Protective film forming sheet roll and method for manufacturing protective film forming sheet roll

Abstract

The present invention provides a protective film forming sheet roll and a manufacturing method thereof, which is less likely to generate a mark caused by winding of a protective film forming film that gives a mark to a protective film. In the protective film forming sheet roll and the manufacturing method thereof, the protective film forming sheet roll is a sheet roll in which a long sheet having a protective film forming film, a first release film provided on one face of the protective film forming film, and a second release film provided on the other face are wound, a peeling force of the first release film from the protective film forming film is set to F1, a peeling force of the second release film from the protective film forming film is set to F2, F1>F2, a loss tangent tan δ of the protective film forming film at 10°C is 10 1.2 or less, and A / tan δ 10 is 2.0 or more when a maximum displacement amount of the long sheet in a vertical direction is set to A [mm] when the long sheet after winding is subjected to a gravitational force in a direction in which a winding axis of the sheet roll is in a vertical direction.

Description

TECHNICAL FIELD

[0001] The present application relates to a protective film forming sheet roll and a method for manufacturing a protective film forming sheet roll. In particular, the present application relates to a protective film forming sheet roll and a method for manufacturing a protective film forming sheet roll, which are less likely to generate marks caused by winding of a protective film forming film that can bring marks to a protective film. BACKGROUND

[0002] In recent years, a semiconductor device is manufactured using a mounting method called flip chip bonding. In this mounting method, when mounting a semiconductor chip having a circuit surface on which a convex electrode such as a bump is formed, the circuit surface side of the semiconductor chip is turned upside down (face down) and is joined to a chip mounting portion. Therefore, the semiconductor device has a structure in which the back surface side of the semiconductor chip on which no circuit is formed is exposed.

[0003] Therefore, in order to protect the semiconductor chip from impact at the time of transportation or the like, a hard protective film formed of an organic material is often formed on the back surface side of the semiconductor chip. Such a protective film is formed by curing after attaching a protective film forming film to the back surface of a semiconductor wafer, for example, or is formed in a non-cured state.

[0004] The protective film forming film and a support film that supports the protective film forming film constitute a long sheet-shaped protective film forming sheet. Before use of the protective film forming film, the long sheet-shaped sheet is usually wound into a sheet roll. Also, when the protective film forming film is used, the long sheet-shaped protective film forming sheet unwound from the sheet roll is cut into a shape substantially the same as that of the semiconductor wafer to be attached, and is attached to the semiconductor wafer.

[0005] Patent Literature 1 discloses a long sheet-shaped adhesive sheet provided with a first sheet and a second sheet on both sides of an adhesive layer. The adhesive layer can be divided into a punched portion and a continuous waste portion, and the adhesive layer of the punched portion is attached as an adhesive film to the back surface of a semiconductor wafer, for example.

[0006] PRIOR ART DOCUMENTS

[0007] PATENT LITERATURE

[0008] Patent Literature 1: International Publication No. 2017 / 145735 SUMMARY

[0009] PROBLEMS TO BE SOLVED BY THE INVENTION

[0010] The manufactured long strip-shaped protective film forming sheet is fixed to the core by using a core fixing tape, and the long strip-shaped protective film forming sheet is wound by a winding device while a predetermined tension is applied to the long strip-shaped protective film forming sheet, thereby forming a protective film forming sheet roll. As a result, stress remains in the wound long strip-shaped protective film forming sheet (protective film forming sheet roll), and a winding pressure is generated in the direction toward the core. The winding pressure has a tendency to be greater in the protective film forming sheet near the core, i.e., the protective film forming sheet at which winding starts, and to be smaller in the protective film forming sheet on the outer periphery side of the sheet roll.

[0011] Further, due to the deviation of the tension at the time of winding and the like, even in the same protective film forming sheet roll, there are positions that are strongly pressed and positions that are slightly pressed, and in the wound protective film forming sheet, the positions that are pressed for a long time sometimes form a mark (a winding mark) due to winding. In particular, the winding pressure is greater at the position at which winding of the protective film forming sheet roll starts, and the winding pressure easily deviates from each other at the positions in the width direction after winding. Further, since a step due to the core fixing tape and the thickness of the protective film forming sheet is generated, the winding pressure due to the step becomes greater, or the winding pressure easily deviates in the width direction. Therefore, in the protective film forming sheet near the core after winding, a winding mark due to being partially strongly pressed is more likely to be generated than in the protective film forming sheet on the outer periphery side of the sheet roll. If such a winding mark is generated, a winding mark is also generated in the protective film forming film that constitutes the protective film forming sheet. As a result, when the protective film forming film is attached to a work and a protective film is formed, a winding mark remains, which causes appearance defects of the protective film.

[0012] However, there is a problem that even if the setting conditions of the winding device are adjusted when the sheet roll is formed, it is difficult to completely suppress a winding mark accompanying the deviation of the winding pressure and the like.

[0013] The present application is made in view of the above-described actual situation, and aims to provide a protective film forming sheet roll in which a winding mark due to winding of a protective film forming film that causes a winding mark to a protective film is less likely to be generated, and a method of manufacturing the protective film forming sheet roll.

[0014] Technical means for solving the technical problem

[0015] The present application is as described below.

[0016] [1] A protective film forming sheet roll formed by winding a long sheet having a protective film forming film, a first release film provided on one face of the protective film forming film, and a second release film provided on the other face of the protective film forming film,

[0017] When a peeling force of the first peeling film from the protective film forming film is set as F1 and a peeling force of the second peeling film from the protective film forming film is set as F2, a relationship of F1 > F2 is satisfied,

[0018] When a loss tangent of the protective film forming film at 10°C is set as tan δ 10 , tan δ 10 is 1.2 or less,

[0019] When a maximum displacement amount of the long sheet in the vertical direction is set as A [mm] when the long sheet after winding is subjected to the action of gravity in the direction in which the winding axis of the sheet roll is in the vertical direction, a relationship of A / tan δ 10 is 2.0 or more is satisfied.

[0020] [2] The protective film forming sheet roll according to [1], wherein a surface of the first peeling film and / or the second peeling film which does not contact the protective film forming film is subjected to a peeling treatment.

[0021] [3] The protective film forming sheet roll according to [1] or [2], wherein the maximum displacement amount A is 2 mm or more.

[0022] [4] The protective film forming sheet roll according to any one of [1] to [3], wherein tan δ 10 is 0.04 or more.

[0023] [5] A method of manufacturing a protective film forming sheet roll, which is a method of manufacturing the protective film forming sheet roll according to any one of [1] to [4], and which has:

[0024] A step of storing the protective film forming sheet roll at a storage temperature of 10°C or less for 25 days or more from 60 days after the protective film forming sheet roll is formed.

[0025] Effects of the Invention

[0026] According to the present application, a protective film forming sheet roll in which a trace is less likely to be generated and a method of manufacturing the same can be provided, the trace being caused by winding of a protective film forming film which gives a trace to a protective film. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1A A perspective view schematically showing one example of the protective film forming sheet roll of the present embodiment.

[0028] Figure 1B An enlarged cross-sectional view of the IB portion. Figure 1A

[0029] Figure 2 A schematic view for explaining the maximum displacement amount A of the long sheet. ​

[0030] Figure 3 A cross-sectional schematic view of one example of the protective film forming sheet of the present embodiment.

[0031] Figure 4 A cross-sectional schematic view to show that the first release film and the second release film have the first release agent layer and the second release agent layer.

[0032] Figure 5 A perspective schematic view of the long sheet of the protective film forming sheet wound from the protective film forming sheet roll of the present embodiment and formed with a notch.

[0033] Figure 6A A cross-sectional schematic view to show that the laminate of the protective film forming film and the first release film is attached to the workpiece.

[0034] Figure 6B A cross-sectional schematic view to show that the protective film forming film attached to the workpiece is protected.

[0035] Explanation of Reference Numerals

[0036] 100: protective film forming sheet roll; 1: protective film forming sheet; 10: protective film forming film; 20: first release film; 21: base material; 22, 23: first release agent layer; 30: second release film; 31: base material; 32: second release agent layer; 70: core; 80: fixing tool. DETAILED DESCRIPTION

[0037] Hereinafter, the present application will be described in detail based on specific embodiments using the drawings.

[0038] First, the main terms used in the present specification will be explained.

[0039] The workpiece is a plate-like body to which the protective film forming film is attached and which is to be processed. As the workpiece, for example, a wafer, a panel can be cited. Specifically, a semiconductor wafer, a semiconductor panel can be cited. As the processed product of the workpiece, for example, a chip obtained by singulating a wafer can be cited. Specifically, a semiconductor chip obtained by singulating a semiconductor wafer can be cited. At this time, the protective film is formed on the back surface side of the wafer.

[0040] The "surface" of the workpiece refers to a face on which a circuit, a bump, or the like, a convex electrode, or the like, is formed, and the "back surface" refers to a face on which a circuit or the like is not formed.

[0041] In the present specification, for example, "(meth)acrylate" is used as a term to indicate both "acrylate" and "methacrylate", and other similar terms are the same.

[0042] In the present specification, the weight ratio of the components constituting each composition is expressed as a solid content ratio.

[0043] (1. Sheets for forming protective films)

[0044] like Figure 1A As shown, the protective film forming roll 100 of this embodiment is a roll formed by winding a long strip used to form a protective film.

[0045] In this embodiment, the strip is a protective film forming sheet having a protective film forming film, a first release film formed on one main surface of the protective film forming film, and a second release film formed on the other main surface of the protective film forming film. The strip is sometimes referred to as protective film forming sheet 1 below. Details of the strip are described below.

[0046] like Figure 1B As shown, the long strip is fixed to the core 70 by a fixing tool 80 such as core fixing tape. Then, the long strip is wound around the core 70 while applying a specified tension using a winding device, thereby forming the protective film forming roll 100. As described above, deviations in winding pressure occur in the completed roll, especially at the locations where the long strip is strongly compressed near the core, which can easily form roll marks on the protective film forming film that can leave marks on the protective film.

[0047] On the other hand, it is speculated that after the film roll is formed, i.e., after winding is completed, the winding pressure at the high winding pressure position gradually decreases over time and approaches the winding pressure at the low winding pressure position. In other words, it is speculated that the deviation in winding pressure will be eliminated over time, and the winding pressure in the film roll will be stabilized (averaged). Therefore, although the deviation in winding pressure in the film roll will eventually be largely eliminated, the curl marks formed before the deviation in winding pressure is eliminated will still remain in the protective film forming film even after the deviation in winding pressure is eliminated.

[0048] Therefore, based on the above speculation, this embodiment controls the characteristics of the film and protective film formation in the film roll in the following manner before the winding pressure in the film roll is stabilized, thereby suppressing the generation of roll marks and promoting the stabilization of winding pressure.

[0049] (1.1 Smoothness of the strip)

[0050] To promote the stabilization of winding pressure, it is necessary to distribute the winding pressure that is concentrated in areas of high winding pressure. For example... Figure 1B As shown, in the protective film forming roll 100, the strips are stacked along the radial direction and are in direct contact with each other. Therefore, even in positions with high winding pressure, as long as the contacting strips can move relative to each other, the strips slide in the direction where the winding pressure decreases, and the winding pressure is dispersed.

[0051] However, if the strips are in strong contact with each other (high winding pressure), they are difficult to move relative to each other because they do not easily slip. On the other hand, if the strips are in slight contact with each other (low winding pressure), they are easy to move relative to each other because they easily slip. Therefore, it is necessary to consider the winding pressure of the roll and set the smoothness of the strips to a specified relationship.

[0052] In this embodiment, the parameter representing the smoothness of the strip considering the winding pressure of the roll is the maximum displacement of the strip wound around the core in the vertical direction when subjected to gravity, in a direction where the winding axis of the roll is vertical. Specifically, as Figure 2 As shown, with only the core 70 of the protective film forming roll supported, the protective film forming roll 100 is lifted 150 mm in a direction with the winding axis O of the protective film forming roll 100 vertical, and held for a predetermined time. After the predetermined time, the maximum amount by which the strip slides from the top of the core is taken as the maximum displacement of the strip. This maximum displacement is... Figure 2 In this context, A[mm] is used to represent the value.

[0053] For the maximum displacement A, even if the materials and dimensions of the films constituting the strip (protective film forming film, release film, etc.) are the same, the maximum displacement A will change if the winding conditions (tension, etc.) when winding the strip are different. That is, the maximum displacement A takes into account the specified winding conditions and is a parameter that reflects the smoothness of the strip in the roll.

[0054] The inventors of this application have discovered that by ensuring a specified relationship between the maximum displacement A and the loss tangent of the protective film forming film at 10°C (described later), roll marks can be suppressed while simultaneously stabilizing the winding pressure. As a result, roll marks are less likely to occur in the protective film forming film of the roll, particularly on the long strips near the core. Therefore, defects in the appearance of the protective film are avoided, and the long strips wound into rolls can be used without waste. Furthermore, the loss tangent of the protective film forming film at 10°C is a parameter related to the generation of roll marks.

[0055] Specifically, if the loss tangent of the protective film formation at 10℃ is set as tanδ 10 Then A / tanδ 10 It is above 2.0. A / tanδ 10 Preferably, the values ​​are 10 or higher, 40 or higher, 90 or higher, or 200 or higher. Additionally, A / tanδ... 10 There is no particular limit to the upper limit, but in this embodiment, it is preferably below 3750, below 1500, or below 750.

[0056] Furthermore, in this embodiment, the maximum displacement A is preferably 2 mm or more, 4 mm or more, 10 mm or more, 20 mm or more, 35 mm or more, or 50 mm or more. By setting the lower limit of the maximum displacement A to the above values, the stabilization of the winding pressure can be further promoted. Additionally, the maximum displacement A is preferably 150 mm or less, less than 150 mm, less than 125 mm, or less than 100 mm. By setting the upper limit of the maximum displacement A to the above values, it is possible to prevent the wound strip from accidentally slipping and deviating from the core during operation, causing the strip to fall off the core and reducing the operability of the roll.

[0057] (2. Sheet for forming protective film)

[0058] Next, the protective film forming sheet for the long strip sheet, which is the subject of this embodiment, will be described. For example... Figure 3 As shown, the protective film forming sheet 1, which is a strip, has a first release film 20 disposed on one main surface 10a of the protective film forming film 10 and a second release film 30 disposed on the other main surface 10b. The protective film forming sheet 1 is used to attach the protective film forming film to a workpiece. After the protective film forming film is attached to the workpiece, it becomes a protective film, forming a protective film for protecting the workpiece or a workpiece being processed.

[0059] In this embodiment, in order to attach the protective film to the workpiece, a protective film forming sheet is unwound from a protective film forming sheet roll and cut into a specified shape. Then, the protective film is attached to the back of the workpiece and protected.

[0060] (3. Protective film formation)

[0061] As described above, after the protective film is attached to the workpiece, it becomes a protective film for protecting the workpiece or the processed part of the workpiece.

[0062] "Protective film formation" refers to the process of making a protective film form a state in which it possesses sufficient properties to protect a workpiece or a processed part of the workpiece. Specifically, when the protective film form is curable, "protective film formation" means turning an uncured protective film form into a cured product. In other words, a protective film formed through protective film formation is a cured product of the protective film form, and it is different from the protective film form itself.

[0063] After the workpiece is stacked on the curable protective film, the protective film can be firmly bonded to the workpiece by curing the protective film, thus forming a durable protective film.

[0064] On the other hand, when the protective film forming film does not contain curable components and is used in a non-cured state, the protective film forming film is protected when it is attached to the workpiece. In other words, the protected film forming film after being protected is the same as the original protective film forming film.

[0065] When high protective performance is not required, it is easy to use a protective film forming film because there is no need to cure the protective film.

[0066] In this embodiment, the protective film is preferably curable. Therefore, the protective film is preferably a cured product. Examples of cured products include, for example, thermosetting products and energy-cured products. In this embodiment, the protective film is more preferably a thermosetting product.

[0067] Furthermore, the protective film forming film preferably exhibits adhesiveness at room temperature (23°C) or by heating. This allows for the bonding of workpieces when they are stacked on the protective film forming film. Therefore, precise positioning can be achieved before the protective film forming film cures.

[0068] The protective film can consist of a single layer or multiple layers. When the protective film has multiple layers, these layers can be the same or different from each other, and there are no particular restrictions on the combination of the layers that make up these multiple layers.

[0069] In this embodiment, the protective film is preferably formed as a single layer. A single-layer protective film can achieve high precision in thickness, thus facilitating production. Furthermore, if the protective film consists of multiple layers, the adhesion between layers and the elasticity of each layer must be considered, posing a risk of peeling off from the adhered object. A single-layer protective film reduces these risks and increases design flexibility.

[0070] There is no particular limitation on the thickness of the protective film, but it is preferably less than 100 μm, 70 μm or less, 45 μm or less, or 30 μm or less. By setting the upper limit of the thickness of the protective film to the above values, the step difference caused by the thickness of the protective film forming sheet at the start of winding can be reduced.

[0071] Furthermore, the thickness of the protective film is preferably 5 μm or more, 10 μm or more, or 15 μm or more. By setting the lower limit of the thickness of the protective film to the above values, it is easy to obtain the performance of protecting the workpiece as a protective film. Furthermore, in the protective film forming roll, the protective film forms a stress-relieving effect, which can further shorten the distance from the core where the curling marks begin to appear.

[0072] In addition, the thickness of the protective film refers to the overall thickness of the protective film. For example, the thickness of a protective film consisting of multiple layers refers to the total thickness of all the layers that make up the protective film.

[0073] (3.1 Loss tangent of protective film formation at 10℃)

[0074] In this embodiment, the protective film at 10°C forms the loss tangent (tanδ). 10 The loss tangent is 1.2 or less. The loss tangent is defined as "loss modulus / storage modulus," a value measured using a dynamic viscoelasticity measuring device based on the response to stress applied to an object. By keeping the loss tangent of the protective film forming film within the above range at 10°C, the components constituting the protective film forming film become slightly elastic, and the protective film forming film is less prone to deformation. Therefore, it tends to be less prone to wrinkles even under high winding pressure of the film roll. Furthermore, by storing the film at a temperature below room temperature (23°C) until the winding pressure of the film roll stabilizes, wrinkles on the protective film forming film in the film roll are easily suppressed. Therefore, this embodiment controls the loss tangent of the protective film forming film at 10°C.

[0075] The loss tangent of the protective film formed at 10℃ (tanδ) 10 Preferably, the loss tangent (tanδ) of the protective film formed at 10°C is 1.0 or less, more preferably 0.9 or less, and even more preferably 0.8 or less. Furthermore, the loss tangent of the protective film formed at 10°C is... 10 The value is preferably 0.04 or higher, more preferably 0.1 or higher, even more preferably 0.2 or higher, and particularly preferably 0.3 or higher. By setting the lower limit of the loss tangent of the protective film formed at 10°C to the above-mentioned value, the phenomenon of cracking of the bent protective film formed in the roll at 10°C can be prevented.

[0076] The loss tangent of the protective film formed at 10℃ (tanδ) 10 The elastic modulus can be determined using well-known methods. For example, the protective film forming film can be prepared into a sample of a specified size. Using a dynamic viscoelasticity measuring device, strain is applied to the sample at a specified frequency within a specified temperature range to determine the elastic modulus. Based on the measured elastic modulus, the loss tangent (tanδ) at 10°C can be calculated. 10 The specific measurement methods will be described in detail in the examples described later.

[0077] (3.2 Composition for forming protective film)

[0078] The composition of the protective film forming film is not particularly limited as long as the protective film forming film possesses the aforementioned physical properties. In this embodiment, the composition constituting the protective film forming film (the composition for forming the protective film) is preferably a resin composition containing at least a polymer component (A), a curing component (B), and a filler material (E). The polymer component can be considered as a component formed by the polymerization reaction of a polymeric compound. Furthermore, the curing component is a component capable of undergoing a curing (polymerization) reaction. In addition, the polymerization reaction in this invention also includes a condensation polymerization reaction.

[0079] Furthermore, components included in polymer compositions are sometimes also curable components. In this embodiment, when the composition for forming a protective film contains such a component that is both a polymer component and a curable component, it is considered that the composition for forming a protective film contains both a polymer component and a curable component.

[0080] (3.2.1 Polymer composition)

[0081] The polymer component (A) imparts film-forming properties to the protective film while providing adequate adhesion, ensuring that the protective film adheres uniformly to the workpiece. The weight-average molecular weight of the polymer component is typically in the range of 50,000 to 2,000,000, preferably 100,000 to 1,500,000, and particularly preferably 200,000 to 1,000,000. Examples of such polymer components include acrylic resins, urethane resins, phenoxy resins, silicone resins, and saturated polyester resins; acrylic resins are particularly preferred.

[0082] Furthermore, unless otherwise stated, in this specification, "weight-average molecular weight" refers to the converted value of polystyrene determined by gel permeation chromatography (GPC). This determination can be performed, for example, using a high-performance GPC apparatus "HLC-8120GPC" manufactured by TOSOH CORPORATION, sequentially connected to a high-performance column "TSK guardcolumn H". XL -H”, TSK Gel GMH XL "TSK Gel G2000 H" XL (All of the above are manufactured by TOSOH CORPORATION) The detector is set as a differential refractometer under the conditions of column temperature: 40℃ and injection rate: 1.0mL / min.

[0083] Examples of acrylic resins include copolymers of methacrylates composed of methacrylate monomers and structural units derived from methacrylate derivatives. Here, alkyl methacrylate monomers with 1 to 18 carbon atoms in the alkyl group are preferred examples; specifically, methyl methacrylate, ethyl methacrylate, propyl methacrylate, and butyl methacrylate are examples. Furthermore, examples of methacrylate derivatives include methacrylic acid, glycidyl methacrylate, and hydroxyethyl methacrylate.

[0084] In this embodiment, glycidyl methacrylate or similar materials are preferably used to introduce glycidyl groups into the acrylic resin. The introduction of glycidyl groups into the acrylic resin improves its compatibility with the epoxy resin, which is described later as a thermosetting component, and tends to easily form a stable protective film. Furthermore, in this embodiment, to control the adhesion or stickiness to the workpiece, hydroxyl groups are preferably introduced into the acrylic resin using hydroxyl groups such as hydroxyethyl acrylate.

[0085] The preferred glass transition temperatures of the acrylic resin are -70~40℃, -35~35℃, -20~30℃, -10~25℃, and -5~20℃. By setting the lower limit of the glass transition temperature of the acrylic resin to the above values, it is easier to reduce the tanδ of the protective film. 10 Furthermore, by setting the upper limit of the glass transition temperature of the acrylic resin to the aforementioned value, the viscosity of the protective film is moderately increased, thereby improving the adhesion between the protective film and the workpiece, and also moderately increasing the bonding strength between the protective film and the workpiece.

[0086] When an acrylic resin has m types of structural units (m being an integer greater than or equal to 2), the glass transition temperature of the acrylic resin can be calculated as follows. That is, when each of the m monomers from which the structural units in the acrylic resin are derived is assigned a unique number from 1 to m and named "monomer m", the glass transition temperature (Tg) of the acrylic resin can be calculated using the Fox formula shown below.

[0087] [Mathematical Expression 1]

[0088]

[0089] In the formula, Tg is the glass transition temperature of acrylic resin; m is an integer greater than or equal to 2; Tgk is the glass transition temperature of the homopolymer of monomer m; Wk is the mass fraction of structural unit m derived from monomer m in acrylic resin, wherein Wk satisfies the following formula.

[0090] [Mathematical Expression 2]

[0091]

[0092] In the formula, m and Wk are the same as those mentioned above.

[0093] As for Tgk, values ​​recorded in polymer datasheets, adhesive datasheets, or polymer handbooks can be used. For example, the Tgk of homopolymers of methyl acrylate is 10°C, the Tgk of homopolymers of n-butyl acrylate is -54°C, the Tgk of homopolymers of methyl methacrylate is 105°C, the Tgk of homopolymers of 2-hydroxyethyl acrylate is -15°C, the Tgk of homopolymers of glycidyl methacrylate is 41°C, and the Tgk of 2-ethylhexyl acrylate is -70°C.

[0094] When the total weight of the composition for forming the protective film is set to 100 parts by mass, the content of the polymer component is preferably 5-80 parts by mass, 8-70 parts by mass, 10-60 parts by mass, 12-55 parts by mass, 14-50 parts by mass, or 15-45 parts by mass. By keeping the content of the polymer component within the above ranges, the viscosity of the protective film-forming film is moderately improved, and the adhesion between the protective film-forming film and the workpiece is also moderately improved. Furthermore, it tends to easily suppress the formation of curling marks.

[0095] (3.2.2 Thermosetting components)

[0096] The curing component (B) forms a hard protective film by curing the protective film-forming film. Thermosetting components, energy-curing components, or mixtures thereof can be used as the curing component. When cured by irradiation with energy rays, the light transmittance of the protective film-forming film decreases due to the presence of fillers and colorants, as described later. Therefore, for example, if the thickness of the protective film-forming film increases, energy-ray curing may become insufficient.

[0097] On the other hand, thermosetting protective film-forming films can be fully cured by heating even when the thickness increases, thus forming protective films with high protective performance. Furthermore, by using common heating equipment such as heating ovens, many protective film-forming films can be heated simultaneously to achieve thermosetting.

[0098] Therefore, in this embodiment, it is desirable that the curable component is thermosetting. That is, the protective film forming film is preferably thermosetting.

[0099] The thermosetting nature of a protective film can be determined as follows: First, the protective film, initially at room temperature (23°C), is heated to a temperature exceeding room temperature, and then cooled to room temperature, resulting in a heated and cooled protective film. Next, the hardness of the heated and cooled protective film is compared with the hardness of the unheated protective film at the same temperature. The film that is harder after heating and cooling is considered thermosetting.

[0100] As thermosetting components, epoxy resins, thermosetting polyimide resins, unsaturated polyester resins, and mixtures thereof are preferred. Thermosetting polyimide resins refer to the general term for polyimide precursors and thermosetting polyimides that can be thermocured to form polyimide resins.

[0101] The epoxy resin, as a thermosetting component, has the property of forming a three-dimensional network structure and a strong coating when heated. Various known epoxy resins can be used as such an epoxy resin. 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, or 300 or more and less than 3,000. Furthermore, the epoxy equivalent of the epoxy resin is preferably 50 to 5,000 g / eq, more preferably 100 to 2,000 g / eq, and even more preferably 150 to 1,000 g / eq.

[0102] Specifically, examples of the aforementioned epoxy resins include glycidyl ethers of phenols such as bisphenol A, bisphenol F, resorcinol, phenyl novolac, and cresol novolac; glycidyl ethers of alcohols such as butanediol, polyethylene glycol, and polypropylene glycol; glycidyl ethers of carboxylic acids such as phthalic acid, isophthalic acid, and tetrahydrophthalic acid; glycidyl-type or alkyl-glycidyl-type epoxy resins formed by replacing the active hydrogen bonded to the nitrogen atom with a glycidyl group in aniline isocyanurate, etc.; and so-called alicyclic epoxides such as vinylcyclohexane diepoxide, 3,4-epoxycyclohexylmethyl-3,4-dicyclohexane carboxylate, and 2-(3,4-epoxy)cyclohexyl-5,5-spiro(3,4-epoxy)cyclohexane-me-dioxane, which introduce epoxy groups by oxidizing the carbon-carbon double bonds within the molecule. In addition, epoxy resins with biphenyl backbone, dicyclohexadiene backbone, naphthalene backbone, etc., can also be used.

[0103] When using a thermosetting component as the curing component (B), it is preferable to simultaneously use a curing agent (C) as an additive. For epoxy resins, a thermoactive latent epoxy resin curing agent is preferred. "Thermoactive latent epoxy resin curing agent" refers to a type of curing agent that does not readily react with epoxy resin at room temperature (23°C) but is activated by heating to a certain temperature or higher and reacts with the epoxy resin. Activation methods for thermoactive latent epoxy resin curing agents include: methods that utilize heating-based chemical reactions to generate active species (anions, cations); methods that stably disperse in epoxy resin near room temperature and then become compatible with and dissolve in epoxy resin at high temperatures to initiate a curing reaction; methods that initiate a curing reaction after dissolving a molecular sieve-encapsulated curing agent at high temperatures; and microencapsulation-based methods, etc.

[0104] In the illustrated methods, it is preferable to use a method in which the epoxy resin is stably dispersed near room temperature, and then the epoxy resin is compatible with and dissolved at high temperature to begin a curing reaction.

[0105] Specific examples of thermoactive latent epoxy resin curing agents include various onium salts or dicarboxylic acid diacid hydrazides, dicyandiamide, amine adduct curing agents, imidazole compounds, and other high-melting-point active hydrogen compounds. These thermoactive latent epoxy resin curing agents can be used alone or in combination of two or more. Dicyandiamide is particularly preferred in this embodiment.

[0106] Furthermore, phenolic resins are preferred as curing agents for epoxy resins. As phenolic resins, condensates of phenols and aldehydes such as alkylphenols, polyphenols, and naphthols can be used without particular restriction. Specifically, phenolic varnish resins, o-cresol varnish resins, p-cresol varnish resins, tert-butylphenol varnish resins, dicyclopentadiene cresol resins, poly(p-vinylphenol) resins, bisphenol A type phenolic varnish resins, or modified versions thereof can be used.

[0107] The phenolic hydroxyl groups contained in these phenolic resins can easily undergo an addition reaction with the epoxy groups of the aforementioned epoxy resins upon heating, thereby forming a cured product with high impact resistance.

[0108] The content of curing agent (C) relative to 100 parts by weight of epoxy resin is preferably 0.01 to 30 parts by weight, 0.1 to 20 parts by weight, 0.2 to 15 parts by weight, or 0.3 to 10 parts by weight. By setting the content of curing agent (C) within the above range, it is easy to obtain the performance of protecting the workpiece as a protective film.

[0109] When using dicyandiamide as a curing agent (C), it is further preferable to simultaneously use a curing accelerator (D). As a curing accelerator, imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole (imidazoliums in which one or more hydrogen atoms are substituted by groups other than hydrogen atoms) are preferred. Among these, 2-phenyl-4,5-dihydroxymethylimidazole is particularly preferred.

[0110] The preferred content of the curing accelerator relative to 100 parts by weight of epoxy resin is 0.01–30 parts by weight, 0.1–20 parts by weight, 0.2–15 parts by weight, or 0.3–10 parts by weight. By setting the content of the curing accelerator (D) within the above range, it is easy to obtain the performance of protecting the workpiece as a protective film.

[0111] When the total weight of the composition for forming the protective film is set to 100 parts by mass, the total content of the thermosetting component and the curing agent is preferably 3 to 80 parts by mass, 5 to 60 parts by mass, 7 to 50 parts by mass, 9 to 40 parts by mass, or 10 to 30 parts by mass. If the thermosetting component and the curing agent are mixed in this proportion, the protective film can easily achieve the performance of protecting the workpiece.

[0112] (3.2.3 Energy-based components that can be solidified by radiation)

[0113] When the curing component (B) is an energy-curing component, the energy-curing component is preferably uncured, preferably adhesive, and more preferably uncured and adhesive.

[0114] Energy-curable components are components that are cured by irradiation with energy rays. They are used to impart film-forming properties, flexibility, etc., to the protective film.

[0115] As an energy-curing component, a compound having an energy-curing group is preferred, for example. Known compounds can be cited as examples of such compounds.

[0116] (3.2.4 Filler Material)

[0117] By including a filler material (E) in the protective film forming film, it becomes easier to adjust the coefficient of thermal expansion of the resulting protective film. By making this coefficient of thermal expansion close to that of the workpiece, the adhesion reliability to the workpiece is further improved. Furthermore, by including a filler material (E) in the protective film forming film, a rigid protective film can be easily obtained, achieving the performance of protecting the workpiece, thereby reducing the moisture absorption rate of the protective film.

[0118] The filler material (E) can be either an organic filler material or an inorganic filler material. From the perspective of shape stability at high temperatures such as 260°C, an inorganic filler material is preferred.

[0119] Preferred inorganic filler materials include, for example, powders of silica, alumina, talc, calcium carbonate, red iron oxide, silicon carbide, and boron nitride; beads formed by spherizing these inorganic filler materials; surface-modified versions of these inorganic filler materials; single-crystal fibers of these inorganic filler materials; and glass fibers. Among these, silica and surface-modified silica are preferred. Surface-modified silica is preferably surface-modified using a coupling agent, and more preferably using a silane coupling agent.

[0120] The average particle size of the filler material is preferably 0.02–10 μm, 0.05–5 μm, or 0.10–3 μm.

[0121] By ensuring that the average particle size of the filler material falls within the aforementioned range, the operability of the composition for forming a protective film becomes favorable. Consequently, the quality of both the composition for forming a protective film and the protective film formed is easily stabilized.

[0122] In addition, unless otherwise stated, "average particle size" in this specification refers to the particle size (D50) at the 50% cumulative value in the particle size distribution curve obtained by laser diffraction scattering.

[0123] When the total weight of the composition for forming the protective film is set to 100 parts by mass, the content of the filler material is preferably 15-80 parts by mass, 30-75 parts by mass, 40-70 parts by mass, or 45-65 parts by mass.

[0124] By setting the lower limit of the filler material content to the above value, it is possible to easily reduce the tanδ of the protective film formation. 10 Furthermore, by setting the upper limit of the filler material content to the aforementioned value, there is a tendency to improve the adhesion between the protective film and the workpiece, and to moderately improve the adhesion between the protective film and the workpiece.

[0125] (3.2.5 Coupling agent)

[0126] The protective film forming film preferably contains a coupling agent (F). By including a coupling agent, the adhesion between the protective film and the workpiece can be improved after the protective film has cured without compromising the heat resistance of the protective film, while also improving water resistance (damp heat resistance). From the perspective of versatility and cost advantages, silane coupling agents are preferred as coupling agents.

[0127] Examples of silane coupling agents include γ-glycidyl etheroxypropyltrimethoxysilane, γ-glycidyl etheroxypropylmethyldiethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-(methacryloyloxypropyl)trimethoxysilane, γ-aminopropyltrimethoxysilane, N-6-(aminoethyl)-γ-aminopropyltrimethoxysilane, N-6-(aminoethyl)-γ-aminopropylmethyldiethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-ureapropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldiethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfide, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, imidazole silane, etc. These silane coupling agents can be used alone or in combination of two or more.

[0128] (3.2.6 Colorant)

[0129] The protective film preferably contains a colorant (G). This can shield the back of the workpiece such as a chip, thereby blocking various electromagnetic waves generated in electronic devices and reducing malfunctions of the workpiece such as a chip.

[0130] As the colorant (G), known pigments such as inorganic pigments, organic pigments, and organic dyes can be used. In this embodiment, inorganic pigments are preferred.

[0131] Inorganic pigments include, for example, carbon black, cobalt pigments, iron pigments, chromium pigments, titanium pigments, vanadium pigments, zirconium pigments, molybdenum pigments, ruthenium pigments, platinum pigments, ITO (indium tin oxide) pigments, and ATO (antimony tin oxide) pigments. Carbon black is particularly preferred because it can block electromagnetic waves over a wide wavelength range.

[0132] The amount of colorant (especially carbon black) incorporated into the protective film forming film can vary 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 colorant incorporated relative to the total mass of the protective film forming film is preferably 0.01–10% by mass, 0.04–7% by mass, or 0.07–4% by mass. By keeping the amount of colorant incorporated within the above range, there is a tendency for the traces of the protective film caused by the rolling marks of the protective film forming sheet to be inconspicuous in appearance.

[0133] The average particle size of the colorant (especially carbon black) is preferably 1 to 500 nm, particularly preferably 3 to 100 nm, and even more preferably 5 to 50 nm. If the average particle size of the colorant is within the above range, the transmittance can be easily controlled within the desired range.

[0134] (3.2.7 Other additives)

[0135] Without impairing the effects of the present invention, the protective film forming composition may also contain, for example, photopolymerization initiators, crosslinking agents, plasticizers, antistatic agents, antioxidants, impurities, tackifiers, release agents, etc. as other additives.

[0136] (4. First peeling membrane)

[0137] The first release film is a film capable of supporting the protective film forming film in a peelable manner. In this embodiment, it is preferable to peel the first release film from the protective film forming film after the protective film forming film has been attached to the workpiece.

[0138] The first release film can consist of one (single) or two or more substrates. From the perspective of controlling peelability, the surface of the substrate can be treated for peelability. That is, the surface of the substrate can be modified, or a material not derived from the substrate can be formed on the surface of the substrate.

[0139] In this embodiment, the first release film preferably has a substrate and a first release agent layer. By having a first release agent layer, the physical properties of the surface of the first release film on which the first release agent layer is formed can be easily controlled.

[0140] Furthermore, in this embodiment, it is preferable that, in addition to forming the first release agent layer on the surface of the first release film on the protective film forming film side, a first release agent layer is also formed on its opposite side. That is, as shown... Figure 4 As shown, in the protective film forming sheet 1, the first release film 20 has a substrate 21 and first release agent layers 22 and 23 formed on two main surfaces of the substrate 21. The main surface 20b of the first release film (the main surface 20b of the first release agent layer 22) is in contact with the main surface 10a of the protective film forming film. The first release agent layer 22 and the first release agent layer 23 may be composed of the same composition or different compositions.

[0141] In the roll, since the strips are stacked along the radial direction, the surface 20a of the first release film that is not in contact with the protective film and the surface 30b of the second release film that is not in contact with the protective film come into contact. Therefore, in the first release film, by subjecting the surface 20a that is not in contact with the protective film to a release treatment (by forming a first release agent layer 23), the contacting strips can easily slide against each other, thus promoting the stabilization of the winding pressure.

[0142] In the first release film, the first release agent layer is preferably formed directly on the surface of the substrate. By forming the first release agent layer directly on the surface of the substrate, the production of the first release film becomes easier, thus reducing costs.

[0143] Furthermore, when forming the first release agent layer on two main surfaces of the substrate, the coating agent containing the composition for the first release agent layer (described later) can be applied to both main surfaces of the substrate to form the first release agent layer, or the coating agent containing the composition for the first release agent layer can be applied to one main surface of the substrate, and the substrate can be wound into a roll. The first release agent layer is formed on the main surface without the coating agent by utilizing the phenomenon (transfer phenomenon) where the components of the composition for the first release agent layer transfer from the main surface with the coating agent to the main surface without the coating agent.

[0144] The thickness of the first release film is not particularly limited, but is preferably 30 μm or more and 100 μm or less. Furthermore, the thickness of the first release film is more preferably 40 μm or more, and even more preferably 45 μm or more. Moreover, the thickness of the first release film is more preferably 80 μm or less, and even more preferably 70 μm or less.

[0145] By setting the lower limit of the thickness of the first release film to the aforementioned value, when a cut is made using the cutting blade described later to reach a portion of the first release film, it is possible to prevent the cutting blade from penetrating the first release film and cutting it. Furthermore, in the protective film forming roll, the first release film acts as a stress buffer, which can further shorten the distance from the core where roll marks begin to appear.

[0146] Furthermore, after the protective film forming sheet is unwound and the protective film forming film is cut, before being transported to the next process, the protective film forming sheet passes through guide rollers and other rollers within the apparatus. At this time, by setting the upper limit of the thickness of the first release film to the aforementioned value, it is possible to prevent the protective film forming film from peeling off from the first release film. This, in turn, reduces the step difference caused by the thickness of the protective film forming sheet at the starting position of winding.

[0147] Furthermore, the thickness of the first release film refers to the overall thickness of the first release film. For example, the thickness of a first release film composed of multiple layers refers to the total thickness of all the layers constituting the first release film.

[0148] In the first release film, for example, it can be determined whether the substrate has undergone a release treatment in the following manner. When the first release agent layer contains the silicone-based release agent described below, surface analysis of the two main surfaces of the first release film is performed using X-ray photoelectron spectroscopy (XPS). The ratio of silicon atoms is calculated based on the obtained spectrum. If it is above a specified value, it is determined that the substrate has undergone a release treatment. The specific measurement method will be described in detail in the examples described later.

[0149] Furthermore, when the substrate is composed of a polyethylene terephthalate film (described later), the water contact angle is measured on both main surfaces of the first release film. If the contact angle is above a specified value, it is determined that the release treatment has been performed. The specific measurement method will be described in detail in the examples described later.

[0150] Furthermore, in this embodiment, when the peeling force for peeling the first release film from the protective film forming film is set as F1 in the protective film forming sheet, and the peeling force for peeling the second release film from the protective film forming film (described later) is set as F2, F1 and F2 satisfy the relationship F1 > F2. By satisfying this relationship, when the second release film is removed from the protective film forming sheet, the protective film forming film 10 that should remain is not removed along with the second release film, and the protective film forming film 10 is easily left on the first release film.

[0151] Therefore, the first peeling membrane is a heavy peeling membrane, and the second peeling membrane is a light peeling membrane.

[0152] In this embodiment, F1 and F2 are load values ​​measured using a tensile testing machine. The specific measurement method will be described in detail in the embodiments described later.

[0153] The following describes the case where the first release film has a substrate and a first release agent layer.

[0154] (4.1 Substrate)

[0155] The substrate of the first release film is not particularly limited as long as it is a material that can support the protective film before it is attached to the workpiece. It is usually composed of a film with resin as the main material (hereinafter referred to as "resin film").

[0156] Specific examples of resin films include polyethylene films, polypropylene films, polybutene films, polybutadiene films, polymethylpentene films, polyvinyl chloride films, vinyl chloride copolymer films, polyethylene terephthalate films, polyethylene naphthalate films, polybutylene terephthalate films, polyurethane films, ethylene vinyl acetate copolymer films, ionomer resin films, ethylene-(meth)acrylate copolymer films, ethylene-(meth)acrylate copolymer films, polystyrene films, polycarbonate films, polyimide films, fluoropolymer films, etc. Furthermore, cross-linked films using these films can also be used. Further, laminated films of these films can also be used. In this embodiment, from the perspectives of environmental safety, cost, and suppressing the rolling up that accompanies the extension of the substrate, polyethylene terephthalate films are preferred.

[0157] For the substrate, the above-mentioned resin film may contain various additives such as colorants, flame retardants, plasticizers, antistatic agents, lubricants, and fillers.

[0158] The thickness of the substrate is not particularly limited as long as it functions appropriately in each step of the protective film forming process and is within the range of the thickness of the first release film. The substrate thickness is preferably 30 μm or more and 100 μm or less. Furthermore, the substrate thickness is more preferably 40 μm or more, and even more preferably 45 μm or more. Furthermore, the substrate thickness is more preferably 80 μm or less, and even more preferably 70 μm or less.

[0159] (4.2 First stripping agent layer)

[0160] The first release agent layer imparts peelability to the first release film, allowing it to peel off from the protective film forming film. Furthermore, when the first release agent layer is formed on the surface of the first release film not in contact with the protective film forming film, it imparts smoothness to the contacted strip. There are no particular limitations as long as the first release agent layer is made of a material capable of imparting peelability. In this embodiment, the first release agent layer can be obtained by curing a first release agent layer containing a release agent with a composition.

[0161] Furthermore, when a first release agent layer is formed on the surface that is not in contact with the protective film, the first release agent layer formed on the surface in contact with the protective film and the first release agent layer formed on the surface that is not in contact with the protective film can be composed of the same composition or different compositions.

[0162] The thickness of the first release agent layer is not particularly limited, but is preferably 30 nm to 200 nm. Furthermore, the thickness of the first release agent layer is more preferably 50 nm or more, and even more preferably 80 nm or more. Moreover, the thickness of the first release agent layer is more preferably 180 nm or less.

[0163] By ensuring the thickness of the first release agent layer is within the aforementioned range, stable peeling performance can be achieved when the protective film is attached to the workpiece.

[0164] (4.3 Composition for the first release agent layer)

[0165] In this embodiment, the composition for the first release agent layer may include, for example, alkyd release agents, silicone release agents, fluorinated release agents, unsaturated polyester release agents, polyolefin release agents, and wax release agents, wherein, preferably, it includes silicone release agents. When the composition for the first release agent layer includes silicone release agents, it preferably includes both silicone release agents and heavy-release additives.

[0166] (4.3.1 Organosilicon-based mold release agents)

[0167] As a silicone-based mold release agent, a silicone mold release agent incorporating silicone with dimethyl polysiloxane as the basic framework can be used.

[0168] When the total weight of the composition for the first stripping agent layer (excluding the catalyst described later) is set to 100 parts by mass, the content of organosilicon formed from dimethylpolysiloxane is preferably less than 100 parts by mass, less than 90 parts by mass, less than 80 parts by mass, or less than 70 parts by mass.

[0169] The silicone can be any of the addition reaction type, condensation reaction type, and energy-curing type such as ultraviolet curing and electron beam curing, with addition reaction type silicone being preferred. Addition reaction type silicone has high reactivity and excellent productivity, and compared with condensation reaction type silicone, it has the advantages of small changes in peel force after manufacturing and no curing shrinkage.

[0170] As a specific example of addition-reaction type organosilicon, organopolysiloxanes with two or more alkenyl groups having 2 to 10 carbon atoms, such as vinyl, allyl, propenyl, and hexenyl, at the end of the molecule and / or on the side chains can be listed.

[0171] When using this type of addition-reaction organosilicon, it is preferable to use both a crosslinking agent and a catalyst simultaneously.

[0172] As a crosslinking agent, examples include organopolysiloxanes having at least two hydrogen atoms bonded to silicon atoms in one molecule.

[0173] Specific examples of crosslinking agents include dimethylsiloxane-methylhydrosiloxane copolymers with methylhydrosiloxane end caps, trimethylsiloxane-methylhydrosiloxane copolymers with methylhydrosiloxane end caps, trimethylsiloxane-methylhydropolysiloxanes with methylhydrosiloxane end caps, and poly(hydrosilsesquioxane).

[0174] Examples of catalysts include particulate platinum, particulate platinum adsorbed on a carbon powder support, chloroplatinic acid, alcohol-modified chloroplatinic acid, olefinic complexes of chloroplatinic acid, palladium, and platinum group metal compounds such as rhodium.

[0175] By using the catalyst described above, the curing reaction of the composition for the first release agent layer can be carried out more effectively.

[0176] From the perspective of keeping the peeling force F1 within the above range, when the total weight of the composition (excluding the catalyst) for the first release agent layer is set to 100 parts by mass, the content of the silicone release agent is preferably 30 to 100 parts by mass or 50 to 100 parts by mass.

[0177] (4.3.2 Heavy stripping additive)

[0178] The heavy-release additive is used to increase the peeling force F1 of the first release film being peeled off from the protective film forming film. Examples of heavy-release additives include silicone resins, silane coupling agents, and other organosilanes, with silicone resins being preferred.

[0179] As an organosilicon resin, it is preferred to use, for example, a siloxane unit [R3SiO] containing a monofunctional siloxane unit. 1 / 2 The M unit of ] and the tetrafunctional siloxane unit [SiO] 4 / 2 The MQ resin has a Q unit. Furthermore, the three Rs in the M unit independently represent a hydrogen atom, a hydroxyl group, or an organic group. From the perspective of easily suppressing organosilicon transfer, one or more of the three Rs in the M unit are preferably hydroxyl or vinyl, more preferably vinyl.

[0180] When the total weight of the composition (excluding catalyst) for the first stripping agent layer is set to 100 parts by mass, the content of the heavy stripping additive is preferably 0 to 50 parts by mass, 5 to 45 parts by mass, or 10 to 40 parts by mass.

[0181] Without impairing the effects of the present invention, the composition for the first release agent layer may contain commonly used additives in the release agent layer. Examples of such additives include dyes and dispersants.

[0182] Furthermore, from the perspective of adjusting the peeling force to a lower level and from the perspective of making it easier to form a release agent layer that utilizes the above-mentioned transfer phenomenon, silicone oil can be added to the composition for the first release agent layer.

[0183] (5. Second peeling membrane)

[0184] The second release film is a film capable of supporting the protective film forming film in a peelable manner. In this embodiment, it is preferable to peel the second release film from the protective film forming film before attaching the protective film forming film to the workpiece.

[0185] Similar to the first release film, the second release film can consist of one (single) or two or more substrates. From the perspective of controlling peelability, the surface of the substrate can be treated for peelability. That is, the surface of the substrate can be modified, or a material not derived from the substrate can be formed on the surface of the substrate.

[0186] In this embodiment, the second release film preferably has a substrate and a second release agent layer. By having a second release agent layer, the physical properties of the surface of the second release film on which the second release agent layer is formed can be easily controlled.

[0187] Furthermore, in this embodiment, the second release agent layer is formed on the side of the protective film forming film of the second release film. That is, as shown... Figure 4 As shown, in the protective film forming sheet 1, the second release film 30 has a substrate 31 and a second release agent layer 32 formed on the protective film forming film side surface of the substrate 31. The main surface 30a of the second release film (the main surface 30a of the second release agent layer 32) is in contact with the main surface 10b of the protective film forming film. In addition to forming the second release agent layer on the protective film forming film side surface of the second release film, the second release agent layer may also be formed on its opposite side surface 30b.

[0188] Furthermore, when forming the second release agent layer on two main surfaces of the substrate, the coating agent containing the composition for the second release agent layer (described later) can be applied to both main surfaces of the substrate to form the second release agent layer, or the coating agent containing the composition for the second release agent layer can be applied to one main surface of the substrate, and the substrate can be wound into a roll. The second release agent layer is formed on the uncoated main surface by utilizing the phenomenon (transfer phenomenon) where the components of the composition for the second release agent layer transfer from the main surface coated with the coating agent to the main surface uncoated with the coating agent.

[0189] Similar to the first release film, in the second release film, the second release agent layer is preferably formed directly on the surface of the substrate. By forming the second release agent layer directly on the surface of the substrate, the production of the second release film becomes easier, thus reducing costs.

[0190] The thickness of the second release film is not particularly limited, but is preferably 10 μm or more and 75 μm or less. Furthermore, the thickness of the second release film is more preferably 18 μm or more, and even more preferably 24 μm or more. Furthermore, the thickness of the second release film is more preferably 60 μm or less, and even more preferably 45 μm or less. From the perspective of ensuring that the peeling force F2 and the peeling force F1 are such that F1 > F2 as described above, the thickness of the second release film is preferably less than or equal to the thickness of the first release film, and more preferably less than the thickness of the first release film.

[0191] Furthermore, the thickness of the second release film refers to the overall thickness of the second release film. For example, the thickness of a second release film composed of multiple layers refers to the total thickness of all the layers constituting the second release film.

[0192] (5.1 Substrate)

[0193] The substrate of the second release film may be appropriately selected from the materials exemplified as the substrate of the first release film.

[0194] (5.2 Second stripping agent layer)

[0195] When the second release film has a second release agent layer, there are no particular limitations as long as the second release agent layer is made of a material that can impart release properties. For example, similar to the first release agent layer, the second release agent layer can be obtained by curing a composition containing a silicone-based release agent into the second release agent layer.

[0196] The second release agent layer composition can be selected from the materials exemplified in the first release agent layer composition, provided that the relationship between F1 and F2 described above is satisfied. Preferably, the content of the material exemplified as a heavy-release additive is less than or does not contain it in the first release agent layer composition.

[0197] Furthermore, from the perspective of adjusting the peeling force to a lower level and from the perspective of making it easier to form a release agent layer that utilizes the above-mentioned transfer phenomenon, silicone oil can be added to the composition for the second release agent layer.

[0198] (6. Method for manufacturing a protective film roll)

[0199] The manufacturing method for the protective film forming roll in this embodiment is not particularly limited, and known methods can be used. For example, firstly, a release agent layer composition (a first release agent layer composition and a second release agent layer composition) for forming the first release film and the second release film is prepared. In this embodiment, from the perspective of adjusting the viscosity to improve the coatability to the substrate, it is preferable to apply a coating agent containing the release agent layer composition comprising the above-mentioned components, diluted with a diluent solvent, to the substrate.

[0200] Examples of diluents include aromatic hydrocarbons such as toluene, fatty acid esters such as ethyl acetate, ketones such as methyl ethyl ketone, and aliphatic hydrocarbons such as hexane and heptane. These diluents can be used individually or in combination.

[0201] The solid content concentration of the coating agent containing the composition for the first release agent layer is preferably 0.3 to 10% by mass, more preferably 0.5 to 5% by mass, and even more preferably 0.5 to 3% by mass. The solid content concentration of the coating agent containing the composition for the second release agent layer is the same as that of the coating agent containing the composition for the first release agent layer.

[0202] In this embodiment, after applying a coating agent containing a composition for a first release agent layer to one side of a substrate using a known method, the first release agent layer is formed by drying and curing the coating. This yields a first release film. A second release film can also be produced in the same manner.

[0203] Then, when forming the release agent layer on the two main surfaces of the substrate, the release agent layer coating agent can be applied to the other surface of the substrate. Alternatively, it can be formed by winding the first release film formed by applying the release agent layer coating agent into a roll, and storing it at 30°C for 7 days, for example, to utilize the above-mentioned transfer phenomenon to transfer the components of the release agent layer composition to the other surface.

[0204] A protective film forming film composition is prepared for forming a protective film forming film. In this embodiment, in the same manner as the composition for the release agent layer, a coating agent prepared by diluting the protective film forming film composition with a diluting solvent is preferably applied to the release film. The type of diluting solvent is only required to be the same as that for the composition for the release agent layer.

[0205] On the other hand, the concentration of the solid component of the coating agent comprising the composition for forming a protective film is preferably 20 to 80% by mass, more preferably 30 to 70% by mass.

[0206] In this embodiment, a coating agent containing a protective film forming composition is applied to the first release agent layer of the first release film or the second release agent layer of the second release film using a known method, and then heated and dried to form a coating film. Next, the second release agent layer of the second release film or the first release agent layer of the first release film is bonded onto the coating film to manufacture a protective film forming sheet (strip). In this embodiment, from the perspective of ensuring that the peel force F1 is within the aforementioned range and that F1 > F2, it is preferable to apply the coating agent containing the protective film forming composition to the first release agent layer of the first release film, rather than the second release agent layer.

[0207] Examples of coating methods for coating agents comprising the various compositions include spin coating, spray coating, bar coating, doctor blade coating, roller coating, roller-type doctor blade coating, scraper coating, mold coating, and gravure coating.

[0208] While adjusting the width direction dimensions by cutting the two sides of the manufactured protective film forming sheet according to the size of the workpiece to which the protective film is to be applied, a winding device is used to apply a specified tension to wind the sheet, thereby producing a protective film forming roll. When the workpiece width is 150mm, the length in the width direction after cutting is preferably in the range of 155 to 194mm; when the workpiece width is 200mm, the length in the width direction after cutting is preferably in the range of 205 to 250mm; when the workpiece width is 300mm, the length in the width direction after cutting is preferably in the range of 305 to 350mm; and when the workpiece width is 450mm, the length in the width direction after cutting is preferably in the range of 455 to 500mm.

[0209] As mentioned above, deviations in the winding pressure of a freshly wound film can result in areas of intense compression. However, when the protective film forming film has a low loss tangent and is not easily deformed, even with deviations in winding pressure, it is less likely to form wrinkles on the protective film forming film. Furthermore, lower temperatures make it easier to maintain a low loss tangent in the protective film forming film. Moreover, as mentioned above, the winding pressure in the film tends to stabilize over time.

[0210] Therefore, in this embodiment, in order to suppress the formation of roll marks on the protective film forming film in the film roll, the freshly wound film roll is stored for a specified time until the winding pressure stabilizes, and the loss tangent of the protective film forming film is maintained at a low level. Specifically, it is preferable to store the film roll for 60 days after its formation, and during these 60 days, the film roll is stored at a storage temperature below 10°C for at least 25 days. In this embodiment, it is preferable to store the film roll at a storage temperature below 10°C for at least 30 days, 35 days, or 40 days during these 60 days.

[0211] The storage period at a storage temperature below 10°C preferably begins within 10 days after the film roll is formed, more preferably within 7 days, and even more preferably within 4 days. Since freshly wound film rolls tend to have large deviations in winding pressure, maintaining a low loss tangent of the protective film forming film can further suppress the formation of curl marks on the protective film forming film in the film roll.

[0212] Furthermore, the storage temperature is preferably -10°C or higher, more preferably -5°C or higher, and even more preferably 0°C or higher. By setting the lower limit of the storage temperature to the above values, the elastic modulus of the protective film forming film can be prevented from becoming too high, and peeling between the protective film forming film and the release film, especially between the protective film forming film and the second release film, can be prevented.

[0213] After the above storage process, the protective film forming roll of this embodiment can be obtained. For the protective film forming roll of this embodiment, the loss tangent tanδ of the protective film forming film at 10°C is... 10 When the value is 1.2 or less, and the wound strip is subjected to gravity in a direction where the winding axis of the sheet is vertical, the maximum displacement of the strip in the vertical direction is set as A [mm], satisfying A / tanδ. 10 With a relationship of 2.0 or higher, even when the protective film forming sheet is unwound from the protective film forming sheet roll of this embodiment to form a protective film, the formation of roll marks on the protective film forming film up to the core side can be suppressed. Therefore, defects in the appearance of the protective film are suppressed, and the protective film forming sheet roll of this embodiment can be used up without waste.

[0214] (7. Manufacturing method of the device)

[0215] As an example of the manufacturing method of the apparatus for forming a protective film roll using the present embodiment, a method for manufacturing a chip with a protective film obtained by processing a wafer with a protective film forming film attached will be described.

[0216] First, such as Figure 5 As shown, a long strip is unwound from the protective film forming roll 100, and a cutting blade 50 is used to form a cut 40 on the long strip that penetrates the second release film 30 and the protective film forming film 10 and reaches a portion of the first release film 20. By removing the second release film and unwanted protective film forming film from the long strip with the cut 40 formed, a circular protective film forming film can be obtained.

[0217] Next, as Figure 6A As shown, a circular protective film 11 is attached to the back surface 60b of the wafer 60, which serves as the workpiece. Figure 6B As shown, a first release film 20 is peeled off from the laminate, and a protective film forming film 11 is applied to form a protective film 15. Next, the wafer with the protective film is individually die-cast to obtain a chip with the protective film. Alternatively, the protective film can be applied after the wafer is individually die-cast.

[0218] Because it suppresses the formation of curl marks on the protective film, marks are also suppressed on the surface of the protective film. Therefore, a chip with a protective film can be obtained in which appearance defects of the protective film are suppressed.

[0219] (8. Variations)

[0220] Figure 4 The following configuration is shown: in the first release film 20, a first release agent layer 23 is formed on the surface 20a that is not in contact with the protective film forming film 10; in the second release film 30, a second release agent layer is not formed on the surface 30b that is not in contact with the protective film forming film 10, but this embodiment is not limited to this configuration.

[0221] For example, it can also be configured such that: in the first release film, a first release agent layer is formed on the surface that does not form a film with the protective film; and in the second release film, a second release agent layer is formed on the surface that does not form a film with the protective film. Alternatively, it can be configured such that: in the first release film, no first release agent layer is formed on the surface that does not form a film with the protective film; and in the second release film, a second release agent layer is formed on the surface that does not form a film with the protective film.

[0222] also, Figure 5 In this process, although the cut for forming the protective film to be attached to the workpiece is circular, it can be any other shape as long as it is a closed shape. Examples of other shapes include polygons such as triangles and ellipses. Furthermore, it is preferable that the closed shape corresponds to the shape of the workpiece.

[0223] The embodiments of the present invention have been described above, but the present invention is not limited to any of the above embodiments and can be modified in various ways within the scope of the present invention.

[0224] Example

[0225] The invention will now be described in more detail using examples, but the invention is not limited to these examples.

[0226] (Preparation of the first release membrane)

[0227] First, in order to prepare the composition for the first release agent layer, the following components are prepared.

[0228] (α) Organosilicon release agents

[0229] (α-1) Organosilicon release agent containing organopolysiloxanes with vinyl groups and organopolysiloxanes with hydrosilyl groups (manufactured by Dow Corning Toray Co., Ltd., BY24-561, solids content 30% by mass)

[0230] (α-2)dimethylpolysiloxane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: X-62-1387, weight average molecular weight: 2000)

[0231] (β) Organosilicon resin

[0232] MQ resin containing vinyl groups (manufactured by Dow Corning Toray Co., Ltd., SD-7292, solids content 71% by mass)

[0233] (γ) catalyst

[0234] Platinum (Pt) catalyst (manufactured by Dow Corning Toray Co., Ltd., SRX-212, 100% by mass of solids)

[0235] Next, 67.5 parts by mass (solid component ratio) of (α-1), 2.5 parts by mass (solid component ratio) of (α-2), 30 parts by mass (solid component ratio) of (β), and 6.7 parts by mass (solid component ratio) of (γ) were mixed and diluted with a mixed solvent of toluene and methyl ethyl ketone (toluene / methyl ethyl ketone = 1 / 1 (mass ratio)) to a solid component concentration of 2% by mass, to prepare a coating agent containing a composition for a first release agent layer.

[0236] In Experimental Examples 1 to 6, a coating agent containing the prepared first release agent layer forming composition was coated onto two main surfaces of a PET film (manufactured by Mitsubishi Chemical Corporation, trade name: DIAFOIL (registered trademark) T-100, thickness: 50 μm) as a substrate, after heating and drying, to form a first release agent layer on the two main surfaces of the PET film, thereby producing a first release film.

[0237] In Experimental Examples 7 and 8, a coating agent containing the prepared first release agent layer forming composition was coated onto a main surface of a PET film (manufactured by Mitsubishi Chemical Corporation, trade name: DIAFOIL (registered trademark) T-100, thickness: 50 μm) as a substrate, after heating and drying, to form a first release agent layer on a main surface of the PET film, thereby producing a first release film, which was then wound into a roll.

[0238] In Experimental Example 9, the coating agent containing the first release agent layer forming composition was not applied to the two main surfaces of the PET film (manufactured by Mitsubishi Chemical Corporation, trade name: DIAFOIL (registered trademark) T-100, thickness: 50 μm), and no release treatment was performed.

[0239] (Preparation of the second release membrane)

[0240] In Experiments 1-6, a PET film with one side having undergone a peeling treatment was used as the second release film ("SP-PET381031" manufactured by Lintec Corporation, 38 μm thick).

[0241] In Experiments 7 and 8, 35 parts by mass (solid content ratio) of an addition-reaction silicone release agent containing polyorganohydrosiloxane (trade name "KS-3656A", solid content: 30% by mass, manufactured by Shin-Etsu Chemical Co., Ltd.) as a crosslinking agent and 1 part by mass (solid content ratio) of a platinum catalyst (trade name "PL50T", manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed and diluted with a solid content concentration of 2% by mass using a mixed solvent of toluene and methyl ethyl ketone (toluene / methyl ethyl ketone = 1 / 1 (mass ratio)) to prepare a coating agent containing a second release agent layer. Next, the coating agent containing the prepared second release agent layer forming composition is coated onto one main surface of a PET film (manufactured by Mitsubishi Chemical Corporation, trade name: DIAFOIL (registered trademark) T-100, thickness: 38 μm) as a substrate, after heating and drying, to form a second release agent layer on one main surface of the PET film, thereby producing a second release film. The wound roll of the second release film is stored at 30°C for 7 days, and a release process is performed on both main surfaces of the PET film using the transfer phenomenon from the coated side to the uncoated side.

[0242] In Experimental Example 9, the coating agent containing the composition for forming the second release agent layer was not applied to the two main surfaces of the PET film (manufactured by Mitsubishi Chemical Corporation, trade name: DIAFOIL (registered trademark) T-100, thickness: 38 μm). That is, the PET film whose two main surfaces had not undergone release treatment was used as the second release film.

[0243] (Preparation of the protective film)

[0244] The following components are mixed according to the mixing ratios (conversion of solid components) shown in Table 1, and diluted with methyl ethyl ketone to a solid component concentration of 50% by mass to prepare a coating agent containing a protective film forming composition.

[0245] (A) Polymer composition

[0246] (A-1) A (meth)acrylate copolymer (weight average molecular weight: 400,000, glass transition temperature: -1℃) is formed by copolymerizing 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.

[0247] (A-2) A (meth)acrylate copolymer (weight average molecular weight: 450,000, glass transition temperature: 2℃) is formed by copolymerizing 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.

[0248] (A-3) A (meth)acrylate copolymer (weight average molecular weight: 800,000, glass transition temperature: -28℃) is formed by copolymerizing 55 parts by weight of n-butyl acrylate, 10 parts by weight of methyl acrylate, 20 parts by weight of glycidyl methacrylate and 15 parts by weight of 2-hydroxyethyl acrylate.

[0249] (A-4) A (meth)acrylate copolymer (weight average molecular weight: 500,000, glass transition temperature: -9°C) is formed by copolymerizing 27 parts by weight of n-butyl acrylate, 38 parts by weight of methyl acrylate, 20 parts by weight of glycidyl methacrylate and 15 parts by weight of 2-hydroxyethyl acrylate.

[0250] (A-5) A (meth)acrylate copolymer (weight average molecular weight: 500,000, glass transition temperature: -2℃) is formed by copolymerizing 17 parts by weight of n-butyl acrylate, 48 parts by weight of methyl acrylate, 20 parts by weight of glycidyl methacrylate and 15 parts by weight of 2-hydroxyethyl acrylate.

[0251] (B) Curing components (thermosetting components)

[0252] (B-1) Bisphenol A type epoxy resin (manufactured by Mitsubishi Chemical Corporation, jER828, epoxy equivalent 184~194g / eq)

[0253] (B-2) Acrylic rubber microparticle-dispersed bisphenol A type liquid epoxy resin (manufactured by NIPPON SHOKUBAI CO.,LTD., BPA328, epoxy equivalent 230g / eq, acrylate rubber content 20phr)

[0254] (B-3) Dicyclopentadiene type epoxy resin (manufactured by DIC CORPORATION, EPICLON HP-7200HH, softening point 88~98℃, epoxy equivalent 255~260g / eq)

[0255] (C) Curing agent: Dicyandiamide (manufactured by Mitsubishi Chemical Corporation, DICY7)

[0256] (D) Curing accelerator: 2-Phenyl-4,5-dihydroxymethylimidazol (manufactured by SHIKOKU CHEMICALS CORPORATION, CUREZOL 2PHZ)

[0257] (E) Filler material

[0258] (E-1) Epoxy-modified spherical silica filler (manufactured by Admatechs, SC2050MA, average particle size 0.5μm)

[0259] (E-2) Silica filler (manufactured by Admatechs, YC100C-MLA, average particle size 0.1μm)

[0260] (F) Silane coupling agent: γ-glycidyl etheroxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM403, methoxy equivalent 12.7 mmol / g, molecular weight 236.3)

[0261] (G) Colorant: Carbon black (manufactured by Mitsubishi Chemical Corporation, MA600B, average particle size 28nm)

[0262] A coating agent containing the prepared protective film forming composition was applied to the surface of the first release film on which the first release agent layer was formed, and dried at 100°C for 2 minutes to form a protective film forming film with a thickness of 20 μm. Next, the surface of the prepared second release film on which the second release agent layer was formed (the reverse side of the surface on which the release agent layer was formed using a transfer phenomenon in Examples 7 and 8) was attached to the protective film forming film, thereby obtaining a protective film forming sheet (a structure of first release film / protective film forming film / second release film) with a first release film formed on one main surface and a second release film formed on the other main surface. The attachment conditions were: temperature 60°C, pressure 0.4 MPa, and speed 1 m / min.

[0263] (Production of film rolls)

[0264] While using a biaxial winding and slitting machine (manufactured by TOIZAKI BUSSAN CO.,LTD.), the protective film forming sheets of Experimental Examples 1 to 9 were cut to a width of 320 mm. Simultaneously, using a core-fixing tape with a width of 5 mm and a thickness of 40 μm, the cut protective film forming sheets were wound in rolls onto a hollow plastic core (core) under the winding conditions a to d described below. This plastic core (core) had the same width (320 mm) as the cut protective film forming sheet and a diameter of 3 inches. That is, in each experimental example, four types of rolls were formed under four different winding conditions. The length of the wound protective film forming sheet was 50 m. The cutting speed was 5 m / min.

[0265] In winding condition a, the ammeter of the magnetic powder brake used to control the tension during winding shows 0.25A; in winding condition b, the ammeter shows 0.30A; in winding condition c, the ammeter shows 0.35A; and in winding condition d, the ammeter shows 0.40A. The higher the current value displayed by the magnetic powder brake ammeter, the greater the tension, and the more firmly the protective film forming sheet is wound.

[0266] The wound protective film forming sheet is left to stand at 23°C for 3 days after winding, then at 5±4°C for 40 days, and then at 23°C for 17 days to obtain the protective film forming sheet roll.

[0267] Next, the following measurements and evaluations were conducted.

[0268] (The loss tangent of the protective film formation at 10℃ is tanδ) 10 )

[0269] The first and second release films are peeled off from the prepared protective film forming sheet, and multiple protective film forming films are stacked to form a laminate of protective film forming films with a thickness of 200 μm ± 20 μm. The laminate is then cut with a width of 4 mm to obtain the test sample.

[0270] Using a viscoelasticity measuring apparatus (RHEOVIBRON DDV-01FP manufactured by ORIENTEC Co., Ltd.), the tanδ of the test specimens used for the above-mentioned tests was measured in tensile mode at a frequency of 11 Hz, a clamping distance of 15 mm, and a heating rate of 3 °C / min. The loss tangent tanδ at 10 °C was then calculated based on these values. 10 The test results of the samples in Experiments 1 to 9 are shown in Table 1.

[0271] (Evaluation of the presence or absence of a stripping treatment for the release membrane)

[0272] Unwind the protective film forming sheet from the obtained roll, and cut three 50mm×50mm protective film forming sheets along the width direction at a position 1m away from the starting part where the protective film forming sheet is fixed to the plastic core by the core fixing tape.

[0273] The first and second release films were peeled off from the cut protective film forming sheet. XPS measurements were performed on the surfaces of the first release film that were not adhered to the protective film forming film under the following conditions. Similarly, XPS measurements were performed on the surfaces of the second release film that were not adhered to the protective film forming film under the following conditions. One XPS measurement was performed on each of the three first release films and three second release films obtained by cutting the protective film forming sheet.

[0274] XPS unit: ULVAC-PHI, INCORRORRATED. QuaneraSXM manufactured.

[0275] X-rays: AlKα (1486.6 eV)

[0276] Removal angle: 45°

[0277] Elements measured: Silicon (Si), Carbon (C), Oxygen (O)

[0278] Based on the obtained measurement results, the silicon atom ratios shown below were calculated for the first and second stripping films according to the measured element amounts (XPS counts), and their average values ​​were calculated.

[0279] Silicon atomic ratio (atomic %) = [(Si elemental mass) / [(C elemental mass) + (O elemental mass) + (Si elemental mass)]] × 100

[0280] Based on the obtained average value, the following judgment criteria were used for evaluation. Judgment A and Judgment B were judged as having undergone peeling treatment. The measurement results of the samples of Experimental Examples 1 to 9 are shown in Table 1.

[0281] Judgment A: The average value of at least one of the first and second release films is 1.0 atomic% or more.

[0282] Criterion B: Criterion A is not met; the average value of at least one of the first and second release films is greater than 0.1 atomic% and less than 1.0 atomic%.

[0283] Criterion C: The average value of the first and second release films is less than 0.1 atomic percent.

[0284] A first release film is prepared before applying a coating agent containing a protective film-forming composition, and three 50mm x 50mm sections are cut from the first release film along its width. Using the XPS apparatus described above, the presence or absence of a release treatment is evaluated on the two main surfaces of the first release film to which the coating agent containing the protective film-forming composition is to be applied, under the same conditions as described above.

[0285] For the first release film samples of Experimental Examples 1-9, the average value of the silicon atomic ratio at 3 locations was confirmed to be above 1.0 atomic%.

[0286] Prepare a second release film to be attached before the protective film is formed, and cut three 50mm x 50mm sections along the width of the second release film. Using the XPS apparatus described above, evaluate whether the surface of the second release film to be attached to the protective film is subjected to a peeling process under the same conditions as described above.

[0287] For the second release film samples of Experimental Examples 1-9, the average value of the silicon atomic ratio at 3 locations was confirmed to be above 1.0 atomic%.

[0288] (Evaluation of the water contact angle of the stripping membrane)

[0289] Unwind the protective film forming sheet from the obtained roll, and cut three 50mm×50mm protective film forming sheets along the width direction at a position 1m away from the starting part where the protective film forming sheet is fixed to the plastic core by the core fixing tape.

[0290] The first and second release films were peeled off from the cut protective film forming sheet. The water contact angle of the surface of the first release film that was not adhered to the protective film forming film was measured under the following conditions. Similarly, the water contact angle of the surface of the second release film that was not adhered to the protective film forming film was measured under the following conditions. The water contact angle of each of the three first release films and three second release films obtained by cutting the protective film forming sheet was measured five times.

[0291] Contact angle measuring device: Kyowa Interface Science, Inc., DM-701 fully automatic contact angle meter

[0292] Dropping volume: 2μL

[0293] Environment: Temperature 23℃, Humidity 50%

[0294] The average values ​​of the measured results were calculated for both the first and second peeling films. Based on these average values, the following criteria were used for evaluation. Case A was considered to have undergone peeling treatment. The measured results for samples from Examples 1 to 9 are shown in Table 1.

[0295] Judgment A: The average value of at least one of the first and second release films is 78 or higher.

[0296] Judgment C: The average value of the first and second release films is below 77.

[0297] (The peeling force F1 that peels the first peeling film off the protective film forming film)

[0298] The second release film is peeled off from the obtained protective film forming sheet. A 25 μm thick layer of well-adhesive PET (manufactured by TOYOBO Co., Ltd., PET25A-4100) with a good adhesion surface is attached to the surface of the protective film forming film exposed by the peeling process using hot lamination (70°C, 1 m / min), thereby producing a laminated sample. The laminated sample is cut into 100 mm wide pieces to prepare a sample for testing. The back side of the first release film of the sample for testing is fixed to a rigid support plate using double-sided tape.

[0299] Using a universal tensile testing machine (manufactured by Shimadzu Corporation, product name "AUTOGRAPH (registered trademark) AG-IS"), the protective film forming film / well-bonded PET composite (integrated type) was peeled from the first release film at a measuring distance of 100 mm, a peel angle of 180°, and a peel speed of 1 m / min, and the load at this time was measured. The average value of the loads measured over 80 mm, excluding the loads in the first and last 10 mm of the measuring distance, was taken as the peel force F1.

[0300] (The peeling force F2 that peels the second peeling film off the protective film forming film)

[0301] The obtained protective film sheet was cut into 100mm wide pieces to prepare the test sample. The back of the first release film of the test sample was fixed to a rigid support plate using double-sided tape.

[0302] Using a universal tensile testing machine (manufactured by Shimadzu Corporation, product name "AUTOGRAPH (registered trademark) AG-IS"), the second release film was peeled from the test sample at a measurement distance of 100 mm, a peel angle of 180°, and a peel speed of 1 m / min, and the load at this time was measured. The average value of the loads over 80 mm, excluding the loads in the first and last 10 mm of the measurement distance, was taken as the peel force F2.

[0303] Comparing the obtained peel forces F1 and F2, it was confirmed that F1 was greater than F2 for all samples.

[0304] (Evaluation of the smoothness of the strip)

[0305] In each experimental example, the protective film forming sheet obtained by winding conditions a to d was placed on a horizontal worktable with the winding axis as the vertical direction. With only the core supported, the protective film forming sheet was lifted to a height of 150 mm at a speed of 150 mm / min. The wound strip was subjected to gravity and held for 1 minute.

[0306] like Figure 2 As shown, after holding for 1 minute, when the height of the upper end of the core is set to 0, the maximum displacement A is defined as the maximum amount of vertical downward displacement of the upper end of the strip that is at the same horizontal plane as the upper end of the core. Furthermore, when the lower end of the strip contacts the worktable, the maximum displacement A is 150 mm. The evaluation results of the four types of rolls wound under winding conditions a to d in each experimental example are shown in Table 1.

[0307] In addition, except for setting the length in the width direction to 305mm and 335mm, the same evaluation was performed on the rolls produced under the same conditions, and the results confirmed that the maximum displacement A hardly changed.

[0308] (Evaluation of the creases)

[0309] From the protective film forming rolls that have undergone smoothness evaluation, long strips are unwound from the outermost layer at a speed of 3 m / min, and the "length from the core" at which roll marks outside the permissible range begin to appear is measured. Five judges simultaneously visually confirm whether a roll mark outside the permissible range is present; if three judges determine it to be outside the permissible range, it is considered a roll mark outside the permissible range. The evaluation results of the four types of rolls wound under winding conditions a to d in each experimental example are shown in Table 1.

[0310] Judgment A: Above 0 meters and below 4 meters

[0311] Judgment B: 4 meters or more, less than 6 meters

[0312] Criterion C: 6 meters or more, less than 8 meters

[0313] Judgment D: 8 meters or more, less than 10 meters

[0314] Judgment E: More than 10 meters

[0315]

[0316] According to Table 1, the loss tangent (tanδ) of the protective film at 10℃ can be confirmed. 10 ), and represent the maximum displacement A [mm] and tanδ of the long strip. 10 The relationship between A / tanδ 10 Within the aforementioned range, the formation of roll marks on the protective film forming film in the protective film forming roll is suppressed.

Claims

1. A protective film forming roll, said roll being formed by winding a strip having a protective film forming film, a first release film disposed on one side of the protective film forming film, and a second release film disposed on the other side of the protective film forming film. The film roll underwent the following process: the film roll was stored for 60 days after its formation, and during these 60 days, it was stored at a temperature below 10°C for at least 25 days. When the peeling force for peeling the first release film from the protective film forming film is set as F1, and the peeling force for peeling the second release film from the protective film forming film is set as F2, the relationship F1 > F2 is satisfied. The loss tangent of the protective film at 10°C is set as tanδ. 10 When, tanδ 10 Below 1.2 When the winding axis of the sheet is vertical, and the wound strip is subjected to gravity, if the maximum displacement of the strip in the vertical direction is set to A mm, then A / tanδ is satisfied. 10 For relationships of 2.0 or higher, The protective film forming composition constituting the protective film forming film contains polymer components, curing components, and filler materials. The polymer component is acrylic resin, and the glass transition temperature of the acrylic resin is -20 to 40°C. The curing component is epoxy resin. When the total weight of the composition for forming the protective film is set to 100 parts by mass, the content of the filler material is 15 to 80 parts by mass, and the content of the polymer component is 5 to 80 parts by mass. In the first and / or second peeling films, the surfaces that are not in contact with the protective film have undergone peeling treatment. The peeling process involves modifying the surface or forming a peeling process on the surface with a material not originating from the surface, so that the contacting strips can easily slide against each other.

2. The protective film forming roll according to claim 1, wherein, The maximum displacement A is 2 mm or more.

3. The protective film forming roll according to claim 1 or 2, wherein, tanδ 10 It is above 0.

04.

4. A method for manufacturing a protective film forming sheet roll, comprising the method for manufacturing a protective film forming sheet roll according to any one of claims 1 to 3, and comprising: The process of storing the protective film forming roll at a storage temperature below 10°C for 25 days or more within 60 days after the formation of the protective film forming roll.

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