Method for manufacturing sheet roll for forming protective film

Abstract

The present invention provides a manufacturing method of a protective film forming sheet roll which is less likely to generate a mark due to winding of a protective film forming film which causes a mark to the protective film. The manufacturing method of the protective film forming sheet roll has a process of storing the 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, for 25 days or more at a storage temperature of 10°C or less from 60 days after the sheet roll is formed, a peel strength of the first release film from the protective film forming film is set to F1, a peel strength of the second release film from the protective film forming film is set to F2, when F1>F2 is satisfied, and a tangent of a loss angle of the protective film forming film at 10°C is set to tan δ 10 , tan δ 10 is 1.2 or less.

Description

TECHNICAL FIELD

[0001] The present application relates to a manufacturing method of a protective film forming sheet roll. In particular, the present application relates to a manufacturing method of a protective film forming sheet roll which is less likely to generate marks caused by winding of a protective film forming film which 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 a semiconductor chip having a circuit surface on which a convex electrode such as a bump is formed is mounted, 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 a protective film forming film is attached 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 strip-shaped protective film forming sheet. Before the protective film forming film is used, the long strip-shaped sheet is usually wound into a sheet roll. Also, when the protective film forming film is used, the long strip-shaped protective film forming sheet unwound from the sheet roll is cut into a shape substantially the same as the attached semiconductor wafer, and is then attached to the semiconductor wafer.

[0005] Patent Literature 1 discloses a long strip-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 to the back surface of a semiconductor wafer as an adhesive film, 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 of protective film-forming sheet is secured to the core using core-securing tape, and then wound using a winding device while applying a predetermined tension to the long strip of protective film-forming sheet. This results in a protective film-forming sheet roll. As a result, stress remains in the wound long strip of protective film-forming sheet (protective film-forming sheet roll), generating a winding pressure toward the core. This winding pressure tends to be greater in the protective film-forming sheet closer to the core, i.e., at the start of winding, and smaller in the protective film-forming sheet on the outer periphery of the roll.

[0011] In addition, due to the deviation of the tension during winding, even in the same protective film forming sheet roll, there are positions that are strongly squeezed and positions that are slightly squeezed. After winding, the positions that are strongly squeezed for a long time sometimes form traces (roll marks) caused by winding in the protective film forming sheet. In particular, the winding pressure at the position where the protective film forming sheet starts to be wound is relatively large, and at the same time, the winding pressure deviations are easily generated between each position in the width direction after winding. Furthermore, since there will be a step difference caused by the thickness of the core fixing tape and the protective film forming sheet, the winding pressure caused by the step difference becomes larger, or a deviation of the winding pressure is easily generated in the width direction. Therefore, after winding, the protective film forming sheet near the core is more likely to produce a roll mark caused by being strongly squeezed in part than the protective film forming sheet on the outer side of the roll. If such a roll mark is generated, a roll mark will also be 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 the workpiece and the protective film is formed, the roll mark remains, which will cause the appearance of the protective film to be poor.

[0012] However, even if the setting conditions of the winding device are adjusted when forming the sheet roll, it is difficult to completely suppress the winding marks caused by the above-mentioned fluctuations in the winding pressure.

[0013] The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a method for producing a protective film-forming sheet roll that is less likely to produce marks caused by winding a protective film-forming film that would otherwise leave marks on the protective film.

[0014] Technical means to solve technical problems

[0015] The solutions of the present invention are as follows.

[0016] [1] A method for producing a sheet roll for forming a protective film, comprising: storing a sheet roll formed by winding a long sheet having a protective film forming film, a first release film provided on one surface of the protective film forming film, and a second release film provided on the other surface of the protective film forming film at a storage temperature of 10°C or less for 25 days or more within 60 days after the sheet roll is formed;

[0017] When the peeling force for peeling the first peeling film from the protective film forming film is F1 and the peeling force for peeling the second peeling film from the protective film forming film is F2, the relationship F1>F2 is satisfied.

[0018] The loss tangent of the protective film forming film at 10°C is defined as tan δ. 10 When tanδ 10 Below 1.2.

[0019] [2] The method for producing a sheet roll for forming a protective film according to [1], wherein the step of storing the sheet at a storage temperature of 10° C. or lower is started within 10 days after the sheet roll is formed.

[0020] [3] The method for producing a protective film-forming sheet roll according to [1] or [2], wherein the storage temperature is -10°C or higher.

[0021] [4] The method for producing a protective film-forming sheet roll according to any one of [1] to [3], wherein the surface of the first release film and / or the second release film that is not in contact with the protective film-forming film is subjected to a release treatment.

[0022] [5] The method for producing a protective film-forming sheet roll according to any one of [1] to [4], wherein tan δ 10 It is above 0.04.

[0023] Effects of the Invention

[0024] According to the present invention, a method for producing a protective film-forming sheet roll that is less likely to produce marks due to winding of a protective film-forming film that would otherwise leave marks on the protective film can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1A This is a perspective schematic diagram of an example of a protective film forming sheet roll according to this embodiment.

[0026] Figure 1B for Figure 1A Schematic diagram of the enlarged cross section of the IB section.

[0027] Figure 2 This is a schematic cross-sectional view of an example of the protective film-forming sheet according to this embodiment.

[0028] Figure 3 It is a cross-sectional schematic diagram showing that the first release film and the second release film have a first release agent layer and a second release agent layer.

[0029] Figure 4 This is a perspective view of a long sheet unwound from a protective film forming sheet roll according to this embodiment and having slits formed therein.

[0030] Figure 5A It is a schematic cross-sectional view showing that a laminate of a protective film-forming film and a first release film is attached to a workpiece.

[0031] Figure 5B It is a schematic cross-sectional view showing that the protective film-forming film attached to the workpiece is converted into a protective film.

[0032] Description of Reference Numerals

[0033] 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

[0034] Hereinafter, the present invention will be described in detail based on specific embodiments with reference to the accompanying drawings.

[0035] First, main terms used in this specification are explained.

[0036] The workpiece is a plate-like object to be processed with a protective film attached thereto. Examples of the workpiece include wafers and panels. Specifically, semiconductor wafers and semiconductor panels can be listed. Examples of processed objects of the workpiece include chips obtained by singulation of wafers. Specifically, semiconductor chips obtained by singulation of semiconductor wafers can be listed. In this case, the protective film is formed on the back side of the wafer.

[0037] The “front surface” of a workpiece refers to a surface on which circuits, convex electrodes such as bumps, etc. are formed, and the “back surface” refers to a surface on which no circuits, etc. are formed.

[0038] In this specification, for example, “(meth)acrylate” is used as a term representing both “acrylate” and “methacrylate”, and the same applies to other similar terms.

[0039] In this specification, the weight ratio of the components constituting each composition is expressed as a solid content ratio.

[0040] (1. Sheet roll for forming protective film)

[0041] (1.1 Form of Sheet Roll for Protective Film Formation)

[0042] Figure 1A An example of a protective film-forming sheet roll manufactured by the manufacturing method of this embodiment is shown. Figure 1A In the figure, the protective film forming sheet roll 100 is a roll obtained by winding a long sheet for forming a protective film.

[0043] (1.2 Sheet for forming protective film)

[0044] First, the long sheet will be described. The protective film forming sheet 1 as a long sheet is used to attach the protective film forming film to the workpiece. Figure 2 As shown, the protective film forming sheet 1 has a structure in which a first release film 20 is disposed on one main surface 10a of a protective film forming film 10 and a second release film 30 is disposed on the other main surface 10b.

[0045] After the protective film-forming sheet 1 is wound into a roll, it is stored until use. During storage, the protective film-forming film is supported by the first release film and the second release film formed on both main surfaces.

[0046] During use, the protective film-forming sheet is unwound from a roll of protective film-forming sheet and the protective film-forming film is cut into a desired shape. After the second release film is removed, the protective film-forming film is applied to the back of the workpiece. After the first release film is removed, the protective film is formed. The protective film protects the workpiece or the object being processed.

[0047] Hereinafter, the protective film-forming film, the first release film, and the second release film constituting the protective film-forming sheet will be described.

[0048] (1.3 Protective film forming film)

[0049] As described above, the protective film-forming film is formed into a protective film after being attached to the workpiece, thereby forming a protective film for protecting the workpiece or a processed object of the workpiece.

[0050] "Protecting" refers to bringing the protective film-forming film into a state with sufficient properties to protect a workpiece or an object to be processed. Specifically, when the protective film-forming film is curable, "protecting" means converting an uncured protective film-forming film into a cured product. In other words, the protective film-forming film that has been protected is a cured product of the protective film-forming film and is different from the protective film-forming film.

[0051] After a workpiece is superimposed on the curable protective film-forming film, the protective film-forming film is cured to firmly adhere the protective film to the workpiece, thereby forming a durable protective film.

[0052] On the other hand, when the protective film forming film does not contain a curable component and is used in an uncured state, the protective film forming film is converted into a protective film when it is attached to the workpiece. In other words, the converted protective film forming film is the same as the protective film forming film.

[0053] When high protective performance is not required, the protective film-forming film does not need to be cured, and thus the protective film-forming film can be easily used.

[0054] In this embodiment, the protective film-forming film is preferably curable. Therefore, the protective film is preferably a cured product. As a cured product, for example, a thermally cured product or an energy-ray cured product can be exemplified. In this embodiment, the protective film is more preferably a thermally cured product.

[0055] Furthermore, the protective film-forming film preferably has adhesive properties at room temperature (23°C), or develops adhesive properties by heating. This allows the workpiece to be laminated when it is placed on the protective film-forming film. This allows for accurate positioning before the protective film-forming film is cured.

[0056] The protective film-forming film may be composed of a single layer or two or more layers. When the protective film-forming film has multiple layers, these multiple layers may be the same or different from each other, and the combination of the layers constituting these multiple layers is not particularly limited.

[0057] In the present embodiment, it is preferred that the protective film forming film is a layer (monolayer). A layer of protective film forming film can obtain a higher precision in thickness and is therefore easy to produce. In addition, if the protective film forming film is composed of multiple layers, it is necessary to consider the interlayer adhesion and the elasticity of each layer, and there is a risk of peeling off from the adherend caused by this. When the protective film forming film is a layer, the above-mentioned risks can be reduced and the degree of freedom of design is also improved.

[0058] The thickness of the protective film-forming film is not particularly limited, but 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-forming film to the above value, the step difference caused by the thickness of the protective film-forming sheet at the start of winding can be reduced.

[0059] Furthermore, the thickness of the protective film-forming film is preferably 5 μm or greater, 10 μm or greater, or 15 μm or greater. By setting the lower limit of the thickness of the protective film-forming film to the above value, the protective film can easily provide the performance of protecting the workpiece. Furthermore, in the protective film-forming sheet roll, the protective film-forming film acts to alleviate stress, thereby further shortening the distance from the core portion where the winding mark begins to appear.

[0060] The thickness of the protective film-forming film refers to the thickness of the entire protective film-forming film. For example, the thickness of a protective film-forming film composed of multiple layers refers to the total thickness of all layers constituting the protective film-forming film.

[0061] (1.3.1 Loss tangent of protective film-forming film at 10°C)

[0062] In this embodiment, the loss tangent (tan δ) of the protective film forming film at 10°C 10) is 1.2 or less. The loss tangent is defined as "loss modulus / storage modulus" and is a value measured using a dynamic viscoelasticity measuring device based on the response to stress applied to an object. By making 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 not easily deformed, so there is a tendency that winding marks are not easily generated even when the winding pressure of the sheet is high. Therefore, this embodiment controls the loss tangent of the protective film-forming film at 10°C.

[0063] Loss tangent (tanδ) of protective film forming film at 10°C 10 ) is preferably 1.0 or less, more preferably 0.9 or less, and further preferably 0.8 or less. In addition, the loss tangent (tan δ) of the protective film forming film at 10°C is 10 ) is preferably 0.04 or more, more preferably 0.1 or more, further preferably 0.2 or more, and particularly preferably 0.3 or more. By setting the lower limit of the loss tangent of the protective film-forming film at 10°C to the above value, the phenomenon of cracking of the curved protective film-forming film in the roll at 10°C can be prevented.

[0064] Loss tangent (tanδ) of protective film forming film at 10°C 10 ) can be measured using a known method. For example, the protective film forming film can be made into a sample of a specified size, and a dynamic viscoelasticity measuring device can be used to apply strain to the sample at a specified frequency within a specified temperature range to measure the elastic modulus. The loss tangent (tanδ) at 10°C can be calculated based on the measured elastic modulus. 10 ). The specific measurement method will be described in detail in the examples described below.

[0065] (1.4 First peeling film)

[0066] The first release film is a film capable of supporting the protective film-forming film in a releasable manner. In this embodiment, it is preferred that the first release film be peeled off from the protective film-forming film after the protective film-forming film is attached to the workpiece.

[0067] The second release film may be composed of a single layer (monolayer) or two or more layers of a substrate. To control the release properties, the surface of the substrate may be subjected to a release treatment. In other words, the surface of the substrate may be modified, or a material other than the substrate may be formed on the surface of the substrate.

[0068] The thickness of the first release film is not particularly limited, but is preferably 30 μm to 100 μm. Furthermore, the thickness of the first release film is more preferably 40 μm or greater, and even more preferably 45 μm or greater. Furthermore, the thickness of the first release film is more preferably 80 μm or less, and even more preferably 70 μm or less.

[0069] By setting the lower limit of the thickness of the first release film to the above value, the cutting blade described later can be used to prevent the cutting blade from penetrating the first release film and cutting the first release film when forming an incision that reaches a portion of the first release film. Furthermore, in the protective film-forming sheet roll, the first release film acts as a stress reliever, further shortening the distance from the core at which the roll mark begins to appear.

[0070] Furthermore, before the protective film-forming sheet is unwound and the protective film-forming film is cut and conveyed to the next process, the protective film-forming sheet passes over rollers such as guide rollers within the apparatus. By setting the upper limit of the thickness of the first release film to the above value, it is possible to prevent the protective film-forming film from peeling off from the first release film. Furthermore, the step difference caused by the thickness of the protective film-forming sheet at the start of winding can be reduced.

[0071] The thickness of the first release film refers to the thickness of the entire first release film. For example, the thickness of a first release film composed of a plurality of layers refers to the total thickness of all layers constituting the first release film.

[0072] In this embodiment, the first release film preferably includes a base material and a first release agent layer. By including the first release agent layer, it is easy to control the physical properties of the surface of the first release film on which the first release agent layer is formed.

[0073] Furthermore, in this embodiment, in the protective film-forming sheet, when the peeling force for peeling the first release film from the protective film-forming film is defined as F1 and the peeling force for peeling the second release film from the protective film-forming film, described later, is defined as F2, F1 and F2 satisfy the relationship F1>F2. This relationship ensures that 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, making it easier for the protective film-forming film 10 to remain on the first release film.

[0074] Therefore, the first release film is a heavy release film, and the second release film is a light release film.

[0075] 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 examples below.

[0076] (1.4.1 Base Material)

[0077] The base material of the first release film is not particularly limited as long as it can support the protective film-forming film before being attached to the workpiece, and is generally composed of a film mainly composed of a resin material (hereinafter referred to as "resin film").

[0078] As the object examples of resin film, polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polyethylene naphthalate film, polybutylene terephthalate film, polyurethane film, ethylene vinyl acetate copolymer film, ionomer resin film, ethylene-(methyl) acrylic acid copolymer film, ethylene-(methyl) acrylate copolymer film, polystyrene film, polycarbonate film, polyimide film, fluororesin film etc. can be used.In addition, the cross-linked film of these films can also be used.Further, the laminated film of these films can also be used.In the present embodiment, from the angles such as environmental safety, cost and the angle of winding up that suppresses the extension of accompanying base material, preferred polyethylene terephthalate film.

[0079] Regarding the base material, the resin film may contain various additives such as a colorant, a flame retardant, a plasticizer, an antistatic agent, a lubricant, and a filler.

[0080] The thickness of the substrate is not particularly limited, as long as it allows the protective film-forming sheet to function appropriately in each process in which it is used and is within the thickness range of the first release film described above. The thickness of the substrate is preferably 30 μm to 100 μm. Furthermore, the thickness of the substrate is more preferably 40 μm or more, and even more preferably 45 μm or more. Furthermore, the thickness of the substrate is more preferably 80 μm or less, and even more preferably 70 μm or less.

[0081] (1.4.2 First Release Agent Layer)

[0082] The first release agent layer imparts releasability to the first release film from the protective film-forming film. The first release agent layer is not particularly limited as long as it is composed of a material that imparts releasability. In this embodiment, the first release agent layer can be obtained by curing a first release agent layer composition containing a release agent.

[0083] In the first release film, it is preferred that the first release agent layer be 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 easy, thereby achieving cost reduction.

[0084] 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 further preferably 80 nm or more. Furthermore, the thickness of the first release agent layer is more preferably 180 nm or less.

[0085] By setting the thickness of the first release agent layer within the above range, stable release performance can be exhibited when the protective film-forming film is attached to a workpiece.

[0086] In this embodiment, it is preferable that the first release agent layer is formed on the surface of the first release film on the protective film forming film side and also on the surface on the opposite side. Figure 3 As shown, in the protective film-forming sheet 1, the first release film 20 comprises a substrate 21, and first release agent layers 22 and 23 formed on both 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.

[0087] In the roll, the long strips are radially stacked, so the surface 20a of the first release film 20 that is not in contact with the protective film-forming film 10 and the surface 30b of the second release film 30 that is not in contact with the protective film-forming film 10 are in contact. Therefore, by subjecting the surface 20a of the first release film 20 that is not in contact with the protective film-forming film 10 to a release treatment (by forming the first release agent layer 23), the contacting long strips can slide easily against each other, thereby facilitating the stabilization of the winding pressure described later.

[0088] (1.5 second peeling film)

[0089] The second release film is a film capable of supporting the protective film-forming film in a releasable manner. In this embodiment, it is preferred that the second release film be peeled off from the protective film-forming film before the protective film-forming film is attached to the workpiece.

[0090] Similar to the first release film, the second release film can be composed of a single substrate (single layer) or two or more layers. To control the release properties, the surface of the substrate may be subjected to a release treatment. In other words, the surface of the substrate may be modified, or a material other than the substrate may be formed on the surface of the substrate.

[0091] 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. To ensure that the peel force F2 and the peel force F1 satisfy the aforementioned condition F1 > F2, 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.

[0092] The thickness of the second release film refers to the thickness of the entire second release film. For example, the thickness of a second release film composed of multiple layers refers to the total thickness of all layers constituting the second release film.

[0093] In this embodiment, the second release film preferably includes a base material and a second release agent layer. By including the second release agent layer, it is easy to control the physical properties of the surface of the second release film on which the second release agent layer is formed.

[0094] (1.5.1 Base Material)

[0095] The base material of the second release film can be appropriately selected from the materials exemplified as the base material of the first release film.

[0096] (1.5.2 Second Release Agent Layer)

[0097] When the second release film has a second release agent layer, the second release agent layer is not particularly limited as long as it is composed of a material that imparts releasability. For example, similar to the first release agent layer, the second release agent layer can be obtained by curing a second release agent layer composition containing a silicone release agent.

[0098] As with the first release film, the second release film preferably has the second release agent layer 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, thereby achieving cost reduction.

[0099] In addition, in this embodiment, the second release agent layer is formed on the protective film forming film side of the second release film. Figure 3 As shown, in the protective film-forming sheet 1, the second release film 30 includes a base material 31 and a second release agent layer 32 formed on the protective film-forming film side of the base material 31. The main surface 30a of the second release film 30 (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 10. In addition to forming the second release agent layer on the protective film-forming film side of the second release film 30, a second release agent layer may also be formed on the opposite surface 30b.

[0100] In addition, when forming the second release agent layer on both main surfaces of the substrate, the coating agent containing the second release agent layer composition 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 second release agent layer composition can be applied to one main surface of the substrate, and then the substrate is wound into a roll, and the second release agent layer is formed on the main surface not coated with the coating agent by utilizing the phenomenon that the components of the second release agent layer composition are transferred from the main surface coated with the coating agent to the main surface not coated with the coating agent (transfer phenomenon).

[0101] (2. Method for Manufacturing a Sheet Roll for Forming a Protective Film)

[0102] In the method for producing a protective film-forming sheet roll according to this embodiment, the protective film-forming sheet comprising the protective film-forming film, the first release film, and the second release film is first produced into a long strip having a longitudinal length significantly longer than a transverse length. This long strip can be produced using a known method, the specific method of which is described below.

[0103] The long sheet is then cut on both sides in the width direction to adjust the width according to the size of the workpiece to which the protective film forming film is to be attached, and is wound up with a winding device applying a predetermined tension, thereby producing a protective film forming sheet roll.

[0104] In addition, when the width of the workpiece is 150 mm, the length in the width direction after cutting is preferably in the range of 155 to 194 mm; when the width of the workpiece is 200 mm, the length in the width direction after cutting is preferably in the range of 205 to 250 mm; when the width of the workpiece is 300 mm, the length in the width direction after cutting is preferably in the range of 305 to 350 mm; and when the width of the workpiece is 450 mm, the length in the width direction after cutting is preferably in the range of 455 to 500 mm.

[0105] like Figure 1B As shown, the long sheet is fixed to the core 70 via a fixing tool 80 such as a core fixing tape, and then the long sheet is wound around the core 70 by a winding device while applying a predetermined tension to the long sheet, thereby forming the protective film forming sheet roll 100. As described above, the winding pressure in the completed sheet roll varies, and particularly at locations where the long sheet is strongly pressed near the core, winding marks of the protective film forming film are likely to form, which can leave marks on the protective film.

[0106] On the other hand, it is speculated that after a roll is formed, that is, after winding is completed, the winding pressure at locations with high winding pressure gradually decreases over time, approaching the winding pressure at locations with low winding pressure. In other words, it is speculated that the winding pressure fluctuations will be eliminated over time, and the winding pressure within the roll will be stabilized (averaged). Therefore, although the winding pressure fluctuations within the roll will eventually be largely eliminated, the winding marks formed before the winding pressure fluctuations are eliminated will still remain in the protective film even after the winding pressure fluctuations are eliminated.

[0107] However, if the loss tangent of the protective film forming film is low and the protective film forming film is not easily deformed, even if the winding pressure varies and there are areas where it is strongly squeezed, winding marks are unlikely to form on the protective film forming film. In addition, as the temperature decreases, the loss tangent of the protective film forming film is easily maintained at a low level. Furthermore, as mentioned above, the winding pressure in the sheet tends to stabilize over time.

[0108] (2.1 Storage Process)

[0109] Therefore, in this embodiment, while maintaining the loss tangent of the protective film-forming film within the above-mentioned range, the sheet roll just wound is stored for a predetermined time until the winding pressure stabilizes.

[0110] Specifically, the method for producing a protective film-forming sheet roll of the present embodiment comprises the steps of forming a protective film-forming film having a loss tangent (tan δ) at 10°C. 10 ) is 1.2 or less to form a protective film film roll, the film roll is stored for 60 days, and during 25 days or more of the 60 days, the film roll is stored at a storage temperature of 10°C or less.

[0111] For the protective film-forming film having a loss tangent (tan δ 10 ) is less than 1.2. By storing the roll at a temperature below 10°C until the winding pressure of the roll is stabilized, the protective film forming film can easily achieve a loss tangent within the above range, thereby suppressing the formation of winding marks on the protective film forming film in the roll.

[0112] The period of storage of the sheet roll at a storage temperature of 10° C. or lower is preferably 30 days or longer, 35 days or longer, 40 days or longer, or 45 days or longer. On the other hand, the period is preferably 60 days or shorter, or 59 days or shorter.

[0113] Furthermore, storage at a storage temperature of 10°C or lower is preferably started within 10 days, more preferably within 7 days, and even more preferably within 4 days after the sheet is formed into a roll. Since the winding pressure of a newly wound sheet tends to vary greatly, the formation of winding marks on the protective film-forming film in the roll can be further suppressed by maintaining the loss tangent of the protective film-forming film at a low level.

[0114] 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 value, the elastic modulus of the protective film-forming film can be prevented from becoming excessively high, and peeling between the protective film-forming film and the release film, particularly between the protective film-forming film and the second release film, can be suppressed.

[0115] The protective film forming sheet roll of the present embodiment can be obtained by the above-mentioned storage step. The loss tangent tanδ of the protective film forming film stored in the above-mentioned storage step at 10°C is 10With a protective film-forming sheet having a thickness of 1.2 or less, even when the protective film-forming sheet is unwound from a protective film-forming sheet roll, the formation of winding marks on the protective film-forming film extending to the protective film-forming sheet on the core side can be suppressed. Therefore, poor appearance of the protective film can be suppressed, and the protective film-forming sheet roll of this embodiment can be used up without waste.

[0116] (2.2 Method for manufacturing long strips)

[0117] The method for producing the protective film forming sheet roll of this embodiment can be performed by producing a long sheet having the above-mentioned structure using a known method. In this embodiment, the first release film has the above-mentioned base material and first release agent layer, and the second release film has the above-mentioned base material and second release agent layer.

[0118] The protective film-forming film is formed using a protective film-forming film composition, the first release agent layer is formed using a first release agent layer composition, and the second release agent layer is formed using a second release agent layer composition.

[0119] Hereinafter, the protective film-forming film composition, the first release agent layer composition, and the second release agent layer composition will be described.

[0120] (2.2.1 Protective Film-Forming Composition)

[0121] As long as the protective film forming film has the above-mentioned physical properties, the composition of the protective film forming film is not particularly limited. In the present embodiment, the composition constituting the protective film forming film (protective film forming film composition) is preferably a resin composition containing at least a polymer component (A), a curable component (B) and a filler (E). The polymer component can be regarded as a component formed by a polymerization reaction of a polymerizable compound. In addition, the curable component is a component that can undergo a curing (polymerization) reaction. In addition, the polymerization reaction in the present invention also includes a polycondensation reaction.

[0122] In addition, components contained in the polymer component may also be curable components. In this embodiment, when the protective film-forming film composition contains such components that are both polymer components and curable components, it is considered that the protective film-forming film composition contains both polymer components and curable components.

[0123] (2.2.1.1 Polymer components)

[0124] The polymer component (A) imparts film-forming properties to the protective film-forming film while providing moderate adhesiveness, ensuring that the protective film-forming film adheres uniformly to the workpiece. The weight-average molecular weight of the polymer component is generally 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, with acrylic resins being particularly preferred.

[0125] In addition, in this specification, unless otherwise specified, "weight average molecular weight" refers to the polystyrene conversion value measured by gel permeation chromatography (GPC). The measurement based on this method can be carried out, for example, in the following manner: using a high-efficiency GPC device "HLC-8120GPC" manufactured by TOSOH CORPORATION, and connecting a high-efficiency chromatography column "TSK guardcolumn H XL -H","TSK Gel GMH XL ”,TSK Gel G2000 H XL ” (all the above are manufactured by TOSOH CORPORATION), with a column temperature of 40°C and a liquid feeding rate of 1.0 mL / min, and a differential refractometer as the detector.

[0126] Examples of acrylic resins include (meth)acrylate copolymers composed of a (meth)acrylate monomer and a structural unit derived from a (meth)acrylic acid derivative. Preferred (meth)acrylate monomers include alkyl (meth)acrylates having an alkyl group with 1 to 18 carbon atoms, specifically methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, and butyl (meth)acrylate. Examples of (meth)acrylic acid derivatives include (meth)acrylic acid, glycidyl (meth)acrylate, and hydroxyethyl (meth)acrylate.

[0127] In this embodiment, glycidyl methacrylate or the like is preferably used to introduce glycidyl groups into the acrylic resin. Acrylic resins with glycidyl groups introduced improve compatibility with the epoxy resin, a thermosetting component described later, and tend to readily produce a protective film-forming film with stable performance. Furthermore, in this embodiment, to control adhesion or tack to workpieces, hydroxyl groups are preferably introduced into the acrylic resin using hydroxyethyl acrylate or the like.

[0128] The glass transition temperature of the acrylic resin is preferably -70 to 40°C, -35 to 35°C, -20 to 30°C, -10 to 25°C, or -5 to 20°C. By setting the lower limit of the glass transition temperature of the acrylic resin to the above value, it is easy to reduce the tan δ of the protective film forming film. 10 Furthermore, by setting the upper limit of the glass transition temperature of the acrylic resin to the above value, the viscosity of the protective film-forming film is appropriately increased, and the adhesion between the protective film-forming film and the workpiece is also improved, and the adhesive force between the protective film and the workpiece is appropriately increased.

[0129] When an acrylic resin has m types of structural units (m is an integer greater than or equal to 2), the glass transition temperature of the acrylic resin can be calculated as follows. Specifically, when each of the m types of monomers from which the structural units in the acrylic resin are derived is sequentially assigned a non-repeating number from 1 to m and designated "monomer m," the glass transition temperature (Tg) of the acrylic resin can be calculated using the Fox equation shown below.

[0130] [Mathematical formula 1]

[0131]

[0132] Wherein, Tg is the glass transition temperature of the acrylic resin; m is an integer greater than or equal to 2; Tgk is the glass transition temperature of the homopolymer of monomer m; and Wk is the mass fraction of the structural unit m derived from monomer m in the acrylic resin, wherein Wk satisfies the following formula.

[0133] [Mathematical formula 2]

[0134]

[0135] Wherein, m and Wk are the same as those described above.

[0136] As Tgk, values ​​described in the Polymer Data Handbook, the Adhesion Handbook, or the Polymer Handbook can be used. For example, the Tgk of a homopolymer of methyl acrylate is 10°C, the Tgk of a homopolymer of n-butyl acrylate is -54°C, the Tgk of a homopolymer of methyl methacrylate is 105°C, the Tgk of a homopolymer of 2-hydroxyethyl acrylate is -15°C, the Tgk of a homopolymer of glycidyl methacrylate is 41°C, and the Tgk of 2-ethylhexyl acrylate is -70°C.

[0137] The content of the polymer component, based on 100 parts by mass of the total weight of the protective film-forming film composition, 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 adjusting the polymer component content within these ranges, the tackiness of the protective film-forming film is appropriately improved, and the adhesion between the protective film-forming film and the workpiece is also appropriately improved. Furthermore, the occurrence of curling marks tends to be suppressed.

[0138] (2.2.1.2 Thermosetting components)

[0139] The curable component (B) forms a hard protective film by curing the protective film-forming film. As the curable component, a thermosetting component, an energy ray curable component, or a mixture thereof can be used. When cured by irradiating energy rays, the protective film-forming film contains fillers and colorants described later, so the light transmittance is reduced. Therefore, for example, when the thickness of the protective film-forming film becomes thicker, energy ray curing tends to become insufficient.

[0140] On the other hand, a thermosetting protective film-forming film can be fully cured by heating even when the thickness increases, thereby forming a protective film with high protective performance. In addition, by using a conventional heating device such as a heating oven, a plurality of protective film-forming films can be heated and thermally cured.

[0141] Therefore, in this embodiment, it is desirable that the curable component is thermosetting. In other words, the protective film-forming film is preferably thermosetting.

[0142] Whether a protective film-forming film is thermosetting can be determined as follows. First, a protective film-forming film at room temperature (23°C) is heated to a temperature exceeding room temperature, and then cooled to room temperature to produce a heated and cooled protective film-forming film. Next, the hardness of the heated and cooled protective film-forming film is compared with the hardness of the pre-heated protective film-forming film at the same temperature. If the heated and cooled protective film-forming film is harder, the protective film-forming film is determined to be thermosetting.

[0143] As the thermosetting component, for example, epoxy resin, thermosetting polyimide resin, unsaturated polyester resin and a mixture thereof are preferably used. Thermosetting polyimide resin is a general term for polyimide precursors and thermosetting polyimides that can be converted into polyimide resins by thermal curing.

[0144] The epoxy resin as the thermosetting component has a property of forming a three-dimensional network structure and a firm coating film when heated. As such an epoxy resin, various known epoxy resins can be used. In the present 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. Further, the epoxy equivalent of the epoxy resin is preferably 50 to 5,000 g / eq, more preferably 100 to 2,000 g / eq, and further preferably 150 to 1,000 g / eq.

[0145] As the epoxy resin, specifically, glycidyl ethers of phenols such as bisphenyl A, bisphenyl F, resorcinol, phenyl novolac, and cresyl 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 in which active hydrogen bonded to a nitrogen atom of aniline isocyanurate and the like is substituted with a glycidyl group; so-called alicyclic type epoxy resins in which an epoxy group is introduced into a carbon-carbon double bond in the molecule by oxidation or the like, such as vinylcyclohexane diepoxide, 3,4-epoxycyclohexylmethyl-3,4-dicyclohexane carboxylate, 2-(3,4-epoxy)cyclohexyl-5,5-spiro(3,4-epoxy)cyclohexane-m-dioxane, and the like can be listed. Further, epoxy resins having a biphenyl skeleton, a bicyclohexadiene skeleton, a naphthalene skeleton, and the like can also be used.

[0146] When the thermosetting component is used as the curable component (B), a curing agent (C) is preferably used as an aid. As the curing agent for the epoxy resin, a thermally active latent epoxy resin curing agent is preferred. The "thermally active latent epoxy resin curing agent" refers to a type of curing agent that does not easily react with the epoxy resin at room temperature (23°C), is activated by heating to a certain temperature or higher, and reacts with the epoxy resin. As the activation method of the thermally active latent epoxy resin curing agent, methods of generating an active species (anion, cation) by a chemical reaction based on heating, a method of being stably dispersed in the epoxy resin at around room temperature, being compatible-dissolved with the epoxy resin at a high temperature, and starting the curing reaction, a method of starting the curing reaction after a molecular sieve-encapsulated type curing agent is dissolved at a high temperature, a method based on microcapsules, and the like are present.

[0147] Among the exemplified methods, the method of being stably dispersed in the epoxy resin at around room temperature, being compatible-dissolved with the epoxy resin at a high temperature, and starting the curing reaction is preferred.

[0148] As specific examples of the heat-activated latent epoxy resin curing agent, various onium salts or, dibasic acid dihydrazide compounds, dicyandiamide, amine adduct curing agents, imidazole compounds, and the like high-melting active hydrogen compounds can be listed. These heat-activated latent epoxy resin curing agents can be used singly or in combination of two or more. The present embodiment is particularly preferable for dicyandiamide.

[0149] Further, as the curing agent for the epoxy resin, a phenol resin is also preferable. As the phenol resin, there are no particular limitations and condensates of phenols such as alkylphenol, polyphenol, naphthol, and aldehydes, and the like can be used. Specifically, phenol novolak resin, o-cresol novolak resin, p-cresol novolak resin, t-butylphenol novolak resin, dicyclopentadiene cresol resin, poly-p-vinylphenol resin, bisphenol A novolak resin, or a modified product thereof, and the like can be used.

[0150] The phenolic hydroxyl groups contained in these phenol resins can easily undergo an addition reaction with the epoxy groups of the above-described epoxy resins by heating, thereby forming a cured product with high impact resistance.

[0151] The content of the curing agent (C) is preferably 0.01 to 30 parts by mass, 0.1 to 20 parts by mass, 0.2 to 15 parts by mass, or 0.3 to 10 parts by mass, relative to 100 parts by mass of the epoxy resin. By setting the content of the curing agent (C) within the above range, the performance of protecting the workpiece as a protective film is easily obtained.

[0152] When dicyandiamide is used as the curing agent (C), it is further preferable to use a curing accelerator (D) at the same time. As the curing accelerator, for example, imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, and the like in which one or more hydrogen atoms are substituted with a group other than hydrogen (imidazoles) are preferable. Among these, 2-phenyl-4,5-dihydroxymethylimidazole is particularly preferable.

[0153] The content of the curing accelerator is preferably 0.01 to 30 parts by mass, 0.1 to 20 parts by mass, 0.2 to 15 parts by mass, or 0.3 to 10 parts by mass, relative to 100 parts by mass of the epoxy resin. By setting the content of the curing accelerator (D) within the above range, the performance of protecting the workpiece as a protective film is easily obtained.

[0154] The total content of the thermosetting component and the curing agent when the total weight of the protective film-forming composition is set to 100 parts by mass 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 blended in such proportions, the performance of protecting the workpiece as a protective film is easily obtained.

[0155] (2.2.1.3 Energy ray curable component)

[0156] When the curable component (B) is an energy ray curable component, the energy ray curable component is preferably uncured, preferably has adhesiveness, and more preferably is uncured and has adhesiveness.

[0157] The energy ray-curable component is a component that is cured by irradiation with energy rays and is a component for imparting film-forming properties, flexibility, and the like to the protective film-forming film.

[0158] As the energy-ray curable component, for example, a compound having an energy-ray curable group is preferable. Examples of such a compound include known compounds.

[0159] (2.2.1.4 Filling materials)

[0160] By including a filler (E) in the protective film-forming film, the thermal expansion coefficient of the protective film obtained by converting the protective film-forming film into a protective film can be easily adjusted. By adjusting the thermal expansion coefficient to be close to that of the workpiece, the reliability of adhesion to the workpiece is further improved. In addition, by including a filler (E) in the protective film-forming film, a hard protective film can be easily obtained, thereby achieving the performance of protecting the workpiece, and further reducing the moisture absorption rate of the protective film.

[0161] The filler (E) may be either an organic filler or an inorganic filler, but is preferably an inorganic filler from the viewpoint of shape stability at high temperatures such as 260°C.

[0162] Preferred inorganic fillers include powders such as silica, alumina, talc, calcium carbonate, red iron oxide, silicon carbide, and boron nitride; spherical beads of these inorganic fillers; surface-modified products of these inorganic fillers; single-crystal fibers of these inorganic fillers; and glass fibers. Among these, silica and surface-modified silica are preferred. Surface-modified silica is preferably surface-modified with a coupling agent, more preferably with a silane coupling agent.

[0163] The average particle size of the filler is preferably 0.02 to 10 μm, 0.05 to 5 μm, or 0.10 to 3 μm.

[0164] By setting the average particle size of the filler within the above range, the workability of the protective film-forming film composition becomes good, and as a result, the quality of the protective film-forming film composition and the protective film-forming film tends to be stabilized.

[0165] In addition, unless otherwise specified, the "average particle size" in this specification refers to the value of the particle size (D50) at the cumulative value of 50% in the particle size distribution curve determined by a laser diffraction scattering method.

[0166] The content of the filler when the total weight of the protective film-forming film composition is 100 parts by mass is preferably 15 to 80 parts by mass, 30 to 75 parts by mass, 40 to 70 parts by mass, or 45 to 65 parts by mass.

[0167] By setting the lower limit of the filler content to the above value, the tan δ of the protective film formation film can be easily reduced. 10 Furthermore, by setting the upper limit of the filler content to the above value, there is a tendency that the adhesion between the protective film-forming film and the workpiece is improved, and the adhesive force between the protective film and the workpiece is moderately improved.

[0168] (2.2.1.5 Coupling agent)

[0169] The protective film-forming film preferably contains a coupling agent (F). The inclusion of a coupling agent can improve the adhesion between the protective film and the workpiece after curing without compromising the heat resistance of the protective film, while also improving water resistance (resistance to moist heat). As a coupling agent, a silane coupling agent is preferred due to its versatility and cost advantages.

[0170] Examples of the silane coupling agent include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-(methacryloxypropyl)trimethoxysilane, γ-aminopropyltrimethoxysilane, N-6-(aminoethyl)-γ-aminopropyltrimethoxysilane, N-6-(aminoethyl)-γ-aminopropylmethyldiethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, bis(3-triethoxysilylpropyl)tetrasulfide, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, and imidazolesilane. These silane coupling agents may be used alone or in combination of two or more.

[0171] (2.2.1.6 Colorants)

[0172] The protective film-forming film preferably contains a colorant (G). This shields the back surface 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.

[0173] As the colorant (G), for example, known pigments such as inorganic pigments, organic pigments, and organic dyes can be used. In the present embodiment, inorganic pigments are preferred.

[0174] As inorganic pigments, 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, ATO (antimony tin oxide) pigments etc. can be listed. Among them, carbon black is particularly preferably used. If it is carbon black, electromagnetic waves of a wider wavelength range can be blocked.

[0175] The amount of colorant (especially carbon black) incorporated into the protective film-forming film may vary depending on the thickness of the protective film-forming film. For example, when the protective film-forming film has a thickness of 20 μm, the amount of colorant incorporated is preferably 0.01 to 10% by mass, 0.04 to 7% by mass, or 0.07 to 4% by mass relative to the total mass of the protective film-forming film. By adjusting the amount of colorant incorporated within the above ranges, traces of the protective film caused by the winding marks of the protective film-forming sheet tend to be less noticeable in appearance.

[0176] The average particle size of the colorant (especially carbon black) is preferably 1 to 500 nm, particularly preferably 3 to 100 nm, and further preferably 5 to 50 nm. When the average particle size of the colorant is within the above range, it is easy to control the light transmittance within the desired range.

[0177] (2.2.1.7 Other additives)

[0178] The protective film-forming film composition may further contain other additives such as a photopolymerization initiator, a crosslinking agent, a plasticizer, an antistatic agent, an antioxidant, a getter, a tackifier, and a release agent, within a range not impairing the effects of the present invention.

[0179] (2.2.2 Composition for First Release Agent Layer)

[0180] In this embodiment, the first release agent layer composition may include, for example, an alkyd release agent, a silicone release agent, a fluorine release agent, an unsaturated polyester release agent, a polyolefin release agent, or a wax release agent. Silicone release agents are preferred. When the first release agent layer composition includes a silicone release agent, it preferably includes both the silicone release agent and a heavy-duty release additive.

[0181] (2.2.2.1 Silicone release agents)

[0182] As the silicone-based release agent, one in which silicone having dimethylpolysiloxane as a basic skeleton is blended can be used.

[0183] The content of the organosilicon composed of dimethylpolysiloxane when the total weight of the first release agent layer composition (excluding the catalyst described below) is 100 parts by mass 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.

[0184] The silicone can be any of an addition-reaction type, a polycondensation type, or an energy-ray-curable type such as an ultraviolet-curable type or an electron-beam-curable type, with addition-reaction type silicone being preferred. Addition-reaction type silicones offer high reactivity and excellent productivity. Compared to polycondensation type silicones, they also have advantages such as minimal post-production variation in release strength and no cure shrinkage.

[0185] Specific examples of the addition reaction type silicone include organopolysiloxanes having two or more alkenyl groups having 2 to 10 carbon atoms, such as vinyl, allyl, propenyl, and hexenyl, at the molecular terminals and / or in the side chains.

[0186] When using such an addition reaction type silicone, it is preferred to use a crosslinking agent and a catalyst together.

[0187] Examples of the cross-linking agent include organopolysiloxanes having at least two hydrogen atoms bonded to silicon atoms in one molecule.

[0188] Specific examples of the crosslinking agent include dimethylhydrogensiloxy-terminated dimethylsiloxane-methylhydrogensiloxane copolymer, trimethylsiloxy-terminated dimethylsiloxane-methylhydrogensiloxane copolymer, trimethylsiloxy-terminated methylhydrogenpolysiloxane, and poly(hydrogen silsesquioxane).

[0189] Examples of the catalyst include fine-particle platinum, fine-particle platinum adsorbed on a carbon powder carrier, chloroplatinic acid, alcohol-modified chloroplatinic acid, olefin complexes of chloroplatinic acid, palladium, and platinum group metal compounds such as rhodium.

[0190] By using the above-mentioned catalyst, the curing reaction of the composition for the first release agent layer can be more efficiently carried out.

[0191] From the viewpoint of ensuring that the release force F1 is within the above range, the content of the silicone-based release agent is preferably 30 to 100 parts by mass or 50 to 100 parts by mass based on 100 parts by mass of the total weight of the first release agent layer composition (excluding the catalyst).

[0192] (2.2.2.2 Heavy Peeling Additives)

[0193] The heavy release additive is used to increase the peeling force F1 for peeling the first release film from the protective film-forming film. Examples of the heavy release additive include silicone resins and organosilanes such as silane coupling agents. Among them, silicone resins are preferably used.

[0194] As the silicone resin, for example, a polysiloxane containing a monofunctional siloxane unit [R3SiO 1 / 2 ] as the M unit, and as the tetrafunctional siloxane unit [SiO 4 / 2] MQ resin having Q units. 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 silicone migration, at least one of the three Rs in the M unit is preferably a hydroxyl group or a vinyl group, more preferably a vinyl group.

[0195] The content of the heavy release additive when the total weight of the first release agent layer composition (excluding the catalyst) is 100 parts by mass is preferably 0 to 50 parts by mass, 5 to 45 parts by mass, or 10 to 40 parts by mass.

[0196] In addition, when forming the first release agent layer on both main surfaces of the substrate, the coating agent containing the first release agent layer composition 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 first release agent layer composition can be applied to one main surface of the substrate, and then the substrate is wound into a roll, and the first release agent layer is formed on the main surface not coated with the coating agent by utilizing the phenomenon that the components of the first release agent layer composition are transferred from the main surface coated with the coating agent to the main surface not coated with the coating agent (transfer phenomenon).

[0197] In the case of the first release film, whether the substrate has undergone a release treatment can be determined, for example, by the following method. When the first release agent layer comprises the aforementioned silicone release agent, surface analysis of both main surfaces of the first release film is performed using X-ray photoelectron spectroscopy (XPS). The silicon atom ratio is calculated from the resulting spectrum, and if it exceeds a specified value, the substrate is determined to have undergone a release treatment. The specific measurement method will be described in detail in the Examples below.

[0198] When the substrate is made of polyethylene terephthalate film, the contact angle of water is measured on both main surfaces of the first release film. If the contact angle is greater than a predetermined value, it is determined to have been subjected to release treatment. The specific measurement method will be described in detail in the examples below.

[0199] (2.2.3 Composition for Second Release Agent Layer)

[0200] The second release agent layer composition can be selected from the materials listed for the first release agent layer composition as long as the relationship between F1 and F2 is satisfied. However, the content of the materials listed as heavy release additives is preferably less than that in the first release agent layer composition, or is not included.

[0201] Furthermore, the first release agent layer composition and the second release agent layer composition may contain additives commonly used in the release agent layer, as long as the effects of the present invention are not impaired. Examples of such additives include dyes and dispersants.

[0202] Furthermore, from the perspective of adjusting the release force to be low and facilitating the formation of a release agent layer utilizing the above-mentioned transfer phenomenon, silicone oil may be added to the release agent layer composition (the first release agent layer composition and the second release agent layer composition).

[0203] (2.2.4 Manufacturing process of long strips)

[0204] To produce a long sheet, first, the protective film-forming film composition, the first release agent layer composition, and the second release agent layer composition are prepared. In this embodiment, from the perspective of adjusting the viscosity and thereby improving coating properties, it is preferred to prepare a coating agent by diluting the protective film-forming film composition and the release agent layer composition containing the above-mentioned components with a diluting solvent.

[0205] Examples of the dilution solvent include organic solvents such as 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 dilution solvents may be used alone or in combination of two or more.

[0206] The solid content concentration of the coating agent containing the protective film-forming film composition is preferably 20 to 80% by mass, more preferably 30 to 70% by mass. Meanwhile, the solid content concentration of the coating agent containing the first release agent layer composition and the second release agent layer composition 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.

[0207] In this embodiment, a coating comprising a first release agent layer composition is applied to one surface of a substrate using a known method, and the coating is dried and cured to form a first release agent layer. This results in a first release film. A second release film can also be produced in the same manner.

[0208] When forming the release agent layer on both main surfaces of the substrate, the release agent layer composition can be applied to the other surface of the substrate. Alternatively, the release agent layer can be formed by winding the first release film coated with the release agent layer composition into a roll and storing it at 30°C for 7 days, for example, to transfer the components of the release agent layer composition to the other surface by utilizing the above-mentioned transfer phenomenon.

[0209] In this embodiment, a coating agent comprising a protective film-forming composition is applied to the first release agent layer of a first release film or the second release agent layer of a second release film using a known method, followed by heating and drying to form a coating film. Subsequently, the second release agent layer of a second release film or the first release agent layer of a first release film is laminated onto the coating film to produce a protective film-forming sheet (long sheet). In this embodiment, from the perspective of ensuring that the release force F1 falls within the above-mentioned range and that F1 > F2, it is preferred that the coating agent comprising the protective film-forming composition be applied to the first release agent layer of the first release film rather than the second release agent layer.

[0210] Examples of the coating method of the coating agent comprising each composition include spin coating, spray coating, bar coating, knife coating, roll coating, knife roll coating, blade coating, die coating, and gravure coating.

[0211] (3. Method for manufacturing the device)

[0212] As an example of a method for manufacturing an apparatus using a protective film forming sheet roll manufactured by the method of this embodiment, a method for manufacturing a chip with a protective film obtained by processing a wafer having a protective film forming film attached thereto will be described.

[0213] First, if Figure 4 As shown, a long sheet is unwound from a protective film forming sheet roll 100, and a cut 40 is formed in the long sheet using a cutting blade 50, penetrating the second release film 30 and the protective film forming film 10 and reaching a portion of the first release film 20. By removing the second release film and unnecessary protective film forming film from the long sheet with the cut 40 formed, a circular protective film forming film can be obtained.

[0214] Then, if Figure 5A As shown, a circular protective film forming film 11 is attached to the back surface 60b of the wafer 60 as a workpiece, as shown in FIG. Figure 5B As shown, the first release film 20 is peeled off from the laminate and the protective film forming film 11 is protected to form a protective film 15. Next, the wafer with the protective film is singulated to obtain chips with a protective film. Alternatively, the protective film can be applied after the wafer is singulated.

[0215] Since the formation of curling marks on the protective film forming film can be suppressed, the formation of marks on the surface of the protective film can also be suppressed. Therefore, a chip with a protective film can be obtained in which the appearance defect of the protective film is suppressed.

[0216] (4. Modification)

[0217] Figure 3The following structure is shown: in the first peeling film 20, a first peeling agent layer 23 is formed on the surface 20a that is not in contact with the protective film forming film 10, and in the second peeling film 30, a second peeling 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 structure.

[0218] For example, a configuration may be adopted in which the first release film has a first release agent layer formed on the surface not in contact with the protective film-forming film, and the second release film has a second release agent layer formed on the surface not in contact with the protective film-forming film. Alternatively, a configuration may be adopted in which the first release film has no first release agent layer formed on the surface not in contact with the protective film-forming film, and the second release film has a second release agent layer formed on the surface not in contact with the protective film-forming film.

[0219] also, Figure 4 Although the cutout for forming the protective film to be attached to the workpiece is circular, other shapes are also possible as long as they are closed. Examples of other shapes include polygons such as triangles and ellipses. Furthermore, it is preferred that the closed shape corresponds to the shape of the workpiece.

[0220] As mentioned above, although embodiment of this invention was demonstrated, this invention is not limited to the said embodiment at all, It can change in various aspects within the scope of this invention.

[0221] Example

[0222] Hereinafter, the present invention will be described in more detail using examples, but the present invention is not limited to these examples.

[0223] (Preparation of the First Release Film)

[0224] First, in order to prepare the composition for the first release agent layer, the following components were prepared.

[0225] (α) Silicone release agent

[0226] (α-1) Silicone-based release agent containing organopolysiloxane having a vinyl group and organopolysiloxane having a hydrosilyl group (manufactured by Dow Corning Toray Co., Ltd., BY24-561, solid content 30% by mass)

[0227] (α-2) Dimethyl polysiloxane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: X-62-1387, weight average molecular weight: 2000)

[0228] (β) Silicone resin

[0229] MQ resin having a vinyl group (manufactured by Dow Corning Toray Co., Ltd., SD-7292, solid content 71% by mass)

[0230] (γ) catalyst

[0231] Platinum (Pt) catalyst (manufactured by Dow Corning Toray Co., Ltd., SRX-212, solid content 100% by mass)

[0232] Next, 67.5 parts by mass (solid content ratio) of (α-1), 2.5 parts by mass (solid content ratio) of (α-2), 30 parts by mass (solid content ratio) of (β), and 6.7 parts by mass (solid content ratio) of (γ) were blended and mixed, and diluted with a mixed solvent of toluene and methyl ethyl ketone (toluene / methyl ethyl ketone = 1 / 1 (mass ratio)) to a solid content concentration of 2% by mass to prepare a coating agent containing a composition for a first release agent layer.

[0233] A coating agent containing the prepared first release agent layer-forming composition was applied to both main surfaces of a PET film (manufactured by Mitsubishi Chemical Corporation, trade name: DIAFOIL (registered trademark) T-100, thickness: 50 μm) serving as a substrate so that a film thickness after heating and drying was 0.15 μm. First release agent layers were formed on both main surfaces of the PET film to produce a first release film.

[0234] (Preparation of the Second Release Film)

[0235] As the second release film, a PET film having one surface subjected to a release treatment ("SP-PET381031" manufactured by Lintec Corporation, thickness 38 μm) was used.

[0236] (Production of protective film-forming film)

[0237] The following components were mixed at the blending ratio (solid content conversion) shown in Table 1, and diluted with methyl ethyl ketone so that the solid content concentration became 50% by mass to prepare a coating agent containing a protective film-forming film composition.

[0238] (A) Polymer component

[0239] (A-1) A (meth)acrylate copolymer (weight average molecular weight: 800,000, glass transition temperature: -28°C) prepared by copolymerizing 55 parts by mass of n-butyl acrylate, 10 parts by mass of methyl acrylate, 20 parts by mass of glycidyl methacrylate, and 15 parts by mass of 2-hydroxyethyl acrylate.

[0240] (A-2) A (meth)acrylate copolymer (weight average molecular weight: 500,000, glass transition temperature: -9°C) prepared by copolymerizing 27 parts by mass of n-butyl acrylate, 38 parts by mass of methyl acrylate, 20 parts by mass of glycidyl methacrylate, and 15 parts by mass of 2-hydroxyethyl acrylate.

[0241] (B) Curable component (thermosetting component)

[0242] (B-1) Bisphenol A epoxy resin (manufactured by Mitsubishi Chemical Corporation, jER828, epoxy equivalent 184 to 194 g / eq)

[0243] (B-2) Acrylate rubber microparticle-dispersed bisphenol A type liquid epoxy resin (manufactured by NIPPON SHOKUBAI CO., LTD., BPA328, epoxy equivalent 230 g / eq, acrylate rubber content 20 phr)

[0244] (B-3) Dicyclopentadiene epoxy resin (manufactured by DIC Corporation, EPICLON HP-7200HH, softening point 88-98°C, epoxy equivalent 255-260 g / eq)

[0245] (C) Curing agent: dicyandiamide (manufactured by Mitsubishi Chemical Corporation, DICY7)

[0246] (D) Curing accelerator: 2-phenyl-4,5-dihydroxymethylimidazole (manufactured by SHIKOKU CHEMICALS CORPORATION, CUREZOL 2PHZ)

[0247] (E) Filler: Epoxy-modified spherical silica filler (manufactured by Admatechs, SC2050MA, average particle size 0.5 μm)

[0248] (F) Silane coupling agent: γ-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM403, methoxy equivalent 12.7 mmol / g, molecular weight 236.3)

[0249] (G) Colorant: Carbon black (manufactured by Mitsubishi Chemical Corporation, MA600B, average particle size 28 nm)

[0250] The coating agent containing the prepared protective film forming film composition was coated on the face of the prepared 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 having a thickness of 20 μm. Subsequently, the face of the prepared second release film on which the second release agent layer was formed was attached to the protective film forming film, thereby obtaining a protective film forming sheet in which the first release film was formed on one main face of the protective film forming film and the second release film was formed on the other main face (a structure of first release film / protective film forming film / second release film). The attachment conditions were a temperature of 60°C, a pressure of 0.4 MPa, and a speed of 1 m / minute.

[0251] (Production of a sheet roll)

[0252] The obtained protective film forming sheet was cut into a width of 320 mm using a two-axle winding slitting machine (manufactured by TOIZAKI BUSSAN CO., LTD.) while being wound on a hollow plastic core (core portion) having the same width as the width of the cut protective film forming sheet (320 mm) and having a diameter of 3 inches in a roll shape by using a core fixing tape having a width of 5 mm and a thickness of 40 μm. The winding conditions were such that the current meter of a magnetic powder brake for controlling the tension at the time of winding showed 0.25 A. The length of the wound protective film forming sheet was 50 m. The cutting speed was 5 m / minute.

[0253] The wound protective film forming sheet (Examples 1 to 3 and Comparative Examples 1 and 2) was stored under the following storage conditions (Modes 1 to 4), thereby obtaining a protective film forming sheet roll.

[0254] In Mode 1, after standing at 23°C for 3 days after winding, the sheet was again stood at 23°C for 17 days after standing at 5±4°C for 40 days (Example 1 and Comparative Example 1). In Mode 2, after standing at 23°C for 3 days after winding, the sheet was again stood at 23°C for 7 days after standing at 5±4°C for 50 days (Example 2). In Mode 3, after standing at 23°C for 3 days after winding, the sheet was again stood at 23°C for 27 days after standing at 5±4°C for 30 days (Example 3). In Mode 4, the sheet was stood at 23°C for 60 days after winding (Comparative Example 4).

[0255] Subsequently, the following measurements and evaluations were performed.

[0256] (10°C under the protective film forming film loss tangent tan δ 10 )

[0257] The first release film and the second release film were peeled from the prepared protective film forming sheet, and a plurality of protective film forming films were laminated to form a laminate of protective film forming films having a thickness of 200 μm±20 μm. The laminate was cut in a width of 4 mm to obtain a test sample for measurement.

[0258] Using a viscoelasticity measuring device ("RHEOVIBRON DDV-01FP" manufactured by ORIENTEC Co., Ltd.), tan δ of the measurement sample was measured in a tensile mode at a frequency of 11 Hz, a distance between the grips of 15 mm, and a temperature increase rate of 3°C / min in the temperature range of -20°C to 50°C, and tan δ at 10°C was calculated from these values. 10 The measurement results of the samples of Examples 1 to 3 and Comparative Examples 1 and 2 are shown in Table 1.

[0259] (Evaluation of the presence or absence of the release treatment of the release film)

[0260] The protective film-forming sheet was unwound from the obtained roll, and 3 pieces of the protective film-forming sheet each having a size of 50 mm x 50 mm were cut in the width direction at a position 1 m from the starting portion at which the protective film-forming sheet was fixed to the plastic core by the core-fixing tape.

[0261] The first release film and the second release film were peeled from the cut protective film-forming sheet, and XPS measurement was performed on the surface of the first release film that was not bonded to the protective film-forming film using the following conditions. Similarly, XPS measurement was performed on the surface of the second release film that was not bonded to the protective film-forming film using the following conditions. The XPS measurement was performed once for each of the 3 pieces of the first release film and the 3 pieces of the second release film obtained by cutting the protective film-forming sheet.

[0262] XPS device: Quantera SXM manufactured by ULVAC-PHI, INCORPORATED.

[0263] X-ray: Al Kα (1486.6 eV)

[0264] Take-off angle: 45°

[0265] Measured elements: silicon (Si), carbon (C), and oxygen atom (O)

[0266] From the obtained measurement results, the silicon atomic ratio shown below was calculated from the amount of each measured element (XPS count) for each of the first release film and the second release film, and the average value thereof was calculated.

[0267] Silicon atomic ratio (atom %) = [(amount of Si element) / [(amount of C element) + (amount of O element) + (amount of Si element)]] x 100

[0268] Based on the obtained average value, evaluation was performed using the following determination criteria. The cases of Determination A and Determination B were determined to have undergone the release treatment. The measurement results of the samples of Examples 1 to 3 and Comparative Examples 1 and 2 are shown in Table 1.

[0269] Judgment A: The average value of at least one of the first release film and the second release film is 1.0 atomic % or more

[0270] Judgment B: Judgment A is not satisfied, and the average value of at least one of the first release film and the second release film is 0.1 atomic % or more and less than 1.0 atomic %

[0271] Judgment C: The average value of both the first release film and the second release film is less than 0.1 atomic %

[0272] A first release film was prepared before application of a coating agent containing a protective film-forming composition. Three sections of the film, each measuring 50 mm x 50 mm, were cut from the first release film along its width. Using the XPS apparatus described above, the surfaces of both main surfaces of the first release film, where the coating agent containing the protective film-forming composition was to be applied, were evaluated for release treatment under the same conditions as described above. The results confirmed that the average silicon atomic ratio at the three sections of the first release film sample was 1.0 atomic % or greater.

[0273] A second release film was prepared before being attached to the protective film-forming film. Three cuts were made from the second release film, each measuring 50 mm x 50 mm, along its width. Using the XPS apparatus described above, the surfaces of both main surfaces of the second release film, intended for attachment to the protective film-forming film, were evaluated for the presence or absence of a release treatment under the same conditions as described above. The results confirmed that the average silicon atomic ratio at the three cuts in the second release film sample was 1.0 atomic % or greater.

[0274] (Evaluation of the contact angle of water on the release film)

[0275] The protective film forming sheet is unwound from the obtained sheet roll, and three 50mm×50mm protective film forming sheets are cut 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.

[0276] The first and second release films were peeled off from the cut protective film-forming sheet, and the water contact angle was measured on the surface of the first release film not in contact with the protective film-forming film under the following conditions. Similarly, the water contact angle was measured on the surface of the second release film not in contact with the protective film-forming film under the following conditions. The water contact angle was measured five times for each of the three first and three second release films obtained by cutting the protective film-forming sheet.

[0277] Contact angle measuring device: Kyowa Interface Science, Inc., fully automatic contact angle meter DM-701

[0278] Drop volume: 2 μL

[0279] Environment: Temperature 23°C, Humidity 50%

[0280] The average of the measurement results for each of the first and second release films was calculated. Based on the obtained averages, evaluation was performed using the following criteria. A rating of A was considered to indicate that the film had undergone a release treatment. The measurement results for the samples of Examples 1 to 3 and Comparative Examples 1 and 2 are shown in Table 1.

[0281] Judgment A: The average value of at least one of the first release film and the second release film is 78 or more Judgment C: The average value of both the first release film and the second release film is 77 or less

[0282] (Peeling force F1 for peeling the first peeling film from the protective film-forming film)

[0283] The second release film was peeled off from the resulting protective film-forming sheet. Using heat lamination (70°C, 1 m / min), the high-adhesion surface of 25 μm-thick high-adhesion PET (PET25A-4100, manufactured by TOYOBO Co., Ltd.) was attached to the surface of the protective film-forming film exposed by peeling to produce a laminate sample. The laminate sample was cut into 100 mm wide pieces to produce a measurement sample. The back of the first release film of the measurement sample was secured to a rigid support plate using double-sided tape.

[0284] A universal tensile testing machine (manufactured by Shimadzu Corporation, product name

[0285] Using a 100mm tester ("AUTOGRAPH (registered trademark) AG-IS"), a composite (integrated) of a protective film-forming film and high-adhesion PET was peeled from a first release film at a peeling speed of 1 m / min and a peeling distance of 100 mm. The load applied during this peeling was measured. The average of the loads over the 80 mm distance, excluding the first and last 10 mm, was taken as the peel force F1.

[0286] (Peeling force F2 for peeling the second peeling film from the protective film-forming film)

[0287] The obtained protective film-forming sheet was cut into 100 mm width to prepare a measurement sample. The back surface of the first release film of the measurement sample was fixed to a hard support plate with a double-sided tape.

[0288] A universal tensile testing machine (manufactured by Shimadzu Corporation, product name

[0289] Using a 100mm test strip ("AUTOGRAPH (registered trademark) AG-IS"), the second release film was peeled from the test sample at a test distance of 100mm, a peel angle of 180°, and a peel rate of 1m / min. The load at this time was measured. The average of the loads over the 80mm distance, excluding the loads in the first 10mm and the last 10mm of the test distance, was taken as the peel force F2.

[0290] Comparison of the obtained peeling forces F1 and F2 confirmed that F1 was larger than F2 for all samples.

[0291] (Evaluation of curl marks)

[0292] After 60 days of storage, a long sheet was unwound from the outermost layer of a protective film-forming sheet roll at a speed of 3 m / min. The length from the core, at which a winding mark outside the acceptable range began to appear, was measured. Five panelists visually inspected the sheet simultaneously to determine if it was an acceptable winding mark. If three panelists judged it to be an acceptable winding mark, it was deemed an acceptable winding mark. The evaluation results for the samples of Examples 1 to 3 and Comparative Examples 1 and 2 are shown in Table 1.

[0293] Judgment A: more than 0 meters and less than 4 meters

[0294] Judgment B: more than 4 meters and less than 6 meters

[0295] Criteria C: more than 6 meters and less than 8 meters

[0296] Judgement D: more than 8 meters and less than 10 meters

[0297] Judgment E: More than 10 meters

[0298] [Table 1]

[0299]

[0300] According to Table 1, the loss tangent (tan δ) of the protective film-forming film at 10°C can be confirmed. 10 ) is 1.2 or less, and when the storage conditions of the protective film-forming sheet roll after winding satisfy the above conditions, the formation of winding marks on the protective film-forming film in the protective film-forming sheet roll is suppressed.

Claims

1. A method for producing a sheet roll for forming a protective film, comprising: storing a sheet roll formed by winding a long sheet having a protective film-forming film, a first release film provided on one surface of the protective film-forming film, and a second release film provided on the other surface of the protective film-forming film at a storage temperature of 10° C. or less for 25 days or more within 60 days after the sheet roll is formed; When the peeling force for peeling the first peeling film from the protective film-forming film is F1 and the peeling force for peeling the second peeling film from the protective film-forming film is F2, the relationship F1>F2 is satisfied. The loss tangent of the protective film-forming film at 10° C. is defined as tan δ. 10 When tanδ 10 is below 1.2, The protective film-forming film composition constituting the protective film-forming film contains a polymer component, a curable component, and a filler. The polymer component is acrylic resin, and the glass transition temperature of the acrylic resin is -20 to 40°C. The curable component is epoxy resin, When the total weight of the protective film-forming film composition is 100 parts by mass, the content of the filler is 15 to 80 parts by mass, and the content of the polymer component is 5 to 80 parts by mass. In the first release film and / or the second release film, the surface not in contact with the protective film-forming film is subjected to a release treatment. The release treatment is a process of modifying the surface or forming a material other than the surface on the surface so that the long pieces in contact can slide easily against each other.

2. The method for producing a protective film-forming sheet roll according to claim 1, wherein: The step of storing the sheet at a storage temperature of 10° C. or lower is started within 10 days after the sheet is formed into the roll.

3. The method for producing a protective film-forming sheet roll according to claim 1 or 2, wherein: The storage temperature is -10°C or above.

4. The method for producing a protective film-forming sheet roll according to claim 1 or 2, wherein: tanδ 10 It is above 0.04.

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