type release agent, fluorine type release agent, unsaturated polyester type release agent, polyolefin type release agent, wax type release agent, among them, silicone type release agent is preferred, especially It is preferable to contain a silicone-based mold release agent and a heavy release additive.

As the silicone-based mold release agent, a silicone mold release agent in which silicone having dimethylpolysiloxane as a basic skeleton is blended can be used.

The silicon oxide may be any of an addition reaction type, a condensation reaction type, and an energy ray curing type such as an ultraviolet curing type and an electron beam curing type, but is preferably an addition reaction type silicon oxide. The addition reaction type siloxane has high reactivity and excellent productivity, and has advantages such as less change in peeling force after manufacture and no curing shrinkage compared to the condensation reaction type.

Specific examples of addition-reaction-type siloxanes include alkenes having 2 to 10 carbon atoms, such as vinyl groups, allyl groups, propenyl groups, and hexenyl groups, at the terminal and/or side chain of the molecule. based organopolysiloxanes. From the viewpoint of lowering the surface elastic modulus, it is preferable that the number of alkenyl groups in the addition reaction type siloxane is small.

When the total weight of the composition for release agent layer (excluding the catalyst described later) is 100 parts by mass, the content of silicon oxide composed of dimethylpolysiloxane is preferably less than 100 parts by mass, more preferably less than 90 parts by mass , more preferably less than 80 parts by mass, particularly preferably less than 70 parts by mass.

When using such an addition reaction type silicon oxide, it is preferable to use a crosslinking agent and a catalyst together.

As a crosslinking agent, the organopolysiloxane which has at least 2 hydrogen atom-bonded silicon atoms in one molecule is mentioned, for example. From the viewpoint of reducing the surface elastic modulus, it is preferable that the content of the crosslinking agent in the release agent layer composition is small.

Specific examples of the crosslinking agent include dimethylhydrosiloxane-terminated dimethylsiloxane-methylhydrosiloxane copolymer, trimethylsiloxane-terminated dimethyl Siloxane-methylhydrosiloxane copolymer, trimethylsiloxane end-capped methylhydropolysiloxane, poly(hydrosilsesquioxane), etc.

Examples of the catalyst include particulate platinum, particulate platinum adsorbed on a carbon powder carrier, chloroplatinic acid, alcohol-modified chloroplatinic acid, olefin complexes of chloroplatinic acid, platinum group metals such as palladium and rhodium. compounds, etc.

By using such a catalyst, the hardening reaction of the composition for release agent layers can be performed more efficiently.

When the total weight of the composition for a release agent layer (excluding the catalyst) is set to 100 parts by mass from the viewpoint of setting the surface elastic modulus within the above-mentioned range and setting the peeling force F1 described later within an appropriate range The content of the silicone-based mold release agent is preferably 30 to 100 parts by mass, more preferably 50 to 100 parts by mass.

The heavy peeling additive is used to increase the peeling force F1 described later. As a heavy release additive, organosilanes, such as a silicone resin and a silane coupling agent, are mentioned, for example, Among them, a silicone resin is preferable.

As the silicone resin, it is preferable to use, for example, an MQ resin containing M units as monofunctional siloxane units [R ₃ SiO _1/2 ] and Q units as tetrafunctional siloxane units [SiO _4/2 ] . In addition, the three Rs in the M unit each independently represent a hydrogen atom, a hydroxyl group or an organic group. From the viewpoint of being easy to suppress silicon-oxygen transfer, one or more of the three Rs in the M unit is preferably a hydroxyl group or a vinyl group, and more preferably a vinyl group. From the viewpoint of lowering the surface elastic modulus, it is preferable that the content of the silicone resin (especially the MQ resin) in the release agent layer composition is small.

When the total weight of the composition for release agent layer (excluding the catalyst) is 100 parts by mass, the content of the heavy release additive is preferably 0 to 50 parts by mass, more preferably 5 to 45 parts by mass, and particularly preferably 10 to 40 parts by mass parts by mass.

The composition for a release agent layer is preferably used as a coating agent containing a diluting solvent in addition to the various active ingredients described above, from the viewpoint of adjusting the viscosity and improving the coatability to the base material. In this specification, an "active ingredient" means a component other than a diluting solvent among components contained in a coating agent containing a composition as an object.

Examples of the dilution solvent include aromatic hydrocarbons such as toluene, fatty acid esters such as ethyl acetate, ketones such as methyl ethyl ketone, organic solvents such as aliphatic hydrocarbons such as hexane and heptane, and the like. These diluents may be used alone or two or more of them may be used simultaneously.

The active ingredient (solid content) concentration of the coating agent containing the composition for a release agent layer is preferably 0.3 to 10 mass %, more preferably 0.5 to 5 mass %, and further preferably 0.5 to 3 mass %.

The composition for release agent layers may contain additives generally used in release agent layers within a range not to impair the effects of the present invention. As such an additive, a dye, a dispersing agent, etc. are mentioned.

In the sheet 10 for protective film forming of this embodiment, it is preferable that the protective film forming film 11 is punched into a predetermined shape. That is, the cutout 14 is preferably formed in the sheet for forming a protective film so that a part of the sheet 10 for forming a protective film has a predetermined closed shape in a plan view of the sheet 10 for forming a protective film. In addition, the shape of the protective film-forming film after punching is preferably smaller than the shape of the workpiece from the viewpoint that the protective-film-forming film does not protrude from the workpiece when the protective-film-forming film is attached to the workpiece.

(3. Manufacturing method of sheet for forming protective film) The manufacturing method of a protective film forming film is not specifically limited. This film can be manufactured using the coating agent containing the said composition for protective film formation films. The coating agent can be prepared by mixing the components constituting the composition for forming a protective film by a known method.

The obtained coating agent is coated with a coating machine such as a roll coater, a knife coater, a roll knife coater, an air knife coater, a die coater, a bar coater, a gravure coater, a curtain coater, or the like. The sheet 10 for protective film formation which has the protective film forming film 11 on the 1st peeling film 12 by cloth and drying on the peeling surface of the 1st peeling film 12 can be obtained. Moreover, a coating agent may be apply|coated to another resin film, it may be dried, and the obtained protective film-forming film may be transcribe|transferred on a 1st peeling film. When the sheet 20 for forming a protective film of another embodiment is to be obtained, the second peeling film 13 is attached to the exposed surface of the protective film forming film 11 laminated with the first peeling film 12 to obtain a sandwich between two peeling films. The sheet 20 for forming a protective film holding the protective film forming film 11 is provided.

(4. Manufacturing method of punching-processed sheet for forming protective film) A method of punching the sheet 10 for forming a protective film to obtain the protective film forming film 16 punched into a predetermined closed shape on the first release film 12 will be described.

(4.1 Punching processing steps) First, the sheet 10 for forming a protective film shown in FIG. 1 without punching is prepared. Using a die (not shown), the cutout 14 is cut out from the protective film forming film 11 side surface of the protective film forming sheet 10 so as to penetrate the protective film forming film 11 and reach a part of the surface of the first release film 12 . An operation in which a cut is made so as to reach a part of the surface without being completely cut is called a half-cut. As a result, the notches 14 are formed in a part of the surface of the sheet 10 for forming a protective film so as to have a predetermined closed shape (see FIGS. 2 and 5 ). Here, when the protective film forming film is transferred onto the semiconductor wafer, the predetermined closed shape is substantially the same as that of the wafer. That is, the notch 14 is formed so that it may become the shape of the workpiece|work to which the protective film forming film 11 is attached, or the shape substantially the same as the area|region in which a protective film should be formed. This step is called "Punching Step".

By the punching step, the protective film forming film 11 is divided into the protective film forming film 16 punched into a predetermined closed shape, and the continuous useless portion 17 around the protective film forming film 16 . In the longitudinal direction of the sheet 10 for protective film forming, the protective film forming film 16 punched into a predetermined closed shape is provided at a plurality of places.

In the punching step, a known punch can be appropriately used. The punching process is performed by half cutting so that the protective film forming film 11 is completely cut and the first release film 12 is not completely cut.

As shown in FIGS. 2 and 4 , the sectional shape of the notch 14 is substantially wedge-shaped, and the width of the notch 14 is wider on the upper surface side of the protective film forming film 11 into which the die enters, and is wider on the lower surface side (the protective film forming film 11 The interface with the first release film 12) is narrowed. The width of the slit 14 is not particularly limited, but the protective film forming film 11 is formed from the viewpoint of preventing contact and adhesion of the punched protective film forming film 16 and the useless portion 17, or from the viewpoint of shortening the contact and adhesion time. The width D of the notch 14 of the lower surface portion (ie, the upper surface portion of the first release film 12 ) is preferably 8 μm or more, more preferably 10 μm or more, still more preferably 15 μm or more, and particularly preferably 20 μm or more. As the width D, the sheet for forming a protective film is cut in the thickness direction, and the width of the cut in the upper surface portion of the cross-section of the first release film 12 can be measured as the width D. The upper limit of the width D is not particularly limited, but in consideration of the width of a dicing blade that can reliably cut the protective film-forming film, it is usually 100 μm or less, preferably 80 μm or less, more preferably 60 μm or less, and still more preferably 40 μm or less. In order to form such a slit 14, it is preferable to use a die having a cutting blade with a wide blade width at the front end as the die.

Through the above steps, the sheet 10 for forming a protective film that has been punched can be obtained. On the protective film forming sheet, when the protective film forming sheet 10 subjected to the punching process is viewed in plan from the upper surface of the protective film forming film 11, a part of the protective film forming sheet has a predetermined closed shape (for example, with the semiconductor crystal The notch 14 is formed so that a circular plane shape may be substantially the same shape), and the notch 14 reaches a part of the 1st peeling film 12 in the thickness direction of the sheet 10 for protective film formation. That is, the cutout is also formed on the surface of the first release film 12 in contact with the protective film forming film 11 . The protective film forming film 11 can be completely cut by reaching the dicing blade to the first release film 12 .

(4.2 Waste removal step) After the punching step and before the scrap removal step, the protective film forming sheet 10 passes through a plurality of rollers such as guide rollers for the purpose of controlling the tension of the protective film forming sheet and the like.

As shown in FIG. 6 , in the waste removal step, the continuous useless portion 17 is peeled off from the first release film 12 , and the punched protective film-forming film 16 is left on the first release film 12 . The peeled-off waste portion 17 is wound around a scrap-lifting roll.

According to the sheet 10 for forming a protective film of the present embodiment, since the adhesion of the protective film forming films to each other is low, the protective film forming film 16 subjected to the punching process and the useless portion 17 occur even when passing through the rollers 19 or the like after the punching process step. The protective film-forming film 16 and the useless portion 17 can be separated again after passing through the rollers for contact and adhesion. As a result, defective removal of waste in the waste removal step can be suppressed.

The punched sheet 10 for forming a protective film can be wound in a roll shape for storage and transportation.

(5. Processing method of workpiece) As an example of a method for processing a workpiece using the punched protective film forming sheet of the present embodiment, a tape protection obtained by processing a wafer to which a protective film forming film is attached is disposed on a substrate. The manufacturing method of the package of the film wafer is demonstrated.

The manufacturing method of the apparatus of this embodiment has at least the following steps 1 to 9. Step 1: Step of punching the sheet 10 for forming a protective film Step 2: Step in which the punched protective film forming sheet passes between rolls Step 3: Step of removing the unnecessary portion 17 of the sheet 10 for forming a protective film Step 4: Step of attaching the protective film forming film 11 of the protective film forming sheet 10 to the back surface of the wafer Step 5: Step of forming the attached protective film into a protective film Step 6: Step of peeling off the first release film from the protective film or the protective film forming film Step 7: The step of singulating wafers with protective films or protective film forming films on the backside to obtain a plurality of wafers with protective films or protective film forming films Step 8: Step of disposing a wafer with a protective film or a protective film-forming film on a substrate Step 9: The step of heating the wafer with the protective film or the protective film-forming film and the substrate disposed on the substrate

Steps 1 to 3 are as described above. Step 5 may be performed before step 6, or may be performed after any one of steps 6 to 9. That is, the step of forming the protective film forming film into a protective film can be performed at any stage after the protective film forming film is attached to the wafer.

With reference to the drawings, a method of manufacturing the apparatus having the above-mentioned steps 1 to 9 will be described.

FIG. 2 , FIG. 4 , and FIG. 5 show the outline of step 1 as described above. FIG. 6 shows the outline of step 3. FIG. As shown in FIG. 9 , the protective film forming film 11 of the protective film forming sheet 10 is attached to the back surface of the wafer 21 (step 4). Then, the attached protective film forming film 11 is converted into a protective film to form a protective film 32 (step 5) to obtain a wafer with a protective film. When the protective film forming film 11 is thermosetting, the protective film forming film 11 may be heated at a predetermined temperature for an appropriate time. In addition, when the protective film forming film 11 is energy ray curable, an energy ray transmissive film may be used as the first release film 12 and the energy ray may be incident from the first release film 12 side.

In addition, hardening of the protective film forming film 11 may be performed after the dicing process mentioned later, and after picking up the wafer with a protective film forming film from a dicing sheet, the protective film forming film 11 may be hardened.

Then, the wafer 21 with a protective film is transferred to a known dicing sheet 22, and the wafer 21 with a protective film is diced, as shown in FIG. wafer 30) (step 7). Then, the dicing sheet 22 is expanded in the planar direction as necessary, and the wafer 30 with the protective film is picked up from the dicing sheet 22 by a suction nozzle (not shown) or the like.

The picked-up wafer 30 with a protective film may be transferred to the next step, or may be temporarily stored and stored on a tray, tape, or the like, and transferred to the next step after a predetermined period of time.

As shown in FIG. 11 , the wafer 30 with the protective film conveyed to the next step is conveyed onto the substrate 50 by the suction nozzle, the terminals on the substrate are separated from the suction nozzle, and are arranged on the convex electrodes 33 such as bumps. At a position where connection can be made to a terminal portion such as a pad (step 8). At this time, another wafer different from the wafer 30 with a protective film may be mounted on the substrate 50 . Therefore, a plurality of wafers can be mounted on this substrate.

The wafer with a protective film arranged at a predetermined position on the substrate is subjected to heat treatment (reflow treatment) (step 9). As the reflux treatment conditions, for example, the maximum heating temperature is preferably 180 to 350° C., and the reflux time is preferably 2 to 10 minutes.

In the reflow process, the convex electrodes 33 of the wafer with a protective film 30 are melted, and are electrically and mechanically connected to the terminal portions on the substrate, and the wafer with a protective film 30 is mounted on the substrate.

(6. Variations) In the above, the embodiment of the present invention has been described by taking, as an example, a sheet for forming a protective film having a double-layer structure having the protective film forming film 11 on the first release film 12 , but the protective film forming film 11 may be exposed on the first peeling film 12 . The second release film 13 is laminated on the surface. That is, the sheet for protective film formation may be the sheet for protective film formation 20 (refer FIG. 3, FIG. 4) of the form in which the protective film formation film 11 is pinched|interposed between the 1st peeling film 12 and the 2nd peeling film 13. At this time, the second peeling film 13 may be peeled off before the protective film forming film 11 is attached to the workpiece.

The material of the protective film forming film 11 of the sheet 20 for protective film forming and its preferable form are the same as those of the above-mentioned embodiment, and the first release film 12 is also the same as that in the description of the above-mentioned embodiment.

In addition, in the present embodiment, in the sheet 20 for forming a protective film, the peeling force at the time of peeling the first peeling film 12 from the protective film forming film 11 is set to F1, and the second peeling force from the protective film forming film 11 is set to F1. When the peeling force at the time of the two peeling films 13 is set to F2, F1 and F2 preferably satisfy the relationship of F1>F2. By satisfying this relationship, when the second peeling film 13 is removed from the protective film forming sheet 20, the protective film forming film 16 that should remain is not removed together with the second peeling film 13, and the protective film forming film 16 can be easily removed. Residues on the first release film 12 can further suppress defective removal of scraps.

Therefore, the first peeling film 12 is a heavy peeling film with a strong peeling force, and the second peeling film 13 is a light peeling film with a weak peeling force.

The peel force F1 is preferably 50 mN/100 mm or more, more preferably 70 mN/100 mm or more, more preferably 90 mN/100 mm or more, still more preferably 110 mN/100 mm or more, and particularly preferably 130 mN/100 mm or more. By making F1 into the said range, it can suppress that the protective film forming film 11 and the 1st peeling film 12 are peeled unexpectedly.

The adjustment of the peeling force can be controlled by, for example, the type of the composition for the release agent layer, the thickness of the release agent layer, and the like. The second peeling film 13 is designed to have a smaller peeling force than the first peeling film 12 . When the second release film 13 has a release agent layer, there is no particular limitation as long as the release agent layer is composed of a material that can impart releasability. For example, the release agent layer of the second release film 13 can be obtained by curing the release agent layer composition containing silicon oxide in the same manner as the release agent layer of the first release film 12 .

The composition for a release agent layer of the second release film 13 can be selected from the materials exemplified in the first release film 12 as long as the relationship between F1 and F2 described above is satisfied. Among these, it is preferable that the content of the material exemplified as the heavy release additive is less than the content in the first release film 12 or not included.

The thickness of the second release film 13 is not particularly limited, but is preferably 10 μm or more and 75 μm or less. Moreover, as for the thickness of a 2nd peeling film, 18 micrometers or more are more preferable, and 24 micrometers or more are still more preferable. Moreover, as for the thickness of a 2nd peeling film, it is more preferable that it is 60 micrometers or less, and it is still more preferable that it is 45 micrometers or less. The thickness of the second peeling film is preferably equal to or less than the thickness of the first peeling film, and more preferably smaller than the thickness of the first peeling film, from the viewpoint of setting the peeling force F2 and the peeling force F1 to the above-mentioned F1>F2.

In addition, the thickness of a 2nd peeling film means the thickness of the whole 2nd peeling film. For example, the thickness of the 2nd peeling film which consists of several layers means the total thickness of all the layers which comprise a 2nd peeling film.

As for the manufacturing method of the sheet 20 for protective film formation, what is necessary is just to stick the 2nd peeling film 13 on the exposed surface of the protective film forming film 11 laminated|stacked with the 1st peeling film 12 as described in embodiment.

When the sheet 20 for forming a protective film is punched, a punch is inserted from the side of the second release film 13 to cut the protective film forming film 11 and the second release film 13 into a predetermined closed shape. The implementation is the same. As a result, the punched protective film forming film 11 and the second peeling film 13 are obtained on the first peeling film 12 . The sheet 20 for forming a protective film that has been punched can be wound into a roll and stored and transported.

In the waste removal step, the second release film 13 and the useless portion 17 are simultaneously wound to remove the second release film 13 and the useless portion 17 . At this time, the completely cut second release film 13 subjected to the punching process is rejoined using a long adhesive tape, so that the second release film 13 can be easily removed. As a result, the protective film forming film 16 cut into a predetermined closed shape remains on the first release film 12 .

The embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments at all, and can be changed in various forms within the scope of the present invention. [Example]

Hereinafter, the present invention will be described in further detail using examples, but the present invention is not limited to these examples.

(Manufacture of sheet for protective film formation) [First release film (heavy release film)] <Coating agent containing the composition for release agent layer> The following composition raw materials for release agent layers were prepared. . Silicone mold release agent containing organopolysiloxane with vinyl group and organopolysiloxane with hydrosilyl group (manufactured by Dow Corning Toray Co., Ltd., BY24-561, solid content is 30% by mass) . Dimethylpolysiloxane (weight average molecular weight: 2000) (manufactured by Shin-Etsu Chemical Co., Ltd., X-62-1387, solid content: 100% by mass) . MQ resin with vinyl group as a heavy release additive (manufactured by Dow Corning Toray Co., Ltd., SD-7292, solid content: 71% by mass) . Platinum (Pt) catalyst (manufactured by Dow Corning Toray Co., Ltd., SRX-212, solid content: 100% by mass)

The above-mentioned raw materials were added to a mixed solvent of toluene and methyl ethyl ketone (toluene/methyl ethyl ketone=1/1 (mass ratio)) at the blending ratio (in terms of solid content) described in Table 1, and the total Solid content was adjusted to 2 mass %, and the coating agent containing the composition for release agent layers was prepared.

<Manufacture of the first release film> On a PET film (manufactured by Mitsubishi Chemical Corporation, trade name: DIAFOIL (registered trademark) T-100, thickness: 50 μm), a film containing a release agent layer composition was applied so that the film thickness after drying was 0.15 μm. The coating agent was heated and dried to form a release agent layer on the PET film, and the first release films (heavy release films) A to C were produced.

<Measurement of Surface Elastic Modulus> The surface elastic modulus of the release-treated surface of the obtained first release film was measured in the following manner. A cantilever made of silicon nitride (manufactured by Bruker Corporation, trade name: MLCT, tip radius: 20 nm, resonance frequency: 125 kHz, spring constant: 0.6 N/m) was set on an atomic force microscope (manufactured by Bruker Corporation, MultiMode 8). The produced first release film was placed on an atomic force microscope, and the surface of the release agent layer of the produced first release film was pressed and pulled away by the provided cantilever with a pressing amount of 2 nm and a scanning speed of 10 Hz. This operation is carried out at 23°C. The force curve obtained by this operation was fitted based on the JKR theoretical formula, and the surface elastic modulus was calculated. For the surface elastic modulus, 4096 points were measured in 1 μm×1 μm on the surface of the release agent layer of the first release film, and the average value of these values was taken and rounded to one decimal place as the surface elastic modulus (MPa). The results are shown in Table 1. [Table 1] first release film Composition for release agent layer [mixing ratio (solid content conversion)] Surface modulus of elasticity [MPa at 23°C] BY24-561 X-62-1387 SD-7292 SRX-212 A 55 15 30 6.7 16 B 67.5 2.5 30 6.7 8 C 60 10 30 6.7 14

[Second release film (light release film)] "SP-PET 381130 (thickness: 38 μm)" manufactured by Lintec Corporation was used.

[Coating agent containing the composition for forming a protective film] The following components were mixed at the blending ratio (solid content conversion) shown in Table 2, and diluted with methyl ethyl ketone so that the solid content concentration might be 50% by mass to prepare a coating agent.

(A) Polymer component (A-1) (methyl acrylate) copolymerized from 10 parts by mass of n-butyl acrylate, 70 parts by mass of methyl acrylate, 5 parts by mass of glycidyl methacrylate and 15 parts by mass of 2-hydroxyethyl acrylate base) acrylate copolymer (weight average molecular weight: 400,000, glass transition temperature: -1°C) (A-2) Copolymerized from 10 parts by mass of n-butyl acrylate, 65 parts by mass of methyl acrylate, 12 parts by mass of glycidyl methacrylate, and 13 parts by mass of 2-hydroxyethyl acrylate ( Meth)acrylate copolymer (weight average molecular weight: 450,000, glass transition temperature: 2°C) (B) Curable component (thermosetting component) (B-1) Bisphenol A epoxy resin (manufactured by Mitsubishi Chemical Corporation, jER828, epoxy equivalent: 184 to 194 g/eq) (B-2) Acrylic rubber particle-dispersed bisphenol A type liquid epoxy resin (manufactured by Nippon Shokubai Co., Ltd., BPA328, epoxy equivalent: 230 g/eq, acrylic rubber content: 20 phr) (B-3) Dicyclopentadiene type epoxy resin (manufactured by DIC CORPORATION, EPICLON HP-7200HH, softening point 88~98°C, epoxy equivalent 255~260g/eq) (C) Curing agent: dicyandiamide (manufactured by Mitsubishi Chemical Corporation, DICY7) (D) Curing accelerator: 2-phenyl-4,5-dihydroxymethylimidazole (manufactured by SHIKOKU CHEMICALS CORPORATION, CUREZOL 2PHZ) (E) Filling material (E-1) Epoxy group-modified spherical silica filler (manufactured by Admatechs, SC2050MA, with an average particle size of 0.5 μm) (E-2) Silica filler (“YC100C-MLA” manufactured by Admatechs, with an average particle size of 0.1 μm) (F) Silane coupling agent: γ-glycidyloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM403, methoxyl equivalent: 12.7 mmol/g, molecular weight: 236.3) (G) Colorant: carbon black (manufactured by Mitsubishi Chemical Corporation, MA600B, average particle size: 28 nm)

[Table 2] blend Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Example 6 Example 7 Example 8 Example 9 polymer composition A-1 155 80 155 155 155 A-2 170 170 200 220 170 Curable ingredient B-1 5 5 5 5 5 5 5 5 B-2 55 55 55 55 55 55 55 55 55 55 B-3 40 40 50 60 45 35 40 45 45 45 Hardener C 1 1 1 1 1 1 1 1 1 1 curing accelerator D 1 1 1 1 1 1 1 1 1 1 Filler E-1 305 305 305 305 315 300 305 315 315 315 E-2 10 10 10 10 10 coupling agent F 2 2 2 2 2 2 2 2 2 2 Colorant G 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5

The prepared composition for forming a protective film was coated on the peeling treatment surface of the first peeling film (any one of the above A to C), and dried at 100° C. for 2 minutes to form a protective film with a thickness of 20 μm. membrane. Then, the 2nd peeling film was stuck on the protective film forming film, and the sheet for protective film forming of the three-layer structure in which the peeling film was formed in both surfaces of the protective film forming film was obtained. As attachment conditions, the temperature was 60° C., the pressure was 0.4 MPa, and the speed was 1 m/min. Then, the sheet for forming a protective film was cut into a width of 208 mm, and wound up to a length of 50 meters to form a roll body.

The following measurement and evaluation were performed using the obtained sheet for protective film formation.

[Adhesion between protective film forming films] The protective film forming film was exposed from the sheet for protective film forming as follows, and the protective film forming films were adhered to each other, and the adhesive force was measured.

<Fixing the protective film forming film to the adhesive tape> I. Peel off the 2nd release film of the sheet for protective film formation of the three-layer structure of the 2nd release film/protective film formation film/1st release film. II. At 23°C, an adhesive tape (product name PET50PL Shin: acrylic adhesive layer/50μm PET substrate) made by Lintec Corporation was attached to the exposed protective film forming film to prepare a "PET substrate/acrylic adhesive layer". A sample of the laminate of the agent layer/protective film forming film/first release film". III. Cut the laminate samples into strips 25mm wide and 250mm long.

<Fixing the protective film forming film to the SUS plate> I. A double-sided tape with a PET film as a core material was attached to the entire surface of a SUS plate (0.5 mm thick x 70 mm x 150 mm). II. Peel off the 2nd release film of the sheet for protective film formation of the three-layer structure of the 2nd release film/protective film formation film/1st release film. III. The exposed protective film-forming film was adhered to the entire surface of the adhesive surface of the double-sided tape to obtain a laminate sample of "SUS plate/double-sided tape/protective film-forming film/first release film". IV. Peel off the first release film to expose the protective film-forming film.

<Measurement of Adhesion> The 1st release film was peeled off from the laminated body sample of "PET base material/acrylic adhesive layer/protective film forming film/1st peeling film", and the protective film forming film was exposed. The laminated body of "PET base material/acrylic adhesive layer/protective film forming film" and the laminated body of "SUS plate/double-sided tape/protective film forming film" are laminated so that the protective film forming films face each other, Bonding was performed at 23 degreeC using the roll of 2 kg.

The adhesive force was measured by the following measurement method after standing for 2 minutes (±20 seconds) after sticking without heating. Using a universal tensile tester (manufactured by Shimadzu Corporation, product name "AUTOGRAPH AG-IS"), the peel force was measured at a measurement distance of 70 mm, a peeling speed of 300 mm/min, a temperature of 23°C, and a peeling angle of 180° . The average of the measured values between the first 10 mm and the last 10 mm and 50 mm, excluding the measurement distance, was taken as "the adhesion between the protective film forming films".

[Peeling force F1 at the time of peeling off the first peeling film from the protective film forming film] The second release film was peeled off from the obtained sheet for forming a protective film. By thermal lamination (70°C, 1 m/min), on the surface of the protective film-forming film exposed by peeling, a 25 μm thick adhesive PET (manufactured by TOYOBO Co., Ltd., PET25A-4100) was attached. Good adhesion surface to make a laminate sample. The laminate sample was cut into a width of 100 mm to prepare a sample for measurement. The back surface of the first release film of the sample for measurement was fixed to a rigid support plate using a double-sided tape.

Using a universal tensile tester (manufactured by Shimadzu Corporation, product name "AUTOGRAPH (registered trademark) AG-IS"), the protective film was formed by peeling off the first peeling film at a peeling angle of 180° and a peeling speed of 1 m/min. Composite (integrated) body of film/good adhesion PET, and the load at this time was measured. The measurement distance was 100 mm in total, and the average of the measured values between the first 10 mm and the last 10 mm and 80 mm was taken as the peeling force F1. The results are shown in Table 2.

[Peeling force F2 when peeling the second release film from the protective film forming film] The obtained sheet for forming a protective film was cut into a width of 100 mm to prepare a sample for measurement. The back surface of the first release film of the sample for measurement was fixed to a rigid support plate using a double-sided tape.

Using a universal tensile tester (manufactured by Shimadzu Corporation, product name "AUTOGRAPH (registered trademark) AG-IS"), the second release film was peeled off from the sample for measurement, and the measurement was performed under the same conditions as in the measurement of F1 above. The load is taken as the peeling force F2.

The obtained peel forces F1 and F2 were compared, and it was confirmed that F1 was larger than F2 for all the samples.

[Punching and scrap removal of sheet for forming protective film] RAD-3600F/12 manufactured by Lintec Corporation was used in the specification for 200mm wafers, the die was inserted from the second release film side of the sheet for protective film formation, and the protective film formation film and the second release film were punched out into circular shapes ( The inner diameter is 198mm). At this time, about the first release film, a notch is cut out so as to be incompletely punched (a punching process step). Half-cuts with different kerf widths are made using four types of dies with different blade widths of the cutting knives. 40 punching operations were performed.

After the punching process step, the sheet for forming a protective film is moved between a plurality of rolls. Then, the circularly punched part is left on the first release film, and the second release film and the peripheral useless part of the circularly punched part are removed (waste removal step). At this time, the second peeling film that has been completely cut by the punching process is rejoined with a long adhesive tape, and then the second peeling film is removed.

<Incision width> The sheet for forming a protective film after the scrap removal step was cut in the thickness direction so that the cut portion of the first release film was not deformed, and the sheet for forming a protective film was kept flat. VE-9800”) to observe the cross section. The width of the notch remaining on the first release film at the interface between the first release film and the protective film-forming film was measured.

The 20th part was selected from the 40 circular parts possessed, and the measurement was performed at 6 points (regular hexagon when the points are connected) at equal intervals on the circumference of the one circle. The minimum value of the 6 points is used as the "cut width". and round up to one decimal place.

The wider the incision width is, the more smoothly the scraps can be removed without the protective film forming films adhering to each other.

＜Evaluation of waste removability＞ At the time of the waste removal step, the number of sheets of the protective film-forming film of the circular portion that floated along with the useless portion was counted among the 40 circular portions possessed. The smaller the number of sheets that floated, the more smoothly the scrap removal was possible because the protective film forming films did not adhere to each other.

The above results are summarized in Table 3. [table 3] protective film forming film Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Example 6 Example 7 Example 8 Example 9 first release film A B B B B B C B B B Surface modulus of elasticity [MPa, at 23°C] 16 8 8 8 8 8 14 8 8 8 Adhesion [N/25mm] 13.6 13.6 10.5 7 18.3 twenty one 13.6 18.3 18.3 18.3 Peeling force F1 [mN/100mm] 125 120 105 90 135 180 125 135 135 135 Cut width [μm] 11 11 11 11 11 11 11 7 16 twenty two The number of defective chips in the evaluation of waste removal 2 1 0 0 4 10 1 6 1 0

From Table 3, it was confirmed that when the adhesion between the protective film forming films was 19 N or less, the protective film forming films did not adhere to each other after the punching process, and the scrap removal could be smoothly performed. In addition, as shown in Example 7, when the notch width is narrowed, the protective film-forming films tend to adhere to each other after the punching process, and the waste removal tends not to be performed smoothly. [industrial availability]

As described above, according to the present invention, it is possible to provide a sheet for forming a protective film and a method for producing the same, which can sufficiently suppress defects in scrap removal even when the notch width at the time of punching is narrow.

10: Sheet for forming protective film 11: Protective film forming film 12: The first release film 13: Second release film 14: Cut 16: The protective film formed by the punching process 17: Useless Parts 19: Roller 20: Sheet for forming protective film 21: Wafer 22: cutting piece 30: Wafer with protective film 31: Wafer 32: Protective film 33: convex electrode 50: Substrate D: width

1 is a schematic cross-sectional view of a sheet for forming a protective film according to an embodiment FIG. 2 is a schematic cross-sectional view showing a state in which the sheet for forming a protective film according to the embodiment is punched. 3 is a schematic cross-sectional view of a sheet for forming a protective film according to another embodiment. It is a cross-sectional schematic diagram which shows the state after the punching process of the sheet for protective film formation of another embodiment. FIG. 5 is a schematic perspective view of the protective film-forming sheet after the punching step. Fig. 6 is a schematic perspective view showing a waste removal step. 7 is a cross-sectional view showing a state in which the sheet for forming a protective film after a punching step has passed through a roll. 8 is a schematic cross-sectional view of an example of a wafer having a protective film obtained by converting the protective film forming film of the present embodiment into a protective film. FIG. 9 is a schematic cross-sectional view for explaining the step of attaching the sheet for forming a protective film of the present embodiment to a wafer. 10 is a schematic cross-sectional view for explaining a step of singulating a wafer with a protective film. 11 is a schematic cross-sectional view for explaining a step of arranging a wafer with a protective film on a substrate.

10: Sheet for forming protective film

11: Protective film forming film

12: The first release film

Claims (6)

A sheet for forming a protective film, which is a long sheet and has a protective film forming film and a first peeling film provided on one surface of the protective film forming film, wherein, The adhesive force after attaching two protective film-forming films at 23° C. for 2 minutes with a load of 2 kgf was 19 N/25 mm or less. The sheet for forming a protective film according to claim 1, wherein the surface elastic modulus of the surface of the first release film in contact with the protective film forming film is 17 MPa or less. The sheet for forming a protective film according to claim 1 or 2, wherein In the sheet for forming a protective film, a cutout is formed so that a part of the sheet for forming a protective film has a predetermined closed shape in plan view of the sheet for forming a protective film, The incision penetrates the protective film forming film in the thickness direction of the protective film forming sheet and reaches a part of the first release film. The sheet for forming a protective film according to claim 3, wherein the width of the cut at the interface between the protective film forming film and the first release film is 8 μm or more. A method for producing a punched sheet for forming a protective film, comprising the step of forming a notch so that a part of the sheet for forming a protective film according to claim 1 or 2 has a predetermined closed shape, The incision penetrates the protective film forming film in the thickness direction of the protective film forming sheet and reaches a part of the first release film. The manufacturing method of the sheet for forming a protective film which has been punched according to claim 5, wherein the width of the cut at the interface between the protective film forming film and the first release film is 8 μm or more.

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