JP2022032572A - Manufacturing method of protective film forming sheet roll - Google Patents

Abstract

To provide a manufacturing method of a protective film forming sheet roll in which marks caused by winding of a protective film forming film resulting in marks on a protective film are less likely to occur.SOLUTION: A protective film forming sheet roll is formed by winding up a long sheet having a protective film forming film, a first release film provided on one side of the protective film forming film, and a second release film provided on the other side of the protective film forming film. The manufacturing method of a protective film forming sheet roll has a step of storing a sheet roll at a storage temperature of 10°C or lower for at least 25 days out of 60 days after the sheet roll is formed. When peeling force of the first release film from the protective film forming film is F1 and peeling force of the second release film from the protective film forming film is F2, a relationship F1>F2 is satisfied. When a loss tangent of the protective film forming film at 10°C is defined as tanδ10, the tanδ10 is 1.2 or less.SELECTED DRAWING: Figure 1A

Description

The present invention relates to a method for manufacturing a sheet roll for forming a protective film. In particular, the present invention relates to a method for manufacturing a protective film forming sheet roll, which is less likely to cause marks due to winding of the protective film forming film that causes marks on the protective film.

In recent years, semiconductor devices have been manufactured by 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 inverted (faced down) to the chip mounting portion and joined. Therefore, the structure is such that the back surface side of the semiconductor chip on which the circuit is not formed is exposed.

Therefore, in order to protect the semiconductor chip from impacts such as during transportation, a hard protective film made of an organic material is often formed on the back surface side of the semiconductor chip. Such a protective film is formed, for example, in a cured or uncured state after the protective film forming film is attached to the back surface of the semiconductor wafer.

The protective film-forming film constitutes a long protective film-forming sheet together with a support film that supports the protective film-forming film. This long sheet is usually wound up into a sheet roll before using the protective film-forming film. When the protective film-forming film is used, the long protective film-forming sheet unwound from the sheet roll is cut out to have substantially the same shape as the semiconductor wafer to be attached, and then attached to the semiconductor wafer. To.

Patent Document 1 discloses a long adhesive sheet in which a first sheet and a second sheet are provided on both sides of an adhesive layer. The adhesive layer is separated into a punched portion and a continuous residue portion, and the adhesive layer of the punched portion is attached as an adhesive film, for example, to the back surface of a semiconductor wafer.

International Publication No. 2017/145735

In the protective film forming sheet roll, the manufactured long protective film forming sheet is fixed to the core portion using a core fixing tape, and a predetermined tension is applied to the long protective film forming sheet by a winding device. It is formed by winding while adding. As a result, stress remains in the wound long protective film forming sheet (protective film forming sheet roll), and winding pressure is generated in the direction toward the core portion. This winding pressure tends to be large in the protective film forming sheet near the core, that is, the protective film forming sheet at the beginning of winding, and small in the protective film forming sheet on the outer peripheral side of the sheet roll.

In addition, due to variations in tension during winding, even in the same protective film forming sheet roll, some parts are strongly pressed and some parts are weakly pressed, and after winding, they are strongly pressed for a long time. Marks (winding marks) due to winding may be formed on the protective film forming sheet at the present locations. In particular, the winding pressure is large at the locations where the protective film forming sheet has begun to be wound, and at the same time, variations in the winding pressure between the wound locations in the width direction are likely to occur. Further, since a step is generated due to the thickness of the core fixing tape and the protective film forming sheet, the winding pressure becomes large due to this step, and the winding pressure tends to vary in the width direction. Therefore, after winding, the protective film forming sheet closer to the core portion is more likely to have winding marks due to being partially strongly pressed than the protective film forming sheet on the outer peripheral side of the sheet roll. When such winding marks are generated, winding marks are also generated on the protective film forming film constituting the protective film forming sheet. As a result, the protective film-forming film is attached to the work, and even when the protective film is formed, winding marks remain, causing a poor appearance of the protective film.

However, even if the setting conditions of the winding device are adjusted when forming the sheet roll, there is a problem that it is difficult to completely suppress the winding marks due to the above-mentioned variation in winding pressure and the like.

It is an object of the present invention to provide a method for producing a protective film forming sheet roll, which is made in view of such an actual situation and is less likely to generate marks due to winding of the protective film forming film that causes marks on the protective film. ..

Aspects of the present invention are as follows.
[1] Protective film forming film and
The first release film provided on one surface of the protective film forming film and
A sheet roll formed by winding a long sheet having a second release film provided on the other surface of the protective film forming film is placed at 10 ° C. or less for 25 days or more within 60 days after the sheet roll is formed. Has a process of storing at the storage temperature of
When the peeling force of the first release film from the protective film-forming film is F1 and the peeling force of the second release film from the protective film-forming film is F2, the relationship of F1> F2 is satisfied.
This is a method for producing a protective film forming sheet roll in which tan δ ₁₀ is 1.2 or less when the loss tangent of the protective film forming film at 10 ° C. is tan δ ₁₀ .

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

[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.

[4] The sheet roll for forming a protective film 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 peeled. It is a manufacturing method of.

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

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a method for producing a protective film-forming sheet roll in which scars due to winding of the protective film-forming film that cause scars on the protective film are less likely to occur.

FIG. 1A is a schematic perspective view of an example of a protective film forming sheet roll according to the present embodiment. FIG. 1B is a schematic enlarged cross-sectional view of the IB portion of FIG. 1A. FIG. 2 is a schematic cross-sectional view of an example of a protective film forming sheet according to the present embodiment. FIG. 3 is a schematic cross-sectional view showing that the first release film and the second release film have the first release agent layer and the second release agent layer. FIG. 4 is a schematic perspective view of a long sheet drawn out from the protective film forming sheet roll according to the present embodiment and having a notch formed therein. FIG. 5A is a schematic cross-sectional view showing that the laminated body of the protective film forming film and the first release film is attached to the work. FIG. 5B is a schematic cross-sectional view showing that the protective film forming film attached to the work has been formed into a protective film.

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

First, the main terms used in the present specification will be described.

The work is a plate-like body to which a protective film forming film is attached and processed. Examples of the work include wafers and panels. Specific examples thereof include semiconductor wafers and semiconductor panels. Examples of the work piece include a chip obtained by separating a wafer into individual pieces. Specifically, a semiconductor chip obtained by fragmenting a semiconductor wafer into pieces is exemplified. In this case, the protective film is formed on the back surface side of the wafer.

The "front surface" of the work refers to a surface on which a circuit, a convex electrode such as a bump, or the like is formed, and the "back surface" refers to a surface on which a circuit or the like is not formed.

In the present specification, for example, "(meth) acrylate" is used as a term indicating both "acrylate" and "methacrylate", and the same applies to other similar terms.

In the present specification, the weight ratio of the components constituting each composition is shown by the solid content ratio.

(1. Sheet roll for forming a protective film)
(1.1 Form of sheet roll for forming protective film)
FIG. 1A shows an example of a protective film forming sheet roll manufactured by the manufacturing method according to the present embodiment. In FIG. 1A, the protective film forming sheet roll 100 is a roll on which a long sheet 1 for forming a protective film is wound.

(1.2 Protective film forming sheet)
First, a long sheet will be described. The protective film forming sheet 1 as a long sheet is used for attaching the protective film forming film to the work. As shown in FIG. 2, in the protective film forming sheet 1, the first release film 20 is arranged on one main surface 10a of the protective film forming film 10, and the second release film 30 is placed on the other main surface 10b. It has an arranged configuration. Hereinafter, the long sheet 1 may be referred to as a protective film forming sheet 1.

The protective film forming sheet 1 is wound as a roll and then stored until use. During storage, the protective film-forming film is supported by a first release film and a second release film formed on both main surfaces.

At the time of use, the protective film-forming sheet is unwound from the protective film-forming sheet roll, and the protective film-forming film is cut into a predetermined shape. After the second release film is peeled off, the protective film forming film is attached to the back surface of the work, and after the first release film is peeled off, the protective film is formed. The protective film protects the work or the workpiece of the work.

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

(1.3 Protective film forming film)
As described above, the protective film forming film is formed into a protective film after being attached to the work, and forms a protective film for protecting the work or the work piece of the work.

"Forming a protective film" is to bring the protective film-forming film into a state having sufficient properties to protect the work or the workpiece of the work. Specifically, when the protective film-forming film is curable, "forming the protective film" means making the uncured protective film-forming film a cured product. In other words, the protective film-forming film is a cured product of the protective film-forming film, and is different from the protective film-forming film.

By superimposing the work on the curable protective film-forming film and then curing the protective film-forming film, the protective film can be firmly adhered to the work and a durable protective film can be formed.

On the other hand, when the protective film-forming film is used in a non-curable state without containing a curable component, the protective film-forming film is formed into a protective film when the protective film-forming film is attached to the work. .. In other words, the protective film-forming film formed into a protective film is the same as the protective film-forming film.

When high protective performance is not required, it is not necessary to cure the protective film-forming film, so that the protective film-forming film can be easily used.

In the present embodiment, the protective film-forming film is preferably curable. Therefore, the protective film is preferably a cured product. Examples of the cured product include a thermosetting product and an energy ray cured product. In the present embodiment, it is more preferable that the protective film is a thermosetting product.

Further, it is preferable that the protective film-forming film has adhesiveness at room temperature (23 ° C.) or exhibits adhesiveness by heating. As a result, both can be bonded when the work is superposed on the protective film forming film. Therefore, positioning can be reliably performed before the protective film-forming film is cured.

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

In the present embodiment, the protective film-forming film is preferably one layer (single layer). The one-layer protective film-forming film is easy to produce because it can obtain high accuracy in terms of thickness. Further, when the protective film forming film is composed of a plurality of layers, it is necessary to consider the adhesion between the layers and the elasticity of each layer, and there is a risk that peeling from the adherend occurs due to these. When the protective film forming film has one layer, the above risk can be reduced and the degree of freedom in design is increased.

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, and 30 μm or less. By setting the upper limit of the thickness of the protective film-forming film to the above value, it is possible to reduce the step caused by the thickness of the protective film-forming sheet at the portion where the film has begun to be wound.

The thickness of the protective film-forming film is preferably 5 μm or more, 10 μm or more, and 15 μm or more. By setting the lower limit of the thickness of the protective film-forming film to the above value, it is easy to obtain the performance of protecting the work as a protective film, and further, the protective film-forming film relaxes stress in the protective film-forming sheet roll. It can work to shorten the length from the core where the winding marks start to appear.

The thickness of the protective film-forming film means the thickness of the entire protective film-forming film. For example, the thickness of the protective film-forming film composed of a plurality of layers means the total thickness of all the layers constituting the protective film-forming film.

(13.1 Loss tangent of protective film forming film at 10 ° C)
In the present embodiment, the loss tangent (tan δ ₁₀ ) of the protective film forming film at 10 ° C. is 1.2 or less. The loss tangent is defined as "loss elastic modulus / storage elastic modulus" and is a value measured by the response to the stress applied to the object by the dynamic viscoelasticity measuring device. By setting 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 that the winding pressure of the sheet roll is increased. Even if it is high, it tends to be difficult to make winding marks. Therefore, in the present embodiment, the loss tangent of the protective film forming film at 10 ° C. is controlled.

The loss tangent (tan δ ₁₀ ) of the protective film forming film at 10 ° C. is preferably 1.0 or less, more preferably 0.9 or less, and further preferably 0.8 or less. Further, the loss tangent (tan δ ₁₀ ) of the protective film forming film at 10 ° C. is preferably 0.04 or more, more preferably 0.1 or more, further preferably 0.2 or more, and 0. It is particularly preferable that the content is 3 or more. Loss of the protective film-forming film at 10 ° C. By setting the lower limit of the tangent to the above value, it is possible to prevent the protective film-forming film bent in the sheet roll from cracking at 10 ° C.

The loss tangent (tan δ ₁₀ ) of the protective film forming film at 10 ° C. may be measured by a known method. For example, a protective film-forming film is used as a sample of a predetermined size, and a dynamic viscoelasticity measuring device is used to strain the sample at a predetermined frequency in a predetermined temperature range to measure the elastic modulus and measure the elasticity. From the rate, the loss tangent (tan δ ₁₀ ) at 10 ° C. can be calculated. The specific measurement method will be described in detail in Examples described later.

(1.4 1st release film)
The first release film is a film capable of releasably supporting the protective film-forming film. In the present embodiment, it is preferable that the first release film is peeled off from the protective film-forming film after the protective film-forming film is attached to the work.

The first release film may be composed of one layer (single layer) or two or more layers of a base material, or the surface of the base material may be peeled from the viewpoint of controlling the peelability. That is, the surface of the base material may be modified, or a material not derived from the base material may be formed on the surface of the base material.

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

Since the lower limit of the thickness of the first release film is the above value, the cutting blade penetrates the first release film when forming a notch that reaches a part of the first release film by using the cutting blade described later. However, it is possible to prevent the first release film from being cut. Further, in the protective film forming sheet roll, the first release film acts to relieve stress, and the length from the core portion where winding marks start to be formed can be further shortened.

Further, since the upper limit of the thickness of the first release film is the above value, the protective film forming sheet is unwound, and the protective film forming sheet is cut out and conveyed to the next step. Passes through a roller such as a guide roller in the apparatus, and at that time, it is possible to prevent the protective film forming film from peeling from the first release film. Further, the step due to the thickness of the protective film forming sheet at the portion where the winding has started can be reduced.

The thickness of the first release film means the thickness of the entire first release film. For example, the thickness of the first release film composed of a plurality of layers means the total thickness of all the layers constituting the first release film.

In the present embodiment, the first release film preferably has a base material and a first release agent layer. By having the first release agent layer, it is easy to control the physical properties of the surface on which the first release agent layer is formed in the first release film.

Further, in the present embodiment, in the protective film forming sheet, the peeling force of the first release film from the protective film forming film is F1, and the peeling force of the second release film described later from the protective film forming film is F2. In some cases, F1 and F2 satisfy the relationship F1> F2. By satisfying such a relationship, when the second release film is removed from the protective film-forming sheet, the protective film-forming film 10 that should remain is not removed together with the second release film, and the protective film-forming film 10 is formed. It becomes easy to leave it on the first release film.

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

In this embodiment, F1 and F2 are load values measured using a tensile tester. The specific measurement method will be described in detail in Examples described later.

(1.4.1 base material)
The base material of the first release film is not particularly limited as long as it is a material that can support the protective film-forming film until the protective film-forming film is attached to the work, and is usually a film mainly made of a resin-based material (hereinafter,). It is composed of "resin film").

Specific examples of the resin film include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polyethylene naphthalate film, and polybutylene terephthalate film. Polyurethane film, ethylene vinyl acetate copolymer film, ionomer resin film, ethylene / (meth) acrylic acid copolymer film, ethylene / (meth) acrylic acid ester copolymer film, polystyrene film, polycarbonate film, polyimide film, fluorine A resin film or the like is used. These crosslinked films are also used. Further, these laminated films may be used. In the present embodiment, the polyethylene terephthalate film is preferable from the viewpoint of suppressing the winding due to the stretching of the base material, in addition to the viewpoint of environmental safety and cost.

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

The thickness of the base material can function appropriately in each step in which the protective film forming sheet is used, and is not particularly limited within the range of the thickness of the first release film described above. The thickness of the base material is preferably 30 μm or more and 100 μm or less. Further, the thickness of the base material is more preferably 40 μm or more, and further preferably 45 μm or more. Further, the thickness of the base material is more preferably 80 μm or less, and further preferably 70 μm or less.

(14.2 First release agent layer)
The first release agent layer imparts the release property from the protective film-forming film to the first release film. The first release agent layer is not particularly limited as long as it is made of a material that can impart releaseability. In the present embodiment, the first release agent layer is obtained by curing a composition for a first release agent layer containing a release agent.

In the first release film, it is preferable that the first release agent layer is directly formed on the surface of the base material. By directly forming the first release agent layer on the surface of the base material, the production of the first release film becomes easy, so that the cost can be reduced.

The thickness of the first release agent layer is not particularly limited, but is preferably 30 nm or more and 200 nm or less. Further, the thickness of the first release agent layer is more preferably 50 nm or more, further preferably 80 nm or more. Further, the thickness of the first release agent layer is more preferably 180 nm or less.

When the thickness of the first release agent layer is within the above range, stable release performance can be exhibited when the protective film-forming film is attached to the work.

Further, in the present embodiment, it is preferable that the first release agent layer is formed not only on the surface of the first release film on the protective film-forming film side but also on the surface on the opposite side thereof. That is, as shown in FIG. 3, in the protective film forming sheet 1, the first release film 20 includes the base material 21 and the first release agent layers 22 and 23 formed on both main surfaces of the base material 21. Has. The main surface 20b of the first release film (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 may be composed of different compositions.

In the sheet roll, since the long sheets 1 are laminated in the radial direction, the surface 20a that is not in contact with the protective film-forming film of the first release film is the surface 30b that is not in contact with the protective film-forming film of the second release film. I'm in contact. Therefore, in the first release film, the surfaces 20a that are not in contact with the protective film forming film are peeled off (because the first release agent layer 23 is formed), so that the long sheets that are in contact with each other are in contact with each other. Is slippery, so it is possible to promote the stabilization of the winding pressure, which will be described later.

(1.5 Second release film)
The second release film is a film that can support the protective film-forming film so that it can be peeled off. In the present embodiment, it is preferable that the second release film is peeled from the protective film-forming film before the protective film-forming film is attached to the work.

Like the first release film, the second release film may be composed of one layer (single layer) or two or more layers of a base material, and the surface of the base material is peeled from the viewpoint of controlling the peelability. It may have been done. That is, the surface of the base material may be modified, or a material not derived from the base material may be formed on the surface of the base material.

The thickness of the second release film is not particularly limited, but is preferably 10 μm or more and 75 μm or less. The thickness of the second release film is more preferably 18 μm or more, and further preferably 24 μm or more. The thickness of the second release film is more preferably 60 μm or less, and further preferably 45 μm or less. The thickness of the second release film is preferably equal to or less than the thickness of the first release film, and is less than the thickness of the first release film, from the viewpoint of making the release force F2 and the release force 1 F1> F2 described above. More preferred.

The thickness of the second release film means the thickness of the entire second release film. For example, the thickness of the second release film composed of a plurality of layers means the total thickness of all the layers constituting the second release film.

In the present embodiment, the second release film preferably has a base material and a second release agent layer. By having the second release agent layer, it is easy to control the physical properties of the surface of the second release agent layer on which the second release agent layer is formed.

(1.5.1 base material)
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.

(1.5.2 Second release agent layer)
When the second release film has the second release agent layer, the second release agent layer is not particularly limited as long as it is made of a material capable of imparting release properties. For example, the second release agent layer is obtained by curing a composition for a second release agent layer containing a silicone-based release agent, similarly to the first release agent layer.

Similar to the first release film, it is preferable that the second release agent layer is directly formed on the surface of the base material in the second release film. By directly forming the second release agent layer on the surface of the base material, the production of the second release film becomes easy, so that the cost can be reduced.

Further, in the present embodiment, the second release agent layer is formed on the surface of the second release film on the protective film-forming film side. That is, as shown in FIG. 3, in the protective film forming sheet 1, the second release film 30 is the base material 31 and the second release agent layer 32 formed on the surface of the base material 31 on the protective film forming film side. Has. The main surface 30a of the second release film (main surface 30a of the second release agent layer 32) is in contact with the main surface 10b of the protective film forming film. Further, the second release agent layer may be formed not only on the surface of the second release film on the protective film forming film side but also on the surface 30b on the opposite side thereof.

When the second release agent layer is formed on both main surfaces of the base material, the coating agent containing the composition for the second release agent layer described later is applied to both main surfaces of the base material to form the base material. Alternatively, after applying the coating agent containing the composition for the second release agent layer to one main surface of the base material, the base material is wound up into a roll, and the coating agent is applied from the main surface to which the coating agent is applied. The second release agent layer is formed on the main surface not coated with the coating agent by utilizing the phenomenon (transfer phenomenon) in which the components of the composition for the second release agent layer are transferred to the main surface not coated with the coating agent. You may.

(2. Manufacturing method of sheet roll for forming protective film)
In the method for producing a protective film-forming sheet roll according to the present embodiment, first, the protective film-forming sheet having the protective film-forming film, the first release film and the second release film described above has a short length in the longitudinal direction. Manufactured as a long sheet that is much longer than the hand length. The long sheet may be manufactured by a known method, and a specific method will be described later.

After that, the long sheet is cut on both sides in the width direction according to the size of the work to which the protective film forming film will be attached, and while adjusting the size in the width direction, a predetermined tension is applied by the winding device. By being wound up, it becomes a sheet roll for forming a protective film.

When the width of the work is 150 mm, the length in the width direction after cutting is preferably in the range of 155 to 194 mm, and when the width of the work is 200 mm, the length in the width direction after cutting is preferable. The length of the work is preferably in the range of 205 to 250 mm, and when the width of the work is 300 mm, the length in the width direction after cutting is preferably in the range of 305 to 350 mm. When the width is 450 mm, the length in the width direction after cutting is preferably in the range of 455 to 500 mm.

As shown in FIG. 1B, in such a sheet roll 100, after fixing the long sheet 1 to the core portion 70 via a fixing means 80 such as a core fixing tape, the long sheet 1 is attached to the long sheet 1 by a winding device. It is formed by winding the long sheet 1 around the core 70 while applying a predetermined tension. As described above, in the sheet roll that has been wound up, the winding pressure varies, and in particular, a protective film is formed that causes a mark of the protective film at a portion strongly pressed on the long sheet near the core. Wind marks on the film are likely to be formed.

On the other hand, after the sheet roll is formed, that is, after the winding is completed, it is presumed that the winding pressure gradually decreases in the portion where the winding pressure is high and approaches the winding pressure in the portion where the winding pressure is low. In other words, it is presumed that the variation in the winding pressure is eliminated over time and the winding pressure in the sheet roll is stabilized (averaged). Therefore, although the variation in the winding pressure in the sheet roll is finally eliminated considerably, the winding marks formed until the variation in the winding pressure is eliminated are the protective film forming film even if the variation in the winding pressure is eliminated. Remains in.

However, if the winding pressure varies and the protective film-forming film has a low loss tangent even if it is strongly pressed, and the protective film-forming film is not easily deformed, winding marks are formed on the protective film-forming film. Hard to form. Further, when the temperature is low, it is easy to keep the loss tangent of the protective film forming film low. Further, as described above, the winding pressure in the sheet roll tends to stabilize with the passage of time.

(2.1 Storage process)
Therefore, in the present embodiment, the sheet roll immediately after winding is stored for a predetermined period until the winding pressure stabilizes, while maintaining the loss tangent of the protective film forming film within the above-mentioned range.

Specifically, the method for producing a protective film-forming sheet roll according to the present embodiment is a sheet roll having a protective film-forming film having a loss tangent (tan δ ₁₀ ) of 1.2 or less at 10 ° C. The sheet roll is stored for 60 days after formation, and the sheet roll is stored at a storage temperature of 10 ° C. or lower for a period of 25 days or more out of 60 days.

Loss of protective film-forming film at 10 ° C. For sheet rolls with a protective film-forming film having a tangent (tan δ ₁₀ ) of 1.2 or less, store the sheet roll at 10 ° C or lower until the winding pressure of the sheet roll stabilizes. This makes it easier for the protective film-forming film to achieve loss tangent within the above range, so that it is possible to suppress the formation of winding marks on the protective film-forming film in the sheet roll.

The period for storing 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, and 45 days or longer. On the other hand, the period is preferably 60 days or less and 59 days or less.

Further, the storage at a storage temperature of 10 ° C. or lower is preferably started within 10 days after the sheet roll is formed, more preferably within 7 days, and further preferably within 4 days. Since there is a tendency for the winding pressure to vary widely in the sheet roll immediately after winding, by ensuring that the loss tangent of the protective film forming film is kept low, the formation of winding marks on the protective film forming film in the sheet roll is formed. It can be further suppressed.

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, it is possible to prevent the elastic modulus of the protective film-forming film from becoming too high, and between the protective film-forming film and the release film, particularly the protective film-forming film and the second. It is possible to suppress the occurrence of peeling from the release film.

Through such a storage step, a sheet roll for forming a protective film according to the present embodiment can be obtained. By storing the protective film-forming sheet having a loss tangent tan δ ₁₀ of 1.2 or less at 10 ° C. of the protective film-forming film in the above storage step, the protective film-forming sheet is unwound from the protective film-forming sheet roll. However, the formation of winding marks on the protective film-forming film is suppressed up to the protective film-forming sheet on the core side. Therefore, the appearance deterioration of the protective film is suppressed, and the protective film forming sheet roll according to the present embodiment can be used up without waste.

(2.2 Manufacturing method of long sheet)
In the method for producing a sheet roll for forming a protective film according to the present embodiment, a long sheet having the above-mentioned structure may be produced by a known method. In the present embodiment, the case where the first release film has the above-mentioned base material and the first release agent layer, and the second release film has the above-mentioned base material and the second release agent layer. explain.

The protective film-forming film is formed by using the composition for the protective film-forming film, the first release agent layer is formed by using the composition for the first release agent layer, and the second release agent layer is the second release agent layer. It is formed using a composition for an agent layer.

Hereinafter, the composition for the protective film forming film, the composition for the first release agent layer, and the composition for the second release agent layer will be described.

(2.2.1 Composition for protective film forming film)
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 (composition for the protective film-forming film) contains at least the polymer component (A), the curable component (B), and the filler (E). It is preferably a resin composition. The polymer component is a component that can be regarded as being formed by a polymerization reaction of a polymerizable compound. Further, the curable component is a component capable of a curing (polymerization) reaction. In the present invention, the polymerization reaction also includes a polycondensation reaction.

Further, the component contained in the polymer component may also correspond to a curable component. In the present embodiment, when the composition for a protective film-forming film contains a component corresponding to both such a polymer component and a curable component, the composition for a protective film-forming film is a polymer component and a curable component. Considered to contain both ingredients.

(2.2.1.1 Polymer component)
The polymer component (A) gives the protective film-forming film an appropriate tack while having film-forming property (film-forming property), and ensures uniform attachment of the protective film-forming film to the work. The weight average molecular weight of the polymer component is usually in the range of 50,000 to 2 million, preferably 100,000 to 1.5 million, and particularly preferably 200,000 to 1,000,000. As such a polymer component, for example, acrylic resin, urethane resin, phenoxy resin, silicone resin, saturated polyester resin and the like are used, and acrylic resin is particularly preferably used.

In the present specification, the "weight average molecular weight" is a polystyrene-equivalent value measured by a gel permeation chromatography (GPC) method unless otherwise specified. For the measurement by such a method, for example, the high-speed GPC apparatus "HLC-8120 GPC" manufactured by Tosoh Corporation is used with the high-speed columns "TSK grade volume H _XL -H", "TSK Gel GMH _XL ", and "TSK Gel G2000 H _XL ". (The above, all manufactured by Tosoh Corporation) are connected in this order, and the detector is used as a differential refractometer under the conditions of a column temperature of 40 ° C. and a liquid feeding rate of 1.0 mL / min.

Examples of the acrylic resin include a (meth) acrylic acid ester copolymer composed of a (meth) acrylic acid ester monomer and a structural unit derived from a (meth) acrylic acid derivative. Here, examples of the (meth) acrylic acid ester monomer include (meth) acrylic acid alkyl esters having an alkyl group having 1 to 18 carbon atoms, and specifically, (meth) methyl acrylate and (meth). Examples thereof include ethyl acrylate, propyl (meth) acrylate, and butyl (meth) acrylate. Examples of the (meth) acrylic acid derivative include (meth) acrylic acid, glycidyl (meth) acrylic acid, and hydroxyethyl (meth) acrylate.

In the present embodiment, it is preferable to introduce a glycidyl group into the acrylic resin by using glycidyl methacrylate or the like. The compatibility between the acrylic resin into which the glycidyl group is introduced and the epoxy resin as a thermosetting component described later is improved, and there is a tendency that a protective film-forming film having stable performance can be easily obtained. Further, in the present embodiment, it is preferable to introduce a hydroxyl group into the acrylic resin by using hydroxyethyl acrylate or the like in order to control the adhesiveness to the work and the adhesive physical characteristics.

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., and −5 to 20 ° C. By setting the lower limit of the glass transition temperature of the acrylic resin to the above value, it becomes easy to reduce the tan δ ₁₀ of the protective film forming film. Further, by setting the upper limit of the glass transition temperature of the acrylic resin to the above value, the tack of the protective film-forming film is appropriately increased, and the adhesive strength of the protective film-forming film with the work is improved, so that the protective film can be used. Adhesion to the work is moderately improved.

（式中、Ｔｇはアクリル樹脂のガラス転移温度であり；ｍは２以上の整数であり；Ｔｇｋはモノマーｍのホモポリマーのガラス転移温度であり；Ｗｋはアクリル樹脂における、モノマーｍから誘導された構成単位ｍの質量分率であり、ただし、Ｗｋは下記式を満たす。）

（式中、ｍ及びＷｋは、前記と同じである。） When the acrylic resin has m types (m is an integer of 2 or more), the glass transition temperature of the acrylic resin can be calculated as follows. That is, when the m-type monomers that induce the constituent units in the acrylic resin are sequentially assigned any unique number from 1 to m and named "monomer m", the glass transition of the acrylic resin is performed. The temperature (Tg) can be calculated using the Fox formula shown below.

(In the formula, Tg is the glass transition temperature of the acrylic resin; m is an integer of 2 or more; Tgk is the glass transition temperature of the homopolymer of the monomer m; Wk is derived from the monomer m in the acrylic resin. It is a mass fraction of the constituent unit m, where Wk satisfies the following formula.)

(In the formula, m and Wk are the same as described above.)

As Tgk, the values described in the polymer data handbook, the adhesive handbook, the Polymer Handbook, and the like can be used. For example, the Tgk of the methyl acrylate homopolymer is 10 ° C, the Tgk of the n-butyl acrylate homopolymer is -54 ° C, the Tgk of the methyl methacrylate homopolymer is 105 ° C, and the Tgk of the 2-hydroxyethyl acrylate homopolymer is-. At 15 ° C, the Tgk of the glycidyl methacrylate homopolymer is 41 ° C, and the Tgk of the 2-ethylhexyl acrylate is −70 ° C.

The content of the polymer component when the total weight of the composition for the protective film forming film is 100 parts by mass is preferably 5 to 80 parts by mass, 8 to 70 parts by mass, 10 to 60 parts by mass, and 12 to 55 parts. It is a mass part, 14 to 50 parts by mass, and 15 to 45 parts by mass. By setting the content of the polymer component within the above range, the tack of the protective film-forming film is appropriately increased, and the adhesive strength of the protective film-forming film with the work is appropriately improved. In addition, it tends to be easy to suppress the occurrence of winding marks.

(2.2.2.12 Thermosetting component)
The curable component (B) cures the protective film-forming film to form a hard protective film. As the curable component, a thermosetting component, an energy ray curable component, or a mixture thereof can be used. When cured by irradiation with energy rays, the protective film-forming film contains a filler and a colorant, which will be described later, so that the light transmittance is lowered. Therefore, for example, when the thickness of the protective film forming film becomes thick, the energy ray curing tends to be insufficient.

On the other hand, the thermosetting protective film-forming film can be sufficiently cured by heating even if its thickness becomes thick, so that a protective film having high protective performance can be formed. Further, by using a normal heating means such as a heating oven, a large number of protective film forming films can be heated at once and thermoset.

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

Whether or not the protective film-forming film is thermosetting can be determined as follows. First, the protective film-forming film at room temperature (23 ° C.) is heated to a temperature exceeding the room temperature, and then cooled to the room temperature to obtain a protective film-forming film after heating and cooling. Next, when the hardness of the protective film-forming film after heating / cooling and the hardness of the protective film-forming film before heating are compared at the same temperature, when the protective film-forming film after heating / cooling is harder. Judges that this protective film-forming film is thermosetting.

As the thermosetting component, for example, an epoxy resin, a thermosetting polyimide resin, an unsaturated polyester resin and a mixture thereof are preferably used. The thermosetting polyimide resin is a general term for a polyimide precursor and a thermosetting polyimide that form a polyimide resin by thermosetting.

Epoxy resin as a thermosetting component has the property of forming a three-dimensional network structure when heated and forming a strong film. As such an epoxy resin, various known epoxy resins are used. In the present embodiment, the molecular weight (formula) 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, and 300 or more and less than 3,000. The epoxy equivalent of the epoxy resin is preferably 50 to 5000 g / eq, more preferably 100 to 2000 g / eq, and even more preferably 150 to 1000 g / eq.

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

When a thermosetting component is used as the curable component (B), it is preferable to use a curing agent (C) in combination as an auxiliary agent. As the curing agent for the epoxy resin, a heat-active latent epoxy resin curing agent is preferable. The "heat-active latent epoxy resin curing agent" is a type of curing agent that is difficult to react with an epoxy resin at room temperature (23 ° C.), is activated by heating at a certain temperature or higher, and reacts with the epoxy resin. The method for activating the heat-active latent epoxy resin curing agent is to generate active species (anions, cations) by a chemical reaction by heating; the epoxy resin is stably dispersed in the epoxy resin near room temperature and is at high temperature. There are methods such as a method of incompatible with and dissolving with and starting a curing reaction; a method of eluting at a high temperature with a molecular sieve-encapsulated type curing agent to start a curing reaction; and a method of using microcapsules.

Among the illustrated methods, a method in which the material is stably dispersed in the epoxy resin near room temperature and is compatible with and dissolved in the epoxy resin at a high temperature to start the curing reaction is preferable.

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

Further, as the curing agent for the epoxy resin, a phenol resin is also preferable. As the phenol resin, a condensate of phenols such as alkylphenol, polyhydric phenol, and naphthol and aldehydes is used without particular limitation. Specifically, phenol novolac resin, o-cresol novolak resin, p-cresol novolak resin, t-butylphenol novolak resin, dicyclopentadiencresol resin, polyparavinylphenol resin, bisphenol A type novolak resin, or modified products thereof. Etc. are used.

The phenolic hydroxyl group contained in these phenolic resins can be easily added and reacted with the epoxy group of the epoxy resin by heating to form a cured product having high impact resistance.

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, and 0.3 to 10 parts by mass with respect to 100 parts by mass of the epoxy resin. It is a mass part. By setting the range of the content of the curing agent (C) to the above range, it is easy to obtain the performance of protecting the work as a protective film.

When dicyandiamide is used as the curing agent (C), it is preferable to further use the curing accelerator (D) in combination. Examples of the curing accelerator include 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxy. Imidazoles such as methylimidazole (imidazole in which one or more hydrogen atoms are substituted with a group other than the hydrogen atom) are preferable. Of these, 2-phenyl-4,5-dihydroxymethylimidazole is particularly preferable.

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, and 0.3 to 10 parts by mass with respect to 100 parts by mass of the epoxy resin. It is a department. By setting the range of the content of the curing accelerator (D) to the above range, it is easy to obtain the performance of protecting the work as a protective film.

The total content of the thermosetting component and the curing agent when the total weight of the composition for the protective film forming film is 100 parts by mass is preferably 3 to 80 parts by mass, 5 to 60 parts by mass, and 7 to 50 parts by mass. Parts, 9 to 40 parts by mass, 10 to 30 parts by mass. When the thermosetting component and the curing agent are blended in such a ratio, it is easy to obtain the performance of protecting the work as a protective film.

(2.2.2.13 Energy ray curable component)
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 uncured and adhesive. ..

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

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

(2.2.1.4 Filler)
Since the protective film-forming film contains the filler (E), the protective film obtained by forming the protective film-forming film into a protective film can easily adjust the coefficient of thermal expansion, and this thermal expansion coefficient can be used as the thermal expansion of the work. By approaching the coefficient, the adhesion reliability with the work is further improved. Further, when the protective film forming film contains the filler (E), a hard protective film can be obtained, the performance of protecting the work can be easily obtained, and the hygroscopicity of the protective film can be reduced.

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 a high temperature of 260 ° C.

Preferred inorganic fillers include, for example, powders of silica, alumina, talc, calcium carbonate, red iron oxide, silicon carbide, boron nitride and the like; spherical beads of these inorganic fillers; surface modified products of these inorganic fillers; these. Single crystal fiber as an inorganic filler; glass fiber and the like can be mentioned. Among these, silica and surface-modified silica are preferable. The surface-modified silica is preferably surface-modified with a coupling agent, and more preferably surface-modified with a silane coupling agent.

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

By setting the range of the average particle size of the filler to the above range, the handleability of the composition for the protective film-forming film is improved. As a result, the quality of the composition for the protective film-forming film and the protective film-forming film is likely to be stable.

In the present specification, the "average particle size" means the value of the particle size (D50) at an integrated value of 50% in the particle size distribution curve obtained by the laser diffraction / scattering method, unless otherwise specified.

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

By setting the lower limit of the content of the filler to the above value, it tends to be easy to reduce the tan δ ₁₀ of the protective film forming film. Further, by setting the upper limit value of the content of the filler to the above value, the adhesive strength of the protective film-forming film with the work tends to be improved, and the adhesive strength of the protective film with the work tends to be appropriately improved.

(2.2.1.5 Coupling agent)
The protective film-forming film preferably contains a coupling agent (F). By containing the coupling agent, after the protective film forming film is cured, the adhesiveness between the protective film and the work can be improved without impairing the heat resistance of the protective film, and water resistance (moisture and heat resistance) can be improved. Can be improved. As the coupling agent, a silane coupling agent is preferable from the viewpoint of its versatility and cost merit.

Examples of the silane coupling agent include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and γ- (methacryloxy). Propyl) 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) tetrasulfan, methyltri Examples thereof include methoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, and imidazolesilane. These can be used alone or in admixture of two or more.

(2.2.1.6 Colorant)
The protective film-forming film preferably contains a colorant (G). As a result, the back surface of the workpiece such as a chip is concealed, so that various electromagnetic waves generated in the electronic device can be blocked and the malfunction of the workpiece such as the chip can be reduced.

As the colorant (G), for example, known ones such as inorganic pigments, organic pigments, and organic dyes can be used. Inorganic pigments are preferred in this embodiment.

Examples of the inorganic pigment include carbon black, cobalt dye, iron dye, chromium dye, titanium dye, vanadium dye, zirconium dye, molybdenum dye, ruthenium dye, platinum dye, and ITO (indium). Examples thereof include a tin oxide) dye and an ATO (antimonth tin oxide) dye. Among these, it is particularly preferable to use carbon black. According to carbon black, electromagnetic waves in a wide wavelength range can be blocked.

The amount of the colorant (particularly carbon black) blended in the protective film-forming film varies depending on the thickness of the protective film-forming film. For example, when the thickness of the protective film-forming film is 20 μm, the entire protective film-forming film is formed. It is preferably 0.01 to 10% by mass, 0.04 to 7% by mass, and 0.07 to 4% by mass with respect to the mass. By setting the blending amount of the colorant within the above range, the marks of the protective film caused by the winding marks of the protective film forming sheet roll tend to be inconspicuous in appearance.

The average particle size of the colorant (particularly 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 a desired range.

(2.2.1.7 Other additives)
The composition for a protective film-forming film can be used as other additives, for example, a photopolymerization initiator, a cross-linking agent, a plasticizer, an antistatic agent, an antioxidant, and a gettering agent, as long as the effects of the present invention are not impaired. , Antistatic agent, release agent and the like may be contained.

(2.2.2 Composition for 1st release agent layer)
In the present embodiment, the composition for the first release agent layer is, for example, an alkyd-based release agent, a silicone-based release agent, a fluorine-based release agent, an unsaturated polyester-based release agent, a polyolefin-based release agent, and a wax. A system release agent can be contained, and among them, a silicone release agent is preferably contained. When the composition for the first release agent layer contains a silicone-based release agent, it is preferable to contain a silicone-based release agent and a heavy release additive.

(2.2.2.1 Silicone mold release agent)
As the silicone release agent, a silicone release agent containing silicone having dimethylpolysiloxane as a basic skeleton can be used.

The content of silicone composed of dimethylpolysiloxane when the total weight of the composition for the first release agent layer (excluding the catalyst described later) is 100 parts by mass is preferably less than 100 parts by mass and less than 90 parts by mass. It is less than 80 parts by mass and less than 70 parts by mass.

The silicone may be any of an addition reaction type, a condensation reaction type, and an energy ray curable type such as an ultraviolet curable type and an electron beam curable type, but an addition reaction type silicone is preferable. The addition reaction type silicone has merits such as high reactivity and excellent productivity, a small change in peeling force after production, and no curing shrinkage as compared with the condensation reaction type.

As a specific example of the addition reaction type silicone, an organopoly having two or more alkenyl groups having 2 to 10 carbon atoms such as a vinyl group, an allyl group, a propenyl group, and a hexenyl group at the terminal and / or side chain of the molecule. Examples include siloxane.

When using such an addition reaction type silicone, it is preferable to use a cross-linking agent and a catalyst in combination.

Examples of the cross-linking agent include organopolysiloxane having a hydrogen atom bonded to at least two silicon atoms in one molecule.

Specific examples of the cross-linking agent include dimethylhydrogensiloxy group-terminated closure dimethylsiloxane-methylhydrogensiloxane copolymer, trimethylsiloxy group-terminated closure dimethylsiloxane-methylhydrogensiloxane copolymer, and trimethylsiloxy group-terminated closure methylhydrogen. Examples thereof include polysiloxane and poly (hydrogencil sesquioxane).

Examples of the catalyst include fine particle platinum, fine particle platinum adsorbed on a carbon powder carrier, platinum chloride acid, alcohol-modified platinum chloride acid, an olefin complex of platinum chloride acid, palladium, and platinum group metal compounds such as rhodium. Can be mentioned.

By using such a catalyst, the curing reaction of the composition for the first release agent layer can proceed more efficiently.

The content of the silicone-based mold release agent when the total weight of the composition for the first release agent layer (excluding the catalyst) is 100 parts by mass is preferably within the above-mentioned range of the release force F1. It is 30 to 100 parts by mass and 50 to 100 parts by mass.

(2.2.2.2 Heavy peeling additive)
The heavy peeling additive is used to increase the peeling force F1 of the first peeling film from the protective film forming film. Examples of the heavy peeling additive include organosilanes such as silicone resin and silane coupling agent, and among these, silicone resin is preferably used.

As the silicone resin, for example, it is preferable to use an MQ resin containing an M unit which is a monofunctional siloxane unit [R ₃ SiO _1/2 ] and a Q unit which is a tetrafunctional siloxane unit [SiO _4/2 ]. The three Rs in the M unit independently represent a hydrogen atom, a hydroxyl group, or an organic group. From the viewpoint of facilitating the suppression of silicone migration, one or more of the three Rs in the M unit is preferably a hydroxyl group or a vinyl group, and more preferably a vinyl group.

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

When the first release agent layer is formed on both main surfaces of the base material, the coating agent containing the composition for the first release agent layer described later is applied to both main surfaces of the base material to form the base material. Alternatively, after applying the coating agent containing the composition for the first release agent layer to one main surface of the base material, the base material is wound up into a roll, and the coating agent is applied from the main surface to which the coating agent is applied. The first release agent layer is formed on the main surface not coated with the coating agent by utilizing the phenomenon (transfer phenomenon) in which the components of the composition for the first release agent layer are transferred to the main surface not coated with the coating agent. You may.

In the first release film, whether or not the substrate has been peeled can be determined, for example, as follows. When the first release agent layer contains the above-mentioned silicone-based release agent, surface analysis is performed on both main surfaces of the first release film by X-ray photoelectron spectroscopy (XPS), and silicon atoms are obtained from the obtained spectrum. If it is equal to or more than a predetermined value, it is judged that the peeling process has been performed. The specific measurement method will be described in detail in Examples described later.

When the base material is made of polyethylene terephthalate film, the contact angle of water is measured on both main surfaces of the first release film, and if the contact angle is equal to or more than a predetermined value, it is determined that the release process has been performed. do. The specific measurement method will be described in detail in Examples described later.

(2.2.3 Composition for 2nd release agent layer)
The composition for the second release agent layer can be selected from the materials exemplified in the composition for the first release agent layer as long as the above relationship between F1 and F2 is satisfied. However, it is preferable that the material exemplified as the heavy release additive is less than or not contained in the composition for the first release agent layer.

The composition for the first release agent layer and the composition for the second release agent layer may contain additives generally 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.

Further, from the viewpoint of adjusting the peeling force to a low level and from the viewpoint of facilitating the formation of the peeling agent layer utilizing the above-mentioned transfer phenomenon, the silicone oil is used as a composition for a peeling agent layer (a first release agent layer composition and a second release agent layer composition). It may be added to the composition for a release agent layer).

(2.2.4 Manufacturing process of long sheet)
When producing a long sheet, first, the above-mentioned composition for a protective film-forming film, a composition for a first release agent layer, and a composition for a second release agent layer are prepared. In the present embodiment, from the viewpoint of adjusting the viscosity and improving the coatability, a coating agent obtained by diluting the composition for a protective film forming film and the composition for a release agent layer containing the above-mentioned components with a diluting solvent is prepared. Is preferable.

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

The solid content concentration of the coating agent containing the composition for the protective film-forming film is preferably 20 to 80% by mass, more preferably 30 to 70% by mass. On the other hand, the solid content concentration of the coating material containing the composition for the first release agent layer and the composition for the second release agent layer is preferably 0.3 to 10% by mass, more preferably 0.5 to 5% by mass. More preferably, it is 0.5 to 3% by mass.

In the present embodiment, a coating agent containing a composition for a first release agent layer is applied to one surface of a substrate by a known method, and then the coating film is dried and cured to form a first release agent layer. Form. As a result, the first release film is obtained. The second release film can also be produced in the same manner.

After that, when the release agent layer is formed on both main surfaces of the substrate, the coating agent of the composition for the release agent layer may be applied to the other surface of the substrate to form the release agent layer. Alternatively, in order to utilize the above-mentioned transfer phenomenon, the first release film formed by applying the coating agent of the release agent layer composition is wound up into a roll and stored at 30 ° C. for 7 days, for example. Then, the components of the composition for the release agent layer may be transferred to the other surface to form the film.

In the present embodiment, a coating agent containing a composition for a protective film-forming film is applied on the first release agent layer of the first release film or on the second release agent layer of the second release film by a known method. After that, it is heated and dried to form a coating film. Next, the second release agent layer of the second release film or the first release agent layer of the first release film is bonded onto the coating film to produce a protective film forming sheet (long sheet). .. In the present embodiment, from the viewpoint of setting the peeling force F1 within the above range and setting F1> F2, the protective film forming film is not on the second release agent layer but on the first release agent layer of the first release film. It is preferable to apply a coating agent containing the composition for use.

Examples of the coating method of the coating agent containing each composition include spin coating method, spray coating method, bar coating method, knife coating method, roll coating method, roll knife coating method, blade coating method, die coating method, and gravure coating method. Is exemplified.

(3. Equipment manufacturing method)
As an example of a method for manufacturing an apparatus using a protective film forming sheet roll manufactured by the method according to the present embodiment, a method for manufacturing a chip with a protective film obtained by processing a wafer to which a protective film forming film is attached. Will be explained.

First, as shown in FIG. 4, the long sheet 1 is unwound from the protective film forming sheet roll 100, and the second release film 30 and the protective film forming film 10 are penetrated through the long sheet by using the cutting blade 50. A notch 40 that reaches a part of the first release film 20 is formed. By removing the second release film and the unnecessary protective film-forming film from the long sheet having the notch 40 formed, a circular protective film-forming film can be obtained.

Next, as shown in FIG. 5A, the circular protective film forming film 11 is attached to the back surface 60b of the wafer 60 as a work, and as shown in FIG. 5B, the first release film 20 is peeled off from the laminate. The protective film forming film 11 is formed into a protective film to form the protective film 15. Subsequently, the wafer having the protective film is fragmented to obtain a chip with the protective film. The protective film may be formed after the wafer is separated into individual pieces.

Since the formation of winding marks is suppressed in the protective film-forming film, the marks are also suppressed on the surface of the protective film. Therefore, it is possible to obtain a chip with a protective film in which poor appearance of the protective film is suppressed.

(4. Modification example)
In FIG. 3, in the first release film 20, the first release 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 release film 30, it is in contact with the protective film forming film 10. Although the structure in which the second release agent layer is not formed is shown on the surface 30b which is not formed, the present embodiment is not limited to this structure.

For example, in the first release film, the first release agent layer is formed on the surface not in contact with the protective film-forming film, and in the second release film, the second release agent layer is formed on the surface not in contact with the protective film-forming film. May be formed. Further, in the first release film, the first release agent layer is not formed on the surface not in contact with the protective film-forming film, and in the second release film, the second release agent is not formed on the surface not in contact with the protective film-forming film. It may be a structure in which layers are formed.

Further, in FIG. 4, the notch forming the protective film forming film to be attached to the work has a circular shape, but any other shape may be used as long as it has a closed shape. Examples of other shapes include polygons such as triangles and ellipses. Further, it is preferable that the closed shape corresponds to the shape of the work.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and may be modified in various ways within the scope of the present invention.

Hereinafter, the invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

(Preparation of the first release film)
First, the following components were prepared in order to prepare the composition for the first release agent layer.
(Α) Silicone-based mold release agent (α-1) Silicone-based mold release agent containing an organopolysiloxane having a vinyl group and an organopolysiloxane having a hydrosilyl group (manufactured by Toray Dow Corning Co., Ltd., BY24-561, Solid content 30% by mass)
(Α-2) Didimethylpolysiloxane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: X-62-1387, weight average molecular weight: 2000)
(Β) Silicone resin MQ resin with vinyl group (manufactured by Toray Dow Corning Co., Ltd., SD-7292, solid content 71% by mass)
(Γ) Catalyst Platinum (Pt) catalyst (manufactured by Toray Dow Corning Co., Ltd., SRX-212, solid content 100% by mass)

Next, (α-1) is 67.5 parts by mass (solid content ratio), (α-2) is 2.5 parts by mass (solid content ratio), (β) is 30 parts by mass (solid content ratio), and 6.7 parts by mass (solid content ratio) of (γ) is mixed and mixed, and a mixed solvent of toluene and methyl ethyl ketone (toluene / methyl ethyl ketone = 1/1 (mass ratio) so that the solid content concentration becomes 2% by mass). ) To prepare a coating agent containing the composition for the first release agent layer.

A coating agent containing the prepared composition for forming a first release agent layer on both main surfaces of a PET film as a base material (manufactured by Mitsubishi Chemical Corporation, trade name: Diafoil (registered trademark) T-100, thickness: 50 μm). Was applied so that the film thickness after heating and drying was 0.15 μm, and a first release agent layer was formed on both main surfaces of the PET film to prepare a first release film.

(Preparation of second release film)
As the second release film, a film in which one surface of the PET film was peeled (“SP-PET38131” manufactured by Lintec, thickness 38 μm) was used.

(Preparation of protective film forming film)
Each of the following components is mixed at the compounding ratio (in terms of solid content) shown in Table 1 and diluted with methyl ethyl ketone so that the solid content concentration becomes 50% by mass to prepare a coating agent containing a composition for a protective film-forming film. did.
(A) Polymer component (A-1) (meth) acrylic acid obtained 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. Ester copolymer (weight average molecular weight: 800,000, glass transition temperature: -28 ° C)
(A-2) A (meth) acrylic acid ester copolymer obtained 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 (weight). Average molecular weight: 500,000, glass transition temperature: -9 ° C)
(B) Curable component (thermosetting component)
(B-1) Bisphenol A type epoxy resin (manufactured by Mitsubishi Chemical Corporation, jER828, epoxy equivalent 184 to 194 g / eq)
(B-2) Acrylic rubber fine particle dispersion bisphenol A type liquid epoxy resin (manufactured by Nippon Shokubai Co., Ltd., BPA328, epoxy equivalent 230 g / eq, acrylic rubber content 20 phr)
(B-3) Dicyclopentadiene type epoxy resin (manufactured by Dainippon Ink and Chemicals, Inc., Epicron HP-7200HH, softening point 88 to 98 ° C., epoxy equivalent 255 to 260 g / eq)
(C) Curing agent: dicyandiamide (manufactured by Mitsubishi Chemical Corporation, DICY7)
(D) Curing accelerator: 2-phenyl-4,5-dihydroxymethylimidazole (manufactured by Shikoku Chemicals Corporation, Curesol 2PHZ)
(E) Filler: Epoxy group-modified spherical silica filler (manufactured by Admatex, SC2050MA, average particle size 0.5 μm)
(F) Silane coupling agent: γ-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM403, methoxy equivalent 12.7 mmol / g, molecular weight 236.3)
(G) Colorant: Carbon black (manufactured by Mitsubishi Chemical Corporation, MA600B, average particle size 28 nm)

A coating agent containing the prepared composition for a protective film-forming film is applied to the surface of the prepared first release film on which the first release agent layer is formed, and dried at 100 ° C. for 2 minutes to protect the thickness of 20 μm. A film-forming film was formed. Subsequently, the surface of the prepared second release film on which the second release agent layer was formed was attached onto the protective film-forming film, whereby the first release film was formed on one main surface of the protective film-forming film. A protective film forming sheet (a first release film / a protective film forming film / a constituent of the second release film) having a second release film formed on the other main surface was obtained. The pasting conditions were a temperature of 60 ° C., a pressure of 0.4 MPa, and a speed of 1 m / min.

(Making a sheet roll)
While cutting the obtained protective film forming sheet to a width of 320 mm using a twin-screw take-up slitter machine (manufactured by Toizaki Bussan Co., Ltd.), a protective film is formed using a centering tape having a width of 5 mm and a thickness of 40 μm. The cut protective film-forming sheet was wound into a roll on a hollow plastic core (core) having the same width (320 mm) as the cut sheet and having a diameter of 3 inches. The winding condition was a condition in which the current meter of the powder brake for controlling the tension at the time of winding showed 0.25A. The length of the wound protective film forming sheet was 50 m. The cutting speed was 5 m / min.

The wound protective film forming sheet (Examples 1 to 3 and Comparative Examples 1 to 2) was stored under the storage conditions (patterns 1 to 4) shown below to obtain a protective film forming sheet roll. ..

In pattern 1, the mixture was allowed to stand at 23 ° C. for 3 days after winding, then allowed to stand at 5 ± 4 ° C. for 40 days, and then allowed to stand again at 23 ° C. for 17 days (Example 1 and Comparative Example 1). In pattern 2, after winding, the mixture was allowed to stand at 23 ° C. for 3 days, then allowed to stand at 5 ± 4 ° C. for 50 days, and then allowed to stand at 23 ° C. for 7 days again (Example 2). In pattern 3, the mixture was allowed to stand at 23 ° C. for 3 days after winding, then allowed to stand at 5 ± 4 ° C. for 30 days, and then allowed to stand at 23 ° C. for 27 days again (Example 3). In pattern 4, it was allowed to stand at 23 ° C. for 60 days after winding (Comparative Example 4).

Subsequently, the following measurements and evaluations were performed.

(Loss of protective film forming film at 10 ° C. Tanδ ₁₀ )
The first release film and the second release film are peeled off from the produced protective film-forming sheet, and a plurality of protective film-forming films are laminated to form a laminate of protective film-forming films having a thickness of 200 μm ± 20 μm. did. This laminate was cut to a width of 4 mm to obtain a sample for measurement.

Using a viscoelasticity measuring device (Orientech's "RHEOVIBRON DDV-01FP"), the above measurement sample was used in a tensile mode under the measurement conditions of a frequency of 11 Hz, a chuck distance of 15 mm, and a temperature rise rate of 3 ° C./min. , Tan δ of the measurement sample from −20 ° C. to 50 ° C. was measured, and the loss tangent tan δ ₁₀ at 10 ° C. was calculated from those values. It is shown in Table 1.

(Evaluation of the presence or absence of peeling treatment of the peeling film)
A protective film-forming sheet is unwound from the obtained sheet roll, and a 50 mm × 50 mm protective film-forming sheet is placed in the width direction at a position 1 m from the portion where the protective film-forming sheet has begun to be fixed to the plastic core by the centering tape. I cut out 3 places.

The first release film and the second release film were peeled off from the cut-out 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 under the following conditions. went. Similarly, XPS measurement was performed on the surface of the second release film that was not bonded to the protective film-forming film under the following conditions. The XPS measurement was performed once for each of the three first release films and the three second release films obtained by cutting out the protective film forming sheet.
XPS device: QuanteraSXM manufactured by ULVAC-PHI
X-ray: AlKα (1486.6eV)
Extraction angle: 45 °
Measuring elements: silicon (Si), carbon (C), oxygen atom (O)

From the obtained measurement results, the silicon atom ratios shown below were calculated for each of the first release film and the second release film from the amount of each measured element (XPS count number), and the average value was calculated.
Silicon atomic ratio (atomic%) = [(Si element amount) / [(C element amount) + (O element amount) + (Si element amount)]] × 100

Based on the obtained average value, evaluation was made according to the following criteria. In the cases of determinations A and B, it was determined that the peeling process was performed. Table 1 shows the measurement results of the samples of Examples 1 to 3 and Comparative Examples 1 and 2.
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. Judgment B: The average value of at least one of the first release film and the second release film does not satisfy the determination A. Judgment of 0.1 atomic% or more and less than 1.0 atomic% C: The average value of both the first release film and the second release film is less than 0.1 atomic%.

A first release film before applying a coating agent containing a composition for a protective film-forming film was prepared, and three places were cut out from the first release film in a size of 50 mm × 50 mm in the width direction. Of both main surfaces of the first release film, the surface to which the coating agent containing the composition for the protective film forming film is to be applied is evaluated for the presence or absence of release treatment under the same conditions as above using the above XPS apparatus. Was done. As a result, it was confirmed that the average value of the silicon atomic ratios at the three locations of the sample of the first release film was 1.0 atomic% or more.

A second release film before being attached to the protective film-forming film was prepared, and three places were cut out from the second release film in a size of 50 mm × 50 mm in the width direction. Of both main surfaces of the second release film, the surface to be attached to the protective film-forming film was evaluated for the presence or absence of release treatment under the same conditions as above using the above XPS device. As a result, it was confirmed that the average value of the silicon atom ratios at the three locations of the sample of the second release film was 1.0 atom% or more.

(Evaluation of water contact angle of release film)
A protective film-forming sheet is unwound from the obtained sheet roll, and a 50 mm × 50 mm protective film-forming sheet is placed in the width direction at a position 1 m from the portion where the protective film-forming sheet has begun to be fixed to the plastic core by the centering tape. I cut out 3 places.

The first release film and the second release film are peeled off from the cut-out protective film-forming sheet, and water contacts the surface of the first release film that has not been bonded to the protective film-forming film under the following conditions. The angle was measured. Similarly, the contact angle of water was measured under the following conditions with respect to the surface of the second release film that was not bonded to the protective film-forming film. The water contact angle was measured 5 times for each of the 3 first release films and the 3 second release films obtained by cutting out the protective film forming sheet.
Contact angle measuring device: Fully automatic contact angle meter DM-701 manufactured by Kyowa Interface Science Co., Ltd.
Drop amount: 2 μL
Environment: Temperature 23 ℃, Humidity 50%

For each of the first release film and the second release film, the average value of the obtained measurement results was calculated. Based on the obtained average value, evaluation was made according to the following criteria. If it is the determination A, it is determined that the peeling process has been performed. Table 1 shows the measurement results of the samples of Examples 1 to 3 and Comparative Examples 1 and 2.
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.

(Peeling force F1 of the first release film from the protective film forming film)
The second release film was peeled off from the obtained protective film forming sheet. A good-adhesive surface of a good-adhesive PET (PET25A-4100, manufactured by Toyobo Co., Ltd.) with a thickness of 25 μm is attached to the surface of the protective film-forming film exposed by peeling by thermal laminating (70 ° C., 1 m / min) to form a laminated body sample. Was produced. A laminated sample was cut into a width of 100 mm to prepare a sample for measurement. The back surface of the first release film of the measurement sample was fixed to a hard support plate with double-sided tape.

Using a universal tensile tester (manufactured by Shimadzu Corporation, product name "Autograph (registered trademark) AG-IS"), a composite (integrated) body of protective film forming film / good adhesive PET was measured at a measurement distance of 100 mm. The film was peeled from the first release film at a peeling angle of 180 ° and a peeling speed of 1 m / min, and the load at that time was measured. Of the measured loads, the average value of the loads between 80 mm excluding the load at the first 10 mm of the measurement distance and the load at the last 10 mm was defined as the peeling force F1.

(Peeling force F2 of the second release film from the protective film forming film)
The obtained protective film forming sheet was cut into a width of 100 mm 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 double-sided tape.

Using a universal tensile tester (manufactured by Shimadzu Corporation, product name "Autograph (registered trademark) AG-IS"), the second release film was removed from the measurement sample at a measurement distance of 100 mm, a release angle of 180 °, and a release speed. Peeling was performed at 1 m / min, and the load at that time was measured. Of the measured loads, the average value of the loads between 80 mm excluding the load at the first 10 mm of the measurement distance and the load at the last 10 mm was defined as the peeling force F2.

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

(Evaluation of winding marks)
From the sheet roll for forming the protective film after storage for 60 days, the long sheet was unwound from the outermost layer at a speed of 3 m / min, and the "length from the core" where unacceptable winding marks began to be formed. It was measured. Whether or not the winding marks were out of the permissible range was visually confirmed by five judges at the same time, and it was judged that three were out of the permissible range. Table 1 shows the evaluation results of the samples of Examples 1 to 3 and Comparative Examples 1 and 2.
Judgment A: 0 meters or more and less than 4 meters Judgment B: 4 meters or more and less than 6 meters Judgment C: 6 meters or more and less than 8 meters Judgment D: 8 meters or more and less than 10 meters Judgment E: 10 meters or more

From Table 1, when the loss tangent (tan δ ₁₀ ) of the protective film forming film at 10 ° C. and the storage condition of the protective film forming sheet roll after winding satisfy the above-mentioned conditions, the protective film forming It was confirmed that the formation of winding marks on the protective film-forming film in the sheet roll was suppressed.

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 portion 80 ... Fixing means

Claims (5)

Protective film forming film and
The first release film provided on one surface of the protective film forming film and
A sheet roll formed by winding a long sheet having a second release film provided on the other surface of the protective film-forming film is formed for 25 days or more out of 60 days after the sheet roll is formed. Has a process of storing at a storage temperature of ℃ or less,
When the peeling force of the first release film from the protective film-forming film is F1 and the peeling force of the second release film from the protective film-forming film is F2, the relationship of F1> F2 is satisfied. ,
A method for producing a protective film forming sheet roll in which tan δ ₁₀ is 1.2 or less when the loss tangent of the protective film forming film at 10 ° C. is tan δ ₁₀ . The method for producing a protective film-forming sheet roll according to claim 1, wherein the step of storing the sheet roll at a storage temperature of 10 ° C. or lower is started within 10 days after the sheet roll is formed. The method for producing a protective film forming sheet roll according to claim 1 or 2, wherein the storage temperature is −10 ° C. or higher. The production of a protective film-forming sheet roll according to any one of claims 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 peel-treated. Method. The method for producing a protective film forming sheet roll according to any one of claims 1 to 4, wherein tan δ ₁₀ is 0.04 or more.

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